75 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

    Solid-State Microwave Electronics

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    Contains reports on six research projects.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-0300California Institute of Technology Contract 952568National Institutes of Health (Grant RR00317) from the Biotechnology Resources Branch, Division of Research Resource

    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 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

    Radio Astronomy

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    Contains reports on three research project.National Science Foundation (Grant GP-21348A#2)California Institute of Technology (Contract 952568)National Aeronautics and Space Administration (Grant NGR 22-009-421)U. S. Air Force - Electronic Systems Division (Contract F19628-73-C-0196

    Retroperitoneal haemorrhage in renal angiomyolipoma causing hepatic functional decompensation: a case report

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    Renal angiomyolipomata usually present as incidental findings on routine imaging, but rarely they may give rise to significant haemorrhage. If bleeding occurs, first-line treatment is currently angiography with selective embolisation. Prophylactic embolisation may be considered in some cases, depending on lesion size and patient co-morbidities

    Gene Transfer to Chicks Using Lentiviral Vectors Administered via the Embryonic Chorioallantoic Membrane

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    The lack of affordable techniques for gene transfer in birds has inhibited the advancement of molecular studies in avian species. Here we demonstrate a new approach for introducing genes into chicken somatic tissues by administration of a lentiviral vector, derived from the feline immunodeficiency virus (FIV), into the chorioallantoic membrane (CAM) of chick embryos on embryonic day 11. The FIV-derived vectors carried yellow fluorescent protein (YFP) or recombinant alpha-melanocyte-stimulating hormone (α-MSH) genes, driven by the cytomegalovirus (CMV) promoter. Transgene expression, detected in chicks 2 days after hatch by quantitative real-time PCR, was mostly observed in the liver and spleen. Lower expression levels were also detected in the brain, kidney, heart and breast muscle. Immunofluorescence and flow cytometry analyses confirmed transgene expression in chick tissues at the protein level, demonstrating a transduction efficiency of ∼0.46% of liver cells. Integration of the viral vector into the chicken genome was demonstrated using genomic repetitive (CR1)-PCR amplification. Viability and stability of the transduced cells was confirmed using terminal deoxynucleotidyl transferase (dUTP) nick end labeling (TUNEL) assay, immunostaining with anti-proliferating cell nuclear antigen (anti-PCNA), and detection of transgene expression 51 days post transduction. Our approach led to only 9% drop in hatching efficiency compared to non-injected embryos, and all of the hatched chicks expressed the transgenes. We suggest that the transduction efficiency of FIV vectors combined with the accessibility of the CAM vasculature as a delivery route comprise a new powerful and practical approach for gene delivery into somatic tissues of chickens. Most relevant is the efficient transduction of the liver, which specializes in the production and secretion of proteins, thereby providing an optimal target for prolonged study of secreted hormones and peptides

    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
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