83 research outputs found

    Emeralds from the Delbegetey deposit (Kazakhstan): mineralogical characteristics and fluid-inclusion study

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    The aim of this study is to provide the first detailed mineralogical and fluid-inc1usion description of emeralds from the Delbegetey deposit (Kazakhstan). The characteristic features of Delbegetey emeralds are established: they have dissolution figures on crystal faces, bluish colour and distinct colour zoning; the refractive indices are ro = 1.566-1.570, E = 1.558-1.562, and the specific gravity is 2.65±0.005, relatively low for natural emeralds; they have very small concentrations of the impurities (Fe, Mg, Na and others) typical of other emeralds, and contain Cr and V; there is a significant preponderance of vapour in fluid inc1usions of all types and there is liquid-to-vapour homogenization of primary fluid inc1usions (at 395-420°C). The lattice oxygen isotope composition data obtained (0180 SMOW value of 11.3%0) situate the deposit within the range characteristic of other granite-related emerald deposits. Emerald crystallization took place in low-density (0.40-0.55 g/cm3 ) aqueous fluid, with the following chemical composition (mol.%): 75.6-97.4 HzO, 0.0-18.4 caz, 0.0-0.9 C~, and 4.06-9.65 wt.% NaCI equiv. salinity. According to the calculated isochores, the pressure offormation ofthe Delbegetey emeralds can be estimated at 570-1240 bar

    La franja aurífera de Xallas (Galicia occidental, España): Las mineralizaciones de Albores dentro de un contexto tectónico y metalogénico evolutivo.

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    Las mineralizaciones de oro de Albores (Galicia occidental) se encuadran dentro de una franja metalogĂ©nica N-S a NE de edad hercĂ­nica-tardihercĂ­nica (franja aurĂ­fera de Xallas). Dicha franja comprende una serie de indicios aurĂ­feros caracterizados por la presencia de una fase sulfurada rica en arsenopirita y otra metĂĄlica con oro/electrum. Estas mineralizaciones encajan generalmente en estructuras frĂĄgiles desarrolladas en zonas de cizalla de componente horizontal y vertical, que incluyen mĂ­lonitas, ultramilonitas, cataclasitas y brechas.Las mineralizaciones de Albores incluyen una paragĂ©nesis compleja consistente en arsenopirita, oro/electrum, pirrotina, marcasita, pirita, bismuto, bismutina, esfalerita, galena y calcopirita. Estudios de inclusionesfluidas en cuarzos acompañantes de la mineralizaciĂłn sugieren que Ă©sta fue depositada por fluidos acuoso-carbĂłnicos complejos de moderada baja salinidad (<56-9 por 100 eq. NaCI; salinidades mĂĄximas) operando en un rango de temperaturas epi a mesotermal (Th: 18Cl°-36Cl° CJ. Estas mineralizaciones se formaron durante un rĂ©gimen extensional desarrollado durante el perĂ­odo comprendido entre la fase deformativa 3 hercĂ­nica (D3; CarbonĂ­fero Medio) y el episodio frĂĄgil tardihercĂ­nico (CarbonĂ­fero Superior/PĂ©rmico Inferior}. La etapa extensional se caracterizĂł por el desarrollo de corredores milonĂ­ticos principalmente extensionales, de bajo ĂĄngulo (zona de cizalla de Xallas) con superposiciĂłn de estructuras frĂĄgiles sobre la fĂĄbrica dĂșctil, estructuras antiformes, y fallas normales de gran ĂĄngulo de carĂĄcter frĂĄgil

    Barriers to health care services for migrants living with HIV in Spain

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    BACKGROUND: In Spain, migrants are disproportionately affected by HIV and experience high rates of late diagnosis. We investigated barriers to health care access among migrants living with HIV (MLWH) in Spain. METHODS: Cross sectional electronic survey of 765 adult HIV-positive migrants recruited within 18 health care settings between July 2013 and July 2015. We collected epidemiological, demographic, behavioral and clinical data. We estimated the prevalence and risk factors of self-reported barriers to health care using multivariable logistic regression. RESULTS: Of those surveyed, 672 (88%) had information on health care access barriers: 23% were women, 63% from Latin America and Caribbean, 14% from Sub-Saharan Africa and 15% had an irregular immigration status. Men were more likely to report barriers than women (24% vs. 14%, P = 0.009). The main barriers were: lengthy waiting times for an appointment (9%) or in the clinic (7%) and lack of a health card (7%). Having an irregular immigration status was a risk factor for experiencing barriers for both men (OR: (4.0 [95%CI: 2.2–7.2]) and women (OR: 10.5 [95%CI: 3.1–34.8]). Men who experienced racial stigma (OR: 3.1 [95%CI: 1.9–5.1]) or food insecurity (OR: 2.1 [95%CI: 1.2–3.4]) were more likely to report barriers. Women who delayed treatment due to medication costs (6.3 [95%CI: 1.3–30.8]) or had a university degree (OR: 5.8 [95%CI: 1.3–25.1]) were more likely to report barriers. CONCLUSION: Health care barriers were present in one in five5 MLWH, were more common in men and were associated to legal entitlement to access care, perceived stigma and financial constraints

