416 research outputs found
Phylogeography of Southeast Asian flying foxes (Chiroptera: Pteropodidae: Pteropus)
Flying foxes (Pteropus) are a genus of Old World fruit bats that are important seed dispersers and pollinators for plants native to the 200,000+ islands in Southeast Asia, yet they are some of the most poorly known bats in the world. They comprise some of the largest known bat species, and are morphologically relatively conserved on the genus level. Pteropus is the most species-rich genus within Pteropodidae, though the origin for this diversity remains incompletely understood. In Chapter 1, I discuss the importance of Pteropus to the ecosystem and as reservoir hosts. In Chapter 2, a molecular phylogeny is presented with Pteropus species organized into fewer species groups than recognized from previous research that better reflected the comprehensive dataset. An increase in relative divergence rate was detected within Pteropus during the Pliocene that led to rapid radiations in three species groups. Additionally, discordant signals from nuclear and mitochondrial genes suggested incomplete lineage sorting and hybridization were present, likely as a result of the young clade age, low genetic variability, and rapid diversification of the genus. In Chapter 3, using the species tree generated in Chapter 2, I tested biogeographic mechanisms and scenarios that resulted in current distributions of Pteropus species using several ancestral area reconstruction methods. Dispersal and founder-event speciation were both important mechanisms through which species expanded into new areas. Wallacea was an integral part of the evolutionary history of Pteropus, and likely the region of origin, a new result uncovered largely a product of the increased taxonomic and geographic sampling. I then used a combination of phylogenetics and population genetics to determine the population connectivity of two commonly studied Pteropus hosts that are of interest to the disease ecology community, P. vampyrus (Chapter 4) and P. alecto (Chapter 5). Host metapopulation dynamics are important for predictions of pathogen diversity, aggressiveness, and transmission. Pteropus vampyrus and P. alecto highlight differences in management strategies needed and pathogen model predictions. Chapter 6 presents a general discussion regarding these findings and future directions for research
Exploring anti-PD-1 resistance mechanisms for therapeutic targeting in NSCLC
View full abstracthttps://openworks.mdanderson.org/leading-edge/1035/thumbnail.jp
Global analyses of human immune variation reveal baseline predictors of postvaccination responses.
A major goal of systems biology is the development of models that accurately predict responses to perturbation. Constructing such models requires the collection of dense measurements of system states, yet transformation of data into predictive constructs remains a challenge. To begin to model human immunity, we analyzed immune parameters in depth both at baseline and in response to influenza vaccination. Peripheral blood mononuclear cell transcriptomes, serum titers, cell subpopulation frequencies, and B cell responses were assessed in 63 individuals before and after vaccination and were used to develop a systematic framework to dissect inter- and intra-individual variation and build predictive models of postvaccination antibody responses. Strikingly, independent of age and pre-existing antibody titers, accurate models could be constructed using pre-perturbation cell populations alone, which were validated using independent baseline time points. Most of the parameters contributing to prediction delineated temporally stable baseline differences across individuals, raising the prospect of immune monitoring before intervention
Variable phenotypes of enterocolitis in interleukin 10-deficient mice monoassociated with two different commensal bacteria
BACKGROUND & AIMS: To explore the hypothesis that selective immune responses to distinct components of the intestinal microflora induce intestinal inflammation, we characterized disease kinetics and bacterial antigen-specific T-cell responses in ex germ-free interleukin 10 -/- and wild-type control mice monoassociated with Enterococcus faecalis , Escherichia coli , or Pseudomonas fluorescens .
METHODS: Colitis was measured by using blinded histological scores and spontaneous interleukin 12 secretion from colonic strip culture supernatants. Interferon gamma secretion was measured from mesenteric or caudal lymph node CD4 + T cells stimulated with bacterial lysate-pulsed antigen-presenting cells. Luminal bacterial concentrations were measured by culture and quantitative polymerase chain reaction.
RESULTS: Escherichia coli induced mild cecal inflammation after 3 weeks of monoassociation in interleukin 10 -/- mice. In contrast, Enterococcus faecalis-monoassociated interleukin 10 -/- mice developed distal colitis at 10-12 weeks that was progressively more severe and associated with duodenal inflammation and obstruction by 30 weeks. Neither bacterial strain induced inflammation in wild-type mice, and germ-free and Pseudomonas fluorescens-monoassociated interleukin 10 -/- mice remained disease free. CD4 + T cells from Enterococcus faecalis- or Escherichia coli-monoassociated interleukin 10 -/- mice selectively produced higher levels of interferon gamma and interleukin 4 when stimulated with antigen-presenting cells pulsed with the bacterial species that induced disease; these immune responses preceded the onset of histological inflammation in Enterococcus faecalis -monoassociated mice. Luminal bacterial concentrations did not explain regional differences in inflammation.
