β-decay half-lives and β-delayed neutron emission probabilities for several isotopes of Au, Hg, Tl, Pb, and Bi, beyond N = 126

Background: There have been measurements on roughly 230 nuclei that are β-delayed neutron emitters. They range from 8 He up to 150La. Apart from 210Tl, with a branching ratio of only 0.007%, no other neutron emitter has been measured beyond A = 150. Therefore, new data are needed, particularly in the region of heavy nuclei around N = 126, in order to guide theoretical models and help understand the formation of the third r-process peak at A ∼ 195. Purpose: To measure both β-decay half-lives and neutron branching ratios of several neutron-rich Au, Hg, Tl, Pb, and Bi isotopes beyond N = 126. Method: Ions of interest were produced by fragmentation of a 238U beam, selected and identified via the GSI-FRS fragment separator. A stack of segmented silicon detectors (SIMBA) was used to measure ion implants and β decays. An array of 30 3 He tubes embedded in a polyethylene matrix (BELEN) was used to detect neutrons with high efficiency and selectivity. A self-triggered digital system is employed to acquire data and to enable time correlations. The latter were analyzed with an analytical model and results for the half-lives and neutron-branching ratios were derived by using the binned maximum-likelihood method. Results: Twenty new β-decay half-lives are reported for 204−206Au, 208–211Hg, 211–216Tl, 215–218Pb, and 218–220Bi, nine of them for the first time. Neutron emission probabilities are reported for 210,211Hg and 211–216Tl. Conclusions: The new β-decay half-lives are in good agreement with previous measurements on nuclei in this region. The measured neutron emission probabilities are comparable to or smaller than values predicted by global models such as relativistic Hartree Bogoliubov plus the relativistic quasi-particle random phase approximation (RHB + RQRPA).Spanish Ministerio de Economía y Competitividad-FPA2011- 28770-C03-03, FPA2008-04972-C03-3, AIC-D2011-0705, FPA2011-24553, FPA2008-6419, FPA2010-17142, FPA2014-52823-C2-1-P, FPA2014- 52823-C2-2-P, and CPAN CSD-2007-00042 (Ingenio2010)Program Severo Ochoa-SEV-2014-0398German Helmholtz Association (Young Investigators)-VH-NG 627 (LISA-Lifetime Spectroscopy for Astrophysics)Nuclear Astrophysics Virtual Institute-VH-VI-417German Bundesministerium für Bildung und Forschung-06MT7178 / 05P12WOFNFSpanish Nuclear Security Council (CSN)-Catedra ArgosUK Science & Technology Facilities Council (STFC)-ST/F012012/

Analysis and results of the 104Sn Coulomb excitation experiment

G. Guastalla, et al. XX International School on Nuclear Physics, Neutron Physics and Applications (Varna 2013); 5 pags.; 1 fig.The analysis of the Coulomb excitation experiment conducted on 104Sn required a strict selection of the data in order to reduce the large background present in the γ-ray energy spectra and identify the γ-ray peak corresponding to the Coulomb excitation events. As a result the B(E2; 0+ →2+) value could be extracted, which established the downward trend towards 100Sn and therefore the robustness of the N=Z=50 core against quadrupole excitations. Published under licence by IOP Publishing LtdA. J. would like to thank the Spanish Ministerio de Ciencia e Innovacion for financial support under Contract No. FPA2011-29854- C04Peer Reviewe

Modelo liviano de medidas para evaluar la mejora de procesos de desarrollo de software MLM-PDS

