280 research outputs found

    First record of Caprella mutica from the Iberian Peninsula: expansion southwards in European waters

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    The caprellid amphipod, Caprella mutica, is a well-known invasive species, originating in the Sea of Japan, which has been rapidly expanding along the coasts of North America, Europe and Oceania for the last forty years. Caprella mutica is frequently associated with man-made structures, especially those dedicated to aquaculture activities, where it can reach high densities of up to 300,000 ind./m2. A well-established population of C. mutica was recently found by SCUBA-divers in Galician waters (north-west Spain) at 6 different man-made floating structures along Ría de Arousa. The record of this species in this location implies a new southernmost limit of distribution, extending the known distribution range in Atlantic European waters and confirming the continuity of the colonization southwards

    Identification of the water stress level in olive trees during pit hardening using the trunk growth rate indicator.

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    Water scarcity is generating an increasing interest in deficit irrigation scheduling. The trunk diameter fluctuations are daily cycles that have been suggested as tools for irrigation scheduling. The trunk growth rate (TGR) was suggested as the best indicator for olive trees during pit hardening. The aim of this work is to clarify how the TGR could be used to identify water stress levels. The experiment was performed during the 2017 season, in a commercial, super-high-density orchard in Carmona (Seville, Spain). Four different irrigation treatments were performed according to midday stem water potential values and TGR. The data obtained were very variable and both indicators presented a wide range of water status throughout the season. The maximum trunk diameter data clearly showed the pattern of the trees water status but the comparison between treatments and the identification of the water stress level was not possible. The average TGR was linked to the midday stem water potential, but with a minimum amount of data. Irrigation scheduling based on the average TGR was difficult because of the great increases in some daily TGR values. For clarity, the pool of data was grouped by midday stem water potential. These water stress levels were characterized using the weekly frequency of TGR values. The increase of water stress reduced the frequency of values between -0.1 and 0.3mm day-1 from 60% to less than 25%. Moderate water stress levels increased the percentage of values lower than -0.3mm day-1 from 7% to 37%. The most severe water stress conditions increased the TGR values between -0.3 and -0.1mm day-1 from 16% up to 22%.IRNASINSTITUTO DE LA GRASACSI

    Characterisation of Medipix3 Silicon Detectors in a Charged-Particle Beam

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    While designed primarily for X-ray imaging applications, the Medipix3 ASIC can also be used for charged-particle tracking. In this work, results from a beam test at the CERN SPS with irradiated and non-irradiated sensors are presented and shown to be in agreement with simulation, demonstrating the suitability of the Medipix3 ASIC as a tool for characterising pixel sensors.Comment: 16 pages, 13 figure

    Pattern of trunk diameter fluctuations of almond trees in deficit irrigation scheduling during the first seasons

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    Irrigation needs in mature almond orchards are very high. Although almond trees grow in rainfed conditions, the yield response is very sensitive to irrigation. Continuous monitoring of the water status could be an adequate tool to optimize deficit irrigation. In this sense, trunk diameter fluctuations appeared as a very promising indicator at the beginning of the century, but few data have been published. The aim of this work is to check threshold values of maximum daily shrikage (MDS) and identify possible limitations to their use in commercial orchards. The experiment was performed in a commercial farm in Dos Hermanas (Seville, Spain) during the 2017 season on a 7-years-old orchard (cv Vairo). The irrigation treatments were Control (100% ETc), sustained deficit irrigation (SDI) with a maximum seasonal irrigation of 100 mm and two regulated deficit treatments (RDI). Both RDI treatments (RDI-1 and RDI-2) were scheduled using the signal of maximum daily shrinkage (signal) and the midday stem water potential (SWP). In RDI-1, full irrigation conditions were provided before kernel filling and during postharvest, using the threshold values suggested in the bibliography. During kernel filling, the water stress level was designed to be -1.5 MPa (SWP) and 1.75 (signal). RDI-2 trees were irrigated using the same scheduling as RDI-1, but target water stress values were higher in kernel filling (-2 MPa and 2.75) and with a maximum seasonal amount of water of 100 mm. SWP in Control trees was near the McCutchan and Shackel baseline for most of the season. None of the deficit treatments reached the signal values suggested. Moreover, the signal values were almost equal between treatments, with no water stress effect. The trunk growth rate (TGR) presented clear differences depending on the water status

