X-ray emission from thin plasmas. Collisional ionization for atoms and ions of H to Zn

Every observation of astrophysical objects involving a spectrum requires atomic data for the interpretation of line fluxes, line ratios and ionization state of the emitting plasma. One of the processes which determines it is collisional ionization. In this study an update of the direct ionization (DI) and excitation-autoionization (EA) processes is discussed for the H to Zn-like isoelectronic sequences. In the last years new laboratory measurements and theoretical calculations of ionization cross sections have become available. We provide an extension and update of previous published reviews in the literature. We include the most recent experimental measurements and fit the cross sections of all individual shells of all ions from H to Zn. These data are described using an extension of Younger's and Mewe's formula, suitable for integration over a Maxwellian velocity distribution to derive the subshell ionization rate coefficients. These ionization rate coefficients are incorporated in the high-resolution plasma code and spectral fitting tool SPEX V3.0.Comment: Accepted for publication in A&A, 22 pages, 18 figure

Improvements in cytological preparations for fluorescent in situ hybridization in Passiflora

Cytological preparations for the fluorescent in situ hybridization (FISH) technique require cytoplasm-free metaphases, with well-spread chromosomes, for the localization of DNA sequences and chromosome mapping. We tested various procedures for FISH analysis of Passiflora cacaoensis, P. gardneri and hybrid F₁ progeny of P. gardneri x P. gibertii. Two treatments with four enzymes and three incubation times were compared. The material was treated with 1.0 M HCl before enzymatic digestion. The following criteria were used to determine the quality of the metaphases: a) lack or presence of cytoplasm; b) well-spread chromosomes or with overlap; c) complete or incomplete chromosome number (2n). The enzyme Pectinex(®) SP ULTRA gave the best performance, with the shortest incubation time. The best results were observed after 30 min of incubation; more than 70% of the metaphases did not have large amounts of cytoplasm or overlapping chromosomes, and about 75% maintained the chromosome number. FISH was carried out using a 45S rDNA probe (pTa71) labeled with biotin and detected with fluorescein isothiocyanate. Sites with strong staining and without nonspecific signals were observed. Our methodological adaptations allowed the preparation of metaphase slides of high quality for the FISH technique, with less time required for the preparation of samples.Fil: Souza, M. M.. Universidade Estadual de Santa Cruz. Departamento de Ciências Biológicas; BrasilFil: Urdampilleta, Juan Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinar de Biología Vegetal (p). Grupo Vinculado Centro de Relevamiento y Evaluacion de Recursos Agricolas y Naturales; ArgentinaFil: Forni Martins, E. R.. Universidade Estadual de Campinas. Instituto de Biologia. Departamento de Biologia Vegetal; Brasi

Charge dynamics and spin blockade in a hybrid double quantum dot in silicon

Electron spin qubits in silicon, whether in quantum dots or in donor atoms, have long been considered attractive qubits for the implementation of a quantum computer due to the semiconductor vacuum character of silicon and its compatibility with the microelectronics industry. While donor electron spins in silicon provide extremely long coherence times and access to the nuclear spin via the hyperfine interaction, quantum dots have the complementary advantages of fast electrical operations, tunability and scalability. Here we present an approach to a novel hybrid double quantum dot by coupling a donor to a lithographically patterned artificial atom. Using gate-based rf reflectometry, we probe the charge stability of this double quantum dot system and the variation of quantum capacitance at the interdot charge transition. Using microwave spectroscopy, we find a tunnel coupling of 2.7 GHz and characterise the charge dynamics, which reveals a charge T2* of 200 ps and a relaxation time T1 of 100 ns. Additionally, we demonstrate spin blockade at the inderdot transition, opening up the possibility to operate this coupled system as a singlet-triplet qubit or to transfer a coherent spin state between the quantum dot and the donor electron and nucleus.Comment: 6 pages, 4 figures, supplementary information (3 pages, 4 figures

