417 research outputs found

    Transport coefficients and nonextensive statistics

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    We discuss the basic transport phenomena in gases and plasmas obeying the qq-nonextensive velocity distribution (power-law). Analytical expressions for the thermal conductivity (KqK_q) and viscosity (ηq\eta_q) are derived by solving the Boltzmann equation in the relaxation-time approximation. The available experimental results to the ratio {KqK_q}/ηq\eta_q constrains the qq-parameter on the interval 0.74q10.74 \leq q \leq 1. In the extensive limiting case, the standard transport coefficients based on the local Gaussian distribution are recovered, and due to a surprising cancellation, the electric conductivity of a neutral plasma is not modified.Comment: 14 pages, 3 figures, REVTEX, submitted to PR

    Misinformation, Indigenous Health Information and HIV prevention among in- school Adolescents, Uganda

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    HIV/AIDS is still a major killer disease among adolescents in sub- Saharan Africa and Uganda in particular. There are many factors attributed to high HIV infections among young people in Uganda such as, multiple sexual partners, low condom use, those born with HIV and poverty. High level misinformation in the indigenous knowledge related to sexuality and HIV prevention remains an under investigated and under documented factor escalating the disease. Yet, the indigenous knowledge health information system is a major critical information source adolescents depend on for health information on HIV prevention in Uganda. Indigenous knowledge informs health interventions for HIV prevention among young people in many African communities and is relied on for decision making on health choices. This paper documents indigenous knowledge on practices for HIV prevention among secondary school adolescents in an urban context in Kampala District. A qualitative case study research design was employed. The findings revealed use of witchcraft, local herbs, male circumcision, elongation of labia menorah, abstinence, sexual taboos like not having sex with women in their menstrual periods and avoiding homosexuality as the key indigenous management practices for HIV prevention. Some of the findings were in agreement with existing biomedical information on prevention strategies while others were in contradiction. The findings also revealed that adolescents have a lot of misinformation on HIV prevention; such information may not support right healthy choices. The study contributes to the body of existing knowledge on HIV prevention using indigenous knowledge practices. The findings appeal to information science professionals to participate in ensuring that communities they serve have access to accurate and timely information to curb health emergencies and improve on health of societies they serve

    Outcomes in rheumatoid arthritis patients treated with abatacept : a UK multi-centre observational study

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    Background Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that causes chronic synovitis, resulting in progressive joint destruction and functional disability and affects approximately 400,000 people in the UK. This real-world study aimed to describe the characteristics, treatment patterns and clinical outcomes of patients who received abatacept in UK clinical practice. Methods This was a multi-centre, retrospective, observational study of patients with RA treated with abatacept at four UK centres between 01 January 2013 and 31 December 2017. Data were collected from medical records of each patient from the index date (date of first bDMARD initiation) until the most recent visit, death or end of study (31 December 2017). Results In total, 213 patients were included in the study. Patients received up to eight lines of therapy (LOTs). Treatment with abatacept, or any other bDMARD, was associated with reductions in DAS28-ESR and DAS28-CRP scores at 6 and 12 months. The distribution of EULAR responses (good/moderate/no response) tended to be more favourable for patients when receiving abatacept than when receiving other bDMARDs (22.8%/41.3%/35.9% versus 16.6%/41.4%/42.1% at 6 months, and 27.9%/36.1%/36.1% versus 21.2%/34.5%/44.2% at 12 months). Patients receiving abatacept at LOT1 (n = 68) spent significantly longer on treatment compared with patients receiving other bDMARDs (53.4 vs. 17.4 months; p< 0.01); a similar trend was observed for LOT2. Among patients who discontinued after 6 months, a greater proportion experienced infection requiring antibiotics when receiving other bDMARDs compared to those receiving abatacept. Conclusions RA patients who received bDMARDs, including abatacept, experienced reduced disease activity. When receiving abatacept as first or second line of therapy, patients persisted with treatment significantly longer than those receiving other bDMARDs

    Being smart about SMART environmental targets

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    Quantum Particles as Conceptual Entities: A Possible Explanatory Framework for Quantum Theory

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    We put forward a possible new interpretation and explanatory framework for quantum theory. The basic hypothesis underlying this new framework is that quantum particles are conceptual entities. More concretely, we propose that quantum particles interact with ordinary matter, nuclei, atoms, molecules, macroscopic material entities, measuring apparatuses, ..., in a similar way to how human concepts interact with memory structures, human minds or artificial memories. We analyze the most characteristic aspects of quantum theory, i.e. entanglement and non-locality, interference and superposition, identity and individuality in the light of this new interpretation, and we put forward a specific explanation and understanding of these aspects. The basic hypothesis of our framework gives rise in a natural way to a Heisenberg uncertainty principle which introduces an understanding of the general situation of 'the one and the many' in quantum physics. A specific view on macro and micro different from the common one follows from the basic hypothesis and leads to an analysis of Schrodinger's Cat paradox and the measurement problem different from the existing ones. We reflect about the influence of this new quantum interpretation and explanatory framework on the global nature and evolutionary aspects of the world and human worldviews, and point out potential explanations for specific situations, such as the generation problem in particle physics, the confinement of quarks and the existence of dark matter.Comment: 45 pages, 10 figure

    Some Consequences of Thermosolutal Convection: The Grain Structure of Castings

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    The essential principles of thermosolutal convection are outlined, and how convection provides a transport mechanism between the mushy region of a casting and the open bulk liquid is illustrated. The convective flow patterns which develop assist in heat exchange and macroscopic solute segregation during solidification; they also provide a mechanism for the transport of dendritic fragments from the mushy region into the bulk liquid. Surviving fragments become nuclei for equiaxed grains and so lead to blocking of the parental columnar, dendritic growth front from which they originated. The physical steps in such a sequence are considered and some experimental data are provided to support the argument

    De novo identification of mammalian ciliary motility proteins using cryo-EM

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    Dynein-decorated doublet microtubules (DMTs) are critical components of the oscillatory molecular machine of cilia, the axoneme, and have luminal surfaces patterned periodically by microtubule inner proteins (MIPs). Here we present an atomic model of the 48-nm repeat of a mammalian DMT, derived from a cryoelectron microscopy (cryo-EM) map of the complex isolated from bovine respiratory cilia. The structure uncovers principles of doublet microtubule organization and features specific to vertebrate cilia, including previously unknown MIPs, a luminal bundle of tektin filaments, and a pentameric dynein-docking complex. We identify a mechanism for bridging 48- to 24-nm periodicity across the microtubule wall and show that loss of the proteins involved causes defective ciliary motility and laterality abnormalities in zebrafish and mice. Our structure identifies candidate genes for diagnosis of ciliopathies and provides a framework to understand their functions in driving ciliary motility
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