    Saharan dust and association between particulate matter and case-specific mortality: a case-crossover analysis in Madrid (Spain)

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    <p>Abstract</p> <p>Background</p> <p>Saharan dust intrusions are a common phenomenon in the Madrid atmosphere, leading induce exceedances of the 50 μg/m<sup>3</sup>- EU 24 h standard for PM<sub>10</sub>.</p> <p>Methods</p> <p>We investigated the effects of exposure to PM<sub>10 </sub>between January 2003 and December 2005 in Madrid (Spain) on daily case-specific mortality; changes of effects between Saharan and non-Saharan dust days were assessed using a time-stratified case-crossover design.</p> <p>Results</p> <p>Saharan dust affected 20% of days in the city of Madrid. Mean concentration of PM<sub>10 </sub>was higher during dust days (47.7 μg/m<sup>3</sup>) than non-dust days (31.4 μg/m<sup>3</sup>). The rise of mortality per 10 μg/m<sup>3 </sup>PM<sub>10 </sub>concentration were always largely for Saharan dust-days. When stratifying by season risks of PM<sub>10</sub>, at lag 1, during Saharan dust days were stronger for respiratory causes during cold season (IR% = 3.34% (95% CI: 0.36, 6.41) versus 2.87% (95% CI: 1.30, 4.47)) while for circulatory causes effects were stronger during warm season (IR% = 4.19% (95% CI: 1.34, 7.13) versus 2.65% (95% CI: 0.12, 5.23)). No effects were found for cerebrovascular causes.</p> <p>Conclusions</p> <p>We found evidence of strongest effects of particulate matter during Saharan dust days, providing a suggestion of effect modification, even though interaction terms were not statistically significant. Further investigation is needed to understand the mechanism by which Saharan dust increases mortality.</p

    Panorámica actual de las especies no indígenas marinas en el mar Cantábrico y Atlántico adyacente (NO-N de la península Ibérica): primera aproximación a la Directiva Marco de Estrategias Marinas en la demarcación noroeste

