7,448 research outputs found

    Higher order Whitehead products and LL_\infty structures on the homology of a DGL

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    We detect higher order Whitehead products on the homology HH of a differential graded Lie algebra LL in terms of higher brackets in the transferred LL_\infty structure on HH via a given homotopy retraction of LL onto HH.Comment: New references and minor correction

    Loss of diversity in the community of small mammals of Doñana National Park (SW Spain): another effect of the local climate change ?

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    Doñana National Park is an important wetland located in the southwest Spain forming part of the Mediterranean Basin, a "biodiversity hotspot" especially vulnerable to climate change. In this study, we investigate changes in diversity and abundance occurred between 1978 and 2016 in the community of small mammals of Doñana and their relationship with local climate changes. Capture-mark-recapture methods were carried out for a total of 16 years, unevenly distributed over four decades. Our findings show a consistent loss of diversity and abundance decline in the community of small mammals. Eliomys quercinus and Rattus rattus have almost disappeared from the area and Apodemus sylvaticus has sharply reduced its abundance parallel to the progressive increase of Mus spretus. Such a process is worrying for conservation as small mammals represent, after rabbits, the most important prey for carnivores and raptors in Doñana. The detected changes could be at least partially explained by the progressive increase in local temperature observed during the study period. In line with this, the species that have suffered a greater decline are those of Eurasian origin and northern distribution as is the case for E. quercinus and R. rattus while the current dominant species, M. spretus, proceeds from Africa and has a Mediterranean distribution. A non-exclusive alternative is that the extreme rarefaction of rabbits may have caused a trophic cascade effect enhancing predation by carnivores and raptors towards gradually smaller species.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Broadening of H2_2O rotational lines by collision with He atoms at low temperature

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    We report pressure broadening coefficients for the 21 electric-dipole transitions between the eight lowest rotational levels of ortho-H2_2O and para-H2_2O molecules by collisions with He at temperatures from 20 to 120 K. These coefficients are derived from recently published experimental state-to-state rate coefficients for H2_2O:He inelastic collisions, plus an elastic contribution from close coupling calculations. The resulting coefficients are compared to the available experimental data. Mostly due to the elastic contribution, the pressure broadening coefficients differ much from line to line, and increase markedly at low temperature. The present results are meant as a guide for future experiments and astrophysical observations.Comment: 2 figures, 2 table

    Conceptual design of the EU-DEMO dual coolant lithium lead equatorial module

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    © 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Within the framework of EUROfusion Program, the Dual Coolant Lithium Lead (DCLL) is one of the four EU breeder blanket concepts that are being investigated as candidates for DEMO. DCLL uses PbLi as the main coolant, tritium breeder, tritium carrier, and neutron multiplier. The main structures, including the first wall, are cooled with helium. The EU program proposed for the next years will consider a DCLL version limited to 550 °C in order to allow the use of conventional materials and technologies. During the first year of EUROfusion activities, a draft design of the DCLL has been proposed. The main blanket performances were adapted to the new specifications and the CAD model of DEMO. The breeder zone has been toroidally divided into four parallel PbLi circuits, separated through stiffening grid radial walls. The PbLi flow routing has been designed to maximize the amount of thermal power extracted by flowing PbLi and to avoid the occurrence of reverse flows due to volumetric heating. Thermal hydraulics, magnetohydrodynamic and neutronics calculations have been performed for the first draft design. The new DCLL design employs Eurofer-alumina-Eurofer sandwich as flow channel insert (FCI).Postprint (published version

    Patients’ opinions about knowing their risk for depression and what to do about it: The PredictD-Qualitative study

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    Background: The predictD study developed and validated a risk algorithm for predicting the onset of major depression in primary care. We aimed to explore the opinion of patients about knowing their risk for depression and the values and criteria upon which these opinions are based. Methods: A maximum variation sample of patients was taken, stratified by city, age, gender, immigrant status, socioeconomic status and lifetime depression. The study participants were 52 patients belonging to 13 urban health centres in seven different cities around Spain. Seven Focus Groups (FGs) were given held with primary care patients, one for each of the seven participating cities. Results: The results showed that patients generally welcomed knowing their risk for depression. Furthermore, in light of available evidence several patients proposed potential changes in their lifestyles to prevent depression. Patients generally preferred to ask their General Practitioners (GPs) for advice, though mental health specialists were also mentioned. They suggested that GPs undertake interventions tailored to each patient, from a ‘‘patient-centred’’ approach, with certain communication skills, and giving advice to help patients cope with the knowledge that they are at risk of becoming depressed. Conclusions: Patients are pleased to be informed about their risk for depression. We detected certain beliefs, attitudes, values, expectations and behaviour among the patients that were potentially useful for future primary prevention programmes on depression.Junta de Andalucía 2008/0195Gobierno Vasco 2008/111021Spanish Network of Primary Care Research (redIAPP) RD06/0018Salud Mental, Servicios y Atención Primaria (SAMSERAP

    Formality criteria in terms of higher Whitehead brackets

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    We provide two criteria for discarding the formality of a differential graded Lie algebra in terms of higher Whitehead brackets, which are the Lie analogue of the Massey products of a differential graded associative algebra. We also show that formality of a differential graded Lie algebra is not equivalent to the collapse of the Quillen spectral sequence. Finally, we use LL_\infty algebras and Quillen's formulation of rational homotopy theory to recover and improve a classical theorem for detecting higher Whitehead products in Sullivan minimal models and give some applications

    Characterization of Carbon-Contaminated B4C-Coated Optics after Chemically Selective Cleaning with Low-Pressure RF Plasma

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    Boron carbide (B4C) is one of the few materials that is expected to be mostly resilient with respect to the extremely high brilliance of the photon beam generated by free electron lasers (FELs) and is thus of considerable interest for optical applications in this field. However, as in the case of many other optics operated at modern light source facilities, B4C-coated optics are subject to ubiquitous carbon contaminations. These contaminations represent a serious issue for the operation of high performance FEL beamlines due to severe reduction of photon flux, beam coherence, creation of destructive interference, and scattering losses. A variety of B4C cleaning technologies were developed at different laboratories with varying success. We present a study regarding the low-pressure RF plasma cleaning of carbon contaminated B4C test samples via inductively coupled O2/Ar, H2/Ar, and pure O2 RF plasma produced following previous studies using the same IBSS GV10x downstream plasma source. Results regarding the chemistry, morphology as well as other aspects of the B4C optical coating before and after the plasma cleaning are reported. We conclude from these comparative plasma processes that pure O2 feedstock plasma only exhibits the required chemical selectivity for maintaining the integrity of the B4C optical coating.Comment: 27 pages, 15 figure
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