Nutritional ergogenics aspects and drug-food interactions in mountaineering.

Entre los principales factores limitantes del rendimiento en el alpinismo destacan el agotamiento de los depósitos de glucógeno muscular y catabolismo proteico elevado, desequilibrio hidroelectrolítico y Mal Agudo de Montaña (MAM). Ante esta situación de gran estrés que se vive en las altitudes elevadas y en estancias superiores a las 3 semanas, se hace imprescindible una óptima alimentación. Aún así, en ocasiones el MAM en los alpinistas es inevitable y en estos casos se hace uso de fármacos para afrontar dicha situación, que si no se realiza bajo un control riguroso, la suplementación puede poner en peligro la salud del alpinista por las posibles interacciones que se dan con los alimentos o ayudas ergonutricionales ingeridasThe main factors limiting climbing performance are the following: muscle glycogen depletion, increased protein catabolism, fluid and electrolyte imbalance and acute mountain sickness (AMS). In this situation of high stress at high altitudes and at stances longer than 3 weeks, the diet it is essential. In the case of AMS, it is also essential the use of drugs, if it is not used in proper conditions, such supplementation could endanger the health of the mountaineer because of the possible interactions with the food and the nutritional ergogenics aids

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

Pollen quality, meiotic abnormalities and poliploidy inSisyrinchium commutatum (Iridaceae)

O comportamento meiótico de Sisyrinchium commutatum (Iridaceae) foi avaliado e associado com as altas taxas de inviabilidae polínica observada em uma população do sudeste do Brasil. Além disso, pela primeira vez, descreve-se o número cromossômico desta espécie, contribuindo assim para a sistemática do grupo. Alguns aspectos da biologia floral são relatados , como a ocorrência de apresentação secundária de pólen e a ausência de autopolinização espontânea e apomixia para esta espécie. Os resultados do presente trabalho confirmam a ação das anormalidades meióticas como possível mecanismo disruptivo na formação de grãos-de-pólen com consequências ao sucesso reprodutivo na população estudada .The meiotic behaviour of Sisyrinchium commutatum (Iridaceae) was studied and associated to the pollen quality observed in a southeastern population in Brazil. For the first time, the chromosome number is reported for this species (2n = 36). Some traits of floral biology were recorded and secondary pollen presentation as well as the absence of autonomous self-fertilization and apomixy were observed. The results of this study confirm the abnormalities in the meiosis process breaking the pollen grain formation with consequences to reproductive success in the studied population.Fil: Avila Jr., Rubem Samuel de. Universidade Federal do Pampa; BrasilFil: Urdampilleta, Juan Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Gil, A. S. Bragança. Museu Paraense Emílio Goeldi; Argentin

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

Iron abundance distribution in the hot gas of merging galaxy clusters

We present XMM-Newton/EPIC observations of six merging galaxy clusters and study the distributions of their temperature, iron (Fe) abundance and pseudo-entropy along the merging axis. For the first time, we focus simultaneously, and in a comprehensive way, on the chemical and thermodynamic properties of the freshly collided intracluster medium (ICM). The Fe distribution of these clusters along the merging axis is found to be in good agreement with the azimuthally-averaged Fe abundance profile in typical non-cool-core clusters out to $r_{500}$. In addition to showing a moderate central abundance peak, though less pronounced than in relaxed systems, the Fe abundance flattens at large radii towards $\sim$0.2-0.3 $Z_\odot$. Although this shallow metal distribution is in line with the idea that disturbed, non-cool-core clusters originate from the merging of relaxed, cool-core clusters, we find that in some cases, remnants of metal-rich and low entropy cool cores can persist after major mergers. While we obtain a mild anti-correlation between the Fe abundance and the pseudo-entropy in the (lower entropy, $K$ = 200-500 keV cm$^2$) inner regions, no clear correlation is found at (higher entropy, $K$ = 500-2300 keV cm$^2$) outer radii. The apparent spatial abundance uniformity that we find at large radii is difficult to explain through an efficient mixing of freshly injected metals, particularly in systems for which the time since the merger is short. Instead, our results provide important additional evidence in favour of the early enrichment scenario - in which the bulk of the metals are released outside galaxies at $z$ > 2-3 - and extend it from cool-core and (moderate) non-cool-core clusters to a few of the most disturbed merging clusters as well. These results constitute a first step towards a deeper understanding of the chemical history of merging clusters.Comment: Accepted for publication in A&A, 21 pages with 17 figures and 19 table

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

Usefulness of combining intermittent hypoxia and physical exercise in the treatment of obesity

Obesity is an important public health problem worldwide and is a major risk factor for a number of chronic diseases such as type 2 diabetes, adverse cardiovascular events and metabolic syndrome related features. Different treatments have been applied to tackle body fat accumulation and its associated clinical manifestations. Often, relevant weight loss is achieved during the first six months under different dietary treatments. From this point, a plateau is reached, and a gradual recovery of the lost weight may occur. Therefore, new research approaches are being investigated to assure weight maintenance. Pioneering investigations have reported that oxygen variations in organic systems may produce changes in body composition. Possible applications of intermittent hypoxia to promote health and in various pathophysiological states have been reported. The hypoxic stimulus in addition to diet and exercise can be an interesting approach to lose weight, by inducing higher basal noradrenalin levels and other metabolic changes whose mechanisms are still unclear. Indeed, hypoxic situations increase the diameter of arterioles, produce peripheral vasodilatation and decrease arterial blood pressure. Furthermore, hypoxic training increases the activity of glycolytic enzymes, enhancing the number of mitochondria and glucose transporter GLUT-4 levels as well as improving insulin sensitivity. Moreover, hypoxia increases blood serotonin, decreases leptin levels while appetite is suppressed. These observations allow considering the hypothesis that intermittent hypoxia induces fat loss and may ameliorate cardiovascular health, which might be of interest for the treatment of obesity. This new strategy may be useful and practical for clinical applications in obese patients

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