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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.
141

Subtracted Approaches to Gene Expression Analysis in Atherosclerosis

Boräng, Stina January 2003 (has links)
Gene expression analysis has evolved as an extensive toolfor elucidation of various biological and molecular eventsoccurring in different organisms. A variety of techniques andsoftware tools have been developed to enable easier and morerapid means of exploring the genetic information. A moreeffective approach than exploring the whole content of genesexpressed under certain conditions is to study fingerprintassays or to use subtracted cDNA libraries to identify onlydifferentially expressed genes. The objective for the work in this thesis has been toexplore differentially expressed genes in atherosclerosis. Thiswas done by applying and modifying a protocol for thesubtractive approach RDA (Representational Difference Analysis)in different model systems. Initially, the molecular effects of an anti-atheroscleroticdrug candidate were elucidated. In addition, two alternativeapproaches to identify differentially expressed genes obtainedafter iterative rounds of RDA subtraction cycles wereevaluated. This revealed that in most cases, the shotgunapproach in which the obtained gene fragments are clonedwithout any prior selection has clear advantages compared tothe more commonly used selection strategy, whereby distinctbands are excised after gel electrophoresis. A key process in the atherosclerotic plaque initiation isthe phenotypic change of macrophages into foam cells, which canbe triggered in a model system by using macrophages exposed tooxidised LDL. To investigate the genes expressed in thisprocess, the RDA technique was combined with microarrayanalysis, which allows for selectivity and sensitivity throughRDA, as well as rapid high-throughput analysis usingmicroarrays. The combination of these techniques enablessignificant differences in gene expression to be detected, evenfor weakly expressed genes and the results to be reliablyvalidated in a high throughput manner. Finally, investigation of the focal nature ofatherosclerotic lesions and gene expression profiling werestudied using in vivo aortic tissues from ApoE-/- and LDLR -/-mice. The study was based on a comparison between localisationsthat are likely, and others that are unlikely, to developatherosclerotic plaques, and the RDA technique was employed toexplore differential gene expression. <b>Keywords:</b>Representational Difference Analysis,atherosclerosis, gene expression profiling
142

The Impact of Cultural Difference on On-line Negotiation

Lin, Chun-yi 25 August 2007 (has links)
The rapid development in global e-business has made the Internet an important and inevitable channel of trade and business communication, including e-negotiations, across countries. To have knowledge of how national culture may affect behavior, decision-making and negotiations is getting more important not only in conducting business but also in daily communications in the Internet age. The purpose of this study is to explore what will be different if people negotiate with counterparts who have different culture background. Will the negotiators behave differently when they negotiate with people who have different cultural background? In order to have more comprehensive understanding of the impact of culture on the actual negotiation behavior of negotiators in a negotiation process, we decided to apply content analysis methodology has been applied to the draft of negotiation interactions collected through the Inspire system which has collected countless records of negotiation activities since 1996.
143

Internationalization motivations - difference in Swedish and Thai entrepreneurs

Sukasemsarn, Pinijnan, Biaobanchong, Thananthorn January 2009 (has links)
Purpose: The purpose of the study is to investigate firstly, the motivations of Swedish and Thai entrepreneurs toward internationalization business by exporting and secondly, the similarity motivation in going internationalization among Swedish and Thai entrepreneurs. Method: The multiple cases design is used in this report by conducting semi-structured interview in order to “generate understanding of the study” (Stenbacka, 2001). Two Swedish companies and three Thai companies have been interviewed. Empirical data was collected by face to face and telephone interview for Swedish companies and e-mail for Thai companies. Conclusion: Both Swedish and Thai entrepreneurs are motivated by both internal and external factors in term of going internationalization. However, there are dissimilarities in each motivation factors.
144

Incitamentsstrukturer i socialbidragssystemet : Leder hårdare krav till ett minskat socialbidragstagande?

Jönsson, Lisa January 2007 (has links)
I denna uppsats studeras hur förändrade incitament i form av hårdare aktiveringskrav för arbetslösa socialbidragstagare i Sveriges kommuner inverkar på andelen socialbidragstagare och socialbidragskostnaderna i kommunerna. Studien möjliggörs av att de svenska kommunerna i varierande utsträckning har infört hårdare aktiveringskrav för arbetslösa socialbidragstagare, varför en difference in differences-analys som renodlar effekten av hårdare krav kan genomföras. Kommunerna klassificeras utifrån graden av aktivitet vad gäller att få socialbidragstagare i aktivering. Väldigt aktiva kommuner jämförs med icke alls aktiva, och en betydande uppsättning kontrollvariabler som kontrollerar för andra skillnader mellan kommungrupperna inkluderas. Resultaten visar att ett införande av hårda aktiveringskrav för arbetslösa socialbidragstagare ger tydliga negativa effekter på andelen socialbidragstagare i kommunerna, i synnerhet för unga socialbidragstagare, men mer begränsade effekter på kommunernas socialbidragskostnader.
145

