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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.

Di Lorenzo A.,Federal University of Minas Gerais
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

It is demonstrated that the statistics for a joint measurement of two conjugate variables in quantum mechanics are expressed through an equation identical to the classical one, provided that joint classical probabilities are replaced by Wigner functions and that the interaction between the system and the detectors is accounted for. This constitutes an extension of Ehrenfest's correspondence principle and is thereby dubbed the strong correspondence principle. Furthermore, it is proved that the detectors provide an additive term to all the cumulants and that if they are prepared in a Gaussian state they contribute only to the first and second cumulants. © 2011 American Physical Society.

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.

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.

Luz R.K.,Federal University of Minas Gerais | Portella M.C.,Sao 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.

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.

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 glycoprotein gp45 epitopes of equine infectious anemia virus, with potential for use as an antigen in indirect diagnostic assays. Synthesis of this peptide has possible applications for the development of new diagnostic tools for this disease.

Silva Gomes J.A.,Federal University of Minas Gerais
Clinical & developmental immunology | Year: 2012

In 2010, the WHO celebrated the 30th anniversary of the smallpox eradication. Ironically, infections caused by viruses related to smallpox are being increasingly reported worldwide, including Monkeypox, Cowpox, and Vaccinia virus (VACV). Little is known about the human immunological responses elicited during acute infections caused by orthopoxviruses. We have followed VACV zoonotic outbreaks taking place in Brazil and analyzed cellular immune responses in patients acutely infected by VACV. Results indicated that these patients show a biased immune modulation when compared to noninfected controls. Amounts of B cells are low and less activated in infected patients. Although present, T CD4(+) cells are also less activated when compared to noninfected individuals, and so are monocytes/macrophages. Similar results were obtained when Balb/C mice were experimentally infected with a VACV sample isolated during the zoonotic outbreaks. Taking together, the data suggest that zoonotic VACVs modulate specific immune cell compartments during an acute infection in humans.

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.

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.

Menezes G.B.,Federal University of Minas Gerais | Mansur D.S.,Imunologia e Parasitologia | McDonald B.,University of Calgary | Kubes P.,University of Calgary | Teixeira M.M.,Federal University of Pernambuco
Pharmacology and Therapeutics | Year: 2011

Sterile injury can trigger an acute inflammatory response, which might be responsible for the pathogenesis of several diseases, including rheumatoid arthritis, lung fibrosis and acute liver failure. A key event for the pathogenesis of these diseases is the recruitment of leukocytes to necrotic areas. Much is known about the mechanisms of recruitment to sites of infection. However, only now is it becoming clear how leukocytes, especially neutrophils, are recruited to areas of tissue damage and necrosis in the absence of infection. Here, we review and discuss mechanisms responsible for sensing and driving the influx of leukocytes, specifically neutrophils, into sites of sterile injury. This knowledge clearly opens new opportunities for therapeutic intervention. © 2011 Elsevier Inc. 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.

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.

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.

de Siqueira L.F.M.,Federal University of Minas Gerais
Revista da Associacao Medica Brasileira | Year: 2010

Febrile seizures are a benign condition of childhood and most children will have only one episode in their lifetime. Nevertheless, a crisis generates major concern in the family and there is much discussion in literature about when to treat as well as which is the best therapeutic approach. This review summarizes data and current recommendations for diagnosis and treatment of patients with febrile seizures.

dos Santos A.F.,Federal University of Minas Gerais
Telemedicine journal and e-health : the official journal of the American Telemedicine Association | Year: 2011

Telehealth resources were implemented in the city of Belo Horizonte, providing tools for the medical assistance model as well as strengthening the quality of primary healthcare attention. The objective of this study was to analyze the characteristics of the incorporation of telehealth resources in Belo Horizonte, Brazil, and its contribution to the structuring of primary healthcare. This study focused on a description of the telehealth projects related to primary healthcare in the city and the results of the implementation process. The sources for this analysis include documents presented to financing institutions, reports from the Belo Horizonte City Department of Health, and articles and technical reports related to the evaluations of the project. The BHTelehealth Project has been established in 148 basic health units in Belo Horizonte. It develops assistance and educational activities by using 3D modeling, interactive videos, and animations. The analysis of this implementation process identified both positive and negative aspects. Telehealth has strengthened the role of primary healthcare as the coordinator of attention. It has reinforced primary care units by widening the scope of attention offered at this level and has provided primary care staff with a powerful arsenal of up-to-date information and tools. BHTelehealth served as a model for implementing the National Telehealth Program, in course in Brazil, involving 900 cities. This is attributed to its positive impact on the training of primary care unit professionals.

Paiva E.A.,Federal University of Minas Gerais
Methods in molecular biology (Clifton, N.J.) | Year: 2011

It is often necessary to process large plant samples for light microscopy studies, but due to structural characteristics of plant tissues, especially intercellular spaces, large vacuoles, and phenolic substances, results are often unsatisfactory. When large samples are embedded in glycol methacrylate (GMA), their core may not polymerize, remaining soft and moist and making it difficult to cut microtome sections. This situation has been erroneously interpreted as the result of poor infiltration, when the soft core of these samples is actually the result of incomplete polymerization. While GMA is in fact present inside samples, unsatisfactory polymerization results from rapid external polymerization that does not allow sufficient hardener to reach the sample core, while the relatively large volume of GMA inside the tissue block also dilutes the hardener. In this chapter we propose a new method for processing large plant specimens that avoids these problems by: (1) slowing the polymerization process through cooling in order to permit the penetration of hardener into the sample core and (2) increasing the hardener:GMA ratio to aid polymerization of the sample core.

Ribeiro R.Q.C.,Minas Gerais State Secretariat for Health Non communicable Disease | Alves L.,Federal University of Minas Gerais
Public Health Nutrition | Year: 2014

Objective To assess the efficacy of two school-based programmes to promote students' willingness to engage in lifestyle changes related to eating habits and physical activity behaviours. Design Elementary school-based health promotion intervention, designed as a multicomponent experimental study, based on a behavioural epidemiological model. Setting Nine intervention and eight comparative public and private elementary schools. Subjects The goal was to determine the impact on the longitudinally assessed outcomes of two programmes that addressed healthy nutrition and active living in a cohort of 2038 children. The evaluations used pre-intervention and follow-up student surveys that were based on the Transtheoretical Model of the stages of behaviour change. Results In the intervention group, there were significant (P < 0·001) differences between the pre-and post-intervention times in the stages of change, with a reduction in the percentage of children at the pre-contemplation and contemplation stages and increased percentages at the preparation, action and maintenance stages, leading to healthier behaviours in fatty food consumption, fruit and vegetable consumption, physical activity and time spent in sedentary activities. The determinants of the behaviour stage were the intervention programme, the type of school and the presence of motivated teachers. The comparison group did not show significant differences between the pre-and post-intervention times for any of the stages of behaviour. Conclusions The intervention programme encouraged the students to make healthy lifestyle choices related to eating habits and physical activity behaviours. Copyright © The Authors 2013.

Summary: This article examines an international controversy over the most visible scientific event of Brazilian physiology in the nineteenth century. In 1881, Brazilian scientist João Baptista Lacerda stated that he had found an efficient antidote to the poison of Brazilian snakes: permanganate of potash (nowadays, potassium permanganate). His findings were given great publicity in Brazil and traveled rapidly around the world. Scientists, especially in France, contradicted Lacerda's claims. They argued that permanganate of potash could not be a genuine antidote to snake bites since it could not neutralize snake venom when diffused in the body. Lacerda turned down such criticism, claiming that clinical observation provided solid evidence for the drug's local action, on the spot surrounding the bite. The controversy over the use of permanganate of potash as an antidote to snake bite illustrates different regimes of proof that could be mobilized in favor of a physiological discovery.

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.

A cross-sectional qualitative study was conducted to establish the perceptions of 77 guardians of preschool children enrolled in a Child Day Care Center in Belo Horizonte/Minas Gerais State, regarding what is a healthy diet and the difficulties faced in having a healthy diet. The instrument used was a pretested semi-structured questionnaire containing leading questions obtained in face-to-face interviews. For data analysis, the Collective Subject Discourse technique was used, which elicited data organization of a verbal nature. It was revealed that the guardians have a notion of what healthy diet is, however their answers implied inadequate eating habits. They attributed insufficient financial resources, lack of time and ingrained eating habits as being the main difficulties in having a healthy diet. These three difficulties are the reasons given by some guardians who do not believe they have a healthy diet. The conclusion drawn is that the guardians need to have a better diet, because their eating habits influence their children's eating habits. These findings revealed the need for food and nutrition education strategies to enable the guardians to recognize and have a healthy diet. © 2015, Associacao Brasileira de Pos - Graduacao em Saude Coletiva. All rights reserved.

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.

Qualitative study with the purpose of analyzing intersectorial actions for health promotion in the context of the Family Health Strategy, identifying experiences, facilitating and restricting factors to the process of building partnerships. Subjects were health managers and informers from social equipment in the territory covered by a local health service in Belo Horizonte/Minas Gerais, Brazil. The results indicate the existence of a wide social network. However, intersectorial health promoting actions are still incipient. Intersectorial actions are faced with the challenge of creating communication spaces that allow the resolution of complex problems. It is concluded that intersectorial actions constitute an innovative strategy which is still under construction, and the paths of which are still being unraveled.

Guimaraes R.C.,Federal University of Minas Gerais
Origins of Life and Evolution of Biospheres | Year: 2015

The distribution of the triplet to amino acid correspondences in the genetic code matrix contains blocks of similarity. There are (a) groups of similar triplets coding for the same amino acid, which is called code degeneracy, and (b) clusters of similar amino acids corresponding to similar triplets. Processes that led to this regionalization have been investigated through a variety of perspectives but no consensus has been reached and no model has been convincing enough to drive experimental tests. Most traditional has been the hypothesis that the code was derived from the standard evolutionary processes of testing variations in the correspondences through the fitness measure of reaching distributions in the matrix space in an optimal manner so that the effects of mutations on protein phenotypes would be minimized, that is, with reduction of the intensity or of the deviant quality of the functional alterations associated with variations. In contrast, the self-referential model for the formation of the code is based on an original regionalization of characters through the concerted superposition of the two components of the encodings: the four modules of dimers of tRNAs are occupied sequentially by sets of amino acids that are also sequentially devoted to fulfilling specific functions in the protein sites and motifs to which they preferentially belong. Therewith, part (b) of the error-minimizing property follows. Part (a) of the property, the code degeneracy, is derived from the synthetase character of developing specificities directed initially to the principal dinucleotides of the triplets, resulting in tetracodonic degeneracy. This was later partly modified during evolution according to the developments of codon usage and the introduction of new amino acids. © 2015, Springer Science+Business Media Dordrecht.

Rocha G.M.,Federal University of Sao Joao del Rei | Kerr L.R.F.S.,Federal University of Ceara | De Brito A.M.,Oswaldo Cruz Foundation | Dourado I.,Federal University of Bahia | Guimaraes M.D.C.,Federal University of Minas Gerais
AIDS and Behavior | Year: 2013

The aim of this study was to assess factors associated with unprotected receptive anal intercourse (URAI) in a sample of MSM recruited by respondent driven sampling in Brazil. Among 3,449 participants, 36.5 % reported URAI. Final logistic model indicated that living with a male partner, illicit drug use, having stable partnership, having sex with men only, having few friends encouraging condom use, and high self-perceived risk for HIV infection were characteristics independently associated with URAI. Intervention strategies should focus on the role of anal sex practices on HIV transmission, address illicit drug use, stigma and expansion of HIV testing and care. © 2013 Springer Science+Business Media New York.

dos Santos A.F.,Federal University of Minas Gerais
Telemedicine journal and e-health : the official journal of the American Telemedicine Association | Year: 2011

The technological innovations that are a part of organizational realities allow for new possibilities in social processes. In Belo Horizonte, Brazil, the municipality established a system of training through videoconferences in primary care connecting professors and professionals from primary care units to discuss assistance problems in medicine, nursing, and dentistry. An evaluation of the professionals' perception regarding the system of training through videoconferences in primary care. The study involved 148 basic health units in the city of Belo Horizonte. A structured survey was applied to a sample of 373 people who used the system in 2008. According to the survey data, 58.6% of the professionals participated in more than three videoconferences in 6 months, whereas 30.3% did not participate in any type of face-to-face training activity; 98% considered the topics interesting and 70% affirmed that the topics discussed helped them when performing assistance tasks. Other aspects that were evaluated as excellent or good include: 36.6% approved the sound quality of the videoconferences, 46.4% approved the image quality, and 43.9% approved the system stability. These results highlight some problems. Nevertheless, 90.2% evaluated the telehealth project as being excellent or good and 96.7% would recommend the implementation of the project in other units. The system of educational training videoconferences can contribute to improving the competence of primary healthcare attention.

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.

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.

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 L.J.C.,Federal University of Vicosa | Oliveira L.J.C.,Federal University of Pampa | Costa M.H.,Federal University of Vicosa | Soares-Filho B.S.,Federal University of Minas Gerais | Coe M.T.,Woods Hole Oceanographic Institution
Environmental Research Letters | Year: 2013

Using simplified climate and land-use models, we evaluated primary forests' carbon storage and soybean and pasture productivity in the Brazilian Legal Amazon under several scenarios of deforestation and increased CO2. The four scenarios for the year 2050 that we analyzed consider (1) radiative effects of increased CO2, (2) radiative and physiological effects of increased CO2, (3) effects of land-use changes on the regional climate and (4) radiative and physiological effects of increased CO2 plus land-use climate feedbacks. Under current conditions, means for aboveground forest live biomass (AGB), soybean yield and pasture yield are 179 Mg-C ha -1, 2.7 Mg-grains ha-1 and 16.2 Mg-dry mass ha -1 yr-1, respectively. Our results indicate that expansion of agriculture in Amazonia may be a no-win scenario: in addition to reductions in carbon storage due to deforestation, total agriculture output may either increase much less than proportionally to the potential expansion in agricultural area, or even decrease, as a consequence of climate feedbacks from changes in land use. These climate feedbacks, usually ignored in previous studies, impose a reduction in precipitation that would lead agriculture expansion in Amazonia to become self-defeating: the more agriculture expands, the less productive it becomes. © 2013 IOP Publishing Ltd.

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

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.

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.

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.

Rezende C.,University of Ottawa | Mammeri A.,University of Ottawa | Boukerche A.,University of Ottawa | Loureiro A.A.F.,Federal University of Minas Gerais
Ad Hoc Networks | Year: 2014

The provision of video dissemination capabilities over vehicular networks improves the service experience from users' side for applications such as heavy traffic notification, hazard warnings and event advertisement. However, the combination of video streaming's stringent requirements and the dynamic topology of Vehicular Ad Hoc Networks (VANETs) poses severe challenges for efficient and effective video dissemination. We propose in this work a receiver-based solution that conducts video transmissions decoupled from the relay nodes selection mechanism, namely REDEC. This solution takes advantage of the reactive nature of the receiver-based approach without incurring excessive collisions and overhead due to the transmission of videos large packets at a high frequency. We have also conducted extensive simulation experiments using variety of scenarios with different densities and data exchange rate. Our results indicate clearly that our proposed REDEC protocol outperforms other solutions and is scalable while fulfilling the end-to-end delay requirements of video streaming. Furthermore, we have observed that REDEC also offers higher video reception rates when compared to existing video streaming solutions. © 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.

Golgher A.,Federal University of Minas Gerais
International Journal of Social Economics | Year: 2016

Purpose The purpose of this paper is to present deprivation in urban Brazil in a multidimensional perspective with dimensions related to households objective information, assets in the household, subjective evaluation concerning the dwelling and expenses. Design/methodology/approach The author used factorial analysis applied to the Brazilian Household Budget Survey. Most dimensions showed a positive correlation with income, while for others it was not observed any significant difference between income ranges. Some types of deprivation specially touched low-income households, while other dimensions differentiated middleincome households, or even higher income households. The author applied a fuzzy perspective to define deprivation membership in each dimension with the use of a modified logistic function. The author observed that households with similar income faced different levels of deprivation in many dimensions. Findings The author showed that there were significant differences in households expense preferences and profiles linked to these findings. Households with high levels of food deprivation relatively spend more on households rent, taxes and services, indicating that shelter and then food in the household are the very basic goods. Larger relative expenses with food in the household indicated higher levels of deprivation in all other dimensions, indicating that due to these higher food expenditures, the households could not overcome the deprivation in other dimensions. Households that spend more on smoke and gambling faced higher deprivation in most dimensions, suggesting different expenses priorities, less household oriented. Originality/value To the best of the knowledge, this is the first attempt to link multidimensional deprivation and expenses profile for Brazilian data. © Emerald Group Publishing Limited.

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.

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.

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.

Apteronotus acidops, new species, is described from the upper Paraná River basin, Brazil. It can be diagnosed from the remaining species of the genus by the following combination of characters: Dorsal snout profile pointed; snout length 46.4 - 63.7 % of head length; oculo-nasal distance 39.2 - 72.1 % of postocular distance; lateral ethmoid with both dorsal and ventral extremities expanded, strongly oblique in orientation; mouth rictus surpassing vertical through anterior eye margin, including its skin folds, in all ages; dorsal head profile nearly horizontal from a vertical through anus to posterior extremity of occipital bone; absence of mid-dorsal white or clear stripe on head and body anteriorly; chin brown; upper lip clear to a vertical through anterior nostril; transversal unpigmented bar or bars posteriorly on the body absent; flanks brown, darker dorsally and pectoral fin hyaline, with chromatophores over rays. Moreover, a key for the apteronotid species from the upper rio Paraná is provided.