Physical rehabilitation in football by mechanical vibration and hypoxia

Las acciones explosivas en el fútbol se triplican respecto a los años 60, llegando a las 200-215 acciones explosivas/partido. Esto supone que la potencia muscular y la capacidad de recuperación sean factores limitantes, pudiendo ser frecuentes las lesiones musculares. Durante la lesión se pierden las cualidades condicionales, menos cuanto más corto sea este periodo. Existen diversos métodos para la mejora de la fuerza y capacidad de recuperación mediante las plataformas vibratorias y la hipoxia intermitente (HI). Mostramos resultados de una intervención con plataforma vibratoria y HI en futbolistas convalescientes de una rotura fibrilar. Este nuevo modelo de entrenamiento puede permitir mejoras la fuerza máxima (p<0,05) y capacidadde recuperación (p<0,05) ayudando en gran medida a no perder las cualidades condicionales.Explosive actions in football are three times over 60 years, reaching 200-215 explosive actions /match. This means that for an elite player, muscular power and resilience are performance limiting factors, which may be frequent muscular injuries. During the injury, conditional qualities are lost, the less the shorter the period. There are several methods for improving the strength and resilience, emphasizing the body vibration training and intermittent hypoxia (IH). In this study, results of an intervention HI vibrating platform and players who have been convalescing from a hamstring injury are shown. The results obtained suggest that this new training model allows for improvements in the levels of maximum force (p <0.05) and resilience (p <0.05). This helps keep the conditional qualities greatly

Hidratación e ingredientes químicos en el deporte: seguridad alimentaria en el contexto europeo

Before, during and after physical activity, hydration is a limiting factor in athletic performance. Therefore, adequate hydration provides benefits for health and performance of athletes. Besides, hydration is associated to the intake of carbohydrates, protein, sodium, caffeine and other substances by different dietary aids, during the training and/or competition by athletes. These requirements have led to the development of different products by the food industry, to cover the nutritional needs of athletes. Currently in the European context, the legal framework for the development of products, substances and health claims concerning to sport products is incomplete and scarce. Under these conditions, there are many products with different ingredients out of European Food Safety Authority (EFSA) control where claims are wrong due to no robust scientific evidence and it can be dangerous for the health. Further scientific evidence should be constructed by new clinical trials in order to assist to the Experts Commitees at EFSA for obtaining robust scientific opinions concerning to the functional foods and the individual ingredients for sport population.Antes, durante y después de la actividad física, la hidratación es un factor limitante en el rendimiento deportivo. Por lo tanto, una adecuada hidratación proporciona beneficios para la salud y el rendimiento de los deportista. Además, la hidratación se asocia a la ingesta de hidratos de carbono, proteínas, sodio, cafeína y otras sustancias durante el entrenamiento y/o competición de los deportistas. Estos requisitos han llevado al desarrollo de diferentes productos por parte de la industria alimentaria, para cubrir las necesidades nutricionales de los deportistas. Actualmente en el contexto europeo, el marco legal para el desarrollo de productos, sustancias y declaraciones nutricionales y de propiedades saludables relativas a productos deportivos, es incompleta y escasa. Hay muchos productos con diferentes ingredientes controlados por la Agencia Europea de Seguridad Alimentaria (EFSA), los cuales poseen declaraciones nutricionales y de propiedades saludables erróneas, debido a la falta o escasa evidencia científica, resultado peligroso para la salud. Se necesita mayor evidencia científica obtenida a través de nuevos ensayos clínicos con el fin de ayudar a los Comités de expertos de la EFSA para la obtención de dictámenes científicos sólidos relativos a los alimentos funcionales y los ingredientes individuales para la población deportiva.AGI and SM are grateful to the National funding agencies, through the Projects AGL2011-23690 (CICYT), CSD007-0063 (CONSOLIDER-INGENIO 2010 ‘Fun-C-Food’), and Consejo Superior de Investigaciones Científicas (CSIC) 201170E041, to the Spanish Ministry of Economy and Competitiveness, and for the support of the Fundación Séneca – Comunidad Autónoma de la Región de Murcia ‘Group of Excellence in Research’ 04486/GERM/06. Sonia Medina Escudero is appointed under a CSIC research contract

