54 research outputs found
Internet, libertad y democracia1
Este documento explora las posibilidades del Internet como medio para la democracia, desde el trabajo de Pierre Lévy, la idea de la acción comunicativa, las ideas en torno a la esfera pública de Al Gore y la idea del proyecto ilustrado a partir de Kant
The extent of non tariff barriers to industrial countries' imports
This paper examines the extent of non-tariffs barriers to sixteen industrial countries' imports. Using three alternative measures it shows that governmental commodity-specific border-measures affect 27% of all imports and over 34% of imports from developing countries. It also shows that during the period 1981-1983,NTBs became significantly more extensive. Detailed statistics reveal considerable variations in NTB coverage by commodity, type of barrier, importer and exporter. The data on which these conclusions are based are compiled from official information at the finest level of disaggregation; they are described in the paper
The extent of non tariff barriers to industrial countries' imports
This paper examines the extent of non-tariffs barriers to sixteen industrial countries' imports. Using three alternative measures it shows that governmental commodity-specific border-measures affect 27% of all imports and over 34% of imports from developing countries. It also shows that during the period 1981-1983,NTBs became significantly more extensive. Detailed statistics reveal considerable variations in NTB coverage by commodity, type of barrier, importer and exporter. The data on which these conclusions are based are compiled from official information at the finest level of disaggregation; they are described in the paper
Passage of Heme-Iron Across the Envelope of Staphylococcus aureus
The cell wall envelope of Gram-positive pathogens functions as a scaffold for the attachment of virulence factors and as a sieve that prevents diffusion of molecules. Here the isdgenes (iron-regulated surface determinant) of Staphylococcus aureus were found to encode factors responsible for hemoglobin binding and passage of heme-iron to the cytoplasm, where it acts as an essential nutrient. Heme-iron passage required two sortases that tether Isd proteins to unique locations within the cell wall. Thus, Isd appears to act as an import apparatus that uses cell wall–anchored proteins to relay heme-iron across the bacterial envelope
Passage of Heme-Iron Across the Envelope of Staphylococcus aureus
The cell wall envelope of Gram-positive pathogens functions as a scaffold for the attachment of virulence factors and as a sieve that prevents diffusion of molecules. Here the isdgenes (iron-regulated surface determinant) of Staphylococcus aureus were found to encode factors responsible for hemoglobin binding and passage of heme-iron to the cytoplasm, where it acts as an essential nutrient. Heme-iron passage required two sortases that tether Isd proteins to unique locations within the cell wall. Thus, Isd appears to act as an import apparatus that uses cell wall–anchored proteins to relay heme-iron across the bacterial envelope
Perlecan Domain V induces VEGf secretion in brain endothelial cells through integrin α5β1 and ERK-dependent signaling pathways.
Perlecan Domain V (DV) promotes brain angiogenesis by inducing VEGF release from brain endothelial cells (BECs) following stroke. In this study, we define the specific mechanism of DV interaction with the α(5)β(1) integrin, identify the downstream signal transduction pathway, and further investigate the functional significance of resultant VEGF release. Interestingly, we found that the LG3 portion of DV, which has been suggested to possess most of DV\u27s angio-modulatory activity outside of the brain, binds poorly to α(5)β(1) and induces less BEC proliferation compared to full length DV. Additionally, we implicate DV\u27s DGR sequence as an important element for the interaction of DV with α(5)β(1). Furthermore, we investigated the importance of AKT and ERK signaling in DV-induced VEGF expression and secretion. We show that DV increases the phosphorylation of ERK, which leads to subsequent activation and stabilization of eIF4E and HIF-1α. Inhibition of ERK activity by U0126 suppressed DV-induced expression and secretion of VEGR in BECs. While DV was capable of phosphorylating AKT we show that AKT phosphorylation does not play a role in DV\u27s induction of VEGF expression or secretion using two separate inhibitors, LY294002 and Akt IV. Lastly, we demonstrate that VEGF activity is critical for DV increases in BEC proliferation, as well as angiogenesis in a BEC-neuronal co-culture system. Collectively, our findings expand our understanding of DV\u27s mechanism of action on BECs, and further support its potential as a novel stroke therapy
Does haemosporidian infection affect hematological and biochemical profiles of the endangered Black-fronted piping-guan (Aburria jacutinga)?
