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Francesconia F.,Federal University of Amazonas | Lupi O.,Rio de Janeiro State Federal University
Clinical Microbiology Reviews | Year: 2012

Myiasis is defined as the infestation of live vertebrates (humans and/or animals) with dipterous larvae. In mammals (including humans), dipterous larvae can feed on the host's living or dead tissue, liquid body substance, or ingested food and cause a broad range of infestations depending on the body location and the relationship of the larvae with the host. In this review, we deeply discuss myiasis as a worldwide infestation with different agents and with its broad scenario of clinical manifestations as well as diagnosis techniques and treatment. © 2012, American Society for Microbiology. All Rights Reserved.

Arya S.,Hong Kong University of Science and Technology | Da Fonseca G.D.,Rio de Janeiro State Federal University | Mount D.M.,University of Maryland University College
Proceedings of the Annual ACM Symposium on Theory of Computing | Year: 2011

We consider an approximate version of a fundamental geometric search problem, polytope membership queries. Given a convex polytope P in RE d, presented as the intersection of halfspaces, the objective is to preprocess P so that, given a query point q, it is possible to determine efficiently whether q lies inside P subject to an error bound ε. Previous solutions to this problem were based on straightforward applications of classic polytope approximation techniques by Dudley (1974) and Bentley et al. (1982). The former yields minimum storage, and the latter yields constant query time. A space-time tradeoff can be obtained by interpolating between the two. We present the first significant improvements to this tradeoff. For example, using the same storage as Dudley, we reduce the query time from O(1/ε (d-1)/2) to O(1/ε(d-1)/4). Our approach is based on a very simple algorithm. Both lower bounds and upper bounds on the performance of the algorithm are presented. To establish the relevance of our results, we introduce a reduction from approximate nearest neighbor searching to approximate polytope membership queries. We show that our tradeoff provides significant improvements to the best known space-time tradeoffs for approximate nearest neighbor searching. Furthermore, this is achieved with constructions that are much simpler than existing methods. © 2011 ACM.

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

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

Kozlowsky-Suzuki B.,Rio de Janeiro State Federal University | Wilson A.E.,Auburn University | da Silva Ferrao-Filho A.,Instituto Oswaldo Cruz
Harmful Algae | Year: 2012

Cyanobacteria, conspicuous photoprokaryotes in aquatic ecosystems, may produce secondary metabolites such as the hepatotoxins, microcystins (MC). While MC have been quantified in numerous aquatic consumers across a variety of ecosystems, there is still debate whether biomagnification or biodilution of MC generally occurs in aquatic foodwebs. Given the threat that MC pose to aquatic foodwebs, livestock, and humans, we synthesized data from 42 studies on the concentration of MC in consumers, such as zooplankton, decapods, molluscs, fishes, turtles and birds, to determine the dominant process. To compare results across studies, we calculated the biomagnification factor (BMF) as the ratio between the MC concentration measured in consumers and their diet. Biomagnification is indicated when BMF mean and associated 95% confidence intervals (CI) >1. Biodilution is shown if a BMF mean and 95% CI <1. As expected, increasing concentrations of MC in diets resulted in increasing concentrations of MC in consumers. Nevertheless, biodilution of MC was evident for most primary consumers. This finding was robust across four datasets that focused on different aspects of data independence and variance, and may be explained by low hydrophobicity of MC, diet preferences, or detoxification. Zooplankton and zooplanktivorous fish, however, showed some potential for biomagnification (i.e. mean BMF. > 1). Plausible, but largely unexplored, possibilities for the relatively higher MC accumulation by these consumers are low detoxification efficiency by zooplankton, MC trophic transfer via the microbial foodweb, contamination of zooplankton net samples with large cyanobacterial colonies and filaments, or the release of both free and bound MC in zooplankton during digestion by fish. Factors related to study design may have influenced the magnitude of MC biodilution. For example, consumers fed diets consisting of highly toxic cyanobacterial lab cultures and large, potentially inedible net phytoplankton showed greater biodilution when compared to seston. Given their hepatotoxic nature, MC concentrations were relatively higher in liver and hepatopancreas tissues than other tissues. Whole organisms exhibited, however, relatively greater MC (i.e. higher BMF) than specific tissues, and this finding could be attributed to the contribution of zooplankton to whole organism MC analyses (89% of BMF estimates. > 1). Finally, BMF was positively related to study length showing that longer exposure to toxic food resulted in higher MC accumulation in consumers, which could have important implications in eutrophic or tropical systems where toxic blooms may persist year-round. © 2012 Elsevier B.V.

OBJECTIVE:: The beneficial effects of estrogen on endothelial function depend on its integrity. This study evaluates the short-term effects of low-dose transdermal estradiol on endothelial function, insulin sensitivity, and blood viscosity in nondiabetic overweight/obese women. METHODS:: Forty-four nondiabetic overweight/obese women with a history of recent menopause were randomly allocated, in a double-blind fashion, to receive transdermal estradiol (1?mg/d, n?=?22) or placebo (n?=?22). The following parameters were assessed: endothelial reactivity (venous occlusion plethysmography and nailfold videocapillaroscopy), plasma levels of soluble adhesion molecules, insulin sensitivity (homeostasis model assessment of insulin resistance and areas under the curve of insulin and glucose during an oral glucose tolerance test), and blood and plasma viscosity. Data were expressed as means?±?SD or medians [first to third quartiles]. RESULTS:: Participants were aged 51.8?±?2.3 years with a body mass index of 31.5?±?2.5?kg/m and time since menopause was 3 [2-5] years. At baseline, no differences between the groups were observed; however, after 3 months of treatment, the following changes were observed in the estradiol group compared with the placebo group: a decrease in the forearm vascular resistance at baseline (36.37 [24.9-51.27] vs 51.3 [40.88-70.03]?mm Hg/mL per min 100?mL tissue, P?

