153 research outputs found

    Mixtec Evangelicals

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    MIXTEC EVANGELICALS is a comparative ethnography of four Mixtec communities in Oaxaca, detailing the process by which economic migration and religious conversion combine to change the social and cultural makeup of predominantly folk-Catholic communities. The book describes the effects on the home communities of the Mixtecs who travel to northern Mexico and the United States in search of wage labor and return having converted from their rural Catholic roots to Evangelical Protestant religions. O’Connor demonstrates the ways that neoliberal policies have forced Mixtecs to migrate and how migration provides the contexts for conversion. Converts challenge the set of customs governing their Mixtec villages by refusing to participate in the Catholic ceremonies and social gatherings that are at the center of traditional village life. Home communities have responded in a number of ways—ranging from expulsion of converts to partial acceptance and adjustments within the village

    Mixtec Evangelicals

    Get PDF
    MIXTEC EVANGELICALS is a comparative ethnography of four Mixtec communities in Oaxaca, detailing the process by which economic migration and religious conversion combine to change the social and cultural makeup of predominantly folk-Catholic communities. The book describes the effects on the home communities of the Mixtecs who travel to northern Mexico and the United States in search of wage labor and return having converted from their rural Catholic roots to Evangelical Protestant religions. O’Connor demonstrates the ways that neoliberal policies have forced Mixtecs to migrate and how migration provides the contexts for conversion. Converts challenge the set of customs governing their Mixtec villages by refusing to participate in the Catholic ceremonies and social gatherings that are at the center of traditional village life. Home communities have responded in a number of ways—ranging from expulsion of converts to partial acceptance and adjustments within the village

    Mixtec Evangelicals

    Get PDF
    MIXTEC EVANGELICALS is a comparative ethnography of four Mixtec communities in Oaxaca, detailing the process by which economic migration and religious conversion combine to change the social and cultural makeup of predominantly folk-Catholic communities. The book describes the effects on the home communities of the Mixtecs who travel to northern Mexico and the United States in search of wage labor and return having converted from their rural Catholic roots to Evangelical Protestant religions. O’Connor demonstrates the ways that neoliberal policies have forced Mixtecs to migrate and how migration provides the contexts for conversion. Converts challenge the set of customs governing their Mixtec villages by refusing to participate in the Catholic ceremonies and social gatherings that are at the center of traditional village life. Home communities have responded in a number of ways—ranging from expulsion of converts to partial acceptance and adjustments within the village

    Theoretical predictions for how temperature affects the dynamics of interacting herbivores and plants

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    Concern about climate change has spurred experimental tests of how warming affects species' abundance and performance. As this body of research grows, interpretation and extrapolation to other species and systems have been limited by a lack of theory. To address the need for theory for how warming affects species interactions, we used consumer-prey models and the metabolic theory of ecology to develop quantitative predictions for how systematic differences between the temperature dependence of heterotrophic and autotrophic population growth lead to temperature-dependent herbivory. We found that herbivore and plant abundances change with temperature in proportion to the ratio of autotrophic to heterotrophic metabolic temperature dependences. This result is consistent across five different formulations of consumer-prey models and over varying resource supply rates. Two models predict that temperaturedependent herbivory causes primary producer abundance to be independent of temperature. This finding contradicts simpler extensions of metabolic theory to abundance that ignore trophic interactions, and is consistent with patterns in terrestrial ecosystems. When applied to experimental data, the model explained 77% and 66% of the variation in phytoplankton and zooplankton abundances, respectively. We suggest that metabolic theory provides a foundation for understanding the effects of temperature change on multitrophic ecological communities

    The shape of density dependence and the relationship between population growth, intraspecific competition and equilibrium population density

