35 research outputs found

    Karst in conglomerates in Catalonia (Spain): morphological forms and sedimentary sequence types recorded on archaeological sites

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    This article aims to make the karst morphological forms to be found in conglomerate rocks, as well as the sedimentary sequence types recorded in such deposits, more widely known. Particular attention is paid to points where prehistoric occupation has been traced, sites such as: the Font Major Cave (Espluga de Francoli, Tarragona), the Hort de la Boquera, the Filador Rock-shelter and the Colls Rock-shelter (Margalef de Montsant, Tarragona), and the Parco Cave (Alôs de Balaguer, Lleida). By means of this approach the characteristics of karst deposits in conglomerate rocks are analyzed both from an archaeological and a sedimentary point of view

    Avalanche of stimulated forward scattering in high harmonic generation

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    © 2016 [Optical Society of America]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.Optical amplifiers in all ranges of the electromagnetic spectrum exhibit an essential characteristic, namely the input signal during the propagation in the amplifier medium is multiplied by the avalanche effect of the stimulated emission to produce exponential growth. We perform a theoretical study motivated and supported by experimental data on a He gas amplifier driven by intense 30-fs-long laser pulses and seeded with attosecond pulse trains generated in a separated Ne gas jet. We demonstrate that the strong-field theory in the frame of high harmonic generation fully supports the appearance of the avalanche effect in the amplification of extreme ultraviolet attosecond pulse trains. We theoretically separate and identify different physical processes taking part in the interaction and we demonstrate that X-ray parametric amplification dominates over others. In particular, we identify strong-field mediated intrapulse X-ray parametric processes as decisive for amplification at the single-atom level. We confirm that the amplification takes place at photon energies where the amplifier is seeded and when the seed pulses are perfectly synchronized with the driving strong field in the amplifier. Furthermore, propagation effects, phase matching and seed synchronization can be exploited to tune the amplified spectral range within the seed bandwidth.Peer ReviewedPostprint (author's final draft

    Prospecció geoarqueològica del curs mitjà del Segre (Artesa de Segre, Foradada, Cubells i Alòs de Balaguer, La Noguera)

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    La prospecció geoarqueològica té com a objectiu la recerca d'assentaments arqueològics mitjançant la informació geomorfològica i edàfica que ens proporciona l'estudi dels dipòsits quaternaris; també permet establir una correlació entre l'evolució del relleu i les ocupacions antròpiques. L'àrea d'aquest estudi és la compresa entre Artesa de Segre i Alòs de Balaguer. Van suscitar la intervenció els treballs que es duen a terme a la cova del Parco (Alòs de Balaguer) a fi de localitzar altres possibles emplaçaments arqueològics i dipòsits quaternaris que complementin les investigacions desenvolupades en aquest indret

