970 resultados para Historical Mortality Events


Relevância:

90.00% 90.00%

Publicador:

Resumo:

The role of public health has been a central topic on the classical debate about the historical mortality decline in Europe. One of these health initiatives were the Milk Depots. Spain set up those centres from the late 19th century until the beginning of the Civil War. The goal of this paper is to evaluate the effect of this health intervention on the infant mortality decline during this period. This study works out three kinds of sources: Statistical Yearbooks, Official documents and local records produced by the same Milk Depot. It analyses data available for all the country and one local case such as the Barcelona’s Milk Depot (1904-1935). The main methodological issue deals with the measurement of the effect of the Milk Depot activities on the pattern of changes of infant mortality. Results suggest that Milk Depots have a positive but quite moderate effect on the improving of overall levels of child survival.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Documenting and preserving the genetic diversity of populations, which conditions their long-term survival, have become a major issue in conservation biology. The loss of diversity often documented in declining populations is usually assumed to result from human disturbances; however, historical biogeographic events, otherwise known to strongly impact diversity, are rarely considered in this context. We apply a multilocus phylogeographic study to investigate the late-Quaternary history of a tree frog (Hyla arborea) with declining populations in the northern and western part of its distribution range. Mitochondrial and nuclear polymorphisms reveal high genetic diversity in the Balkan Peninsula, with a spatial structure moulded by the last glaciations. While two of the main refugial lineages remained limited to the Balkans (Adriatic coast, southern Balkans), a third one expanded to recolonize Northern and Western Europe, loosing much of its diversity in the process. Our findings show that mobile and a priori homogeneous taxa may also display substructure within glacial refugia ('refugia within refugia') and emphasize the importance of the Balkans as a major European biodiversity centre. Moreover, the distribution of diversity roughly coincides with regional conservation situations, consistent with the idea that historically impoverished genetic diversity may interact with anthropogenic disturbances, and increase the vulnerability of populations. Phylogeographic models seem important to fully appreciate the risks of local declines and inform conservation strategies.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

A physically based gust parameterisation is added to the atmospheric mesoscale model FOOT3DK to estimate wind gusts associated with storms over West Germany. The gust parameterisation follows the Wind Gust Estimate (WGE) method and its functionality is verified in this study. The method assumes that gusts occurring at the surface are induced by turbulent eddies in the planetary boundary layer, deflecting air parcels from higher levels down to the surface under suitable conditions. Model simulations are performed with horizontal resolutions of 20 km and 5 km. Ten historical storm events of different characteristics and intensities are chosen in order to include a wide range of typical storms affecting Central Europe. All simulated storms occurred between 1990 and 1998. The accuracy of the method is assessed objectively by validating the simulated wind gusts against data from 16 synoptic stations by means of “quality parameters”. Concerning these parameters, the temporal and spatial evolution of the simulated gusts is well reproduced. Simulated values for low altitude stations agree particularly well with the measured gusts. For orographically exposed locations, the gust speeds are partly underestimated. The absolute maximum gusts lie in most cases within the bounding interval given by the WGE method. Focussing on individual storms, the performance of the method is better for intense and large storms than for weaker ones. Particularly for weaker storms, the gusts are typically overestimated. The results for the sample of ten storms document that the method is generally applicable with the mesoscale model FOOT3DK for mid-latitude winter storms, even in areas with complex orography.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

