Belo Horizonte, Brazil
Belo Horizonte, Brazil

Universidade Federal de Minas Gerais is a federal university located in Belo Horizonte, state of Minas Gerais, Brazil. UFMG is one of Brazil's five largest universities, being the largest federal university. It offers 75 undergraduate degrees, including a Medicine degree, Law and Economics, plus Engineering and Science and Art degrees. It offers 57 PhD programs, 66 MSc programs, 79 Post-Baccalaureate programs and 38 medical internship programs. UFMG has a population of 49,254 students.The undergratuate students are admitted through the national biannual exams called Unified Selection System . Its undergraduate courses were ranked in 1st place in the 2007 results for the National Student's Performance Exam and 4th place in the 2008 results. Its Computer Science course was considered the best in the country, as well the Social science course, from FAFICH by the latest edition of ENADE.The rector of UFMG is Clelio Campolina Diniz. Past students include former Brazilian presidents Juscelino Kubitschek and Tancredo Neves; writer, medical doctor and diplomat João Guimarães Rosa, writers Fernando Sabino, Pedro Nava and Cyro dos Anjos; plastic surgeon Ivo Pitanguy, poet Carlos Drummond de Andrade and musicians Fernando Brant, Samuel Rosa of Skank and Fernanda Takai of Pato Fu.UFMG is the tenth in the rankings of best universities in Latin America, according QS World University Rankings . As reported by the Academic Ranking of World Universities , UFMG is one of the five best universities in Brazil in 2013, and in the World Rank is in the range of 301-400 best universities. Wikipedia.

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Couto C.A.,Federal University of Minas Gerais | Bittencourt P.L.,Portuguese Hospital | Porta G.,University of Sao Paulo | Abrantes-Lemos C.P.,University of Sao Paulo | And 3 more authors.
Hepatology | Year: 2014

Reactivity and titers of autoantibodies vary during the course of autoimmune hepatitis (AIH), and some autoantibodies have been associated with disease activity and adverse outcomes after treatment. The aim of this study was to assess the autoantibody behavior in AIH and its significance as predictors of biochemical and histological remission. A total of 117 patients with AIH (mean age 18.6 [4-69] years) were evaluated and tested for autoantibodies at disease onset and successively (mean 3.2 [2-6] times) after a mean follow-up evaluation of 70 [20-185] months. Antismooth muscle (ASMA), antiliver kidney microsome type 1 (anti-LKM1), antiliver cytosol type 1 (anti-LC1), antimitochondrial, antinuclear (ANA), and antiactin antibodies (AAA) were determined at disease onset and 379 other times during the follow-up evaluation through indirect immunofluorescence in rodent tissues, HEp-2 cells, and human fibroblasts. Anti-SLA/LP were assessed 45 times in the follow-up evaluation of 19 patients using enzyme-linked immunosorbent assay (ELISA). Upon admission, AIH types 1 and 2 were observed in 95 and 17 patients, respectively. Five subjects had AIH with anti-SLA/LP as the sole markers. Patients initially negative for AAA did not develop these antibodies thereafter. ANA were detected de novo in six and three subjects with AIH types 1 and 2, respectively. After treatment, only ASMA (>1:80) and AAA (>1:40) were significantly associated with biochemical (76.9% and 79.8%) and histological features (100% and 100%) of disease activity (P<0.001). Conclusion: With the exception of ANA, the autoantibody profile does not markedly vary in the course of AIH. The persistence of high titers of ASMA and/or AAA in patients with AIH is associated with disease activity. © 2013 by the American Association for the Study of Liver Diseases.

Santos J.C.,Federal University of Uberlandia | de Almeida-Cortez J.S.,Federal University of Pernambuco | Fernandes G.W.,Federal University of Minas Gerais
Revista Brasileira de Entomologia | Year: 2011

Diversity of gall-inducing insects in the tropical dry forest (caatinga) of Pernambuco. We report on the richness of galling insects in the vegetation of caatinga of Pernambuco state, Brazil. We recorded 64 different types of galls collected primarily from leaves and stems of 48 species of host plants belonging to 17 families and 31 genera. The most common gall morphological types were spheroid and discoid, glabrous, predominantly green and with one chamber. The main gall inducing taxon was the Cecidomyiidae (Diptera). The results of this study contribute to existing knowledge of galling insect and host-plant diversity in caatinga.

Trkman P.,University of Ljubljana | McCormack K.,DRK Research | De Oliveira M.P.V.,Federal University of Minas Gerais | De Oliveira M.P.V.,Centro Universitario | Ladeira M.B.,Federal University of Minas Gerais
Decision Support Systems | Year: 2010

The paper investigates the relationship between analytical capabilities in the plan, source, make and deliver area of the supply chain and its performance using information system support and business process orientation as moderators. Structural equation modeling employs a sample of 310 companies from different industries from the USA, Europe, Canada, Brazil and China. The findings suggest the existence of a statistically significant relationship between analytical capabilities and performance. The moderation effect of information systems support is considerably stronger than the effect of business process orientation. The results provide a better understanding of the areas where the impact of business analytics may be the strongest. © 2010 Elsevier B.V. All rights reserved.

Heaney L.,University of Oxford | Cabello A.,University of Seville | Santos M.F.,Federal University of Minas Gerais | Vedral V.,University of Oxford | Vedral V.,National University of Singapore
New Journal of Physics | Year: 2011

Quantum nonlocality is typically assigned to systems of two or more well-separated particles, but nonlocality can also exist in systems consisting of just a single particle when one considers the subsystems to be distant spatial field modes. Single particle nonlocality has been confirmed experimentally via a bipartite Bell inequality. In this paper, we introduce an N-party Hardy-like proof of the impossibility of local elements of reality and a Bell inequality for local realistic theories in the case of a single particle superposed symmetrically over N spatial field modes (i.e. N qubit W state). We show that, in the limit of large N, the Hardy-like proof effectively becomes an all-versus-nothing (or Greenberger-Horne-Zeilinger (GHZ)-like) proof, and the quantum-classical gap of the Bell inequality tends to be the same as that in a three-particle GHZ experiment. We describe how to test the nonlocality in realistic systems. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Bernardes M.A.d.S.,Federal University of Minas Gerais | von Backstrom T.W.,Stellenbosch University
Solar Energy | Year: 2010

Numerical simulations are carried out to study the performance of two schemes of power output control applicable to solar chimney power plants. Either the volume flow or the turbine pressure drop is used as independent control variable. Values found in the literature for the optimum ratio of turbine pressure drop to pressure potential vary between 2/3 and 0.97. It is shown that the optimum ratio is not constant during the whole day and it is dependent of the heat transfer coefficients applied to the collector. This study is a contribution towards understanding solar chimney power plant performance and control and may be useful in the design of solar chimney turbines. © 2009 Elsevier Ltd. All rights reserved.

Knipp M.,Max Planck Institute for Chemistry | Pereira M.H.,Federal University of Minas Gerais
Analytical Biochemistry | Year: 2012

All species of the genus Rhodnius have a characteristic red coloration in their salivary glands due to the presence of heme proteins. Some of these secreted proteins, known as nitrophorins (NPs), are responsible for many of the antihemostatic activities of Rhodnius saliva such as anticoagulant and antihistamine. Several NPs have been described (NP1-4 and NP7), where NP7 is the only one with affinity to phospholipid membranes. Computational prediction suggested that NP7 also has an extended N-terminal tail on signal peptide cleavage; however, the complementary DNA does not allow the determination of the exact site of signal peptidase cleavage. On the other hand, according to previous studies, the exact length of the N-terminus has important consequences for the nitric oxide binding properties of NP7. Here, a method was developed to select phospholipid membrane-attaching proteins from homogenized tissue for analysis by mass spectrometry. The method was used to determine the exact N-terminus of the ferriheme protein NP7 from homogenates of the salivary glands of 5th instar nymphal stages of Rhodnius prolixus. © 2012 Elsevier Inc. All rights reserved.

Guimaraes R.C.,Federal University of Minas Gerais
Arquivos de Gastroenterologia | Year: 2014

Objective - To review some aspects of the etiopathogenesis of peptic ulcerous disease especially on the basis of studies on its correlation with Helicobacter pylori (H. pylori). Methods - A search was made in the data bases MEDLINE, LILACS and PubMed, and in Brazilian and foreign books, referring to the incidence and prevalence of infection by H. pylori and of peptic ulcerous disease in various populations of different countries. Results - It was observed that the prevalence of H. pylori infection is similar in individuals with peptic ulcerous disease and the general population. There are differences between countries with respect to the prevalence of infection and of gastric or duodenal peptic ulcers. In many countries the prevalence of infection by H. pylorishows stability while the prevalence of peptic ulcerous disease is declining. The prevalence of peptic ulcerous disease without H. pylori infection varies between 20% and 56% in occidental countries. Discussion - The observations might be suggestive of H. pylori being only one more factor to be summed together with other aggressive components in the genesis of peptic ulcerous disease. We would therewith be returning to the classic concept that peptic gastric and duodenal ulcers have multifactorial etiology and would result from imbalance between aggressive and defensive factors. The focus of studies should be enriched with the identification of the defensive factors and of other aggressive factors besides the well known H. pylori and non-steroidal anti-inflammatory drugs, since these two aggressors do not exhaust the full causal spectrum.

Carvalho A.R.R.,Australian National University | Santos M.F.,Federal University of Minas Gerais | Santos M.F.,National University of Singapore
New Journal of Physics | Year: 2011

In composed quantum systems, the presence of local dissipative channels causes loss of coherence and entanglement at a rate that grows with the temperature of the reservoirs. However, here we show that if temperature is artificially added to the system, entanglement decay can be significantly slowed down or even suppressed conditioned on suitable local monitoring of the reservoirs. We propose a scheme for implementing joint reservoir monitoring applicable in different experimental setups, such as trapped ions, circuit and cavity QED or quantum dots coupled to nanowires, and we analyze its general robustness against detection inefficiencies and the non-zero temperature of the natural reservoir. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Rocha F.L.,Institute Previdencia Dos Servidores Do Estado Of Minas Gerais | Stumpf B.P.,Institute Previdencia Dos Servidores Do Estado Of Minas Gerais | Hara C.,Faculdade da Saude e Ecologia Humana | Fuzikawa C.,Federal University of Minas Gerais
Journal of Psychopharmacology | Year: 2013

Depression is common in Parkinson's disease (PD) and is associated with several poor outcomes. However the literature regarding treatment with antidepressants in this population is controversial. The aim of this paper was to systematically review all randomized controlled trials that studied the efficacy of antidepressants for depression in PD (dPD). Studies were retrieved from PubMed (1966-July 2012), Cochrane Library (-July 2012, issue 7), Embase (1980-July 2012), PsycINFO (1980-July 2012), Lilacs (1982-July 2012), secondary references, clinical trials registries and a thesis database. Only double-blind, randomized controlled trials in which an antidepressant was given as the main treatment and compared with placebo and/or another antidepressant were included. Out of the 1438 studies retrieved, only six could be included. Taking into account the five placebo-controlled trials, the overall risk ratio (RR) for response was 1.36 (0.98, 1.87), indicating no statistically significant superiority of antidepressants over placebo. However, in the sensitivity analysis, the RR for response was 1.41 (1.01, 1.96) and 1.48 (1.05, 2.10) after exclusion of one study with questionable results, and when only studies with low risk of bias were considered, respectively. No specific antidepressant class was superior to placebo. In general antidepressant medications were well tolerated. The results suggest antidepressants may be efficacious in the treatment of dPD. However, the results were unstable. In fact, the small number of trials and methodological drawbacks preclude definitive conclusions about their efficacy and tolerability in dPD. © The Author(s) 2013.

Brandao F.G.S.L.,Federal University of Minas Gerais | Brandao F.G.S.L.,National University of Singapore | Horodecki M.,University of Gdansk | Oppenheim J.,University of Cambridge | And 3 more authors.
Physical Review Letters | Year: 2013

The ideas of thermodynamics have proved fruitful in the setting of quantum information theory, in particular the notion that when the allowed transformations of a system are restricted, certain states of the system become useful resources with which one can prepare previously inaccessible states. The theory of entanglement is perhaps the best-known and most well-understood resource theory in this sense. Here, we return to the basic questions of thermodynamics using the formalism of resource theories developed in quantum information theory and show that the free energy of thermodynamics emerges naturally from the resource theory of energy-preserving transformations. Specifically, the free energy quantifies the amount of useful work which can be extracted from asymptotically many copies of a quantum system when using only reversible energy-preserving transformations and a thermal bath at fixed temperature. The free energy also quantifies the rate at which resource states can be reversibly interconverted asymptotically, provided that a sublinear amount of coherent superposition over energy levels is available, a situation analogous to the sublinear amount of classical communication required for entanglement dilution. © 2013 American Physical Society.

Kuhn G.C.S.,Federal University of São Carlos | Kuhn G.C.S.,Federal University of Minas Gerais | Kuttler H.,Ludwig Maximilians University of Munich | Moreira-Filho O.,Federal University of São Carlos | Heslop-Harrison J.S.,University of Leicester
Molecular Biology and Evolution | Year: 2012

Concerted evolution leading to homogenization of tandemly repeated DNA arrays is widespread and important for genome evolution. We investigated the range and nature of the process at chromosomal and array levels using the 1.688 tandem repeats of Drosophila melanogaster where large arrays are present in the heterochromatin of chromosomes 2, 3, and X, and short arrays are found in the euchromatin of the same chromosomes. Analysis of 326 euchromatic and heterochromatic repeats from 52 arrays showed that the homogenization of 1.688 repeats occurred differentially for distinct genomic regions, from euchromatin to heterochromatin and from local arrays to chromosomes. We further found that most euchromatic arrays are either close to, or are within introns of, genes. The short size of euchromatic arrays (one to five repeats) could be selectively constrained by their role as gene regulators, a situation similar to the so-called "tuning knobs." © The Author 2011.

Cabello A.,University of Seville | Cunha M.T.,Federal University of Minas Gerais
Physical Review Letters | Year: 2011

It has been argued that any test of quantum contextuality is nullified by the fact that perfect orthogonality and perfect compatibility cannot be achieved in finite precision experiments. We introduce experimentally testable two-qutrit violations of inequalities for noncontextual theories in which compatibility is guaranteed by the fact that measurements are performed on separated qutrits. The inequalities are inspired by the basic building block of the Kochen-Specker proof of quantum contextuality for a qutrit, despite the fact that their proof is completely independent of it. © 2011 American Physical Society.

Lima-Costa M.F.,Federal University of Minas Gerais | Ribeiro A.L.P.,Federal University of Minas Gerais
Stroke | Year: 2010

Background and Purpose: Previous case-control studies have suggested a causal link between Chagas disease, which is caused by the protozoan Trypanosoma cruzi, and stroke. We investigated the relationship between Chagas disease and long-term stroke mortality in a large community-based cohort of older adults. Methods: Participants were 1398 (80.3% from total) residents aged 60 years in Bambuí City, Brazil. The end point was death from stroke. Potential confounding variables included age, sex, conventional stroke risk factors, and high sensitive C-reactive protein. Results: Participants of this study were followed from 1997 to 2007 leading to 9740 person-years of observation. The baseline prevalence of T. cruzi infection was 37.5% and the overall mortality rate from stroke was 4.62 per 1000 person-years. The risk of death from stroke among T. cruzi-infected participants was twice that of those noninfected (adjusted hazard ratio, 2.36; 95% CI, 1.25 to 4.44). A B-type natriuretic peptide level in the top quartile was a strong and independent predictor of stroke mortality among those infected (adjusted hazard ratio, 2.72; 95% CI, 1.25 to 5.91). The presence of both a high B-type natriuretic peptide level and electrocardiographic atrial fibrillation increased the risk of stroke mortality by 11.49 (95% CI, 3.19 to 41.38) in these individuals. Conclusions: This study provides new evidence supporting a causal link between Chagas disease and stroke. The results also showed that B-type natriuretic peptide alone or in association with atrial fibrillation has prognostic value for stroke mortality in T. cruzi chronically infected older adults. © 2010 American Heart Association, Inc.

Gazzinelli R.T.,University of Massachusetts Medical School | Gazzinelli R.T.,Federal University of Minas Gerais | Kalantari P.,University of Massachusetts Medical School | Fitzgerald K.A.,University of Massachusetts Medical School | Golenbock D.T.,University of Massachusetts Medical School
Nature Reviews Immunology | Year: 2014

Innate immune receptors have a key role in immune surveillance by sensing microorganisms and initiating protective immune responses. However, the innate immune system is a classic 'double-edged sword' that can overreact to pathogens, which can have deleterious effects and lead to clinical manifestations. Recent studies have unveiled the complexity of innate immune receptors that function as sensors of Plasmodium spp. in the vertebrate host. This Review highlights the cellular and molecular mechanisms by which Plasmodium infection is sensed by different families of innate immune receptors. We also discuss how these events mediate both host resistance to infection and the pathogenesis of malaria. © 2014 Macmillan Publishers Limited. All rights reserved.

Cabello A.,University of Seville | Cabello A.,Federal University of Minas Gerais | Cunha M.T.,Federal University of Minas Gerais
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

It has been recently conjectured that the state-independency of quantum contextuality may be lost when the indistinguishability of identical particles is taken into account. Here, we show that quantum state-independent contextuality exists for any system of more than one identical bosonic qudit, and for most systems of fermionic qudits. The only exception is the case of d fermionic qudits, since there the dimension of the antisymmetric subspace is 1, which is insufficient for contextuality. For all the other cases, either the symmetry precludes the existence of physical states or we provide an explicit method to produce quantum state-independent contextual correlations. © 2013 American Physical Society.

Tonezzer M.,University of Trento | Tonezzer M.,CNR Institute of Materials for Electronics and Magnetism | Lacerda R.G.,Federal University of Minas Gerais
Sensors and Actuators, B: Chemical | Year: 2010

An integration of zinc oxide (ZnO) nanowires (NWs) onto carbon microfibers (μC) using electrochemical deposition and thermal oxidation approach has been developed and used as a versatile resistive (oxidizing and reducing) gas sensor. This architecture is attractive because it allows mechanical flexibility, low cost and large-area fabrication. Being structured at both microscale and nanoscale, the ZnO nanowires-carbon microfiber (ZnO-μC) sensor possesses a greater surface area, giving rise to a strong and rapid response/recovery time. Additionally, the ZnO-μC sensor is simple to manufacture, has a very low power consumption (less than 0.6 μW) and is prepared without any lithographic process. The sensor exhibits excellent oxygen (down to 2 ppm) and hydrogen (down to 4 ppm) sensing characteristics, showing a fast response on gas exposure (less than 10 s) and very good reversibility. Furthermore, the carbon microfiber is as flexible as a fabric is, thus, the ZnO-μC sensor could also be used in applications where flexibility is required. This architecture can also be expanded to other nanowire materials (CuO, Fe2O3, etc) widening the range of detected gases. We therefore believe that the integration of nanowires with carbon microfibers has the potential for being the next generation of simple and low cost sensor devices. © 2010 Elsevier B.V.

Moura C.,Federal University of Bahia | Prado N.,General Hospital of Vitoria da Conquista | Acurcio F.,Federal University of Minas Gerais
Clinical Drug Investigation | Year: 2011

Background and Objectives: Drug-drug interactions (DDIs) are one cause of adverse drug events and can cause harm to hospitalized patients. Little has been done to study the relationship between potential DDIs and an increased length of stay (LOS) in the intensive care unit (ICU). The aim of this study was to determine the frequency of potential DDIs during ICU stays and to determine whether the frequency of these adverse events was associated with ICU LOS. Methods: This retrospective cohort study was conducted from January to December 2007 in the ICU of the General Hospital of Vitó ria da Conquista, Brazil. The study population comprised all patients aged >18 years admitted to the hospital's ICU. Demographic and prescription data were collected from medical files. All prescriptions administered during the period were examined. Potential DDIs were identified and classified according to the book Drug Interaction Facts. The median LOS was determined by the Kaplan-Meier method and Cox proportional hazards models were fitted to analyse the relationship between potential DDIs and the LOS. Results: The study population comprised 236 adults, 158 (67%) of them men, between the ages of 18 and 96 years, with a mean ± SD age of 50 ± 20 years. The median LOS among patients with at least one DDI was 12 days compared with 5 days among those with no DDIs (p< 0.01). Multiple Cox proportional regression analyses showed that a prolonged ICU stay was positively associated with DDIs (hazard ratio [HR] 0.54; 95% CI 0.37, 0.80; p < 0.01), where an HR <1 indicates a variable that increases the risk of prolonged stay (i.e. an adverse outcome). This association was true even after controlling for the cost of hospitalization, the number of procedures and the number of prescribed drugs. Conclusion: In this study, DDIs were found to be associated with a longer ICU stay. Given that LOS is an important indicator of the quality of health care delivered and that DDIs are considered avoidable, specific measures are necessary to increase the recognition of DDIs. E-prescriptions and dispensing programmes associated with a DDI knowledge base can help health professionals identify hazardous drug combinations. © 2011 Adis Data Information BV. All rights reserved.

Cabello A.,University of Seville | Badziag P.,University of Stockholm | Terra Cunha M.,Federal University of Minas Gerais | Bourennane M.,University of Stockholm
Physical Review Letters | Year: 2013

Contextuality and nonlocality are two fundamental properties of nature. Hardy's proof is considered the simplest proof of nonlocality and can also be seen as a particular violation of the simplest Bell inequality. A fundamental question is: Which is the simplest proof of contextuality? We show that there is a Hardy-like proof of contextuality that can also be seen as a particular violation of the simplest noncontextuality inequality. Interestingly, this new proof connects this inequality with the proof of the Kochen-Specker theorem, providing the missing link between these two fundamental results, and can be extended to an arbitrary odd number n of settings, an extension that can be seen as a particular violation of the n-cycle inequality. © 2013 American Physical Society.

Lu J.,National University of Singapore | Gomes L.C.,National University of Singapore | Gomes L.C.,Federal University of Minas Gerais | Nunes R.W.,Federal University of Minas Gerais | And 2 more authors.
Nano Letters | Year: 2014

Heteroepitaxy of two-dimensional (2D) crystals, such as hexagonal boron nitride (BN) on graphene (G), can occur at the edge of an existing heterointerface. Understanding strain relaxation at such 2D laterally fused interface is useful in fabricating heterointerfaces with a high degree of atomic coherency and structural stability. We use in situ scanning tunneling microscopy to study the 2D heteroepitaxy of BN on graphene edges on a Ru(0001) surface with the aim of understanding the propagation of interfacial strain. We found that defect-free, pseudomorphic growth of BN on a graphene edge "substrate" occurs only for a short distance (<1.29 nm) perpendicular to the interface, beyond which misfit zero-dimensional dislocations occur to reduce the elastic strain energy. Boundary states originating from a coherent zigzag-linked G/BN boundary are observed to greatly enhance the local conductivity, thus affording a new avenue to construct one-dimensional transport channels in G/BN hybrid interface. © 2014 American Chemical Society.

Amaral B.,Federal University of Minas Gerais | Amaral B.,Federal University of Ouro Preto | Amaral B.,Autonomous University of Barcelona | Cunha M.T.,Federal University of Minas Gerais | Cabello A.,University of Seville
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We show that the exclusivity (E) principle singles out the set of quantum correlations associated with any exclusivity graph assuming the set of quantum correlations for the complementary graph. Moreover, we prove that, for self-complementary graphs, the E principle, by itself (i.e., without further assumptions), excludes any set of correlations strictly larger than the quantum set. Finally, we prove that, for vertex-transitive graphs, the E principle singles out the maximum value for the quantum correlations assuming only the quantum maximum for the complementary graph. This opens the door for testing the impossibility of higher-than-quantum correlations in experiments. © 2014 American Physical Society.

Fonseca C.T.,Federal University of Minas Gerais | Oliveira S.C.,Federal University of Minas Gerais
Frontiers in Immunology | Year: 2015

The successful development of vaccines depends on the knowledge of the immunological mechanisms associated with the elimination of the pathogen. In the case of schistosomes, its complex life cycle and the mechanisms developed to evade host immune system, turns the development of a vaccine against the disease into a very difficult task. Identifying the immunological effector mechanisms involved in parasite attrition and the major targets for its response is a key step to formulate an effective vaccine. Recent studies have described some promising antigens to compose a subunit vaccine and have pointed to some immune factors that play a role in parasite elimination. Here, we review the immune components and effector mechanisms associated with the protective immunity induced by those vaccine candidates and the lessons we have learned from the studies of the acquired resistance to infection in humans. We will also discuss the immune factors that correlate with protection and therefore could help to evaluate those vaccine formulations in clinical trials. © 2015 Fonseca, Oliveira and Alves.

The public policies adopted by the Unified Health System (SUS) in Brazil have gone through successive transformations, striving to reassert health as a universal right. The user acceptance of the guidelines of the National Humanization Policy for Care and Management of the SUS -Humanize SUS - is taking shape and relevance in Primary Healthcare (PHC) to ensure humanized access and resolution of the health demands of users and communities in Brazil. A critical analysis of the bibliographical output in Brazil from 1989 to 2009 was conducted regarding acceptance of implementation and qualification of SUS in PHC. The databases consulted were SciELO, Lilacs and Medline. The results revealed progress in broadening access to PHC services and health professionals more sensitive to the needs of users and communities. However, lack of coordination in integrated networks, excess demand, the hegemonic biomedical model, lack of training and democratic and reflexive spaces to reorganize the work process have been raising increasingly more incisive questions about the potential of this guideline for the implementation and qualification of SUS.

Schmidt M.I.,Federal University of Rio Grande do Sul | Duncan B.B.,Federal University of Rio Grande do Sul | E Silva G.A.,State University of Rio de Janeiro | Menezes A.M.,Federal University of Pelotas | And 3 more authors.
The Lancet | Year: 2011

Non-communicable diseases (NCDs) have become a major health priority in Brazil - 72 of all deaths were attributable to NCDs in 2007. They are also the main source of disease burden, with neuropsychiatric disorders being the single largest contributor. Morbidity and mortality due to NCDs are greatest in the poor population. Although the crude NCD mortality increased 5 between 1996 and 2007, age-standardised mortality declined by 20. Declines were primarily for cardiovascular and chronic respiratory diseases, in association with the successful implementation of health policies that lead to decreases in smoking and the expansion of access to primary health care. Of note, however, the prevalence of diabetes and hypertension is rising in parallel with that of excess weight; these increases are associated with unfavourable changes of diet and physical activity. Brazil has implemented major policies for the prevention of NCDs, and its age-adjusted NCD mortality is falling by 1·8 per year. However, the unfavourable trends for most major risk factors pose an enormous challenge and call for additional and timely action and policies, especially those of a legislative and regulatory nature and those providing cost-effective chronic care for individuals affected by NCDs. © 2011 Elsevier Ltd.

Naoumkina M.A.,Samuel Roberts Noble Foundation | Modolo L.V.,Federal University of Minas Gerais | Huhman D.V.,Samuel Roberts Noble Foundation | Urbanczyk-Wochniak E.,Samuel Roberts Noble Foundation | And 3 more authors.
Plant Cell | Year: 2010

Saponins, an important group of bioactive plant natural products, are glycosides of triterpenoid or steroidal aglycones (sapogenins). Saponins possess many biological activities, including conferring potential health benefits for humans. However, most of the steps specific for the biosynthesis of triterpene saponins remain uncharacterized at the molecular level. Here, we use comprehensive gene expression clustering analysis to identify candidate genes involved in the elaboration, hydroxylation, and glycosylation of the triterpene skeleton in the model legume Medicago truncatula. Four candidate uridine diphosphate glycosyltransferases were expressed in Escherichia coli, one of which (UGT73F3) showed specificity for multiple sapogenins and was confirmed to glucosylate hederagenin at the C28 position. Genetic loss-of-function studies in M. truncatula confirmed the in vivo function of UGT73F3 in saponin biosynthesis. This report provides a basis for future studies to define genetically the roles of multiple cytochromes P450 and glycosyltransferases in triterpene saponin biosynthesis in Medicago. © 2010 American Society of Plant Biologists.

Fernandes A.P.,Federal University of Minas Gerais | Coelho E.A.F.,Federal University of Minas Gerais | Machado-Coelho G.L.L.,Federal University of Ouro Preto | Grimaldi G.,Instituto Oswaldo Cruz | And 2 more authors.
Current Opinion in Microbiology | Year: 2012

Visceral leishmaniasis is a major health problem in Latina America, as well as the Mediterranean region of Europe and Asia. We aimed to develop a vaccine against visceral leishmaniasis targeting the intracellular amastigotes, which is the parasite stage that persists throughout infections with Leishmania parasites. With this in mind, we identified an amastigote specific antigen (A2) that contains an immunogenic epitope for CD4+ T helper (Th) cells and multiple repetitive units encoding CD8+ cytotoxic T lymphocyte (CTL) epitopes. Vaccine formulations containing the recombinant A2 associated with saponin, alum and IL-12 or expressed by attenuated adenovirus were shown to be protective in mice, dogs and nonhuman-primates. We are currently identifying novel amastigote specific immunogenic proteins that could be aggregated to A2 to further improve the level of vaccine-induced cell-mediated immunity and protection against visceral leishmaniasis. © 2012 Elsevier Ltd.

Alexandre S.S.,Federal University of Minas Gerais | Lucio A.D.,Federal University of Lavras | Neto A.H.C.,National University of Singapore | Nunes R.W.,Federal University of Minas Gerais
Nano Letters | Year: 2012

Ab initio calculations indicate that while the electronic states introduced by tilt grain boundaries in graphene are only partially confined to the defect core, a translational grain boundary introduces states near the Fermi level that are very strongly confined to the core of the defect, and display a ferromagnetic instability. The translational boundary lies along a graphene zigzag direction and its magnetic state is akin to that which has been theoretically predicted to occur on zigzag edges of graphene ribbons. Unlike ribbon edges, the translational grain boundary is fully immersed within the bulk of graphene, hence its magnetic state is protected from the contamination and reconstruction effects that have hampered experimental detection of the magnetic ribbon states. Moreover, our calculations suggest that charge transfer between grain boundaries and the bulk in graphene is short ranged, with charge redistribution confined to ∼5 Å from the geometric center of the 1D defects. © 2012 American Chemical Society.

Da Silva D.L.,Federal University of Minas Gerais | Fernandes S.A.,Federal University of Viçosa | Sabino A.A.,Federal University of Minas Gerais | De Fa A.,Federal University of Minas Gerais
Tetrahedron Letters | Year: 2011

A new and efficient methodology is proposed for obtaining 3,4-dihydropyrimidin-2(1H)-ones/-thiones through Biginelli reactions. It is based on the use of less than the stoichiometric amount ofp-sulfonic acid calixarenes as organocatalysts. A number of aromatic aldehydes as well as urea or thiourea can be employed for successfully synthesizing the corresponding Biginelli adducts. The described methodology is devoid of metal-containing catalysts, which in turn is very attractive for safely producing 3,4-dihydro-pyrimidin-2-(1H)-ones/-thiones of pharmacological interest. In addition, the catalyst efficiency is not compromised after its successive use in reactions. This is the first report about the application of calixarenes as catalysts in the multicomponent Biginelli reaction. © 2011 Elsevier Ltd. All rights reserved.

Tsolis R.M.,University of California at Davis | Xavier M.N.,University of California at Davis | Santos R.L.,Federal University of Minas Gerais | Baumler A.J.,University of California at Davis
Infection and Immunity | Year: 2011

Salmonella serotypes are a major cause of human morbidity and mortality worldwide. Over the past decades, a series of animal models have been developed to advance vaccine development, provide insights into immunity to infection, and study the pathogenesis of human Salmonella disease. The successive introduction of new animal models, each suited to interrogate previously neglected aspects of Salmonella disease, has ushered in important conceptual advances that continue to have a strong and sustained influence on the ideas driving research on Salmonella serotypes. This article reviews important milestones in the use of animal models to study human Salmonella disease and identify research needs to guide future work. © 2011, American Society for Microbiology.

Reis C.E.G.,University of Brasilia | Alvarez-Leite J.I.,Federal University of Minas Gerais | Bressan J.,Federal University of Viçosa | Alfenas R.C.,Federal University of Viçosa
Diabetes Technology and Therapeutics | Year: 2012

Bariatric surgery has been used to treat type 2 diabetes mellitus (T2DM); however, its efficacy is still debatable. This literature review analyzed articles that evaluated the effects of bariatric surgery in treatment of T2DM in obese patients with a body mass index (BMI) of <35kg/m 2. A paired t test was applied for the analysis of pre-and postintervention mean BMI, fasting plasma glucose (FPG), and glycosylated hemoglobin (A1c) values. A significant (P<0.001) reduction in BMI (from 29.95±0.51kg/m 2 to 24.83±0.44kg/m 2), FPG (from 207.86±8.51mg/dL to 113.54±4.93mg/dL), and A1c (from 8.89±0.15% to 6.35±0.18%) was observed in 29 articles (n=675). T2DM resolution (A1c <7% without antidiabetes medication) was achieved in 84.0% (n=567) of the subjects. T2DM remission, control, and improvement were observed in 55.41%, 28.59%, and 14.37%, respectively. Only 1.63% (n=11) of the subjects presented similar or worse glycemic control after the surgery. T2DM remission (A1c <6% without antidiabetes medication) was higher after mini-gastric bypass (72.22%) and laparoscopic/Roux-en-Y gastric bypass (70.43%). According to the Foregut and Hindgut Hypotheses, T2DM results from the imbalance between the incretins and diabetogenic signals. The procedures that remove the proximal intestine and do ileal transposition contribute to the increase of glucagon-like peptide-1 levels and improvement of insulin sensitivity. These findings provide preliminary evidence of the benefits of bariatric-metabolic surgery on glycemic control of T2DM obese subjects with a BMI of <35kg/m 2. However, more clinical trials are needed to investigate the metabolic effects of bariatric surgery in T2DM remission on pre-obese and obese class I patients. © Copyright 2012, Mary Ann Liebert, Inc. 2012.

Orefice R.L.,Federal University of Minas Gerais
Polymer | Year: 2010

The relationship between shape-memory behavior and structure was studied using three series of poly(ester-urethanes) with varying amounts of hard segment. The materials were designed to display a three-phase structure consisting of a disperse phase of crystallites and hard domains embedded in an amorphous matrix based on soft segment. Structure and thermal properties of the resultant materials were investigated using techniques such as modulated differential scanning calorimetry (MDSC), dynamic mechanical analysis (DMA) and small angle X-ray scattering (SAXS). The results revealed morphological changes in the materials during a low temperature shape-memory cycle. To study shape recovery, a deformed specimen was evaluated on a heating stage mounted at the SAXS beamline. Furthermore, to study the effect of temperature during recovery, the specimens were subjected to different thermo-cycles. Under each set of conditions, the phase morphology and composition were investigated. Temporary shape was stored by the metastable structure formed during deformation. The recovery was triggered by the melting of crystallites and hydrogen bonding between hard domains. The recovery process was divided into three stages. Bulk incompatibility and entropic recovery determined the final polyurethane morphology. © 2010 Elsevier Ltd. All rights reserved.

Paulino J.O.S.,Federal University of Minas Gerais
IEEE Transactions on Electromagnetic Compatibility | Year: 2010

This paper presents a time-domain formula for the calculation of the horizontal electric field in the vicinity of the lightning channel. The formula is based on the incident azimuthal magnetic field, so that it does not depend on the assumptions considered in the calculation of the magnetic field, such as return stroke model or propagation effects. The application of the formula with the magnetic field calculated from perfectly conducting earth provided results that agreed very well with results from Sommerfeld integrals, even in the vicinity of the lightning channel, where the CoorayRubinstein formula does not hold. The deviations of the results of the formula with respect to the Sommerfeld integrals are on the order of a few percent, which is the same order of magnitude as the deviations involved in the numerical evaluation of Sommerfeld integrals. © 2010 IEEE.

Le Stradic S.,University of Liège | Buisson E.,University of Avignon | Fernandes G.W.,Federal University of Minas Gerais
Applied Vegetation Science | Year: 2014

Aim: The campos rupestres are species-rich tropical mountain grasslands in southeast Brazil that are threatened by mining and quarrying. Eight years following a strong disturbance (i.e. quarrying for gravel exploitation during the asphalting of highway MG-010), spontaneous succession did not occur on degraded areas. This study was therefore designed to test the restoration technique of hay transfer as a means of enhancing seed dispersal from the reference ecosystems to the degraded areas. Location: Campo rupestre grasslands, Serra do Cipó, Minas Gerais, Brazil. Methods: Nine degraded areas representing three kinds of substrate (latosol, sandy and stony) were selected. Hay transfer was carried out using hay collected in two kinds of grassland (i.e. campos arenosos and campos pedregosos) year-round in 2010, in order to maximize the seed pool. The collected hay was distributed on 40 cm × 40 cm quadrats among the three types of substrate, with and without geotextile, according to the following protocol: hay from campo arenoso grasslands was spread on all types of substrate, while hay from campo pedregoso grasslands was used on stony substrate only. Results: Few seedlings emerged within 14 mo of the treatment application, despite the large number of seeds contained in the hay, indicating that hay transfer may not be a useful method for restoring degraded areas of campos rupestres. The seedlings emerging on the degraded areas mainly belonged to ruderal species. Therefore, we suggest that, although poor soil conditions could limit seedling establishment, germination issues of the campo rupestre species are the first limitation for restoring degraded campos rupestres using hay transfer. Conclusion: Our results highlight the inherent difficulty in restoring degraded areas of campos rupestres; their protection must be made a high conservation priority. Currently threatened by mining and quarrying, we tested to restore campos rupestres, neotropical grasslands, using hay transfer. Few seedlings emerged within 14 mo despite the large number of seeds contained in the hay. We suggest that germination issues of the campo rupestre species are the first limitation for restoring degraded campos rupestres using hay transfer. © 2013 International Association for Vegetation Science.

Pinho G.P.d.,Federal University of Viçosa | Neves A.A.,Federal University of Viçosa | Queiroz M.E.L.R.d.,Federal University of Viçosa | Silverio F.O.,Federal University of Minas Gerais
Food Chemistry | Year: 2010

In this work, a simple and low cost method, based on solid-liquid extraction with low temperature purification (SLE-LTP), was optimized and validated for the determination of chlorpyrifos, λ-cyhalothrin, cypermethrin and deltamethrin in tomato samples. The analyses were performed by the GC-ECD and confirmed by the GC-MS. The method requires 4 g of tomato and an extraction mixture (8.0 mL acetonitrile, 0.5 mL water and 1.5 mL ethyl acetate), which was established by mixture experimental design. After optimization, pesticide recovery rates ranged from 79% to 97%, with a standard deviation of less than 5%. The SLE-LTP analytical characteristics were compared very favorably to the matrix solid phase dispersion technique, which used ethyl acetate and Florisil for extraction. © 2009 Elsevier Ltd. All rights reserved.

Ling X.,CAS Beijing National Laboratory for Molecular | Moura L.G.,Federal University of Minas Gerais | Moura L.G.,Federal University of Viçosa | Pimenta M.A.,Federal University of Minas Gerais | Zhang J.,CAS Beijing National Laboratory for Molecular
Journal of Physical Chemistry C | Year: 2012

In the chemical enhancement mechanism for Raman scattering, the two types of charge-transfer models, the excited-state and the ground-state charge-transfer mechanisms, present the different dependence of the enhanced Raman signals on the excitation wavelength. To investigate the type of charge-transfer mechanism in graphene-enhanced Raman scattering (GERS), the Raman excitation profiles of the copper phthalocyanine (CuPc) molecule were obtained in the range of 545-660 nm. The profiles in the GERS system were fitted well with the function of the ordinary resonant Raman scattering expression, where the incident and scattered resonance peaks were well-distinguished with the energy difference equaling the energy of the molecular vibrations. This result meets the prediction of ground-state charge transfer, in which model the dependence of the enhanced Raman signals on the excitation wavelength is the same as that of the ordinary Raman scattering, and rules out the prediction of the excited-state charge transfer because of no the possible charge-transfer resonance peak observed. Therefore, the GERS was proved to be a ground-state charge-transfer mechanism. Meanwhile, because the Raman excitation profiles of molecule can be obtained in the GERS system easily, which is usually difficult to obtain due to the self-absorption of the molecules, GERS opens up a new way to suppress this effect. This work contributes the deeper understanding of the graphene-enhanced Raman scattering. © 2012 American Chemical Society.

de Araujo V.E.M.,Federal University of Minas Gerais | Morais M.H.F.,Federal University of Minas Gerais | Reis I.A.,Institute Ciencias Exatas | Carneiro M.,Federal University of Minas Gerais
PLoS Neglected Tropical Diseases | Year: 2012

Background: In Brazil, lethality from visceral leishmaniasis (VL) is high and few studies have addressed prognostic factors. This historical cohort study was designed to investigate the prognostic factors for death from VL in Belo Horizonte (Brazil). Methodology: The analysis was based on data of the Reportable Disease Information System-SINAN (Brazilian Ministry of Health) relating to the clinical manifestations of the disease. During the study period (2002-2009), the SINAN changed platform from a Windows to a Net-version that differed with respect to some of the parameters collected. Multivariate logistic regression models were performed to identify variables associated with death from VL, and these were included in prognostic score. Principal Findings: Model 1 (period 2002-2009; 111 deaths from VL and 777 cured patients) included the variables present in both SINAN versions, whereas Model 2 (period 2007-2009; 49 deaths from VL and 327 cured patients) included variables common to both SINAN versions plus the additional variables included in the Net version. In Model 1, the variables significantly associated with a greater risk of death from VL were weakness (OR 2.9; 95%CI 1.3-6.4), Leishmania-HIV co-infection (OR 2.4; 95%CI 1.2-4.8) and age ≥60 years (OR 2.5; 95%CI 1.5-4.3). In Model 2, the variables were bleeding (OR 3.5; 95%CI 1.2-10.3), other associated infections (OR 3.2; 95%CI 1.3-7.8), jaundice (OR 10.1; 95%CI 3.7-27.2) and age ≥60 years (OR 3.1; 95%CI 1.4-7.1). The prognosis score was developed using the variables associated with death from VL of the latest version of the SINAN (Model 2). The predictive performance of which was evaluated by sensitivity (71.4%), specificity (73.7%), positive and negative predictive values (28.9% and 94.5%) and area under the receiver operating characteristic curve (75.6%). Conclusions: Knowledge regarding the factors associated with death from VL may improve clinical management of patients and contribute to lower mortality. © 2012 de Araújo et al.

Barbosa I.G.,Federal University of Minas Gerais | Bauer M.E.,Grande Rio University | MacHado-Vieira R.,University of Sao Paulo | MacHado-Vieira R.,U.S. National Institutes of Health | Teixeira A.L.,Federal University of Minas Gerais
Neural Plasticity | Year: 2014

Bipolar disorder (BD) is a severe, chronic, and recurrent psychiatric illness. It has been associated with high prevalence of medical comorbidities and cognitive impairment. Its neurobiology is not completely understood, but recent evidence has shown a wide range of immune changes. Cytokines are proteins involved in the regulation and the orchestration of the immune response. We performed a review on the involvement of cytokines in BD. We also discuss the cytokines involvement in the neuroprogression of BD. It has been demonstrated that increased expression of cytokines in the central nervous system in postmortem studies is in line with the elevated circulating levels of proinflammatory cytokines in BD patients. The proinflammatory profile and the immune imbalance in BD might be regarded as potential targets to the development of new therapeutic strategies. © 2014 Izabela Guimarães Barbosa et al.

