516 research outputs found

    Reducing the fine-tuning of gauge-mediated SUSY breaking

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    Despite their appealing features, models with gauge-mediated supersymmetry breaking (GMSB) typically present a high degree of fine-tuning, due to the initial absence of the top trilinear scalar couplings, At = 0. In this paper, we carefully evaluate such a tuning, showing that is worse than per mil in the minimal model. Then, we examine some existing proposals to generate At ≠ 0 term in this context. We find that, although the stops can be made lighter, usually the tuning does not improve (it may be even worse), with some exceptions, which involve the generation of At at one loop or tree level. We examine both possibilities and propose a conceptually simplified version of the latter; which is arguably the optimum GMSB setup (with minimal matter content), concerning the fine-tuning issue. The resulting fine-tuning is better than one per mil, still severe but similar to other minimal supersymmetric standard model constructions. We also explore the so-called “little A2t /m2 problem”, i.e. the fact that a large At -term is normally accompanied by a similar or larger sfermion mass, which typically implies an increase in the fine-tuning. Finally, we find the version of GMSB for which this ratio is optimized, which, nevertheless, does not minimize the fine-tuningThis work has been partially supported by the MICINN, Spain, under contract FPA2013-44773-P, Consolider-Ingenio CPAN CSD2007-00042, as well as MULTIDARK CSD2009-00064. We also thank the Spanish MINECO Centro de excelencia Severo Ochoa Program under Grant SEV-2012-0249. S.R. is supported by the Campus of Excellence UAM+CSIC and K.R. by the Spanish Research Council (CSIC) within the JAE-Doc progra

    Evaluación del efecto de la harina de ramio en la alimentación avícola

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    The Ramio (Boehmeria nivea), by means of many studies and realised industrial and agricultura! investigations at International level, has demonstrated that it owns many benefits and Utilities like protein source for poultries. It presents/displays many facilities since it is a culture that adapts very well to any type ofclimate and especially to a tropical climate as of our Coast and East, apartfrom which its foliage owns a high protein and very tempting contení for the poultries, cattle and pig. The young of poultries of the chickens of fattening is especially one of most popular in our country according to the numbers given by the SICA in the 2004, and one of the main problems in which to production costs it talks about is its feeding due to the high prices ofthe ingredients. By this different forms lookfor and develop to lower the price ofthese costs and ofobtaining tempting producís ofgood origin and to our animal. One of those forms could be the production of our own protein sources through culture of plañís that have given to good results in other countries and of easy introduction and propagation in our climate and that represents a small investment for our producers. The test lasted 42 days and 4 were evaluatedyou díctate, with 0%, 5%, 10% and 15% offlour of ramio. 250 chickens were used Ross baby of 1 doy in 4 treatments of 5 repetitions each. Thefood was similar to the used one commercially, that is to soy, ramio initial until the 28 days of age and thefmished one until the 42 days. The final result was better, statistically significant with 5% offlour of ramio (treatment 2), as much in weight with 1965,22 grams, like in nutritional conversión 2.37. Product of the greaterfood consumption, 4671,1 grams

    A hybrid ARIMA and artificial neural networks model to forecast particulate matter in urban areas: The case of Temuco, Chile

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    Air quality time series consists of complex linear and non-linear patterns and are difficult to forecast. Box-Jenkins Time Series (ARIMA) and multilinear regression (MLR) models have been applied to air quality forecasting in urban areas, but they have limited accuracy owing to their inability to predict extreme events. Artificial neural networks (ANN) can recognize non-linear patterns that include extremes. A novel hybrid model combining ARIMA and ANN to improve forecast accuracy for an area with limited air quality and meteorological data was applied to Temuco, Chile, where residential wood burning is a major pollution source during cold winters, using surface meteorological and PM10 measurements. Experimental results indicated that the hybrid model can be an effective tool to improve the PM10 forecasting accuracy obtained by either of the models used separately, and compared with a deterministic MLR. The hybrid model was able to capture 100% and 80% of alert and pre-emergency episodes, respectively. This approach demonstrates the potential to be applied to air quality forecasting in other cities and countries

    Synthesis and Characterization of Nanocrystalline ZnO Doped with Al3+ and Ni2+ by a Sol-Gel Method Coupled with Ultrasound Irradiation

