612 research outputs found

    Cambiando los paradigmas: el reto de la sostenibilidad en la arquitectura

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    ¿Cómo tendrá que cambiar la arquitectura para adaptarse al reto de la sostenibilidad? Si nos atenemos a la definición del concepto de sostenibilidad, se cuestionarán los factores que determinan nuestra manera de pensar la arquitectura. Situada en un contexto más amplio, el papel histórico de la arquitectura en la creciente independencia de la civilización con respecto a los factores climáticos se verá iluminado para proporcionar un ejemplo concreto del proceso teleológico de automatización. De manera análoga, si nos fijamos en las tipologías de la casa y el rascacielos, la noción complementaria a la huella ecológica sería la huella cultural. Se debate su efecto duradero y su profundo arraigo. En resumen, se subrayan una cantidad de pasos que los arquitectos, los educadores, y la sociedad en general deberán tomar en relación a la noción de calidad en la arquitectura. Una cuestión clave será la ubicua institución de las comisiones de control de proyectos que aseguren un proceso público y transparente de debate de la calidad arquitectónica previo a la realización de cualquier tipo de edificio: mejor revisar varias veces antes que construir de manera errónea una sola vez

    La esquina como revelación. De Schinkel a Mies

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    Este ensayo es un estudio sobre el rol cultural de la esquina visto a través de dos importantes edificios, cada uno diseñado por un arquitecto diferente: Karl Friedrich Schinkel (1781-1841) y Ludwig Mies van der Rohe (1886-1969). El tratamiento de las esquinas en el Altes Museum (Berlín, 1824-1830) y en la Neue Nationalgalerie (Berlín, 1963-1968) son, según propone este ensayo, referentes de amplios significados culturales en relación a actitudes cambiantes sobre el conocimiento, la comprensión del mundo y la certeza

    Effects of phthalate exposure on asthma may be mediated through alterations in DNA methylation

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    Background: phthalates may increase the asthma risk in children. Mechanisms underlying this association remain to be addressed. This study assesses the effect of phthalate exposures on epigenetic changes and the role of epigenetic changes for asthma. In the first step, urine and blood samples from 256 children of the Childhood Environment and Allergic diseases Study (CEAS) were analyzed. Urine 5OH-MEHP levels were quantified as an indicator of exposure, and asthma information was collected. DNA methylation (DNA-M) was measured by quantitative PCR. In the screening part of step 1, DNA-M of 21 potential human candidate genes suggested by a toxicogenomic data were investigated in 22 blood samples. Then, in the testing part of step 1, positively screened genes were tested in a larger sample of 256 children and then validated by protein measurements. In step 2, we replicated the association between phthalate exposure and gene-specific DNA-M in 54 children in the phthalate contaminated food event. In step 3, the risk of DNA-M for asthma was tested in 256 children from CEAS and corroborated in 270 children from the Isle of Wight (IOW) birth cohort. Results: differential methylation in three genes (AR, TNF?, and IL-4) was identified through screening. Testing in 256 children showed that methylation of the TNF? gene promoter was lower when children had higher urine 5OH-MEHP values (??=??0.138, P?=?0.040). Functional validation revealed that TNF? methylation was inversely correlated with TNF? protein levels (??=??0.18, P?=?0.041). In an additional sample of 54 children, we corroborated that methylation of the TNF? gene promoter was lower when urine 5OH-MEHP concentrations were higher. Finally, we found that a lower methylation of 5?CGI region of TNF? was associated with asthma in 256 CEAS children (OR?=?2.15, 95% CI?=?1.01 to 4.62). We replicated this in 270 children from the IOW birth cohort study. Methylation of the CpG site cg10717214 was negatively associated with asthma, when children had ‘AA’ or ‘AG’ genotype of the TNF? single nucleotide rs1800610. Conclusions: effects of phthalate exposure on asthma may be mediated through alterations in DNA methylatio

