245 research outputs found

    Occurrence, antibiotic resistance, and survival of fecal enterococci in turkey litter

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    The United States Environmental Protection Agency’s National Water Quality Inventory and the Commonwealth of Virginia’s 305(b)/303(d) Water Quality Assessment Integrated Report show fecal bacteria to be the most common cause of impairment for both streams and estuaries. Human and animal sources have both been identified as significant contributors of pathogenic bacteria to surface waters. In this study, turkey litter from a farm in Shenandoah County, VA was surveyed for total culturable bacteria and total culturable enterococci before and after a transition to organic rearing practices. The enterococci were identified to species phenotypically using the Biolog Microbial Identification System and resistance to twelve antibiotics (ampicillin, doxycycline, chloramphenicol, ciprofloxacin, erythromycin, gentamicin, linezolid, quinipristin/dalfopristin, rifampin, streptomycin, tetracycline, vancomycin) was determined using the Kirby-Bauer disc diffusion method with automated image analysis using a BiomicTM plate reader. The effect of temperature (5◦C, 30◦C) and moisture (2O, ~35% H2O) on the survival of Enterococcus faecium in turkey litter was determined by inoculating sterilized turkey litter with a stock culture of bacteria and quantifying colony forming units over time. The transition to organic rearing practices resulted in a reduction in the proportion of enterococci resistant to doxycycline, gentamicin, and tetracycline, and an increase in the proportion of enterococci resistant to ciprofloxacin, erythromycin, and streptomycin. Enterococci isolated from the litter of organically raised birds were resistant to fewer antibiotics than enterococci isolated from the litter of conventionally raised birds. There was an interaction between moisture and temperature on the survival of E. faecium in turkey litter, with bacteria levels dropping most quickly in warm and dry conditions. The transition to organic practices has an immediate effect on antibiotic resistance patterns in enterococci, including an overall reduction from 4.02 to 3.45 antibiotic resistance phenotypes. Results of this study indicate that when applying turkey litter to land, fecal bacteria will likely survive for prolonged periods especially in cool moist conditions; therefore, it is recommended that prior to land application bacteria loads in litter should be reduced by composting or other treatment

    Economically Optimal Distiller Grain Inclusion in Beef Feedlot Rations: Recognition of Omitted Factors

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    With the rapid expansion of the ethanol industry, the feeding landscape familiar to the feedlot industry is changing. While concerns regarding rising corn prices persist, many within the industry are looking at distiller’s grains, a by-product of ethanol production, to serve as a feed substitute. The question remains as to what extent these two feed sources are substitutable. The purpose of this study is to identify the economically optimal inclusion rate of distiller’s grains in beef feedlot rations, considering an array of often omitted factors. Most currently prevailing recommendation rates are strictly biologically based and frequently reference only one feeding trial. Unique economic factors considered in this research include the impact of by-product inclusion rates on animal performance (utilizing recently conducted meta-analysis from 17 relevant feeding trials), enhanced likelihood of death loss from heightened sulfur content, and manure disposal costs. Results indicate that excluding these factors can significantly impact optimal inclusion levels and that reliance on a single or few feeding trials may greatly bias results.distiller’s grains, livestock rations, manure disposal cost,

    Economically Optimal Distiller Grain Inclusion in Beef Feedlot Rations: Recognition of Omitted Factors

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    With the rapid expansion of the ethanol industry, the feeding landscape familiar to the feedlot industry is changing. While concerns regarding rising corn prices persist, many within the industry are looking at distillers grains, a by-product of ethanol production, to serve as a feed substitute. The question remains as to what extent these two feed sources are substitutable. The purpose of this study is to identify the economically optimal inclusion rate of distillers grains in beef feedlot rations, considering an array of often omitted factors. Most currently prevailing recommendation rates are strictly biologically based and frequently reference only one feeding trial. Unique economic factors considered in this research include the impact of by-product inclusion rates on animal performance (utilizing recently conducted meta-analysis from 17 relevant feeding trials), enhanced likelihood of death loss from heightened sulfur content, and manure disposal costs. Results indicate that excluding these factors can significantly impact optimal inclusion levels and that reliance on a single or few feeding trials may greatly bias results.Livestock Production/Industries,