ABSTRACT Given the decline of shallow-water red coral populations resulting from over-exploitation and mass mortality events, deeper populations below 50 metres depth (mesophotic populations) are currently the most harvested; unfortunately, very little is known about their biology and ecology. The persistence of these populations is tightly linked to their adult density, reproductive success, larval dispersal and recruitment. Moreover, for their conservation, it is paramount understand processes such as connectivity within and among populations. Here, for the first time, genetic variability and structuring of Corallium rubrum populations collected in the Tyrrhenian Sea ranging from 58 to 118 metres were analyzed using ten microsatellite loci and two mitochondrial markers (mtMSH and MtC). The aims of the work were 1) to examine patterns of genetic diversity within each geographic area (Elba, Ischia and Praiano) and 2) to define population structuring at different spatial scales (from tens of metres to hundreds of kilometres). Based on microsatellite data set, significant deviations from Hardy-Weinberg equilibrium due to elevated heterozygote deficiencies were detected in all samples, probably related to the presence of null alleles and/or inbreeding, as was previously observed in shallow-water populations. Moreover, significant levels of genetic differentiation were observed at all spatial scale, suggesting a recent isolation of populations. Biological factors which act at small spatial scale and/or abiotic factors at larger scale (e.g. summer gyres or absence of suitable substrata for settlement) could determine this genetic isolation. Using mitochondrial markers, significant differences were found only at wider scale (between Tuscany and Campania regions). These results could be related to the different mutation rate of the molecular makers or to the occurrence of some historical links within regions. A significant isolation by distance pattern was then observed using both data sets, confirming the restricted larval dispersal capability of the species. Therefore, the hypothesis that deeper populations may act as a source of larvae helping recovery of threatened shallow-water populations is not proved. Conservation strategies have to take into account these results, and management plans of deep and currently harvested populations have to be defined at a regional or sub regional level, similarly to shallow-water populations. Nevertheless, further investigations should be needed to understand better the genetic structuring of this species in the mesophotic zone, e.g. extending studies to other Mediterranean deep-water populations.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The surf clams Mesodesma mactroides Reeve, 1854 and Donax hanleyanus Philippi, 1847 are the two dominating species in macrobenthic communities of sandy beaches off northern Argentina, with the latter now surpassing M. mactroides populations in abundance and biomass. Before stock decimation caused by exploitation (during the 1940s and 1950s) and mass mortality events (1995, 1999 and 2007) M. mactroides was the prominent primary consumer in the intertidal ecosystem and an important economic resource in Argentina. Since D. hanleyanus was not commercially fished and not affected by mass mortality events, it took over as the dominant species, but did never reach the former abundance of M. mactroides. Currently abundance and biomass of both surf clams are a multiple smaller than those of forty years ago, indicating the conservation status of D. hanleyanus and M. mactroides as endangered. Therefore the aim of this study is to analyse the population dynamics (population structure, growth and reproductive biology) of D. hanleyanus and M. mactroides, and to compare the results with historical data in order to detect possible differences within surf clam populations forty years ago and at present.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

