7,466 research outputs found

    Sesión de Bioinformática

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    Comunicaciones a congreso

    Attributing trends in extremely hot days to changes in atmospheric dynamics

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    This paper presents a method for attributing regional trends in the frequency of extremely hot days (EHDs) to changes in the frequency of the atmospheric patterns that characterize such extraordinary events. The study is applied to mainland Spain and the Balearic Islands for the extended summers of the period 1958–2008, where significant and positive trends in maximum temperature (Tx) have been reported during the second half of the past century.This study was supported by the Spanish government and the Fondo Europeo de Desarrollo Regional (FEDER) through the projects SPEQTRES (CGL2011-29672-C02-02) and REPAIR (CGL2014-59677-R). J. P. Montavez also acknowledges the financial support from Fundacion Seneca (Ref 19640/EE/14)

    Teams as Complex Adaptive Systems: Reviewing 17 Years of Research

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    At the turn of the century Arrow, McGrath, and Berdahl (2000) portrayed teams as complex adaptive systems (CAS). And yet, despite broad agreement that this approach facilitates a better understanding of teams, it has only now been timidly incorporated into team research. To help fully incorporate the logic of teams as CAS in the science of teams, we review extant research on teams' approached from a nonlinear dynamical system theory. Using a systematic review approach, we selected 92 articles published over the last 17 years, in order to integrate what we know about teams as CAS. Our review reveals the evidence supporting teams as CAS, and the set of analytical techniques to analyze team data from this perspective. Our work contributes to teams' theory and practice by offering ways to identify both research methods and managing techniques that scholars and practitioners may apply to study and manage teams as CAS

    The ciliary machinery is repurposed for T cell immune synapse trafficking of LCK

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    Upon engagement of the T cell receptor with an antigen-presenting cell, LCK initiates TCR signaling by phosphorylating its activation motifs. However, the mechanism of LCK activation specifically at the immune synapse is a major question. We show that phosphorylation of the LCK activating Y394, despite modestly increasing its catalytic rate, dramatically focuses LCK localization to the immune synapse. We describe a trafficking mechanism whereby UNC119A extracts membrane-bound LCK by sequestering the hydrophobic myristoyl group, followed by release at the target membrane under the control of the ciliary ARL3/ARL13B. The UNC119A N terminus acts as a “regulatory arm” by binding the LCK kinase domain, an interaction inhibited by LCK Y394 phosphorylation, thus together with the ARL3/ARL13B machinery ensuring immune synapse focusing of active LCK. We propose that the ciliary machinery has been repurposed by T cells to generate and maintain polarized segregation of signals such as activated LCK at the immune synapse

    Substructure and halo density profiles in a Warm Dark Matter Cosmology

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    We performed a series of high-resolution simulations designed to study the substructure of Milky Way-size galactic halos (host halos) and the density profiles of halos in a warm dark matter (WDM) scenario with a non-vanishing cosmological constant. The virial masses of the host halos range from 3.5 x 10^12 to 1.7 x 10^12 solar masses and they have more than 10^5 particles each. A key feature of the WDM power spectrum is the free-streaming length R_f which fixes an additional parameter for the model of structure formation. We analyze the substructure of host halos using three R_f values: 0.2, 0.1, and 0.05 Mpc and compare results to the predictions of the cold dark matter (CDM) model. We find that guest halos (satellites) do form in the WDM scenario but are more easily destroyed by dynamical friction and tidal disruption than their counterparts in a CDM model. The small number of guest halos that we find within the virial radii of host halos at z = 0 in the WDM models is the result of a less efficient halo accretion and a higher satellite destruction rate. Under the assumption that each guest halo hosts a luminous galaxy, we find that the observed circular velocity function of satellites around the Milky Way and Andromeda is well described by the R_f = 0.1 Mpc WDM model. In the R_f = 0.1-0.2 Mpc models, the surviving subhalos at z=0 have an average concentration parameter c_1/5 which is approximately twice smaller than that of the corresponding CDM subhalos. This difference, very likely, produces the higher satellite destruction rate found in the WDM models. The density profile of host halos is well described by the NFW fit whereas guest halos show a wide variety of density profiles (abridged).Comment: Uses emulateapj.sty: 10 pages, 4 figures, ApJ accepted. Some changes have been introduced as suggested by the referee: (1) the description of the numerical simulations was sligthly modified to make it clearer, (2) the ellipticities of the host halos are now measured, and (3) the discussion section was divided in two subsections and enlarge

