Thermal and electrohydrodynamic plumes: a compartive study

This paper deals with self similar thermal and electrohydrodynamic (EHD) plumes. The former arises from hot lines or points, whereas the latter arises when sharp metallic contours submerged in non conducting liquids support high electrostatic potential, resulting in charge injection. Although the motive force is buoyancy in one case and Coulomb force in the other, it is shown that the solution for EHD plumes is the same as for thermal plumes in the limit of large Prandtl numbers. We present the analysis of axisymmetric plumes for large values of Prandtl number, and this analysis is subsequently applied to EHD plumes. The validity of the approximations for EHD plumes is discussed in the light of experimental data.Ministerio de ciencia y tecnología PB93-118

Sobre Ilex cubana Loes. (Aquifoliaceae) y especies afines

Se realiza la revisión taxonómica de cuatro especies del género Ilex L., distribuidas en el sector fitogeográfico Cuba-oriental según clasificación de Samek (1973). Se valoraron los resultados del análisis de numerosos materiales de herbario, así como estGonzález Gutiérrez, P. A. 2004. About Ilex cubana Loes. (Aquifoliaceae) and related species. Bot. Complut. 28: 93-100. The taxonomic revision of four species of Ilex L. spread in Eastern Cuba, according to the classification of Samek (1973), is carried out. Taking into account the results of morphological studies and filed's observations, Ilex turquinensis Alain, Ilex nunezii Borhidi and Ilex nannophylla Borhidi & Muñiz are considered heterotipic synonyms of Ilex cubana Loes. The description of this species is offered as well as data about its geographical distribution

Preferences of young consumers for joints obtained from the technological division of the rabbit carcass evaluated by photographic images

Una muestra de 405 jóvenes de Andalucía, con edades comprendidas entre 18 y 32 años y con un 54,3% de mujeres, se sometió a dos pruebas de valoración de fotografías con la finalidad de conocer, por una parte, su preferencia entre las piezas pata trasera, pata delantera, pieza lomo y caja torácica procedentes del despiece tecnológico de la canal de conejo y, por otra parte, su preferencia entre la pieza lomo y las chuletas de lomo obtenidas de esta pieza por sección transversal al raquis. En la primera prueba el orden de preferencia, de mayor a menor atractivo, fue la pata trasera, la pieza lomo, la pata delantera y la caja torácica (P<0,001) tanto en hombres como en mujeres y si eran o no consumidores de carne de conejo. En la segunda prueba la pieza lomo fue mejor valorada que las chuletas de lomo (P<0,001) por el conjunto de los sujetos de la muestra, por ambos sexos y por los jóvenes que consumían carne de conejo, mientras que los no consumidores de carne de conejo no mostraron diferencias de valoración entre ambas presentaciones (P>0,05). Los resultados ilustran la mayor aceptación que pueden tener para los consumidores las piezas de la canal con mayor cantidad de carne, sugiriéndose que estas diferencias de preferencia entre piezas de la canal podrían influir en eventuales decisiones de compra de despieces de carne de conejo.A sample of 405 young people from Andalusia (Spain), aged between 18 and 32 years and 54.3% of women was subjected to two tests consisting in scoring of photographic images in order to study i) their preference among hind leg, fore leg, loin and thoracic cage joints obtained from the technological division of the rabbit carcass, and ii) their preference between the loin joint and loin chops obtained by transverse cutting of the raquis. In the first test the decreasing degree of preference was the hind leg, the loin joint, the fore leg and the thoracic cage (P <0.001) in both men and women and whether they were rabbit meat consumer or not. In the second test loin joint reached higher score than loin chops (P <0.001) for all the individuals in the sample, for both sexes and for young people who consume rabbit meat, while non rabbit meat consumers showed no difference in preference between the two presentations (P> 0.05). The results illustrate the higher acceptance that young consumers may show for joints of the carcass with higher meat content, this suggesting that differences in preference among carcass joints could influence any decisions to purchase cuts of rabbit meat

Contributos da educação intercultural na construção de uma sociedade pluralista e democrática numa perspectiva comparada – Portugal e Espanha

