La libre circulación de pilotos de líneas aéreas en el derecho comunitario europeo

Actas de: Seminario sobre derecho aeronáutico celebrado en Madrid del 13 al 14 de mayo de 1998

Mismatched Training and Test Distributions Can Outperform Matched Ones

In learning theory, the training and test sets are assumed to be drawn from the same probability distribution. This assumption is also followed in practical situations, where matching the training and test distributions is considered desirable. Contrary to conventional wisdom, we show that mismatched training and test distributions in supervised learning can in fact outperform matched distributions in terms of the bottom line, the out-of-sample performance, independent of the target function in question. This surprising result has theoretical and algorithmic ramifications that we discuss

Fatal dual infection of avian polyomavirus and psittacine beak and feather disease virus in Chile

oai:ojs2.ajvs.cl:article/1A 6 week old Plum-headed parakeet (Psittacula cyanocephala) from a private bird collection in the Metropolitan Region of Chile died after presenting depression, ataxia, tremors of the head, subcutaneous hemorrhage and delayed crop emptying. Histological examination of liver tissue revealed intranuclear viral inclusion bodies and focal necrosis. Liver tissues and blood contained both avian polyomavirus (APV) and psittacine beak and feather disease (PBFD) viral nucleic acids (DNA), indicating dual viral infection. The purpose of this report is to describe the first case of concurrent psittacine beak and feather disease virus PBFDV and APV infection in a psittacine bird in captivity in Chile. PBFDV has not been reported until now in Chile

Reliability evaluation of III-V concentrator solar cells

Concentrator solar cells have been proposed as an interesting way of reducing the cost of photovoltaic electricity. However, in order to compete with conventional solar modules it is necessary not only to reduce costs but also to evaluate and increase the present reliability. Concentrator solar cells work at higher temperature, solar radiation and current stress than conventional solar cells and a carefully reliability analysis is needed. In this paper a reliability analysis procedure, that is being developed, is presented

Using Biotic Interaction Networks for Prediction in Biodiversity and Emerging Diseases

Networks offer a powerful tool for understanding and visualizing inter-species interactions within an ecology. Previously considered examples, such as trophic networks, are just representations of experimentally observed direct interactions. However, species interactions are so rich and complex it is not feasible to directly observe more than a small fraction. In this paper, using data mining techniques, we show how potential interactions can be inferred from geographic data, rather than by direct observation. An important application area for such a methodology is that of emerging diseases, where, often, little is known about inter-species interactions, such as between vectors and reservoirs. Here, we show how using geographic data, biotic interaction networks that model statistical dependencies between species distributions can be used to infer and understand inter-species interactions. Furthermore, we show how such networks can be used to build prediction models. For example, for predicting the most important reservoirs of a disease, or the degree of disease risk associated with a geographical area. We illustrate the general methodology by considering an important emerging disease - Leishmaniasis. This data mining approach allows for the use of geographic data to construct inferential biotic interaction networks which can then be used to build prediction models with a wide range of applications in ecology, biodiversity and emerging diseases

Geminivirus C2 protein represses genes involved in sulphur assimilation and this effect can be counteracted by jasmonate treatment

Geminiviruses are plant viruses that infect a broad range of crops and cause extensive losses worldwide, having an important economic impact. C2, a multifunctional pathogenicity factor encoded by geminiviruses, has been recently shown to suppress the responses to jasmonates in the host plant, which might at least partially explain its well-established role in pathogenicity. Sulphur is one of the essential macro-elements for plant life, and is considered to have a role in plant defence, in a phenomenon named sulphur-induced resistance (SIR) or sulphur-enhanced defence (SED). In this work, we show that geminivirus C2 protein represses the expression of genes involved in the sulphur assimilation pathway in Arabidopsis, but, interestingly, this effect can be neutralized by exogenous jasmonate treatment. These preliminary results may raise the idea that geminiviruses might be affecting sulphur metabolism, and maybe counteracting SIR/SED, through the manipulation of the jasmonate signalling pathway, which would define a novel strategy in plant-virus interactions and may unveil SIR/SED as an important player in the plant defence against viruses.Ministerio de Ciencia y Innovación/FEDER AGL2007-66062-C02-02/AGR AGL2010-22287-CO2European Regional Development Fund (ERDF) BIO2010-15201Junta de Andalucía BIO­27