Almeida V.,Federal University of Minas Gerais | Getschko D.,Pontifical Catholic University of São Paulo | Afonso C.,Instituto Nupef
IEEE Internet Computing | Year: 2015

Various domains have adopted multistakeholder models (MSMs) to address and deal with global challenges, such as sustainability, environment, climate, and Internet governance. Here, the authors examine the use of MSMs and their historical evolution, fundamentals, and characteristics. They also present examples of how such models are used in the global Internet governance ecosystem. Finally, the article presents a series of research questions that can be tackled to improve the efficiency of multistakeholder processes. © 1997-2012 IEEE.

Leite C.C.,Federal University of Viçosa | Costa M.H.,Federal University of Viçosa | Soares-Filho B.S.,Federal University of Minas Gerais | De Barros Viana Hissa L.,Federal University of Minas Gerais
Global Biogeochemical Cycles | Year: 2012

The evaluation of impacts of land use change is in general limited by the knowledge of past land use conditions. Most publications on the field present only a vague description of the earlier patterns of land use, which is usually insufficient for more comprehensive studies. Here we present the first spatially explicit reconstruction of historical land use patterns in Brazil, including both croplands and pasturelands, for the period between 1940 and 1995. This reconstruction was obtained by merging satellite imagery with census data, and provides a 5′ × 5′ yearly data set of land use for three different categories (cropland, natural pastureland and planted pastureland) for Brazil. The results show that important land use changes occurred in Brazil. Natural pasture dominated in the 1950s and 1960s, but since the beginning of 1970s it has been gradually replaced by planted pasture, especially in southeast and center west of Brazil. The croplands began its expansion in the 1960s reaching extensive areas in almost all states in 1980. Carbon emissions from historical land use changes were calculated by superimposing a composite biomass map on grids of a weighted average of the fractions of the vegetation types and the replacement land uses. Net emissions from land use changes between 1940 and 1995 totaled 17.2;9.0 Pg-C (90% confidence range), averaging 0.31;0.16 Pg-C yr-1, but reaching up to 0.47;0.25 Pg-C yr-1 during the 1960s and through 1986-1995. Despite international concerns about Amazon deforestation emissions, 72% of Brazil's carbon emissions during the period actually came from deforestation in the Atlantic Forest and Cerrado biomes. Brazil's carbon emissions from land use change are about 11 times larger than its emissions from fossil fuel burning, although only about 18.1% of the native biomass has been lost due to agricultural expansion, which is similar to the global mean (17.7%). Copyright 2012 by the American Geophysical Union.

Moura A.R.,Federal University of Uberlandia | Pires A.S.T.,Federal University of Minas Gerais | Pereira A.R.,Federal University of Viçosa
Journal of Magnetism and Magnetic Materials | Year: 2014

In this paper we study the influence of the single-ion anisotropy in the two-dimensional biquadratic Heisenberg model (ABHM) on the square lattice at zero and finite low temperatures. It is common to represent the bilinear and biquadratic terms by J1=Jcosθ and J2=Jsinθ, respectively, and the many phases present in the model as a function of θ are well documented. However we have adopted a constant value for the bilinear constant (J1=1) and small values of the biquadratic term (| J2|Dc, the excited states are gapped and there is no spin long-range order (LRO) even at zero temperature. Using Schwinger bosonic representation and Self-Consistent Harmonic Approximation (SCHA), we have studied the quantum and thermal phase transitions as a function of the bilinear and biquadratic constants. © 2014 Elsevier B.V.

Jentzsch N.S.,Postgraduate Institute | Camargos P.,Federal University of Säo João del Rei | Camargos P.,Federal University of Minas Gerais | Sarinho E.S.C.,Federal University of Pernambuco | Bousquet J.,Service des Maladies Respiratoires
Respiratory Medicine | Year: 2012

There are only a few studies assessing the relationship between adherence rate to ICS, as assessed by electronic monitoring, and the level of asthma control in childhood. The present study was carried out to examine the relationship between adherence to beclomethasone diproprionate (BDP) as well as other factors related to poor asthma control. In this prospective cohort study, 102 steroid naïve randomly selected subjects with persistent asthma, aged 5-14 years were prescribed 500-750 μg daily of BDP-CFC and followed during one year. Adherence to BDP was measured electronically in the 4th, 8th and 12th months of study. The level of asthma control was classified as either controlled or uncontrolled instead of the current three categories recommended by the Global Initiative for Asthma (GINA). Mean adherence rate was higher in patients with controlled asthma during follow-up, but went down from 60.4% in the 4th month to 49.8% in the 12th month (p = 0.038). Conversely, among patients with uncontrolled asthma, the mean adherence rate decreased from 43.8% to 31.2% (p = 0.001). Multivariate analysis showed that the level of asthma control was independently associated to the adherence rate in all follow-up visits (p-values equal or lower than 0.005). The level of asthma control was directly proportional to adherence rate. Our results suggest that a BDP daily dose by 300 μg seems to be enough to attain control over mild and moderate persistent asthma, including exercise induced asthma. © 2011 Elsevier Ltd. All rights reserved.

Agency: Cordis | Branch: FP7 | Program: CP-FP-SICA | Phase: SSH.2012.2.1-2 | Award Amount: 1.33M | Year: 2013

DESAFIO means challenge in both Portuguese and Spanish. The guiding concept of our proposal is to make a contribution towards tackling what is arguably one of the major challenges facing Brazil and Latin American countries in the 21st century: eradicating structural social inequality in the access to essential water and sanitation services. The overarching objective of our proposal is assessing existing experiences and developing new strategies that bring about sustainable, appropriate, and innovative socio-technical solutions to foster economic and social development through social transformation in vulnerable communities, particularly with reference to access to safe water supply and sanitation in urban, peri-urban, and rural areas of South America, with a particular emphasis on Brazil. These strategies will be developed through research and networking that actively engages beneficiary communities, practitioners, local authorities, and other relevant actors in their planning, design, assessment, implementation, monitoring, validation, and diffusion. Our transdisciplinary approach is predicated on a close interaction with non-academic actors in the production and validation of knowledge, among other things to underpin policy and behavioural transformations. We have selected a number of case studies that will cover a range of situations and characteristics, from informal settlements in the urban periphery of world megacities (Rio de Janeiro, Brazil) and in peri-urban areas of provincial capitals (Cali, Colombia), favelas located in the heart of booming mid-range urban centres (Recife, Brazil), to small rural villages (Mondomo, Colombia) and communities in semi-arid areas (Cear and Minas Gerais, Brazil and Santa Fe, Argentina). We will endeavour to draw lessons and develop recommendations that are applicable to other socio-cultural and economic contexts across the developing world.

Borges A.M.,University of Swansea | Borges A.M.,Federal University of Minas Gerais | Healey G.D.,University of Swansea | Sheldon I.M.,University of Swansea
American Journal of Reproductive Immunology | Year: 2012

Problem: Bacterial infections commonly cause bovine endometritis and infertility via innate immune pathways. However, mechanistic studies using isolated cells or chopped tissue may be compromised by the disruption of endometrial architecture and release of damage-associated molecular patterns. So, this study aimed to establish an ex vivo model of intact bovine endometrium to study innate immunity and inflammation. Method of study: Intact bovine endometrium explants were collected using a sterile 8-mm punch biopsy and cultured ex vivo with bacteria or pathogen-associated molecules. Interleukin accumulation was measured, and tissue viability was assessed by microscopy, TdT-mediated biotin-dUTP nick-end labelling and lactate dehydrogenase assay. Results: Intact endometrium explants accumulated IL-6, IL-1β and IL-8 in response to Gram-negative or Gram-positive bacteria, and their purified pathogen-associated molecules; inflammatory responses were dependent on the stage of oestrous cycle. Explants of intact endometrium maintained viability and tissue architecture, and had lower basal accumulation of interleukins compared with explants using chopped endometrium. Conclusion: This study established a tractable ex vivo model of intact endometrium to explore the mechanisms of immunity and inflammation in the bovine endometrium. © 2012 John Wiley & Sons A/S.

Agency: Cordis | Branch: H2020 | Program: RIA | Phase: SC1-PM-22-2016 | Award Amount: 15.59M | Year: 2016

ZIKAlliance is a multidisciplinary project with a global One Health approach, built: on a multi-centric network of clinical cohorts in the Caribbean, Central & South America; research sites in countries where the virus has been or is currently circulating (Africa, Asia, Polynesia) or at risk for emergence (Reunion Island); a strong network of European and Brazilian clinical & basic research institutions; and multiple interfaces with other scientific and public health programmes. ZIKAlliance will addrees three key objectives relating to (i) impact of Zika virus (ZIKV) infection during pregnancy and short & medium term effects on newborns, (ii) associated natural history of ZIKV infection in humans and their environment in the context of other circulating arboviruses and (iii) building the overall capacity for preparedness research for future epidemic threats in Latin America & the Caribbean. The project will take advantage of large standardised clinical cohorts of pregnant women and febrile patients in regions of Latin America and the Caribbean were the virus is circulating, expanding a preexisting network established by the IDAMS EU project. I will also benefit of a very strong expertise in basic and environmental sciences, with access to both field work and sophisticated technological infrastructures to characterise virus replication and physiopathology mechanisms. To meet its 3 key objectives, the scientific project has been organised in 9 work packages, with WP2/3 dedicated to clinical research (cohorts, clinical biology, epidemiology & modeling), WP3/4 to basic research (virology & antivirals, pathophysiology & animal models), WP5/6 to environmental research (animal reservoirs, vectors & vector control) , WP7/8 to social sciences & communication, and WP9 to management. The broad consortium set-up allow gathering the necessary expertise for an actual interdisciplinary approach, and operating in a range of countries with contrasting ZIKV epidemiological status.

Leite I.C.,ENSP. Fiocruz | Machado C.J.,Federal University of Minas Gerais
Revista de Saude Publica | Year: 2010

Objective: To analyze the infl uence of demographic, socioeconomic, health, and contextual factors of the Brazilian federation units on the functional disability of the elderly. Methods: Cross-sectional study based on data from the 2003 PNAD (Brazilian National Household Survey), of IBGE (Brazilian Institute of Geography and Statistics) and Ipea (Institute of Applied Economic Research). The sample was composed of 33,515 individuals aged 60 years and older. The dependent variable was functional disability, measured by difficulty in climbing slopes or stairs. The independent variables were divided into two levels: individual (demographic, socioeconomic and health-related characteristics) and contextual (Gini Index and Gross Domestic Product per capita by Brazilian state in 2000). A multinomial and multilevel logistic regression model was utilized in order to estimate the effect of the independent variables on the functional disability of the elderly. Results: Functional disability was associated with demographic, socioeconomic and health factors. At the individual level, sex, level of schooling, income, occupation, self-perception of health and chronic diseases were the factors that were most strongly related to functional disability. At the contextual level, income inequality proved to exert an important infl uence. Conclusions: Self-perception of health is the factor that is most strongly related to the functional disability of the elderly in Brazil, followed by chronic diseases. Sex, occupation, level of schooling and income are also highly associated with it. Actions that approach the main factors associated with functional disability can contribute significantly to the well-being and quality of life of the elderly.

Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: NMP-2010-1.3-1 | Award Amount: 13.15M | Year: 2011

The growing development, production and use of engineered nanomaterials and associated products will increase exposure of both humans and ecosystems to these new materials. However, current knowledge is still incomplete and established test methods are as yet inappropriate to reliably assess the extent of exposure and risk of materials at the nano-scale. There is an urgent need to develop methods to overcome the current limitations of existing hazard and risk assessment schemes and to generate the body of reference data needed as the basis for regulative requirements and for measures to safeguard production, application and the disposal of nanomaterials. The proposed project will mobilize the critical mass of international scientific knowledge and technical expertise required to address these questions. Current analytical and toxicity test methods and models will be put to test and subjected to rigorous intercalibration and validation. Where necessary, methods and test materials will be modified, adapted and validated, and new reliable reference methods developed, in cooperation with international standardisation bodies and the concerned industry, to support both pre and co-normative activities and to make the applicability of existing RA and LCA schemes to ENPs more reliable. The feasibility of validated measurement, characterization and test methods will be assessed by selected case studies to help the significant improvement of the performance of existing exposure monitoring systems as well as the development of new risk management and reduction strategies.

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: HEALTH.2011.1.4-5 | Award Amount: 3.99M | Year: 2012

Resolution of inflammation is a key determinant of pathology, and an active process which involves diverse pathways and molecules. The general objective of the TIMER Consortium is to identify and validate new molecules involved in the resolution of inflammation as a basis for the development of innovative therapeutic strategies in chronic inflammatory and autoimmune diseases. The project will involve discovery of new natural or synthetic pro-resolving molecules for plant and animals and investigation on endogenous inflammation pro-resolving mechanisms identified by various partners of the Consortium, including atypical chemokine receptors, decoy receptors, and microRNA. Tapping resources of natural compounds will be a major thrust. Efforts will be mainly focused on the regulation by pro-resolving agents on two molecular systems of key relevance in inflammation: the chemokine system, which regulates recruitment, permanence and egress of leukocyte in tissues; and the TLR/IL-1R system, which is central for the activation of infiltrating leukocytes. To this purpose, the project will capitalize on, and bring added value to a strong tradition of the Consortium in the fields of: leukocyte recruitment and activation; negative regulators of inflammation; industrial-academic collaboration; identification and characterization of innovative inhibitors of natural origin; European-Brazilian collaboration.

News Article | October 23, 2015

Sheets of graphene and other materials that are virtually two-dimensional hold great promise for electronic, optical, and other high-tech applications. But the biggest limitation in unleashing this potential has been figuring out how to make these materials in the form of anything larger than tiny flakes. Now researchers at MIT and elsewhere may have found a way to do so. The group has determined a way to make large sheets of one such material, called molybdenum telluride, or MoTe . The team says their method is also likely to work for many similar 2-D materials, and could make widespread applications feasible. The findings have been published in the Journal of the American Chemical Society by a team including MIT postdoc Lin Zhou; professors Mildred Dresselhaus, Jing Kong, and Tomás Palacios; and eight others at MIT, the China University of Petroleum, Central South University in China, the National Tsing-hua University in Taiwan, and Saitama University and Tohoku University in Japan. “This material has a similar bandgap to silicon” — a characteristic needed in order to make transistors and solar cells — “and in single-layer form it has a direct bandgap,” Zhou says, which allows better light emission. “It also has strong absorption for solar radiation,” which is key to making practical solar cells, she says. Molybdenum telluride can exist in two different forms; one is metallic, meaning it conducts electricity well, and the other is a natural semiconductor, lending itself to applications in electronics. Controlling how the material is made allows the researchers to create whichever form is needed for a particular use. The new method is based on chemical vapor deposition (CVD), and makes it possible to create sheets of any thickness, and of a size limited only by the dimensions of the CVD chamber used for deposition. One challenge the team had to overcome was that the atoms of molybdenum telluride are very weakly bound to each other, so the tendency of the two precursor materials to form molybdenum telluride is low. “This makes it more challenging to make, compared to other similar materials,” Zhou says. The researchers were able to overcome this by using several stages of deposition, beginning with a layer of pure molybdenum. “This method makes it easy, because you only need to control one material,” Zhou says. This step is followed by oxidation of that layer; this material is then removed and powdered tellurium is added, vaporized in a carrier gas of hydrogen and argon, at a temperature of 700 degrees Celsius. The use of hydrogen in the process, the team found, is crucial to producing a uniform MoTe film. The material should be immediately usable to create electronic devices including field-effect transistors, which the team has already demonstrated in the lab. “Our process can grow sheets that have a very large area, are very homogeneous, and have high quality,” Zhou says. The team now aims to explore adapting this process to create large sheets of other promising thin materials: “2-D materials are a big family with different properties,” Zhou says. She and her colleagues will examine whether versions of the process can work with other compounds. Molybdenum telluride also lends itself to applications in spintronics, Zhou says, an emerging technology based on the spins of electrons rather than their charge, as in conventional electronics. Physicist Ado Jorio of the Federal University of Minas Gerais, Brazil, who was not involved in this work, says, “What is most impressive is that this group has been able to consecutively develop new formulae to produce almost any low-dimensional material they want, always scalable with the highest quality worldwide.” And Vincent Meunier, a physicist at Rensselaer Polytechnic Institute who was also not associated in this research, adds, “One of the many advantages of the proposed approach stems from its simplicity. The consequences of this development are likely to be numerous, as it provides a versatile and scalable technique to develop macroscopic amounts of atomically thin films, thereby surmounting major roadblocks faced by layered-materials based research so far.” The work was supported by the National Science Foundation, the Office of Naval Research, and the International Postdoctoral Exchange Fellowship Program.

Prates M.O.,Federal University of Minas Gerais | Cabral C.R.B.,University of Campinas | Lachos V.H.,Federal University of Amazonas
Journal of Statistical Software | Year: 2013

We present the R package mixsmsn, which implements routines for maximum likelihood estimation (via an expectation maximization EM-type algorithm) in finite mixture models with components belonging to the class of scale mixtures of the skew-normal distribution, which we call the FMSMSN models. Both univariate and multivariate responses are considered. It is possible to fix the number of components of the mixture to be fitted, but there exists an option that transfers this responsibility to an automated procedure, through the analysis of several models choice criteria. Plotting routines to generate histograms, plug-in densities and contour plots using the fitted models output are also available. The precision of the EM estimates can be evaluated through their estimated standard deviations, which can be obtained by the provision of an approximation of the associated information matrix for each particular model in the FMSMSN family. A function to generate artificial samples from several elements of the family is also supplied. Finally, two real data sets are analyzed in order to show the usefulness of the package.

Jacobs D.M.,Autonomous University of Madrid | Vaz D.V.,University of Connecticut | Vaz D.V.,Federal University of Minas Gerais | Michaels C.F.,University of Connecticut
Journal of Experimental Psychology: Human Perception and Performance | Year: 2012

In cart-pole balancing, one moves a cart in 1 dimension so as to balance an attached inverted pendulum. We approached perception-action and learning in this task from an ecological perspective. This entailed identifying a space of informational variables that balancers use as they perform the task and demonstrating that they improve by traversing the space to the loci of more useful variables. We presented a novel information space-including fractional derivatives of pendulum angle (e.g., halfway between angle and angular velocity)-as possible information for balancing. Fourteen college students tried to meet a criterion of balancing the pole for 30 s on 3 of 5 successive trials, up to a maximum of 150 attempts. Loci in the fractional derivative space predicted the time series of force production well. Systematic differences were seen in loci as a function of success, and systematic changes in locus were seen with learning. The fractional derivatives were shown to predict pole angles a short time interval into the future, allowing balancers to prospectively control the action and thereby nullify visuomotor delay. In addition to loci in the information space, we analyzed loci in a calibration space, reflecting the gain relating force to information. © 2012 American Psychological Association.

Turvey M.T.,University of Connecticut | Turvey M.T.,Haskins Laboratories | Fonseca S.T.,Federal University of Minas Gerais
Journal of Motor Behavior | Year: 2014

For any given animal, the sources of mechanical disturbances inducing tissue deformation define environment from the perspective of the animal's haptic perceptual system. The system's achievements include perceiving the body, attachments to the body, and the surfaces and substances adjacent to the body. Among the perceptual systems, it stands alone in having no defined medium. There is no articulated functional equivalent to air and water, the media that make possible the energy transmissions and diffusions underpinning the other perceptual systems. To identify the haptic system's medium the authors focus on connective tissue and the conjunction of muscular, connective tissue net, and skeletal (MCS) as the body's proper characterization. The challenge is a biophysical formulation of MCS as a continuum that, similar to air and water, is homogeneous and isotropic. The authors hypothesized a multifractal tensegrity (MFT) with the shape and stability of the constituents of each scale, from individual cell to whole body, derivative of continuous tension and discontinuous compression. Each component tensegrity of MFT is an adjustive-receptive unit, and the array of tensions in MFT is information about MCS. The authors extend the MFT hypothesis to body-brain linkages, and to limb perception phenomena attendant to amputation, vibration, anesthesia, neuropathy, and microgravity. © 2014 Copyright Taylor & Francis Group, LLC.

Santos F.P.,Federal University of Minas Gerais | Roman-Lopes A.,University of La Serena | Franco G.A.P.,Federal University of Minas Gerais
Astrophysical Journal | Year: 2012

The RCW41 star-forming region is embedded within the Vela Molecular Ridge, hosting a massive stellar cluster surrounded by a conspicuous H II region. Understanding the role of interstellar magnetic fields and studying the newborn stellar population is crucial to building a consistent picture of the physical processes acting on this kind of environment. We carried out a detailed study of the interstellar polarization toward RCW41 with data from an optical and near-infrared polarimetric survey. Additionally, deep near-infrared images from the 3.5meter New Technology Telescope were used to study the photometric properties of the embedded young stellar cluster, revealing several YSO candidates. By using a set of pre-main-sequence isochrones, a mean cluster age in the range 2.5-5.0millionyears was determined, and evidence of sequential star formation was revealed. An abrupt decrease in R-band polarization degree was noticed toward the central ionized area, probably due to low grain alignment efficiency caused by the turbulent environment and/or the weak intensity of magnetic fields. The distortion of magnetic field lines exhibits dual behavior, with the mean orientation outside the area approximately following the borders of the star-forming region and directed radially toward the cluster inside the ionized area, in agreement with simulations of expanding H II regions. The spectral dependence of polarization allowed a meaningful determination of the total-to-selective extinction ratio by fittings of the Serkowski relation. Furthermore, a large rotation of polarization angle as a function of wavelength was detected toward several embedded stars. © 2012. The American Astronomical Society. All rights reserved..

Maia C.A.,Federal University of Minas Gerais | Andrade C.R.,Federal University of Minas Gerais | Hardouin L.,University of Notre Dame
Automatica | Year: 2011

This paper deals with the control of discrete event systems subject to synchronization and time delay phenomena, which can be described by using the max-plus algebra. The objective is to design a feedback controller to guarantee that the system evolves without violating time restrictions imposed on the state. To this end an equation is derived, which involves the system, the feedback and the restriction matrices. Conditions concerning the existence of a feedback are discussed and sufficient conditions that ensure the computation of a causal feedback are presented. To illustrate the results of this paper, a workshop control problem is presented. © 2011 Elsevier Ltd. All rights reserved.

De Carvalho M.G.,Nokia Inc. | Laender A.H.F.,Federal University of Minas Gerais | Goncalves M.A.,Federal University of Minas Gerais | Da Silva A.S.,Federal University of Amazonas
IEEE Transactions on Knowledge and Data Engineering | Year: 2012

Several systems that rely on consistent data to offer high-quality services, such as digital libraries and e-commerce brokers, may be affected by the existence of duplicates, quasi replicas, or near-duplicate entries in their repositories. Because of that, there have been significant investments from private and government organizations for developing methods for removing replicas from its data repositories. This is due to the fact that clean and replica-free repositories not only allow the retrieval of higher quality information but also lead to more concise data and to potential savings in computational time and resources to process this data. In this paper, we propose a genetic programming approach to record deduplication that combines several different pieces of evidence extracted from the data content to find a deduplication function that is able to identify whether two entries in a repository are replicas or not. As shown by our experiments, our approach outperforms an existing state-of-the-art method found in the literature. Moreover, the suggested functions are computationally less demanding since they use fewer evidence. In addition, our genetic programming approach is capable of automatically adapting these functions to a given fixed replica identification boundary, freeing the user from the burden of having to choose and tune this parameter. © 2006 IEEE.

Cunningham K.A.,University of California at San Francisco | Bouagnon A.D.,University of California at San Francisco | Barros A.G.,Instituto Nacional Of Ciencia E Tecnologia Of Medicina Molecular | Lin L.,University of California at San Francisco | And 3 more authors.
PLoS Genetics | Year: 2014

AMP-activated protein kinase (AMPK) is an evolutionarily conserved master regulator of metabolism and a therapeutic target in type 2 diabetes. As an energy sensor, AMPK activity is responsive to both metabolic inputs, for instance the ratio of AMP to ATP, and numerous hormonal cues. As in mammals, each of two genes, aak-1 and aak-2, encode for the catalytic subunit of AMPK in C. elegans. Here we show that in C. elegans loss of aak-2 mimics the effects of elevated serotonin signaling on fat reduction, slowed movement, and promoting exit from dauer arrest. Reconstitution of aak-2 in only the nervous system restored wild type fat levels and movement rate to aak-2 mutants and reconstitution in only the ASI neurons was sufficient to significantly restore dauer maintenance to the mutant animals. As in elevated serotonin signaling, inactivation of AAK-2 in the ASI neurons caused enhanced secretion of dense core vesicles from these neurons. The ASI neurons are the site of production of the DAF-7 TGF-β ligand and the DAF-28 insulin, both of which are secreted by dense core vesicles and play critical roles in whether animals stay in dauer or undergo reproductive development. These findings show that elevated levels of serotonin promote enhanced secretions of systemic regulators of pro-growth and differentiation pathways through inactivation of AAK-2. As such, AMPK is not only a recipient of hormonal signals but can also be an upstream regulator. Our data suggest that some of the physiological phenotypes previously attributed to peripheral AAK-2 activity on metabolic targets may instead be due to the role of this kinase in neural serotonin signaling. © 2014 Cunningham et al.

Cortez E.,Federal University of Amazonas | Da Silva A.S.,Federal University of Amazonas | Goncalves M.A.,Federal University of Minas Gerais | De Moura E.S.,Federal University of Amazonas
Proceedings of the ACM SIGMOD International Conference on Management of Data | Year: 2010

Information extraction by text segmentation (IETS) applies to cases in which data values of interest are organized in implicit semi-structured records available in textual sources (e.g. postal addresses, bibliographic information, ads). It is an important practical problem that has been frequently addressed in the recent literature. In this paper we introduce ONDUX (On Demand Unsupervised Information Extraction), a new unsupervised probabilistic approach for IETS. As other unsupervised IETS approaches, ONDUX relies on information available on pre-existing data to associate segments in the input string with attributes of a given domain. Unlike other approaches, we rely on very effective matching strategies instead of explicit learning strategies. The effectiveness of this matching strategy is also exploited to disambiguate the extraction of certain attributes through a reinforcement step that explores sequencing and positioning of attribute values directly learned on-demand from test data, with no previous human-driven training, a feature unique to ONDUX. This assigns to ONDUX a high degree of flexibility and results in superior effectiveness, as demonstrated by the experimental evaluation we report with textual sources from different domains, in which ONDUX is compared with a state-of-art IETS approach. © 2010 ACM.

Gazzinelli R.T.,Oswaldo Cruz Foundation | Gazzinelli R.T.,Federal University of Minas Gerais | Gazzinelli R.T.,University of Massachusetts Medical School | Mendonca-Neto R.,Federal University of Minas Gerais | And 4 more authors.
Cell Host and Microbe | Year: 2014

Recent studies have revealed remarkable species specificity of the Toll-like receptors (TLRs) TLR11 and TLR12 and the immunity-related GTPase (IRG) proteins that are essential elements for detection and immune control of Toxoplasma gondii in mice, but not in humans. The biological and evolutionary implications of these findings for the T. gondii host-pathogen relationship and for human disease are discussed. © 2014 Elsevier Inc.

Bechinger B.,CNRS Institute of Chemistry | Resende J.M.,Federal University of Minas Gerais | Aisenbrey C.,CNRS Institute of Chemistry
Biophysical Chemistry | Year: 2011

Solid-state NMR spectroscopy is a powerful technique for the investigation of membrane-associated peptides and proteins as well as their interactions with lipids, and a variety of conceptually different approaches have been developed for their study. The technique is unique in allowing for the high-resolution investigation of liquid disordered lipid bilayers representing well the characteristics of natural membranes. Whereas magic angle solid-state NMR spectroscopy follows approaches that are related to those developed for solution NMR spectroscopy the use of static uniaxially oriented samples results in angular constraints which also provide information for the detailed analysis of polypeptide structures. This review introduces this latter concept theoretically and provides a number of examples. Furthermore, ongoing developments combining solid-state NMR spectroscopy with information from solution NMR spectroscopy and molecular modelling as well as exploratory studies using dynamic nuclear polarization solid-state NMR will be presented. © 2010 Elsevier B.V. All rights reserved.

Soares-Filho B.,Federal University of Minas Gerais | Rajao R.,Federal University of Minas Gerais | Macedo M.,Federal University of Minas Gerais | Macedo M.,Woods Hole Oceanographic Institution | And 5 more authors.
Science | Year: 2014

Brazil's controversial new Forest Code grants amnesty to illegal deforesters, but creates new mechanisms for forest conservation.

Cherchiglia A.L.,Federal University of Minas Gerais | Cabral L.A.,Federal University of Tocantins | Nemes M.C.,Federal University of Minas Gerais | Sampaio M.,Federal University of Minas Gerais
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We investigate the appearance of arbitrary, regularization-dependent parameters introduced by divergent integrals in two a priori finite but superficially divergent amplitudes: the Higgs decay into two photons and the two-photon scattering. We use a general parametrization of ultraviolet divergences which makes explicit such ambiguities. Thus we separate in a consistent way using implicit regularization the divergent, finite, and regularization-dependent parts of the amplitudes which in turn are written as surface terms. We find that, although finite, these amplitudes are ambiguous before the imposition of physical conditions, namely, momentum routing invariance in the loops of Feynman diagrams. In the examples we study, momentum routing invariance turns out to be equivalent to gauge invariance. We also discuss the results obtained by different regularizations and show how they can be reproduced within our framework allowing for a clear view on the origin of regularization ambiguities. © 2013 American Physical Society.

Reis W.,Federal University of Minas Gerais | Corradi W.,Federal University of Minas Gerais | De Avillez M.A.,University of Évora | Santos F.P.,Federal University of Minas Gerais
Astrophysical Journal | Year: 2011

The Sun is located inside an extremely low density region called the Local Bubble (LB). Although they have been studied through a large variety of techniques, the contours of its neutral boundary, defined by a dense wall of interstellar gas and dust, are still an open issue. Our aim is to determine the interstellar reddening in the LB region by means of Strömgren photometry, validating the conclusions through a comparison with high-resolution three-dimensional (3D) hydrodynamical models of the Local and Loop I bubbles' formation and evolution. We have obtained color excesses and distances using the uvbyHβ data of the General Catalogue of Photometric Data, complemented by 820 stars from more recent catalogs, for b ≤ 60°. A set of restrictive exclusion criteria has been applied to eliminate E(b - y) values inappropriate for the study of the interstellar medium (ISM). The final sample has 8492 stars located up to 500pc from the Sun. Our main results are as follows: (1) the large-scale distribution of the interstellar dust in the LB is highly inhomogeneous; (2) on the Galactic plane, E(b - y) ≥ 0040 is observed at a distance of d ≈ 80-100pc from l ≥ 270°until l ≤ 45°; (3) the color excess suggests that there are many tunnels and holes in the LB wall; and (4) there is a clear correlation between E(b - y) and the spatial density distribution of the interstellar gas inferred from the simulations. © 2011. The American Astronomical Society. All rights reserved.

Macia L.,Monash University | Thorburn A.N.,Monash University | Binge L.C.,Monash University | Marino E.,Monash University | And 5 more authors.
Immunological Reviews | Year: 2012

Certain autoimmune diseases as well as asthma have increased in recent decades, particularly in developed countries. The hygiene hypothesis has been the prevailing model to account for this increase; however, epidemiology studies also support the contribution of diet and obesity to inflammatory diseases. Diet affects the composition of the gut microbiota, and recent studies have identified various molecules and mechanisms that connect diet, the gut microbiota, and immune responses. Herein, we discuss the effects of microbial metabolites, such as short chain fatty acids, on epithelial integrity as well as immune cell function. We propose that dysbiosis contributes to compromised epithelial integrity and disrupted immune tolerance. In addition, dietary molecules affect the function of immune cells directly, particularly through lipid G-protein coupled receptors such as GPR43. © 2011 John Wiley & Sons A/S.

Marini-Filho O.J.,Chico Mendes Institute of Biodiversity Conservation | Fernandes G.W.,Federal University of Minas Gerais
Arthropod-Plant Interactions | Year: 2012

Insect galls are important nutrient sinks in the plant, ultimately affecting its reproductive success. We assessed the influence of a stem galler on the survival of plant shoots and whether these are able to concentrate nutrients in the gall's tissues; thus testing the nutrient sink hypothesis. We measured gall sizes and nutrient concentrations in a Brazilian Cerrado plant, Diplusodon orbicularis, and its Cecidomyiidae stem galler. Galls grew larger on thicker shoots. Also, these shoots suffered smaller mortality from gall attack, while thinner shoots were commonly associated with the death of the shoot distal to the gall. Apical shoots suffered higher mortality, while basal shoots suffered lower mortality and were proportionally less attacked. Galled tissues were more nutrient rich than non-galled tissues. The nutrients P, Ca, and Mg were more concentrated inside the galls when compared to tissues in non-galled stems. Gallers also seem to be able to reduce toxic Al concentration in the plant tissues, as Al occurred in smaller concentrations inside the galls than out of them. Although stem gallers feed on tissues of low nutritional value, these are in a favourable position to intercept flowing nutrients and water. The death of small galled shoots possibly is due to the lack of essential nutrients and energy drained, or water restriction in them. © 2011 Springer Science+Business Media B.V.

Rocha P.M.B.,Federal University of Minas Gerais | Neves F.S.,Federal University of Minas Gerais | Correa H.,Federal University of Minas Gerais | Correa H.,Instituto Nacional Of Ciencia E Tecnologia Of Medicina Molecular
Comprehensive Psychiatry | Year: 2013

Objective A growing amount of data suggests that sleep dysfunction is frequently observed in bipolar disorder (BD) patients even when they do not fulfill the criteria for major mood episodes. Thus, we performed a case-control study assessing sleep status in a group of euthymic BD patients and a group of health controls. Methods A total of 209 subjects (104 health controls and 105 BD patients) were enrolled in the study. The Pittsburgh Sleep Quality Index (PSQI) was used for sleep assessment. Inclusion criteria for the BD group were a diagnosis of BD, following DSM-IV-TR criteria, according to the MINI-plus structured clinical interview. Euthymia was established as a score lower than 7 both in the Hamilton Depression Rating Scale (HDRS) and in the Young Mania Rating Scale (YMRS). Health controls were also interviewed using the MINI-plus and included in this study if they were free of any current or past DSM-IV-TR axis I psychiatric disorder as well the actual use of psychopharmacological medications. Results While 21.2 % of the control group displayed poor sleep quality according to the global PSQI-BR score, 82.9 % of the euthymic BD patients had poor sleep quality (p = 0.000). PSQI sleep duration subcomponent showed comparable results in the two groups (p = 0.535), even though BD patients had significant disruptions in sleep latency (p = 0.000) and sleep efficiency (p = 0.000) subcomponents. Conclusion We were able to show that BD patients, even in euthymic phase, exhibit a significantly worse sleep quality as compared with health controls as assessed by PSQI total score and five of its seven subcomponents. © 2013 Elsevier Inc. All rights reserved.

Nigam V.,Federal University of Paraiba | Olarte C.,Pontifical Xavierian University | Pimentel E.,Federal University of Minas Gerais
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The combination of timed, spatial, and epistemic information is often needed in the specification of modern concurrent systems. We propose the proof system SELL, which extends linear logic with subexponentials with quantifiers over subexponentials, therefore allowing for an arbitrary number of modalities. We then show how a proper structure of the subexponential signature in SELL allows for the specification of concurrent systems with timed, spatial, and epistemic modalities. In the context of Concurrent Constraint Programming (CCP), a declarative model of concurrency, we illustrate how the view of subexponentials as specific modalities is general enough to modularly encode into SELL variants of CCP with these three modalities, thus providing a proof-theoretic foundations for those calculi. © 2013 Springer-Verlag.

Cota G.F.,Rene Rachou Institute | Cota G.F.,Eduardo Of Menezes Hospital | de Sousa M.R.,Federal University of Minas Gerais | Rabello A.,Rene Rachou Institute
PLoS Neglected Tropical Diseases | Year: 2011

Background and Objectives: Visceral leishmaniasis (VL) is a common complication in AIDS patients living in Leishmania-endemic areas. Although antiretroviral therapy has changed the clinical course of HIV infection and its associated illnesses, the prevention of VL relapses remains a challenge for the care of HIV and Leishmania co-infected patients. This work is a systematic review of previous studies that have described predictors of VL relapse in HIV-infected patients. Review Methods: We searched the electronic databases of MEDLINE, LILACS, and the Cochrane Central Register of Controlled Trials. Studies were selected if they included HIV-infected individuals with a VL diagnosis and patient follow-up after the leishmaniasis treatment with an analysis of the clearly defined outcome of prediction of relapse. Results: Eighteen out 178 studies satisfied the specified inclusion criteria. Most patients were males between 30 and 40 years of age, and HIV transmission was primarily via intravenous drug use. Previous VL episodes were identified as risk factors for relapse in 3 studies. Two studies found that baseline CD4+ T cell count above 100 cells/mL was associated with a decreased relapse rate. The observation of an increase in CD4+ T cells at patient follow-up was associated with protection from relapse in 5 of 7 studies. Meta-analysis of all studies assessing secondary prophylaxis showed significant reduction of VL relapse rate following prophylaxis. None of the five observational studies evaluating the impact of highly active antiretroviral therapy use found a reduction in the risk of VL relapse upon patient follow-up. Conclusion: Some predictors of VL relapse could be identified: a) the absence of an increase in CD4+ cells at follow-up; b) lack of secondary prophylaxis; and c) previous history of VL relapse. CD4+ counts below 100 cells/mL at the time of primary VL diagnosis may also be a predictive factor for VL relapse. © 2011 Cota et al.

Harko T.,University College London | Lobo F.S.N.,University of Lisbon | Otalora G.,Federal University of Minas Gerais | Saridakis E.N.,National Technical University of Athens | Saridakis E.N.,Pontifical Catholic University of Valparaíso
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We construct an extension of f(T) gravity with the inclusion of a nonminimal torsion-matter coupling in the action. The resulting theory is a novel gravitational modification, since it is different from both f(T) gravity, as well as from the nonminimal curvature-matter-coupled theory. The cosmological application of this new theory proves to be very interesting. In particular, we obtain an effective dark energy sector whose equation-of-state parameter can be quintessence- or phantom-like, or exhibit the phantom-divide crossing, while for a large range of the model parameters the universe enters in a de Sitter, dark-energy-dominated, accelerating phase. Additionally, we can obtain early-time inflationary solutions too, and thus provide a unified description of the cosmological history. © 2014 American Physical Society.

Jaime P.C.,University of Sao Paulo | da Silva A.C.F.,Coordenacao Geral de Alimentacao e Nutricao | Gentil P.C.,Coordenacao Geral de Educacao Alimentar e Nutricional | Claro R.M.,Federal University of Minas Gerais | Monteiro C.A.,University of Sao Paulo
Obesity Reviews | Year: 2013

Summary: Obesity prevalence in the Brazilian adult population is 12.5% among men and 16.9% among women. Obesity control has been a subject of concern in Brazilian health policies since the publication of the National Food and Nutrition Policy in 1999. The initiatives include a comprehensive national intersectorial plan for obesity prevention and control focused on confronting its social and environmental causes, development of a food and nutrition education framework aimed at intersectorial public policies in the food and nutritional security field, promotion and provision of healthy food in school environments (linked to family farming), structuring nutrition actions in primary healthcare in the national healthcare system, promoting community physical activity, food regulation and control, and encouragement of public participation and food control. We conclude that several initiatives have been developed in Brazil to deal with the challenge of implementing an intergovernmental, intersectorial response to reverse the rising overweight and obesity rates. The success of this response will depend on a governance model that promotes joint and integrated action by different sectors and active participation of society to consolidate the actions, places and laws that protect health and promote healthy lifestyles. © 2013 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of the International Association for the Study of Obesity.

Silva A.T.,University of Lisbon | Portela M.M.,University of Lisbon | Naghettini M.,Federal University of Minas Gerais
Hydrology and Earth System Sciences | Year: 2012

An exploratory analysis on the variability of flood occurrence rates in 10 Portuguese watersheds is made, to ascertain if that variability is concurrent with the principle of stationarity. A peaks-over-threshold (POT) sampling technique is applied to 10 long series of mean daily streamflows and to 4 long series of daily rainfall in order to sample the times of occurrence (POT time data) of the peak values of those series. The kernel occurrence rate estimator, coupled with a bootstrap approach, was applied to the POT time data to obtain the time dependent estimated occurrence rate curves, λ

Benevenuto F.,Federal University of Ouro Preto | Rodrigues T.,Federal University of Minas Gerais | Cha M.,KAIST | Almeida V.,Federal University of Minas Gerais
Information Sciences | Year: 2012

Understanding how users navigate and interact when they connect to social networking sites creates opportunities for better interface design, richer studies of social interactions, and improved design of content distribution systems. In this paper, we present an in-depth analysis of user workloads in online social networks. This study is based on detailed clickstream data, collected over a 12-day period, summarizing HTTP sessions of 37,024 users who accessed four popular social networks: Orkut, MySpace, Hi5, and LinkedIn. The data were collected from a social network aggregator website in Brazil, which enables users to connect to multiple social networks with a single authentication. Our analysis of the clickstream data reveals key features of the social network workloads, such as how frequently people connect to social networks and for how long, as well as the types and sequences of activities that users conduct on these sites. Additionally, we gather the social network topology of Orkut, so that we could analyze user interaction data in light of the social graph. Our data analysis suggests insights into how users interact with friends in Orkut, such as how frequently users visit their friends' and non-immediate friends' pages. Results show that browsing, which cannot be inferred from crawling publicly available data, accounts for 92% of all user activities. Consequently, compared to using only crawled data, silent interactions like browsing friends' pages increase the measured level of interaction among users. Additionally, we find that friends requesting content are often within close geographical proximity of the uploader. We also discuss a series of implications of our findings for efficient system and interface design as well as for advertisement placement in online social networks. © 2012 Elsevier Inc. All rights reserved.

Agency: Cordis | Branch: FP7 | Program: CSA-CA | Phase: NMP-2008-2.6-3 | Award Amount: 1.14M | Year: 2009

A key thrust of FP7 is to promote international collaborative research with third countries. The EULASUR project will address the Call for Co-ordination Action in Materials by creating a cooperation platform for forming strategic research partnerships between scientists, policy makers, technology transfer and industrial experts in the EC and 3 Latin-American countries belonging to MERCOSUR: Brazil, Uruguay and Argentina (BRAU). Research topics will be identified within the fields of i) advanced functional ceramics and ii) hybrid materials and nanomaterials where significant opportunities exist for mutually beneficial actions between the two regions. The goals are designed to gain first hand knowledge of the state of the art research in these fields through summer schools, exchanges and partnership actions. The project will also address the social, political and cultural factors impacting technology transfer and collaboration between the EU and BRAU countries. The core activities of EULASUR are based on some research Groups of Excellence that already cooperate bilaterally and will integrate them with additional groups to generate a stable, integrated scientific platform of international excellence interested to collaborate in the development of materials research in specific topics of interest to both regions. The EULASUR partnership is composed of 15 research centres, 8 from Europe and 7 from BRAU countries selected on the basis of: excellence in research, complementary skills and access to national and international R&D policy makers. Government representatives will participate in the EULASUR Advisory Board. Industrial companies and technological centres are expected to take part in the project activities. EULASUR has 5 WPs. 3 designed to build contacts and identify opportunities, 1 to disseminate results to key stakeholders and policy makers and 1 management and progress measures. Each WP has two WP Leaders: one from BRAU and the other from the EU.

