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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Conditional regulation of Hoxa2 gene expression in CG4 cells

Wang, Juan (Monica) 02 August 2007
Oligodendrocytes (OLs) are the glial cells responsible for the synthesis and maintenance of myelin in the central nervous system. Recently, Hoxa2 was found by our laboratory to be expressed by OLs and down-regulated at the terminal differentiation stage during oligodendrogenesis in mice (Nicolay et al., 2004b). To further investigate the role of Hoxa2 in oligodendroglial development, a tetracycline regulated controllable expression system was utilized to establish two stable cell lines where the expression level of Hoxa2 gene could be up-regulated (CG4-SHoxa2 [sense Hoxa2]) or down-regulated (CG4-ASHoxa2 [Antisense Hoxa2]) in CG4 glial cells. Morphologically, no obvious differences were observed between CG4-SHoxa2 and CG4 wild-type cells, whereas CG4-ASHoxa2 cells exhibited much shorter processes compared with those of CG4 wild-type cells. Data from BrdU uptake assays indicated that an up-regulation of Hoxa2 gene promoted the proliferation of CG4-SHoxa2 cells. PDGF&alphaR (Platelet-derived growth factor [PDGF] receptor alpha), a receptor for the mitogen PDGF that enhances the survival and proliferation of OLs, was assessed at the mRNA level in both CG4 and CG4-SHoxa2 cells, but no significant differences were observed between Hoxa2 up-regulated cells and wild-type CG4 cells with respect to the mRNA level of PDGF&alphaR. In addition, specific investigations of the differentiation of CG4-SHoxa2 cells were carried out by characterizing the composition of stage specific oligodendroglial subpopulations in culture. Our immunocytochemical study did not indicate the differentiation course of the genetically engineered cells was significantly altered compared to CG4 wild-type cells, although results from semi-quantitative RT-PCR of oligodendrocyte-specific ceramide galactosyltransferase (CGT) and myelin basic protein (MBP) indicate that the differentiation of CG4-SHoxa2 cells was delayed when Hoxa2 gene was up-regulated.
222

Exploring the On-line Partitioning of Posets Problem

Rosenbaum, Leah F. 09 March 2012 (has links)
One question relating to partially ordered sets (posets) is that of partitioning or dividing the poset's elements into the fewest number of chains that span the poset. In 1950, Dilworth established that the width of the poset - the size of the largest set composed only of incomparable elements - is the minimum number of chains needed to partition that poset. Such a bound in on-line partitioning has been harder to establish, and work has evalutated classes of posets based on their width. This paper reviews the theorems that established val(2)=5 and illustrates them with examples. It also covers some of the work on establishing bounds for on-line partitioning with the Greedy Algorithm. The paper concludes by contributing a bound on incomparable elements in graded, (t+t)-free, finite width posets.
223

Las promociones publicitarias en la prensa. Evolución y análisis sistemático de las promociones realizadas entre los años 1990-1998 en la prensa de información general de Cataluña

