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Complex Interplay (complex + interplay)
Selected AbstractsComplex interplay between glutamate receptors and intracellular Ca2+ stores during ischaemia in rat spinal cord white matterTHE JOURNAL OF PHYSIOLOGY, Issue 1 2006Mohamed Ouardouz Electrophysiological recordings of propagated compound action potentials (CAPs) and axonal Ca2+ measurements using confocal microscopy were used to study the interplay between AMPA receptors and intracellullar Ca2+ stores in rat spinal dorsal columns subjected to in vitro combined oxygen and glucose deprivation (OGD). Removal of Ca2+ or Na+ from the perfusate was protective after 30 but not 60 min of OGD. TTX was ineffective with either exposure, consistent with its modest effect on ischaemic depolarization. In contrast, AMPA antagonists were very protective, even after 60 min of OGD where 0Ca2++ EGTA perfusate was ineffective. Similarly, blocking ryanodine receptor-mediated Ca2+ mobilization from internal stores (0Ca2++ nimodipine or 0Ca2++ ryanodine), or inositol 1,4,5-trisphosphate (IP3)-dependent Ca2+ release (block of group 1 metabotropic glutamate receptors with 1-aminoindan-1,5-dicarboxylic acid, inhibition of phospholipase C with U73122 or IP3 receptor block with 2APB; each in 0Ca2+) were each very protective, with the combination resulting in virtually complete functional recovery after 1 h OGD (97 ± 32% CAP recovery versus 4 ± 6% in artificial cerebrospinal fluid). AMPA induced a rise in Ca2+ concentration in normoxic axons, which was greatly reduced by blocking ryanodine receptors. Our data therefore suggest a novel and surprisingly complex interplay between AMPA receptors and Ca2+ mobilization from intracellular Ca2+ stores. We propose that AMPA receptors may not only allow Ca2+ influx from the extracellular space, but may also significantly influence Ca2+ release from intra-axonal Ca2+ stores. In dorsal column axons, AMPA receptor-dependent mechanisms appear to exert a greater influence than voltage-gated Na+ channels on functional outcome following OGD. [source] Homoepitaxy of ZnTe on (100) oriented substrates: Technology issues and MOVPE growth aspectsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10-11 2005M. Traversa Abstract The metalorganic vapour phase epitaxy of ZnTe on single crystal (100)ZnTe:P wafers is reported. The technological steps to prepare a substrate surface suitable for the high quality homoepitaxy of ZnTe are identified and optimised in terms of structural and morphological properties of overgrown epilayers. Removal of ,7 µm of material from the ZnTe:P wafers by chemical etching in 1% Br2 -methanol solution proved necessary to achieve a sufficiently smooth and homogeneous surface; in-situ H2 heat treatment of the wafers at 350°C immediately before growth ensures optimal desorption of residual oxides, allowing epilayer crystalline quality comparable to the substrate. However, the structure of epilayers degrades for growth temperatures (TG) above 350 °C due to the occurrence of stacking faults (SFs) within ,200-300 nm from the epilayer-substrate interface. Accordingly, the epilayer band-edge luminescence vanishes below 350 nm, indicating a worsening of the material radiative efficiency in very thin epilayers. The epilayer surface morphology is the result of a complex interplay between SF nucleation and Te:Zn ad-atom stoichiometry during growth. Almost featureless morphologies are obtained for growth at 350 °C, i.e. under nearly stoichiometric surface conditions. Pyramid-like hillocks develop instead for TG , 360 °C, corresponding to Te-rich surface conditions, their density rapidly increasing up to around 9 × 106 cm,2 at TG = 400 °C. Hillocks occur in close pairs on the epilayer surface, their nucleation being strongly reduced if a thin ZnTe buffer layer is grown at low (325 °C) temperature, i.e. if SFs do not occur at the epilayer-substrate interface. This demonstrates that hillocks form as a result of three-dimensional growth around partial dislocations pairs bounding SFs, the phenomenon being driven by Te ad-atoms experiencing a Schwoebel potential barrier at the surface step edges around the dislocations. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The heel and toe of the cell's foot: A multifaceted approach for understanding the structure and dynamics of focal adhesionsCYTOSKELETON, Issue 11 2009Haguy Wolfenson Abstract Focal adhesions (FAs) are large clusters of transmembrane receptors of the integrin family and a multitude of associated cytoplasmic "plaque" proteins, which connect the extracellular matrix-bound receptors with the actin cytoskeleton. The formation of nearly stationary FAs defines a boundary between the dense and highly dynamic actin network in lamellipodium and the sparser and more diverse cytoskeletal organization in the lamella proper, creating a template for the organization of the entire actin network. The major "mechanical" and "sensory" functions of FAs; namely, the nucleation and regulation of the contractile, myosin-II-containing stress fibers and the mechanosensing of external surfaces depend, to a major extent, on the dynamics of molecular components within FAs. A central element in FA regulation concerns the positive feedback loop, based on the most intriguing feature of FAs; that is, their dependence on mechanical tension developing by the growing stress fibers. FAs grow in response to such tension, and rapidly disassemble upon its relaxation. In this article, we address the mechanistic relationships between the process of FA development, maturation and dissociation and the dynamic molecular events, which take place in different regions of the FA, primarily in the distal end of this structure (the "toe") and the proximal "heel," and discuss the central role of local mechanical forces in orchestrating the complex interplay between FAs and the actin system. Cell Motil. Cytoskeleton 66: 1017,1029, 2009. © 2009 Wiley-Liss, Inc. [source] Inhibitory functioning across ADHD subtypes: Recent findings, clinical