12 research outputs found

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    A study of the nocturnal flows generated in the north side of the Pyrenees

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    During night-time, with clear-skies and weak-synoptic pressure gradients, the organization of the flow at lower levels is mainly controlled by the local effects, such as terrain or surface heterogeneities. This is the case of the thermal differences between the air adjacent to the slopes and over the nearby plains that generate downslope winds. The foothills of the north Pyrenees are selected to study the temporal and spatial scales of the downslope winds through a high-resolution mesoscale simulation. From the analysis of the model outputs and the observations, it is found that the organization of the flow at lower levels can be separated in three well-defined regions. At the mountain slopes, downslope winds appear close to the surface whereas down-valley winds form later, after the accumulation of air in the bottom of the valleys due to the downslope winds. At the foothills, the turning of the wind (from upslope to downslope) starts before sunset but it depends on the distance to the Pyrenees, the closer the earlier. Finally, at the Garonne river plain down-river winds are formed at the end of the night, after the accumulation of the downslope winds from the Pyrenees and the Massif Central. Furthermore, the physical mechanisms that take place while the downslope winds travel from the mountain to the plain regions are analysed. © 2014 Elsevier B.V.This work was funded through the projects CGL2009-12797-C03-01 and CGL2012-37416-C04-01 of the Spanish Government, supplied by the European Regional Development Fund (FEDER), and with a contract JAE-Doc of the Junta para la Ampliación de Estudios program from CSIC supplied by the European Social FundPeer Reviewe

    Stably stratified atmospheric boundary layer: study trough large-eddy simulations, mesoscale modelling and observations

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    La capa límit atmosfèrica és l'àrea directament influenciada per la presència de la superfície de la terra i la seva alçada és d'uns centenars de metres a uns pocs quilòmetres. Durant el vespre, el refredament radiatiu estratifica establement l'aire prop del sòl i es forma el que es coneix com a Capa Límit Estable (CLE). D'avui en dia, la CLE és un règim que encara no està prou ben caracteritzat. La turbulència, que no és homogènia ni isòtropa, i la gran importància dels efectes locals com l'orografia, entre d'altres factors, dificulten l'estudi d'aquest règim. Per aquest motiu, la CLE és objecte d'especial atenció, sobretot a l'hora de millorar la seva representació en models tant de temps com de clima.Aquest treball es centra en l'estudi de la CLE mitjançant 3 eines diferents: 1) simulacions explícites de grans remolins (més conegudes com a simulacions LES), per determinar el comportament dels moviments turbulents, on les resolucions són de l'ordre de metres; 2) simulacions mesoscalars, per caracteritzar els efectes locals, on les resolucions són de l'ordre de kilòmetres; 3) anàlisi de les observacions sota aquestes condicions per tal de caracteritzar i entendre millor els fenòmens observats.En primer lloc s'estudia el rang d'estabilitats a on el model LES, que considera la teoria de Kolmogorov per la dissipació de l'energia, funciona correctament. Els resultats del model són realistes tal com mostra la seva comparació amb les mesures de dues campanyes experimentals (SABLES-98 i CASES-99). Per explorar