248 research outputs found

    Agent organisations: from independent agents to virtual organisations and societies of agents

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    Real world applications using agent-based solutions can include many agents that needs to communicate and interact with each other in order to meet their objectives. In organisations; Agent open multi-agent systems, problems can include not only the organisation of a large number of agents, but can also be heterogeneous and of unpredictable provenance or behavior. An overview of the alternatives for dealing with these problems is presented, highlighting the way they try to solve or mitigate them. This approach allows the development of complex systems in which there are agents that show very different behaviours and that are able to adapt to unforeseen changes in the environment. This makes it possible to simulate socio-technical or natural environments and observe their possible evolution without the ethical considerations involved in experimenting in real environments.This work has been developed as part of “Virtual-Ledgers-Tecnologías DLT/Blockchain y Cripto-IOT sobre organizaciones virtuales de agentes ligeros y su aplicación en la eficiencia en el transporte de última milla”, ID SA267P18, project financed by Junta Castilla y León, Consejería de Educación, and FEDER funds. It has been partially supported by the European Regional Development Fund (ERDF) through the Interreg Spain-Portugal V-A Program (POCTEP) under grant 0631_DIGITEC_3_E (Smart growth through the specialization of the cross-border business fabric in advanced digital technologies and blockchain.)

    Linking tourism, retirement migration and social capital

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    A general trend in the study of international retirement migration has been the increased attention paid to the social contacts and network connections of the migrants in both the destination and the origin areas. These studies have examined the extent to which migrants build social relationships with their neighbours and the host society while also maintaining social links with their countries of origin, addressing the central role that leisure travel plays in sustaining increasingly dispersed social networks and maintaining the social capital of these networks and of the individuals involved in them. Using a case study approach to examine British retirement migration to Spain, we explore the relevance of transnational social networks in the context of international retirement migration, particularly the intensity of bidirectional visiting friends and relatives (VFR) tourism flows and the migrants' social contacts with friends and/or family back in their home country. Building on the concept of social capital and Putnam's distinction between bonding and bridging social capital, we propose a framework for the analysis of the migrants' international social networks. The results of a study conducted based on a sample of 365 British retirees living in the coast of Alicante (Spain) show both the strength of the retirees' international bonding social capital and the role of 'VFR's travel and communication technologies in sustaining the migrants' transnational social practices and, ultimately, their international bonding social capital. It also provides evidence for the reinforcing links between tourism-related mobility and amenity-seeking migration in later life. © 2013 © 2013 Taylor & Francis

    Production and Characterization of a new Copper(II) Propanoate-Isonicotinamide Adduct obtained via Slow Evaporation and using Supercritical CO2 as an Antisolvent

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    A new adduct of isonicotinamide (INA) with copper(II) propanoate [Cu(C3)2] was prepared [Cu2(C3)4(INA)4] using two different methods. This type of compound shows high fungicidal activity. Solvent evaporation from ethanol rendered crystals suitable for single-crystal X-ray diffraction. Furthermore, a new semicontinuous method capable of simultaneous crystallization and micronization of the adduct using supercritical CO2, the supercritical antisolvent technique (SAS), was also assessed. Crystals were characterized using powder X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis coupled with mass spectrometry, scanning electron microscopy, and microelemental analysis. In the adduct, two copper(II) ions are coordinated through two bridging and two chelating carboxylates to the propanoate anions forming approximately a plane. Each metal ion is then coordinated with the pyridine nitrogen of two different INA molecules that behave as monodentate ligands. The amide groups of the INA form H-bonds with other amide and carboxylate groups forming a molecular crystal with a three-dimensional H-bond arrangement of the binuclear units. With the SAS technique, crystals 100-fold smaller than those obtained by slow evaporation were obtained, proving SAS as a suitable method for mixed-ligand complexes preparation with reduced particle size and therefore expected bioavailability enhancement

    A de novo complete BRCA1 gene deletion identified in a Spanish woman with early bilateral breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Germline mutations in either of the two tumor-suppressor genes, <it>BRCA1 </it>and <it>BRCA2</it>, account for a significant proportion of hereditary breast and ovarian cancer cases. Most of these mutations consist of deletions, insertions, nonsense mutations, and splice variants, however an increasing number of large genomic rearrangements have been identified in these genes.</p> <p>Methods</p> <p>We analysed <it>BRCA1 </it>and <it>BRCA2 </it>genes by direct sequencing and MLPA. We confirmed the results by an alternative MLPA kit and characterized the <it>BRCA1 </it>deletion by Array CGH.</p> <p>Results</p> <p>We describe the first case of a patient with no strong family history of the disease who developed early-onset bilateral breast cancer with a <it>de novo </it>complete <it>BRCA1 </it>gene deletion in the germinal line. The detected deletion started from the region surrounding the <it>VAT1 </it><it>locus </it>to the beginning of <it>NBR1 </it>gene, including the <it>RND2</it>, Ψ<it>BRCA1</it>, <it>BRCA1 </it>and <it>NBR2 </it>complete genes.</p> <p>Conclusion</p> <p>This finding supports the large genomic rearrangement screening of <it>BRCA </it>genes in young breast cancer patients without family history, as well as in hereditary breast and ovarian cancer families previously tested negative for other variations.</p

