400 research outputs found

    When the ground cover brings guests: is Anaphothrips obscurus a friend or a foe for the biological control of Tetranychus urticae in clementines?

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    Biological control of Tetranychus urticae Koch (Acari: Tetranychidae), a key pest of clementines, can be improved in this crop with the establishment of a ground cover of Festuca arundinacea Schreber (Poaceae). This cover houses an abundant and diverse community of predatory Phytoseiidae mites including Euseius stipulatus (Athias-Henriot), Neoseiulus barkeri Hughes, Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot and a dense population of the grass thrips Anaphothrips obscurus Müller (Thysanoptera: Thripidae) throughout the year. The aim of this study was to determine whether the presence of this thrips species could be related to the improvement in the biological control of T. urticae. Therefore, the capacity of the abovementioned phytoseiids to feed and reproduce on A. obscurus and their feeding preferences when T. urticae and A. obscurus were simultaneously offered, were analyzed. The results show that E. stipulatus, N. barkeri and N. californicus have a type II functional response when offered A. obscurus nymphs, whereas P. persimilis barely feeds on this thrips species. Furthermore, N. barkeri and N. californicus can reproduce feeding only on thrips. Regarding prey preference, the Tetranychus spp.-specialist P. persimilis preferably preyed on T. urticae, the generalists N. barkeri and E. stipulatus preferred A. obscurus, and the selective predator of tetranychid mites N. californicus showed no preference. Therefore, we hypothesize that the enhanced biological control of T. urticae observed could be related to A. obscurus becoming an alternative prey for non-specialist phytoseiids, without altering the control exerted by the T. urticae-specialist P. persimilis and likely reducing intraguild predation

    Educational Warehouse: Modular, Private and Secure Cloudable Architecture System for Educational Data Storage, Analysis and Access

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    [Abstract] Data in the educational context are becoming increasingly important in decision-making and teaching-learning processes. Similar to the industrial context, educational institutions are adopting data-processing technologies at all levels. To achieve representative results, the processes of extraction, transformation and uploading of educational data should be ubiquitous because, without useful data, either internal or external, it is difficult to perform a proper analysis and to obtain unbiased educational results. It should be noted that the source and type of data are heterogeneous and that the analytical processes can be so diverse that it opens up a practical problem of management and access to the data generated. At the same time, ensuring the privacy, identity, confidentiality and security of students and their data is a “sine qua non” condition for complying with the legal issues involved while achieving the required ethical premises. This work proposes a modular and scalable data system architecture that solves the complexity of data management and access. On the one hand, it allows educational institutions to collect any data generated in both the teaching-learning and management processes. On the other hand, it will enable external access to this data under appropriate privacy and security conditions.Generalitat de Catalunya; 2017 SGR 93

    High--Resolution 3D Simulations of Relativistic Jets

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    We have performed high-resolution 3D simulations of relativistic jets with beam flow Lorentz factors up to 7, a spatial resolution of 8 cells per beam radius, and for up to 75 normalized time units to study the morphology and dynamics of 3D relativistic jets. Our simulations show that the coherent fast backflows found in axisymmetric models are not present in 3D models. We further find that when the jet is exposed to non-axisymmetric perturbations, (i) it does not display the strong perturbations found for 3D classical hydrodynamic and MHD jets (at least during the period of time covered by our simulations), and (ii) it does propagate according to the 1D estimate. Small 3D effects in the relativistic beam give rise to a lumpy distribution of apparent speeds like that observed in M87. The beam is surrounded by a boundary layer of high specific internal energy. The properties of this layer are briefly discussed.Comment: 15 pages, 4 figures. Accepted to be publish in the ApJ Letters. Tar+gzip documen

    Basketball game-related statistics that discriminate between teams season-long success

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    The aim of the present study was to identify the game-related statistics that discriminate between season-long successful and unsuccessful basketball teams participating in the Spanish Basketball League (LEB1). The sample included all 145 average records per season from the 870 games played between the 2000-2001 and the 2005-2006 regular seasons. The following game-related statistics were gathered from the official box scores of the Spanish Basketball Federation: 2- and 3-point field-goal attempts (both successful and unsuccessful), free-throws (both successful and unsuccessful), defensive and offensive rebounds, assists, steals, turnovers, blocks (both made and received), and fouls (both committed and received). To control for season variability, all results were normalized to minutes played each season and then converted to z-scores. The results allowed discrimination between best and worst teams' performances through the following game-related statistics: assists (SC=0.47), steals (SC=0.34), and blocks (SC=0.30). The function obtained correctly classified 82.4% of the cases. In conclusion, season-long performance may be supported by players' and teams' passing skills and defensive preparation

    Accelerated long-term forgetting in resected and seizure-free temporal lobe epilepsy patients

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    Episodic memory impairments caused by temporal lobe epilepsy (TLE) are well documented in the literature. Standard clinical episodic memory tests typically include a 30-min delayed recall test. However, in the past decade, it has become apparent that this standard test does not capture the full range of memory problems in TLE patients. Some patients perform well on a standard 30-min delayed recall test, but show Accelerated Long-term Forgetting (ALF) after 24 h. Although ALF has been investigated in patients with different types of epilepsy, current research on resected TLE patients is missing. In the present study, resected TLE patients were compared to a control group matched on initial learning. They showed normal performance on verbal recall after 30 min, but impairments became apparent after one week. Moreover, the significant interaction between participant group and memory test delay demonstrated that the patients indeed showed an acceleration in forgetting. Furthermore, ALF was present in both left and right resected TLE patients, which contradicts the presence of material-specific hemispheric differences in ALF. In addition, ALF was observed in seizure-free resected TLE patients, thereby demonstrating that this factor is not crucial for long-term memory deficits. The outcome shows that clinicians are likely to underestimate memory deficits in resected TLE patients and, therefore, advocates for the inclusion of ALF tests in standard clinical batteries for both pre- and post-surgery testing sessions

