Population interactions

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  • Host Factors in Infection For any infectious process to occur, the pathogen and the host must first encounter each other. Factors such as geography, environment, and behavior thus influence the likelihood of infection. Although the initial encounter between a susceptible host and a virulent organism frequently results in disease, some organisms can be harbored in the host for years before disease becomes clinically evident. For a complete view, individual patients must be considered in the context of the population to which they belong.

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  • This book is about the distribution and abundance of different types of organism, and about the physical, chemical but especially the biological features and interactions that determine these distributions and abundances. Unlike some other sciences, the subject matter of ecology is apparent to everybody: most people have observed and pondered nature, and in this sense most people are ecologists of sorts. But ecology is not an easy science.

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  • The activity of the full-length hammerhead ribozyme requires a tertiary interaction between its distal loops leading to the closure of the molecule and its stabilization in the active conformation.

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  • The line between depressive and anxiety disorders in perinatal as well as general populations is often blurred; when the EPDS has been factor-analyzed, although there are separate factors corresponding to depression and anxiety, several items have moderate loadings on both factors (Swalm, et al., 2010). Some services refer to antenatal or postnatal “distress” rather than attempt to differentiate depression from anxiety, and often women report a mix of anxious and depressed symptoms.

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  • Contraceptive use accounts for a substantial portion of the variation in observed fertility rates (others include age of marriage, abortion rates, post- partum amenorrhea and abstinence, and occurrence of marital separations). Although there have been dramatic increases in the use of family planning services, unmet need for family planning remains very high in low-prevalence regions.

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  • Understanding and quantitative describing of marine ecosystems requires an integration of physics, chemistry and biology. The coupling between physics, which regulates for example nutrient availability and the physical position of many organisms is particularly important and thus cannot be described by biology alone. Therefore the appropriate basis for theoretical investigations of marine systems are coupled models, which integrate physical, chemical and biological interactions.

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  • Chapter 15 Ecological Applications at the Level of Population Interactions: Pest Control and Harvest Management 15.1 Introduction Humans are very much a part of all ecosystems. Our activities sometimes motivate us to drive towards extinction the species we identify as pests, to kill individuals of species we harvest for food or fiber while ensuring the persistence of their populations.

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  • Challenges to sustaining the productivity of oceanic and coastal fisheries have become more critical and complex as these fisheries reach the upper limits to ocean harvests. In addition, it is now clear that we are managing interactive and dynamic food webs rather than sets of independent single-species populations.

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  • Chapter 19 The Influence of Population Interactions on Community Structure 19.1 Introduction Individual species can influence the composition of whole communities in a variety of ways. Every species provides resources for others that prey upon or parasitize them, but some species provide a wide range of resources that are used by a large number of consumer species.

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  • Chapter 20 Food Webs In the previous chapter we began to consider how population interactions can shape communities. Our focus was on interactions between species occupying the same trophic level or between members of adjacent trophic levels.

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  • Poverty is higher in remote rural areas and in inner cities, but the rural elderly are much more likely to be poor than those living in urban areas. Thirteen percent of rural elders 60 years and older were poor in 2000, compared with nine percent of elders living in a metro area [20]. Thus we expect to find the most evidence of impeded access for the poor elderly who reside in rural areas. We interact the proportion of elderly in poverty with the proportion in rural areas to include in the model.

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  • Large herbivores are, and have for a long time been, among the major drivers for forming the shape and function of terrestrial ecosystems. These animals may modify primary production, nutrient cycles, soil properties, fire regimes as well as other biota. Some large herbivore species/populations are at the edge of extinction and great effort is being made to save them. Other species/populations are under discussion for reintroduction. Still other species occur in dense populations and cause conflicts with other land use interests.

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  • Our new insight is on the interaction between relative labor turnover dynamics and lack of insurers’ premium flexibility. A related possibility is that high labor turnover may be preferred by some employers, especially small firms that employ homogenous workers with low job-specific human capital. Workers tolerant of high turnover tend to be younger and healthier. By not offering health insurance, despite the tax advantage, these firms deter older and less healthy workers.

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  • This is an industry that is still evolving, developing, and growing. It has gone from commercial banking to syndicated transactions and equities, and more recently, into debt issuance and structured products. Its sophistication and product offerings have developed along with this change. At an earlier stage, industry growth was in part a reflection of economic growth in the Islamic world, fuelled primarily by oil wealth. This created a growing middle-wealth segment and hence made banking a necessary service to the larger segment of the population.

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  • Research show that RVT doesn’t has any side effect on fertility. In 200 cases of pregnancy after RVT 66% lead to neonate birth. Premature birth before 37th week happened in 27% of the cases. Abortion rate in first trimester was 16-20% like general population and second trimester abortion was 9.5% (Plante et al., 2005; Jolley et al., 2007). If the tumor volume is less than 500mm, tumor size is less than 2 cm and invasion depth of stroma is less than 2mm we can do ultraconservative operations include simple trachelectomy or extensive conization with knife. In this...

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  • Ageing can generally be described as the process of growing old and is an intricate part of the life cycle. Basically it is a multi-dimensional process and affects almost every aspect of human life. Introduction to the study of human ageing have typically emphasized changes in demography focusing on the ‘ageing of population’- a trend, which has characterized industrial societies throughout the twentieth century but in recent decades, has become a worldwide phenomenon.

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  • The main focus of this book is the presentation of the “inertial” view of population growth. This view provides a rather simple model for complex population dynamics, and is achieved at the level of the single species, without invoking species interactions. An important part of our account is the maternal effect. Investment of mothers in the quality of their daughters makes the rate of reproduction of the current generation depend not only on the current environment but also on the environment experienced by the preceding generation....

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  • Content can be integrated into portals and other tools using the Dialog Application Programming Interface (Dialog API), an XML-based web service that enables Dialog’s extensive content collection and renowned search engine to be integrated transparently into websites, enterprise portals, corporate intranets and extranets, software applications and other interactive services. Dialog API supports Web Services Description Language (WSDL) and Simple Object Access Protocol (SOAP) for integrating Dialog content into compatible platforms....

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  • Virtually every organism serves as the host for a complement of parasites. Parasitism is so common that it is rare to find classes of animals without members that have adopted a parasitic mode of living. Evidence gained from various archeological studies indicates that parasitic diseases existed in prehistoric human populations. Since there is no evidence to suggest that our long and intimate association with parasites will ever end, it seems reasonable to propose that the study of human parasites warrants some consideration.

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  • Despite the long-established recommendations and public health messages, the population is still failing to achieve a healthy balanced diet. To date public health messages for dietary intakes have focused on the impact on health outcomes and have not addressed any of the wider issues relating to sustainability. It is recognised that this could be complex, but it is important to add some of the wider issues of sustainability into current dietary advice if a single, consistent message about the diet is to be given to the public, government and industry.

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