5,598 research outputs found

    Ionizing Radiation, an Instrument in Chemical Evolution Studies: Scope and Perspectives

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    The study of synthesis and stability of molecules in different environments it’s been part of chemistry evolution and origin of life studies for more than 70 years. Various kinds of ionizing radiation have been analyzed as possible sources of energy for the transformations undergone by the first organic molecules. Now experimental and computational simulation approaches continue with different groups of organic molecules, in search for more information that help us to understand and reconstruct somehow the mechanisms that toke place on early Earth and space. In that line, this paper presents first approach of keto acids stability to ionizing radiation, an interesting group of molecules involved in the Krebs cycle and glycolysis. Preliminary results obtained by HPLC/UV analysis of irradiating aqueous solutions of 5 keto acids ranging from 3 to 6 carbons with a 60Co gamma ray source, using doses up to 53 kGy, show different stabilities and a general tendency of shifting the keto-enol equilibrium to the enol tautomer before decomposition

    Estradiol valerate and alcohol intake: dose-response assessments

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    BACKGROUND: An injection of estradiol valerate (EV) provides estradiol for a prolonged period. Recent research indicates that a single 2.0 mg injection of EV modifies a female rat's appetite for alcoholic beverages. This research extends the initial research by assessing 8 doses of EV (from .001 to 2.0 mg/female rat), as well assessing the effects of 2.0 mg EV in females with ovariectomies. RESULTS: With the administration of EV, there was a dose-related loss of bodyweight reaching the maximum loss, when it occurred, at about 4 days after injections. Subsequently, rats returned to gaining weight regularly. Of the doses tested, only the 2.0 mg dose produced a consistent increase in intake of ethanol during the time previous research indicated that the rats would show enhanced intakes. There was, however, a dose-related trend for smaller doses to enhance intakes. Rats with ovariectomies showed a similar pattern of effects, to intact rats, with the 2 mg dose. After extensive histories of intake of alcohol, both placebo and EV-treated females had estradiol levels below the average measured in females without a history of alcohol-intake. CONCLUSION: The data support the conclusion that pharmacological doses of estradiol can produce enduring changes that are manifest as an enhanced appetite for alcoholic beverages. The effect can occur among females without ovaries

    Recognition of host Clr-b by the inhibitory NKR-P1B receptor provides a basis for missing-self recognition

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    The interaction between natural killer (NK) cell inhibitory receptors and their cognate ligands constitutes a key mechanism by which healthy tissues are protected from NK cell-mediated lysis. However, self-ligand recognition remains poorly understood within the prototypical NKR-P1 receptor family. Here we report the structure of the inhibitory NKR-P1B receptor bound to its cognate host ligand, Clr-b. NKR-P1B and Clr-b interact via a head-to-head docking mode through an interface that includes a large array of polar interactions. NKR-P1B:Clr-b recognition is extremely sensitive to mutations at the heterodimeric interface, with most mutations severely impacting both Clr-b binding and NKR-P1B receptor function to implicate a low affinity interaction. Within the structure, two NKR-P1B:Clr-b complexes are cross-linked by a non-classic NKR-P1B homodimer, and the disruption of homodimer formation abrogates Clr-b recognition. These data provide an insight into a fundamental missing-self recognition system and suggest an avidity-based mechanism underpins NKR-P1B receptor function

    A Systems Genetics Approach Implicates USF1, FADS3, and Other Causal Candidate Genes for Familial Combined Hyperlipidemia

