Flow injection determination of readily assimilable nitrogen compounds during vinification

A flow injection method for the determination of readily assimilable nitrogen (r.a.n.), i.e. ammonium and aminated nitrogen, is reported. The difference in pH of the sample in the presence and absence of formaldehyde, which blocks the amino function, provides the value of r.a.n. by monitoring the changes in absorbance of bromothymol blue at 616 nm. The detection and quantification limits are 10 and 11.6 mg l-1, respectively; the reproducibility and repeatability are 3.94 mg l-1 and 1.35 mg l-1, respectively; and the sample throughput is 20 samples h-1. The method has been applied to the analysis of 120 samples of must and wine subjected to biological aging. The proposed method also provides good correlation with the reference method used in routine analysis, and it is faster and gives sufficient precision for wineries requirements

Determination of Arsenic, Mercury and Barium in herbarium mount paper using dynamic ultrasound-assisted extraction prior to atomic fluorescence and absorption spectrometry

A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Flourescence spectrometers as detectors was developed to analyse mercury, arsenic and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimised by a multivariate approach. The optimal conditions were found to be 1% HNO3 extractant solution used at a flow rate of 1 mL min-1. The duty cycle and amplitude of the ultrasonic probe was found to be 50% in both cases with an ultrasound power of 400 W. The optimal distance between the probe and the top face of the extraction chamber was found to be 0 cm. Under these conditions the time required for complete extraction of the three analytes was 25 min. Cold vapour and hydride generation coupled to atomic fluorescence spectrometry was utilized to determine mercury and arsenic, respectively. The chemical and instrumental conditions were optimized to provide detection limits of 0.01ng g-1 and 1.25 ng g-1 for mercury and arsenic, respectively. Barium was determined by graphite-furnace atomic absorption spectrometry, with a detection limit of 25 ng g-1. By using 0.5 g of sample, the concentrations of the target analytes varied for the different types of paper and ranged between 0.4–2.55 µg g-1 for Ba, 0.035–10.47 µg g-1 for As and 0.0046–2.37 µg g-1 for Hg

Stress compensation by gap monolayers for stacked InAs/GaAs quantum dots solar cells

In this work we report the stacking of 10 and 50 InAs quantum dots layers using 2 monolayers of GaP for stress compensation and a stack period of 18 nm on GaAs (001) substrates. Very good structural and optical quality is found in both samples. Vertical alignment of the dots is observed by transmission electron microscopy suggesting the existence of residual stress around them. Photocurrent measurements show light absorption up to 1.2 μm in the nanostructures together with a reduction in the blue response of the device. As a result of the phosphorus incorporation in the barriers, a very high thermal activation energy (431 meV) has also been obtained for the quantum dot emission

Distribución de metales pesados en sedimentos de las marismas del Odiel (Huelva, España)

Se ha analizado la distribución y contenido total de metales pesados (Co, Cu, Fe, Mn, Ni y Pb) en sedimentos de las Marismas del Odiel (SO España). Las concentraciones de estos elementos, obtenidas por espectrofotometría de absorción atómica, fueron muy elevadas para la mayoría de los elementos analizados. Su distribución no es homogénea, ni presenta un patrón geográfico marcadamente definido, pudiéndose encontrar altos niveles repartidos por toda la marisma. Existe cierto gradiente topográfico, con mayores concentraciones en puntos de menor cota. Los puntos de muestreo más aislados de la incidencia mareal y los más expuestos a mar abierto registraron los niveles más bajos.Atomic absorption spectroscopy has permitted the determination of the content of heavy metals and their distribution in sediments of the Odiel Saltmarhes (SWSpain). Avery high metal concentration has been found in most of the samples investigated but their distribution is non-homogeneous and this prevents establishing a geographical pattern. Nevertheless, a certain topographic gradient can be observed: lower levels present the highest concentrations whereas areas unaccessible by tide fluctuations or those exposed to the sea present the lowest index of contamination

The T=1 capsid protein of Penicillium chrysogenum virus is formed by a repeated helix-rich core indicative of gene duplication

et al.Penicillium chrysogenum virus (PcV), a member of the Chrysoviridae family, is a double-stranded RNA (dsRNA) fungal virus with a multipartite genome, with each RNA molecule encapsidated in a separate particle. Chrysoviruses lack an extracellular route and are transmitted during sporogenesis and cell fusion. The PcV capsid, based on a T=1 lattice containing 60 subunits of the 982-amino-acid capsid protein, remains structurally undisturbed throughout the viral cycle, participates in genome metabolism, and isolates the virus genome from host defense mechanisms. Using three-dimensional cryoelectron microscopy, we determined the structure of the PcV virion at 8.0 Å resolution. The capsid protein has a high content of rod-like densities characteristic of α-helices, forming a repeated α-helical core indicative of gene duplication. Whereas the PcV capsid protein has two motifs with the same fold, most dsRNA virus capsid subunits consist of dimers of a single protein with similar folds. The spatial arrangement of the α-helical core resembles that found in the capsid protein of the L-A virus, a fungal totivirus with an undivided genome, suggesting a conserved basic fold. The encapsidated genome is organized in concentric shells; whereas the inner dsRNA shells are well defined, the outermost layer is dense due to numerous interactions with the inner capsid surface, specifically, six interacting areas per monomer. The outermost genome layer is arranged in an icosahedral cage, sufficiently well ordered to allow for modeling of an A-form dsRNA. The genome ordering might constitute a framework for dsRNA transcription at the capsid interior and/or have a structural role for capsid stability. Copyright © 2010, American Society for Microbiology. All Rights Reserved.This work was supported by grants from the Spanish Ministry of Science and Innovation (BFU 2008-02328/BMC and S-0505-Mat-0238 to J.L.C. and BIO2008-02361 to J.R.C.) and the NIH Intramural Research Program with support from the Center for Information Technology.Peer Reviewe

