961 resultados para Ciencias ambientales
Resumo:
En la tercera edición del curso “Investigando la biodiversidad: presente y futuro” organizado por el CIBIO (Universidad de Alicante), se ha querido dar un enfoque aún más práctico a través de diferentes talleres en los que los alumnos han podido aprender y participar de manera activa mediante actividades como: la edición digital de fotografía de la naturaleza, la historia y elaboración de herberos y la utilización de los insectos en la gastronomía. Sobre este último taller versa este artículo que resume las actividades realizadas durante el mismo después de que en la primera parte del taller se impartieran conocimientos de distinta índole sobre esta actividad.
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The aim of this work was to investigate the alkaloid patterns of Lapiedra martinezii and their relation to biogeography and phenology focused in a phylogenetic comparison. Plants from 14 populations of L. martinezii, covering almost its entire distribution area, were subjected to morphological, ecological, and phytochemical analysis. Experiments for different alkaloid-type content are proposed as a new tool for analysis of plant distribution. Several plants were transplanted for weekly observation of their phenological changes, and alkaloids from different plant organs were extracted, listed, and compared. The alkaloid pattern of L. martinezii comprises 49 compounds of homolycorine, lycorine, tazettine, haemantamine, and narciclasine types. The populations located in the north and south margins of the distribution area displayed alkaloid patterns different from those of the central area. Changes in these patterns during their phenological cycle may be related to a better defence for plant reproduction. L. martinezii is an old relict plant, and it has maintained some of the more primitive morphological features and alkaloid profiles of the Mediterranean Amaryllidaceae. The variations in alkaloid content observed could be interpreted in a phylogenetic sense, and those found in their phenological changes, in an adaptive one.
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In an attempt to reveal the relationships between alkaloid biosynthesis and phylogeny, we investigated by GC–MS the alkaloid patterns of 22 species and 3 hybrids (from 45 locations) from seven main sections of the genus Narcissus (Amaryllidaceae). The results indicate that the first alkaloids to evolve in the genus Narcissus were of the lycorine- and homolycorine-type. The alkaloid pattern of the Nevadensis section supports its recent separation from the Pseudonarcissus section. The plants of Narcissus pallidulus (Ganymedes section) show a predominance of Sceletium-type compounds, which are quite rare in the Amaryllidaceae family. Two successful evolutionary strategies involving alkaloid biosynthesis and leading to an expansion in taxa and occupied area were determined. Firstly, a diversification of alkaloid patterns and a high alkaloid concentration in the organs of the large Narcissus species (in the Pseudonarcissus section) resulted in an improved chemical defence in diverse habitats. Secondly, both plant size and alkaloid biosynthesis were reduced (in the Bulbocodium and Apodanthi sections) relegated to dry pastures and rocky places.
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Saproxylic beetle diversity is high at the Cabañeros National Park (central Spain), where woodland habitats exhibit remarkable heterogeneity. Our aim was to explain the diversity of saproxylic beetles, focusing on species turnover among mature woodland types. We surveyed five woodland types that represented the heterogeneity of the park’s woodland habitats. Beetles were collected using window traps over a period of 20 months. The Jaccard Similarity Index was used as indirect value of beta diversity among woodlands and to test the relation between species turnover and geographical distance. We also identified the contribution of species turnover to landscape diversity by using a partitioning model. Moreover, the presence of mixed woodlands (more than one tree species) allowed us to attempt to valorise the effect of tree species (coupled with their historical management) on species turnover among woodlands. Finally, we looked for different saproxylic beetle preferences for habitat and tree species using an indicator value method. We found that saproxylic beetle species composition varied significantly among the studied woodlands. The variation in species turnover was independent from the distance among woodlands, which suggested that beetle dispersal abilities could not explain this high turnover. Tree species within woodlands were a key factor that increased diversity turnover in woodlands and, consequently, the diversity of the park. Moreover, we found saproxylic beetle species that had different habitat and tree species preferences. We conclude that woodland heterogeneity (highly affected by woodland composition) seems to be the driving force for saproxylic beetle diversity in this protected area.
