Excitation Control: Balancing PSD-95 Function at the Synapse

Excitability of individual neurons dictates the overall excitation in specific brain circuits. This process is thought to be regulated by molecules that regulate synapse number, morphology and strength. Neuronal excitation is also influenced by the amounts of neurotransmitter receptors and signaling molecules retained at particular synaptic sites. Recent studies revealed a key role for PSD-95, a scaffolding molecule enriched at glutamatergic synapses, in modulation of clustering of several neurotransmitter receptors, adhesion molecules, ion channels, cytoskeletal elements and signaling molecules at postsynaptic sites. In this review we will highlight mechanisms that control targeting of PSD-95 at the synapse, and discuss how this molecule influences the retention and clustering of diverse synaptic proteins to regulate synaptic structure and strength. We will also discuss how PSD-95 may maintain a balance between excitation and inhibition in the brain and how alterations in this balance may contribute to neuropsychiatric disorders

Floristic analysis and biogeography of Tubiflorae in Egypt

The species distribution and biogeography of the Egyptian Tubiflorae were exam-ined in detail. We found 284 species of vascular plants belonging to 96 genera and 12 families, making the Egyptian Tubiflorae richer in species than that of other arid region floras: Libya and Saudi Arabia. The most species rich families were Scrophulariaceae, Boraginaceae, Labiatae, Convolvulaceae and Solanaceae, constituting more than 85% of the totál species in the order. The generic spectrum dominated by a suite of species-rich genera (Convolvulus, Heliotropium, Veronica, Solanum, Salvia, Cuscuta, Echium, Ipomoea and Orobanche). Therophytes were the most dominant life forms among the families, followed by chamaephytes and hemicryptophytes. Boraginaceae and Scrophulariaceae had the highest share of annuals. Remarkable distribution patterns of the life forms in the seven studied biogeographic zones were noticed. Trees were dominant in the Mediterranean zone, while shrubs, perennial herbs and therophytes were dominant in the Sinai. Altogether 8 endemic species and 14 near-endemics were included in the Tubiflorae of Egypt; mostly from Southern Sinai. We found that Labiatae and Scrophulariaceae were the families with higher concentration of endemics. Notably, Teucrium was among the genera of the Mediterranean Africa with highest endemism. Gamma diversity varied from 171 in the Sinai Peninsula to 43 and 39 in the Oases of the western Desert and along the Red Sea, respectively. Interestingly, highest significant values of similarity and species turnover (béta diversity) were observed between the Oases and the Nile lands. It is worthy noting the com-bined effect of both temperature and precipitation on gamma diversity of Tubiflorae in the 7 biogeographic zones. Our results indicated that almost one-half of the species showed a certain degree of consistency, i.e., with narrow geographic expansion. On the basis of UPGMA clustering and PCoA analysis, 4 floristic groups were recognized, each include one or more biogeographic zone. The occurrence of the species of Tubiflorae in the adjacent régiónál arid floras and their phytochorological afflnities, were discussed

Effet des fibrates sur la synthèse périphérique et le métabolisme hépatique de la bilirubine, un endobiotique aux propriétés anti-oxydantes et athéro-protectrice

La bilirubine, metabolite de Thème, est un antioxydant puissant exerçant des fonctions athéro-protectrices à des concentrations modérées; cependant elle est neurotoxique à des concentrations élevées. Synthétisée lors du métabolisme de l'hème par l'action successive des enzymes, hème-oxygénase (HO-1) et biliverdine-réductase (BVR), la bilirubine est métabolisée par l'UDP-glucuronosyltransférase (UGT1A1) dans le foie, afin d'être éliminée sous forme glucurono-conjuguée par le transporteur, Multidrug resistance Related Protein (MRP)2. Dans le cadre de la présente étude, nous avons validé une explication pharmacologique supplémentaire du mode d'action des fibrates, médication actuellement sur le marché dans le traitement de la dyslipidémie (prévenant l'athérosclérose in vivo). Les données obtenues démontrent que les fibrates modulent positivement les enzymes de la synthèse et du métabolisme de la bilirubine, favorisant ainsi ses propriétés antioxydantes et athéro-protectrice dans la paroi vasculaire et protègent l'organisme contre ses accumulations toxiques au niveau hépatique. Donc, un mode d'action additionnel des fibrates, pourrait être pris en considération, résultant en une élévation modérée de la concentration locale de la bilirubine et profitant de ses capacités antioxydantes et par la suite athéro-protectrices

Influence de l'élancement du pressiomètre sur la mesure des propriétés de résistance et de déformation des argiles en conditions non drainées

Expansion d'une cavité cylindrique -- Le critère de Tresca -- Le critère de Von Mises -- Expansion d'une cavité cylindrique dans un sol élasto-plastique -- L'essai pressiométrique -- Aperçu sur les essais pressiométriques -- Élancement du pressiomètre -- Théories d'interprétations -- Analyse numérique de l'essai pressiométrique -- Présentation du programme FLAC 3.4 -- Maillages choisis -- Données du calcul -- Effet de la finesse du maillage -- Chargement

Islamic financial principles and their application in project financing

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1988.Includes bibliographical references.by Ibrahim Ali El-Husseini.M.S

The genetics of asthma and the promise of genomics-guided drug target discovery

Asthma is an inflammatory airway disease that is estimated to affect 339 million people globally. The symptoms of about 5-10% of patients with asthma are not adequately controlled with current therapy, and little success has been achieved in developing drugs that target the underlying mechanisms of asthma rather than suppressing symptoms. Over the past 3 years, well powered genetic studies of asthma have increased the number of independent asthma-associated genetic loci to 128. In this Series paper, we describe the immense progress in asthma genetics over the past 13 years and link asthma genetic variants to possible drug targets. Further studies are needed to establish the functional significance of gene variants associated with asthma in subgroups of patients and to describe the biological networks within which they function. The genomics-guided discovery of plausible drug targets for asthma could pave the way for the repurposing of existing drugs for asthma and the development of new treatments