Thermal nucleation of cavities in liquid helium at negative pressures

We have investigated the nucleation rate at which cavities are formed in 4He and 3He at negative pressures due to thermal fluctuations. To this end, we have used a density functional that reproduces the He liquid-gas interface along the coexistence line. The inclusion of thermal effects in the calculation of the barrier against nucleation results in a sizable decrease of the absolute value of the tensile strength above 1.5 K.

Comparative genomics of the vertebrate insulin/TOR signal transduction pathway: A network-level analysis of selective pressures

Complexity of biological function relies on large networks of interacting molecules. However, the evolutionary properties of these networks are not fully understood. It has been shown that selective pressures depend on the position of genes in the network. We have previously shown that in the Drosophila insulin/target of rapamycin (TOR) signal transduction pathway there is a correlation between the pathway position and the strength of purifying selection, with the downstream genes being most constrained. In this study, we investigated the evolutionary dynamics of this well-characterized pathway in vertebrates. More specifically, we determined the impact of natural selection on the evolution of 72 genes of this pathway. We found that in vertebrates there is a similar gradient of selective constraint in the insulin/TOR pathway to that found in Drosophila. This feature is neither the result of a polarity in the impact of positive selection nor of a series of factors affecting selective constraint levels (gene expression level and breadth, codon bias, protein length, and connectivity). We also found that pathway genes encoding physically interacting proteins tend to evolve under similar selective constraints. The results indicate that the architecture of the vertebrate insulin/TOR pathway constrains the molecular evolution of its components. Therefore, the polarity detected in Drosophila is neither specific nor incidental of this genus. Hence, although the underlying biological mechanisms remain unclear, these may be similar in both vertebrates and Drosophila.

Tratamiento de la hiperhidrosis plantar con toxina butolínica tipo A

El problema de hiperhidrosis afecta al 0,5% de la población, y puede causar considerable estrés emocional, dificultando en ocasiones la vida personal, laboral y social del paciente, llevándole, por ejemplo, a evitar un acto como dar la mano o quitarse los zapatos en público. Por otra parte, el excesivo sudor puede ocasionar maceración cutánea, acrocianosis, queratoderma e incluso deshidratación. La forma más frecuente de hiperhidrosis es la idiopática y en el 60% de los casos afecta a palmas y plantas de los pies. En este artículo presentamos la aplicación del tratamiento con la toxina butolínica tipo A.

Soporte plantar ergonómico

Los autores exponen la metodología de confección y las indicaciones terapéuticas del soporte plantar ergonómico de Tomás Céspedes. La experiencia en la aplicación de este soporte, alcanza los casi diez años, si bien se han efectuado diversas modificaciones, tanto en el diseño como en la utilización de nuevos materiales.

Metodologia de confección de moldes o férula plantar

En la confección de un molde o férula plantar cabe conseguir unos objetivos que repercutirán en el paciente. Este molde debe reunir unas características de funcionalidad para poder adaptar en él un tratamiento ortopodológico eficaz, sea cual sea la alteración biomecánica o estructural existente.

Bases para la aplicación de un soporte plantar en un pie equino varo

Los autores describen el plan de tratamiento ortopodológico para un pie equinovaro. Ofrecen una metodología ordenada, priorizando objetivos y diversas alternativas ortopédicas.

Deformación en flexión plantar del primer radio

La posición del primer radio tanto desde el plano frontal como desde el plano sagital, es de vital importancia para la consecución de una correcta y adecuada marcha, así como para mantener la estructura anatómica del pie durante la bipedestación estática. La deformidad en flexión plantar del primer radio modifica estos parámetros creando mecanismos compensatorios que pueden afectar a otras unidades funcionales articulares, tanto del mediopié como del retropié, lo que puede dar lugar a un patrón de metatarsalgia de difícil valoración al tener que contemplar y analizar varios diagnósticos y sus respectivos patrones mecánicos: el equino de columna lateral, el retropié varo compensado y el primer radio plantarflexionado flexible. Se presenta un caso clínico para su análisis conjunto.

Estudio del proceso evolutivo de la huella plantar

1. Cronología del proceso evolutivo del estudio de la huella plantar. 2. Descripción y análisis de las biometrías del pie realizadas con los diferentes sistemas de obtención de la 1a huella plantar.