Companies in software development in Colombia face a number of problems such as the construction of software in a artesian, empirical and disorganized way. Therefore, it is necessary for these companies to implement projects to improve their development processes, because ensure the quality of products, by improving their software processes, is a step that should give to be able to compete in the market. To implement process improvement models, it is not enough to say whether a company is actually getting benefits, definitely one of the first actions in a to improvement project is to be able to determine the current status of the process. Only by measuring it is possible to know the state of a process in an objective ay, and only through this it is possible to plan strategies and solutions, about improvements to make, depending on the objectives of the organization. This paper proposes a light model to assess software development process, which seeks to help the Colombian software development companies to determine whether the process of implementing improvements, being effective in achieving the objectives and goals set to implement this, through the use of measures to evaluate the process of improving their development processes, allowing characterize the current practices of the company, identifying weaknesses, strengths and abilities of the processes that are carried out within this and thus control or prevent the causes of low quality, or deviations in costs or planning.MSC: 68Uxx, 68NxxLas empresas de desarrollo de software en Colombia enfrentan una serie de problemas tales como la construcción de software de forma artesanal, empírica y desorganizada. Por esto, es necesario que implementen proyectos para mejorar sus procesos de desarrollo, ya que asegurar la calidad de los productos,a través de la mejora de sus procesos de software, es un paso que deben dar para estar en condiciones de competir en el mercado nacional e internacional. Implementar modelos de mejora de procesos no es suficiente para decir siuna empresa realmente está obteniendo beneficios, definitivamente una de las primeras acciones en un proyecto de mejora es el poder determinar el estadoactual del proceso. Sólo midiendo es posible conocer el estado de un proceso de manera objetiva, y sólo gracias a esto se pueden planificar estrategias y soluciones acerca delas mejoras a realizar y según los objetivos de la organización. Este artículo propone un modelo liviano de medidas para evaluar un proyecto de mejora deprocesos de software, con el cual se busca ayudar a las empresas de desarrollode software colombianas a determinar si el proceso de mejora que implementan está siendo eficaz con relación a los objetivos y metas establecidas al inicio del proyecto. Esto se lleva a cabo a través del uso de medidas que permiten evaluar el proceso de mejora de sus procesos, facilitando la caracterizaciónde las prácticas actuales de la empresa y la identificación de las debilidades, fortalezas y habilidades de los procesos que son llevados a cabo dentro de ésta, permitiendo controlar y evitar las causas de baja calidad y desviaciones encostos o en planificación.MSC: 68Uxx, 68Nx

Modelo liviano de medidas para evaluar la mejora de procesos de desarrollo de software MLM-PDS

Software development companies in Colombia face a series of problems such as building software in an artisanal, empirical and disorganized way. For this reason, it is necessary that they implement projects to improve their development processes, since ensuring the quality of the products, through the improvement of their software processes, is a step that they must take to be in a position to compete in the market National and international. Implementing process improvement models is not enough to say if a company is really making a profit, definitely one of the first actions in an improvement project is to determine the current status of the process. Only by measuring it is possible to know the status of a process objectively, and only thanks to this can strategies and solutions be planned about the improvements to be made and according to the objectives of the organization. This article proposes a lightweight model of measures to evaluate a software process improvement project, which seeks to help Colombian software development companies determine if the improvement process they are implementing is being effective in relation to the objectives and goals established at the beginning of the project. This is carried out through the use of measures that allow to evaluate the process of improvement of its processes, facilitating the characterization of the current practices of the company and the identification of the weaknesses, strengths and abilities of the processes that are carried out within of this, allowing to control and avoid the causes of low quality and deviations encostos or in planning.Las empresas de desarrollo de software en Colombia enfrentan una serie de problemas tales como la construcción de software de forma artesanal, empírica y desorganizada. Por esto, es necesario que implementen proyectos para mejorar sus procesos de desarrollo, ya que asegurar la calidad de los productos,a través de la mejora de sus procesos de software, es un paso que deben dar para estar en condiciones de competir en el mercado nacional e internacional. Implementar modelos de mejora de procesos no es suficiente para decir siuna empresa realmente está obteniendo beneficios, definitivamente una de las primeras acciones en un proyecto de mejora es el poder determinar el estadoactual del proceso. Sólo midiendo es posible conocer el estado de un proceso de manera objetiva, y sólo gracias a esto se pueden planificar estrategias y soluciones acerca delas mejoras a realizar y según los objetivos de la organización. Este artículo propone un modelo liviano de medidas para evaluar un proyecto de mejora deprocesos de software, con el cual se busca ayudar a las empresas de desarrollode software colombianas a determinar si el proceso de mejora que implementan está siendo eficaz con relación a los objetivos y metas establecidas al inicio del proyecto. Esto se lleva a cabo a través del uso de medidas que permiten evaluar el proceso de mejora de sus procesos, facilitando la caracterizaciónde las prácticas actuales de la empresa y la identificación de las debilidades, fortalezas y habilidades de los procesos que son llevados a cabo dentro de ésta, permitiendo controlar y evitar las causas de baja calidad y desviaciones encostos o en planificación

Strain-induced coupling of electrical polarization and structural defects in SrMnO3 films

