210 research outputs found

    Preliminary conceptual model of the Cerro Blanco caldera-hosted geothermal system (Southern Puna, Argentina): Inferences from geochemical investigations.

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    The Cerro Blanco Caldera (CBC) is the youngest collapse caldera system in the Southern Central Andes (Southern Puna, Argentina). The CBC is subsiding with at an average velocity of 0.87 cm/year and hosts an active geothermal system. A geochemical characterization of emitted fluids was carried out based on the chemical and isotopic compositions of fumaroles, and thermal and cold springs discharged in this volcanic area with the aim of constructing the first hydrogeochemical conceptual model and preliminary estimate the geothermal potential. The main hydrothermal reservoir, likely hosted within the pre-caldera basement rocks, has a Na+-Clˉ(HCO3)ˉ composition with estimated temperatures ≥135 °C. The unconsolidated, fine-grained Cerro Blanco ignimbrite likely acts as the cap-rock of the hydrothermal system. The presence of phreatic eruption breccias in the surrounding area of the geothermal fumaroles supports the effectiveness of the pyroclastic deposit as sealing rocks. The isotopic data of water (δ18O and δD) indicate a meteoric recharge of the hydrothermal reservoir, suggesting as recharge areas the sectors surrounding the CBC, mainly towards the W and NW where large outcrops of the pre-caldera basement exist. A fault-controlled hydraulic connection between the hot springs and the hydrothermal reservoir is proposed for the Los Hornitos area. The fumaroles show the typical compositional features of hydrothermal fluids, being dominated by water vapor with significant concentrations of H2S, CH4 and H2. Considering the high geothermal gradient of this area (∼104 °C/km) and the relatively high fraction of mantle He (∼39%) calculated on the basis of the measured R/Ra values, the hydrothermal aquifer likely receives inputs of magmatic fluids from the degassing magma chamber. The preliminary geothermal potential at CBC was evaluated with the Volume Method, calculating up to E = 11.4*1018 J. Both the scarce presence of superficial thermal manifestations and the occurrence of an efficient cap-rock likely contribute to minimize the loss of thermal energy from the reservoir. The results here presented constitute the necessary base of knowledge for further accurate assessment of the geothermal potential and ultimately the implementation of the geothermal resource as a viable energy alternative for small localities or mining facilities isolated from the National Interconnected System due to their remote localization.Published1022136A. Geochimica per l'ambiente e geologia medicaJCR Journa

    Caracterización del HLA en una familia colombiana endogámica con síndrome de Usher

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    Resumen El síndrome de Usher es una enfermedad autosómica recesiva que se caracteriza por presentar retinitis pigmentosa, hipoacusia neurosensorial congénita y disfunción vestibular. El propósito de este trabajo es realizar la caracterización de hla en una familia colombiana endogámica que presenta síndrome de Usher. La metodología consiste en que con un previo consentimiento informado se realizó una genealogía de la familia y a cuatro pacientes confirmados clínicamente con síndrome de Usher y a cuatro fenotípicamente sanos se les tomó 5 ml de sangre periférica en tubos de venopunción con edta para luego realizar el aislamiento del dna por la técnica de salting out, conservados en buffer te a -8 °C y ajustada la muestra a una concentración de 8 μg/ml. Posteriormente a través de la técnica de pcr-ssp de mediana resolución se caracterizaron los antígenos de hla *a, *b, *drb1 y *dqb1. Los resultados obtenidos indican que la familia oriunda del Departamento del Huila presenta una marcada endogamia detectándose que todos los hermanos afectados, sus padres son hermanos también y una de las parejas a su vez tuvo una niña afectada, por lo que sus abuelos y padres son hermanos. En lo referente al hla, los alelos más frecuentemente encontrados fueron a30 b42 dr1 dq5 y a3 b45 dr12 y dq7, que no están asociados a la enfermedad. Estos resultados sugieren que dada la endogamia que muestra esta familia se presenta una gran acumulación de polimorfismos y mutaciones, por lo que es necesario realizar un proceso de asesoría genética para disminuir el riesgo de recurrencia. Abstract Usher syndrome is an autosomal recessive disease characterized by retinitis pigmentosa, congenital sensorineural hearing loss and vestibular dysfunction. The purpose of this work was to characterize hla in an inbred Colombian family that presents Usher Syndrome. The Methodology consisted in that a genealogy of the family was made and previous informed consent, from four patients clinically confirmed with Usher Syndrome and four phenotypically healthy patients 5 ml of peripheral blood were taken in venipuncture tubes with edta and then the dna isolation was performed with the technique of salting out, preserved in te buffer at -8 °C and adjusted the sample to a concentration of 8 μg/ml. The hla *A, *B, *DRB1 and *DQB1 antigens were then characterized by the medium-resolution pcr-ssp techniqu

    Caracterización del HLA en una familia colombiana endogámica con síndrome de Usher