Intervención dietético-nutricional en la prevención de la deficiencia de hierro

En este artículo se expone evidencia científica sobre la anemia ferropénica fundamentalmente desde aspectos dietético-nutricionales que inciden en la biodisponibilidad del hierro de los alimentos. La anemia constituye un problema de salud pública a nivel mundial, padeciéndolo aproximadamente 2000 millones de personas y afectando fundamentalmente a lactantes, ancianos, adolescentes, mujeres en edad fértil y embarazadas. Como consecuencia de esta enfermedad, la capacidad para realizar trabajo físico, la inmunidad celular y la capacidad bactericida de los neutrófilos se ven sensiblemente alteradas. Además, la anemia puede producir: mayor susceptibilidad a infecciones, especialmente, del tracto respiratorio, disminución de la termogénesis en ambientes fríos, alteraciones funcionales del tubo digestivo, fallo en la movilización de la vitamina A hepática, disminución de la velocidad de crecimiento, alteraciones en el desarrollo mental y motor, menor transferencia de hierro al feto, mayor riesgo de parto prematuro o morbilidad perinatal, entre otras. Dentro de los factores que interfieren en la absorción del hierro, los dietéticos son de gran relevancia. Las proteínas cárnicas, ácidos orgánicos, la vitamina C y la A y los fructooligosacáridos (FOS), favorecen su absorción mientras que ciertas proteínas del huevo y de la leche, polifenoles, fitatos, fibra insoluble y minerales como el fósforo, calcio o el zinc, afectan negativamente a la biodisponibilidad del hierro. Las diferentes técnicas culinarias también pueden aumentar o disminuir la biodisponibilidad del hierro. La información recopilada sobre los factores favorecedores e inhibidores de la absorción del hierro, se ha utilizado para, a modo de conclusión, marcar unas pautas dietético-nutricionales para las personas que padecen o tienen predisposición a padecer anemia.This paper outlines the scientific evidence of iron deficiency anemia from dietary and nutritional issues that affect iron-bioavailability from food. Anemia is a worldwide public health problem, with about 2000 million people who suffer from it and mainly affects older infants, adolescents, women of childbearing age and pregnant women. As a consequence of this disease, alterations have been reported: in physical work capacity, cellular immunity and bactericidal capacity of neutrophils. Further more, an increased susceptibility to infections, specially respiratory tract, decreased thermogenesis in cold environments , functional disorders of the gastrointestinal tract, failure in the mobilization of liver vitamin A, decreased growth rate, impaired mental and motor development, less transfer of iron to the fetus, increased risk of preterm delivery, perinatal morbidity, and others. Among the factors that interfere with iron absorption, the diet is one of the most important. Meat proteins, organic acids, vitamin C and A and fructooligosaccharides (FOS), promote the absorption. While egg, milk proteins, polyphenols, phytates, fiber and minerals such as phosphorus, calcium or zinc affect negatively the ironbioavailability. The information collected about the stimulating factors and inhibitors of iron absorption has been used to, as a conclusion, make dietary and nutritional guidelines for those who are predisposed to suffer from anemia

FeCoCp3 Molecular Magnets as Spin Filters

Metallorganic molecules have been proposed as excellent spin filters in molecular spintronics because of the large spin-polarization of their electronic structure. However, most of the studies involving spin transport, have disregarded fundamental aspects such as the magnetic anisotropy of the molecule and the excitation of spin-flip processes during electron transport. Here, we study a molecule containing a Co and an Fe atoms stacked between three cyclopentadienyl rings that presents a large magnetic anisotropy and a S=1. These figures are superior to other molecules with the same transition metal, and improves the spin-filtering capacities of the molecule. Non-equilibrium Green's functions calculations based on density functional theory predict excellent spin-filtering properties both in tunnel and contact transport regimes. However, exciting the first magnetic state drastically reduces the current's spin polarization. Furthermore, a difference of temperature between electrodes leads to strong thermoelectric effects that also suppress spin polarization. Our study shows that in-principle good molecular candidates for spintronics need to be confronted with inelastic and thermoelectric effects

Science with hot astrophysical plasmas

We present some recent highlights and prospects for the study of hot astrophysical plasmas. Hot plasmas can be studied primarily through their X-ray emission and absorption. Most astrophysical objects, from solar system objects to the largest scale structures of the Universe, contain hot gas. In general we can distinguish collisionally ionised gas and photoionised gas. We introduce several examples of both classes and show where the frontiers of this research in astrophysics can be found. We put this also in the context of the current and future generation of X-ray spectroscopy satellites. The data coming from these missions challenge the models that we have for the calculation of the X-ray spectra