1,449 research outputs found
Understanding the tsunami with a simple model
In this paper, we use the approximation of shallow water waves (Margaritondo
G 2005 Eur. J. Phys. 26 401) to understand the behaviour of a tsunami in a
variable depth. We deduce the shallow water wave equation and the continuity
equation that must be satisfied when a wave encounters a discontinuity in the
sea depth. A short explanation about how the tsunami hit the west coast of
India is given based on the refraction phenomenon. Our procedure also includes
a simple numerical calculation suitable for undergraduate students in physics
and engineering
Concreto autoadensável em regiões costeiras de clima quente
O concreto autoadensável (CAA no Brasil e SCC internacionalmente) já vem sendo aplicado há aproximadamente 20 anos e vem se tornando alternativa tecnicamente viável para aplicação em lugar do concreto convencional vibrado (CC). Atualmente, constata-se que os estudos sobre o SCC avançaram muito e já possível responder a quase todas as indagações acerca do comportamento do SCC frente ao CC, vantagens e possíveis desvantagens nos aspectos técnicos de aplicacação e utilização
Gene expression in epithelial cells in response to pneumovirus infection
Respiratory syncytial virus (RSV) and pneumonia virus of mice (PVM) are viruses of the family Paramyxoviridae, subfamily pneumovirus, which cause clinically important respiratory infections in humans and rodents, respectively. The respiratory epithelial target cells respond to viral infection with specific alterations in gene expression, including production of chemoattractant cytokines, adhesion molecules, elements that are related to the apoptosis response, and others that remain incompletely understood. Here we review our current understanding of these mucosal responses and discuss several genomic approaches, including differential display reverse transcription-polymerase chain reaction (PCR) and gene array strategies, that will permit us to unravel the nature of these responses in a more complete and systematic manner
Parvalbumin promoter hypermethylation in postmortem brain in schizophrenia
Deficits of brain parvalbumin (PV) are a consistent finding in schizophrenia and models of psychosis. We investigated whether this is associated with abnormal PV gene (PVALB) methylation in the brain in schizophrenia. Bisulfite pyrosequencing was used to determine cytosine (CpG) methylation in a PVALB promoter sequence. Greater PVALB methylation was found in schizophrenia hippocampus, while no differences were observed in prefrontal cortex. LINE-1 methylation, a measure of global methylation, was also elevated in both regions in schizophrenia, although the PVALB change was independent of this effect. These results provide the first evidence that PVALB promoter methylation is abnormal in schizophrenia and suggest that this epigenetic finding may relate to the reduction of PV expression seen in the disease
Brazilian scientific funding agency budgets have not matched the country's economic growth
Abstract The growth of the Brazilian economy in recent years has created an atmosphere of optimism in various segments of Brazilian society, with several important international repercussions. In this paper, we analyze in detail how this economic growth is reflected in investments in science and technology made by major academic funding agencies. As a result, we observed a discrepancy in the growth of funding input and the growth of the Brazilian gross domestic product. This fact associated with an increased academic output entails negative consequences for the system. This may be a symptom of an academic community not fully understood by society and vice versa. Finally, we believe that a long-lasting important change in investment policy in science is necessary in order to ensure financial security for the academic system as a whole
Inflammatory responses to acute pneumovirus infection in neonatal mice
Background: The innate immune responses of neonates differ dramatically from those of adults. Here we examine the acute inflammatory responses of neonatal and weanling mice infected with pneumonia virus of mice (PVM), a rodent pathogen (family Paramyxoviridae, genus Pneumovirus) that replicates the sequelae of severe respiratory syncytial virus infection. Results: We demonstrate that virus replication proceeds indistinguishably in all age groups (inoculated at 1, 2, 3 and 4 weeks of age), although inflammatory responses vary in extent and character. Some of the biochemical mediators detected varied minimally with age at inoculation. Most of the mediators evaluated demonstrated elevated expression over baseline correlating directly with age at the time of virus inoculation. Among the latter group are CCL2, CCL3, and IFN-γ, all cytokines previously associated with PVM-induced inflammatory pathology in mature mice. Likewise, we detect neutrophil recruitment to lung tissue in all age groups, but recruitment is most pronounced among the older (3 - 4 week old) mice. Interestingly, all mice exhibit failure to thrive, lagging in expected weight gain for given age, including the youngest mice that present little overt evidence of inflammation. Conclusions: Our findings among the youngest mice may explain in part the phenomenon of atypical or minimally symptomatic respiratory infections in human neonates, which may be explored further with this infection model
