914 resultados para Community-level effects
Resumo:
Males in many animal species differ greatly from females in morphology, physiology and behaviour. Ants, bees and wasps have a haplodiploid mechanism of sex determination whereby unfertilized eggs become males while fertilized eggs become females. However, many species also have a low frequency of diploid males, which are thought to develop from diploid eggs when individuals are homozygous at one or more sex determination loci. Diploid males are morphologically similar to haploids, though often larger and typically sterile. To determine how ploidy level and sex-locus genotype affect gene expression during development, we compared expression patterns between diploid males, haploid males and females (queens) at three developmental timepoints in Solenopsis invicta. In pupae, gene expression profiles of diploid males were very different from those of haploid males but nearly identical to those of queens. An unexpected shift in expression patterns emerged soon after adult eclosion, with diploid male patterns diverging from those of queens to resemble those of haploid males, a pattern retained in older adults. The finding that ploidy level effects on early gene expression override sex effects (including genes implicated in sperm production and pheromone production/perception) may explain diploid male sterility and lack of worker discrimination against them during development.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
The Division of Community Action Agencies is located within the Iowa Department of Human Rights and is the focal point for Community Action Agency activities within Iowa government. The Division of Community Action Agencies exists to develop and expand the capacity at the community level to assist families and individuals to achieve economic and social self-sufficiency, and to ensure that the basic energy needs of Iowa’s low-income population are met. The Division is comprised of the Bureau of Community Services, the Bureau of Energy Assistance and the Bureau of Weatherization.
Resumo:
Different components of global change can have interacting effects on biodiversity and this may influence our ability to detect the specific consequences of climate change through biodiversity indicators. Here, we analyze whether climate change indicators can be affected by land use dynamics that are not directly determined by climate change. To this aim, we analyzed three community-level indicators of climate change impacts that are based on the optimal thermal environment and averagelatitude of the distribution of bird species present at local communities. We used multiple regression models to relate the variation in climate change indicators to: i) environmental temperature; and ii) three landscape gradients reflecting important current land use change processes (land abandonment, fire impacts and urbanization), all of them having forest areas at their positive extremes. We found that, with few exceptions, landscape gradients determined the figures of climate change indicators as strongly as temperature. Bird communities in forest habitats had colder-dwelling bird species with more northerndistributions than farmland, burnt or urban areas. Our results show that land use changes can reverse, hide or exacerbate our perception of climate change impacts when measured through community-level climate change indicators. We stress the need of an explicit incorporation of the interactions between climate change and land use dynamics to understand what are current climate change indicators indicating and be able to isolate real climate change impacts
Resumo:
Community-level patterns of functional traits relate to community assembly and ecosystem functioning. By modelling the changes of different indices describing such patterns - trait means, extremes and diversity in communities - as a function of abiotic gradients, we could understand their drivers and build projections of the impact of global change on the functional components of biodiversity. We used five plant functional traits (vegetative height, specific leaf area, leaf dry matter content, leaf nitrogen content and seed mass) and non-woody vegetation plots to model several indices depicting community-level patterns of functional traits from a set of abiotic environmental variables (topographic, climatic and edaphic) over contrasting environmental conditions in a mountainous landscape. We performed a variation partitioning analysis to assess the relative importance of these variables for predicting patterns of functional traits in communities, and projected the best models under several climate change scenarios to examine future potential changes in vegetation functional properties. Not all indices of trait patterns within communities could be modelled with the same level of accuracy: the models for mean and extreme values of functional traits provided substantially better predictive accuracy than the models calibrated for diversity indices. Topographic and climatic factors were more important predictors of functional trait patterns within communities than edaphic predictors. Overall, model projections forecast an increase in mean vegetation height and in mean specific leaf area following climate warming. This trend was important at mid elevation particularly between 1000 and 2000 m asl. With this study we showed that topographic, climatic and edaphic variables can successfully model descriptors of community-level patterns of plant functional traits such as mean and extreme trait values. However, which factors determine the diversity of functional traits in plant communities remains unclear and requires more investigations.
Resumo:
Airborne particles can come from a variety of sources and contain variable chemical constituents. Some particles are formed by natural processes, such as volcanoes, erosion, sea spray, and forest fires, while other are formed by anthropogenic processes, such as industrial- and motor vehicle-related combustion, road-related wear, and mining. In general, larger particles (those greater than 2.5 μm) are formed by mechanical processes, while those less than 2.5 μm are formed by combustion processes. The chemical composition of particles is highly influenced by the source: for combustion-related particles, factors such as temperature of combustion, fuel type, and presence of oxygen or other gases can also have a large impact on PM composition. These differences can often be observed at a regional level, such as the greater sulphate-composition of PM in regions that burn coal for electricity production (which contains sulphur) versus regions that do not. Most countries maintain air monitoring networks, and studies based on the resulting data are the most common basis for epidemiology studies on the health effects of PM. Data from these monitoring stations can be used to evaluate the relationship between community-level exposure to ambient particles and health outcomes (i.e., morbidity or mortality from various causes). Respiratory and cardiovascular outcomes are the most commonly assessed, although studies have also considered other related specific outcomes such as diabetes and congenital heart disease. The data on particle characteristics is usually not very detailed and most often includes some combination of PM2.5, PM10, sulphate, and NO2. Other descriptors that are less commonly found include particle number (ultrafine particles), metal components of PM, local traffic intensity, and EC/OC. Measures of association are usually reported per 10 μg/m3 or interquartile range increase in pollutant concentration. As the exposure data are taken from regional monitoring stations, the measurements are not representative of an individual's exposure. Particle size is an important descriptor for understanding where in the human respiratory system the particles will deposit: as a general rule, smaller particles penetrate to deeper regions of the lungs. Initial studies on the health effects of particulate matter focused on mass of the particles, including either all particles (often termed total suspended particulate or TSP) or PM10 (all particles with an aerodynamic diameter less than 10 μm). More recently, studies have considered both PM10 and PM2.5, with the latter corresponding more directly to combustion-related processes. UFPs are a dominant source of particles in terms of PNC, yet are negligible in terms of mass. Very few epidemiology studies have measured the effect of UFPs on health; however, the numbers of studies on this topic are increasing. In addition to size, chemical composition is of importance when understanding the toxicity of particles. Some studies consider the composition of particles in addition to mass; however this is not common, in part due the cost and labour involved in such analyses.