156 research outputs found

    Modelos predictivos de la distribución preferencial de larvas de peces demersales en la parte sur de la corriente de California

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    Habitat characterization provides predictive information about the distribution of species and is useful for as­sessing habitat quality and population stability. Larval abundance of six frequent and abundant demersal species and the relationship of each with the environment were analysed through generalized additive models to determine their preferential distribution and predictive response to the environmental variables in the southern part of the California Current (25-31°N) between two periods of data collection: 1997-2000 and 2006-2010. Essentially, the main associated variables governing the distribution patterns were related to common and oceanographic characteristics of the water column (temperature and salinity at 50 m depth, dynamic height and degree of water column stratification); however, the set of variables and their ranges are usually species-specific. Species of northern distribution, Sebastes sp. and Citharichtys stigmaeus, were recorded mainly in newly emerged, relatively unstratified waters characterized by a shallow mixed layer and low temperatures. Low dynamic height values were the most significant predictor of larval distribution for Merluccius productus. Citharichthys xanthostigma and Symphurus atricaudus were widespread, distributed across the study area mainly in autumn in unstratified or stratified waters and at a shallow mixed layer. Particularly C. Xanthostigma and S. Lucioceps were related to high dynamic height val­ues, likely influenced by a coastal flow towards the pole, as evidenced by counter-currents.La caracterización del hábitat proporciona información predictiva sobre la distribución de las especies y es útil para evaluar la calidad del hábitat y estabilidad de la población. La abundancia larval de seis especies demersales frecuentes y abundantes y de su relación con el medio ambiente se analizaron a través de modelos aditivos generalizados (GAM) para determinar su distribución preferencial y respuesta a las variables ambientales en la parte sur de la corriente de California (25-31°N) entre dos periodos de datos recolectados 1997-2000 y 2006-2010. Esencialmente, las principales variables aso­ciadas que rigen los patrones de distribución fueron en términos de las variables comunes y oceanográficas de la columna de agua (temperatura y salinidad a 50 m de profundidad, altura dinámica y grado de estratificación de la columna de agua), sin embargo, el conjunto de variables y los rangos suelen ser específicos de la especie. Especies con distribución norteña, Sebas­tes sp. y Citharichtys stigmaeus, se registraron principalmente en aguas de surgencia, identificadas por aguas relativamente no estratificadas, poca profundidad de capa mixta y menor temperatura; y menor altura dinámica, como el predictor más significativo de la distribución de larvas de Merluccius productus. Citharichthys xanthostigma y Symphurus atricaudus se distribuyeron ampliamente a lo largo del área de estudio preferentemente en otoño, en aguas no estratificadas o estratificadas y baja profundidad de la capa de mezcla, pero particularmente C. Xanthostigma y S. Lucioceps en valores altos de alturas dinámicas probablemente influenciadas por el flujo costero hacia el polo indicado por las contracorrientes

    Charged-current inclusive neutrino cross sections in the SuperScaling model

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    SuperScaling model (SuSA) predictions to neutrino-induced charged-current π+ production in the Δ-resonance region are explored under MiniBooNE experimental conditions. The SuSA charged-current π+ results are in good agreement with data on neutrino flux-averaged double-differential cross sections. The SuSA model for quasielastic scattering and its extension to the pion production region are used for predictions of charged-current inclusive neutrino- nucleus cross sections. The contribution of two-particle-two-hole vector meson-exchange current excitations is also considered within a fully relativistic model. Results are compared with the T2K experimental data for inclusive scattering.España, DGI y Fundación FEDER FIS2011-28738-C02-01, FPA2013-41267Junta de Andalucía CSD2007-0004

    Meson-exchange currents and quasielastic predictions for charged-current neutrino-12C scattering in the superscaling approach

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    We evaluate and discuss the impact of meson-exchange currents (MECs) on charged-current quasielastic neutrino cross sections. We consider the nuclear transverse response arising from two-particle two-hole states excited by the action of electromagnetic, purely isovector meson-exchange currents in a fully relativistic framework based on the work by the Torino Collaboration [A. D. Pace, M. Nardi, W. M. Alberico, T. W. Donnelly, and A. Molinari, Nucl. Phys. A726, 303 (2003)]. An accurate parametrization of this MEC response as a function of the momentum and energy transfers involved is presented. Results of neutrino-nucleus cross sections using this MEC parametrization together with a recent scaling approach for the one-particle one-hole contributions (named SuSAv2) are compared with experimental data.DGI FIS2011-28738-C02-0Junta de Andalucía QM-160U.S. Department of Energy DE- SC001109DGI FIS2011-24149Junta de Andalucía FQM22

    Archaeosomes made of Halorubrum tebenquichense total polar lipids: A new source of adjuvancy

