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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.
71

Living on the Edge: transport sustainability in Perth’s Liveable Neighbourhoods

ryno.sar@bigpond.com, Ryan William Falconer January 2008 (has links)
Following World War Two, land use and transport policy and practice in most major Australian cities was modelled on the US experience. As such, these cities have become characterised by urban sprawl (indicated by segregated zoning and low development densities) and car dependence. In Perth, Western Australia, these characteristics are particularly evident despite, or perhaps because, the city has a strong regional planning system unlike most American cities. Car dependence and sprawl are in turn linked to dependence on fossil fuels for transport energy. Increasingly, too, links are being found between conventional planning outcomes and public health. For example, research has linked car dependence with a variety of health conditions including respiratory illness, overweight and obesity. Moreover, research is increasingly linking sprawl and car dependence with social justice issues because people on limited income and with decreased mobility struggle to undertake their life’s work. In response to these concerns the Western Australian planning system introduced Liveable Neighbourhoods, a new design code, which was meant to reduce car dependence and sprawl. This code has its roots in New Urbanism and appears to have been taken up more rapidly in Perth than elsewhere. No large-scale evaluation of New Urbanism has previously been conducted anywhere. This thesis reports on an extensive literature review, travel survey (n=211), perceptual study (n=992) and environmental study, which together sought to evaluate whether the Liveable Neighbourhoods (LN) design code is contributing to a sustainable transport agenda. In total, 46 neighbourhoods (11 LNs and 35 CNs) were compared. The research found that despite residents of Liveable Neighbourhoods driving less and walking more than residents of conventional neighbourhoods (CNs) (a switch of 9% with some associated health advantages), there was little else to indicate that LN is achieving its goals as transport VKT and fuel use was identical due to regional transport requirements diminishing any local walkability advantages. There was strong supportive evidence that LNs were not significantly different to CNs. For example, there were few differences in perception of opportunity for more sustainable travel and residents of CNs actually had better access, on average, to key destinations, including shops (i.e. the average distance to key destinations was 2.2 kilometres compared with 2.5 kilometres in LNs). Also, residential lot densities were well below what were intended by LN and in both LNs and CNs the time for public transport to get people to work was over 90 minutes compared with around 30 minutes by car. The results reveal that there must be significant revisions to the LN code and how it is applied, because there is no evidence that new neighbourhoods are improving regional transport sustainability. In particular, residential densities and land use mix appear to be too low to encourage community self-sufficiency, indicated by few neighbourhoods being anchored by key destinations. These matters are not mandated in the LN guidelines making them powerless to bring significant change. More generally, the thesis questions the extent to which New Urbanism can promote a sustainable transport agenda wherever it is applied unless it mandates real changes in land use and transit not just local walkability.
72

Field dependence and student achievement in technology-based learning: a meta-analysis

Karon, Dragon 11 1900 (has links)
This investigation was a synthesis of 35 research studies with a total sample size of 3,082 students selected on the basis of Witkin’s theory of Field Dependence-Independence. The Hunter-Schmidt approach to meta-analysis was used to determine if a difference in achievement exists between field dependent and field independent students within technology-based learning environments, and whether study, treatment or methodology variables influenced the effect size outcome. The results indicated an achievement difference in favor of field independent learners with a total mean weighted effect size of 0.426 and a pooled standard deviation of 0.311. However, a large proportion of population variance was not accounted for through statistical corrections. A subsequent moderator analysis indicated that the total heterogeneity for each moderator was significant; suggesting the variance among effect sizes was greater than could be expected by sampling error, and unidentified variables and study artifacts likely contributed to the overall effect size.
73

Processing and Properties of Ultrathin Perovskite Manganites

Johnsson, Peter January 2003 (has links)
No description available.
74

Characterization of Substance P (SP) Aminoterminal SP (1-7) Binding in Brain Regions and Spinal Cord of the Male Rat : Studies on the Interaction with Opioid Related Pathways