    3D Simulations of Relativistic Precessing Jets Probing the Structure of Superluminal Sources

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    We present the results of a three-dimensional, relativistic, hydrodynamic simulation of a precessing jet into which a compact blob of matter is injected. A comparison of synthetic radio maps computed from the hydrodynamic model, taking into account the appropriate light travel time delays, with those obtained from observations of actual superluminal sources shows that the variability of the jet emission is the result of a complex combination of phase motions, viewing angle selection effects, and non-linear interactions between perturbations and the underlying jet and/or the external medium. These results question the hydrodynamic properties inferred from observed apparent motions and radio structures, and reveal that shock-in-jet models may be overly simplistic.Comment: Accepted for publication in ApJL. 4 pages, 5 figures (4 in color

    Quercus suber dieback alters soil respiration and nutrient availability in Mediterranean forests

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    12 páginas.-- 5 figuras.-- 1 tablas.-- 106 referencias.-- Additional Supporting Information may be found in the online version of this article: http://dx.doi.org/10.1111/1365-2745.12618.-- Data available from the Dryad Digital Repository, http://dx.doi.org/10.5061/dryad.6nd4k (Avila et al. 2016)An increase in tree mortality rates has been recently detected in forests world-wide. However, few works have focused on the potential consequences of forest dieback for ecosystem functioning. Here we assessed the effect of Quercus suber dieback on carbon, nitrogen and phosphorus cycles in two types of Mediterranean forests (woodlands and closed forests) affected by the aggressive pathogen Phytophthora cinnamomi. We used a spatially explicit neighbourhood approach to analyse the direct effects of Q. suber dieback on soil variables, comparing the impact of Q. suber trees with different health status, as well as its potential long-term indirect effects, comparing the impact of non-declining coexistent species. Quercus suber dieback translated into lower soil respiration rates and phosphorus availability, whereas its effects on nitrogen varied depending on forest type. Coexistent species differed strongly from Q. suber in their effects on nutrient availability, but not on soil respiration rates. Our models showed low interannual but high intra-annual variation in the ecosystem impacts of tree dieback. Synthesis. Our results support that tree dieback might have important short- and long-term impacts on ecosystem processes in Mediterranean forests. With this work, we provide valuable insights to fill the existent gap in knowledge on the ecosystem-level impacts of forest dieback in general and P. cinnamomi-driven mortality in particular. Because the activity and range of this pathogen is predicted to increase due to climate warming, these impacts could also increase in the near future altering ecosystem functioning world-wideThis research was supported by the Ministerio de Ciencia e Innovación (MICINN) projects CGL2008-04503-C03-03, CGL2010-21381 and CGL2011-26877. J.M.A. was supported by a FPU-MEC grant (AP2010-0229) and B.I. by a FPI-MICINN grant (BES-2009-017111).Peer reviewe

    Primera encuesta de "Nuestro cinema"

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    Casinos Guillén, A.; Marinel·lo Roca, R.; Gómez Ibáñez, J. (1932). Primera encuesta de "Nuestro cinema". Nuestro cinema. (6):161-167. http://hdl.handle.net/10251/42816.Importación Masiva161167

    Psychosocial status of Physical Education teachers according to socio-demographic characteristics

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    Actualmente, los docentes están expuestos a riesgos psicosociales propios del contexto educativo y es importante superar y anticiparse a las adversidades que ello conlleva. Por ello, este estudio pretende analizar los niveles de estrés, síndrome de burnout y resiliencia en profesores de educación física, así como establecer las relaciones existentes en función del género y la situación sociolaboral. El estudio tuvo un diseño no experimental, descriptivo, comparativo y correlacional, con medición en un solo grupo. La muestra estuvo compuesta por 415 profesores de educación física de toda España, con un rango de edad de 21-53 años (M=28,78±6,15) y una distribución heterogénea, representando el 69,4% del género masculino y el 30,6% del género femenino. Para registrar los aspectos sociodemográficos se utilizó la Escala de Estrés Percibido (PSS), el Inventario de Burnout de Maslach (MBI), la Escala de Resiliencia de Connor-Davidson (CD-RISC) y un cuestionario Ad- Hoc. Finalmente se observa que, para el síndrome de burnout, la subescala con mayor puntuación es el agotamiento emocional, seguida de la realización personal y la despersonalización. Para la resiliencia, se observa que la subescala con mayor puntuación es la competencia personal, seguida de la aceptación positiva, el control y el propósito, la tolerancia a los acontecimientos negativos y las influencias espirituales.Currently, teachers are exposed to psychosocial risks specific to the educational context and it is important to overcome and anticipate the adversities involved. Therefore, this study aims to analyse the levels of stress, burnout syndrome and resilience in physical education teachers, as well as to establish the existing relationships according to gender and sociooccupational situation. The study had a non-experimental, descriptive, comparative and correlational design, with measurement in a single group. The sample consisted of 415 physical education teachers from all over Spain, with an age range of 21-53 years (M=28.78±6.15) and a heterogeneous distribution, representing 69.4% of the male gender and 30.6% of the female gender. The Perceived Stress Scale (PSS), the Maslach Burnout Inventory (MBI), the Connor-Davidson Resilience Scale (CD-RISC) and an Ad-Hoc questionnaire were used to record socio-demographic aspects. Finally, it is observed that, for burnout syndrome, the subscale with the highest score is emotional exhaustion, followed by self-fulfilment and depersonalisation. For resilience, the highest scoring subscale is personal competence, followed by positive acceptance, control and purpose, tolerance of negative events and spiritual influences
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