Valoración crítica sobre los derechos de la discapacidad en relación con las pruebas de diagnóstico prenatal : reflexiones y recomendaciones.

Para mucha gente, la realización de pruebas de diagnóstico prenatal para impedir el nacimiento de bebés con discapacidad les parece indiscutiblemente buena. Incluso si la prueba no va a ayudar esa vez a que nazca un niño sano, da a los futuros padres la oportunidad de intentar otra vez para poder concebir. Sin embargo, para otros el diagnóstico prenatal les parece algo muy diferente. Si uno reflexiona sobre la historia del trato que nuestra sociedad da a las personas con discapacidad, no resulta difícil ver por qué la gente que se encuentra identificada con el movimiento de derechos a favor de los discapacitados, puede contemplar estas pruebas como algo peligroso. Para los miembros de este movimiento, el vivir con rasgos de discapacidad no tiene por qué resultar perjudicial o desventajoso para las expectativas que un individuo tenga para llevar una vida que valga la pena, o para las familias en las que se desarrollan, o para la sociedad en su conjunto. Aunque este movimiento no mantiene una postura única sobre el diagnóstico prenatal, muchos de sus miembros creen que el apoyo público al diagnóstico prenatal, muchos de sus miembros creen que el apoyo público al diagnóstico prenatal y al aborto basados en la presencia de discapacidad, contradice la filosofía y los objetivos básicos de este movimiento.

Upper limit on the cosmic-ray photon flux above 10(19) eV using the surface detector of the Pierre Auger Observatory

A method is developed to search for air showers initiated by photons using data recorded by the surface detector of the Auger Observatory. The approach is based on observables sensitive to the longitudinal shower development, the signal risetime and the curvature of the shower front. Applying this method to the data, tipper limits on the flux of photons of 3.8 x 10(-3), 2.5 x 10(-3), and 2.2 x 10(-3) km(-2) sr(-1) yr(-1) above 10(19) eV, 2 x 10(19) eV, and 4 x 10(19) eV are derived, with corresponding limits on the fraction of photons being 2.0%, 5.1%, and 31% (all limits at 95% c.l.). These photon limits disfavor certain exotic models of sources of cosmic rays. The results also show that the approach adopted by the Auger Observatory to calibrate the shower energy is not strongly biased by a contamination from photons. (C) 2008 Elsevier B.V. All rights reserved.

Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei

Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of the cosmic rays with the highest-energies, which are correlated with the positions of relatively nearby active galactic nuclei (AGN) [Pierre Auger Collaboration, Science 318 (2007) 938]. The correlation has maximum significance for cosmic rays with energy greater than similar to 6 x 10(19) eV and AGN at a distance less than similar to 75 Mpc. We have confirmed the anisotropy at a confidence level of more than 99% through a test with parameters specified a priori, using an independent data set. The observed correlation is compatible with the hypothesis that cosmic rays with the highest-energies originate from extra-galactic sources close enough so that their flux is not significantly attenuated by interaction with the cosmic background radiation (the Greisen-Zatsepin-Kuz`min effect). The angular scale of the correlation observed is a few degrees, which suggests a predominantly light composition unless the magnetic fields are very weak outside the thin disk of our galaxy. Our present data do not identify AGN as the sources of cosmic rays unambiguously, and other candidate sources which are distributed as nearby AGN are not ruled out. We discuss the prospect of unequivocal identification of individual sources of the highest-energy cosmic rays within a few years of continued operation of the Pierre Auger Observatory. (C) 2008 Elsevier B.V. All rights reserved.

Atmospheric effects on extensive air showers observed with the surface detector of the Pierre Auger observatory

Atmospheric parameters, Such as pressure (P), temperature (T) and density (rho proportional to P/T), affect the development of extensive air showers initiated by energetic cosmic rays. We have Studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a similar to 10% seasonal modulation and similar to 2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of P and rho. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory. (C) 2009 Elsevier B.V. All rights reserved.