    Uncovering Ecosystem Service Bundles through Social Preferences

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    Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem’s capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem’s capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs

    LISTA NEGRA Y LISTA DE ALERTA DE ESPECIES EXÓTICAS INVASORAS ACUÁTICAS DE LA PENÍNSULA IBÉRICA - Ejercicio de exploraciĂłn del horizonte transnacional centrado en las especies exĂłticas invasoras acuĂĄticas de alto riesgo para las aguas interiores ibĂ©ricas.

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    Un objetivo importante de LIFE INVASAQUA es desarrollar herramientas que mejoren la gestión y sean mås eficientes en el marco de Alerta Temprana y Respuesta Råpida (EWRR) para las Especies Exóticas Invasoras (EEI) en la Península Ibérica. La exploración del horizonte para las EEI de alto riesgo es båsica para aplicar medidas que reduzcan las nuevas invasiones y para centrar los esfuerzos en las especies ya registradas. Desarrollamos un ejercicio transnacional de exploración del horizonte centrado en las aguas interiores de España y Portugal con el fin de proporcionar una lista negra de las EEI acuåticas actualmente establecidas y una lista de alerta de las EEI acuåticas potenciales que pueden suponer una amenaza para los ecosistemas acuåticos y los sectores socioeconómicos en el futuro. Para la exploración del horizonte seguimos un enfoque estructurado de 5 pasos que combinaba las pruebas existentes sobre las EEI con una puntuación de expertos de los taxones priorizados. En la lista negra final se priorizaron 126 EEI, que representan el 41,2% de los taxones exóticos registrados en las aguas continentales ibéricas. Las 24 primeras especies tenían un riesgo de impacto muy alto porque obtuvieron los valores måximos en el proceso de puntuación de la evaluación de riesgos. Ademås, la lista de alerta incluía 89 EEI con un riesgo significativo de invasión en la Península Ibérica en el futuro, estando 11 taxones en cabeza con un riesgo muy alto de invasión

    Search for the Xb and other hidden-beauty states in the π+π−ϒ(1S) channel at ATLAS

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    This Letter presents a search for a hidden-beauty counterpart of the X(3872) in the mass ranges of 10.05–10.31 GeV and 10.40–11.00 GeV, in the channel Xb→π+π−ϒ(1S)(→Ό+Ό−), using 16.2 fb−1 of pp   collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the Xb cross section and branching fraction, relative to those of the ϒ(2S), at the 95% confidence level using the CLS approach. These limits range from 0.8% to 4.0%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the ϒ(13DJ), , and states also reveal no significant signals

    Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

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    The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements and provide comparisons to detector simulations

    Measurement of indirect CP asymmetries in D-0 -&gt; K-K+ and D-0 -&gt; pi(-)pi(+) decays using semileptonic B decays

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    Time-dependent CPCP asymmetries in the decay rates of the singly Cabibbo-suppressed decays D0→K−K+D^0\rightarrow K^-K^+ and D0→π−π+D^0\rightarrow \pi^-\pi^+ are measured in pppp collision data corresponding to an integrated luminosity of 3.0 fb−1^{-1} collected by the LHCb experiment. The D0D^0 mesons are produced in semileptonic bb-hadron decays, where the charge of the accompanying muon is used to determine the initial state as D0D^0 or Dˉ0\bar{D}^0. The asymmetries in effective lifetimes between D0D^0 and Dˉ0\bar{D}^0 decays, which are sensitive to indirect CPCP violation, are determined to be \begin{align*} A_{\Gamma}(K^-K^+) = (-0.134 \pm 0.077 \; {}^{+0.026}_{-0.034})\% \, A_{\Gamma}(\pi^-\pi^+) = (-0.092\pm 0.145 \; {}^{+0.025}_{-0.033})\% \, \end{align*} where the first uncertainties are statistical and the second systematic. This result is in agreement with previous measurements and with the hypothesis of no indirect CPCP violation in D0D^0 decays.Comment: 20 pages, 4 figure
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