Forlenza O.V.,University of Sao Paulo | De-Paula V.J.R.,University of Sao Paulo | Diniz B.S.O.,Federal University of Minas Gerais
ACS Chemical Neuroscience | Year: 2014

Lithium is a well-established therapeutic option for the acute and long-term management of bipolar disorder and major depression. More recently, based on findings from translational research, lithium has also been regarded as a neuroprotective agent and a candidate drug for disease-modification in certain neurodegenerative disorders, namely, Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and, more recently, Parkinson's disease (PD). The putative neuroprotective effects of lithium rely on the fact that it modulates several homeostatic mechanisms involved in neurotrophic response, autophagy, oxidative stress, inflammation, and mitochondrial function. Such a wide range of intracellular responses may be secondary to two key effects, that is, the inhibition of glycogen synthase kinase-3 beta (GSK-3β) and inositol monophosphatase (IMP) by lithium. In the present review, we revisit the neurobiological properties of lithium in light of the available evidence of its neurotrophic and neuroprotective properties, and discuss the rationale for its use in the treatment and prevention of neurodegenerative diseases. © 2014 American Chemical Society.

Dias A.,Federal University of Ouro Preto | Lage M.M.,Federal University of Itajubá | Khalam L.A.,Indian National Institute for Interdisciplinary Science and Technology | Sebastian M.T.,Indian National Institute for Interdisciplinary Science and Technology | Moreira R.L.,Federal University of Minas Gerais
Chemistry of Materials | Year: 2011

Ca2LnTaO6 (Ln = lanthanides, Y, and In) and Ca 2InNbO6 ceramics were prepared by the solid-state route, and their vibrational properties were investigated using Raman scattering and infrared spectroscopy. The correct crystal structure and phonon mode features for this lanthanide series in Ca-based double perovskites were determined using experimental data besides group-theoretical models. It was observed that the ceramics with Y, Er, and In exhibit orthorhombic, Pbnm (D2h16) structures, similarly to those previously observed in Ca2LnNbO 6 ceramics, whereas the materials with La, Nd, Sm, Eu, Gd, Tb, and Ho show a monoclinic P21/n (C2h5) structure, like Sr 2LnTaO6 ceramics. Together with another two previous publications (Dias, A.; Khalam, L. A.; Sebastian, M. T.; Paschoal, C. W. A.; Moreira, R. L. Chem. Mater. 2006, 18, 214-220 and Dias, A.; Khalam, L. A.; Sebastian, M. T.; Lage, M. M.; Matinaga, F. M.; Moreira, R. L. Chem. Mater. 2008, 20, 5253-5259), the present results conclude the study for the A 2LnTaO6 materials with alkaline-earth metals in the A-site, showing the changing in the crystalline structure as a function of the chemical environment. © 2010 American Chemical Society.

Carey B.J.,Rice University | Patra P.K.,Rice University | Patra P.K.,University of Bridgeport | Ci L.,Rice University | And 2 more authors.
ACS Nano | Year: 2011

Most materials respond either elastically or inelastically to applied stress, while repeated loading can result in mechanical fatigue. Conversely, bones and other biomechanical tissues have the ability to strengthen when subjected to recurring elastic stress. The cyclic compressive loading of vertically aligned carbon nanotube/poly(dimethylsiloxane) nanocomposites has revealed a self-stiffening response previously unseen in synthetic materials. This behavior results in a permanent increase in stiffness that continues until the dynamic stress is removed and resumes when it is reapplied. The effect is also specific to dynamic loads, similar to the localized self-strengthening that occurs in biological structures. These observations help to elucidate the complex interactions between matrix materials and nanostructures, and control over this mechanism could lead to the development of adaptable structural materials and active, load-bearing artificial connective tissues. © 2011 American Chemical Society.

Da Rocha Martins J.,Federal University of Piauí | Da Rocha Martins J.,Federal University of Minas Gerais | Chacham H.,Federal University of Minas Gerais
ACS Nano | Year: 2011

We investigate structural and electronic properties of B-C-N (boron-carbon-nitrogen) layers and nanotubes considering the positional disorder of the B, C, and N atoms, using a combination of first principles and simulated annealing calculations. During the annealing process, we find that the atoms segregate into isolated, irregularly shaped graphene islands immersed in BN. We also find that the formation of the carbon islands strongly affects the electronic properties of the materials. For instance, in the case of layers and nanotubes with the same number of B and N atoms, we find that the band gap increases during the simulated annealing. This indicates that, for a given stoichiometry, the electronic and optical properties of B-C-N layers and nanotubes can be tuned by growth kinetics. We also find that the excess of B or N atoms results in large variations in the band gap and work function. © 2011 American Chemical Society.

Rodrigues M.-T.F.,Federal University of Minas Gerais | Ajayan P.M.,Rice University | Silva G.G.,Federal University of Minas Gerais
Journal of Physical Chemistry B | Year: 2013

In this work a self-assembly technique is presented, allowing the fast formation of carbon black thin films. It consists in the controlled addition of a stable carbon material's dispersion over the water surface, disturbed by a vortex. The vortex, although not essential for the film formation, was found to drastically improve film homogeneity. A physical chemical study concerning how several parameters could be used to tune film properties was also conducted. The self-assembled films, which can be picked up in any hydrophilic substrate, showed a good electrical conductivity and a high optical transparency. As an application example, films about 200 nm thick were employed as supercapacitor electrodes. © 2013 American Chemical Society.

Schmidt T.M.,Federal University of Minas Gerais | Miwa R.H.,Federal University of Minas Gerais | Fazzio A.,University of Sao Paulo
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

Based upon first-principles methods, we investigate the magnetic anisotropy and spin texture of Co impurities embedded at the interlayer van der Waals (vdW) spacings and onto the topmost Se network of the topological insulator Bi 2Se 3. The interaction of the magnetic impurity with the surface spin texture breaks time-reversal symmetry, opening up a surface band gap. For a Co atom adsorbed onto the surface, the net magnetic moment is aligned perpendicular to the surface plane, with anisotropy energy of 6 meV. On the other hand, for the Co impurity at the vdW interlayers, the net magnetic moment is aligned in plane. While pristine Bi 2Se 3 presents a helical spin texture in the massless surface Dirac cone and states resonant within the valence band, the presence of the Co impurity reduces the planar spin helicity of now massive Dirac fermions. © 2011 American Physical Society.

Lopez-Uribe M.M.,Cornell University | Zamudio K.R.,Cornell University | Cardoso C.F.,Federal University of Minas Gerais | Danforth B.N.,Cornell University
Molecular Ecology | Year: 2014

Understanding the impact of past climatic events on the demographic history of extant species is critical for predicting species' responses to future climate change. Palaeoclimatic instability is a major mechanism of lineage diversification in taxa with low dispersal and small geographical ranges in tropical ecosystems. However, the impact of these climatic events remains questionable for the diversification of species with high levels of gene flow and large geographical distributions. In this study, we investigate the impact of Pleistocene climate change on three Neotropical orchid bee species (Eulaema bombiformis, E. meriana and E. cingulata) with transcontinental distributions and different physiological tolerances. We first generated ecological niche models to identify species-specific climatically stable areas during Pleistocene climatic oscillations. Using a combination of mitochondrial and nuclear markers, we inferred calibrated phylogenies and estimated historical demographic parameters to reconstruct the phylogeographical history of each species. Our results indicate species with narrower physiological tolerance experienced less suitable habitat during glaciations and currently exhibit strong population structure in the mitochondrial genome. However, nuclear markers with low and high mutation rates show lack of association with geography. These results combined with lower migration rate estimates from the mitochondrial than the nuclear genome suggest male-biased dispersal. We conclude that despite large effective population sizes and capacity for long-distance dispersal, climatic instability is an important mechanism of maternal lineage diversification in orchid bees. Thus, these Neotropical pollinators are susceptible to disruption of genetic connectivity in the event of large-scale climatic changes. © 2014 John Wiley & Sons Ltd.

Costa V.V.,Federal University of Minas Gerais | Jacinto M.J.,University of Sao Paulo | Rossi L.M.,University of Sao Paulo | Landers R.,University of Campinas | Gusevskaya E.V.,Federal University of Minas Gerais
Journal of Catalysis | Year: 2011

Ruthenium hydroxide supported on silica-coated magnetic nanoparticles was shown to be an efficient heterogeneous catalyst for the liquid-phase oxidation of a wide range of alcohols using molecular oxygen as a sole oxidant in the absence of co-catalysts or additives. The material was prepared through the loading of the amino modified support with ruthenium(III) ions from an aqueous solution of ruthenium(III) chloride followed by treatment with sodium hydroxide to form ruthenium hydroxide species. Characterizations suggest that ruthenium hydroxide is highly dispersed on the support surface, with no ruthenium containing crystalline phases being detected. Various carbonylic monoterpenoids important for fragrance and pharmaceutical industries can be obtained in good to excellent yields starting from biomass-based monoterpenic alcohols, such as isoborneol, perillyl alcohol, carveol, and citronellol. The catalyst undergoes no metal leaching and can be easily recovered by the application of an external magnet and re-used. © 2011 Elsevier Inc. All rights reserved.

Pauling J.,Max Planck Institute for Informatics | Pauling J.,Saarland University | Rottger R.,Max Planck Institute for Informatics | Tauch A.,Bielefeld University | And 3 more authors.
Nucleic Acids Research | Year: 2012

Post-genomic analysis techniques such as next-generation sequencing have produced vast amounts of data about micro organisms including genetic sequences, their functional annotations and gene regulatory interactions. The latter are genetic mechanisms that control a cell's characteristics, for instance, pathogenicity as well as survival and reproduction strategies. CoryneRegNet is the reference database and analysis platform for corynebacterial gene regulatory networks. In this article we introduce the updated version 6.0 of CoryneRegNet and describe the updated database content which includes, 6352 corynebacterial regulatory interactions compared with 4928 interactions in release 5.0 and 3235 regulations in release 4.0, respectively. We also demonstrate how we support the community by integrating analysis and visualization features for transiently imported custom data, such as gene regulatory interactions. Furthermore, with release 6.0, we provide easy-to- use functions that allow the user to submit data for persistent storage with the CoryneRegNet database. Thus, it offers important options to its users in terms of community demands. CoryneRegNet is publicly available at http://www © The Author(s) 2011.

de Souza M.M.,Federal University of Bahia | Windmoller C.C.,Federal University of Minas Gerais | Hatje V.,Federal University of Bahia
Marine Pollution Bulletin | Year: 2011

This study determined the concentrations of major and trace elements in shellfish (oysters, clams and mussels) and conducted an assessment of the health risks due to the consumption of contaminated seafood. Samples were collected at 34 sites along Todos os Santos Bay, Brazil. The elements were determined by ICP OES and Hg by Direct Mercury Analysis. Relatively high concentrations of trace elements (As, Zn, Se and Cu) were found in seafood tissues. Potential daily intake of As, Co, Se, Zn and Cu associated to shellfish consumption suggested relevant non-carcinogenic risk for all studied locations. Copper was the element that posed the greatest non-carcinogenic risk, while Pb posed the highest carcinogenic risk. Health risks for humans were greatest from the consumption of mussels. Contaminated shellfish offer the greatest risk for children, subsistence fishers and subsistence shellfish consumers. © 2011 Elsevier Ltd.

Casarotto P.C.,University of Sao Paulo | Terzian A.L.B.,Max Planck Institute For Psychiatrie | Terzian A.L.B.,Ludwig Maximilians University of Munich | Aguiar D.C.,Federal University of Minas Gerais | And 4 more authors.
Neuropsychopharmacology | Year: 2012

The midbrain dorsal periaqueductal gray (dPAG) has an important role in orchestrating anxiety-and panic-related responses. Given the cellular and behavioral evidence suggesting opposite functions for cannabinoid type 1 receptor (CB 1) and transient receptor potential vanilloid type-1 channel (TRPV1), we hypothesized that they could differentially influence panic-like reactions induced by electrical stimulation of the dPAG. Drugs were injected locally and the expression of CB 1 and TRPV1 in this structure was assessed by immunofluorescence and confocal microscopy. The CB 1-selective agonist, ACEA (0.01, 0.05 and 0.5 pmol) increased the threshold for the induction of panic-like responses solely at the intermediary dose, an effect prevented by the CB 1-selective antagonist, AM251 (75 pmol). Panicolytic-like effects of ACEA at the higher dose were unmasked by pre-treatment with the TRPV1 antagonist capsazepine (0.1 nmol). Similarly to ACEA, capsazepine (1 and 10 nmol) raised the threshold for triggering panic-like reactions, an effect mimicked by another TRPV1 antagonist, SB366791 (1 nmol). Remarkably, the effects of both capsazepine and SB366791 were prevented by AM251 (75 pmol). These pharmacological data suggest that a common endogenous agonist may have opposite functions at a given synapse. Supporting this view, we observed that several neurons in the dPAG co-expressed CB 1 and TRPV1. Thus, the present work provides evidence that an endogenous substance, possibly anandamide, may exert both panicolytic and panicogenic effects via its actions at CB 1 receptors and TRPV1 channels, respectively. This tripartite set-point system might be exploited for the pharmacotherapy of panic attacks and anxiety-related disorders. © 2012 American College of Neuropsychopharmacology. All rights reserved.

Lana-Peixoto M.A.,Federal University of Minas Gerais | Callegaro D.,University of Sao Paulo
Arquivos de Neuro-Psiquiatria | Year: 2012

Neuromyelitis optica (NMO) has been traditionally described as the association of recurrent or bilateral optic neuritis and longitudinally extensive transverse myelitis (LETM). Identification of aquaporin-4 antibody (AQP4-IgG) has deeply changed the concept of NMO. A spectrum of NMO disorders (NMOSD) has been formulated comprising conditions which include both AQP4-IgG seropositivity and one of the index events of the disease (recurrent or bilateral optic neuritis and LETM). Most NMO patients harbor asymptomatic brain MRI lesions, some of them considered as typical of NMO. Some patients with aquaporin-4 autoimmunity present brainstem, hypothalamic or encephalopathy symptoms either preceding an index event or occurring isolatedly with no evidence of optic nerve or spinal involvement. On the opposite way, other patients have optic neuritis or LETM in association with typical lesions of NMO on brain MRI and yet are AQP4-IgG seronegative. An expanded spectrum of NMO disorders is proposed to include these cases.

Maximiano R.V.,Federal University of Minas Gerais | Beams R.,University of Rochester | Novotny L.,University of Rochester | Jorio A.,Federal University of Minas Gerais | Cancado L.G.,Federal University of Minas Gerais
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

A theory describing the near-field Raman enhancement in two-dimensional (2D) systems is presented. The analysis quantifies the near-field Raman intensity as a function of the tip-sample distance, Raman polarizability tensor components, incident laser beam configuration, and tip orientation relative to the sample plane. Our results show that the near-field Raman intensity is inversely proportional to the 10th and 8th power of the tip-sample distance in the incoherent and coherent scattering regimes, respectively. Optimal conditions for the tip inclination angle for different configurations are determined, and the results can be used as a guide for tip-enhanced Raman spectroscopy (TERS) experiments in 2D systems such as graphene, two-dimensional electron gases, and topological insulators. © 2012 American Physical Society.

Martins J.D.R.,Federal University of Piauí | Chacham H.,Federal University of Minas Gerais
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

We perform a theoretical study of nitrogen-rich B-C-N graphene-type alloys through a combination of Monte Carlo and ab initio methods. Different from the B/N = 1 limit, where both calculations and experiments indicate segregation into BN and C regions, the simulations of the N-rich alloys result in solid solution materials, with isolated carbon substituting boron sites of BN. We show that this is a consequence of the competition between bond energies. As a result of the solid solution morphology, the electronic structure of N-rich alloys depict a ∼1.5 eV wide, half-filled carbon impurity band that would result in either metallic behavior or disorder-induced semiconducting behavior with a mobility gap. © 2012 American Physical Society.

Mota N.F.O.,Federal University of Minas Gerais | Wanderley M.G.L.,University of Sao Paulo
Brittonia | Year: 2014

As part of the results of an inventory of Xyridaceae species from the Rio Preto State Park, Minas Gerais, Brazil, three species of Xyris are proposed as new to science. Xyris nigra, with its blackish and globose spikes, X. scoparia, with linear leaf blades and densely caespitose habit, and X. velutina, with margins of the leaf blades conspicuously villous, are here described and illustrated. For each species, comments are provided on ecology, phenology, and conservation status, in addition to comparisons with morphologically similar species. © 2013 The New York Botanical Garden.

Santos M.F.,Federal University of Minas Gerais | Terra Cunha M.,Federal University of Minas Gerais | Chaves R.,ICFO - Institute of Photonic Sciences | Carvalho A.R.R.,Australian National University
Physical Review Letters | Year: 2012

Spontaneous emission and the inelastic scattering of photons are two natural processes usually associated with decoherence and the reduction in the capacity to process quantum information. Here we show that, when suitably detected, these photons are sufficient to build all the fundamental blocks needed to perform quantum computation in the emitting qubits while protecting them from deleterious dissipative effects. We exemplify this by showing how to efficiently prepare graph states for the implementation of measurement-based quantum computation. © 2012 American Physical Society.

Diniz B.S.,University of Sao Paulo | Teixeira A.L.,Federal University of Minas Gerais | Miranda A.S.,Federal University of Minas Gerais | Talib L.L.,University of Sao Paulo | And 2 more authors.
Journal of Psychiatric Research | Year: 2012

Background: The Glial Cell-line derived neurotrophic factor (GDNF) is part of the TGF-β superfamily and is abundantly expressed in the central nervous system. Changes in GDNF homeostasis have been reported in affective disorders. Aim: To assess serum GDNF concentration in elderly subjects with late-life depression, before antidepressant treatment, as compared to healthy elderly controls. Methods: Thirty-four elderly subjects with major depression and 37 age and gender-matched healthy elderly controls were included in this study. Diagnosis of major depression was ascertained by the SCID interview for DSM-IV and the severity of depressive symptoms was assessed by the Hamilton Depression Rating Scale (HDRS-21). Serum GDNF concentration were determined by sandwich ELISA. Results: Patients with major depression showed a significant reduction in GDNF levels as compared to healthy elderly controls (p < 0.001). Also, GDNF level was negatively correlated with HDRS-21 scores (r = -0.343, p = 0.003). Discussion: Our data provide evidence that GDNF may be a state marker of depressive episode in older adults. Changes in the homeostatic control of GDNF production may be a target to development of new antidepressant strategies. © 2011 Elsevier Ltd.

Background: Developmental Coordination Disorder (DCD) is characterized by impaired development of motor coordination, with impact on daily life activities and academic performance. The Motor Coordination and Dexterity Assessment (MCDA) was created to offer Brazilian rehabilitation professionals a valid and reliable instrument for detecting DCD. Objective: To examine the MCDA criterion validity. Methods: One hundred and eighty one children aged 7 and 8 years from the metropolitan region of Belo Horizonte, MG, Brazil, pre-selected using the Developmental Coordination Disorder Questionnaire (DCDQ-Brazil), were evaluated with the MCDA and the Movement Assessment Battery for Children (MABC-II). Concurrent validity was assessed using Spearman correlation index and the predictive validity was calculated using sensitivity, specificity, positive and negative predictive values. ROC curves were constructed to determine the optimal cutoff point of MCDA. Results: Spearman correlation between the total scores of MCDA and MABC-II at 7 and 8 years were 0.596 (p=0.000) and 0.730 (p=0.000), respectively. The cutoff points defined by the ROC curves approached the 40th percentile, corresponding to a sensitivity of 0.91 and 0.74 and specificity of 0.74 and 0.90 for children 7 and 8 years old, respectively. Conclusion: The results indicate moderate values of concurrent and predictive validity of the MCDA. Future studies should reexamine the cutoff points of the MCDA in other random samples, representative of Brazilian children 4 to 8 years of age. The predictive validity of the full instrument for DCD should be re-examined in well defined clinical samples. © Revista Brasileira de Fisioterapia.

Hotez P.J.,Baylor College of Medicine | Hotez P.J.,Baylor University | Hotez P.J.,Rice University | Fujiwara R.T.,Federal University of Minas Gerais
Microbes and Infection | Year: 2014

Today, the nation of Brazil leads the Western Hemisphere in terms of the number of its citizens living with neglected tropical diseases (NTDs). These diseases continue to trap Brazil's "bottom 20 million" in extreme poverty. © 2014.

Beams R.,University of Rochester | Cancado L.G.,Federal University of Minas Gerais | Oh S.-H.,University of Minnesota | Jorio A.,Federal University of Minas Gerais | Novotny L.,ETH Zurich
Physical Review Letters | Year: 2014

Inelastic light scattering in crystals has historically been treated as a spatially incoherent process, giving rise to incoherent optical radiation. Here we demonstrate that Raman scattering can be spatially coherent, in which case it depends on the dimensionality and symmetry of the scatterer. Using near-field spectroscopy, we measure a correlation length of ∼30nm for the optical phonons in graphene, the results varying with vibrational symmetries and spatial confinement of the phonons. © 2014 American Physical Society.

Aguiar M.C.O.,Federal University of Minas Gerais | Dobrosavljevic V.,Florida State University
Physical Review Letters | Year: 2013

We present a large N solution of a microscopic model describing the Mott-Anderson transition on a finite-coordination Bethe lattice. Our results demonstrate that strong spatial fluctuations, due to Anderson localization effects, dramatically modify the quantum critical behavior near disordered Mott transitions. The leading critical behavior of quasiparticle wave functions is shown to assume a universal form in the full range from weak to strong disorder, in contrast to disorder-driven non-Fermi liquid ("electronic Griffiths phase") behavior, which is found only in the strongly correlated regime. © 2013 American Physical Society.

Campos A.C.,Federal University of Minas Gerais | Fogaca M.V.,University of Sao Paulo | Aguiar D.C.,Federal University of Minas Gerais | Guimaraes F.S.,University of Sao Paulo
Revista Brasileira de Psiquiatria | Year: 2013

Anxiety and stress-related disorders are severe psychiatric conditions that affect performance in daily tasks and represent a high cost to public health. The initial observation of Charles Darwin that animals and human beings share similar characteristics in the expression of emotion raise the possibility of studying the mechanisms of psychiatric disorders in other mammals (mainly rodents). The development of animal models of anxiety and stress has helped to identify the pharmacological mechanisms and potential clinical effects of several drugs. Animal models of anxiety are based on conflict situations that can generate opposite motivational states induced by approach-avoidance situations. The present review revisited the main rodent models of anxiety and stress responses used worldwide. Here we defined as "ethological" the tests that assess unlearned/unpunished responses (such as the elevated plus maze, light-dark box, and open field), whereas models that involve learned/ punished responses are referred to as "conditioned operant conflict tests" (such as the Vogel conflict test). We also discussed models that involve mainly classical conditioning tests (fear conditioning). Finally, we addressed the main protocols used to induce stress responses in rodents, including psychosocial (social defeat and neonatal isolation stress), physical (restraint stress), and chronic unpredictable stress. © 2013 Associaçaõ Brasileira de Psiquiatria.

Sato D.K.,Tohoku University | Lana-Peixoto M.A.,Federal University of Minas Gerais | Fujihara K.,Tohoku University | De Seze J.,CHU de Strasbourg
Brain Pathology | Year: 2013

Neuromyelitis optica (NMO) is an inflammatory neurologic disease clinically characterized by severe optic neuritis (ON) and transverse myelitis (TM). The relationship between NMO and multiple sclerosis (MS) has long been a matter of debate. However, the discovery of an NMO-specific autoantibody, NMO-immunoglobulin G/aquaporin 4 (AQP4) antibody, has dramatically advanced our understanding of the disease, and the clinical, magnetic resonance imaging (MRI), optical coherence tomography, and laboratory examinations have clarified unique features of NMO that are distinct from MS. The term NMO spectrum disorders (NMOSD) incorporating spatially limited forms was introduced, as patients with recurrent or simultaneous bilateral ON or recurrent longitudinally extensive TM (LETM) alone are also often AQP4 antibody-seropositive. Moreover, studies of seropositive cases have shown that more than half of them have brain lesions, some of which are unique to NMO, and can be the onset manifestation. Some clinical features of AQP4 antibody-seronegative NMO differ from seropositive, but it remains unknown whether they are pathologically distinct. Immunosuppressive treatments are effective for acute attacks and prevention of relapses of NMOSD, and new molecularly targeted drugs are under investigation. Importantly, some disease modifying drugs for MS may exacerbate NMOSD, making early differential diagnosis of the two diseases crucial. We review the evolving clinical spectrum, the updated clinical, MRI, neuro-ophthalmological and laboratory findings, and the current status of treatment in NMOSD. © 2013 International Society of Neuropathology.

Cancado L.G.,Federal University of Minas Gerais | Beams R.,University of Rochester | Jorio A.,Federal University of Minas Gerais | Novotny L.,ETH Zurich
Physical Review X | Year: 2014

A theoretical study describing the coherence properties of near-field Raman scattering in two- and onedimensional systems is presented. The model is applied to the Raman modes of pristine graphene and graphene edges. Our analysis is based on the tip-enhanced Raman scheme, in which a sharp metal tip located near the sample surface acts as a broadband optical antenna that transfers the information contained in the spatially correlated (but nonpropagating) near field to the far field. The dependence of the scattered signal on the tip-sample separation is explored, and the theory predicts that the signal enhancement depends on the particular symmetry of a vibrational mode. The model can be applied to extract the correlation length Lc of optical phonons from experimentally recorded near-field Raman measurements. The coherence properties of optical phonons have been broadly explored in the time and frequency domains, and the spatially resolved approach presented here provides a complementary methodology for the study of local material properties at the nanoscale.

Rodriguez-Nieva J.F.,Massachusetts Institute of Technology | Saito R.,Tohoku University | Costa S.D.,Federal University of Minas Gerais | Dresselhaus M.S.,Massachusetts Institute of Technology
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

The effect of 13C isotope impurities on the phonon properties of graphene is discussed theoretically. We calculated the values of the phonon lifetimes due to isotope impurity scattering for all values of densities, isotopic masses, and for all wave vectors using second-order perturbation theory. We found that for natural concentrations of 13C, the contribution of isotopic scattering to the phonon lifetime of the optical modes is negligible when compared to the electron-phonon interaction. Nevertheless, for atomic concentrations of 13C as high as ρ=0.5 both contributions become comparable. Our results are compared with recent experimental results and we find good agreement both in the 13C atomic density dependence of the lifetime as well as in the calculated spectral width of the G-band. Due to phonon scattering by 13C isotopes, some graphene phonon wave functions become localized in real space. Numerical calculations show that phonon localized states exist in the high-energy optical phonon modes and in regions of flat phonon dispersion. In particular, for the case of in-plane optical phonon modes, a typical localization length is on the order of 3 nm for 13C atomic concentrations of ρ≈0.5. Optical excitation of phonon modes may provide a way to experimentally observe localization effects for phonons in graphene. © 2012 American Physical Society.

Araujo P.T.,Massachusetts Institute of Technology | Mafra D.L.,Massachusetts Institute of Technology | Mafra D.L.,Federal University of Minas Gerais | Sato K.,Tohoku University | And 3 more authors.
Physical Review Letters | Year: 2012

Phonon self-energy corrections have mostly been studied theoretically and experimentally for phonon modes with zone-center (q=0) wave vectors. Here, gate-modulated Raman scattering is used to study phonons of a single layer of graphene originating from a double-resonant Raman process with q 0. The observed phonon renormalization effects are different from what is observed for the zone-center q=0 case. To explain our experimental findings, we explored the phonon self-energy for the phonons with nonzero wave vectors (q 0) in single-layer graphene in which the frequencies and decay widths are expected to behave oppositely to the behavior observed in the corresponding zone-center q=0 processes. Within this framework, we resolve the identification of the phonon modes contributing to the G Raman feature at 2450cm -1 to include the iTO+LA combination modes with q 0 and also the 2iTO overtone modes with q=0, showing both to be associated with wave vectors near the high symmetry point K in the Brillouin zone. © 2012 American Physical Society.

Almeida-Santos A.F.,Federal University of Minas Gerais | Moreira F.A.,Federal University of Minas Gerais | Guimaraes F.S.,University of Sao Paulo | Aguiar D.C.,Federal University of Minas Gerais
Pharmacology Biochemistry and Behavior | Year: 2013

The transient receptors potential vanilloid type 1 channels (TRPV1) are expressed in several brain regions related to defensive behaviors, including the dorsolateral periaqueductal gray (dlPAG). The endocannabinoid anandamide, in addition to its agonist activity at cannabinoid type 1 (CB1), is also proposed as an endogenous agonist of these receptors, through which it could facilitate anxiety-like responses. The aim of this work was to test the hypothesis that TRPV1 in the dlPAG of rats would mediate panic-like responses in two models, namely the escape responses induced by chemical stimulation of this structure or by exposure to the elevated T-Maze (ETM). Antagonism of TRPV1 with capsazepine injected into the dlPAG reduced the defense response induced by local NMDA-injection, suggesting an anti-aversive effect. In the ETM, capsazepine inhibited escape response, suggesting a panicolytic-like effect. Interestingly, this effect was prevented by a CB1 antagonist (AM251). The present study showed that antagonism of TRPV1 in the dlPAG induces panicolytic-like effects, which can be prevented by a CB1 antagonist. Therefore, these antiaversive effects of TRPV1 blockade may ultimately occur due to a predominant action of anandamide through CB1 receptors. © 2013 Elsevier Inc.

Kim S.E.,University of Texas Health Science Center at San Antonio | Turkington K.,University of Texas Health Science Center at San Antonio | Kushmerick C.,Federal University of Minas Gerais | Kim J.H.,University of Texas Health Science Center at San Antonio
Journal of Neurophysiology | Year: 2013

Auditory brain stem circuits rely on fast, precise, and reliable neurotransmission to process auditory information. To determine the fundamental role of myelination in auditory brain stem function, we examined the evoked auditory brain stem response (ABR) from the Long Evans shaker (LES) rat, which lacks myelin due to a genetic deletion of myelin basic protein. In control rats, the ABR evoked by a click consisted of five well-defined waves (denoted waves I-V). In LES rats, waves I, IV, and V were present, but waves II and III were undetectable, indicating disrupted function in the earliest stages of central nervous system auditory processing. In addition, the developmental shortening of the interval between waves I and IV that normally occurs in control rats was arrested and resulted in a significant increase in the central conduction time in LES rats. In brain stem slices, action potential transmission between the calyx of Held terminals and the medial nucleus of the trapezoid body (MNTB) neurons was delayed and less reliable in LES rats, although the resting potential, threshold, input resistance, and length of the axon initial segment of the postsynaptic MNTB neurons were normal. The amplitude of glutamatergic excitatory postsynaptic currents (EPSCs) and the degree of synaptic depression during highfrequency stimulation were not different between LES rats and controls, but LES rats exhibited a marked slow component to the EPSC decay and a much higher rate of presynaptic failures. Together, these results indicate that loss of myelin disrupts brain stem auditory processing, increasing central conduction time and reducing the reliability of neurotransmission. © 2013 the American Physiological Society.

Lima N.P.,VALE SA | Valadao G.E.S.,Federal University of Minas Gerais | Peres A.E.C.,Federal University of Minas Gerais
Minerals Engineering | Year: 2013

In iron ore concentration, reverse cationic flotation of quartz has been successfully employed for particles below 150 μm previously deslimed. Amine and starch are used, respectively, as quartz collector and iron oxides depressant. Understanding the mechanisms of reagents interaction is relevant to improve the separation selectivity, especially for high amine dosages. The term clathrate was used to explain this interaction, meaning a molecular compound in which molecules of one species occupy the empty spaces in the lattice of the other species, resulting in the depression of hydrophobic minerals. Laboratory scale experiments were carried out with itabirite iron ore in three different size ranges. The clathrate formation between molecules of amine and starch may explain the increase of SiO2 content in the concentrates of the coarse size range (-150 + 45 μm) due to an increase in amine dosage. © 2013 Elsevier Ltd. All rights reserved.

Babinski M.,University of Sao Paulo | Pedrosa-Soares A.C.,Federal University of Minas Gerais | Trindade R.I.F.,University of Sao Paulo | Martins M.,Federal University of Minas Gerais | And 2 more authors.
Gondwana Research | Year: 2012

Glacigenic diamictite successions of the Macaúbas Group are widespread in the western domain of the Araçuaí orogen, east of the São Francisco craton (Brazil). Diamictites also occur on this craton and in the African counterpart of the Araçuaí orogen, the West Congo belt. Detrital zircon grains from the matrix of diamictites and sandstones from the Macaúbas Group were dated by the U-Pb SHRIMP technique. The geochronological study sets the maximum depositional age of the glacial diamictites at 900Ma, and indicates multiple sources for the Macaúbas basin with ages ranging from 900 to 2800Ma. Sm-Nd T DM model ages, determined on whole rock samples, range from 1.8Ga to 2.5Ga and get older up-section. Comparison of our data with those from the cratonic area suggest that these glacial deposits can be correlated to the Jequitaí and Carrancas diamictites in the São Francisco craton, and to the Lower Mixtite Formation of the West Congolian Group, exposed in Africa. The 900-1000Ma source is most probably represented by the Zadinian-Mayumbian volcanic rocks and related granites from the West Congo belt. However, one of the most voluminous sources, with ages in the 1.1-1.3Ga interval, has not been detected in the São Francisco-Congo craton. Possible sources for these grains could occur elsewhere in Africa, or possibly from within the Brasília Belt in western central Brazil. © 2011 International Association for Gondwana Research.

Reis A.M.M.,Federal University of Minas Gerais | Cassiani S.H.B.,University of Sao Paulo
Clinics | Year: 2011

OBJECTIVES: To investigate the prevalence of potential drug interactions at the intensive care unit of a university hospital in Brazil and to analyze their clinical significance. METHODS: This cross-sectional retrospective study included 299 patients who had been hospitalized in the intensive care unit of the hospital. The drugs administered during the first 24 hours of hospitalization, in the 50th length-of-stay percentile and at the time of discharge were analyzed to identify potential drug-drug and drug-enteral nutrition interactions using DRUG-REAX® software. The drugs were classified according to the anatomical therapeutic chemical classification. RESULTS: The median number of medications per patient was smaller at the time of discharge than in the 50th length-of-stay percentile and in the first 24 hours of hospitalization. There was a 70% prevalence of potential drug interactions at the intensive care unit at the studied time points of hospitalization. Most of the drug interactions were either severe or moderate, and the scientific evidence for the interactions was, in general, either good or excellent. Pharmacodynamic interactions presented a subtle predominance in relation to pharmacokinetic interactions. The occurrence of potential drug interactions was associated with the number of medications administered and the length of stay. Medications that induced cytochrome P450, drugs that prolong the QT interval and cardiovascular drugs were pharmacotherapy factors associated with potential drug interactions. CONCLUSION: The study showed that potential drug interactions were prevalent in the intensive care unit due to the complexity of the pharmacotherapies administered. The interactions were associated with the number of drugs, the length of stay and the characteristics of the administered medications. © 2011 CLINICS.

Aguiar D.C.,Federal University of Minas Gerais | Moreira F.A.,Federal University of Minas Gerais | Terzian A.L.,systemIC | Terzian A.L.,Max Planck Institute of Psychiatry | And 4 more authors.
Neuroscience and Biobehavioral Reviews | Year: 2014

The Transient Receptor Potential Vanilloid Type-1 (TRPV1) was first characterized in primary afferent fibers as a receptor for capsaicin (the pungent ingredient of chili peppers). Later on, this cation-permeable ion channel was also described in the central nervous system, where its main putative endogenous ligand is N-arachidonoyl ethanolamide (an endocannabinoid, also known as anandamide). Recent results employing genetic, pharmacological and histochemical techniques indicate that TRPV1 tonically modulate anxiety, fear and panic responses in brain regions related to defensive responses, such as the dorsal periaqueductal gray, the hippocampus and the medial prefrontal cortex. Genetic deletion or antagonism of this ion channel induces anxiolytic-like effects in several animal models. The main mechanism responsible for TRPV1-mediated effects on anxiety seems to involve facilitation of glutamatergic neurotransmission. In addition, there is evidence for interactions with other neurotransmitter systems, such as nitric oxide and endocannabinoids. © 2014 Elsevier Ltd.

Bottcher J.,University of Sao Paulo | Kohayakawa Y.,University of Sao Paulo | Procacci A.,Federal University of Minas Gerais
Random Structures and Algorithms | Year: 2012

Let G be a graph on n vertices with maximum degree Δ. We use the Lovász local lemma to show the following two results about colourings χ of the edges of the complete graph K n. If for each vertex v of K n the colouring χ assigns each colour to at most (n - 2)/(22.4Δ 2) edges emanating from v, then there is a copy of G in K n which is properly edge-coloured by χ. This improves on a result of Alon, Jiang, Miller, and Pritikin [Random Struct. Algorithms 23(4), 409-433, 2003]. On the other hand, if χ assigns each colour to at most n/(51Δ 2) edges of K n, then there is a copy of G in K n such that each edge of G receives a different colour from χ. This proves a conjecture of Frieze and Krivelevich [Electron. J. Comb. 15(1), R59, 2008]. Our proofs rely on a framework developed by Lu and Székely [Electron. J. Comb. 14(1), R63, 2007] for applying the local lemma to random injections. In order to improve the constants in our results we use a version of the local lemma due to Bissacot, Fernández, Procacci, and Scoppola [preprint, arXiv:0910.1824]. © 2011 Wiley Periodicals, Inc.

Ruiz-Cardenas R.,Federal University of Minas Gerais | Krainski E.T.,Federal University of Paraná | Rue H.,Norwegian University of Science and Technology
Computational Statistics and Data Analysis | Year: 2012

Inference in state-space models usually relies on recursive forms for filtering and smoothing of the state vectors regarding the temporal structure of the observations, an assumption that is, from our view point, unnecessary if the dataset is fixed, that is, completely available before analysis. In this paper, we propose a computational framework to perform approximate full Bayesian inference in linear and generalized dynamic linear models based on the Integrated Nested Laplace Approximation (INLA) approach. The proposed framework directly approximates the posterior marginals of interest disregarding the assumption of recursive updating/estimation of the states and hyperparameters in the case of fixed datasets and, therefore, enable us to do fully Bayesian analysis of complex state-space models more easily and in a short computational time. The proposed framework overcomes some limitations of current tools in the dynamic modeling literature and is vastly illustrated with a series of simulated as well as well known real-life examples from the literature, including realistically complex models with correlated error structures and models with more than one state vector, being mutually dependent on each other. R code is available online for all the examples presented. © 2011 Elsevier B.V. All rights reserved.

Montoro L.A.,Federal University of Minas Gerais | Matsubara E.Y.,University of Sao Paulo | Rosolen J.M.,University of Sao Paulo
Journal of Power Sources | Year: 2014

This is a detailed study of how impurities can affect the mechanisms of lithium storage in composite electrodes consisting of a three-dimensional single-walled carbon nanotube (SWCNT) bundles network. To remove impurities such as fullerenes, amorphous carbon, catalyst, and nanographite, we submitted the SWCNT bundles to an appropriate chemical treatment before using them to prepare the electrode. Then, we analyzed how this treatment influenced electrode potential, fading capacity, and specific capacity. Additionally, we evaluated the electrode prepared with high-purity SWNCT bundles by galvanostatic intermittent titration, to obtain lithium transport parameters under thermodynamic conditions. We achieved an intrinsic specific capacity of 400 mAh g-1 for the purified SWCNT bundles prepared by an arc-reactor method. The transport parameters revealed that the electrode underwent electronic transition of the semiconducting-metal type. The chemical diffusion coefficient ranged from 10-4 to 10-18 cm2 s-1 with decreasing electrode potential. © 2014 Elsevier B.V. All rights reserved.

Glaser T.,University of Sao Paulo | Resende R.R.,Federal University of Minas Gerais | Ulrich H.,University of Sao Paulo
Cell Communication and Signaling | Year: 2013

Purinergic receptors participate, in almost every cell type, in controlling metabolic activities and many physiological functions including signal transmission, proliferation and differentiation. While most of P2Y receptors induce transient elevations of intracellular calcium concentration by activation of intracellular calcium pools and forward these signals as waves which can also be transmitted into neighboring cells, P2X receptors produce calcium spikes which also include activation of voltage-operating calcium channels. P2Y and P2X receptors induce calcium transients that activate transcription factors responsible for the progress of differentiation through mediators including calmodulin and calcineurin. Expression of P2X2 as well as of P2X7 receptors increases in differentiating neurons and glial cells, respectively. Gene expression silencing assays indicate that these receptors are important for the progress of differentiation and neuronal or glial fate determination. Metabotropic receptors, mostly P2Y1 and P2Y2 subtypes, act on embryonic cells or cells at the neural progenitor stage by inducing proliferation as well as by regulation of neural differentiation through NFAT translocation. The scope of this review is to discuss the roles of purinergic receptor-induced calcium spike and wave activity and its codification in neurodevelopmental and neurodifferentiation processes. © 2013 Glaser et al.; licensee BioMed Central Ltd.

Schmertmann C.P.,Florida State University | Assuncao R.M.,Federal University of Minas Gerais | Potter J.E.,University of Texas at Austin
Demography | Year: 2010

Many important questions and theories in demography focus on changes over time, and on how those changes differ over geographic and social space. Space-time analysis has always been important in studying fertility transitions, for example. However, demographers have seldom used formal statistical methods to describe and analyze time series of maps. One formal method, used widely in epidemiology, criminology, and public health, is Knox's space-time interaction test. In this article, we discuss the potential of the Knox test in demographic research and note some possible pitfalls. We demonstrate how to use familiar proportional hazards models to adapt the Knox test for demographic applications. These adaptations allow for nonrepeatable events and for the incorporation of structural variables that change in space and time. We apply the modified test to data on the onset of fertility decline in Brazil over 1960-2000 and show how the modified method can produce maps indicating where and when diffusion effects seem strongest, net of covariate effects.

Roman-Campos D.,University of Sao Paulo | Cruz J.S.,Federal University of Minas Gerais
Life Sciences | Year: 2014

Beriberi is a disease caused by thiamine deficiency (TD), which may lead to heart problems, including heart failure. Despite the fact that thiamine prevalence is reduced in the industrialized world, it remains a health hazard especially due to chronic alcohol consumption. Diagnosing the presence of TD based on both electrocardiogram and echocardiogram exams is particularly challenging because of its non-specific symptoms. TD diagnosis is unique, which then leads to determination of its severity. If thiamine infusion abrogates its symptomology, only then can the case be definitely diagnosed as TD. Another condition eliciting increased likelihood of developing TD in humans is furosemide administration to heart failure patients. Furosemide administration worsens heart failure due to heightened TD. However, literature data provided are contradictory and require clarification. Up until now, the rat has been the preferred TD animal model. However, the results are even more contradictory than those in humans. It seems that if the rat TD models are separated into two distinct groups, according to animal age, the results appear to be more consistent: younger rats are more prone to develop TD signs similar to those found in humans. Their symptoms stem from changes in cardiac myocyte function that are reversed after thiamine supplementation. However, it remains an open question as to why only younger rats are able to develop human-like symptoms and deserve further investigation. © 2013 Elsevier Inc. All rights reserved.