    Competències i habilitats transversals entre geologia i arqueologia prehistòrica

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    En aquest treball es desenvolupa una proposta concreta per abordar alguns dels objectius pedagògics, com ara la transversalitat, el treball en equip o la necessitat d'incrementar els coneixements pràctics. La perspectiva des de la que s'ha realitzat ha estat la de la col·laboració interdisciplinària entre docents universitaris que treballen en dos àmbits científics ben diferents: geologia i arqueologia prehistòrica.S'ha desenvolupat una eina pedagògica on els estudiants poden desenvolupar habilitats i capacitats com les esmentades a partir del seguiment d'un cas d'estudi concret: la determinació i procedència dels elements petris utilitzats en la construcció del sepulcre megalític de Puigseslloses (Osona). La proposta es basa en el seguiment i la participació dels estudiants en tot el procés de la recerca: el plantejament del problema historicoarqueològic, la definició de les vies d'estudi concretes, el seu desenvolupament, l'obtenció de resultats i la seva discussió interdisciplinària.En este trabajo se desarrolla una propuesta concreta para abordar algunos de los objetivos pedagógicos, como la transversalidad, el trabajo en equipo o la necesidad de incrementar los conocimientos prácticos. La perspectiva desde la que se ha realizado ha sido la de la colaboración interdisciplinaria entre docentes universitarios que trabajan en dos ámbitos científicos bien distintos: Geología y Arqueología Prehistórica. Se ha desarrollado una herramienta pedagógica a través de la cual los estudiantes pueden desarrollar habilidades y capacidades como las mencionadas a partir del seguimiento de un caso de estudio concreto: la determinación y procedencia de los elementos pétreos utilizados en la construcción del sepulcro megalítico de Puigseslloses (Osona). La propuesta se basa en que los estudiantes sigan y participen en todo el proceso de la investigación, desde el planteamiento del problema histórico-arqueológico, la definición de las vías de estudio concretas, su desarrollo y la obtención de resultados, hasta su discusión interdisciplinaria.This study develops a specific proposal for addressing some of the educational goals of the EHEA such as transversality, teamwork and the need to increase practical knowledge. The perspective from which the study was conducted was interdisciplinary cooperation among university professors who work in two quite different fields of science: geology and prehistoric archaeology. A pedagogical tool was developed in which students can develop skills and abilities such as the ones mentioned above by pursuing a specific case study: the description and provenance of stone elements used to build the megalithic sepulchre in Puigseslloses (Osona). The proposal is based on students' following and participating in the entire research process: posing the historical-archaeological problem, defining the specific avenues of study, conducting the study, getting the results and holding an interdisciplinary discussion of these results

    Neurocognitive profile of the post-COVID condition in adults in Catalonia. A mixed method prospective cohort and nested case-control study: Study Protocol

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    The diagnosis of the post-COVID condition is usually achieved by excluding other diseases; however, cognitive changes are often found in the post-COVID disorder. Therefore, monitoring and treating the recovery from the post-COVID condition is necessary to establish biomarkers to guide the diagnosis of symptoms, including cognitive impairment. Our study employs a prospected cohort and nested case-control design with mixed methods, including statistical analyses, interviews, and focus groups. Our main aim is to identify biomarkers (functional and structural neural changes, inflammatory and immune status, vascular and vestibular signs and symptoms) easily applied in primary care to detect cognitive changes in post-COVID cases. The results will open up a new line of research to inform diagnostic and therapeutic decisions with special considerations for cognitive impairment in the post-COVID condition

    Gene Promoter Evolution Targets the Center of the Human Protein Interaction Network

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    Assessing the contribution of promoters and coding sequences to gene evolution is an important step toward discovering the major genetic determinants of human evolution. Many specific examples have revealed the evolutionary importance of cis-regulatory regions. However, the relative contribution of regulatory and coding regions to the evolutionary process and whether systemic factors differentially influence their evolution remains unclear. To address these questions, we carried out an analysis at the genome scale to identify signatures of positive selection in human proximal promoters. Next, we examined whether genes with positively selected promoters (Prom+ genes) show systemic differences with respect to a set of genes with positively selected protein-coding regions (Cod+ genes). We found that the number of genes in each set was not significantly different (8.1% and 8.5%, respectively). Furthermore, a functional analysis showed that, in both cases, positive selection affects almost all biological processes and only a few genes of each group are located in enriched categories, indicating that promoters and coding regions are not evolutionarily specialized with respect to gene function. On the other hand, we show that the topology of the human protein network has a different influence on the molecular evolution of proximal promoters and coding regions. Notably, Prom+ genes have an unexpectedly high centrality when compared with a reference distribution (P = 0.008, for Eigenvalue centrality). Moreover, the frequency of Prom+ genes increases from the periphery to the center of the protein network (P = 0.02, for the logistic regression coefficient). This means that gene centrality does not constrain the evolution of proximal promoters, unlike the case with coding regions, and further indicates that the evolution of proximal promoters is more efficient in the center of the protein network than in the periphery. These results show that proximal promoters have had a systemic contribution to human evolution by increasing the participation of central genes in the evolutionary process

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

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    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe
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