implications, and future directionsDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2008Zachary W. Adams Abstract Although growing consensus supports the role of deficient behavioral inhibition as a central feature of the combined subtype of ADHD (ADHD/C; Barkley 1997 Psychol Bull 121:65,94; Nigg 2001 Psychol Bull 127:571,598), little research has focused on how this finding generalizes to the primarily inattentive subtype (ADHD/I). This question holds particular relevance in light of recent work suggesting that ADHD/I might be better characterized as a disorder separate from ADHD/C (Diamond 2005 Dev Psychopathol 17:807,825; Milich et al. 2001 Clin Psychol Sci Pract 8:463,488). This article describes major findings in the area of inhibitory performance in ADHD and highlights recent research suggesting important areas of divergence between the subtypes. In particular, preliminary findings point to potential differences between the subtypes with respect to how children process important contextual information from the environment, such as preparatory cues that precede responses and rewarding or punishing feedback following behavior. These suggestive findings are discussed in the context of treatment implications, which could involve differential intervention approaches for each subtype targeted to the specific deficit profiles that characterize each group of children. Future research avenues aimed toward building a sound theoretical model of ADHD/I and a better understanding of its relation to ADHD/C are also presented. Specifically, investigators are encouraged to continue studying the complex interplay between inhibitory and attentional processes, as this area seems particularly promising in its ability to improve our understanding of the potentially distinct pathologies underlying the ADHD subtypes. © 2008 Wiley-Liss, Inc. Dev Disabil Res Rev 2008;14:268,275. [source] Analysis of regulatory elements of E-cadherin with reporter gene constructs in transgenic mouse embryosDEVELOPMENTAL DYNAMICS, Issue 2 2003Marc P. Stemmler Abstract Proper regulation of E-cadherin,mediated cell adhesion is important during early embryonic development and in organogenesis. In mice, E-cadherin is expressed from the fertilized egg onward and becomes down-regulated during gastrulation in mesoderm and its derivatives, but its expression is maintained in all epithelia. E-cadherin promoter analyses led to the identification of binding sites for two transcriptional repressors, Snail and SIP1, which are able to mediate down-regulation in vitro, but little is known about the regulatory elements that govern E-cadherin transcriptional activity in vivo. Here, we compared the developmentally regulated expression of a series of lacZ -reporter transgenes fused to different sequences of the murine E-cadherin gene between ,6 kb, including the promoter, and +16 kb, covering one third of intron 2. Four different segments with distinct regulatory properties were identified. The promoter fragment from +0.1 to ,1.5 kb remains inactive in most cases but occasionally induces ectopic expression in mesodermal tissues, although it contains binding sites for the repressors Snail and SIP1. This promoter fragment also lacks positive elements needed for the activation of transcription in ectoderm and endoderm. Sequences from ,1.5 to ,6 kb harbor regulatory elements for brain-specific expression and, in addition, insulator or silencer elements, because they are consistently inactive in the mesoderm. Only if sequences from +0.1 to +11 kb are combined with the promoter fragments is E-cadherin,specific transgene expression observed in endoderm and certain epithelia. Sequences between +11 and +16 kb contain cis -active elements that generally enhance transcription. Our analyses show that E-cadherin expression is governed by a complex interplay of multiple regulatory regions dispersed throughout large parts of the locus. Developmental Dynamics 227:238,245, 2003. © 2003 Wiley-Liss, Inc. [source] Glucose homeostasis and the gastrointestinal tract: insights into the treatment of diabetesDIABETES OBESITY & METABOLISM, Issue 1 2008D. Maggs The gastrointestinal tract is increasingly viewed as a critical organ in glucose metabolism because of its role in delivering glucose to the circulation and in secreting multiple glucoregulatory hormones that, in concert with insulin and glucagon, regulate glucose homeostasis. Under normal conditions, a complex interplay of these hormones acts to maintain plasma glucose within a narrow range despite large variations in the availability of glucose, particularly during transition from the fasting to fed state. In the fed state, the rate at which nutrients are passed from the stomach to the duodenum, termed gastric emptying rate, is a key determinant of postprandial glucose flux. In patients with diabetes, the regulation of glucose metabolism is disrupted resulting in fasting and postprandial hyperglycaemia. Elucidation of the role of the gastrointestinal tract, gut-derived glucoregulatory peptides and gastric emptying rate offers a new perspective on glucose homeostasis and the respective importance of these factors in the diabetes state. This review will highlight the importance of the gastrointestinal tract in playing a key role in glucose homeostasis, particularly in the postprandial period, and the role of established or new therapies that either leverage or modify gastrointestinal function to improve glycaemic state. [source] Worldwide distribution of Pseudomonas aeruginosa clone C strains in the aquatic environment and cystic fibrosis patientsENVIRONMENTAL MICROBIOLOGY, Issue 7 2005Ute Römling Summary Highly successful bacterial clones have the ability to effectively colonize environmental niches and patients. However, the factors which determine the complex interplay between the colonization of environmental niches and patients are mainly unknown. In this study we show that Pseudomonas aeruginosa clone C strains are distributed worldwide and highly prone to infect cystic fibrosis (CF) patients in Canada, England, France and Germany. In Hanover, Germany and Vancouver, Canada, clone C strains are highly prevalent in the CF patient community, although the mechanisms of acquisition may have been different. All clone C strains showed highly related macrorestriction fragment pattern of the whole genome as visualized by pulsed-field gel electrophoresis and harboured the 102 kbp plasmid pKLC102. Comparison of three prevalent P. aeruginosa clones with different distribution between the environment and patients revealed that neither enhanced biofilm formation nor antibiotic resistance was responsible for the spread of clone C. Clone M, which was highly prevalent in the clinical environment such as sanitary facilities, lacked motility, which could explain its relatively low prevalence in CF patients. Elucidation of the mechanisms which lead to the prevalence of clone C strain in patients and the environment requires the investigation of additional phenotypes. [source] The diffusion of environmental policy innovations: cornerstones of an analytical frameworkENVIRONMENTAL POLICY AND GOVERNANCE, Issue 2 2005Kerstin Tews Abstract Comparative policy analysis increasingly faces the challenge of incorporating external forces on national policy developments into its analytical framework. Scholars of international relations have recognized that the behaviour of states , in terms of policy outputs , converges even in the absence of binding international agreements. These two branches of research can be bridged by the concept of policy diffusion. Diffusion analysis asks for those conditions that favour or hinder the spread of policy innovations within the international system. However, the scientific community struggles with different meanings and notions of the term policy diffusion. Thus, the aim of this paper is to offer a general conceptual framework for the study of diffusion processes within the international system. Understanding the process of policy diffusion requires an analysis of the complex interplay between transnational and international forces, national factors and the characteristics of policy innovations. By providing a conceptual framework this paper hopes not only to contribute to the theoretical debate but also to give guidance for empirical research. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment. [source] PLASTICITY IN REPRODUCTIVE PHENOTYPES REVEALS STATUS-SPECIFIC CORRELATIONS BETWEEN BEHAVIORAL, MORPHOLOGICAL, AND PHYSIOLOGICAL SEXUAL TRAITSEVOLUTION, Issue 5 2008Charlie K. Cornwallis Reproductive success is determined by a complex interplay between multiple sexual traits that promote mate acquisition and, following copulation, provide control over paternity. The intensity of sexual competition that individuals experience often fluctuates, and here we investigate how this influences the expression of reproductive traits and their relationships. We show in the fowl, Gallus gallus, that males of different social status, which experience different intensities of sexual competition, before and after copulation, have different reproductive phenotypes. Dominant males are more vigilant, feed less, and have larger sexual ornaments than subordinate males. Experimentally manipulating social status revealed that these differences were phenotypically plastic, indicating multiple sexual traits were dependent on the social environment. We integrated these data with previous published findings on changes in sperm numbers and velocity to show that relationships between traits were different for males when they were dominant and when they were subordinate. Furthermore, when males switched status a complex array of negative and positive correlations between the degree traits changed was observed. Our results suggest that variation in the intensity of sexual competition generates reversible plasticity in reproductive phenotypes and that relationships between sexual traits may be variable and influence the evolution of reproductive strategies. [source] Geoarchaeology of the Kostenki,Borshchevo sites, Don River Valley, RussiaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 2 2007Vance T. Holliday The Kostenki,Borshchevo localities include 26 Upper Paleolithic sites on the first and second terraces along the west bank of the Don River, near Voronezh on the central East European Plain. Geoarchaeological research from 2001 through 2004 focused on sites Kostenki 1, 12, and 14, with additional work at Kostenki 11 and 16, and Borshchevo 5. The strata are grouped into three units (bottom up): Unit 1, > 50 ka, consists of coarse alluvium (representing upper terrace 2 deposits) and colluvium, overlain by fine-grained sediments. Unit 2 includes archaeological horizons sealed within two sets of thin lenses of silt, carbonate, chalk fragments, and organic-rich soils (termed the Lower Humic Bed and Upper Humic Bed) dating 50,30 ka. Separating the humic beds is a volcanic ash lens identified as the Campanian Ignimbrite Y5 tephra, dated elsewhere by Ar/Ar to ca. 40 ka. The humic beds appear to result from the complex interplay of soil formation, spring deposition, slope action, and other processes. Several horizons buried in the lower part of Unit 2 contain Upper Paleolithic assemblages. The springs and seeps, which are still present in the area today, emanated from the bedrock valley wall. Their presence may account for the unusually high concentration of Upper Paleolithic sites in this part of the central East European Plain. Unit 3, < 30 ka, contains redeposited loess with a buried soil (Gmelin Soil) overlain by a primary full-glacial loess with an associated Chernozem (Mollisol), forming the surface of the second terrace. © 2007 Wiley Periodicals, Inc. [source] Geography of Stock MarketsGEOGRAPHY COMPASS (ELECTRONIC), Issue 4 2009Dariusz Wójcik Geography matters for stock markets. Stock market actors and institutions do not just have to be somewhere, but where they are in relation to other actors and institutions has an effect on their behaviour and