999 resultados para Variable Spin Lock Experiment


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Autistic spectrum disorder (ASD) is characterised by qualitative alterations in reciprocal social interactions. Some recent studies show alterations in gaze patterns during social perception and rest-functional abnormalities in the ‘social brain network’. This study investigated: i) social perception gaze patterns in children with ASD and controls, ii) the relationship between autism clinical severity and social perception gaze patterns, iii) the relationship between resting cerebral blood flow (rCBF) and social perception gaze patterns. Methods: Nine children with ASD and 9 children with typical development were studied. Eye-tracking was used to detect gaze patterns during presentation of stimuli depicting social scenes. Autism clinical severity was established using the Autism Diagnostic Interview Revised (ADI-R). Arterial spin labelling MRI was used to quantify rCBF. Results: The ASD group looked less at social regions and more at non-social regions than controls. No significant correlation was found between ASD clinical severity and social perception gaze patterns. In the ASD group, gaze behaviour was related to rCBF in the temporal lobe regions at trend level. Positive correlations were found between temporal rCBF and gaze to the face region, while negative correlations were found between temporal rCBF and gaze to non-social regions. Conclusions: These preliminary results suggest that social perception gaze patterns are altered in children with ASD, and could be related to temporal rCBF.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper studies the role of hearing aids in voice identification by hearing-impaired children.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En la actualidad todas las organizaciones se ven enmarcadas en un contexto competitivo al cual hay que responder con una serie de estrategias orientadas a satisfacer de mejor manera las expectativas cada vez más marcadas y selectivas de los clientes. Dentro de esta óptica la generación de valor agregado en los diferentes procesos productivos donde el factor humano es vital, es necesario partir de la premisa: “que el contar con Recurso Humano motivado devengará positivamente sus esfuerzos hacia la empresa traduciéndose en eficiencia y eficacia en los procesos productivos”. Es por esta razón que se ha buscado analizar la situación de los colaboradores de la Fundación Mariana de Jesús realizando un Diagnóstico del Clima Laboral que nos permita determinar la influencia ambiental en la motivación de los mismos y conocer cual es la situación actual del clima laboral según una serie de factores definidos para este caso. Además en base a estos resultados se han elaborado recomendaciones y líneas de acción de las debilidades encontradas en la institución mencionada.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Para muchas empresas la cultura organizacional se considera como una estrategia, que puede ser efectiva a la hora de mejorar las condiciones actuales y futuras de las organizaciones, especialmente si éstas se están enfrentando a grandes cambios. Por lo expuesto, el presente trabajo de investigación sobre la cultura organizacional puede convertirse en una herramienta administrativa muy útil para los directivos de la organización. El desarrollo de la investigación tiene cuatro momentos identificados claramente: en el primer capítulo se realiza un análisis teórico, donde se hablará sobre las organizaciones, tipos de estructuras, la cadena de valor y la administración estratégica. En el segundo capítulo hablaremos sobre la cultura organizacional, tipos de culturas y especialmente analizaremos cómo se crea y mantiene una cultura. En el tercer capítulo se aborda el tema sobre el cambio organizacional y finalmente en el cuarto capítulo, se realiza el análisis de las encuestas aplicadas en la empresa Óptica los Andes de la cultura organizacional y estilos de dirección. En el último capítulo se detallan las conclusiones y las recomendaciones para llegar a la cultura organizacional deseada.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tras quince años de la “asociación estratégica UE-ALC”, los múltiples y profundos cambios en el sistema internacional han tenido gran impacto sobre estas relaciones birregionales. Por ello hay que replantear cuáles son los cambios en la percepciones mutuas de las dos regiones, y observar el nuevo contexto geopolítico, tomando nota de la pérdida de influencia de los EEUU en la región y el auge de Asia, especialmente China. La “asociación estratégica” no ha conducido ni a una convergencia de intereses ni a una reconocible compatibilidad normativa. Además, la UE ha perdido su papel de “modelo” para los procesos de integración, en una región que tiene aún más heterogeneidad por sus diferentes modelos de desarrollo. Por ello se hace necesario asumir una geometría variable para la adaptación de las relaciones birregionales a la realidad del siglo XXI.