Upper limit on the cosmic-ray photon fraction at EeV energies from the Pierre Auger Observatory

From direct observations of the longitudinal development of ultra-high energy air showers performed with the Pierre Auger Observatory, upper limits of 3.8%, 2.4%, 3.5% and 11.7% (at 95% c.l.) are obtained on the fraction of cosmic-ray photons above 2, 3, 5 and 10 EeV (1 EeV equivalent to 10(18) eV), respectively. These are the first experimental limits on ultra-high energy photons at energies below 10 EeV. The results complement previous constraints on top-down models from array data and they reduce systematic uncertainties in the interpretation of shower data in terms of primary flux, nuclear composition and proton-air cross-section. (C) 2009 Elsevier B.V. All rights reserved.

The fluorescence detector of the Pierre Auger Observatory

The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions. (C) 2010 Elsevier B.V All rights reserved.

A study of the effect of molecular and aerosol conditions in the atmosphere on air fluorescence measurements at the Pierre Auger Observatory

The air fluorescence detector of the Pierre Auger Observatory is designed to perforin calorimetric measurements of extensive air showers created by Cosmic rays of above 10(18) eV. To correct these measurements for the effects introduced by atmospheric fluctuations, the Observatory contains a group Of monitoring instruments to record atmospheric conditions across the detector site, ail area exceeding 3000 km(2). The atmospheric data are used extensively in the reconstruction of air showers, and are particularly important for the correct determination of shower energies and the depths of shower maxima. This paper contains a summary of the molecular and aerosol conditions measured at the Pierre Auger Observatory since the start of regular operations in 2004, and includes a discussion of the impact of these measurements oil air shower reconstructions. Between 10(18) and 10(20) eV, the systematic Uncertainties due to all atmospheric effects increase from 4% to 8% in measurements of shower energy, and 4 g cm(-2) to 8 g cm(-2) in measurements of the shower maximum. (C) 2010 Elsevier B.V. All rights reserved.

Causalidade: uma abordagem teórica

O trabalho desenvolvido tem por objetivo uma sistematização teórica do estudo do conceito da causalidade na Psicologia. Aborda a contribuição da Epistemologia nas obras de Hume, Kant e Maine Biran e, mais recentemente, Mario Bunge, e da Epistemologia Genética nos estudos desenvolvidos por Jean Piaget. Na Psicologia Contemporânea, temos a obra dos psicólogos K. Koffka, W. Köhler e S. Asch dentro da Psicologia da Gestalt, que apresenta relevante in fluência nos atuais trabalhos desenvolvidos' em Psicologia sobre o conceito de causalidade. A posição gestaltista aparece influenciando a obra de Michotte, de caráter fenomenológico. Ainda, em todo o trabalho dos psicólogos sociais em 'relação à causalidade. Inicialmente em Heider, o qual formula a noção de atribuição de causalidade, objeto de estudos por vários autores, entre os quais destacamos Jones e Davis, Kelley e Kruglanski. Concluímos considerando, em termos avaliativos, as diversas perspectivas teóricas apresentadas, o que nos permite um questionamento da posição atual da psicologia nos estudos sobre a causalidade.

Rapid climate change during the Weichselian Lateglacial in Ireland: Chironomid-inferred summer temperatures from Fiddaun, Co. Galway

A lacustrine sediment core from Fiddaun, western Ireland was studied to reconstruct summer temperature changes during the Weichselian Lateglacial. This site is located close to the Atlantic Ocean; and so is potentially sensitive to climatic changes associated with changes in ocean circulation. The record, comprising the end of the Weichselian Pleniglacial to the early Holocene, was analysed for fossil chironomids, lithology, and oxygen and carbon isotopes in the sedimentary carbonates. These proxies clearly show rapid warming at the onset of the Lateglacial Interstadial, relatively high summer temperatures during the Interstadial, pronounced cooling during the Younger Dryas, and subsequent warming at the transition to the Holocene. Chironomid-inferred mean July air temperatures for the Interstadial are ~12.5–14.5 °C, ~7.5 °C for the Younger Dryas, and ~15.0 °C for the early Holocene. Furthermore, this research provides evidence for at least two cold events during the Interstadial. These more moderate temperature oscillations can be correlated to Greenland Interstadial events 1b and 1d, on the basis of the age-depth model for the Fiddaun sequence. Based on multiple proxies, the first cold oscillation (GI-1d) was the more severe of the two in Ireland.

