Effects of the neutrino mass splitting on the non-linear matter power spectrum

We have performed cosmological N-body simulations which include the effect of the masses of the individual neutrino species. The simulations were aimed at studying the effect of different neutrino hierarchies on the matter power spectrum. Compared to the linear theory predictions, we find that non-linearities enhance the effect of hierarchy on the matter power spectrum at mildly non-linear scales. The difference between the different hierarchies is about 0.5% for a sum of neutrino masses of 0.1eV. Albeit this is a small effect, it is potentially measurable from upcoming surveys. In combination with neutrinoless double-beta decay experiments, this opens up the possibility of using the sky to determine if neutrinos are Majorana or Dirac fermions.Comment: 5 pages, 5 figures, submitted to ApJ

Recovering Physical Parameters from Galaxy Spectra Using MOPED

We derive physical parameters of galaxies from their observed spectrum, using MOPED, the optimized data compression algorithm of Heavens, Jimenez & Lahav 2000. Here we concentrate on parametrising galaxy properties, and apply the method to the NGC galaxies in Kennicutt's spectral atlas. We focus on deriving the star formation history, metallicity and dust content of galaxies. The method is very fast, taking a few seconds of CPU time to estimate 17 parameters, and so specially suited to study of large data sets, such as the Anglo-Australian 2 degree field galaxy survey and the Sloan Digital Sky Survey. Without the power of MOPED, the recovery of star formation histories in these surveys would be impractical. In the Kennicutt atlas, we find that for the spheroidals a small recent burst of star formation is required to provide the best fit to the spectrum. There is clearly a need for theoretical stellar atmospheric models with spectral resolution better than 1\AA if we are to extract all the rich information that large redshift surveys contain in their galaxy spectra.Comment: Submitted to MNRAS, 19 page

INTERNATIONAL IMPORTS AND THE SAFETY OF THE U.S. FOOD AND FIBER SYSTEM

The trend towards globalization has led an increase in the U.S. Food trade. Threats of bio-terrorism and safety of the agriculture production system have become larger concerns to U.S consumers and policy makers. This paper analyzes how agriculture imports have changed in the past years; and how the government has reacted to the vulnerability of the U.S. food supply system to bio terrorism and invasive pests. Changes in budgets for the Food Safety Inspection Service (FSIS) and Animal and Plant Health Inspection Services (APHIS), agencies who are in part responsible for the food security, were compared to the increase in imports to provide a gauge for the response of the Federal Government to these threats.globalization, food imports, food safety, bio terrorism, invasive pests and diseases, homeland security, APHIS, FSIS, Financial Economics, International Relations/Trade,

Overcharging of DNA in the presence of salt: Theory and Simulation

A study of a model rod-like polyelectrolyte molecule immersed into a monovalent or divalent electrolyte is presented. Results from the hypernetted-chain/mean spherical approximation (HNC/MSA) theory, for inhomogeneous charged fluids, {\ch are} compared with molecular dynamics (MD) simulations. As a particular case, the parameters of the polyelectrolyte molecule are mapped to those of a DNA molecule. An excellent qualitative, and in some cases quantitative, agreement between HNC/MSA and MD is found. Both, HNC/MSA and MD, predict the occurrence of overcharging, which is not present in the Poisson-Boltzmann theory. Mean electrostatic potential and local concentration profiles, $\zeta$-potential and charge distribution functions are obtained and discussed in terms of the observed overcharging effect. Particularly interesting results are a very non-monotonic behavior of the $\zeta$-potential, as a function of the rod charge density, and the overcharging by {\em monovalent} counterions.Comment: 11 pages, 8 figures, RevTex, published in J. Phys. Chem. B 2001, vol. 105, pags. 1098

Simulating Physical Interactions between an Articulated Mobile Vehicle and a Terrain

International audienceThis paper deals with the problem of simulating the notions of a complex land vehicle moving in a natural environment. The contribution presented here is a motion generator which predicts the dynamic behaviour of the vehicle when executing a given nominal motion plan. This plan is expressed in terms of a channel to follow and of a set of intermediate subgoals to reach. Solving this motion generation problem requires to explicitly reason about the geometric and the physical aspects of the movements that the vehicle has to execute. In our approach, this is done using two basic constructions derived from the concept of physical model : the 'generalized obstades" are used for physically guiding the movements of the vehicle using an explicit model of the vehicle/terrain interactions, and the "physical targets' are used to map the strategic information onto our physical representation of the world and to introduce the force feedback gestural control