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    Resumen El síndrome de Usher es una enfermedad autosómica recesiva que se caracteriza por presentar retinitis pigmentosa, hipoacusia neurosensorial congénita y disfunción vestibular. El propósito de este trabajo es realizar la caracterización de hla en una familia colombiana endogámica que presenta síndrome de Usher. La metodología consiste en que con un previo consentimiento informado se realizó una genealogía de la familia y a cuatro pacientes confirmados clínicamente con síndrome de Usher y a cuatro fenotípicamente sanos se les tomó 5 ml de sangre periférica en tubos de venopunción con edta para luego realizar el aislamiento del dna por la técnica de salting out, conservados en buffer te a -8 °C y ajustada la muestra a una concentración de 8 μg/ml. Posteriormente a través de la técnica de pcr-ssp de mediana resolución se caracterizaron los antígenos de hla *a, *b, *drb1 y *dqb1. Los resultados obtenidos indican que la familia oriunda del Departamento del Huila presenta una marcada endogamia detectándose que todos los hermanos afectados, sus padres son hermanos también y una de las parejas a su vez tuvo una niña afectada, por lo que sus abuelos y padres son hermanos. En lo referente al hla, los alelos más frecuentemente encontrados fueron a30 b42 dr1 dq5 y a3 b45 dr12 y dq7, que no están asociados a la enfermedad. Estos resultados sugieren que dada la endogamia que muestra esta familia se presenta una gran acumulación de polimorfismos y mutaciones, por lo que es necesario realizar un proceso de asesoría genética para disminuir el riesgo de recurrencia. Abstract Usher syndrome is an autosomal recessive disease characterized by retinitis pigmentosa, congenital sensorineural hearing loss and vestibular dysfunction. The purpose of this work was to characterize hla in an inbred Colombian family that presents Usher Syndrome. The Methodology consisted in that a genealogy of the family was made and previous informed consent, from four patients clinically confirmed with Usher Syndrome and four phenotypically healthy patients 5 ml of peripheral blood were taken in venipuncture tubes with edta and then the dna isolation was performed with the technique of salting out, preserved in te buffer at -8 °C and adjusted the sample to a concentration of 8 μg/ml. The hla *A, *B, *DRB1 and *DQB1 antigens were then characterized by the medium-resolution pcr-ssp techniqu

    Caracterización del HLA en una familia colombiana endogámica con síndrome de Usher

    Get PDF
    El síndrome de Usher es una enfermedad autosómica recesiva que se caracteriza por presentar retinitis pigmentosa, hipoacusia neurosensorial congénita y disfunción vestibular. El propósito de este trabajo es realizar la caracterización de hla en una familia colombiana endogámica que presenta síndrome de Usher. La metodología consiste en que con un previo consentimiento informado se realizó una genealogía de la familia y a cuatro pacientes confirmados clínicamente con síndrome de Usher y a cuatro fenotípicamente sanos se les tomó 5 ml de sangre periférica en tubos de venopunción con edta para luego realizar el aislamiento del dna por la técnica de salting out, conservados en buffer te a -8 °C y ajustada la muestra a una concentración de 8 μg/ml. Posteriormente a través de la técnica de pcr-ssp de mediana resolución se caracterizaron los antígenos de hla *a, *b, *drb1 y *dqb1. Los resultados obtenidos indican que la familia oriunda del Departamento del Huila presenta una marcada endogamia detectándose que todos los hermanos afectados, sus padres son hermanos también y una de las parejas a su vez tuvo una niña afectada, por lo que sus abuelos y padres son hermanos. En lo referente al hla, los alelos más frecuentemente encontrados fueron a30 b42 dr1 dq5 y a3 b45 dr12 y dq7, que no están asociados a la enfermedad. Estos resultados sugieren que dada la endogamia que muestra esta familia se presenta una gran acumulación de polimorfismos y mutaciones, por lo que es necesario realizar un proceso de asesoría genética para disminuir el riesgo de recurrencia

    Dichotomy of Tyrosine Hydroxylase and Dopamine Regulation between Somatodendritic and Terminal Field Areas of Nigrostriatal and Mesoaccumbens Pathways

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    Measures of dopamine-regulating proteins in somatodendritic regions are often used only as static indicators of neuron viability, overlooking the possible impact of somatodendritic dopamine (DA) signaling on behavior and the potential autonomy of DA regulation between somatodendritic and terminal field compartments. DA reuptake capacity is less in somatodendritic regions, possibly placing a greater burden on de novo DA biosynthesis within this compartment to maintain DA signaling. Therefore, regulation of tyrosine hydroxylase (TH) activity may be particularly critical for somatodendritic DA signaling. Phosphorylation of TH at ser31 or ser40 can increase activity, but their impact on L-DOPA biosynthesis in vivo is unknown. Thus, determining their relationship with L-DOPA tissue content could reveal a mechanism by which DA signaling is normally maintained. In Brown-Norway Fischer 344 F1 hybrid rats, we quantified TH phosphorylation versus L-DOPA accumulation. After inhibition of aromatic acid decarboxylase, L-DOPA tissue content per recovered TH protein was greatest in NAc, matched by differences in ser31, but not ser40, phosphorylation. The L-DOPA per catecholamine and DA turnover ratios were significantly greater in SN and VTA, suggesting greater reliance on de novo DA biosynthesis therein. These compartmental differences reflected an overall autonomy of DA regulation, as seen by decreased DA content in SN and VTA, but not in striatum or NAc, following short-term DA biosynthesis inhibition from local infusion of the TH inhibitor α-methyl-p-tyrosine, as well as in the long-term process of aging. Such data suggest ser31 phosphorylation plays a significant role in regulating TH activity in vivo, particularly in somatodendritic regions, which may have a greater reliance on de novo DA biosynthesis. Thus, to the extent that somatodendritic DA release affects behavior, TH regulation in the midbrain may be critical for DA bioavailability to influence behavior

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

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    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentreofmassframeisusedtosuppressthelargemultijetbackground.ThecrosssectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

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    A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

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    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV
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