Scaling Evolution of Universal Dark-Matter Halo Density Profiles

Dark-matter halos show a universal density profile with a scaling such that less massive systems are typically denser. This mass-density relation is well described by a proportionality between the characteristic density of halos and the mean cosmic density at halo formation time. It has recently been shown that this proportionality could be the result of the following simple evolutionary picture. Halos form in major mergers with essentially the same, cosmogony-dependent, dimensionless profile, and then grow inside-outside, as a consequence of accretion. Here we verify the consistency of this picture and show that it predicts the correct zero point of the mass-density relation.Comment: 9 pages, 1 Table and 1 postscript figure, latex uses aaspp4.sty, accepted for publication in The Astrophysical Journal Letter

La Reconversión de la Vigilancia Epidemiológica en Vigilancia de Salud Pública

ResumenA pesar de que los procedimientos tradicionales de vigilancia epidemiológica incluyeran en su origen una función estratégica, más allá del control de las epidemias, en nuestro país el sistema de enfermedades de declaración obligatoria ha sido el único caso de vigilancia que ha merecido tal consideración. Este sistema sufre, desde hace unos años, una grave crisis, debido a la poca utilidad de unos resultados; sea como consecuencia de la falta de usuarios que los empleen para tomar decisiones sanitarias; bien porque se ocupa exclusivamente de enfermedades transmisibles o de brotes epidémicos agudos.Al margen de este sistema oficial de vigilancia, en los últimos años se han ido desarrollando fuentes y procedimientos informativos de gran interés sanitario como los registros de cáncer, las estadísticas de accidentes de tráfico o las de contaminación atmosférica. A su vez, la elaboración de políticas en las que se comprometen objetivos de salud, demandan también instrumentos informativos capaces de racionalizar tales objetivos y de permitir la evaluación de las intervenciones llevadas a cabo para corregirlos. Se describen, pues los principales sistemas de información útiles para la vigilancia.Concluimos que el término de vigilancia de la salud pública define mejor sus funciones de a) seguimiento y evaluación de las políticas de salud y b) detección e investigación de epidemias. Por último, identificamos algunos elementos de la reconversión, como son: a) completar las ausencias de información detectadas, especialmente en relación a los efectos adversos de las intervenciones sanitarias y los riesgos laborales y ambientales; b) facilitar el acceso a la información a través de la creación de bases de datos automatizadas; y c) homogeneizar las distintas fuentes de datos de interés sanitario.SummaryAlthough epidemiological surveillance include originaly a strategic function, beyond epidemic control, in Spain the communicable diseases control system has been the only surveillance scheme. This system suffer a severe crisis, probably due to the scarse uses of the information and/or because the system produce exclusively information about communicable diseases or outbreaks.In the lastfewyears, information sources and procedure have been developed out of the official surveillance, such as cancer register, traffic accidents or air contamination statistics and so on. Moreover, national and regional health plans which signify specific health objectives entail information tools with ability to rank and evaluate the interventions. The principal health information system useful to surveillance has been described.We conclude that the expression public health surveillance define much better the functions of a) monitoring and evaluation of the health policy and b) detection and research of epidemics. Finally, we identify some elements for the change, such as: a) to include information related to adverse effects of the sanitary interventions, and environmental and occupational hazards; b) to facilitate the access of information by means of self-operating database and c) to make comparable the different information sources

Decoherence in supernova neutrino transformations suppressed by deleptonization

In the dense-neutrino region at 50-400 km above the neutrino sphere in a supernova, neutrino-neutrino interactions cause large flavor transformations. We study when the multi-angle nature of the neutrino trajectories leads to flavor decoherence between different angular modes. We consider a two-flavor mixing scenario between nu_e and another flavor nu_x and assume the usual hierarchy F(nu_e)>F{antinu_e)>F(nu_x)=F(antinu_x) for the number fluxes. We define epsilon=(F(nu_e)-F(antinu_e))/(F(antinu_e)-F(antinu_x)) as a measure for the deleptonization flux which is the one crucial parameter. The transition between the quasi single-angle behavior and multi-angle decoherence is abrupt as a function of epsilon. For typical choices of other parameters, multi-angle decoherence is suppressed for epsilon>0.3, but a much smaller asymmetry suffices if the neutrino mass hierarchy is normal and the mixing angle small. The critical epsilon depends logarithmically on the neutrino luminosity. In a realistic supernova scenario, the deleptonization flux is probably enough to suppress multi-angle decoherence.Comment: 17 pages, 12 figures. Misprint in Eq (14) correcte

A Data Fusion Technique to Detect Wireless Network Virtual Jamming Attacks

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Wireless communications are potentially exposed to jamming due to the openness of the medium and, in particular, to virtual jamming, which allows more energy-efficient attacks. In this paper we tackle the problem of virtual jamming attacks on IEEE 802.11 networks and present a data fusion solution for the detection of a type of virtual jamming attack (namely, NAV attacks), based on the real-time monitoring of a set of metrics. The detection performance is evaluated in a number of real scenarios

