Enhancing the superconducting transition temperature of BaSi2 by structural tuning

We present a joint experimental and theoretical study of the superconducting phase of the layered binary silicide BaSi2. Compared with the layered AlB2 structure of graphite or diboride-like superconductors, in the hexagonal structure of binary silicides the sp3 arrangement of silicon atoms leads to corrugated sheets. Through a high-pressure synthesis procedure we are able to modify the buckling of these sheets, obtaining the enhancement of the superconducting transition temperature from 4 K to 8.7 K when the silicon planes flatten out. By performing ab-initio calculations based on density functional theory we explain how the electronic and phononic properties of the system are strongly affected by changes in the buckling. This mechanism is likely present in other intercalated layered superconductors, opening the way to the tuning of superconductivity through the control of internal structural parameters.Comment: Submitte

Composition and barometric implications of the amphiboles from the Maladeta plutonic complex (Central Pyrenees, Huesca-Lérida)

[Abstract] The composition of the amphiboles in basic rocks (gabbros and diorites), granodiorites, monzogranites with minor amphibole and mafic microgranular enclaves from the Maladetta massif, corresponds to calcic terms (magnesioHornblende, actinolitic hornblende and actinolite), with reduced values ofAl tot• The main substitutional types are edenite, pargasite and Ti-Tschermakite, with other minor types, generating compositions with an AIIV excess. The application of three of the proposed calibrations for the Altot in Horblende geobarometer, gives anomalously low pressure values for the cristallyzation of the plutonic rock-types, suggesting that the amphibole crystals were formed below 2 Kbar of pressure, and in a continous way to subsolidus conditions,probably at the same time as AI-saturating phases formed

Association of Polymorphisms in the Interleukin 6 Receptor Complex with Obesity and Hyperandrogenism

10 pages, 5 tables.Objective: Interleukin-6 (IL-6), is an inflammatory cytokine that may influence the pathogenesis of obesity and hyperandrogenism. IL-6 exerts its actions through a heterodimeric receptor consisting of two membrane-bound glycoproteins: an 80-kDa IL-6 binding unit (IL6R-alpha) and a 130-kDa IL-6 signal transducer (gp130). Genetic variability at these loci might contribute to explain the development of obesity and hyperandrogenism. Research Methods and Procedures: We have evaluated the possible association of several polymorphisms in the IL6R-alpha and gp130 genes with obesity and/or hyperandrogenism in a case-control study involving 143 hyperandrogenic patients and 45 healthy women from Spain. Results: A microsatellite CA-repeat polymorphism in the IL6R-alpha locus was associated with obesity. The frequency of the common 149-bp allele was markedly increased in obese women compared with controls when considering patients and controls as a whole (0.41 vs. 0.29, chi2 = 17.085, p < 0.050). On the other hand, the uncommon Arg148 allele of the Gly148Arg polymorphism in the gp130 gene was more frequent in controls compared with hyperandrogenic patients (0.17 vs. 0.08, chi2 = 5.605, p = 0.026). Controls carrying Arg148 alleles had lower 11-deoxycortisol and 17-hydroxyprogesterone concentrations, a lower response of androstenedione to 1–24 adrenocorticotropin, and an almost significant decrease in free testosterone levels, suggesting that Arg148 alleles in the gp130 gene have a protective effect against androgen excess and adrenal hyperactivity. Discussion: Polymorphisms in the gp130 and IL6R-alpha loci influence hyperandrogenism and obesity, respectively. Our present results further suggest that proinflammatory genotypes are involved in the pathogenesis of these common metabolic disorders.This work was supported by grants from the Consejería de Educación, Comunidad de Madrid, Spain (Proyectos 08.6/0022/1998, 08.6/0024.2/2000, and 08.6/0010/2001), and from the Fondo de Investigación Sanitaria, Ministerio de Sanidad y Consumo, Spain (Proyectos FIS 00/0414 and 02/0741 to H.F.E.-M.Peer reviewe

Web based hybrid volumetric visualisation of urban GIS data: Integration of 4D Temperature and Wind Fields with LoD-2 CityGML models

City models visualisation, buildings, structures and volumetric information, is an important task in Computer Graphics and Urban Planning -- The different formats and data sources involved in the visualisation make the development of applications a big challenge -- We present a homogeneous web visualisation framework using X3DOM and MEDX3DOM for the visualisation of these urban objects -- We present an integration of different declarative data sources, enabling the utilization of advanced visualisation algorithms to render the models -- It has been tested with a city model composed of buildings from the Madrid University Campus, some volumetric datasets coming from Air Quality Models and 2D layers wind datasets -- Results show that the visualisation of all the urban models can be performed in real time on the Web -- An HTML5 web interface is presented to the users, enabling real time modifications of visualisation parameter

Association of the polycystic ovary syndrome with genomic variants related to insulin resistance, type 2 diabetes mellitus, and obesity

