1,864 research outputs found

    Induction, characterization, and cell transfer of autoimmune tubulointerstitial nephritis

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    Induction, characterization, and cell transfer of autoimmune tubulointerstitial nephritis. Autoimmune tubulointerstitial nephritis (TIN) was induced in Lewis (LEW) rats by immunization with homologous Brown–Norway (BN) rat renal basement membrane (RBM), complete Freund's adjuvant and Bordetella pertussis vaccine. The BN strain has a tubular basement membrane (TBM) antigen (Ag+) detectable by immunofluorescence which is lacking in unmodified LEW rat TBM. Development of TIN in LEW rats correlated with TBM Ag+ immunogens from homologous and heterologous RBM preparations. By day 14 after immunization TIN developed characterized by elevated serum creatinine levels and by tubular destruction with focal, circumscribed lesions containing epithelioid cells, giant cells and mononuclear cell infiltrates. Approximately 60% of the mononuclear cells bore T cell antigens with most cells expressing la markers. Immunofluorescence and elution studies revealed no selective IgG fixation to TBM at day 14 despite high titers of circulating alloantibody reactive with the immunizing TBM. Intravenous transfer of LNC and/or splenic cells (3.5 to 7 × 108) to naive LEW rats resulted in less severe but histologically identical TIN in seven days with T cell subpopulations similar to those seen in the active model. This model strongly suggests an initiating role for cell–mediated immunity in TIN in the rat and may provide a parallel to human TIN

    External Tank (ET) Bipod Fitting Bolted Attachment Locking Insert Performance

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    Following STS-107, the External Tank (ET) Project implemented corrective actions and configuration changes at the ET bipod fitting. Among the corrective actions, the existing bolt lock wire which provided resistance to potential bolt rotation was removed. The lock wire removal was because of concerns with creating voids during foam application and potential for lock wire to become debris. The bolts had been previously lubricated to facilitate assembly but, because of elimination of the lock wire, the ET Project wanted to enable the locking feature of the insert. Thus, the lubrication was removed from bolt threads and instead applied to the washer under the bolt head. Lubrication is necessary to maximize joint pre-load while remaining within the bolt torque specification. The locking feature is implemented by thread crimping in at four places in the insert. As the bolt is torqued into the insert the bolt threads its way past the crimped parts of the insert. This provides the locking of the bolt, as torque is required to loosen the joint after clamping

    National cross-sectional study of the sociodemographic characteristics of Aotearoa New Zealand's regulated health workforce pre-registration students: A mirror on society?

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    Objectives To provide a sociodemographic profile of students enrolled in their first year of a health professional pre-registration programme offered within New Zealand (NZ) tertiary institutions. Design Observational, cross-sectional study. Data were sought from NZ tertiary education institutions for all eligible students accepted into the first ar of a health professional programme for the 5-year period 2016-2020 inclusive. Variables of interest: gender, citizenship, ethnicity, rural classification, socioeconomic deprivation, school type and school socioeconomic scores. Analyses were carried out using the R statistics software. Setting Aotearoa NZ. Participants All students (domestic and international) accepted into the first ar of a health professional programme leading to registration under the Health Practitioners Competence Assurance Act 2003. Results NZ's health workforce pre-registration students do not reflect the diverse communities they will serve in several important dimensions. There is a systematic under-representation of students who identify as Māori and Pacific, and students who come from low socioeconomic and rural backgrounds. The enrolment rate for Māori students is about 99 per 100 000 eligible population and for some Pacific ethnic groups is lower still, compared with 152 per 100 000 for NZ European students. The unadjusted rate ratio for enrolment for both Māori students and Pacific students versus Other' students is approximately 0.7. Conclusions We recommend that: (1) there should be a nationally coordinated system for collecting and reporting on the sociodemographic characteristics of the health workforce pre-registration; (2) mechanisms be developed to allow the agencies that fund tertiary education to base their funding decisions directly on the projected health workforce needs of the health system and (3) tertiary education funding decisions be based on Te Tiriti o Waitangi (the foundational constitutional agreement between the Indigenous people, Māori and the British Crown signed in 1840) and have a strong pro-equity focus

    Socio-demographic profile of medical students in Aotearoa, New Zealand (2016-2020): a nationwide cross-sectional study

