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Brendan D. Cowled Michael P. Ward Shawn W. Laffan Francesca Galea M. Graeme Garner Anna J. MacDonald Ian Marsh Petra Muellner Katherine Negus Sumaiya Quasim Andrew P. Woolnough Stephen D. Sarre 《PloS one》2012,7(10)
Infectious wildlife diseases have enormous global impacts, leading to human pandemics, global biodiversity declines and socio-economic hardship. Understanding how infection persists and is transmitted in wildlife is critical for managing diseases, but our understanding is limited. Our study aim was to better understand how infectious disease persists in wildlife populations by integrating genetics, ecology and epidemiology approaches. Specifically, we aimed to determine whether environmental or host factors were stronger drivers of Salmonella persistence or transmission within a remote and isolated wild pig (Sus scrofa) population. We determined the Salmonella infection status of wild pigs. Salmonella isolates were genotyped and a range of data was collected on putative risk factors for Salmonella transmission. We a priori identified several plausible biological hypotheses for Salmonella prevalence (cross sectional study design) versus transmission (molecular case series study design) and fit the data to these models. There were 543 wild pig Salmonella observations, sampled at 93 unique locations. Salmonella prevalence was 41% (95% confidence interval [CI]: 37–45%). The median Salmonella DICE coefficient (or Salmonella genetic similarity) was 52% (interquartile range [IQR]: 42–62%). Using the traditional cross sectional prevalence study design, the only supported model was based on the hypothesis that abundance of available ecological resources determines Salmonella prevalence in wild pigs. In the molecular study design, spatial proximity and herd membership as well as some individual risk factors (sex, condition score and relative density) determined transmission between pigs. Traditional cross sectional surveys and molecular epidemiological approaches are complementary and together can enhance understanding of disease ecology: abundance of ecological resources critical for wildlife influences Salmonella prevalence, whereas Salmonella transmission is driven by local spatial, social, density and individual factors, rather than resources. This enhanced understanding has implications for the control of diseases in wildlife populations. Attempts to manage wildlife disease using simplistic density approaches do not acknowledge the complexity of disease ecology. 相似文献
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Mechanistic Approaches to Community Ecology: A New Reductionism 总被引:2,自引:0,他引:2
Mechanistic approaches to community ecology are those whichemploy individual ecological conceptsthose ofbehavioral ecology, physiological ecology, and ecomorphologyas theoretical bases for understanding community patterns. Suchapproaches, which began explicitly about a decade ago, are justnow coming into prominence. They stand in contrast to more traditionalapproaches, such as MacArthur and Levins (1967),which interpretcommunity ecology almost strictly in terms of "megaparameters.". Mechanistic approaches can be divided into those which use populationdynamics as a major component of the theory and those whichdo not; examples of the two are about equally common. The firstapproach sacrifices a highly detailed representation of individualecological processes; the second sacrifices an explicit representationof the abundance and persistence of populations. Three subdisciplines of ecologyindividual, populationand community ecologyform a "perfect" hierarchy in Beckner's(1974) sense. Two other subdisciplinesecosystem ecologyand evolutionary ecologylie somewhat laterally to thishierarchy. The modelling of community phenomena using sets ofpopulation-dynamical equations is argued as an attempt at explanationvia the reduction of community to population ecology. Much ofthe debate involving Florida State ecologists is over whetheror not such a relationship is additive (or conjunctive), a verystrong form of reduction. I argue that reduction of communityto individual ecology is plausible via a reduction of populationecology to individual ecology. Approaches that derive the population-dynamicalequations used in population and community ecology from individual-ecologicalconsiderations, and which provide a decomposition of megaparametersinto behavioral and physiological parameters, are cited as illustratinghow the reduction might be done. I argue that "sufficient parameters"generally will not enhance theoretical understanding in communityecology. A major advantage of the mechanistic approach is that variationin population and community patterns can be understood as variationin individual-ecological conditions. In addition to enrichingthe theory, this allows the best functional form to be chosenfor modeling higher-level phenomena, where "best" is definedas biologically most appropriate rather than mathematicallymost convenient. Disadvantages of the mechanistic approach arethat it may portend an overly complex, massive and special theory,and that it naturally tends to avoid many-species phenomenasuch as indirect effects. The paper ends with a scenario fora mechanistic-ecological utopia. 相似文献
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Rebecca McLain Melissa Poe Kelly Biedenweg Lee Cerveny Diane Besser Dale Blahna 《Human ecology: an interdisciplinary journal》2013,41(5):651-665