7 pages, 2 tables.-- Results from this work were presented at the 85th Annual Meeting of The Endocrine Society, Philadelphia, PA, June 2003.We have evaluated the possible association of polycystic ovary syndrome (PCOS) with 15 genomic variants previously described to influence insulin resistance, obesity, and/or type 2 diabetes mellitus. Seventy-two PCOS patients and 42 healthy controls were genotyped for 15 variants in the genes encoding for paraoxonase (three variants), plasma cell differentiation antigen glycoprotein, human sorbin and SH3 domain containing 1, plasminogen activator inhibitor-1, peroxisome proliferator-activated receptor-gamma2, protein tyrosine phosphatase 1B (two variants), adiponectin (two variants), IGF1, IGF2, IGF1 receptor, and IGF2 receptor. Compared with controls, PCOS patients were more frequently homozygous for the -108T variant in paraoxonase (36.6% vs. 9.5%; P = 0.002) and homozygous for G alleles of the ApaI variant in IGF2 (62.9% vs. 38.1%; P = 0.018). Paraoxonase is a serum antioxidant enzyme and, because -108T alleles result in decreased paraoxonase expression, this increase in oxidative stress might result in insulin resistance. G alleles of the ApaI variant in IGF2 may increase IGF2 expression, and IGF2 stimulates adrenal and ovarian androgen secretion. In conclusion, the paraoxonase -108 C-->T variant and the ApaI polymorphism in the IGF2 gene are associated with PCOS and might contribute to increased oxidative stress, insulin resistance, and hyperandrogenism in this prevalent disorder.This work was supported by grants from the Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Spain (FIS 00/0414, 02/0741, and 02/0578 and RGDM G03/212) and from the Consejería de Educación, Comunidad de Madrid, Spain (CAM 08.6/0024/2000 and 08.6/0010/2001).Peer reviewe

Characters of the Stephanian-Permian Bronchales basin and the tourmalinization associated to calc-alkaline rhyolites (Teruel Province)

[Resumen] La turmalinización que afecta a riolitas calco-alcalinas presentes en la fosa transtensional de Bronchales, con edad Autuniense, destaca por el elevado contenido en B (0.87 O/o de promedio). Esta mineralización muestra un enriqueciIl\iento de HREE y un empobrecimiento en LREE debido a que el fluido mineralizante (rico en F) pudo ejercer una función acomplejante para estos elementos y, también, con carácter selectivo, para As, Sn, Sb y Bi.[Abstract] Calc-alkaline rhyolites of Bronchales transtensional basin (Autunian age) are affected by a tourmalinization process. Tourmalinized rhyolites with 0.87 O/o ofboron as average value show As, Sb, Sn and Bi increments over nontourmalinized ones, as well as important enrichments of HREE over LREE possibly because tourmalinization fluids were enriched in complexing agents (i.e .F)

On the Variety of Heyting Algebras with Successor Generated by All Finite Chains

Contrary to the variety of Heyting algebras, finite Heyting algebras with successor only generate a proper subvariety of that of all Heyting algebras with successor. In particular, all finite chains generate a proper subvariety, SLH!, of the latter. There is a categorical duality between Heyting algebras with successor and certain Priestley spaces. Let X be the Heyting space associated by this duality to the Heyting algebra with successor H. If there is an ordinal and a filtration S on X such that X = X, the height of X is the minimun ordinal ≤ such that Xc = ∅. In this case, we also say that H has height . This filtration allows us to write the space X as a disjoint union of antichains. We may think that these antichains define levels on this space. We study the way of characterize subalgebras and homomorphic images in finite Heyting algebras with successor by means of their Priestley spaces. We also depict the spaces associated to the free algebras in various subcategories of SLH!.

Errata on “On the Variety of Heyting Algebras with Successor Generated by all Finite Chains”

Errata on “On the Variety of Heyting Algebras with Successor Generated by all Finite Chains

AIR POLLUTION DIFFERENCES IN SIMULATION PATTERNS BY USING MM5-CMAQ AND WRF-CMAQ: SUMMER 2003 EUROPEAN POLLUTION EPISODE

One of the most important advantages of the modern and state-of-the-art air quality modelling systems is the capability to produce air pollution forecasts and particularly for ozone. In this contribution, we have applied the CMAQ (EPA) air quality modelling system to produce ozone air quality forecasts and compare the results for the 2003 August, episode in Europe. Modern air quality modelling systems are composed by a complete, modern and robust mesoscale meteorological model and a chemical transport module. Two mesoscale meteorological models are used in this application: a) the well-known MM5 model developed by PSU/NCAR (USA) and the next generation b) mesoscale model WRF. The MM5/WRF-chemical transport model requires emission data sets according to the grid spatial and temporal resolution. In this application we have considered a model domain of more than 5000 x 5000 km with 27 km of spatial resolution, centered over Madrid city (Spain) and covering a substantial part of the North of Africa and most of the Western European region. We have used the 5-10, August, 2003 period where maximum ozone values reach around 30