No momento que hoje vivemos, a problemática das relações interculturais apresenta-se-nos de uma forma particularmente intensa. O projecto europeu desenvolve-se e aprofunda-se, o fenómeno dos nacionalismos propaga-se por toda a Europa, tornando por demais evidentes todas as idiossincrasias nacionais e multiplicidades culturais. Paralelamente verificamos fenómenos de deslocação de populações em larga escala e particularmente em Portugal e Espanha, tradicionais países de emigração, nestes últimos anos somos confrontados com vagas massivas de imigrantes quer de países africanos e sul-americanos, quer mais recentemente do leste europeu. A imigração na Península Ibérica é presentemente uma realidade inelutável especialmente se considerarmos a quantidade e a diversidade de origens dos imigrantes. A melhoria das condições de vida após os primeiros anos de imigração e os programas de reagrupamento familiar levam a que nos últimos anos o número de crianças imigrantes tenha aumentado quer no sistema educativo português quer no espanhol. Este facto por si só poderá explicar a necessidade crescente de criar espaços na escola para a educação intercultural, uma vez que esta surge como local privilegiado de socialização e aquisição da própria cultura e simultaneamente como forma de interacção comunicante com a cultura do «outro». Neste contexto procuraremos efectuar uma análise da situação em que se encontra a educação intercultural em Espanha e Portugal, enraizando-a na educação para a cidadania, tentando assim encontrar pontos comuns de actuação e simultaneamente aprender com as experiências realizadas em ambos os países, contribuindo para a construção de uma sociedade verdadeiramente multicultural

Hierarchical Up/Down Routing Architecture for Ethernet backbones and campus networks

We describe a new layer two distributed and scalable routing architecture. It uses an automatic hierarchical node identifier assignment mechanism associated to the rapid spanning tree protocol. Enhanced up/down mechanisms are used to prohibit some turns at nodes to break cycles, instead of blocking links like the spannning tree protocol does. The protocol performance is similar or better than other turn prohibition algorithms recently proposed with lower complexity O(Nd) and better scalability. Simulations show that the fraction of prohibited turns over random networks is less than 0.2. The effect of root bridge election on the performance of the protocol is limited both in the random and regular networks studied. The use of hierarchical, tree-descriptive addresses simplifies the routing, and avoids the need of all nodes having a global knowleddge of the network topology. Routing frames through the hierarchical tree at very high speed is possible by progressive decoding of frame destination address, without routing tables or port address learning. Coexistence with standard bridges is achieved using combined devices: bridges that forward the frames having global destination MAC addresses as standard bridges and frames with local MAC frames with the proposed protocol.Publicad

Un instrumento para evaluar el uso y las actitudes hacia los videojuegos

En el presente trabajo presentamos un cuestionario elaborado para conocer la opinión de diferentes grupos de sujetos sobre el uso y las actitudes que se tienen ante los videojuegos. En nuestra opinión todos los juegos, tradicionales o informáticos, tienen un potencial educativo importante. Los alumnos pueden aprender con ellos entre otras cosas: conocimientos, habilidades, estrategias, destrezas o relaciones interpersonales. Este es un tema muy controvertido para padres y educadores que hay que comenzar a estudiar para ir desechando todos los mitos que sobre él se han creado.In this work we present a questionnaire made to know the opinion that different students have on the uses and the attitudes about videogames. In our opinion every game, both traditional and computer games, have an important educative potential. Students can learn with them: knowledge, abilities, strategies, skills or interpersonal relations, among other things. This subject is quite controverted among parents and educators. We might begin to study in order to avoid all myths related to it

Prevalence of self-treatment with complementary products and therapies for weight loss: A randomized, cross-sectional Study in Overweight and Obese Patients in Colombia