A detailed ecological, micro-structural and skeletal Sr/Ca study of a 3.42 m thick Goniopora reef profile from an emerged Holocene reef terrace at the northern South China Sea reveals at least nine abrupt massive Goniopora stress and mortality events occurred in winter during the 7.0-7.5 thousand calendar years before present (cal. ka BP) (within the Holocene climatic optimum). Whilst calculated Sr/Ca-SST (sea surface temperature) maxima during this period are comparable to those in the 1990s, Sr/Ca-SST minima are significantly lower, probably due to stronger winter monsoons. Such generally cooler winters, superimposed by further exceptional winter cooling on inter-annual to decadal scales, may have caused stress and mortality of the corals about every 50 years. Sea level rose by similar to 3.42 m during this period, with present sea-level reached at similar to 7.3 ka BP and a sea-level highstand of at least similar to 1.8 m occurred at similar to 7.0 ka. The results show that it took about 20-25 years for a killed Goniopora coral reef to recover. (C) 2004 Elsevier B.V. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The frequency and intensity of disturbance on living coral reefs have been accelerating for the past few decades, resulting in a changed seascape. What is unclear but vital for management is whether this acceleration is natural or coincident only with recent human impact. We surveyed nine uplifted early to mid-Holocene (11,000-3700 calendar [cal] yr B.P.) fringing and barrier reefs along similar to 27 km at the Huon Peninsula, Papua New Guinea. We found evidence for several episodes of coral mass mortality, but frequency was < 1 in 1500 yr. The most striking mortality event extends > 16 km along the ancient coastline, occurred ca. 9100-9400 cal yr B.P., and is associated with a volcanic ash horizon. Recolonization of the reef surface and resumption of vertical reef accretion was rapid (< 100 yr), but the post-disturbance reef communities contrasted with their pre-disturbance counterparts. Assessing the frequency, nature, and long-term ecological consequences of mass-mortality events in fossil coral reefs may provide important insights to guide management of modern reefs in this time of environmental degradation and change.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Current procedures for flood risk estimation assume flood distributions are stationary over time, meaning annual maximum flood (AMF) series are not affected by climatic variation, land use/land cover (LULC) change, or management practices. Thus, changes in LULC and climate are generally not accounted for in policy and design related to flood risk/control, and historical flood events are deemed representative of future flood risk. These assumptions need to be re-evaluated, however, as climate change and anthropogenic activities have been observed to have large impacts on flood risk in many areas. In particular, understanding the effects of LULC change is essential to the study and understanding of global environmental change and the consequent hydrologic responses. The research presented herein provides possible causation for observed nonstationarity in AMF series with respect to changes in LULC, as well as a means to assess the degree to which future LULC change will impact flood risk. Four watersheds in the Midwest, Northeastern, and Central United States were studied to determine flood risk associated with historical and future projected LULC change. Historical single framed aerial images dating back to the mid-1950s were used along with Geographic Information Systems (GIS) and remote sensing models (SPRING and ERDAS) to create historical land use maps. The Forecasting Scenarios of Future Land Use Change (FORE-SCE) model was applied to generate future LULC maps annually from 2006 to 2100 for the conterminous U.S. based on the four IPCC-SRES future emission scenario conditions. These land use maps were input into previously calibrated Soil and Water Assessment Tool (SWAT) models for two case study watersheds. In order to isolate effects of LULC change, the only variable parameter was the Runoff Curve Number associated with the land use layer. All simulations were run with daily climate data from 1978-1999, consistent with the 'base' model which employed the 1992 NLCD to represent 'current' conditions. Output daily maximum flows were converted to instantaneous AMF series and were subsequently modeled using a Log-Pearson Type 3 (LP3) distribution to evaluate flood risk. Analysis of the progression of LULC change over the historic period and associated SWAT outputs revealed that AMF magnitudes tend to increase over time in response to increasing degrees of urbanization. This is consistent with positive trends in the AMF series identified in previous studies, although there are difficulties identifying correlations between LULC change and identified change points due to large time gaps in the generated historical LULC maps, mainly caused by unavailability of sufficient quality historic aerial imagery. Similarly, increases in the mean and median AMF magnitude were observed in response to future LULC change projections, with the tails of the distributions remaining reasonably constant. FORE-SCE scenario A2 was found to have the most dramatic impact on AMF series, consistent with more extreme projections of population growth, demands for growing energy sources, agricultural land, and urban expansion, while AMF outputs based on scenario B2 showed little changes for the future as the focus is on environmental conservation and regional solutions to environmental issues.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In recent years, haying has extended to Iberian Mediterranean dry grasslands potentially impacting on grassland bird ecology. We evaluated the impact of haying on a grassland bird community of South Portugal. Our main goals were: (1) to investigate the exposure of different species to haying, (2) to investigate potential removal of nests and dead birds from hayed fields by haying machinery using the ratio (REC) between the expected number of records and the number of records collected and (3) to link clutch destruction and bird mortality with haying management practices. Hayed fields were surveyed for signs of breeding and birds censused prior to mowing. Linear models were computed, linking the REC with haying machinery and sward properties. GLMs and model averaging were used to obtain models linking clutch destruction, bird mortality and haying management variables. Only 4 % of records evidenced successful nesting attempts (N = 177). REC evaluation suggested high nest or dead bird removal by the machinery, particularly in fields with lower vegetation biomass prior to cutting. Sickle bar mowers and one-rotor rotary rakes returned higher REC but lower probability of found nests removed from the original nesting sites comparatively to discs mowers and wheel rakes. Higher probabilities of mortality events were found in fields mown earlier (but not in all years). On the other hand, lower mortality was found in fields raked with two-rotor rotary rakes. Delayed haying, silage production in temporary crops and the use haying machinery enabling simultaneously mowing and gathering hay in lines are discussed as management alternatives.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