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    The logistic growth model is one of the most frequently used formalizations of density dependence affecting population growth, persistence and evolution. Ecological and evolutionary theory, and applications to understand population change over time often include this model. However, the assumptions and limitations of this popular model are often not well appreciated. Here, we briefly review past use of the logistic growth model and highlight limitations by deriving population growth models from underlying consumer–resource dynamics. We show that the logistic equation likely is not applicable to many biological systems. Rather, density‐regulation functions are usually non‐linear and may exhibit convex or concave curvatures depending on the biology of resources and consumers. In simple cases, the dynamics can be fully described by the Schoener model. More complex consumer dynamics show similarities to a Maynard Smith–Slatkin model. We show how population‐level parameters, such as intrinsic rates of increase and equilibrium population densities are not independent, as often assumed. Rather, they are functions of the same underlying parameters. The commonly assumed positive relationship between equilibrium population density and competitive ability is typically invalid. We propose simple relationships between intrinsic rates of increase and equilibrium population densities that capture the essence of different consumer–resource systems. Relating population level models to underlying mechanisms allows us to discuss applications to evolutionary outcomes and how these models depend on environmental conditions, like temperature via metabolic scaling. Finally, we use time‐series from microbial food chains to fit population growth models as a test case for our theoretical predictions. Our results show that density‐regulation functions need to be chosen carefully as their shapes will depend on the study system's biology. Importantly, we provide a mechanistic understanding of relationships between model parameters, which has implications for theory and for formulating biologically sound and empirically testable predictions

    Trunnion Corrosion Causing Failure in Metal-on-Polyethylene Total Hip Arthroplasty with Monolithic Femoral Components

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    We describe nine patients who had total hip arthroplasty failure [titanium alloy monolithic stem, cobalt-chromium head (32 mm or 36 mm), highly cross-linked polyethylene liner, metal socket] related to metal wear debris generated at the trunnion. Symptoms included pain with onset 2.9 years after THA. Preoperative serum cobalt metal ion levels were elevated [mean 8.8 ng/ml (normal < 0.9 ng/ml)] and were higher than chromium levels [mean 1.2 ng/ml (normal < 0.3 ng/ml)]. All patients had debridement of the periarticular soft tissues, stem retention, revision to ceramic head and new liner; two patients had acetabular revision. At early follow-up, 7 of 8 available patients did well, with improved cobalt (0.6 ng/ml) and little change in chromium levels. We recommend heightened awareness regarding this mode of failure

    The REFLECT Statement: Reporting Guidelines for Randomized Controlled Trials in Livestock and Food Safety: Explanation and Elaboration

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    Concerns about the completeness and accuracy of reporting of randomized clinical trials (RCTs) and the impact of poor reporting on decision-making have been documented in the medical field over the past several decades. Experience from RCTs in human medicine would suggest that failure to report critical trial features can be associated with biased estimated effect measures, and there is evidence to suggest similar biases occur in RCTs conducted in livestock populations. In response to these concerns, standardized guidelines for reporting RCTs were developed and implemented in human medicine. The Consolidated Standards of Reporting Trials (CONSORT) statement was first published in 1996 with a revised edition published in 2001. The CONSORT statement consists of a 22-item checklist for reporting a RCT and a flow diagram to follow the number of participants at each stage of a trial. An explanation and elaboration document not only defines and discusses the importance of each of the items, but also provides examples of how this information could be supplied in a publication. Differences between human and livestock populations necessitate modifications to the CONSORT statement to maximize its usefulness for RCTs involving livestock. These have been addressed in an extension of the CONSORT statement titled the REFLECT statement: Methods and processes of creating reporting guidelines for randomized control trials for livestock and food safety. The modifications made for livestock trials specifically addressed the common use of group housing and group allocation to intervention in livestock studies, the use of a deliberate challenge model in some trials, and common use of non-clinical outcomes, such as contamination with a foodborne pathogen. In addition, the REFLECT statement for RCTs in livestock populations proposed specific terms or further clarified terms as they pertained to livestock studies

    Recent Trends in Local-Scale Marine Biodiversity Reflect Community Structure and Human Impacts

