731 resultados para 831
Resumo:
This paper describes research that has sought to create a structured and integrated methodology that guides manufacturers through the decision of strategic positioning within global supply chains. The position of a company is concerned with deciding a boundary and configuration of internal and external business activities to the company and is directly related to initiatives such as outsourcing, make or buy, and offshoring. This paper provides an in-depth description of this concept, describes work carried out to form a methodology for strategic positioning within the global supply chain, and presents the details of the methodology. This research has made a significant contribution to the knowledge on how manufacturing companies can form a strategic positioning within global supply chains.
Resumo:
Link adaptation (LA) plays an important role in adapting an IEEE 802.11 network to wireless link conditions and maximizing its capacity. However, there is a lack of theoretic analysis of IEEE 802.11 LA algorithms. In this article, we propose a Markov chain model for an 802.11 LA algorithm (ONOE algorithm), aiming to identify the problems and finding the space of improvement for LA algorithms. We systematically model the impacts of frame corruption and collision on IEEE 802.11 network performance. The proposed analytic model was verified by computer simulations. With the analytic model, it can be observed that ONOE algorithm performance is highly dependent on the initial bit rate and parameter configurations. The algorithm may perform badly even under light channel congestion, and thus, ONOE algorithm parameters should be configured carefully to ensure a satisfactory system performance. Copyright © 2011 John Wiley & Sons, Ltd.
Resumo:
Purpose - This research aims to assess the risks and benefits of outsourcing for organisations, sectors and nations. The literature on outsourcing contains little evidence of research on holistic issues of its impact at systems levels beyond the firm, notably sectors and nations. Design/methodology/approach - A Delphi study with senior strategists from private and public sectors captured perspectives and specific observations on benefits and risks of outsourcing. Emergent issues on outsourcing policy, strategy and decision-making processes were synthesised into a framework for analysing factors associated with outsourcing. Findings - The findings suggest that a more holistic view of outsourcing is needed, linking local, organisational issues with sector and national level actions and outcomes. In this way, aggregate risks and benefits can be assessed at different systems levels. Research limitations/implications - Future research might address the motivations for outsourcing; currently there is little research evidence to assess whether outsourcing is a mechanism for failing to solve internal problems, and moving responsibility and risk out of the firm. Additionally most outsourcing research to date has concentrated on an activity either being "in" or "out"; there is little research exploring the circumstances in which mixed models might be appropriate. Practical implications - The framework provides an aid to research and an aide memoire for managers considering outsourcing. Originality/value - This paper contributes to knowledge on understanding of outsourcing at different systems levels, particularly highlighting the implications of outsourcing for sectors and nations. Previously most research has focused at the level of the firm or dyadic relationship. © Emerald Group Publishing Limited.
Resumo:
Background - Recent studies have implicated variants of the transcription factor 7-like 2 (TCF7L2) gene in genetic susceptibility to type 2 diabetes mellitus in several different populations. The aim of this study was to determine whether variants of this gene are also risk factors for type 2 diabetes development in a UK-resident South Asian cohort of Punjabi ancestry. Methods - We genotyped four single nucleotide polymorphisms (SNPs) of TCF7L2 (rs7901695, rs7903146, rs11196205 and rs12255372) in 831 subjects with diabetes and 437 control subjects. Results - The minor allele of each variant was significantly associated with type 2 diabetes; the greatest risk of developing the disease was conferred by rs7903146, with an allelic odds ratio (OR) of 1.31 (95% CI: 1.11 – 1.56, p = 1.96 × 10-3). For each variant, disease risk associated with homozygosity for the minor allele was greater than that for heterozygotes, with the exception of rs12255372. To determine the effect on the observed associations of including young control subjects in our data set, we reanalysed the data using subsets of the control group defined by different minimum age thresholds. Increasing the minimum age of our control subjects resulted in a corresponding increase in OR for all variants of the gene (p ≤ 1.04 × 10-7). Conclusion - Our results support recent findings that TCF7L2 is an important genetic risk factor for the development of type 2 diabetes in multiple ethnic groups.
Resumo:
In the past decade, the East-Central European countries were provided significant external capacity building assistance to help their emergence as donors of foreign aid. This paper aims to map these capacity development programmes and identify where they have helped and what challenges remain for the new donors. The main conclusion is that although capacity building has been instrumental in building organisational structures, working procedures and training staff, deeper underlying problems such as low levels of financing, lacking political will, the need for visibility and low staff numbers continue to hinder the new international development policies. Copyright © 2013 John Wiley & Sons, Ltd.
