Resonance of Double-Diffusive Convection in a Porous Medium Heated with a Sinusoidal Exciting Temperature

studied numerically. The left vertical wall of the cavity is heated with a temperature varying sinusoidally in time, while the opposite cold wall is maintained at a constant temperature. The same walls of the cavity are salted with constant and different concentrations (the concentration of the heated wall is higher than that of the cooled one). The remaining horizontal walls are considered adiabatic and impermeable. The parameters governing the problem are the amplitude of the variable temperature (0 £ a £ 1), its period (0.0001 £ t £ 10), the buoyancy forces ratio (-5 £ N £ +5), the Lewis number (0.1 £ Le £ 10) and the thermal Darcy-Rayleigh number (RT = 400). Effects of these parameters on fluid flow, temperature and concentration distributions and mean heat and mass transfers within the cavity are analyzed. Results obtained show that both heat and mass transfers could be significantly enhanced or reduced, with respect to those generated in the case of constant heating conditions by proper choice of the parameters related to the periodic temperature

Height Partition Effect on Combined Mixed Convection and Surface Radiation in a Vented Rectangular Cavity

The present paper reports numerical results of mixed convection and surface radiation within a horizontal ventilated cavity heated from below and provided with an adiabatic thin partition on the heated surface. Air, a radiatively transparent medium, is considered to be the cooling fluid. The effect of the governing parameters, which are the Reynolds number, 200 Re 5000, the relative height of the baffle, 0 Hb 0.75, and the emissivity of the walls, 0 1, on the fluid flow and heat transfer characteristics is studied in detail. The maximum and mean temperatures, the ratio, QE/QL, of the heat quantities leaving the cavity through the exit, QE, and through the left vertical cold side, QL, are also presented versus the above controlling parameters

Western Saharan and Southern Moroccan Sahrawis: National Identity and Mobilization.

Depto. de Relaciones Internacionales e Historia GlobalFac. de Ciencias Políticas y SociologíaTRUEpu

Los esfuerzos para dirección de bosque de alcornoque y sus efectos sobre conservación de suelo, la meseta Shoul, región de Rabat, Marruecos

The Shoul oak grove is a forested ecosystem inherited from a Holocene phase of ecological optimum; its evolution, through the double geologic and human temporality, and in relation with several processes of degradation, led to the progressive loss of its environmental equilibrium and further to the reduction of its economic contributions. The fragility of these forests is the consequence of the convergence of two main factors, i) the intrinsic fragility of the forested environment based on an unstable balance between the tree, the leached soils and their moisture content ; ii) the anthropological action on the forest environment and its degradation with the change of its floristic composition. During the colonization the new context was at the origin of the new social and economic relation between the forest and the surrounding populations. The current use of this oak grove is in a classic scheme of the reports society / forest in Morocco. The population is especially of pastoral main activity in the bordering communes. But the oak groves of Mamora-Sehoul are integrated into the area of influence of several cities, what exposes the forest to the risks of uncontrolled urbanization. These oak groves are thus in the centre of interest of several stakeholders with opposite behaviour and a new paradigm of relation rural/urban. Through a double approach, environmental and socio-economic, this paper will try to bring elements of answer by analyzing the interactions between a forest which reached an alarming threshold of degradation and a society affected by important changes in its modes of intervention and exploitation.La arboleda de roble Shoul es un ecosistema arbolado heredado de una fase de Holocene de grado óptimo ecológico; su evolución, por la doble temporalidad geológica y humana, y en relación con varios procesos de degradación, conducida a la pérdida progresiva de su equilibrio ambiental y con relación a la reducción de sus contribuciones económicas. La fragilidad de estos bosques es la consecuencia de la convergencia de dos factores principales, i) la fragilidad intrínseca del ambiente arbolado basado en un equilibrio(saldo) inestable entre el árbol, los suelos leached y su contenido de humedad; ii) la acción antropológica sobre el ambiente forestal y su degradación con el cambio de su composición floristic. Durante la colonización el nuevo contexto estaba en el origen de la nueva relación social y económica entre el bosque y las poblaciones circundantes. El empleo corriente de esta arboleda de roble está en un esquema clásico de la sociedad de informes / el bosque en Marruecos. La población es sobre todo de actividad pastoral principal en las comunas de lindar. Pero las arboledas de roble de Mamora-Sehoul son integradas en el área de influencia de varias ciudades, que expone el bosque a los riesgos de urbanización incontrolada. Estas arboledas de roble son así en el centro de interés de varios tenedores de apuestas con el comportamiento de enfrente y un nuevo paradigma de relación rural/urbana. Por un doble acercamiento, ambiental y socioeconómico, este papel(periódico) tratará de traer los elementos de respuesta por analizando las interacciones entre un bosque que alcanzó un umbral alarmante de degradación y una sociedad afectada por cambios importantes de sus modos de intervención y explotación

Soluble Isoforms of Vascular Endothelial Growth Factor Are Predictors of Response to Sunitinib in Metastatic Renal Cell Carcinomas

Angiogenesis is the target of several agents in the treatment of malignancies, including renal cell carcinoma (RCC). There is a real need for surrogate biomarkers that can predict selection of patients who may benefit from antiangiogenic therapies, prediction of disease outcome and which may improve the knowledge regarding mechanism of action of these treatments. Tyrosine kinase inhibitors (TKI) have proven efficacy in metastatic RCC (mRCC). However, the molecular mechanisms underlying the clinical response to these drugs remain unclear.The present study aimed to identify molecular biomarkers associated with the response to sunitinib, a Tyrosine kinase inhibitor. To evaluate this relationship, primary tumors from 23 metastatic RCC patients treated by sunitinib were analyzed for a panel of 16 biomarkers involved in tumor pathways targeted by sunitinib, using real-time quantitative reverse-transcriptase PCR. Nine of the 23 patients (39%) responded to sunitinib. Among transcripts analyzed, only the levels of vascular endothelial growth factor (VEGF) soluble isoforms (VEGF(121) and VEGF(165)) were associated with the response to sunitinib (P = 0.04 for both). Furthermore, the ratio of VEGF soluble isoforms (VEGF(121)/VEGF(165)) was significantly associated with prognosis (P = 0.02).This preliminary study provides a promising tool that might help in the management of metastatic RCC, and could be extended to other tumors treated by TKI

EMMPRIN Promotes Melanoma Cells Malignant Properties through a HIF-2alpha Mediated Up-Regulation of VEGF-Receptor-2

EMMPRIN's expression in melanoma tissue was reported to be predictive of poor prognosis. Here we demonstrate that EMMPRIN up-regulated VEGF receptor-2 (VEGFR-2) in two different primary melanoma cell lines and consequently increased migration and proliferation of these cells while inhibiting their apoptosis. SiRNA inhibition of VEGFR-2 expression abrogated these EMMPRIN effects. EMMPRIN regulation of VEGFR-2 was mediated through the over-expression of HIF-2α and its translocation to the nucleus where it forms heterodimers with HIF-1β. These results were supported by an in vivo correlation between the expression of EMMPRIN with that of VEGFR-2 in human melanoma tissues as well as with the extent of HIF-2α localization in the nucleus. They demonstrate a novel mechanism by which EMMPRIN promotes tumor progression through HIF-2α/VEGFR-2 mediated mechanism, with an autocrine role in melanoma cell malignancy. The inhibition of EMMPRIN in cancer may thus simultaneously target both the VEGFR-2/VEGF system and the matrix degrading proteases to block tumor cell growth and invasion