53 research outputs found
Tracking the oxygen isotopic signature from the rainfall to the speleothems in Ortigosa de Cameros caves (La Rioja, Spain)
A one-year monitoring survey has been carried out in La Paz and La Viña Caves in the Ortigosa de Cameros Cave System (NE Iberian Peninsula), in order to track the oxygen isotope signal from rainfall to speleothem calcite, assessing the ability of this signal to retain environmental information. Oxygen isotope signals of rainfall events, drip water —sampled every three months—, and speleothem calcite, precipitated over three-months, are compared. Water dripping follows precipitation events in winter, spring and summer, more closely in the near-surface drip points than in the deeper ones. In autumn, dripping is delayed with respect to rainfall, suggesting that water stays in the epikarst before dripping resumes after summer. This delay causes a deviation of the total drip water signal (average δ<sup>18</sup>O=−8.39‰ V-SMOW) from the rainfall signal (average δ<sup>18</sup>O=−7.41‰ V-SMOW). On the contrary, in winter the isotopic signal of drip water keeps the rainfall signal. Calcite isotopic signal (total average δ<sup>18</sup>O=−6.83‰ V-PDB) shows a small offset (0.62–0.75%) with respect to the signal predicted by drip water oxygen composition; this points to a limited kinetic effect in calcite precipitation, therefore calcite retains the signal of rainfall, especially in winter.<br><br>Durante un año se han monitorizado las cuevas de La Paz y La Viña en el Sistema de Cuevas de Ortigosa de Cameros (NE de la Península Ibérica) para rastrear la señal isotópica del oxígeno desde la lluvia a la calcita espeleotémica, y así valorar la capacidad de esta señal para conservar información medioambiental. Se han comparado las señales isotópicas del oxígeno de los eventos de la lluvia, el agua de goteo (muestreada trimestralmente) y la calcita espeleotémica, precipitada también durante cada trimestre. El goteo en las cuevas responde a la precipitación en invierno, primavera y verano, más estrechamente en los puntos más próximos a la superficie que en los profundos. En otoño hay un retraso entre la lluvia y el goteo, lo que sugiere que el agua permanece por un tiempo en el epikarst, antes de que se reanude el goteo después del verano. Este retraso provoca que la señal isotópica del agua de goteo (media total de δ<sup>18</sup>O=−8.39‰ V-SMOW) se desvíe de la señal de la lluvia (media de δ<sup>18</sup>O=−7,41‰ V-SMOW). Por el contrario, en invierno la señal isotópica del agua de goteo es muy semejante a la de la lluvia. La composición isotópica de la calcita espeleotémica (media total de δ<sup>18</sup>O=−6,83‰ V-PDB) presenta un pequeño desfase (0,62–0,75%) respecto al valor que le correspondería por la composición isotópica del agua de goteo; esto indica que los efectos cinéticos durante la precipitación de la calcita son limitados, por lo que ésta conserva la señal de la lluvia, especialmente en invierno
Toward a Test Environment for Autonomous Controllers
In the last two decades, an increasing attention has been dedicated on the use of high level task planning in robotic control, aiming to deploy advanced robotics systems in challenging scenarios where a high autonomy degree is required. Nevertheless, an interesting open problem in the literature is the lack of a well defined methodology for approaching the design of deliberative systems and for fairly comparing different approaches to deliberation. This paper presents the general idea of an environment for facilitating knowledge engineering for autonomy and in particular to facilitate accurate experiments on planning and execution systems for robotics. It discusses features of the On-Ground Autonomy Test Environment (OGATE), a general testbench for interfacing deliberative modules. In particular we present features of an initial instance of such system built to support the GOAC robotic software
Plan de negocio para la importaci?n y comercializaci?n de bicicletas, repuestos y accesorios en el mercado peruano
En el desarrollo del presente plan de negocio se determin? que el negocio de importaci?n y comercializaci?n de bicicletas, accesorios y repuestos en el mercado peruano es viable y rentable, ya que el valor actual neto (VAN) resulta ser de $20,562 y la tasa interna de retorno (TIR) de 14.25%, el cual supera al WACC (costo promedio de capital). Para lograr este escenario favorable y viable del negocio la empresa BIKELIFE deber? ejecutar los planes: estrat?gico, marketing, operaciones, recursos humanos y TI detallados en la presente tesis, que servir?n para la implementaci?n y buen funcionamiento de la empresa. De la misma forma se desarroll? las partes de la cadena de abastecimiento de tal forma de optimizar las operaciones en costo y tiempo
Remarks on Semileptonic B and D Decays into Orbitally Excited Mesons
We have obtained the differential decay rate and calculated the branching
ratios of the exclusive semileptonic decays , where is a
p-wave meson, using the nonrelativistic ISGW quark model. Our results are
compared with the predictions of the ISGW2 model. We have computed some
branching ratios that were not reported or were reported with 0.00 in this
model. For example, we find that , and , which seems to be
at the reach of forthcoming experiments. Furthermore, we have classified the
decays in two groups and compared the semileptonic and
nonleptonic decays including a tensor meson in the final state.Comment: 11 pages, LaTe
Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV
We report the first measurement of charged particle elliptic flow in Pb-Pb
collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron
Collider. The measurement is performed in the central pseudorapidity region
(||<0.8) and transverse momentum range 0.2< < 5.0 GeV/. The
elliptic flow signal v, measured using the 4-particle correlation method,
averaged over transverse momentum and pseudorapidity is 0.087 0.002
(stat) 0.004 (syst) in the 40-50% centrality class. The differential
elliptic flow v reaches a maximum of 0.2 near = 3
GeV/. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow
increases by about 30%. Some hydrodynamic model predictions which include
viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/389
Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks: The GR@ACE project
INTRODUCTION: Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways. METHODS: Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets. RESULTS: We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444. DISCUSSION: The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series
Hypertriton Production in p-Pb Collisions at √sNN = 5.02 TeV
The study of nuclei and antinuclei production has proven to be a powerful
tool to investigate the formation mechanism of loosely bound states in
high-energy hadronic collisions. The first measurement of the production of
in p-Pb collisions at = 5.02
TeV is presented in this Letter. Its production yield measured in the rapidity
interval -1 < y < 0 for the 40% highest multiplicity p-Pb collisions is . The measurement is compared with the expectations of statistical
hadronisation and coalescence models, which describe the nucleosynthesis in
hadronic collisions. These two models predict very different yields of the
hypertriton in small collision systems such as p-Pb and therefore the
measurement of is crucial to distinguish between them.
The precision of this measurement leads to the exclusion with a significance
larger than 6 of some configurations of the statistical hadronisation,
thus constraining the production mechanism of loosely bound states
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