Santana López, Eva 01 February 2002 (has links)
El objeto de la tesis es analizar y sistematizar un fenómeno de comunicación empresarial que en el caso de España, y más concretamente Catalunya, adquiere unas características especiales en cuanto a profusión, liberalidad y originalidad: las promociones en la prensa. Se ha dividido en tres grandes bloques: el marco teórico de la Promoción de Ventas (evolución histórica del término, delimitación del concepto, principales características definitorias y el establecimiento de una clasificación de las técnicas básicas). Seguidamente se ha procedido a contextualizar la prensa con relación a la época desde inicios de los 80 a finales de los 90. Por último, se ha procedido a desarrollar el tema central de la investigación, la evolución y análisis de las promociones en el sector de la prensa. Para ello se han auditado las actas de la Oficina de Justificación de la Difusión (OJD) entre los años 1990-1998 y entrevistado en profundidad a los responsables de los diarios seleccionados (Avui, La Vanguardia, El Periódico de Catalunya, El País y el Mundo), entendiendo como tales a Directores Generales, Directores de Marketing o de Comunicación.La hipótesis de la investigación defiende la rentabilidad de las promociones a pesar que los costes que supone realizarlas (producción, distribución y comunicación mediante campaña publicitaria) no son superados, por norma, por los ingresos (aumento de ejemplares vendidos e inversión de los patrocinadores) Aunque no se ha entrado en el detalle del balance de gastos e ingresos debido a la confidencialidad de los mismos, los datos generales y unánimes aportados por los entrevistados así lo corroboran. Sin embargo, tras contabilizar las promociones desarrolladas durante nueve años por las cinco cabeceras seleccionadas en el estudio comprobamos que las promociones no han dejado de crecer en número y ni en días del año. Es decir cada vez hay más promociones y durante más tiempo. Por todo ello, se ha defendido la hipótesis de la rentabilidad de la inversión en promociones por parte de los diarios si bien, no en relación costes / ingresos (ya que como se ha dicho los primeros superan a los segundos) sino en términos de garantizar la audiencia, y por tanto la inversión publicitaria, a través de una rentabilidad indirecta. Como se verá, las promociones en la prensa cumplen la función de mantener una difusión promedio a lo largo del año que permita al diario garantizar un número determinado de lectores suficiente como para que a los anunciantes les interese comprar espacio publicitario. / The objective of this thesis is to analyse and systematize a business communication phenomenon which in Spain's case and more precisely in Catalonia, acquires several special characteristics, concerning profusion, liberality and originality: the Press sales promotion's .It has been divided into three sections. Firstly the sales promotion's theoretical context, (the historic evolution of the term, delimitation of the concept, main definition characteristics and the establishment of the classification's basic techniques). Secondly the press has been contextualised in relation to the beginning of the 80's until the late 1990's. Finally the main issue of our investigation, the evolution and analysis of the sales promotion in the Press sector, has been developed in detail. For this reason the certificates from the oficina de la justificación de la difusión (Justification broadcasting office), have been audited between 1990 and 1998. We have also interviewed in ernest those reponsable for the selected Newspapers (Avui, La Vanguardia, El Periódico de Catalunya, EL País y el mundo). Understood as CEO's, Marketing Directors and Communications directors. We defended the sales promotions rentability, in spite of the costs (production, distribution and communication) are not overcomed normally, by the revenue (journals saled and sponsor income) . Though we haven't entered into detail with regards to the spending and the income balance due to it's confidentiality, the general data unanimously supplied by those who were interviewed, support this fact. Nevertheless after auditing the promotion development during nine years by the chosen five. We prove that the promotions have not decreased in number, nor in global daily production figures. That is to say, each time there are more sales promotion and for longer periods of time.Therefore the rentability hypothesis of the investment in promotions has been defended by the daily Newspapers, no with regards to cost-income (as mentioned above) but rather in terms of guaranteeing the audience and therefore the publications investment, through indirect rentability. As we will see, the press sales promotions fulfil the function of maintaining an average broadcasting during the year, that allows the newspapers to guarantee a determined number of readers. Sufficient so as to keep the sales promotions interested in buying their publicity spaces.
224

Content-Adaptive Automatic Image Sharpening

Tajima, Johji, Kobayashi, Tatsuya January 2010 (has links)
No description available.
225

Automatisk detektering av diken i LiDAR-data / Automatic detection of ditches in LiDAR collected data

Wasell, Richard January 2011 (has links)
Den här rapporten har utrett möjligheten att automatiskt identifiera diken frånflygburet insamlat LiDAR-data. Den metod för identifiering som har valts harförst skapat en höjdbild från LiDAR-data. Därefter har den tagit fram kandidatertill diken genom att vektorisera resultatet från en linjedetektering. Egenskaper-na för dikeskandidaterna har sedan beräknats genom en analys av höjdprofilerför varje enskild kandidat, där höjdprofilerna skapats utifrån ursprungliga data.Genom att filtrera kandidaterna efter deras egenskaper kan dikeskartor med an-vändarspecificerade mått på diken presenteras i ett vektorformat som underlättarvidare användning. Rapporten beskriver hur algoritmen har implementerats ochpresenterar också exempel på resultat. Efter en analys av algoritmen samt förslagpå förbättringar presenteras den viktigaste behållningen av rapporten; Att det ärmöjligt med automatisk detektering av diken. / This Master’s thesis is investigating the possibility of automatically identifyingditches in airborne collected LiDAR data. The chosen approach to identificationcommences by creating an elevation picture from the LiDAR data. Then it usesthe result of a line detection to exhibit candidates for ditches. The properties forthe various candidates are calculated through an analysis of the elevation profile forthe candidates, where the elevation profiles are created from the original data. Byfiltering the candidates according to their calculated properties, maps with ditchesconforming to user-specified limits are created and presented in vector format.This thesis describes how the algorithm is implemented and gives examples ofresults. After an analysis of the algorithm and a proposal for improvements, itis suggested that automatic detection of ditches in LiDAR collected data is anachievable objective.
226