AbstractBackground:The use of complementary and alternative medicine for weight loss is becoming increasingly common worldwide. In overweight or obese patients, this practice could be harmful. Available data concerning the use of complementary therapies and products (CTPs) for weight loss in these patients in Colombia are limited.Objectives:The aims of this study were to determine the prevalence of self-treatment with CTPs in overweight or obese patients in Colombia and to explore the relationship between CTP use and demographic, anthropometric, and biochemical parameters.Methods:This randomized, cross-sectional study was conducted at a registered dieticians' office located at the Center for Nutritional Care, School of Nutrition and Dietetics, University of Antioquia, Medellín, Colombia, and at an outpatient clinic attended by a registered dietician located at the Pablo Tobón Uribe Hospital, Medellín, Colombia. The study enrolled a random sample of overweight (body mass index [BMI], 25–30 kg/m2) or obese (BMI, >30 kg/m2) male and female patients aged 20 to 50 years received nutritional treatment in Colombia in 2002. Data concerning the use of weight-loss CTPs were gathered, and their possible association with demographic, anthropometric, and biochemical data was explored.Results:This randomized study comprised 94 patients (70 women, 24 men; mean [SD] age, 36.5 [9.7] years; mean [SD] BMI, 28.4 [4.2] kg/m2). Forty-nine (52.1%) patients reported self-treatment with weight-loss CTPs; 40 (42.6%) patients used complementary products, and 21 (22.3%) used complementary therapies. Among the products, inadequately identified herbal medicines (ie, absence of available information concerning the composition of the products or information could not be obtained from the patient [many of the products used were not authorized for distribution in Colombia]), folkloric or home remedies, and commercial diets were most commonly used (40.0%, 40.0%, and 27.5%, respectively). The use of CTPs was more prevalent in women compared with men (P < 0.001; odds ratio [OR] = 6.43). In women, CTP use was significantly higher in patients with a higher educational level (P = 0.008; OR = 3.82) and in those who were single (P = 0.038; OR = 2.97). The use of CTPs was also more frequent in patients with a negative view of their current nutritional therapy (P = 0.002; OR = 6.8).Conclusions:In the small group of overweight and obese patients in this study, 52.1% used CTPs. In obese women, those with a higher educational level and/or who were single were more likely to use CTPs. Patients were also more likely to use CTPs if they had a negative view of their current nutritional therapy

Maternal behaviour and welfare of the domestic and wild rabbit doe and its litter

El conejo europeo (Oryctolagus cuniculus), además de tener importancia faunística en el Mediterráneo occidental, es una especie ganadera relevante que es la base de un subsector pecuario industrializado orientado a la producción de carne en varios países, sobre todo europeos, mientras que en algunos pa- íses en vías de desarrollo se explota bajo sistemas alternativos orientados a la integración de renta y a la seguridad alimentaria. A la orientación cárnica se suman otras aptitudes productivas heterogéneas que configuran una gran diversidad de sistemas de producción cunícola. Este trabajo revisa el comportamiento materno de la coneja y de su camada, incluyendo su regulación endocrina, tanto en el animal silvestre como en la producción cunícola comercial y alternativa, y se relaciona con los factores de manejo, con la productividad en granja y con el bienestar de la especie. Se analizan también las implicaciones que las normativas sobre bienestar animal comportan respecto al alojamiento, manejo y satisfacción de las necesidades etológicas de las conejas reproductoras y de los gazapos durante la cría, caracterizadas, fundamentalmente, porque en algunos países tienden a proporcionar más espacio y enriquecimiento ambiental en las jaulas.The European rabbit (Oryctolagus cuniculus), in addition to its faunal interest in the western Mediterranean, is a relevant species which in several European countries is the basis of a meat-oriented, industrial livestock subsector, while in many developing countries rabbits are raised under alternative systems aimed at income integration and food security. In addition to meat production, other productive orientations exist that generate a variety of rabbit production systems. This paper reviews the ethology of maternal behaviour of the breeding doe and her litter, including its endocrine regulation, both in wild animal and in industrial and alternative farming systems, and its relation to management factors, productivity and performance as well as the welfare of the species. It also discusses the implications of the regulations concerning animal welfare on housing, management and satisfaction of behavioural needs of breeding does and their litters, which in some countries tend to provide more space and environmental enrichment in cage

Comparación de los hábitos de consumo de carne de conejo entre consumidores jóvenes y compradores tradicionales de Sevilla

Se estudiaron los hábitos de consumo de carne de conejo de 499 estudiantes universitarios y de 399 compradores en mercados tradicionales de Sevilla (España). Los estudiantes universitarios afirmaron haber probado (67,9%) y consumir actualmente (38,6%) la carne de conejo en menor proporción que los compradores tradicionales (prueban: 84,5%; consumen: 46,6%). Ambos grupos afirman que les gusta esta carne en la misma proporción (78%).Las mujeres, sobre todo jóvenes, afirmaron haber probado y que les gusta en menor proporción esta carne que en el caso de los hombres. Se reveló además un mayor hábito de consumo y preferencia por la carne de conejo de monte en comparación con la del de granja, siendo la carne de conejo de monte preferida a la del de granja por un 88,2% de los consumidores sin distinción de grupo. Se dedujo una disminución del consumo de la carne de conejo entre los jóvenes en comparación con los compradores en mercados tradicionales