més a fons els resultats LES i per comparar-los amb les mesures s'han utilitzat les Funcions de Distribució de Probabilitat (PDF). Aquests resultats LES són també comparables als obtinguts amb altres models LES, tal com mostra la intercomparació de models LES, més coneguda com a GABLS.Un cop desenvolupades totes les eines necessàries es fa un LES d'un cas més realista, basat en les observacions d'un màxim de vent de capes baixes (més conegut com a Low-Level Jet, LLJ). L'anàlisi combinat dels resultats LES i les mesures permet entendre millor els processos de barreja que tenen lloc a través de la inversió. Finalment, la contribució dels efectes locals s'estudia mitjançant les simulacions mesoscalars, en aquest cas centrades a l'illa de Mallorca. Durant el vespre es veu com les circulacions locals es desenvolupen a les conques (de longitud al voltant de 25km), formant-se, per exemple, vents catabàtics o LLJ com l'estudiat anteriorment. En aquest cas les simulacions es verifiquen amb imatges de satèl·lit NOAA i observacions de les estacions automàtiques de mesures, donant resultats semblants.The atmospheric boundary layer is the area directly influenced by the presence of the Earth's surface and its height is from hundreds of meters to few kilometres. During the night, the radiative cooling stratifies the layer close to the surface and it forms the Stably-stratified Atmospheric Boundary Layer (SBL). Nowadays, the SBL is a regime not well enough characterized, yet. Turbulence, which is not homogeneous either isotropic, and the great importance of the local effects, like the orography, among other factors, make the SBL be a difficult regime to study. Even so, the SBL is an object of special attention, especially when improving its representation in numerical prediction models or climate models.This work focuses on the study of the SBL through 3 different tools: 1) Large-Eddy Simulations (LES), to determine the turbulent motions, where the resolutions are about 1m; 2) Mesoscale simulations, to characterize the local effects, where resolutions are about 1km; 3) Analysis of the observations under these conditions in order to better characterize and understand the observed phenomena.In first place, it is studied the range of stabilities where the LES model, that considers the Kolmogorov theory for the dissipation of the energy, works correctly. The results are realistic as the comparison with measures from two experimental campaigns (SABLES-98 and CASES-99) shows. To explore the results more thoroughly, and to compare the LES results to the measurements, the Probability Density Functions (PDF) have been used. The LES results are also comparable to the ones obtained with other LES models, as the intercomparison of different LES models show, better known as GABLS.Then, a more realistic case is performed using the LES model, based on observations of a Low-Level Jet (LLJ). The combined inspection of the LES results and the observations allow to better understand the mixing processes that take place through the inversion layer. Finally, the contribution of the local effects is studied through a mesoscale simulation. Here the attention is focused on the Mallorca Island. During the night, the model is able to reproduce the local circulations is a basin of a characteristic size of 25km. The main features obtained previously from the LES of the LLJ are also reproduced by the mesoscale model. These runs are verified with NOAA satellite images and observations from the automatic surface weather stations, giving that the model is able to reproduce realistic results