From Waste to Healing Biopolymers: Biomedical Applications of Bio-Collagenic Materials Extracted from Industrial Leather Residues in Wound Healing

The biomedical properties of a porous bio-collagenic polymer extracted from leather industrial waste residues have been investigated in wound healing and tissue regeneration in induced wounds in rats. Application of the pure undiluted bio-collagen to induced wounds in rats dramatically improved its healing after 7 days in terms of collagen production and wound filling as well as in the migration and differentiation of keratinocytes. The formulation tested was found to be three times more effective than the commercial reference product Catrix® (Heal Progress (HP): 8 ± 1.55 vs. 2.33 ± 0.52, p < 0.001; Formation of Collagen (FC): 7.5 ± 1.05 vs. 2.17 ± 0.75, p < 0.001; Regeneration of Epidermis (RE): 13.33 ± 5.11 vs. 5 ± 5.48, p < 0.05)

Las razas berrendas en el área de Despeñaperros

Las razas Berrenda en Negro y Berrenda en Colorado son razas autóctonas, rústicas y maternales que suelen usarse para cruce industrial, se encuentran en peligro de extinción, al estar disminuyendo sus efectivos, y mezclándose, cada vez más, entre sí y con otras razas. El objetivo de este trabajo fue mostrar el estado actual y el grado de diferenciación de los bovinos Berrendo en Negro y Berrendo en Colorado localizados en el entorno de Despeñaperros en base a las características externas que presentan tanto a partir de sus caracteres zoométricos, como morfológicos y fanerópticos. Para ello se han muestreado un total de 160 reproductoras distribuidas en 13 rebaños, la mayoría de los cuales criaban conjuntamente ambas razas Berrendas. Para los cálculos se utilizó el programa estadístico Statistical 6.0 para Windows, realizándose pruebas T de diferenciación entre razas para las variables zoométricas y pruebas ML_2 para los cualitativos. Las variables zoométricas Alzada a la Cruz (ACR) y Diámetro Bicostal (LB) para la Berrenda en Negro y ACR para la Berrenda en Colorado mostraron valores inferiores a los definidos por el estándar de la raza. Para los caracteres cualitativos sección y forma del cuerno, tamaño de las orejas, longitud del cuello, inclinación de la grupa, finura de la cola y nalga, en ambas razas, existen discrepancias entre lo obtenido y lo dictaminado por el estándar de la raza. Se han encontrado diferencias significativas entre ambas razas tanto para el desarrollo del cuerno, como para el perfil cefálico, tamaño de la ubre, vientre y nalga, con un nivel de significación de p<0.05

Gobiernos y sindicatos ante la reforma del estado del bienestar. ¿Ruptura del diálogo social en la periferia de la eurozona?

The article tackles the transformations in the production of public policies in Spain, Italy, Ireland and Portugal within the context of the Great Recession. From 2008 onwards, the periphery of the Eurozone has been under strong financial strain, which has reduced the margin for discretion of national political actors. Public policy-making has had to be adapted to a new scenario of implicit or explicit conditionality, depending on the case. Welfare reform in the four member states has been performed under the supervision of European institutions and following the imperatives of fiscal consolidation. European conditionality has negatively impacted on social pacts as mechanisms for the determination of public policies. The financial and economic crisis in the periphery of the Euro has implied the de-activation of the corporatist dynamics of social dialogue and has introduced significant changes in the models of socio-economic governance of these countries.El artículo aborda las transformaciones del sistema de producción de políticas públicas en España, Italia, Irlanda y Portugal en el contexto de la crisis económica. Desde 2008, los países de la periferia del Euro han sido sometidos a intensas presiones financieras, que han reducido el margen de discrecionalidad de los actores nacionales en los procesos de determinación política. La toma de decisiones ha debido adaptarse a un nuevo escenario de condicionalidad expresa o implícita, según el caso. La reforma del Estado del Bienestar en los cuatro países se ha producido bajo la supervisión de las instituciones comunitarias y atendiendo al imperativo de priorizar el objetivo de consolidación fiscal. La condicionalidad europea ha dañado la funcionalidad de los pactos sociales como instrumento de elaboración de políticas públicas. La crisis de la periferia del Euro ha implicado la desactivación de las dinámicas corporatistas de diálogo social y ha introducido importantes cambios en los modelos de gobernanza socio-económica de estos países