Current state of knowledge of freshwater malacostracans of Chile

Indexación: ScieloLa fauna de crustáceos malacostráceos limnéticos, en el territorio de Chile continental, está compuesta por seis especies de camarones, i.e., cinco parastácidos de los géneros Parastacus, Samastacus y Virilastacus y un palemónido del género Cryphiops, 18 especies de anomuros del género Aegla, siete especies de anfípodos gamarídeos del género Hyallela y una especie de isópodo aselotano del género Heterias. La distribución conjunta abarca desde Arica a Punta Arenas, pero la mayor parte de las especies tiene rango geográfico restringido. La mayor densidad de taxa ocurre entre las regiones VIII y X, donde el número de taxa por Región varía entre 11 y 15, siendo la X Región la que tiene el número mayor. Índices derivados de un estudio sobre relaciones filogenéticas de las especies chilenas de Aegla, combinados con criterios propuestos por IUCN (2001), calificó a A. concepcionensis y A. expansa como especies Extintas y a A. papudo, A. l. laevis y A. spectabilis como Críticamente Amenazadas. Además, asignó máxima prioridad de conservación a la zona comprendida entre las cuencas del río Tucapel y del río Toltén. El estado de conservación de las especies de Parastacidae fue establecido por Bahamonde et al. (1998) y complementado por Rudolph & Crandall (2005). El estado de conservación de las especies de Hyalella y del isópodo Heterias exul no ha sido determinado. Se percibe que las amenazas a la conservación de las especies de malacostráceos limnéticos en Chile derivan principalmente de perturbaciones antropogénicas de la integridad y salud ambiental de las cuencas hidrográficas, particularmente entre las Regiones IV a VIII. Palabras claves: Malacostráceos, diversidad, conservación, Amphipoda, Isopoda, Decapoda, Chile, limnología. -------------------------------------------------------------------------------- ABSTRACT The continental Chilean limnetic malacostracan fauna is currently composed of six species of crayfish / shrimp, i.e., five parastacids in the genus Parastacus, Samastacus and Virilastacus, and one palaemonid in the genus Cryphiops, eighteen species of anomuran crabs in the genus Aegla, seven species of gammaridean amphipods in the genus Hyalella, and one species of asellotan isopod in the genus Heterias. The distribution of the set of thirty one species of malacostracans spans from Arica in the north to Magallanes in the far south. However, most species have a restricted geographic range, comprising one or a few hydrographical contiguous basins along the latitudinal gradient. The largest concentration of malacostracan species is found between the VIII and X Administrative Regions of Chile; being the X the largest with fifteen taxa. Indices derived from a phylogenetic study concerning the relationship of the Chilean species of Aegla, and considering the conservation criteria proposed by UICN (2001), qualified A. concepcionensis and A. expansa as Extinct in the Wild, and A. papudo, A. l. laevis and A. spectabilis as Critically Endangered species. Furthermore, it assigned maximum conservation priority to the coastal area between the Tucapel and the Tolten rivers. The conservation status of the species of Parastacidae was established by Bahamonde et al. (1998), and supplemented by Rudolph & Crandall (2005). The conservation status of Hyalella and Heterias species has not yet been determined. It is apparent that threats to the conservation of a large number of limnetic malacostracan species in Chile arise from non quantified anthropogenic perturbations of the limnetic environment, particularly between the IV and VIII Regions. Keywords: Malacostracans, diversity, conservation, Amphipoda, Isopoda, Decapoda, Chile, limnology