CONCLUSIONS: Different commensal bacterial species selectively initiate immune-mediated intestinal inflammation with distinctly different kinetics and anatomic distribution in the same host
Recommendations for a core outcome set for measuring standing balance in adult populations: a consensus-based approach
Standing balance is imperative for mobility and avoiding falls. Use of an excessive number of standing balance measures has limited the synthesis of balance intervention data and hampered consistent clinical practice.To develop recommendations for a core outcome set (COS) of standing balance measures for research and practice among adults.A combination of scoping reviews, literature appraisal, anonymous voting and face-to-face meetings with fourteen invited experts from a range of disciplines with international recognition in balance measurement and falls prevention. Consensus was sought over three rounds using pre-established criteria.The scoping review identified 56 existing standing balance measures validated in adult populations with evidence of use in the past five years, and these were considered for inclusion in the COS.Fifteen measures were excluded after the first round of scoring and a further 36 after round two. Five measures were considered in round three. Two measures reached consensus for recommendation, and the expert panel recommended that at a minimum, either the Berg Balance Scale or Mini Balance Evaluation Systems Test be used when measuring standing balance in adult populations.Inclusion of two measures in the COS may increase the feasibility of potential uptake, but poses challenges for data synthesis. Adoption of the standing balance COS does not constitute a comprehensive balance assessment for any population, and users should include additional validated measures as appropriate.The absence of a gold standard for measuring standing balance has contributed to the proliferation of outcome measures. These recommendations represent an important first step towards greater standardization in the assessment and measurement of this critical skill and will inform clinical research and practice internationally
Fluoroquinolone and Other Antimicrobial Resistance in Invasive Pneumococci, Hong Kong, 1995–2001
Fluoroquinolone resistance among invasive pneumococci in Hong Kong was high and a result of clonal expansion and spread
Schistosomiasis among Recreational Users of Upper Nile River, Uganda, 2007
After recreational exposure to river water in Uganda, 12 (17%) of 69 persons had evidence of schistosome infection. Eighteen percent self-medicated with praziquantel prophylaxis immediately after exposure, which was not appropriate. Travelers to schistosomiasis-endemic areas should consult a travel medicine physician
The Impact of Thyroid Cancer and Post-Surgical Radioactive Iodine Treatment on the Lives of Thyroid Cancer Survivors: A Qualitative Study
BACKGROUND: Adjuvant treatment with radioactive iodine (RAI) is often considered in the treatment of well-differentiated thyroid carcinoma (WDTC). We explored the recollections of thyroid cancer survivors on the diagnosis of WDTC, adjuvant radioactive iodine (RAI) treatment, and decision-making related to RAI treatment. Participants provided recommendations for healthcare providers on counseling future patients on adjuvant RAI treatment. METHODS: We conducted three focus group sessions, including WDTC survivors recruited from two Canadian academic hospitals. Participants had a prior history of WDTC that was completely resected at primary surgery and had been offered adjuvant RAI treatment. Open-ended questions were used to generate discussion in the groups. Saturation of major themes was achieved among the groups. FINDINGS: There were 16 participants in the study, twelve of whom were women (75%). All but one participant had received RAI treatment (94%). Participants reported that a thyroid cancer diagnosis was life-changing, resulting in feelings of fear and uncertainty. Some participants felt dismissed as not having a serious disease. Some participants reported receiving conflicting messages from healthcare providers on the appropriateness of adjuvant RAI treatment or insufficient information. If RAI-related side effects occurred, their presence was not legitimized by some healthcare providers. CONCLUSIONS: The diagnosis and treatment of thyroid cancer significantly impacts the lives of survivors. Fear and uncertainty related to a cancer diagnosis, feelings of the diagnosis being dismissed as not serious, conflicting messages about adjuvant RAI treatment, and treatment-related side effects, have been raised as important concerns by thyroid cancer survivors
Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter.