Climatic and environmental changes during the Weichselian Lateglacial Interstadial in the Weerterbos region, the Netherlands

Lake sediment records from the Weerterbos region, in the southern Netherlands, were studied to reconstruct summer temperature and environmental changes during the Weichselian Lateglacial Interstadial. A sediment core obtained from a small lacustrine basin was analysed for multiple proxies, including lithological changes, oxygen isotopes of bulk carbonates, pollen and chironomids. It was found that the oxygen isotope record differed strongly from the other proxies. Based on a comparison with three additional lake sediment records from the same region, it emerged that the oxygen isotope records were strongly affected by local environmental conditions, impeding the distinction of a regional palaeoclimate signal. The chironomid-inferred July air temperature reconstruction produced inferred interstadial temperatures ranging between ∼15° and 18°C, largely consistent with previously published results from the northern part of the Netherlands. A temporary regressive phase in the pollen record, which can be tentatively correlated with the Older Dryas, preceded the expansion of birch woodland. Despite differences between the four pollen records from the Weerterbos region, a comparable regressive vegetation phase that was possibly the result of a shift to drier conditions could be discerned in all of the profiles. In addition, a temporary temperature decline of ∼1.5°C was inferred from the chironomid record during this regressive phase. The multi-proxy approach used here enabled a direct comparison of inferred changes in temperature, vegetation and environmental conditions at an individual site, while the multi-site approach provided insight into the factors influencing the pollen and isotope records from these small-scale depressions.

Validation of climate model-inferred regional temperature change for late-glacial Europe

Comparisons of climate model hindcasts with independent proxy data are essential for assessing model performance in non-analogue situations. However, standardized palaeoclimate data sets for assessing the spatial pattern of past climatic change across continents are lacking for some of the most dynamic episodes of Earth’s recent past. Here we present a new chironomid-based palaeotemperature dataset designed to assess climate model hindcasts of regional summer temperature change in Europe during the late-glacial and early Holocene. Latitudinal and longitudinal patterns of inferred temperature change are in excellent agreement with simulations by the ECHAM-4 model, implying that atmospheric general circulation models like ECHAM-4 can successfully predict regionally diverging temperature trends in Europe, even when conditions differ significantly from present. However, ECHAM-4 infers larger amplitudes of change and higher temperatures during warm phases than our palaeotemperature estimates, suggesting that this and similar models may overestimate past and potentially also future summer temperature changes in Europe.

Clinical performance of a sutureless aortic bioprosthesis: five-year results of the 3f Enable long-term follow-up study.

OBJECTIVE Sutureless valves are designed to facilitate surgical implantation, including less-invasive techniques in aortic valve replacement, by maintaining surgical precision of implantation compared with transcatheter techniques. Long-term clinical experience with sutureless valves is lacking. We report the 5-year follow-up results of an international, prospective, multicenter study evaluating the clinical performance and safety of the 3f Enable valve (Medtronic Inc, Minneapolis, Minn). METHODS Between March 2007 and December 2009, 141 patients (54 male; mean age, 76.1±5.7 years) undergoing aortic valve replacement with the 3f Enable valve were enrolled in 10 European sites. The mean follow-up was 2.76 years (range, 2 days to 5.1 years; total, 388.7 patient-years). Echocardiographic valvular hemodynamic and morphologic analyses were performed by an independent core laboratory. RESULTS The mean systolic gradient was 10.4±4.4 mm Hg at discharge and 7.7±4.1 mm Hg at 5 years. The mean effective orifice area was 1.7±0.5 cm2 at discharge and 1.6±0.2 cm2 at 5 years. Freedom from all-cause and valve-related mortality was 87.6%±2.9% and 96.8%±1.6% at 1 year (113 patients at risk) and 77.0%±7.5% and 93.8%±4.8% at 5 years (24 patients at risk), respectively. Six patients underwent reoperation (4 because of major paravalvular leakage and 2 because of endocarditis). Freedom from reoperation was 95.4%±1.9% at 1 year and 95.4%±6.1% at 5 years. No structural valve deterioration occurred during the follow-up period. CONCLUSIONS The sutureless 3f Enable valve represents a safe and effective treatment for aortic valve stenosis, providing an excellent hemodynamic profile. This study represents the longest follow-up study for a sutureless bioprosthesis. Sutureless valves may become an option for all patients with indicated biological aortic valve replacement.