performance. Hence, the geography of stock markets is crucial to the spatial distribution of financial services and centres. On another level, the evolution and structure of stock markets involves a complex interplay of politics, technology, economy and culture, and can never be explained with economic models alone. Finally, stock markets do not just reflect economy and society, they influence how economy and society work. The current financial crisis only underscores the value of geography as a lens through which to view stock markets, and the significance of the latter in the world economy. [source] Synergistic effects associated with climate change and the development of rocky shore molluscsGLOBAL CHANGE BIOLOGY, Issue 3 2005R. Przeslawski Abstract Global climate change and ozone layer thinning will simultaneously expose organisms to increasingly stressful conditions. Early life stages of marine organisms, particularly eggs and larvae, are considered most vulnerable to environmental extremes. Here, we exposed encapsulated embryos of three common rocky shore gastropods to simultaneous combinations of ecologically realistic levels of ultraviolet radiation (UVR), water temperature stress and salinity stress to identify potential interactions and associated impacts of climate change. We detected synergistic effects with increases in mortality and retardation in development associated with the most physiologically stressful conditions. The effects of UVR were particularly marked, with mortality increasing up to 12-fold under stressful conditions. Importantly, the complex outcomes observed on applying multiple stressors could not have been predicted from examining environmental variables in isolation. Hence, we are probably dramatically underestimating the ecological impacts of climate change by failing to consider the complex interplay of combinations of environmental variables with organisms. [source] Centralization and Decentralization in Administration and Politics: Assessing Territorial Dimensions of Authority and PowerGOVERNANCE, Issue 1 2001Paul D. Hutchcroft Throughout the world, diverse countries are implementing programs of decentralization as a means of promoting both democratic and developmental objectives. Unfortunately, however, scholarship has yet to offer a comprehensive framework within which to assess and reform central-local relations. This article seeks to overcome the "division of labor" that has long separated analyses of administrative and political structures, and to provide stronger conceptual vocabulary for describing and analyzing the complexities of centralization and decentralization in both administration and politics. After developing two distinct continua of administrative and political centralization/decentralization, the paper then combines them in a single matrix able to highlight the wide range of strategies and outcomes that emerge from the complex interplay of the two spheres. Depending on where a country lies within the matrix, it is argued, strategies of decentralization may do more harm than good. Strategies of devolution are especially problematic in settings with strong local bosses, and should never be attempted without careful analysis of the preexisting character of central-local ties. [source] Electronic and Magnetic Properties of SrTiO3/LaAlO3 Interfaces from First PrinciplesADVANCED MATERIALS, Issue 26-27 2010Hanghui Chen Abstract A number of intriguing properties emerge upon the formation of the epitaxial interface between the insulating oxides LaAlO3 and SrTiO3. These properties, which include a quasi two-dimensional conducting electron gas, low temperature superconductivity, and magnetism, are not present in the bulk materials, generating a great deal of interest in the fundamental physics of their origins. While it is generally accepted that the novel behavior arises as a result of a combination of electronic and atomic reconstructions and growth-induced defects, the complex interplay between these effects remains unclear. In this report, we review the progress that has been made towards unraveling the complete picture of the SrTiO3/LaAlO3 interface, focusing primarily on present ab initio theoretical work and its relation to the experimental data. In the process, we highlight some key unresolved issues and discuss how they might be addressed by future experimental and theoretical studies. [source] HIV and the body: a review of multidisciplinary managementHIV MEDICINE, Issue 2010J Rockstroh Abstract The increase in the life expectancy achieved following the introduction of more effective antiretroviral therapy (ART) in recent years now means that the HIV-infected population are for the first time being exposed to the age-related diseases that affect the general population. Nevertheless, the prevalence of these diseases (which include cardiovascular disease, dyslipidaemia, glucose intolerance and diabetes) is higher, and their onset earlier in the HIV population, probably due to the complex interplay between HIV infection, coinfection with hepatitis B and C, and ART. As a result, HIV physicians are now required to adopt a new approach to the management of HIV, which involves screening and regular monitoring of all HIV-infected individuals for the presence of comorbidities and prompt referral to other clinical specialties when required. If this challenge to patient management is to be overcome, it is clear that educating physicians in the diagnosis and treatment of age-associated comorbidities is essential, either through ongoing programmes such as the HIV and the Body initiative, an overarching independent medical education programme established in 2007 and overseen by an independent Steering Committee, organized and funded by Gilead, and/or through internal training. To assist in this process, this article provides an overview of common comorbidities affecting HIV-infected persons and provides practical guidance on their management. [source] Heavy metal concentrations during storm events in a rehabilitated industrialized