De-Paula O.C.,Federal University of Minas Gerais | Das Gracas Sajo M.,Paulista University
Nordic Journal of Botany | Year: 2011

We examined the embryological development of anthers and ovules from Astraea (A. lobata and A. praetervisa) and Croton (C. floribundus, C. fuscescens, C. glandulosus, C. lundianus, C. piptocalyx, C. urucurana and C. triqueter) focusing on features with systematic significance for the group. Some of these features are common in Euphorbiaceae including: a dicotyledonous type of anther wall formation, a secretory tapetum, a mixed origin of the outer ovule integument, an epidermal origin of the inner ovule integument, the occurrence of many archesporial cells inside the ovules and a megagametophyte of the Polygonum-type. Other features, such as the presence of styloid crystals in the tapetum, an idioblast with a druse in the endothecium, simultaneous and successive microsporogenesis, and a functional micropylar megaspore, have not previously been reported in the family. These characters appear to distinguish Croton and Astraea from other Euphorbiaceae and possibly represents autapomorphies for the tribe Crotoneae. © 2011 The Authors.

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.

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.

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.

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.

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).

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.

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.

Palhares R.M.,Federal University of Minas Gerais | Mozelli L.A.,Federal University of Ouro Preto
Mathematical Problems in Engineering | Year: 2011

New analysis and control design conditions of discrete-time fuzzy systems are proposed. Using fuzzy Lyapunov's functions and introducing slack variables, less conservative conditions are obtained. The controller guarantees system stabilization and H performance. Numerical tests and a practical experiment in Chua's circuit are presented to show the effectiveness. © 2011 Leonardo Amaral Mozelli and Reinaldo Martinez Palhares.

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.

Oliveira M.M.,Federal University of Minas Gerais
Neurosurgery | Year: 2015

BACKGROUND:: Brain tumors are complex 3-dimensional lesions. Their resection involves training and the use of the multiple microsurgical techniques available for removal. Simulation models, with haptic and visual realism, may be useful for improving the bimanual technical skills of neurosurgical residents and neurosurgeons, potentially decreasing surgical errors and thus improving patient outcomes. OBJECTIVE:: To describe and assess an ex vivo placental model for brain tumor microsurgery using a simulation tool in neurosurgical psychomotor teaching and assessment. METHODS:: Sixteen human placentas were used in this research project. Intravascular blood remnants were removed by continuous saline solution irrigation of the 2 placental arteries and placental vein. Brain tumors were simulated using silicone injections in the placental stroma. Eight neurosurgeons and 8 neurosurgical residents carried out the resection of simulated tumors using the same surgical instruments and bimanual microsurgical techniques used to perform human brain tumor operations. Face and content validity was assessed using a subjective evaluation based on a 5-point Likert scale. Construct validity was assessed by analyzing the surgical performance of the neurosurgeon and resident groups. RESULTS:: The placenta model simulated brain tumor surgical procedures with high fidelity. Results showed face and content validity. Construct validity was demonstrated by statistically different surgical performances among the evaluated groups. CONCLUSION:: Human placentas are useful haptic models to simulate brain tumor microsurgical removal. Results using this model demonstrate face, content, and construct validity. ABBREVIATION:: VR, virtual reality © by the Congress of Neurological Surgeons.

Souza R.A.,Federal University of Minas Gerais
Jornal brasileiro de nefrologia : 'orgão oficial de Sociedades Brasileira e Latino-Americana de Nefrologia | Year: 2011

The complications of vascular access have been the major cause of hospitalization among patients with end stage renal disease (ESRD) on Haemodialysis (HD). Despite recommendations to decrease the use of central venous catheter (CVC) it still represents the main access for children and adolescents who start HD. This study aimed to evaluate, through a retrospective cohort study, the initial type, the incidence of complications and reasons for failure of vascular access in children and adolescents aged 0 to younger than 18 years who started HD from 1997 to 2007. 251 accesses were studied in 61 patients, 97 arteriovenous fistula (AVF) and 154 temporary uncuffed CVC. 51% of study patients began HD with CVC. The mean age of patients at the start of HD was 12.5 years. The predominant underlying disease was glomerulonephritis (46%). The main cause of CVC removal was infection in 35%. The mean survival of the uncuffed CVC was 40 days. AVF primary failure was detected in 37.8% of the fistulas. Considering the patent fistulas, the main cause of failure was thrombosis (84%). Infection did not caused any loss of AVF. When comparing the two types of access we find a risk of infection 34 times higher in patients using CVC against AVF. Infection was the major cause of CVC removal, and our results suggest that uncuffed CVC must be avoided for ESRD children and adolescents on HD and replaced by AVF or cuffed CVC, whenever it is feasible. Thrombosis was the main cause of AVF loss, urging the need of implementation of a program for early detection of access failure.

Couto H.L.,Federal University of Minas Gerais
Applied Immunohistochemistry and Molecular Morphology | Year: 2016

Follistatin is a potent native activin antagonist that is expressed in the normal mammary gland and in different breast proliferative diseases. Despite experimental evidence that follistatin can modulate the breast cancer cell cycle, the clinical significance of follistatin expression in these tumors is unknown. The aim of this study was to correlate the intensity of follistatin expression in invasive breast cancer with some of its clinical and pathologic features, such as the disease stage and the hormonal receptor status. Paraffin blocks of tumor samples that had been fixed in buffered formalin were obtained from 154 women subjected to surgery for breast cancer between 2008 and 2012. Sections from all paraffin blocks were cut and processed together by immunohistochemistry using a commercial monoclonal antibody to human follistatin. The intensity of follistatin staining was unrelated to the menopausal status, the disease stage, the grade, progesterone receptor expression, and local or systemic recurrence. However, follistatin immunoreactivity was significantly stronger in estrogen receptor (ER)-negative tumors than in ER-positive tumors. These findings suggest that follistatin expression in invasive breast cancer is unrelated to the disease severity and the risk of recurrence, but is more intense in ER-negative tumors. Copyright 2016 Wolters Kluwer Health, Inc. All rights reserved.

Vianna H.R.,Federal University of Minas Gerais
Jornal brasileiro de nefrologia : 'orgão oficial de Sociedades Brasileira e Latino-Americana de Nefrologia | Year: 2011

Chronic kidney disease (CKD) is a serious public health problem whose prevalence has increased in the last few years. Its progression is associated with high morbidity and mortality. Several factors are associated with the onset and progression of CKD, such as obesity, hypertension and diabetes mellitus. Beyond these factors, there is evidence of a pathophysiological role for inflammation in CKD. Several cytokines and chemokines have been detected in the plasma and urine of patients at early stages of CKD, and have also been related to CKD complications. The expression of these mediators and renal injury may be influenced by drugs such as angiotensin-converting enzyme inhibitors, statins and antagonists of cytokine receptors. Modulation of the immune-inflammatory response can become a target for CKD treatment. The aim of this study was to review the scientific evidence on the role of inflammation in CKD, especially the effects of cytokines and chemokines.

Magalhaes L.M.,Federal University of Minas Gerais
The Journal of infectious diseases | Year: 2013

This study was designed to investigate whether the expression of interleukin 17 (IL-17) is associated with the indeterminate or cardiac clinical forms of Chagas disease and whether IL-17 expression can be correlated with patients' cardiac function. Our results demonstrated that cardiac Chagas patients have a lower intensity of expression of IL-17 by total lymphocytes and lower frequency of circulating T helper 17 cells. Correlative analysis showed that high IL-17 expression was associated with better cardiac function, as determined by left ventricular ejection fraction and left ventricular diastolic diameter values. Therefore, IL-17 expression can be a protective factor to prevent myocardial damage in human Chagas disease.

Marques G.F.,Federal University of Minas Gerais | Tilmant A.,Laval University
Water Resources Research | Year: 2013

The coordination of reservoir operation is critical for water systems' efficiency. Improved coordination requires sharing information, demanding a clear understanding of the potential gains and its distribution among the users to motivate engagement in coordinated operations and bearing of transaction costs. In a multiuser, multireservoir system, the evaluation of the potential coordination gains is not trivial because it requires the simultaneous evaluation of numerous trade offs. This paper presents a methodology to identify the likely upper and lower bounds in multireservoir system benefits, providing a reference framework for analyzing the economic value of coordination. The methodology is applied to a large-scale multireservoir system in Brazil. The methods rely on the comparison between two management scenarios. The first one mimics typical system operation based on individually designed rule curves, which are likely to perform on the lower bound. This is compared with fullscale system-wide optimization through an Stochastic Dual Dynamic Programming algorithm to represent fully coordinated reservoir operation (upper bound). For our case study, results indicate that better coordination reduced spills and improved releases timing according to reservoirs characteristics and location, allowing overall gains between 3% and 8% in energy and 7.9% in revenues, with revenues mostly improved by coordination in dry years. Larger reservoirs presented the highest gains in absolute terms, while the smaller ones presented the highest relative increases. By indicating individual gains at each reservoir, valuable information is produced to support future negotiations and benefit sharing among different agents, being water agencies or power companies. Key Points Evaluation of upper and lower bounds in reservoir system coordination Better coordination improves reservoir operation for higher benefits Better coordination allows more efficient use of available water storage ©2013. American Geophysical Union. All Rights Reserved.

Malta M.,ENSP FIOCRUZ | Ralil Da Costa M.,Federal University of Minas Gerais | Bastos F.I.,ICICT FIOCRUZ
Current HIV/AIDS Reports | Year: 2014

HIV-positive people who use drugs (PWUDs) are particularly vulnerable for suboptimal access to highly active antiretroviral therapy (HAART). We conducted a systematic review to identify factors associated with suboptimal HAART access among this population. Studies evaluating HAART access among active PWUDs as a primary outcome, presenting multivariate analysis and conducted after January 1997 were included. Of 122 studies matching the search criteria, only 14 (11.4 %) met the inclusion criteria. All selected studies were prospective cohorts and included young adults, 13 were conducted in North America or western Europe and one in Ukraine. Selected studies measured HAART access using different strategies, however, all identified PWUDs as less likely to receive HAART, when compared to those who never used drugs or former PWUDs. Additional factors associated with suboptimal HAART access include: recent incarceration, lack of health insurance, unstable housing, depression, non-white ethnicity, female PWUDs, and health professionals stigma/prejudice. Factors associated with higher rates of HIV-treatment access included: alcohol and/or drug addiction treatment (especially methadone maintenance therapy), regular source of primary care, treatment and care from the same provider (most of the time) and larger physician experience in HIV-management. PWUDs face a synergy of social and structural factors that influence their suboptimal access to HAART, struggling with poor living conditions, inadequate access to specialized care and stigma/discrimination from health professionals. Renewed strategies and effective interventions should be developed and scaled-up, in order to assure equitable HAART access, decrease morbidity and mortality among PWUDs. © 2013 Springer Science+Business Media.

Brochero Martinez F.E.,Federal University of Minas Gerais
Finite Fields and their Applications | Year: 2015

Abstract In this article, we show explicitly all central irreducible idempotents and their Wedderburn decomposition of the dihedral group algebra FqD2n, in the case when every divisor of n divides q-1. This characterization depends to the relation of the irreducible idempotents of the cyclic group algebra FqCn and the central irreducible idempotents of the group algebras FqD2n. © 2015 Elsevier Inc.

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.

Malekan M.,Federal University of Minas Gerais
Journal of the Brazilian Society of Mechanical Sciences and Engineering | Year: 2016

Detonation-driven fracture problems in tube under dynamic load have received plenty of attention because of various ranges of applications, such as oil and gas pipeline systems, new rocket engine such as pulse detonation engine, and pressurized aircraft fuselages. This paper reports the crack growth modeling in a thin aluminum tube under gaseous detonation load. Because of three-dimensional fracture dynamics with gas dynamics coupled phenomena, analytical modeling is complicated. Thus, a finite element method was applied. The finite element modeling and simulation of the tube under detonation moving load were performed using commercial code Abaqus. This simulation leads to obtain structural response of the tube to detonation load. The simulations were compared with experimental and analytical results from the literature for elasto-dynamic response of cylindrical shells with finite length under internal detonation loading. Cohesive element with traction–separation law was used for crack growth modeling along with crack tip opening displacement value obtained from experimental–numerical analysis from previous research. The final section of the paper is dedicated to investigating differences and comparisons between the numerical crack propagation simulations and experimental results reported in the literature. It has been demonstrated that using cohesive elements with some modifications can improve the numerical accuracy. The obtained results are more similar to the experimental results than numerical results available in literature. © 2014, The Brazilian Society of Mechanical Sciences and Engineering.

Martins J.D.R.,Federal University of Piaui | 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.

Reis G.S.,Federal University of Minas Gerais
Jornal brasileiro de nefrologia : orgão oficial de Sociedades Brasileira e Latino-Americana de Nefrologia | Year: 2012

This paper aims to show the utility of molecular biology for diagnose Bartter syndrome (BS) by the case report of two sisters and to propose a diagram for the molecular approach of this syndrome. The two reported cases presented prematurity, pregnancy complicated with polyhydramnio and low birth weight. During the first year of life, children exhibited polyuria, polydipsia and failure to thrive, leading to the investigation of renal tubular diseases and innate errors of metabolism. The laboratorial exams suggested BS, but the definitive diagnostic was only obtained by the detection of homozygous mutation on the exon 5 of the gene KCNJ1, resulting in a substitution of the aminoacid alanin for valin on codon 214 (A214V) in both DNA stripes in the two sisters and a heterozygous mutation in their parents. The definitive diagnostic of BS is frequently very difficult to be obtained. Consequently, considering the reported cases, we showed the utility of molecular techniques for the definitive diagnostic of BS and we proposed a diagram for the rational use of these techniques.

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.

Hamaguchi M.,Lappeenranta University of Technology | Cardoso M.,Federal University of Minas Gerais | Vakkilainen E.,Lappeenranta University of Technology
Energies | Year: 2012

The current global conditions provide the pulp mill new opportunities beyond the traditional production of cellulose. Due to stricter environmental regulations, volatility of oil price, energy policies and also the global competitiveness, the challenges for the pulp industry are many. They range from replacing fossil fuels with renewable energy sources to the export of biofuels, chemicals and biomaterials through the implementation of biorefineries. In spite of the enhanced maturity of various bio and thermo-chemical conversion processes, the economic viability becomes an impediment when considering the effective implementation on an industrial scale. In the case of kraft pulp mills, favorable conditions for biofuels production can be created due to the availability of wood residues and generation of black liquor. The objective of this article is to give an overview of the technologies related to the production of alternative biofuels in the kraft pulp mills and discuss their potential and prospects in the present and future scenario. © 2012 by the authors.

Martins N.R.S.,Federal University of Minas Gerais
Revista Brasileira de Ciencia Avicola | Year: 2012

Avian influenza (AI) is considered an exotic disease in the Brazilian poultry industry, according to the National Avian Health Program (PNSA), with permanent monitoring of domestic, exotic and native avian species. Brazil presents privileged environmental conditions of reduced risk. In addition, all commercial poultry and conservation holdings are registered in state or national inventories and geographically located (GPS) for health control. Poultry health standards are adopted for the conformity to the international market, mostly for the intensified poultry destined for exportation, but also for companion exotic and native conservation facilities. Guidelines for monitoring and the diagnosis of AI are published by the PNSA and follow the standards proposed by the international health code (World Organization for Animal Health, Organization International des Epizooties - OIE) and insure the free of status for avian influenza virus (AIV) of LPAIV-low pathogenicity AIV and HPAIV-high pathogenicity AIV. In addition, the infections by mesogenic and velogenic Newcastle disease virus, Mycoplasma gallisepticum, M. synoviae and M. meleagridis, Salmonella enteric subspecies enterica serovar Gallinarum biovars Gallinarum and Pullorum are eradicated from reproduction. Controlled infections by S.enterica subspecies enterica serovars Enteritidis and Typhimurium are monitored for breeders. The vaccination of chickens in ovo or at hatch against Marek's disease is mandatory. Broiler production is an indoor activity, confinement which insures biosecurity, with safe distances from the potential AIV reservoir avian species. Worldwide HPAIV H5N1 notifications to the OIE, in March 2011, included 51 countries.

Han M.Y.,Columbia University | Brant J.C.,Columbia University | Brant J.C.,Federal University of Minas Gerais | Kim P.,Columbia University
Physical Review Letters | Year: 2010

We report an electron transport study of lithographically fabricated graphene nanoribbons (GNRs) of various widths and lengths. At the charge neutrality point, a length-independent transport gap forms whose size is inversely proportional to the GNR width. In this gap, electrons are localized, and charge transport exhibits a transition between thermally activated behavior at higher temperatures and variable range hopping at lower temperatures. By varying the geometric capacitance, we find that charging effects constitute a significant portion of the activation energy. © 2010 The American Physical Society.

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.

Auffeves A.,CNRS Neel Institute | Gerace D.,University of Pavia | Portolan S.,CNRS Neel Institute | Drezet A.,CNRS Neel Institute | Franca Santos M.,Federal University of Minas Gerais
New Journal of Physics | Year: 2011

We study the temporal correlations of the field emitted by an electromagnetic resonator coupled to a mesoscopic number of two-level emitters that are incoherently pumped by a weak external drive. We solve the master equation of the system for increasing number of emitters and as a function of the cavity quality factor, and we identify three main regimes characterized by well-distinguished statistical properties of the emitted radiation. For small cavity decay rates, the emission events are uncorrelated and the number of photons in the emitted field becomes larger than one, resembling the buildup of a laser field inside the cavity. At intermediate decay rates (as compared with the emitter-cavity coupling) and for a few emitters, the statistics of the emitted radiation is bunched and strikingly dependent on the parity of the number of emitters. The latter property is related to the cooperativity of the emitters mediated by their coupling to the cavity mode, and its connection with steadystate subradiance is discussed. Finally, in the bad cavity regime the typical situation of emission from a collection of individual emitters is recovered. We also analyze how the cooperative behavior evolves as a function of pure dephasing, which allows us to recover the case of a classical source made of an ensemble of independent emitters, similar to what is obtained for a very leaky cavity. State-of-the-art techniques of Q-switch of resonant cavities, allied with he recent capability of tuning single emitters in and out of resonance, suggest this system to be a versatile source of different quantum states of light. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Pires A.S.T.,Federal University of Minas Gerais
Journal of Magnetism and Magnetic Materials | Year: 2015

Using the SU(3) Schwinger boson formalism, also named the flavor theory, I study the ferroquadrupolar phase of the bilinear-biquadratic Heisenberg model on the honeycomb lattice at zero temperature. The dispersion relations, the quadrupole moment and the static quadrupole structure factor are calculated. © 2015 Elsevier B.V. All rights reserved.

