988 resultados para core-periphery relationship
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Thesis (Ph.D.)--University of Washington, 2016-04
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The folding of HIV gp41 into a 6-helix bundle drives virus-cell membrane fusion. To examine the structural relationship between the 6-helix bundle core domain and other regions of gp41, we expressed in Escherichia coli, the entire ectodomain of HIV-2(ST) gp41 as a soluble, trimeric maltose-binding protein (MBP)/gp41 chimera. Limiting proteolysis indicated that the Cys-591-Cys-597 disulfide-bonded region is outside a core domain comprising two peptides, Thr-529-Trp-589 and Val-604-Ser-666. A biochemical examination of MBP/gp41 chimeras encompassing these core peptides; indicated that the N-terminal polar segment, 521-528, and C-terminal membrane-proximal segment, 658-666, cooperate in stabilizing the ectodomain. A functional interaction between sequences outside the gp41 core may contribute energy to membrane fusion. (C) 2004 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.
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Microhardness maps of cross-sections of high-pressure diecast test bars of AZ91 have been determined. Specimens with rectangular cross-sections, 1, 2 and 3 mm thick, or with a circular cross-section 6.4 mm in diameter, have been studied. The hardness is generally higher near the edges in all specimens, and more so near the corners of the rectangular specimens. The hardness at the center of the castings is generally lower, due to a coarser solidification microstructure and the concentration of porosity. The evidence confirms that the surface of the castings is harder than the core, but it does not support the concept of a skin with a sharp. and definable boundary. This harder layer is irregular in hardness and depth and is not equally hard on opposite sides of the casting. The mean hardness obtained by integrating the microhardness maps over the entire cross-section increased with decreasing thickness of the bars, and was found to be in good correlation with each bar's yield strength. (c) 2005 Elsevier B.V. All rights reserved.
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The heritability of conscientiousness has been one of the least explored of the NEO PI domains. Here we focus on the facet scales of the conscientiousness domain, estimating both their heritability and their correlations with measures of IQ and academic achievement (Queensland Core Skills Test; QCST) in a sample of adolescent twins and their non-twin siblings. Our findings confirmed positive associations between IQ and the facets of Competence and Dutifulness (ranging 0.11-0.27), with academic achievement showing correlations of 0.27 and 0.15 with these same facets and 0.15 with Deliberation. All conscientiousness facets were influenced by genes (broad sense heritabilities ranging 0.18-0.49) and unique environment, but common environment was judged unimportant. A multivariate genetic analysis including Competence, Dutifulness, IQ (verbal, performance) and QCST scores showed that common variance was primarily explained by a general additive genetic factor (loadings ranging 0.15-0.84). Future multivariate genetic analysis which incorporates Openness to Experience dimensions may improve the interpretation of these findings. (c) 2005 Elsevier Ltd. All rights reserved.
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This insightful book shows how small and medium enterprises (SMEs) from some of the traditionally less dynamic peripheral economies of the 'old' EU - namely Ireland, Italy, Portugal and Spain - have responded to the twin challenges of globalisation and industrial restructuring. Through a series of unique case studies the contributing authors discuss how these economies, and in particular the SME sector, can be transformed. The book begins by examining the key drivers of the globally competitive SME sector in the EU, before moving on to explore the relationship between multinational enterprises (MNEs), SMEs and industrial development. The authors investigate important policy implications and provide lessons for SME development and growth. With empirical and theoretical contributions on SMEs in both the manufacturing and the services sectors, this essential book will be invaluable for researchers and policymakers in small business economics and management. Postgraduate students of entrepreneurship, business economics, industrial economics and European studies will appreciate this unique set of insights.
The core executive's approach to regulation:from 'better regulation' to 'risk-tolerant deregulation'
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This article examines changes in the New Labour core executive’s approach to regulation and its relationship with risk, through analysing documentary, legislative and press sources concerning approaches to regulatory decision-making. It claims that an initial commitment to ‘better regulation’ has gradually been replaced by explicit support for deregulation. A reduction in the scope of regulation was also promoted by the Thatcher and Major governments. The New Labour core executive shares previous (Conservative) administrations’ concern to include business in deregulatory decision-making. However, the article claims that there is one significant difference in the New Labour deregulatory approach: a new toleration of risk. Deregulation is, now, described as a corrective to regulators’ over-reactions to perceived risks, which, it is claimed, are holding back economic and technological progress. However, this new approach excludes competing views concerning how risk should be regulated. In particular, it does not engage with widespread popular views that governments should continue to protect against risk.
