Platelet-activating factor causes ventilation-perfusion mismatch in humans

We hypothesized that platelet-activating factor (PAF), a potent inflammatory mediator, could induce gas exchange abnormalities in normal humans. To this end, the effect of aerosolized PAF (2 mg/ml solution; 24 micrograms) on ventilation-perfusion (VA/Q) relationships, hemodynamics, and resistance of the respiratory system was studied in 14 healthy, nonatopic, and nonsmoking individuals (23 +/- 1 [SEM]yr) before and at 2, 4, 6, 8, 15, and 45 min after inhalation, and compared to that of inhaled lyso-PAF in 10 other healthy individuals (24 +/- 2 yr). PAF induced, compared to lyso-PAF, immediate leukopenia (P < 0.001) followed by a rebound leukocytosis (P < 0.002), increased minute ventilation (P < 0.05) and resistance of the respiratory system (P < 0.01), and decreased systemic arterial pressure (P < 0.05). Similarly, compared to lyso-PAF, PaO2 showed a trend to fall (by 12.2 +/- 4.3 mmHg, mean +/- SEM maximum change from baseline), and arterial-alveolar O2 gradient increased (by 16.7 +/- 4.3 mmHg) (P < 0.02) after PAF, because of VA/Q mismatch: the dispersion of pulmonary blood flow and that of ventilation increased by 0.45 +/- 0.1 (P < 0.01) and 0.29 +/- 0.1 (P < 0.04), respectively. We conclude that in normal subjects, inhaled PAF results in considerable immediate VA/Q inequality and gas exchange impairment. These results reinforce the notion that PAF may play a major role as a mediator of inflammation in the human lung.

Creencias y conocimiento acerca de la competencia lingüística de alumnado inmigrante: el caso de la provincia de Huesca

Ante la creciente incorporación de alumnado de origen inmigrante a nuestros centros educativos, y dada la práctica inexistencia de estudios empíricos que aborden esta nueva situación, entre el profesorado suelen primar ciertas creencias o ideas previas que condicionan las respuestas educativas en torno al proceso de enseñar la lengua o lenguas de la sociedad de acogida a estos alumnos. Nuestra investigación, a partir de la evaluación del conocimiento lingüístico adquirido en castellano por parte de un grupo de alumnos y alumnas de 1º de ESO, ha analizado algunos de los factores que determinan sus niveles de competencia lingüística. Ello, además de contrastar determinadas creencias sobre el aprendizaje de la lengua de estos colectivos, nos ha permitido formular ciertas indicaciones o sugerencias para abordar la cuestión

Economics breeds culture

Several recent papers document the influence and long lasting effects of technology on preferences. Simultaneously, cultural factors are often invoked to explain heterogeneity in preferences. These two ideas suggest that culture determines the short run equilibrium values of economic variables, but, in the long run, culture changes in response to the underlying economic fundamentals. We build a model in which preferences are endogenous and the diversity in preferences (the "cultural" diversity) is explained by the variation in the relevant economic fundamentals. This can help explain observed differences in labor market attachment among groups defined e.g., by citizenship, ethnicity or gender.

Sota terra: excavant als escenaris de la Batalla de l'Ebre. Televisió de Catalunya, 14 de juny de 2010

Sembla que donar a conèixer l"arqueologia com a disciplina amb metodologia científica i caràcter professional no sigui una tasca fàcil. Vèncer la idea que es ven en pel·lícules de l"estil d"Indiana Jones implica que cal fer una tasca de difusió de la disciplina cap al gran públic, mostrant les diferents cares que té avui dia de forma didàctica, entretinguda i rigorosa. En un principi la idea del programa Sota Terra, emès per TV3 entre el juny i el setembre del 2010, era precisament aquesta. Tal i com ho afirmen els responsables a la plana web del programa:"Hi ha diversió, humor, aventura i rigor. Per l"ordre que es vulgui". En realitat, però, veurem que alguns elements no són tan clars, com a mínim en el capítol que ressenyem: Excavant als escenaris de la Batalla de l"Ebre, emès el 14 de juny del 2010.

A missing spatial link in institutional quality

History tells that institutions evolve gradually over time, pushing new ideas across borders and cultures. Globalisation is argued to accelerate this process. We examine the spatial links of different political institutions across borders. Applying various tests for spatial proximity, we do not find evidence of contemporaneous spatial links. This result is robust to various measures of distance and of cultural proximity across countries. Instead, when we analyse long run dynamics diffusion of institutions seems to occur only gradually.