The effects of pinning on critical currents of superconducting films

Using molecular dynamics simulations, we analyze the effects of artificial periodic arrays of pinning sites on the critical current of superconducting thin films as a function of vortex density. We analyze two types of periodic pinning array: hexagonal and Kagomé. For the Kagome pinning network we make calculations using two directions of transport current: along and perpendicular to the main axis of the lattice. Our results show that the hexagonal pinning array presents higher critical currents than the Kagomé and random pinning configuration for all vortex densities. In addition, the Kagomé networks show anisotropy in their transport properties. © 2012 Springer Science+Business Media, LLC.

A critical analysis of the ubiquity of linear local-regional richness relationships

Synthesis Despite theoretical criticisms, the ubiquity of linear relationships between local and regional species richness has long been used to justify it as a valid framework to conclude that local communities are not saturated with species. However, we reanalyzed published studies with a new unbiased method and found no prevalence of linear relationships and more than 40% of misclassifications, including textbook examples. We thus conclude that the prevailing argument in favor of associating a valid ecological interpretation to local-regional species richness plots, its ubiquity, is not sustained, and that ecologists could use for instance metacommunity theory to make inference on the strength of local and regional processes. Identifying the relative importance of regional and local processes to local species diversity is a central issue to many questions in basic and applied ecology. One widely-used method is to plot local species richness against its regional richness to infer whether regional or local processes determine local diversity. However, this method increases the tendency to find regional prevalence as suggested by a recent simulation. We reanalyzed studies in the literature with an unbiased method and found no prevalence of either regional or local processes. In addition, almost 40% of the studies and 50% of the ecology textbook examples using the traditional method were misclassified. Our findings reinforce the need of alternative, novel tools identified by for instance metacommunity theory to go beyond the studies of local-regional relationships in the ecological literature that focus on the interdependence of regional and local processes.© 2013 The Authors. Oikos © 2013 Nordic Society Oikos.

Critical review of the rural agro-based industries project proposal

Revisa los proyectos para establecer industrias agricolas de pequena escala con enfasis en operaciones de tipo artesanal que sirvan como incentivos para aumentar la produccion primaria y permitir la participacion de la poblacion rural en su propio desarrollo.

Critical evaluation of the performance of the ECCM countries under the Agricultural Marketing Protocol (AMP) and the Guaranteed Market Scheme (GMS)

Includes bibliography

Chile's macroeconomic policies in the 1990s as seen from the vantage point of the Central Bank

Includes bibliography

Commercial policy in the underdeveloped countries (from the point of view of Latin America)

Publicado también en español: La política comercial en los países insuficientemente desarrollados desde el punto de vista latinoamericano. Economía, v. 19, No 69-70, p 25-45, 4o trimestre 1960 y 1o trimestre 1961; y en: American Economic Review, v. 49, No 2, p. 251-273, May 1959

Critical adsorption of polyelectrolytes onto charged Janus nanospheres

Based on extensive Monte Carlo simulations and analytical considerations we study the electrostatically driven adsorption of flexible polyelectrolyte chains onto charged Janus nanospheres. These net-neutral colloids are composed of two equally but oppositely charged hemispheres. The critical binding conditions for polyelectrolyte chains are analysed as function of the radius of the Janus particle and its surface charge density, as well as the salt concentration in the ambient solution. Specifically for the adsorption of finite-length polyelectrolyte chains onto Janus nanoparticles, we demonstrate that the critical adsorption conditions drastically differ when the size of the Janus particle or the screening length of the electrolyte are varied. We compare the scaling laws obtained for the adsorption-desorption threshold to the known results for uniformly charged spherical particles, observing significant disparities. We also contrast the changes to the polyelectrolyte chain conformations close to the surface of the Janus nanoparticles as compared to those for simple spherical particles. Finally, we discuss experimentally relevant physicochemical systems for which our simulations results may become important. In particular, we observe similar trends with polyelectrolyte complexation with oppositely but heterogeneously charged proteins.

A Critical Review of Properties of Darunavir and Analytical Methods for Its Determination

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Limit cycles of cubic polynomial differential systems with rational first integrals of degree 2

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Critical training of mass media documentalists

This study takes the old myth of objectivity in media discourse to one of the most important but unrecognized actors in the process of its construction: the mass media information scientist or documentalist. Accepting the subjective presence of the documentalist in his/her productions, this article opts for the recognition and explicit statement of this role, recommending two actions. First, we suggest that public higher education institutions combine the technical training of mass media documentalists with training in critical thinking skills. Our study analysed the subjects covered in course syllabi to detect the deficiencies to be addressed in meeting this objective. Second, we propose alternative lines of training that can contribute to cross-training of mass media documentalists in those degree programs to ensure that they acquire the needed skills in critical analysis.

A note about splittings of groups and commensurability under a cohomological point of view

Let G be a group, let S be a subgroup with infinite index in G and let FSG be a certain Z2G-module. In this paper, using the cohomological invariant E(G, S, FSG) or simply E˜(G, S) (defined in [2]), we analyze some results about splittings of group G over a commensurable with S subgroup which are related with the algebraic obstruction “singG(S)" defined by Kropholler and Roller ([8]. We conclude that E˜(G, S) can substitute the obstruction “singG(S)" in more general way. We also analyze splittings of groups in the case, when G and S satisfy certain duality conditions.

Report of 15 injuries caused by lionfish (pterois volitans) in aquarists in Brazil: a critical assessment of the severity of envenomations

Lionfish are venomous fish that belong to the Scorpaenidae family. Individuals of this family and those of the Synanceiidae family comprise most of the existing venomous fish in the world. Lionfish are originally found in the Indo-Pacific, but they have received special attention in the last years for their dissemination in the Atlantic Ocean, with the emergence of large populations in the USA, Caribbean and South America. Because of its beauty, this fish has always been present in private and commercial aquariums around the world. Herein, we describe 15 envenomations in aquarists registered in a period of eighteen years (1997-2014). The stings caused excruciating pain and marked inflammation, with local erythema, edema, heat, paleness and cyanosis. In one case, it was possible to observe vesicles and blisters. There were no skin necroses or marked systemic manifestations. We discuss the possible coming of the fish to South America and the circumstances and clinical impact of the envenomations.

A critical comparison of different approaches to sediment-quality assessments in the Santos estuarine system in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)