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The effect of ecstasy/polydrug use on prospective memory and executive processesHadjiefthyvoulou, Florentia January 2012 (has links)
The purpose of this thesis was to examine the range of prospective memory and executive function deficits in ecstasy/polydrug users and the role of these processes in accounting for the observed prospective memory performance deficits. Using a variety of laboratory and self-report measures of prospective memory and a self-report measure of executive function, ecstasy/polydrug users were tested in laboratory settings on measures of event and time-based, short and long term prospective memory as well as on a wide range of executive function components. It was found that ecstasy/polydrug users in relation to non-users experience more general prospective memory problems as ecstasy/polydrug-related deficits were evident on both time and event-based and short and long-term prospective memory. Ecstasy/polydrug users also demonstrated deficits on executive processes suggesting that recreational drug users are impaired in a broader range of executive function and ecstasy/polydrug-related deficits are not restricted to the three-model component of executive function. It was also found that executive dysfunction is associated with poorer time-based prospective memory and perhaps some of the drug related prospective memory deficits are mediated by drug related executive function impairment. Finally, although few prospective memory or executive function performance deficits were evident among cannabis-only users a trend was evident in all investigations; ecstasy/polydrug users perform the worst, cannabis-only users at intermediate levels and drug-naïve perform the best. The most striking finding of the present thesis was that the recreational use of cocaine was associated with PM deficits; an association that consistently emerged in all studies of PM performance. The outcomes of the present thesis provide a fruitful direction for future research.
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Vigilancia Entomológica de Aedes aegypti Linnaeus, 1762 (Diptera: Culicidae) Transmisor del virus del dengue en el Distrito de Villa El Salvador durante los meses de Enero-Junio del 2011Sánchez Ortiz, Vanessa Jocelyn January 2012 (has links)
Aedes aegypti Linnaeus, 1762 es una especie de Diptero que pertenece a la familia Culicidae, subgénero Stegomyia Theobald, 1901. La investigación túvo como objetivos: Realizar vigilancia epidemiológica de Aedes aegypti en el distrito de Villa El Salvador, determinar indicadores entomológicos: Índice Aédico (IA), Índice de Recipientes (IR) e Índice de Breteau (IB) y si existía diferencias significativas entre ellos. Para ellos se realizó un diseño de estudio donde se incluye el protocolo establecido por el Ministerio de Salud para el estudio de la localidad, visita a las viviendas y colección de muestras. Al comparar las fluctuaciones de los Índices Entomológicos (IE): Índice Aédico (IA), Índice de Recipientes (IR) e Índice de Breteau (IB), por sectores y meses se observó que no existieron diferencias estadísticamente significativas. Solo se halló foco positivos de Aedes aegypti durante los meses de Marzo y Abril en los sectores 2 y 3 respectivamente. Aun cuando se focalizó el análisis para los dos meses y sectores, estadísticamente no se encontraron diferencias significativas ni riesgo entomológico; esto último de acuerdo a los porcentaje establecidos en la estratificación de riesgo entomológico.Aedes aegypti Linnaeus, 1762 is a species of Diptera that belongs to the Culicidae family, subgenus Stegomyia Theobald, 1901. This study aimed to: perform a surveillance of Aedes aegypti in the district of Villa El Salvador, determine the entomological indicators: Aédico Index (AI), Container Index (RI) and Breteau Index (BI) and if there were significant differences between them. For those purposes, it a study design that includes the established Ministry of Health protocol for the study of the town, home visitings and sample collection. When comparing the fluctuations of the Entomological indices (EI): Aédico Index (AI), Container Index (RI) and Breteau Index (BI), by sector and months, no statistically significant differences were observed. The only positive focus for Aedes aegypti was found during the months of March and April in sectors two and three, respectively. Although further analysis was focused for the two months and sectors mentiones, no statistically significant differences or entomological risk was found, the latter according to the percentage specified in entomological risk stratification
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Cosmological simulations of galactic disc assemblyHouse, Elisa January 2011 (has links)
We address the issue of kinematic heating in disc galaxies by analysing a suite of cosmological Milky Way-type disc simulations run with different particle-and grid-based hydrodynamical codes and different resolution, and compare them with observations of the Milky Way. By studying the kinematics of disc stars in these simulations, we seek to determine whether or not the existence of a fragile thin disc is possible within a cosmological framework, where multiple mergers and interactions are the essence of galaxy formation. We study the velocity dispersion-age relation for disc stars at $z=0$ and find that four of the simulations, the stellar disc appears to undergo continual/secular heating. Two other simulations suggest a “saturation” in the heating profile for young stars in the disc. None of the simulations have thin discs as old as that of the Milky Way. We also analyse the kinematics of disc stars at the time of their birth, and find that in some simulations old stars are born cold within the disc and are subsequently heated, while other simulations possess old stellar populations, which are born relatively hot. The models which are in better agreement with observations of the Milky Way's stellar disc undergo significantly lower minor-merger/assembly activity after the last major merger. By running a set of isolated Milky Way-type simulations with different resolution and different density thresholds for star formation we conclude that, on top of the effects of mergers, there exists a ``floor'' in the dispersion that is related to the underlying treatment of the heating and cooling of the interstellar medium, and the low density threshold which such codes use for star formation. A persistent issue in simulations