872 research outputs found
Trypanosoma rangeli is phylogenetically closer to Old World trypanosomes than to Trypanosoma cruzi.
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Trypanosoma rangeli and Trypanosoma cruzi are generalist trypanosomes sharing a wide range of mammalian hosts; they are transmitted by triatomine bugs, and are the only trypanosomes infecting humans in the Neotropics. Their origins, phylogenetic relationships, and emergence as human parasites have long been subjects of interest. In the present study, taxon-rich analyses (20 trypanosome species from bats and terrestrial mammals) using ssrRNA, glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH), heat shock protein-70 (HSP70) and Spliced Leader RNA sequences, and multilocus phylogenetic analyses using 11 single copy genes from 15 selected trypanosomes, provide increased resolution of relationships between species and clades, strongly supporting two main sister lineages: lineage Schizotrypanum, comprising T. cruzi and bat-restricted trypanosomes, and Tra[Tve-Tco] formed by T. rangeli, Trypanosoma vespertilionis and Trypanosoma conorhini clades. Tve comprises European T. vespertilionis and African T. vespertilionis-like of bats and bat cimicids characterised in the present study and Trypanosoma sp. Hoch reported in monkeys and herein detected in bats. Tco included the triatomine-transmitted tropicopolitan T. conorhini from rats and the African NanDoum1 trypanosome of civet (carnivore). Consistent with their very close relationships, Tra[Tve-Tco] species shared highly similar Spliced Leader RNA structures that were highly divergent from those of Schizotrypanum. In a plausible evolutionary scenario, a bat trypanosome transmitted by cimicids gave origin to the deeply rooted Tra[Tve-Tco] and Schizotrypanum lineages, and bat trypanosomes of diverse genetic backgrounds jumped to new hosts. A long and independent evolutionary history of T. rangeli more related to Old World trypanosomes from bats, rats, monkeys and civets than to Schizotrypanum spp., and the adaptation of these distantly related trypanosomes to different niches of shared mammals and vectors, is consistent with the marked differences in transmission routes, life-cycles and host-parasite interactions, resulting in T. cruzi (but not T. rangeli) being pathogenic to humans.This study was supported by grants awarded to MMGT and EPC from CNPq (National Council for Scientific and Technological Development) PROAFRICA, PROSUL and UNIVERSAL programs, CAPES (Coordination for the Improvement of Higher Education Personnel) PNIPB, PNPD and PROTAX programs, and FAPESP (SĂŁo Paulo Research Foundation; process 2016/07487-0). Genome sequencing was supported by the Assembling the Tree of Life (ATOL) Project of the National Science Foundation, USA (NSF DEB-0830056), and TCC-USP (Trypanosomatid Culture Collection of the University of SĂŁo Paulo) projects. OEA received PhD fellowships from CNPq (PROTAX) and COLCIENCIAS (Administrative Department of Science, Technology and Innovation, Colombia); PAO is a postdoctoral fellow of CAPES (PNPD); LL and AGCM are supported by a postdoctoral fellowship from CAPES (PROTAX)
Comparative ecology of the European eel, Anguilla anguilla (L.1758), in a large Iberian river
A total of 1,816 eels were sampled in
1988, from seven sampling areas. Four areas were
located in brackish water and the remaining three
were located in freshwater reaches of the
Tagus river basin. Eels were more abundant in
the middle estuary and decreased both in the
upstream and in the downstream directions, with
a predominance of males in higher density areas.
Smaller individuals preferred more peripheral areas, such as margins and upper reaches in the
brackish water zone, and the tributaries of the
freshwater habitats. It was assumed that this
distribution pattern resulted from three main
factors: (i) the dominance of larger specimens;
(ii) the need to avoid predators and; (iii) the
search for better trophic conditions. The condition
of the individuals generally decreased toward
the upper reaches, apparently due to a corresponding
decrease in feeding intensity. The presence
of the Belver dam in the main river, 158 km
upstream from the sea, seemed to impose major
alterations to the described patterns. The concentration
of specimens below this impassable
obstacle yielded a reduction in the proportion of
females and a decrease in the condition and
survival of the eels, contributing to a reduction in
the spawning success of this population. Suggestions
to diminish the effects of the dam, and to
preserve the fishery are also presente
Characteristics and current direct costs of hospital admissions due to occupational accidents in the southwest of Bahia from 2005 to 2007
Population-Attributable Risks for Ischemic Stroke in a Community in South Brazil: A Case-Control Study
Background: Risk factors for ischemic stroke are mostly known, but it is still unclear in most countries, what are their combined population-attributable risk percent (PAR%). In a case-control study the individual odds ratios (ORs) and the individual and combined PAR%, including risk factors not addressed in previous studies were estimated. Methods: Cases and controls were selected from patients attending to an emergency department. Cases were patients aged with 45 years or more with the first episode of ischemic stroke, characterized by a focal neurological deficit or change in the mental status occurring during the previous 24 hours. Controls, matched to cases by age and gender, were selected from patients without neurological complaints. Results: 133 cases and 272 controls were studied. Odds ratios for ischemic stroke were: atrial fibrillation (27.3; CI 95 % 7.5