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    We hypothesized that a common SNP in the 3' untranslated region of the upstream transcription factor 1 (USF1), rs3737787, may affect lipid traits by influencing gene expression levels, and we investigated this possibility utilizing the Mexican population, which has a high predisposition to dyslipidemia. We first associated rs3737787 genotypes in Mexican Familial Combined Hyperlipidemia (FCHL) case/control fat biopsies, with global expression patterns. To identify sets of co-expressed genes co-regulated by similar factors such as transcription factors, genetic variants, or environmental effects, we utilized weighted gene co-expression network analysis (WGCNA). Through WGCNA in the Mexican FCHL fat biopsies we identified two significant Triglyceride (TG)-associated co-expression modules. One of these modules was also associated with FCHL, the other FCHL component traits, and rs3737787 genotypes. This USF1-regulated FCHL-associated (URFA) module was enriched for genes involved in lipid metabolic processes. Using systems genetics procedures we identified 18 causal candidate genes in the URFA module. The FCHL causal candidate gene fatty acid desaturase 3 (FADS3) was associated with TGs in a recent Caucasian genome-wide significant association study and we replicated this association in Mexican FCHL families. Based on a USF1-regulated FCHL-associated co-expression module and SNP rs3737787, we identify a set of causal candidate genes for FCHL-related traits. We then provide evidence from two independent datasets supporting FADS3 as a causal gene for FCHL and elevated TGs in Mexicans

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Estudio aerobiológico de la diversidad polínica y su potencial alergénico en el oasis del sur de Mendoza, Argentina

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    Los conocimientos provenientes del campo de estudio de la Aerobiología favorecen el análisis inmunológico de los alérgenos atmosféricos procedentes de polen y esporas fúngicas. Esto posibilita conocer la carga alergénica del aire en el ambiente y de esta manera, valorar mejor la relación exposición / reacción / clínica en los pacientes en tratamiento por alergias. No existen estudios previos de este tema realizados a nivel regional ni provincial en Mendoza. Una base de datos de identificación de posibles alérgenos provenientes de la polinización de espacios verdes urbanos en la ciudad de San Rafael y General Alvear contribuye a la epidemiología ambiental sobre las afecciones alérgicas respiratorias inducidas por polen y esporas. En esta presentación damos a conocer un proyecto de investigación en Aerobiología, con el fin de generar conocimiento aerobiológico de la zona urbana del oasis del sur mendocino (San Rafael y General Alvear), que contribuye a conocer la carga alergénica proveniente de granos de polen y esporas presentes en el ambiente. Para ello, se están llevando a cabo tres líneas de trabajo que consisten en: (1) el relevamiento, localización y mapeo de la vegetación urbana en floración, (2) la elaboración de una colección de referencia palinológica, y (3) el muestreo diario de aeropartículas atmosféricas urbanas. Se presentan los resultados preliminares obtenidos desde el inicio del proyecto y se muestran las líneas de trabajo que seguirá el curso de esta investigación. A futuro, los estudios aerobiológicos permitirían el desarrollo de programas de seguimiento, prevención y control en los índices de la cantidad de polen y esporas presentes en la atmósfera. Esta herramienta puede describir el potencial alergénico en espacios urbanos sus perjuicios ambientales. De esta manera, una investigación con estas características puede ser un aporte directo a la formulación de políticas de salud pública y planificación urbana de la ciudad.Fil: Guerci, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; Argentina. Instituto de Enseñanza Superior 9-011 del Atuel; ArgentinaFil: Rojo, Leandro David. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; ArgentinaFil: Indiveri, Martina. Gobierno de la Provincia de Mendoza. Hospital Teodoro Schestakow.; ArgentinaFil: Nuñez Sada, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Farina, Lucia. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; ArgentinaFil: Aguilar, Mariano. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Llano, Carina Lourdes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Mendoza; ArgentinaFil: Lucero, A.. Universidad de Mendoza; ArgentinaFil: Negreira, Gabriel Alfredo. Instituto de Enseñanza Superior 9-011 del Atuel; ArgentinaFil: Vazquez, Maria Soledad. Universidad Tecnologica Nacional. Facultad Reg.san Rafael. Instituto de Evolucion, Ecologia Historica y Ambiente. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mendoza. Instituto de Evolucion, Ecologia Historica y Ambiente.; ArgentinaFil: Rodriguez, L. F.. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Gallardo, C. A.. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Giraudo, S. B.. Museo Municipal de Historia Natural San Rafael - Unidad Asociada al CCT Mendoza; ArgentinaXIV Encuentro del Centro Internacional de Ciencias de la TierraSan RafaelArgentinaCentro Internacional para Estudios de la TierraComisión Nacional de Energía AtómicaUniversidad Nacional de CuyoUniversidad Tecnológica Nacional. Facultad Regional San Rafae

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30
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