A clear signature of the breakup modes for 9Be on a proton target at 5.6 MeV/nucleon

The breakup of 9Be is studied via an inelastic scattering experiment on a proton target at 5.6 A MeV in inverse kinematics. Two of the three cluster constituents (α and α) as well as the proton target recoil were recorded in a triple coincidence mode allowing a full kinematics approach analysis. In this respect relative α - α and α - n, Q-value and 9Be excitation spectra, energy spectra for all fragments as well as the energy spectrum of the recoil proton were reconstructed. A clear signature of the two breakup sequential modes (5He + 4He and 8Be + n) was identified via the recoiling proton reconstructed spectra together with the direct breakup decay. A strong 5He + 4He mode was observed compatible with previous beta decay experiments

Influence of single-neutron stripping on near-barrier ⁶He+²⁰⁸Pb and ⁸He+²⁰⁸Pb elastic scattering

The influence of single-neutron stripping on the near-barrier elastic scattering angular distributions for the 6,8He+208Pb systems is investigated through coupled reaction channels (CRC) calculations fitting recently published data to explore the differences in the absorptive potential found in the scattering of these two neutron-rich nuclei. The inclusion of the coupling reduces the elastic cross section in the Coulomb-nuclear interference region for 8He scattering, whereas for 6He its major impact is on the large-angle elastic scattering. The real and imaginary dynamic polarization potentials are obtained by inverting the CRC elastic scattering S-matrix elements. These show that the main absorptive features occur between 11 and 12 fm for both projectiles, while the attractive features are separated by about 1 fm, with their main structures occurring at 10.5 fm for 6He and 11.5 fm for 8He

Elastic Scattering of 6He on Heavy Targets at Coulomb Barrier Energies

Elastic cross sections for the scattering of 6He projectiles by 208Pb at 27 MeV have been studied. The data have been analyzed within the framework of the Optical Model using Saxon–Woods phenomenological form factors for both the real and imaginary parts of the nuclear potential. The elastic scattering data suggests the presence of a long range absorption mechanisms which might be related to the halo structure of 6He.Ministerio Ciencia y Tecnología FPA2002-04181- C04-04 y FPA2000-1592-C03-0

Strategies towards sustainability environmental from the local areas and the university

El propósito del presente trabajo es explorar un posible arreglo socioambiental pensado desde lo local que propicie el desarrollo sustentable, por medio del privilegio de la articulación de lo social (ciudadanía y educación) con el medio ambiente (capacidad de renovación). El planteamiento central es que ante un modelo social dominante que es insustentable, en el sentido que refuerza la desigualdad socioeconómica y el deterioro ambiental; se demanda pensar y actuar en formas novedosas e integradoras de lo social con la natural y del presente con el futuro para hacer posible sentar bases para un desarrollo sustentable de largo plazo. Para tal fin, se formula un arreglo que articule lo social (ciudadanía y educación) con el medio ambiente (capacidad de renovación) desde ámbitos locales, por medio de estrategias de acción gestionadas socialmente.The aim of this paper is to explore and present a suitable socio-environmental proposal conducive to sustainable development considering the local aspects emphasizing on the joint between the social (citizenship and education) with the environmental (renewability). The rationale of the study is that having a dominant unsustainable social model that reinforces socioeconomic inequality and environmental degradation, a need of developing more integrative and innovative ways to cope with the social and the natural as well as the present and the future is required in order to lay the foundations for a more long-term sustainable development. To that end, a suitable arrangement is presented in order to articulate the social aspects (citizenship and education) to the environmental ones (renewability) from a local perspective, managed through social action strategies.Fil: González López, Sergio. Universidad Autónoma del Estado de México. Instituto de Estudios sobre la Universidad.Fil: Salvador Benítez, J. Loreto. Universidad Autónoma del Estado de México. Instituto de Estudios sobre la Universidad.Fil: Arand a Sánchez, José María. Universidad Autónoma del Estado de México. Instituto de Estudios sobre la Universidad

Large scale risk-assessment of wind-farms on population viability of a globally endangered long-lived raptor

