Download or read book Complexity in Host pathogen Dynamics written by Yang Xie and published by . This book was released on 2015 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging infectious diseases impact both human and wildlife populations. Infectious agents, in particular the aquatic fungus Batrachochytrium dendrobatidis (chytrid), have an influential role in driving global amphibian population declines. The emergence of the chytrid fungus has aspects of both geographic spread as well as climate shifts altering environmental conditions and host-pathogen interactions. My dissertation examines the spatial spread of chytrid by host dispersal at the metapopulation level, as well as how spatial risk from chytrid is associated with the climate. In Chapter 2 of my thesis, I examine preexisting conclusions in the wildlife disease literature on the relationship between disease spread mediated by host dispersal and metapopulation persistence. I show how explicit inclusion of local dynamics and dispersal-induced synchronization alters conclusions derived by previous metapopulation disease models. Contrary to existing models that do not include explicit local dynamics, I find that synchronization increases metapopulation extinction risks and regional persistence is optimized at intermediate dispersal levels when disease transmission rate from external sources are low. However, at high rates of external infections, I come to the similar conclusion that increased dispersal monotonically increases metapopulation persistence. In Chapter 3, I use a spatially explicit, individual-based model to simulation disease spread dynamics in a set of connected mountain yellow-legged frog population. I compare the simulated disease forecasts to field data, and test for the sensitivity of these results to assumptions of host dispersal potential. I find that chytrid is able to spread across the majority of the metapopulation even with assumptions of low host dispersal potential and that metapopulation extinction rate increases with increased host dispersal. In Chapter 4, I examine how chytrid distribution is influenced by climatic variables based on the most comprehensive and up-to-date set of global chytrid surveillance data. Using a machine learning algorithm, I generate predictions showing how chytrid distributions might be expected to change according to IPCC projected scenarios of future climate change. I conclude that chytrid distribution is likely to shift to higher altitudes and latitudes with overall increases in environmental suitability in the high latitudes of the Northern Hemisphere. The chosen input climatic variables yields excellent performance when predicting chytrid occurrence at a site, but no single variable has dominant predictive power. My dissertation provides insight into the applicability of conclusions derived from existing metapopulation disease models to specific conservation contexts. Much research has been invested in the chytrid-amphibian system at the individual and population level, yet how disease management might integrate into conservation planning targeted at the metapopulation level remains largely unknown. My research will form an important part in addressing amphibian conservation in spatially-fragmented, pathogen-ridden landscapes, which is especially important in today's changing climate.
Download or read book Disease Ecology written by Sharon K. Collinge and published by Oxford University Press. This book was released on 2006-01-26 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many infectious diseases of recent concern, including malaria, cholera, plague, and Lyme disease, have emerged from complex ecological communities, involving multiple hosts and their associated parasites. Several of these diseases appear to be influenced by human impacts on the environment, such as intensive agriculture, clear-cut forestry, and habitat loss and fragmentation; such environmental impacts may affect many species that occur at trophic levels below or above the host community. These observations suggest that the prevalence of both human and wildlife diseases may be altered in unanticipated ways by changes in the structure and composition of ecological communities. Predicting the epidemiological ramifications of such alteration in community composition will require strengthening the current union between community ecology and epidemiology. Disease Ecology highlights exciting advances in theoretical and empirical research towards understanding the importance of community structure in the emergence of infectious diseases. To date, research on host-parasite systems has tended to explore a limited set of community interactions, such as a community of host species infected by a single parasite species, or a community of parasites infecting a single host. Less effort has been devoted to addressing additional complications, such as multiple-host-multiple-parasite systems, sequential hosts acting on different trophic levels, alternate hosts with spatially varying interactions, effects arising from trophic levels other than those of hosts and parasites, or stochastic effects resulting from small population size in at least one alternate host species. The chapters in this book illustrate aspects of community ecology that influence pathogen transmission rates and disease dynamics in a wide variety of study systems. The innovative studies presented in Disease Ecology communicate a clear message: studies of epidemiology can be approached from the perspective of community ecology, and students of community ecology can contribute significantly to epidemiology.