Time and Frequency Evolution of the Precursors in Dispersive Media and their Applications

Safian, Reza 26 February 2009 (has links)
Until now, few rigorous studies of the precursors in structures exhibiting superluminal group velocities have been performed. One dimensional photonic crystals(1DPC) and active Lorentzian media are among the ones which are able to exhibit superluminal propagation. In the first part of the thesis we have studied the evolution of the precursors in active Lorentzian media and 1DPC. The problem of the propagation of the precursors in active Lorentzian media is addressed, by employing the steepest descent method to provide a detailed description of the propagation of the pulse inside the dispersive medium in the time domain. The problem of the time and frequency evolution of the precursors in 1DPC is studied, using the finite-difference time-domain (FDTD) techniques in conjunction with joint time-frequency analysis (JTFA). Our study clearly shows that the precursor fields associated with superluminal pulse propagation travel at subluminal speeds. It is also shown that FDTD analysis and JTFA can be combined to study the dynamic evolution of the transient and steady state pulse propagation in dispersive media. The second part of the thesis concentrates on the applications of the precursors. An interesting property of the precursors is their lower than exponential attenuation rate inside a lossy dielectric, such as water. This property of the precursors has made them an interesting candidate for applications such as ground penetrating radar and underwater communication. It was recently pointed out that a pulse which is generated inside of water and assumes the shape of the Brillouin precursor would be optimally suited for long range propagation in water (described by the single-pole Debye model). Here, we have considered the optimal pulse propagation problem, accounting for the interaction of the pulse with the air/water interface at oblique incidence. In addition, we argue that pulse excitations which are rough approximation of the Brillouin precursor will eventually evolve into the Brillouin precursor itself shortly after they enter water. Therefore, the excitation of a long-propagating pulse is not sensitive to its shape. Finally, we studied the performance of the optimized pulse in terms of the energy of the scattered field from an object inside water. Based on the simulation results the optimized pulse scattered field has higher energy compared to pulses with the same energy and different temporal distribution. The FDTD technique is employed in all the simulations.
146

Time and Frequency Evolution of the Precursors in Dispersive Media and their Applications

Safian, Reza 26 February 2009 (has links)
Until now, few rigorous studies of the precursors in structures exhibiting superluminal group velocities have been performed. One dimensional photonic crystals(1DPC) and active Lorentzian media are among the ones which are able to exhibit superluminal propagation. In the first part of the thesis we have studied the evolution of the precursors in active Lorentzian media and 1DPC. The problem of the propagation of the precursors in active Lorentzian media is addressed, by employing the steepest descent method to provide a detailed description of the propagation of the pulse inside the dispersive medium in the time domain. The problem of the time and frequency evolution of the precursors in 1DPC is studied, using the finite-difference time-domain (FDTD) techniques in conjunction with joint time-frequency analysis (JTFA). Our study clearly shows that the precursor fields associated with superluminal pulse propagation travel at subluminal speeds. It is also shown that FDTD analysis and JTFA can be combined to study the dynamic evolution of the transient and steady state pulse propagation in dispersive media. The second part of the thesis concentrates on the applications of the precursors. An interesting property of the precursors is their lower than exponential attenuation rate inside a lossy dielectric, such as water. This property of the precursors has made them an interesting candidate for applications such as ground penetrating radar and underwater communication. It was recently pointed out that a pulse which is generated inside of water and assumes the shape of the Brillouin precursor would be optimally suited for long range propagation in water (described by the single-pole Debye model). Here, we have considered the optimal pulse propagation problem, accounting for the interaction of the pulse with the air/water interface at oblique incidence. In addition, we argue that pulse excitations which are rough approximation of the Brillouin precursor will eventually evolve into the Brillouin precursor itself shortly after they enter water. Therefore, the excitation of a long-propagating pulse is not sensitive to its shape. Finally, we studied the performance of the optimized pulse in terms of the energy of the scattered field from an object inside water. Based on the simulation results the optimized pulse scattered field has higher energy compared to pulses with the same energy and different temporal distribution. The FDTD technique is employed in all the simulations.
147

