Development and application of a one-step low cost procedure to concentrate viruses from seawater samples

A novel and simple procedure for concentrating adenoviruses from seawater samples is described. The technique entails the adsorption of viruses to pre-flocculated skimmed milk proteins, allowing the flocs to sediment by gravity, and dissolving the separated sediment in phosphate buffer. Concentrated virus may be detected by PCR techniques following nucleic acid extraction. The method requires no specialized equipment other than that usually available in routine public health laboratories, and due to its straightforwardness it allows the processing of a larger number of water samples simultaneously. The usefulness of the method was demonstrated in concentration of virus in multiple seawater samples during a survey of adenoviruses in coastal waters.

Effect of Tocopherol Extract, Staphylococcus carnosus Culture, and Celery Concentrate Addition on Quality Parameters of Organic and Conventional Dry-Cured Sausages

The effects of the addition to sausage mix of tocopherols (200 mg/kg), a conventional starter culture with or without Staphylococcus carnosus, celery concentrate (CP) (0.23% and 0.46%), and two doses of nitrate (70 and 140 mg/kg expressed as NaNO(3)) on residual nitrate and nitrite amounts, instrumental CIE Lab color, tocol content, oxidative stability, and overall acceptability were studied in fermented dry-cured sausages after ripening and after storage. Nitrate doses were provided by nitrate-rich CP or a chemical grade source. The lower dose complies with the EU requirements governing the maximum for ingoing amounts in organic meat products. Tocopherol addition protected against oxidation, whereas the nitrate dose, nitrate source, or starter culture had little influence on secondary oxidation values. The residual nitrate and nitrite amounts found in the sausages with the lower nitrate dose were within EU-permitted limits for organic meat products and residual nitrate can be further reduced by the presence of the S. carnosus culture. Color measurements were not affected by the CP dose. Product consumer acceptability was not affected negatively by any of the factors studied. As the two nitrate sources behaved similarly for the parameters studied, CP is a useful alternative to chemical ingredients for organic dry-cured sausage production.

Coalition formation in a contest game with three heterogeneous players

We analyze the incentives for cooperation of three players differing in their efficiency of effort in a contest game. We concentrate on the non-cooperative bargaining foundation of coalition formation, and therefore, we adopt a two-stage model. In the first stage, individuals form coalitions following a bargaining protocol similar to the one proposed by Gul (1989). Afterwards, coalitions play the contest game of Esteban and Ray (1999) within the resulting coalition structure of the first stage. We find that the grand coalition forms whenever the distribution of the bargaining power in the coalition formation game is equal to the distribution of the relative efficiency of effort. Finally, we use the case of equal bargaining power for all individuals to show that other types of coalition structures may be observed as well.

An empirical analysis of wealth taxation: equity Vs.tax compliance

Capital taxation is currently under debate, basically due to problems of administrative control and proper assessment of the levied assets. We analyze both problems focusing on a capital tax, the annual wealth tax (WT), which is only applied in five OECD countries, being Spain one of them. We concentrate our analysis on top 1% adult population, which permits us to describe the evolution of wealth concentration in Spain along 1983-2001. On average top 1% holds about 18% of total wealth, which rises to 19% when tax incompliance and under-assessment is corrected for housing, the main asset. The evolution suggests wealth concentration has risen. Regarding WT, we analyze whether it helps to reduce wealth inequality or, on the contrary, it reinforces vertical inequity (due to especial concessions) and horizontal inequity (due to the de iure and to de facto different treatment of assets). We analyze in detail housing and equity shares. By means of a time series analysis, we relate the reported values with reasonable price indicators and proxies of the propensity to save. We infer net tax compliance is extremely low, which includes both what we commonly understand by (gross) tax compliance and the degree of under-assessment due to fiscal legislation (for housing). That is especially true for housing, whose level of net tax compliance is well below 50%. Hence, we corroborate the difficulties in taxing capital, and so cast doubts on the current role of the WT in Spain in reducing wealth inequality.

Aplicació de la termoquimiolisi - cromatografia de gasos - espectrometria de masses a l'estudi de la matèria orgànica del sòl

Estudi realitzat a partir d’una estada a la Université de Poitiers, França, entre 2007 i 2009. El treball s'ha centrat en dues activitats bàsiques. El treball realitzat s’ha centrat en dues activitats bàsiques. D’una banda, la posada a punt d'un protocol de fraccionament de la matèria orgànica del sòl, per extraccions successives amb solvents alcalins després d'una seqüència de pretractaments al sòl: cap pretractament, atac amb àcid (per destruir els carbonats), atac amb ditionit (per reduir els òxids de Fe i Al i facilitar l'extracció de la matèria orgànica associada a aquests compostos). El protocol dóna una visió de conjunt de la situació de la matèria orgànica del sòl, combinant aspectes físics (protecció, precipitació, oclusió per carbonats) i químics (grau d'humificació). D’altra banda, l'aprenentatge de la tècnica de termoquimiolisi-cromatografia de gasos-espectrometria de masses. Aquest era l'objectiu de l'estada a Poitiers, al qual hem donat prioritat. Ens hem centrat en l'estudi de fraccions físiques (densimètriques) obtingudes en estudis anteriors sobre sòls forestals. Les fraccions considerades són: fracció lleugera (FL), tres fraccions ocluïdes (OC1, OC2 i OC3) i fracció densa (FD). L’aplicació de la termoquimiolisi permet de caracteritzar diversos grups de substàncies, de les quals ens hem centrat en alguns indicadors bioquímics: àcids grasos, alcohols, diàcids, productes fenòlics i altres productes aromàtics, derivats de carbohidrats. L’estudi de conjunt d’aquests productes indica que és a les fraccions ocluïdes (que solen ser minoritàries a tots els horitzons) on la matèria orgànica d’origen microbià és dominant, mentre que a les fraccions lleugera (FL) i densa (FD) la matèria orgànica d’origen vegetal sembla dominant. Es preveu aplicar aquesta tècnica a l’estudi de les fraccions obtingudes a la primera part del treball, actualment congelades i a l’espera de ser processades.