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    Background: Archaeosomes (ARC), vesicles prepared from total polar lipids (TPL) extracted from selected genera and species from the Archaea domain, elicit both antibody and cell-mediated immunity to the entrapped antigen, as well as efficient cross priming of exogenous antigens, evoking a profound memory response. Screening for unexplored Archaea genus as new sources of adjuvancy, here we report the presence of two new Halorubrum tebenquichense strains isolated from grey crystals (GC) and black mood (BM) strata from a littoral Argentinean Patagonia salt flat. Cytotoxicity, intracellular transit and immune response induced by two subcutaneous (sc) administrations (days 0 and 21) with BSA entrapped in ARC made of TPL either form BM (ARC-BM) and from GC (ARC-GC) at 2% w/w (BSA/lipids), to C3H/HeN mice (25 μg BSA, 1.3 mg of archaeal lipids per mouse) and boosted on day 180 with 25 μg of bare BSA, were determined. Results: DNA G+C content (59.5 and 61.7% mol BM and GC, respectively), 16S rDNA sequentiation, DNA-DNA hybridization, arbitrarily primed fingerprint assay and biochemical data confirmed that BM and GC isolates were two non-previously described strains of H. tebenquichense. Both multilamellar ARC mean size were 564 ± 22 nm, with -50 mV zeta-potential, and were not cytotoxic on Vero cells up to 1 mg/ml and up to 0.1 mg/ml of lipids on J-774 macrophages (XTT method). ARC inner aqueous content remained inside the phago-lysosomal system of J-774 cells beyond the first incubation hour at 37°C, as revealed by pyranine loaded in ARC. Upon subcutaneous immunization of C3H/HeN mice, BSA entrapped in ARC-BM or ARC-GC elicited a strong and sustained primary antibody response, as well as improved specific humoral immunity after boosting with the bare antigen. Both IgG1 and IgG2a enhanced antibody titers could be demonstrated in long-term (200 days) recall suggesting induction of a mixed Th1/Th2 response. Conclusion: We herein report the finding of new H. tebenquichense non alkaliphilic strains in Argentinean Patagonia together with the adjuvant properties of ARC after sc administration in mice. Our results indicate that archaeosomes prepared with TPL from these two strains could be successfully used as vaccine delivery vehicles

    Petrología y geoquímica del magmatismo Jurásico-Cretácico vinculado a las mineralizaciones de Fe-Cu del cerro Pepita, SO del Chubut

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    Fe-Gu skarn arel hydrothermal deposils, al the Pepita Hill ('Al Chubut Pruvince), are relató to Jurassic-Cretaccous magmatism. Detailed petrographic studies arel Mole rock cieocliernical analyses perforrned on andesite fk-D.vs (Lago La Plata Fm) arad rhyolític-dacitic dikesand subvolcanic bodies (ElGato Fm) allowed tocharacterize the meta-aluminous to weakly per-aluminous, tholeiite-calc-alkaline signature, associated to a magrnaticarcsetting. The iron source of the El Abuelo ore deposit is possiblyrelated to the tholeiitic affinity of rocks from Lago La Plata Forrnation

    Sequential Electron Transport and Vibrational Excitations in an Organic Molecule Coupled to Few-Layer Graphene Electrodes

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    Graphene electrodes are promising candidates to improvereproducibility and stability in molecular electronics through new electrode−molecule anchoring strategies. Here we report sequentialelectron transport in few-layer graphene transistors containing individualcurcuminoid-based molecules anchored to the electrodes via π −π orbital bonding. We show the coexistence of inelastic co-tunneling excitations with single-electron transport physics due to an intermediate molecule−electrode coupling; we argue that an intermediate electron−phononcoupling is the origin of these vibrational-assisted excitations. Theseexperimental observations are complemented with density functionaltheory calculations to model electron transport and the interaction between electrons and vibrational modes of thecurcuminoid molecule. We find that the calculated vibrational modes of the molecule are in agreement with theexperimentally observed excitation

    Archaeosomes made of Halorubrum tebenquichense total polar lipids: A new source of adjuvancy