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    Zinc oxide is one of the most important semiconducting metal oxides and one of the most promising n-type materials, but its practical use is limited because of both its high thermal conductivity and its low electrical conductivity. Numerous studies have shown that doping with metals in ZnO structures leads to the modification of the band gap energy. In this work, Al-doped ZnO, Ni-doped ZnO, and undoped ZnO nanocrystalline powders were prepared by a sol&-gel method coupled with ultrasound irradiation, and the results show the influence of Al3+ and Ni2+ ions in the ZnO network. The doping concentrations in ZnO of 0.99 atom % for ZnO&-Al and 0.80 atom % for ZnO&-Ni were obtained by X-ray Fluorescence (XRF). X-ray Diffraction (XRD) and Raman Spectroscopy showed a decreased intensity and broadening of main peaks, indicating metallic ions. The crystallite size of the sample was decreased from 24.5 nm (ZnO) to 22.0 nm (ZnO&-Al) and 21 nm (ZnO&-Ni). The textural and morphological properties were analyzed via Nitrogen Adsorption (BET method) and Field Emission Scanning Electron Microscopy (FESEM).The authors of this paper wish to thank Advanced Nanostructured Materials and Applications Network for its support via Secretaría de Educación Pública (SEP)

    Milk production of lacaune sheep with different degrees of crossing with manchega sheep in a commercial flock in Spain

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    The objective of the present study was to evaluate the effect of the grade of crossbreeding (Lacaune x Manchega) and environmental factors on milk production in a commercial flock in Spain. A total of 5769 milk production records of sheep with different degrees of purity of the Lacaune breed crossed with Manchega were used as follows: 100% Lacaune (n = 2960), 7/8 Lacaune (n = 502), 13/16 Lacaune (n = 306), 3/4 (n = 1288), 5/8 Lacaune (n = 441) and 1/2 Lacaune: Manchega (n = 272). Additional available information included the number of parity (1 to 8), litter size (single or multiple), and the season of the year of lambing (spring, summer, autumn and winter). A mixed model was used to evaluate the level of crossbreeding and environmental factors on milk production. The 100% Lacaune sheep presented the highest milk production with respect to the F1 Lacaune x Manchega sheep (p < 0.01), showing that as the degree of gene absorption increases with the Manchega breed, it presents lower milk yield. The 100%, 13/16, and 3/4 Lacaune genotypes had the highest milk yields with respect to the 1/2 Lacaune/Manchega breed (p < 0.001). The Lacaune registered on average 181.1 L in a period adjusted to 160 days of lactation (1.13 L/ day). Likewise, the parity number, litter size, and season of lambing effects showed significant differences (p < 0.01). It was concluded that 13/16 and 3/4 Lacaune/Manchega ewes presented the highest milk yields with respect to the other crosses

    Proyecto eMadrid: metodologías educativas, ludificación y calidad

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    Esta comunicación presenta un conjunto de trabajos de investigación sobre metodologías docentes, ludificación y calidad realizados en el seno del proyecto eMadrid, de la Comunidad Autónoma de Madrid. En primer lugar se resumen los trabajos realizados en los dos primeros años del proyecto. Posteriormente se presentan las líneas de trabajo previstas para los dos años restantesEstos trabajos se han financiado parcialmente por el proyecto eMadrid (S2013/ICE-2715) de la Comunidad de Madrid, los proyectos FLEXOR (TIN2014-52129-R), RESET (TIN2014-53199-C3-1-R) e iProg (TIN2015-66731-C2-1-R) del Ministerio de Economía y Competitividad, y el proyecto “Adaptación de la metodología PhyMEL a la formación clínica mediante el uso de simuladores” financiado por la empresa Medical Simulato

    Integrative Oncogenomic Analysis of Microarray Data in Hematologic Malignancies

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    During the last decade, gene expression microarrays and array-based comparative genomic hybridization (array-CGH) have unraveled the complexity of human tumor genomes more precisely and comprehensively than ever before. More recently, the simultaneous assessment of global changes in messenger RNA (mRNA) expression and in DNA copy number through "integrative oncogenomic" analyses has allowed researchers the access to results uncovered through the analysis of one-dimensional data sets, thus accelerating cancer gene discovery. In this chapter, we discuss the major contributions of DNA microarrays to the study of hematological malignancies, focusing on the integrative oncogenomic approaches that correlate genomic and transcriptomic data. We also present the basic aspects of these methodologies and their present and future application in clinical oncology

    Hypoalbuminemia in the outcome of patients with non-variceal upper gastrointestinal bleeding

