149 research outputs found

    Western Kentucky University Libraries, Preparing Information Literate Students at WKU: Report of the Task Force on Universal Information Literacy

    Get PDF
    Purpose: The Task Force on Universal Information Literacy was formed in the fall of 2010 and charged with reviewing the advisability and viability of providing information literacy instruction to every student at WKU

    Mars Sample Handling and Requirements Panel (MSHARP)

    Get PDF
    In anticipation of the return of samples from Mars toward the end of the first decade of the next century, NASA's Office of Space Sciences chartered a panel to examine how Mars samples should be handled. The panel was to make recommendations in three areas: (1) sample collection and transport back to Earth; (2) certification of the samples as nonhazardous; and (3) sample receiving, curation, and distribution. This report summarizes the findings of that panel. The samples should be treated as hazardous until proven otherwise. They are to be sealed within a canister on Mars, and the canister is not to be opened until within a Biosafety Hazard Level 4 (BSL-4) containment facility here on Earth. This facility must also meet or exceed the cleanliness requirements of the Johnson Space Center (JSC) facility for curation of extraterrestrial materials. A containment facility meeting both these requirements does not yet exist. Hazard assessment and life detection experiments are to be done at the containment facility, while geochemical characterization is being performed on a sterilized subset of the samples released to the science community. When and if the samples are proven harmless, they are to be transferred to a curation facility, such as that at JSC

    Exosome-Producing Follicle Associated Epithelium Is Not Involved in Uptake of PrPd from the Gut of Sheep (Ovis aries): An Ultrastructural Study

    Get PDF
    In natural or experimental oral scrapie infection of sheep, disease associated prion protein (PrPd) often first accumulates in Peyer's patch (PP) follicles. The route by which infectivity reaches the follicles is unknown, however, intestinal epithelial cells may participate in intestinal antigenic presentation by delivering exosomes as vehicles of luminal antigens. In a previous study using an intestinal loop model, following inoculation of scrapie brain homogenate, inoculum associated PrPd was detected by light microscopy shortly (15 minutes to 3.5 hours) after inoculation in the villous lacteals and sub-mucosal lymphatics. No PrPd was located within the follicle-associated epithelium (FAE), sub-FAE domes or the PP follicles. To evaluate this gut loop model and the transportation routes in more detail, we used electron microscopy (EM) to study intestinal tissues exposed to scrapie or control homogenates for 15 minutes to 10 days. In addition, immuno-EM was used to investigate whether exosomes produced in the FAE may possess small amounts of PrPd that were not detectable by light microscopy. This study showed that the integrity of the intestinal epithelium was sustained in the intestinal loop model. Despite prominent transcytotic activity and exosome release from the FAE of the ileal PP in sheep, these structures were not associated with transportation of PrPd across the mucosa. The study did not determine how infectivity reaches the follicles of PPs. The possibility that the infectious agent is transported across the FAE remains a possibility if it occurs in a form that is undetectable by the methods used in this study. Infectivity may also be transported via lymph to the blood and further to all other lymphoid tissues including the PP follicles, but the early presence of PrPd in the PP follicles during scrapie infection argues against such a mechanism

    Use of a preclinical test in the control of classical scrapie

    Get PDF
    Scrapie control in Great Britain (GB) was originally based on the National Scrapie Plan's Ram Genotyping scheme aimed at reducing the susceptibility of the national flock. The current official strategy to control scrapie in the national flock involves culling susceptible genotypes in individual, known affected flocks (compulsory scrapie flock scheme or CSFS). However, the recent development of preclinical test candidates means that a strategy based on disease detection may now be feasible. Here, a deterministic within-flock model was used to demonstrate that only large flocks with many home-bred ewes are likely to be a significant risk for flock-to-flock transmission of scrapie. For most other flocks, it was found that the CSFS could be replaced by a strategy using a currently available live test without excessive risk to other farmers, even if the proportion of susceptible genotypes in the flock is unusually large. Even for flocks that represent a high risk of harbouring a high prevalence of infection, there would be limited probability of onward transmission if scrapie is detected soon after disease introduction (typically less than 5 years). However, if detection of disease is delayed, the existing CSFS strategy may be the most appropriate control measure in these cases

