840 resultados para Visual research methods : image, society and representation
Resumo:
It is known that parallel pathways exist within the visual system. These have been described as magnocellular and parvocellular as a result of the layered organisation of the lateral geniculate nucleus and extend from the retina to the cortex. Dopamine (DA) and acetylcholine (ACH) are neurotransmitters that are present in the visual pathway. DA is present in the retina and is associated with the interplexiform cells and horizontal cells. ACH is also present in the retina and is associated with displaced amacrine cells; it is also present in the superior colliculus. DA is found to be significantly depleted in the brain of Parkinson's disease (PD) patients and ACH in Alzheimer's disease (AD) patients. For this reason these diseases were used to assess the function of DA and ACH in the electrophysiology of the visual pathway. Experiments were conducted on young normals to design stimuli that would preferentially activate the magnocellular or parvocellular pathway. These stimuli were then used to evoke visual evoked potentials (VEP) in patients with PD and AD, in order to assess the function of DA and ACH in the visual pathway. Electroretinograms (ERGs) were also measured in PD patients to assess the role of DA in the retina. In addition, peripheral ACH function was assessed by measuring VEPs, ERGs and contrast sensitivity (CS) in young normals following the topical instillation of hyoscine hydrobromide (an anticholinergic drug). The results indicate that the magnocellular pathway can be divided into two: a cholinergic tectal-association area pathway carrying luminance information, and a non-cholinergic geniculo-cortical pathway carrying spatial information. It was also found that depletion of DA had very little effect on the VEPs or ERGs, confirming a general regulatory function for this neurotransmitter.
Resumo:
With economic activity in emerging markets growing at 40 percent, and with 10 percent and more of the firms in the Global Fortune 500 now headquartered in emerging economies, intense interest lies in the globalization of business activities, including the sales function. This systematic review of the international sales literature in a selection of the most influential journals explains, consolidates, and analyzes current knowledge. This paper also explores the challenges inherent in conducting international sales research, including conceptualization, research management, and data collection issues. Finally, we suggest ways to move forward for researchers in this field, including pertinent topics and how methodological and practical constraints might be addressed.
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Purpose – The purpose of this paper is to demonstrate how the conceptual lens of corporate social responsibility (CSR), business and civil society can be used to explore “less popular causes” (in this case, a community-based public sector empirical study of initiatives with offenders) and, in particular, respond to the question used by Walzer “In which society can lives be best led?” Design/methodology/approach – This is a formative and summative evaluation study of a National Offender Management “community payback” offender scheme based in the UK using a mixed method, predominantly qualitative approach that integrates theory and practice. Findings – The paper finds that citizenship actions of front-line public sector employees, working in partnership with other agencies in the community, embody the essence of Walzer's notion of CSR and civil society by going beyond the call of duty to provide additional training and moral support for the community offenders. Originality/value – The paper contributes towards an understanding of how CSR and civil society debates can inform wider aspects of public policy and business through its application to areas of society that are perceived to be “challenging” and “undeserving”.
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This paper describes the work undertaken in the Scholarly Ontologies Project. The aim of the project has been to develop a computational approach to support scholarly sensemaking, through interpretation and argumentation, enabling researchers to make claims: to describe and debate their view of a document's key contributions and relationships to the literature. The project has investigated the technicalities and practicalities of capturing conceptual relations, within and between conventional documents in terms of abstract ontological structures. In this way, we have developed a new kind of index to distributed digital library systems. This paper reports a case study undertaken to test the sensemaking tools developed by the Scholarly Ontologies project. The tools used were ClaiMapper, which allows the user to sketch argument maps of individual papers and their connections, ClaiMaker, a server on which such models can be stored and saved, which provides interpretative services to assist the querying of argument maps across multiple papers and ClaimFinder, a novice interface to the search services in ClaiMaker.