The Accessibility City. When Transport Infrastructure Matters in Urban Spatial Structure

Suburbanization is changing the urban spatial structure and less monocentric metropolitan regions are becoming the new urban reality. Focused only on centers, most works have studied these spatial changes neglecting the role of transport infrastructure and its related location model, the “accessibility city”, in which employment and population concentrate in low-density settlements and close to transport infrastructure. For the case of Barcelona, we consider this location model and study the population spatial structure between 1991 and 2006. The results reveal a mix between polycentricity and the accessibility city, with movements away from the main centers, but close to the transport infrastructure.

Asymptotic flocking dynamics for the kinetic Cucker-Smale model

In this paper, we analyse the asymptotic behavior of solutions of the continuous kinetic version of flocking by Cucker and Smale [16], which describes the collective behavior of an ensemble of organisms, animals or devices. This kinetic version introduced in [24] is here obtained starting from a Boltzmann-type equation. The large-time behavior of the distribution in phase space is subsequently studied by means of particle approximations and a stability property in distances between measures. A continuous analogue of the theorems of [16] is shown to hold for the solutions on the kinetic model. More precisely, the solutions will concentrate exponentially fast their velocity to their mean while in space they will converge towards a translational flocking solution.

Anàlisi i tècniques de processat del senyal per a la generació de mapes eòlics

L’emplaçament del projecte es situa a un parc eòlic marítim, on es vol observar el vent a través del radar VAD, Velocity Azimuth Display, per poder controlar la velocitat de rotació dels aerogeneradors, i poder substituir els actuals anemòmetres. No ens centrarem en el control d’aquest, sinó que l’objectiu principal d’aquest projecte és analitzar el funcionament i processat de dades del VAD. Es proposaran, simularan i estudiaran noves tècniques d’estimació espectral per obtenir una millora important amb les mesures de velocitat, direcció i divergència del vent, per tal de construir un radar més robust a pertorbacions. A més a més, també il·lustrarem mapes eòlics obtinguts a partir de tot el processat.

Metropolitan Areas in Spain and Italy

Metropolitan areas concentrate the main share of population, production and consumption in OECD countries. They are likely to be the most important units for economic, social and environmental analysis as well as for the development of policy strategies. However, one of the main problems that occur when adopting metropolitan areas as units of analysis and policy in European countries is the absence of widely accepted standards for identifying them. This severe problem appeared when we tried to perform comparative research between Spain and Italy using metropolitan areas as units of analysis. The aim of this paper is to identify metropolitan areas in Spain and Italy using similar methodologies. The results allow comparing the metropolitan realities of both countries as well as providing the metropolitan units that can be used in subsequent comparative researches. Two methodologies are proposed: the Cheshire-GEMACA methodology (FUR) and an iterative version of the USA-MSA algorithm, particularly adapted to deal with polycentric metropolitan areas (DMA). Both methods show a good approximation to the metropolitan reality and produce very similar results: 75 FUR and 67 DMA in Spain (75% of total population and employment), and 81 FUR and 86 DMA in Italy (70% of total population and employment).

Why do creative industries cluster? An analysis of the determinants of clustering of creative industries

Creative industries tend to concentrate mainly around large- and medium-sized cities, forming creative local production systems. The text analyses the forces behind clustering of creative industries to provide the first empirical explanation of the determinants of creative employment clustering following a multidisciplinary approach based on cultural and creative economics, evolutionary geography and urban economics. A comparative analysis has been performed for Italy and Spain. The results show different patterns of creative employment clustering in both countries. The small role of historical and cultural endowments, the size of the place, the average size of creative industries, the productive diversity and the concentration of human capital and creative class have been found as common factors of clustering in both countries.

Productivity, quality, and export intensities

We study how firm and foreign market characteristics affect the geographic distribution of exporter' sales. To this purpose, we use export intensities (the ratio of exports to sales) across destinations as our key measures of firms'relative involvement in heterogeneous foreign markets. In a representative sample of Italian manufacturing firms, we find a robust negative correlation between revenue-TFP and export intensity to low-income destinations and, more generally, that the correlations between export intensities and TFP are increasing in per capita income of the foreign destinations. We argue that these (and other) empirical regularities can arise from the interplay between (endogenous) cross-firm heterogeneity in product quality and cross-country heterogeneity in quality consumption. To test this conjecture, we propose a new strategy to proxy for product quality that allows to exploit some unique features of our dataset. Our results strongly suggest that firms producing higher-quality products tend to concentrate their sales in the domestic and other high-income markets.

