684 research outputs found

    Activist Bibliography as Abolitionist Pedagogy in the American Prison Writing Archive

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    This article describes how undergraduate coursework performs activist bibliography for the largest and first fully searchable digital archive of testimony writing by currently incarcerated people, the American Prison Writing Archive (APWA). The authors argue that when teachers invite students to participate as citizen archivists for the APWA as coursework, through contributing crowdsourced metadata such as transcription and subject tagging, the incarcerated writers whose manuscripts they edit become the epistemological center of the course. Through this pedagogy, APWA authors create and disseminate knowledge about the emotional and physical tolls of incarceration and the need for prison abolition. The article features two case studies in undergraduate teaching assignments: (a) students performing subject tagging of APWA testimony in a literature course, and (b) students transcribing APWA manuscripts in a literacy studies course. Both engage students in activist bibliographical work and digital humanities for a public audience that increases the functionality and content in the archive, defies carceral censorship, and demystifies broad public and political misinformation about prisons and imprisoned people. By detailing two possibilities for incorporating APWA editing into literature and literacy curricula, and its potential to ideologically transform student citizen archivists, the authors hope to attract more instructors to include this editorial work in their syllabi and extend our call for critical action within and beyond the archive. (In the issue section Rethinking Catalogs and Archives

    Learning to Learn: Theta Oscillations Predict New Learning, which Enhances Related Learning and Neurogenesis

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    Animals in the natural world continuously encounter learning experiences of varying degrees of novelty. New neurons in the hippocampus are especially responsive to learning associations between novel events and more cells survive if a novel and challenging task is learned. One might wonder whether new neurons would be rescued from death upon each new learning experience or whether there is an internal control system that limits the number of cells that are retained as a function of learning. In this experiment, it was hypothesized that learning a task that was similar in content to one already learned previously would not increase cell survival. We further hypothesized that in situations in which the cells are rescued hippocampal theta oscillations (3–12 Hz) would be involved and perhaps necessary for increasing cell survival. Both hypotheses were disproved. Adult male Sprague-Dawley rats were trained on two similar hippocampus-dependent tasks, trace and very-long delay eyeblink conditioning, while recording hippocampal local-field potentials. Cells that were generated after training on the first task were labeled with bromodeoxyuridine and quantified after training on both tasks had ceased. Spontaneous theta activity predicted performance on the first task and the conditioned stimulus induced a theta-band response early in learning the first task. As expected, performance on the first task correlated with performance on the second task. However, theta activity did not increase during training on the second task, even though more cells were present in animals that had learned. Therefore, as long as learning occurs, relatively small changes in the environment are sufficient to increase the number of surviving neurons in the adult hippocampus and they can do so in the absence of an increase in theta activity. In conclusion, these data argue against an upper limit on the number of neurons that can be rescued from death by learning

    Reduced TRPC Channel Expression in Psoriatic Keratinocytes Is Associated with Impaired Differentiation and Enhanced Proliferation

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    Psoriasis is a characteristic inflammatory and scaly skin condition with typical histopathological features including increased proliferation and hampered differentiation of keratinocytes. The activation of innate and adaptive inflammatory cellular immune responses is considered to be the main trigger factor of the epidermal changes in psoriatic skin. However, the molecular players that are involved in enhanced proliferation and impaired differentiation of psoriatic keratinocytes are only partly understood. One important factor that regulates differentiation on the cellular level is Ca2+. In normal epidermis, a Ca2+ gradient exists that is disturbed in psoriatic plaques, favoring impaired keratinocyte proliferation. Several TRPC channels such as TRPC1, TRPC4, or TRPC6 are key proteins in the regulation of high [Ca2+]ex induced differentiation. Here, we investigated if TRPC channel function is impaired in psoriasis using calcium imaging, RT-PCR, western blot analysis and immunohistochemical staining of skin biopsies. We demonstrated substantial defects in Ca2+ influx in psoriatic keratinocytes in response to high extracellular Ca2+ levels, associated with a downregulation of all TRPC channels investigated, including TRPC6 channels. As TRPC6 channel activation can partially overcome this Ca2+ entry defect, specific TRPC channel activators may be potential new drug candidates for the topical treatment of psoriasis