Resumo:
The yeast Saccharomyces cerevisiae is an important model organism for the study of cell biology. The similarity between yeast and human genes and the conservation of fundamental pathways means it can be used to investigate characteristics of healthy and diseased cells throughout the lifespan. Yeast is an equally important biotechnological tool that has long been the organism of choice for the production of alcoholic beverages, bread and a large variety of industrial products. For example, yeast is used to manufacture biofuels, lubricants, detergents, industrial enzymes, food additives and pharmaceuticals such as anti-parasitics, anti-cancer compounds, hormones (including insulin), vaccines and nutraceuticals. Its function as a cell factory is possible because of the speed with which it can be grown to high cell yields, the knowledge that it is generally recognized as safe (GRAS) and the ease with which metabolism and cellular pathways, such as translation can be manipulated. In this thesis, these two pathways are explored in the context of their biotechnological application to ageing research: (i) understanding translational processes during the high-yielding production of membrane protein drug targets and (ii) the manipulation of yeast metabolism to study the molecule, L-carnosine, which has been proposed to have anti-ageing properties. In the first of these themes, the yeast strains, spt3?, srb5?, gcn5? and yTHCBMS1, were examined since they have been previously demonstrated to dramatically increase the yields of a target membrane protein (the aquaporin, Fps1) compared to wild-type cells. The mechanisms underlying this discovery were therefore investigated. All high yielding strains were shown to have an altered translational state (mostly characterised by an initiation block) and constitutive phosphorylation of the translational initiation factor, eIF2a. The relevance of the initiation block was further supported by the finding that other strains, with known initiation blocks, are also high yielding for Fps1. A correlation in all strains between increased Fps1 yields and increased production of the transcriptional activator protein, Gcn4, suggested that yields are subject to translational control. Analysis of the 5´ untranslated region (UTR) of FPS1 revealed two upstream open reading frames (uORFs). Mutagenesis data suggest that high yielding strains may circumvent these control elements through either a leaky scanning or a re-initiation mechanism. In the second theme, the dipeptide L-carnosine (ß-alanyl-L-histidine) was investigated: it has previously been shown to inhibit the growth of cancer cells but delay senescence in cultured human fibroblasts and extend the lifespan of male fruit flies. To understand these apparently contradictory properties, the effects of L-carnosine on yeast were studied. S. cerevisiae can respire aerobically when grown on a non-fermentable carbon source as a substrate but has a respiro-fermentative metabolism when grown on a fermentable carbon source; these metabolisms mimic normal cell and cancerous cell metabolisms, respectively. When yeast were grown on fermentable carbon sources, in the presence of L-carnosine, a reduction in cell growth and viability was observed, which was not apparent for cells grown on a non-fermentable carbon source. The metabolism-dependent mechanism was confirmed in the respiratory yeast species Pichia pastoris. Further analysis of S. cerevisiae yeast strains with deletions in their nutrient-sensing pathway, which result in an increase in respiratory metabolism, confirmed the metabolism-dependent effects of L-carnosine.
Resumo:
In order to address problems of information overload in digital imagery task domains we have developed an interactive approach to the capture and reuse of image context information. Our framework models different aspects of the relationship between images and domain tasks they support by monitoring the interactive manipulation and annotation of task-relevant imagery. The approach allows us to gauge a measure of a user's intentions as they complete goal-directed image tasks. As users analyze retrieved imagery their interactions are captured and an expert task context is dynamically constructed. This human expertise, proficiency, and knowledge can then be leveraged to support other users in carrying out similar domain tasks. We have applied our techniques to two multimedia retrieval applications for two different image domains, namely the geo-spatial and medical imagery domains. © Springer-Verlag Berlin Heidelberg 2007.
Resumo:
Advances in statistical physics relating to our understanding of large-scale complex systems have recently been successfully applied in the context of communication networks. Statistical mechanics methods can be used to decompose global system behavior into simple local interactions. Thus, large-scale problems can be solved or approximated in a distributed manner with iterative lightweight local messaging. This survey discusses how statistical physics methodology can provide efficient solutions to hard network problems that are intractable by classical methods. We highlight three typical examples in the realm of networking and communications. In each case we show how a fundamental idea of statistical physics helps solve the problem in an efficient manner. In particular, we discuss how to perform multicast scheduling with message passing methods, how to improve coding using the crystallization process, and how to compute optimal routing by representing routes as interacting polymers.