Vieira L.F.M.,Federal University of Minas Gerais | Lee U.,Alcatel - Lucent | Gerla M.,University of California at Los Angeles
IEEE Journal on Selected Areas in Communications | Year: 2010

A SEA Swarm (Sensor Equipped Aquatic Swarm) is a collection of mobile underwater sensors that moves as a group with water current and enables 4D (space and time) monitoring of local underwater events such as contaminants and intruders. For prompt alert reporting, mobile sensors routes events to mobile sinks (i.e., autonomous underwater vehicles) via geographic routing that is known to be most efficient under mobility and scarce acoustic bandwidth. In order for a packet to be routed to the destination using geographical routing, it requires to know the location of the destination. This is accomplished by having a location service that returns the location of a requested node. Our goal is to design such location service for SEA Swarm. In this paper, we analyze various design choices to realize an efficient location service in SEA Swarm scenarios. We find that conventional ad hoc network location service protocols cannot be directly used, because the entire swarm moves along water current. We prove that maintaining location information in a 2D plane is a better design choice. Given this, we propose a bio-inspired location service called a Phero-Trail location service protocol. In Phero-Trail, location information is stored in a 2D upper hull of a SEA Swarm, and a mobile sink uses its trajectory (à la a pheromone trail of ants) projected to the 2D hull to maintain location information. This enables mobile sensors to efficiently locate a mobile sink. Our results show that Phero- Trail performs better than existing approaches. © 2010 IEEE.

Beams R.,University of Rochester | Gustavo Cancado L.,Federal University of Minas Gerais | Novotny L.,ETH Zurich
Journal of Physics Condensed Matter | Year: 2015

In this article we review Raman studies of defects and dopants in graphene as well as the importance of both for device applications. First a brief overview of Raman spectroscopy of graphene is presented. In the following section we discuss the Raman characterization of three defect types: point defects, edges, and grain boundaries. The next section reviews the dependence of the Raman spectrum on dopants and highlights several common doping techniques. In the final section, several device applications are discussed which exploit doping and defects in graphene. Generally defects degrade the figures of merit for devices, such as carrier mobility and conductivity, whereas doping provides a means to tune the carrier concentration in graphene thereby enabling the engineering of novel material systems. Accurately measuring both the defect density and doping is critical and Raman spectroscopy provides a powerful tool to accomplish this task. © 2015 IOP Publishing Ltd.

Parreiras R.O.,Pontifical Catholic University of Minas Gerais | Ekel P.Ya.,Pontifical Catholic University of Minas Gerais | Martini J.S.C.,University of Sao Paulo | Martini J.S.C.,Sao Paulo Electrical Energy Transmission Company | Palhares R.M.,Federal University of Minas Gerais
Information Sciences | Year: 2010

The present paper proposes a flexible consensus scheme for group decision making, which allows one to obtain a consistent collective opinion, from information provided by each expert in terms of multigranular fuzzy estimates. It is based on a linguistic hierarchical model with multigranular sets of linguistic terms, and the choice of the most suitable set is a prerogative of each expert. From the human viewpoint, using such model is advantageous, since it permits each expert to utilize linguistic terms that reflect more adequately the level of uncertainty intrinsic to his evaluation. From the operational viewpoint, the advantage of using such model lies in the fact that it allows one to express the linguistic information in a unique domain, without losses of information, during the discussion process. The proposed consensus scheme supposes that the moderator can interfere in the discussion process in different ways. The intervention can be a request to any expert to update his opinion or can be the adjustment of the weight of each expert's opinion. An optimal adjustment can be achieved through the execution of an optimization procedure that searches for the weights that maximize a corresponding soft consensus index. In order to demonstrate the usefulness of the presented consensus scheme, a technique for multicriteria analysis, based on fuzzy preference relation modeling, is utilized for solving a hypothetical enterprise strategy planning problem, generated with the use of the Balanced Scorecard methodology. © 2009 Elsevier Inc. All rights reserved.

Lee Ho L.,University of Sao Paulo | Quinino R.C.,Federal University of Minas Gerais
International Journal of Production Economics | Year: 2013

Recently, Wu et al. (2009) proposed the use of an npx chart to monitor a process mean by attribute inspection as an alternative to the use of an X̄ chart. Motivated by the simplicity of this control chart and its good performance, the possibility of using a similar chart, an npS 2 control chart, to monitor the variability of a process was explored, and the results are described in this paper. A comparison of the proposed npS 2 control chart with the S2 and R control charts is presented, and a numerical example is provided to demonstrate the use of the npS 2 control chart. © 2013 Elsevier B.V.

Machado A.N.,University of Sao Paulo | Soares S.M.,Federal University of Minas Gerais
Revista Latino-Americana de Enfermagem | Year: 2013

Objective: To compare the ability and performance of Basic Activities of Daily Living of dependent elderly individuals cared for in a geriatric healthcare center. Method: cross-sectional, observational study with quantitative approach. The Functional Independence Measure (FIM) was applied in 109 elderly individuals cared for in a geriatric healthcare center. Of these, 60 individuals were classified as dependent in the case of basic activities of daily living described according to the International Classification of Functionality, Disability and Health (ICF). The process of triangulation reinforced reliability of data, which included information provided by patients and caregivers and that contained in medical files and objective assessment. Results: The average age was 81.0±7.1 with a predominance of women. The difference between ability and performance was statistically significant (p<0.05) in most daily tasks. Conclusion: The contribution of this study in using ICF was semi-quantitatively interpreting its qualifiers, which enabled more objective comparisons and inferences, and revealed a clear distance between the performance and ability of these individuals in most of the assessed activities. © 2013 Revista Latino-Americana de Enfermagem.

Marques A.H.,University of Sao Paulo | Bjorke-Monsen A.-L.,University of Bergen | Teixeira A.L.,Federal University of Minas Gerais | Silverman M.N.,Uniformed Services University of the Health Sciences
Brain Research | Year: 2015

Abstract Evidence suggests that maternal and fetal immune dysfunction may impact fetal brain development and could play a role in neurodevelopmental disorders, although the definitive pathophysiological mechanisms are still not completely understood. Stress, malnutrition and physical inactivity are three maternal behavioral lifestyle factors that can influence immune and central nervous system (CNS) functions in both the mother and fetus, and may therefore, increase risk for neurodevelopmental/psychiatric disorders. First, we will briefly review some aspects of maternal-fetal immune system interactions and development of immune tolerance. Second, we will discuss the bidirectional communication between the immune system and CNS and the pathways by which immune dysfunction could contribute to neurodevelopmental disorders. Third, we will discuss the effects of prenatal stress and malnutrition (over and undernutrition) on perinatal programming of the CNS and immune system, and how this might influence neurodevelopment. Finally, we will discuss the beneficial impact of physical fitness during pregnancy on the maternal-fetal unit and infant and how regular physical activity and exercise can be an effective buffer against stress- and inflammatory-related disorders. Although regular physical activity has been shown to promote neuroplasticity and an anti-inflammatory state in the adult, there is a paucity of studies evaluating its impact on CNS and immune function during pregnancy. Implementing stress reduction, proper nutrition and ample physical activity during pregnancy and the childbearing period may be an efficient strategy to counteract the impact of maternal stress and malnutrition/obesity on the developing fetus. Such behavioral interventions could have an impact on early development of the CNS and immune system and contribute to the prevention of neurodevelopmental and psychiatric disorders. Further research is needed to elucidate this relationship and the underlying mechanisms of protection. This article is part of a Special Issue entitled SI: Neuroimmunology in Health And Disease. © 2014 Elsevier B.V.

Reis A.M.M.,Federal University of Minas Gerais | Cassiani S.H.D.B.,University of Sao Paulo
European Journal of Clinical Pharmacology | Year: 2011

Purpose: Adverse drug events (ADEs) are harmful and occur with alarming frequency in critically ill patients. Complex pharmacotherapy with multiple medications increases the probability of a drug interaction (DI) and ADEs in patients in intensive care units (ICUs). The objective of the study is to determine the frequency of ADEs among patients in the ICU of a university hospital and the drugs implicated. Also, factors associated with ADEs are investigated. Methods: This cross-sectional study investigated 299 medical records of patients hospitalized for 5 or more days in an ICU. ADEs were identified through intensive monitoring adopted in hospital pharmacovigilance and also ADE triggers. Adverse drug reactions (ADR) causality was classified using the Naranjo algorithm. Data were analyzed through descriptive analysis, and through univariate and multiple logistic regression. Results: The most frequent ADEs were ADRs type A, of possible causality and moderate severity. The most frequent ADR was drug-induced acute kidney injury. Patients with ADEs related to DIs corresponded to 7% of the sample. The multiple logistic regression showed that length of hospitalization (OR=1.06) and administration of cardiovascular drugs (OR=2.2) were associated with the occurrence of ADEs. Conclusion: Adverse drug reactions of clinical significance were the most frequent ADEs in the ICU studied, which reduces patient safety. The number of ADEs related to drug interactions was small, suggesting that clinical manifestations of drug interactions that harm patients are not frequent in ICUs. © 2011 Springer-Verlag.

Amaral-Carvalho V.,University of Sao Paulo | Caramelli P.,University of Sao Paulo | Caramelli P.,Federal University of Minas Gerais
Cognitive and Behavioral Neurology | Year: 2012

OBJECTIVE:: To provide normative data for healthy middle-aged and elderly Brazilians performance on the Addenbrooke Cognitive Examination-Revised (ACE-R) and to investigate the effects of age, sex, and schooling on test performance. BACKGROUND:: The ACE-R is a brief cognitive battery that assesses various aspects of cognition. Its 5 subdomains (Attention and Orientation, Memory, Verbal Fluency, Language, and Visuospatial Abilities) are commonly impaired in Alzheimer disease or frontotemporal dementia. METHODS:: We evaluated 144 cognitively healthy volunteers (50% men, 50% women) aged 50 to 93 years, with 4 to 24 years of schooling. We divided the participants into 4 age groups, each of which was then stratified into 3 groups according to years of education. We assessed all participants with the ACE-R, the Mattis Dementia Rating Scale, and the Cornell Scale for Depression in Dementia. RESULTS:: Years of education affected all ACE-R subscores. Age influenced the Verbal Fluency subscore (P<0.001) and the ACE-R total score (P<0.05). Sex affected the Attention and Orientation (P=0.037) and Mini-Mental State Examination subscores (P=0.048), but not the ACE-R total score (P>0.05). CONCLUSIONS:: The performance of healthy middle-aged and elderly individuals on the ACE-R battery is strongly influenced by education and, to a lesser extent, by age. These findings are of special relevance in countries with populations that have marked heterogeneity in educational levels. Copyright © 2012 by Lippincott Williams & Wilkins.

Bleicher L.,Federal University of Minas Gerais | Lemke N.,São Paulo State University | Garratt R.C.,University of Sao Paulo
PLoS ONE | Year: 2011

Correlated mutation analysis has a long history of interesting applications, mostly in the detection of contact pairs in protein structures. Based on previous observations that, if properly assessed, amino acid correlation data can also provide insights about functional sub-classes in a protein family, we provide a complete framework devoted to this purpose. An amino acid specific correlation measure is proposed, which can be used to build networks summarizing all correlation and anti-correlation patterns in a protein family. These networks can be submitted to community structure detection algorithms, resulting in subsets of correlated amino acids which can be further assessed by specific parameters and procedures that provide insight into the relationship between different communities, the individual importance of community members and the adherence of a given amino acid sequence to a given community. By applying this framework to three protein families with contrasting characteristics (the Fe/Mn-superoxide dismutases, the peroxidase-catalase family and the C-type lysozyme/α-lactalbumin family), we show how our method and the proposed parameters and procedures are related to biological characteristics observed in these protein families, highlighting their potential use in protein characterization and gene annotation. © 2011 Bleicher et al.

Bartholomeu D.C.,Federal University of Minas Gerais | de Paiva R.M.C.,Federal University of Minas Gerais | Mendes T.A.O.,Federal University of Minas Gerais | DaRocha W.D.,Federal University of Paraná | Teixeira S.M.R.,Federal University of Minas Gerais
PLoS Pathogens | Year: 2014

Trypanosomatids are unicellular protozoans of medical and economical relevance since they are the etiologic agents of infectious diseases in humans as well as livestock. Whereas Trypanosoma cruzi and different species of Leishmania are obligate intracellular parasites, Trypanosoma brucei and other trypanosomatids develop extracellularly throughout their entire life cycle. After their genomes have been sequenced, various comparative genomic studies aimed at identifying sequences involved with host cell invasion and intracellular survival have been described. However, for only a handful of genes, most of them present exclusively in the T. cruzi or Leishmania genomes, has there been any experimental evidence associating them with intracellular parasitism. With the increasing number of published complete genome sequences of members of the trypanosomatid family, including not only different Trypanosoma and Leishmania strains and subspecies but also trypanosomatids that do not infect humans or other mammals, we may now be able to contemplate a slightly better picture regarding the specific set of parasite factors that defines each organism's mode of living and the associated disease phenotypes. Here, we review the studies concerning T. cruzi and Leishmania genes that have been implicated with cell invasion and intracellular parasitism and also summarize the wealth of new information regarding the mode of living of intracellular parasites that is resulting from comparative genome studies that are based on increasingly larger trypanosomatid genome datasets. © 2014 Bartholomeu et al.

Arima E.Y.,University of Texas at Austin | Barreto P.,Instituto do Homem e Meio Ambiente da Amazonia | Araujo E.,Instituto do Homem e Meio Ambiente da Amazonia | Soares-Filho B.,Federal University of Minas Gerais
Land Use Policy | Year: 2014

Reducing carbon emissions from deforestation and forest degradation now constitutes an important strategy for mitigating climate change, particularly in developing countries with large forests. Given growing concerns about global climate change, it is all the more important to identify cases in which economic growth has not sparked excessive forest clearance. We address the recent reduction of deforestation rates in the Brazilian Amazon by conducting a statistical analysis to ascertain if different levels of environmental enforcement between two groups of municipalities had any impact on this reduction. Our analysis shows that these targeted, heightened enforcement efforts avoided as much as 10,653km2 of deforestation, which translates into 1.44×10-1PgC in avoided emissions for the 3 y period. Moreover, most of the carbon loss and land conversion would have occurred at the expense of closed moist forests. Although such results are encouraging, we caution that significant challenges remain for Brazil's continued success in this regard, given recent changes in the forestry code, ongoing massive investments in hydro power generation, reductions of established protected areas, and growing demand for agricultural products. © 2014 Elsevier Ltd.

Lin C.-W.C.,University of Sydney | Haas M.,University of Technology, Sydney | Maher C.G.,University of Sydney | MacHado L.A.C.,Federal University of Minas Gerais | Van Tulder M.W.,EMGO Institute for Health and Care Research
European Spine Journal | Year: 2011

Healthcare costs for low back pain (LBP) are increasing rapidly. Hence, it is important to provide treatments that are effective and cost-effective. The purpose of this systematic review was to investigate the cost-effectiveness of guideline-endorsed treatments for LBP. We searched nine clinical and economic electronic databases and the reference list of relevant systematic reviews and included studies for eligible studies. Economic evaluations conducted alongside randomised controlled trials investigating treatments for LBP endorsed by the guideline of the American College of Physicians and the American Pain Society were included. Two independent reviewers screened search results and extracted data. Data extracted included the type and perspective of the economic evaluation, the treatment comparators, and the relative costeffectiveness of the treatment comparators. Twenty-six studies were included. Most studies found that interdisciplinary rehabilitation, exercise, acupuncture, spinal manipulation or cognitive-behavioural therapy were costeffective in people with sub-acute or chronic LBP. Massage alone was unlikely to be cost-effective. There were inconsistent results on the cost-effectiveness of advice, insufficient evidence on spinal manipulation for people with acute LBP, and no evidence on the cost-effectiveness of medications, yoga or relaxation. This review found evidence supporting the cost-effectiveness of the guidelineendorsed treatments of interdisciplinary rehabilitation, exercise, acupuncture, spinal manipulation and cognitivebehavioural therapy for sub-acute or chronic LBP. There is little or inconsistent evidence for other treatments endorsed in the guideline. © The Author(s) 2011.

Pena S.D.J.,GENE Nucleo de Genetica Medica | Pena S.D.J.,Federal University of Minas Gerais | Coimbra R.L.M.,State University Londrina
Clinical Genetics | Year: 2015

We have recently performed exome analysis in a 7year boy who presented in infancy with an encephalopathy characterized by ataxia and myoclonic epilepsy. Parents were not consanguineous and there was no family history of the disease. Exome analysis did not show any pathogenic variants in genes known to be associated with seizures and/or ataxia in children, including all known human channelopathies. However, we have identified a mutation in KCNA2 that we believe to be responsible for the disease in our patient. This gene, which encodes a member of the potassium channel, voltage-gated, shaker-related subfamily, has not been previously described as a cause of disease in humans, but mutations of the orthologous gene in mice (Kcna2) are known to cause both ataxia and convulsions. The mutation is c.890C>A, leading to the amino acid substitution p.Arg297Gln, which involves the second of the critical arginines in the S4 voltage sensor. This mutation is characterized as pathogenic by five different prediction programs. RFLP analysis and Sanger sequencing confirmed the presence of the mutation in the patient, but not in his parents, characterizing it as de novo. We believe that this discovery characterizes a new channelopathy. © 2015 John Wiley & Sons A/S.

Pires D.E.V.,Federal University of Minas Gerais | De Melo-Minardi R.C.,Federal University of Minas Gerais | Da Silveira C.H.,Federal University of Itajubá | Campos F.F.,Federal University of Minas Gerais | Meira Jr. W.,Federal University of Minas Gerais
Bioinformatics | Year: 2013

Motivation: Receptor-ligand interactions are a central phenomenon in most biological systems. They are characterized by molecular recognition, a complex process mainly driven by physicochemical and structural properties of both receptor and ligand. Understanding and predicting these interactions are major steps towards protein ligand prediction, target identification, lead discovery and drug design. Results: We propose a novel graph-based-binding pocket signature called aCSM, which proved to be efficient and effective in handling large-scale protein ligand prediction tasks. We compare our results with those described in the literature and demonstrate that our algorithm overcomes the competitor's techniques. Finally, we predict novel ligands for proteins from Trypanosoma cruzi, the parasite responsible for Chagas disease, and validate them in silico via a docking protocol, showing the applicability of the method in suggesting ligands for pockets in a real-world scenario. © 2013 The Author. Published by Oxford University Press. All rights reserved.

Dresselhaus M.S.,Massachusetts Institute of Technology | Jorio A.,Federal University of Minas Gerais | Saito R.,Tohoku University
Annual Review of Condensed Matter Physics | Year: 2010

Recent advances in Raman spectroscopy for characterizing graphene, graphite, and carbon nanotubes are reviewed comparatively. We first discuss the first-order and the double-resonance (DR) second-order Raman scattering mechanisms in graphene, which give rise to the most prominent Raman features. Then, we review phonon-softening phenomena in Raman spectra as a function of gate voltage, which is known as the Kohn anomaly. Finally, we review exciton-specific phenomena in the resonance Raman spectra of single-wall carbon nanotubes (SWNTs). Raman spectroscopy of SWNTs has been especially useful for understanding many fundamental properties of all sp2 carbons, given SWNTs can be either semiconducting or metallic depending on their geometric structure, which is denoted by two integers (n,m). Copyright © 2010 by Annual Reviews. All rights reserved.

Schmidt T.M.,Federal University of Minas Gerais | Miwa R.H.,Federal University of Minas Gerais | Fazzio A.,University of Sao Paulo
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

Using first-principles calculations it is demonstrated that Co doped graphenelike ZnO sheet presents ferromagnetic coupling. The Co atoms are energetically barrierless absorbed in the Zn sites, suffering a Jahn-Teller distortion. The results reveal that the origin of the ferromagnetic coupling, different from the bulk 3D ZnO stacking, is mainly guided by a direct exchange interaction without any additional defect. This ferromagnetic coupling is due to the system topology, namely, it is a direct consequence of the two-dimensional character of the ZnO monolayer within graphenelike structure. Increasing the number of ZnO layers the ferromagnetic coupling vanishes. © 2010 The American Physical Society.

Moura E.C.,University of Sao Paulo | Malta D.C.,Secretariat of Health Surveillance | Malta D.C.,Federal University of Minas Gerais
Revista Brasileira de Epidemiologia | Year: 2011

Objective: To estimate the prevalence of alcohol consumption, identify the associated sociodemographic characteristics in 2006, and evaluate consumption trends from 2006 to 2009. Methods: We evaluated 54,369 adults living in the 26 Brazilian state capitals and the Federal District. Usual consumption was related to drinking at least one dose of alcohol in the past 30 days, and binge consumption meant 5 or more doses for men and 4 or more for women at least once in the past 30 days. Results: The usual consumers represented 38.1% of the studied population and the binge drinkers were 16.2%; both frequencies were higher among men than women. The variables associated to the usual and abusive alcohol consumption were age, marital status and insertion in the job market for both genders and skin color for women. Schooling was only associated for usual consumers. Conclusion: The trend of abusive alcohol consumption increased in both genders. Data endorse the need for national public policies aiming to prevent the abusive consumption of alcohol, mainly among the youngest.

Chemale F.,University of Brasilia | Dussin I.A.,University of Sao Paulo | Alkmim F.F.,DEGEO EM UFOP | Martins M.S.,Federal University of Minas Gerais | And 3 more authors.
Gondwana Research | Year: 2012

New U-Pb in situ zircon dating provides a new approach for the study of the Espinhaço Supergroup units exposed in the São Francisco Craton and Araçuaí Orogen. Located in Southern Espinhaço, Minas Gerais, the following two basins were formed in intraplate conditions: (i) the Lower Espinhaço Basin is marked by a volcano-sedimentary sequence with alluvial, fluvial and eolian deposits that were formed from 1.68. Ga to 1.80. Ga; (ii) the overlying sequence, called the Upper Espinhaço Basin, is a rift-sag basin that presents basal diamond-bearing continental deposits (the Sopa-Brumadinho Formation) with a younger zircon peak at 1192. Ma, which is the maximum age for deposition of the upper units. The obtained U-Pb detrital zircon data of the studied units show age groupings related to the orogenic cycles of Jequié (Neoarchean) and Transamazonian (Paleoproterozoic), which are associated with the stability period from 1.8. Ga to 0.91. Ga in the São Franscico Craton, and record deposition during at least the three basinal cycles. The Stenian-Tonian ages of the Upper Espinhaço Basin units (906. Ma to 1192. Ma) suggest a direct link with the evolution of the Rodinia Supercontinent and represent a marker for Mesoproterozoic to Early Neoproterozoic evolution in the São Franscico Craton and adjacent areas. © 2011 International Association for Gondwana Research.

Beams R.,University of Rochester | Cancado L.G.,Federal University of Minas Gerais | Novotny L.,University of Rochester
Nano Letters | Year: 2011

We developed a novel optical defocusing method for studying spatial coherence of photoexcited electrons and holes near edges of graphene. Our method is applied to measure the localization l D of the disorder-induced Raman D band (∼1350 cm -1) with a resolution of a few nanometers. Raman scattering experiments performed in a helium bath cryostat reveal that as temperature is decreased from 300 to 1.55 K, the length l D increases. We found that the localization of the D band varies as 1/T 1/2, giving strong evidence that l D scales with the coherence length of photoexcited electrons near graphene edges. © 2011 American Chemical Society.

Diniz B.S.,Federal University of Minas Gerais | Machado-Vieira R.,University of Sao Paulo | Machado-Vieira R.,National Institute of Mental Health | Forlenza O.V.,University of Sao Paulo
Neuropsychiatric Disease and Treatment | Year: 2013

In the last two decades, a growing body of evidence has shown that lithium has several neuroprotective effects. Several neurobiological mechanisms have been proposed to underlie these clinical effects. Evidence from preclinical studies suggests that neuroprotection induced by lithium is mainly related to its potent inhibition of the enzyme glycogen synthase kinase-3β (GSK-3β) and its downstream effects, ie, reduction of both tau protein phosphorylation and amyloid-β42 production. Additional neuroprotective effects include increased neurotrophic support, reduced proinflammatory status, and decreased oxidative stress. More recently, neuroimaging studies in humans have demonstrated that chronic use is associated with cortical thickening, higher volume of the hippocampus and amygdala, and neuronal viability in bipolar patients on lithium treatment. In line with this evidence, observational and case registry studies have shown that chronic lithium intake is associated with a reduced risk of Alzheimer's disease in subjects with bipolar disorder. Evidence from recent clinical trials in patients with mild cognitive impairment suggests that chronic lithium treatment at subtherapeutic doses can reduce cerebral spinal fluid phosphorylated tau protein. Overall, convergent lines of evidence point to the potential of lithium as an agent with disease modifying properties in Alzheimer's disease. However, additional long-term studies are necessary to confirm its efficacy and safety for these patients, particularly as chronic intake is necessary to achieve the best therapeutic results. © 2013 Diniz et al, publisher and licensee Dove Medical Press Ltd.

Dresselhaus M.S.,Massachusetts Institute of Technology | Jorio A.,Federal University of Minas Gerais | Hofmann M.,Massachusetts Institute of Technology | Dresselhaus G.,Massachusetts Institute of Technology | Saito R.,Tohoku University
Nano Letters | Year: 2010

Raman spectroscopy is here shown to provide a powerful tool to differentiate between two different sp2 carbon nanostructures (carbon nanotubes and graphene) which have many properties in common and others that differ. Emphasis is given to the richness of both carbon nanostructures as prototype examples of nanostructured materials. A glimpse toward future developments in this field is presented. © 2010 American Chemical Society.

Ribeiro A.L.P.,Federal University of Minas Gerais | Duncan B.B.,Federal University of Rio Grande do Sul | Brant L.C.C.,Federal University of Minas Gerais | Lotufo P.A.,University of Sao Paulo | And 2 more authors.
Circulation | Year: 2016

Brazil is a large country, with an evolving economy, but marked social inequalities. The population is formed by an admixture of native Brazilians, Europeans, and Africans; is predominantly urban; and faces rapid aging. Time trends related to health behaviors show a substantial reduction in smoking rates, but a rising prevalence of overweight and obesity, unhealthy eating habits, and insufficient physical activity. The high prevalence of hypertension and the increasing prevalence of diabetes mellitus are also causes for concern. Cardiovascular disease (CVD) has been the leading cause of mortality since the 1960s and has accounted for a substantial percentage of all hospitalizations. In 2011, CVD was responsible for 31% of all deaths, with ischemic heart disease (31%) and cerebrovascular diseases (30%) being the leading CVD causes. Despite an increase in the overall number of CVD deaths, the age-adjusted mortality rates for CVD declined 24% between 2000 and 2011. Health care delivered by Brazil's universal public health system, which focuses on primary prevention, has contributed to this achievement. However, the decline in age-adjusted mortality differs according to race, sex, and socioeconomic status with black individuals and lower-income populations sustaining the greatest impact of CVD, especially at younger ages. With one of the world's largest public health systems in terms of population coverage, Brazil has the means to implement actions to confront the high burden of CVD, focusing on health promotion and comprehensive care. Insufficient funding, low education levels, and social inequalities remain as the main barriers to be overcome. © 2016 American Heart Association, Inc.

Dresselhaus M.S.,Massachusetts Institute of Technology | Jorio A.,Federal University of Minas Gerais | Souza Filho A.G.,Federal University of Ceará | Saito R.,Tohoku University
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2010

This review discusses advances that have been made in the study of defect-induced double-resonance processes in nanographite, graphene and carbon nanotubes, mostly coming from combining Raman spectroscopic experiments with microscopy studies and from the development of new theoretical models. The disorder-induced peak frequencies and intensities are discussed, with particular emphasis given to how the disorder-induced features evolve with increasing amounts of disorder. We address here two systems, ionbombarded graphene and nanographite, where disorder is represented by point defects and boundaries, respectively. Raman spectroscopy is used to study the 'atomic structure' of the defect, making it possible, for example, to distinguish between zigzag and armchair edges, based on selection rules of phonon scattering. Finally, a different concept is discussed, involving the effect that defects have on the lineshape of Raman-allowed peaks, owing to local electron and phonon energy renormalization. Such effects can be observed by near-field optical measurements on the G′ feature for doped single-walled carbon nanotubes. © 2010 The Royal Society.

Galford G.L.,University of Vermont | Soares-Filho B.,Federal University of Minas Gerais | Cerri C.E.P.,University of Sao Paulo
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2013

The Brazilian Amazon frontier shows how remarkable leadership can work towards increased agricultural productivity and environmental sustainability without new greenhouse gas emissions. This is due to initiatives among various stakeholders, including national and state government and agents, farmers, consumers, funding agencies and non-governmental organizations. Change has come both from bottom-up and top-down actions of these stakeholders, providing leadership, financing and monitoring to foster environmental sustainability and agricultural growth. Goals to reduce greenhouse gas emissions from land-cover and land-use change in Brazil are being achieved through a multitiered approach that includes policies to reduce deforestation and initiatives for forest restoration, aswell as increased and diversified agricultural production, intensified ranching and innovations in agricultural management. Here, we address opportunities for the Brazilian Amazon in working towards low-carbon rural development and environmentally sustainable landscapes. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

Campos A.C.,Federal University of Minas Gerais | Moreira F.A.,Federal University of Minas Gerais | Gomes F.V.,University of Sao Paulo | del Bel E.A.,University of Sao Paulo | Guimaraes F.S.,University of Sao Paulo
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2012

Cannabidiol (CBD) is amajor phytocannabinoid present in the Cannabis sativa plant. It lacks the psychotomimetic and other psychotropic effects that the main plant compound D9-tetrahydrocannabinol (THC) being able, on the contrary, to antagonize these effects. This property, together with its safety profile, was an initial stimulus for the investigation of CBD pharmacological properties. It is now clear thatCBDhas therapeutic potential over a wide range of non-psychiatric and psychiatric disorders such as anxiety, depression and psychosis. Although the pharmacological effects of CBD in different biological systems have been extensively investigated by in vitro studies, the mechanisms responsible for its therapeutic potential are still not clear. Here, we review recent in vivo studies indicating that these mechanisms are not unitary but rather depend on the behavioural response being measured. Acute anxiolytic and antidepressant-like effects seem to rely mainly on facilitation of 5-HT1Amediated neurotransmission in key brain areas related to defensive responses, including the dorsal periaqueductal grey, bed nucleus of the stria terminalis and medial prefrontal cortex. Other effects, such as anti-compulsive, increased extinction and impaired reconsolidation of aversive memories, and facilitation of adult hippocampal neurogenesis could depend on potentiation of anandamide mediated neurotransmission. Finally, activation of TRPV1 channels may help us to explain the antipsychotic effect and the bell-shaped dose-response curves commonly observed withCBD. Considering its safety profile and wide range of therapeutic potential, however, further studies are needed to investigate the involvement of other possible mechanisms (e.g. inhibition of adenosine uptake, inverse agonism at CB2 receptor, CB1 receptor antagonism, GPR55 antagonism, PPARg receptors agonism, intracellular (Ca2+) increase, etc.), on CBD behavioural effects. © 2012 The Royal Society.

Cunha D.M.,Federal University of Minas Gerais | Tomal A.,University of Sao Paulo | Poletti M.E.,University of Sao Paulo
Physics in Medicine and Biology | Year: 2012

In this work, a Monte Carlo code was used to investigate the performance of different x-ray spectra in digital mammography, through a figure of merit (FOM), defined as , with CNR being the contrast-to-noise ratio in image and being the average glandular dose. The FOM was studied for breasts with different thicknesses t (2 cm ≤ t ≤ 8 cm) and glandular contents (25%, 50% and 75% glandularity). The anode/filter combinations evaluated were those traditionally employed in mammography (Mo/Mo, Mo/Rh, Rh/Rh), and a W anode combined with Al or K-edge filters (Zr, Mo, Rh, Pd, Ag, Cd, Sn), for tube potentials between 22 and 34 kVp. Results show that the W anode combined with K-edge filters provides higher values of FOM for all breast thicknesses investigated. Nevertheless, the most suitable filter and tube potential depend on the breast thickness, and for t ≥ 6 cm, they also depend on breast glandularity. Particularly for thick and dense breasts, a W anode combined with K-edge filters can greatly improve the digital technique, with the values of FOM up to 200% greater than that obtained with the anode/filter combinations and tube potentials traditionally employed in mammography. For breasts with t < 4 cm, a general good performance was obtained with the W anode combined with 60 m of the Mo filter at 2425 kVp, while 60 m of the Pd filter provided a general good performance at 2426 kVp for t = 4 cm, and at 2830 and 2931 kVp for t = 6 and 8 cm, respectively. © 2012 Institute of Physics and Engineering in Medicine.

Fogaca M.V.,University of Sao Paulo | Reis F.M.C.V.,University of Sao Paulo | Campos A.C.,University of Sao Paulo | Campos A.C.,Federal University of Minas Gerais | Guimaraes F.S.,University of Sao Paulo
European Neuropsychopharmacology | Year: 2014

The prelimbic medial prefrontal cortex (PL) is an important encephalic structure involved in the expression of emotional states. In a previous study, intra-PL injection of cannabidiol (CBD), a major non-psychotomimetic cannabinoid present in the Cannabis sativa plant, reduced the expression of fear conditioning response. Although its mechanism remains unclear, CBD can facilitate 5HT1A receptor-mediated neurotransmission when injected into several brain structures. This study was aimed at verifying if intra-PL CBD could also induce anxiolytic-like effect in a conceptually distinct animal model, the elevated plus maze (EPM). We also verified if CBD effects in the EPM and contextual fear conditioning test (CFC) depend on 5HT1A receptors and previous stressful experience. CBD induced opposite effects in the CFC and EPM, being anxiolytic and anxiogenic, respectively. Both responses were prevented by WAY100,635, a 5HT1A receptor antagonist. In animals that had been previously (24h) submitted to a stressful event (2h-restraint) CBD caused an anxiolytic, rather than anxiogenic, effect in the EPM. This anxiolytic response was abolished by previous injection of metyrapone, a glucocorticoid synthesis blocker. Moreover, restraint stress increased 5HT1A receptors expression in the dorsal raphe nucleus, an effect that was attenuated by injection of metyrapone before the restraint procedure. Taken together, these results suggest that CBD modulation of anxiety in the PL depend on 5HT1A-mediated neurotransmission and previous stressful experience. © 2013 Elsevier B.V. and ECNP.

Federal University of Pará, Federal University of Minas Gerais, Museu Paraense Emilio Goeldi, Instituto Evandro Chagas and Secretaria Executiva De Saude Publica Do Estado Do Para | Date: 2013-05-13

The present invention describes the obtaining process of the dichloromethane fraction and subfractions from Eleutherine plicata, popularly known as marupazinho, marupari, palmeirinha, coquinho, marupa, marupa, marup-piranga, and lirio-folha-de-palmeira. This invention comprises the obtaining process of pharmaceutical compositions that contain the dichloromethane fraction and/or naphthoquinone, as well as its use for malaria treatment. Extract and fractions were assayed and presented antiplasmodial activity, particularly against chloroquine-resistant Plasmodium falciparum (clone W2).

Federal University of Minas Gerais and Rice University | Date: 2014-02-26

In some embodiments, the present disclosure pertains to energy storage compositions that comprise a clay and an ionic liquid. In some embodiments, the clay is a bentonite clay and the ionic liquid is a room temperature ionic liquid (RTIL). In some embodiments, the clay and the ionic liquid are present in the energy storage compositions of the present disclosure in a weight ratio of 1:1. In some embodiments, the ionic liquid further comprises a lithium-containing salt that is dissolved in the ionic liquid. In some embodiments, the energy storage compositions of the present disclosure further comprise a thermoplastic polymer, such as polyurethane. In some embodiments, the thermoplastic polymer constitutes about 10% by weight of the energy storage composition. In some embodiments, the energy storage compositions of the present disclosure are associated with components of energy storage devices, such as electrodes and separators. In some embodiments, the energy storage compositions of the present disclosure are associated with an energy storage device, such as a battery or a capacitor.

Letellier C.,University of Rouen | Aguirre L.A.,Federal University of Minas Gerais
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2013

This Letter is devoted to the dynamical analysis of fractional-order systems, namely the Rössler and a modified Lorenz system. The work here described compares the dynamical regimes of such fractional-order systems to that of the corresponding standard systems. It turns out that most of the chaotic attractors are topologically equivalent to those found in the original integer-order systems, although in some particular (and apparently rare) cases unusual bifurcation patterns and attractors are found. © 2013 Elsevier B.V. All rights reserved.

Torres G.,Harvard - Smithsonian Center for Astrophysics | Vaz L.P.R.,Federal University of Minas Gerais | Lacy C.H.,University of Arkansas | Claret A.,Institute Astrofisica Of Andalucia
Astronomical Journal | Year: 2014

We report differential photometric observations and radial-velocity measurements of the detached, 1.69 day period, double-lined eclipsing binary AQ Ser. Accurate masses and radii for the components are determined to better than 1.8% and 1.1%, respectively, and are M 1 = 1.417 ± 0.021 M , M 2 = 1.346 ± 0.024 M , R 1 = 2.451 ± 0.027 R , and R 2 = 2.281 ± 0.014 R . The temperatures are 6340 ± 100 K (spectral type F6) and 6430 ± 100 K (F5), respectively. Both stars are considerably evolved, such that predictions from stellar evolution theory are particularly sensitive to the degree of extra mixing above the convective core (overshoot). The component masses are different enough to exclude a location in the H-R diagram past the point of central hydrogen exhaustion, which implies the need for extra mixing. Moreover, we find that current main-sequence models are unable to match the observed properties at a single age even when allowing the unknown metallicity, mixing length parameter, and convective overshooting parameter to vary freely and independently for the two components. The age of the more massive star appears systematically younger. AQ Ser and other similarly evolved eclipsing binaries showing the same discrepancy highlight an outstanding and largely overlooked problem with the description of overshooting in current stellar theory. © 2014. The American Astronomical Society. All rights reserved.

Mozelli L.A.,Federal University of Säo João del Rei | Souza F.O.,Federal University of Säo João del Rei | Palhares R.M.,Federal University of Minas Gerais
International Journal of Robust and Nonlinear Control | Year: 2011

This paper proposes a new Lyapunov-Krasovskii functional to cope with stability analysis and control design for time-delay nonlinear systems modeled in the Takagi-Sugeno (TS) fuzzy form. The delay-dependent conditions are formulated as linear matrix inequalities (LMIs), solvable through several numerical tools. By using the Gu's discretization technique and by employing an appropriated fuzzy functional, less conservative conditions are obtained. Numerical results illustrate the efficiency of the proposed methods. © 2010 John Wiley & Sons, Ltd.

Luiz De Paula E.,Federal University of Minas Gerais | Mano V.,Federal University of Säo João del Rei | Pereira F.V.,Federal University of Minas Gerais
Polymer Degradation and Stability | Year: 2011

This paper reports the preparation of bionanocomposites based on poly(d,l-lactide) and cellulose nanowhiskers (PDLLA/CNWs) and studies the influence of the CNWs on the hydrolytic degradation behavior of the polylactide. The hydrolytic degradation process was studied in a phosphate buffer medium through the sample weight loss and also by FTIR, DSC and TGA measurements. The presence of CNWs induced a strong delay in the hydrolytic degradation of the PDLLA, even when the concentration of the nanofillers was only 1%. This effect was related to the physical barrier created by the highly crystalline CNWs that inhibited water absorption and hence retarded the hydrolytic degradation of the bionanocomposites. In addition, the incorporation of cellulose nanocrystals in the PDLLA also made the biopolymer more thermally stable, increasing the initial temperature of mass loss even after the degradation in phosphate medium. The results presented here show the possibility of controlling the biodegradability and prolonging the service life of a polylactide through the incorporation of a small quantity of nanofillers obtained from renewable materials. © 2011 Elsevier Ltd. All rights reserved.

Acuna M.J.,Pontifical Catholic University of Chile | Pessina P.,University Pompeu Fabra | Olguin H.,Pontifical Catholic University of Chile | Cabrera D.,Pontifical Catholic University of Chile | And 6 more authors.
Human Molecular Genetics | Year: 2014

Duchenne muscular dystrophy (DMD) is the most common inherited neuromuscular disease, and is characterized by the lack of dystrophin, muscle wasting, increased transforming growth factor (TGF)-β Smad-dependent signalling and fibrosis. Acting via the Mas receptor, angiotensin-1-7 [Ang-(1-7)], is part of the renin-angiotensin system, with the opposite effect to that of angiotensin II. We hypothesized that the Ang-(1-7)/Mas receptor axis might protect chronically damaged tissues as in skeletal muscle of the DMD mouse model mdx. Infusion or oral administration of Ang-(1-7) in mdx mice normalized skeletal muscle architecture, decreased local fibrosis and improved muscle function in vitro and in vivo. These positive effects were mediated by the inhibition of TGF-β Smad signalling, which in turn led to reduction of the pro-fibrotic microRNA miR-21 concomitant with a reduction in the number of TCF4 expressing fibroblasts. Mdx mice infused with Mas antagonist (A-779) and mdx deficient for the Mas receptor showed highly deteriorated muscular architecture, increased fibrosis and TGF-β signalling with diminished muscle strength. These results suggest that this novel compound Ang-(1-7) might be used to improve quality of life and delay death in individuals with DMD and this drug should be investigated in further pre-clinical trials. © The Author 2013. Published by Oxford University Press. All rights reserved.

Barbosa C.F.,Brazilian Center for Research and Development in Telecommunications | Paulino J.O.S.,Federal University of Minas Gerais | Boaventura W.D.C.,Federal University of Minas Gerais
IEEE Transactions on Electromagnetic Compatibility | Year: 2013

This paper presents a time-domain method for the calculation of the horizontal electric field at the earth surface due to lightning, when the earth structure is made up of two parallel horizontal layers of finitely conducting earth. The method is based on the assessment of the electric field at the surface considering the earth as homogeneous and with the electrical parameters of the first layer. The contribution of the second layer is considered by computing the waves reflected from the boundary between the layers, after they have propagated through the first layer. The paper also shows that the displacement currents could be neglected during the wave reflection, which leads to a simple expression for the reflection coefficient. The results from the method presented in this paper agree with results calculated using a known frequency-domain expression. © 1964-2012 IEEE.

Gontijo-Amaral C.,Federal University of Minas Gerais | Guimaraes E.V.,Federal University of Minas Gerais | Camargos P.,Federal University of Minas Gerais | Camargos P.,Federal University of Säo João del Rei
American Journal of Clinical Nutrition | Year: 2012

Background: Magnesium is one of the most important minerals in the body. Although some studies reported that patients with cystic fibrosis (CF) lack magnesium, no international study has assessed the importance of oral magnesium supplementation in CF patients. Objective: We prospectively investigated the long-term effect of oral magnesium supplementation on respiratory muscle strength by using manuvacuometry and the Shwachman-Kulczycki (SK) score among children and adolescents with CF. Design: This double-blind, randomized, placebo-controlled crossover study included 44 CF patients (aged 7-19 y; 20 males) who were randomly assigned to receive magnesium (n = 22; 300 mg/d) or placebo (n = 22) for 8 wk with a 4-wk washout period between trials. All patients were undergoing conventional treatment of CF. The experimental protocol included clinical evaluation, assessment of urinary concentration of magnesium, and manuvacuometric measurements [maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP)]. MIP was the primary outcome. Results: Urinary magnesium increased after the administration of magnesium (change: 36.38 mg/d after magnesium compared with 0.72 mg/d after placebo; P , 0.001). Moreover, MIP and MEP significantly improved only after magnesium administration (change in MIP: 11% predicted after magnesium compared with 0.5% predicted after placebo; change in MEP: 11.9% predicted after magnesium compared with 0.8% predicted after placebo; P < 0.001 for both). Magnesium administration had a beneficial effect on clinical variables assessed by the SK score (change: 4.48 points after magnesium compared with -1.30 points after placebo; P < 0.001). Conclusion: Oral magnesium supplementation helped improve both the SK score and respiratory muscle strength in pediatric patients with CF. This trial was registered at as CAAEO 559.0.203.000-07. © 2012 American Society for Nutrition.

