J. García

Effect of fiber source on cecal fermentation and nitrogen recycled through cecotrophy in rabbits.

The influence of fiber source on fiber digestion in rabbits was investigated. Six fibrous feedstuffs with wide differences in chemical composition and particle size were selected: paprika meal, olive leaves, alfalfa hay, soybean hulls, sodium hydroxide-treated barley straw, and sunflower hulls. Six diets were formulated to contain one of these ingredients as the sole source of fiber. To avoid nutrient imbalances, fiber sources were supplemented with different proportions of a fiber-free concentrate, based on soy protein isolate, wheat flour, lard, and a vitamin and mineral mix, to obtain diets containing at least 3% nitrogen and 5% starch. Daily soft feces excretion, and its NDF, and total and microbial nitrogen content were determined in 60 fattening rabbits (10 per diet). Seven days after the last cecotrophy control, the same animals were used to determine weight of stomach, cecum and their contents, and cecal fermentation traits (pH, VFA and ammonia concentrations, and buffer properties of cecal contents). Stepwise regression analysis showed a positive effect (P < .001) on soft feces excretion, total and microbial nitrogen concentrations in soft feces, cecal acidity, and total VFA in the cecum of dietary pectic constituents (2.9, 3.5, 2.5, .9, and 6.6%) and proportion of fine particles (< .315 mm) (1.8, .9, 1.3, .15, and .9%) per each increment of one percentage unit of the independent variables. Proportion of fine particles also increased weight of cecal contents (P < .001). Soft feces excretion and weight of stomach and of its contents increased (P < .001) by 5.2, 2.8, and 10.2% per each percentage unit increment of proportion of large particles (> 1.25 mm). Degree of lignification of NDF decreased total nitrogen concentration in soft feces and cecal VFA concentration (P < .001). Source of fiber affected cecal pH not only by its influence on the cecal concentrations of the final products of fermentation, but also through its effect on the pH of dry cecal contents (P < .001). The latter was negatively correlated with dietary proportion of fine particles, degree of lignification of NDF, and base-buffering capacity of dry cecal contents (r = -.52, -.37, and -.49, respectively). From these results, we conclude that pectic constituent concentration, degree of lignification of NDF, and particle size are the variables that best characterize the influence of the source of fiber on soft feces excretion and cecal fermentation traits in rabbits.

Assessment of human body influence on exposure measurements of electric field in indoor enclosures.

Personal exposure meters (PEMs) used for measuring exposure to electromagnetic fields (EMF) are typically used in epidemiological studies. As is well known, these measurement devices cause a perturbation of real EMF exposure levels due to the presence of the human body in the immediate proximity. This paper aims to model the alteration caused by the body shadow effect (BSE) in motion conditions and in indoor enclosures at the Wi-Fi frequency of 2.4 GHz. For this purpose, simulation techniques based on ray-tracing have been carried out, and their results have been verified experimentally. A good agreement exists between simulation and experimental results in terms of electric field (E-field) levels, and taking into account the cumulative distribution function (CDF) of the spatial distribution of amplitude. The Kolmogorov-Smirnov (KS) test provides a P-value greater than 0.05, in fact close to 1. It has been found that the influence of the presence of the human body can be characterized as an angle of shadow that depends on the dimensions of the indoor enclosure. The CDFs show that the E-field levels in indoor conditions follow a lognormal distribution in the absence of the human body and under the influence of BSE. In conclusion, the perturbation caused by BSE in PEMs readings cannot be compensated for by correction factors. Although the mean value is well adjusted, BSE causes changes in CDF that would require improvements in measurement protocols and in the design of measuring devices to subsequently avoid systematic errors.

Home Monitoring of Elderly for Early Detection of Changes in Activity and Behavior Patterns

28 real homes of elderly have been monitored during three weeks by a platform based on the BUSing protocol that consists of 5 sensors of presence and 5 sensors of action.