    Identification of Class I HLA T Cell Control Epitopes for West Nile Virus

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    The recent West Nile virus (WNV) outbreak in the United States underscores the importance of understanding human immune responses to this pathogen. Via the presentation of viral peptide ligands at the cell surface, class I HLA mediate the T cell recognition and killing of WNV infected cells. At this time, there are two key unknowns in regards to understanding protective T cell immunity: 1) the number of viral ligands presented by the HLA of infected cells, and 2) the distribution of T cell responses to these available HLA/viral complexes. Here, comparative mass spectroscopy was applied to determine the number of WNV peptides presented by the HLA-A*11:01 of infected cells after which T cell responses to these HLA/WNV complexes were assessed. Six viral peptides derived from capsid, NS3, NS4b, and NS5 were presented. When T cells from infected individuals were tested for reactivity to these six viral ligands, polyfunctional T cells were focused on the GTL9 WNV capsid peptide, ligands from NS3, NS4b, and NS5 were less immunogenic, and two ligands were largely inert, demonstrating that class I HLA reduce the WNV polyprotein to a handful of immune targets and that polyfunctional T cells recognize infections by zeroing in on particular HLA/WNV epitopes. Such dominant HLA/peptide epitopes are poised to drive the development of WNV vaccines that elicit protective T cells as well as providing key antigens for immunoassays that establish correlates of viral immunity. © 2013 Kaabinejadian et al

    Loss of Octarepeats in Two Processed Prion Pseudogenes in the Red Squirrel, Sciurus vulgaris

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    The N-terminal region of the mammalian prion protein (PrP) contains an ‘octapeptide’ repeat which is involved in copper binding. This eight- or nine-residue peptide is repeated four to seven times, depending on the species, and polymorphisms in repeat number do occur. Alleles with three repeats are very rare in humans and goats, and deduced PrP sequences with two repeats have only been reported in two lemur species and in the red squirrel, Sciurus vulgaris. We here describe that the red squirrel two-repeat PrP sequence actually represents a retroposed pseudogene, and that an additional and older processed pseudogene with three repeats also occurs in this species as well as in ground squirrels. We argue that repeat numbers may tend to contract rather than expand in prion retropseudogenes, and that functional prion genes with two repeats may not be viable

    Characterization of patients with embolic strokes of undetermined source in the NAVIGATE ESUS randomized trial

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    Background: The New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial vs. ASA to Prevent Embolism in Embolic Stroke of Undetermined Source (NAVIGATE-ESUS) trial is a randomized phase-III trial comparing rivaroxaban versus aspirin in patients with recent ESUS. Aims: We aimed to describe the baseline characteristics of this large ESUS cohort to explore relationships among key subgroups. Methods: We enrolled 7213 patients at 459 sites in 31 countries. Prespecified subgroups for primary safety and efficacy analyses included age, sex, race, global region, stroke or transient ischemic attack prior to qualifying event, time to randomization, hypertension, and diabetes mellitus. Results: Mean age was 66.9 ± 9.8 years; 24% were under 60 years. Older patients had more hypertension, coronary disease, and cancer. Strokes in older subjects were more frequently cortical and accompanied by radiographic evidence of prior infarction. Women comprised 38% of participants and were older than men. Patients from East Asia were oldest whereas those from Latin America were youngest. Patients in the Americas more frequently were on aspirin prior to the qualifying stroke. Acute cortical infarction was more common in the United States, Canada, and Western Europe, whereas prior radiographic infarctions were most common in East Asia. Approximately forty-five percent of subjects were enrolled within 30 days of the qualifying stroke, with earliest enrollments in Asia and Eastern Europe. Conclusions: NAVIGATE-ESUS is the largest randomized trial comparing antithrombotic strategies for secondary stroke prevention in patients with ESUS. The study population encompasses a broad array of patients across multiple continents and these subgroups provide ample opportunities for future research

    Semiconductor-based narrow-line and high-brilliance 193-nm laser system for industrial applications

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    We present a novel industrial-grade prototype version of a continuous-wave 193 nm laser system entirely based on solid state pump laser technology. Deep-ultraviolet emission is realized by frequency-quadrupling an amplified diode laser and up to 20 mW of optical power were generated using the nonlinear crystal KBBF. We demonstrate the lifetime of the laser system for different output power levels and environmental conditions. The high stability of our setup was proven in > 500 h measurements on a single spot, a crystal shifter multiplies the lifetime to match industrial requirements. This laser improves the relative intensity noise, brilliance, wall-plug efficiency and maintenance cost significantly. We discuss first lithographic experiments making use of this improvement in photon efficiency
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