Ecosystem-based planning and management have stimulated the need to gather sociocultural values and human uses of land in formats accessible to diverse planners and researchers. Human Ecology Mapping (HEM) approaches offer promising spatial data gathering and analytical tools, while also addressing important questions about human-landscape connections. This article reviews and compares the characteristics of three HEM approaches that are increasingly used in natural resource management contexts, each focused on a particular aspect of human-environmental interactions. These aspects include tenure and resource use (TRU), local ecological knowledge (LEK), and sense of place (SOP). We discuss their origins, provide examples of their use, and identify challenges to their application. Our review serves as a guide for environmental managers, planners, and communities interested in gathering spatial data on aspects of human ecology important in ecosystem-based management and planning, and for scientists designing socioecological research. 相似文献
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Winifred Creamer 《American anthropologist》1998,100(3):796-797
Integrating Archaeological Demography: Multidisciplinary Approaches to Prehistoric Population. Richard R. Paine. ed. Carbondale: Southern Illinois University at Carbondale, 1997.396pp. 相似文献
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Linking Microbial and Ecosystem Ecology Using Ecological Stoichiometry: A Synthesis of Conceptual and Empirical Approaches 总被引:1,自引:0,他引:1
Currently, one of the biggest challenges in microbial and ecosystem ecology is to develop conceptual models that organize
the growing body of information on environmental microbiology into a clear mechanistic framework with a direct link to ecosystem
processes. Doing so will enable development of testable hypotheses to better direct future research and increase understanding
of key constraints on biogeochemical networks. Although the understanding of phenotypic and genotypic diversity of microorganisms
in the environment is rapidly accumulating, how controls on microbial physiology ultimately affect biogeochemical fluxes remains
poorly understood. We propose that insight into constraints on biogeochemical cycles can be achieved by a more rigorous evaluation
of microbial community biomass composition within the context of ecological stoichiometry. Multiple recent studies have pointed
to microbial biomass stoichiometry as an important determinant of when microorganisms retain or recycle mineral nutrients.
We identify the relevant cellular components that most likely drive changes in microbial biomass stoichiometry by defining
a conceptual model rooted in ecological stoichiometry. More importantly, we show how X-ray microanalysis (XRMA), nanoscale
secondary ion mass spectroscopy (NanoSIMS), Raman microspectroscopy, and in situ hybridization techniques (for example, FISH)
can be applied in concert to allow for direct empirical evaluation of the proposed conceptual framework. This approach links
an important piece of the ecological literature, ecological stoichiometry, with the molecular front of the microbial revolution,
in an attempt to provide new insight into how microbial physiology could constrain ecosystem processes. 相似文献
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Rebecca E. Koch Katherine L. Buchanan Stefania Casagrande Ondi Crino Damian K. Dowling Geoffrey E. Hill Wendy R. Hood Matthew McKenzie Mylene M. Mariette Daniel W.A. Noble Alexandra Pavlova Frank Seebacher Paul Sunnucks Eve Udino Craig R. White Karine Salin Antoine Stier 《Trends in ecology & evolution》2021,36(4):321-332
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SARGENT ROBERT CRAIG; RUSH VICTOR N.; WISENDEN BRIAN D.; YAN HONG Y. 《Integrative and comparative biology》1998,38(1):82-96
SYNOPSIS. Sexual selection theory predicts a coevolution betweenmale sexual ornamentation and female preference. The implicationof this prediction for sensory ecology is that there shouldbe a tight coupling between the physiology of male signal productionand the physiology of female signal reception. Indicator modelsof sexual selection predict that male ornamentation is correlatedwith male condition, and that female preference is correlatedwith male ornamentation. Indicator models of sexual selectionhave a conceptual overlap with resource acquisition and investmentmodels of behavioral ecology. Empirical studies with fishes,particularlywith guppies (Poecilia reticulata) and threespinesticklebacks (Gasterosteus aculeatus), suggest a strong connectionbetween acquired resources, male condition, male ornamentation,male courtship, and female preference. 相似文献
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Bruce T. Milne 《Ecosystems》1998,1(5):449-456
Studies of complex systems in other disciplines provide models and analytical strategies for understanding ecosystems and
landscapes. The emphasis is on invariant properties, particularly processes that create scaling relations over wide ranges
of scale, both in time and space. Translations between levels of ecological organization may be accomplished by succinct characterizations
of processes that operate at fine scales, followed by renormalization group analysis to reveal patterns at broad scales. The
self-organized patterns found in simple ecosystem, landscape, and forest-fire models may be explained as feedback between
the system state and control parameters. Critical phenomena and phase transitions are expected in open, dissipative systems
where long-range correlations defy predictions based on average population densities, a concept that becomes irrelevant as
nonstationary conditions prevail. Thus, complexity theory for open systems relates to the ecology of self-entailing ecosystems
that function as their own environments and thereby create constraints through emergence.
