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81.
The fitness benefits of multiple mating determine the strength of sexual selection in each sex. This is traditionally quantified by the number of offspring born to once versus multiply mated individuals. In species with (bi)parental care, however, this measure may overestimate the benefits of multiple mating since having several mates can increase offspring number but decrease offspring quality. We analyzed short- and long-term fitness consequences of multiple marriages for both sexes in humans in preindustrial Finnish populations, where monogamy was socially enforced and remarriage was possible only after widowhood. Remarriage increased the lifetime number of offspring sired by men by lengthening their reproductive span but was unrelated to the lifetime number of births for women. However, neither men's nor women's long-term fitness, measured as their number of grandchildren, was significantly increased or decreased by remarriage. These associations were not modified by individual wealth. Our results suggest that despite increasing the number of offspring sired by men, the long-term fitness benefits of serial monogamy may be negligible for both sexes when parental investment is crucial for offspring success and continues to adulthood. They also demonstrate the importance of incorporating long-term fitness measures when quantifying the benefits of mating and reproductive strategies.  相似文献   
82.
In our study, we aimed to investigate the influence of landscape patterns on the diversity of birds in four urban parks. The parks are located in a region that has a high value of regional biodiversity and is also highly urbanized (Jundiai, state of São Paulo [SP], in Southeastern Brazil). Using a set of aerial photos, the surrounding landscape was divided into two regions (rings) and corresponding landscape metrics were calculated. The presence of bird species was recorded monthly over a one‐year period and classified according to selected ecological criteria. The land cover of the areas surrounding each park was primarily buildings and residences. Bird diversity was significantly correlated with the presence/proximity of water bodies. We state that the potential of the parks to harbor bird species is not negligible. Managing the area surrounding a park to increase the percentage of forested area and the size of forest fragments is as crucial as managing the core park area, especially for improving its attractiveness for new bird species.  相似文献   
83.
Environmental Science and Pollution Research - Polypyrrole (PPy) conducting films, doped with 4-amino-3-hydroxynaphthalene sulfonic acid (AHNSA), were electrosynthesized by anodic oxidation of...  相似文献   
84.
Community structure and microcystin accumulation of freshwater molluscs were studied before and after cyanobacterial proliferations, in order to assess the impact of toxic blooms on molluscs and the risk of microcystin transfer in food web. Observed decrease in mollusc abundance and changes in species richness in highly contaminated waters were not significant; however, relative abundances of taxa (prosobranchs, pulmonates, bivalves) were significantly different before and after cyanobacterial bloom. Pulmonates constituted the dominant taxon, and bivalves never occurred after bloom. Microcystin accumulation was significantly higher in molluscs from highly (versus lowly) contaminated waters, in adults (versus juveniles) and in pulmonates (versus prosobranchs and bivalves). Results are discussed according to the ecology of molluscs, their sensitivity and their ability to detoxify.  相似文献   
85.
At the onset of the 2010 statutory deadline for the respect of the European National Emission Ceiling directive, two questions arise. Will the engaged regulations for the respect of ozone air quality thresholds be fully efficient on the most polluted regions? How can we design the continuation of ozone control in those areas? This study is based on refined 3D modelling studies over a French Mediterranean region. It compares 2001 and 2003 situations with several prospective 2010 emission scenarios with, for the first time, the evaluation of local action plans. The degree of compliance with air quality regulation is investigated and the impact of emission control on the local potential for ozone formation is discussed. The results show that current efforts on emissions, although substantial and efficient, are not sufficient yet to abrogate all the ozone threshold exceedances. They also highlight the gap between regulatory and effective emission control, as well as the need for regional regulations to complete national efforts. Finally, the simulations indicate that large-scale emission control significantly helps reducing rural ozone (?20 ppbv) but affects much fewer (?2 to ?10 ppbv) the highest peaks. The continuation and the strengthening of ozone policies under their current form in such regions are considered.  相似文献   
86.
An ensemble-trajectory analysis technique known as Quantitative Transport Bias Analysis was applied to determine which geographic areas systematically contributed to above- and below-average fine particle mass (PM2.5) over eastern North America. Six-hour average measurements from 12 rural or suburban locations in eastern North America collected using a tapered element oscillating microbalance were individually associated with corresponding 3-day back-trajectories for the warm seasons (May-September) of 2000 and 2001. Much of the populated areas of northeastern North America were implicated in the build-up of PM2.5 to above-average concentrations. The finer structure of the Quantitative Transport Bias Analysis pattern indicated that transport from the Ohio River Valley, particularly the eastern portion of this area, was most often associated with the highest PM2.5 concentrations. In addition, air masses originating over a relatively large area from southeast Ohio to the western part of Virginia and the western Kentucky to central Tennessee area tended to result in relatively high PM2.5 concentrations over northeastern North America. These observation-based findings were consistent with the spatial distribution of the main sulfur dioxide emissions sources and the major oxides of nitrogen point sources.  相似文献   
87.
Experiments have been conducted to determine diel variations in photoinduced Hg0 oxidation in lake water under natural Hg0(aq) concentrations. Pseudo-first-order rates of photooxidation (k') were calculated for water freshly collected in a Canadian Shield lake, Lake Croche (45 degrees 56' N, 74 degrees 00' W), at different periods of the day and subsequently incubated in the dark. Hg0 oxidation rates ranged from 0.02 to 0.07 h(-1), increasing from sunrise to noon and then decreasing throughout the remainder of the day. These changes paralleled those in sunlight intensity integrated over 1 h preceding water collection, and suggested that the water freshly collected in daylight was rich in photochemically produced Hg0 oxidants. It was also estimated that under intense solar radiation, even if oxidation rates reached a peak, reduction of Hg(II) was the prevalent redox process. Inversely, Hg0 oxidation overcame DGM production during the night or at periods of weaker light intensity. Overall, these findings explain the decreases in the DGM pool generally observed overnight. They also support previous reports that, during summer days, volatilization of Hg0 from water represent an important step in the Hg cycle in freshwater systems.  相似文献   
88.
Extractive reserves constitute an innovative approach to match conservation and development objectives, which were originally envisaged as part of a land struggle by forest dwellers in Brazil. In spite of the idea's popularity and the attempts to apply the concept to different tropical regions, there has been little analysis of the combined conservation and development performance of extractive reserve programs. We present a detailed analysis of deforestation and demographic and socioeconomic changes in Alto Juruá, the first extractive reserve created in Brazil in 1990. Forest cover has remained fairly stable. Population has declined slightly, with some internal displacements. The cash economy base has shifted from the original rubber production to a diversified portfolio of agriculture and livestock, and there has been a dramatic rise in nonagrarian income. We conclude that the Reserve represents a very dynamic setting with positive conservation and development outcomes during its first decade.  相似文献   
89.
Environmental Science and Pollution Research - Cadmium is inconsistently associated with blood pressure (BP) and hypertension. Our study focuses to understand the association between urinary...  相似文献   
90.
Environmental Science and Pollution Research - Massive Sargassum sp. beachings have been occurring on Caribbean shores since 2011. The sargassum involved in such events are S. fluitans and S....  相似文献   
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