Silva T.H.,University of Birmingham | Silva T.H.,French Institute for Research in Computer Science and Automation | Vaz De Melo P.O.S.,Federal University of Minas Gerais | Almeida J.M.,Federal University of Minas Gerais | Loureiro A.A.F.,Federal University of Minas Gerais
IEEE Wireless Communications | Year: 2014

The ubiquitous availability of computing technology such as smartphones, tablets, and other easily portable devices, and the worldwide adoption of social networking sites make it increasingly possible for one to be connected and continuously contribute to this massively distributed information publishing process. In this scenario, people act as social sensors, voluntarily providing data that capture their daily life experiences, and offering diverse observations on both the physical world (e.g., location) and the online world (e.g., events). This large amount of social data can provide new forms of valuable information that are currently not available on this scale via any traditional data collection methods, and can be used to enhance decision making processes. In this article, we argue that location-based social media systems, such as Instagram and Foursquare, can act as valuable sources of large-scale sensing, providing access to important characteristics of urban social behavior much more quickly than traditional methods. We also discuss different applications and techniques that can exploit the data shared in these systems to enable large-scale and nearreal- time analyses and visualization of different aspects of city dynamics. © 2002-2012 IEEE.

Bader M.,Max Delbrück Center for Molecular Medicine | Bader M.,Charité - Medical University of Berlin | Bader M.,University of Lübeck | Bader M.,Federal University of Minas Gerais | And 4 more authors.
Pharmacological Reviews | Year: 2014

TheMas-relatedGprotein–coupled receptors (Mrgprs or Mas-related genes) comprise a subfamily of receptors named after the first discovered member, Mas. For most Mrgprs, pruriception seems to be the major function based on the following observations: 1) they are relatively promiscuous in their ligand specificity with best affinities for itch-inducing substances; 2) they are expressed in sensory neurons and mast cells in the skin, the main cellular components of pruriception; and 3) they appear in evolution first in tetrapods, which have arms and legs necessary for scratching to remove parasites or other noxious substances from the skin before they create harm. Because parasites coevolved with hosts, each species faced different parasitic challenges, which may explain another striking observation, the multiple independent duplication and expansion events of Mrgpr genes in different species as a consequence of parallel adaptive evolution. Their predominant expression in dorsal root ganglia anticipates additional functions of Mrgprs in nociception. Some Mrgprs have endogenous ligands, such as b-alanine, alamandine, adenine, RF-amide peptides, or salusin-b. However, because the functions of these agonists are still elusive, the physiologic role of the respective Mrgprs needs to be clarified. The best studied Mrgpr is Mas itself. It was shown to be a receptor for angiotensin-1–7 and to exert mainly protective actions in cardiovascular and metabolic diseases. This review summarizes the current knowledge about Mrgprs, their evolution, their ligands, their possible physiologic functions, and their therapeutic potential. © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

Oliveira M.D.,Embrapa Pantanal | Hamilton S.K.,Michigan State University | Jacobi C.M.,Federal University of Minas Gerais
Aquatic Invasions | Year: 2010

The bivalve Limnoperna fortunei (Dunker, 1857), also called golden mussel, is native to Asia but becoming dispersed around the world. The golden mussel resembles the invasive dreissenid bivalves in many respects, and although much less studied it evidently has broader environmental tolerances. The golden mussel was introduced into the La Plata River estuary (South America) and quickly expanded upstream to the north, into the tropical Paraguay River reaching a large floodplain area in Brazil known as the Pantanal wetland. The golden mussel tolerates environmental conditions in the Pantanal that would be inhospitable for most bivalves, but mussel mortality has been observed during the most extreme oxygen depletion events. Based on knowledge about the limiting factors for the golden mussel in the Pantanal wetland, its potential distribution was predicted for the remainder of the Paraguay River basin where the species is not present, as well as in other river systems throughout Brazil. Forecasts of potential distribution in Brazilian river systems were based on physicochemical limitations for shell calcification, and specifically on lower thresholds of dissolved calcium concentrations and the calcium carbonate (calcite) index of saturation, which may be a better indicator of calcification potential in low-calcium waters than calcium concentration alone. In addition to examining spatial patterns in calcium and calcification potential, these and other limnological and climate variables were used in ecological niche modeling using GARP and Maxent algorithms. Forecasts of potential distributions in three major North American river systems (Mississippi, Colorado, and Rio Grande) were based mainly on water temperature because calcium availability and calcification evidently would not be limiting to golden mussel establishment in those waters. Due to the greater tolerance of the golden mussel to conditions known to limit other bivalves, as well as its greater ability for shell calcification in low-calcium water, the golden mussel could potentially become broadly distributed throughout Brazil. According to its thermal tolerance L. fortunei could become established in the Mississippi, Colorado and Rio Grande drainage systems, although the northern Mississippi River system including the Missouri River may be too cool in the winter to support the golden mussel. © 2010 The Author(s).

Ribeiro F.M.,Federal University of Minas Gerais | DeVries R.A.,University of Western Ontario | Hamilton A.,University of Western Ontario | Guimaraes I.M.,Federal University of Minas Gerais | And 3 more authors.
Human Molecular Genetics | Year: 2014

Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder caused by a polyglutamine expansion in the amino-terminal region of the huntingtin protein, which promotes progressive neuronal cell loss, neurological symptoms and death. In the present study, we show that blockade ofmGluR5 with MTEP promotes increased locomotor activity in both control (HdhQ20/Q20) and mutant HD (HdhQ111/Q111) mice. Although acute injection of MTEP increases locomotor activity in both control and mutant HD mice, locomotor activity is increased in only control mice, not mutant HD mice, following the genetic deletion of mGluR5. Interestingly, treatment of mGluR5 knockout mice with either D1 or D2 dopamine antagonists eliminates the increased locomotor activity of mGluR5 knockout mice. Amphetamine treatment increases locomotor activity in control mice, but not mGluR5 null mutant HD mice. However, the loss ofmGluR5 expression improves rotarod performance anddecreases thenumber of huntingtinintranuclear inclusions in mutantHDmice. These adaptationsmay be due to mutant huntingtin-dependent alterations in gene expression, as microarray studies have identified several genes that are altered in mutant, but not wild-type HD mice lacking mGluR5 expression. qPCR experiments confirm that the mRNA transcript levels of dynein heavy chain, dynactin 3 and dynein light chain-6 are altered following the genetic deletion of mGluR5 in mutant HD mice, as compared with wild-type mutant HD mice. Thus, our data suggest that mutant huntingtin protein and mGluR5 exhibit a functional interaction that may be important for HD-mediated alterations in locomotor behavior and the development of intranuclear inclusions. © The Author 2013. Published by Oxford University Press. All rights reserved.

Nogueira-Machado J.A.,Institute Ensino E Pesquisa Da Santa Casa Of Belo Horizonte | Volpe C.M.D.O.,Institute Ensino E Pesquisa Da Santa Casa Of Belo Horizonte | Veloso C.A.,Institute Ensino E Pesquisa Da Santa Casa Of Belo Horizonte | Chaves M.M.,Federal University of Minas Gerais
Expert Opinion on Therapeutic Targets | Year: 2011

Introduction: Despite advances in treatment of diabetes mellitus, its prevalence continues to rise globally. Medications available are unable to control the vascular complications. Proposals for new therapeutic targets must take into account the hyperglycemia-induced signaling pathways that give rise to the inflammatory profile of the disease. Areas covered: How high-mobility-group box-1 (HMGB1) protein, acting as an activator of Toll-like receptors (TLR) and receptors for advanced glycation end products (RAGE), creates a functional tripod that contributes to increased production of pro-inflammatory mediators, and sustains the chronic inflammatory state associated with diabetes. The interaction of TLR2 and TRL4 with host-derived ligands, which links diabetic complications with the innate immune response, and the activation of RAGE, which induces a cascade of metabolic responses, leading to the production and secretion of pro-inflammatory cytokines. Expert opinion: Considering the involvement of the innate immune system, in association with the role of HMGB1 as an activator of TLR and RAGE, diabetes should be considered and treated as a metabolic and immunological disease, triggered by hyperglycemia. HMGB1 plays a central role in mediating injury and inflammation, and interactions involving HMGB1TLRRAGE constitute a tripod that trigger NF-κB activation. Blockade or downregulation of HMGB1, and/or control of the inflammatory tripod, represent a promising therapeutic approach for the treatment of diabetes. © 2011 Informa UK, Ltd.

Nunes M.C.P.,Federal University of Minas Gerais | Dones W.,Ryder Memorial Hospital | Morillo C.A.,Hamilton Health Sciences | Encina J.J.,Hospital Universitario Japones | Ribeiro A.L.,Federal University of Minas Gerais
Journal of the American College of Cardiology | Year: 2013

Chagas disease, caused by the parasite Trypanosoma cruzi, is a serious health problem in Latin America and is an emerging disease in non-endemic countries. In recent decades, the epidemiological profile of the disease has changed due to new patterns of immigration and successful control in its transmission, leading to the urbanization and globalization of the disease. Dilated cardiomyopathy is the most important and severe manifestation of human chronic Chagas disease and is characterized by heart failure, ventricular arrhythmias, heart blocks, thromboembolic phenomena, and sudden death. This article will present an overview of the clinical and epidemiological aspects of Chagas disease. It will focus on several clinical aspects of the disease, such as chronic Chagas disease without detectable cardiac pathology, as well as dysautonomia, some specific features, and the principles of treatment of chronic cardiomyopathy. © 2013 by the American College of Cardiology Foundation Published by Elsevier Inc.

Brandao F.G.S.L.,Federal University of Minas Gerais | Eisert J.,University of Potsdam | Eisert J.,Free University of Berlin | Horodecki M.,University of Gdansk | Yang D.,China Jiliang University
Physical Review Letters | Year: 2011

Entangled inputs can enhance the capacity of quantum channels, this being one of the consequences of the celebrated result showing the nonadditivity of several quantities relevant for quantum information science. In this work, we answer the converse question (whether entangled inputs can ever render noisy quantum channels to have maximum capacity) to the negative: No sophisticated entangled input of any quantum channel can ever enhance the capacity to the maximum possible value, a result that holds true for all channels both for the classical as well as the quantum capacity. This result can hence be seen as a bound as to how "nonadditive quantum information can be." As a main result, we find first practical and remarkably simple computable single-shot bounds to capacities, related to entanglement measures. As examples, we discuss the qubit amplitude damping and identify the first meaningful bound for its classical capacity. © 2011 American Physical Society.

Souza K.C.,Federal University of Minas Gerais | Mohallem N.D.S.,Federal University of Minas Gerais | Sousa E.M.B.,Brazilian National Nuclear Energy Commission
Journal of Sol-Gel Science and Technology | Year: 2010

The synthesis of nanostructured magnetic materials has been intensively researched because of their large field of applications as magnetic carriers in drug targeting, hyperthermia in tumor treatment, among others. Much effort has been invested in magnetic nanoparticles for bioapplications. However, as these nanoparticles present high specific surface area, unprotected nanoparticles can easily form aggregates and react with oxygen in the air. They can also rapidly biodegrade when directly exposed to biological systems. In this context, we have explored the possibility of synthesizing a mesoporous SiO2-Fe 3O4 nanocomposite and its AC magnetic-field-induced heating properties. The magnetite nanocomposite was obtained by impregnation of an iron precursor into a silica framework. The proposed method involves the preparation of an iron oxide precursor in ethanol and the subsequent impregnation of SBA-15 mesoporous hexagonal silica. Iron oxide was formed inside the porous structure, thus producing the magnetic device. The nanocomposite was characterized by X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), N2 adsorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Measurements of AC magnetic-field- induced heating properties of the obtained nanocomposite, both of the solid form and in aqueous solution, under different applied magnetic fields showed that it is suitable as a hyperthermia agent for biological applications. © Springer Science+Business Media, LLC 2009.

Souza F.D.O.,Federal University of Säo João del Rei | Palhares R.M.,Federal University of Minas Gerais
Neurocomputing | Year: 2010

This paper presents a new linear matrix inequality (LMI) stability criterion for continuous-time artificial neural networks (ANN) with interval time-varying delay. The varying-time delay is taken as composition of a nominal positive value subject to a time-varying perturbation. The methodology is based on Gu's discretization technique and a strategy that decouples the system matrices from the Lyapunov functional matrices. Two numerical examples are performed to support the theoretical predictions. © 2010 Elsevier B.V.

Murca T.M.,Federal University of Minas Gerais | Almeida T.C.S.,Federal University of Minas Gerais | Raizada M.K.,University of Florida | Ferreira A.J.,Federal University of Minas Gerais
Experimental Physiology | Year: 2012

In this study, we evaluated whether the activation of endogenous angiotensin-converting enzyme 2 (ACE2) would improve the cardiovascular autonomic dysfunction of diabetic rats. Ten days after induction of type 1 diabetes (streptozotocin, 50 mg kg-1i.v.), the rats were treated orally with 1-[(2-dimethylamino)ethylamino]-4-(hydroxymethyl)-7-[(4-methylphenyl) sulfonyl oxy]-9H-xanthene-9-one (XNT), a newly discovered ACE2 activator (1 mg kg-1 day-1), or saline (equivalent volume) for 30 days. Autonomic cardiovascular parameters were evaluated in conscious animals, and an isolated heart preparation was used to analyse cardiac function. Diabetes induced a significant decrease in the baroreflex bradycardia sensitivity, as well as in the chemoreflex chronotropic response and parasympathetic tone. The XNT treatment improved these parameters by ∼76% [0.82 ± 0.09 versus 1.44 ± 0.17 Ratio between changes in pulse interval and changes in mean arterial pressure (ΔPI/ΔmmHg)], ∼85% (-57 ± 9 versus-105 ± 10 beats min-1) and ∼205% (22 ± 2 versus 66 ± 12 beats min-1), respectively. Also, XNT administration enhanced the bradycardia induced by the chemoreflex activation by ∼74% in non-diabetic animals (-98 ± 16 versus-170 ± 9 Δbeats min-1). No significant changes were observed in the mean arterial pressure, baroreflex tachycardia sensitivity, chemoreflex pressor response and sympathetic tone among any of the groups. Furthermore, chronic XNT treatment ameliorated the cardiac function of diabetic animals. However, the coronary vasoconstriction observed in diabetic rats was unchanged by ACE2 activation. These findings indicate that XNT protects against the autonomic and cardiac dysfunction induced by diabetes. Thus, our results provide evidence for the viability and effectiveness of oral administration of an ACE2 activator for the treatment of the cardiovascular autonomic dysfunction caused by diabetes. © 2012 The Authors. Experimental Physiology © 2012 The Physiological Society.

Paulino J.O.S.,Federal University of Minas Gerais | Barbosa C.F.,Brazilian Center for Research and Development in Telecommunications | Do Couto Boaventura W.,Federal University of Minas Gerais
IEEE Transactions on Electromagnetic Compatibility | Year: 2014

This paper analyzes the effect of a two-layer ground on the current induced in the shield of a buried cable due to lightning flashes. Each layer is assumed to be horizontal, homogeneous, isotropic, and having its own electrical parameters: conductivity, permittivity, and permeability. The inducing horizontal electric field is calculated for the incident azimuthal magnetic field and it is used for the calculation of the induced current. The calculation method is validated by comparing its results with results published in the literature. The currents induced in the shield of a buried cable by typical return-stroke current waveforms are calculated. The results show that the induced current waveform is initially determined by the first layer but, for later times, it follows the current that would be induced if the ground was homogeneous and had the characteristics of the second layer. © 2013 IEEE.

De Oliveira M.M.,Federal University of Säo João del Rei | Dickman R.,Federal University of Minas Gerais
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014

We study the two-species symbiotic contact process, recently proposed by de Oliveira, Santos, and Dickman [Phys. Rev. E 86, 011121 (2012)PLEEE81539-375510.1103/PhysRevE.86.011121]. In this model, each site of a lattice may be vacant or host single individuals of species A and/or B. Individuals at sites with both species present interact in a symbiotic manner, having a reduced death rate μ<1. Otherwise, the dynamics follows the rules of the basic contact process, with individuals reproducing to vacant neighbor sites at rate λ and dying at a rate of unity. We determine the full phase diagram in the λ-μ plane in one and two dimensions by means of exact numerical quasistationary distributions, cluster approximations, and Monte Carlo simulations. We also study the effects of asymmetric creation rates and diffusion of individuals. In two dimensions, for sufficiently strong symbiosis (i.e., small μ), the absorbing-state phase transition becomes discontinuous for diffusion rates D within a certain range. We report preliminary results on the critical surface and tricritical line in the λ-μ-D space. Our results raise the possibility that strongly symbiotic associations of mobile species may be vulnerable to sudden extinction under increasingly adverse conditions. © 2014 American Physical Society.

Avila A.F.,Federal University of Minas Gerais | Eduardo A.C.,Federal University of Säo João del Rei | Neto A.S.,Federal University of Minas Gerais
Computers and Structures | Year: 2011

This paper deals with the molecular mechanics simulations of graphene nanostructures and their vibration behavior for potential applications on nano-electronics and nanocomposites. The fundamental frequencies for CNTs range from 10 to 250 GHz and 100 to 1000 GHz for the cantilevered and bridged conditions, respectively. As the ratio L/d increases the fundamental frequency decreases, as expected. A decrease on fundamental frequencies with the bending waviness was noticed for all conditions. The mode shape for bent carbon nanotubes seems to be a superposition of the vibration mode and the bending mode for the zigzag configuration. Multi-layered graphene nanosheets were also investigated. The fundamental frequencies ranged from 50 to 150 GHz, with an odd/even shape mode switch. © 2010 Elsevier Ltd. All rights reserved.

Nair D.K.,Indian Institute of Technology Bombay | Menna-Barreto R.F.S.,Oswaldo Cruz Institute | Da Silva Junior E.N.,Federal University of Minas Gerais | Mobin S.M.,Indian Institute of Technology Bombay | Namboothiri I.N.N.,Indian Institute of Technology Bombay
Chemical Communications | Year: 2014

Cascade reactions of 1,3-dicarbonyls with Morita-Baylis-Hillman acetates of nitroalkenes using a quinine derived chiral squaramide organocatalyst led to the formation of pyranones and pyranonaphthoquinones in good to excellent yields and high diastereo- and enantioselectivities. Representative examples of the reaction scale-up with a much lower catalyst loading without an appreciable loss of selectivities and synthetic transformations of the products are also reported here. The compounds described herein for the first time were evaluated against the infective bloodstream form of Trypanosoma cruzi, the etiological agent of Chagas disease, since the structures are related to bioactive α-lapachones. © the Partner Organisations 2014.

Mozelli L.A.,Federal University of Säo João del Rei | Palhares R.M.,Federal University of Minas Gerais | Mendes E.M.A.M.,Federal University of Minas Gerais
IET Control Theory and Applications | Year: 2010

This study is divided in three parts. In the first part, the equivalence of recent strategies for stability analysis, namely the null term, the Finsler's lemma and the descriptor approach is demonstrated in the context of fuzzy Lyapunov functions (FLFs). In the sequel, this study presents new insights concerning the extension of typical right-hand side relaxations and the use of the FLF structure. Finally, an alternative less conservative non-parallel distributed compensation control design is proposed that generalises previous approaches. © 2010 The Institution of Engineering and Technology.

Baccarini L.M.R.,Federal University of Säo João del Rei | de Menezes B.R.,Federal University of Minas Gerais | Caminhas W.M.,Federal University of Minas Gerais
Mechanical Systems and Signal Processing | Year: 2010

The study of induction motor behavior under not normal conditions and the ability to detect and predict these conditions has been an area of increasing interest. Early detection and diagnosis of incipient faults are desirable for interactive evaluation over the running condition, product quality guarantee, and improved operational efficiency of induction motors. The main difficulty in this task is the lack of accurate analytical models to describe a faulty motor. This paper proposes a dynamic model to analyze electrical and mechanical faults in induction machines and includes net asymmetries and load conditions. The model permits to analyze the interactions between different faults in order to detect possible false alarms. Simulations and experimental results were performed to confirm the validity of the model. © 2009 Elsevier Ltd. All rights reserved.

Rocha F.L.,Institute Previdencia Dos Servidores Do Estado Of Minas Gerais Ipsemg | Fuzikawa C.,Federal University of Minas Gerais | Riera R.,Federal University of São Paulo | Hara C.,Faculdade da Saude e Ecologia Humana
Journal of Clinical Psychopharmacology | Year: 2012

The objective was to perform a systematic review and meta-analysis of studies that assessed the effect of the combination of antidepressants from the beginning of the treatment of major depressive disorder. Studies were retrieved from PubMed (1966 to August 2010), Cochrane Library (August 2010), Embase (1980 to August 2010), PsycINFO (1980 to August 2010), Lilacs (1982 to August 2010), clinical trials registry, thesis database (, and secondary references. All randomized controlled trials that compared a combination of antidepressants with a single antidepressant from the beginning of the treatment of major depressive disorder in adults were included. Data analysis was performed using the Review Manager 5.0. Of 3492 studies retrieved, five satisfied the inclusion criteria. In one study, only data about dropouts were included. Antidepressant combination was shown to be better than a single antidepressant considering remission (relative risk [RR], 2.71; 95% confidence interval [CI], 1.69-4.35) and response (RR, 1.55; 95% CI, 1.21-1.97). Mirtazapine plus selective serotonin reuptake inhibitor (SSRI) was superior to an isolated SSRI for remission (RR, 1.88; 95% CI, 1.06-3.33). Tricyclic antidepressant plus SSRI was superior to SSRI for remission and response (RR, 8.58; 95% CI, 1.70-43.32 and RR, 1.78; 95% CI, 1.07-2.93, respectively). There was no difference between combined and monotherapy groups in dropouts owing to adverse effects. The results suggest that antidepressant combination is more efficient than a single antidepressant without a significant decrease in tolerability. However, the small number of clinical trials and methodological problems precludes definitive conclusions. Copyright © 2012 by Lippincott Williams & Wilkins.

Santos R.A.S.,Federal University of Minas Gerais | Ferreira A.J.,Federal University of Minas Gerais | Verano-Braga T.,Federal University of Minas Gerais | Verano-Braga T.,University of Southern Denmark | Bader M.,Max Delbrück Center for Molecular Medicine
Journal of Endocrinology | Year: 2013

Angiotensin (Ang)-(1-7) is now recognized as a biologically active component of the renin- angiotensin system (RAS). Ang-(1-7) appears to play a central role in the RAS because it exerts a vast array of actions, many of them opposite to those attributed to the main effector peptide of the RAS, Ang II. The discovery of the Ang-converting enzyme (ACE) homolog ACE2 brought to light an important metabolic pathway responsible for Ang-(1-7) synthesis. This enzyme can form Ang-(1-7) from Ang II or less efficiently through hydrolysis of Ang I to Ang-(1-9) with subsequent Ang-(1-7) formation by ACE. In addition, it is nowwell established that the G protein-coupled receptor Mas is a functional binding site for Ang-(1-7). Thus, the axis formed by ACE2/Ang-(1-7)/Mas appears to represent an endogenous counterregulatory pathway within the RAS, the actions of which are in opposition to the vasoconstrictor/ proliferative arm of the RAS consisting of ACE, Ang II, andAT1 receptor. In this brief review, we will discuss recent findings related to the biological role of the ACE2/Ang-(1-7)/Mas arm in the cardiovascular and renal systems, as well as in metabolism. In addition, we will highlight the potential interactions of Ang-(1-7) and Mas with AT1 and AT2 receptors. © 2013 Society for Endocrinology.

De Oliveira M.M.,Federal University of Säo João del Rei | Dickman R.,Federal University of Minas Gerais
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2011

We study a contact process with creation at first- and second-neighbor sites and inhibition at first neighbors, in the form of an annihilation rate that increases with the number of occupied first neighbors. Mean-field theory predicts three phases: inactive (absorbing), active symmetric, and active asymmetric, the latter exhibiting distinct sublattice densities on a bipartite lattice. These phases are separated by continuous transitions; the phase diagram is re-entrant. Monte Carlo simulations in two dimensions verify these predictions qualitatively, except for a first-neighbor creation rate of zero. (In the latter case one of the phase transitions is discontinuous.) Our numerical results confirm that the symmetric-asymmetric transition belongs to the Ising universality class, and that the active-absorbing transition belongs to the directed percolation class, as expected from symmetry considerations. © 2011 American Physical Society.

Oliveira S.F.,Federal University of Minas Gerais | Bisker G.,Massachusetts Institute of Technology | Bakh N.A.,Massachusetts Institute of Technology | Gibbs S.L.,University of Florida | And 2 more authors.
Carbon | Year: 2015

Since the discovery of low-dimensional carbon allotropes, there is increasing interest in using carbon nanomaterials for biomedical applications. Carbon nanomaterials have been utilized in the biomedical field for bioimaging, chemical sensing, targeting, delivery, therapeutics, catalysis, and energy harvesting. Each application requires tailored surface functionalization in order to take advantage of a desired property of the nanoparticles. Herein, we review the surface immobilization of bio-molecules, including proteins, peptides, and enzymes, and present the recent advances in synthesis and applications of these conjugates. The carbon scaffold and the biological moiety form a complex interface which presents a challenge for achieving efficient and robust binding while preserving biological activity. Moreover, some applications require the utilization of the protein-nanocarbon system in a complex environment that may hinder its performance or activity. We analyze different strategies to overcome these challenges when using carbon nanomaterials as protein carriers, explore various immobilization techniques along with characterization methods, and present recent demonstrations of employing these systems for biomedical applications. Finally, we consider the challenges and future directions of this field. © 2015 Elsevier Ltd. All rights reserved.

Garcia Batista C.,Federal University of Säo João del Rei | Goncalves Do Rego C.,Federal University of Minas Gerais
IEEE Antennas and Wireless Propagation Letters | Year: 2013

This letter introduces a finite-difference time-domain (FDTD) propagation method employing a moving window algorithm and a new formulation based on three features: high-order and unconditionally stable method with a material independent perfect matched layer (PML) formulation. The achievement is an efficient and accurate time-domain (multiband) propagation method. The formulation is validated through an analytic problem. Finally, we analyze two measurement campaigns with HF and VHF signals to evaluate the performance of method. © 2002-2011 IEEE.

Pereira E.,Federal University of Minas Gerais | Falcao R.,Federal University of Säo João del Rei | Lemos H.C.F.,Federal University of Säo João del Rei
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

We analytically compute the thermal conductivity of anharmonic crystals with self-consistent stochastic reservoirs. We develop an integral representation for the heat current, assume the approximation of discrete times, and in a perturbative analysis that is rigorously supported by a convergent cluster expansion compute the thermal conductivity for a chain with quartic anharmonic on-site potential. In the high anharmonicity regime, the result for the dependence of the conductivity on temperature is the same as for the system without inner reservoirs. The presented formalism is quite general and is also valid for inhomogeneous systems in any space dimension. © 2013 American Physical Society.

Cimini Jr. C.A.,Federal University of Minas Gerais | Fonseca B.Q.A.,Energy Company of Minas Gerais CEMIG
International Journal of Electrical Power and Energy Systems | Year: 2013

The Brazilian transmission system is characterized by installations that average 20 years of operation. Competitiveness of the energy sector, lack of resources for new investments and the aging of the system lead to the necessity of not only to reform but also to optimize it in order to face the increasing demand of the Brazilian energy market. The overhead electrical conductor is naturally the most important element on the transport of electrical energy and requires careful predictive and preventive maintenance programs. Therefore, it is of fundamental importance to predict the operational life of overhead electrical conductors using mathematical models so that their energy transport capacity can be optimized. However, it is necessary to validate such models by means of test programs so that their predictions can be trusted. One of the most important factors on the structural decay of overhead electrical conductors is the variation of the temperature profile in the event of the rupture of one or more of its Aluminum wires by fatigue or fretting. Therefore, models that include this temperature variation must be validated through test programs that can experimentally establish a mathematical relationship which considers effects such as contact resistance, material thermo-mechanical properties modification, annealing of the material and the presence of defects. The objective of this work is to evaluate the effect of progressive Aluminum wire rupture on the temperature profile of an ACSR (Aluminum Conductor Steel Reinforced) overhead electrical conductor, not only on the section of the damage but also along the length of the conductor. A test procedure was developed and performed to establish this effect. Results were compared to a mathematical model and showed that the temperature profile dependency of the increasing rupture of Aluminum wires is not linear and includes effects other than the cross section loss. © 2013 Elsevier Ltd. All rights reserved.

Santos J.P.,Federal University of Säo João del Rei | Sa Barreto F.C.,Federal University of Säo João del Rei | Sa Barreto F.C.,Federal University of Minas Gerais
Physica A: Statistical Mechanics and its Applications | Year: 2015

Spin correlation identities for the Ashkin-Teller model are derived. From the correlation identities effective field approximation results for the magnetization, the specific heat, the critical frontiers and tricritical points are obtained. First-order transitions in three-dimensional lattices are predicted. The results of the effective field approximation are compared to those obtained by other methods. © 2014 Elsevier B.V. All rights reserved.

Brandao F.G.S.L.,Federal University of Minas Gerais | Christandl M.,ETH Zurich | Yard J.,Los Alamos National Laboratory
Communications in Mathematical Physics | Year: 2011

Squashed entanglement is a measure for the entanglement of bipartite quantum states. In this paper we present a lower bound for squashed entanglement in terms of a distance to the set of separable states. This implies that squashed entanglement is faithful, that is, it is strictly positive if and only if the state is entangled. We derive the lower bound on squashed entanglement from a lower bound on the quantum conditional mutual information which is used to define squashed entanglement. The quantum conditional mutual information corresponds to the amount by which strong subadditivity of von Neumann entropy fails to be saturated. Our result therefore sheds light on the structure of states that almost satisfy strong subadditivity with equality. The proof is based on two recent results from quantum information theory: the operational interpretation of the quantum mutual information as the optimal rate for state redistribution and the interpretation of the regularised relative entropy of entanglement as an error exponent in hypothesis testing. The distance to the set of separable states is measured in terms of the LOCC norm, an operationally motivated norm giving the optimal probability of distinguishing two bipartite quantum states, each shared by two parties, using any protocol formed by local quantum operations and classical communication (LOCC) between the parties. A similar result for the Frobenius or Euclidean norm follows as an immediate consequence. The result has two applications in complexity theory. The first application is a quasipolynomial-time algorithm solving the weak membership problem for the set of separable states in LOCC or Euclidean norm. The second application concerns quantum Merlin-Arthur games. Here we show that multiple provers are not more powerful than a single prover when the verifier is restricted to LOCC operations thereby providing a new characterisation of the complexity class QMA. © 2011 Springer-Verlag.

Valente M.T.,Federal University of Minas Gerais | Borges V.,COTEMIG | Passos L.,University of Waterloo
IEEE Transactions on Software Engineering | Year: 2012

The extraction of nontrivial software product lines (SPL) from a legacy application is a time-consuming task. First, developers must identify the components responsible for the implementation of each program feature. Next, they must locate the lines of code that reference the components discovered in the previous step. Finally, they must extract those lines to independent modules or annotate them in some way. To speed up product line extraction, this paper describes a semi-automatic approach to annotate the code of optional features in SPLs. The proposed approach is based on an existing tool for product line development, called CIDE, that enhances standard IDEs with the ability to associate background colors with the lines of code that implement a feature. We have evaluated and successfully applied our approach to the extraction of optional features from three nontrivial systems: Prevayler (an in-memory database system), JFreeChart (a chart library), and ArgoUML (a UML modeling tool). © 2012 IEEE.

Brandao F.G.S.L.,Federal University of Minas Gerais | Christandl M.,ETH Zurich | Yard J.,Los Alamos National Laboratory
Proceedings of the Annual ACM Symposium on Theory of Computing | Year: 2011

We present a quasipolynomial-time algorithm for solving the weak membership problem for the convex set of separable, i.e. non-entangled, bipartite density matrices. The algorithm decides whether a density matrix is separable or whether it is ∈-away from the set of the separable states in time exp(O(∈-2 log|A| log|B|)), where |A| and |B| are the local dimensions, and the distance is measured with either the Euclidean norm, or with the so-called LOCC norm. The latter is an operationally motivated norm giving the optimal probability of distinguishing two bipartite quantum states, each shared by two parties, using any protocol formed by quantum local operations and classical communication (LOCC) between the parties. We also obtain improved algorithms for optimizing over the set of separable states and for computing the ground-state energy of mean-field Hamiltonians. The techniques we develop are also applied to quantum Merlin-Arthur games, where we show that multiple provers are not more powerful than a single prover when the verifier is restricted to LOCC protocols, or when the verification procedure is formed by a measurement of small Euclidean norm. This answers a question posed by Aaronson et al. (Theory of Computing 5, 1, 2009) and provides two new characterizations of the complexity class QMA, a quantum analog of NP. Our algorithm uses semidefinite programming to search for a symmetric extension, as first proposed by Doherty, Parrilo and Spedialieri (Phys. Rev. A, 69, 022308, 2004). The bound on the runtime follows from an improved de Finetti-type bound quantifying the monogamy of quantum entanglement. This result, in turn, follows from a new lower bound on the quantum conditional mutual information and the entanglement measure squashed entanglement. © 2011 ACM.

Hardouin L.,University of Angers | Maia C.A.,Federal University of Minas Gerais | Cottenceau B.,University of Angers | Lhommeau M.,University of Angers
IEEE Transactions on Automatic Control | Year: 2010

This technical note deals with the state estimation for max-plus linear systems. This estimation is carried out following the ideas of the observer method for classical linear systems. The system matrices are assumed to be known, and the observation of the input and of the output is used to compute the estimated state. The observer design is based on the residuation theory which is suitable to deal with linear mapping inversion in idempotent semiring. © 2010 IEEE.

Jota P.R.S.,Federal University of Minas Gerais | Silva V.R.B.,City Hall of Belo Horizonte | Jota F.G.,Federal University of Minas Gerais
International Journal of Electrical Power and Energy Systems | Year: 2011

Building energy management systems has become very significant to monitor and control loads, mainly due to the tariff and demand side management programs. This technology allows the performance of key energy management functions such as organizing energy use data, identifying energy consumption anomalies, managing energy costs, and automating demand response strategies. Load management techniques allow the energy manager to reshape the building load curve and reduce the peak demand. The synthesis of load shapes is one of the most critical steps in evaluating load management programs. The energy manager should be able to recognize the typical shape of the daily load curve in order to manage the energy use. This paper presents a methodology to perform the synthesis of load shapes. On that purpose, it is essential to identify typical daily load curves as well as the best way to find their representative model. By getting to know the typical load curves of a building, an energy manager may predict load and peak demands. Results have shown the efficiency of clustering technology in the analysis of time series data such as load curves. Using historical data, the total accumulated energy in the end of the day as well as the maximum peak demand of the day may be predicted. © 2011 Elsevier Ltd. All rights reserved.

Brandao F.G.S.L.,ETH Zurich | Brandao F.G.S.L.,Federal University of Minas Gerais | Christandl M.,ETH Zurich
Physical Review Letters | Year: 2012

We provide quantitative bounds on the characterization of multiparticle separable states by states that have locally symmetric extensions. The bounds are derived from two-particle bounds and relate to recent studies on quantum versions of de Finetti's theorem. We discuss algorithmic applications of our results, in particular a quasipolynomial-time algorithm to decide whether a multiparticle quantum state is separable or entangled (for constant number of particles and constant error in the norm induced by one-way local operations and classical communication, or in the Frobenius norm). Our results provide a theoretical justification for the use of the search for symmetric extensions as a test for multiparticle entanglement. © 2012 American Physical Society.

Barak B.,Microsoft | Brandao F.G.S.L.,Federal University of Minas Gerais | Harrow A.W.,University of Washington | Kelner J.,Massachusetts Institute of Technology | And 2 more authors.
Proceedings of the Annual ACM Symposium on Theory of Computing | Year: 2012

We study the computational complexity of approximating the 2-to-q norm of linear operators (defined as ∥A∥ 2→q = max v≠0∥Av| q/∥v∥ 2) for q > 2, as well as connections between this question and issues arising in quantum information theory and the study of Khot's Unique Games Conjecture (UGC). We show the following: 1. For any constant even integer q ≥ 4, a graph G is a small-set expander if and only if the projector into the span of the top eigenvectors of G's adjacency matrix has bounded 2→q norm. As a corollary, a good approximation to the 2→q norm will refute the Small-Set Expansion Conjecture - - a close variant of the UGC. We also show that such a good approximation can be obtained in exp(n 2/q) time, thus obtaining a different proof of the known subexponential algorithm for Small-Set-Expansion. 2. Constant rounds of the "Sum of Squares" semidefinite programing hierarchy certify an upper bound on the 2→4 norm of the projector to low degree polynomials over the Boolean cube, as well certify the unsatisfiability of the "noisy cube" and "short code" based instances of Unique-Games considered by prior works. This improves on the previous upper bound of exp(log O(1) n) rounds (for the "short code"), as well as separates the "Sum of Squares"/"Lasserre" hierarchy from weaker hierarchies that were known to require ω(1) rounds. 3. We show reductions between computing the 2→4 norm and computing the injective tensor norm of a tensor, a problem with connections to quantum information theory. Three corollaries are: (i) the 2→4 norm is NP-hard to approximate to precision inverse-polynomial in the dimension, (ii) the 2→4 norm does not have a good approximation (in the sense above) unless 3-SAT can be solved in time exp(√n poly log(n)), and (iii) known algorithms for the quantum separability problem imply a non-trivial additive approximation for the 2→4 norm. © 2012 ACM.

Iemini F.,Federal University of Minas Gerais | Debarba T.,Federal University of Minas Gerais | Debarba T.,University of Waterloo | Vianna R.O.,Federal University of Minas Gerais
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We discuss a general notion of quantum correlations in fermionic or bosonic indistinguishable particles. Our approach is mainly based on the identification of the algebra of single-particle observables, which allows us to devise an activation protocol in which the quantumness of correlations in the system leads to a unavoidable creation of entanglement with the measurement apparatus. Using the distillable entanglement, or the relative entropy of entanglement, as entanglement measure, we show that our approach is equivalent to the notion of minimal disturbance in a single-particle von Neumann measurement, also leading to a geometrical approach for its quantification. © 2014 American Physical Society.

Mendes F.,Miami Medical Center | Couto C.A.,Federal University of Minas Gerais | Levy C.,University of Miami
Clinics in Liver Disease | Year: 2011

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH) each account for approximately 5% of liver transplants per year performed in the United States and Europe. Even though outcomes are excellent, with reported 5-year patient and graft survival exceeding 90% and 80%, 80% and 75%, 72% and 65% for PBC, PSC, and AIH, respectively, the issue of recurrent autoimmune liver disease after orthotopic liver transplantation is increasingly recognized as a cause of graft dysfunction, death, and need for retransplantation. This article reviews diagnostic criteria, epidemiology, risk factors, and outcomes of recurrent PBC, PSC, and AIH after liver transplantation. © 2011 Elsevier Inc.

Roque M.,Center for Reproductive Medicine | Valle M.,Center for Reproductive Medicine | Guimaraes F.,Center for Reproductive Medicine | Sampaio M.,Center for Reproductive Medicine | And 2 more authors.
Fertility and Sterility | Year: 2015

Objective To compare in vitro fertilization (IVF) outcomes between fresh embryo transfer (ET) and frozen-thawed ET (the "freeze-all" policy), with fresh ET performed only in cases without progesterone (P) elevation. Design Prospective, observational, cohort study. Setting Private IVF center. Patient(s) A total of 530 patients submitted to controlled ovarian stimulation (COS) with a gonadotropin-releasing hormone-antagonist protocol, and cleavage-stage, day-3 ET. Intervention(s) None. Main Outcome Measure(s) Ongoing pregnancy rates. Result(s) A total of 530 cycles were included in the analysis: 351 in the fresh ET group (when P levels were ≤1.5 ng/mL on the trigger day); and 179 cycles in the freeze-all group (ET performed after endometrial priming with estradiol valerate, at 6 mg/d, taken orally). For the fresh ET group vs. The freeze-all group, respectively, the implantation rate was 19.9% and 26.5%; clinical pregnancy rate was 35.9% and 46.4%; and ongoing pregnancy rate was 31.1% and 39.7%. Conclusion(s) The IVF outcomes were significantly better in the group using the freeze-all policy, compared with the group using fresh ET. These results suggest that even in a select group of patients that underwent fresh ET (P levels 1.5 ng/mL), endometrial receptivity may have been impaired by COS, and outcomes may be improved by using the freeze-all policy. © 2015 American Society for Reproductive Medicine.

Castilho F.M.,Federal University of Minas Gerais | De Sousa M.R.,Federal University of Minas Gerais | Mendonca A.L.P.,Federal University of Minas Gerais | Ribeiro A.L.P.,Federal University of Minas Gerais | Caceres-Loriga F.M.,Institute Cardiologia y Cirurgia Cardiovascular ICCC
Journal of Thrombosis and Haemostasis | Year: 2014

Background: Prosthetic heart valve thrombosis is a life-threatening condition for which treatment has not been evaluated by randomized trials. Objectives: To compare surgery with thrombolytic therapy for the treatment of prosthetic valve thrombosis. Methods: A comprehensive systematic review was carried out by independent researchers using PubMed, Web of Knowledge, HINARI, LILACS and EMBASE, including papers indexed up to 23 October 2013 with at least 10 patients, evaluating one or both treatment options. Outcomes of interest were death, stroke, bleeding, embolic events and success. Study quality was assessed by the Newcastle-Ottawa Scale (ranges from 0 to 9). Comprehensive Meta Analysis Software was used to pool study results, for publication bias analysis and for meta-regression. Results: Forty-eight studies were included (2302 patients). No randomized study was identified, and all were observational in design. Study quality varied from 4 to 6 stars using the Newcastle-Ottawa Scale. Mortality for surgery was 18.1% (95%CI, 14.6-22.1; I2, 62% [42-75]), while mortality for thrombolytic therapy was 6.6% (95% CI, 4.8-8.9; I2, 0% [0-13]). Surgical mortality appeared to increase with NYHA-class, according to meta-regression. Other results related to surgery and thrombolytic therapy, respectively, were: embolic events, 4.6% (2.9-7.3) and 12.8% (10.8-15.2); stroke, 4.3%,(2.7-6.6%) and 5.6%,(4.3-7.4%); success rate, 81.9% (77.2-85.8) and 80.7% (75.6-85.0); bleeding, 4.6% (2.9-7.1) and 6.8% (5.4-8.6); and death or stroke, 19.0% (14.8-24.2) and 11.4% (8.7-14.7). Conclusion: Mortality in patients treated by thrombolytic therapy for valve prosthesis thrombosis is significantly lower than in patients treated surgically. As we cannot yet ascertain whether this difference is due to the treatment alone, more studies are now necessary to further clarify these findings. © 2014 International Society on Thrombosis and Haemostasis.

Guadanucci J.P.L.,Federal University of Minas Gerais | Wendt I.,University of Hohenheim
Journal of Natural History | Year: 2014

The genus Ischnocolus is redefined based on type material, and extra specimens. Representatives of the genus are distinguished by clavate tarsal trichobothria arranged in median apical row; by the maxillae with lighter colour on prolateral edge. Males of the genus Ischnocolus Ausserer are recognized by the cheliceral intumescence, sigmoid ventral furrow on palpal tibia, unequal cymbium lobes, tibial apophysis absent, great number of spines on ventral side of tibia I, and male superior tarsal claws bipectinate. Species included are: Ischnocolus valentinus (Dufour) [= I. holosericeus L. Koch, I. triangulifer Ausserer, I. algericus Thorell, I. fuscostriatus Simon, I. maroccanus (Simon), I. mogadorensis (Simon), I. numidus Simon, I. tripolitanus Caporiacco, Avicularia andalusiaca Simon], Ischnocolus hancocki Smith, Ischnocolus jickelii L. Koch (senior-synonym of Chaetopelma adenense Simon) and Ischnocolus ignoratus sp. nov. Ischnocolus tomentosus Thorell is considered incertae sedis. The following species are considered species inquirenda: I. tunetanus Pavesi and I. fasciculatus Strand. © 2013 Taylor & Francis.