Trends in economic research: an international perspective

Given the recent efforts in several countries to reorganize the research institutional setting to improve research productivity, our analysis addresses the following questions: To which extent has the recent awareness over international quality standards in economics around the world been reflected in research performance? How have individual countries fared? Do research quantity and quality indicators tell us the same story? We concentrate on trends taking place since the beginning of the 1990s and rely on a very comprehensive database of scientific journals, to provide a cross-country comparison of the evolution of research in economics. Our findings indicate that Europe is catching-up with the US but, in terms of influential research, the US maintains a dominant position. The main continental European countries, Germany, France, Italy and Spain, experienced some of the largest growth rates in economic scientific output. Other European countries, namely the UK, Norway, the Netherlands, Denmark, and Sweden, have shown remarkable progress in per capita output. Collaborative research seems to be a key factor explaining the relative success of some European countries, in particular when it comes to publishing in top journals, attained predominantly through international collaborations.

Disseny i implementació d'un marc de treball (framework) de presentació per aplicacions J2EE

Aquest document cobrirà diferents aspectes relacionats amb el disseny d'un framework de presentació orientat a aplicacions web. Començarem analitzant quins serien els aspectes o característiques esperades d'una solució d'aquest tipus, sempre des de la subjectivitat i l'experiència, com pot ser el concepte de zero configuration, el qual intenta reduir el nombre de fitxers de configuració necessaris per a la posada en marxa, o el de convention over configuration, el qual intenta reduir el nombre de decisions que els desenvolupadors hagin de prendre, guanyant en flexibilitat però sense perdre flexibilitat, i sobretot permetent al desenvolupador concentrar-se en aquells aspectes que són particulars a la seva solució.

Exploration of geological variability and possible processes through the use of compositional data analysis: an example using scottish metamorphosed

Developments in the statistical analysis of compositional data over the last twodecades have made possible a much deeper exploration of the nature of variability,and the possible processes associated with compositional data sets from manydisciplines. In this paper we concentrate on geochemical data sets. First we explainhow hypotheses of compositional variability may be formulated within the naturalsample space, the unit simplex, including useful hypotheses of subcompositionaldiscrimination and specific perturbational change. Then we develop through standardmethodology, such as generalised likelihood ratio tests, statistical tools to allow thesystematic investigation of a complete lattice of such hypotheses. Some of these tests are simple adaptations of existing multivariate tests but others require specialconstruction. We comment on the use of graphical methods in compositional dataanalysis and on the ordination of specimens. The recent development of the conceptof compositional processes is then explained together with the necessary tools for astaying- in-the-simplex approach, namely compositional singular value decompositions. All these statistical techniques are illustrated for a substantial compositional data set, consisting of 209 major-oxide and rare-element compositions of metamorphosed limestones from the Northeast and Central Highlands of Scotland.Finally we point out a number of unresolved problems in the statistical analysis ofcompositional processes

A Log-linear model of grain size influence on the geochemistry of sediments

Sediment composition is mainly controlled by the nature of the source rock(s), and chemical (weathering) and physical processes (mechanical crushing, abrasion, hydrodynamic sorting) during alteration and transport. Although the factors controlling these processes are conceptually well understood, detailed quantification of compositional changes induced by a single process are rare, as are examples where the effects of several processes can be distinguished. The present study was designed to characterize the role of mechanical crushing and sorting in the absence of chemical weathering. Twenty sediment samples were taken from Alpine glaciers that erode almost pure granitoid lithologies. For each sample, 11 grain-size fractions from granules to clay (ø grades &-1 to &9) were separated, and each fraction was analysed for its chemical composition.The presence of clear steps in the box-plots of all parts (in adequate ilr and clr scales) against ø is assumed to be explained by typical crystal size ranges for the relevant mineral phases. These scatter plots and the biplot suggest a splitting of the full grain size range into three groups: coarser than ø=4 (comparatively rich in SiO2, Na2O, K2O, Al2O3, and dominated by “felsic” minerals like quartz and feldspar), finer than ø=8 (comparatively rich in TiO2, MnO, MgO, Fe2O3, mostly related to “mafic” sheet silicates like biotite and chlorite), and intermediate grains sizes (4≤ø &8; comparatively rich in P2O5 and CaO, related to apatite, some feldspar).To further test the absence of chemical weathering, the observed compositions were regressed against three explanatory variables: a trend on grain size in ø scale, a step function for ø≥4, and another for ø≥8. The original hypothesis was that the trend could be identified with weathering effects, whereas each step function would highlight those minerals with biggest characteristic size at its lower end. Results suggest that this assumption is reasonable for the step function, but that besides weathering some other factors (different mechanical behavior of minerals) have also an important contribution to the trend.Key words: sediment, geochemistry, grain size, regression, step function