Botros, Milad January 2008 (has links)
Binding sites for substance P(1-7), SP(1-7) have been identified and characterized for the first time in crude membrane fraction from rat CNS using tritiated ([3H]) SP(1-7) as tracer. These putative receptors were investigated in relation to their affinity for tachykinins, opioid peptides and sigma receptor ligands. [3H]-SP(1-7) specifically binds to high affinity binding sites identified as receptor targets for the heptapeptide SP (1-7). Two distinct binding sites were observed in the spinal cord. One site is recognized by high affinity for SP(1-7) with a Kd of 0.5 nM, whereas the other site showed low affinity for the heptapeptide (Kd=12 nM). In the brain, the binding of SP(1-7) fitted a single site binding model with a Kd of 4.4 nM and a Ki of 4.2 nM. Further, using the spinal cord membranes the binding of [3H]-SP (1-7) was weakly displaced by SP and other N-terminal fragments thereof and no or negligible affinity was observed for ligands of the NK-1, NK-2 and NK-3 tachykinin receptors, C-terminal SP(5-11), Tyr-w-MIF-1 or the mu-opioid receptor antagonists naloxone and naloxonazine. On the other hand it was significantly displaced by endomorphin-2, DAMGO, and Try-MIF-1 and exhibit some affinity for MIF-1, ß-casomorphin and endomorphin-1. However, only endomorphin-2, DAMGO and Tyr-MIF-1 showed affinity in the close range of the native peptide SP(1-7). The affinity of endomorphin-2 for the spinal cord site was 10 times lower than that of SP(1-7) but more than 100 times higher than the affinity recorded for endomorphin-1. Tyr-MIF-1 but not Tyr-w-MIF-1 showed similar affinity as endomorphin-2 for SP(1-7) site. All peptides exhibiting high affinity at the SP(1-7) site, have a phenylalanine or a leucine residue in their C-terminal structure. Further, synthetic analogues of SP(1-7) were tested for their affinity for the SP(1-7) receptor in the rat spinal cord. An important finding here was that the receptor-ligand-interaction was favoured by the C-terminal region of SP(1-7). Residues at positions 5-7 appeared crucial for binding to the specific SP(1-7) site. The presence of the amidated Phe7 residue was extremely critical for binding to the SP(1-7) site.The analogue Gln5-Gln6-Phe7-NH2 was almost equipotent with the parent peptide in the SP (1-7) receptor binding assay. Furthermore, the SP(1-7)-amide potently and dose dependently reduced several signs of the reaction to morphine withdrawal and was significantly attenuated by the addition of the sigma agonist SK-10047. In conclusion, the work presented in this thesis has contributed the characterization of the properties of highly selective binding sites for SP(1-7) in the rat spinal cord and VTA. These sites appear to be distinct from the µ-opioid receptor or any of the known neurokinin receptors. The study further indicates that the SP(1-7)-amide mimics the effect of the nativ heptapeptide and that the mechanisms for its action involve a sigma receptor site.
75

Probing Mesocorticolimbic Dopamine Function in Alcohol Dependence Using Dextroamphetamine: Behavioural and FMRI Studies

Balducci, Xavier Laurent 15 July 2009 (has links)
Background: A dysfunctional mesocorticolimbic dopamine system has been reported in alcohol dependence and major depressive disorder. Probing mesocorticolimbic dopamine function in severe depression using dextroamphetamine revealed an altered behavioural response and a disrupted mesocorticolimbic circuitry in behavioural and functional magnetic resonance imaging (fMRI) studies. The purpose of this study was to use a similar approach in alcohol dependence. Behavioural Study: to assess dextroamphetamine subjective effects in alcohol-dependent and depressed alcohol-dependent participants. FMRI Study: to assess how the mesocorticolimbic circuitry would respond to a dextroamphetamine challenge in alcohol-dependent participants exposed to alcohol cues. Methods: In both studies, a single oral 30 mg dose of dextroamphetamine was the pharmacological intervention. Behavioural Study: randomized, double-blind, placebo-controlled, between-subject study. Eighteen alcohol-dependent and 22 depressed alcohol-dependent participants were compared using validated self-report drug effect tools (e.g. Addiction Research Center Inventory). FMRI Study: single-blind, between-subject study. FMRI blood oxygen level–dependent (BOLD) activation was measured in 14 alcohol-dependent and 9 healthy control participants during an alcohol-cue exposure task pre- and post-drug. Results: Behavioural Study: DRUG (F1,40=18.6; p<0.001) and GROUP (F1,40=16.6; p<0.001) main effects but no GROUPxDRUG interaction effects (F1,40=0.02; p=0.88) were detected, even when only severely depressed alcohol-dependent individuals were included (F1,30=0.04; p=0.84). FMRI Study: Alcohol-dependent participants exhibited greater ventral striatal activation compared to controls pre-drug and post-drug effect (F1,40=20.1; z=3.8; p<0.001; k>10; (x=10;y=-2;z=-14)). A GROUPxDRUG interaction effect was detected in the medial orbitofrontal cortex (mOFC) (F1,40=21.5; z=4.0; p<0.001; k>10; (x=-12;y=28;z=-20). The alcohol-dependent group exhibited a negligible mOFC response across both pre- and post-drug scanning sessions. In contrast, controls exhibited attenuation of mOFC response post-drug. Conclusion: The lack of significant GROUPxDRUG interaction effects in the Behavioural Study may suggest different neurobiological mechanisms underlying alcohol dependence and depression mesocorticolimbic dysfunction. Alcohol dependence appeared to mitigate the impact of depression severity on participants’ behavioural responses to dextroamphetamine. The FMRI Study data suggest there may be ventral striatal and mOFC disruption in alcohol-dependent participants. We suggest the mOFC may be involved in the reported loss of prefrontal modulation of dopamine cell activity in alcohol dependence. This supports a key role for the mOFC in mesocorticolimbic dysfunction in alcohol dependence.
76