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This study examines the role of capabilities in core marketing-related business processes–product development management (PDM), supply chain management (SCM) and customer relationship management (CRM)–in translating a firm’s market orientation (MO) into firm performance. The study is the first to examine the interplay of all three business process capabilities simultaneously, while investigating how environmental conditions moderate their performance effects. A moderated mediation analysis of 468 product-focused firms finds that PDM and CRM process capabilities play important mediating roles, whereas SCM process capability does not mediate the relationship between MO and performance. However, the relative importance of the capabilities as mediators varies along the degree of environmental turbulence, and under certain conditions, an increase in the level of business process capability may even turn detrimental.
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We consider various lexicographic allocation procedures for coalitional games with transferable utility where the payoffs are computed in an externally given order of the players. The common feature of the methods is that if the allocation is in the core, it is an extreme point of the core. We first investigate the general relationship between these allocations and obtain two hierarchies on the class of balanced games. Secondly, we focus on assignment games and sharpen some of these general relationship. Our main result is the coincidence of the sets of lemarals (vectors of lexicographic maxima over the set of dual coalitionally rational payoff vectors), lemacols (vectors of lexicographic maxima over the core) and extreme core points. As byproducts, we show that, similarly to the core and the coalitionally rational payoff set, also the dual coalitionally rational payoff set of an assignment game is determined by the individual and mixed-pair coalitions, and present an efficient and elementary way to compute these basic dual coalitional values. This provides a way to compute the Alexia value (the average of all lemacols) with no need to obtain the whole coalitional function of the dual assignment game.
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Recent studies found that organizations have been investing significant capital in developing teams and employees in geographic areas where labor and resources are considerably cheaper. Furthermore, organizations are moving core operational activities such as research and development and back-office processes to globally distributed teams. ^ However, several factors that are inherent to these virtual teams can have a negative impact on employee perceptions and engagement; specifically, the physical and temporal differences between employees and their supervisors, the lack of meaningful social interaction intrinsic to working relationships, and cultural biases that can be fostered when close, daily interactions is not there to help bridge the dissimilarity. ^ When strategies are not in place to mitigate these deficiencies, it can cause virtual employees to disengage emotionally and intellectually from the organization, or lead them to feel justified in working against the best interest of the company. ^ Past research indicates that although deviant behavior in the workplace is not new, transgressions committed by employees have been increasing significantly every year. Beyond the focus of why employees are motivated to act against the organization, to what extent do the recent changes to the organization’s structure influence this type of behavior through their actions at the macro (organizational) and micro level (leadership). ^ In addition, there is a related phenomenon that has aided the transformation of the workplace—namely, the ubiquity of technology. In the context of workplace deviance, established research has documented an increasing trend of employees utilizing company technology as a medium and amplifier when harming the organization. It is important to understand whether technology has facilitated or hindered workplace deviance by virtue of the technology itself (as a means), and as part of the new employee roles created by the evolving technology (i.e., virtual employees). Therefore, it is important to identify how individual attitudes and behaviors can be affected by an employee’s degree of virtuality. ^ This study will add to the understanding of how social interaction and physical proximity, leadership and other perception factors contribute to the changes organizations are experiencing as their structure evolves and adapts to compete in the new global environment. ^
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Recent studies found that organizations have been investing significant capital in developing teams and employees in geographic areas where labor and resources are considerably cheaper. Furthermore, organizations are moving core operational activities such as research and development and back-office processes to globally distributed teams. However, several factors that are inherent to these virtual teams can have a negative impact on employee perceptions and engagement; specifically, the physical and temporal differences between employees and their supervisors, the lack of meaningful social interaction intrinsic to working relationships, and cultural biases that can be fostered when close, daily interactions is not there to help bridge the dissimilarity. When strategies are not in place to mitigate these deficiencies, it can cause virtual employees to disengage emotionally and intellectually from the organization, or lead them to feel justified in working against the best interest of the company. Past research indicates that although deviant behavior in the workplace is not new, transgressions committed by employees have been increasing significantly every year. Beyond the focus of why employees are motivated to act against the organization, to what extent do the recent changes to the organization’s structure influence this type of behavior through their actions at the macro (organizational) and micro level (leadership). In addition, there is a related phenomenon that has aided the transformation of the workplace – namely, the ubiquity of technology. In the context of workplace deviance, established research has documented an increasing trend of employees utilizing company technology as a medium and amplifier when harming the organization. It is important to understand whether technology has facilitated or hindered workplace deviance by virtue of the technology itself (as a means), and as part of the new employee roles created by the evolving technology (i.e, virtual employees). Therefore, it is important to identify how individual attitudes and behaviors can be affected by an employee’s degree of virtuality. This study will add to the understanding of how social interaction and physical proximity, leadership and other perception factors contribute to the changes organizations are experiencing as their structure evolves and adapts to compete in the new global environment.