    Laboratory Experiments on Convective Entrainment Using a Saline Water Tank

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    Entrainment fluxes in a shear-free convective boundary layer have been measured with a saline water tank set-up. The experiments were targeted towards measuring the entrainment behaviour for medium to high Richardson numbers and use a two-layer design, i.e. two stacked non-stratified (neutral) layers with different densities. With laser induced fluorescence (LIF), the entrainment flux of a fluorescent dye is measured for bulk Richardson numbers in the range 30-260. It is proposed that a carefully chosen combination of top-down and bottom-up processes improves the accuracy of LIF-based entrainment observations. The observed entrainment fluxes are about an order of magnitude lower than reported for thermal water tanks: the derived buoyancy entrainment ratio, A, is found to be A ≈ 0.02, which is to be compared with A ≈ 0.25 for a thermal convection tank (Deardorff et al., J Fluid Mech 100:41-64, 1980). An extensive discussion is devoted to the influence of the Reynolds and Prandtl numbers in laboratory experiments on entrainment. © 2014 Springer Science+Business Media Dordrecht.One of us (MAJ) acknowledges research project CGL2006-12474 from the Spanish GovernmentPeer Reviewe

    The BLLAST field experiment: Boundary-Layer late afternoon and sunset turbulence

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    Lothon, Marie et al.© 2014 Author(s). Due to the major role of the sun in heating the earth's surface, the atmospheric planetary boundary layer over land is inherently marked by a diurnal cycle. The afternoon transition, the period of the day that connects the daytime dry convective boundary layer to the night-time stable boundary layer, still has a number of unanswered scientific questions. This phase of the diurnal cycle is challenging from both modelling and observational perspectives: it is transitory, most of the forcings are small or null and the turbulence regime changes from fully convective, close to homogeneous and isotropic, toward a more heterogeneous and intermittent state. These issues motivated the BLLAST (Boundary-Layer Late Afternoon and Sunset Turbulence) field campaign that was conducted from 14 June to 8 July 2011 in southern France, in an area of complex and heterogeneous terrain. A wide range of instrumented platforms including full-size aircraft, remotely piloted aircraft systems, remote-sensing instruments, radiosoundings, tethered balloons, surface flux stations and various meteorological towers were deployed over different surface types. The boundary layer, from the earth's surface to the free troposphere, was probed during the entire day, with a focus and intense observation periods that were conducted from midday until sunset. The BLLAST field campaign also provided an opportunity to test innovative measurement systems, such as new miniaturized sensors, and a new technique for frequent radiosoundings of the low troposphere. Twelve fair weather days displaying various meteorological conditions were extensively documented during the field experiment. The boundary-layer growth varied from one day to another depending on many contributions including stability, advection, subsidence, the state of the previous day's residual layer, as well as local, meso-or synoptic scale conditions. Ground-based measurements combined with tethered-balloon and airborne observations captured the turbulence decay from the surface throughout the whole boundary layer and documented the evolution of the turbulence characteristic length scales during the transition period. Closely integrated with the field experiment, numerical studies are now underway with a complete hierarchy of models to support the data interpretation and improve the model representations.The BLLAST field experiment was made possible thanks to the contribution of several institutions and supports: INSU-CNRS (Institut National des Sciences de l’Univers, Centre national de la Recherche Scientifique, LEFE-IMAGO program), Météo-France, Observatoire Midi-Pyrénées (University of Toulouse), EUFAR (EUropean Facility for Airborne Research) BLLATE-1&2, COST ES0802 (European Cooperation in the field of Scientific and Technical) and the Spanish MINECO projects CGL2009–08609, CGL2012–37416–C04–03, CGL2012–37416– C04–02 and CGL2011-13477-EPeer Reviewe

    Estimation of cold pool areas and chilling hours through satellite-derived surface temperatures

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    © 2015 Elsevier B.V. A methodology is proposed to identify the coldest areas of the island of Mallorca through satellite-derived surface temperatures. Land-surface temperatures from the Meteosat Second Generation (MSG-LST) just before sunrise for 1 year starting on September 1, 2007, were used. Fields for situations with clear skies and weak wind nights were selected, corresponding to 173 days of the year under study. Under these conditions, cold pools were generated in the centre of the three main basins of the island, in agreement with previous numerical and climatological studies. Maps of minimum air temperature and chilling hours, averaged over a season or annually, were obtained from the MSG-LST fields. These maps were then associated with the requirements of actual crop distributions.This work was funded through the projects CGL2009-12797-C03-01 and CGL2012-37416-C04-01 of the Spanish Government, supplied by the European Regional Development Fund (FEDER), and with a JAE-Doc contract from the Junta para la Ampliación de Estudios program from CSIC supplied by the European Social Fund 2007-2013Peer Reviewe

    The effect of the ambient conditions on the life cycle of a bulbous plant

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    To evaluate how weather conditions affect the life cycle of a bulbous plant species, a methodology is proposed here using Crocus cambessedesii, a plant that is endemic to Mallorca and Menorca. Data from an experimental field study conducted from 2007 to 2013 in the south west of Mallorca is taken together with meteorological observations from Palma Airport, located about 10 km away from the site. The bias in the observations between the Airport and the field site is discussed, as well as the importance of performing meteorological measurements in situ to have a better knowledge of the local processes. It is found that flowering and fruiting periods start when the mean temperature is between the range of 16-20◦C and 10-14◦C, respectively. In addition, a certain amount of soil water content is needed (it has been raining during the previous days). These results are in agreement with those obtained for Crocus sativus, extensively studied for economic interests. Finally, some recommendations are made to apply this methodology to plants in other locations or other speciesM.A. Jimenez acknowledges the financial support from JAE-Doc program (CSIC, co-funded by the ESF)Peer reviewe

    Evaluation of the surface energy budget equation with experimental data and the ECMWF model in the Ebro Valley