Silva B.C.,Federal University of Minas Gerais | Silva B.C.,Columbia University | Bilezikian J.P.,Columbia University
Annual Review of Medicine | Year: 2011

Although safe and effective agents are currently available to treat osteoporosis, fragility fractures remain a significant problem worldwide. Recent improvements in the understanding of the cellular, biochemical, and molecular pathways of bone biology have led to the development of newer agents to treat osteoporosis, which may lead to further improvements in outcomes. In this review, we summarize the most recent advances in the field, including new modes of administration of existing drug classes, various approaches to combination therapy, and drugs with novel mechanisms of action to treat osteoporosis. © 2011 by Annual Reviews. All rights reserved.

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.

Souza F.O.,Federal University of Minas Gerais
IET Control Theory and Applications | Year: 2013

The delay-dependent stability problem for systems with time-delay varying in an interval is addressed in this study. Based on Lyapunov-Krasovskii theory the proposed methods formulated as linear matrix inequality problems are able to check the stability interval when the time-varying delay d(t) belongs to an interval [τ1, τ2]. The Lyapunov - Krasovskii functional (LKF) selected in the present paper is simpler than some ones considered in the literature. However, the criteria obtained, based on this simple LKF, outperformed the similar existing ones in all numerical tests accomplished in this paper. Notation: Through out this paper the superscript T stands for transpose. 0 refers to a null matrix with appropriate dimensions. For a real symmetric matrix M, the notation M> 0 (< 0) means that M is the positive (negative) definite. The symmetric term in a matrix is denoted by *. © The Institution of Engineering and Technology 2013.

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.

Zhouri A.,Federal University of Minas Gerais
Journal of Environment and Development | Year: 2010

Since the 1970s, the ghost of an "international conspiracy" to occupy the Brazilian Amazon has emerged against the backdrop of shifting social and political realities. This article looks at how Brazilian political elites and military forces have influenced national interpretations of environmentalism and indigenous peoples' rights. It considers the formation of long-standing images and ideas perpetuated through economic plans like Avança Brasil, Growth Accelerated Program (PAC), and the Initiative for the Integration of Regional Infrastructure in South America (IIRSA) as well as international environmental initiatives such as on reducing emissions from deforestation and forest degradation in developing countries (REDD). Environmentalists and indigenous peoples have been viewed as opponents to economic growth and barriers to development. These images reflect entrenched political positions within Brazilian society, largely unrecognized on the international stage but critical to understanding Brazil's ambiguous positions in international negotiations. © 2010 SAGE Publications.

Mozelli L.A.,Federal University of Sao Joao del Rei | Souza F.O.,Federal University of Sao Joao 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.

Rajao R.,Federal University of Minas Gerais
Environmental Science and Policy | Year: 2013

This paper discusses the dynamics behind the establishment of scientific representations (e.g. reports, measurements, experiments) to the detriment of local representations (e.g. oral accounts, metaphors, symbols) in environmental policy-making in the Global South. To this end, the paper attempts to understand why local accounts of the Amazon in recent decades have gradually been replaced by satellite-based remote sensing (RS) technology in the region's policy-making. RS technology is shown to provide representations that match policy-makers discourses as regards the importance of: visibility, since satellite images are believed to provide a transparent window from which the Amazon can be seen by policy-makers working from centres of power; comprehensiveness, since the data obtained through RS claims to represent the entire region; and determinacy, as forecasting and spatial correlation techniques establish deterministic links between particular factors (e.g. the presence of farmers, inflation) and environmental issues (e.g. increases in deforestation). From this examination, it is argued that rather than focusing on identifying the essential differences between local and scientific representation, more attention should be paid to how different kinds of representations are in harmony or conflict with historically rooted governance discourses. The article also indicates that in order to revalue local representations in environmental policy-making it is necessary to challenge particular discourses which are "taken-for-granted" in governance practices at the present time. © 2012 Elsevier Ltd.

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.

Guimaraes R.C.,Federal University of Minas Gerais
Origins of Life and Evolution of Biospheres | Year: 2011

An investigation of the biosynthesis pathways producing glycine and serine was necessary to clarify an apparent inconsistency between the self-referential model (SRM) for the formation of the genetic code and the model of coevolution of encodings and of amino acid biosynthesis routes. According to the SRM proposal, glycine was the first amino acid encoded, followed by serine. The coevolution model does not state precisely which the first encodings were, only presenting a list of about ten early assignments including the derivation of glycine from serine-this being derived from the glycolysis intermediate glycerate, which reverses the order proposed by the self-referential model. Our search identified the glycine-serine pathway of syntheses based on one-carbon sources, involving activities of the glycine decarboxylase complex and its associated serine hydroxymethyltransferase, which is consistent with the order proposed by the self-referential model and supports its rationale for the origin of the genetic code: protein synthesis was developed inside an early metabolic system, serving the function of a sink of amino acids; the first peptides were glycine-rich and fit for the function of building the early ribonucleoproteins; glycine consumption in proteins drove the fixation of the glycine-serine pathway. © 2010 Springer Science+Business Media B.V.

Garcia C.C.,Federal University of Minas Gerais
Discovery medicine | Year: 2010

Traditionally, disease is thought to result from an insufficient response of the host to infection, leading to increased replication of microorganisms and consequently disease. However, infection may not necessarily lead to disease and disease is not only the result of uncontrolled replication of a microorganism. Indeed, the inflammatory response triggered by certain infections is frequently the cause of tissue damage and death. The present review argues that it is possible to separate mechanisms necessary for the host response to deal with infection from those which cause unwanted inflammation and drive disease. By understanding mechanisms which drive disease and where/how interaction leads to disease, we may be able to devise novel therapies to alleviate suffering of patients. Below, we will describe three situations--influenza, dengue and sepsis--in which unwanted (excessive, misplaced or altered) inflammation is responsible for disease induction. In these three situations, we will also describe some examples of molecules which have been found to drive disease but appear not to be essential for the ability of the host to control infection.

Marciano R.C.,Federal University of Minas Gerais
Jornal brasileiro de nefrologia : orgão oficial de Sociedades Brasileira e Latino-Americana de Nefrologia | Year: 2010

In the last decades there was a striking improvement in survival of children with chronic kidney disease. As life expectancy has increased in children with CKD, concern has risen about its physical, psychological, and social consequences. The aim of this study was to perform a review of the psychological consequences of CKD in the pediatric population, with the focus on mental disorders and on quality of life. We also reviewed studies regarding emotional and social effects and their possible influences on treatment adhesion. Several studies have shown impairment on quality of life and on mental health of these patients. A better understanding of emotional consequences of CKD in pediatric population possibly can reduce the impact of the renal disease on children. Moreover, a comprehensive approach of children and adolescents with CKD might result in a better clinical control and improve treatment adhesion.

Dias A.,Federal University of Ouro Preto | Lage M.M.,Federal University of Itajuba | 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.

Generoso S.D.V.,Federal University of Minas Gerais
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2016

PURPOSE OF REVIEW: Dietary fiber and prebiotics have been the focus of research and discussion for decades, but there are still pending concepts and definitions, in particular when addressing their use in the prevention and treatment of diarrhea. The purpose of this review is to present the latest advances in the understanding of dietary fiber and prebiotics, to review their proven role in the management of diarrhea, and to postulate the best timings and optimal doses. RECENT FINDINGS: The use of prebiotics has encompassed not only prevention but also the treatment of distinct types of diarrhea, at different treatment moments, and with regard to various different markers of outcome. Furthermore, the description of soluble fibers claiming to be prebiotics, and vice versa, has too often been the tone in the literature, which has led to misconceptions in classification and, consequently, confusion over the interpretation of results. It remains difficult to establish a consensus about the real impact of fiber and prebiotics on the prevention and therapy of diarrhea. SUMMARY: The review highlights the overlapping concepts of fiber and prebiotics, and supports the need for adequate individualization of their use, according to the goal – either prevention or treatment of diarrhea – as well as the optimal timing and dose to be used. Nonetheless, viscous soluble fibers seem to be the best option in treating diarrhea, whereas prebiotics are more important in preventing and avoiding recurrence. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

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.

Moreira R.L.,Federal University of Minas Gerais
Applied Physics Letters | Year: 2012

The role of the sample crystallinity on the electrocaloric effect (ECE) of ferroelectric polymers was investigated in miscible blends of poly(vinylidene fluoride-trifluoroethylene) and poly(methyl methacrylate). Polarization switching measurements gave the electric field required to realize full dipole realignment. Conformational entropy and temperature changes were obtained from the thermal dependence of the dielectric permittivity in the paraelectric phase. The obtained ECE values were relatively high: they reached 18.6 J/kgK and 4.7 K for the pure copolymer and decreased ca. 74% for a 70% crystallinity decreasing. The sample crystallinity appears clearly as a key parameter controlling the ECE in non-oriented ferroelectric polymers. © 2012 American Institute of Physics.

Povoa L.M.C.,Federal University of Goais | Rapini M.S.,Federal University of Minas Gerais
Science and Public Policy | Year: 2010

This article presents an analysis of the technology transfer process from universities and public research institutes to firms in Brazil. In particular, this study is concerned with the role of patents in this process. Although there is a certain enthusiasm in promoting technology transfer offices to manage university patents, the importance of patents to the technology transfer process is not yet well understood in literature. We conducted a survey with leaders of research groups from universities and public research institutes that developed and transferred technology to firms. The results show that patents are one of the least-used channels of technology transfer by universities and public research institutes. But the importance of the channels varies according to the type of technology transferred and to the firms' industry. © Beech Tree Publishing 2010.

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.

Bandarra Filho E.P.,Federal University of Uberlandia | Barbieri P.E.L.,Federal University of Minas Gerais
Experimental Thermal and Fluid Science | Year: 2011

This article reports an experimental investigation on flow boiling heat transfer and pressure drop of refrigerant R-134a in a smooth horizontal and two microfinned tubes from different manufacturers with the same geometric characteristics. Experiments have been carried out in an experimental facility developed for change of phase studies with a test section made with 9.52mm external diameter, 1.5m long copper tubes, electrically heated by tape resistors wrapped on the external surface. Tests have been performed under the following conditions: inlet saturation temperature of 5°C, vapor qualities from 5% to 90%, mass velocity from 100 to 500kg/sm2, and a heat flux of 5kW/m2. Experimental results indicated that the heat transfer performance was basically the same for both microfin tubes. The pressure drop is higher in the microfinned tubes in comparison to the smooth tube over the whole range of mass velocities and vapor qualities. The enhancement factor, used to evaluate the combination of heat transfer and pressure drop, is higher than one for both tubes for mass velocities lower than 300kg/sm2. Values lower than one have been obtained for both tubes in the mass velocity upper range as a result of a significant pressure drop increment not followed by a correspondent increment in the heat transfer coefficient. Some images, illustrating the flow patterns, were obtained from the visualization section, located in the exit of the test section with the same internal diameter of the tested tube. © 2010 Elsevier Inc.

Roberti de Siqueira F.,University of Campinas | Robson Schwartz W.,Federal University of Minas Gerais | Pedrini H.,University of Campinas
Neurocomputing | Year: 2013

Texture information plays an important role in image analysis. Although several descriptors have been proposed to extract and analyze texture, the development of automatic systems for image interpretation and object recognition is a difficult task due to the complex aspects of texture. Scale is an important information in texture analysis, since a same texture can be perceived as different texture patterns at distinct scales. Gray level co-occurrence matrices (GLCM) have been proved to be an effective texture descriptor. This paper presents a novel strategy for extending the GLCM to multiple scales through two different approaches, a Gaussian scale-space representation, which is constructed by smoothing the image with larger and larger low-pass filters producing a set of smoothed versions of the original image, and an image pyramid, which is defined by sampling the image both in space and scale. The performance of the proposed approach is evaluated by applying the multi-scale descriptor on five benchmark texture data sets and the results are compared to other well-known texture operators, including the original GLCM, that even though faster than the proposed method, is significantly outperformed in accuracy. © 2013 Elsevier B.V.

Cardoso F.,Federal University of Minas Gerais
Handbook of Clinical Neurology | Year: 2011

Sydenham's chorea (SC) is the neurologic expression of acute rheumatic fever (ARF). Despite the declining incidence of ARF worldwide, it remains the most common cause of acute chorea in children. It is characterized by a combination of motor and nonmotor features. In addition to chorea, among the first are decreased muscle tone and tics. Nonmotor features include obsessions, compulsions, attention deficit, emotional lability, decreased verbal fluency, and executive dysfunction. Most patients present with nonneurologic features of ARF, such as carditis and arthritis. The pathogenesis is thought to involve streptococcus-induced antibodies which cross-react with antigens of the basal ganglia. The diagnosis is made on purely clinical grounds since there is no biological marker of the illness. The management is based on use of antichoreic agents, such as valproic acid and neuroleptics, and prophylaxis of new bouts of streptococcus infection with antibiotics. Although the motor features of SC come into spontaneous remission in the majority of patients, a significant proportion of individuals remain with persistent chorea. © 2011 Elsevier B.V.

Moddel M.,University of Leipzig | Janke W.,University of Leipzig | Bachmann M.,University of Georgia | Bachmann M.,Federal University of Mato Grosso | Bachmann M.,Federal University of Minas Gerais
Physical Review Letters | Year: 2014

We construct the complete structural phase diagram of polymer adsorption at substrates with attractive stripelike patterns in the parameter space spanned by the adsorption affinity of the stripes and temperature. Results were obtained by extensive generalized-ensemble Monte Carlo simulations of a generic model for the hybrid organic-inorganic system. By comparing with adhesion properties at homogeneous substrates, we find substantial differences in the formation of adsorbed polymer structures if translational invariance at the surface is broken by a regular pattern. Beside a more specific understanding of polymer adsorption processes, our results are potentially relevant for the design of macromolecular pattern recognition devices such as sensors. © 2014 American Physical Society.

Lima L.S.,Federal University of Minas Gerais
Physica C: Superconductivity and its Applications | Year: 2016

We have used the Green's functions method at finite temperature and the Kubo's formalism, to calculate the electron conductivity σ(ω) in the generalized two-dimensional Hubbard model. We have obtained a behavior superconductor for the system to T > T0. The AC conductivity falls to zero in ω=ω0, where ω0 depends on Δ, which is the gap of the system. The behavior gotten is according of with the behavior of the superconductors of high Tc where there is a changes abruptly from a Mott's insulator state to superconductor. © 2016 Elsevier B.V.All rights reserved.

Santos S.H.S.,Federal University of Minas Gerais | Santos S.H.S.,State University of Montes Claros | Andrade J.M.O.,State University of Montes Claros
Peptides | Year: 2014

Angiotensin-(1-7) is one of the most important active peptides of the renin-angiotensin system (RAS) with recognized cardiovascular relevance; however several studies have shown the potential therapeutic role of Ang-(1-7) on treating and preventing metabolic disorders as well. This peptide achieves a special importance considering that in the last few decades obesity and metabolic syndrome (MS) have become a growing worldwide health problem. Angiotensin (Ang) II is the most studied component of RAS and is increased during obesity, diabetes and dyslipidemia (MS); some experimental evidence has shown that Ang II modulates appetite and metabolism as well as mechanisms that induce adipose tissue growth and metabolism in peripheral organs. Recent articles demonstrated that Ang-(1-7)/Mas axis modulates lipid and glucose metabolism and counterregulates the effects of Ang II. Based on these data, angiotensin-converting enzyme 2 (ACE2)/Ang-(1-7)/Mas pathway activation have been advocated as a new tool for treating metabolic diseases. This review summarizes the new evidence from animal and human experiments indicating the use of Ang-(1-7) in prevention and treatment of obesity and metabolic disorders. © 2014 Elsevier Inc.

Mozelli L.A.,Federal University of Ouro Preto | Palhares R.M.,Federal University of Minas Gerais
Systems and Control Letters | Year: 2011

In this paper a new Lyapunov function is proposed for stability analysis of linear time-varying systems. This new function carries more information regarding parameter variation leading to less conservative conditions. Using Finsler's lemma and a suitable form to describe the high-order time-derivatives of the parameters, finite sets of LMIs are obtained which are progressively less conservative as a pair of parameters grow. Previous results can be seen as a special case and numerical examples are carried out for the sake of illustration. © 2011 Elsevier B.V. All rights reserved.

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.

Rezende H.C.,Federal University of Uberlandia | Nascentes C.C.,Federal University of Minas Gerais | Coelho N.M.M.,Federal University of Uberlandia
Microchemical Journal | Year: 2011

Cloud point extraction (CPE) is proposed as a preconcentration procedure for the determination of Cd in soft drinks by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS). The cadmium reacted with pyridyl-azo-naphthol (PAN) to form hydrophobic chelates, which were extracted into the micelles of Triton X-114 in a solution buffered at pH 9. NaCl was used for the phase separation. The variables which affect the preconcentration were optimized using a 23 factorial design and central composite design (CCD). A response surface maximum point was obtained, and the critical values were a concentration of 0.13mmolL-1 PAN, 0.03% m/v Triton X-114 and 2.3% m/v NaCl. Under the optimized conditions, after the extraction and preconcentration steps, a sample volume of 100μL was introduced into the hot Ni tube using water as the carrier at a flow rate of 0.4mLmin-1. The values obtained for the detection limit, relative standard deviation and preconcentration factor were 0.0178μgL-1, 4.1% (n=8) and 55.5, respectively. The accuracy of the proposed method was demonstrated by performing addition-recovery experiments. Recoveries varied from 88 to 104%. © 2010 Elsevier B.V.

