612 research outputs found

    Occurrence of Salmonella-Specific Bacteriophages in Swine Feces Collected from Commercial Farms

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    Salmonella is one of the leading causes of human foodborne illness and is associated with swine production. Bacteriophages are naturally occurring viruses that prey on bacteria and have been suggested as a potential intervention strategy to reduce Salmonella levels in food animals on the farm and in the lairage period. If phages are to be used to improve food safety, then we must understand the incidence and natural ecology of both phages and their hosts in the intestinal environment. This study investigates the incidence of phages that are active against Salmonella spp. in the feces of commercial finishing swine. Fecal samples (n = 60) were collected from each of 10 commercial swine finishing operations. Samples were collected from 10 randomly selected pens throughout each operation; a total of 600 fecal samples were collected. Salmonella spp. were found in 7.3% (44/600) of the fecal samples. Bacteriophages were isolated from fecal samples through two parallel methods: (1) initial enrichment in Salmonella Typhimurium; (2) initial enrichment in Escherichia coli B (an indicator strain), followed by direct spot testing against Salmonella Typhimurium. Bacteriophages active against Salmonella Typhimurium were isolated from 1% (6/600) of the individual fecal samples when initially enriched in Salmonella Typhimurium, but E. coli B-killing phages were isolated from 48.3% (290/600) of the fecal samples and only two of these phages infected Salmonella Typhimurium on secondary plating. Collectively, our results indicate that bacteriophages are widespread in commercial swine, but those capable of killing Salmonella Typhimurium may be present at relatively low population levels. These results indicate that phages (predator) populations may vary along with Salmonella (prey) populations; and that phages could potentially be used as a food safety pathogen reduction strategy in swine

    Evaluation of Phage Treatment as a Strategy to Reduce Salmonella Populations in Growing Swine

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    Salmonella is a foodborne pathogenic bacterium that causes human illnesses and morbidity and mortality in swine. Bacteriophages are viruses that prey on bacteria and are naturally found in many microbial environments, including the gut of food animals, and have been suggested as a potential intervention strategy to reduce Salmonella levels in the live animal. The present study was designed to determine if anti-Salmonella phages isolated from the feces of commercial finishing swine could reduce gastrointestinal populations of the foodborne pathogen Salmonella Typhimurium in artificially inoculated swine. Weaned pigs (n = 48) were randomly assigned to two treatment groups (control or phage-treated). Each pig was inoculated with Salmonella Typhimurium (2 × 1010 colony forming units/pig) via oral gavage at 0 h and fecal samples were collected every 24 h. Swine were inoculated with a phage cocktail via oral gavage (3 × 109 plaque forming units) at 24 and 48 h. Pigs were humanely killed at 96 h, and cecal and rectal intestinal contents were collected for quantitative and qualitative analysis. Fecal Salmonella populations in phage-treated pigs were lower (p \u3c 0.09) than controls after 48 h. Phage treatment reduced intestinal populations of inoculated Salmonella Typhimurium in pigs compared to controls at necropsy. Cecal populations were reduced (p = 0.07) by phage treatment \u3e1.4 log10 colony forming units/g digesta, and rectal populations were numerically reduced. The number of pigs that contained inoculated Salmonella Typhimurium was reduced by phage treatment, but a significant (p \u3c 0.05) reduction was only observed in the rectum. We conclude that phages can be a viable tool to reduce Salmonella in swine. Further research needs to be performed to determine the most efficacious dosing regimens and the most effective combinations of phages targeting the diverse Salmonella population found in swine before they can enter the food supply

    Retirement from sport and the loss of athletic identity

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    The purpose of this study was to examine how a sample of elite athletes coped with distressful reactions to retirement from sport. As part of a larger research project, 15 former elite athletes were identified as having experienced severe emotional difficulties upon athletic career termination. Through use of a micronarrative methodology, it was determined that account making can be a significant moderator of distress during the career transition process. In addition, the quality of the account making was found to be related to present affect and overall success in coping with athletic retirement. Finally, changes in athletic identity were found to be significant determinants of adjustment for athletes upon career termination. Suggestions are presented for future research on treatment strategies for distressful reactions to retirement from sport

    Feeding back about eco-feedback: How do consumers use and respond to energy monitors?