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ITCT-Lagrangian-2K4 (Intercontinental Transport and Chemical Transformation) experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of air masses in the free troposphere away from emissions. To this end, attempts were made to intercept and sample air masses several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts from two Lagrangian models that were used to direct the aircraft into target air masses. A novel technique then identifies Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole air samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these "coincident matches'' is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown, and the downwind minus upwind differences in tracers are discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We use a simplified atmospheric general circulation model (AGCM) to investigate the response of the lower atmosphere to thermal perturbations in the lower stratosphere. The results show that generic heating of the lower stratosphere tends to weaken the sub-tropical jets and the tropospheric mean meridional circulations. The positions of the jets, and the extent of the Hadley cells, respond to the distribution of the stratospheric heating, with low latitude heating displacing them poleward, and uniform heating displacing them equatorward. The patterns of response to the low latitude heating are similar to those found to be associated with solar variability in previous observational data analysis, and to the effects of varying solar UV radiation in sophisticated AGCMs. In order to investigate the chain of causality involved in converting the stratospheric thermal forcing to a tropospheric climate signal we conduct an experiment which uses an ensemble of model spin-ups to analyse the time development of the response to an applied stratospheric perturbation. We find that the initial effect of the change in static stability at the tropopause is to reduce the eddy momentum flux convergence in this region. This is followed by a vertical transfer of the momentum forcing anomaly by an anomalous mean circulation to the surface, where it is partly balanced by surface stress anomalies. The unbalanced part drives the evolution of the vertically integrated zonal flow. We conclude that solar heating of the stratosphere may produce changes in the circulation of the troposphere even without any direct forcing below the tropopause. We suggest that the impact of the stratospheric changes on wave propagation is key to the mechanisms involved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper it is argued that rotational wind is not the best choice of leading control variable for variational data assimilation, and an alternative is suggested and tested. A rotational wind parameter is used in most global variational assimilation systems as a pragmatic way of approximately representing the balanced component of the assimilation increments. In effect, rotational wind is treated as a proxy for potential vorticity, but one that it is potentially not a good choice in flow regimes characterised by small Burger number. This paper reports on an alternative set of control variables which are based around potential vorticity. This gives rise to a new formulation of the background error covariances for the Met Office's variational assimilation system, which leads to flow dependency. It uses similar balance relationships to traditional schemes, but recognises the existence of unbalanced rotational wind which is used with a new anti-balance relationship. The new scheme is described and its performance is evaluated and compared to a traditional scheme using a sample of diagnostics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The long-term stability, high accuracy, all-weather capability, high vertical resolution, and global coverage of Global Navigation Satellite System (GNSS) radio occultation (RO) suggests it as a promising tool for global monitoring of atmospheric temperature change. With the aim to investigate and quantify how well a GNSS RO observing system is able to detect climate trends, we are currently performing an (climate) observing system simulation experiment over the 25-year period 2001 to 2025, which involves quasi-realistic modeling of the neutral atmosphere and the ionosphere. We carried out two climate simulations with the general circulation model MAECHAM5 (Middle Atmosphere European Centre/Hamburg Model Version 5) of the MPI-M Hamburg, covering the period 2001–2025: One control run with natural variability only and one run also including anthropogenic forcings due to greenhouse gases, sulfate aerosols, and tropospheric ozone. On the basis of this, we perform quasi-realistic simulations of RO observables for a small GNSS receiver constellation (six satellites), state-of-the-art data processing for atmospheric profiles retrieval, and a statistical analysis of temperature trends in both the “observed” climatology and the “true” climatology. Here we describe the setup of the experiment and results from a test bed study conducted to obtain a basic set of realistic estimates of observational errors (instrument- and retrieval processing-related errors) and sampling errors (due to spatial-temporal undersampling). The test bed results, obtained for a typical summer season and compared to the climatic 2001–2025 trends from the MAECHAM5 simulation including anthropogenic forcing, were found encouraging for performing the full 25-year experiment. They indicated that observational and sampling errors (both contributing about 0.2 K) are consistent with recent estimates of these errors from real RO data and that they should be sufficiently small for monitoring expected temperature trends in the global atmosphere over the next 10 to 20 years in most regions of the upper troposphere and lower stratosphere (UTLS). Inspection of the MAECHAM5 trends in different RO-accessible atmospheric parameters (microwave refractivity and pressure/geopotential height in addition to temperature) indicates complementary climate change sensitivity in different regions of the UTLS so that optimized climate monitoring shall combine information from all climatic key variables retrievable from GNSS RO data.