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    Background: Archaeosomes (ARC), vesicles prepared from total polar lipids (TPL) extracted from selected genera and species from the Archaea domain, elicit both antibody and cell-mediated immunity to the entrapped antigen, as well as efficient cross priming of exogenous antigens, evoking a profound memory response. Screening for unexplored Archaea genus as new sources of adjuvancy, here we report the presence of two new Halorubrum tebenquichense strains isolated from grey crystals (GC) and black mood (BM) strata from a littoral Argentinean Patagonia salt flat. Cytotoxicity, intracellular transit and immune response induced by two subcutaneous (sc) administrations (days 0 and 21) with BSA entrapped in ARC made of TPL either form BM (ARC-BM) and from GC (ARC-GC) at 2% w/w (BSA/lipids), to C3H/HeN mice (25 μg BSA, 1.3 mg of archaeal lipids per mouse) and boosted on day 180 with 25 μg of bare BSA, were determined. Results: DNA G+C content (59.5 and 61.7% mol BM and GC, respectively), 16S rDNA sequentiation, DNA-DNA hybridization, arbitrarily primed fingerprint assay and biochemical data confirmed that BM and GC isolates were two non-previously described strains of H. tebenquichense. Both multilamellar ARC mean size were 564 ± 22 nm, with -50 mV zeta-potential, and were not cytotoxic on Vero cells up to 1 mg/ml and up to 0.1 mg/ml of lipids on J-774 macrophages (XTT method). ARC inner aqueous content remained inside the phago-lysosomal system of J-774 cells beyond the first incubation hour at 37°C, as revealed by pyranine loaded in ARC. Upon subcutaneous immunization of C3H/HeN mice, BSA entrapped in ARC-BM or ARC-GC elicited a strong and sustained primary antibody response, as well as improved specific humoral immunity after boosting with the bare antigen. Both IgG1 and IgG2a enhanced antibody titers could be demonstrated in long-term (200 days) recall suggesting induction of a mixed Th1/Th2 response. Conclusion: We herein report the finding of new H. tebenquichense non alkaliphilic strains in Argentinean Patagonia together with the adjuvant properties of ARC after sc administration in mice. Our results indicate that archaeosomes prepared with TPL from these two strains could be successfully used as vaccine delivery vehicles.Facultad de Ciencias Exacta

    Osteocyte deficiency in hip fractures

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    Osteocytes play a central role in the regulation of bone remodeling. The aim of this study was to explore osteocyte function, and particularly the expression of SOST, a Wnt inhibitor, in patients with hip fractures. Serum sclerostin levels were measured by ELISA. The expression of several osteocytic genes was studied by quantitative PCR in trabecular samples of the femoral head of patients with hip fractures, hip osteoarthritis and control subjects. The presence of sclerostin protein and activated caspase 3 was revealed by immunostaining. There were no significant differences in serum sclerostin between the three groups. Patients with fractures have fewer lacunae occupied by osteocytes (60 ± 5% vs. 64 ± 6% in control subjects, P = 0.014) and higher numbers of osteocytes expressing activated caspase 3, a marker of apoptosis. The proportion of sclerostin-positive lacunae was lower in patients with fractures than in control subjects (34 ± 11% vs. 69 ± 10%, P = 2 × 10(-8)). The proportion of sclerostin-positive osteocytes was also lower in patients. RNA transcripts of SOST, FGF23 and PHEX were also less abundant in fractures than in control bones (P = 0.002, 5 × 10(-6), and 0.04, respectively). On the contrary, in patients with osteoarthritis, there was a decreased expression of SOST and FGF23, without differences in PHEX transcripts or osteocyte numbers. Osteocyte activity is altered in patients with hip fractures, with increased osteocyte apoptosis and reduced osteocyte numbers, as well as decreased transcription of osteocytic genes. Therefore, these results suggest that an osteocyte deficiency may play a role in the propensity to hip fractures

    The Lick AGN Monitoring Project 2016 : velocity-resolved Hβ lags in luminous Seyfert galaxies

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    Funding: K.H. acknowledges support from STFC grant ST/R000824/1.We carried out spectroscopic monitoring of 21 low-redshift Seyfert 1 galaxies using the Kast double spectrograph on the 3 m Shane telescope at Lick Observatory from April 2016 to May 2017. Targetingactive galactic nuclei (AGN) with luminosities of λLλ(5100 Å) ≈ 1044 erg s−1 and predicted Hβ lags of∼ 20–30 days or black hole masses of 107–108.5 M⊙, our campaign probes luminosity-dependent trends in broad-line region (BLR) structure and dynamics as well as to improve calibrations for single-epoch estimates of quasar black hole masses. Here we present the first results from the campaign, including Hβ emission-line light curves, integrated Hβ lag times (8–30 days) measured against V -band continuum light curves, velocity-resolved reverberation lags, line widths of the broad Hβ components, and virial black hole mass estimates (107.1–108.1 M⊙). Our results add significantly to the number of existing velocity-resolved lag measurements and reveal a diversity of BLR gas kinematics at moderately high AGN luminosities. AGN continuum luminosity appears not to be correlated with the type of kinematics that its BLR gas may exhibit. Follow-up direct modeling of this dataset will elucidate the detailed kinematics and provide robust dynamical black hole masses for several objects in this sample.Publisher PDFPeer reviewe

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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