    Mycobacterium tuberculosis Beijing Genotype, Northern Malawi

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    In a 7-year population-based study in Malawi, we showed that Beijing genotype tuberculosis (TB) increased as a proportion of TB cases. All the Beijing genotype strains were fully drug sensitive. Contact histories, TB type, and case-fatality rates were similar for Beijing and non-Beijing genotype TB

    The impacts of climate change on UK energy demand

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    The impacts of climate change on the energy system are diverse; this article focuses on the potential effects on UK energy demand and the ramifications for national infrastructure building on the findings of the UK’s 2012 Climate Change Risk Assessment. It reviews the available literature, where it exists, on the relationships among current energy demand, weather and climate change, and the implications for these relationships due to mitigation plans and potential adaptation responses. The review highlights the mechanisms by which future climate change, in particular changes in mean and extreme temperature, could affect the annual amount of UK energy demand and the seasonal, daily and spatial variation of the impacts. Published literature quantifying the effects of climate change on UK energy demand is limited; thus, where evidence is not available, information on the current relationship between weather and demand is combined with expert judgement to highlight potential demand responses to a changing climate without quantification. The impacts identified could have significant implications for the long-term planning of energy infrastructure and system operation and building design, depending on their magnitude, highlighting the need for further research in this area

    Aberrant Maturation of the Uncinate Fasciculus Follows Exposure to Unpredictable Patterns of Maternal Signals

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    Across species, unpredictable patterns of maternal behavior are emerging as novel predictors of aberrant cognitive and emotional outcomes later in life. In animal models, exposure to unpredictable patterns of maternal behavior alters brain circuit maturation and cognitive and emotional outcomes. However, whether exposure to such signals in humans alters the development of brain pathways is unknown. In mother–child dyads, we tested the hypothesis that exposure to more unpredictable maternal signals in infancy is associated with aberrant maturation of corticolimbic pathways. We focused on the uncinate fasciculus, the primary fiber bundle connecting the amygdala to the orbitofrontal cortex and a key component of the medial temporal lobe–prefrontal cortex circuit. Infant exposure to unpredictable maternal sensory signals was assessed at 6 and 12 months. Using high angular resolution diffusion imaging, we quantified the integrity of the uncinate fasciculus using generalized fractional anisotropy (GFA). Higher maternal unpredictability during infancy presaged greater uncinate fasciculus GFA in children 9–11 years of age (n = 69, 29 female). In contrast to the uncinate, GFA of a second corticolimbic projection, the hippocampal cingulum, was not associated with maternal unpredictability. Addressing the overall functional significance of the uncinate and cingulum relationships, we found that the resulting imbalance of medial temporal lobe–prefrontal cortex connectivity partially mediated the association between unpredictable maternal sensory signals and impaired episodic memory function. These results suggest that unbalanced maturation of corticolimbic circuits is a mechanism by which early unpredictable sensory signals may impact cognition later in life

    Identifying the Neural Correlates of Anticipatory Postural Control: A Novel fMRI Paradigm

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    Altered postural control in the trunk/hip musculature is a characteristic of multiple neurological and musculoskeletal conditions. Previously it was not possible to determine if altered cortical and subcortical sensorimotor brain activation underlies impairments in postural control. This study used a novel fMRI-compatible paradigm to identify the brain activation associated with postural control in the trunk and hip musculature. BOLD fMRI imaging was conducted as participants performed two versions of a lower limb task involving lifting the left leg to touch the foot to a target. For the supported leg raise (SLR) the leg is raised from the knee while the thigh remains supported. For the unsupported leg raise (ULR) the leg is raised from the hip, requiring postural muscle activation in the abdominal/hip extensor musculature. Significant brain activation during the SLR task occurred predominantly in the right primary and secondary sensorimotor cortical regions. Brain activation during the ULR task occurred bilaterally in the primary and secondary sensorimotor cortical regions, as well as cerebellum and putamen. In comparison with the SLR, the ULR was associated with significantly greater activation in the right premotor/SMA, left primary motor and cingulate cortices, primary somatosensory cortex, supramarginal gyrus/parietal operculum, superior parietal lobule, cerebellar vermis, and cerebellar hemispheres. Cortical and subcortical regions activated during the ULR, but not during the SLR, were consistent with the planning, and execution of a task involving multisegmental, bilateral postural control. Future studies using this paradigm will determine mechanisms underlying impaired postural control in patients with neurological and musculoskeletal dysfunction
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