Recursos, intereses y difusión de modelos para la política regional de I+D: la Comunidad de Madrid

Se agradece la financiación de la CICYT a través del Plan Nacional de I+D (SEC1999-0829-C02-01), así como las facilidades otorgadas por la Dirección general de Investigación de la Comunidad de Madrid, especialmente por Francisco Rubia y Alfonso González Hermoso

Decoding the spermatogonial stem cell niche under physiological and recovery conditions in adult mice and humans

The intricate interaction between spermatogonial stem cell (SSC) and testicular niche is essential for maintaining SSC homeostasis; however, this interaction remains largely uncharacterized. In this study, to characterize the underlying signaling pathways and related paracrine factors, we delineated the intercellular interactions between SSC and niche cell in both adult mice and humans under physiological conditions and dissected the niche-derived regulation of SSC maintenance under recovery conditions, thus uncovering the essential role of C-C motif chemokine ligand 24 and insulin-like growth factor binding protein 7 in SSC maintenance. We also established the clinical relevance of specific paracrine factors in human fertility. Collectively, our work on decoding the adult SSC niche serves as a valuable reference for future studies on the aetiology, diagnosis, and treatment of male infertility.</p

Genetic diversity fuels gene discovery for tobacco and alcohol use

Tobacco and alcohol use are heritable behaviours associated with 15% and 5.3% of worldwide deaths, respectively, due largely to broad increased risk for disease and injury(1-4). These substances are used across the globe, yet genome-wide association studies have focused largely on individuals of European ancestries(5). Here we leveraged global genetic diversity across 3.4 million individuals from four major clines of global ancestry (approximately 21% non-European) to power the discovery and fine-mapping of genomic loci associated with tobacco and alcohol use, to inform function of these loci via ancestry-aware transcriptome-wide association studies, and to evaluate the genetic architecture and predictive power of polygenic risk within and across populations. We found that increases in sample size and genetic diversity improved locus identification and fine-mapping resolution, and that a large majority of the 3,823 associated variants (from 2,143 loci) showed consistent effect sizes across ancestry dimensions. However, polygenic risk scores developed in one ancestry performed poorly in others, highlighting the continued need to increase sample sizes of diverse ancestries to realize any potential benefit of polygenic prediction.Peer reviewe

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

Exposer l’art contemporain depuis les années 1960 : les statuts et les rôles des commissaires d’exposition

Exhibitions are at the centre of contemporary art activities. With the rise of the art market, the advent of fairs and biennials, the modernization of existing museums and the establishment of new places, exhibition curators are increasingly playing an important role in contemporary art.My research dissertation in the second year of a master's degree aims to analyse the statutes and roles of contemporary art curators on the artistic territory. It concludes that the curatorial professions are now experiencing a phase of professionalization and structuration. This work is multifaceted and depends on the institution and their mission. Versatility is the hard core of their curatorial activity. Thus, the barriers to entry into curatorial practices do not exist. Nevertheless, the major inequalities of remuneration, the difficulty to be paid for and lack of subsidies are the main obstacles to the activity.Characterized by social poly-identities, curators of contemporary art are overwhelmingly multi-active in the artistic and cultural fields, with four main profiles: museum professionals, independent curators, curators-critics and curators-artists. As an intermediary, they facilitate the translation and mediation of the artwork to the public. In addition, they also play an important role in a territorial development policy. Artists' friends, they contribute to the professionalization and mobility of artists in the art market through exhibition.This research opens the door, not only to present more precisely the current situation of curators, but also to discover their roles and status in the field of contemporary art. Research on curatorial professions allowed me to develop some fundamental ideas to study political constraints to curatorial activities. So I hope, in my future research, to analyse it more deeply at global level.Les expositions sont au centre des activités artistiques contemporaines. Avec l'essor du marché d'art autonome, l’avènement des foires et des biennales, la modernisation des musées existants et l’établissement de lieux nouveaux, les commissaires d’exposition jouent de plus en plus un rôle important dans l’art contemporain.Mon mémoire de recherche en deuxième année de master vise à analyser les statuts et les rôles des commissaires d’exposition d’art contemporain sur le territoire artistique. Il en conclut que les métiers du commissariat connaissent maintenant une phase de professionnalisation et de structuration. Ce travail est multiforme et dépend de l'institution et de sa mission. La polyvalence est le noyau dur de l’activité curatoriale. Ainsi, les barrières à l'entrée dans les pratiques curatoriales n'existent pas. Néanmoins, les fortes inégalités de rémunérations, la difficulté à se faire rétribuer et manque de subventions sont les principaux freins à l’activité.Caractérisés par des polyidentités sociales, les commissaires d’art contemporain sont très majoritairement pluriactifs sur les champs artistique et culturel, dans lesquels figurent quatre profils principaux : professionnels de musée, commissaires d’exposition indépendants, commissaires-critiques et commissaires-artistes. En tant qu’intermédiaires, ils facilitent la traduction et la médiation de l’œuvre d'art au public. De plus, ils jouent aussi un rôle important dans le cadre d'une politique de développement territorial. Amis des artistes, ils contribuent à la professionnalisation et à la mobilité des artistes dans le marché de l’art par le biais d’expositions.Cette recherche ouvre la porte, non seulement pour présenter plus précisément la situation actuelle des commissaires d’exposition, mais aussi pour découvrir leurs rôles et statuts dans le domaine de l’art contemporain. La recherche sur le métier du commissariat m’a permis de développer quelques idées fondamentales pour étudier les contraintes politiques des activités curatoriales. J'espère donc, dans ma future recherche, l’analyser plus profondément à l’échelle mondiale