Infectious diseases can cause deleterious effects on bird species, leading to population decline and extinction. Haemosporidia can be recognized by their negative effects on host fitness, including reproductive success and immune responses. In captivity, outbreaks of haemosporidian infection have been observed in birds in zoos and aviaries. The endemic Brazilian Atlantic rainforest species Aburria jacutinga is one of the most endangered species in the Cracidae family, and wild populations of this species are currently found mainly in conservation areas in only two Brazilian states. In this study, we aimed to evaluate the effects of avian haemosporidia on hematological and biochemical parameters in two captive populations of A. jacutinga. Forty-two animals were assessed, and the haemosporidian prevalence was similar for males and females. The occurrence of haemosporidian infection in captive A. jacutinga observed in this study was similar to results found in other captive and wild birds in Brazil. We found three different lineages of haemosporidia. Two lineages were identified as Plasmodium sp., one of which was previously detected in Europe and Asia, and the other is a new lineage closely related to P. gallinaceum. A new third lineage was identified as Haemoproteus sp. We found no significant differences in hematological and biochemical values between infected and non-infected birds, and the haemosporidian lineage did not seem to have an impact on the clinical and physiological parameters of A. jacutinga. This is the first report on an evaluation of natural haemosporidian infections diagnosed by microscopic and molecular methods in A. jacutinga by hematology, blood biochemistry, and serum protein values. Determining physiological parameters, occurrence and an estimation of the impact of haemosporidia in endangered avian species may contribute to the management of species rehabilitation and conservation
The Multiscenario Multienvironment BioSecure Multimodal Database (BMDB)
A new multimodal biometric database designed and acquired within the
framework of the European BioSecure Network of Excellence is presented. It is
comprised of more than 600 individuals acquired simultaneously in three
scenarios: 1) over the Internet, 2) in an office environment with desktop PC,
and 3) in indoor/outdoor environments with mobile portable hardware. The three
scenarios include a common part of audio/video data. Also, signature and
fingerprint data have been acquired both with desktop PC and mobile portable
hardware. Additionally, hand and iris data were acquired in the second scenario
using desktop PC. Acquisition has been conducted by 11 European institutions.
Additional features of the BioSecure Multimodal Database (BMDB) are: two
acquisition sessions, several sensors in certain modalities, balanced gender
and age distributions, multimodal realistic scenarios with simple and quick
tasks per modality, cross-European diversity, availability of demographic data,
and compatibility with other multimodal databases. The novel acquisition
conditions of the BMDB allow us to perform new challenging research and
evaluation of either monomodal or multimodal biometric systems, as in the
recent BioSecure Multimodal Evaluation campaign. A description of this campaign
including baseline results of individual modalities from the new database is
also given. The database is expected to be available for research purposes
through the BioSecure Association during 2008Comment: Published at IEEE Transactions on Pattern Analysis and Machine
Intelligence journa
Ground-breaking Exoplanet Science with the ANDES spectrograph at the ELT
In the past decade the study of exoplanet atmospheres at high-spectral
resolution, via transmission/emission spectroscopy and cross-correlation
techniques for atomic/molecular mapping, has become a powerful and consolidated
methodology. The current limitation is the signal-to-noise ratio during a
planetary transit. This limitation will be overcome by ANDES, an optical and
near-infrared high-resolution spectrograph for the ELT. ANDES will be a
powerful transformational instrument for exoplanet science. It will enable the
study of giant planet atmospheres, allowing not only an exquisite determination
of atmospheric composition, but also the study of isotopic compositions,
dynamics and weather patterns, mapping the planetary atmospheres and probing
atmospheric formation and evolution models. The unprecedented angular
resolution of ANDES, will also allow us to explore the initial conditions in
which planets form in proto-planetary disks. The main science case of ANDES,
however, is the study of small, rocky exoplanet atmospheres, including the
potential for biomarker detections, and the ability to reach this science case
is driving its instrumental design. Here we discuss our simulations and the
observing strategies to achieve this specific science goal. Since ANDES will be
operational at the same time as NASA's JWST and ESA's ARIEL missions, it will
provide enormous synergies in the characterization of planetary atmospheres at
high and low spectral resolution. Moreover, ANDES will be able to probe for the
first time the atmospheres of several giant and small planets in reflected
light. In particular, we show how ANDES will be able to unlock the reflected
light atmospheric signal of a golden sample of nearby non-transiting habitable
zone earth-sized planets within a few tenths of nights, a scientific objective
that no other currently approved astronomical facility will be able to reach.Comment: 66 pages (103 with references) 20 figures. Submitted to Experimental
Astronom
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