2,106 research outputs found

    How Bees Respond Differently to Field Margins of Shrubby and Herbaceous Plants in Intensive Agricultural Crops of the Mediterranean Area

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    (1) Intensive agriculture has a high impact on pollinating insects, and conservation strategies targeting agricultural landscapes may greatly contribute to their maintenance. The aim of this work was to quantify the effect that the vegetation of crop margins, with either herbaceous or shrubby plants, had on the abundance and diversity of bees in comparison to non-restored margins. (2) The work was carried out in an area of intensive agriculture in southern Spain. Bees were monitored visually and using pan traps, and floral resources were quantified in crop margins for two years. (3) An increase in the abundance and diversity of wild bees in restored margins was registered, compared to non-restored margins. Significant differences in the structure of bee communities were found between shrubby and herbaceous margins. Apis mellifera and mining bees were found to be more polylectic than wild Apidae and Megachilidae. The abundance of A. mellifera and mining bees was correlated to the total floral resources, in particular, to those offered by the Boraginaceae and Brassicaceae; wild Apidae and Megachilidae were associated with the Lamiaceae. (4) This work emphasises the importance of floral diversity and shrubby plants for the maintenance of rich bee communities in Mediterranean agricultural landscapes

    Senior Games

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    Nuestro proyecto pretende prestar atención a un grupo de personas que no siempre recibe toda la que necesita. Estas son las personas mayores, las cuales sufren un declive cognitivo debido al envejecimiento. Debido a esto, hemos desarrollado un videojuego serio que servirá para estudiar y analizar (GA) las capacidades de las personas mayores, como: memoria, orientación, atención, planificación o percepción. No pretendemos que el videojuego resuelva ni mejore los deterioros o problemas que presenten los jugadores por sí mismo. La función del videojuego es recoger, de manera entretenida y a la vez rigurosa, datos sobre el comportamiento de nuestros jugadores frente a situaciones típicas de la vida cotidiana que puedan suponer un reto para sus capacidades cognitivas. Estos datos recogidos se envían estandarizados a un servidor para su almacenamiento y cuantificación. Nuestro objetivo es que la información resultante pueda ser utilizada por psicólogas expertas en este ámbito, para detectar de manera prematura detrimentos en las capacidades de personas mayores. Lo cual, pueda servir para evitar la evolución de problemas más graves, o para encontrar posibles soluciones a los ya encontrados. Siguiendo este proceso el trabajo podría aportar beneficios terapéuticos a las personas mayores

    The ecology of the Mar Menor coastal lagoon: A fast changing ecosystem under human pressure

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    The Mar Menor is a hypersaline coastal lagoon, with a surface area of 135 km2 and a perimeter of 59.51 km. It is located on the southwestern Mediterranean coastline (3742′00′′N, 0047′00′′W) with a mean depth of 3.6 m and a maximum depth of 6 m. “La Manga,” a sandy bar 22 km long and 100–900 m wide, acts as a barrier between the lagoon and the Mediterranean Sea. It is crossed by five more or less functional inlets called golas. Four are shallow (less than 1 m deep) and one of them, El Estacio, was widened and dug to a 5-m depth to make it a navigational channel. Altogether a total width of lagoon entrances is about 645 m, giving Mar Menor a restriction ratio of 0.015. Mar Menor is therefore a restricted lagoon according to the classification proposed by Kjerfve1 (see Chapter 6). There are two main islands and three other smaller islands, one of which is artificially connected to La Manga

    Observed degradation in photovoltaic plants affected by hot-spots

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    A number of findings have shown that the test procedures currently available to determine the reliability and durability of photovoltaic (PV) modules are insufficient to detect certain problems. To improve these procedures, ongoing research into the actual performance of the modules in the field is required. However, scientific literature contains but few references to field studies of defective modules. This article studies two different localized heating phenomena affecting the PV modules of two large-scale PV plants in Spain. The first problem relates to weak solder joints whilst the second is due to microcracks on the module cells. For both cases, the cause is identified, and consideration is given with regard to the effect on performance, the potential deterioration over time, and a way to detect the problems identified. The findings contained in this paper will prove to be of considerable interest to maintenance personnel at large-scale PV plants and also to those responsible for setting module quality standards and specifications, and even the PV module manufacturers themselves