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    The modern biodiversity crisis reflects global extinctions and local introductions. Human activities have dramatically altered rates and scales of processes that regulate biodiversity at local scales [1-7]. Reconciling the threat of global biodiversity loss [2, 4, 6-9] with recent evidence of stability at fine spatial scales [10,11] is a major challenge and requires a nuanced approach to biodiversity change that integrates ecological understanding. With a new dataset of 471 diversity time series spanning from 1962 to 2015 from marine coastal ecosystems, we tested (1) whether biodiversity changed at local scales in recent decades, and (2) whether we can ignore ecological context (e.g., proximate human impacts, trophic level, spatial scale) and still make informative inferences regarding local change. We detected a predominant signal of increasing species richness in coastal systems since 1962 in our dataset, though net species loss was associated with localized effects of anthropogenic impacts. Our geographically extensive dataset is unlikely to be a random sample of marine coastal habitats; impacted sites (3% of our time series) were underrepresented relative to their global presence. These local-scale patterns do not contradict the prospect of accelerating global extinctions [2,4,6-9] but are consistent with local species loss in areas with direct human impacts and increases in diversity due to invasions and range expansions in lower impact areas. Attempts to detect and understand local biodiversity trends are incomplete without information on local human activities and ecological context

    The REFLECT Statement: Methods and Processes of Creating Reporting Guidelines for Randomized Controlled Trials for Livestock and Food Safety by Modifying the CONSORT Statement

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    The conduct of randomized controlled trials in livestock with production, health and food-safety outcomes presents unique challenges that may not be adequately reported in trial reports. The objective of this project was to modify the CONSORT (Consolidated Standards of Reporting Trials) statement to reflect the unique aspects of reporting these livestock trials. A 2-day consensus meeting was held on 18–19 November 2008 in Chicago, IL, USA, to achieve the objective. Prior to the meeting, a Web-based survey was conducted to identify issues for discussion. The 24 attendees were biostatisticians, epidemiologists, food-safety researchers, livestock-production specialists, journal editors, assistant editors and associate editors. Prior to the meeting, the attendees completed a Web-based survey indicating which CONSORT statement items may need to be modified to address unique issues for livestock trials. The consensus meeting resulted in the production of the REFLECT (Reporting Guidelines for Randomized Control Trials) statement for livestock and food safety and 22-item checklist. Fourteen items were modified from the CONSORT checklist and an additional sub-item was proposed to address challenge trials. The REFLECT statement proposes new terminology, more consistent with common usage in livestock production, to describe study subjects. Evidence was not always available to support modification to or inclusion of an item. The use of the REFLECT statement, which addresses issues unique to livestock trials, should improve the quality of reporting and design for trials reporting production, health and food-safety outcomes

    Does fish larval dispersal differ between high and low latitudes?

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    Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of The Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society B Biological Sciences 280 (2013): 20130327, doi:10.1098/rspb.2013.0327.Several factors lead to expectations that the scale of larval dispersal and population connectivity of marine animals differs with latitude. We examine this expectation for demersal shorefishes, including relevant mechanisms, assumptions, and evidence. We explore latitudinal differences in: 1) biological (e.g., species composition, spawning mode, pelagic larval duration (PLD)), 2) physical (e.g., water movement, habitat fragmentation), and 3) biophysical factors (primarily temperature, which could strongly affect development, swimming ability, or feeding). Latitudinal differences exist in taxonomic composition, habitat fragmentation, temperature, and larval swimming, and each could influence larval dispersal. Nevertheless, clear evidence for latitudinal differences in larval dispersal at the level of broad faunas is lacking. For example, PLD is strongly influenced by taxon, habitat, and geographic region, but no independent latitudinal trend is present in published PLD values. Any trends in larval dispersal may be obscured by a lack of appropriate information, or use of ‘off the shelf’ information that is biased with regard to the species assemblages in areas of concern. Biases may also be introduced from latitudinal differences in taxa or spawning modes, as well as limited latitudinal sampling. We suggest research to make progress on the question of latitudinal trends in larval dispersal.TK was supported by the Norwegian Research Council through project MENUII #190286. JML was supported by ARC Discovery Grant DP110100695. JEC and RRW were supported by the Partnership for the Interdisciplinary Study of Coastal Oceans, funded by The David and Lucille Packard Foundation and the Gordon and Betty Moore Foundation.2014-03-2
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