Evaluation of an indoor localization system for a mobile robot

Although indoor localization has been a wide researched topic, obtained results may not fit the requirements that some domains need. Most approaches are not able to precisely localize a fast moving object even with a complex installation, which makes their implementation in the automated driving domain complicated. In this publication, common technologies were analyzed and a commercial product, called Marvelmind Indoor GPS, was chosen for our use case in which both ultrasound and radio frequency communications are used. The evaluation is given in a first moment on small indoor scenarios with static and moving objects. Further tests were done on wider areas, where the system is integrated within our Robotics Operating System (ROS)-based self-developed 'Smart PhysIcal Demonstration and evaluation Robot (SPIDER)' and the results of these outdoor tests are compared with the obtained localization by the installed GPS on the robot. Finally, the next steps to improve the results in further developments are discussed

Impact of RFID technologies on helicopter processes: Assessment on customer oriented indicators

International audienceThis paper deals with the introduction of RFID (Radio Frequency IDentification) technologies on board of helicopters. These technologies can help to support the traceability of aircraft parts during their entire lifecycle. RFID technologies are widely used within logistics processes. Today, the challenge is to use them to follow the maintenance of parts on helicopters. The chip of RFID tags will store the part identification and the associated usage data. On-board technologies are expensive to embed because of hardening requirements. The development of the information system will also generate a significant cost. To counterbalance the costs, the added value of such technologies within the aeronautical context and the potential improvements for both the aircraft manufacturer and the final operator have to be analyzed. This paper emphasizes the advantages of RFID technologies and quantifies the expected benefits of their integration

Simulation of aircraft maintenance improvement using RFID systems

International audienceThe paper describes the maintenance process applied to an aircraft part along periodic maintenance operations and/or failure repairs. This paper deals with the assessment of RFID (Radio Frequency IDentification) technology contribution to the follow-up of aircraft parts. The construction of a simulation model and validation of the study are based on both experts' knowledge and data on flight and maintenance operations. Each stage of the maintenance process is modelled in terms of time (average times and boundaries) and the transition probability between stages. The impact of RFID technologies in the overall maintenance process is assessed. The main use of the analysis is the evaluation of different maintenance strategies and a first quantification of the impacts related to introducing RFID in maintenance processes. It should be helpful to support the decisions on RFID integration. The model could be used to design a decision support tool for maintenance designers and managers

Factores asociados a la adherencia al tratamiento farmacológico en pacientes adultos con epilepsia. Hospital Nacional Daniel Alcides Carrión, 2022

En Perú, la epilepsia impone una carga de enfermedad significativa pues se estima que se presenta en 11.9 – 32.1 por cada 1000 personas (9). Los pacientes con epilepsia tienen un mayor riesgo de mortalidad prematura que la población general. Así mismo, los pacientes con epilepsia tienen más probabilidades de sufrir comorbilidades psiquiátricas como ansiedad o depresión (10). La terapia farmacológica se considera el tratamiento principal para la epilepsia, y por tanto la adherencia a la terapia farmacológica es un componente integral del manejo del paciente (9,10). Sin embargo, se ha identificado una baja adherencia en este grupo de pacientes, que se ha relacionado con ingresos hospitalarios e incremento en la morbilidad. De acuerdo al estudio de Dávila (11), el 77.63% de pacientes presentó un nivel de adherencia bajo, así mismo de acuerdo a Castillo y Rojas (12), 30.15% de pacientes con epilepsia no cumplieron con el tratamiento farmacológico. En ese sentido disponer de información sobre los factores asociados a la adherencia al tratamiento farmacológico en este tipo de pacientes es relevante. A nivel del Hospital Nacional Daniel Alcides Carrión diariamente son atendidos 15 pacientes con epilepsia, en quienes se ha observado una mala adherencia al tratamiento farmacológico, Por ello, conocer los factores que condicionan la adherencia a este manejo es fundamental para sugerir estrategias para superar estos factores. Por tal motivo se propone la ejecución del presente trabajo de investigación