Broadband distortion modeling in Lyman-α\alpha forest BAO fitting

In recent years, the Lyman-$\alpha$ absorption observed in the spectra of high-redshift quasars has been used as a tracer of large-scale structure by means of the three-dimensional Lyman-$\alpha$ forest auto-correlation function at redshift $z\simeq 2.3$, but the need to fit the quasar continuum in every absorption spectrum introduces a broadband distortion that is difficult to correct and causes a systematic error for measuring any broadband properties. We describe a $k$-space model for this broadband distortion based on a multiplicative correction to the power spectrum of the transmitted flux fraction that suppresses power on scales corresponding to the typical length of a Lyman-$\alpha$ forest spectrum. Implementing the distortion model in fits for the baryon acoustic oscillation (BAO) peak position in the Lyman-$\alpha$ forest auto-correlation, we find that the fitting method recovers the input values of the linear bias parameter $b_{F}$ and the redshift-space distortion parameter $\beta_{F}$ for mock data sets with a systematic error of less than 0.5\%. Applied to the auto-correlation measured for BOSS Data Release 11, our method improves on the previous treatment of broadband distortions in BAO fitting by providing a better fit to the data using fewer parameters and reducing the statistical errors on $\beta_{F}$ and the combination $b_{F}(1+\beta_{F})$ by more than a factor of seven. The measured values at redshift $z=2.3$ are $\beta_{F}=1.39^{+0.11\ +0.24\ +0.38}_{-0.10\ -0.19\ -0.28}$and$b_{F}(1+\beta_{F})=-0.374^{+0.007\ +0.013\ +0.020}_{-0.007\ -0.014\ -0.022}$(1$\sigma$, 2$\sigma$and 3$\sigma$ statistical errors). Our fitting software and the input files needed to reproduce our main results are publicly available.Comment: 28 pages, 15 figures, matches the published versio

Background Modelling with Associated Confidence

Non

Annual traffic noise levels estimation based on temporal stratification

© 2017. This version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper proposes a temporal sampling strategy that increases the accuracy of long-term noise level estimation and allows to establish the estimation error according to the number of sampled days. Days of the week are stratified into working days and weekend days. This research shows how to use measurements of Leq on working days to estimate the corresponding values for weekend days. This is possible because working days have higher noise levels and less variability than weekend days. The improvement in accuracy allows for a reduction in the number of required sampled days compared to taking samples randomly, which would help to reduce the uncertainty in environmental noise assessment. As a reference, to obtain a 90% confidence interval of ±1 dB for Lday, the proposed sampling strategy reduces the required measurement days by more than 38%. For LDEN, the reduction is close to 18% of the total number of days. The proposed strategy could be adapted to different environments by simply changing a few parameters.Peer ReviewedPostprint (author's final draft

Microclimate modification by tree windbreaks in Florida farms

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Florida citrus and vegetable crops generate billions in revenue every year. However, winds, freezes, hurricanes, and citrus canker (Xanthomonas campestris) impact production. Windbreaks located perpendicular to the prevailing wind can reduce soil erosion and increase irrigation efficiency and farm production mostly by simply modifying microclimate. Windbreaks can also control the spread of pathogens such as citrus canker. To study how tree windbreaks modify microclimate in southern Florida, weather stations were established in 2008 along transects behind a 1-row eastern redcedar (Juniperus virginiana) windbreak at the Southwest Florida Research and Education Center (SWFREC/University of Florida) at Immokalee, and a 1-row cadaghi (Corymbia torelliana) windbreak at C&B Farms, Clewiston, to assess spatial variation in wind speed, temperature, and relative humidity at 2m above the ground. The windbreaks significantly reduced wind speed; minimum wind speed was at two times the windbreak height (2H) behind dense (17 [percent] porosity) redcedar and at 6H behind relatively porous (20 [percent] porosity) cadaghi when the wind direction was nearly perpendicular to the windbreak. Wind speed at 2H behind eastern redcedar was approximately 5 [percent] of the open wind speed and at 6H behind cadaghi was approximately 3-30 [percent]. Wind speed at 14H behind cadaghi and redcedar windbreak was approximately 60 [percent] and 80 [percent] of the open wind speed, respectively. Temperature behind both windbreaks was relatively warmer than in the open. However, the extent of temperature and relative humidity modification was less compared to wind speed. Windbreaks are an effective use of forest trees to modify microclimate and appreciably enhance Florida farm production.Bijay Tamang (1), Donald L Rockwood1 and Michael G. Andreu (2) ; 1. PO Box 110410, School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611. 2. SFRC, University of Florida, Gulf Coast REC - Plant City, 1200 N Park Road, Plant City, FL 33563.Includes bibliographical references

Temporal and spatial stratification for the estimation of nocturnal long-term noise levels

Noise pollution in cities is mainly caused by the vehicular traffic but, depending on the place under assessment, it could be affected by the land use. For noise assessment and strategic noise mapping, the night period equivalent level (), which evaluates sleep disturbance, is one of the requirements of the European Directive 2002/49/EC to be presented for the equivalent time of one year. This research aims to find the influence of the land use in the weekdays stratification to improve the accuracy of the long-term noise level estimation for the night period. It is found that depending on the land use of the place under assessment, the weekdays temporal and spatial stratification could be affected by leisure activities. From a statistical analysis based on a clustering procedure of samples in 19 points, it is observed that both, temporal and spatial stratification depend on the intensity of the surrounding leisure activity, and not on traffic. Following these stratification criteria, a sampling method is presented that reduces by 47% the number of days needed to estimate the annual levels with respect to random samplingPostprint (author's final draft