Communication Network Analysis in Smart Grid

Lohani, Satyendra Nath January 2012 (has links)
With the world suffering from energy crisis, Smart Grid is the expanding research topic that deals vigorously with the current problems. It promotes decentralized renewable energy generation system, participate many local energy producers to energy market, adds vehicle to grid (V2G), minimize the energy loss in the electrical system, and participate many active consumers to the real market. It is an emerging project that needs an expert from many fields, thus it opens door of opportunities for many people around the globe. The present thesis deals with the communication scenario in smart grid. Communication is the backbone of Smart Grid and the thesis tries to highlight the available communication technologies for smart grid application. The thesis discuss most profitable communication technologies used for this purpose which are power line communication and wireless communication, in which power line communication aspects and characteristics are covered more than wireless communication for its use are seen more in upcoming days. In all the thesis will outline the opportunities and challenges of power line communication and wireless communication for smart grid application.
227

Dynamic Judgments of Spatial Extent: Behavioural, Neural, and Computational Studies

Hurwitz, Marc 17 December 2010 (has links)
Judgments of spatial relationships are often made when the object or observer are moving. Behaviourally, there is evidence that these ‘dynamic’ judgments of spatial extent differ from static judgments. Here I used three separate techniques for exploring dynamic judgments: first, a line bisection paradigm was employed to study ocular and pointing judgments of spatial extent while manipulating line length, position, speed, acceleration, and direction of scanning (Experiments 1-4); second, functional MRI (fMRI) was used to examine whether distinct brain regions were involved in dynamic versus static judgments of spatial extent (Exp 5); and finally, a mathematical and computational model of dynamic judgments was developed to provide a framework for interpreting the experimental results. In the behavioural experiments, substantial differences were seen between static and dynamic bisection, suggesting the two invoke different neural processes for computing spatial extent. Surprisingly, ocular and pointing judgments produced distinct bisection patterns that were uncorrelated, with pointing somewhat more impervious to manipulations such as scan direction and position than ocular bisections. However, a new experimental task for probing dynamic judgments (the ‘no line’ Experiment 4) found that scan direction can influence both hand behaviour. Functional MRI demonstrated that dynamic relative to static judgments produced activations in the cuneus and precuneus bilaterally, left cerebellum, and medial frontal gyrus, with reduced activation relative to static judgments observed in the supramarginal gyrus bilaterally. Dynamic bisections relative to a control condition produced activations in the right precuneus and left cerebellum, as well as in left superior parietal lobule, left middle temporal gyrus, and right precentral gyrus. It may be the case that velocity processing and temporal estimates are integrated primarily in the cuneus and precuneus bilaterally to produce estimates of spatial extent under dynamic scanning conditions. These results highlight the fact that dynamic judgments of spatial extent engage brain regions distinct from those employed to make static judgments, supporting the behavioural results that these are separate and distinct. Finally, a mathematical model was proposed for dynamic judgments of spatial extent, based on the idea that, rather than using an ‘all-or-none’ approach, spatial working memory actually takes about 100 ms to reach full representational strength for any given point in space. The model successfully explains many of the effects seen in the behavioural experiments including the effects of scan direction, velocity, line length, and position. In conjunction with the neuroimaging data, it also suggests why neglect patients may fail to show rightward bisection biases when making dynamic judgments of spatial extent. Overall, this work provides novel insights into how the brain executes dynamic judgments of spatial extent.
228

