878 research outputs found

    Symmetry breaking and clustering in a vibrated granular gas with several macroscopically connected compartments

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    The spontaneous symmetry breaking in a vibro-fluidized low-density granular gas in three connected compartments is investigated. When the total number of particles in the system becomes large enough, particles distribute themselves unequally among the three compartments. Particles tend to concentrate in one of the compartments, the other two having the (relatively small) same average number of particles. A hydrodynamical model that accurately predicts the bifurcation diagram of the system is presented. The theory can be easily extended to the case of an arbitrary number of connected compartments

    Transversal inhomogeneities in dilute vibrofluidized granular fluids

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    The spontaneous symmetry breaking taking place in the direction perpendicular to the energy flux in a dilute vibrofluidized granular system is investigated, using both a hydrodynamic description and simulation methods. The latter include molecular dynamics and direct Monte Carlo simulation of the Boltzmann equation. A marginal stability analysis of the hydrodynamic equations, carried out in the WKB approximation, is shown to be in good agreement with the simulation results. The shape of the hydrodynamic profiles beyond the bifurcation is discussed

    Differential Spo0A-mediated effects on transcription and replication of the related Bacillus subtilis phages Nf and ϕ29 explain their different behaviours in vivo

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    Members of groups 1 (e.g. ϕ29) and 2 (e.g. Nf) of the ϕ29 family of phages infect the spore forming bacterium Bacillus subtilis. Although classified as lytic phages, the lytic cycle of ϕ29 can be suppressed and its genome can become entrapped into the B. subtilis spore. This constitutes an alternative infection strategy that depends on the presence of binding sites for the host-encoded protein Spo0A in the ϕ29 genome. Binding of Spo0A to these sites represses ϕ29 transcription and prevents initiation of DNA replication. Although the Nf genome can also become trapped into B. subtilis spores, in vivo studies showed that its lytic cycle is less susceptible to spo0A-mediated suppression than that of ϕ29. Here we have analysed the molecular mechanism underlying this difference showing that Spo0A differently affects transcription and replication initiation of the genomes of these phages. Thus, whereas Spo0A represses all three main early promoters of ϕ29, it only represses one out of the three equivalent early promoters of Nf. In addition, contrary to ϕ29, Spo0A does not prevent the in vitro initiation of Nf DNA replication. Altogether, the differences in Spo0A-mediated regulation of transcription and replication between ϕ29 and Nf explain their different behaviours in vivo

    Cuarenta años de difusión científica

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    Editorial.[EN]: Celebrating forty years of unbroken publication of the Revista Española de Drogodependencias (RED) in 2016 is the excuse put forward to look through the history of this journal and its development as regards its objectives, editorial policy, format and presentation. Over all these years, in which new journals have been seen to come out and some indeed disappear as a result of the difficult situation which publishing scientific texts in Spain is going through, the RED has managed to adapt to the new times and improve the criteria for evaluating the quality of journals, drawing this increasingly closer to international standards.[ES]: La celebración de los 40 años de edición ininterrumpida de la Revista Española de Drogodependencias (RED) en 2016 sirve de pretexto para repasar la historia de esta revista y su evolución en lo referente a objetivos, política editorial, formato y presentación. A lo largo de todos estos años, en los que se ha visto nacer y también, como no, desaparecer nuevas revistas como consecuencia de la difícil situación por la que atraviesa la edición de publicaciones científicas en España, la RED ha conseguido adaptarse a los nuevos tiempos y mejorar los criterios para evaluar la calidad de las revistas y acercarla cada vez más a estándares internacionales.Peer reviewe