Letter.-- et al.Local perturbations in complex oxides, such as domain walls, strain and defects, are of interest because they can modify the conduction or the dielectric and magnetic response, and can even promote phase transitions. Here, we show that the interaction between different types of local perturbations in oxide thin films is an additional source of functionality. Taking SrMnO 3 as a model system, we use nonlinear optics to verify the theoretical prediction that strain induces a polar phase, and apply density functional theory to show that strain simultaneously increases the concentration of oxygen vacancies. These vacancies couple to the polar domain walls, where they establish an electrostatic barrier to electron migration. The result is a state with locally structured room-temperature conductivity consisting of conducting nanosized polar domains encased by insulating domain boundaries, which we resolve using scanning probe microscopy. Our 'nanocapacitor' domains can be individually charged, suggesting stable capacitance nanobits with a potential for information storage technology.M.F., D.M. and M.L. acknowledge funding from grant ‘ETH-06 12-2’ and from SNF proposal no. 200021-149192. The authors acknowledge funding through the SNF R’equip Program (no. 206021-144988). Financial support from Spanish Ministerio de Economía y Competitividad through projects MAT2011-27553-C02, MAT2012-38213-C02-01, MAT2014-51982-C2 and from Regional Gobierno de Aragón through project E26 is acknowledged.Peer Reviewe

Nature of antiferromagnetic order in epitaxially strained multiferroic SrMnO3 thin films

et al.Epitaxial films of SrMnO3 and bilayers of SrMnO3/La0.67Sr0.33MnO3 have been deposited by pulsed laser deposition on different substrates, namely, LaAlO3 (001), (LaAlO3)0.3(Sr2AlTaO6)0.7 (001), and SrTiO3 (001), allowing us to perform an exhaustive study of the dependence of antiferromagnetic order and exchange bias field on epitaxial strain. The Néel temperatures (TN) of the SrMnO3 films have been determined by low-energy muon spin spectroscopy. In agreement with theoretical predictions, TN is reduced as the epitaxial strain increases. From the comparison with first-principles calculations, a crossover from G-type to C-type antiferromagnetic orders is proposed at a critical tensile strain of around 1.6±0.1%. The exchange bias (coercive) field, obtained for the bilayers, increases (decreases) by increasing the epitaxial strain in the SrMnO3 layer, following an exponential dependence with temperature. Our experimental results can be explained by the existence of a spin-glass (SG) state at the interface between the SrMnO3 and La0.67Sr0.33MnO3 films. This SG state is due to the competition between the different exchange interactions present in the bilayer and favored by increasing the strain in the SrMnO3 layer.This work was supported by the Spanish Ministerio de Economía y Competitividad through Project Nos. MAT2011-28532-C03-02, MAT2011-27553-C02, MAT2012- 38213-C02-01, and MAT2014-51982-C2 including FEDER funding, by the Aragon Regional Government through projects E26 and CTPP4/11 and by the European Union under the Seventh Framework Programme under a contract for an Integrated Infrastructure Initiative Reference 312483-ESTEEM2. N. Marcano acknowledges the support of the Centro Universitario de la Defensa en Zaragoza (through Project 2013-03).Peer Reviewe

Integración de técnicas de usabilidad y accesibilidad en el proceso de desarrollo de software de las mipymes

El creciente uso de productos usables y accesibles, ha transformado la forma de desarrollar software. Estos aspectos hacen par te del Diseño centrado en el Usuario DCU, como guía par a mejorar la calidad de vida, lograr un mejor entendimiento, ampliar el mercado e incrementar la satisfacción del cliente. A pesar de esto, la importancia del DCU dentro del proceso de desarrollo de software solo se considera como un atributo final del producto y no como un elemento inherente e incluyente durante el transcurso del desarrollo. Esta ausencia de aplicación se presenta aun más en los procesos de desarrollo de las micro, pequeñas y medianas empresas productor as de software MiPyMEs PS, que algunas veces no cuentan con un proceso bien definido. La utilización de técnicas de usabilidad y accesibilidad se puede ver reflejado en beneficios de tiempo, costo y calidad, ejes centrales en la continuidad y prosperidad del los objetivos del negocio. Este tr abajo, aún en desarrollo, muestra los principios básicos del DCU junto con el papel que puede jugar en el éxito de un producto al incluir lo en el proceso de desarrollo de software

Is the association between health-related quality of life and fatigue mediated by depression in patients with multiple sclerosis? A Spanish cross-sectional study