    Leveraging Container Technologies in a GIScience Project: A Perspective from Open Reproducible Research

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    Scientific reproducibility is essential for the advancement of science. It allows the results of previous studies to be reproduced, validates their conclusions and develops new contributions based on previous research. Nowadays, more and more authors consider that the ultimate product of academic research is the scientific manuscript, together with all the necessary elements (i.e., code and data) so that others can reproduce the results. However, there are numerous difficulties for some studies to be reproduced easily (i.e., biased results, the pressure to publish, and proprietary data). In this context, we explain our experience in an attempt to improve the reproducibility of a GIScience project. According to our project needs, we evaluated a list of practices, standards and tools that may facilitate open and reproducible research in the geospatial domain, contextualising them on Peng’s reproducibility spectrum. Among these resources, we focused on containerisation technologies and performed a shallow review to reflect on the level of adoption of these technologies in combination with OSGeo software. Finally, containerisation technologies proved to enhance the reproducibility and we used UML diagrams to describe representative work-flows deployed in our GIScience project

    Holography, degenerate horizons and entropy

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    We show that a realization of the correspondence AdS_2/CFT_1 for near extremal Reissner-Nordstrom black holes in arbitrary dimensional Einstein-Maxwell gravity exactly reproduces, via Cardy's formula, the deviation of the Bekenstein-Hawking entropy from extremality. We also show that this mechanism is valid for Schwarzschild-de Sitter black holes around the degenerate solution dS_2xS^n. These results reinforce the idea that the Bekenstein-Hawking entropy can be derived from symmetry principles.Comment: LaTex file, 23 pages, 1 figure; several corrections, to appear in Nucl. Phys.

    Predicting the dynamic criteria of basketball players: The influence of the 'Big Five', job experience, and motivation

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    The present study analyses the prediction of the effectiveness and its fluctuations of 34 semi-professional basketball players throughout a sport season using the dynamic criteria as theoretical framework. The predictor variables (the Big Five personality factors, job experience and motivation) were obtained by means of self-report, while effectiveness was determined through objective data (statistics of matches). The predictive models were developed using generalized maximum entropy formulation, and results show that: (1) the relevance of the predictors of effectiveness is different each time they are analysed; (2) all variables except conscientiousness predict the fluctuations, and openness to experience is the most influential predictor; and (3) job experience is less relevant than personality and motivation. Finally, some recommendations are made regarding the choice of predictors for the selection of basketball players

    Dynamic Criteria: a Longitudinal Analysis of Professional Basketball Players" Outcomes

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    This paper describes the fluctuations of temporal criteria dynamics in the context of professional sport. Specifically, we try to verify the underlying deterministic patterns in the outcomes of professional basketball players. We use a longitudinal approach based on the analysis of the outcomes of 94 basketball players over ten years, covering practically players" entire career development. Time series were analyzed with techniques derived from nonlinear dynamical systems theory. These techniques analyze the underlying patterns in outcomes without previous shape assumptions (linear or nonlinear). These techniques are capable of detecting an intermediate situation between randomness and determinism, called chaos. So they are very useful for the study of dynamic criteria in organizations. We have found most players (88.30%) have a deterministic pattern in their outcomes, and most cases are chaotic (81.92%). Players with chaotic patterns have higher outcomes than players with linear patterns. Moreover, players with power forward and center positions achieve better results than other players. The high number of chaotic patterns found suggests caution when appraising individual outcomes, when coaches try to find the appropriate combination of players to design a competitive team, and other personnel decisions. Management efforts must be made to assume this uncertainty
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