    STC power for 15MW of PV comparing nameplate, initial power and power after 4 years

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    To date, the majority of quality controls performed at PV plants are based on the measurement of a small sample of individual modules. Consequently, there is very little representative data on the real Standard Test Conditions (STC) power output values for PV generators. This paper presents the power output values for more than 1300 PV generators having a total installed power capacity of almost 15.3 MW. The values were obtained by the INGEPER-UPNA group, in collaboration with the IES-UPM, through a study to monitor the power output of a number of PV plants from 2006 to 2009. This work has made it possible to determine, amongst other things, the power dispersion that can be expected amongst generators made by different manufacturers, amongst generators made by the same manufacturer but comprising modules of different nameplate ratings and also amongst generators formed by modules with the same characteristics. The work also analyses the STC power output evolution over time in the course of this 4-year study. The values presented here could be considered to be representative of generators with fault-free modules

    CO2 antropogénico en la región de las Azores

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    The AZORES-I cruise was conducted in August 1998, spanning the length of three latitudinal large-scale sections at 22, 28 and 32ºW. The oceanic carbon system was oversampled by measuring total alkalinity, total inorganic carbon and pH. It is thus possible to estimate anthropogenic CO2 (CANT) and to investigate its relationship with the main water masses that are present. C CANT is calculated using the latest back-calculation techniques: φCTº and TrOCA methods. Although the two approaches produce similar vertical distributions, the results of the TrOCA method show higher CANT variability and produce higher inventories than those of the φCTº method. The large proportion of Mediterranean Water found in the northern part of the study area is the main cause of the observed increase northwards of C CANT inventories. Changes in C CANT inventories between 1981 and 2004 are evaluated using data from the TTO-NAS, OACES-93 and METEOR-60/5 cruises. According to the φCTº and TrOCA approaches, the average long-term rates of C CANT inventory change are 1.32±0.11 mol C m-2 y-1 (P=0.008) and 1.18±0.16 mol C m-2 y-1 (P=0.018), respectively. During the 1993-1998 a significant increase in the C CANT storage rate was detected by the φCTº method. It is thought that this stems directly from the enhanced Labrador Seawater formation after the increased advection observed at the time.La campaña de macro-escala Azores I se desarrolló durante el mes de agosto de 1998 y consta de tres secciones meridionales centradas en 22, 28 y 32ºW. El sobre-muestreo realizado del sistema del carbónico, con medidas de alcalinidad total, carbono inorgánico total y pH, ha permitido el cálculo del CO2 antropogénico (CANT) e investigar su distribución en las masas de agua presentes. El CANT se calculó mediante las últimas técnicas de retro-cálculo disponibles: los métodos φCTº y TrOCA. A pesar de que ambos procedimientos producen distribuciones verticales similares, los resultados del método TrOCA indican mayores inventarios y variabilidad de CANT que los estimados por el método φCTº. La elevada proporción de agua mediterránea presente al norte de la región estudiada es la causa principal del aumento hacia el norte de los inventarios de CANT. Las tasas de cambio en los inventarios de CANT entre 1981 y 2004 se han evaluado utilizando datos de las campañas TTO-NAS, OACES-93 y METEOR-60/5. Según los métodos φCTº y TrOCA, las tasas de cambio promedio a largo plazo del inventario de CANT en esta zona son de 1.32±0.11 mol C m -2 y-1 (p-valor=0.008) y de 1.18±0.16 mol C m-2 y-2 (p-valor=0.018), respectivamente. Durante el periodo 1993-1998 el método φCTº detecta un aumento significativo de la tasa de acumulación de CANT provocado posiblemente por las elevadas tasas de formación de agua de Labrador, derivadas del aumento de la advección observada en dicho periodo