Download or read book Disease Ecology written by Sharon K. Collinge and published by Oxford University Press. This book was released on 2006-01-26 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: The chapters in this book llustrate aspects of communityy ecology that influence pathogen transmission rates and disease dynamics in a wide variety of study systems.
Download or read book Environmental Influences on Host pathogen Dynamics of the Amphibian Chytrid Fungus written by Julia C. Buck and published by . This book was released on 2013 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: The causes of the global biodiversity crisis are varied and complex. Anthropogenic threats may act in isolation, or interact additively or synergistically with each other or with natural stressors to affect sensitive taxa. The recent emergence of many infectious diseases in wildlife has brought attention to the role of disease in population declines and species extinctions. Both abiotic and biotic components of the environment may mitigate or exacerbate effects of pathogens on their hosts through direct or indirect mechanisms. The effects of the environment on host-pathogen dynamics are complex, context-dependent, and in need of further examination. One particularly sensitive group, amphibians, is at the leading edge of the sixth mass extinction. The emerging infectious disease (EID) chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatis (Bd), is implicated in population declines and extinctions of amphibians globally. My disseration addresses questions pertaining to environmental influences on disease dynamics of Bd. As described in chapter 1, various abiotic and biotic components of the environment may affect host-pathogen dynamics of Bd, resulting in changes to the dynamics of Bd transmission and spread. Chapter 2 examines the influence of an abiotic factor, the insecticide (carbaryl) and three different assemblages of larval Pacific treefrogs (Pseudacris regilla) and Cascades frogs (Rana cascadae) on host-pathogen dynamics of Bd within a community context. I found separate effects of each treatment on amphibian growth and development, but no interactive effects among the treatments. However, Bd appeared to reduce phytoplankton abundance and increase periphyton biomass, an unexpected result that merited further investigation. One possible explanation for the results described in chapter 2 is that zooplankton might consume Bd zoospores, the infective stage of the pathogen, a hypothesis that I examine in chapter 3. I conducted laboratory experiments and confirmed the presence of Bd zoospores in the gut of Daphnia sp. through quantitative PCR and visual inspection. I discuss conservation implications of this finding. To determine whether predation on Bd zoospores by zooplankton could reduce infection in amphibians, I conducted a mesocosm experiment, which is described in chapter 4. I found complex effects on species interactions: competition between larval Cascades frogs and zooplankton for phytoplankton resources reduced phytoplankton concentration, zooplankton abundance, and survival of amphibians. These effects were diminished in the presence of Bd, suggesting that zooplankton may have at least partially substituted Bd zoospores for phytoplankton in their diet, thus stimulating competitive release. However, competitive effects between zooplankton and larval amphibians overshadowed indirect positive benefits of zooplankton predation on Bd zoospores. In chapter 4, competitive effects between zooplankton and larval amphibians for phytoplankton suggested that host-pathogen dynamics might be affected by the host???s supply of resources. Chapter 5 describes a mesocosm experiment that examined how eutrophication might affect Bd-infected Pacific treefrogs and other members of the aquatic community. Nutrient additions caused increased algal growth, which benefitted herbivorous larval amphibians. Larvae exposed to Bd altered their growth, development, and diet, and allocated resources differently than unexposed individuals. However, nutrient supplementation did not alter the response of larval amphibians to Bd. As described in chapter 6, consideration of hosts and pathogens as functional members of the ecological communities in which they exist can lead to important insights in host-pathogen dynamics. My PhD research may contribute to control measures for the emerging infectious disease chytridiomycosis.
Download or read book Wildlife Disease Ecology written by Kenneth Wilson and published by Cambridge University Press. This book was released on 2019-11-14 with total page 693 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduces readers to key case studies that illustrate how theory and data can be integrated to understand wildlife disease ecology.
Download or read book Evolutionary Dynamics of Plant Pathogen Interactions written by Jeremy J. Burdon and published by Cambridge University Press. This book was released on 2019-01-31 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: A broad view of plant-pathogen interactions illustrating the fundamental reciprocal role pathogens and hosts play in shaping each other's ecology and evolution.