Goussevskaia O.,Federal University of Minas Gerais | Wattenhofer R.,ETH Zurich
Ad Hoc Networks | Year: 2013

In this article we study the problem of scheduling wireless links in the physical interference model with interference decoding capability. We analyze two models with different decoding strategies that explore the fact that interfering signals should not be treated as random noise, but as well-structured signals. The first model makes use of successive interference cancelation, which allows the strongest signal to be iteratively decoded and subtracted from a collision, thus enabling the decoding of weaker simultaneous signals. The second model explores the fact that routers are able to forward the interfered signal of a pair of nodes that wish to exchange a message and these nodes are able to decode the collided messages by subtracting their own contribution from the interfered signal. We prove that the scheduling problem remains NP-complete in both models. Moreover, we propose a polynomial-time scheduling algorithm that uses successive interference cancelation to compute short schedules for network topologies formed by nodes arbitrarily distributed in the Euclidean plane. We prove that the proposed algorithm is correct in the physical interference model and provide simulation results demonstrating the performance of the algorithm in different network topologies. We compare the results to solutions without successive interference cancelation and observe that considerable throughput gains are obtained in certain scenarios. © 2013 Elsevier B.V.

Couto M.V.,Institute of Informatics | Valente M.T.,Federal University of Minas Gerais | Figueiredo E.,Federal University of Minas Gerais
Proceedings of the European Conference on Software Maintenance and Reengineering, CSMR | Year: 2011

Software Product Line (SPL) is a development paradigm that targets the creation of variable software systems. Despite the increasing interest in product lines, research in the area usually relies on small systems implemented in the laboratories of the authors involved in the investigative work. This characteristic hampers broader conclusions about industry-strength product lines. Therefore, in order to address the unavailability of public and realistic product lines, this paper describes an experiment involving the extraction of a SPL for ArgoUML, an open source tool widely used for designing systems in UML. Using conditional compilation we have extracted eight complex and relevant features from ArgoUML, resulting in a product line called ArgoUML-SPL. By making the extracted SPL publicly available, we hope it can be used to evaluate the various flavors of techniques, tools, and languages that have been proposed to implement product lines. Moreover, we have characterized the implementation of the features considered in our experiment relying on a set of product-line specific metrics. Using the results of this characterization, it was possible to shed light on the major challenges involved in extracting features from real-world systems. © 2011 IEEE.

Cancado L.G.,Federal University of Minas Gerais | Novotny L.,ETH Zurich
ACS Nano | Year: 2016

In conventional optical spectroscopy, lenses are used to focus light on the sample and to collect light scattered from the sample. Focusing increases the signal intensity, but it amounts to angular (k-space) averaging and leads to information loss. In this issue of ACS Nano, Budde and collaborators record radiation patterns of Raman scattering from a single layer of graphene, revealing the angular distribution of the scattered field. The authors show that the radiation patterns render the spatial symmetry of vibrational modes. Furthermore, their results demonstrate that depolarization effects occurring in the focal region must be taken into account for proper interpretation of Raman intensities. We outline here the working principle of this new approach and discuss future applications for studies of graphene and other low-dimensional systems. © 2016 American Chemical Society.

News Article | November 15, 2015

General view from above of a dam owned by Vale SA and BHP Billiton Ltd that burst, in Mariana, Brazil, November 10, 2015. Nine people were killed, 19 are still listed as missing and 500 people were displaced from their homes when the dams burst at an iron ore mine in southeastern Brazil on Nov. 5. The sheer volume of water disgorged by the dams and laden with mineral waste across nearly 500 km is staggering: 60 million cubic meters, the equivalent of 25,000 Olympic swimming pools or the volume carried by about 187 oil tankers. President Dilma Rousseff compared the damage to the 2010 oil spill by BP PLC in the Gulf of Mexico and Environment Minister Izabella Teixeira called it an "environmental catastrophe." Scientists say the sediment, which may contain chemicals used by the mine to reduce iron ore impurities, could alter the course of streams as they harden, reduce oxygen levels in the water and diminish the fertility of riverbanks and farmland where floodwater passed. Samarco Mineração SA, a joint venture between mining giants Vale SA and BHP Billiton and owner of the mine, has repeatedly said the mud is not toxic. But biologists and environmental experts disagree. Local authorities have ordered families rescued from the flood to wash thoroughly and dispose of clothes that came in contact with the mud. "It's already clear wildlife is being killed by this mud," said Klemens Laschesfki, professor of geosciences at the Federal University of Minas Gerais. "To say the mud is not a health risk is overly simplistic." As the heavy mud hardens, Laschesfki says, it will make farming difficult. And so much silt will settle along the bottom of the Rio Doce and the tributaries that carried the mud there that the very course of watershed could change. "Many regions will never be the same," he says. Researchers are testing the river water and results should be published over the coming weeks, giving a better idea of the contents of the mining waste. One cause for concern is that compounds known as ether amines could have been used at the mine to separate silica from the iron ore, in order to produce a better quality product. According to mining industry research and scientific literature published in recent years, the compounds are commonly used at Brazilian mines, including Samarco's. At least some of the compounds, according to the website of Air Products, a company that produces them, "are not readily biodegradable and have high toxicity to aquatic organisms." They can also raise PH levels to a point that is environmentally harmful. "There will be serious problems using the water from the river now," says Pedro Antonio Molinas, a water resources engineer and mining industry consultant familiar with the region. Samarco did not respond to questions about whether it used the compounds or whether they were in the so-called tailings pond whose contents burst through the broken dams. The disaster is the latest assault on the Rio Doce, or "Sweet River", one of the main routes connecting mineral-rich Minas Gerais state with the Atlantic Ocean. Once lined with thick rainforest and populated by indigenous tribes, the waterway has long suffered because of ravenous demand for the minerals nearby. So synonymous is it with the mining industry that Vale, which means "valley" in Portuguese, refers to the land through which the river runs. Before a name change in 2007, the miner was formally known as the Vale of the Rio Doce Company. Its banks now barren, and bed full of silt, the river grew prone to flooding with heavy rains that over the years devastated communities along its more than 800 km course. More recently it was plagued by drought. On Thursday, the river running a reddish brown, farmhands moved livestock away from its banks, afraid to let cattle drink the water. At a picnic table, Nilo Candido da Silva, 74, said he never saw devastation on this scale during a life spent by the river. "I don't think I'll ever see it go back to normal," said Silva, gazing at thick mud and shredded trees where last week the river rose but now just a brown trickle flows. A fish lay dead in the mud. As the mud flows toward the ocean, environmentalists fear its impact on the coast too. "Who had the brilliant idea of opening the dams along the river?" asked marine biologist Andre Ruschi in a Facebook post, referring to the decision by authorities to open dams along the Rio Doce to allow the surge to dissipate and proceed toward the ocean. The mouth of the Rio Doce is a nesting area for endangered sea turtles, an animal sensitive to chemical changes in the water. The beaches are expected to turn a deep red. "It's a huge shock for nature," said Professor David Zee, an expert in oceanography and the environment at the State University in Rio de Janeiro.

News Article | February 15, 2017

TORONTO, ON--(Marketwired - February 09, 2017) - Verde AgriTech (TSX: NPK) ("Verde" or the "Company") is pleased to announce it has been granted an environmental license. The Company's targeted production for the first half of 2017 is 19,500 tonnes of Super Greensand (see February 29, 2016 press release) and 500 tonnes of Alpha (see April 20, 2016 press release). The Company's next steps to start production are: The Company's next steps for domestic and international sales are: Execution of all steps are already underway in advanced stages. "With this long awaited environmental license, Verde leaps towards production. Years of agricultural research and tests will soon enable the swift deployment and market adoption of our multinutrient products," commented President & CEO, Cristiano Veloso. Verde's Super Greensand has been approved for use in organic agriculture in the United States by OMRI. According to the United States Organic Trade Association, sales of organic products totaled US$43.3 billion in 2015. Verde is pleased to welcome Mr. Paulo Sergio Ribeiro Machado to the Company's Board of Directors. Mr. Machado is a former executive at Vale and has spent his career developing and operating large mining projects. From 1988 to 2002, Mr. Machado was the General Manager of Vale's Igarapé Bahia Gold Mine, at the time the largest gold producer in Latin America, where he was responsible for implementation, operation and decommissioning. Between 2002 and 2006 Mr. Machado was the Director for all iron ore mines in the central region of Minas Gerais state, overseeing management and operations of mining activities, plants and railway terminals. Mr. Machado holds degrees in Mining Engineering and Geology from the Federal University of Minas Gerais (UFMG) and was a member of the Board of Directors of CEMIG, one of the largest and most important electric energy utilities in Brazil Mr. Machado will take the Board seat of Mr. Antônio Schettino, who has served as Director since 2013 and now leaves the Board due to personal reasons. The Company wishes to thank Mr. Schettino for his invaluable contribution during these past years. Verde AgriTech promotes sustainable and profitable agriculture through the development of its Cerrado Verde Project. Cerrado Verde, located in the heart of Brazil's largest agricultural market, is the source of a potassium-rich deposit from which the Company intends to produce solutions for crop nutrition, crop protection, soil improvement and increased sustainability. Neither the TSX nor its regulation services provider (as that term is defined in the policies of the TSX) accepts responsibility for the adequacy or accuracy of this release. This press release contains certain "forward looking statements", which include but is not limited to, statements with respect to the future financial or operating performance of the company, its subsidiaries and its projects, and statements regarding use of proceeds. Forward looking statements can generally be identified by the use of words such as "plans", "expects", or "does not expect" or "is expected", "anticipates" or "does not anticipate", or "believes", "intends", "forecasts", "budget", "scheduled", "estimates" or variations of such words or phrases or state that certain actions, event, or results "may", "could", "would", "might", or "will be taken", "occur" or "be achieved". Forward looking statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the company to be materially different from any future results, performance or achievements expressed or implied by said statements. There can be no assurances that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in said statements. Accordingly, readers should not place undue reliance on forward-looking statements.

Carozo V.,Federal University of Rio de Janeiro | Carozo V.,National Institute of Metrology of Brazil | Almeida C.M.,National Institute of Metrology of Brazil | Ferreira E.H.M.,National Institute of Metrology of Brazil | And 4 more authors.
Nano Letters | Year: 2011

When two identical two-dimensional periodic structures are superposed, a mismatch rotation angle between the structures generates a superlattice. This effect is commonly observed in graphite, where the rotation between graphene layers generates Moiré patterns in scanning tunneling microscopy images. Here, a study of intravalley and intervalley double-resonance Raman processes mediated by static potentials in rotationally stacked bilayer graphene is presented. The peak properties depend on the mismatch rotation angle and can be used as an optical signature for superlattices in bilayer graphene. An atomic force microscopy system is used to produce and identify specific rotationally stacked bilayer graphenes that demonstrate the validity of our model. © 2011 American Chemical Society.

Valente O.S.,Pontifical Catholic University of Minas Gerais | Pasa V.M.D.,Federal University of Minas Gerais | Belchior C.R.P.,Federal University of Rio de Janeiro | Sodre J.R.,Pontifical Catholic University of Minas Gerais
Fuel | Year: 2011

This work presents the physical-chemical properties of fuel blends of waste cooking oil biodiesel or castor oil biodiesel with diesel oil. The properties evaluated were fuel density, kinematic viscosity, cetane index, distillation temperatures, and sulfur content, measured according to standard test methods. The results were analyzed based on present specifications for biodiesel fuel in Brazil, Europe, and USA. Fuel density and viscosity were increased with increasing biodiesel concentration, while fuel sulfur content was reduced. Cetane index is decreased with high biodiesel content in diesel oil. The biodiesel blends distillation temperatures T10 and T50 are higher than those of diesel oil, while the distillation temperature T 90 is lower. A brief discussion on the possible effects of fuel property variation with biodiesel concentration on engine performance and exhaust emissions is presented. The maximum biodiesel concentration in diesel oil that meets the required characteristics for internal combustion engine application is evaluated, based on the results obtained. © 2011 Elsevier Ltd All rights reserved.

Mothe D.,Federal University of Rio de Janeiro | Avilla L.S.,Rio de Janeiro State Federal University | Cozzuol M.A.,Federal University of Minas Gerais
Journal of Mammalian Evolution | Year: 2013

The taxonomic history of South American Gomphotheriidae is very complex and controversial. Three species are currently recognized: Amahuacatherium peruvium, Cuvieronius hyodon, and Notiomastodon platensis. The former is a late Miocene gomphothere whose validity has been questioned by several authors. The other two, C. hyodon and N. platensis, are Quaternary taxa in South America, and they have distinct biogeographic patterns: Andean and lowland distributions, respectively. South American gomphotheres became extinct at the end of the Pleistocene. We conducted a phylogenetic analysis of Proboscidea including the South American Quaternary gomphotheres, which resulted in two most parsimonious trees. Our results support a paraphyletic Gomphotheriidae and a monophyletic South American gomphothere lineage: C. hyodon and N. platensis. The late Miocene gomphothere record in Peru, Amahuacatherium peruvium, seems to be a crucial part of the biogeography and evolution of the South American gomphotheres. © 2012 Springer Science+Business Media, LLC.

Almeida Cunha A.,Federal University of Minas Gerais | Almeida Cunha A.,Federal University of Rio de Janeiro
Journal for Nature Conservation | Year: 2010

Specific impacts and benefits of nature tourism on species, ecosystem and socio-economic aspects have to be addressed in detail. This study compared diurnal medium-large vertebrate richness and abundance in a visited (VT) and a non-visited trail (NVT) in the mountain forest of Serra dos OÕãos National Park (SONP), a priority area for nature conservation in the Atlantic Forest hotspot. Results suggest that richness and abundance of medium-large mammals and birds are significantly reduced in VT, however sample effort was insufficient for further analysis. In the absence of adequate data, protected area managers have to guarantee infrastructure and control, but first, limit access by visitors, to small sized groups and low in frequency, guaranteeing large refuges for wildlife, and effective contributions for nature conservation with real socio-economic benefits at local and regional scales. The Brazilian government is investing in tourism in National Parks, including SONP, but there are no directives to monitor and manage potential negative impacts. Researchers and managers need to work together to couple this economic activity with environmental conservation in SONP and other protected areas in Brazil. © 2010 Elsevier GmbH.

Carneiro R.G.S.,Federal University of Minas Gerais | Burckhardt D.,Naturhistorisches Museum
Zootaxa | Year: 2013

Psidium myrtoides (Myrtaceae) shelters the gall inducer Nothotrioza myrtoidis gen. et sp. n. (Hemiptera: Psylloidea) which is described and illustrated here. Nothotrioza belongs to the family Triozidae and is probably most closely related to Neolithus, a monotypic Neotropical genus associated with Sapium (Euphorbiaceae). Three species are recognized with-in Nothotrioza: the type species N. myrtoidis sp. n. associated with Psidium myrtoides, N. cattleiani sp. n. (misidentified by Butignol & Pedrosa-Macedo as Neotrioza tavaresi) with Psidium cattleianum, and N. tavaresi (Crawford) comb. n. (from Neotrioza) with an unidentified species of Malpighiaceae, respectively. A lectotype is designated here for Neotrioza tavaresi. Also, the diversity of insect galls associated with P. myrtoides and the biology of N. myrtoidis were examined. N. myrtoidis presents five instars and an annual life cycle synchronised with the phenology of P. myrtoides. Gall size was proportional to the insect developmental stages, and rates of parasitism and mortality were 15.7 % and 29.8 %, respective-ly. The red colour is an important macroscopic diagnostic feature of the gall that could be associated with parasite-free condition of the galling insect. The biological features presented by the system Psidium myrtoides - Nothotrioza myrtoidis are in accordance with other systems involving sucking galling insects, however, it is exceptional by its univoltine life cycle associated with a perennial plant in the Neotropics. The galls induced by the three known Nothotrioza spp. are mor-phologically similar, i.e. closed, globoid and unilocular, as well as the opening mechanism for releasing the adults. Copyright © 2013 Magnolia Press.

The black shale-hosted selenide vein-type deposit at Tilkerode, eastern Harz, Germany, has specular hematite enclosed in clausthalite (PbSe). The specular hematite has Ti and V in amounts of up to ∼1 wt.% TiO2 and ∼3 wt.% V2O5, and subordinate, but important, contents of Mo (22-372 ppm) and B (up to 68 ppm). The Tilkerode hematite serves as a reference for hydrothermal hematite formed at relatively low temperatures (<150 °C). The composition of the Tilkerode hematite is compared with that of two generations of specular hematite from itabirite-hosted iron-ore deposits in the Quadrilátero Ferrífero of Minas Gerais, Brazil. The first generation of specular hematite represents an early tectonic hematitisation of dolomitic itabirite at Águas Claras and occurs as fine-grained crystals. Reconnaissance data indicate that the Águas Claras hematite is poorer in Ti and V, relative to the Tilkerode hematite, but has ∼5-10 ppm B and ∼7-11 ppm Li. The second generation of specular hematite defines the pervasive tectonic foliation of the Gongo Soco iron ore. This hematite has Ti contents of up to ∼2 wt.% TiO2 and subordinate amounts of V (62-367 ppm); its B and Li concentrations are mostly below <2 ppm B and <1 ppm Li. The presence of Ti and B in the Tilkerode hematite can be explained by highly saline, B-bearing fluids that were capable of mobilising otherwise immobile Ti. The Mo signature of the Tilkerode hematite suggests that Mo was derived from the host black shale. In Minas Gerais, B and Li were incorporated into the early tectonic hematite from saline fluids at relatively low temperatures (Águas Claras) and then released during metamorphic hematite growth at higher temperatures, as suggested by the foliation-defining hematite without B-Li signature (Gongo Soco). © 2013 Springer-Verlag Berlin Heidelberg.

Queiroz L.P.,Federal University of Santa Catarina | Silva Junior A.A.,Federal University of Minas Gerais
Headache | Year: 2015

Background/Objectives In Brazil, several epidemiological studies on headache have been produced, most with an emphasis on prevalence and the association of primary headaches with some sociodemographic characteristics of the population. Data on the burden of headache, however, are scarce. The aim of this paper is to review all Brazilian population-based studies on headache, as well as to analyze the Migraine Disability Assessment Score (MIDAS) data collected with the PhD thesis of the senior author (LPQ). Method A literature review was performed using the keywords ("headache" or "migraine") and ("epidemiology" or "prevalence") and (Brazil). Another part of this paper will look at unpublished data on disability (MIDAS), collected with the prevalence data of the Brazilian nationwide epidemiological study of headache. Results There are 6 published epidemiological studies of headache in Brazil. The mean 1-year prevalence of headache in Brazil is 70.6%, of migraine 15.8%, of tension-type headache (TTH) 29.5%, and of chronic daily headache (CDH) 6.1%. Disability is significantly higher: in females compared to males; in patients with migraine and CDH compared to patients with TTH; and in those with headaches ≥15 days per month rather than those with episodic headaches. There was also a positive relationship between pain intensity and severity of disability. Patients with higher disability used more both abortive and prophylactic medication. Conclusions The mean prevalence of headache in Brazil, and some of its subtypes, is similar to the rates described in other countries of the world. Disability is higher in females, in patients with migraine, in individuals with headaches ≥15 days per month, and in those with severe head pain. © 2015 American Headache Society.

Miyares R.L.,Carnegie Institution for Science | Miyares R.L.,Johns Hopkins University | De Rezende V.B.,Federal University of Minas Gerais | Farber S.A.,Carnegie Institution for Science
DMM Disease Models and Mechanisms | Year: 2014

Dyslipidemias are a major cause of morbidity and mortality in the world, particularly in developed nations. Investigating lipid and lipoprotein metabolism in experimentally tractable animal models is a crucial step towards understanding and treating human dyslipidemias. The zebrafish, a well-established embryological model, is emerging as a notable system for studies of lipid metabolism. Here, we describe the value of the lecithotrophic, or yolk-metabolizing, stages of the zebrafish as a model for studying lipid metabolism and lipoprotein transport. We demonstrate methods to assay yolk lipid metabolism in embryonic and larval zebrafish. Injection of labeled fatty acids into the zebrafish yolk promotes efficient uptake into the circulation and rapid metabolism. Using a genetic model for abetalipoproteinemia, we show that the uptake of labeled fatty acids into the circulation is dependent on lipoprotein production. Furthermore, we examine the metabolic fate of exogenously delivered fatty acids by assaying their incorporation into complex lipids. Moreover, we demonstrate that this technique is amenable to genetic and pharmacologic studies. © 2014. Published by The Company of Biologists Ltd.

Cancado L.G.,Federal University of Minas Gerais | Jorio A.,Federal University of Minas Gerais | Ferreira E.H.M.,National Institute of Metrology of Brazil | Stavale F.,National Institute of Metrology of Brazil | And 6 more authors.
Nano Letters | Year: 2011

We present a Raman study of Ar+-bombarded graphene samples with increasing ion doses. This allows us to have a controlled, increasing, amount of defects. We find that the ratio between the D and G peak intensities, for a given defect density, strongly depends on the laser excitation energy. We quantify this effect and present a simple equation for the determination of the point defect density in graphene via Raman spectroscopy for any visible excitation energy. We note that, for all excitations, the D to G intensity ratio reaches a maximum for an interdefect distance ∼3 nm. Thus, a given ratio could correspond to two different defect densities, above or below the maximum. The analysis of the G peak width and its dispersion with excitation energy solves this ambiguity. © 2011 American Chemical Society.

Coutinho D.C.O.,Federal University of Minas Gerais | Monnerat-Cahli G.,Federal University of Rio de Janeiro | Ferreira A.J.,Federal University of Minas Gerais | Medei E.,Federal University of Rio de Janeiro
Europace | Year: 2014

Aims Diabetic patients present a high level of cardiac arrhythmias and risk of cardiac sudden death. The renin-angiotensin system (RAS) plays a key role in diabetes and cardiac diseases. The present study aimed to evaluate whether an angiotensin-converting enzyme 2 (ACE2) activator, diminazene aceturate (DIZE), could improve the streptozotocin (STZ)-induced electrical changes in ventricular repolarization in hyperglycaemic rats.Methods and results Hyperglycaemia was induced in Wistar male rats with STZ (60 mg/kg/iv). After 4 weeks of STZ injection, rats were daily treated with saline (control) or DIZE (1 mg/kg/gavage) for four consecutive weeks. The cardiac electrical function was evaluated in vivo by electrocardiogram and in vitro by cardiac action potential records in different pacing frequencies. Treatment with DIZE was not able to reverse hyperglycaemia nor body weight loss. However, DIZE reversed hyperglycaemia-induced cardiac electrical changes in ventricular repolarization. Specifically, animals treated with DIZE showed shorter QT and QTc intervals. In addition, ACE2 activation was capable to shorten the cardiac action potential and also reverse the arrhythmic markers. Diminazene aceturate treatment did not induce arrhythmic events in normal, as well as in hyperglycaemic animals.Conclusion Our data indicate that activation of ACE2 has a beneficial effect in hyperglycaemic rats, improving the cardiac electrical function. Thus, DIZE represents a promising new therapeutic agent to treat hyperglycaemia-induced cardiac electrical changes in ventricular repolarization. © 2014 Published on behalf of the European Society of Cardiology. All rights reserved.

Pantuzzo F.L.,Federal University of Minas Gerais | Pantuzzo F.L.,National Institute of Science and Technology | Ciminelli V.S.T.,Federal University of Minas Gerais | Ciminelli V.S.T.,National Institute of Science and Technology
Water Research | Year: 2010

Long-term stability of arsenic residues is investigated by determining arsenic phases remaining in gold mining residues after two decades of impoundment. The residues, generated by arsenic coprecipitation with iron and lime, were disposed of in-lined sites for 9-16 years (pit C) and 16-23 years (pits A and B). Arsenic is present in the residues as As(V) species, predominantly in the form of amorphous iron arsenate (55-75% Astotal, pits A and B; 55-70% Astotal, pit C) and sorbed onto amorphous iron-oxyhydroxides (20-33% Astotal, pits A and B; 22-37% Astotal, pit C). The presence of minor Ca-arsenate phases (undefined composition) and Al-arsenate coprecipitates is also indicated. The passive enrichment of iron in pits A and B, and the relative low concentration of calcium, sulfur and arsenic if compared to those of pit C, suggest that a soluble Ca-arsenate phase (e.g. CaHAsO4.H2O), a fraction of gypsum and As(III) were dissolved along 16-23 years of residue disposal. The presence of As(V) only and excess iron demonstrates the importance of the oxidation state and high Fe/As ratio on long-term stability of arsenic residues. © 2010 Elsevier Ltd.

Franco G.A.P.,Federal University of Minas Gerais | Alves F.O.,Institute Of Ciencies Of Lespai Csic Ieec | Girart J.M.,Institute Of Ciencies Of Lespai Csic Ieec
Astrophysical Journal | Year: 2010

We use R-band CCD linear polarimetry collected for about 12,000 background field stars in 46 fields of view toward the Pipe nebula to investigate the properties of the polarization across this dark cloud. Based on archival Two Micron All Sky Survey data, we estimate that the surveyed areas present total visual extinctions in the range 0.6mag ≤ AV ≤ 4.6 mag. While the observed polarizations show a well-ordered large-scale pattern, with polarization vectors almost perpendicularly aligned to the cloud's long axis, at core scales one sees details that are characteristics of each core. Although many observed stars present degrees of polarization that are unusual for the common interstellar medium (ISM), our analysis suggests that the dust grains constituting the diffuse parts of the Pipe nebula seem to have the same properties as the normal Galactic ISM. Estimates of the second-order structure function of the polarization angles suggest that most of the Pipe nebula is magnetically dominated and that turbulence is sub-Alvénic. The Pipe nebula is certainly an interesting region to investigate the processes that prevailed during the initial phases of low-mass stellar formation. © 2010. The American Astronomical Society.

Isetts B.J.,University of Minnesota | Brummel A.R.,Ambulatory Clinical Pharmacy Services | De Oliveira D.R.,Fairview Pharmacy Services LLC | Moen D.W.,Federal University of Minas Gerais
Medical Care | Year: 2012

BACKGROUND: The appropriate use of medications can influence quality performance measures and costs. Drug-related morbidity and mortality represents a public health challenge due to the ineffective and unsafe consequences of medication use. This article addresses the impact of team-based care that incorporates comprehensive medication therapy management on per capita expenditures, quality performance measures, and resolution of drug therapy problems. METHODS: A team-based medication therapy management system developed over 13 years in an integrated health system in 4 Minnesota innovation clinic sites was assessed in terms of: (1) differences in total median health expenditures compared with noninnovation clinics, (2) improvements on 5 performance benchmarks for patients with diabetes in comparison with statewide results, and (3) resolution of drug therapy problems. RESULTS: Spending growth was 11% less in innovation clinics than that in 38 noninnovation clinics. Median per member per month health care costs measured at 5 intervals over a 15-month period were significantly lower in innovation than in noninnovation sites (P=0.05). Forty percent of patients with diabetes in the innovation clinics achieved all 5 performance benchmark treatment goals in 2009, with a range from 34% to 45%, compared with the statewide result of 17.5% of patients achieving all 5 benchmarks. In addition, over 4000 drug therapy problems were reported to be resolved. CONCLUSIONS: Team-based care helped to achieve quality performance and control spending growth through medication therapy management in a patient-centered medical home innovation. Copyright © 2012 by Lippincott Williams & Wilkins.

Walborn S.P.,Federal University of Rio de Janeiro | Monken C.H.,Federal University of Minas Gerais | Padua S.,Federal University of Minas Gerais | Souto Ribeiro P.H.,Federal University of Rio de Janeiro
Physics Reports | Year: 2010

The transverse spatial effects observed in photon pairs produced by parametric down-conversion provide a robust and fertile testing ground for studies of quantum mechanics, non-classical states of light, correlated imaging and quantum information. Over the last 20 years there has been much progress in this area, ranging from technical advances and applications such as quantum imaging to investigations of fundamental aspects of quantum physics such as complementarity relations, Bell's inequality violation and entanglement. The field has grown immensely: a quick search shows that there are hundreds of papers published in this field, some with hundreds of citations. The objective of this article is to review the building blocks and major theoretical and experimental advances in the field, along with some possible technical applications and connections to other research areas. © 2010 Elsevier B.V.

Valente O.S.,Pontifical Catholic University of Minas Gerais | Pasa V.M.D.,Federal University of Minas Gerais | Belchior C.R.P.,Federal University of Rio de Janeiro | Sodre J.R.,Pontifical Catholic University of Minas Gerais
Science of the Total Environment | Year: 2012

The exhaust emissions from a diesel power generator operating with waste cooking oil biodiesel blends have been studied. Fuel blends with 25%, 50% and 75% of biodiesel concentration in diesel oil were tested, varying engine load from 0 to 25kW. The original engine settings for diesel oil operation were kept the same during the experiments with the biodiesel blends. The main physical-chemical characteristics of the fuel blends used were measured to help with the analysis of the emission results. The results show that the addition of biodiesel to the fuel increases oxides of nitrogen (NOX), carbon monoxide (CO) and hydrocarbon (HC) emissions. Carbon dioxide (CO2) and exhaust gas opacity were also increased with the use of biodiesel. Major increase of NOX was observed at low loads, while CO and HC were mainly increased at high loads. Using 50% of biodiesel in diesel oil, the average increase of CO2, CO, HC and NOX throughout the load range investigated was 8.5%, 20.1%, 23.5% and 4.8%, respectively. © 2012 Elsevier B.V..

Kendall G.,University of Nottingham | Knust S.,Clausthal University of Technology | Ribeiro C.C.,Federal University of Fluminense | Urrutia S.,Federal University of Minas Gerais
Computers and Operations Research | Year: 2010

Sports have worldwide appeal. Professional sport leagues involve significant investments in players. Events such as the Olympics Games, the Football World Cup and the major golf and tennis tournaments generate huge worldwide television audiences and many sports are multi-million dollar industries. A key aspect of sporting events is the ability to generate schedules that optimize logistic issues and that are seen as fair to all those who have an interest. This is not just restricted to generating the fixtures, but also to other areas such as assigning officials to the games in the competitions. This paper provides an annotated bibliography for sports scheduling articles. This area can be traced back over 40 years. It is noticeable that the number of papers has risen in recent years, demonstrating that scientific interest is increasing in this area. © 2009 Elsevier Ltd. All rights reserved.

Vidal C.E.L.,Federal University of Minas Gerais | Gontijo E.C.D.M.,Federal University of Minas Gerais | Lima L.A.,Federal University of Rio de Janeiro
Cadernos de Saude Publica | Year: 2013

This retrospective cohort study aimed to analyze the epidemiological profile of individuals that attempted suicide from 2003 to 2009 in Barbacena, Minas Gerais State, Brazil, to calculate the mortality rate from suicide and other causes, and to estimate the risk of death in these individuals. Data were collected from police reports and death certificates. Survival analysis was performed and Cox multiple regression was used. Among the 807 individuals that attempted suicide, there were 52 deaths: 12 by suicide, 10 from external causes, and 30 from other causes. Ninety percent of suicide deaths occurred within 24 months after the attempt. Risk of death was significantly greater in males, married individuals, and individuals over 60 years of age. Standardized mortality ratio showed excess mortality by suicide. The findings showed that the mortality rate among patients that had attempted suicide was higher than expected in the general population, indicating the need to improve health care for these individuals.

Smith J.M.,University of Massachusetts Amherst | Cruz F.R.B.,Federal University of Minas Gerais
Physica A: Statistical Mechanics and its Applications | Year: 2014

One of the most important problems in today's modeling of transportation networks is an accurate estimate of travel time on arterial links, highway, and freeways. There are a number of deterministic formulas that have been developed over the years to achieve a simple and direct way to estimate travel times for this complex task. Realistically, however, travel time is a random variable. These deterministic formula are briefly reviewed and also a new way to compute travel time over arterial links, highway, and freeways, is presented based on an analytical state dependent queueing model. One of the features of the queueing model is that it is analyzed within the context of the theoretical three-phase traffic flow model. We show that the model provides a quantitative foundation alternative to qualitative three-phase traffic flow theory. An important property shown with the model is that the travel time function is not convex, but a sigmoid S-shaped (i.e. logistic curve). Extensive analytical and simulation experiments are shown to verify the S-shaped nature of the travel time function and the use of the model's method of estimation of travel time over vehicular traffic links as compared with traditional approaches. Finally, it is shown that the point-of-inflection of the S-shaped curve represents the threshold point where the traffic flow volume switches from Free Flow to Congested Flow. © 2013 Elsevier B.V. All rights reserved.

Liberto N.A.,Campus Universitario | De Paiva Silva S.,Campus Universitario | De Fatima A.,Federal University of Minas Gerais | Fernandes S.A.,Campus Universitario
Tetrahedron | Year: 2013

A simple, green and efficient protocol was developed using β-cyclodextrin as a solid catalyst for the solvent-free synthesis of various Biginelli adducts. The advantages of our protocol included the following: (i) a metal-free methodology; (ii) high yields; (iii) simple and efficient work-up procedures; (iv) improved results under solvent-free conditions. β-cyclodextrin-catalyzed the Biginelli reactions for various aldehydes, demonstrating that it is an efficient and eco-friendly catalyst for the preparation of heterocyclic compounds. © 2013 Elsevier Ltd. All rights reserved.

Hickert L.R.,Federal University of Rio Grande do Sul | Souza-Cruz P.B.D.,Federal University of Rio Grande do Sul | Rosa C.A.,Federal University of Minas Gerais | Ayub M.A.Z.,Federal University of Rio Grande do Sul
Bioresource Technology | Year: 2013

Co-fermentation and simultaneous saccharification of rice hull hydrolysate (RHH) were investigated for the production of ethanol and xylitol by Saccharomyces cerevisiae, Spathaspora arborariae, or the combination of both. In bioreactor cultures under oxygen limitation, S. cerevisiae was capable of metabolizing glucose from RHH, which contained small amounts of acetic acid, furfural, and hydroxymethylfurfural, achieving ethanol yields of 0.45 and concentrations of 10.5gL-1. In the co-culture of S. cerevisiae and S. arborariae pentoses and hexoses from RHH, were converted to ethanol and xylitol, with yields of 0.48 and 0.39, and concentrations of 11gL-1 and 3gL-1, respectively. The simultaneous saccharification and co-fermentation using both yeasts produced ethanol and xylitol to final concentrations of 14.5gL-1 and 3gL-1, respectively. Results showed good prospects to use co-cultures of S. cerevisiae and S. arborariae for the bioconversion of RHH into ethanol and xylitol without further detoxification. © 2013 Elsevier Ltd.

Dickman R.,Federal University of Minas Gerais | Rolla L.T.,Ecole Normale Superieure de Paris | Sidoravicius V.,Centrum Wiskunde and Informatica
Journal of Statistical Physics | Year: 2010

We study a particle system with hopping (random walk) dynamics on the integer lattice ℤ d. The particles can exist in two states, active or inactive (sleeping); only the former can hop. The dynamics conserves the number of particles; there is no limit on the number of particles at a given site. Isolated active particles fall asleep at rate λ > 0, and then remain asleep until joined by another particle at the same site. The state in which all particles are inactive is absorbing. Whether activity continues at long times depends on the relation between the particle density ζ and the sleeping rate λ. We discuss the general case, and then, for the one-dimensional totally asymmetric case, study the phase transition between an active phase (for sufficiently large particle densities and/or small λ) and an absorbing one. We also present arguments regarding the asymptotic mean hopping velocity in the active phase, the rate of fixation in the absorbing phase, and survival of the infinite system at criticality. Using mean-field theory and Monte Carlo simulation, we locate the phase boundary. The phase transition appears to be continuous in both the symmetric and asymmetric versions of the process, but the critical behavior is very different. The former case is characterized by simple integer or rational values for critical exponents (β = 1, for example), and the phase diagram is in accord with the prediction of mean-field theory. We present evidence that the symmetric version belongs to the universality class of conserved stochastic sandpiles, also known as conserved directed percolation. Simulations also reveal an interesting transient phenomenon of damped oscillations in the activity density. © The Author(s) 2010.

Latrubesse E.M.,University of Texas at Austin | Cozzuol M.,Federal University of Minas Gerais | da Silva-Caminha S.A.F.,Federal University of Mato Grosso | Rigsby C.A.,East Carolina University | And 2 more authors.
Earth-Science Reviews | Year: 2010

On the basis of paleontological content (vertebrates and palynology) and facies analysis from river banks, road cuts, and three wells, we have assigned the uppermost levels of the Solimões Formation in western Amazonia, Brazil, to the Late Miocene. The vertebrate fossil record from outcropping sediments is assigned to the Huayquerian-Mesopotamian mammalian biozones, spanning 9-6.5. Ma. Additionally, we present results that demonstrate that deposits in Peruvian Amazonia attributed to Miocene tidal environments are actually fluvial sediments that have been misinterpreted (both environmentally and chronologically) by several authors.The entire Late Miocene sequence was deposited in a continental environment within a subsiding basin. The facies analysis, fossil fauna content, and palynological record indicate that the environment of deposition was dominated by avulsive rivers associated with megafan systems, and avulsive rivers in flood basins (swamps, lakes, internal deltas, and splays). Soils developed on the flatter, drier areas, which were dominated by grasslands and gallery forest in a tropical to subtropical climate.These Late Miocene sediments were deposited from westward of the Purus arch up to the border of Brazil with Peru (Divisor Ranges) and Bolivia (Pando block). Eastward of the Iquitos structural high, however, more detailed studies, including vertebrate paleontology, need to be performed to calibrate with more precision the ages of the uppermost levels of the Solimões Formation.The evolution of the basin during the late Miocene is mainly related to the tectonic behavior of the Central Andes (~3°-15°S). At approximately 5. Ma, a segment of low angle of subduction was well developed in the Nazca Plate, and the deformation in the Subandean foreland produced the inland reactivation of the Divisor/Contamana Ranges and tectonic arrangements in the Eastern Andes. During the Pliocene southwestern Brazilian Amazonia ceased to be an effective sedimentary basin, and became instead an erosional area that contributed sediments to the Amazon fluvial system. At that time, the lowland fluvial systems of southwestern Amazonia (the Purus, Jurua and Javarí basins) become isolated from the Andes by the newly formed north-flowing Ucayali system and south-east flowing Madre de Dios System. It was during the early Pliocene that the Amazon fluvial system integrated regionally and acquired its present appearance, and also when it started to drain water and sediments on a large scale to the Atlantic Ocean. © 2010 Elsevier B.V.

Roy A.,University of Western Ontario | Guatimosim S.,Federal University of Minas Gerais | Prado V.F.,University of Western Ontario | Gros R.,University of Western Ontario | Prado M.A.M.,University of Western Ontario
Molecular Medicine | Year: 2014

The autonomic nervous system is an important modulator of cardiac signaling in both health and disease. In fact, the significance of altered parasympathetic tone in cardiac disease has recently come to the forefront. Both neuronal and nonneuronal cholinergic signaling likely play a physiological role, since modulating acetylcholine (ACh) signaling from neurons or cardiomyocytes appears to have significant consequences in both health and disease. Notably, many of these effects are solely due to changes in cholinergic signaling, without altered sympathetic drive, which is known to have significant adverse effects in disease states. As such, it is likely that enhanced ACh-mediated signaling not only has direct positive effects on cardiomyocytes, but it also offsets the negative effects of hyperadrenergic tone. In this review, we discuss recent studies that implicate ACh as a major regulator of cardiac remodeling and provide support for the notion that enhancing cholinergic signaling in human patients with cardiac disease can reduce morbidity and mortality. These recent results support the idea of developing large clinical trials of strategies to increase cholinergic tone, either by stimulating the vagus or by increased availability of Ach, in heart failure. © 2014, Uninversity of Michigan. All rights reserved.

Lima R.D.F.,Federal University of Minas Gerais | Prado V.F.,University of Western Ontario | Prado M.A.M.,University of Western Ontario | Kushmerick C.,Federal University of Minas Gerais
Journal of Neurochemistry | Year: 2010

Mammalian motor nerve terminals contain hundreds of thousands of synaptic vesicles, but only a fraction of these vesicles is immediately available for release, the remainder forming a reserve pool. The supply of vesicles is replenished through endocytosis, and newly formed vesicles are refilled with acetylcholine through a process that depends on the vesicular acetylcholine transporter (VAChT). During expression of short-term plasticity, quantal release can be increased, but it is unknown whether this reflects enhanced recruitment of vesicles from the reserve pool or rapid recycling. We examined spontaneous and evoked release of acetylcholine at endplates from genetically modified VAChT KDHOM mice that express approximately 30% of the normal level of VAChT to determine steps rate-limited by synaptic vesicle filling. Quantal content and quantal size were reduced in VAChT KDHOM mice compared with wild-type controls. Although high-frequency stimulation did not reduce quantal size further, the post-tetanic increase in end-plate potential amplitude or MEPP frequency was significantly smaller in VAChT KDHOM mice. This was the case even when tetanic depression was eliminated using an extracellular solution containing reduced Ca2+ and raised Mg 2+. These results reveal the dependence of short-term plasticity on the level of VAChT expression and efficient synaptic vesicle filling. © 2010 International Society for Neurochemistry.

Suarez-Kurtz G.,Instituto Nacional Do Cancer | Pena S.D.,Federal University of Minas Gerais | Hutz M.H.,Federal University of Rio Grande do Sul
Pharmacogenomics | Year: 2012

Background: New drug applications submitted to regulatory agencies in developing countries rarely include data from local clinical trials. We used the FST statistics to explore the pharmacogenomic diversity of the Brazilian population and its potential implications in drug regulatory assessment and decisions. Methods: The FST analyses were based on data for 44 polymorphisms in 12 pharmacogenes among 1034 healthy Brazilians, recruited in four different geographical regions and self-identified as branco (white) pardo (brown) or preto (black). Each region/color group comprised 83-89 individuals. The Utah residents of northern and western European ancestry and Yoruba people from Nigeria, Africa, cohorts of the HapMap project were used as proxies of the European and sub-Saharan African ancestral roots of Brazilians, respectively. Results: Allele-specific FST values for the overall Brazilian cohort revealed low genetic divergence between white and brown (F ST = 0.005 ± 0.006, mean ± standard deviation), white and black (0.013 ± 0.017) and brown and black (0.004 ± 0.005) individuals. However, the distribution of FST values for white vs brown (p < 0.0001, analysis of variance) and white vs black (p < 0.0001) differed significantly across the geographical regions. Considerably larger pharmacogenomic divergence was observed between black Brazilians and Yoruba people from Nigeria, Africa (FST = 0.028 ± 0.035) compared to white Brazilians vs Utah residents of northern and western European ancestry (0.007 ± 0.010). Conclusion: The present FST analyses highlight the challenge faced by Brazilian regulatory agencies when assessing the relevance to Brazilians of pharmacogenomic data derived from foreign populations, with distinct biogeographical ancestries. This challenge is compounded by the heterogeneity of the Brazilian population with respect to the frequency distribution of pharmacogenomic polymorphisms across color categories and geographical regions. © 2012 Future Medicine Ltd.

