110 research outputs found
Bayesian spatio-temporal CPUE standardization: Case study of European sardine (Sardina pilchardus) along the western coast of Portugal
Understanding the key factors influencing population dynamics of fish stocks requires
knowledge of their spatial distribution and seasonal habitat selection, but these spatio-temporal
dynamics are often not explicitly included in ecological studies and stock
assessment models. This study standardized the data of sardine fishery-dependent
catch-per-
unit-
effort
(CPUE) from the west coast of Portugal using Bayesian hierarchical
spatio-temporal
models (BHSTM) with the integrated nested Laplace approximation
(INLA). Sardine CPUE was best explained by length of the vessel, vessel ID,
month, year, and location (latitude, longitude). In terms of spatio-temporal
distribution,
sardine biomass prediction maps showed a constant pattern that changed every
quarter of the year. In addition, sardine CPUE index showed a cyclical trend along the
year with minimum values in July and maximum peak in November. This approach
provided insights on variables and corresponding modelling effects that may be relevant
in spatio-temporal
fishery-dependent
data standardization, and that could be
applied to other fish species and areas.En prens
Bayesian spatio-temporal CPUE standardization: case study of European sardine (Sardina pilchardus) along the western coast of Portugal
Fishery data is one of the most accessible sources of information currently used for ecological studies and stock assessments. Unlike scientific surveys that are usually restricted to a given time of the year, fisheries dependent data is almost continuously available in time. Moreover, the information collected from the fisheries is less expensive and time consuming. However, for use as a relative abundance index, fishery-dependent data requires standardization as catch-per-unit-effort (CPUE) in order to remove the impact of vessel-specific differences and fishing behavior. Understanding the key factors that influence the population dynamics of fish species implies assessment of their spatial distribution and seasonal habitat selection but, spatio-temporal dependence issues are often not explicitly included in the modeling process. This study standardizes sardine fishery-dependent data obtained from the west coast of Portugal as CPUE by means of a Bayesian hierarchical spatio-temporal model using integrated nested Laplace approximation (INLA). This is one of the first studies of the region to provide maps of the relative abundance of this species for all months of the year. The best model included length of the vessel, vessel ID, month, year and location (latitude, longitude), while none of the five environmental covariates (Chl-a, SST, bathymetry, current velocity and direction) were relevant. In terms of spatial distribution, sardines were more abundant in the northern area, especially during the last quarter of the year. The applied methodology has contributed to improve our knowledge of European sardine distribution throughout the year, providing accurate predictive maps and insights into the standardization process of fishery-dependent data that could also be applied to other fish species and areas
Balancing risk, intimacy and (non)compliance: a qualitative study of sex across household during COVID-19 social restrictions
Government controls over intimate relationships, imposed to limit the spread of Sars-CoV-2, were unprecedented in modern times. This study draws on data from qualitative interviews with 18 participants in Natsal-COVID, a quasi-representative web-panel survey of the British population (n = 6,654 people), reporting that they had sex with someone from outside their household in the preceding four weeks; a period in which contact between households was restricted in the UK. Whilst only 10% of people reported sexual contact outside their household, among single people and those in non-cohabiting relationships, rates were much higher (Natsal-COVID). Our findings show that individuals did not take decisions to meet up with sexual partners lightly. Participants were motivated by needs-for connection, security, intimacy and a sense of normality. People balanced risks-of catching COVID-19, social judgement and punishment for rule-breaking-against other perceived risks, including to their mental health or relationships. We used situated rationality and social action theories of risk to demonstrate that people weighed up risk in socially situated ways and exhibited complex decision-making when deciding not to comply with restrictions. Understanding motivations for non-compliance is crucial to informing future public health messaging which accounts for the needs and circumstances of all population members
Efeitos da ELTGOL e do Flutter® nos volumes pulmonares dinâmicos e estáticos e na remoção de secreção de pacientes com bronquiectasia
Efeito do teor de água e tamanho de partÃcula na decomposição térmica de pastas de cimento moÃdas
Um método alternativo para produção de concretos ecoeficientes seria a substituição parcial de cimento Portland por resÃduos de pastas e argamassas submetidas a um tratamento termomecânico. Neste contexto, este estudo avalia a influência da relação água/cimento (a/c) e do tamanho médio das partÃculas na decomposição térmica do cimento hidratado. Pastas de cimento com três relações a/c (0,40, 0,50 e 0,60) e curadas por 28 dias foram moÃdas para obtenção de granulometrias com tamanho médio de 0,60 mm e 0,15 mm. A decomposição térmica das pastas foi analisada por termogravimetria (TGA), difração de raios X (DRX) e espectroscopia no infravermelho por Transformada de Fourier (FTIR). A análise de TGA indica que o teor de água quimicamente combinada é favorecido pelo aumento da relação a/c entre 0,40 e 0,50, mas é constante para a/c de 0,50 e 0,60. A redução do tamanho médio quase não interfere nas curvas de TGA. De acordo com as análises por DRX e TGA, a maior parte dos hidratos se decompõe até 500-550°C, enquanto que silicatos de cálcio e aluminatos de cálcio similares à s fases anidras do cimento Portland foram detectados na pasta aquecida a 750°C. Assim, temperaturas mais altas seriam necessárias para a completa recuperação do cimento anidro em pastas hidratadas. Palavras-chave: Pasta de cimento Portland, decomposição térmica, relação água/cimento, tamanho de partÃculas, análises térmicas
Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax.