catchmentHYDROLOGICAL PROCESSES, Issue 10 2003W. H. Blake Abstract Water quality data collected on a fortnightly or monthly basis are inadequate for assessment and modelling of many water quality problems as storm event samples are underrepresented or missed. This paper examines the stormflow dynamics of heavy metals (Pb, Cu, Cd and Zn) in the Nant-y-Fendrod stream, South Wales, which has been affected by 250 years of metal smelting, followed by 35 years of landscape rehabilitation measures. For storm events of contrasting (very dry and very wet) antecedent conditions in May 2000 and February 2001, respectively, temporal changes in streamwater heavy metal concentrations above and below an in-line flood detention lake are analysed. At the upstream site, peaks in total metal concentration were recorded on the rising limb for Pb (0·150 mg l,1) and Cu (0·038 mg l,1) but on the falling limb for Zn (1·660 mg l,1) and Cd (0·006 mg l,1) in the summer 2000 storm event, yielding clockwise and anticlockwise hysteretic loops respectively. In contrast, metal concentrations, although high throughout the winter storm event, were diluted somewhat during the storm peak itself. The Pb and Cu appear to be supplied by quickflow processes and transported in close association with fine sediment, whereas Zn and Cd are delivered to the channel and lake by slower subsurface seepage in dissolved form. In the winter 2001 event, antecedent soil moisture and shallow groundwater levels were anomalously high and seepage sources of dissolved metals dominated. Downstream of the lake, Pb and Cu levels and suspended sediment were high in the summer storm, but low in the winter storm, suggesting retention with deposition of fine sediment in the lake during the latter. In the winter storm, Zn and Cd levels were higher downstream than upstream of the lake, perhaps because of additional seepage inputs from the surrounding slopes, which failed to have an impact during summer. An understanding of the complex interplay of antecedent soil moisture and the dynamics of subsurface seepage pathways in relation to the three-dimensional distribution of sources is important in modelling heavy metal fluxes and levels in contaminated urban catchments. Copyright © 2003 John Wiley & Sons, Ltd. [source] Harnessing human dendritic cell subsets for medicineIMMUNOLOGICAL REVIEWS, Issue 1 2010Hideki Ueno Summary:, Immunity results from a complex interplay between the antigen-non-specific innate immune system and the antigen-specific adaptive immune system. The cells and molecules of the innate system employ non-clonal recognition receptors including lectins, Toll-like receptors, NOD-like receptors, and helicases. B and T lymphocytes of the adaptive immune system employ clonal receptors recognizing antigens or their derived peptides in a highly specific manner. An essential link between innate and adaptive immunity is provided by dendritic cells (DCs). DCs can induce such contrasting states as immunity and tolerance. The recent years have brought a wealth of information on the biology of DCs revealing the complexity of this cell system. Indeed, DC plasticity and subsets are prominent determinants of the type and quality of elicited immune responses. In this article, we summarize our recent studies aimed at a better understanding of the DC system to unravel the pathophysiology of human diseases and design novel human vaccines. [source] Trust, power and interorganizational information systems: the case of the electronic trading community TransLeaseINFORMATION SYSTEMS JOURNAL, Issue 1 2000David K. Allen Abstract. This paper focuses on Cap Gemini's electronic commerce system, TransLease. TransLease is an interorganizational information system (IOS), which facilitates electronic commerce between motor vehicle leasing and repair companies. During our investigation, the system was used by approximately 1000 repair agents working for seven of the UK's leading vehicle leasing and contract hire companies. This system was originally developed by AT&T and acquired by Cap Gemini in July 1998. At the time of acquisition, the system was seen as being of high strategic value, although it was also seen as underperforming. This paper reports the results of an action research project, which formed one element of the process by which Cap Gemini investigated the former problem. In the paper, TransLease is described as a complex electronic community, dependent upon the existence of symbiotic relationships. As such, the problems that the system users and developers experienced can be attributed to factors that impeded the mutual benefit accruing from participation in the system. The efficacy of the terms of exchange and the degree to which participants mutually benefit through electronic interaction is determined by the complex interplay of a number of relational and organizational factors. The research therefore illustrates the importance of the ,soft' organizational issues in IOS management and development, and suggests a conceptual model of the factors relevant in this case. At the time of this study, TransLease was still in the early stages of its life cycle, having only been available in the marketplace for approximately 18 months. During this time, through recognizing the complex problems and issues detailed in this paper, Cap Gemini accordingly redressed the way in which the system was managed and maintained. TransLease is now seen as having matured into a highly successful example of an IOS , a view reflected by its position as market leader in the industry. As this paper will show, the key to improving the existing service has been the emphasis Cap Gemini now places on managing the ,soft' aspects of the electronic community. [source] ENSO variability, teleconnections and climate change,INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 15 2001Henry F. Diaz Abstract An overview is presented of the principal features of the El Niño,Southern Oscillation (ENSO) teleconnections in terms of regional patterns of surface temperature, precipitation