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Multiple Facets (multiple + facet)
Selected AbstractsMultiple facets of environmental impacts from Hurricane KatrinaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2010Marc Slattery No abstract is available for this article. [source] Cellular oxygen sensing, signalling and how to survive translational arrest in hypoxiaACTA PHYSIOLOGICA, Issue 2 2009M. Fähling Abstract Hypoxia is a consequence of inadequate oxygen availability. At the cellular level, lowered oxygen concentration activates signal cascades including numerous receptors, ion channels, second messengers, as well as several protein kinases and phosphatases. This, in turn, activates trans -factors like transcription factors, RNA-binding proteins and miRNAs, mediating an alteration in gene expression control. Each cell type has its unique constellation of oxygen sensors, couplers and effectors that determine the activation and predominance of several independent hypoxia-sensitive pathways. Hence, altered gene expression patterns in hypoxia result from a complex regulatory network with multiple divergences and convergences. Although hundreds of genes are activated by transcriptional control in hypoxia, metabolic rate depression, as a consequence of reduced ATP level, causes inhibition of mRNA translation. In a multi-phase response to hypoxia, global protein synthesis is suppressed, mainly by phosphorylation of eIF2-alpha by PERK and inhibition of mTOR, causing suppression of 5,-cap-dependent mRNA translation. Growing evidence suggests that mRNAs undergo sorting at stress granules, which determines the fate of mRNA as to whether being translated, stored, or degraded. Data indicate that translation is suppressed only at ,free' polysomes, but is active at subsets of membrane-bound ribosomes. The recruitment of specific mRNAs into subcellular compartments seems to be crucial for local mRNA translation in prolonged hypoxia. Furthermore, ribosomes themselves may play a significant role in targeting mRNAs for translation. This review summarizes the multiple facets of the cellular adaptation to hypoxia observed in mammals. [source] Investor Recognition, Liquidity, and Exchange Listings in the Reformed MarketsFINANCIAL MANAGEMENT, Issue 2 2006Pankaj K. Jain We examine multiple facets of firms' descisions to list on the NYSE. Although the average Nasdaq spreads are now comparable to the average NYSE spreads, we find that firms continue to switch from Nasdaq to the NYSE, and that they experience positive cumulative abnormal returns on listing. Using a simultaneous ststem of equations approach, we establish that enhanced investor recognition mainly explains this phenomenon. A logistic regression suggesrts that corporate listing choice is consistent with these findings, since eligible unlisted firms already have high volumes and recognition and might not benefit as much as do firms that actually switch. [source] Kisspeptin and the Preovulatory Gonadotrophin-Releasing Hormone/Luteinising Hormone Surge in the Ewe: Basic Aspects and Potential Applications in the Control of OvulationJOURNAL OF NEUROENDOCRINOLOGY, Issue 7 2010A. Caraty The identification of the neural mechanisms controlling ovulation in mammals has long been a ,holy grail' over recent decades, although the recent discovery of the kisspeptin systems has totally changed our views on this subject. Kisspeptin cells are the major link between gonadal steroids and gonadotrophin-releasing hormone (GnRH) neurones. In the female rodent, kisspeptin cells of the preoptic area are involved in the positive-feedback action of oestrogen on GnRH secretion, although the picture appears more complicated in the ewe. As in rodents, activation of preoptic kisspeptin neurones accompanies the GnRH surge in the ewe but an active role for arcuate kisspeptin neurones has also been proposed. Experimentally, kisspeptin is able to restore reproductive function when the hypothalamic-hypophyseal ovarian axis is quiescent. For example, i.v. infusion of a low dose of peptide in anoestrous ewes induces an immediate and sustained release of gonadotrophin, which subsides and then provokes a luteinising hormone (LH) surge a few hours later. This pharmacological intervention induces the same hormonal changes normally observed during the follicular phase of the oestrous cycle, including the secretion of oestrogen and its negative- and positive-feedback actions on the secretion of LH and follicle-stimulating hormone. Accordingly, a high percentage of kisspeptin-infused animals ovulated. Although the multiple facets of how the kisspeptin systems modulate GnRH secretion are not totally understood, the demonstration that exogenous kisspeptin administration can induce ovulation in anovulatory animals paves the way for future therapeutic applications aiming to control reproduction. [source] Adolescent Behavioral, Affective, and Cognitive Engagement in School: Relationship to DropoutJOURNAL OF SCHOOL HEALTH, Issue 9 2009Isabelle Archambault PhD ABSTRACT BACKGROUND: High school dropout represents an important public health issue. This study assessed the 3 distinct dimensions of student engagement in high school and examined the relationships between the nature and course of such experiences and later dropout. METHODS: We administered questionnaires to 13,330 students (44.7% boys) from 69 high schools in the province of Quebec (Canada). During 3 consecutive high school years, students reported their behavioral, emotional, and cognitive engagement to school. Information on later dropout status was obtained through official records. RESULTS: Although many adolescents remained highly engaged in high school, one third reported changes, especially decreases in rule compliance, interest in school, and willingness to learn. Students reporting low engagement or important decrements in behavioral investment from the beginning of high school presented higher risks of later dropout. CONCLUSION: School-based interventions should address the multiple facets of high school experiences to help adolescents successfully complete their basic schooling. Creating a positive social-emotional learning environment promises better adolescent achievement and, in turn, will contribute to a healthier lifestyle. [source] Government,nonprofit relations in comparative perspective: evolution, themes and new directionsPUBLIC ADMINISTRATION & DEVELOPMENT, Issue 1 2002Jennifer M. Brinkerhoff This overview article for the Symposium on Government,Nonprofit Relations in Comparative Perspective summarizes our current understanding of government,nonprofit relations, addresses several themes emerging from the collective papers and Symposium discussions, and discusses new and evolving trends in government,nonprofit relations. The review of government,nonprofit relations encompasses governance models and their incorporation of nonprofits, sector failures and their contribution to government,nonprofit relationships, and cross-sectoral analytic frameworks. Themes addressed include the material and normative benefits sought through nonprofits; various features of government,nonprofit interactions, including their increasing range and multiple facets, the impact of origins, relationship dynamism, and impacts; and what is public and what is private. The article concludes with the identification of selected new and evolving trends, including the influence of information technology on organizational structures and processes, the rise of supranational spheres of government,nonprofit interaction, the continuing tension between cooperation and identity maintenance, and simultaneous global lesson sharing and an emphasis on local-level problem-solving, where nonprofits are viewed as a means to maintaining continuity and redefining community. The article situates our understanding of government,nonprofit relations in a comparative perspective that accounts for dominant global paradigms, increasing interdependence among actors and nations, and evolving models of governance at all levels. Copyright © 2002 John Wiley & Sons, Ltd. [source] The evolution of the gas content of galaxy groupsASTRONOMISCHE NACHRICHTEN, Issue 9-10 2009E.M. Wilcots Abstract We examine multiple facets of the evolution of the gas content of galaxy groups. Complementing building evidence that a tremendous amount of galaxy transformation takes place in the group environment we find evidence of similar transformation of the gas content. In dynamically young groups galaxy-galaxy interactions appear to be responsible for depositing large quantities of neutral gas into the intergalactic medium. The gas content of dynamically evolved groups, however, is characterized by extended halos of diffuse hot gas. We also find that groups may harbor significant quantities of heretofore undetected baryons and that feedback from AGN may be responsible for heating the intragroup medium (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | |||||||||||||