Franco G.A.P.,Federal University of Minas Gerais
Astronomy and Astrophysics | Year: 2012

Context. The line-of-sight towards Puppis-Vela contains some of the most interesting and elusive objects in the solar neighbourhood, including the Gum nebula, the IRAS Vela shell, the Vela SNR, and dozens of cometary globules. Aims. We investigate the distribution of the interstellar dust towards six small volumes of the sky in the region of the Gum nebula. Methods. New high-quality four-colour uvby and Hβ Strömgren photometry obtained for 352 stars in six selected areas of Kapteyn and complemented with data obtained in a previous investigation for two of these areas, were used to estimate the colour excess and distance to these objects. The obtained colour excess versus distance diagrams, complemented with other information, when available, were analysed in order to infer the properties of the interstellar medium permeating the observed volumes. Results. On the basis of the overall standard deviation in the photometric measurements, we estimate that colour excesses and distances are determined with an accuracy of 0 m010 and better than 30%, respectively, for a sample of 520 stars. A comparison with 37 stars in common with the new Hipparcos catalogue attests to the high quality of the photometric distance determination. The obtained colour excess versus distance diagrams testify to the low density volume towards the observed lines-of-sight. Very few stars out to distances of 1 kpc from the Sun have colour excesses larger than E(b-y) = 0. Conclusions. In spite of the low density character of the interstellar medium towards the Puppis-Vela direction, the obtained reddening as a function of the distance indicates that two or more interstellar structures are crossed towards the observed lines-of-sight. One of these structures may be associated with the very low density "wall" of the Local Cavity, which has a distance of 100-150 pc from the Sun. Another structure might be related to the Gum nebula, and if so, its front face would be located at ∼350 pc from the Sun. © 2012 ESO.

This study was designed to evaluate analgesia (pain intensity and analgesic consumption) and the time of discharge of patients who underwent ilioinguinal (II) and iliohypogastric (IH) nerve block associated with wound infiltration with 0.75% ropivacaine, or not, after inguinal hernia repair surgery under spinal anesthesia. This was a prospective, randomized, double-blind study with 34 patients undergoing inguinal hernia repair. Patients were divided into two groups: control (C) and II and IH nerve block (B). Group C (n = 17) received spinal anesthesia with 15 mg hyperbaric 0.5% bupivacaine and Group B (n = 17) received spinal anesthesia with 15 mg hyperbaric 0.5% bupivacaine associated with II and IH nerve block (10 mL of 0.75% ropivacaine) and surgical wound infiltration (10 mL of 0.75% ropivacaine). The following data were analyzed: demographic data, pain intensity according to the visual analog scale (VAS), and number of doses of analgesics (dipyrone, ketorolac and nalbuphine) in the immediate postoperative period, as well as at the time of hospital discharge. The VAS at rest was significantly lower in Group B compared with Group C (p < 0.05), three hours after the procedure, with no differences on VAS during movement in all postoperative periods. The number of doses of analgesics during the postoperative period was similar in both groups, but patients in Group B were discharged earlier than in Group C. II and IH nerve block associated with surgical wound infiltration with 0.75% ropivacaine provides better postoperative analgesia and early hospital discharge in patients undergoing inguinal hernia repair under spinal anesthesia.

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.

Pena S.D.J.,Federal University of Minas Gerais
Brazilian Journal of Medical and Biological Research | Year: 2011

Personalized pharmacogenomics aims to use individual genotypes to direct medical treatment. Unfortunately, the loci relevant for the pharmacokinetics and especially the pharmacodynamics of most drugs are still unknown. Moreover, we still do not understand the role that individual genotypes play in modulating the pathogenesis, the clinical course and the susceptibility to drugs of human diseases which, although appearing homogeneous on the surface, may vary from patient to patient. To try to deal with this situation, it has been proposed to use interpopulational variability as a reference for drug development and prescription, leading to the development of "race-targeted drugs". Given the present limitations of genomic knowledge and of the tools needed to fully implement it today, some investigators have proposed to use racial criteria as a palliative measure until personalized pharmacogenomics is fully developed. This was the rationale for the FDA approval of BiDil for treatment of heart failure in African Americans. I will evaluate the efficacy and safety of racial pharmacogenomics here and conclude that it fails on both counts. Next I shall review the perspectives and the predicted rate of development of clinical genomic studies. The conclusion is that "next-generation" genomic sequencing is advancing at a tremendous rate and that true personalized pharmacogenomics, based on individual genotyping, should soon become a clinical reality.

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.

Pessoa Rocha N.,Federal University of Minas Gerais
Neuroimmunomodulation | Year: 2014

The etiology of Parkinson's disease (PD) is complex and not fully understood, most probably because of the multiplicity of factors involved. Inflammatory and abnormal immune responses have been hypothesized to play a crucial role in PD. Not only in the brain, but also peripherally, inflammation is believed to contribute to the onset and progression of the neurodegenerative process seen in PD. Furthermore, increased inflammatory responses have been described both in the brain and peripheral blood of PD subjects. Although PD is considered a motor disorder, nonmotor symptoms are extremely frequent and disabling. Cognitive impairment and mood alterations are such symptoms that deserve increased attention since on the one hand they can appear even before typical motor disturbances are recognized, and on the other hand they are associated with high morbidity and mortality. A growing body of evidence suggests the existence of a link between inflammatory-immune responses and the occurrence of depression and cognitive impairment in PD patients. However, not all data are equally conclusive and are sometimes even conflicting. The aim of this brief review is to give an overview of the possible role that inflammation and immunomodulation may play in PD together with their putative impact on mood and cognitive alterations. What clearly emerges from this work is the fact that studies performed until now lack standardized and comparable methods to analyze both clinical and biological parameters. It is thus difficult to conclusively link mood and cognitive changes to underlying pathological mechanisms. Additional studies in this direction are warranted to convincingly establish or refute any causative relation. © 2014 S. Karger AG, Basel.

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.

Pors B.-J.,Leiden University | Monken C.H.,Leiden University | Monken C.H.,Federal University of Minas Gerais | Eliel E.R.,Leiden University | Woerdman J.P.,Leiden University
Optics Express | Year: 2011

We demonstrate experimentally how orbital-angularmomentum entanglement of two photons evolves under the influence of atmospheric turbulence. Experimental results are in excellent agreement with our theoretical model, which combines the formalism of two-photon coincidence detection with a Kolmogorov description of atmospheric turbulence. We express the robustness to turbulence in terms of the dimensionality of the measured correlations. This dimensionality is surprisingly robust: Scaling up our system to real-life dimensions, a horizontal propagation distance of 2 km seems viable. © 2011 Optical Society of America.

Callisto M.,Federal University of Minas Gerais | Graca M.A.S.,University of Coimbra
International Review of Hydrobiology | Year: 2013

Fine particulate organic matter (FPOM) is abundant in rivers, but the quality and quantity of FPOM in low-order streams have been investigated less frequently than the dynamics of coarse particulate organic matter (CPOM). We (i) assessed the quantity and quality of FPOM in several low-order mountain streams and the relationship between the quantity of FPOM and invertebrate abundance and (ii) evaluated the importance of microbial colonization to the growth of the FPOM consumer Chironomus riparius. FPOM availability ranged from 0.3 to 25.9g ash-free dry mass (AFDM)/m2 and was significantly higher during summer than during autumn. The density of invertebrates (10-13,500 individuals/m2) and FPOM were correlated (R=0.74). Chironomids were the most abundant organisms in the depositional zones where FPOM accumulated. Typically, FPOM nitrogen content was <1%, C:N ranged from 21 to 30%, and lignin ranged from 44 to 66%. Nitrogen content was generally lower during the autumn than summer. The ergosterol content of the FPOM was significantly lower (18μg/g AFDM) than that determined for leaves, from either water or soil. Chironomids fed with FPOM obtained from milled oak leaves, natural FPOM and sterile FPOM had 80, 45, and 0% emergence, respectively. We concluded that FPOM varies seasonally in quantity and quality in low-order streams and is a poor food resource relative to CPOM. Microbial colonization of FPOM could be important for the trophic ecology of collector species in low-order streams. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The repeated painful experiences in newborns may have short- and long-time effects, especially in premature infants. The use of sweetened solutions during painful procedures has been recommended as a measure of pain relief. This study aims to evaluate the evidence of the effect of oral sucrose or glucose for acute pain relief in premature infants. An integrative review was conducted in the MEDLINE and LILACS databases. Eight articles were selected from 2005 to 2010. The analyzis of these articles revealed the analgesic effect of glucose and sucrose in acute procedures. No significant side effects were found in infants who received glucose/sucrose. We emphasize the importance of the use of the pain assessment scale most closely related to the predominant population in the Neonatal Intensive Care Unit, a scale easy to be used and handled by health professionals.

Lima M.E.A.,Federal University of Minas Gerais
International Forum of Psychoanalysis | Year: 2012

The purpose of this essay is to consider the role and the meaning attributed to the concept of work by an analysis of Freud's cultural writings. It concludes that there are important deficiencies in Freudian theorization about this topic which have led to the naturalization of man and society and, as a result, to an ahistorical view of social processes. These deficiencies have been frequently pointed out in the criticism made of Freud's work. © 2012 The International Federation of Psychoanalytic Societies.

Brandao F.G.S.L.,Imperial College London | Brandao F.G.S.L.,Federal University of Minas Gerais | Plenio M.B.,Imperial College London | Plenio M.B.,University of Ulm
Communications in Mathematical Physics | Year: 2010

Given many independent and identically-distributed (i.i.d.) copies of a quantum system described either by the state ρ or σ (called null and alternative hypotheses, respectively), what is the optimal measurement to learn the identity of the true state? In asymmetric hypothesis testing one is interested in minimizing the probability of mistakenly identifying ρ instead of σ, while requiring that the probability that σ is identified in the place of ρ is bounded by a small fixed number. Quantum Stein's Lemma identifies the asymptotic exponential rate at which the specified error probability tends to zero as the quantum relative entropy of ρ and σ. We present a generalization of quantum Stein's Lemma to the situation in which the alternative hypothesis is formed by a family of states, which can moreover be non-i.i.d. We consider sets of states which satisfy a few natural properties, the most important being the closedness under permutations of the copies. We then determine the error rate function in a very similar fashion to quantum Stein's Lemma, in terms of the quantum relative entropy. Our result has two applications to entanglement theory. First it gives an operational meaning to an entanglement measure known as regularized relative entropy of entanglement. Second, it shows that this measure is faithful, being strictly positive on every entangled state. This implies, in particular, that whenever a multipartite state can be asymptotically converted into another entangled state by local operations and classical communication, the rate of conversion must be non-zero. Therefore, the operational definition of multipartite entanglement is equivalent to its mathematical definition. © Springer-Verlag 2010.

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.

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.

Noronha T.F.,Federal University of Minas Gerais | Resende M.G.C.,AT&T | Ribeiro C.C.,Federal University of Fluminense
Journal of Global Optimization | Year: 2011

The problem of routing and wavelength assignment in wavelength division multiplexing optical networks consists in routing a set of lightpaths and assigning a wavelength to each of them, such that lightpaths whose routes share a common fiber are assigned different wavelengths. This problem was shown to be NP-hard when the objective is to minimize the total number of wavelengths used. We propose a genetic algorithm with random keys for routing and wavelength assignment with the goal of minimizing the number of different wavelengths used in the assignment. This algorithmextends the best heuristic in the literature by embedding it into an evolutionary framework. Computational results show that the new heuristic improves the state-of-the-art algorithms in the literature. © AT & T Intellectual Property 2010.

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.

Mini R.A.F.,Pontifical Catholic University of Minas Gerais | Loureiro A.A.F.,Federal University of Minas Gerais
Computer Communications | Year: 2012

Wireless sensor networks have the potential to be applied in different applications such as habitat, environmental and industrial monitoring. Each sensor node is responsible for performing sensing, processing and communication functions that depend on a power source, which is typically represented by a battery that has a limited energy capacity. Energy awareness is a very important design consideration for protocols and algorithms in sensor networks. Energy management in WSNs involves not only reducing the energy consumption of a single sensor node but also maximizing the lifetime of the entire network. Furthermore, energy awareness should be incorporated into every stage of the wireless sensor network design and operation with the goal of making dynamic tradeoffs between energy consumption, system performance, and operational fidelity. The design of a WSN should consider the amount of energy each protocol can spend to perform its tasks. Using this idea, we can associate a finite energy budget for each network activity, and ask this activity to achieve its best performance using only its budget. This should be considered a basic principle to design algorithms for networks that are battery powered, especially for wireless sensor networks. In this paper, we present this strategy and show how it can be used to construct the energy map of a wireless sensor network. Our goal is to construct the best energy map using only a defined amount of energy. Simulation results show that we can approach the performance limits using the proposed finite energy budget model. © 2012 Elsevier B.V. All rights reserved.

Jorio A.,Federal University of Minas Gerais | Souza Filho A.G.,Federal University of Ceara
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.

Paiva E.A.S.,Federal University of Minas Gerais | Martins L.C.,Instituto Federal Of Educacao Ciencia E Tecnologia Do Sul Of Minas Gerais
Plant Biology | Year: 2014

Nectaries occur widely in Convolvulaceae. These structures remain little studied despite their possible importance in plant-animal interactions. In this paper, we sought to describe the structure and ultrastructure of the receptacular nectaries (RNs) of Ipomoea cairica, together with the dynamics of nectar secretion. Samples of floral buds, flowers at anthesis and immature fruits were collected, fixed and processed using routine methods for light, scanning and transmission electron microscopy. Circadian starch dynamics were determined through starch measurements on nectary sections. The secretion samples were subjected to thin layer chromatography. RNs of I. cairica were cryptic, having patches of nectar-secreting trichomes, subglandular parenchyma cells and thick-walled cells delimiting the nectary aperture. The glandular trichomes were peltate type and had typical ultrastructural features related to nectar secretion. The nectar is composed of sucrose, fructose and glucose. Nectar secretion was observed in young floral buds and continued as the flower developed, lasting until the fruit matured. The starch content of the subglandular tissue showed circadian variation, increasing during the day and decreasing at night. The plastids were distinct in different portions of the nectary. The continuous day-night secretory pattern of the RNs of I. cairica is associated with pre-nectar source circadian changes in which the starch acts as a buffer, ensuring uninterrupted nectar secretion. This circadian variation may be present in other extrafloral nectaries and be responsible for full daytime secretion. We conclude that sampling time is relevant in ultrastructural studies of dynamic extranuptial nectaries that undergo various changes throughout the day. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Melo L.G.C.,Federal University of Minas Gerais
Journal of the Optical Society of America B: Optical Physics | Year: 2015

This paper investigates the electromagnetic behavior of transverse magnetic (TM) surface plasmon-polaritons guided by a magnetostatically biased, laterally infinite graphene surface at the interface between two dielectric materials. We present the theory for the reflectance calculation of a graphene-based attenuated total reflection (ATR) device, and analyze the conditions for the observation of surface polaritons in the 500 GHz-5 THz frequency range. In the absence of magnetostatic field B0, TM surface excitations in graphene are generated only by TM-polarized incident waves. In the presence of B0, the surface conductivity of graphene becomes a tensor, allowing surface polaritons to be excited by transverse electric (TE) polarized incident waves as well. Features in the ATR reflectance curves for TM-or TE-polarized incident radiation for several B0 are identified as corresponding to TM surface waves for the range of frequency examined. It is observed that the surface excitations produced by TE incident light display stronger confinement than the surface polaritons excited by TM incident light. Knowledge of the electromagnetic properties of graphene-dielectric structures may be valuable for modern applications in the field of tunable plasmonic graphene electronics at the far-infrared. © 2015 Optical Society of America.

This article aims to compare the trends for risk and protective factors for NCD in the population with and without health insurance. Analysis of temporal trends of the Vigitel phone survey, collected annually in adult population. Were used analyzed the temporal series of variables referent to risk and protective factors for NCD, from 2008 to 2013. Variables were compared according to the possession or not of health insurance using simple linear regression model. There was a reduction in the prevalence of smoking in the population with and without health insurance, in 0.72% and 0,69% per year respectively. The consumption of fruits and vegetables grew 0,8% and 0.72% per year respectively among the population with and without health insurance. Physical activity in leisure time increased 1.17% and 1.01% per year among population with and without health insurance. Excess weight increased in 1.03% and obesity in 0.74% p.y in the population with health insurance and 1.53% and 0.95% p.y without health insurance. Mammography increased 2.4% in the population without health insurance. Vigitel monitoring showed improvement in the indicators in the population with and without health insurance. © 2015, Associacao Brasileira de Pos - Graduacao em Saude Coletiva. 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.

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.

Dickman A.G.,Pontifical Catholic University of Minas Gerais | Dickman R.,Federal University of Minas Gerais
American Journal of Physics | Year: 2015

We discuss a lattice model of vector-mediated transmission of a disease to illustrate how simulations can be applied in epidemiology. The population consists of two species, human hosts and vectors, which contract the disease from one another. Hosts are sedentary, while vectors (mosquitoes) diffuse in space. Examples of such diseases are malaria, dengue fever, and Pierce's disease in vineyards. The model exhibits a phase transition between an absorbing (infection free) phase and an active one as parameters such as infection rates and vector density are varied. © 2015 American Association of Physics Teachers.

Nogueira L.,Sloan Kettering Cancer Center | Nogueira L.,Federal University of Minas Gerais | Corradi R.,Hospital Israel Pinheiro | Eastham J.A.,Sloan Kettering Cancer Center
BJU International | Year: 2010

Prostate-specific antigen (PSA) has been used for detecting prostate cancer since 1994. Although it is the best cancer biomarker available, PSA is not perfect. It lacks both the sensitivity and specificity to accurately detect the presence of prostate cancer. None of the PSA thresholds currently in use consistently identify patients with prostate cancer and exclude patients without cancer. Novel approaches to improve our ability to detect prostate cancer and predict the course of the disease are needed. Additional methods for detecting prostate cancer have been evaluated. Despite the discovery of many new biomarkers, only a few have shown some clinical value. These markers include human kallikrein 2, urokinase-type plasminogen activator receptor, prostate-specific membrane antigen, early prostate cancer antigen, PCA3, α-methylacyl-CoA racemase and glutathione S-transferase φ hypermethylation. We review the reports on biomarkers for prostate cancer detection, and their possible role in the clinical practice. © 2009 BJU International.