    Acceptability, feasibility and cost of point of care testing for sexually transmitted infections among South African adolescents where syndromic management is standard of care

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    BACKGROUND: Young people (YP) in southern Africa are at substantial risk of HIV and sexually transmitted infections (STIs). Despite the epidemiological and biological link between STIs and HIV transmission and acquisition, infections such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) remain widely undiagnosed. Syndromic STI management is the standard of care in low- and middle-income countries (LMICs) despite a high prevalence of asymptomatic infections. We conducted an observational study to explore the acceptability, feasibility, and cost of a STI test-and-treat service for YP in Cape Town. METHODS: YP attending a mobile clinic (MC) and a youth centre clinic (YC) were offered STI screening. Urine testing for CT and NG using a 90-min molecular point-of-care (POC) test on the GeneXpert platform was conducted and treatment provided. Data were collated on demographics, sexual behaviour, presence of symptoms, uptake of same-day treatment, prevalence of CT/NG, and service acceptability. RESULTS: Three hundred sixty six participants were enrolled (median age 20, 83% female).57% (209/366) of participants tested positive for either CT (126/366, 34%) or NG (57/366, 16%) or co-infection (26/366, 7%). Clinical symptoms were a poor predictor of GeneXpert diagnosed CT or NG, with a sensitivity of 46.8% and 54.0% for CT and NG respectively. Although half of participants initially chose to receive same day results and treatment, only a third waited for results on the day. The majority of participants (91%) rated the service highly via a post-visit acceptability questionnaire. CONCLUSION: Curable STIs are highly prevalent in this population. STI screening using POC testing was feasible and acceptability was high. The study provides further impetus for moving policy beyond syndromic management of STIs in South Africa

    A combined maximum-likelihood analysis of the high-energy astrophysical neutrino flux measured with IceCube

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    Evidence for an extraterrestrial flux of high-energy neutrinos has now been found in multiple searches with the IceCube detector. The first solid evidence was provided by a search for neutrino events with deposited energies 30\gtrsim30 TeV and interaction vertices inside the instrumented volume. Recent analyses suggest that the extraterrestrial flux extends to lower energies and is also visible with throughgoing, νμ\nu_\mu-induced tracks from the Northern hemisphere. Here, we combine the results from six different IceCube searches for astrophysical neutrinos in a maximum-likelihood analysis. The combined event sample features high-statistics samples of shower-like and track-like events. The data are fit in up to three observables: energy, zenith angle and event topology. Assuming the astrophysical neutrino flux to be isotropic and to consist of equal flavors at Earth, the all-flavor spectrum with neutrino energies between 25 TeV and 2.8 PeV is well described by an unbroken power law with best-fit spectral index 2.50±0.09-2.50\pm0.09 and a flux at 100 TeV of (6.71.2+1.1)1018GeV1s1sr1cm2\left(6.7_{-1.2}^{+1.1}\right)\cdot10^{-18}\,\mathrm{GeV}^{-1}\mathrm{s}^{-1}\mathrm{sr}^{-1}\mathrm{cm}^{-2}. Under the same assumptions, an unbroken power law with index 2-2 is disfavored with a significance of 3.8 σ\sigma (p=0.0066%p=0.0066\%) with respect to the best fit. This significance is reduced to 2.1 σ\sigma (p=1.7%p=1.7\%) if instead we compare the best fit to a spectrum with index 2-2 that has an exponential cut-off at high energies. Allowing the electron neutrino flux to deviate from the other two flavors, we find a νe\nu_e fraction of 0.18±0.110.18\pm0.11 at Earth. The sole production of electron neutrinos, which would be characteristic of neutron-decay dominated sources, is rejected with a significance of 3.6 σ\sigma (p=0.014%p=0.014\%).Comment: 16 pages, 10 figures; accepted for publication in The Astrophysical Journal; updated one referenc

    Dispersion and release of embelin from electrospun biodegradable, polymeric, membranes