and mid-tropospheric atmospheric circulation. The discussion is cast in the context of variations in the associations over time, with decadal scale changes emphasized. In the five decades or so for which we have adequate records to reliably analyse the global aspects of ENSO effects on regional climates around the world, we have witnessed one major decadal scale change in the overall pattern of sea-surface temperatures (SST) in the global ocean, and concomitant changes in the atmospheric response to those changes. The analysis underscores the connection between low frequency changes in tropical SST, ENSO and decadal scale changes in the general atmospheric circulation, pointing to the complex interplay between the canonical ENSO system, slow changes in SST in the Indo-Pacific over the last century, and long-term changes in the atmospheric circulation itself. Published in 2001 by John Wiley & Sons, Ltd. [source] Immigrant Gateways and Hispanic Migration to New Destinations,INTERNATIONAL MIGRATION REVIEW, Issue 3 2009Daniel T. Lichter Our understanding of the underlying demographic components of population change in new Hispanic destinations is limited. In this paper, we (1) compare Hispanic migration patterns in traditional settlement areas with new growth in emerging Hispanic destinations; (2) examine the role of immigration vis-à-vis domestic migration in spurring Hispanic population redistribution; and (3) document patterns of migrant selectivity, distinguishing between in-migrants and non-migrant Hispanics at both the origin and destination. We use several recent datasets, including the 1990 and 2000 Public Use Microdata Samples (which include new regional geocodes), and the 2005 and 2006 files of the American Community Survey. Our results document the widespread dispersion of the Hispanic population over the 1990,2006 period from established Hispanic gateways into new Hispanic areas and other parts of the country. Nearly one-half of Hispanic net migration in new destinations comes from domestic gains. In contrast, both established and other Hispanic areas depend entirely on immigration, with each losing domestic migrants to high growth areas. Migrant flows also are highly differentiated by education, citizenship, and nativity. To fully understand the spatial diffusion of Hispanics requires a new appreciation of the complex interplay among immigration, internal domestic migration, and fertility. [source] Regulation of glucose transporter type 4 isoform gene expression in muscle and adipocytesIUBMB LIFE, Issue 3 2007Seung-Soon Im Abstract The gene expression of glucose transporter type 4 isoform (GLUT4) is known to be controlled by metabolic, nutritional, or hormonal status. Understanding the molecular mechanisms governing GLUT4 gene expression is critical, because glucose disposal in the body depends on the activities of GLUT4 in the muscle and adipocytes. The GLUT4 activities are regulated by a variety of mechanisms. One of them is transcriptional regulation. GLUT4 gene expression is regulated by a variety of transcriptional factors in muscle and adipose tissue. These data are accumulating regarding the transcriptional factors regulating GLUT4 gene expression. These include MyoD, MEF2A, GEF, TNF-,, TR-1,, KLF15, SREBP-1c, C/EBP-,, O/E-1, free fatty acids, PAPR,, LXR,, NF-1, etc. These factors are involved in the positive or negative regulation of GLUT4 gene expression. In addition, there is a complex interplay between these factors in transactivating GLUT4 promoter activity. Understanding the mechanisms controlling GLUT4 gene transcription in these tissues will greatly promote the potential therapeutic drug development for obesity and T2DM. IUBMB Life, 59: 134-145, 2007 [source] Entrepreneurial nurses and midwives in the United Kingdom: an integrative reviewJOURNAL OF ADVANCED NURSING, Issue 5 2007Vari Drennan Abstract Title.,Entrepreneurial nurses and midwives in the United Kingdom: an integrative review Aim., This paper is a report of an integrative literature review to investigate: (a) the extent of entrepreneurial activity by nurses, midwives and health visitors in the United Kingdom and (b) the factors that influenced these activities. Background., Internationally, social and commercial entrepreneurial activity is regarded as important for economic growth and social cohesion. Methods., Seventeen bibliographic databases were searched using single and combined search terms: ,entrepreneur$', ,business', ,private practice', ,self-employ$', ,intrapreneur$',social enterprise$',mutuals', ,collectives', ,co-op' and ,social capital' which were related to a second layer of terms ,Nurs$', ,Midwi$', ,Visit$'. ,Entrepreneur$' Private Midwi$, Independent Midwi$, and ,nursing workforce'. In addition, hand searches of non-indexed journals and grey literature searches were completed. The following inclusion criteria were: (a) describing nurses, midwife and/or health visitor entrepreneurship (b) undertaken in the UK, and (c) reported between January 1996 and December 2005. Results., Of 154 items included only three were empirical studies; the remainder were narrative accounts. While quality of these accounts cannot be verified, they provide as complete an account as possible in this under-researched area. The numbers of nurses, midwives and health visitors acting entrepreneurially were very small and mirror international evidence. A categorization of entrepreneurial activity was inductively constructed by employment status and product offered. ,Push' and ,pull' influencing factors varied between types of entrepreneurial activity. Conclusion., Empirical investigation into the extent to which nurses and midwives respond to calls for greater entrepreneurialism should take account of the complex interplay of contextual factors (e.g. healthcare legislation), professional and managerial experience and demographic factors. [source] Predictors of Nursing Home Placement in African Americans with DementiaJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2004Joseph E. Gaugler