Lemos A.,Federal University of Minas Gerais | Caminhas W.,University of Campinas | Gomide F.,University of Campinas
IEEE Transactions on Fuzzy Systems | Year: 2011

This paper introduces a class of evolving fuzzy rule-based system as an approach for multivariable Gaussian adaptive fuzzy modeling. The system is an evolving TakagiSugeno (eTS) functional fuzzy model, whose rule base can be continuously updated using a new recursive clustering algorithm based on participatory learning. The fuzzy sets of the rule antecedents are multivariable Gaussian membership functions, which have been adopted to preserve information between input variable interactions. The parameters of the membership functions are estimated by the clustering algorithm. A weighted recursive least-squares algorithm updates the parameters of the rule consequents. Experiments considering time-series forecasting and nonlinear system identification are performed to evaluate the performance of the approach proposed. The multivariable Gaussian evolving fuzzy models are compared with alternative evolving fuzzy models and classic models with fixed structures. The results suggest that multivariable Gaussian evolving fuzzy modeling is a promising approach for adaptive system modeling. © 2006 IEEE.

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.

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.

Saldanha P.L.,Federal University of Minas Gerais | Monken C.H.,University of Oxford
New Journal of Physics | Year: 2011

The Bialynicki-Birula-Sipe photon wave function formalism is extended to include the interaction between photons and continuous nonabsorptive media. When the second quantization of this formalism is introduced, a new method for describing the quantum interactions between light and matter emerges. As an example of the application of the method, an expression for the quantum state of the twin photons generated by parametric downconversion is derived in agreement with previous treatments, but with a more intuitive interpretation. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Mohallem J.R.,Federal University of Minas Gerais
American Journal of Physics | Year: 2015

The troublesome topic of Galilean invariance in Lagrangian mechanics is discussed in two situations: (i) A particular case involving a rheonomic constraint in uniform motion and (ii) the general translation of an entire system and the constants of motion involved. A widespread impropriety in most textbooks is corrected, concerning a condition for the equality h = E to hold. © 2015 American Association of Physics Teachers.

Souza H.A.,Federal University of Minas Gerais
Genetics and molecular research : GMR | Year: 2012

Dimorphandra mollis (Leguminosae), known as faveiro and fava d'anta, is a tree that is widely distributed throughout the Brazilian Cerrado (a savanna-like biome). This species is economically valuable and has been extensively exploited because its fruits contain the flavonoid rutin, which is used to produce medications for human circulatory diseases. Knowledge about its genetic diversity is needed to guide decisions about the conservation and rational use of this species in order to maintain its diversity. DNA extraction is an essential step for obtaining good results in a molecular analysis. However, DNA isolation from plants is usually compromised by excessive contamination by secondary metabolites. DNA extraction of D. mollis, mainly from mature leaves, results in a highly viscous mass that is difficult to handle and use in techniques that require pure DNA. We tested four protocols for plant DNA extraction that can be used to minimize problems such as contamination by polysaccharides, which is more pronounced in material from mature leaves. The protocol that produced the best DNA quality initially utilizes a sorbitol buffer to remove mucilaginous polysaccharides. The macerated leaf material is washed with this buffer until there is no visible mucilage in the sample. This protocol is adequate for DNA extraction both from young and mature leaves, and could be useful not only for D. mollis but also for other species that have high levels of polysaccharide contamination during the extraction process.

Castro L.R.,Federal University of Minas Gerais
Arquivos brasileiros de cardiologia | Year: 2011

Non-ST-segment elevation acute coronary syndrome is associated with elevation of brain natriuretic peptide and markers of myocardial necrosis, although its relationship with the TIMI score and left ventricular function are largely unknown. To evaluate the correlation between plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and markers of myocardial necrosis [creatine phosphokinase muscle-brain fraction (CK-MB) and troponin I], TIMI risk score and left ventricular ejection fraction in patients with non-ST-segment elevation acute coronary syndrome. Eighty-seven patients with non-ST-segment elevation acute coronary syndrome were divided into two groups: 37 (42.5%) with unstable angina and 50 (57.5%) with non-ST-segment elevation myocardial infarction. Left ventricular ejection fraction more than 40% was found in 86.2% of the total sample. Serum levels of NT-proBNP was higher in patients with non-ST elevation myocardial infarction than in those with unstable angina (p<0.001). Increased levels of NT-proBNP were associated with increases in troponin I (rs=0.425, p<0.001), peak CK-MB (rs=0.458, p<0.001) and low left ventricular ejection fraction (rs=-0.345, p=0.002); no correlation was found with the TIMI risk score (rs=0.082, p=0.44). Multivariate analysis revealed that left ventricular ejection fraction and troponin I levels were independently correlated with NT-proBNP levels (p=0.017 and p=0.002, respectively). Increased levels of NT-proBNP in patients with non-ST-segment elevation acute coronary syndrome are not related exclusively to low left ventricular ejection fraction, but can also be caused by the presence of myocardial ischemia and necrosis.

Navarro M.A.,Brazilian Nuclear Technology Development Center (CDTN) | Santos A.A.C.,Federal University of Minas Gerais
Progress in Nuclear Energy | Year: 2011

The fuel assemblies of the Pressurized Water Reactors (PWR) are constituted of rod bundles arranged in a regular square configuration by spacer grids placed along its length. The presence of the spacer grids promote two antagonist effects on the core: a desirable increase of the local heat transfer downstream the grids and an adverse increase of the pressure drop due to the constriction on the coolant flow area. Most spacer grids are designed with mixing vanes which cause a cross and swirl flow between and within the subchannels, enhancing even more the heat transfer performance in the grid vicinity. The improvement of the heat transfer increases the departure from the nucleate boiling ratio, allowing higher operating power in the reactor. Due to these important thermal and fluid dynamic features, experimental and theoretical investigations have been carried out in the past years for the development of spacer grid design. More recently, the Computational Fluid Dynamics (CFD) using three dimensional Reynolds Averaged Navier Stokes (RANS) analysis has been used efficiently for this purpose. Many computational works have been performed, but the appropriate numerical procedure for the flow in rod bundle simulations is not yet a consensus. This work presents results of flow simulations performed with the commercial code CFX 11.0 in a PWR 5 × 5 rod bundle segment with a split vane spacer grid. The geometrical configuration and flow conditions used in the experimental studies performed by Karoutas et al. were assumed in the simulations. To make the simulation possible with a limited computational capacity and acceptable mesh refinement, the computational domain was divided in 7 sub-domains. The sub-domains were simulated sequentially applying the outlet results of a previous sub-domain as inlet condition for the next. In this study the k-ε turbulence model was used. The simulations were also compared with those performed by Karoutas et al. in half a subchannel and In et al. in one subchannel computational domains. Comparison between numerical and experimental results of lateral and axial velocities along of the rod bundle show good agreement for all evaluated heights downstream the spacer grid. The present numerical procedure shows better predictions than Karoutas et al. model especially further from the spacer grid where the peripheral subchannels have more influence in the average flow. © 2011 Elsevier Ltd. All rights reserved.

Pires A.S.T.,Federal University of Minas Gerais
Solid State Communications | Year: 2014

Using a modified spin wave theory, we study the two-dimensional spin S=1 Heisenberg antiferromagnet with both spin and spatial anisotropies and competitive next-nearest neighbor interaction J2, at zero temperature. The magnetization as a function of J2 shows the existence of three different phases namely, ordered Néel, disordered and ordered collinear phases. The existence of the disordered phase depends on the values of the anisotropy parameters. The model shows a very rich phase diagram. © 2014 Elsevier Ltd.

Costa A.G.,Federal University of Minas Gerais
Geoscience Canada | Year: 2016

Brazil’s heritage buildings were built using different types of natural stone, including sandstone, limestone, quartzite, granite, gneiss, steatite (soapstone) and schist. Historic buildings are located in cities such as Recife, Olinda, Salvador, Rio de Janeiro, Congonhas and Ouro Preto; some are over 300 years old. They show evidence of different alteration and decay processes, with the latter leading to a loss of value because of physical and chemical modifications in intrinsic properties of the natural stones used. Consequently, these buildings function as open-air laboratories, and contribute to the study of deterioration in such monuments. On going investigation of alteration and decay reveals that they are affected by a diverse group of processes that are, in part, influenced by lithological factors. This understanding will contribute to the choice of preservation methods that will be applied in order to arrest degradation. © 2016 GAC/AGC®.

Pires A.S.T.,Federal University of Minas Gerais
Solid State Communications | Year: 2014

Using the SU(3) Schwinger bosons formalism, in a mean field approximation, I have calculated the dynamical quadrupole structure factor in the ferroquadrupolar phase of the S=1 Heisenberg model with bilinear and biquadratic exchange interactions on the triangular lattice. I have calculated the dynamical quadrupolar structure factor, which in principle could be measurable using resonant inelastic x-ray scattering, and provide evidence for the existence of spin-nematic order. There is a possibility that my calculations could be applied to the compound NiGa2S4. © 2014 Elsevier Ltd. All rights reserved.

de Paula G.A.,Federal University of Minas Gerais
The International journal of oral & maxillofacial implants | Year: 2012

The goal of this study was to compare the stress distribution of tooth-implant-supported prostheses (TISPs) and solely implant-supported prostheses (ISPs) with two different pontic spans (three units versus four units). Two-dimensional finite element models were constructed from the radiographs of polyester resin casts to mimic TISPs and ISPs. In all, eight models were analyzed. Occlusal loads of 15 N and 30 N were applied to the premolars and molars, respectively. The lateral and inferior borders of the models were constrained, with all degrees of freedom equal to zero. Eight-node elements with plane strain assumption were used for simulation. The authors found that TISPs with a short span and wider-diameter implants resulted in more homogenous stress distribution and less stress concentration on the implants. The long span yielded higher stress concentrations on the implants and between the pontics. In all models analyzed, stress concentrations were present in the implants.

Lambertucci J.R.,Federal University of Minas Gerais
Revista da Sociedade Brasileira de Medicina Tropical | Year: 2014

Different aspects of hepatosplenic schistosomiasis are revisited here. Manson's schistosomiasis causes periportal fibrosis and portal hypertension in approximately 6% of infected subjects, usually with preservation of their hepatic function. The assessment of liver involvement is of major importance in determining the prognosis and risk of complications from schistosomiasis, such as upper digestive bleeding secondary to variceal rupture. For many years, the diagnosis of hepatosplenic schistosomiasis and liver fibrosis was made by abdominal palpation and the finding of liver and/or spleen enlargement. However, there is no consensus regarding the clinical parameters of the liver and spleen to be considered in this physical evaluation. For the last three decades, abdominal ultrasound (US) has become the best imaging technique to evaluate liver fibrosis caused by schistosomiasis mansoni. However, US is a subjective procedure and is therefore examiner-dependent. Magnetic resonance imaging (MRI) findings have provided valuable information in addition to ultrasound and clinical examination. The combination of a comprehensive history and physical examination, basic laboratory tests (a stool examination for Schistosoma mansoni eggs and a blood cell count), biomarkers for liver fibrosis/portal hypertension and imaging methods seem to offer the best approach for evaluating patients with this disease. In situations where research is involved or in patients with severe disease, MRI may be considered.

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.

Pereira E.,Federal University of Minas Gerais
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

We address the heat flow study starting from microscopic models of matter: we develop an approach and investigate some anharmonic graded mass crystals, with weak interparticle interactions. We calculate the thermal conductivity, and show the existence of rectification and negative differential thermal resistance. Our formalism allows us to understand the mechanism behind the phenomena, and shows that the properties of graded materials make them genuine thermal diodes. © 2010 The American Physical Society.

Valverde L.D.F.,Federal University of Minas Gerais
Applied Immunohistochemistry and Molecular Morphology | Year: 2016

The present study sought to evaluate and compare the immunoexpression of proteins minichromosome maintenance (MCM) 3 and Ki-67 in oral squamous cell carcinoma (OSCC) to assess the potential of these proteins as markers of cellular proliferation. Twenty-eight cases of OSCC, 9 of tumor-free resection margins (TM), and 4 of non-neoplastic oral mucosa (NNM) were subjected to immunohistochemistry to detect the expression of proteins MCM3 and Ki-67. All OSCCs demonstrated positivity for both proteins. In these tumors, greater MCM3 immunoreactivity was observed in comparison with Ki-67, whereas TMs and NNMs exhibited greater Ki-67 expression compared with MCM3. The immunoexpression of Ki-67 seemed to be influenced by the inflammatory process, particularly in TM and NNM. Our findings indicate that although both MCM3 and Ki-67 represent reliable markers of cellular proliferation in OSCC, as MCM3 expression does not appear to be influenced by external factors, this protein may emerge as a novel marker of cellular proliferation in these types of tumors. Copyright 2016 Wolters Kluwer Health, Inc. All rights reserved.

Gomes M.T.,Federal University of Minas Gerais
Frontiers in cellular and infection microbiology | Year: 2012

Innate immunity serves as the first line of defense against infectious agents such as intracellular bacteria. The innate immune platform includes Toll-like receptors (TLRs), retinoid acid-inducible gene-I-like receptors and other cytosolic nucleic acid sensors, nucleotide-binding and oligomerization domain-like receptors, adaptors, kinases and other signaling molecules that are required to elicit effective responses against different pathogens. Our research group has been using the Gram-negative bacteria Brucella abortus as a model of pathogen. We have demonstrated that B. abortus triggers MAPK and NF-κB signaling pathways in macrophages in a MyD88 and IRAK-4-dependent manner. Furthermore, we claimed that so far TLR9 is the most important single TLR during Brucella infection. The identification of host receptors that recognize pathogen-derived nucleic acids has revealed an essential role for nucleic acid sensing in the triggering of immunity to intracellular pathogens. Besides TLRs, herein we describe recent advances in NOD1, NOD2, and type I IFN receptors in innate immune pathways during B. abortus infection.

Saldanha P.L.,Federal University of Minas Gerais | Saldanha P.L.,University of Oxford
Optics Communications | Year: 2011

We defend a natural division of the energy density, energy flux and momentum density of electromagnetic waves in linear media in electromagnetic and material parts. In this division, the electromagnetic part of these quantities have the same form as in vacuum when written in terms of the macroscopic electric and magnetic fields, the material momentum is calculated directly from the Lorentz force that acts on the charges of the medium, the material energy is the sum of the kinetic and potential energies of the charges of the medium and the material energy flux results from the interaction of the electric field with the magnetized medium. We present reasonable models for linear dispersive non-absorptive dielectric and magnetic media that agree with this division. We also argue that the electromagnetic momentum of our division can be associated with the electromagnetic relativistic momentum, inspired on the recent work of Barnett [Phys. Rev. Lett. 104 (2010) 070401] that showed that the Abraham momentum is associated with the kinetic momentum and the Minkowski momentum is associated with the canonical momentum. © 2011 Elsevier B.V. All rights reserved.

Neves A.G.M.,Federal University of Minas Gerais
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

The Eigen quasispecies model in a periodically moving sharp-peak landscape considered in previous seminal works and is analyzed in greater detail. We show here, through a more rigorous analysis, that results in those papers are qualitatively correct. In particular, we obtain a phase diagram for the existence of a quasispecies with the same shape as in the above cited paper by C. Ronnewinkel, with upper and lower thresholds for the mutation rate between which a quasispecies may survive. A difference is that the upper value is larger and the lower value is smaller than the previously reported ones, so that the range for quasispecies existence is always larger than thought before. The quantitative information provided might also be important in understanding genetic variability in virus populations and has possible applications in antiviral therapies. The results in the quoted papers were obtained by studying the populations only at some few genomes. As we will show, this amounts to diagonalizing a 3×3 matrix. Our work is based instead in a different division of the population allowing a finer control of the populations at various relevant genetic sequences. The existence of a quasispecies will be related to Perron-Frobenius eigenvalues. Although huge matrices of sizes 2l, where l is the genome length, may seem necessary at a first look, we show that such large sizes are not necessary and easily obtain numerical and analytical results for their eigenvalues. © 2010 The American Physical Society.

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.

Paiva E.A.S.,Federal University of Minas Gerais
Journal of the Torrey Botanical Society | Year: 2012

The occurrence of colleters in Eudicotyledons is probably significantly underestimated as a consequence of the scarcity of structural studies directed towards them and the difficulties to determine their function. The present work aims to report the occurrence of colleters in Cariniana estrellensis and describe their morphological and functional aspects; for this, leaves at different stages of expansion were collected and studied using light, and scanning and transmission electron microscopy. The young leaves of C. estrellensis are involute and have colleters along the margins. These colleters appear to be functional in very young leaves and produce pectic secretions that spread over the entire leaf surface. The colleters are clavate and sessile, and have a central axis composed of parenchymatic cells as well as a secretory epidermis covered by a cuticle. The central cells have vacuolate cytoplasm with few organelles and reserve substances. The cytoplasm of the epidermal cells has numerous dictyosomes during the secretory phase, with few plastids and mitochondria. The secretions coating on the leaf surfaces appear to contribute to maintaining the water balance of the young leaves, thus the main function of the colleters in this species appears to be to protect the leaves from excessive transpiration loses. © Torrey Botanical Club.

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.

