296 research outputs found

    Seasonal changes of benthic communities in a temporary stream of Ibiza (Balearic Islands)

    Get PDF
    Seasonal changes in benthic communities (diatoms and invertebrates) in a temporary stream of the Ibiza island (Balearic Islands, Spain) were studied. The physico-chemical parameters, diatom quality indices and some invertebrate metrics were used to describe and identify the observed temporal changes in benthic communities. A total of 43 diatom taxa and 51 invertebrate taxa were identified. Only 4 diatom species appeared in all the samples: Achnanthidium minutissimum, Diploneis oblongella, Navicula veneta and Nitzschia inconspicua. The invertebrate community was dominated by the orders Diptera, Oligochaeta and Gastropoda along the sampling period. Changes in the physico-chemical parameters of the water and hydrological events determined the structure of the benthic communities in this temporary stream.Se han estudiado los cambios estacionales de las comunidades bentónicas (diatomeas e invertebrados) en un arroyo temporal de la isla de Ibiza (Islas Baleares, España). Los parámetros físico-químicos, índices diatomológicos de calidad y algunos métricos de invertebrados se han utilizado para describir e identificar los cambios temporales que se observan en las comunidades bentónicas. Se han identificado un total de 43 taxones de diatomeas y 51 taxones de invertebrados. Únicamente 4 especies aparecen en todas las muestras: Achnanthidium minutissimum, Diploneis oblongella, Navicula veneta y Nitzschia inconspicua. La comunidad de invertebrados estuvo dominada por los órdenes Diptera, Oligochaeta y Gastropoda a lo largo del período de muestreo. Los cambios en los parámetros físico-químicos del agua y los eventos hidrológicos determinaron la estructura de la comunidad bentónica en este río temporal

    La conservación del patrimonio agroindustrial. Propuestas para la reutilización de los antiguos mataderos municipales y análisis de costes

    Get PDF
    La creciente demanda de alimentos en las áreas urbanas, junto con los avances en los transportes y la aparición de nuevas fuentes de energía propiciaron a finales del siglo XIX la construcción de diversas industrias agroalimentarias en el medio rural español. Un ejemplo de este patrimonio agroindustrial son los antiguos mataderos municipales, edificados en un gran número de localidades de la geografía española con el objetivo de evitar sacrificios clandestinos de ganado y de mejorar las condiciones higiénicas de la carne. Las cada vez mayores exigencias técnicas y sanitarias para este tipo de construcciones a partir de la década de los 70 y la progresiva sustitución de las instalaciones municipales por mataderos privados más modernos y de mayor capacidad provocaron el cierre y posterior abandono de muchos de estos edificios en las décadas siguientes. En el presen te trabajo se muestran cuatro propuestas concretas para la reutilización de este tipo de construcciones. A partir de la información recopilada de varios proyectos fin de carrera desarrollados por alumnos de la Escuela Técnica Superior de Ingenieros Agrónom os de Madrid, se describen las actuaciones y trabajos de rehabilitación necesarios en cada caso y se ofrece un estudio comparativo de costes entre proyectos de reutilización y obra nuev

    A multimetric diatom index to assess the ecological status of coastal Galician rivers (NW Spain)

    Get PDF
    There are many rivers in northwest Spain as a consequence of the mountainous landscape and the granitic geology subjected to Atlantic influences. Water and epilithic diatoms samples were collected at 72 sites in Galicia flowing into the Atlantic Ocean and Cantabrian Sea in summer 2002–2003 and spring 2004. These sites included minimally disturbed sites, defined as reference sites, and impacted sites which were influenced by different human pressures. We used the diatom assemblages to calculate diatom indices using the Omnidia software, but we also developed new metrics based on the similarity of species composition in reference sites. The response of the metrics was tested in relation to physicochemical variables. We developed a diatom multimetric index (MDIAT) as a combination of metric values. The sensitivity of the MDIAT to organic and nutrient stressors supports the use of this index to classify the ecological status of Galician rivers. The MDIAT showed higher correlations with some variables and nutrients than the individual metrics. According to the MDIAT, 69% of the sites sampled in Galician coastal rivers achieve good ecological status. The MDIAT has been developed specifically for Galician granitic rivers (NW Spain), and has been intercalibrated at the European level in the Central Baltic Rivers GIG. Our study validates the application of this multimetric index to evaluate the water quality in coastal Galician river

    Web-based education in Spanish Universities. A Comparison of Open Source E-Learning Platforms

    Get PDF
    Web-based education or „e-learning‟ has become a critical component in higher education for the last decade, replacing other distance learning methods, such as traditional computer training or correspondence learning. The number of university students who take on-line courses is continuously increasing all over the world. In Spain, nearly a 90% of the universities have an institutional e-learning platform and over 60% of the traditional on-site courses use this technology as a supplement to the traditional face-to-face classes. This new form of learning allows the disappearance of geographical barriers and enables students to schedule their own learning process, among some other advantages. On-line education is developed through specific software called „e-learning platform‟ or „virtual learning environment‟ (VLE). A considerable number of web-based tools to deliver distance courses are currently available. Open source software packages such as Moodle, Sakai, dotLRN or Dokeos are the most commonly used in the virtual campuses of Spanish universities. This paper analyzes the possibilities that virtual learning environments provide university teachers and learners and offers a technical comparison among some of the most popular e-learning learning platforms