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Using information from two recently published atlases of threatened invertebrate species in peninsular Spain, we examined the climatic, land use and geographic characteristics of the 100 km2 UTM cells with most likelihood of suffering extinctions (extinction cells), as well as the attributes of the species prone to population extinctions. Extinction cells have had significantly (1) lower precipitation values, (2) higher temperatures, (3) higher percentages of anthropic land uses or (4) higher rates of anthropization during the last 20 years than the remaining cells. Nevertheless, probable extinctions may occur under a wide range of climatic and anthropization change rates and these variables can only explain a low proportion (~5 %) of variability in the occurrence or number of extinction cells. Aquatic species seem to suffer higher local extinction rates than terrestrial species. Interestingly, many invertebrate species with approximately 25 or less occurrence cells are on a clear trajectory towards extinction. These results outline the difficulties and uncertainties in relating probable population extinctions with climatic and land use changes in the case of invertebrate data. However, they also suggest that a third of the considered Spanish threatened species could have lost some of their populations, and that current conservation efforts are insufficient to reverse this tendency.
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The choice of sampling methods to survey saproxylic beetles is a key aspect to assessing conservation strategies for one of the most endangered assemblages in Europe. We evaluated the efficiency of three sampling methods: baited tube traps (TT), window traps in front of a hollow opening (WT), and emergence traps covering tree hollows (ET) to study richness and diversity of saproxylic beetle assemblages at species and family levels in Mediterranean woodlands. We also examined trap efficiency to report ecological diversity, and changes in the relative richness and abundance of species forming trophic guilds: xylophagous, saprophagous/saproxylophagous, xylomycetophagous, predators and commensals. WT and ET were similarly effective in reporting species richness and diversity at species and family levels, and provided an accurate profile of both the flying active and hollow-linked saproxylic beetle assemblages. WT and ET were the most complementary methods, together reporting more than 90 % of richness and diversity at both species and family levels. Diversity, richness and abundance of guilds were better characterized by ET, which indicates higher efficiency in outlining the ecological community of saproxylics that inhabit tree hollows. TT were the least effective method at both taxonomic levels, sampling a biased portion of the beetle assemblage attracted to trapping principles, however they could be used as a specific method for families such as Bostrichiidae, Biphyllidae, Melyridae, Mycetophagidae or Curculionidae Scolytinae species. Finally, ET and WT combination allows a better characterization of saproxylic assemblages in Mediterranean woodland, by recording species with different biology and linked to different microhabitat types.
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Aim: High gamma diversity in tropical montane forests may be ascribed to high geographical turnover of community composition, resulting from population isolation that leads to speciation. We studied the evolutionary processes responsible for diversity and turnover in assemblages of tropical scarab beetles (Scarabaeidae) by assessing DNA sequence variation at multiple hierarchical levels. Location: A 300-km transect across six montane forests (900–1100 m) in Costa Rica. Methods: Assemblages of Scarabaeidae (subfamilies Dynastinae, Rutelinae, Melolonthinae) including 118 morphospecies and > 500 individuals were sequenced for the cox1 gene to establish species limits with a mixed Yule–coalescent method. A species-level phylogenetic tree was constructed from cox1 and rrnL genes. Total diversity and turnover among assemblages were then assessed at three hierarchical levels: haplotypes, species and higher clades. Results: DNA-based analyses showed high turnover among communities at all hierarchical levels. Turnover was highest at the haplotype level (community similarity 0.02–0.12) and decreased with each step of the hierarchy (species: 0.21–0.46; clades: 0.41–0.43). Both compositional and phylogenetic similarities of communities were geographically structured, but turnover was not correlated with distance among forests. When three major clades were investigated separately, communities of Dynastinae showed consistently higher alpha diversity, larger species ranges and lower turnover than Rutelinae and Melolonthinae. Main conclusions: Scarab communities of montane forests show evidence of evolutionary persistence of communities in relative isolation, presumably tracking suitable habitats elevationally to accommodate climatic changes. Patterns of diversity on all hierarchical levels seem to be determined by restricted dispersal, and differences in Dynastinae could be explained by their greater dispersal ability. Community-wide DNA sequencing across multiple lineages and hierarchical levels reveals the evolutionary processes that led to high beta diversity in tropical montane forests through time.