Resumo:
The so-called "internal modes" localized near the domain boundaries in quasi-two dimensional antiferromagnets are investigated. The possible localized states are classified and their frequency dependences on the system discreteness parameter λ=J/β, which describes the ratio of the magnitudes of the exchange interplane interaction and the magnetic anisotropy, are found. A sudden change in the spectrum of the local internal modes is observed at a critical value of this parameter, λ=λb=3/4, where the domain wall shifts from a collinear to a canted shape. When λ<λb there are one symmetric and two antisymmetric local modes, and when λ>λb the modes are two symmetric, one antisymmetric, and one shear. For discreteness parameters close to the critical value, the frequencies of some of the local modes lie deep inside the gap for the linear AFM magnon spectrum and can be observed experimentally. © 2010 American Institute of Physics.
Resumo:
A világgazdasági válság óta eltelt nyolc évtizedben Magyarországon számos rendszerváltozás ment végbe a gazdaságban és a politikában. Sokak szerint a szabadpiactól a szabadpiacig vezető kör bezárult, és ismét rendszerválság előtt állunk. Míg a jövő természetesen bizonytalanságokkal terhes, és így értelemszerűen nem kiszámítható, a múlt egyértelmű tanulsága az, hogy a közéletet végig formáló felzárkózási törekvés egészében sikertelennek bizonyult. Ennek alapja elemzésünk központi rejtélye egy régi fejlődéselméleti feladvány: miért van az, hogy Argentínához vagy újabban Olaszországhoz és Portugáliához hasonlóan a jó politika rossz eredményekkel jár(t), és fordítva? Miért szakadt el végletesen és történetileg is a gazdasági és a politikai ésszerűség egymástól? __________________ Hungary has undergone several changes of economic and political system in the eighty years since the Great Depression. According to many, the circle from market economy to market economy has closed and we face another systemic crisis. Although the future is naturally full of uncertainties and is not by its very nature predictable, the clear lesson from the past is that the effort to catch up, which shaped public life throughout, has been unsuccessful on the whole. The basis for this and the central riddle in this analysis is an old puzzle in development theory: how is it that good policies had bad results and vice versa, as was the case in Argentina, and recently in Italy and Portugal? Why did economic and political rationality part company for good, even in historical terms?
Resumo:
In the past decade, the East-Central European countries were provided significant external capacity building assistance in order to help their emergence as donors of foreign aid. This paper aims to map these capacity development programs and identify where they have helped and what challenges remain for the new donors. The main conclusion is that while capacity building has been instrumental in building organizational structures, working procedures and training staff, deeper underlying problems such as low levels of financing, lacking political will, the need for visibility and low staff numbers continue to hinder the new international development policies.
Resumo:
Background During recent years laparoscopic cholecystectomy has dramatically increased, sometimes resulting in overtreatment. Aim of this work was to retrospectively analyze all laparoscopic cholecystectomies performed in a single center in order to find the percentage of patients whose surgical treatment may be explained with this general trend, and to speculate about the possible causes. Methods 831 patients who underwent a laparoscopic cholecystectomy from 1999 to 2008 were retrospectively analyzed. Results At discharge, 43.08% of patients were operated on because of at least one previous episode of biliary colic before the one at admission; 14.08% of patients presented with acute lithiasic cholecystitis; 14.68% were operated on because of an increase in bilirubin level; 1.56% were operated on because of a previous episode of jaundice with normal bilirubin at admission; 0.72% had gallbladder adenomas, 0.72% had cholangitis, 0.36% had biliodigestive fistula and one patient (0.12%) had acalculous cholecystitis. By excluding all these patients, 21.18% were operated on without indications. Conclusions The broadening of indications for laparoscopic cholecystectomy is undisputed and can be considered a consequence of new technologies that have been introduced, increased demand from patients, and the need for practice by inexperienced surgeons. If not prevented, this trend could continue indefinitely.