Nutrition-Related Factors and the Progression of Metabolic Syndrome Characteristics over Time in Older Adults: Analysis of the TUDA Cohort
Metabolic syndrome (MetS) is associated with an increased risk of cardiovascular disease and type 2 diabetes mellitus by an estimated two- and five-fold, respectively. Nutrition intervention could help to prevent the progression of MetS and associated pathologies with age, but the precise dietary components and related factors are not well understood. Therefore, the aim of this study was to evaluate the role of nutrition-related factors in MetS as well as the progression of MetS and its components over a 7-year follow-up period in older adults. This investigation involved the secondary analysis of data from the North–South of Ireland Trinity-Ulster-Department of Agriculture (TUDA) study of community-dwelling older adults (≥60 y), which were sampled at baseline (2008–2012; n = 5186) and follow-up (2015–2018; n = 953). Participants were deemed to have MetS if they met at least three of the following criteria: waist circumference (≥102 cm for males, ≥88 cm for females); HDL cholesterol (<1.0 mmol/L for males, <1.3 mmol/L for females); triglycerides (≥1.7 mmol/L); blood pressure (systolic ≥ 130 and/or diastolic ≥ 85 mmHg); and HbA1c (≥39 mmol/mol). The prevalence of MetS increased with advancing age (67% at baseline vs. 74% at follow-up). The factors at baseline that were predictive of a higher MetS risk at follow-up included waist circumference (OR 1.04, 95% CI 1.00–1.08; p = 0.038) and triglycerides (OR 1.77, 95% CI 1.21–2.59; p = 0.003). In a detailed dietary analysis conducted at the follow-up time point, higher protein intake (g/kg body weight) was associated with a lower risk of MetS (OR 0.06, 95% CI 0.02–0.20; p < 0.001), abdominal obesity (OR 0.10, 95% CI 0.02–0.51; p = 0.006), and hypertension (OR 0.022, 95% CI 0.00–0.80; p = 0.037), and a higher MUFA intake (g/day) was associated with a lower risk of MetS (OR 0.88, 95% CI 0.78–1.00; p = 0.030). No other dietary factors were significantly associated with MetS. In terms of protein quality, participants with MetS compared to those without consumed fewer high-quality protein foods (p = 0.009) and consumed more low-quality protein foods (p < 0.001). Dietary intervention along with other strategies focusing on potentially modifiable risk factors may delay the progression of MetS in older adults. Efforts to enhance the quantity and quality of protein intake may be warranted to reduce MetS in certain at-risk groups
Efficient replication of pneumonia virus of mice (PVM) in a mouse macrophage cell line
Pneumonia virus of mice (PVM; family Paramyxoviridae, subfamily Pneumovirinae) is a natural respiratory pathogen of rodent species and an important new model for the study of severe viral bronchiolitis and pneumonia. However, despite high virus titers typically detected in infected mouse lung tissue in vivo, cell lines used routinely for virus propagation in vitro are not highly susceptible to PVM infection. We have evaluated several rodent and primate cell lines for susceptibility to PVM infection, and detected highest virus titers from infection of the mouse monocyte-macrophage RAW 264.7 cell line. Additionally, virus replication in RAW 264.7 cells induces the synthesis and secretion of proinflammatory cytokines relevant to respiratory virus disease, including tumor necrosis factor-α (TNF-α), interferon-β (IFN-β), macrophage inflammatory proteins 1α and 1β (MIP-1α and MIP-1β) and the functional homolog of human IL-8, mouse macrophage inflammatory peptide-2 (MIP-2). Identification and characterization of a rodent cell line that supports the replication of PVM and induces the synthesis of disease-related proinflammatory mediators will facilitate studies of molecular mechanisms of viral pathogenesis that will complement and expand on findings from mouse model systems
What are health policy and systems research priorities for universal health coverage in South Africa?
We report here on the process and findings of a research prioritisation exercise for universal health coverage (UHC) in South Africa,
conducted during the course of 2019. As plans to roll out National Health Insurance (NHI) gather momentum and we transition into a
pandemic recovery phase, we believe that it is now time to revisit these priorities, while recognising that experiences with the COVID‑19
pandemic have revealed new system challenges and strengths and introduced new priorities. The UHC research priority-setting
methodology followed a stepwise process of collation of evidence, expert brainstorming and the development of a survey completed by
68 members of the Public Health Association of South Africa. Themes related to leadership and governance were ranked most highly, and
with other priorities generated, provide an initial road map of knowledge needs that could guide individual institutions and commissioning
by funding bodies. We further reflect on the importance of researcher-decision-maker dialogue and strengthening the contribution of
health policy and systems research to policy and practice, especially as new reforms are implemented
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