7,023 research outputs found

    Evaluation of a novel digital environment for learning medical parasitology.

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    open access articleEukaryotic parasites represent a serious human health threat requiring health professionals with parasitology skills to counteract this threat. However, recent surveys highlight an erosion of teaching of parasitology in medical and veterinary schools, despite reports of increasing instances of food and water borne parasitic infections. To address this we developed a web-based resource, DMU e-ParasitologyÂź, to facilitate the teaching and learning of parasitology, comprising four sections: theoretical; virtual laboratory; virtual microscopy; virtual clinical case studies. Testing the package was performed using a questionnaire given to ninety-five Pharmacy students in 2017/18 to assess effectiveness of the package as a teaching and learning tool. 89.5% of students reported appropriate acquisition of knowledge of the pathology, prevention and treatment of some parasitic diseases. 82.1% also welcomed the clinical specialism of the package as it helped them to acquire basic diagnostic skills, through learning infective features/morphology of the parasites

    The growth threshold conjecture: a theoretical framework for understanding T-cell tolerance

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    Adaptive immune responses depend on the capacity of T cells to target specific antigens. As similar antigens can be expressed by pathogens and host cells, the question naturally arises of how can T cells discriminate friends from foes. In this work, we suggest that T cells tolerate cells whose proliferation rates remain below a permitted threshold. Our proposal relies on well-established facts about T-cell dynamics during acute infections: T-cell populations are elastic (they expand and contract) and they display inertia (contraction is delayed relative to antigen removal). By modelling inertia and elasticity, we show that tolerance to slow-growing populations can emerge as a population-scale feature of T cells. This result suggests a theoretical framework to understand immune tolerance that goes beyond the self versus non-self dichotomy.M.A.H. has been partially supported by MINECO grant no. MTM2014-53156. The rest of the authors have not received any particular financial support for this work

    Determination of the Jet Energy Scale at the Collider Detector at Fermilab

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    A precise determination of the energy scale of jets at the Collider Detector at Fermilab at the Tevatron ppˉp\bar{p} collider is described. Jets are used in many analyses to estimate the energies of partons resulting from the underlying physics process. Several correction factors are developed to estimate the original parton energy from the observed jet energy in the calorimeter. The jet energy response is compared between data and Monte Carlo simulation for various physics processes, and systematic uncertainties on the jet energy scale are determined. For jets with transverse momenta above 50 GeV the jet energy scale is determined with a 3% systematic uncertainty

    On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63

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    Interstellar dust grain alignment causes polarization from UV to mm wavelengths, allowing the study of the geometry and strength of the magnetic field. Over the last couple of decades, observations and theory have led to the establishment of the radiative alignment torque mechanism as a leading candidate to explain the effect. With a quantitatively well constrained theory, polarization can be used not only to study the interstellar magnetic field, but also the dust and other environmental parameters. Photodissociation regions, with their intense, anisotropic radiation fields, consequent rapid H2 formation, and high spatial density-contrast provide a rich environment for such studies. Here we discuss an expanded optical, NIR, and mm-wave study of the IC 63 nebula, showing strong H2 formation-enhanced alignment and the first direct empirical evidence for disalignment due to gas-grain collisions using high-resolution HCO+(J = 1-0) observations. We find that a relative amount of polarization is marginally anticorrelated with column density of HCO+. However, separating the lines of sight of optical polarimetry into those behind, or in front of, a dense clump as seen from Îł Cas, the distribution separates into two well defined sets, with data corresponding to "shaded" gas having a shallower slope. This is expected if the decrease in polarization is caused by collisions since collisional disalignment rate is proportional to RC∝nT" role="presentation">RC∝nT−−√ . Ratios of the best-fit slopes for the "illuminated" and "shaded" samples of lines of sight agrees, within the uncertainties, with the square root of the two-temperature H2 excitation in the nebula seen by Thi et al.Fil: Soam, Archana. Sofia Science Center; Estados UnidosFil: Anderson, B. G. Sofia Science Center; Estados UnidosFil: Acosta Pulido, Jose. Instituto de Astrofisica de Canarias; EspañaFil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂ­ficas. Instituto Argentino de RadioastronomĂ­a. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto Argentino de RadioastronomĂ­a; ArgentinaFil: Vaillancourt, J. E.. Lincoln Laboratory; Estados UnidosFil: Widicus Weaver, S. L.. Department Of Chemistry; Estados UnidosFil: Piirola, V.. University Of Turku; FinlandiaFil: Gordon, M. S.. Sofia Science Center; Estados Unido

    The innate immune sensor Toll-like receptor 2 controls the senescence-associated secretory phenotype

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    Cellular senescence is a stress response program characterized by a robust cell cycle arrest and the induction of a proinflammatory senescence-associated secretory phenotype (SASP) that is triggered through an unknown mechanism. Here, we show that, during oncogene-induced senescence (OIS), the Toll-like receptor 2 (TLR2) and its partner TLR10 are key mediators of senescence in vitro and in murine models. TLR2 promotes cell cycle arrest by regulating the tumor suppressors p53-p21 , p16 , and p15 and regulates the SASP through the induction of the acute-phase serum amyloids A1 and A2 (A-SAAs) that, in turn, function as the damage-associated molecular patterns (DAMPs) signaling through TLR2 in OIS. Last, we found evidence that the cGAS-STING cytosolic DNA sensing pathway primes TLR2 and A-SAAs expression in OIS. In summary, we report that innate immune sensing of senescence-associated DAMPs by TLR2 controls the SASP and reinforces the cell cycle arrest program in OIS

    Socioeconomic Factors and All Cause and Cause-Specific Mortality among Older People in Latin America, India, and China: A Population-Based Cohort Study

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    Cleusa Ferri and colleagues studied mortality rates in over 12,000 people aged 65 years and over in Latin America, India, and China and showed that chronic diseases are the main causes of death and that education has an important effect on mortality
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