Wind-farms receive public and governmental support as an alternative energy source mitigating air pollution. However, they can have adverse effects on wildlife, particularly through collision with turbines. Research on wind-farm effects has focused on estimating mortality rates, behavioural changes or interspecific differences in vulnerability. Studies dealing with their effects on endangered or rare species populations are notably scarce. We tested the hypothesis that wind-farms increase extinction probability of long-lived species through increments in mortality rates. For this purpose, we evaluate potential consequences of wind-farms on the population dynamics of a globally endangered long-lived raptor in an area where the species maintains its greatest stronghold and wind-farms are rapidly increasing. Nearly one-third of all breeding territories of our model species are in wind-farm risk zones. Our intensive survey shows that wind-farms decrease survival rates of this species differently depending on individual breeding status. Consistent with population monitoring, population projections showed that all subpopulations and the meta-population are decreasing. However, population sizes and, therefore, time to extinction significantly decreased when wind-farm mortality was included in models. Our results represent a qualitative warning exercise showing how very low reductions in survival of territorial and non-territorial birds associated with wind-farms can strongly impact population viability of long-lived species. This highlights the need for examining long-term impacts of wind-farms rather than focusing on short-term mortality, as is often promoted by power companies and some wildlife agencies. Unlike other non-natural causes of mortality difficult to eradicate or control, wind-farm fatalities can be lowered by powering down or removing risky turbines and/or farms, and by placing them outside areas critical for endangered birds. © 2009 Elsevier Ltd. All rights reserved.Peer Reviewe

nlstac: Non-Gradient Separable Nonlinear Least Squares Fitting

A new package for nonlinear least squares fitting is introduced in this paper. This package implements a recently developed algorithm that, for certain types of nonlinear curve fitting, reduces the number of nonlinear parameters to be fitted. One notable feature of this method is the absence of initialization which is typically necessary for nonlinear fitting gradient-based algorithms. Instead, just some bounds for the nonlinear parameters are required. Even though convergence for this method is guaranteed for exponential decay using the max-norm, the algorithm exhibits remarkable robustness, and its use has been extended to a wide range of functions using the Euclidean norm. Furthermore, this data-fitting package can also serve as a valuable resource for providing accurate initial parameters to other algorithms that rely on them

The ALHAMBRA photometric system

This paper presents the characterization of the optical range of the ALHAMBRA photometric system, a 20 contiguous, equal-width, medium-band CCD system with wavelength coverage from 3500A to 9700A. The photometric description of the system is done by presenting the full response curve as a product of the filters, CCD and atmospheric transmission curves, and using some first and second order moments of this response function. We also introduce the set of standard stars that defines the system, formed by 31 classic spectrophotometric standard stars which have been used in the calibration of other known photometric systems, and 288 stars, flux calibrated homogeneously, from the Next Generation Spectral Library (NGSL). Based on the NGSL, we determine the transformation equations between Sloan Digital Sky Survey (SDSS) ugriz photometry and the ALHAMBRA photometric system, in order to establish some relations between both systems. Finally we develop and discuss a strategy to calculate the photometric zero points of the different pointings in the ALHAMBRA project.Comment: Astronomical Journal on the 14th of January 201

Papel de las bacterias del ácido láctico en verduras fermentadas

The consumption of fermented vegetables is widespread throughout the world and represents an important component of the human diet with considerable contribution to the food supply for a world popula­tion in continuous growth. Many of the fermented vegetables share a general process which requires salting and acidification steps. Among the microorganisms responsible for fermentation, lactic acid bacteria are the most relevant with important organoleptic, quality and safety benefits. This review deals with the microbial ecology of fermented vegetables focusing on the biodiversity of lactic acid bacteria, the most important molecular tech­niques used for their identification and genotyping, their importance for the formation of biofilms as well as their use as starter cultures for obtaining high-quality and safe vegetable products.El consumo de vegetales fermenta­dos está muy extendido en el mundo y representa un componente importante de la dieta humana con un apoyo considerable a la cadena alimentaria para una población mundial en continuo crecimiento. Muchos de los vege­tales fermentados comparten un proceso general, que requiere una puesta en salmuera y acidificación. Entre los microorganismos responsables de la fermentación, las bacterias del ácido láctico son las más relevantes con una importante influencia sobre aspectos organolépticos, de calidad y seguridad del producto final. Esta revisión trata sobre la ecología microbiana de los vegetales fermentados, prestando especial atención a la biodiversidad de las bacterias del ácido láctico, las técnicas moleculares más importantes utilizadas para su identificación y genotipado, su importancia para la formación de biofilms y su uso como cultivos iniciadores multifuncionales para la obtención de productos vegetales de alta calidad y seguridad