De Oliveira Chaves A.,Federal University of Minas Gerais
Central European Journal of Geosciences | Year: 2013

New evidence supported by petrography (including mineral chemistry), lithogeochemistry, U-Pb geochronology by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), and physicochemical study of fluid and melt inclusions by LA-ICP-MS and microthermometry, point to an orogenic setting of Lagoa Real (Bahia-Brazil) involving uraniferous mineralization . Unlike the previous models in which uraniferous albitites represent Na-metasomatised 1.75 Ga anorogenic granitic rocks, it is understood here that they correspond to metamorphosed sodium-rich and quartz-free 1.9 Ga late-orogenic syenitic rocks (Na-metasyenites). These syenitic rocks are rich not only in albite, but also in U-rich titanite (source of uranium). The interpretation of geochemical data points to a petrogenetic connection between alkali-diorite (local amphibolite protolith) and sodic syenite by fractional crystallization through a transalkaline series. This magmatic differentiation occurred either before or during shear processes, which in turn led to albitite and amphibolite formation. The metamorphic reactions, which include intense recrystallization of magmatic minerals, led uraninite to precipitate at 1.87 Ga under Oxidation/Reduction control. A second population of uraninites was also generated by the reactivation of shear zones during the 0.6 Ga Brasiliano Orogeny. The geotectonic implications include the importance of the Orosirian event in the Paramirim Block during paleoproterozoic Sǎo Francisco Craton edification and the influence of the Brasiliano event in the Paramirim Block during the West-Gondwana assembly processes. The regional microcline-gneiss, whose protolith is a 2.0 Ga syn-collisional potassic granite, represents the albitite host rock. The microcilne-gneiss has no petrogenetic association to the syenite (albitite protolith) in magmatic evolutionary terms. © Versita Sp. z o.o.

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.

De Mello Ferreira A.,Federal University of Minas Gerais | Marchesiello M.,Joseph Fourier University | Thivel P.-X.,Joseph Fourier University | Thivel P.-X.,CNRS Physical Eletrochemistry Materials and Interfaces Lab
Separation and Purification Technology | Year: 2013

Electrocoagulation (EC) is an efficient technique for cleaning wastewater containing heavy metals before discharge in the environment. Studies on EC are usually conducted by adding supporting electrolyte to the medium investigated so as to increase the electrolyte conductivity and improve the sacrificial anodic dissolution of the electrodes. The present study was conducted with low-conductivity natural water (Grenoble tap water) artificially polluted with copper, zinc and nickel. It shows that addition of supporting salts is not necessary to obtain high removal efficiencies. For these metals, elimination rates above 95% were obtained after only 60 min of treatment, especially in the case of aluminum electrodes. These high removal efficiencies can be explained by the partial precipitation of copper and zinc before treatment owing to the highest pH value of natural water (compared with distilled water), by pH increase during EC caused by the reduction of water on the cathode, and by possible co-precipitation of calcium carbonate (formed from calcium and bicarbonate ions present in tap water) and metallic hydroxide species produced by the anodic dissolution of the electrodes. © 2013 Elsevier B.V. All rights reserved.

Macedo A.V.,Federal University of Minas Gerais
Hematology/oncology and stem cell therapy | Year: 2010

An 18-year-old male underwent an allogeneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myeloid leukemia (CML) in the first late chronic phase. On day 132, he was readmitted to the hospital with nausea, vomiting and nodular lesions on endoscopy. A diagnosis of granulocytic sarcoma of the stomach was made. Bone marrow cytogenetic analysis for the Philadelphia chromosome and nested polymerase chain reaction for BCR-ABL1 were both negative. Immunosuppression was abruptly discontinued, and by day 180, all gastric lesions had completely disappeared. However, there were histological signs of graft-versus-host disease. The patient developed progressive anorexia and elevated hepatic enzymes, which prompted the reintroduction of cyclosporine. Considering the risk of another relapse, imatinib mesylate (IM) 600 mg/day was started. The patient Is condition improved, and there was no evidence of disease recurrence at 36 months after relapse. Relapse of CML is the commonest cause of treatment failure after allo-HSCT. On rare occasions, a localized extramedullary presentation is seen. Unless properly treated, other extramedullary relapse sites and/or marrow infiltration usually occur. Withdrawal of immunosuppression, along with IM therapy seems to be an acceptable approach in this setting.

Prokop J.W.,University of Akron | Santos R.A.S.,Federal University of Minas Gerais | Milsted A.,University of Akron
PLoS ONE | Year: 2013

The renin-angiotensin system is involved in multiple conditions ranging from cardiovascular disorders to cancer. Components of the pathway, including ACE, renin and angiotensin receptors are targets for disease treatment. This study addresses three receptors of the pathway: AT1, AT2, and MAS and how the receptors are similar and differ in activation by angiotensin peptides. Combining biochemical and amino acid variation data with multiple species sequence alignments, structural models, and docking site predictions allows for visualization of how angiotensin peptides may bind and activate the receptors; allowing identification of conserved and variant mechanisms in the receptors. MAS differs from AT1 favoring Ang-(1-7) and not Ang II binding, while AT2 recently has been suggested to preferentially bind Ang III. A new model of Ang peptide binding to AT1 and AT2 is proposed that correlates data from site directed mutagenesis and photolabled experiments that were previously considered conflicting. Ang II binds AT1 and AT2 through a conserved initial binding mode involving amino acids 111 (consensus 325) of AT1 (Asn) interacting with Tyr (4) of Ang II and 199 and 256 (consensus 512 and 621, a Lys and His respectively) interacting with Phe (8) of Ang II. In MAS these sites are not conserved, leading to differential binding and activation by Ang-(1-7). In both AT1 and AT2, the Ang II peptide may internalize through Phe (8) of Ang II propagating through the receptors' conserved aromatic amino acids to the final photolabled positioning relative to either AT1 (amino acid 294, Asn, consensus 725) or AT2 (138, Leu, consensus 336). Understanding receptor activation provides valuable information for drug design and identification of other receptors that can potentially bind Ang peptides. © 2013 Prokop et al.

Kokshenev V.B.,Federal University of Minas Gerais | Christiansen P.E.R.,Aalborg Zoo
Biological Journal of the Linnean Society | Year: 2010

The standard differential scaling of proportions in limb long bones (length against circumference) was applied to a phylogenetically wide sample of the Proboscidea, Elephantidae and the Asian (Elephas maximus) and African (Loxodonta africana) elephants. In order to investigate allometric patterns in proboscideans and terrestrial mammals with parasagittal limb kinematics, the computed slopes between long bone lengths and circumferences (slenderness exponents) were compared with published values for mammals, and studied within a framework of the theoretical models of long bone scaling under gravity and muscle forces. Limb bone allometry in E. maximus and the Elephantidae is congruent with adaptation to bending and/or torsion induced by muscular forces during fast locomotion, as in other mammals, whereas the limb bones in L. africana appear to be adapted for coping with the compressive forces of gravity. Hindlimb bones are therefore more compliant than forelimb bones, and the resultant limb compliance gradient in extinct and extant elephants, contrasting in sign to that of other mammals, is shown to be a new important locomotory constraint preventing elephants from achieving a full-body aerial phase during fast locomotion. Moreover, the limb bone pattern of African elephants, indicating a noncritical bone stress not increasing with increments in body weight, explains why their mean and maximal body masses are usually above those for Asian elephants. Differences in ecology may be responsible for the subtle differences observed in vivo between African and Asian elephants, but they appear to be more pronounced when revealed via mechanical patterns dictated by limb bone allometry. © 2010 The Linnean Society of London.

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.

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.

Sampaio R.F.,Federal University of Minas Gerais | Augusto V.G.,University Estadual Of Minas Gerais Uemg
Brazilian Journal of Physical Therapy | Year: 2012

Background: The rapid aging of the workforce has motivated the development of studies that seek to maintain good health conditions, work ability, autonomy and the social integration of workers. Objectives: To present the theoretical framework, available measurements and models for promoting work ability. Discussion: In the field of rehabilitation, the sedimentation of the conceptual model of the ability to work has a normative role and may be useful for assessing whether a person has a temporary or permanent loss of capacity as well as for defining a specific rehabilitation program. The concept may further help determine different aspects, both internal and external to the person, that could result in improved or restored work ability. Conclusion: In order to enhance the available measurements, propose new interventions for promoting work ability and to further its use as an outcome measure in rehabilitation, it is necessary to assume that the predictors relate to the individuals, their work and their life outside of work in dynamic interactions that require analytical methods which account for the multidimensionality of the construct.

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.

Saldanha P.L.,Federal University of Minas Gerais
Optics Express | Year: 2010

It is proposed a natural and consistent division of the momentum of electromagnetic waves in linear, non-dispersive and non-absorptive dielectric and magnetic media into material and electromagnetic parts. The material part is calculated using directly the Lorentz force law and the electromagnetic momentum density has the form ε0E× B, without an explicit dependence on the properties of the media. The consistency of the treatment is verified through the obtention of a correct momentum balance equation in many examples and showing the compatibility of the division with the Einstein's theory of relativity by the use of a gedanken experiment. An experimental prediction for the radiation pressure on mirrors immersed in linear dielectric and magnetic media is also made. © 2010 Optical Society of America.

Pereira E.,Federal University of Minas Gerais
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2010

We show the existence of thermal rectification in the graded mass quantum chain of harmonic oscillators with self-consistent reservoirs. Our analytical study allows us to identify the ingredients leading to the effect. The presence of rectification in this effective, simple model (representing graded mass materials, systems that may be constructed in practice) indicates that rectification in graded mass quantum systems may be an ubiquitous phenomenon. Moreover, as the classical version of this model does not present rectification, our results show that, here, rectification is a direct result of the quantum statistics. © 2010 Elsevier B.V. All rights reserved.

Visacro S.,Federal University of Minas Gerais
IEEE Transactions on Industry Applications | Year: 2015

This paper presents an overview on the response of grounding electrodes subject to lightning currents with a focus on industrial environment. The influent parameters of lightning currents are discussed, and the lightning response of electrodes is analyzed based on experimental and simulated results to provide the fundamental knowledge required in this field for engineers working in industrial plants. © 1972-2012 IEEE.

Lima L.S.,Federal University of Minas Gerais
Journal of Magnetism and Magnetic Materials | Year: 2016

We study the influence of the site disorder in the long range order and in the spin transport in the two-dimensional Heisenberg antiferromagnet with ion-single anisotropy, in the square lattice in T=0 using the SU(3) Schwinger boson theory. We analyze these properties in the regime of Bose-Einstein condensation, where the bosons tz are condensed: = . In particular, we discuss the influence of the site disorder in the spin transport of this model and in the critical properties, where Dc separates Néel's phase, D < Dc, gapless phase, of the disordered phase, gapped phase, D > Dc, in the spin conductivity. We find that the behavior of the long-range order for D < Dc in the model without impurities with the concentration of nonmagnetic impurities does not affect the spin conductivity. © 2016 Elsevier B.V. All rights reserved.

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.

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.

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.

Souza F.D.O.,Federal University of Sao Joao 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.

Silva C.M.,Hemominas Foundation | Giovani P.,UNIFENAS | Viana M.B.,Federal University of Minas Gerais
Pediatric Blood and Cancer | Year: 2011

Background: Transcranial Doppler ultrasonography (TCD) is an important way of detecting risk of ischemic stroke in children with sickle cell anemia. Procedure: A random sample of 262 FS-hemoglobin children from a newborn screening inception cohort in Brazil (1998-2005) was followed up to May 2009. Pulsed TCD followed STOP protocol. Children with mean blood flow velocity <170 cm/sec in cerebral arteries were classified as low risk; between 170 and 184, low conditional risk; between 185 and 199, high conditional risk; and ≥200, high risk. Results: Median age, 6.2 years (2-11.2 years); 147 female; 13 children (5%) had ischemic stroke prior to TCD; 186/249 (74.7%) were classified as low risk; 19 (7.6%) as low conditional; 7 (2.8%) as high conditional; and 8 (3.2%) as high risk; inadequate tests, 11.6%. The probability of ischemic stroke at 10 years was 8.3% (SEM 2.3%); of stroke or high-risk TCD 15.6% (3.5%). Children with stroke or altered TCD (conditional and high risk) were compared to children with normal examinations. They were younger (P = 0.03), with lower hemoglobin (P = 0.003), higher leukocytosis (P = 0.015), and higher reticulocytosis (P < 0.001). Episodes per year of acute chest syndrome were also higher in that group, but not significantly (P = 0.09). Reticulocytosis remained the only significant variable upon multivariate analysis (P = 0.004). Basilar and middle cerebral artery velocities were significantly correlated (R = 0.55; P < 0.001). Conclusions: Probability of stroke was similar to international reports; of belonging to high-risk group, lower. High-reticulocyte count was the most important factor associated with cerebrovascular disease. Basilar artery velocity >130 cm/sec seems to be an indirect sign of an underlying cerebrovascular disease. © 2010 Wiley-Liss, Inc.

Ferreira A.S.,Usiminas SA | Mansur M.B.,Federal University of Minas Gerais
Process Safety and Environmental Protection | Year: 2011

Statistical tools were used to analyse the spray roasting operation so as to identify the main operating variables for the production of commercial value iron oxide (Fe2O3) by pyrohydrolysis from steel pickling liquors. The study was carried out using a 24 factorial design of experiments and the effects of the following variables were investigated based on large scale experimental data: temperature, liquor feed flow rate, pressure and feed air/COG (coke oven gas) ratio. The quality of Fe2O 3 was evaluated according to the contents of Cl, Fe, Si, Mn and H2O, as well as pH and granulometry. For the conditions investigated, the major influencing variables were temperature and feed flow rate; in fact, commercial value Fe2O3 was obtained solely at higher evaluated levels of temperature and flow rate. The contents of Fe, Si and Mn in the Fe2O3 were affected by the content of respective species in the feed liquor, which in turn depends on the type of steel treated in the pickling line. Simple statistical models were proposed to describe some Fe2O3 characteristics. Before this study, only 10% of the Fe2O3 produced at USIMINAS was commercialized, due mainly to the high content of chloride (approximately 0.45%, w/w). Today, all oxide produced meets quality requirements. © 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Saldanha P.L.,Federal University of Minas Gerais
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

In an recent work with the title "Asking Photons Where They Have Been," Danan et al. experimentally demonstrate an intriguing behavior of photons in an interferometer [Phys. Rev. Lett. 111, 240402 (2013)PRLTAO0031- 900710.1103/PhysRevLett.111.240402]. In their words: "The photons tell us that they have been in the parts of the interferometer through which they could not pass." They interpret the results using the two-state vector formalism of quantum theory and say that, although an explanation of the experimental results in terms of classical electromagnetic waves in the interferometer is possible (and they provide a partial description), it is not so intuitive. Here we present a more detailed classical description of their experimental results, showing that it is actually intuitive. The same description is valid for the quantum wave function of the photons propagating in the interferometer. In particular, we show that it is essential that the wave propagates through all parts of the interferometer to describe the experimental results. We hope that our work helps to give a deeper understanding of these interesting experimental results. © 2014 American Physical Society.

Luz E.J.D.S.,Federal University of Ouro Preto | Menotti D.,Federal University of Ouro Preto | Schwartz W.R.,Federal University of Minas Gerais
Expert Systems with Applications | Year: 2014

Traditional strategies, such as fingerprinting and face recognition, are becoming more and more fraud susceptible. As a consequence, new and more fraud proof biometrics modalities have been considered, one of them being the heartbeat pattern acquired by an electrocardiogram (ECG). While methods for subject identification based on ECG signal work with signals sampled in high frequencies (>100 Hz), the main goal of this work is to evaluate the use of ECG signal in low frequencies for such aim. In this work, the ECG signal is sampled in low frequencies (30 Hz and 60 Hz) and represented by four feature extraction methods available in the literature, which are then feed to a Support Vector Machines (SVM) classifier to perform the identification. In addition, a classification approach based on majority voting using multiple samples per subject is employed and compared to the traditional classification based on the presentation of single samples per subject each time. Considering a database composed of 193 subjects, results show identification accuracies higher than 95% and near to optimality (i.e., 100%) when the ECG signal is sampled in 30 Hz and 60 Hz, respectively, being the last one very close to the ones obtained when the signal is sampled in 360 Hz (the maximum frequency existing in our database). We also evaluate the impact of: (1) the number of training and testing samples for learning and identification, respectively; (2) the scalability of the biometry (i.e., increment on the number of subjects); and (3) the use of multiple samples for person identification. © 2013 Elsevier Ltd. All rights reserved.

Tilmant A.,Laval University | Arjoon D.,Laval University | Marques G.F.,Federal University of Minas Gerais
Journal of Water Resources Planning and Management | Year: 2014

Following three decades of rather low investment in dams, many regions throughout the world are now seeking to further develop new storage capacity to meet exploding demands for water and to hedge against the risk posed by climate change. Storage capacity is often perceived as a key element of climate change adaptation strategies, while at the same time contributing to socioeconomic development through irrigation, energy generation, fish production, and municipal and industrial water supply. The benefits provided by dams must be balanced with the associated environmental and social costs, which can take various forms, such as the degradation of ecosystems because of altered flow regimes and the relocation of people from the impoundment area. The benefits of storage essentially come from the ability to move water in time, making it available during the low-flow season when it becomes more valuable. As river basins develop and new dams are constructed, it may be important for planning and operational purposes to assess the individual contribution of each reservoir to the benefits of storage. This paper presents a methodology to determine the economic value of storage in multireservoir systems based on the marginal net benefit functions of storage and on hydroeconomic modeling. A cascade of reservoirs in the Euphrates river basin is used to illustrate the methodology. © 2014 American Society of Civil Engineers.

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.

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.

Sonter L.J.,University of Queensland | Barrett D.J.,University of Queensland | Barrett D.J.,CSIRO | Soares-Filho B.S.,Federal University of Minas Gerais | Moran C.J.,University of Queensland
Global Environmental Change | Year: 2014

Global demand for minerals is often considered an insignificant driver of land-use change because mines are small. We (1) investigated evidence supporting a link between global demand for steel and land-use change in Brazil's Iron Quadrangle, and (2) quantified the extent of land-use change and associated impacts on native vegetation. Historic land-use change was quantified using Landsat TM, relationships between demand for steel and land-use change were investigated using a simple linear model, and future scenarios were simulated using a calibrated land-use change model. Results support our hypothesis that global demand for steel drives extensive land-use change in the Iron Quadrangle, where increased steel production was correlated with increased iron ore production and mine expansion, and with increased charcoal production and plantation expansion. The direct impacts of mining on native vegetation were disproportionate to their relatively small spatial extent, while direct impacts of plantations were spatially extensive, as were their impacts on surrounding native vegetation. Additionally, evidence of two indirect impacts emerged during 1990-2010. Plantation expansion decreased native forest regrowth, while competition for land between mining companies and urban developers increased deforestation pressures. In combination, global demand for steel affected the majority of land in the Iron Quadrangle; however, many impacts were poorly captured by current land management approaches. Similar processes may operate in other mining regions, where global demand for minerals drives production of multiple resources (non-renewable and renewable) and thus extensive land-use change. © 2014 Elsevier Ltd.