    Transcription factor NFE2L2/NRF2 is a regulator of macroautophagy genes

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    Autophagy is a highly coordinated process that is controlled at several levels including transcriptional regulation. Here, we identify the transcription factor NFE2L2/NRF2 (nuclear factor, erythroid 2 like 2) as a regulator of autophagy gene expression and its relevance in a mouse model of Alzheimer disease (AD) that reproduces impaired APP (amyloid β precursor protein) and human (Hs)MAPT/TAU processing, clearance and aggregation. We screened the chromatin immunoprecipitation database ENCODE for 2 proteins, MAFK and BACH1, that bind the NFE2L2-regulated enhancer antioxidant response element (ARE). Using a script generated from the JASPAR's consensus ARE sequence, we identified 27 putative AREs in 16 autophagy-related genes. Twelve of these sequences were validated as NFE2L2 regulated AREs in 9 autophagy genes by additional ChIP assays and quantitative RT-PCR on human and mouse cells after NFE2L2 activation with sulforaphane. Mouse embryo fibroblasts of nfe2l2-knockout mice exhibited reduced expression of autophagy genes, which was rescued by an NFE2L2 expressing lentivirus, and impaired autophagy flux when exposed to hydrogen peroxide. NFE2L2-deficient mice co-expressing HsAPP(V717I) and HsMAPT(P301L), exhibited more intracellular aggregates of these proteins and reduced neuronal levels of SQSTM1/p62, CALCOCO2/NDP52, ULK1, ATG5 and GABARAPL1. Also, colocalization of HsAPP(V717I) and HsMAPT(P301L) with the NFE2L2-regulated autophagy marker SQSTM1/p62 was reduced in the absence of NFE2L2. In AD patients, neurons expressing high levels of APP or MAPT also expressed SQSTM1/p62 and nuclear NFE2L2, suggesting their attempt to degrade intraneuronal aggregates through autophagy. This study shows that NFE2L2 modulates autophagy gene expression and suggests a new strategy to combat proteinopathies

    Human–landscape interactions in the Conquezuela–Ambrona Valley (Soria, continental Iberia): From the early Neolithic land use to the origin of the current oak woodland

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    The sedimentological, geochemical and palynological analyses performed in the Conquezuela palaeolake (41°11′N; 2°33′W; 1124 m a.s.l.) provide a detailed, multiproxy palaeoenvironmental reconstruction in one of the key areas of inner Iberian Neolithic colonization. Combined with archaeobotanical and archaeological data from well-dated settlements along the Conquezuela–Ambrona Valley we investigate how environmental conditions may affect both socio-economic adaptations and livelihood strategies of prehistoric communities. The first evidences of early Neolithic occupation in the valley ca. 7250–6450 cal yr BP (5300–4500 BC) coincided with the onset of a period (7540–6200 cal yr BP, 5590–4250 BC) with higher water availability and warmer climate as alluvial environments were substituted by carbonate-wetland environments in the basin. The Conquezuela record supports an early Neolithic colonization of the inner regions of Iberia favored by warmer and humid climate features and with preferential settlement patterns associated to lakes. The maximum human occupation of the valley occurred during the mid–late Neolithic and Chalcolithic (6200–3200 cal yr BP, 4250–1250 BC) as evidenced by the high number of archaeological sites. Although a number of hydrological oscillations have been detected during this period, the intense landscape transformation at basin-scale, leading to a deforested landscape, was largely a consequence of widespread farming and pastoral practices. Socio-economic activities during Bronze, Iron and Roman times modified this inherited landscape, but the second largest ecosystem transformation only occurred during Mediaeval times when a new agrarian landscape developed with the expansion of stockbreeding transhumance. The current vegetation cover characterized by patches of holm and marcescent oaks and fields reflects an intense human management combining both extensive herding with agrarian activities in order to transform the previous forested landscape into a dehesa-like system.The funding for the present study derives from DINAMO2 (CGL-BOS 2012-33063) and AGRIWESTMED (ERC Grant Agreement #230561) projects, provided by the Spanish Inter-Ministry Commission of Science and Technology (CICYT) and the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013). XRF data were obtained at the XRF Core Scanner Laboratory (CRG Marine Geosciences, University of Barcelona). Josu Aranbarri acknowledges the predoctoral funding provided by the Basque Country Government (ref: FI-2010-5). Graciela Gil-Romera hold a post-doctoral contract funded by “Juan de la Cierva” (ref: JCI2009-04345) program. Eduardo García-Prieto and Maria Leunda are supported by predoctoral FPI grants BES-2010-038593 and BES-2013-063753, respectively. We also thank Elena Royo for her help with the lab procedures and the two anonymous referees for their valuable suggestions.Peer reviewe

    GEICAM Guidelines for the Management of Patients with Breast Cancer During the COVID-19 Pandemic in Spain

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    Breast cancer (BC) is the most common cancer in women in Spain. During the COVID-19 pandemic caused by the SARSCoV-2 virus, patients with BC still require timely treatment and follow-up; however, hospitals are overwhelmed with infected patients and, if exposed, patients with BC are at higher risk for infection and serious complications if infected. Thus, health care providers need to evaluate each BC treatment and in-hospital visit to minimize pandemic-associated risks while maintaining adequate treatment efficacy. Here we present a set of guidelines regarding available options for BC patient management and treatment by BC subtype in the context of the COVID-19 pandemic. Owing to the lack of evidence about COVID-19 infection, these recommendations are mainly based on expert opinion, medical organizations’ and societies’ recommendations, and some published evidence. We consider this a useful tool to facilitate medical decision making in this health crisis situation we are facing
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