Effects of biasing on the galaxy power spectrum at large scales

n this paper we study the effect of biasing on the power spectrum at large scales. We show that even though non-linear biasing does introduce a white noise contribution on large scales, the $P(k)\propto k^n$ behavior of the matter power spectrum on large scales may still be visible and above the white noise for about one decade. We show, that the Kaiser biasing scheme which leads to linear bias of the correlation function on {\em large} scales, also generates a linear bias of the {\rm power spectrum} on rather small scales. This is a consequence of the divergence on small scales of the pure Harrison-Zeldovich spectrum. However, biasing becomes k-dependent when we damp the underlying power spectrum on small scales. We also discuss the effect of biasing on the baryon acoustic oscillations.Comment: 9 pages, 4 figures. One figure and comments clarifying the linear biasing on small scales and references added. V3 version accepted in PR

CCS and NH_3 Emission Associated with Low-Mass Young Stellar Objects

In this work we present a sensitive and systematic single-dish survey of CCS emission (complemented with ammonia observations) at 1 cm, toward a sample of low- and intermediate-mass young star-forming regions known to harbor water maser emission, made with NASA's 70 m antenna at Robledo de Chavela, Spain. Out of the 40 star-forming regions surveyed in the CCS (2_(1)-1_(0)) line, only six low-mass sources show CCS emission: one transitional object between the prestellar and protostellar Class 0 phase (GF9-2), three Class 0 protostars (L1448-IRS3, L1448C, and B1-IRS), a Class I source (L1251A), and a young T Tauri star (NGC 2071 North). Since CCS is considered an "early-time" (≲10^5 yr) molecule, we explain these results by either proposing a revision of the classification of the age of NGC 2071 North and L1251A, or suggesting the possibility that the particular physical conditions and processes of each source affect the destruction/production of the CCS. No statistically significant relationship was found between the presence of CCS and parameters of the molecular outflows and their driving sources. Nevertheless, we found a significant relationship between the detectability of CCS and the ammonia peak intensity (higher in regions with CCS), but not with its integrated intensity. This tendency may suggest that the narrower ammonia line widths in the less turbulent medium associated with younger cores may compensate for the differences in ammonia peak intensity, rendering differences in integrated intensity negligible. From the CCS detection rate we derive a lifetime of this molecule of ≃(0.7-3) × 10^4 yr in low-mass star-forming regions

Cinemómetro piezoeléctrico de alta exactitud (VUAE)

Se ha desarrollado un sistema electrónico computerizado, portátil y de bajo consumo, denominado Medidor de Velocidad de Vehículos por Ultrasonidos de Alta Exactitud, VUAE. La alta exactitud de la medida conseguida en el VUAE hace que pueda servir de medida de referencia de la velocidad de un vehículo circulando en carretera. Por tanto el VUAE puede usarse como medida de referencia que permita estimar el error de los cinemómetros comerciales. El VUAE está compuesto por n (n≥2) parejas de emisores y receptores piezoeléctricos de ultrasonidos, denominados E-Rult. Los emisores de las n parejas E-Rult generan n barreras de ultrasonidos, y los receptores piezoeléctricos captan la señal de los ecos cuando el vehículo atraviesa las barreras. Estos ecos se procesan digitalmente para conseguir señales representativas. Posteriormente, utilizando la técnica de la correlación cruzada de señales, se ha podido estimar con alta exactitud la diferencia de tiempos entre los ecos captados en cada barrera. Con los tiempos entre ecos y con la distancia entre cada una de las n barreras de ultrasonidos se puede realizar una estimación de la velocidad del vehículo con alta exactitud. El VUAE se ha contrastado con un sistema de velocidad de referencia, basado en cables piezoeléctricos.Peer reviewe

An Application of Cooperative Game Theory to Distributed Control

18th World CongressThe International Federation of Automatic ControlMilano (Italy) August 28 - September 2, 2011In this paper we propose to study the underlying properties of a given distributed control scheme in which a set of agents switch between different communication strategies that define which network links are used in order to regulate to the origin a set of unconstrained linear systems. The problems of how to decide the time-varying communication strategy, share the benefits/costs and detect which are the most critical links in the network are solved using tools from game theory. The proposed scheme is demonstrated through a simulation example