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This research study deals with the quantification and characterization of the EPS obtained from two 25 L bench scale membrane bioreactors (MBRs) with micro-(MF-MBR) and ultrafiltration (UF-MBR) submerged membranes. Both reactors were fed with synthetic water and operated for 168 days without sludge extraction, increasing their mixed liquor suspended solid (MLSS) concentration during the experimentation time. The characterization of soluble EPS (EPSs) was achieved by the centrifugation of mixed liquor and bound EPS (EPSb) by extraction using a cationic resin exchange (CER). EPS characterization was carried out by applying the 3-dimensional excitation–emission matrix fluorescence spectroscopy (3D-EEM) and high-performance size exclusion chromatography (HPSEC) with the aim of obtaining structural and functional information thereof. With regard to the 3D-EEM analysis, fluorescence spectra of EPSb and EPSs showed 2 peaks in both MBRs at all the MLSS concentrations studied. The peaks obtained for EPSb were associated to soluble microbial by-product-like (predominantly protein-derived compounds) and to aromatic protein. For EPSs, the peaks were associated with humic and fulvic acids. In both MBRs, the fluorescence intensity (FI) of the peaks increased as MLSS and protein concentrations increased. The FI of the EPSs peaks was much lower than for EPSb. It was verified that the evolution of the FI clearly depends on the concentration of protein and humic acids for EPSb and EPSs, respectively. Chromatographic analysis showed that the intensity of the EPSb peak increased while the concentrations of MLSS did. Additionally, the mean MW calculated was always higher the higher the MLSS concentrations in the reactors. MW was higher for the MF-MBR than for the UF-MBR for the same MLSS concentrations demonstrating that the filtration carried out with a UF membrane lead to retentions of lower MW particles.
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To study the possibility of producing better water quality from municipal wastewater, a membrane bioreactor (MBR) pilot plant with flat sheet (FS) and hollow fiber (HF) membranes coupled with another pilot plant equipped with nanofiltration (NF)/reverse osmosis (RO) membranes were operated to treat municipal wastewater from the wastewater treatment plant (WWTP) Rincón de León, Alicante (Spain). This study was focused on improving the quality of the permeate obtained from the MBR process when complemented by NF or RO stages with respect to salinity, organic matter and nutrients. Furthermore, the removal efficiencies of 10 EMPs were evaluated, comparing the reductions achieved between the wastewater treatment by MBR (adsorption to sludge and biodegradation) and the later treatment using NF or RO (mainly size exclusion). The results showed that the high quality of water was obtained which is appropriate for reuse with salinity removal efficiencies higher than 97%, 96% for total organic carbon (TOC), 91% for nitrates View the MathML sourceNO3- and 99% for total phosphorous (TP). High removal efficiencies were obtained for the majority of the analyzed EMP compounds.
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Anomala eucoma Bates, 1888 is redescribed and a lectotype from Guatemala is designated. Three new species from Costa Rica, A. flavacoma new species, A. megaparamera new species, and A. pseudoeucoma new species, are described, and a distribution map is given. The internal sac (endophallus) of the species covered is illustrated, and its use in separating closely related species in this region is discussed. An identification key for morphologically similar species from the Neotropical region is provided.