Hopkins K.,University of Texas at Austin | de Lima Amaral E.F.,Federal University of Minas Gerais | Mourao A.N.M.,University of Ottawa
Birth | Year: 2014

Background: High cesarean section rates in Brazilian public hospitals and higher rates in private hospitals are well established. Less is known about the relationship between payment source and cesarean section rates within public and private hospitals. Methods: We analyzed the 1998, 2003, and 2008 rounds of a nationally representative household survey (PNAD), which includes type of delivery, where it took place, and who paid for it. We construct cesarean section rates for various categories, and perform logistic regression to determine the relative importance of independent variables on cesarean section rates for all births and first births only. Results: Brazilian cesarean section rates were 42 percent in 1998 and 53 percent in 2008. Women who delivered publicly funded births in either public or private hospitals had lower cesarean section rates than those who delivered privately financed deliveries in public or private hospitals. Multivariate models suggest that older age, higher education, and living outside the Northeast region all positively affect the odds of delivering by cesarean section; effects are attenuated by the payment source-hospital type variable for all women and even more so among first births. Conclusions: Cesarean section rates have risen substantially in Brazil. It is important to distinguish payment source for the delivery to have a better understanding of those rates. © 2014 Wiley Periodicals, Inc.

Arabkoohsar A.,Islamic Azad University | Farzaneh-Gord M.,Shahrood University of Technology | Deymi-Dashtebayaz M.,Hakim Sabzevari University | Machado L.,Federal University of Minas Gerais | Koury R.N.N.,Federal University of Minas Gerais
Renewable Energy | Year: 2015

Natural gas pressure reduction station (CGS) is one of the most important pieces in natural gas transmission system. In a CGS, the high inlet natural gas (NG) pressure has to be reduced down to a much lower value. Pressure reduction is usually implemented by utilizing throttling valves. Due to the positive Joule-Thompson coefficient of NG, this pressure drop causes significant temperature fall and consequently hydrate forming in the NG stream. The hydrates may prevent stable NG flow through the pipeline. To prevent hydrate forming, the NG should be preheated by some heaters which burn huge amount of fuel. In this work, firstly, adding a solar heating system aiming to reduce the heater fuel consumption and secondly, replacing the throttling valve by a turbo expander in order to utilize the NG stream exergy are proposed. The proposed configuration is simulated for Birjand CGS as a case study. For the simulation, the locally available solar irradiation is estimated by employing solar engineering formulations and the NG availability is calculated by thermodynamics correlations. Net present value (NPV) method is also employed to analyze the proposed system effectiveness economically, resulting to only 3.5 years of pay back ratio. © 2015 Elsevier Ltd.

Ligeiro R.,Federal University of Minas Gerais | Melo A.S.,Federal University of Rio Grande do Sul | Melo A.S.,Federal University of Goais | Callisto M.,Federal University of Minas Gerais
Freshwater Biology | Year: 2010

Lotic ecosystems can be studied on several spatial scales, and usually show high heterogeneity at all of them in terms of biological and environmental characteristics. Understanding and predicting the taxonomic composition of biological communities is challenging and compounded by the problem of scale. Additive diversity partitioning is a tool that can show the diversity that occurs at different scales. We evaluated the spatial distribution of benthic macroinvertebrates in a tropical headwater catchment (S.E. Brazil) during the dry season and compared alpha and beta diversities at the scales of stream segments, reaches, riffles and microhabitats (substratum types: gravels, stones and leaf litter). We used family richness as our estimate of diversity. Sampling was hierarchical, and included three stream segments, two stream reaches per segment, three riffles per reach, three microhabitats per riffle and three Surber sample units per microhabitat. Classification analysis of the 53 families found revealed groups formed in terms of stream segment and microhabitat, but not in terms of stream reaches and riffles. Separate partition analyses for each microhabitat showed that litter supported lower alpha diversity (28%) than did stones (36%) or gravel (42%). In all cases, alpha diversity at the microhabitat scale was lower than expected under a null model that assumed no aggregation of the fauna. Beta diversity among patches of the microhabitats in riffles depended on substratum type. It was lower than expected in litter, similar in stone and higher in gravel. Beta diversities among riffles and among reaches were as expected under the null model. On the other hand, beta diversity observed was higher than expected at the scale of stream segments for all microhabitat types. We conclude that efficient diversity inventories should concentrate sampling in different microhabitats and stream sites. In the present study, sampling restricted to stream segments and substratum types (i.e. excluding riffles and stream reaches) would produce around 75% of all observed families using 17% of the sampling effort employed. This finding indicates that intensive sampling (many riffles and reaches) in few stream segments does not result in efficient assessment of diversity in a region. © 2009 Blackwell Publishing Ltd.

Neto B.A.D.,University of Brasilia | Lapis A.A.M.,Federal University of Rio Grande do Sul | Da Silva Junior E.N.,Federal University of Minas Gerais | Dupont J.,Federal University of Rio Grande do Sul
European Journal of Organic Chemistry | Year: 2013

2,1,3-Benzothiadiazole (BTD) is one of the most important nuclei used in the chemistry of photoluminescent compounds and applicable for light technology. The understanding of its properties and reactions is fundamental for the design and application of these derivatives in molecular organic electronic devices and for other technologies. As a result of their potential as constituents of organic light-emitting diodes, solar cells, liquid crystals, dyes, photovoltaic cells, and many others, attention has been focused on BTD π-extended derivatives with potential use in this exciting area. Herein, we describe their syntheses, properties, reactions, and selected examples of applications in light technology using by BTD (small molecules) as the core. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Santos S.H.S.,Federal University of Minas Gerais | Santos S.H.S.,Laboratory of Health Science | Simoes e Silva A.C.,Federal University of Minas Gerais
Current Clinical Pharmacology | Year: 2014

The Renin-Angiotensin System (RAS) is recognized as the main biological system involved in cardiovascular and hydroelectrolyte homeostasis. It is well established in literature that RAS blockers retard the progression of renal failure in type 1 [angiotensin converting enzyme (ACE) inhibitors] and in type 2 [angiotensin type 1 receptor (AT1) antagonists] diabetes mellitus and in non-diabetic chronic kidney diseases. More recently, it was shown that newer therapeutic agents, the renin inhibitors, also exert renoprotective actions. Obesity is recognized as a proinflammatory state often associated with kidney diseases. Recent publications have associated the RAS axis imbalance leading to a predominance of Angiotensin II effects with changes in adipokine levels and actions. In this context, the aim of the current review is to present current evidence on the potential role of RAS blockers in modulating the interaction between adipokines and obesity-related renal disorders. © 2014 Bentham Science Publishers.

Nagem R.,Ipsemg Hospital | Lazaro-Da-Silva A.,Federal University of Minas Gerais
Obesity Surgery | Year: 2012

Background: Cholecystolithiasis (CL) is a common occurrence after bariatric surgery. Few studies have prospectively analyzed not only gallstone formation after Roux-en-Y gastric bypass (RYGBP), but also its complications and symptoms. This study aimed to identify the incidence of CL itself and symptomatic CL after RYGBP as well as the presence of predictive factors for CL. Methods: A prospective observational study was performed on 40 morbidly obese patients free of gallbladder disease undergoing RYGBP at a public hospital in Brazil between February and October 2007. They were followed up clinically, biochemically (lipid profile), and ultrasonographically at 6 months and 1, 2, and 3 years after surgery. Postoperative prophylactic bile salt therapy (ursodiol) was not prescribed. Of the 40 patients, 38 completed the 3-year follow-up. They were divided into two groups: those who formed gallstones and those who did not. These groups were compared with respect to gender, age, preoperative body mass index (BMI) and lipid profile results, and postoperative percentage of excess BMI lost (%EBL) and lipid profile results. Results: The overall postoperative incidence of CL was 28.9 % (11 out of 38), with a 15.7 % incidence of symptomatic CL (6 out of 38). Gender, age, preoperative BMI, postoperative %EBL, and preoperative and postoperative lipid profile results were not identified as predictive factors for CL after RYGBP. Conclusions: There was a high incidence of CL after RYGBP, occurring primarily in the first 2 years postoperatively. There was no identified predictive factor for gallstone formation after RYGBP. Most patients who formed gallstones were symptomatic, some with potentially severe complications. © 2012 Springer Science + Business Media, LLC.

Santos Jr. J.F.C.,Federal University of Minas Gerais | Dottori H.,Federal University of Rio Grande do Sul | Grosbol P.,European Southern Observatory
Astronomy and Astrophysics | Year: 2013

Context. A recent JHKs study of several grand-design spiral galaxies, including NGC2997, shows a bimodal distribution of their system of star clusters and star forming complexes in colour-magnitude and colour-colour diagrams. In a comparison with stellar population models including gas, the (J - H) vs. (H - Ks) diagram reveals that embedded clusters, still immersed in their parental clouds of gas and dust, generally have a redder (H - Ks) colour than older clusters, whose gas and dust have already been ejected. This bimodal behaviour is also evident in the colour-magnitude diagram MK vs. (J - Ks), where the brightest clusters split into two sequences separating younger from older clusters. In addition, the reddening-free index Qd = (H - Ks) - 0.884 (J - H) has been shown to correlate with age for the young clusters and thus provided an effective way to differentiate the embedded clusters from the older ones. Aims. We aim to study the behaviour of these photometric indices for star cluster systems in the Local Group. In particular, we investigate the effectiveness of the Qd index in sorting out clusters of different ages at their early evolutionary stages. In addition, the whole set of homogeneous measurements will serve as a template for analyses of the populations belonging to distant galaxies that are unresolved clusters or complexes. Methods. Surface photometry was carried out for 2MASS images of populous clusters younger than ~100 Myr whose ages were available. The integrated magnitude and colours were measured to a limiting radius and combined to generate the photometric diagrams. Some clusters, particularly the embedded ones, were studied for the first time using this method. Results. The integrated magnitudes and colours extracted from the surface photometry of the most populous clusters/complexes in the Local Group show the expected bimodal distribution in the colour - colour and colour - magnitude diagrams. In particular, we confirm the index Qd as a powerful tool for distinguishing clusters younger than about 7Myr from older clusters. © ESO 2013.

AS Engineering E CONSULTORIA LTDA. and Federal University of Minas Gerais | Date: 2013-05-29

The present invention discloses a method for preparing and using an absorbent material for apolar compounds or mixtures of apolar compounds, such as organic solvents, mineral oil and derivatives thereof, lubricant oils, edible oils, inter alia. The absorbent material is composed of an fabric matrix of high porosity, low density and high mechanical resistance. This matrix is rendered water-proof, thus acquiring the property of absorbing apolar compounds or mixtures of apolar compounds.

Souza W.F.,Petrobras | Pereira M.C.,Sudan University of Science and Technology | A. Oliveira L.C.,Federal University of Minas Gerais
Fuel | Year: 2012

Composites formed by carbon over magnetite were synthesized by impregnating iron oxide with glycerine. The formation of onion-like carbon was found, presenting concentric turbostratic shells with interplanar spacing of approximately 0.32 nm. The composite presented spherical iron oxide particles with magnetic and amphiphilic properties, which is interesting for use as a catalyst in the petrochemical industry. The magnetic composite presented a high catalytic activity for oxidation of quinoline in the aqueous and mainly in the organic medium. © 2012 Elsevier Ltd. All rights reserved.

Maillard P.,Federal University of Minas Gerais | Bercher N.,CNRS Geophysical Research and Oceanographic Laboratory | Calmant S.,CNRS Geophysical Research and Oceanographic Laboratory
Remote Sensing of Environment | Year: 2015

Radar-based satellite altimetry is well recognized for oceanographic applications. For continental hydrology, its use is complicated by a number of environmental factors such as river width and shape, land cover type in the vicinity of the river banks, and the topography of the relief. These factors make precision vary significantly. Locations where the satellites cross the river can be used as "virtual gauging stations" that can complement the existing network of in situ stations. This article describes processing techniques that take some of these environmental factors (river shape and width) into account to improve the precision of altimetry measurements of the water level. These techniques are based on some a priori information about the river banks and on modeling a phenomenon called "off-nadir hooking". This approach is tested on the São Francisco River in Brazil, which for most of its path is considered narrow for satellite altimetry applied to hydrology. Data from Envisat cover the period 2002-2010 while the recently launched SARAL satellite provided data for 2013. The results show that the accuracy varies significantly depending on a number of environmental factors some of which are discussed in depth. In about one-half of the 16 satellite water gauging stations, the RMS errors are lower than 60. cm and in some cases better than 30. cm. These variations could not be directly related to the river width, but appear to be mostly related to the land cover and to the processing chain that often extracts altimetry points from an off-nadir location. All processing is fully described and the results are presented for both the Envisat/RA-2 and SARAL/Altika altimeters. © 2014 Elsevier Inc.

Faria A.F.M.,Federal University of Minas Gerais | De Souza M.A.M.,UNIMONTES Medical School | Geber S.,Federal University of Minas Gerais
Menopause | Year: 2011

Objective: The aim of this study was to evaluate the effect of estrogen on the vascular resistance of the central retinal artery in postmenopausal women, compared with placebo, using transorbital ultrasound with Doppler velocimetry. Methods: We performed a prospective, randomized, triple-blinded placebo-controlled study. A total of 51 healthy postmenopausal women (follicle-stimulating hormone, >40 IU/L) with a mean (SD) age of 53.6 (4.8) years were studied. Participants were randomly allocated into two groups: placebo (n = 23) and estrogen (0.625 mg conjugated estrogens; n = 28). Transorbital Doppler velocimetric ultrasound was performed before and after treatment in sitting and supine positions. Results: The mean age was similar in both groups. The pulsatility index of the central retinal arteries had a significant decrease after the use of estrogen, when women were evaluated in the sitting position. Women who received placebo did not show any difference in pulsatility index of the central retinal arteries after treatment. When the same comparison was done with participants in the supine position, no difference was observed in either group. Conclusions: Our study demonstrates that estrogen reduces the vascular resistance of the central retinal artery in postmenopausal women because of a vasodilatory effect. © 2011 by The North American Menopause Society.

Penido M.G.M.G.,Federal University of Minas Gerais | Srivastava T.,University of Missouri - Kansas City | Alon U.S.,University of Missouri - Kansas City
Journal of Urology | Year: 2013

Purpose: Due to environmental and social changes (and possibly obesity) as new risk factors for stone formation in adults and changes in imaging techniques, we assessed whether etiologies of primary pediatric urolithiasis have changed, and if relationships exist between the condition and obesity or imaging technique. Materials and Methods: All pediatric patients with documented primary urolithiasis who underwent serum and 24-hour urine analyses between 1999 and 2010 were evaluated. Age at diagnosis, gender, body mass index and imaging technique were recorded. Results: Of the 222 patients (48% male) all had normal serum creatinine, electrolytes and minerals. Primary pediatric urolithiasis was diagnosed by ultrasound in 73% of cases and computerized tomography in 27%. Mean ± SD annual incidence of urolithiasis per 1,000 clinic visits increased from 2.4 ± 1.5 in the first half of the study period to 6.2 ± 2.1 in the second half (p <0.005). Mean ± SD age at diagnosis was 11.8 ± 3.8 years and body mass index was 21.7 ± 5.7 (rate of overweight 15%). A total of 140 patients had urine output less than 1.0 ml/kg per hour, with this being the only abnormality in 54. Hypercalciuria was observed in 46% of patients, hypocitraturia in 10% and high calcium-to-citrate ratio in 51%. Mild absorptive hyperoxaluria was noted in 3 patients and hyperuricosuria in 11, with all 14 exhibiting at least 1 additional abnormality. Cystinuria was present in 1 patient. No etiology was identified in 20 patients (9.0%). Conclusions: Oliguria and hypercalciuria continue to be the most common etiologies of pediatric primary urolithiasis, followed by hypocitraturia. The recent increase in stone incidence is unlikely due to increased use of computerized tomography. Incidence of obesity was not higher than in the general population. Hyperoxaluria and cystinuria are rare, and thus might not be indicated in the initial analysis. © 2013 American Urological Association Education and Research, Inc.

Alvisi P.P.,Petrobras | Lins V.F.C.,Federal University of Minas Gerais
Engineering Failure Analysis | Year: 2011

After 5 years processing about 6500m3/day of reduced crude oil with an average total acid number of 1.2mgKOH/g and total sulfur content of 0.8wt%, a vacuum distillation plant had its operations interrupted to suffer maintenance and inspection. Following theoretical considerations, this work shows the inspection outcome and tries to stress the several morphologies resulting from the naphthenic acid attack as well as different types of action by which the naphthenic acid corrosion occurs in a vacuum distillation plant. © 2011 Elsevier Ltd.

Da Silva A.Q.G.,Federal University of Minas Gerais | Da Silva A.Q.G.,University of New Mexico | Fontes M.A.P.,Federal University of Minas Gerais | Kanagy N.L.,University of New Mexico
Brain Research | Year: 2011

Sleep apnea is characterized by increased sympathetic activity and is associated with systemic hypertension. Angiotensin (Ang) peptides have previously been shown to participate in the regulation of sympathetic tone and arterial pressure in the hypothalamic paraventricular nucleus (PVN) neurons. We investigated the role of endogenous Ang peptides within the PVN to control blood pressure in a rat model of sleep apnea-induced hypertension. Male Sprague-Dawley rats (250 g), instrumented with bilateral guide cannulae targeting the PVN, received chronic infusion of Ang antagonists (A-779, Ang-(1-7) antagonist; losartan and ZD7155, AT1 antagonists; PD123319, AT2 receptor antagonist, or saline vehicle). A separate group received an infusion of the GABAA receptor agonist (muscimol) to inhibit PVN neuronal activity independent of angiotensin receptors. After cannula placement, rats were exposed during their sleep period to eucapnic intermittent hypoxia (IH; nadir 5% O2; 5% CO2 to peak 21% O2; 0% CO2) 20 cycles/h, 7 h/day, for 14 days while mean arterial pressure (MAP) was measured by telemetry. In rats receiving saline, IH exposure significantly increased MAP (+ 12 ± 2 mm Hg vs. Sham -2 ± 1 mm Hg P < 0.01). Inhibition of PVN neurons with muscimol reversed the increase in MAP in IH rats (MUS: -9 ± 4 mm Hg vs. vehicle + 12 ± 2 mm Hg; P < 0.01). Infusion of any of the Ang antagonists also prevented the rise in MAP induced by IH (A-779: -5 ± 1 mm Hg, losartan: -9 ± 4 mm Hg, ZD7155: -11 ± 4 mm Hg and PD123319: -4 ± 3 mm Hg; P < 0.01). Our results suggest that endogenous Ang peptides acting in the PVN contribute to IH-induced increases in MAP observed in this rat model of sleep apnea-induced hypertension. © 2010 Elsevier B.V. All rights reserved.

De Rezende R.B.,Stockholm School of Economics | Ferreira M.S.,Federal University of Minas Gerais
Journal of Forecasting | Year: 2013

This paper compares the in-sample fitting and the out-of-sample forecasting performances of four distinct Nelson-Siegel class models: Nelson-Siegel, Bliss, Svensson, and a five-factor model we propose in order to enhance the fitting flexibility. The introduction of the fifth factor resulted in superior adjustment to the data. For the forecasting exercise the paper contrasts the performances of the term structure models in association with the following econometric methods: quantile autoregression evaluated at the median, VAR, AR, and a random walk. As a pattern, the quantile procedure delivered the best results for longer forecasting horizons. Copyright © 2011 John Wiley & Sons, Ltd.

Penido M.G.M.G.,Federal University of Minas Gerais | Alon U.S.,University of Missouri - Kansas City
Pediatric Nephrology | Year: 2014

The common denominator for all types of rickets is hypophosphatemia, leading to inadequate supply of the mineral to the growing bone. Hypophosphatemia can result from insufficient uptake of the mineral from the gut or its disproportionate losses in the kidney, the latter being caused by either tubular abnormalities per se or the effect on the tubule of circulating factors like fibroblast growth factor-23 and parathyroid hormone (PTH). High serum levels of the latter result in most cases from abnormalities in vitamin D metabolism which lead to decreased calcium absorption in the gut and hypocalcemia, triggering PTH secretion. Rickets is a disorder of the growth plate and hence pediatric by definition. However, it is important to recognize that the effect of hypophosphatemia on other parts of the skeleton results in osteomalacia in both children and adults. This review addresses the etiology, pathophysiologic mechanisms, clinical manifestations and treatment of entities associated with hypophosphatemic rickets due to perturbations in renal tubular function. © 2013 IPNA.

Penido M.G.M.G.,Federal University of Minas Gerais | Alon U.S.,University of Missouri - Kansas City
Pediatric Nephrology | Year: 2012

Phosphate is one of the most abundant minerals in the body, and its serum levels are regulated by a complex set of processes occurring in the intestine, skeleton, and kidneys. The currently known main regulators of phosphate homeostasis include parathyroid hormone (PTH), calcitriol, and a number of peptides collectively known as the phosphatonins of which fibroblast growth factor-23 (FGF-23) has been best defined. Maintenance of extracellular and intracellular phosphate levels within a narrow range is important for many biological processes, including energy metabolism, cell signaling, regulation of protein synthesis, skeletal development, and bone integrity. The presence of adequate amounts of phosphate is critical for the process of apoptosis of mature chondrocytes in the growth plate. Without the presence of this mineral in high enough quantities, chondrocytes will not go into apoptosis, and the normal physiological chain of events that includes invasion of blood vessels and the generation of new bone will be blocked, resulting in rickets and delayed growth. In the rest of the skeleton, hypophosphatemia will result in osteomalacia due to an insufficient formation of hydroxyapatite. This review will address phosphate metabolism and its role in bone health. © 2012 IPNA.

Chilingaryan S.A.,Federal University of Minas Gerais | Rodriguez-Lara B.M.,National Institute of Astrophysics, Optics and Electronics
Journal of Physics A: Mathematical and Theoretical | Year: 2013

We study a system composed of two nonidentical qubits coupled to a single-mode quantum field. We calculate the spectra of the system in the deep-strong-coupling regime via perturbation theory up to second-order corrections and show that it converges to two forced oscillator chains for cases well into that regime. Our predictions are confirmed by the numerical calculation of the spectra using a parity decomposition of the corresponding Hilbert space. The numerical results point to two interesting types of behavior in the ultra-strong-coupling regime: the rotating wave approximation is valid for some particular cases and there exist crossings in the spectra within each parity subspace. We also present the normal modes of the system and give an example of the time evolution of the mean photon number, population inversion, von Neumann entropy and Wootters concurrence in the ultra-strong- and deep-strong-coupling regimes. © 2013 IOP Publishing Ltd.

Oliveira L.C.A.,Federal University of Minas Gerais | Portilho M.F.,Petrobras | Silva A.C.,Federal University of Minas Gerais | Taroco H.A.,Federal University of Minas Gerais | Souza P.P.,Federal University of Minas Gerais
Applied Catalysis B: Environmental | Year: 2012

The niobia (Nb 2O 5) obtained in this study was modified by pretreatment with hydrogen peroxide to produce a bifunctional catalyst (Nb 2O 5//H 2O 2) with both acidic and oxidizing properties. The oxidizing properties of niobia were obtained by the generation of peroxo groups on the catalyst surface. The catalytic conversion of glycerin showed high activity using H 2O 2 as the oxidant. The catalytic tests monitored by mass spectrometry (ESI-MS) suggested the formation of ethers obtained by the condensation of glycerol (m/z=167, 223, 240). Furthermore, it was observed that the modification of the catalyst directs the formation of larger molecules such as triglycerol compared to niobia without pretreatment with H 2O 2. © 2012 Elsevier B.V.

Pinto H.A.,Federal University of Minas Gerais | Brant S.V.,University of New Mexico | de Melo A.L.,Federal University of Minas Gerais
Acta Tropica | Year: 2014

Species of Trichobilharzia are the main etiological agents of cercarial dermatitis in humans, which is considered a re-emerging disease. Despite the diversity and global distribution of species of this genus, studies of Trichobilharzia are scarce in South America. The goal of our investigations is better understand the diversity, distribution and life cycle of avian schistosomes and their likely role in causing dermatitis in Brazil. As part of this effort, cercariae found in naturally infected Physa marmorata were identified by morphological and molecular (mitochondrial cox1, nuclear ITS1 and 28S gene regions) methods as Trichobilharzia sp. These cercariae are similar morphologically to T. jequitibaensis described previously from Brazil and similar genetically to the North American physid transmitted species T. querquedulae and T. physellae. This is the first report of a potential agent of cercarial dermatitis from naturally infected snails from Brazil and first molecular characterization of a South American species of Trichobilharzia. A discussion follows concerning the potential role of this species has in outbreaks of dermatitis in Brazil. © 2014 Elsevier B.V.

Barbosa J.A.A.,Vila da Serra Hospital | Mota C.C.C.,Federal University of Minas Gerais | Simoes E Silva A.C.,Federal University of Minas Gerais | Nunes M.D.C.P.,Ecocenter Hospital Socor | Barbosa M.M.,Ecocenter Hospital Socor
European Heart Journal Cardiovascular Imaging | Year: 2013

AimsObesity has become a major health problem worldwide. Cardiovascular abnormalities have been described not only in obese adults but also in obese children and adolescents. The aim of the present study was to investigate left and right, systolic and diastolic ventricular dysfunction in obese paediatric patients without comorbidities using 2D speckle tracking longitudinal strain.Methods and resultsDoppler echocardiogram was performed on 50 obese children and adolescents with body mass index (BMI) above the 95th percentile (OG) and 46 non-obese sex- and age-matched controls (CG). Systolic and diastolic functions of both ventricles were investigated through conventional Doppler echocardiography. Tissue Doppler imaging (TDI), colour Doppler myocardial imaging (CDMI), and two-dimensional (2D) speckle tracking were also used to analyse ventricular performance in both groups. Left-ventricular (LV) ejection fraction was similar between groups (68.2 ± 6.2 vs. 68.3 ± 5.3, P = 0.931). Left-ventricular diastolic parameters did not differ between groups, except for a lower mitral A wave (61.6 ± 13.0 vs. 51.9 ± 10.0 cm/s, P > 0.001) and higher E/A ratio (1.8 ± 0.5 vs. 2.1 ± 0.4, P = 0.007) in the controls. Left-ventricular global strain was lower in the OG by both methods (CDMI: 22.0 ± 2.8 vs. 24.6 ± 2.7%, P = 0.020; 2D speckle tracking: 18.4 ± 1.6 vs. 20.4 ± 1.7%, P < 0.001). In multivariate analysis, 2D longitudinal global strain correlated negatively with BMI, r = -0.433, p = 0.002.ConclusionAlthough EF was not different between the two groups, LV 2D speckle tracking longitudinal strain was lower in the obese group, even in the absence of other comorbidities, indicating that obesity effects on LV function is an early finding in obesity. © 2013 Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013.

Robles Robles R.A.,National Institute of Astrophysics, Optics and Electronics | Chilingaryan S.A.,Federal University of Minas Gerais | Rodriguez-Lara B.M.,National Institute of Astrophysics, Optics and Electronics | Lee R.-K.,National Tsing Hua University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

We study the ground state of a finite-size ensemble of interacting qubits driven by a quantum field. We find a maximally entangled W state in the ensemble part of the system for a certain region of the coupling parameters. The area of this region decreases as the ensemble size increases and, in the classical limit, becomes the line in parameter space that defines the phase transition of the system. In the classical limit, we also study the dynamics of the system and its transition from order to disorder for initial energies close to the ground-state energy. We find that a critical energy providing this transition is related to the minimum of the projection of the total angular momentum of the quantum system in the z direction. © 2015 American Physical Society.

Silva L.S.,Federal University of Minas Gerais | Silva L.S.,Banco Do Brazil SA | Barreto S.M.,Federal University of Minas Gerais
BMC Public Health | Year: 2010

Background. In most countries, the financial service sector has undergone great organizational changes in the past decades, with potential negative impact on bank workers' mental health. The aim of this paper is to estimate the prevalence of minor psychiatric disorders (MPD) among Brazilian bank workers and to investigate whether they are associated with an adverse psychosocial working environment. Methods. A cross-sectional study of a random sample of 2,500 workers in a Brazilian state bank in 2008. The presence of MPD was determined by the General Health Questionnaire.(GHQ). Psychosocial work conditions were assessed by means of the Effort-Reward Imbalance (ERI) and Job Content Questionnaire (JCQ). The presence and magnitude of the independent associations between MPD and adverse psychosocial working conditions were determined by Prevalence Ratios, obtained by Poisson regression. Results. From 2,337 eligible workers, 88% participated. The prevalence of MPD was greater among women (45% vs. 41%; p > 0.05). In the multivariate analysis, the prevalence of MPD was twice as high among bank workers exposed to high psychological demand and low control at work and under high effort and low reward working conditions. The lack of social support at work and the presence of over-commitment were also associated with higher prevalence of MPD. A negative interaction effect was found between over-commitment and effort-reward imbalance. Conclusion. The prevalence of MPD is high among bank workers. The results reinforce the association between MPD and adverse psychosocial working conditions, assessed by the JCQ and ERI models. The direction of the interaction observed between over-commitment and ERI was contrary to what was expected. © 2010 Silva and Barreto; licensee BioMed Central Ltd.

Lazzari C.R.,CNRS Research Institute of Insect Biology | Pereira M.H.,Federal University of Minas Gerais | Lorenzo M.G.,Centro Of Pesquisa Rene Rachou
Memórias do Instituto Oswaldo Cruz | Year: 2013

Many arthropod species have adopted vertebrate blood as their main food source. Blood is rich in nutrients and, except for the presence of parasites, sterile. However, this food source is not freely available, nor is obtaining it devoid of risk. It circulates inside vessels hidden underneath the skin of mobile hosts that are able to defend themselves and even predate the insects that try to feed on them. Thus, the haematophagous lifestyle is associated with major morphological, physiological and behavioural adaptations that have accumulated throughout the evolutionary history of the various lineages of blood-sucking arthropods. These adaptations have significant consequences for the evolution of parasites as well as for the epidemiology of vector-transmitted diseases. In this review article, we analyse various aspects of the behaviour of triatomine bugs to illustrate how each behavioural trait represents a particular adaptation to their close association with their hosts, which may easily turn into predators. Our aim is to offer to the reader an up-to-date integrative perspective on the behaviour of Chagas disease vectors and to propose new research avenues to encourage both young and experienced colleagues to explore this aspect of triatomine biology.

Cota G.F.,Laboratory of Clinical Research | Cota G.F.,Eduardo Of Menezes Hospital | de Sousa M.R.,Federal University of Minas Gerais | Fereguetti T.O.,Eduardo Of Menezes Hospital | Rabello A.,Laboratory of Clinical Research
PLoS Neglected Tropical Diseases | Year: 2013

Objective:We conducted a systematic literature review with indirect comparison of studies evaluating therapeutic efficacy and toxicity associated to visceral leishmaniasis (VL) therapy among HIV infected individuals.Main outcome measurements:The outcomes of interest were clinical and parasitological cure, mortality, and adverse events.Methods:PRISMA guidelines for systematic reviews and Cochrane manual were followed. Sources were MEDLINE, LILACS, EMBASE, Web of Knowledge databases and manual search of references from evaluated studies. We included all studies reporting outcomes after VL treatment, regardless of their design. Study quality was evaluated systematically by using the Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomized studies in meta-analyses. Comprehensive Meta-Analysis software v.2.2.048 was used to perform one-group meta-analysis of study arms with the same drug to estimate global rates of success and adverse events with each drug. These estimates were used, when possible, to indirectly compare treatment options, adjusted for CD4 count. Direct comparison was pooled when available.Results:Seventeen studies reporting five treatment regimens and outcome of 920 VL episodes occurring in HIV infected individuals were included. The main outstanding difference in outcome among the treatment regimens was observed in mortality rate: it was around 3 times higher with high-dose antimony use (18.4%, CI 95% 13.3-25%), indirectly compared to lipid formulations of amphotericin B treatment (6.1%, CI 95% 3.9-9.4%). It was observed, also by indirect comparison, higher rates of clinical improvement in study arms using amphotericin B than in study arms using pentavalent antimonial therapy (Sbv). The parasitological cure, an outcome that presented some degree of risk of selection and verification bias, had rates that varied widely within the same treatment arm, with high heterogeneity, hampering any formal comparison among drugs. One direct comparison of amphotericin and antimoniate was possible combining results of two studies and confirming the superiority of amphotericin.Conclusions:Available evidence suggests that amphotericin is superior to antimony treatment. Death rate using antimoniate high dose is unacceptably high. Randomized controlled trials are necessary to compare different formulations and doses of amphotericin, alternative therapies and drug combinations. © 2013 Cota et al.

Pinheiro P.F.M.,Odilon Behrens Hospital | e Silva A.C.S.,Federal University of Minas Gerais | Pereira R.M.,Odilon Behrens Hospital
World Journal of Gastroenterology | Year: 2012

Esophageal atresia (EA) with or without tracheoesophageal fistula (TEF) is the most common congenital anomaly of the esophagus. The improvement of survival observed over the previous two decades is multifactorial and largely attributable to advances in neonatal intensive care, neonatal anesthesia, ventilatory and nutritional support, antibiotics, early surgical intervention, surgical materials and techniques. Indeed, mortality is currently limited to those cases with coexisting severe life-threatening anomalies. The diagnosis of EA is most commonly made during the first 24 h of life but may occur either antenatally or may be delayed. The primary surgical correction for EA and TEF is the best option in the absence of severe malformations. There is no ideal replacement for the esophagus and the optimal surgical treatment for patients with long-gap EA is still controversial. The primary complications during the postoperative period are leak and stenosis of the anastomosis, gastro-esophageal reflux, esophageal dysmotility, fistula recurrence, respiratory disorders and deformities of the thoracic wall. Data regarding long-term outcomes and follow-ups are limited for patients following EA/TEF repair. The determination of the risk factors for the complicated evolution following EA/TEF repair may positively impact long-term prognoses. Much remains to be studied regarding this condition. This manuscript provides a literature review of the current knowledge regarding EA. © 2012 Baishideng. All rights reserved.

Franca A.S.,Federal University of Minas Gerais | Oliveira L.S.,Federal University of Minas Gerais | Nunes A.A.,Vilma Alimentos | Alves C.C.O.,Federal University of Minas Gerais
Bioresource Technology | Year: 2010

Defective coffee press cake, a residue from coffee oil biodiesel production, was evaluated as an adsorbent for removal of basic dyes (methylene blue - MB) from aqueous solutions. The adsorbent was prepared by microwave treatment, providing a significant reduction in processing time coupled to an increase in adsorption capacity in comparison to conventional carbonization in a muffle furnace. Batch adsorption tests were performed at 25 °C and the effects of particle size, contact time, adsorbent dosage and initial solution pH were investigated. Adsorption kinetics was better described by a second-order model. The experimental adsorption equilibrium data were fitted to Langmuir, Freundlich and Tempkin adsorption models, with Langmuir providing the best fit. The results presented in this study show that microwave activation presents great potential as an alternative method in the production of adsorbents. © 2009 Elsevier Ltd. All rights reserved.

Jorio A.,Federal University of Minas Gerais | Souza Filho A.G.,Federal University of Ceará
Annual Review of Materials Research | Year: 2016

This article reviews recent advances on the use of Raman spectroscopy to study and characterize carbon nanostructures. It starts with a brief survey of Raman spectroscopy of graphene and carbon nanotubes, followed by recent developments in the field. Various novel topics, including Stokes-anti-Stokes correlation, tip-enhanced Raman spectroscopy in two dimensions, phonon coherence, and high-pressure and shielding effects, are presented. Some consequences for other fields-quantum optics, near-field electromagnetism, archeology, materials and soil sciences-are discussed. The review ends with a discussion of new perspectives on Raman spectroscopy of carbon nanostructures, including how this technique can contribute to the development of biotechnological applications and nanotoxicology. Copyright © 2016 by Annual Reviews. All rights reserved.

Mansur H.S.,Federal University of Minas Gerais | Mansur A.A.P.,Federal University of Minas Gerais | Curti E.,Federal University of Juiz de fora | De Almeida M.V.,Federal University of Juiz de fora
Carbohydrate Polymers | Year: 2012

Novel carbohydrate-based hybrids combining chitosan and chemically modified chitosan with CdS inorganic nanoparticles were designed and prepared via aqueous route at room temperature. N,N,N-trimethylchitosan (TM-chitosan) was synthesized aiming at substantially improving the water solubility of chitosan for producing stable colloidal systems. UV-vis spectroscopy, photoluminescence spectroscopy, Nuclear magnetic resonance spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the synthesis and the relative stability of biopolymer-capped CdS nanocrystals. The results have clearly indicated that chitosan and chitosan-derivative (TM-chitosan) were remarkably effective on nucleating and stabilizing CdS nanoparticles in aqueous suspensions. In addition, the CdS nanocrystals were produced in the so-called "quantum-size confinement regime", with the calculated average size below 3.5 nm and fluorescent activity in the visible range of the spectra. Therefore, a new single-step process was developed for the bioconjugation of quantum dots with water soluble chemically functionalized carbohydrates at room temperature for potential biomedical applications. © 2012 Elsevier Ltd.

Menezes De Padua C.A.,Federal University of Minas Gerais | Moura C.S.,McGill University
Clinical Drug Investigation | Year: 2014

Background and Objective: Although not designed for research purposes, medical charts can be a unique source for obtaining information on long-term adverse drug reactions. This study aimed to assess the availability of key information on paper-based patient medical records needed to detect long-term adverse reactions to antiretroviral therapy (ART). Methods: This is an ongoing historical cohort study carried out in three public HIV/AIDS referral centers in Belo Horizonte, Brazil. Medical charts of treatment-naïve HIV-infected adult patients initiating ART between 2001 and 2005 were reviewed for a follow-up period of up to 5 years after the first ART prescription. Descriptive analysis was performed by estimating the absolute and relative frequencies of selected variables. The Naranjo algorithm was employed to assess the availability of data on long-term adverse outcomes in medical charts. Results: A total of 233 medical charts were eligible for study and 26.1 % contained at least one long-term adverse reaction, corresponding to 45 cases of dyslipidemia (19.3 %), 16 (6.9 %) of lipodystrophy and 5 of type 2 diabetes mellitus (2.1 %). Temporal relationship and ART switch could be better documented from medical charts. Information on reasons for ART switching and alternative causes for adverse reactions was very lacking. Conclusions: Specific tools should be developed and included in medical routines to improve adverse reaction reporting by physicians and other health professionals. This could be implemented simultaneously with the transition from paper to electronic medical charts in Brazil, facilitating the identification of long-term adverse reactions to antiretroviral drugs in epidemiological studies and in clinical practice. © 2014 Springer International Publishing.

Barbosa M.P.T.,Federal University of Minas Gerais | Da Costa Rocha M.O.,Federal University of Minas Gerais | De Oliveira A.B.,Federal University of Minas Gerais | Lombardi F.,University of Milan | Ribeiro A.L.P.,Federal University of Minas Gerais
Europace | Year: 2013

AimsImplantable cardioverter-defibrillators (ICDs) are now a first-line option for prevention of sudden death in Chagas disease (ChD). However, efficacy and safety of ICD treatment in ChD remains controversial. The aim of our study was to compare clinical outcome after ICD implantation in ChD and non-ChD patients.Methods and resultsThe study population consists of patients who received ICD implantation in a tertiary Reference Center for ChD in Brazil. The primary endpoint of the study was appropriate therapy (appropriate shocks or anti-tachycardia pacing); the secondary endpoint was the event-free survival defined as absence of death or appropriate therapy. Three hundred thirty-five patients were followed for the median time of 266 days. Sixty-five patients had ChD. Appropriate ICD therapy occurred in 32 (49.2%) ChD and in 19 (27.1%) non-ChD patients (P=0.005). Ventricular tachycardia occurred in 27 (42%) ChD and in 16 (23%) non-ChD (P = 0.01) patients. There was a statistically significant difference in event-free survival between the group of patients with and without ChD (P=0.004). The median event-free survival was 230 days (95% confidence interval, CI: 113-347) in patients with ChD and 549 days (95% CI: 412-687) in non-ChD patients. Chagas disease double the risk of the patient to have appropriate therapy (hazard ratio, HR = 2.2, 95% CI = 1.2-4.3, P = 0.02) and appropriate therapy or death (HR = 2.2, 95% CI = 1.2-4.2, P = 0.01) in multivariate analysis. There were 16 deaths (11.8%) with 8 deaths in each group and five inappropriate shocks (3.7%) with one in ChD patients (1.6%).ConclusionThe higher frequency of appropriate ICD therapy and the shorter event-free survival in ChD patients are consistent with the presence of an arrhythmogenic substrate that characterizes this cardiomyopathy. © 2013 The Author.

Bendo C.B.,Federal University of Minas Gerais | Paiva S.M.,Federal University of Minas Gerais | Varni J.W.,Texas A&M University | Vale M.P.,Federal University of Minas Gerais
Community Dentistry and Oral Epidemiology | Year: 2014

Objectives To evaluate the impact of traumatic dental injuries (TDI) on oral health-related quality of life (OHRQoL) among Brazilian adolescents. Methods A population-based case-control study was carried out, which was nested to a cross-sectional study with a sample of 1215 adolescents aged 11-14 years from Belo Horizonte, Brazil. OHRQoL was measured using the Brazilian version of the Child Perceptions Questionnaire (CPQ11-14)-Impact Short Form (ISF:16). Two-step cluster analysis was performed to define cases and controls based on CPQ11-14-ISF:16 scores. This method considers the pattern of responses for each item separately and how important each item is to the formation of clusters. The case group included those adolescents who presented higher negative impact on OHRQoL (n = 405), while the control group included those with lower negative impact (n = 810). Two controls for each case were individually matched from the same school and gender. The main independent variable was TDI, diagnosed by the Andreasen's classification. Untreated dental caries, malocclusion, and age were confounding variables. Conditional logistic regression analysis was performed with the significance level set at 5%. Results A multiple conditional logistic regression model demonstrates that adolescents diagnosed with fracture involving dentin and/or pulp had a 2.40-fold greater chance of presenting high negative impact on QHRQoL [95% CI = 1.26-4.58; P = 0.008] than those without evidence of fractures. Enamel fracture only [P = 0.065] and restored fractures [P = 0.072] were not statistically associated with OHRQoL. Conclusions Adolescents with more severe untreated TDI, such as fractures involving dentin and/or pulp, were more likely to self-report a higher negative impact on their OHRQoL than those without TDI. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Carr I.M.,University of Leeds | Markham S.A.F.,University of Leeds | Pena S.D.J.,Federal University of Minas Gerais
Human Mutation | Year: 2011

In some clinical and research settings, it is often necessary to identify the true level of "identity by descent" (IBD) between two individuals. However, as the individuals become more distantly related, it is increasingly difficult to accurately calculate this value. Consequently, we have developed a computer program that uses genome-wide SNP genotype data from related individuals to estimate the size and extent of IBD in their genomes. In addition, the software can compare a couple's IBD regions with either the autozygous regions of a relative affected by an autosomal recessive disease of unknown cause, or the IBD regions in the parents of the affected relative. It is then possible to calculate the probability of one of the couple's children suffering from the same disease. The software works by finding SNPs that exclude any possible IBD and then identifies regions that lack these SNPs, while exceeding a minimum size and number of SNPs. The accuracy of the algorithm was established by estimating the pairwise IBD between different members of a large pedigree with varying known coefficients of genetic relationship (CGR). © 2011 Wiley Periodicals, Inc.