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    Objective To determine the socio-demographic profile of all students enrolled to study medicine in Aotearoa New Zealand (NZ). Design and setting Observational, cross-sectional study. Data were sought from the Universities of Auckland and Otago, the two NZ tertiary education institutions providing medical education, for the period 2016-2020 inclusive. These data are a subset of the larger project 'Mirror on Society' examining all regulated health professional enrolled students in NZ. Variables of interest: gender, citizenship, ethnicity, rural classification, socioeconomic deprivation, school type and school socioeconomic scores. NZ denominator population data (18-29 years) were sourced from the 2018 census. Participants 2858 students were enrolled to study medicine between 2016 and 2020 inclusive. Results There were more women (59.1%) enrolled to study medicine than men (40.9%) and the majority (96.5%) were in the 18-29 years age range. Maori students (rate ratio 0.92; 95% CI 0.84 to 1.0) and Pacific students (rate ratio 0.85; 95% CI 0.73 to 0.98) had lower overall rates of enrolment. For all ethnic groups, irrespective of rural or urban origin, enrolment rates had a nearly log-linear negative relationship with increasing socioeconomic deprivation. Enrolments were lower for students from rural areas compared with those from urban areas (rate ratio 0.53; 95% CI 0.46-0.61). Overall NZ's medical students do not reflect the diverse communities they will serve, with under-representation of Maori and Pacific students and students who come from low socioeconomic and rural backgrounds. Conclusions To meaningfully address these issues, we suggest the following policy changes: universities commit and act to Indigenise institutional ways of knowing and being; selection policies are reviewed to ensure that communities in greatest need of doctors are prioritised for enrolment into medicine (specifically, the impact of low socioeconomic status should be factored into selection decisions); and the government fund more New Zealanders to study medicine

    Detailed analysis of the cell-inactivation mechanism by accelerated protons and light ions

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    Published survival data for V79 cells irradiated by monoenergetic protons, helium-3, carbon, and oxygen ions and for CHO cells irradiated by carbon ions have been analyzed using the probabilistic two-stage model of cell inactivation. Three different classes of DNA damages formed by traversing particles have been distinguished, namely severe single-track damages which might lead to cell inactivation directly, less severe damages where cell inactivation is caused by their combinations, and damages of negligible severity that can be repaired easily. Probabilities of single ions to form these damages have been assessed in dependence on their linear energy transfer (LET) values. Damage induction probabilities increase with atomic number and LET. While combined damages play crucial role at lower LET values, single-track damages dominate in high-LET regions. The yields of single-track lethal damages for protons have been compared with the Monte Carlo estimates of complex DNA lesions, indicating that lethal events correlate well with complex DNA double-strand breaks. The decrease in the single-track damage probability for protons of LET above approx. 30 keV/μ\mum, suggested by limited experimental evidence, is discussed, together with the consequent differences in the mechanisms of biological effects between protons and heavier ions. Applications of the results in hadrontherapy treatment planning are outlined.Comment: submitted to Physics in Medicine and Biolog

    HARP/ACSIS: A submillimetre spectral imaging system on the James Clerk Maxwell Telescope

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    This paper describes a new Heterodyne Array Receiver Programme (HARP) and Auto-Correlation Spectral Imaging System (ACSIS) that have recently been installed and commissioned on the James Clerk Maxwell Telescope (JCMT). The 16-element focal-plane array receiver, operating in the submillimetre from 325 to 375 GHz, offers high (three-dimensional) mapping speeds, along with significant improvements over single-detector counterparts in calibration and image quality. Receiver temperatures are \sim120 K across the whole band and system temperatures of \sim300K are reached routinely under good weather conditions. The system includes a single-sideband filter so these are SSB figures. Used in conjunction with ACSIS, the system can produce large-scale maps rapidly, in one or more frequency settings, at high spatial and spectral resolution. Fully-sampled maps of size 1 square degree can be observed in under 1 hour. The scientific need for array receivers arises from the requirement for programmes to study samples of objects of statistically significant size, in large-scale unbiased surveys of galactic and extra-galactic regions. Along with morphological information, the new spectral imaging system can be used to study the physical and chemical properties of regions of interest. Its three-dimensional imaging capabilities are critical for research into turbulence and dynamics. In addition, HARP/ACSIS will provide highly complementary science programmes to wide-field continuum studies, and produce the essential preparatory work for submillimetre interferometers such as the SMA and ALMA.Comment: MNRAS Accepted 2009 July 2. 18 pages, 25 figures and 6 table
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