Recent updates and perspectives on approaches for the development of vaccines against visceral leishmaniasis
All rights reserved. Visceral leishmaniasis (VL) is one of the most important tropical diseases worldwide. Although chemotherapy has been widely used to treat this disease, problems related to the development of parasite resistance and side effects associated with the compounds used have been noted. Hence, alternative approaches for VL control are desirable. Some methods, such as vector control and culling of infected dogs, are insufficiently effective, with the latter not ethically recommended. The development of vaccines to prevent VL is a feasible and desirable measure for disease control, for example, some vaccines designed to protect dogs against VL have recently been brought to market. These vaccines are based on the combination of parasite fractions or recombinant proteins with adjuvants that are able to induce cellular immune responses, however, their partial efficacy and the absence of a vaccine to protect against human leishmaniasis underline the need for characterization of new vaccine candidates. This review presents recent advances in control measures for VL based on vaccine development, describing extensively studied antigens, as well as new antigenic proteins recently identified using immuno-proteomic techniquesThis work was supported by grants from Instituto Nacional de CiĂȘncia e Tecnologia em Nano-BiofarmacĂȘutica, Rede Nanobiotec/Brasil-Universidade Federal de UberlĂąndia/CAPES, PRONEX-FAPEMIG (APQ-01019-09), FAPEMIG (CBB-APQ-00819-12 and CBB-APQ-01778-2014), and CNPq (APQ-482976/2012-8, APQ-488237/2013-0, and APQ-467640/2014-9). EAFC and LRG are recipients of the grant from CNPq. MACF is the recipient of grants from FAPEMIG/CAPE
Transtornos mentais comuns entre estudantes de medicina da Universidade Federal de Sergipe: estudo transversal
Objetivo: Estimar a prevalĂȘncia de transtorno mental comum e fatores associados entre estudantes de Medicina da Universidade Federal de Sergipe. MĂ©todo: Estudo transversal com 473 dos 512 matriculados em 2006, aplicando o Self Reporting Questionnaire-20 e um questionĂĄrio estruturado sobre caracterĂsticas sociodemogrĂĄficas, processo ensino-aprendizagem e vivĂȘncias psicoemocionais. Os calouros foram excluĂdos apĂłs comparação inicial com os alunos do 2° ao 12° perĂodos. AnĂĄlise estatĂstica por regressĂŁo logĂstica mĂșltipla, apĂłs estatĂstica descritiva e cĂĄlculo das ORs simples e ajustadas. Resultados: A prevalĂȘncia de transtorno mental comum geral foi de 40% (n = 473), mas com a retirada dos calouros, aumentou para 42,5% (n = 433) entre os alunos do 2°
ao 12° semestre, sendo maior entre aqueles que não acreditavam ter adquirido habilidades para se tornarem bons médicos (OR = 2,82), que se sentiam pouco confortåveis com as atividades do curso (OR = 3,75), que se consideravam emocionalmente tensos (OR = 2,14), nos que não se consideravam felizes
(OR = 2,85), nos que achavam que o curso era menos do que esperavam (OR = 1,64) e nos que tiveram diagnóstico prévio de transtorno mental feito por psiquiatra (OR = 3,78). Conclusão: Os resultados sugerem a necessidade de mudanças no processo ensino-aprendizagem, bem como estruturação de
programas para cuidar da saĂșde mental dos estudantes. _________________________________________________________________________________________ ABSTRACT: Objective: Estimate the prevalence of common mental disorder and its associated factors among medical students of the Universidade Federal de Sergipe. Method: A cross-sectional study was carried out,
applying Self Reporting Questionnaire-20 to 473 students from the 512 medical students enrolled in 2006 and compared with compared with a structured questionnaire by the authors containing information on the
socio-demographic characteristics, the teachingâlearning process and the
psycho-emotional experiences of the students. Freshmen were excluded after initial comparison with the students already exposed to the medical course. Statistical analysis by multiple logistic regression after calculating simple and adjusted odds ratio (OR). Results: The general prevalence of common mental disorder was 40% (n = 473); after exclusion of the freshmen it increased to 42.5% among students from the 2nd to the 12th semester.It was higher among those who did not have faith in their acquisition of the skills needed to become a good doctor (OR = 2.82), who felt less comfortable about course activities (OR = 3.75), who considered themselves emotionally stressed (OR = 2.14), among those who did not consider themselves happy (OR = 2.85), who believed that the course did not match their expectations
(OR = 1.64) and those who had a prior diagnosis of mental disorder by a psychiatrist (OR = 3.78). Conclusion: The results suggest the necessity of changes to the teaching-learning process and the establishment of a preventive mental health program for medical students
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
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