Probing Mesocorticolimbic Dopamine Function in Alcohol Dependence Using Dextroamphetamine: Behavioural and FMRI Studies

Balducci, Xavier Laurent 15 July 2009 (has links)
Background: A dysfunctional mesocorticolimbic dopamine system has been reported in alcohol dependence and major depressive disorder. Probing mesocorticolimbic dopamine function in severe depression using dextroamphetamine revealed an altered behavioural response and a disrupted mesocorticolimbic circuitry in behavioural and functional magnetic resonance imaging (fMRI) studies. The purpose of this study was to use a similar approach in alcohol dependence. Behavioural Study: to assess dextroamphetamine subjective effects in alcohol-dependent and depressed alcohol-dependent participants. FMRI Study: to assess how the mesocorticolimbic circuitry would respond to a dextroamphetamine challenge in alcohol-dependent participants exposed to alcohol cues. Methods: In both studies, a single oral 30 mg dose of dextroamphetamine was the pharmacological intervention. Behavioural Study: randomized, double-blind, placebo-controlled, between-subject study. Eighteen alcohol-dependent and 22 depressed alcohol-dependent participants were compared using validated self-report drug effect tools (e.g. Addiction Research Center Inventory). FMRI Study: single-blind, between-subject study. FMRI blood oxygen level–dependent (BOLD) activation was measured in 14 alcohol-dependent and 9 healthy control participants during an alcohol-cue exposure task pre- and post-drug. Results: Behavioural Study: DRUG (F1,40=18.6; p<0.001) and GROUP (F1,40=16.6; p<0.001) main effects but no GROUPxDRUG interaction effects (F1,40=0.02; p=0.88) were detected, even when only severely depressed alcohol-dependent individuals were included (F1,30=0.04; p=0.84). FMRI Study: Alcohol-dependent participants exhibited greater ventral striatal activation compared to controls pre-drug and post-drug effect (F1,40=20.1; z=3.8; p<0.001; k>10; (x=10;y=-2;z=-14)). A GROUPxDRUG interaction effect was detected in the medial orbitofrontal cortex (mOFC) (F1,40=21.5; z=4.0; p<0.001; k>10; (x=-12;y=28;z=-20). The alcohol-dependent group exhibited a negligible mOFC response across both pre- and post-drug scanning sessions. In contrast, controls exhibited attenuation of mOFC response post-drug. Conclusion: The lack of significant GROUPxDRUG interaction effects in the Behavioural Study may suggest different neurobiological mechanisms underlying alcohol dependence and depression mesocorticolimbic dysfunction. Alcohol dependence appeared to mitigate the impact of depression severity on participants’ behavioural responses to dextroamphetamine. The FMRI Study data suggest there may be ventral striatal and mOFC disruption in alcohol-dependent participants. We suggest the mOFC may be involved in the reported loss of prefrontal modulation of dopamine cell activity in alcohol dependence. This supports a key role for the mOFC in mesocorticolimbic dysfunction in alcohol dependence.
77

Evolution of 3D User Distribution Models in Real Network Simulator

Bladlund, Sara January 2010 (has links)
The report treats the development and evaluation of a three dimensional user distribution model for a real network simulator. The simulator is used to create realistic predictions of real networks with the use of high resolution maps including a building data base and network data and also an advanced radio model for LTE. Previously all simulations have been performed with a two dimensional user distribution, i.e. all users situated on the ground level. Since it is considered plausible that many LTE users will be indoors in buildings with multiple floors, several three dimensional user distribution models with users not only on the ground floor but also on the higher floors has been developed and implemented in the simulator. The models all account for the change in path loss and SINR to be expected and have been compared in computational time and credibility. The simulations show that by the use of such a three dimensional model there is a significant improvement at low loads but at high loads the interference becomes dominant and the results show a deterioration and approaches the results of the ordinary two dimensional model. The seventh and last model to be investigated shows a desirable computational speed that still does not compromise too much with the accuracy and detailing of the model and is therefore recommended for normal use.
78

Studying on stock indexes return¡¦s dependence¡GApplication of dynamic copula method