Effects of Post-Fire Deadwood Management on Soil Macroarthropod Communities

Dead wood comprises a vast amount of biological legacies that set the scene for ecological regeneration after wildfires, yet its removal is the most frequent management strategy worldwide. Soil-dwelling organisms are conspicuous, and they provide essential ecosystem functions, but their possible affection by different post-fire management strategies has so far been neglected. We analyzed the abundance, richness, and composition of belowground macroarthropod communities under two contrasting dead-wood management regimes after a large wildfire in the Sierra Nevada Natural and National Park (Southeast Spain). Two plots at different elevation were established, each containing three replicates of two experimental treatments: partial cut, where trees were cut and their branches lopped off and left over the ground, and salvage logging, where all the trees were cut, logs were piled, branches were mechanically masticated, and slash was spread on the ground. Ten years after the application of the treatments, soil cores were extracted from two types of microhabitat created by these treatments: bare-soil (in both treatments) and under-logs (in the partial cut treatment only). Soil macroarthropod assemblages were dominated by Hemiptera and Hymenoptera (mostly ants) and were more abundant and richer in the lowest plot. The differences between dead-wood treatments were most evident at the scale of management interventions: abundance and richness were lowest after salvage logging, even under similar microhabitats (bare-soil). However, there were no significant differences between microhabitat types on abundance and richness within the partial cut treatment. Higher abundance and richness in the partial cut treatment likely resulted from higher resource availability and higher plant diversity after natural regeneration.This study was supported by Project 10/2005 from the Organismo Autónomo de Parques Nacionales (Spanish Government), CGL2008–01671 from the Spanish Ministerio de Ciencia e Innovación, and P12-RNM-2705 from Junta de Andalucía. Programa Nacional de incentivo a investigadores (PRONII) and Programa de vinculación de científicos y tecnólogos from Comisión Nacional de Ciencia y Tecnología (Paraguay). A.B.L. acknowledges a postdoctoral grant from the Alexander von Humboldt Foundation. C.R.M-G. had a Ph.D. grant from the National University of Asunción (Paraguay) and Carolina Foundation (Spain)

Automatic neural generalized font identification

The final publication is available at Springer via http://dx.doi.org/10.1007/978-1-4471-1599-1_116Proceedings of the 8th International Conference on Artificial Neural Networks, Skövde, Sweden, 2–4 September 1998Neural methods are gaining a steady acceptance as powerful tools in a variety of pattern detection problems, OCR certainly being one of them. The concrete implementation of these neural OCR systems is of course a well guarded corporate secret, but in broad terms it can be said that in most of the cases, multilayer perceptrons (MLPs) are used. There are several reasons for the MLPs’ success. To begin with, they are based in well understood mathematical and statistical principles and there are efficient tools and methodologies for their training and evaluation. Furthermore they have good generalization properties.With partial support of grant TIC 95-965 of Spain's CICy

Globular Clusters: DNA of Early-Type galaxies?

This paper explores if the mean properties of Early-Type Galaxies (ETG) can be reconstructed from "genetic" information stored in their GCs (i.e., in their chemical abundances, spatial distributions and ages). This approach implies that the formation of each globular occurs in very massive stellar environments, as suggested by some models that aim at explaining the presence of multi-populations in these systems. The assumption that the relative number of globular clusters to diffuse stellar mass depends exponentially on chemical abundance, [Z/H], and the presence of two dominant GC sub-populations blue and red, allows the mapping of low metallicity halos and of higher metallicity (and more heterogeneous) bulges. In particular, the masses of the low-metallicity halos seem to scale up with dark matter mass through a constant. We also find a dependence of the globular cluster formation efficiency with the mean projected stellar mass density of the galaxies within their effective radii. The analysis is based on a selected sub-sample of galaxies observed within the ACS Virgo Cluster Survey of the {\it Hubble Space Telescope}. These systems were grouped, according to their absolute magnitudes, in order to define composite fiducial galaxies and look for a quantitative connection with their (also composite) globular clusters systems. The results strengthen the idea that globular clusters are good quantitative tracers of both baryonic and dark matter in ETGs.Comment: 20 pages, 28 figures and 5 table