Exposure to ambient fine particulate matter (PM2.5) is a major global health concern. Quantitative estimates of attributable mortality are based on disease-specific hazard ratio models that incorporate risk information from multiple PM2.5 sources (outdoor and indoor air pollution from use of solid fuels and secondhand and active smoking), requiring assumptions about equivalent exposure and toxicity. We relax these contentious assumptions by constructing a PM2.5-mortality hazard ratio function based only on cohort studies of outdoor air pollution that covers the global exposure range. We modeled the shape of the association between PM2.5 and nonaccidental mortality using data from 41 cohorts from 16 countries-the Global Exposure Mortality Model (GEMM). We then constructed GEMMs for five specific causes of death examined by the global burden of disease (GBD). The GEMM predicts 8.9 million [95% confidence interval (CI): 7.5-10.3] deaths in 2015, a figure 30% larger than that predicted by the sum of deaths among the five specific causes (6.9; 95% CI: 4.9-8.5) and 120% larger than the risk function used in the GBD (4.0; 95% CI: 3.3-4.8). Differences between the GEMM and GBD risk functions are larger for a 20% reduction in concentrations, with the GEMM predicting 220% higher excess deaths. These results suggest that PM2.5 exposure may be related to additional causes of death than the five considered by the GBD and that incorporation of risk information from other, nonoutdoor, particle sources leads to underestimation of disease burden, especially at higher concentrations
Bullying escolar: um fenômeno multifacetado
School bullying can involve children in different ways, making them play different roles, among them, victims, bullies and bully-victims. The aim of this study was to describe how bullying occurs in high social vulnerability schools of Florianópolis metropolitan area and the roles played by students in this phenomenon. Overall, 409 children and adolescents from the 3rd to 5th grades and of two public elementary schools aged 8-16 years (X = 11.14) participated in this study. As a tool, the Olweus Questionnaire adapted to the Brazilian population was used. For data analysis, descriptive statistics and inferential statistics were applied by the Mann Whitney and Kruskal Wallis tests. As for results, 29.8% of boys and 40.5% of girls reported being victims; 32.3% of boys and 24.6% of girls reported being bullies. Victims were the most willing to help a colleague who is suffering from bullying (X = 1.54; p> 0.001), even if they do not know the victims (X = 1.57; p> 0.004). Bullies are differentiated from the group that does not participate (X = 1.73) and the group of victims (X = 2.34), being those who felt less alone (x = 1.47; p> 0.001). It was concluded that the information obtained in this study is indispensable in the search for alternatives to reduce school bullying. The strengthening of relations between school and students and a better preparation of teachers and school staff are extremely necessary to try to minimize the effects of risk factors to which these children are exposed and consequently violence at school.O bullying escolar pode envolver crianças de diferentes
maneiras, fazendo com que essas assumam papéis diferenciados.
Dentre estes, têm-se vÃtimas, agressores e vÃtimas-agressoras. O
objetivo deste estudo foi descrever como ocorre o bullying em
escolas de alta vulnerabilidade social da Grande Florianópolis
e os papéis assumidos pelos alunos nesse fenômeno. Quanto ao
método, participaram 409 crianças e adolescentes do terceiro
ao quinto ano e da quarta à sexta série do ensino fundamental,
de duas escolas públicas municipais, com idades entre 8 e 16
anos (X=11,14). Como instrumento, utilizou-se o Questionário
de Olweus adaptado à população brasileira. Para a análise
dos dados, empregaram-se a estatÃstica descritiva e estatÃstica
inferencial por meio dos testes Mann Whitney e Kruskal Wallis.
Quanto aos resultados, 29,8% dos meninos e 40,5% das meninas
relataram terem sido vÃtimas; já 32,3% dos meninos e 24,6%
das meninas relataram terem sido agressores. As vÃtimas foram
as que se mostraram mais dispostas a ajudar como podem um
colega que esteja sofrendo agressão (X=1,54; p>0,001), mesmo
que não o conheçam (X=1,57; p>0,004). Em contrapartida,
os agressores se diferenciaram do grupo que não participa
(X=1,73) e do grupo das vÃtimas (X=2,34), sendo aqueles que
menos se sentiram sozinhos (X=1,47; p>0,001). Concluiu-se
que as informações obtidas neste estudo são indispensáveis
na busca de alternativas para redução do bullying escolar. O
fortalecimento das relações entre escola e alunos, e um maior
preparo dos professores e funcionários são extremamente
necessários para tentar minimizar os efeitos dos fatores de
risco a que essas crianças estão expostas e consequentemente a
violência na escola.CAPES - Proc. nº 0815/14-4CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT)Projeto Estratégico da FCT: UID/CED/00317/201
- …