Resumo:
Math literacy is imperative to succeed in society. Experience is key for acquiring math literacy. A preschooler's world is full of mathematical experiences. Children are continually counting, sorting and comparing as they play. As children are engaged in these activities they are using language as a tool to express their mathematical thinking. If teachers are aware of these teachable moments and help children bridge their daily experiences to mathematical concepts, math literacy may be enhanced. This study described the interactions between teachers and preschoolers, determining the extent to which teachers scaffold children's everyday language into expressions of mathematical concepts. Of primary concern were the teachers' responsive interactions to children's expressions of an implicit mathematical utterance made while engaged in block play. The parallel mixed methods research design consisted of two strands. Strand 1 of the study focused on preschoolers' use of everyday language and the teachers' responses after a child made a mathematical utterance. Twelve teachers and 60 students were observed and videotaped while engaged in block play. Each teacher worked with five children for 20 minutes, yielding 240 minutes of observation. Interaction analysis was used to deductively analyze the recorded observations and field notes. Using a priori codes for the five mathematical concepts, it was found children produced 2,831 mathematical utterances. Teachers ignored 60% of these utterances and responded to, but did not mediate 30% of them. Only 10% of the mathematical utterances were mediated to a mathematical concept. Strand 2 focused on the teacher's view of the role of language in early childhood mathematics. The 12 teachers who had been observed as part of the first strand of the study were interviewed. Based on a thematic analysis of these interviews three themes emerged: (a) the importance of a child's environment, (b) the importance of an education in society, and (c) the role of math in early childhood. Finally, based on a meta-inference of both strands, three themes emerged: (a) teacher conception of math, (b) teacher practice, and (c) teacher sensitivity. Implications based on the findings involve policy, curriculum, and professional development.
Resumo:
Approaches to quantify the organic carbon accumulation on a global scale generally do not consider the small-scale variability of sedimentary and oceanographic boundary conditions along continental margins. In this study, we present a new approach to regionalize the total organic carbon (TOC) content in surface sediments (<5 cm sediment depth). It is based on a compilation of more than 5500 single measurements from various sources. Global TOC distribution was determined by the application of a combined qualitative and quantitative-geostatistical method. Overall, 33 benthic TOC-based provinces were defined and used to process the global distribution pattern of the TOC content in surface sediments in a 1°x1° grid resolution. Regional dependencies of data points within each single province are expressed by modeled semi-variograms. Measured and estimated TOC values show good correlation, emphasizing the reasonable applicability of the method. The accumulation of organic carbon in marine surface sediments is a key parameter in the control of mineralization processes and the material exchange between the sediment and the ocean water. Our approach will help to improve global budgets of nutrient and carbon cycles.
Resumo:
Surface samples, mostly from abyssal sediments of the South Atlantic, from parts of the equatorial Atlantic, and of the Antarctic Ocean, were investigated for clay content and clay mineral composition. Maps of relative clay mineral content were compiled, which improve previous maps by showing more details, especially at high latitudes. Large-scale relations regarding the origin and transport paths of detrital clay are revealed. High smectite concentrations are observed in abyssal regions, primarily derived from southernmost South America and from minor sources in Southwest Africa. Near submarine volcanoes of the Antarctic Ocean (South Sandwich, Bouvet Island) smectite contents exhibit distinct maxima, which is ascribed to the weathering of altered basalts and volcanic glasses. The illite distribution can be subdivided into five major zones including two maxima revealing both South African and Antarctic sources. A particularly high amount of Mg- and Fe-rich illites are observed close to East Antarctica. They are derived from biotite-bearing crystalline rocks and transported to the west by the East Antarctic Coastal Current. Chiorite and well-crystallized dioctaedral illite are typical minerals enriched within the Subantarctic and Polarfrontal-Zone but of minor importance off East Antarctica. Kaolinite dominates the clay mineral assemblage at low latitudes, where the continental source rocks (West Africa, Brazil) are mainly affected by intensive chemical weathering. Surprisingly, a slight increase of kaolinite is observed in the Enderby Basin and near the Filchner-Ronne Ice shelf. The investigated area can be subdivided into ten, large-scale clay facies zones with characteristic possible source regions and transport paths. Clay mineral assemblages of the largest part of the South Atlantic, especially of the western basins are dominated by chlorite and illite derived from the Antarctic Peninsula and southernmost South America and supported by advection within the Circumantarctic Deep Water flow. In contrast, the East Antarctic provinces are relatively small. Assemblages of the eastern basins north of 30°S are strongly influenced by African sources, controlled by weathering regimes on land and by a complex interaction of wind, river and deep ocean transport. The strong gradient in clay mineral composition at the Brazilian slope indicate a relatively low contribution of tropically derived assemblages to the western basins.