BACKGROUND: The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax. METHODS: We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences), Peru (PER, n = 23), Colombia (COL, n = 31), and Mexico (MEX, n = 19). PRINCIPAL FINDINGS/CONCLUSIONS: We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10-4 and 6.2 × 10-4) as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed) in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o) gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092). Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between parasite lineages from geographically diverse sites. Further genome-wide analyses are required to test the demographic scenario suggested by our data
Impacts of COVID-19 on sexual behaviour in Britain: findings from a large, quasi-representative survey (Natsal-COVID).
OBJECTIVES: Physical restrictions imposed to combat COVID-19 dramatically altered sexual lifestyles but the specific impacts on sexual behaviour are still emerging. We investigated physical and virtual sexual activities, sexual frequency and satisfaction in the 4 months following lockdown in Britain in March 2020 and compared with pre-lockdown. METHODS: Weighted analyses of web panel survey data collected July/August 2020 from a quota-based sample of 6654 people aged 18-59 years in Britain. Multivariable regression took account of participants' opportunity for partnered sex, gender and age, to examine their independent associations with perceived changes in sexual frequency and satisfaction. RESULTS: Most participants (86.7%) reported some form of sex following lockdown with physical activities more commonly reported than virtual activities (83.7% vs 52.6%). Altogether, 63.2% reported sex with someone ('partnered sex') since lockdown, three-quarters of whom were in steady cohabiting relationships. With decreasing relationship formality, partnered sex was less frequently reported, while masturbation, sex toy use and virtual activities were more frequently reported. Around half of all participants perceived no change in partnered sex frequency compared with the 3 months pre-lockdown, but this was only one-third among those not cohabiting, who were more likely to report increases in non-partnered activities than those cohabiting. Two-thirds of participants perceived no change in sexual satisfaction; declines were more common among those not cohabiting. Relationship informality and younger age were independently associated with perceiving change, often declines, in sexual frequency and satisfaction. CONCLUSIONS: Our quasi-representative study of the British population found a substantial minority reported significant shifts in sexual repertoires, frequency and satisfaction following the introduction of COVID-19 restrictions. However, these negative changes were perceived by some more than others; predominantly those not cohabiting and the young. As these groups are most likely to experience adverse sexual health, it is important to monitor behaviour as restrictions ease to understand the longer term consequences, including for health services
Social distancing measures to control the COVID-19 pandemic: potential impacts and challenges in Brazil.
The COVID-19 pandemic has challenged researchers and policy makers to identify public safety measures forpreventing the collapse of healthcare systems and reducingdeaths. This narrative review summarizes the available evidence on the impact of social distancing measures on the epidemic and discusses the implementation of these measures in Brazil. Articles on the effect of social distancing on COVID-19 were selected from the PubMed, medRXiv and bioRvix databases. Federal and state legislation was analyzed to summarize the strategies implemented in Brazil. Social distancing measures adopted by the population appear effective, particularly when implemented in conjunction with the isolation of cases and quarantining of contacts. Therefore, social distancing measures, and social protection policies to guarantee the sustainability of these measures, should be implemented. To control COVID-19 in Brazil, it is also crucial that epidemiological monitoring is strengthened at all three levels of the Brazilian National Health System (SUS). This includes evaluating and usingsupplementary indicators to monitor the progression of the pandemic and the effect of the control measures, increasing testing capacity, and making disaggregated notificationsand testing resultstransparentand broadly available
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