Resumo:
Some basic points from the automated creation of a Bulgarian WordNet – an analogue of the Princeton WordNet, are treated. The used computer tools, the received results and their estimation are discussed. A side effect from the proposed approach is the receiving of patterns for the Bulgarian syntactic analyzer.
Resumo:
The paper considers the use and the information support of the most important mathematical Application Packages (AP), such as Maple, Matlab, Mathcad, Mathematica, Statistica and SPSS – mostly used during Calculus tuition in Universities. The main features of the packages and the information support in the sites of the producers are outlined, as well as their capacity for work in Internet, together with educational sites and literature related to them. The most important resources of the TeX system for preparation of mathematical articles and documents are presented.
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This is a review of methodology for the algorithmic study of some useful models in point process and queueing theory, as discussed in three lectures at the Summer Institute at Sozopol, Bulgaria. We provide references to sources where the extensive details of this work are found. For future investigation, some open problems and new methodological approaches are proposed.
Resumo:
Purpose: This research paper aims to examine the global trends in publishing in the leading marketing journals between 1964 and 2008, focusing on how public policy intervention in the assessment and funding of academic research has influenced Britain's relative productivity in the world's leading marketing journals. Design/methodology/approach: The method was an audit of contributions to the leading journals based on the authors' affiliation, country of origin and country in which they obtained their doctoral training. Findings: The results show that the proportion of leading marketing publications by authors affiliated to British universities have held steady at about 2 per cent, while the productivity of several other countries has accelerated past Britain. However, to retain that share, Britain has increasingly depended upon importing people whose PhD is not British. This contrasts with some other European countries that are now more productive than Britain, but mainly recruit locals with local PhDs. The pattern of decline in the UK is related to the impact of Britain's research assessment exercise and the continuation of relatively weak social science research training. Research limitations/implications: The analysis is limited by only looking at one academic discipline and only the top few academic journals in the field. Practical implications: The findings have implications at several levels. At a national policy level it questions the value of the research assessment exercises that appear to have presided over a decline in research productivity. For institutions, it questions the value in investing in developing local talent when success has come to those who buy talent internationally. Perhaps, the major implication arises from Britain's academic productivity declining while neighbouring countries have grown in international excellence. Originality/value: At a time when the continuation of expensive university research assessments is being questioned the research findings add value to the current debate in showing how that very process has accompanied academic decline. © Emerald Group Publishing Limited.
Resumo:
Ez a műhelytanulmány a 2009-ben lezajlott Nemzetközi Termelési Stratégia Kutatás (International Manufacturing Strategy Survey) hazai eredményeit foglalja össze az első elemzések alapján. Az eredményeket összevetettük a kutatás nemzetközi adatbázisával is, ezért a kutatásban részt vevő vállalatok és más érdeklődők a hazai vállalatok nemzetközi versenyképességéről is képet kaphatnak a termelés területén. Sajnos az elemzések nem hoztak túl kedvező eredményeket: a hazai mezőny sem saját magához, sem a nemzetközi mezőnyhöz képest nem tudott érdemben fejlődni az elmúlt 4 évben. = This study summarizes the first Hungarian results of the International Manufacturing Strategy Survey that took place in 2009. Hungarian data are compared to the international database of the research, as well. Thus participating companies and other interesting readers can get a picture about the international competitiveness of Hungarian companies at the field of production. Unfortunately the results are not very favourable: the Hungarian companies could not make considerable progress neither in comparison to their own previous results nor to international companies in the last three years.