OBJECTIVES: To determine the mediating effects of depression on health-related quality of life and fatigue in individuals with multiple sclerosis (MS). DESIGN: A cross-sectional study. SETTING: Tertiary urban hospital. PARTICIPANTS: One hundred and eight patients (54% women) with MS participated in this study. OUTCOME MEASURES: Demographic and clinical data (weight, height, medication and neurological impairment), fatigue (Fatigue Impact Scale), depression (Beck Depression Inventory-II) and health-related quality of life (Short-Form Health Survey 36) were collected. RESULTS: Fatigue was significantly associated with bodily pain, physical function, mental health and depression. Depression was associated with bodily pain and mental health. The path analysis found direct effects from physical function, bodily pain and depression to fatigue (all, P<0.01). The path model analysis revealed that depression exerted a mediator effect from bodily pain to fatigue (B=-0.04, P<0.01), and from mental health to fatigue (B=-0.16, P<0.01). The amount of fatigue explained by all predictors in the path model was 37%. CONCLUSIONS: This study found that depression mediates the relationship between some health-related quality of life domains and fatigue in people with MS. Future longitudinal studies focusing on proper management of depressive symptoms in individuals with MS will help determine the clinical implications of these finding

Gender differences in variables associated with sleep quality in chronic tension type headache

We aimed to evaluate gender differences in the relationships between headache features, sleep quality, anxiety, depressive symptoms, and burden of headache in 193 patients (73 percent women) with chronic tension type headache (CTTH). Sleep quality was assessed with the Pittsburgh Sleep Quality Index. Headache features were collected with a four-week diary. The Hospital Anxiety and Depression Scale was used to assess anxiety/depressive symptoms. Headache Disability Inventory was used to evaluate the burden of headache. In men with CTTH, sleep quality was positive correlated with headache frequency (r = 0.310; p = .018), emotional (r = 0.518; p < .001) and physical (r = 0.468; p < .001) burden of headache, and depressive symptoms (r = 0.564; p < .001). In women, positive correlations were observed between sleep quality and headache intensity (r = 0.282; p < .001), headache frequency (r = 0.195; p = .021), emotional burden (r = 0.249; p = .004), and depressive symptoms (r = 0.382; p < .001). The results of stepwise regression analyses revealed that depressive symptoms and emotional burden of headache explained 37.2 percent of the variance in sleep quality in men (p < .001), whereas depressive symptoms and headache intensity explained 17.4 percent of the variance in sleep quality in women (p < .001) with CTTH. Gender differences associated with poor sleep should be considered for proper management of individuals with CTTH

Strained SrMnO3 thin films: engineering multiferroic properties

Resumen del trabajo presentado al "European Congress and Exhibition on Advanced Materials Processes" celebrado en Sevilla (España) del 8 al 13 de septiembre de 2013.-- et al.Multiferroic materials showing simultaneous magnetic and ferroelectric ordering have become the subject of intensive research in recent years. The scarcity of these materials due to the different phenomena responsible for both properties [1], and also, the weak magnetoelectric coupling in most of them force to develop new methods to avoid the excluding mechanisms of ferroelectricity and magnetism. Recent theoretical predictions suggested that epitaxially strained SrMnO3 should become multiferroic [2] by means of the interplay of spins, lattice phonons and strain of the perovskite unit cell. In this system, Mn4+ (d3 ion) is expected to drive both the magnetic order (Mn-O-Mn magnetic superexchange interaction) and the required non-centrosymmetric distortion for ferroelectric order (Mn4+ off-centers from MnO6 octahedra), and therefore a strong magnetoelectric coupling with similar ordering temperatures is expected. Here, we have investigated the effect of epitaxial strain on the structure, electrical and magnetic properties of SrMnO3 (SMO) thin films. Pulsed laser deposition technique was used to grow strained SMO thin films onto different substrates ranging from -1% compressive to 4% tensile mismatch. Coherent cube-on-cube growth is borne out by X-ray diffraction measurements, which also show that under appropriate deposition conditions and substrate selection the perovskite pseudo-cubic phase is stabilized in thin films. The growth of the samples has been monitored by in situ RHEED measurements. Selected films were observed by scanning transmission electron microscopy, which prove the homogeneity and defect-free crystal quality of films. Chemical composition mapping, stoichiometry and 4+ oxidation state of Mn were corroborated by electron energy loss spectroscopy. Nonlinear optics measurements reveal that SMO films, under epitaxial stress, emitt optical second harmonic generation signal, pointing to inversion symmetry being broken (necessary condition for ferroelectricity). Electric measurements were carried out to further investigate the ferroelectric nature of SMO films, thus assessing the possibility of non-d0 cations off-centring.Peer Reviewe