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    AbstractIntroduction and aimThe role of serum albumin level in patients with non-variceal upper gastrointestinal bleeding (NVUGB) has not been extensively studied. Our aim was to evaluate the role of serum albumin on admission in terms of in-hospital mortality in patients with NVUGB.Materials and methodsPatients admitted with NVUGB during a 4-year period were prospectively included. Demographic, clinical, and laboratory data were collected. ROC curve analysis was used to determine the cutoff value for serum albumin on admission that made a distinction between deceased patients and survivors with respect to serum albumin on admission, as well as its overall performance compared with the Rockall score.Results185 patients with NVUGB were evaluated. Men predominated (56.7%) and a mean age of 59.1±19.9 years was found. Mean serum albumin on admission was 2.9±0.9g/dl with hypoalbuminemia (< 3.5g/dl) detected on admission in 71.4% of cases. The ROC curve found that the best value for predicting hospital mortality was an albumin level of 3.1g/dl (AUROC 0.738). Mortality in patients with albumin ≥ 3.2g/dl was 1.2% compared with 11.2% in patients with albumin<3.2g/dl (P=.009; OR 9.7, 95%CI 1.2-76.5). There was no difference in overall performance between the albumin level (AUORC 0.738) and the Rockall score (AUROC 0.715) for identifying mortality.ConclusionsPatients with hypoalbuminemia presenting with NVUGB have a greater in-hospital mortality rate. The serum albumin level and the Rockall score perform equally in regard to identifying the mortality rate

    Vulnerability and resilience of high-mountain pine forests of the Gredos range (Ávila, Spanish Central System): two thousand years of socio-ecological dynamics

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    RESUMEN: En este trabajo se presenta el análisis palinológico de la turbera de Pozo de la Nieve, localizada en el Parque Natural del Valle de Iruelas (Ávila), un área de alto valor sociocultural dentro de la Sierra de Gredos (Sistema Central). Con el objetivo de relacionar los cambios en el paisaje con la explotación de los recursos naturales y eventos climáticos, en primer lugar se han realizado 7 dataciones radiocarbónicas que sitúan el inicio del registro sedimentario ca. 240 cal BC. Los datos polínicos indican la existencia de un denso pinar altimontano dominado por Pinus sylvestris/nigra desde la Segunda Edad de Hierro hasta el periodo islámico. A partir del periodo cristiano las actividades antrópicas se intensifican, especialmente la ganadería en la Edad Contemporánea, lo cual conlleva la progresiva desaparición del pinar de alta montaña y el desarrollo de pastizales mediante el manejo del fuego, situación que culmina con el desarrollo del paisaje actual dominado por piornales pirófilos.ABSTRACT: We present the palynological study of Pozo de la Nieve peat bog, located in a very valuable socio-cultural placement within the Iruelas Valley Natural Park (Gredos range, Iberian Central System). We have focused in relating landscape changes to natural resources management and climatic events. Firstly, we carried out seven radiocarbon dates suggesting the origin of this record ca. 240 cal BC. The palynological data show the existence of dense high-mountain pine woodlands dominated by Pinus sylvestris/nigra from the Late Iron Age to the Muslim period. Later, from the Christian period, anthropogenic activities have intensified, especially livestock grazing in the Contemporary Age. Its consequences are the progressive disappearance of highmountain pine forests and the extension of grasslands by means of fire, which has shaped current landscape dominated by broom communities.Este trabajo ha sido financiado por el proyecto Desirè-HAR2013-43701-P (Plan Nacional I+D+I, Ministerio de Economía y Competitividad de España). Sebastián Pérez Díaz está financiado por el Programa Estatal de Promoción del Talento y su Empleabilidad en I+D+i en la modalidad Juan de la Cierva-Incorporación. Mónica Ruiz Alonso está financiada por el Programa Estatal de Promoción del Talento y su Empleabilidad en I+D+i en la modalidad Juan de la Cierva-Formación

    Interaction potential between dynamic dipoles: polarized excitons in strong magnetic fields

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    The interaction potential of a two-dimensional system of excitons with spatially separated electron-hole layers is considered in the strong magnetic field limit. The excitons are assumed to have free dynamics in the xx-yy plane, while being constrained or `polarized' in the zz direction. The model simulates semiconductor double layer systems under strong magnetic field normal to the layers. The {\em residual} interaction between excitons exhibits interesting features, arising from the coupling of the center-of-mass and internal degrees of freedom of the exciton in the magnetic field. This coupling induces a dynamical dipole moment proportional to the center-of-mass magnetic moment of the exciton. We show the explicit dependence of the inter-exciton potential matrix elements, and discuss the underlying physics. The unusual features of the interaction potential would be reflected in the collective response and non-equilibrium properties of such system.Comment: REVTEX - 11 pages - 1 fi
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