    The Democratic Biopolitics of PrEP

    Get PDF
    PrEP (Pre-Exposure Prophylaxis) is a relatively new drug-based HIV prevention technique and an important means to lower the HIV risk of gay men who are especially vulnerable to HIV. From the perspective of biopolitics, PrEP inscribes itself in a larger trend of medicalization and the rise of pharmapower. This article reconstructs and evaluates contemporary literature on biopolitical theory as it applies to PrEP, by bringing it in a dialogue with a mapping of the political debate on PrEP. As PrEP changes sexual norms and subjectification, for example condom use and its meaning for gay subjectivity, it is highly contested. The article shows that the debate on PrEP can be best described with the concepts ‘sexual-somatic ethics’ and ‘democratic biopolitics’, which I develop based on the biopolitical approach of Nikolas Rose and Paul Rabinow. In contrast, interpretations of PrEP which are following governmentality studies or Italian Theory amount to either farfetched or trivial positions on PrEP, when seen in light of the political debate. Furthermore, the article is a contribution to the scholarship on gay subjectivity, highlighting how homophobia and homonormativity haunts gay sex even in liberal environments, and how PrEP can serve as an entry point for the destigmatization of gay sexuality and transformation of gay subjectivity. ‘Biopolitical democratization’ entails making explicit how medical technology and health care relates to sexual subjectification and ethics, to strengthen the voice of (potential) PrEP users in health politics, and to renegotiate the profit and power of Big Pharma

    Variable tau accumulation in murine models with abnormal prion protein deposits

    Get PDF
    Rona Barron - ORCID: 0000-0003-4512-9177 https://orcid.org/0000-0003-4512-9177The conversion of cellular prion protein (PrP) into a misfolded isoform is central to the development of prion diseases. However, the heterogeneous phenotypes observed in prion disease may be linked with the presence of other misfolded proteins in the brain. While hyperphosphorylated tau (p.tau) is characteristic of Alzheimer's disease (AD), p.tau is also observed in human prion diseases. To explore this association in the absence of potential effects due to aging, drug treatment, agonal stage and postmortem delay we analyzed p.tau and PrP immunopositivity in mouse models. Analyses were performed on mice inoculated with prion agents, and mice with PrP amyloid in the absence of prion disease. We observed that p.tau was consistently present in animals with prion infectivity (models that transmit disease upon serial passage). In contrast, p.tau was very rarely observed or absent in mice with PrP amyloid plaques in the absence of prion replication. These data indicate that the formation of p.tau is not linked to deposition of misfolded PrP, but suggest that the interaction between replication of infectivity and host factors regulate the formation of p.tau and may contribute to the heterogeneous phenotype of prion diseases.https://doi.org/10.1016/j.jns.2017.10.040383pubpubDecember 201

    Prions in Milk from Ewes Incubating Natural Scrapie

    Get PDF
    Since prion infectivity had never been reported in milk, dairy products originating from transmissible spongiform encephalopathy (TSE)-affected ruminant flocks currently enter unrestricted into the animal and human food chain. However, a recently published study brought the first evidence of the presence of prions in mammary secretions from scrapie-affected ewes. Here we report the detection of consistent levels of infectivity in colostrum and milk from sheep incubating natural scrapie, several months prior to clinical onset. Additionally, abnormal PrP was detected, by immunohistochemistry and PET blot, in lacteal ducts and mammary acini. This PrPSc accumulation was detected only in ewes harbouring mammary ectopic lymphoid follicles that developed consequent to Maedi lentivirus infection. However, bioassay revealed that prion infectivity was present in milk and colostrum, not only from ewes with such lympho-proliferative chronic mastitis, but also from those displaying lesion-free mammary glands. In milk and colostrum, infectivity could be recovered in the cellular, cream, and casein-whey fractions. In our samples, using a Tg 338 mouse model, the highest per ml infectious titre measured was found to be equivalent to that contained in 6 ”g of a posterior brain stem from a terminally scrapie-affected ewe. These findings indicate that both colostrum and milk from small ruminants incubating TSE could contribute to the animal TSE transmission process, either directly or through the presence of milk-derived material in animal feedstuffs. It also raises some concern with regard to the risk to humans of TSE exposure associated with milk products from ovine and other TSE-susceptible dairy species

    An overview of animal prion diseases

    Get PDF
    Prion diseases are transmissible neurodegenerative conditions affecting human and a wide range of animal species. The pathogenesis of prion diseases is associated with the accumulation of aggregates of misfolded conformers of host-encoded cellular prion protein (PrPC). Animal prion diseases include scrapie of sheep and goats, bovine spongiform encephalopathy (BSE) or mad cow disease, transmissible mink encephalopathy, feline spongiform encephalopathy, exotic ungulate spongiform encephalopathy, chronic wasting disease of cervids and spongiform encephalopathy of primates. Although some cases of sporadic atypical scrapie and BSE have also been reported, animal prion diseases have basically occurred via the acquisition of infection from contaminated feed or via the exposure to contaminated environment. Scrapie and chronic wasting disease are naturally sustaining epidemics. The transmission of BSE to human has caused more than 200 cases of variant Cruetzfeldt-Jacob disease and has raised serious public health concerns. The present review discusses the epidemiology, clinical neuropathology, transmissibility and genetics of animal prion diseases
    • 

    corecore