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    In this work, microfiber meshes containing embelin, a poorly water-soluble bioactive agent, were prepared by solubilizing embelin in a biodegradable and biocompatible polymer matrix of poly(ε-caprolactone) (PCL). Plain or drug-loaded, highly porous, fibrous membranes with a high area-to-volume ratio were obtained by electrospinning. Non-woven microfibrous meshes were formed by uniform bead-free fibers with a mean diameter of 1.2 μm. Non-porous films were obtained by solution casting, and were used for comparison. The drug-loading content of the prepared systems was appropriate for topical applications. The thermal properties revealed that the crystallinity of embelin significantly decreased, the drug having almost completely dissolved in the PCL fibers. The in situ bioavailability of embelin, an antimycotic agent, is an important aspect to consider in topical drug applications. The drug-loaded systems presented different contact areas with the biological environment. When comparing the ability to expose embelin with the biological environment of the prepared systems, drug-loaded fibrous scaffolds showed a higher bioavailability of the bioactive agent because of an increase by 86% in the area-to-volume ratio, providing an effective area per unit mass that was 5.8-fold higher than that of the film. For the meshes, 90% embelin release was observed after 12h of exposure to phosphate-buffered saline, whereas for the films a comparable level of release occurred only after 72h.Fil: Cortez Tornello, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Feresin, Gabriela Egly. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Tapia, Alejandro. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Veiga, Itiara G.. Universidade Estadual de Campinas; BrasilFil: Moraes, Ângela M.. Universidade Estadual de Campinas; BrasilFil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Cuadrado, Teresita Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentin

    The IceCube Neutrino Observatory - Contributions to ICRC 2015 Part II: Atmospheric and Astrophysical Diffuse Neutrino Searches of All Flavors

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    Papers on atmospheric and astrophysical diffuse neutrino searches of all flavors submitted to the 34th International Cosmic Ray Conference (ICRC 2015, The Hague) by the IceCube Collaboration.Comment: 66 pages, 36 figures, Papers submitted to the 34th International Cosmic Ray Conference, The Hague 2015, v2 has a corrected author lis

    Characterization of the Atmospheric Muon Flux in IceCube

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    Muons produced in atmospheric cosmic ray showers account for the by far dominant part of the event yield in large-volume underground particle detectors. The IceCube detector, with an instrumented volume of about a cubic kilometer, has the potential to conduct unique investigations on atmospheric muons by exploiting the large collection area and the possibility to track particles over a long distance. Through detailed reconstruction of energy deposition along the tracks, the characteristics of muon bundles can be quantified, and individual particles of exceptionally high energy identified. The data can then be used to constrain the cosmic ray primary flux and the contribution to atmospheric lepton fluxes from prompt decays of short-lived hadrons. In this paper, techniques for the extraction of physical measurements from atmospheric muon events are described and first results are presented. The multiplicity spectrum of TeV muons in cosmic ray air showers for primaries in the energy range from the knee to the ankle is derived and found to be consistent with recent results from surface detectors. The single muon energy spectrum is determined up to PeV energies and shows a clear indication for the emergence of a distinct spectral component from prompt decays of short-lived hadrons. The magnitude of the prompt flux, which should include a substantial contribution from light vector meson di-muon decays, is consistent with current theoretical predictions.Comment: 36 pages, 39 figure

    Measurement of the Atmospheric νe\nu_e Spectrum with IceCube

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    We present a measurement of the atmospheric νe\nu_e spectrum at energies between 0.1 TeV and 100 TeV using data from the first year of the complete IceCube detector. Atmospheric νe\nu_e originate mainly from the decays of kaons produced in cosmic-ray air showers. This analysis selects 1078 fully contained events in 332 days of livetime, then identifies those consistent with particle showers. A likelihood analysis with improved event selection extends our previous measurement of the conventional νe\nu_e fluxes to higher energies. The data constrain the conventional νe\nu_e flux to be 1.30.3+0.41.3^{+0.4}_{-0.3} times a baseline prediction from a Honda's calculation, including the knee of the cosmic-ray spectrum. A fit to the kaon contribution (ξ\xi) to the neutrino flux finds a kaon component that is ξ=1.30.4+0.5\xi =1.3^{+0.5}_{-0.4} times the baseline value. The fitted/measured prompt neutrino flux from charmed hadron decays strongly depends on the assumed astrophysical flux and shape. If the astrophysical component follows a power law, the result for the prompt flux is 0.00.0+3.00.0^{+3.0}_{-0.0} times a calculated flux based on the work by Enberg, Reno and Sarcevic.Comment: PRD accepted versio
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