    Upregulation of NKG2D ligands impairs hematopoietic stem cell function in Fanconi anemia

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    Cellular immune response; Immunology; Stem cellsRespuesta inmune celular; Inmunología; Células madreResposta immune cel·lular; Immunologia; Cèl·lules mareFanconi anemia (FA) is the most prevalent inherited bone marrow failure (BMF) syndrome. Nevertheless, the pathophysiological mechanisms of BMF in FA have not been fully elucidated. Since FA cells are defective in DNA repair, we hypothesized that FA hematopoietic stem and progenitor cells (HSPCs) might express DNA damage–associated stress molecules such as natural killer group 2 member D ligands (NKG2D-Ls). These ligands could then interact with the activating NKG2D receptor expressed in cytotoxic NK or CD8+ T cells, which may result in progressive HSPC depletion. Our results indeed demonstrated upregulated levels of NKG2D-Ls in cultured FA fibroblasts and T cells, and these levels were further exacerbated by mitomycin C or formaldehyde. Notably, a high proportion of BM CD34+ HSPCs from patients with FA also expressed increased levels of NKG2D-Ls, which correlated inversely with the percentage of CD34+ cells in BM. Remarkably, the reduced clonogenic potential characteristic of FA HSPCs was improved by blocking NKG2D–NKG2D-L interactions. Moreover, the in vivo blockage of these interactions in a BMF FA mouse model ameliorated the anemia in these animals. Our study demonstrates the involvement of NKG2D–NKG2D-L interactions in FA HSPC functionality, suggesting an unexpected role of the immune system in the progressive BMF that is characteristic of FA.This work was supported by the “Ministerio de Ciencia e Innovación y Competitividad y Fondo Europeo de Desarrollo Regional (FEDER)” (SAF2015-68073-R, SAF2015-64152-R, and RTI2018-097125-B-I00); Next Generation EU; Plan de Recuperación Transformación y Resilencia (Instituto de Salud Carlos III; TERAV) (RD12/0019/0023); Programs of the European Commission (HEALTHF5-2012-305421 and EUROFANCOLEN); the “Ministerio de Sanidad, Servicios Sociales e Igualdad” (EC11/060 and EC11/550 “Comunidad de Madrid” (AvanCell, B2017/BMD-3692); and the ICREA-Academia program

    Environmental genomics of "Haloquadratum walsbyi" in a saltern crystallizer indicates a large pool of accessory genes in an otherwise coherent species

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    BACKGROUND: Mature saturated brine (crystallizers) communities are largely dominated (>80% of cells) by the square halophilic archaeon "Haloquadratum walsbyi". The recent cultivation of the strain HBSQ001 and thesequencing of its genome allows comparison with the metagenome of this taxonomically simplified environment. Similar studies carried out in other extreme environments have revealed very little diversity in gene content among the cell lineages present. RESULTS: The metagenome of the microbial community of a crystallizer pond has been analyzed by end sequencing a 2000 clone fosmid library and comparing the sequences obtained with the genome sequence of "Haloquadratum walsbyi". The genome of the sequenced strain was retrieved nearly complete within this environmental DNA library. However, many ORF's that could be ascribed to the "Haloquadratum" metapopulation by common genome characteristics or scaffolding to the strain genome were not present in the specific sequenced isolate. Particularly, three regions of the sequenced genome were associated with multiple rearrangements and the presence of different genes from the metapopulation. Many transposition and phage related genes were found within this pool which, together with the associated atypical GC content in these areas, supports lateral gene transfer mediated by these elements as the most probable genetic cause of this variability. Additionally, these sequences were highly enriched in putative regulatory and signal transduction functions. CONCLUSION: These results point to a large pan-genome (total gene repertoire of the genus/species) even in this highly specialized extremophile and at a single geographic location. The extensive gene repertoire is what might be expected of a population that exploits a diverse nutrient pool, resulting from the degradation of biomass produced at lower salinities

    U-Pb SHRIMP zircon dating of Grenvillian metamorphism in Western Sierras Pampeanas (Argentina) : correlation with the Arequipa-Antofalla craton and constraints on the extent of the Precordillera Terrane