Received: 14 April 1998; accepted 26 May 1998 相似文献
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微生物分子生态技术:16SrRNA/DNA方法 总被引:17,自引:0,他引:17
综述了以16SrRNA/DNA为基础的分子生物学技术在环境微生物种群分析中的应用,目的是使相关的科研人员能够对16SrRNA/DNA技术有一个比较完整的了解,并可以开展初步的实验工作。主要内容包括:DNA指纹技术、16rDNA文库的建立、DNA测序及微生物分类鉴定(即系统发育树分析)、基因探针设计和测试、荧光原位杂交和核酸印迹杂交等。 相似文献
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SYNOPSIS. Studies on the relation of temperature to tolerance,preference, metabolic rate, performance, circulation, and growthof sockeye salmon all point to a physiological optimum in theregion of 15°C. Natural occurrence is limited in time andspace at temperatures above 18°C despite being able to tolerate24°C. Forms of physiological inadequacy can be demonstratedwhich account for such restrictions in distribution. Predictivepower for locating and accounting for concentrations of youngfish in thermally stratified lakes appeared to provide "proof"for the controlling influence of the physiological optimum temperature.Early literature on the ecology of sockeye supported this view.Recent studies using midwater trawls and sonar detection reveala diurnal behavior pattern which points to a more subtle interactionof biotic andabiotic factors governing vertical distributionin which the controlling force appears to be bioenergetic efficiency.It is concluded that a mechanism of behavioral thermoregulationhas evolved which favorably balances daily metabolic expendituresin order to conserve energy when food is limited. 相似文献
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The Potential of Genomic Approaches to Rotifer Ecology 总被引:1,自引:1,他引:1
Rotifers are a key component of many freshwater ecosystems, but surveys of the composition of rotifer communities are limited by the labor-intensiveness of sample processing, particularly of non-planktonic taxa, and by the shortage of investigators qualified to identify a broad range of rotifer species. Additional problems are posed by species that must be identified from living specimens, and by members of cryptic species complexes. As DNA sequencing becomes easier and cheaper, it has become practical to obtain representative DNA sequences from identified rotifer species for use in genome-based surveys to determine which rotifers are present in a new sample, avoiding the difficulties of traditional surveys. Here we discuss two genome-based tools used in surveys of microbial communities: serial analysis of gene tags (SAGT) and microarray hybridization. SAGT is a method for inexpensively obtaining characteristic short DNA sequences from a sample that can both identify taxa for which the tag sequence is known and signal the presence of additional uncharacterized species. Microarray hybridization allows detection of DNA sequences in the sample that are identical or similar to sequences present on the microarray. We also report the construction and hybridization of a small microarray of rotifer sequences, demonstrating that this method can discriminate among bdelloid families, and is likely to make much finer discriminations if appropriate sequences are present on the microarray. These techniques are most powerful when combined with traditional systematics in collaborative efforts, which may be fostered through the data base of rotifer biology, WheelBase (http://jbpc.mbl.edu/wheelbase). 相似文献
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Ambient temperatures were significantly correlated with alligator(Alligator mississippiensis) nesting activity. Nesting occurredearliest when March-April-May ambient temperatures were highest.Rainfall had no significant relationship with time of nestingactivity although water levels did affect the degree of nesting.The bulk of the nesting took place within a 2-week period eachyear. Nesting chronology and factors affecting nesting were investigatedat Rockefeller Refuge from 1964 through 1987. Courtship activitiesgenerally began in early April and progressively intensifieduntil early June. From late May through the first week of Junecourtship and copulation were intense, the females ovulated,and the high point of spermatogenesis occurred. Factors whichseriously affected nesting success were floods, droughts, andpredation. Salinity levels affected nesting densities alongthe coast. Nesting success (% of