Resumo:
Jelen dolgozat a Miles és Snow (1978) által kidolgozott stratégiai tipológiával kapcsolatos legjelentősebb kutatások megállapításait igyekszik összefoglalni. A szerző az elmúlt három évtized Miles és Snow-i kutatásaiban leginkább érintett területek alapján osztályozza a feldolgozott cikkeket, majd részletesen ismerteti a Kutató, Elemző, Védekező és Reagáló stratégiát követő vállalatokra vonatkozó marketing- és teljesítményimplikációkat. A vizsgálatok korlátainak és hiányosságainak feltárását követően a Miles és Snow-i stratégiai típusok aktuális elméleti, kutatás-módszertani és gyakorlati kihívásainak, valamint alulkutatott aspektusainak bemutatásával a cikk útmutatást kínál a stratégiai menedzsment leendő kutatóinak is. / === / The present paper strives to summarize the findings of the most important and outstanding researches concerning the strategic typology developed by Miles and Snow (1978). The present author classifies the reviewed articles of the past three decades according their mostly covered research areas, then exposes in detail the marketing and performance implications of the Prospector, Analyzer, Defender and Reactor strategic types pursued by the firms. After the exploration of the limitations and deficiencies of the past empirical investigations, by the demonstration of the actual conceptual, methodological and practical challenges as well as the underresearched aspects of strategic types of Miles and Snow, the artricle also offers fruitful guidelines to future researchers of strategic.
Resumo:
A cikk a páros összehasonlításokon alapuló pontozási eljárásokat tárgyalja axiomatikus megközelítésben. A szakirodalomban számos értékelő függvényt javasoltak erre a célra, néhány karakterizációs eredmény is ismert. Ennek ellenére a megfelelő módszer kiválasztása nem egy-szerű feladat, a különböző tulajdonságok bevezetése elsősorban ebben nyújthat segítséget. Itt az összehasonlított objektumok teljesítményén érvényesülő monotonitást tárgyaljuk az önkonzisztencia és önkonzisztens monotonitás axiómákból kiindulva. Bemutatásra kerülnek lehetséges gyengítéseik és kiterjesztéseik, illetve egy, az irreleváns összehasonlításoktól való függetlenséggel kapcsolatos lehetetlenségi tétel is. A tulajdonságok teljesülését három eljárásra, a klasszikus pontszám eljárásra, az ezt továbbfejlesztő általánosított sorösszegre és a legkisebb négyzetek módszerére vizsgáljuk meg, melyek mindegyike egy lineáris egyenletrendszer megoldásaként számítható. A kapott eredmények új szempontokkal gazdagítják a pontozási eljárás megválasztásának kérdését. _____ The paper provides an axiomatic analysis of some scoring procedures based on paired comparisons. Several methods have been proposed for these generalized tournaments, some of them have been also characterized by a set of properties. The choice of an appropriate method is supported by a discussion of their theoretical properties. In the paper we focus on the connections of self-consistency and self-consistent-monotonicity, two axioms based on the comparisons of object's performance. The contradiction of self-consistency and independence of irrel-evant matches is revealed, as well as some possible reductions and extensions of these properties. Their satisfiability is examined through three scoring procedures, the score, generalised row sum and least squares methods, each of them is calculated as a solution of a system of linear equations. Our results contribute to the problem of finding a proper paired comparison based scoring method.
Resumo:
Absztakt: Ez a műhelytanulmány a 2013-2014-ben lezajlott Nemzetközi Termelési Stratégia Kutatás (International Manufacturing Strategy Survey) hazai eredményeit foglalja össze az első elemzések alapján. Az eredményeket összevetettük a kutatás nemzetközi adatbázisával is, ezért a kutatásban részt vevő vállalatok és más érdeklődők a hazai vállalatok nemzetközi versenyképességéről is képet kaphatnak a termelés területén ______ This study summarizes the first Hungarian results of the International Manufacturing Strategy Survey that took place in 2013-2014. Hungarian data are compared to the international database of the research, as well. Thus participating companies and other interesting readers can get a picture about the international competitiveness of Hungarian companies at the field of production.