70 research outputs found

    Development of a stratospheric and mesospheric microwave temperature sounder experiment

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    A passive microwave spectrometer system for measuring global atmospheric temperature profiles from 0-75 km altitude was developed and analyzed. The system utilizes 12 channels near the 5 mm wavelength oxygen absorption band and is designed to provide global coverage by scanning perpendicular to the orbital track of a polar orbiting satellite. A significant improvement in the accuracy of theoretical atmospheric microwave transmittance functions was achieved through the development of a first-order approximation to overlapping line theory for the oxygen molecule. This approximation is particularly important in the troposphere and lower stratosphere where pressure-broadening blends nearby lines. Ground-based and aircraft observations of several resonances of stratospheric oxygen generally support the theory. The 23, 25, 29, and 31 atmospheric oxygen lines were measured and the frequencies of several such oxygen lines were measured with improved precision. The polarization and Zeeman splitting of the atmospheric 27 line was also observed

    Radio Astronomy

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    Contains reports on isx research projects.National Aeronautics and Space Administration, Langley Research Center (Contract NAS1-10693)National Science Foundation (Grant GP-21348)National Science Foundation (Grant GP-14589)California Institute of Technology Contract 952568Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-030

    Radio Astronomy

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    Contains reports on four research projects.Joint Services Electronics Program (Contract DAAB07-71-C-0300)California Institute of Technology (Contract 952568)National Aeronautics and Space Administration (Contract NAS1-10693)National Science Foundation (Grant GP-21348A#2

    Radio Astronomy

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    Contains reports on eight research projects.National Aeronautics and Space Administration, Langley Research Center (Contract NAS1-10693)California Institute of Technology Contract 952568Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-0300National Science Foundation (Grant GP-20769A#1)National Science Foundation (Grant GP-21348A#1

    Morbillivirus Glycoprotein Expression Induces ER Stress, Alters Ca2+ Homeostasis and Results in the Release of Vasostatin

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    Although the pathology of Morbillivirus in the central nervous system (CNS) is well described, the molecular basis of neurodegenerative events still remains poorly understood. As a model to explore Morbillivirus-mediated CNS dysfunctions, we used canine distemper virus (CDV) that we inoculated into two different cell systems: a monkey cell line (Vero) and rat primary hippocampal neurons. Importantly, the recombinant CDV used in these studies not only efficiently infects both cell types but recapitulates the uncommon, non-cytolytic cell-to-cell spread mediated by virulent CDVs in brain of dogs. Here, we demonstrated that both CDV surface glycoproteins (F and H) markedly accumulated in the endoplasmic reticulum (ER). This accumulation triggered an ER stress, characterized by increased expression of the ER resident chaperon calnexin and the proapoptotic transcription factor CHOP/GADD 153. The expression of calreticulin (CRT), another ER resident chaperon critically involved in the response to misfolded proteins and in Ca2+ homeostasis, was also upregulated. Transient expression of recombinant CDV F and H surface glycoproteins in Vero cells and primary hippocampal neurons further confirmed a correlation between their accumulation in the ER, CRT upregulation, ER stress and disruption of ER Ca2+ homeostasis. Furthermore, CDV infection induced CRT fragmentation with re-localisation of a CRT amino-terminal fragment, also known as vasostatin, on the surface of infected and neighbouring non-infected cells. Altogether, these results suggest that ER stress, CRT fragmentation and re-localization on the cell surface may contribute to cytotoxic effects and ensuing cell dysfunctions triggered by Morbillivirus, a mechanism that might potentially be relevant for other neurotropic viruses

    TRAF6 and IRF7 Control HIV Replication in Macrophages

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    The innate immune system recognizes virus infection and evokes antiviral responses which include producing type I interferons (IFNs). The induction of IFN provides a crucial mechanism of antiviral defense by upregulating interferon-stimulated genes (ISGs) that restrict viral replication. ISGs inhibit the replication of many viruses by acting at different steps of their viral cycle. Specifically, IFN treatment prior to in vitro human immunodeficiency virus (HIV) infection stops or significantly delays HIV-1 production indicating that potent inhibitory factors are generated. We report that HIV-1 infection of primary human macrophages decreases tumor necrosis factor receptor-associated factor 6 (TRAF6) and virus-induced signaling adaptor (VISA) expression, which are both components of the IFN signaling pathway controlling viral replication. Knocking down the expression of TRAF6 in macrophages increased HIV-1 replication and augmented the expression of IRF7 but not IRF3. Suppressing VISA had no impact on viral replication. Overexpression of IRF7 resulted in enhanced viral replication while knocking down IRF7 expression in macrophages significantly reduced viral output. These findings are the first demonstration that TRAF6 can regulate HIV-1 production and furthermore that expression of IRF7 promotes HIV-1 replication

    Patients' evaluations of European general practice--revisited after 11 years

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    Contains fulltext : 98199.pdf (publisher's version ) (Closed access)BACKGROUND: /st> In the last decade many things have changed in healthcare systems, primary care practices and populations. OBJECTIVE: /st> To describe evaluations of general practice care by patients with a chronic illness in 2009 and compare these with a previous study done in 1998. DESIGN: /st> A descriptive analysis of patients' evaluations, using data from the European practice assessment Cardio study on cardiovascular patients in eight European countries in 2009. We compared these evaluations with a subgroup of patients with self-defined chronic illness from the study in 1998, using a linear regression model. MAIN OUTCOME MEASURE: /st> Patients' evaluation of general practice using the EUROPEP questionnaire. The EUROPEP is a 23-item validated measure of patient evaluations of general practice care. RESULTS: /st> In 2009, 7472 patients from 251 practices participated in the study with an overall response rate of 49.6%. The percentage of patients with positive evaluations (good/excellent) was 80% or higher for all items, except for the waiting time. More positive evaluations were found in older patients, patients with a longer attachment to the practice, patients with a higher self-evaluation of their health, patients with fewer mental health problems and less pain/discomfort. The comparison between 1998 and 2009 showed no overall trends for all countries combined. Whereas English patients became fairly more positive about general practice in 2009, German patients became slightly less positive, although still more positive than English patients. CONCLUSION: /st> Overall, the patients' evaluations of general practice were very positive in family practice care in the years 1998 and 2009. The trends over the years need to be carefully interpreted over time
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