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.

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.

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.

Pires A.S.T.,Federal University of Minas Gerais
Physica A: Statistical Mechanics and its Applications | Year: 2012

We study the XY antiferromagnet with S=1 and single-ion anisotropy on a triangular lattice using the bond operator formalism in two cases: the J1- J2 model, which includes a next-nearest-neighbor coupling J2, and the spatially-anisotropic J1-J1′ model, in which the nearest-neighbor interaction takes a value J1′ along one of the bond directions. The introduction of frustrating second-neighbor interactions leads, at intermediate values of the coupling, to the existence of a disordered phase with the possibility of a quantum liquid behavior. The effect of the frustration on the quantum phase transition is studied. The phase diagrams at T=0 are presented. © 2012 Elsevier B.V. All rights reserved.

Ribeiro A.L.,Federal University of Minas Gerais
Journal of the American Heart Association | Year: 2014

Electrocardiography has been considered an important tool in the management of Chagas disease (ChD) patients, although its value in elderly infected patients is unknown. This study was designed to investigate the prevalence and prognostic value of electrocardiographic abnormalities in Trypanosoma cruzi infected and noninfected older adults. We studied 1462 participants in Bambuí City, Brazil, with electrocardiogram (ECG) records classified by the Minnesota Code. Follow-up time was 10 years; the endpoint was mortality. Adjustment for potential confounding variables included age, gender, conventional risk factors, and B-type natriuretic peptide (BNP). The mean age was 69 years (60.9% women). The prevalence of ChD was 38.1% (n=557). ECG abnormalities were more frequent in ChD patients (87.6% versus 77.7%, P<0.001). Right bundle branch block (RBBB) with left anterior hemiblock (LAH) was strongly related to ChD (OR: 11.99 [5.60 to 25.69]). During the mean follow-up time of 8.7 years, 556 participants died (253 with ChD), and only 89 were lost to follow-up. ECG variables of independent prognostic value for death in ChD included absence of sinus rhythm, frequent ventricular and supraventricular premature beats, atrial fibrillation, RBBB, old and possible old myocardial infarction, and left ventricular hypertrophy. The presence of any major ECG abnormalities doubled the risk of death in ChD patients (HR: 2.18 [1.35 to 3.53]), but it also increased the risk in non-ChD subjects (HR: 1.50 [1.07 to 2.10]); the risk of death increased with the number of major abnormalities in the same patient. ECG abnormalities are more common among elderly Chagas disease patients and strongly predict adverse outcomes.

Chiarini-Garcia H.,Federal University of Minas Gerais
Methods in molecular biology (Clifton, N.J.) | Year: 2011

Glycol methacrylate (GMA), a water and ethanol miscible plastic resin, is a medium handy to use for light microscopy embedding that has a number of advantages than paraffin embedding. The GMA improves the histological, morphometrical, and immunohistochemical evaluations, mainly due to the accurate assessment of cytological details. This chapter focuses on our experience in the GMA processing and describes in detail the fixation, embedding, and staining methods that we have been using for testes evaluations.

Moreira F.A.,Federal University of Minas Gerais | Moreira F.A.,University of Cambridge | Dalley J.W.,University of Cambridge
European Journal of Pharmacology | Year: 2015

Many drugs abused by humans acutely facilitate, either directly or indirectly, dopamine neurotransmission in the mesolimbic pathway. As a consequence dopamine receptor agonists and antagonists have been widely investigated as putative pharmacological therapies for addiction. This general strategy, however, has had only limited success due in part to poor treatment adherence and efficacy and the significant adverse effects of dopaminergic medications. In this perspective, we discuss the potential therapeutic use of dopamine receptor partial agonists in addiction, developed initially as antipsychotic agents. Recent research indicates that the dopamine D2 receptor partial agonists, such as aripiprazole, also shows useful ancillary efficacy in several animal models of psychostimulant and opioid addiction. Notably, these findings suggest that unlike full dopamine receptor agonists and antagonists these compounds have low abuse liability and are generally well tolerated. Indeed, partial dopamine agonists attenuate the rewarding properties of opioids without interfering with their analgesic effects. Herein we discuss the utility and potential of dopamine receptor partial agonists as treatments for both stimulant and non-stimulant drug addiction. © 2015 Elsevier B.V. All rights reserved.

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.

Meira W.,Federal University of Minas Gerais
Computer Communications | Year: 2015

This work presents an algorithm for deployment of roadside units based on partial mobility information. We propose the partition of the road network into same size urban cells, and we use the migration ratios between adjacent urban cells in order to infer the better locations for the deployment of the roadside units. Our goal is to identify those α locations maximizing the number of distinct vehicles experiencing at least one V2I contact opportunity. We compare our strategy to two deployment algorithms: MCP-g relies on full mobility information (full knowledge of the vehicles trajectories), while MCP-kp does not assume any mobility information at all. Results demonstrate that our strategy increases the number of distinct vehicles contacting the infrastructure in 6.8% when compared to MCP-kp. On the other hand, MCP-g overcomes our strategy by 8.5%. We must evaluate whether the 8.5% improvement worthies tracking the trajectories of vehicles. Complementary, the marginal contribution of adding a new roadside unit becomes much more assertive when employing our strategy, enabling a better evaluation of the return on investments by network designers. Such guarantees are not provided by MCP-kp, and they are too weak in MCP-g. © 2015 Elsevier B.V. All rights reserved.

Pires A.S.T.,Federal University of Minas Gerais
Solid State Communications | Year: 2014

The SU(3) Schwinger bosons formalism is used to study the three dimensional anisotropic Heisenberg antiferromagnet with nearest and next-nearest neighbor interactions in the XY plane (and only nearest neighbor interactions along the z direction) and single ion anisotropy. The quantum phase transitions from the gapped disordered state to the ordered phases are studied. The phase diagram at zero temperature is calculated. We have two kinds of quantum phase transitions: one induced by the single-ion anisotropy term, and another caused by competitive interactions. © 2014 Elsevier Ltd.All rights nreserved.

Almeida M.B.,Federal University of Minas Gerais
Journal of the American Society for Information Science and Technology | Year: 2013

Looking for ontology in a search engine, one can find so many different approaches that it can be difficult to understand which field of research the subject belongs to and how it can be useful. The term ontology is employed within philosophy, computer science, and information science with different meanings. To take advantage of what ontology theories have to offer, one should understand what they address and where they come from. In information science, except for a few papers, there is no initiative toward clarifying what ontology really is and the connections that it fosters among different research fields. This article provides such a clarification. We begin by revisiting the meaning of the term in its original field, philosophy, to reach its current use in other research fields. We advocate that ontology is a genuine and relevant subject of research in information science. Finally, we conclude by offering our view of the opportunities for interdisciplinary research. © 2013 ASIS&T.

Carneiro M.M.,Federal University of Minas Gerais
Jornal Brasileiro de Reproducao Assistida | Year: 2016

Uterine leiomyomas, also known as uterine fibroids or uterine myomas, are the most common benign gynecologic tumors found in women of reproductive age. In spite of the numerous published studies evaluating the hormonal dependency, epidemiology, molecular biology, pathology, and genetics of leiomyomas, many questions remain unanswered. The remodeling of the uterus in response to hormonal stimuli and its return to a basal state may be related to adult stem/progenitor cells residing in the endometrial and myometrial layers. Recent published papers on stem cells and their paracrine interactions with more specialized cell populations within leiomyomas may help establish the missing link between the development of treatments designed to stop the growth of leiomyomas and therapies devised to eliminate them. Therefore, this study aimed to address the current paradigm regarding the evidence available on the role of stem/progenitor cells in the pathogenesis of uterine leiomyoma. Only a handful of studies involving humans have been published to date describing the presence of somatic stem cells (SSCs) in the myometrium and leiomyomas. No solid conclusion has been established thus far. Despite the fact that these studies strongly pointed to the vital role human leiomyoma stem cells might play in initiating the development of myomas, huge gaps still persist in the literature. Studies to identify putative myometrial and leiomyoma-specific markers might offer new possibilities for understanding the origin of these tumors and perhaps help develop new nonsurgical noninvasive treatments. © 2016, Sociedade Brasileira de Reproducao Assistida. All rights reserved.

Junqueira D.R.,Federal University of Minas Gerais
Cochrane database of systematic reviews (Online) | Year: 2012

Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction presenting as a prothrombotic disorder related to antibody-mediated platelet activation. It is a poorly understood paradoxical immune reaction resulting in thrombin generation in vivo, which leads to a hypercoagulable state and the potential to initiate venous or arterial thrombosis. A number of factors are thought to influence the incidence of HIT including the type and preparation of heparin (unfractionated heparin (UFH) or low molecular weight heparin (LMWH)) and the heparin-exposed patient population, with the postoperative patient population presenting a higher risk.Although LMWH has largely replaced UFH as a front-line therapy, there is evidence supporting a lack of superiority of LMWH compared with UFH regarding prevention of deep vein thrombosis and pulmonary embolism following surgery, and similar frequencies of bleeding have been described with LMWH and UFH. The decision as to which of these two preparations of heparin to use may thus be influenced by adverse reactions such as HIT. We therefore sought to determine the relative impact of UFH and LMWH specifically on HIT in postoperative patients receiving thromboembolism prophylaxis. The objective of this review was to compare the incidence of HIT and HIT complicated by thrombosis in patients exposed to UFH versus LMWH in randomised controlled trials (RCTs) of postoperative heparin therapy. The Cochrane Peripheral Vascular Diseases Group searched their Specialised Register (March 2012) and CENTRAL (2012, Issue 2). In addition, the authors searched LILACS (March 2012) and additional trials were sought from reference lists of relevant publications. We were interested in comparing the incidence of HIT occurring during exposure to UFH or LMWH after any surgical intervention. Therefore, we studied RCTs in which participants were postoperative patients allocated to receive UFH or LMWH, in a blinded or unblinded fashion. Eligible studies were required to have as an outcome clinically diagnosed HIT, defined as a relative reduction in the platelet count of 50% or greater from the postoperative peak (even if the platelet count at its lowest remained > 150 x 10(9)/L) occurring within five to 14 days after the surgery, with or without a thrombotic event occurring in this timeframe. Additionally, circulating antibodies associated with the syndrome were required to have been investigated through laboratory assays. Two review authors independently extracted data and assessed the risk of bias. Disagreements were resolved by consensus with participation of a third author. In total two studies involving 923 participants met all the inclusion criteria and were included in the review. Pooled analysis showed a statistically significant reduction in the risk of HIT with LMWH compared with UFH (risk ratio (RR) 0.24, 95% confidence interval (CI) 0.07 to 0.82; P = 0.02). This result suggests that patients treated with LMWH would have a relative risk reduction (RRR) of 76% in the probability of developing HIT compared with patients treated with UFH.Venous thromboembolism (VTE) complicating HIT occurred in 12 of 17 patients who developed HIT. Pooled analysis showed a statistically significant reduction in HIT complicated by VTE with LMWH compared with UFH (RR 0.20, 95% CI 0.04 to 0.90; P = 0.04). This result indicates that patients using LMWH would have a RRR of 80% for developing HIT complicated by VTE compared with patients using UFH. Arterial thrombosis occurred in only one patient who received UFH and there were no amputations or deaths documented. There was a lower incidence of HIT and HIT complicated by VTE in postoperative patients undergoing thromboprophylaxis with LMWH compared with UFH. This is consistent with the current clinical use of LMWH over UFH as front-line heparin therapy. However, conclusions are limited by a scarcity of high quality evidence. We did not expect the paucity of RCTs including HIT as an outcome as heparin is one of the most commonly used drugs worldwide and HIT is a life-threatening adverse drug reaction. To address the scarcity of clinically-relevant information on the topic of HIT as a whole, HIT should be included as an outcome in future RCTs of heparin, and HIT as an adverse drug reaction should be considered in clinical recommendations regarding monitoring of the platelet count for HIT.

Simoes C.C.,Federal University of Minas Gerais
Genetics and molecular research : GMR | Year: 2012

Aluminum (Al) toxicity restricts root growth and agricultural yield in acid soils, which constitute approximately 40% of the potentially arable lands worldwide. The two main mechanisms of Al tolerance in plants are internal detoxification of Al and its exclusion from root cells. Genes encoding membrane transporters and accessory transcription factors, as well as cis-elements that enhance gene expression, are involved in Al tolerance in plants; thus studies of these genes and accessory factors should be the focus of molecular breeding efforts aimed at improving Al tolerance in crops. In this review, we describe the main genetic and molecular studies that led to the identification and cloning of genes associated with Al tolerance in plants. We include recent findings on the regulation of genes associated with Al tolerance. Understanding the genetic, molecular, and physiological aspects of Al tolerance in plants is important for generating cultivars adapted to acid soils, thereby contributing to food security worldwide.

Carneiro M.M.,Federal University of Minas Gerais
BioMed research international | Year: 2013

Endometriosis is a chronic benign gynecologic disease that can cause pelvic pain and infertility affecting almost 10% of reproductive-age women. Deeply infiltrating endometriosis (DIE) is a specific entity responsible for painful symptoms which are related to the anatomic location of the lesions. Definitive diagnosis requires surgery, and histological confirmation is advisable. The aim of this paper is to review the current literature regarding the possibility of diagnosing DIE accurately before surgery. Despite its low sensitivity and specificity, vaginal examination and evaluation of specific symptoms should not be completely omitted as a basic diagnostic tool in detecting endometriosis and planning further therapeutic interventions. Recently, transvaginal ultrasound (TVUS) has been reported as an excellent tool to diagnose DIE lesions in different locations (rectovaginal septum, retrocervical and paracervical areas, rectum and sigmoid, and vesical wall) with good accuracy. There are neither sufficiently sensitive and specific signs and symptoms nor diagnostic tests for the clinical diagnosis of DIE, resulting in a great delay between onset of symptoms and diagnosis. Digital examination, in addition to TVS, may help to gain better understanding of the anatomical extent and dimension of DIE which is of crucial importance in defining the best surgical approach.

Paiva E.A.S.,Federal University of Minas Gerais
American Journal of Botany | Year: 2012

Premise of the study: While mahogany (Swietenia macrophylla) is one of the most important forest species in the Amazon region, little is known about its reproductive biology. Knowledge about the nectary structure and dynamics of nectar production of this species represent a key step toward understanding its relationship with pollinators. Methods: Mahogany tree fl oral buds and fl owers in anthesis were collected, fi xed, and processed for study by light and transmission and scanning electron microscopy. The chemical composition of nectar and the nectary pigments was also studied.Key results: Both staminate and pistillate fl owers have nectaries, which contain a papillose epidermis and stomata. The nectariferous tissue is parenchymatous, with the cell cytoplasm primarily containing mitochondria and plastids. Secretory activity initiates at the beginning of anthesis, which occurs at nightfall. Flowers undergoing anthesis become structurally modifi ed, with starch grains in the plastids disappearing. The number of plastoglobuli in the plastids also increases when nectaries change color from pale yellow to intense red. Pistillate and staminate flowers produce meager nectar rewards. Conclusions: Changes in plastoglobuli number seem to be related to an increase in carotenes and color changes during anthesis. Carotenes can be linked to the protection of the plant against oxidative stress, which results from secretory activities. Nectary color has a limited role as a pollinator attractant. Floral rewards comprise small nectar droplets in both fl ower types, in addition to a few pollen grains in staminate fl owers. These meager rewards are probably adapted to attract small generalist insects. © 2012 Botanical Society of America.

Silva L.S.,Federal University of Minas Gerais
Revista de saúde pública | Year: 2012

To assess the association between exposure to adverse psychosocial working conditions and poor self-rated health among bank employees. A cross-sectional study including a sample of 2,054 employees of a government bank was conducted in 2008. Self-rated health was assessed by a single question: "In general, would you say your health is (...)." Exposure to adverse psychosocial working conditions was evaluated by the effort-reward imbalance model and the demand-control model. Information on other independent variables was obtained through a self-administered semi-structured questionnaire. A multiple logistic regression analysis was performed and odds ratio calculated to assess independent associations between adverse psychosocial working conditions and poor self-rated health. The overall prevalence of poor self-rated health was 9%, with no significant gender difference. Exposure to high demand and low control environment at work was associated with poor self-rated health. Employees with high effort-reward imbalance and overcommitment also reported poor self-rated health, with a dose-response relationship. Social support at work was inversely related to poor self-rated health, with a dose-response relationship. Exposure to adverse psychosocial work factors assessed based on the effort-reward imbalance model and the demand-control model is independently associated with poor self-rated health among the workers studied.

To analyze expenditure on treatment for postmenopausal osteoporosis and associated factors on mean per capita expenditure. A probabilistic-deterministic linkage between the database of Authorizations for Highly Complex Procedures and the mortality information system was constructed, resulting in a historical cohort of patients using high-cost medications for the treatment of postmenopausal osteoporosis, between 2000-2006. Mean monthly spending on medicines was stratified by age group and described according to demographic and clinical characteristics and the type of drug used. A linear regression model was used to assess the impact of demographic and clinical characteristics on per capita mean monthly expenditure on medicines. We identified 72,265 women who received drugs for the treatment of postmenopausal osteoporosis. The average monthly expenditure per capita in the first year of treatment was $ 54.02 (sd $ 86.72). The population was predominantly composed of women aged 60-69 years old, who had started treatment in 2000, resident in the Southeast of Brazil, who had previously suffered osteoporotic fractures, and Alendronate sodium was the drug most commonly used at baseline. For most of the patients, the same active ingredient remained in use throughout the treatment period. During the program, 6,429 deaths were identified among participants. More than a third of women remained in treatment for up to 12 months. Raloxifen and calcitonin were the therapeutic alternatives with the greatest impact on the average monthly expenditure on medicine using alendronate sodium as a reference standard. Due to the high impact of the type of drug used on expenditure on medication, it is recommended that criteria for prescribing and dispensing be established by prioritizing those with lower costs and greater effectiveness in order to optimize the process of pharmaceutical care and provide the population with a greater number of pharmaceutical units.