Chan, Shih-Hung 20 June 2012 (has links)
In this paper, we study on the stock indexes return¡¦s dependence structure of the U.S. versus other G5 members during the 2008 subprime mortgage financial crisis. The sample series are weekly returns of the MSCI stock price indexes from 2003 to 2011. The model structure is combined with marginal model and copula model. We model the marginal distributions of our returns using the univariate skewed Student t AR¡]1¡^-GARCH model of Hansen¡]1994¡^, and we model the time-varying copula of Patton¡]2006¡^to measure the dependence structure between stock indexes returns. By analyzing the time series behavior of the dynamic copula parameters, we find that,¡]1¡^the dependence of stock indexes returns increased significantly between U.S. and other G5 members in early subprime mortgage financial crisis, which means the dependence structure has contagion effect.¡]2¡^Except the dependence structure between U.S. and Japan, the other dependence structure between U.S. and other G5 members in later subprime mortgage financial crisis have the phenomenon of interdependence, and their average tail dependence increased significantly.¡]3¡^By the above, international portfolio constructed by correlation coefficient will failed to diversify the downside risk and the systematic risk will be increased in financial crisis period, which is similar with the 2008 subprime mortgage financial crisis. Therefore, the construction of an international portfolio must consider the asymmetric dependence structure between the stock indexes returns.
79

The Essence of the Taiwan Labour Regime- A Historical Institutionalism Review

Zhang, Wei-yi 31 August 2012 (has links)
This thesis is trying to answer the question: why the labor regime of Taiwan would toward the direction is not conducive to the Taiwan¡¦s labor? There are a large number of previous articles had analyzed the labor regime of Taiwan. Most of them were focused on how the single factor influenced the labor regime¡¦s establishment or on how to analyze the static institute. We argue that approaches had a similar problem is unable to offer an integral explanation, which is no matter how the institute has changed still maintaining not conducive to the Taiwan¡¦s labor. Therefore we aim to broaden the perspection, by evolving the social surroundings, the interactions amount actors and institutions development, to outline a much more comprehensive picture of the labor regime than previous articles could do. This thesis uses path dependence which conception is the historical institutionalist used to explain how the institute be operated and how it had constrained actors¡¦ behavior. I would display my research method as follow. First, as we could see is path dependence not only brought us a far more exhaustive imagination of the labor regime but told us the importance of the diachronic comparison. Therefore the first step of this study sets the time of observation during 1980 to 2010. In order to emerged and convenient to observe the historical development of labor regime, we chosen every ten years for a period of time, which meant that period of chapter 2 would be set within 1980 to 90, chapter 3 would be set within 1990 to 2000, and chapter 4 would be set within 2000 to 10. Then by comparing these three periods¡¦ similarities, we could easily to extract those similarities and recognize the development path of labor regime. Second, we claimed that labor regime is constituted by three components: one is social surroundings, one is institute, and the other is three actors include nation, capital and labor. This thesis had planned that every chapter should to discuss about how those three components influence each other. After comparing those three periods, the major finding is we could explicitly figure out the path of the labor regime which has towards to flexibilize and commoditize the labor market. Beside this conclusion could explain our research question, we also trying to describe the Taiwan¡¦s labor regime a comprehensive imagination.
80

Essays on time series and causality analysis in financial markets

Zohrabyan, Tatevik 15 May 2009 (has links)
Financial market and its various components are currently in turmoil. Many large corporations are devising new ways to overcome the current market instability. Consequently, any study fostering the understanding of financial markets and the dependencies of various market components would greatly benefit both the practitioners and academicians. To understand different parts of the financial market, this dissertation employs time series methods to model causality and structure and degree of dependence. The relationship of housing market prices for nine U.S. census divisions is studied in the first essay. The results show that housing market is very interrelated. The New England and West North Central census divisions strongly lead house prices of the rest of the country. Further evidence suggests that house prices of most census divisions are mainly influenced by house price changes of other regions. The interdependence of oil prices and stock market indices across countries is examined in the second essay. The general dependence structure and degree is estimated using copula functions. The findings show weak dependence between stock market indices and oil prices for most countries except for the large oil producing nations which show high dependence. The dependence structure for most oil consuming (producing) countries is asymmetric implying that stock market index and oil price returns tend to move together more during the market downturn (upturn) than a market boom (downturn). In the third essay, the relationship among stock returns of ten U.S. sectors is studied. Copula models are used to explore the non-linear, general association among the series. The evidence shows that sectors are strongly related to each other. Energy sector is relatively weakly connected with the other sectors. The strongest dependence is between the Industrials and Consumer Discretionary sectors. The high dependence suggests small (if any) gains from industry diversification in U.S. In conclusion, the correct formulation of relationships among variables of interest is crucial. This is one of the fundamental issues in portfolio analysis. Hence, a thorough examination of time series models that are used to understand interactions of financial markets can be helpful for devising more accurate investment strategies.

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