Numerical Simulation of Baroclinic Jovian Vortices

We examine the evolution of baroclinic vortices in a time-dependent, nonlinear numerical model of a Jovian atmosphere. The model uses a normal-mode expansion in the vertical, using the barotropic and first two baroclinic modes. Results for the stability of baroclinic vortices on an f plane in the absence of a mean zonal flow are similar to results of Earth vortex models, although the presence of a fluid interior on the Jovian planets shifts the stability boundaries to smaller length scales. The presence of a barotropic mean zonal flow in the interior stabilizes vortices against instability and significantly modifies the finite amplitude form of baroclinic instabilities. The effect of a zonal flow on a form of barotropic instability produces periodic oscillations in the latitude and longitude of the vortex as observed at the level of the cloud tops. This instability may explain some, but not all, observations of longitudinal oscillations of vortices on the outer planets. Oscillations in aspect ratio and orientation of stable vortices in a zonal shear flow are observed in this baroclinic model, as in simpler twodimensional models. Such oscillations are also observed in the atmospheres of Jupiter and Neptune. The meridional propagation and decay of vortices on a β plane is inhibited by the presence of a mean zonal flow. The direction of propagation of a vortex relative to the mean zonal flow depends upon the sign of the meridional potential vorticity gradient; combined with observations of vortex drift rates, this may provide a constraint on model assumption for the flow in the deep interior of the Jovian planets

Type 1 Interferons Inhibit Myotube Formation Independently of Upregulation of Interferon-Stimulated Gene 15

Introduction: Type 1 interferon (IFN)-inducible genes and their inducible products are upregulated in dermatomyositis muscle. Of these, IFN-stimulated gene 15 (ISG15) is one of the most upregulated, suggesting its possible involvement in the pathogenesis of this disease. To test this postulate, we developed a model of type 1 IFN mediated myotube toxicity and assessed whether or not downregulation of ISG15 expression prevents this toxicity. Methods: Mouse myoblasts (C2C12 cell line) were cultured in the presence of type 1 or type 2 IFNs and ISG15 expression assessed by microarray analysis. The morphology of newly formed myotubes was assessed by measuring their length, diameter, and area on micrographs using imaging software. ISG15 expression was silenced through transfection with small interference RNA. Results: Type 1 IFNs, especially IFN-beta, increased ISG15 expression in C2C12 cells and impaired myotube formation. Silencing of ISG15 resulted in knockdown of ISG15 protein, but without phenotypic rescue of myotube formation. Discussion IFN-beta affects myoblast differentiation ability and myotube morphology in vitro.These studies provide evidence that ISG15, which is highly upregulated in dermatomyositis muscle, does not appear to play a key role in IFN-beta-mediated C2C12 myoblast cell fusion

Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 instrument

International audienceOrganic compounds play a central role in troposphere chemistry and increasingly are a viable target for remote sensing observations. In this paper, infra-red spectral features of three organic compounds are investigated in thermal emission spectra recorded by a balloon-borne instrument, MIPAS-B2, operating at high spectral resolution. It is demonstrated, for the first time, that PAN and acetone can be detected in infra-red remote sensing spectra of the upper troposphere; detection results are presented at tangent altitudes of 10.4 km and 7.5 km (not acetone). In addition, the results provide the first observation of spectral features of formic acid in thermal emission, as opposed to solar occultation, and confirm that concentrations of this gas are likely to be measurable in the free troposphere, given accurate spectroscopic data. For PAN, two bands are observed centred at 794 cm?1 and 1163 cm?1. For acetone and formic acid, one band has been detected for each so far with band centres at 1218 cm?1 and 1105 cm?1 respectively. Mixing ratios inferred at 10.4 km tangent altitude are 180 pptv and 530 pptv for PAN and acetone respectively, and 200 pptv for formic acid with HITRAN 2000 spectroscopy. Accuracies are on the order of 30 to 50%. The detection technique applied here is verified by examining weak but known signatures of CFC-12 and HCFC-22 in the same spectral regions as those of the organic compounds, with results confirming the quality of both the instrument and the radiative transfer model. The results suggest the possibility of global sensing of the organic compounds studied here which would be a major step forward in verifying and interpreting global tropospheric model calculations

Representaciones ecológicas en la infancia y estilos de vida

En aquest treball, hi analitzem diferents concepcions de les funcions simbòliques de les representacions, i des d'aquest plantejament indaguem si els nens i les nenes de diferents cultures i edats mostren similituds en els estils i en les maneres d'entendre la vida i el seu manteniment. Estudiem els dibuixos d'una illa imaginària que han produït nens i nenes -de sis a dotze anys- de l'Argentina, Colòmbia, l'Espanya i Anglaterra. Un dibuix de com la veurien en el moment d'arribar-hi i un altre de la mateixa illa després d'un any de viure-hi. Les produccions pictòriques han permès fer l'apropament a les representacions ecològiques dels infants dels diferents països i a les transformacions que introdueixen en l'ambient natural per a la seva adaptació.In this paper, we analyse the different conceptions of the symbolic functions of representations. Based on this we explore if boys and girls of different cultures and age groups show similarities in their ways of understanding life and how it is maintained. We studied two pictures of an imaginary island drawn by six to twelve year-old children from Argentina, Colombia, Spain and Great Britain. One of the pictures represented the island as they would see it on arrival to the island and the other one represented the island one year later. The pictures allowed us to approach the ecological representations of the children in their different countries as well as the transformations that they introduce in the natural environment to adapt to it.En este trabajo, analizamos diferentes concepciones de las funciones simbólicas de las representaciones, y desde este planteamiento indagamos si niños y niñas de distintas culturas y edades muestran similitudes en los estilos y formas de entender la vida y su mantenimiento. Estudiamos dos dibujos de una isla imaginaria que han producido niños y niñas -de seis a doce años- de Argentina, Colombia, España e Inglaterra. Un dibujo de cómo la verían a la llegada y otro de la misma isla pasado un año de vivir en ella. Las producciones pictóricas han permitido el acercamiento a las representaciones ecológicas de los niños y las niñas de los diferentes países y a las transformaciones que introducen en el ambiente natural para su adaptación a él