Comparative analysis of indoor location technologies for monitoring of elderly

The objective of this study is the assessment of the accuracy of the operation of three indoor localization platforms based on wireless short range technologies: platform of UWB-based localization, platform of RFID-based localization and domotic platform based on BUSing protocol. The tests of location were performed in a simulation environment whose size was proportional to a real home. A route consisting of a sequence of rooms was defined. Each platform under test was installed in the tested environment, and the predefined route was realized by a volunteer three times, once to test each platform. The platform that presents the best results was those based on BUSing protocol and UWB technology, with an error rate of localization of 4.25%. Taking into account that the application context is the monitoring of elderly, the advantages and disadvantages of the tested platforms were also evaluated.

Assessment of Exposure from Wi-Fi Devices

In the last decade the number of wireless devices operating at the frequency band of 2.4 GHz has increased in several settings, such as: healthcare, occupational and household. The working conditions of a Wi-Fi module have been analyzed. The levels of electromagnetic (EM) field in near field conditions were measured inside an anechoic chamber with a specific absorption rate (SAR) fully automated test system, DASY5PRO. The obtained results were compared with the levels set by international regulations to analyze the exposure to EM fields. In close areas to the device, the obtained electric field levels show that local exposure can reach the most restrictive value of 3 V/m that is established in the International Electrotechnical Commission Standard of Electromedical Devices.

Assessment of Statistical Distribution of Exposure to Electromagnetic Fields from Social Alarm Devices

Social alarm devices are used to assist patients, elderly and disabled people in distress situations. Environments equipped with such wireless, sensitive and responsive devices are referred to as being Ambient Assisted Living (AAL). The use of such devices and transmission sources based on short range wireless technologies involves the increase of levels of electromagnetic (EM) fields in residential environments.

Analysis of Exposure of Social Alarm Devices in Near Field Conditions

Despite of the rapidly increasing number of short range wireless applications and devices in healthcare environments, very little is know about the radiofrequency (RF) exposure due to such devices.

Assessment on a Safe use of a Home Telemedicine System regarding Electromagnetic Compatibility

Recent advances in wireless technologies have produced an increase in wireless instrumentation present in urban homes (wireless routers, cell phones, DECT technology, etc). Thus, the background level of electromagnetic fields has been on the increase. On the other hand, technological advances in miniaturization and wireless communications have enabled the development of wireless biomonitoring devices.

El desarrollo de un proyecto de aprendizaje electrónico: la experiencia de la Escuela Nacional de Sanidad

Resumen Objetivo En este articulo se expone el desarrollo de un modelo de aprendizaje electronico realizado en la Escuela Nacional de Sanidad por especialistas de diferentes disciplinas (salud publica, pedagogia, informatica, administracion, gestion y calidad). Material y metodos El proyecto se dividio en 4 fases: conceptualizacion, analisis de recursos y funciones, elaboracion de contenidos y composicion del curso. Resultados La experiencia nos permitio identificar los procedimientos institucionales requeridos para la realizacion de cursos por Internet y obtener una serie de documentos (modelo pedagogico, guia de elaboracion de materiales, pautas para elaborar la guia de estudio, pautas para los profesores y tutores y manual de uso de la plataforma) que constituyen la base de nuestro modelo de formacion virtual. Asimismo, nos permitio constatar la complejidad de este tipo de formacion, la cantidad de recursos que requiere y los enormes esfuerzos de coordinacion y de trabajo en grupo que son necesarios para obtener un producto final de calidad. No obstante, a pesar de que los esfuerzos iniciales son muy grandes en relacion con los resultados obtenidos, con el tiempo esa relacion se invierte. Conclusiones La formacion a traves de Internet es una apuesta de futuro que se rentabiliza y tiene sentido a largo plazo y que siempre debe ponerse en marcha con el objetivo de agregar valor a las posibilidades de formacion ya existentes. No se trata de transformar una formacion en otra, sino de crear nuevas posibilidades y oportunidades de aprendizaje mediante el uso de las nuevas tecnologias de la informacion y comunicacion.