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Precise knowledge of the phase relationship between climate changes in the two hemispheres is a key for understanding the Earth's climate dynamics. For the last glacial period, ice core studies have revealed strong coupling of the largest millennial-scale warm events in Antarctica with the longest Dansgaard-Oeschger events in Greenland through the Atlantic meridional overturning circulation. It has been unclear, however, whether the shorter Dansgaard-Oeschger events have counterparts in the shorter and less prominent Antarctic temperature variations, and whether these events are linked by the same mechanism. Here we present a glacial climate record derived from an ice core from Dronning Maud Land, Antarctica, which represents South Atlantic climate at a resolution comparable with the Greenland ice core records. After methane synchronization with an ice core from North Greenland, the oxygen isotope record from the Dronning Maud Land ice core shows a one-to-one coupling between all Antarctic warm events and Greenland Dansgaard-Oeschger events by the bipolar seesaw. The amplitude of the Antarctic warm events is found to be linearly dependent on the duration of the concurrent stadial in the North, suggesting that they all result from a similar reduction in the meridional overturning circulation.
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Various studies have demonstrated that the stable hydrogen isotopic composition (dD) of terrestrial leaf waxes tracks that of precipitation (dDprecip) both spatially across climate gradients and over a range of different timescales. Yet, reconstructed estimates of dDprecip and corresponding rainfall typically remain largely qualitative, due mainly to uncertainties in plant ecosystem net fractionation, relative humidity, and the stability of the amount effect through time. Here we present dD values of the C31n-alkane (dDwax) from a marine sediment core offshore the Northwest (NW) African Sahel covering the past 100 years and overlapping with the instrumental record of rainfall. We use this record to investigate whether accurate, quantitative estimates of past rainfall can be derived from our dDwax time series. We infer the composition of vegetation (C3/C4) within the continental catchment area by analysis of the stable carbon isotopic composition of the same compounds (d13Cwax), calculated a net ecosystem fractionation factor, and corrected the dDwax time series accordingly to derive dDprecip. Using the present-day relationship between dDprecip and the amount of precipitation in the tropics, we derive quantitative estimates of past precipitation amounts. Our data show that (a) vegetation composition can be inferred from d13Cwax, (b) the calculated net ecosystem fractionation represents a reasonable estimate, and (c) estimated total amounts of rainfall based on dDwax correspond to instrumental records of rainfall. Our study has important implications for future studies aiming to reconstruct rainfall based on dDwax; the combined data presented here demonstrate that it is feasible to infer absolute rainfall amounts from sedimentary dDwax in tandem with d13Cwax in specific depositional settings.
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TEX86 (TetraEther indeX of tetraethers consisting of 86 carbon atoms) is a sea surface temperature (SST) proxy based on the distribution of archaeal isoprenoid glycerol dialkyl glycerol tetraethers (GDGTs). In this study, we appraise the applicability of TEX86 and TEX86L in subpolar and polar regions using surface sediments. We present TEX86 and TEX86L data from 160 surface sediment samples collected in the Arctic, the Southern Ocean and the North Pacific. Most of the SST estimates derived from both TEX86 and TEX86L are anomalously high in the Arctic, especially in the vicinity of Siberian river mouths and the sea ice margin, plausibly due to additional archaeal contributions linked to terrigenous input. We found unusual GDGT distributions at five sites in the North Pacific. High GDGT-0/crenarchaeol and GDGT-2/crenarchaeol ratios at these sites suggest a substantial contribution of methanogenic and/or methanotrophic archaea to the sedimentary GDGT pool here. Apart from these anomalous findings, TEX86 and TEX86L values in the surface sediments from the Southern Ocean and the North Pacific do usually vary with overlaying SSTs. In these regions, the sedimentary TEX86-SST relationship is similar to the global calibration, and the derived temperature estimates agree well with overlaying annual mean SSTs at the sites. However, there is a systematic offset between the regional TEX86L-SST relationships and the global calibration. At these sites, temperature estimates based on the global TEX86L calibration are closer to summer SSTs than annual mean SSTs. This finding suggests that in these subpolar settings a regional TEX86L calibration may be a more suitable equation for temperature reconstruction than the global calibration.