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    To date, a multitude of studies have examined the empirical effect of feedback on energy consumption yet very few have examined how feedback might work and the processes it involves. Moreover, it remains to be seen if the theoretical claims made concerning how feedback works can be substantiated using empirical data. To start to address this knowledge gap, the present research used qualitative data analysis to examine how consumers use and respond to energy monitors. The findings suggest feedback may increase both the physical and conscious visibility of consumption as well as knowledge about consumption. Accordingly, support was evident for the theoretical assertions that feedback transforms energy from invisible to visible, prompts motivated users to learn about their energy habits, and helps address information deficits about energy usage. We conclude by evaluating the feasibility of feedback to substantially reduce consumption and discuss ways in which feedback could be improved to aid its effectiveness in the long term before discussing the implication our findings may have for government policy

    Working landscapes need at least 20% native habitat

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    International agreements aim to conserve 17% of Earth's land area by 2020 but include no area‐based conservation targets within the working landscapes that support human needs through farming, ranching, and forestry. Through a review of country‐level legislation, we found that just 38% of countries have minimum area requirements for conserving native habitats within working landscapes. We argue for increasing native habitats to at least 20% of working landscape area where it is below this minimum. Such target has benefits for food security, nature's contributions to people, and the connectivity and effectiveness of protected area networks in biomes in which protected areas are underrepresented. We also argue for maintaining native habitat at higher levels where it currently exceeds the 20% minimum, and performed a literature review that shows that even more than 50% native habitat restoration is needed in particular landscapes. The post‐2020 Global Biodiversity Framework is an opportune moment to include a minimum habitat restoration target for working landscapes that contributes to, but does not compete with, initiatives for expanding protected areas, the UN Decade on Ecosystem Restoration (2021–2030) and the UN Sustainable Development Goals

    The Skewness of Commodity Futures Returns

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    This article studies the relation between the skewness of commodity futures returns and expected returns. A trading strategy that takes long positions in commodity futures with the most negative skew and shorts those with the most positive skew generates significant excess returns that remain after controlling for exposure to well-known risk factors. A tradeable skewness factor explains the cross-section of commodity futures returns beyond exposures to standard risk premia. The impact that skewness has on future returns is explained by investors’ preferences for skewness under cumulative prospect theory and selective hedging practices

    Rethinking the concept of labour

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    Is labour a useful concept for anthropology today? This essay attempts to respond theoretically to the challenge that the contributions to this special issue empirically pose. The essay rethinks the concept of labour by addressing three questions that deal with the relation of human work effort and capital accumulation: the first refers to alienation; the second to the difference between abstract and concrete labour; and the third to ambiguity. Over the years, these issues have addressed particular aspects of social reproduction, helping define labour as a concept, albeit a heterogeneous one, that is relationally linked to capital. Dislocation, together with the parallel concepts of dispossession, disorganization, disconnection, and differentiation, emerges prominently in the analyses of contemporary labour transformations and specificities. Finally, the essay engages with seemingly disappearing labour futures and what this means for the concept of labour. What is the value of work for capital and, conversely, the value of labouring for people today

    Gravel-bed river floodplains are the ecological nexus of glaciated mountain landscapes

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    Sherpa Romeo green journal: open accessGravel-bed river floodplains in mountain landscapes disproportionately concentrate diverse habitats, nutrient cycling, productivity of biota, and species interactions. Although stream ecologists know that river channel and floodplain habitats used by aquatic organisms are maintained by hydrologic regimes that mobilize gravel-bed sediments, terrestrial ecologists have largely been unaware of the importance of floodplain structures and processes to the life requirements of a wide variety of species. We provide insight into gravel-bed rivers as the ecological nexus of glaciated mountain landscapes. We show why gravel-bed river floodplains are the primary arena where interactions take place among aquatic, avian, and terrestrial species from microbes to grizzly bears and provide essential connectivity as corridors for movement for both aquatic and terrestrial species. Paradoxically, gravel-bed river floodplains are also disproportionately unprotected where human developments are concentrated. Structural modifications to floodplains such as roads, railways, and housing and hydrologicaltering hydroelectric or water storage dams have severe impacts to floodplain habitat diversity and productivity, restrict local and regional connectivity, and reduce the resilience of both aquatic and terrestrial species, including adaptation to climate change. To be effective, conservation efforts in glaciated mountain landscapes intended to benefit the widest variety of organisms need a paradigm shift that has gravel-bed rivers and their floodplains as the central focus and that prioritizes the maintenance or restoration of the intact structure and processes of these critically important systems throughout their length and breadth.Ye

    A mitotic recombination map proximal to the APC locus on chromosome 5q and assessment of influences on colorectal cancer risk

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    Mitotic recombination is important for inactivating tumour suppressor genes by copy-neutral loss of heterozygosity (LOH). Although meiotic recombination maps are plentiful, little is known about mitotic recombination. The APC gene (chr5q21) is mutated in most colorectal tumours and its usual mode of LOH is mitotic recombination.
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