RESUMO - A obesidade constitui um importante problema de saúde pública com consequências económicas de grande dimensão. Os obesos têm um risco acrescido de contrair doenças e de sofrer morte prematura devido a problemas como a diabetes, hipertensão arterial, AVC, insuficiência cardíaca e algumas neoplasias malignas. O presente estudo tem como objectivo estimar o custo económico indirecto (valor da produção perdida) associado à obesidade em Portugal no ano de 2002. O estudo adopta uma abordagem tipo custos da doença baseada na prevalência. Os dados são retirados do Inquérito Nacional de Saúde e estatísticas de rotina publicadas pelo INE e por outros organismos oficiais. Consideram-se como obesas pessoas com índice de massa corporal (IMC) ≥ 30 kg/m2 e estabelecem-se como limites etários para participação em actividades económicas produtivas as idades compreendidas entre os 15 e os 64 anos. A estratégia de imputação de custos ao factor de risco obesidade caracteriza- se por estimar, para a população portuguesa, as proporções de doença e morte prematura atribuíveis à obesidade e em multiplicar as estimativas populacionais encontradas pelo valor da produtividade económica potencial das pessoas afectadas. O custo indirecto total da obesidade em Portugal no ano de 2002 foi estimado em 199,8 milhões de euros. A mortalidade contribuiu com 58,4% deste valor (117 milhões de euros) e a morbilidade com 41,6% (83 milhões de euros). Os custos da morbilidade advêm de mais de 1,6 milhões de dias de incapacidade anuais, principalmente por faltas ao trabalho associadas a doenças do sistema circulatório e diabetes tipo II. Os custos da mortalidade são o resultado de 18 733 potenciais anos de vida activa perdidos, numa razão de 3 mortes masculinas por cada morte feminina. Os resultados indicam que a obesidade acarreta consideráveis perdas económicas para o país. Comparando os resultados com um estudo complementar que calculou os custos directos (em cuidados de saúde) da obesidade, verifica-se que a componente indirecta representa 40,2% do total dos custos da obesidade. A implementação de estratégias que prevenissem ou reduzissem a incidência e prevalência de obesidade em Portugal poderia gerar ganhos de produtividade elevados. Para conhecer a dimensão destes ganhos é necessária mais investigação sobre os benefícios clínicos e relação custo-efectividade de estratégias para a redução da obesidade.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Many terrestrial and marine systems are experiencing accelerating decline due to the effects of global change. This situation has raised concern about the consequences of biodiversity losses for ecosystem function, ecosystem service provision, and human well-being. Coastal marine habitats are a main focus of attention because they harbour a high biological diversity, are among the most productive systems of the world and present high anthropogenic interaction levels. The accelerating degradation of many terrestrial and marine systems highlights the urgent need to evaluate the consequence of biodiversity loss. Because marine biodiversity is a dynamic entity and this study was interested global change impacts, this study focused on benthic biodiversity trends over large spatial and long temporal scales. The main aim of this project was to investigate the current extent of biodiversity of the high diverse benthic coralligenous community in the Mediterranean Sea, detect its changes, and predict its future changes over broad spatial and long temporal scales. These marine communities are characterized by structural species with low growth rates and long life spans; therefore they are considered particularly sensitive to disturbances. For this purpose, this project analyzed permanent photographic plots over time at four locations in the NW Mediterranean Sea. The spatial scale of this study provided information on the level of species similarity between these locations, thus offering a solid background on the amount of large scale variability in coralligenous communities; whereas the temporal scale was fundamental to determine the natural variability in order to discriminate between changes observed due to natural factors and those related to the impact of disturbances (e.g. mass mortality events related to positive thermal temperatures, extreme catastrophic events). This study directly addressed the challenging task of analyzing quantitative biodiversity data of these high diverse marine benthic communities. Overall, the scientific knowledge gained with this research project will improve our understanding in the function of marine ecosystems and their trajectories related to global change.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Mass mortality events are increasing dramatically in all coastal marine environments. Determining the underlying causes of mass mortality events has proven difficult in the past because of the lack of prior quantitative data on populations and environmental variables. Four-year surveys of two shallow-water sponge species, Ircinia fasciculata and Sarcotragus spinosulum, were carried out in the western Mediterranean Sea. These surveys provided evidence of two severe sponge die-offs (total mortality ranging from 80 to 95% of specimens) occurring in the summers of 2008 and 2009. These events primarily affected I. fasciculata, which hosts both phototrophic and heterotrophic microsymbionts, while they did not affect S. spinosulum, which harbors only heterotrophic bacteria. We observed a significant positive correlation between the percentage of injured I. fasciculata specimens and exposure time to elevated temperature conditions in all populations, suggesting a key role of temperature in triggering mortality events. A comparative ultrastructural study of injured and healthy I. fasciculata specimens showed that cyanobacteria disappeared from injured specimens, which suggests that cyanobacterial decay could be involved in I. fasciculata mortality. A laboratory experiment confirmed that the cyanobacteria harbored by I. fasciculata displayed a significant reduction in photosynthetic efficiency in the highest temperature treatment. The sponge disease reported here led to a severe decrease in the abundance of the surveyed populations. It represents one of the most dramatic mass mortality events to date in the Mediterranean Sea

Relevância:

80.00% 80.00%

Publicador:

Resumo:

There is still limited understanding of the processes underlying benthic species dynamics in marine coastal habitats, which are of disproportionate importance in terms of productivity and biodiversity. The life-history traits of long-lived benthic species in these habitats are particularly poorly documented. In this study, we assessed decadal patterns of population dynamics for ten sponge and anthozoan species that play key structural roles in coralligenous outcrops (~25 m depth) in two areas of the NW Mediterranean Sea. This study was based on examination of a unique long-term photographic series, which allowed analysis of population dynamics over extensive spatial and time spans for the very first time. Specifically, 671 individuals were censused annually over periods of 25-, 15-, and 5-years. This long-term study quantitatively revealed a common life-history pattern among the ten studied species, despite the fact they present different growth forms. Low mortality rates (3.4% yr−1 for all species combined) and infrequent recruitment events (mean value of 3.1±0.5 SE recruits yr−1) provided only a very small fraction of the new colonies required to maintain population sizes. Overall, annual mortality and recruitment rates did not differ significantly among years; however, some species displayed important mortality events and recruitment pulses, indicating variability among species. Based on the growth rates of these 10 species, we projected their longevity and, obtained a mean estimated age of 25-200 years. Finally, the low to moderate turnover rates (mean value 0.80% yr−1) observed among the coralligenous species were in agreement with their low dynamics and persistence. These results offer solid baseline data and reveal that these habitats are among the most vulnerable to the current increases of anthropogenic disturbances.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

BACKGROUND AND OBJECTIVES: Sudden cardiac death (SCD) is a severe burden of modern medicine. Aldosterone antagonist is publicized as effective in reducing mortality in patients with heart failure (HF) or post myocardial infarction (MI). Our study aimed to assess the efficacy of AAs on mortality including SCD, hospitalization admission and several common adverse effects. METHODS: We searched Embase, PubMed, Web of Science, Cochrane library and clinicaltrial.gov for randomized controlled trials (RCTs) assigning AAs in patients with HF or post MI through May 2015. The comparator included standard medication or placebo, or both. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Event rates were compared using a random effects model. Prospective RCTs of AAs with durations of at least 8 weeks were selected if they included at least one of the following outcomes: SCD, all-cause/cardiovascular mortality, all-cause/cardiovascular hospitalization and common side effects (hyperkalemia, renal function degradation and gynecomastia). RESULTS: Data from 19,333 patients enrolled in 25 trials were included. In patients with HF, this treatment significantly reduced the risk of SCD by 19% (RR 0.81; 95% CI, 0.67-0.98; p = 0.03); all-cause mortality by 19% (RR 0.81; 95% CI, 0.74-0.88, p<0.00001) and cardiovascular death by 21% (RR 0.79; 95% CI, 0.70-0.89, p<0.00001). In patients with post-MI, the matching reduced risks were 20% (RR 0.80; 95% CI, 0.66-0.98; p = 0.03), 15% (RR 0.85; 95% CI, 0.76-0.95, p = 0.003) and 17% (RR 0.83; 95% CI, 0.74-0.94, p = 0.003), respectively. Concerning both subgroups, the relative risks respectively decreased by 19% (RR 0.81; 95% CI, 0.71-0.92; p = 0.002) for SCD, 18% (RR 0.82; 95% CI, 0.77-0.88, p < 0.0001) for all-cause mortality and 20% (RR 0.80; 95% CI, 0.74-0.87, p < 0.0001) for cardiovascular mortality in patients treated with AAs. As well, hospitalizations were significantly reduced, while common adverse effects were significantly increased. CONCLUSION: Aldosterone antagonists appear to be effective in reducing SCD and other mortality events, compared with placebo or standard medication in patients with HF and/or after a MI.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Increasing evidence suggests oceanic traits may play a key role in the genetic structuring of marine organisms. Whereas genetic breaks in the open ocean are well known in fishes and marine invertebrates, the importance of marine habitat characteristics in seabirds remains less certain. We investigated the role of oceanic transitions versus population genetic processes in driving population differentiation in a highly vagile seabird, the Cory"s shearwater, combining molecular, morphological and ecological data from 27 breeding colonies distributed across the Mediterranean (Calonectris diomedea diomedea) and the Atlantic (C. d. borealis). Genetic and biometric analyses showed a clear differentiation between Atlantic and Mediterranean Cory"s shearwaters. Ringing-recovery data indicated high site fidelity of the species, but we found some cases of dispersal among neighbouring breeding sites (<300 km) and a few long distance movements (>1000 km) within and between each basin. In agreement with this, comparison of phenotypic and genetic data revealed both current and historical dispersal events. Within each region, we did not detect any genetic substructure among archipelagos in the Atlantic, but we found a slight genetic differentiation between western and eastern breeding colonies in the Mediterranean. Accordingly, gene flow estimates suggested substantial dispersal among colonies within basins. Overall, genetic structure of the Cory"s shearwater matches main oceanographic breaks (Almería-Oran Oceanic Front and Siculo-Tunisian Strait), but spatial analyses suggest that patterns of genetic differentiation are better explained by geographic rather than oceanographic distances. In line with previous studies, genetic, phenotypic and ecological evidence supported the separation of Atlantic and Mediterranean forms, suggesting the 2 taxa should be regarded as different species.