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    ©2015. American Geophysical Union. All Rights Reserved. In numerical models of the climate system and in other applications, the surface energy budget is usually considered closed, allowing for estimation of missing terms as the residual of the others. Real measurements of this budget show significant uncertainties in the values of each flux and imbalances that range between 5% and more than 50%, as shown in recent literature. In this article, a derivation of the surface energy budget equation from the prognostic temperature equation is presented and the hypotheses are discussed. Minor terms, which are usually neglected, such as tendency or advection, are estimated. Then, the 2-year statistics for a station in the Ebro Valley are analyzed, focusing on the imbalance, which is found to increase as the other terms in the equation increase, with values on the order of 30% of the net radiation. The same location seen by the model of the European Center for Medium-Range Weather Forecasts (ECMWF) is analyzed. Large differences between observations and model simulation results occur at a daily scale although the average terms are comparable, with a systematic overestimation of the ground and sensible heat fluxes by the model. Key Points Analysis of the imbalance of the observed surface energy budget Daily and nightly averaged annual cycles of the observed SEB Comparison between ECMWF model values and observationsThis work was partially supported by grant CGL2012-37416-C04-01 of the Spanish Ministry of Economy and Competitiveness, supplemented with FEDER funds, and by a JAE-DOC contract of the Spanish National Research Council (CSIC)Peer Reviewe

    Study of a sea-breeze case through momentum, temperature, and turbulence budgets

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    © 2014 American Meteorological Society. A simulation with the Méso-NH model over the island of Mallorca, Spain, has been made in a case of synoptic high pressure (5 June 2010) that allowed the development of sea breezes (SB) in the three main basins of the island. The results compare well to the available observations and are qualitatively very close to a previous idealized study with no synoptic forcing made by Ramis and Romero in 1995. The temporal and spatial structure of the SB in the southeastern basin is analyzed with the use of the momentum, temperature, and turbulence kinetic energy budgets provided by the numerical model. Five stages of evolution from before dawn to after sunset are discussed, identifying the main physical mechanisms at play. The morning land heating warms the land and the air over it until an air temperature gradient is created and a marine flow accelerates inland, dragged by turbulence in the low layers. The upper part of the inland current and the layers just above are dominated by compensatory motions, which oppose the corresponding pressure gradient at these levels. These mechanisms last while the SB is active, with significant effects from the local topography, and they decrease in intensity as sunset approaches. This relatively simple case has been used to check the goodness of two analytical models of the SB that perform relatively well because they use turbulence as a surrogate for the missing advection terms in the layers above 200 m. These models are formulated here in a more consistent manner in the turbulence parameterization than were the original propositions.Peer Reviewe

    Resolving the abundance and air- sea fluxes of airborne microorganisms in the North Atlantic Ocean

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    © 2014 Mayol, Jiménez, Herndl, Duarte and Arrieta. Airborne transport of microbes may play a central role in microbial dispersal, the maintenance of diversity in aquatic systems and in meteorological processes such as cloud formation. Yet, there is almost no information about the abundance and fate of microbes over the oceans, which cover >70% of the Earth's surface and are the likely source and final destination of a large fraction of airborne microbes. We measured the abundance of microbes in the lower atmosphere over a transect covering 17° of latitude in the North Atlantic Ocean and derived estimates of air-sea exchange of microorganisms from meteorological data. The estimated load of microorganisms in the atmospheric boundary layer ranged between 6×104 and 1.6×107 microbes per m2 of ocean, indicating a very dynamic air-sea exchange with millions of microbes leaving and entering the ocean per m2 every day. Our results show that about 10% of the microbes detected in the boundary layer were still airborne 4 days later and that they could travel up to 11,000 km before they entered the ocean again. The size of the microbial pool hovering over the North Atlantic indicates that it could play a central role in the maintenance of microbial diversity in the surface ocean and contribute significantly to atmospheric processes.This is a contribution to the Malaspina Expedition 2010, funded by the INGENIO 2010 CONSOLIDER program (ref. CDS2008-00077) of the Spanish Ministry of Economy and Competitiveness, and projects from the Austrian Science Fund (FWF, I486-B09 and P23234-B11) and project MEDEA from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013, ERC grant agreement No. 268595). Eva Mayol and María A. Jiménez acknowledge the “Junta para la Ampliación de Estudios” program (JAE-predoc and JAE-doc contracts, respectively) from CSIC, supplied by the European Social Fund. Jesús M. Arrieta was supported by a “Ramón y Cajal” fellowship by the former Ministry of Science and Innovation of the Spanish GovernmentPeer Reviewe
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