Conditional regulation of Hoxa2 gene expression in CG4 cells

Wang, Juan (Monica) 02 August 2007 (has links)
Oligodendrocytes (OLs) are the glial cells responsible for the synthesis and maintenance of myelin in the central nervous system. Recently, Hoxa2 was found by our laboratory to be expressed by OLs and down-regulated at the terminal differentiation stage during oligodendrogenesis in mice (Nicolay et al., 2004b). To further investigate the role of Hoxa2 in oligodendroglial development, a tetracycline regulated controllable expression system was utilized to establish two stable cell lines where the expression level of Hoxa2 gene could be up-regulated (CG4-SHoxa2 [sense Hoxa2]) or down-regulated (CG4-ASHoxa2 [Antisense Hoxa2]) in CG4 glial cells. Morphologically, no obvious differences were observed between CG4-SHoxa2 and CG4 wild-type cells, whereas CG4-ASHoxa2 cells exhibited much shorter processes compared with those of CG4 wild-type cells. Data from BrdU uptake assays indicated that an up-regulation of Hoxa2 gene promoted the proliferation of CG4-SHoxa2 cells. PDGF&alphaR (Platelet-derived growth factor [PDGF] receptor alpha), a receptor for the mitogen PDGF that enhances the survival and proliferation of OLs, was assessed at the mRNA level in both CG4 and CG4-SHoxa2 cells, but no significant differences were observed between Hoxa2 up-regulated cells and wild-type CG4 cells with respect to the mRNA level of PDGF&alphaR. In addition, specific investigations of the differentiation of CG4-SHoxa2 cells were carried out by characterizing the composition of stage specific oligodendroglial subpopulations in culture. Our immunocytochemical study did not indicate the differentiation course of the genetically engineered cells was significantly altered compared to CG4 wild-type cells, although results from semi-quantitative RT-PCR of oligodendrocyte-specific ceramide galactosyltransferase (CGT) and myelin basic protein (MBP) indicate that the differentiation of CG4-SHoxa2 cells was delayed when Hoxa2 gene was up-regulated.
229

Front-line employees make efforts on banks : an empirical case study in Chinese commercial banks

XU, XIAODAN, YUAN, XIN January 2011 (has links)
In order to reduce the risks, banks has two ways to evaluate the loan exposure. One is credit rating, and the other one is pledge collaterals. Many literatures and financial regulations are emphasizing on the importance of credit rating. However, with the illustration of a plenty of empirical study, the pledging collaterals are the popular way which was using by “lazy” banks. Credit rating or pledging with collaterals is the gap between theories and practices.  The aim of this thesis is to figure the factors which make the gap between the theories and practices. At last, the front-line employees are paid attention on. Since front-line employees are the first and direct one who contact customers. Reliability and responsiveness has a space to develop by training first-line employees, moral hazard controlling, and sectoral specialization the credit inspection.
230

Hur väljer företag att publicera CSR? : En undersökning av tre företags externa CSR-kommunikation

Carlson, Madeleine January 2009 (has links)
Uppsatsen bygger på en undersökning om hur tre företag arbetar med CSR. Syftet med undersökningen har varit att granska hur de utvalda företagen väljer att kommunicera dess CSR-arbete till externa intressenter.De frågeställningar studien bygger på är: Hur väljer företag att kommunicera CSR? Kommunicerar företag inom olika branscher CSR på samma sätt? Ser företag inom olika branscher samhällsansvaret på likvärdigt sätt? Finns det någon koppling mellan företags externa kommunikation av CSR och företags medierelation? Under arbetets gång har en respondent från respektive företag intervjuats. En innehållsanalys har även genomförts av företagens hemsidor. Undersökningen har gett författaren kunskap om att de undersökta företagen anser att CSR-arbetet bör finnas utspritt inom hela verksamheten och inte enbart skötas av en person. För att lyckas nå ut till sina externa intressenter på ett effektivt och trovärdigt sätt måste det sociala ansvaret vara en självklarhet för alla inom organisationen och vara en del av företagets vision. Synen på samhällsansvaret skiljde sig mellan företagen vilket kan bero på att det är en tolkningsfråga vad företagen anser är ett socialt samhällsansvar. Dock satte samtliga företag som deltagit i undersökningen in miljöfrågor och sociala frågor i begreppet. De olika företagen som befinner sig i olika branscher arbetar med liknande frågor fast deras tillvägagångssätt och huvudfråga kan skilja sig något mellan branscherna. Hur företagen än väljer att definiera begreppet och hur de än väljer att arbeta med dessa frågor är det en stor fördel att även kommunicera vad de gör till media. Media kan nämligen vara en effektiv kanal för företaget att nå ut till sina intressenter samt att skapa trovärdighet

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