Effects of Supervised Multimodal Exercise Interventions on Cancer-Related Fatigue: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective. Cancer-related fatigue (CRF) is the most common and devastating problem in cancer patients even after successful treatment. This study aimed to determine the effects of supervised multimodal exercise interventions on cancer-related fatigue through a systematic review and meta-analysis. Design. A systematic review was conducted to determine the effectiveness of multimodal exercise interventions on CRF. Databases of PubMed, CENTRAL, EMBASE, and OVID were searched between January and March 2014 to retrieve randomized controlled trials. Risk of bias was evaluated using the PEDro scale. Results. Nine studies (n=772) were included in both systematic review and meta-analysis. Multimodal interventions including aerobic exercise, resistance training, and stretching improved CRF symptoms (SMD=-0,23; 95% CI: −0.37 to −0.09; P=0,001). These effects were also significant in patients undergoing chemotherapy (P<0,0001). Nonsignificant differences were found for resistance training interventions (P=0,30). Slight evidence of publication bias was observed (P=0,04). The studies had a low risk of bias (PEDro scale mean score of 6.4 (standard deviation (SD) ± 1.0)). Conclusion. Supervised multimodal exercise interventions including aerobic, resistance, and stretching exercises are effective in controlling CRF. These findings suggest that these exercise protocols should be included as a crucial part of the rehabilitation programs for cancer survivors and patients during anticancer treatments.This paper and own authors data described in this paper were supported by the grant from Vicerrectoría de Investigaciones, Universidad de Santo Tomás (Contract no. 617-3-2013)

La cuota de mercado como indicador de competitividad en los destinos turísticos: sentido y limitaciones

The market share is the most widely used indicator in the analysis of competitiveness in trade of goods and services. However, their use in tourism is subject to a widespread controversy, especially in those cases where goes together to the territorial analysis. This is because the goals of maximization of this variable by policy-makers, can lead to growth policies that jeopardize the economic and environmental sustainability of a resource-limited destinations. This paper discusses the use, validity and limitations of the market share as an indicator of competitiveness in tourism.La cuota de mercado es el indicador más difundido en el análisis de la competitividad empresarial para todo tipo de bienes y servicios. Sin embargo, su uso en turismo está sometido a una amplia controversia, especialmente cuando el objeto de estudio es la competitividad de los destinos turísticos. Ello es debido a que objetivos de maximización de esta variable en la planificación, pueden conllevar la implementación de políticas de crecimiento comprometedoras de la sostenibilidad económica y ambiental de los citados destinos. Teniendo en cuenta estas consideraciones, en el presente trabajo se discute el uso, validez y limitaciones de la cuota de mercado como indicador de la competitividad de los destinos turísticos

Identificación de escarpes de movimientos de ladera mediante técnicas de teledetección

En este trabajo se presentan los resultados de la aplicación de técnicas de teledetección a la identificación de escarpes de movimientos de ladera en macizos rocosos de las Cordilleras Béticas. Se han aplicado varias técnicas para hacer una primera aproximación visual, desde realces y filtrados texturales de las imágenes pancromáticas, hasta composiciones en color real y falso, fusiones, índices de vegetación (NDVI) y análisis de componentes principales a imágenes multiespectrales, correspondientes a diferentes sensores (Landsat ETM, Spot 5 e Ikonos). A través de un análisis SIG, se han calculado estadísticos básicos de las imágenes completas y de los píxeles correspondientes a diferentes tipologías de movimientos de ladera (desprendimientos, deslizamientos y corrientes de derrubios) y además se ha determinado el coeficiente de Kolmogorov-Smirnov para estimar la correlación entre imágenes y movimientos. Se han observado algunas correlaciones, siendo además la signatura espectral diferente dependiendo de la tipología. Los desprendimientos aparecen en las zonas más oscuras de las imágenes, mientras los deslizamientos y las corrientes de derrubios aparecen en las zonas más claras. De esta manera, la clasificación digital permite identificar los escarpes de los movimientos, pero parcialmente mezcladas con otros ocupaciones del suelo como suelos, roca fresca y materiales aluviales. El empleo de filtros texturales, que presentan valores elevados en zonas movilizadas resuelve esta ambigüedad. La conclusión es la necesidad de combinar la clasificación digital con los análisis texturales para identificar los escarpes de los movimientos de ladera.In this work we present the results of an analysis applied to identification of landslides features using remote sensing techniques in rock masses at the Betic Cordilleras. Several techniques are used to facilitate an approach to landslide identification, from enhancement and textural filtering of panchromatic images, to colour compositions and fusions, vegetation index (NDVI), and principal component analysis of multi-spectral imagery, corresponding to different sensors (Landsat ETM, Spot 5 and Ikonos). By means a GIS analysis, we compute basic statistics of whole images and pixels corresponding to different landslides typologies (rock falls, rock slides and debris flows) and in addition Kolmogorov-Smirnov coefficient to estimate the correlation between images and movements. Some correlations are observed, being besides the spectral signature different depending on landslides typology. Rock falls appear in darker zones of images while rock slides and especially debris flows appear in clearer zones. In this way, digital classification allows identify landslides scarps, but partially mixed with other land-uses such as soils, fresh rock and alluvial materials. The employment of textural filters, that present higher values in landslides zones, resolves this confusion. The conclusion is the need of combining digital classification and textural analysis to identify landslide features or mobilized areas