Cameron L.C.,Rio de Janeiro State Federal University
Methods | Year: 2012

Mass Spectrometry Imaging (MSI, also called Imaging Mass Spectrometry) can be used to map molecules according to their chemical abundance and spatial distribution. This technique is not widely used in mass spectrometry circles and is barely known by other scientists. In this review, a brief overview of the mass spectrometer hardware used in MSI and some of the possible applications of this powerful technique are discussed. I intend to call attention to MSI uses from cell biology to histopathology for biological scientists who have little background in mass spectrometry. MSI facts and perspectives are presented from a non-mass spectrometrist point of view. © 2012.

BACKGROUND:: Epidemiological studies demonstrate an inverse association between serum magnesium and incidence of cardiovascular disease. Diuretics commonly cause hypomagneseamia. METHOD:: We evaluated effects of magnesium supplementation on blood pressure (BP) and vascular function in thiazide-treated hypertensive women in a randomized, double-blind, clinical trial. Hypertensive women (40–65 years) on hydrochlorothiazide and mean 24-h BP at least 130/80?mmHg were divided into placebo and supplementation (magnesium chelate 600?mg/day) groups. Patients were evaluated for nutritional and biochemical parameters, office and ambulatory blood pressure monitoring, brachial flow-mediated dilatation (FMD), peripheral arterial tonometry, assessment of carotid intima–media thickness, central hemodynamic parameters and pulse wave velocity at inclusion and after 6-month follow-up. RESULTS:: The magnesium group had a significant reduction in SBP (144?±?17 vs. 134?±?14?mmHg, P?=?0.036) and DBP (88?±?9 vs. 81?±?8?mmHg, P?=?0.005) at 6 months, without effect on plasma glucose, lipids, or arterial stiffness parameters. The placebo group showed a significant increase in carotid intima-media thickness (0.78?±?0.13 vs. 0.89?±?0.14?mm, P?=?0.033) without change in the magnesium group (0.79?±?0.16 vs. 0.79?±?0.19?mm, P?=?0.716) after 6 months. The magnesium group demonstrated a significant increase in variation of FMD vs. the placebo group (+3.7?±?2.1 vs. 2.4?±?1.2%, P?=?0.015). There was a significant correlation between the intracellular magnesium variation and FMD (r?=?0.44, P?=?0.011). CONCLUSION:: Magnesium supplementation was associated with better BP control, improved endothelial function and amelioration of subclinical atherosclerosis in these thiazide-treated hypertensive women. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

With the rise of modern physics, emphasis was given on both the atomistic view and corpuscular structure of matter, thus providing the basis for Newton's definition of mass. When quantum mechanics and general relativity came out, emphasis was given on the concepts of energy and field. Agreement is needed as to a final comprehension on what matter is, viz. defining its ontological status. Here we shall present some contemporary standpoints, both showing that (i) a philosophical demand on the ontological status of matter remains to be attended, complementary to epistemological analysis, and that (ii) using of mathematical symbolism to underpin the concepts of mass, energy and field handled by epistemological analysis doesn't seem to be enough to account for a whole view of matter, additionaly requiring some complementary ontological perspective. © Sociedade Brasileira de Física.

Vieira M.T.C.,Rio de Janeiro State Federal University
Pediatric Infectious Disease Journal | Year: 2016

BACKGROUND:: Methicillin-resistant Staphylococcus aureus (MRSA) colonization has been linked to HIV-related sexual and social behaviors. MRSA risk factors may be different for HIV-infected children, adolescents and young adults. We investigated the association of MRSA colonization, persistent colonization and genotypes with potential risk factors among HIV-infected youth. METHODS:: For this case-control study, patients 24 years of age or younger attending 2 HIV reference centers were recruited from February to August 2012 and followed for 1 year. Nasal swabs were collected at enrollment and every 3 months. MRSA clones were characterized by staphylococcal chromosomal cassete mec typing, spa typing and multilocus sequence typing. We compared MRSA colonization and persistent colonization with patient demographic and clinical characteristics. RESULTS:: Among 117 participants, MRSA colonization frequency (calculated for each collection based on the number of positive cultures per patient) was 12.8% at the first collection. The average MRSA colonization frequency was 10.4%. Our results showed 11.1% were persistent carriers (subjects with more than 1 positive culture in at least 3). Crowding was the only factor associated with MRSA colonization (p=0.018). Persistent carriers had significantly higher (4.2 times) odds of living in a crowded household (95% confidence interval - 1.1 - 16.2). We observed high genetic diversity among MRSA isolates, with t002/ST5 and t318/ST30 being the most frequent. CONCLUSIONS:: MRSA colonization among HIV-infected youth is more closely related to living in a low-income or slum community than to HIV-related clinical factors. High genetic MRSA isolate diversity in our population suggests frequent transmission. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

This research objectives were: to discover the sociodemographic profile of the nursing staff that works in the hospital emergency service, identify the main types of occupational violence suffered by this team. Cross-sectional descriptive study done in a general hospital in Duque de Cazxias/Rio de Janeiro. The data, collected on August, 2009, was put in tables for subsequent univariate analysis. The sample of respondents comprised 30 workers. The analyzed data showed that the majority of employees interviewed were victims of occupational violence (76.7%). The main causes of occupational violence were the companions (87.0%) followed by patients (52.2%). The more frequentform of aggression was verbal aggression (100.0%). The results showed that these workers have little expectation on changing the current situation and do not believe that their managers can assist them in the problem.

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