Resumo:
Tras el trabajo previo de diseño de la asignatura Iniciación a la Investigación en Biología, el equipo multidisciplinar de profesores y profesoras de la Red Docente INVES ha desarrollado una metodología propia de trabajo en equipo, no sólo entre el diferente profesorado que la compone, sino también con el profesorado de la asignatura Estadística, con la que se comparten objetivos de aprendizaje comunes. Se ha optimizado el sistema de evaluación del trabajo colaborativo del alumnado, mediante el uso de rubricas y auto-evaluación. Dicho trabajo consiste en el diseño y desarrollo de un proyecto de investigación bibliométrico de temática biológica realizado por los estudiantes, propiciando la adquisición de competencias transversales mediante una dinámica de trabajo en grupo que culmina en la edición de unas Jornadas Científicas. Por otra parte, se han consensuado criterios comunes de evaluación continua, mejorando en la eficiencia de la evaluación, y determinado un incremento de la capacidad de aprendizaje del alumnado a lo largo de los cursos 2010-11 al 2013-14. La oferta formativa se completa mediante la formación de un grupo de Alto Rendimiento Académico con docencia en lengua inglesa. Esto permite al alumnado implementar el objetivo general de compresión de lengua extranjera inglés en lo relativo al ámbito científico.
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Durante el curso académico 2013-2014 ha tenido lugar la implantación del último curso del Grado en Biología. Esto permite hacer un análisis completo de la implantación del título así como un estudio sobre el diseño y desarrollo del Trabajo de fin de Grado y la adaptación del Programa de Prácticas externas. Estrategias de trabajo a través de las comisiones de semestre, comisión de garantía de calidad del Centro, reuniones con el alumnado, grupos de acción tutorial, etc. han permitido detectar anomalías y reforzar aspectos positivos para el correcto funcionamiento del título. Cabe resaltar la alta participación del alumnado en la asignatura optativa de prácticas externas, así como un número elevado de alumnos/as matriculados en las optativas de cuarto curso vinculadas al Itinerario 2: Biotecnología y Biosanitaria. En cuanto a los Trabajos de Fin de Grado en curso, destaca el elevado número de trabajos experimentales, seguidos de los bibliográficos y en menor medida, los vinculados a empresas/instituciones.
Resumo:
En la actualidad son muy pocos los usos vigentes. Aunque los dátiles son la materia utilizada con mayor frecuencia, también se han empleado la savia, el polen y el cogollo tierno o palmito. Los dátiles de Phoenix dactylifera se utilizaron como analgésico y para tratar la anemia y trastornos digestivos, o para fortalecer las encías, en el tratamiento de la disfunción eréctil y como afrodisiacos, para facilitar el parto y calmar los dolores postparto, y tratar el prolapso de la matriz o para el exceso de flujo menstrual. También se utilizaron como diuréticos, para la disuria y en trastornos de la vejiga. El uso que más claramente ha persistido es el tratamiento de diversos problemas respiratorios. En uso externo se utilizaron para tratar problemas de la piel, heridas, hemorragias y hemorroides. De la palmera de Canarias (Phoenix canariensis), especialmente en la isla de la Gomera, la savia cruda o guarapo, su concentrado o miel de palma y los resultantes de su fermentación (vino de palma) se consumen como alimento y también se utilizan como diurético, remedio de trastornos génitourinarios, digestivo, para infecciones de la cavidad bucal, expectorante, antitusígeno y para las irritaciones de garganta. En el Toledo de Al-Andalus las espatas de P. dactylifera se utilizaron, hace casi mil años, en el tratamiento de la debilidad, los dolores, nefritis, las enfermedades de la vejiga, trastornos hepáticos (también como preventivo), diarrea, trastornos digestivos, dolores en el abdomen y en el estómago, excesivo sangrado menstrual, úlceras en la piel y sarna, dolores articulares y trastornos cardiacos. La fitoterapia racional debería prestar atención a este recurso, considerar la evidencia científica disponible (farmacológica e incluso clínica) e incorporarlo a nuestro repertorio terapéutico.
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Eight new species of Anomala from Costa Rica are described: A. arthuri new species, A. cupreovariolosa new species, A. ferrea new species, A. nigroflava new species, A. semilla new species, A. solisi new species, A. volsellata new species, A. zumbadoi new species and a distribution map of each is given. The male genitalia (aedeagus and endophallus) of the species covered are illustrated.
Resumo:
En este trabajo se aporta una nueva cita para Thorectes valencianus (Coleoptera: Geotrupidae). Este coleóptero es un endemismo iberolevantino catalogado como Vulnerable en la lista roja de la UICN y localizado en la sierra de Escalona (Orihuela, Alicante).