    Nuevas aportaciones al conocimiento de la evolución tectonometamórfica del complejo de Cabo Ortegal (NW de España)

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    [Resumen] El Complejo de Cabo Ortegal es una unidad a16ctona constituida en gran parte por rocas ultrabásicas, básicas y neises. Estas rocas han sufrido un metamorfismo polifásico en el que se distinguen cuatro episodios, de forma que el grado más elevado se alcanza durante la primera fase (facies granulita y eclogita), teniendo lugar después una retrogradación progresiva hasta la facies de los esquistos verdes. La evolución de la deformación ha tenido también lugar en cuatro fases, de forma que la primera es posterior a los dos primeros episodios metamórficos. Las tres primeras fases de deformación representan una importante deformación por cizalla tangencial, mientras que la cuarta da lugar al amplio sinforme en cuyo núcleo se sitúa el complejo. Las rocas de Cabo Ortegal representan probablemente una secuencia ofiolítica subducida durante el Ordov!cico y obducida con posterioridad al Devónico inferior como con secuencia de una colisión continental.[Abstract] The Cabo Ortegal Complex is an allochthonous unit made up of ultrabasic rocks, basic rocks and gneisses. These rocks have suffered a poliphasic metamorphism in which four episodes can be established. The highest degree of metamorphism (granulitic and eclogitic facies) took place during the first phase followed a~erwards by a progressive retrogresion to greenschist facies. Four phases of deformation can also be distinguished being the first later than the first two metamorphic episodes. The three earlier tectonic phases represent an important sheardeformation while the forth gives way to the wide sinform of Cabo Ortegal. The rocks of the Cabo Ortegal Complex would be an ophiolitic sequence subducted during Ordovician times and obducted after the lower Devonian, due to a continental collision

    Mechanisms of Action of Non-Canonical ECF Sigma Factors

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    Extracytoplasmic function (ECF) sigma factors are subunits of the RNA polymerase specialized in activating the transcription of a subset of genes responding to a specific environmental condition. The signal-transduction pathways where they participate can be activated by diverse mechanisms. The most common mechanism involves the action of a membrane-bound anti-sigma factor, which sequesters the ECF sigma factor, and releases it after the stimulus is sensed. However, despite most of these systems following this canonical regulation, there are many ECF sigma factors exhibiting a non-canonical regulatory mechanism. In this review, we aim to provide an updated and comprehensive view of the different activation mechanisms known for non-canonical ECF sigma factors, detailing their inclusion to the different phylogenetic groups and describing the mechanisms of regulation of some of their representative members such as EcfG from Rhodobacter sphaeroides, showing a partner-switch mechanism; EcfP from Vibrio parahaemolyticus, with a phosphorylation-dependent mechanism; or CorE from Myxococcus xanthus, regulated by a metal-sensing C-terminal extension.Spanish Government (PID2020-112634GB-I00)FEDER funds (grant A-BIO-126-UGR20

    Metal-responsive RNA polymerase extracytoplasmic function (ECF) sigma factors

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    In order to survive, bacteria must adapt to multiple fluctuations in their environment, including coping with changes in metal concentrations. Many metals are essential for viability, since they act as cofactors of indispensable enzymes. But on the other hand, they are potentially toxic because they generate reactive oxygen species or displace other metals from proteins, turning them inactive. This dual effect of metals forces cells to maintain homeostasis using a variety of systems to import and export them. These systems are usually inducible, and their expression is regulated by metal sensors and signal-transduction mechanisms, one of which is mediated by extracytoplasmic function (ECF) sigma factors. In this review, we have focused on the metalresponsive ECF sigma factors, several of which are activated by iron depletion (FecI, FpvI and PvdS), while others are activated by excess of metals such as nickel and cobalt (CnrH), copper (CarQ and CorE) or cadmium and zinc (CorE2). We focus particularly on their physiological roles, mechanisms of action and signal transduction pathways.This work has been supported by the Spanish Government, grant BFU2016-75425-P to Aurelio Moraleda-Muñoz (70% funded by FEDER)
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