Download or read book Parasite Communities Patterns and Processes written by Gerald W. Esch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: We first discussed the possibility of organizing a symposium on helminth communities in June, 1986. At that time, we were engaged in writing a joint paper on potential structuring mechanisms in helminth communities; we disagreed on a number of issues. We felt the reason for such debate was because the discipline was in a great state of flux, with many new concepts and approaches being introduced with increasing frequency. After consider able discussion about the need, scope and the inevitable limitations of such a symposium, we decided that the time was ripe to bring other ecologists, engaged in similar research, face-to-face. There were many individuals from whom to choose; we selected those who were actively publishing on helminth communities or those who had expertise in areas which we felt were particularly appropriate. We compiled a list of potential participants, contacted them and received unanimous support to organize such a symposium. Our intent was to cover several broad areas, fully recognizing that breadth negates depth (at least with a publisher's limitation on the number of pages). We felt it important to consider patterns amongst different kinds of hosts because this is where we had disagreed among ourselves.
Download or read book The Stockholm Paradigm written by Daniel R. Brooks and published by University of Chicago Press. This book was released on 2019-07-19 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contemporary crisis of emerging disease has been a century and a half in the making. Human, veterinary, and crop health practitioners convinced themselves that disease could be controlled by medicating the sick, vaccinating those at risk, and eradicating the parts of the biosphere responsible for disease transmission. Evolutionary biologists assured themselves that coevolution between pathogens and hosts provided a firewall against disease emergence in new hosts. Most climate scientists made no connection between climate changes and disease. None of these traditional perspectives anticipated the onslaught of emerging infectious diseases confronting humanity today. As this book reveals, a new understanding of the evolution of pathogen-host systems, called the Stockholm Paradigm, explains what is happening. The planet is a minefield of pathogens with preexisting capacities to infect susceptible but unexposed hosts, needing only the opportunity for contact. Climate change has always been the major catalyst for such new opportunities, because it disrupts local ecosystem structure and allows pathogens and hosts to move. Once pathogens expand to new hosts, novel variants may emerge, each with new infection capacities. Mathematical models and real-world examples uniformly support these ideas. Emerging disease is thus one of the greatest climate change–related threats confronting humanity. Even without deadly global catastrophes on the scale of the 1918 Spanish Influenza pandemic, emerging diseases cost humanity more than a trillion dollars per year in treatment and lost productivity. But while time is short, the danger is great, and we are largely unprepared, the Stockholm Paradigm offers hope for managing the crisis. By using the DAMA (document, assess, monitor, act) protocol, we can “anticipate to mitigate” emerging disease, buying time and saving money while we search for more effective ways to cope with this challenge.
Download or read book Host Manipulation by Parasites written by David P. Hughes and published by Oxford University Press. This book was released on 2012-06-07 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parasites that manipulate the behaviour of their hosts represent striking examples of adaptation by natural selection. This text provides an authoritative review of host manipulation by parasites that assesses developments in the field and lays out a framework for future research.
Download or read book Ecology of Infectious Diseases in Natural Populations written by B. T. Grenfell and published by Cambridge University Press. This book was released on 1995-09-07 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: A combination of ecology and epidemiology in natural, unmanaged, animal and plant populations.
Download or read book Complex Population Dynamics written by Peter Turchin and published by Princeton University Press. This book was released on 2013-02-15 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Why do organisms become extremely abundant one year and then seem to disappear a few years later? Why do population outbreaks in particular species happen more or less regularly in certain locations, but only irregularly (or never at all) in other locations? Complex population dynamics have fascinated biologists for decades. By bringing together mathematical models, statistical analyses, and field experiments, this book offers a comprehensive new synthesis of the theory of population oscillations. Peter Turchin first reviews the conceptual tools that ecologists use to investigate population oscillations, introducing population modeling and the statistical analysis of time series data. He then provides an in-depth discussion of several case studies--including the larch budmoth, southern pine beetle, red grouse, voles and lemmings, snowshoe hare, and ungulates--to develop a new analysis of the mechanisms that drive population oscillations in nature. Through such work, the author argues, ecologists can develop general laws of population dynamics that will help turn ecology into a truly quantitative and predictive science. Complex Population Dynamics integrates theoretical and empirical studies into a major new synthesis of current knowledge about population dynamics. It is also a pioneering work that sets the course for ecology's future as a predictive science.