PhD The objective of the present study was to identify predictors of institutionalization in African Americans who suffer from dementia. Data were derived from the Medicare Alzheimer's Disease Demonstration Evaluation (MADDE), which collected information on Alzheimer's patients and their family caregivers over a 3-year period. The baseline MADDE sample included 667 older African Americans suffering from dementia recruited from eight catchment areas in the United States. A Cox proportional hazards model was used to create a predictive model of institutionalization. Subsequent analyses found that care recipient age, sex, Medicaid eligibility, and cognitive impairment; site; and caregiving burden were significant predictors of time to placement. The results, among the first to examine predictors of nursing home placement of cognitively impaired African Americans, emphasize the clinical implications and complex interplay of race, dementia, and caregiving context in the institutionalization process. [source] Sexual Assault and Defendant/Victim Intoxication: Jurors' Perceptions of Guilt,JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 2 2000ANNE-MARIE WALL The present research investigates how defendant and claimant intoxication operates in sexual-assault trials. Participants (N= 323) were provided with a description of a sexualassault trial in which the intoxication level (sober, moderate, extreme) of both parties was systematically varied. While the introduction of alcohol altered participants' perceptions of the case and of the parties involved, a complex interplay between the defendant's and complainant's level of intoxication was apparent. When the complainant was sober, harsher judgments were rendered when the defendant was intoxicated, particularly at the extreme level. In contrast, when the complainant was moderately intoxicated, more guilty verdicts occurred when the defendant was similarly inebriated. Finally, when the complainant was extremely intoxicated, the defendant's beverage consumption did not exert any discemible impact. Evaluations of both parties' abilities to self-regulate their behavior and for the female target to become sexually disinhibited were also influenced by the intoxication manipulation. [source] Effects of bird predation on arthropod abundance and tree growth across an elevational gradientJOURNAL OF AVIAN BIOLOGY, Issue 4 2010W. Scott Schwenk Considerable uncertainty surrounds the conditions under which birds can cause trophic cascades. In a three-year experiment, we studied the direct and indirect effects of insectivorous birds on arthropod abundance, herbivory, and growth of striped maple Acer pensylvanicum saplings in a northern hardwood forest of central New Hampshire, USA. We manipulated bird predation by erecting exclosures around saplings and directly manipulated herbivory by removing herbivores. We also examined how climate modifies these interactions by replicating the experiment at three locations along an elevational gradient. Effects of bird predation were variable. Overall, mean arthropod biomass was 20% greater on saplings within bird exclosures than on controls (p<0.05). The mean biomass of leaf-chewing herbivores, primarily Lepidoptera larvae, was 25% greater within exclosures but not statistically different from controls. To a lesser degree, mean herbivore damage to foliage within exclosures exceeded that of controls but differences were not significant. We also did not detect significant treatment effects on sapling shoot growth. The high understory vegetation density relative to bird abundance, and low rate of herbivory during the study (mean 5% leaf area removed, controls), may have limited the ability of birds to affect sapling growth. Climate effects operated at multiple scales, resulting in a complex interplay of interactions within the food web. Regional synchrony of climatic conditions resulted in annual fluctuations in herbivore abundance and tree growth that were shared across elevations. At the same time, local environmental variation resulted in site differences in the plant, herbivore, and bird communities. These patterns resulted in a mosaic of top,down strengths across time and space, suggesting an overall pattern of limited effects of birds on plant growth, possibly interspersed with hotspots of trophic cascades. [source] In silico modulation of apoptotic Bcl-2 proteins by mistletoe lectin-1: Functional consequences of protein modificationsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2008Tasneem A. Khwaja Abstract The mistletoe lectin-1 (ML-1) modulates tumor cell apoptosis by triggering signaling cascades through the complex interplay of phosphorylation and O -linked N -acetylglucosamine (O -GlcNAc) modification in pro- and anti-apoptotic proteins. In particular, ML-1 is predicted to induce dephosphorylation of Bcl-2-family proteins and their alternative O -GlcNAc modification at specific, conserved Ser/Thr residues. The sites for phosphorylation and glycosylation were predicted and analyzed using Netphos 2.0 and YinOYang 1.2. The involvement of modified Ser/Thr, and among them the potential Yin Yang sites that may undergo both types of posttranslational modification, is proposed to mediate apoptosis modulation by ML-1. J. Cell. Biochem. 103: 479,491, 2008. © 2007 Wiley-Liss, Inc. [source] Alterations in the temporal expression and function of cadherin-7 inhibit cell migration and condensation during chondrogenesis of chick limb mesenchymal cells in vitroJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2009Dongkyun Kim Endochondral bone formation requires a complex interplay among immature mesenchymal progenitor cells to form the cartilaginous anlagen, which involves migration, aggregation and condensation. Even though condensation of chondrogenic progenitors is an essential step in this process, its mechanism(s) has not been well studied. Here, we show that cadherin-7 plays a central role in cellular condensation by modulating cell motility and migration. In this study, many mesenchymal cells failed to migrate, and precartilage condensation was inhibited, after knockdown of endogenous cadherin-7 levels. Exposure of mesenchymal cells to SB203580 (a specific inhibitor of p38MAPK), LiCl (an inhibitor of GSK-3,) or overexpression of ,-catenin resulted in inhibition of cadherin-7 levels and, subsequently, suppression of cell migration. Collectively, our results suggest that cadherin-7 controls cell migration in chick limb bud mesenchymal cells, and that p38MAPK and GSK signals are responsible for regulating cadherin-7-mediated cell migration. J. Cell. Physiol. 