Evaluación de la efectividad de las Técnicas de Activación Muscular® en la resolución de la fasciosis plantar en corredores habituales: ensayo clínico aleatorizado.

Pregunta clínica de investigación: ¿es efectiva la Técnica de Activación Muscular® (MAT®) en la resolución de la fasciosis plantar (FP) en personas corredoras habituales? Objetivo: determinar si la terapia combinada mediante ejercicios de MAT® mejora los resultados obtenidos con el procedimiento convencional en el tratamiento de la FP en personas deportistas en la ciudad de Lleida. Metodología: En este ensayo clínico experimental ha participado un total de 264 pacientes, corredores habituales con FP de más de un mes y menos de un año de evolución, que han sido derivados por sus médicos de atención primaria. La muestra se ha dividido de forma aleatoria en dos grupos, uno control que sigue un protocolo convencional (educación sanitaria, AINEs y estiramietos) y el grupo experimental, al que se le ha aplicado la intervención de MAT®. La duración del estudio es de dos años, y cada intervención dura 4 semanas con un seguimiento a 6 y 12 meses. Un analista externo es el encargado del análisis de la información mediante el programa SPSS 15.0. Los resultados se miden mediante las variables de: dolor a la presión, grosor de la aponeurosis, percepción del estado de los pies, rango de movimiento articular (RMA) de tobillo y 1era metetarsofalángica (MTF) y tiempo de vuelta a la carrera entre otras.

Erratum: Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6–4-fold following a before–after control–impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2–77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9–48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure

Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6–4-fold following a before–after control–impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2–77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9–48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure

Economic growth and atmospheric pollution in Spain: discussing the environmental Kuznets curve by hypothesis

The environmental Kuznets curve (EKC) hypothesis posits an inverted U relationship between environmental pressure and per capita income. Recent research has examined this hypothesis for different pollutants in different countries. Despite certain empirical evidence shows that some environmental pressures have diminished in developed countries, the hypothesis could not be generalized to the global relationship between economy and environment at all. In this article we contribute to this debate analyzing the trends of annual emission flux of six atmospheric pollutants in Spain. The study presents evidence that there is not any correlation between higher income level and smaller emissions, except for SO2 whose evolution might be compatible with the EKC hypothesis. The authors argue that the relationship between income level and diverse types of emissions depends on many factors. Thus it cannot be thought that economic growth, by itself, will solve environmental problems.

Income growth and atmospheric pollution in Spain: an input-output approach

The relationships between economic growth and environmental pressures are complex. Since the early nineties, the debate on these relationships has been strongly influenced by the Environmental Kuznets Curve hypothesis, which states that during the first stage of economic development environmental pressures increase as per capita income increases, but once a critical turning-point has been reached these pressures diminish as income levels continue to increase. However, to date such a delinking between economic growth and emission levels has not happened for most atmospheric pollutants in Spain. The aim of this paper is to analyse the relationship between income growth and nine atmospheric pollutants in Spain. In order to obtain empirical outcomes for this analysis, we adopt an input-output approach and use NAMEA data for the nine pollutants. First, we undertake a structural decomposition analysis for the period 1995-2000 to estimate the contribution of various factors to changes in the levels of atmospheric emissions. And second, we estimate the emissions associated with the consumption patterns of different groups of households classified according to their level of expenditure

Effect of high pressure processing on the microbiology of skin-vacuum packaged sliced meat products: cooked pork ham, dry cured pork ham and marinated beef loin

High hydrostatic pressure is being increasingly investigated in food processing. It causes microbial inactivation and therefore extends the shelf life and enhances the safety of food products. Yeasts, molds, and vegetative cells of bacteria can be inactivated by pressures in the range of 200 to 700 MPa. Microorganisms are more or less sensitive to pressure depending on several factors such as type, strain and the phase or state of the cells. In general, Gram-positive organisms are usually more resistant than Gram-negative. High pressure processing modifies the permeability of the cell membrane, the ion exchange and causes changes in morphology and biochemical reactions, protein denaturations and inhibition of genetic mechanisms. High pressure has been used successfully to extend the shelf life of high-acid foods such as refrigerated fruit juices, jellies and jams. There is now an increasing interest in the use of this technology to extend the shelf life of low-acid foods such as different types of meat products.