55 research outputs found
On rigidly rotating perfect fluid cylinders
The gravitational field of a rigidly rotating perfect fluid cylinder with
gamma- law equation of state is found analytically. The solution has two
parameters and is physically realistic for gamma in the interval (1.41,2].
Closed timelike curves always appear at large distances.Comment: 10 pages, Revtex (galley
Geographic Information Systems (GIS) in Assessing Dental Health
The present study investigated the distribution profile of dental caries and its association with areas of social deprivation at the individual and contextual level. The cluster sample consisted of 1,002 12-year-old schoolchildren from Piracicaba, SP, Brazil. The DMFT Index was used for dental caries and the Care Index was used to determine access to dental services. On the individual level, variables were associated with a better oral status. On the contextual level, areas were not associated with oral status. However, maps enabled determining that the central districts have better social and oral conditions than the deprived outlying districts
Captura de Desmodus rotundus em regiões de mata e manguezais do Estado do Maranhão: um estudo longitudinal
O presente trabalho teve por objetivos investigar o número de capturas e o controle do morcego hematófago Desmodus rotundus, em pequenas propriedades localizadas no município de Cedral no estado do Maranhão, que foi escolhido por ter sido efetuado o maior número de capturas do estado, sendo todas ao redor de currais. O controle oficial é realizado pela aplicação de pasta vampiricida de uso tópico a base de warfarina a 2%. Para o estudo foram utilizadas fichas de controle de morcegos hematófagos capturados em currais, como também, foi aplicado um questionário a campo para identificação dos locais com maior número de capturas. No período de 2005 a 2010 foram estudados os resultados de 223 buscas ativas por D. rotundus, em 101 propriedades. Foi capturado um total de 408 morcegos hematófagos, distribuídos em 190 das 223 buscas. Em todos os espécimes de D. rotundus capturados foi realizado o tratamento, que consistiu na aplicação da pasta vampiricida, no dorso do animal. Nas propriedades estudadas, verificou-se que dos 754 animais expostos, 344 foram agredidos. Destes, os bovinos foram a maior oferta de alimento aos Desmodus (49%), seguidos dos equídeos (18%), aves (15%), suínos (9%) e caprinos (8%). Apesar dos bovinos terem sido os mais atacados, em função do efetivo disponível, verificou-se uma preferência dos morcegos hematófagos por eqüídeos. As falhas nas capturas ocorreram onde havia poucos animais agredidos. Após análise de seis anos de realização do programa de controle com pasta vampiricida, verificou-se que a proporção de macho e fêmeas de D. rotundus capturados foi 1,08 machos para cada fêmea, o que demonstra que o tratamento foi mais efetivo nas fêmeas, uma vez que no primeiro ano do estudo, a proporção era de 1,21 fêmeas para cada macho. Verificou-se ainda que o controle foi realizado com sucesso em 95% das propriedades trabalhadas, com uma média de tempo de três anos de trabalho com até seis capturas por propriedade. Ao exame dos animais agredidos verificou-se que a área do pescoço dos grandes animais e dos caprinos são as mais atingidas, sugerindo o pouso direto dos morcegos sobre o animal. Uma representação pequena dos proprietários entrevistados vacinavam seus animais (57%), e destes apenas um fazia o reforço de vacinação. Concluiu-se que nas regiões de mangue e/ou matas, o controle foi efetivo nas capturas em currais, sendo prudente verificar a ocorrência de novas agressões, dentro de 15 dias e nos primeiros três meses. No planejamento de controle de D. rotundus em curral, deve ser considerado que o número de morcegos capturados é semelhante ao número de mordidas recentes. Em relação às criações domésticas de subsistências, D. rotundus se alimenta de fontes distintas, com uma menor predileção pelas aves
Genomics and epidemiology for gastric adenocarcinomas (GE4GAC): a Brazilian initiative to study gastric cancer
Abstract Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings
Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants
© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
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