221: 161,170, 2009. © 2009 Wiley-Liss, Inc [source] A Mitochondrial view of aging, reactive oxygen species and metastatic cancerAGING CELL, Issue 4 2010Warren Ladiges Summary This perspective article highlights the growing evidence placing mitochondria and mitochondrial function at the center of cancer as an age-related disease. The discussion starts from the mitochondrial free radical hypothesis that predicts the involvement of endogenous mitochondrial reactive oxygen species (ROS) in cancer development and summarizes studies demonstrating the impact of the modulation of ROS levels on cancer development and metastasis. Cancer is fundamentally a complex interplay of cell growth, division, metastasis and death- processes connected to mitochondria through energy metabolism. Based on this evidence, therapeutics focused on mitochondrial function and mitochondrial ROS production are an attractive approach to modulating the progression of metastatic cancer and the general improvement of human health span. [source] Invasive alien plants infiltrate bird-mediated shrub nucleation processes in arid savannaJOURNAL OF ECOLOGY, Issue 4 2007S. J. MILTON Summary 1,The cultivation and dissemination of alien ornamental plants increases their potential to invade. More specifically, species with bird-dispersed seeds can potentially infiltrate natural nucleation processes in savannas. 2To test (i) whether invasion depends on facilitation by host trees, (ii) whether propagule pressure determines invasion probability, and (iii) whether alien host plants are better facilitators of alien fleshy-fruited species than indigenous species, we mapped the distribution of alien fleshy-fruited species planted inside a military base, and compared this with the distribution of alien and native fleshy-fruited species established in the surrounding natural vegetation. 3Abundance and diversity of fleshy-fruited plant species was much greater beneath tree canopies than in open grassland and, although some native fleshy-fruited plants were found both beneath host trees and in the open, alien fleshy-fruited plants were found only beneath trees. 4Abundance of fleshy-fruited alien species in the natural savanna was positively correlated with the number of individuals of those species planted in the grounds of the military base, while the species richness of alien fleshy-fruited taxa decreased with distance from the military base, supporting the notion that propagule pressure is a fundamental driver of invasions. 5There were more fleshy-fruited species beneath native Acacia tortilis than beneath alien Prosopis sp. trees of the equivalent size. Although there were significant differences in native plant assemblages beneath these hosts, the proportion of alien to native fleshy-fruited species did not differ with host. 6Synthesis. Birds facilitate invasion of a semi-arid African savanna by alien fleshy-fruited plants, and this process does not require disturbance. Instead, propagule pressure and a few simple biological observations define the probability that a plant will invade, with alien species planted in gardens being a major source of propagules. Some invading species have the potential to transform this savanna by overtopping native trees, leading to ecosystem-level impacts. Likewise, the invasion of the open savanna by alien host trees (such as Prosopis sp.) may change the diversity, abundance and species composition of the fleshy-fruited understorey. These results illustrate the complex interplay between propagule pressure, facilitation, and a range of other factors in biological invasions. [source] Non-phenolic radical-trapping antioxidantsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2009Mario C. Foti Abstract Objectives The aim of this review article is to introduce the reader to the mechanisms, rates and thermodynamic aspects of the processes involving the most biologically relevant non-phenolic radical-trapping antioxidants. Key findings Antioxidant defences in living organisms rely on a complex interplay between small molecules and enzymes, which cooperate in regulating the concentrations of potentially harmful oxidizing species within physiological limits. The noxious effects of an uncontrolled production of oxygen- and nitrogen-centered radicals are amplified by chain reactions (autoxidations), sustained mainly by peroxyl radicals (ROO,), that oxidize and alter essential biomolecules such as lipids, lipoproteins, proteins and nucleic acids. Summary Non-phenolic antioxidants represent an important and abundant class of radical scavengers in living organisms. These compounds react with peroxyl radicals through various mechanisms: (i) formal H-atom donation from weak X-H bonds (X = O, N, S), as in the case of ascorbic acid (vitamin C), uric acid, bilirubin and thiols; (ii) addition reactions to polyunsaturated systems with formation of C-radicals poorly reactive towards O2, for example ,-carotene and all carotenoids in general; (iii) co-oxidation processes characterized by fast cross-termination reactions, for example ,-terpinene; and (iv) catalytic quenching of superoxide (O2,,) with a superoxide dismutase-like mechanism, for example di-alkyl nitroxides and FeCl3. Kinetic data necessary to evaluate and rationalize the effects of these processes are reported. The mechanisms underlying the pro-oxidant effects of ascorbate and other reducing agents are also discussed. [source] | ||||||||||||||||||||||||||||||||||||||||||||||