Empati gentemot människor med olika etniciteter

Nurminen, Piritta, Svedlin, Maria January 2009 (has links)
Kvinnor har visats vara mer empatiska än män vid självskattning samt att vita och svarta barn känner mer empati för en målperson med samma hudfärg. Denna studies syfte var att undersöka om män och kvinnor kände olika mycket empati beroende på målpersonens etni-citet, om det fanns några könsskillnader i empati samt om något av könen väckte mer empati. Deltagarna var 208 män och kvinnor med svensk och invandrarbakgrund, majoriteten studerade på Mälardalens högskola. Resultatet visade en signifikant disordinal interaktion där svenska deltagare visade högre empati för en svensk målperson än vad de gjorde för en invandrad och invandrardeltagare visade högre empati för en invandrad målperson än vad de gjorde för en svensk. Ingen huvudeffekt för empati och deltagarnas etnicitet fanns. Män uppvisade signifikant lägre empati än kvinnor. Inget av könen väckte signifikant mer empati. Vikten av upplevd likhet mellan målperson och empatisör diskuterades och vidare forskning med äldre deltagare föreslogs.
148

Simulation of Seismic Real and Virtual Data Using the 3d Finite-difference Technique and Representation Theorem

Yang, Xiujun 15 May 2009 (has links)
Seismic modeling is a technique for simulating wave propagation through the subsurface. For a given geological model, seismic modeling allows us to generate snapshots of wave propagation and synthetic data. In my dissertation, for real seismic events I have chosen to implement the finite-difference modeling technique. When adequate discretization in space and time is possible, the finite-difference technique is by far one of the most accurate tools for simulating elastic-wave propagation through complex geological models. In recent years, a significant amount of work has been done in our group using 2D finite-difference modeling. For complex salt structures which exploration and pro- duction industries meet today, 2D finite-difference modeling is not sufficient to study subsalt imaging or the demultiple of subsalt models. That is why I have developed a 3D finite-difference modeling code. One of the key challenges that I have met in developing the 3D finite-difference code is to adapt the absorbing boundary conditions. Absorbing boundary conditions are needed to describe the infinite geological models by limited computing domain. I have validated the 3D finite-difference code by comparing its results with analytic solutions. I have used 3D finite-difference program to generate data corresponding to 3D complex model which describes salt and subsalt structures of Gulf of Mexico. The resulting data include reflections, diffractions and other scattering phenomena. I have also used finite-difference program in anisotropic context to show that we can effectively predict shear-wave splitting and triplication in the data. There are new sets of events that are not directly recorded in seismic data, they have been called virtual events. These events are turning to be as important as real events in modern data processing. Therefore we also have to learn how to model them. Unfortunately, they cannot yet be modeled directly from finite-difference. Here I will describe how to model these events by using cross correlation type representation theorem. As illustration of how important of virtual events for seismic data process- ing, I also described an internal multiple attenuation technique which utilized virtual events.
149

The Study of Gender Difference of kindergarten Children in Study and Play

Li, Pei-hua 27 July 2004 (has links)
The purpose of this study is to explore gender difference of kindergarten children in learning area choice and play behavior. The purposes of this study were: (1) Inquire relation between gender and learning centers choice of kindergarten children. (2) Analysis kindergarten children¡¦s play model of gender difference. (3) After gender course, exploration to young children¡¦s interaction and gender behavior. Participants were a kindergarten class ten boys and seven girls .This research is an ethnography methodology with participant observation, informal interview, formally interview and literature review to collect data. After gender course, observation young child behavior and attitude's development at play. Final findings direct to under several aspects make illustrate: (1) young children¡¦s gender difference of choosing learning centers; (2) gender difference of play development; (3) curriculum with gender and play correlation.
150

Analysis and Application of the Model Order Reduction Method in the Finite-Difference Time-Domain Algorithm

Su, Hsin-Hsiang 28 July 2005 (has links)
It is well known that the finite difference time domain (FDTD) method is a powerful numerical analysis tool for solving electromagnetic problems. In a simulated area, in order to discretize an object which is much smaller than the others, a very small space increment is needed and hence the time step should be decreased too for stability consideration in traditional FDTD. The small space and time increments will respectively increase the memory requirement and calculation time. To overcome these problems, some numerical methods were developed, such as the subcell and nonuniform grid method, to handle the small feature size. This thesis describes an efficient method for generating FDTD subcell equations. We construct a second order macromodel system instead of the subcell region in conventional FDTD. The macromodel system can be reduced with model order reduction techniques (MOR) and then translated into new FDTD update equations. When the problem contains several objects of the same size and material properties, the MOR subcell has the advantage of reusability. This means that the reduce-order model of the object needs to be generated only once nonetheless can be applied to every position where the objects originally occupied.

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