Goncalves B.,Federal University of Juiz de fora | Dias Junior M.M.,Federal University of Juiz de fora | Ribeiro B.J.,Federal University of Minas Gerais
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

The exact Foldy-Wouthuysen transformation is performed in order to study the Dirac field interacting with many possible external fields associated with CPT-Lorentz violation. We also derived the calculation of equations of motion as well as the generalized Lorentz force corrected by the mentioned external fields. The main point is the interaction between the Dirac particle and the terms that have the multiplication of the electromagnetic field and the terms that break CPT-Lorentz. Finally, with the transformed Hamiltonian we were able to write an expression for the bound state of the theory and analyze it in the atomic experiments context. This result is an analytical expression that gives the possibility of the weakness of CPT-Lorentz terms to be compensated by the presence of a strong magnetic field. © 2014 American Physical Society.

Cota G.F.,Laboratory of Clinical Research | Cota G.F.,Hospital Eduardo Of Menezes | de Sousa M.R.,Federal University of Minas Gerais | Demarqui F.N.,Federal University of Minas Gerais | Rabello A.,Laboratory of Clinical Research
PLoS Neglected Tropical Diseases | Year: 2012

Background: Human visceral leishmaniasis (VL), a potentially fatal disease, has emerged as an important opportunistic condition in HIV infected patients. In immunocompromised patients, serological investigation is considered not an accurate diagnostic method for VL diagnosis and molecular techniques seem especially promising. Objective: This work is a comprehensive systematic review and meta-analysis to evaluate the accuracy of serologic and molecular tests for VL diagnosis specifically in HIV-infected patients. Methods: Two independent reviewers searched PubMed and LILACS databases. The quality of studies was assessed by QUADAS score. Sensitivity and specificity were pooled separately and compared with overall accuracy measures: diagnostic odds ratio (DOR) and symmetric summary receiver operating characteristic (sROC). Results: Thirty three studies recruiting 1,489 patients were included. The following tests were evaluated: Immunofluorescence Antibody Test (IFAT), Enzyme linked immunosorbent assay (ELISA), immunoblotting (Blot), direct agglutination test (DAT) and polimerase chain reaction (PCR) in whole blood and bone marrow. Most studies were carried out in Europe. Serological tests varied widely in performance, but with overall limited sensitivity. IFAT had poor sensitivity ranging from 11% to 82%. DOR (95% confidence interval) was higher for DAT 36.01 (9.95-130.29) and Blot 27.51 (9.27-81.66) than for IFAT 7.43 (3.08-1791) and ELISA 3.06 (0.71-13.10). PCR in whole blood had the highest DOR: 400.35 (58.47-2741.42). The accuracy of PCR based on Q-point was 0.95; 95%CI 0.92-0.97, which means good overall performance. Conclusion: Based mainly on evidence gained by infection with Leishmania infantum chagasi, serological tests should not be used to rule out a diagnosis of VL among the HIV-infected, but a positive test at even low titers has diagnostic value when combined with the clinical case definition. Considering the available evidence, tests based on DNA detection are highly sensitive and may contribute to a diagnostic workup. © 2012 Cota et al.

Queiroz D.M.M.,Federal University of Minas Gerais | Rocha A.M.C.,Federal University of Minas Gerais | Crabtree J.E.,University of Leeds
Gut Microbes | Year: 2013

Helicobacter pylori infection is predominantly acquired early in life. The prevalence of the infection in childhood is low in developed countries, whereas in developing countries most children are infected by 10 y of age. In poor resource settings, where malnutrition, parasitic/enteropathogen and H. pylori infection co-exist in young children, H. pylori might have potentially more diverse clinical outcomes. This paper reviews the impact of childhood H. pylori infection in developing countries that should now be the urgent focus of future research. The extra-gastric manifestations in early H. pylori infection in infants in poor resource settings might be a consequence of the infection associated initial hypochlorhydria. The potential role of H. pylori infection on iron deficiency, growth impairment, diarrheal disease, malabsorption and cognitive function is discussed in this review. © 2013 Landes Bioscience.

Chrcanovic B.R.,Av. Raja Gabaglia 1000 1209 | Abreu M.H.N.G.,Federal University of Minas Gerais
Oral and Maxillofacial Surgery | Year: 2013

Purpose: This systematic review attempted to answer the focused questions: "What is the survival rate of zygomatic implants (ZIs)?" and "What are the most common complications related to surgery of zygomatic implants?" Methods: An electronic search without date or language restrictions was undertaken in PubMed in March 2012. Titles and abstracts from these results (n = 123) were read for identifying studies that meet the eligibility criteria. Eligibility criteria included studies reporting clinical series of zygomatic implants (ZIs). Because of the scarcity of articles with high-level grades of evidence, all articles, including studies with few case reports, were considered for inclusion. All reference lists of the selected and review studies were hand-searched for additional papers that might meet the eligibility criteria. Simple case report articles were not included. Review articles without original data were excluded. Quantitative data extracted from the included studies that provided data for the period of failure of ZIs were used for the calculation of interval survival rate during each follow-up period and cumulative survival rate (CSR) over a 12-year period. Results: Thirty-seven studies were identified without repetition and five more studies were included by hand-searching, giving a total of 42; 12 evaluated the use of ZI applied with immediate function protocols and 3 for rehabilitating patients after maxillary resections for tumor ablations. These latter three studies showed smaller ZI success. Postoperative complications reported were as follows: 70 cases of sinusitis, 48 of soft tissue infection, 15 of paresthesia, and 17 cases of oroantral fistulas. However, this number may be underestimated, since most of the studies did not mention the presence or absence of these complications. Most ZI failures were detected at the abutment connection phase (6 months after the surgery of implant placement) or before. The CSR over a 12-year period was 96.7 %. Conclusions: Despite the high survival rate observed, there is an impending need for conducting randomized controlled clinical trials to test the efficacy of these implants in comparison with the other techniques to treat the atrophic maxilla. Thus, the findings reported in the review must be interpreted with considerable caution. Moreover, more studies with longer follow-up periods involving adequate number of ZIs are needed. This will help to obtain a better understanding of the survival of ZIs in a long term. It is suggested that multicenter, randomized controlled clinical trials and longer clinical studies should be implemented in this area, before recommending routine use of ZIs for patients could be given. The placement of zygomatic implants requires very experienced surgeons because it is not risk free since delicate anatomic structures such as the orbita and brain may be involved. © 2012 Springer-Verlag.

Turrer H.D.G.,Samarco Mineraao S. A. Ponta Ubu | Peres A.E.C.,Federal University of Minas Gerais
Minerals Engineering | Year: 2010

Iron ore concentration through flotation represents an important application of reagents in mineral processing. Nowadays all Brazilian iron ore concentrators use starch as iron oxides depressant. This study evaluated the application of other depressants, which are commonly used in other flotation systems. Six carboxymethylcelluloses, three lignosulphonates, one guar gum, and four humic acids samples were investigated in the reverse cationic flotation. Laboratory flotation tests showed that only two polymers (one carboxymethylcellulose and guar gum) reached the same performance as starch. The superior performance of these reagents was due to the presence of the glucopyranose ring. The use of polymers blends led to promising results. © 2010 Elsevier Ltd. All rights reserved.

Federal University of Minas Gerais and Minasfungi De Brazil | Date: 2013-03-20

The present invention refers to pharmaceutical formulations obtained from the aqueous extract of the fungus Agaricus blazei and its purified fractions for the treatment of leishmaniasis. More particularly, the present invention discloses formulations preferably for topic and oral use, in form of solid, semi-solid and liquid pharmaceutical formulations selected from a group consisting of gel, cream, ointment, pastes, emulsions in general, solutions, tablets and capsules for the treatment of canine and human cutaneous and visceral leishmaniasis.

Nunes M.C.P.,Federal University of Minas Gerais | Gelape C.L.,Federal University of Minas Gerais | Ferrari T.C.A.,Federal University of Minas Gerais
International Journal of Infectious Diseases | Year: 2010

Objectives: To describe the epidemiological, clinical, and laboratory profile of infective endocarditis (IE) at a Brazilian tertiary care center, and to identify the predictors of in-hospital mortality. Methods: Data from 62 patients who fulfilled the modified Duke's criteria for IE during a seven-year period were gathered prospectively. The Cox proportional hazards model was used to identify predictive factors for death. Results: The mean age of patients was 45 years, and 39 patients (63%) were male. The median time from admission to diagnosis was 15 days. Rheumatic heart disease was the predominant underlying heart condition (39%), followed by valvular prosthesis (31%). Neurological complications were observed in 12 patients (19%). Echocardiography demonstrated one or more vegetations in 84% of cases. The infective agent was identified in 65% of cases, and the most frequent causative agents were staphylococci (48%), followed by streptococci (20%). The median duration of hospitalization was 39 days. Surgery was performed during the acute phase of the IE in 53% of cases. The overall in-hospital mortality was 31%. On multivariate analysis, vegetation length >13. mm remained the only independent predictor of in-hospital mortality (hazard ratio 1.05 per millimeter, 95% confidence interval 1.003-1.110, p=0.038). Conclusions: IE remains a severe disease affecting the young population in Brazil, and rheumatic heart disease continues to be the most common underlying heart condition. Large vegetation size, assessed early in the course of IE by transesophageal echocardiography, along with the clinical and microbiological features, may predict in-hospital death. © 2009 International Society for Infectious Diseases.

Petroianu A.,Federal University of Minas Gerais
International Journal of Surgery | Year: 2012

Appendicitis is the most common abdominal emergency. While the clinical diagnosis may be straightforward in patients who present with classic signs and symptoms, atypical presentations may result in diagnostic confusion and delay in treatment. Abdominal pain is the primary presenting complaint of patients with acute appendicitis. Nausea, vomiting, and anorexia occur in varying degrees. Abdominal examination reveals localised tenderness and muscular rigidity after localisation of the pain to the right iliac fossa. Laboratory data upon presentation usually reveal an elevated leukocytosis with a left shift. Measurement of C-reactive protein is most likely to be elevated. The advances in imaginology trend to diminish the false positive or negative diagnosis. Radiographic image of faecal loading image in the caecum has a sensitivity of 97% and a negative predictive value that is 98%. In experienced hands, ultrasound may have a sensitivity of 90% and specificity higher than 90%. Helical CT has reported a sensitivity that may reach 95% and specificity higher than 95%. Despite all medical advances, the diagnosis of acute appendicitis continues to be a medical challenge. © 2012 Surgical Associates Ltd.

Ribeiro A.L.,Federal University of Minas Gerais | Nunes M.P.,Federal University of Minas Gerais | Teixeira M.M.,Federal University of Minas Gerais | Rocha M.O.C.,Federal University of Minas Gerais
Nature Reviews Cardiology | Year: 2012

Chagas cardiomyopathy is the most severe and life-threatening manifestation of human Chagas disease-A 'neglected' tropical disease caused by the protozoan parasite Trypanosoma cruzi. The disease is endemic in all continental Latin American countries, but has become a worldwide problem because of migration of infected individuals to developed countries, mainly in Europe and North America. Chagas cardiomyopathy results from the combined effects of persistent parasitism, parasite-driven tissue inflammation, microvascular and neurogenic dysfunction, and autoimmune responses triggered by the infection. Clinical presentation varies widely according to the extent of myocardial damage, and manifests mainly as three basic syndromes that can coexist in an individual patient: heart failure, cardiac arrhythmia, and thromboembolism. NYHA functional class, left ventricular systolic function, and nonsustained ventricular tachycardia are important prognostic markers of the risk of death. Management of Chagas cardiomyopathy focuses on the treatment of the three main syndromes. The use of β-blockers in patients with Chagas disease and heart failure is safe, well tolerated, and should be encouraged. Most specialists and international institutions now recommend specific antitrypanosomal treatment of patients with chronic Chagas disease, even in the absence of evidence obtained from randomized clinical trials. Further research on the management of patients with Chagas cardiomyopathy is necessary. © 2012 Macmillan Publishers Limited. All rights reserved.

Background/Objectives:The association between gluten and body weight is inconsistent. Previously, we showed that a gluten-free diet reduces weight gain without changing food intake in mice fed high-fat diets. In the present study, we investigated the effects of gluten intake on fat metabolism, thermogenesis and energy expenditure in mice fed a standard or high-fat diet.Methods:Mice were fed four different experimental diets during 8 weeks: a control-standard diet (CD), a CD added with 4.5% of wheat gluten (CD-G), a high-fat diet (HFD) and a HFD added with 4.5% of wheat gluten (HFD-G). After 8 weeks, the mice received 99mTc-radiolabeled gluten orally to study gluten absorption and biodistribution or they underwent indirect calorimetry. After killing, subcutaneous and brown adipose tissues (SAT and BAT) were collected to assess thermogenesis-related protein expression. Lipid metabolism was studied in adipocyte cultures from the four groups.Results:Despite having had the same energy intake, CD-G and HFD-G mice exhibited increased body weight and fat deposits compared with their respective controls. 99mTc-GLU or its peptides were detected in the blood, liver and visceral adipose tissue, suggesting that gluten can even reach extraintestinal organs. Uncoupling protein-1 expression was reduced in the BAT of HFD-G and in the SAT of CD-G and HFD-G mice. Indirect calorimetry showed lower oxygen volume consumption in CD-G and HFD-G groups compared with their controls. In HFD mice, daily energy expenditure was reduced with gluten intake. Gluten also reduced adiponectin, peroxisome proliferator-activated receptor (PPAR)-α and PPARγ and hormone-sensitive lipase in cultures of isolated adipocytes from HFD mice, whereas in the CD-G group, gluten intake increased interleukin-6 expression and tended to increase that of tumor necrosis factor.Conclusions:Wheat gluten promotes weight gain in animals on both HFD and CD, partly by reducing the thermogenic capacity of adipose tissues.International Journal of Obesity advance online publication, 27 October 2015; doi:10.1038/ijo.2015.204. © 2015 Macmillan Publishers Limited

Guidoni D.L.,Federal University of Minas Gerais | Mini R.A.F.,Pontifical Catholic University of Minas Gerais | Loureiro A.A.F.,Federal University of Minas Gerais
Computer Networks | Year: 2010

In this work, we propose on-line models to design heterogeneous sensor network topologies with small world features. The proposed model takes into account the data communication flow in this kind of network to create network shortcuts toward the sink node in such a way that the communication between the sink and the sensor nodes is optimized. The endpoints of these shortcuts are nodes with more powerful hardware, leading to a heterogeneous sensor network. We evaluate the on-line models and show that they present the same small world features observed in the theoretical models. When the shortcuts are created toward the sink node, with a small number of powerful sensors, the network presents better small world features and interesting tradeoffs between energy and latency in the data communication when compared with the Random Additional Model. We evaluate the resilience of the on-line models considering general and specific failures and, in both cases, the proposed model is more robust and presents a graceful degradation of the network latency, which shows the resilience of those models. © 2009 Elsevier B.V. All rights reserved.

Reglinska-Matveyev N.,Imperial College London | Andersson H.M.,Imperial College London | Rezende S.M.,Federal University of Minas Gerais | Dahlback B.,Lund University | And 3 more authors.
Blood | Year: 2014

Protein S is a cofactor for tissue factor pathway inhibitor (TFPI), accelerating the inhibition of activated factor X (FXa). TFPI Kunitz domain 3 residue Glu226 is essential for enhancement of TFPI by protein S. To investigate the complementary functional interaction site on protein S, we screened 44 protein S point, composite or domain swap variants spanning the whole protein S molecule for their TFPI cofactor function using a thrombin generation assay. Of these variants, two protein S/growth arrest-specific 6 chimeras, with either the whole sex hormone-binding globulin (SHBG)-like domain (Val243-Ser635; chimera III) or the SHBG laminin G-type 1 subunit (Ser283-Val459; chimera I), respectively, substituted by the corresponding domain in growth arrest-specific 6, were unable to enhance TFPI. The importance of the protein S SHBG-like domain (and its laminin G-type 1 subunit) for binding and enhancement of TFPI was confirmed in FXa inhibition assays and using surface plasmon resonance. In addition, protein S bound to C4b binding protein showed greatly reduced enhancement of TFPI-mediated inhibition of FXa compared with free protein S. We show that binding of TFPI to the protein S SHBG-like domain enables TFPI to interact optimally with FXa on a phospholipid membrane. © 2014 by The American Society of Hematology.

Costa A.G.,Federal University of Minas Gerais
Geological Society Special Publication | Year: 2015

The cultural heritage of Brazil built with natural stone is expressive and shows a great variety of rock types. The main differences between rock types are found when a comparison is made between the buildings located in the coastal zone and those located inland. In historical cities located on the coast, European limestones were widely used. Within the Brazilian interior, especially in the current State of Minas Gerais, a large number of historic buildings can be noticed. In this State, despite the large volumes of granites and gneisses and other less common rock types such as gabbros, basalts and sandstones, steatite and different types of schist, beside quartzites, were the rock types most commonly used in the construction of those 18th- and 19th-century buildings. This paper focuses on the extent and quality based on the use of steatites and schists in historic buildings in Brazil, which is part of a research project in progress. Assembled data justifies the inclusion of these rocks in the database on the rocks of world cultural heritage. The advancement of these studies may contribute to the maintenance and preservation of this heritage and the appropriate new uses of these rocks, as well as to propose some of them as Global Heritage Stone Resource for their international recognition. © The Geological Society of London 2015.

Brandao F.G.S.L.,Federal University of Minas Gerais | Datta N.,University of Cambridge
IEEE Transactions on Information Theory | Year: 2011

We obtain expressions for the optimal rates of one-shot entanglement manipulation under operations which generate a negligible amount of entanglement. As the optimal rates for entanglement distillation and dilution in this paradigm, we obtain the max- and min-relative entropies of entanglement, the two logarithmic robustnesses of entanglement, and smoothed versions thereof. This gives a new operational meaning to these entanglement measures. Moreover, by considering the limit of many identical copies of the shared entangled state, we partially recover the recently found reversibility of entanglement manipulation under the class of operations which asymptotically do not generate entanglement. © 2011 IEEE.

Giannetti A.V.,Federal University of Minas Gerais
Journal of Neurological Surgery, Part A: Central European Neurosurgery | Year: 2013

Background Intraventricular cavernomas are rare and generally treated by microsurgical approach. With the advances in neuroendoscopy, intraventricular lesions have been managed by this technique. However, tumor size and vascular nature are considered restrictive factors. As far as we are concerned, there are two cases in the literature of intraventricular cavernoma resection done by neuroendoscopy. Case We describe a case of a man who presented with hydrocephalus secondary to a mesencephalic cavernoma and a second cavernous angioma located at the dorsum thalamus. This second lesion was successfully removed using a pure neuroendoscopic technique at the same time as a third ventriculostomy was performed. Conclusion As neuroendoscopy evolves, we see that lesions considered impossible to be managed by neuroendoscopy before today are being treated with the advantages that the minimally invasive surgery offers. © 2013 Georg Thieme Verlag KG.

Leonel A.J.,Federal University of Minas Gerais | Alvarez-Leite J.I.,Federal University of Minas Gerais
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2012

PURPOSE OF REVIEW: Butyrate is physiologically produced by the microbial fermentation of dietary fibers and plays a plurifunctional role in intestinal cells. This review examines the recent findings regarding the role and mechanisms by which butyrate regulates intestinal metabolism and discusses how these findings could improve the treatment of several gastrointestinal disorders. RECENT FINDINGS: Butyrate is more than a primary nutrient that provides energy to colonocytes and acts as a cellular mediator in those cells through several mechanisms. One remarkable property of butyrate is its ability to inhibit histone deacetylases, which is associated with the direct effects of butyrate and results in gene regulation, immune modulation, cancer suppression, cell differentiation, intestinal barrier regulation, oxidative stress reduction, diarrhea control, visceral sensitivity and intestinal motility modulation. All of these actions make butyrate an important factor for the maintenance of gut health. SUMMARY: From studies published over 30 years, there is no doubt of the important role that butyrate plays in maintaining intestinal homeostasis. However, despite these effects, clinical studies are still required to validate the routine use of butyrate in clinical practice and, specifically, in the treatment of intestinal diseases. © 2012 Wolters Kluwer Health.

Vasconcelos-Santos D.V.,Federal University of Minas Gerais | Vasconcelos-Santos D.V.,Centro Brasileiro Of Ciencias Visuais
Current Opinion in Ophthalmology | Year: 2012

Purpose of Review: To provide an overview of ocular toxoplasmosis, the leading cause of infectious posterior uveitis, focusing on recent trends of disease epidemiology, pathogenesis, diagnosis, therapy and prevention. Recent Findings: Novel aspects of epidemiology, including growing importance of water transmission are discussed. The historical controversy of congenital versus postnatally acquired toxoplasmosis is revisited. Recent insights into pathogenesis of ocular toxoplasmosis are also reviewed, tipping the delicate balance between parasite virulence and host immunity. Diagnosis of ocular toxoplasmosis is also discussed in the light of serological, molecular and imaging tools. Finally, a critical analysis of current and emerging therapies for ocular toxoplasmosis is made. Preventive aspects are also commented upon. Summary: Waterborne toxoplasmosis is increasingly recognized in outbreaks and in endemic areas. The importance of postnatally acquired toxoplasmosis is now well established, but should not lead to underestimation of congenital disease. Genetic determination of parasite virulence/individual susceptibility might correlate with disease outcomes. Serological, molecular and imaging tools may improve the diagnosis and follow-up of individuals with ocular toxoplasmosis. Despite emergence of alternative therapeutic regimens, including intravitreal antibiotics, classical therapy with sulfadiazine/pyrimethamine is still standard for toxoplasmic retinochoroiditis. Adequate prophylaxis is expected to have an effect in ocular burden of toxoplasmosis. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Schroder U.,Federal University of Minas Gerais
Journal of Pragmatics | Year: 2010

This article analyses cross-cultural differences in speech styles found in 40 interviews conducted on two groups composed of 20 German and 20 Brazilian respondents. After illustrating the preponderant differences in language use, we relate the speech styles characteristic of each group to the particular functions of speech they serve. Results of the analysis show the phatic, poetic and expressive functions to be the most dominant in the Brazilian group, whereas the use of the referential and the metalinguistic functions seem to be more common in the German responses. Finally, the article shows that these findings can be partially explained by their embedding in distinct cultural and historical backgrounds and through an interrelationship with other studies in the field of cross-cultural pragmatics. © 2009 Elsevier B.V. All rights reserved.

Oliveira A.G.,Federal University of Minas Gerais | Oliveira C.A.,Federal University of Minas Gerais
Life Sciences | Year: 2011

The epididymal region plays an important role in the reproduction of roosters, as it is the site of functions important in the maintenance of fertility, including fluid and calcium reabsorption and sperm surface modifications. About 10 years ago, a reproductive dysfunction characterized by the formation of luminal calcium stones in the epididymal region of roosters was described. This anomaly, known as epididymal lithiasis, is associated with a significant decrease in the fertility of affected roosters. This reproductive anomaly has been observed in multiple countries and is thought to negatively impact the poultry industry; however, the cause of epididymal lithiasis has not been fully determined. Several hypotheses have been proposed to explain the origin of epididymal lithiasis, including the presence of an infectious agent within the epididymal region, an autoimmune response, increased dietary calcium and vitamin D3 intake and the presence of genetic susceptibility factors; however, none of these has been proven to be the primary cause of the calcium stone formation. Nonetheless, considerable evidence suggests that regardless of the primary cause of epididymal lithiasis, this anomaly could result from a hormonal imbalance or a local impairment of calcium homeostasis in the epididymal region. The objectives of this mini-review are to 1) summarize the reproductive alterations observed in animals affected by epididymal lithiasis, 2) discuss the hypotheses proposed to explain the cause of luminal stone formation and 3) provide perspectives for future studies of this reproductive disorder. © 2011 Elsevier Inc.

Weber G.,Federal University of Minas Gerais
Bioinformatics | Year: 2013

The mesoscopic statistical physics models, known generically as Peyrard-Bishop (PB) models, have found many applications for the study of oligonucleotide properties. Unfortunately, PB models have not reached a wider non-specialized audience for the lack of freely available software implementations. Here we present an extensible C++ implementation of four variants of the PB model, which allows the user to calculate melting temperatures from tested model parameters. Even for a non-specialist, it should be straightforward to change these parameters to reflect different experimental environments or different types of oligonucleotides. For users with some proficiency in C++ programming, it should be feasible to extend the code to other PB models owing to the generic programming implementation adopted for TfReg. Pre-calculated parameters are included that allow the immediate calculation of melting temperatures and thermal equivalence indexes for DNA and RNA. © 2013 The Author. Published by Oxford University Press. All rights reserved.

In June 2013, Brazil faced the largest and most significant mass protests in a generation. These were exacerbated by the population's disenchantment towards its highly fragmented party system, which is composed by a very large number of political parties. Under these circumstances, presidents are constrained by informal coalition governments, bringing very harmful consequences to the country. In this work I propose ARRANGE, a dAta dRiven method foRAssessing and reduciNG party fragmEntation in a country. ARRANGE uses as input the roll call data for congress votes on bills and amendments as a proxy for political preferences and ideology. With that, ARRANGE finds the minimum number of parties required to house all congressmen without decreasing party discipline. When applied to Brazil's historical roll call data, ARRANGE was able to generate 31 distinct configurations that, compared with the status quo, have (i) a significant smaller number of parties, (ii) a higher discipline of partisans towards their parties and (iii) a more even distribution of partisans into parties. ARRANGE is fast and parsimonious, relying on a single, intuitive parameter. © 2015 Pedro O. S. Vaz de Melo.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in anymedium, provided the original author and source are credited.

Furtado L.F.V.,Federal University of Minas Gerais | Rabelo T.M.L.,Federal University of Minas Gerais
Veterinary Parasitology | Year: 2015

Mutations in the β-tubulin isotype 1 gene at codons 167 (F167Y), 198 (E198A) and 200 (F200Y) have been associated with benzimidazole resistance in helminths. The F200Y polymorphism has previously been described for Ancylostom caninum; however, the F167Y polymorphism has not been investigated in members of the Ancylostomatidae family. The aim of this study was to screen for the F167Y polymorphism in A. caninum isolates recovered from naturally infected dogs in two Brazilian states. No mutation was observed at codon 167 in the 230 analyzed samples from the two populations; however, it is possible that this change may be present at a low frequency in other populations of the same species. These results highlight the importance of monitoring the genetic basis involved in the drug resistance process. © 2015 Elsevier B.V.

Pereira L.B.,Federal University of Minas Gerais
Anais Brasileiros de Dermatologia | Year: 2014

Impetigo is a common cutaneous infection that is especially prevalent in children. Historically, impetigo is caused by either group A β-hemolytic streptococci or Staphylococcus aureus. Currently, the most frequently isolated pathogen is S. aureus. This article discusses the microbiologic and virulence factors of group A β- hemolytic streptococci and Staphylococcus aureus, clinical characteristics, complications, as well as the approach to diagnosis and management of impetigo. Topical agents for impetigo therapy are reviewed. © 2014 by Anais Brasileiros de Dermatologia.

Gontijo B.,Federal University of Minas Gerais
Clinics in Dermatology | Year: 2014

Most infantile hemangiomas have a spontaneous and uneventful involution and, hence, may be treated expectantly. Others, however, will present some complication along their evolution that may require prompt therapeutic interventions. Ulceration is the most common complication, and amblyopia is frequently associated with periocular tumors. Airways hemangiomas may be life-threatening, and disfigurement can heavily impact the patient's quality of life. © 2014 Elsevier Inc.

Brandao T.A.S.,Utah State University | Brandao T.A.S.,Federal University of Minas Gerais | Johnson S.J.,Utah State University | Hengge A.C.,Utah State University
Archives of Biochemistry and Biophysics | Year: 2012

The movement of a conserved protein loop (the WPD-loop) is important in catalysis by protein tyrosine phosphatases (PTPs). Using kinetics, isotope effects, and X-ray crystallography, the different effects arising from mutation of the conserved tryptophan in the WPD-loop were compared in two PTPs, the human PTP1B, and the bacterial YopH from Yersinia. Mutation of the conserved tryptophan in the WPD-loop to phenylalanine has a negligible effect on k cat in PTP1B and full loop movement is maintained. In contrast, the corresponding mutation in YopH reduces kcat by two orders of magnitude and the WPD loop locks in an intermediate position, disabling general acid catalysis. During loop movement the indole moiety of the WPD-loop tryptophan moves in opposite directions in the two enzymes. Comparisons of mammalian and bacterial PTPs reveal differences in the residues forming the hydrophobic pocket surrounding the conserved tryptophan. Thus, although WPD-loop movement is a conserved feature in PTPs, differences exist in the molecular details, and in the tolerance to mutation, in PTP1B compared to YopH. Despite high structural similarity of the active sites in both WPD-loop open and closed conformations, differences are identified in the molecular details associated with loop movement in PTPs from different organisms. © 2012 Elsevier Inc. All rights reserved.

Costa M.A.,Federal University of Minas Gerais | Assuncao R.M.,Federal University of Minas Gerais | Kulldorff M.,Harvard University
Computational Statistics and Data Analysis | Year: 2012

Spatial clustering methodologies that are capable of detecting and delineating irregular clusters can provide information about the geographical spread of various diseases under surveillance. This paper proposes and compares three spatial scan statistics designed to detect clusters with irregular shapes. The proposed methods use geographical boundary information to construct a graph in which a cluster growing process is performed based on likelihood function maximization. Constraints on cluster shape are imposed through early stopping, a double connection requirement and a maximum linkage criteria. The methods are evaluated using simulated data sets with either circular or irregular clusters, and compared to the circular and elliptic scan statistics. Results show that for circular clusters, the standard circular scan statistic is optimal, as expected. The double connection, elliptic maximum linkage scan statistics also achieve good results. For irregularly-shaped clusters, the elliptic, maximum linkage and double connected scan statistics are optimal for different cluster models and by different evaluation criteria, but the circular scan statistic also performs well. If the emphasis is on statistical power for cluster detection, the simple circular scan statistic is attractive across the board choice. If the emphasis is on the accurate determination of cluster size, shape and boundaries, the double connected, maximum linkage and elliptical scan statistics are often more suitable choices. All methods perform well though, with the exception of the unrestricted dynamic minimum spanning tree scan statistic and the early stopping scan statistic, which we do not recommend. © 2011 Elsevier B.V. All rights reserved.

Indicators of healthcare utilization and quality were compared in a probabilistic sample of adults (N = 7,534) covered by private health plans, the Family Health Strategy (FHS), and "traditional" primary care clinics (UBS) in Belo Horizonte, Minas Gerais State, Brazil. After adjusting for demographics, health conditions, and socioeconomic status, indicators of healthcare utilization (longitudinality, health-seeking, and medical consultations) showed better performance among users of the FHS and private health plans compared to those covered by the UBS. Hospitalizations, preventive tests, and flu vaccinations varied little between sources of care. Quality indicators (difficulty in making an appointment, waiting lines, complaints about obtaining medications, and receiving an appointment within 24 hours) were better among private health plans. Recommending one's healthcare providers to others was more frequent among FHS users (61.9%) and those with private health plans (55.6%), compared to those served by UBS (45.4%).

Bolivar Guarin M.E.,Federal University of Minas Gerais | De Melo Moreira A.,Federal University of Minas Gerais | Speziali N.L.,Federal University of Minas Gerais
Journal of Applied Crystallography | Year: 2013

Polycrystalline samples of mixed Yb1-x Tb x MnO3 (x = 0, 0.25, 0.50, 0.75 and 1) were prepared by a solid state reaction procedure. Detailed crystal structure studies were performed using X-ray diffraction data obtained at room temperature. The application of the Rietveld method confirmed the reported hexagonal P63 cm and orthorhombic Pnma phases for x = 0 (YbMnO3) and x = 1 (TbMnO3), respectively. A single hexagonal phase was also observed for x = 0.25, while in the case of x = 0.50 and x = 0.75 both phases coexist in the produced samples. Crystallographic parameters for the pure compounds are in agreement with those found in the literature. Changes in the lattice parameters, unit-cell volume, polyhedral distortions and tilting observed in the mixed compounds are explained as a function of x. Sharing of Tb3+ and Yb3+ ions between different sites is discussed. © 2013 International Union of Crystallography.

De Avelar D.M.,Federal University of Minas Gerais | Filho E.J.F.,Federal University of Minas Gerais | Linardi P.M.,Federal University of Minas Gerais
Journal of Medical Entomology | Year: 2013

Tunga hexalobulata (Siphonaptera: Tungidae), new species of tungid sand flea belonging to the penetrans group, is described with illustrations of adult female parasitizing Bos indicus (L., 1758) from Brazil. It differs from the 12 other known species of Tunginae by the presence of six anterior humps in the neosome. It also can be differentiated from other species of the penetrans group by lesser size of the neosome, presence of three posterodorsally bristles in antennal segment II, and the extension of the posterior arm of the preoral internal sclerotization. © 2013 Entomological Society of America.

Silva L.A.,Federal University of Minas Gerais | Andrade R.O.,Federal University of Minas Gerais | Carneiro A.C.A.V.,Federal University of Minas Gerais | Vitor R.W.A.,Federal University of Minas Gerais
PLoS ONE | Year: 2014

Although several Toxoplasma gondii genotyping studies have been performed in Brazil, studies of isolates from animals in the state of Minas Gerais are rare. The objective of this study was to conduct a genotypic characterization of T. gondii isolates obtained from dogs, free-range chickens, and humans in Minas Gerais and to verify whether the T. gondii genotypes circulating in domestic animals correspond to the genotypes detected in humans. Genetic variability was assessed by restricted fragment length polymorphism at 11 loci (SAG1, 5′+3′SAG2, SAG2 alt, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Twelve different genotypes were identified among the 24 isolates studied, including 8 previously identified genotypes and 4 new genotypes. The genetic relationship of the 24 T. gondii isolates, together with the genotypes previously described from 24 human newborns with congenital toxoplasmosis, revealed a high degree of similarity among the genotypes circulating in humans and animals in Minas Gerais. The most common genotypes among these species were BrII, BrIII, ToxoDB #108, and ToxoDB #206. Restricted fragment length polymorphism at the CS3 locus of these 48 isolates showed that the majority of isolates presented alleles I (50%) or II (27%). Isolates harboring allele III at the CS3 locus presented low virulence for mice, whereas those harboring alleles I or II presented higher virulence. These results confirm the utility of marker CS3 for predicting the virulence of Brazilian isolates of T. gondii in mice. No association was found between the allele type and clinical manifestations of human congenital toxoplasmosis. This is the first report of T. gondii genotyping that verifies the overlapping genotypes of T. gondii from humans and animals in the same geographic region of Brazil. Our results suggest that there is a common source of infection to the species studied, most likely oocysts contaminating the environment. © 2014 Silva et al.

Sandoval J.R.,Federal University of Minas Gerais
PloS one | Year: 2013

The Altiplano region of the South American Andes is marked by an inhospitable climate to which the autochthonous human populations adapted and then developed great ancient civilizations, such as the Tiwanaku culture and the Inca Empire. Since pre-Columbian times, different rulers established themselves around the Titicaca and Poopo Lakes. By the time of the arrival of Spaniards, Aymara and Quechua languages were predominant on the Altiplano under the rule of the Incas, although the occurrence of other spoken languages, such as Puquina and Uruquilla, suggests the existence of different ethnic groups in this region. In this study, we focused on the pre-Columbian history of the autochthonous Altiplano populations, particularly the Uros ethnic group, which claims to directly descend from the first settlers of the Andes, and some linguists suggest they might otherwise be related to Arawak speaking groups from the Amazon. Using phylogeographic, population structure and spatial genetic analyses of Y-chromosome and mtDNA data, we inferred the genetic relationships among Uros populations (Los Uros from Peru, Uru-Chipaya and Uru-Poopo from Bolivia), and compared their haplotype profiles with eight Aymara, nine Quechua and two Arawak (Machiguenga and Yanesha) speaking populations from Peru and Bolivia. Our results indicated that Uros populations stand out among the Altiplano populations, while appearing more closely related to the Aymara and Quechua from Lake Titicaca and surrounding regions than to the Amazon Arawaks. Moreover, the Uros populations from Peru and Bolivia are genetically differentiated from each other, indicating a high heterogeneity in this ethnic group. Finally, our results support the distinctive ancestry for the Uros populations of Peru and Bolivia, which are likely derived from ancient Andean lineages that were partially replaced during more recent farming expansion events and the establishment of complex civilizations in the Andes.

Percope De Andrade M.A.,Federal University of Minas Gerais | Campos T.V.D.O.,Federal University of Minas Gerais | Abreu-E-Silva G.M.D.,Federal University of Minas Gerais
Arthroscopy - Journal of Arthroscopic and Related Surgery | Year: 2015

Purpose This article discusses current evidence in nutraceuticals and viscosupplementation uses in osteoarthritis (OA) treatment. Methods A search was carried out to identify systematic reviews, randomized controlled trials, review articles, and original articles (PubMed and Cochrane Database) about nutraceuticals and viscosupplementation. The keywords used were nutraceuticals, glucosamine, chondroitin, diacerein, avocado, soybean unsaponifiables, nutraceuticals, and viscosupplementation, independently or combined with the terms "review" and "randomized." Results Glucosamine hydrochloride has no effect on pain management, although the sulfate formulation has a moderate effect. Diacerein leads to pain relief, with a superior carryover effect when compared with placebo. Avocado and soybean unsaponifiables may have positive effects on knee and hip OA, but long-term results could not be confirmed. Despite the American Academy of Orthopaedic Surgeons' recommendation against the use of hyaluronic acid in OA, some systematic reviews found some benefits in the knee. Conclusions There is no evidence that nutraceuticals or viscosupplementation influences OA's natural progression. However, some of these agents seem to reduce pain and improve function. Level of Evidence Level IV, systematic review of studies with Level I through Level IV evidence. © 2015 Arthroscopy Association of North America.

Bosco De Magalhaes A.R.,Federal University of Minas Gerais
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011

The relation between microscopic symmetries in the system-environment interaction and the emergence of robust states is studied for many linearly coupled harmonic oscillators. Different types of symmetry, which are introduced into the model as terms in the coupling constants between each system's oscillator and a common reservoir, lead to distinct robust modes. Since these modes are partially or completely immune to the symmetric part of the environmental noise, they are good candidates for building quantum memories. A comparison of the model investigated here, with bilinear system-reservoir coupling, and a model where such coupling presents an exponential dependence on the variables of interest is performed. © 2011 Elsevier B.V. All rights reserved.

Cherchiglia A.L.,Federal University of Minas Gerais | Sampaio M.,Federal University of Minas Gerais | Nemes M.C.,Federal University of Minas Gerais
International Journal of Modern Physics A | Year: 2011

Implicit Regularization (IReg) is a candidate to become an invariant framework in momentum space to perform Feynman diagram calculations to arbitrary loop order. In this work we present a systematic implementation of our method that automatically displays the terms to be subtracted by Bogoliubov's recursion formula. Therefore, we achieve a twofold objective: we show that the IReg program respects unitarity, locality and Lorentz invariance and we show that our method is consistent since we are able to display the divergent content of a multiloop amplitude in a well-defined set of basic divergent integrals in one-loop momentum only which is the essence of IReg. Moreover, we conjecture that momentum routing invariance in the loops, which has been shown to be connected with gauge symmetry, is a fundamental symmetry of any Feynman diagram in a renormalizable quantum field theory. © 2011 World Scientific Publishing Company.

Bolivar A.O.,Federal University of Minas Gerais
Annals of Physics | Year: 2011

We obtain a non-Markovian quantum master equation directly from the quantization of a non-Markovian Fokker-Planck equation describing the Brownian motion of a particle immersed in a generic environment (e.g. a non-thermal fluid). As far as the especial case of a heat bath comprising of quantum harmonic oscillators is concerned, we derive a non-Markovian Caldeira-Leggett master equation on the basis of which we work out the concept of non-equilibrium quantum thermal force exerted by the harmonic heat bath upon the Brownian motion of a free particle. The classical limit (or dequantization process) of this sort of non-equilibrium quantum effect is scrutinized, as well. © 2011 Elsevier Inc.

Felipe J.C.C.,Federal University of Minas Gerais | Brito L.C.T.,Federal University of Lavras | Sampaio M.,Federal University of Minas Gerais | Nemes M.C.,Federal University of Minas Gerais
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

We show in a diagrammatic and regularization independent analysis that the quadratic contribution to the beta function which has been conjectured to render quantum electrodynamics asymptotically free near the Planck scale has its origin in a surface term. Such surface term is intrinsically arbitrarily valued and it is argued to vanish in a consistent treatment of the model. © 2011 Elsevier B.V.

Weber G.,Federal University of Minas Gerais
EPL | Year: 2011

Peyrard-Bishop (PB) models are used for the study of denaturation in DNA. Unfortunately, there is little connection of these models to linear nearest-neighbour models which are extensively used for the calculation of melting temperatures in biochemistry. Here we use the Joyeux-Buyukdagli (JB) model, a variant of the PB model which incorporates stacking enthalpies, and carry out a fitting procedure to experimental melting temperatures where we let the enthalpies vary freely. We start out with a single value for the enthalpy for all combinations of base pairs and after the fitting we obtain a new set of enthalpies which correlate very strongly with the measured enthalpies. This result provides the needed support for the use of experimental enthalpies in the JB/PB model. Copyright © EPLA, 2011.

Luz R.K.,Federal University of Minas Gerais | Portella M.C.,São Paulo State University
Anais da Academia Brasileira de Ciencias | Year: 2015

The aim of this work was to investigate the effects of daily prey concentration during the first 15 days of active feeding of Hoplias lacerdae larvae, and the juvenile size on the feed training. In the first phase, the larvae received five Artemianauplii concentrations (P). In the second phase, the juveniles from each treatment were trained to accept formulated diet. Superior growth was related to higher initial daily prey concentrations (900 and 1100 nauplii larvae-1). During feed training, the growth tendency was similar to that verified in the first phase. The lowest values of specific growth rate (SGR) were registered after the introduction of the semi-moist diet used in the feed training. However, the values of SGR recovered along the experiment and similar rates were found among the treatments. Survival, mortality and cannibalism were similar in the different treatments at the end of both phases. It can be concluded that: the prey concentration affects growth of H. lacerdae during the first 15 days of active feeding, and feed training can be initialized with juveniles of about 16 mm of total length. © 2015, Academia Brasileira de Ciencias. All rights reserved.

We used complex hypervariable repeats to evaluate the genetic diversity and structure of Prochilodus costatus (Characiformes), an ecologically and economically important species endemic to the São Francisco River basin. Hydroelectric dams along the river have led to population fragmentation, which can limit gene flow. Restocking from hatcheries has been used to repopulate declining populations. To determine how fragmentation and hatchery supplementation affect P. costatus population structure, we studied populations from three sites up and downstream of the Gafanhoto Dam (Pará River, State of Minas Gerais). High levels of genetic diversity were found within populations (0.926 to 0.873); the three populations showed significant differentiation (F(ST) = 0.16), suggesting that populations from the three sites were affected by fragmentation of the river and by hatchery contributions. These results will be useful for developing a management and conservation plan for fish species in this area.

Santos E.M.,Federal University of Minas Gerais
Genetics and molecular research : GMR | Year: 2012

Equine infectious anemia caused by equine infectious anemia virus is an important disease due to its high severity and incidence in animals. We used a phage display library to isolate peptides that can be considered potential markers for equine infectious anemia diagnosis. We selected peptides using IgG purified from a pool comprised of 20 sera from animals naturally infected with equine infectious anemia virus. The diagnostic potential of these peptides was investigated by ELISA, Western blot and dot blot with purified IgG and serum samples. Based on the results, we chose a peptide mimetic for g