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    Simposio Ibérico de Estudios de Biología Marina (18º. 2014. Gijón (España))La introducción de especies invasoras no indígenas es un problema cada vez más común a escala mundial, siendo considerado una de mayores amenazas para la conservación de la biodiversidad de todo el planeta. Estas invasiones biológicas causan graves problemas ecológicos y en muchos casos ocasionan también importantes pérdidas a la economía local. La gravedad y el alcance de los impactos generados por las especies invasoras es tal, que en los últimos años ha trascendido del ámbito científico al político-social, siendo considerado como uno de los descriptores de la calidad ambiental en la Directiva Marco de la Estrategia Marina (MSFD 2008/56/EC). A pesar de la envergadura y repercusión de este problema, el estudio de las especies invasoras en aguas de la península Ibérica no ha sido abordado hasta fechas muy recientes, estando en su mayoría centrado en el ámbito continental de los ecosistemas dulceacuícolas y en el ámbito marino de la cuenca mediterránea de la península. Para las costas noratlánticas españolas(las cuales constituyen la demarcación noroeste de la Directiva Marco de la Estrategia Marina) los datos existentes son bastante escasos y sobre todo dispersos, siendo también en muchos casos de afiliación taxonómica dudosa. En este trabajo se presenta la primera revisión actualizada de las especies marinas reportadas como no indígenas (exóticas, no autóctonas, alóctonas o “alien”) ocriptogénicas para el mar Cantábrico y el Atlántico adyacente (costas de Galicia) hasta la actualidad; incluyendo también nuevas adiciones procedentes de los muestreos realizadosen las costas cantábricas y atlántico-gallegas entre los años 2010 y 2014. El área de estudio fue dividida en cuatro zonas (A-D) de Oeste a Este. En esta revisión no se reconocen como alóctonosy/o criptogénicosalgunos taxones previamente reportados como tales, ya que según nuestro criterio se tratan de especies nativas y/o especies que están extendiendo sus rangos de distribución de forma natural, en muchos casos como consecuencia de los fenómenos de calentamiento global. Se listan un total de 287 taxones considerados como no indígenas y/o criptogénicos para el área de estudio, constituyendo estos últimos aproximadamente un tercio del total (92 taxones). Para las taxones alóctonos(195), se ha seguido la clasificación de Zenetoset al. basada en el grado de invasión de las mismas. Las especies consideradas como “casuales” representaron aproximadamente una quinta parte del total (17%), mientras que las especies “establecidas” constituyeron algo menos de la mitad (41%). Finalmente, alrededor de un 6% de los taxones recogidos (17) se categorizaron como “invasores” para las aguas objeto de estudio. En función de las zonas geográficas en las que fue dividida el área de estudio, la gran mayoría de las especies (78%) fueron detectadas para una sola zona; un 21% lo fueron para al menos dos zonas; un 11% para tres y sólo un 6% de las especies fueron detectadas en las cuatro zonas (formando parte de éstas, 10 de las especies consideradas “invasoras”). Taxonómicamente, los filos con un mayor número de especies introducidas son los moluscos y los anélidos, agrupando, cada uno de ellos, un 21% del total de especies; seguidos del grupo de las algas rojas (16%) y de los artrópodos (14%). Otros filos que representan porcentajes mucho menores son los cnidarios (7%), los briozoos (5%), las algas pardas (4%), las ascidias (4%), los poríferos (3%), las algasverdes (2%), los gusanos nemertinos (<1%) y los equinodermos (<1%). El filo con mayor número de especies consideradas como “invasoras” es el grupo las algas rojas con 7 especies

    Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund

    Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund

    An Overview of the 2014 ALMA Long Baseline Campaign

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    A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.Comment: 11 pages, 7 figures, 2 tables; accepted for publication in the Astrophysical Journal Letters; this version with small changes to affiliation

    Clinical experience with integrase inhibitors in HIV-2-infected individuals in Spain.

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    Background: HIV-2 is a neglected virus despite estimates of 1–2 million people being infected worldwide. The virus is naturally resistant to some antiretrovirals used to treat HIV-1 and therapeutic options are limited for patients with HIV-2. Methods: In this retrospective observational study, we analysed all HIV-2-infected individuals treated with inte- grase strand transfer inhibitors (INSTIs) recorded in the Spanish HIV-2 cohort. Demographics, treatment modal- ities, laboratory values, quantitative HIV-2 RNA and CD4 counts as well as drug resistance were analysed. Results: From a total of 354 HIV-2-infected patients recruited by the Spanish HIV-2 cohort as of December 2017, INSTIs had been given to 44, in 18 as first-line therapy and in 26 after failing other antiretroviral regimens. After a median follow-up of 13 months of INSTI-based therapy, undetectable viraemia for HIV-2 was achieved in 89% of treatment-naive and in 65.4% of treatment-experienced patients. In parallel, CD4 gains were 82 and 126cells/mm3, respectively. Treatment failure occurred in 15 patients, 2 being treatment-naive and 13 treatment-experienced. INSTI resistance changes were recognized in 12 patients: N155H (5), Q148H/R (3), Y143C/G (3) and R263K (1). Conclusions: Combinations based on INSTIs are effective and safe treatment options for HIV-2-infected individ- uals. However, resistance mutations to INSTIs are selected frequently in failing patients, reducing the already limited treatment options
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