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    The Sierras Pampeanas of Argentina, the largest outcrop of pre-Andean crystalline basement in southern South America, resulted from plate interactions along the proto-Andean margin of Gondwana, from as early as Mesoproterozoic to Late Paleozoic times (e.g., Ramos, 2004, and references therein). Two discrete Paleozoic orogenic belts have been recognized: the Early Cambrian Pampean belt in the eastern sierras, and the Ordovician Famatinian belt, which partially overprints it to the west (e.g., Rapela et al., 1998). In the Western Sierras Pampeanas, Mesoproterozoic igneous rocks (ca. 1.0–1.2 Ga) have been recognized in the Sierra de Pie de Palo (Fig. 1) (McDonough et al., 1993 M.R. McDonough, V.A. Ramos, C.E. Isachsen, S.A. Bowring and G.I. Vujovich, Edades preliminares de circones del basamento de la Sierra de Pie de Palo, Sierras Pampeanas occidentales de San Juán: sus implicancias para el supercontinente proterozoico de Rodinia, 12° Cong. Geol. Argentino, Actas vol. 3 (1993), pp. 340–342.McDonough et al., 1993, Pankhurst and Rapela, 1998 and Vujovich et al., 2004) that are time-coincident with the Grenvillian orogeny of eastern and northeastern North America (e.g., Rivers, 1997 and Corrievau and van Breemen, 2000). These Grenvillian-age rocks have been considered to be the easternmost exposure of basement to the Precordillera Terrane, a supposed Laurentian continental block accreted to Gondwana during the Famatinian orogeny (Thomas and Astini, 2003, and references therein). However, the boundaries of this Grenvillian belt are still poorly defined, and its alleged allochthoneity has been challenged (Galindo et al., 2004). Moreover, most of the Grenvillian ages so far determined relate to igneous protoliths, and there is no conclusive evidence for a Grenvillian orogenic belt, other than inferred from petrographic evidence alone (Casquet et al., 2001). We provide here the first evidence, based on U–Pb SHRIMP zircon dating at Sierra de Maz, for a Grenville-age granulite facies metamorphism, leading to the conclusion that a continuous mobile belt existed throughout the proto-Andean margin of Gondwana in Grenvillian times

    Annexin A6 Is Critical to Maintain Glucose Homeostasis and Survival During Liver Regeneration in Mice

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    Background and Aims: Liver regeneration requires the organized and sequential activation of events that lead to restoration of hepatic mass. During this process, other vital liver functions need to be preserved, such as maintenance of blood glucose homeostasis, balancing the degradation of hepatic glycogen stores, and gluconeogenesis (GNG). Under metabolic stress, alanine is the main hepatic gluconeogenic substrate, and its availability is the rate‐limiting step in this pathway. Na+‐coupled neutral amino acid transporters (SNATs) 2 and 4 are believed to facilitate hepatic alanine uptake. In previous studies, we demonstrated that a member of the Ca2+‐dependent phospholipid binding annexins, Annexin A6 (AnxA6), regulates membrane trafficking along endo‐ and exocytic pathways. Yet, although AnxA6 is abundantly expressed in the liver, its function in hepatic physiology remains unknown. In this study, we investigated the potential contribution of AnxA6 in liver regeneration. Approach and Results: Utilizing AnxA6 knockout mice (AnxA6−/−), we challenged liver function after partial hepatectomy (PHx), inducing acute proliferative and metabolic stress. Biochemical and immunofluorescent approaches were used to dissect AnxA6−/− mice liver proliferation and energetic metabolism. Most strikingly, AnxA6−/− mice exhibited low survival after PHx. This was associated with an irreversible and progressive drop of blood glucose levels. Whereas exogenous glucose administration or restoration of hepatic AnxA6 expression rescued AnxA6−/− mice survival after PHx, the sustained hypoglycemia in partially hepatectomized AnxA6−/− mice was the consequence of an impaired alanine‐dependent GNG in AnxA6−/− hepatocytes. Mechanistically, cytoplasmic SNAT4 failed to recycle to the sinusoidal plasma membrane of AnxA6−/− hepatocytes 48 hours after PHx, impairing alanine uptake and, consequently, glucose production. Conclusions: We conclude that the lack of AnxA6 compromises alanine‐dependent GNG and liver regeneration in mice

    Susceptibilidad a movimientos de ladera inducidos por terremotos en Alcoy (Alicante) y sectores adyacentes

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    We present an approach developed to estimate the seismically-induced landslide susceptibility of the Alcoy (Alicante) area. It combines the Newmark's method of evaluation of slope stability with a seismic hazard study o f the region through a GIS. The obtained results show that the distribution of susceptible areas is closely related to the position of river valleys, specially the Molinar and Serpis rivers. Due to Alcoy city has developed around these rivers, some zones of the city show moderate to high susceptibility, which is in accordance with historical data which describe the occurrence of seismically-induced landslides along these valleys. The results emphasize areas of susceptibility that actually are being occupied, thus pointing out the necessity of incorporating this information into the land use planning.Este trabajo ha sido financiado por el proyecto CTI-DIB/2002/177
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