    Epidemiological Study of Thogoto and Dhori Virus Infection in People Bitten by Ticks, and in Sheep, in an Area of Northern Spain

    Get PDF
    There is little information on Thogoto virus (THOV) and Dhori virus (DHOV)infection in Spain. A total of 283 serum samples from 150 human subjects (78 males, 72 females) bitten by ticks, as well as samples from 120 sheep (one per animal), were studied by immunofluorescence assay. All human and animal subjects were from the province of Palencia in northern Spain. Eight human subjects had antibodies against THOV (seroprevalence: 5.3%) and six had antibodies against DHOV (seroprevalence: 4%); titers ranged between 1/32-1/256 and 1/32-1/128, respectively. No significant differences were seen in seroprevalence in terms of gender or age, although people with antibodies were significantly more likely to have had contact with livestock for professional reasons. One subject with an acute infection had IgM antibodies to both viruses and seroconverted to IgG. For the sheep, 24 serum samples were positive for antibodies to THOV (seroprevalence: 20%) and 32 for antibodies to DHOV (seroprevalence: 26.8%); titers ranged between 1/16 and 1/128. The seroprevalence of both viruses was significantly higher in animals < 4 years of age. Together, these results reveal the circulation of DHOV and THOV in humans and sheep in the province of Palencia. Sheep might be used as indicators of the presence of these organisms

    Screening of Forestry Workers in Guadalajara Province (Spain) for Antibodies to Lymphocytic Choriomeningitis Virus, Hantavirus, Rickettsia spp. and Borrelia burgdorferi

    Get PDF
    Exposure to Lymphocytic choriomeningitis virus (LCMV), hantaviruses, Rickettsia spp. and Borrelia burgdorferi among forestry workers from a province in central Spain (Guadalajara) was examined by serological screening. This is the first such study in this rural area, where people often live and work in proximity to domestic and wild animals. Immunofluorescent analyses of the serum of 100 forestry workers detected IgG antibodies to LCMV in 2% (CL 95% 0.55%&#8211;7.0%) of this population, to hantaviruses in 4% (CL 95% 1.6%&#8211;8.3%) for the serum amyloid A (SAA) serotype, and 2% (CL 95% 0.55%&#8211;7.0%) for the Seoul virus (SEO) serotype (samples also positive for SAA), to Rickettsia in 8% (CL 95% 4.1%&#8211;15%) (3% (CL 95% 1.0%&#8211;8.5%) for R. typhi and 5% (CL 95% 2.2%&#8211;11.2%) for R. slovaca, and to B. burgdorferi in 7% (CL 95% 3.4%&#8211;13.8%). The number of people who have been exposed to these organisms is commonly underestimated since most infections are asymptomatic. Greater epidemiological surveillance may therefore be recommended

    A comparative analysis of ABE Bachelor of Science programs in European and US Universities.

    Get PDF
    European Universities are involved in series of great changes regarding teaching and education organization during the last few years. The origin of these changes is the creation of the so-called European Higher Education Area (EHEA), which main target is to harmonize the different University studies throughout Europe. As a consequence, most of the programs of studies in all degrees are suffering changes in order to converge to common structures. Taking advantage of the actual process, some European universities are moving from traditional Agricultural Engineering programs to a more wide discipline named recently as Biosystems Engineering, which is a science- based engineering discipline that integrates engineering science and design with applied biological, environmental and agricultural sciences, broadening in this way the area of application of Engineering sciences not strictly to agricultural sciences, but to the biologic al sciences in general, including the agricultural sciences. This paper presents a comparative study of different Bachelor of Science degrees offered by American and European Universities in the field of Agricultural/Biosystems Engineering. To carry out the analysis 40 programs accredited by ABET in American Universities and 50 European programs. Among other questions, the total number of credits, the number of semesters, the kind of modules and the distribution of subjects in groups (Basic Sciences, Engineering Fundamentals, Agricultural/Biological Sciences, Humanities & Economic Sciences, Applied Agricultural/Biological Engineering and electives) are discussed in the paper. The information provided can be an useful starting point in future definitions of new or renewed degrees with the aim of advancing in internationalization of the programs and helping student’s mobility

    Reuse of vacant agro-industrial buildings. The case of the public slaughterhouses in Spain

    Get PDF
    Nearly 3000 slaughterhouses (74% of them public facilities) were built in Spain during the last decades of the nineteenth century and the first half of the twentieth century. The need to comply with new technical requirements and regulations on the hygiene of the meat passed in the 70s and the gradual replacement of public facilities by larger and more modern private slaughterhouses have subsequently led to the closure and abandonment of many of these buildings. Public slaughterhouses generally consisted of several single-storey and open-plan buildings located around a courtyard. Although originally they were preferably located on the outskirts of the towns, many slaughterhouses are now placed inside the built up areas, due to the urban development. The present work aims to contribute to a better understanding of these agro-industrial buildings and to provide ideas for their conservation and reuse. A review on the historical evolution and the architectural features of the public slaughterhouses in Spain is presented and different examples of old vacant slaughterhouses reused to accommodate libraries, offices, community centres, exhibition halls or sports centres, among others, are shown in the paper
    corecore