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.

Zunino L.,CONICET | Rosso O.A.,Federal University of Minas Gerais | Rosso O.A.,University of Buenos Aires | Soriano M.C.,University of the Balearic Islands
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2011

The time evolution of the output of a semiconductor laser subject to delayed optical feedback can exhibit high-dimensional chaotic fluctuations. In this contribution, our aim is to quantify the degree of unpredictability of this hyperchaotic time evolution. To that end, we estimate permutation entropy, a novel information-theory-derived quantifier particularly robust in a noisy environment. The permutation entropy is defined as a functional of a symbolic probability distribution, evaluated using the Bandt-Pompe recipe to assign a probability distribution function to the time series generated by the chaotic system. This measure quantifies the diversity of orderings present in the associated time series. In order to evaluate the performance of this novel quantifier, we compare with the results obtained by using a more standard chaos quantifier, namely the Kolmogorov-Sinai entropy. Here, we present numerical results showing that the permutation entropy, evaluated at specific time-scales involved in the chaotic regime of the semiconductor laser subject to optical feedback, give valuable information about the degree of unpredictability of the chaotic laser dynamics. The influence of additive observational noise on the proposed tool is also investigated. © 2011 IEEE.

Streva E.R.,Pontifical Catholic University of Minas Gerais | Pasa V.M.D.,Federal University of Minas Gerais | Sodre J.R.,Pontifical Catholic University of Minas Gerais
Fuel | Year: 2011

Blends of 75% gasoline and 25% ethanol (E25) are unique fuels used in Brazil. The natural E25 oxidation process due to aging under atmospheric conditions has been investigated. To evaluate aging effects on the properties of commercially available fuel blends, two samples of regular E25, one sample of regular E25 with additives, and one sample of high octane E25 were tested. The samples were analyzed as new and in aging periods of 30 and 180 days. Fuel density, distillation temperatures T10, T50 and T 90, motor and research octane number, as well as concentrations of ethanol, oxygen, olefins, total aromatics, benzene and saturates were evaluated. It was observed an increase of fuel density, distillation temperatures, aromatics and oxygen concentration, and a decrease of the concentration of olefins with aging. The results indicate that the use of aged fuel in automotive engines may increase fuel consumption, carbon deposits formation, carbon monoxide and hydrocarbon emissions. © 2010 Elsevier Ltd. All rights reserved.

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.

Background In plants, the products of secretory activity leave the protoplast and cross the plasma membrane by means of transporters, fusion with membranous vesicles or, less commonly, as result of disintegration of the cell. These mechanisms do not address an intriguing question: How do secretory products cross the cell wall? Furthermore, how do these substances reach the external surface of the plant body? Such diverse substances as oils, polysaccharides or nectar are forced to cross the cell wall and, in fact, do so. How are chemical materials that are repelled by the cell wall or that are sufficiently viscous to not cross passively released from plant cells? Scope and Conclusions I propose a cell-cycle model developed based on observations of different secreting systems, some unpublished results and an extensive literature review, aiming to understand the processes involved in both the secretory process and the release of secretion products. In the absence of facilitated diffusion, a mechanical action of the protoplast is necessary to ensure that some substances can cross the cell wall. The mechanical action of the protoplast, in the form of successive cycles of contraction and expansion, causes the material accumulated in the periplasmic space to cross the cell wall and the cuticle. This action is particularly relevant for the release of lipids, resins and highly viscous hydrophilic secretions. The proposed cell-cycle model and the statements regarding exudate release will also apply to secretory glands not elaborated upon here. Continuous secretion of several days, as observed in extrafloral nectaries, salt glands and some mucilage-producing glands, is only possible because the process is cyclical. © 2016 The Author.

(Spatial patterns of tree community dynamics are detectable in a small (4 ha) and disturbed fragment of the Brazilian Atlantic forest) The dynamics of the tree community of a fragment of tropical semideciduous forest was investigated in south-eastern Brazil. Surveys were carried out in 2000 and 2005 in 29 20 × 20 m plots. The main purpose was to assess the possibility of detecting spatial patterns of dynamics that could be related to the heterogeneity of both the environment and disturbance history in a small forest area (4.0 ha). Rates of mortality and recruitment of trees and gain and loss of basal area were obtained for the whole sample, four pre-defined soil habitats, diameter classes and twelve tree populations. The tree community was rather unstable in the period, once mortality rates surpassed recruitment rates and loss rates of basal area surpassed gain rates all-over the area denoting the prevalence of a degradation process, possibly triggered by a clear felling in 1985 that reduced the area of the fragment in 26%. The tree community dynamics showed no spatial autocorrelation but was not evenly distributed throughout the fragment. This spatial heterogeneity was chiefly determined by the disturbance history of each site while environmental heterogeneity played a secondary but significant role. The main causes of disturbance heterogeneity were the extension of the adjacent felled area, cattle trampling and selective logging. The environmental variables that most strongly correlated with the variations of the dynamics rates were those related to the availability of light, water and mineral nutrients. In contrast with the overall trends, three understory species expanded in the period, possibly at the expense of the steeply declining density of mid-sized trees.

Mesquita A.R.,Federal University of Minas Gerais | Hespanha J.P.,University of California at Santa Barbara | Nair G.N.,University of Melbourne
Automatica | Year: 2012

In lossy networks the probability of successful communication can be significantly increased by transmitting multiple copies of a same message through independent channels. In this paper we show that communication protocols that exploit this by dynamically assigning the number of transmitted copies of the same data can significantly improve the control performance in a networked control system with only a modest increase in the total number of transmissions. We develop techniques to design communication protocols that exploit the transmission of multiple packets while seeking a balance between stability/estimation performance and communication rate. An average cost optimality criterion is employed to obtain a number of optimal protocols applicable to networks with different computational capabilities. We also discuss stability results under network contention when multiple nodes utilize these protocols. © 2012 Elsevier Ltd. All rights reserved.

Figueiredo F.,Federal University of Minas Gerais
WSDM 2013 - Proceedings of the 6th ACM International Conference on Web Search and Data Mining | Year: 2013

User generated content (UGC) has emerged as the predominant form of media publishing on the Web 2.0. Motivated by the large adoption of video sharing on the Web 2.0, the objective of our work is to understand and predict popularity trends (e.g, will a video be viral?) and hits (e.g, how may views will a video receive?) of user generated videos. Such knowledge is paramount to the effective design of various services including content distribution and advertising. Thus, in this paper we formalize the problem of predicting trends and hits in user generated videos. Also, we describe our research methodology on approaching this problem. To the best of knowledge, our work is novel in focusing on the problem of predicting popularity trends complementary to hits. Moreover, we intend on evaluating efficacy of our results not only based on common statistical error metrics, but also on the possible online advertising revenues our predictions can generate. After describing our proposal, we here summarize our latest findings regarding (1) uncovering common popularity trends; (2) measuring associations between UGC features and popularity trends; and (3) assessing the effectiveness of models for predicting popularity trends. © 2013 ACM.

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.

Iemini F.,Federal University of Minas Gerais | Iemini F.,CNR Institute of Neuroscience | Mazza L.,CNR Institute of Neuroscience | Rossini D.,CNR Institute of Neuroscience | And 2 more authors.
Physical Review Letters | Year: 2015

In this Letter we present, in a number conserving framework, a model of interacting fermions in a two-wire geometry supporting nonlocal zero-energy Majorana-like edge excitations. The model has an exactly solvable line, on varying the density of fermions, described by a topologically nontrivial ground state wave function. Away from the exactly solvable line we study the system by means of the numerical density matrix renormalization group. We characterize its topological properties through the explicit calculation of a degenerate entanglement spectrum and of the braiding operators which are exponentially localized at the edges. Furthermore, we establish the presence of a gap in its single particle spectrum while the Hamiltonian is gapless, and compute the correlations between the edge modes as well as the superfluid correlations. The topological phase covers a sizable portion of the phase diagram, the solvable line being one of its boundaries. © 2015 American Physical Society.

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.

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.

Velloso I.S.,Federal University of Minas Gerais
Revista gaúcha de enfermagem / EENFUFRGS | Year: 2010

Reflections on power relations in nursing practice involves questions related to the daily practice of nursing staff as well the subjectivity of those involved in them. Nursing practice is more than a practice in itself. It assumes the dimension of meaning ascribed to it by different subjects who interact in the places where the practice takes place. We propose a reflection about power relations in nursing practice, considering their complexity, the many processes that constitute them and the circumstances that determine the ways of thinking about and acting in relation to them. Such reflection implies to think about the subject's subjectivity the way professional boundaries are established, and the effects of these relations upon the subjects involved, since power relations are in continuous transformations.

This paper aims to evaluate the nineteen years of the National Health System in Brazil, under the prism of equity. It takes into account the current political context in Brazil in the 80s, that the democratization of the country and the health sector could, per se, lead to a more equitable situation regarding the access to health services. Democracy and equity concepts are here discussed; analyzing which situations may facilitate or make it difficult its association in a theoretical plan, applying them to the Brazilian context in a more general form and, to emphasizing practical implications to the National Health System and to groups of activism related to health reforms. It also seeks to show the limits and possibilities of these groups with regards to the reduction of inequality, in reation to the access to health services, which still remain. To conclude, the author points out the need for other movements to be established which seek the reduction of such and other inequalities, such as access to education, housing, etc, drawing special attention to the role played by the State, which is questioned regarding its incapacity of promoting equity, once it presents itself as being powerful when approaching other matters.

Lima L.S.,Federal University of Minas Gerais
Journal of Magnetism and Magnetic Materials | Year: 2016

We use the SU(3) Schwinger's boson theory to study the spin transport in the biquadratic Heisenberg chains in a square lattice with a distribution of non-magnetic impurities on the lattice. We verify the influence of the site dilution in the Ac and Dc spin conductivities of this model in the Bose-Einstein condensation regime in which the bosons t are condensed. Our results show that the decreasing of the gap Δ with -β suffers a change for different concentrations x of non-magnetic impurities, however the point (in the -β axis) where the gap cancels does not change with x. Therefore, the size of the region ω, where the spin conductivity goes to zero decreases with the increase of x until the point where x=0.5, where the size of this region tends to zero. © 2015 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.

Gironacci M.M.,University of Buenos Aires | Adamo H.P.,University of Buenos Aires | Corradi G.,University of Buenos Aires | Santos R.A.,Federal University of Minas Gerais | And 2 more authors.
Hypertension | Year: 2011

Angiotensin (Ang) (1-7) is the endogenous ligand for the G protein-coupled receptor Mas, a receptor associated with cardiac, renal, and cerebral protective responses. Physiological evidence suggests that Mas receptor (MasR) undergoes agonist-dependent desensitization, but the underlying molecular mechanism regulating receptor activity is unknown. We investigated the hypothesis that MasR desensitizes and internalizes on stimulation with Ang-(1-7). For this purpose, we generated a chimera between the MasR and the yellow fluorescent protein (YFP; MasR-YFP). MasR-YFP-transfected HEK 293T cells were incubated with Ang-(1-7), and the relative cellular distribution of MasR-YFP was observed by confocal microscopy. In resting cells, MasR-YFP was mostly localized to the cell membrane. Ang-(1-7) induced a redistribution of MasR-YFP to intracellular vesicles of various sizes after 5 minutes. Following the time course of [ 125I]Ang-(1-7) endocytosis, we observed that half of MasR-YFP underwent endocytosis after 10 minutes, and this was blocked by a MasR antagonist. MasR-YFP colocalized with Rab5, the early endosome antigen 1, and the adaptor protein complex 2, indicating that the R is internalized through a clathrin-mediated pathway and targeted to early endosomes after Ang-(1-7) stimulation. A fraction of MasR-YFP also colocalized with caveolin 1, suggesting that at some point MasR-YFP traverses caveolin 1-positive compartments. In conclusion, MasR undergoes endocytosis on stimulation with Ang-(1-7), and this event may explain the desensitization of MasR responsiveness. In this way, MasR activity and density may be tightly controlled by the cell. © 2011 American Heart Association, Inc.

Linardi P.M.,Federal University of Minas Gerais | Krasnov B.R.,Ben - Gurion University of the Negev
Medical and Veterinary Entomology | Year: 2013

The effects of host-related, parasite-related and environmental factors on the diversity and abundance of two ectoparasite taxa, fleas (Insecta: Siphonaptera) and mites (Acari: Mesostigmata), parasitic on small mammals (rodents and marsupials), were studied in different localities across Brazil. A stronger effect of host-related factors on flea than on mite assemblages, and a stronger effect of environmental factors on mite than on flea assemblages were predicted. In addition, the effects of parasite-related factors on flea and mite diversity and abundance were predicted to manifest mainly at the scale of infracommunities, whereas the effects of host-related and environmental factors were predicted to manifest mainly at the scale of component and compound communities. This study found that, in general, diversity and abundance of flea and mite assemblages at two lower hierarchical levels (infracommunities and component communities) were affected by host-related, parasite-related and environmental factors, and compound communities were affected mainly by host-related and environmental factors. The effects of factors differed between fleas and mites: in fleas, community structure and abundance depended on host diversity to a greater extent than in mites. In addition, the effects of factors differed among parasite assemblages harboured by different host species. © 2012 The Royal Entomological Society.

Coelho L.G.,Federal University of Minas Gerais
Arquivos de gastroenterologia | Year: 2013

Signicant progress has been obtained since the Second Brazilian Consensus Conference on Helicobacter pylori Infection held in 2004, in São Paulo, SP, Brazil, and justify a third meeting to establish updated guidelines on the current management of H. pylori infection. The Third Brazilian Consensus Conference on H pylori Infection was organized by the Brazilian Nucleus for the Study of Helicobacter, a Department of the Brazilian Federation of Gastroenterology and took place on April 12-15, 2011, in Bento Gonçalves, RS, Brazil. Thirty-one delegates coming from the five Brazilian regions and one international guest, including gastroenterologists, pathologists, epidemiologists, and pediatricians undertook the meeting. The participants were allocated in one of the five main topics of the meeting: H pylori, functional dyspepsia and diagnosis; H pylori and gastric cancer; H pylori and other associated disorders; H pylori treatment and retreatment; and, epidemiology of H pylori infection in Brazil. The results of each subgroup were submitted to a final consensus voting to all participants. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. Seventy per cent and more votes were considered as acceptance for the final statement. This article presents the main recommendations and conclusions to guide Brazilian doctors involved in the management of H pylori infection.

Aguirre L.A.,Federal University of Minas Gerais
Automatica | Year: 2014

This work discusses the identification of single-block smooth nonlinear discrete-time polynomial models with non-smooth steady-state features. Based on bifurcation theory, conditions are developed and used to determine some general aspects of the model structure and also to determine some constraints on the parameters required to guarantee the aforementioned features. The procedure uses only smooth functions of the regressors, a single possibly smooth input and some prior knowledge about the steady-state behavior. The non-smooth static function is here obtained by interchanging the stability of two sets of equilibria at the break-point, which corresponds to guaranteeing a transcritical bifurcation. This work discusses how to determine the domain over which the results are valid. The procedure is illustrated with simulated and experimental data. © 2014 Elsevier Ltd. All rights reserved.

Viegas S.M.F.,Pontifical Catholic University of Minas Gerais | Penna C.M.M.,Federal University of Minas Gerais
Ciencia e Saude Coletiva | Year: 2013

In the context of the Unified Health System (SUS), health actions and services constitute a social right to be guaranteed by the State and managed under the responsibility of three autonomous spheres of government. This is a holistic multiple case study with a qualitative approach based on the assumptions of Comprehensive Everyday Sociology, which originated from a PhD thesis. It sought to understand the construction of comprehensive health practices in the daily work of family health teams and managers of the cities in Vale do Jequitinhonha - Minas Gerais, Brazil. The individuals studied were professionals from the Family Health Teams, support staff and managers with a total of 48 participants. In order to reveal the construction of the whole, the data show that "SUS is universal, but quotas are the norm." Bearing in mind its limitations, it is difficult to ensure that SUS is a right for all. Thus, regulation is essential to order, guide, define and optimize the use of resources available for comprehensive care and also guarantee public access to actions and services in a timely and equitable manner.

Fernandes R.C.P.,Federal University of Bahia | Carvalho F.M.,Federal University of Bahia | Assuncao A.A.,Federal University of Minas Gerais
Cadernos de Saude Publica | Year: 2011

The prevalence of musculoskeletal disorders among workers in the plastics industry in Salvador, Bahia State, Brazil was estimated. Cases were defined by reported symptoms of pain in the previous 12 months, lasting more than a week or having monthly minimum frequency, which had given rise to restrictions at work or to seeking medical attention, or where respondents had a severity score greater than or equal to 3 (on a numerical scale of 0 to 5). A stratified proportional random sample of 577 workers was studied. The prevalence of musculoskeletal disorders, considering of all body segments, was 50.1%. The prevalence of musculoskeletal disorders was higher among women than among men at distal upper extremities (34.6% and 11.6% respectively) and also in the region of the neck, shoulder or upper part of the back (27.4% and 17.6% respectively). There was no difference between genders for the prevalence of lower back pain (21.2% and 21.4% respectively); 65% of cases in this region had reports of pain in the previous seven days. Due to the importance and prevalence of musculoskeletal disorders, it is necessary that their measurement in epidemiological studies be done properly.

Le Stradic S.,University of Liege | 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.

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.

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.

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.

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.