109 research outputs found
Modelo anual de la dinámica sedimentaria en una marisma mareal mediterránea.
Se ha detectado un patrón estacional en la dinámica sedimentaria en zonas de marisma baja, relacionado
con la distribución anual de las precipitaciones característica del clima mediterráneo, que induce cambios en el
caudal de los ríos y en la cantidad y distribución de los aportes de partículas finas que entran en el estuario. En
este escenario se pone de manifiesto cómo la presencia de vegetación (Spartina maritima) favorece la acreción y
estabilización de sedimentos. En planicies desprovistas de vegetación, los mayores niveles de acreción se registran
durante primavera y principios de verano. Las lluvias otoñales determinan un aumento del caudal de los ríos,
con un incremento en el aporte de sedimentos y removilización de éstos en las zonas desnudas. Parte de estos sedimentos
quedarán entonces retenidos en las zonas provistas de vegetación. Durante este periodo de otoño es cuando
esta vegetación alcanza sus mayores valores de biomasa, maximizando así su papel como estabilizador de sedimentos.We have found a seasonal pattern operating on the lower areas of a tidal marsh, in relation to the characteristic
annual distribution of the rainfall in a Mediterranean climate which induces changes in river flows and in
quantity and distribution of loam sediments entering the estuary. Also, the presence of vegetation (S. maritima)
favours the accretion rate and the sediment stabilization. Bare muds record the maximum values of accretion during
Spring and early Summer. Autumn rainfalls increase the river flow what means a new input of sediments and the
movilization of the old ones from the bare muds; the vegetation raises the maximum biomass and it traps and stabilizes
these sediments.Dirección General de Investigación Científica y Técnica. Gobierno de España-PB94-145
Bone remodeling: A tissue-level process emerging from cell-level molecular algorithms
<div><p>The human skeleton undergoes constant remodeling throughout the lifetime. Processes occurring on microscopic and molecular scales degrade bone and replace it with new, fully functional tissue. Multiple bone remodeling events occur simultaneously, continuously and independently throughout the body, so that the entire skeleton is completely renewed about every ten years.Bone remodeling is performed by groups of cells called Bone Multicellular Units (BMU). BMUs consist of different cell types, some specialized in the resorption of old bone, others encharged with producing new bone to replace the former. These processes are tightly regulated so that the amount of new bone produced is in perfect equilibrium with that of old bone removed, thus maintaining bone microscopic structure.To date, many regulatory molecules involved in bone remodeling have been identified, but the precise mechanism of BMU operation remains to be fully elucidated. Given the complexity of the signaling pathways already known, one may question whether such complexity is an inherent requirement of the process or whether some subset of the multiple constituents could fulfill the essential role, leaving functional redundancy to serve an alternative safety role. We propose in this work a minimal model of BMU function that involves a limited number of signals able to account for fully functional BMU operation. Our main assumptions were i) at any given time, any cell within a BMU can select only one among a limited choice of decisions, i.e. divide, die, migrate or differentiate, ii) this decision is irreversibly determined by depletion of an appropriate internal inhibitor and iii) the dynamics of any such inhibitor are coupled to that of specific external mediators, such as hormones, cytokines, growth factors. It was thus shown that efficient BMU operation manifests as an emergent process, which results from the individual and collective decisions taken by cells within the BMU unit in the absence of any external planning.</p></div
Diferencias físico-químicas del solomillo (illiopsoas y psoas menor) de las cuatro estirpes de cerdo ibérico reconocidas en el catálogo oficial de razas de ganado de España
Ministerio de Agricultura y Pesca, Alimentación y Medio Ambient
Comparisons of ball possession, match running performance, player prominence and team network properties according to match outcome and playing formation during the 2018 FIFA World Cup
The aims of this study conducted in national teams during the 2018 Russia FIFA World Cup were: i) to verify the possible variations of ball possession, match running performance, player prominence, team network properties according to match outcome and playing formation; and ii) to investigate the relationships between player prominence and total distance covered according to team ball possession. Sixty-one matches were analysed over the course of the competition (n=988 player observations). Running performance was examined using total distance covered in (TDIP) and out of possession, and that travelled in different speed-range categories. Player prominence (micro) and team network properties (macro) were obtained using social network analysis where completed passes between teammates were counted (n=28019 passes). Main findings were: i) with the exception of clustering coefficients which indicate the level of interconnectivity between close teammates (win = draw > loss), match outcome was unaffected by ball possession, running and network measures ; iii) teams employing a 1‒4‒2‒3‒1 formation reported greater values for ball possession, TDIP, and micro/macro network measures compared to those playing 1‒4‒4‒2 and 1‒4‒3‒3 formations; iv) TDIP tended to be related to most player prominence variables, even though the magnitude of coefficients varied considerably according to network measures and playing positions. This study has provided additional insights into elite soccer match-play performance
Comparative genomics of quinolone‐resistant and susceptible Campylobacter jejuni of poultry origin from major poultry producing European countries (GENCAMP)
Image analysis to identify objects in filters obtained from turbidity plumes
The study of turbidity plumes developed in front of the river mouth, have an increasing
scientific interest due to its contribution to infralittoral sediment transport and deposition. River
plume evolution and deposition in submarine fans related to environmental constrains could be
interpreted by the analysis of suspended particulate matter (SPM) retained during the filtering
process. In this study, a new methodology approach to obtain quantitative results in sediment filters,
using custom digital image processing techniques, is presented and some promising preliminary
results are obtained. This procedure could avoid time-consuming during SPM analysis allowing an
easy way to obtain fast and quantitative information, which might lead to a better interpretation and
comprehension of factors involved in the evolution of riverine turbidity plumes.Versión del edito
Measurement of the W-boson mass in pp collisions at √s=7 TeV with the ATLAS detector
A measurement of the mass of the W boson is presented based on proton–proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fb−1 of integrated luminosity. The selected data sample consists of 7.8×106 candidates in the W→μν channel and 5.9×106 candidates in the W→eν channel. The W-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yielding
mW=80370±7 (stat.)±11(exp. syst.)
±14(mod. syst.) MeV
=80370±19MeV,
where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W+ and W−bosons yields mW+−mW−=−29±28 MeV
A communal catalogue reveals Earth's multiscale microbial diversity
Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe
A communal catalogue reveals Earth’s multiscale microbial diversity
Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity
Cold atoms in space: community workshop summary and proposed road-map
We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies.publishedVersio
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