Download or read book Janeway s Immunobiology written by Kenneth Murphy and published by Garland Science. This book was released on 2010-06-22 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Janeway's Immunobiology CD-ROM, Immunobiology Interactive, is included with each book, and can be purchased separately. It contains animations and videos with voiceover narration, as well as the figures from the text for presentation purposes.
Download or read book Occupancy Estimation and Modeling written by Darryl I. MacKenzie and published by Elsevier. This book was released on 2017-11-17 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: Occupancy Estimation and Modeling: Inferring Patterns and Dynamics of Species Occurrence, Second Edition, provides a synthesis of model-based approaches for analyzing presence-absence data, allowing for imperfect detection. Beginning from the relatively simple case of estimating the proportion of area or sampling units occupied at the time of surveying, the authors describe a wide variety of extensions that have been developed since the early 2000s. This provides an improved insight about species and community ecology, including, detection heterogeneity; correlated detections; spatial autocorrelation; multiple states or classes of occupancy; changes in occupancy over time; species co-occurrence; community-level modeling, and more. Occupancy Estimation and Modeling: Inferring Patterns and Dynamics of Species Occurrence, Second Edition has been greatly expanded and detail is provided regarding the estimation methods and examples of their application are given. Important study design recommendations are also covered to give a well rounded view of modeling. - Provides authoritative insights into the latest in occupancy modeling - Examines the latest methods in analyzing detection/no detection data surveys - Addresses critical issues of imperfect detectability and its effects on species occurrence estimation - Discusses important study design considerations such as defining sample units, sample size determination and optimal effort allocation
Download or read book Plant Pathology written by Christian Joseph Cumagun and published by BoD – Books on Demand. This book was released on 2012-04-04 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant pathology is an applied science that deals with the nature, causes and control of plant diseases in agriculture and forestry. The vital role of plant pathology in attaining food security and food safety for the world cannot be overemphasized.
Download or read book The Causes of Evolution written by John Burdon Haldane and published by Princeton University Press. This book was released on 1990-10-10 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: J.B.S. Haldane (1892-1964), one of the founders of the science of population genetics, was also one of the greatest practitioners of the art of explaining science to the layperson. Haldane was a superb story-teller, as his essays and his children's books attest. In The Causes of Evolution he not only helped to marry the new science of genetics to the older one of evolutionary theory but also provided an accessible introduction to the genetical basis of evolution by natural selection. Egbert Leigh's new introduction to this classic work places it in the context of the ongoing study of evolution. Describing Haldane's refusal to be confined by a "System" as a "light-hearted" one, Leigh points out that we are now finding that "Haldane's questions are the appropriate next stage in learning how adaptation can evolve. We are now ready to reap the benefit of the fact that Haldane was a free man in the sense that really matters."
Download or read book The Epidemiology of Plant Diseases written by B. Michael Cooke and published by Springer Science & Business Media. This book was released on 2006-06-18 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant disease epidemiology is a dynamic science that forms an essential part of the study of plant pathology. This book brings together a team of 35 international experts. Each chapter deals with an essential component of the subject and allows the reader to fully understand how each exerts its influence on the progress of pathogen populations in plant populations over a defined time scale. This edition has new, revised and updated chapters.
Download or read book Molecular Aspects of Plant Pathogen Interaction written by Archana Singh and published by Springer. This book was released on 2018-02-15 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book offers an integrated overview of plant–pathogen interactions. It discusses all the steps in the pathway, from the microbe–host-cell interface and the plant’s recognition of the microbe to the plant’s defense response and biochemical alterations to achieve tolerance / resistance. It also sheds light on the classes of pathogens (bacteria, fungus and viruses); effector molecules, such as PAMPs; receptor molecules like PRRs and NBS-LRR proteins; signaling components like MAPKs; regulatory molecules, such as phytohormones and miRNA; transcription factors, such as WRKY; defense-related proteins such as PR-proteins; and defensive metabolites like secondary metabolites. In addition, it examines the role of post-genomics, high-throughput technology (transcriptomics and proteomics) in studying pathogen outbreaks causing crop losses in a number of plants. Providing a comprehensive picture of plant-pathogen interaction, the updated information included in this book is valuable for all those involved in crop improvement.