nests which produced live hatchlings)averaged 68.3% for 266 nests followed during a 4-yr study. Hatchingsuccess (% of eggs which hatched) averaged 58.2% for 154 nestsfollowed during two nesting seasons. Habitat selection, home ranges, and daily movements were delineatedfor adult males and females. Courtship occurs in deep open waterduring springtime. Adult females selectively seek out densevegetation adjacent to isolated ponds for nesting during thesummer. Adult and sub-adult males tend to prefer open waterall year round and only occasionally venture into the more secludedand heavily vegetated areas used by the females. Home rangesizes and daily movements were much larger for adult males thanfor adult females. Laboratory studies evaluated the effectsof four different egg incubation temperatures on hatching success,sex determination, size at hatching, and growth rates to 18mo of age. The results indicate that incubation temperaturecan have a profound effect on sex ratios, hatchling size, andpost-hatching growth. No significant differences were observedin hatching success at the four different temperatures. 相似文献
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Environmental stress and nutrient/productivity models predict the responses of community structure along gradients of physical conditions and bottom-up effects. Although both models have succeeded in helping to understand variation in ecological communities, most tests have been qualitative. Until recently, two roadblocks to more quantitative tests in marine environments have been a lack of (1) inexpensive, field-deployable technology for quantifying (e.g.) temperature, light, salinity, chlorophyll, and productivity, and (2) methods of quantifying the sub-organismal mechanisms linking environmental conditions to their ecological expression. The advent of inexpensive remote-sensing technology, adoption of molecular techniques such as quantification of heat-shock proteins and RNA:DNA ratios, and the formation of interdisciplinary alliances between ecologists and physiologists has begun to overcome these roadblocks. An integrated eco-physiological approach focuses on the determinants of: distributional limits among microhabitat patches and along (local-scale) environmental gradients (e.g., zonation); among-site (mesoscale) differences in community pattern; and geographic (macroscale) differences in ecosystem structure. These approaches promise new insights into the physiological mechanisms underlying variation in processes such as species interactions, physical disturbance, survival and growth. Here, we review two classes of models for community dynamics, and present examples of ecological studies of these models in consumer-prey systems. We illustrate the power of new molecular tools to characterize the sub-organismal responses of some of the same consumers and prey to thermal stress and food concentration. Ecological and physiological evidence tends to be consistent with model predictions, supporting our argument that we are poised to make major advances in the mechanistic understanding of community dynamics along key environmental gradients. 相似文献
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Multiple lines of evidence (LOE) are often considered when examining the potential impact of contaminated sediment. Three strategies are explored for combining information within and/or among different LOE. One technique uses a multivariate strategy for clustering sites into groups of similar impact. A second method employs meta-analysis to pool empirically derived P-values. The third method uses a quantitative estimation of probability derived from odds ratios. These three strategies are compared with respect to a set of data describing reference conditions and a contaminated area in the Great Lakes. Common themes in these three strategies include the critical issue of defining an appropriate set of reference/control conditions, the definition of impact as a significant departure from the normal variation observed in the reference conditions, and the use of distance from the reference distribution to define any of the effect measures. Reasons for differences in results between the three approaches are explored and strategies for improving the approaches are suggested. 相似文献