of disc galaxies is the formation of large spheroidal components, and disc galaxies with larger bulge to disc ratios than is observed. This problem is alleviated by supernova feedback. We found that by increasing the feedback in the simulations, we decrease the amount of stars that are accreted onto the main galaxy. The star formation is quenched more efficiently in low mass satellites when stronger feedback is implemented as well as in the main halo. These effects result in a disc galaxy, which has formed less stars overall, but more importantly, contains less accreted stars. As the strong stellar feedback quenches the star formation in the small building blocks, the metallicity of the accreted stars is lower than in the case where less feedback was used. In the context of hierarchical formation, mass assembly is expected to be scale free. Yet the properties of galaxies depend strongly on their mass. We examine how baryonic physics has different effects at different mass scales by analysing three cosmological simulations using the same initial conditions that are scaled to three different masses. Despite their identical dark matter merger history, we show that the simulated galaxies have significantly different stellar accretion histories. As we go down in mass, the lowest mass progenitors are unable to form stars, resulting in a low mass galaxy with less accreted stars. The overall chemical properties are also distinct at the different mass scales, as one might expect from the mass-metallicity relation of observed galaxies. We examine gradients of chemical abundances with radius and with height above the disc, and look for properties that are retained at different mass scales and properties which change, often dramatically. We analyse the kinematic and chemical properties of their accreted and in-situ populations. Again, trends can be found that persist at all mass scales, providing signatures of hierarchical structure formation. We find that accreted populations in the high mass simulation did not resemble any of the populations in the lower mass galaxies, showing that the chemical properties of proto-galaxies, which merge at high redshift to form massive galaxies, differ from the properties of low mass galaxies that survive at z=0. We probe further the signatures of hierarchical structure formation at smaller scales, in dwarf galaxies. We analysed the morphologies, kinematics and chemical properties of two simulated dwarf galaxies with different merger histories. We again analyse the accreted and in-situ populations. Observations of dwarf galaxies have found that they are comprised of multiple components. Our simulated dwarfs indicate that such populations may indeed be a manifestation of the hierarchical formation process in action in these lower mass galaxies. In one simulated dwarf, the in-situ stellar component forms a thin disc and a thick disc. We show that the thick disc in this simulation forms from in-situ stars that are born kinematically hot in the disc from early gas-rich mergers. The thin disc is formed quiescently from the later infall of gas. The accreted stars in the simulation were found to form an extended stellar halo. Chemical signatures of the three populations are also explored. The second dwarf we analysed has different galactic components, a result found to be due to the different merger history of this galaxy. The last major merger in this simulation occurs early on in the formation process between two proto-galaxies of similar mass. The result is a dwarf galaxy comprised of a disc formed of in-situ stars and a flattened rotating stellar halo formed of accreted stars. The angular momentum of the accreted and old in-insitu stars is obtained from the last major merger. We discuss the resemblance of this flattened rotating stellar halo to fast rotating flattened elliptical galaxies, and propose that such structures may explain some of the observed extra-galactic thick discs. These studies show that galactic properties emerge through the complex inter-play between hierarchical structure formation, star formation, and feedback from supernovae. Different modelling of these processes will alter the simulated galaxy's properties, and detailed comparisons with observations can then be made to determine the dominant processes responsible for different galactic properties. We remain optimistic that further improvement in modelling will allow deeper insights into the processes of galaxy formation and evolution.
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An index of Kansas laws relating to child welfareBurgess, Floy Thomson. January 1923 (has links)
Call number: LD2668 .T4 1923 B874 / Master of Science
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The cluster and large scale environments of quasars at z < 0.9Harris, Kathryn January 2011 (has links)
We present an investigation into the environments of quasars with respect to galaxy clus- ters, and environment evolution with redshift and luminosity. The positions of quasars with respect to clusters have been studied using cluster and quasar catalogues available, covering the redshift range 0.2 < z < 1.2. The 2D projected separations and the 3D separations have been found and the orientation of the quasar with respect to the major axis of the closest cluster calculated, introducing new information to previous work. The positions of quasars with respect to clusters of galaxies will give an indication of the large scale environment of quasars and potentially clues as to which formation mechanisms are likely to dominate at various redshifts. For example, galaxy mergers are most likely to occur in galaxy group environments and will create luminous quasars. Galaxy harassment is more likely to occur on the outskirts of galaxy clusters and create lower luminosity AGN. Secular processes such as bar instability can also create AGN and are likely to be the cause of nuclear activity in isolated galaxies. The aim of this work is to study the large scale environment over a large redshift range and study the evolution as well as any change in environment with quasar luminosity and redshift. Another aim of this work is to study the orientation of a quasar with respect to a galaxy cluster. If galaxy clusters lie orientated along filaments, the position of a quasar with respect to a cluster will give an indication as to where quasars lie with respect to the filament and therefore the large scale structure. There is a deficit of quasars lying close to cluster centres for 0.4 < z < 0.8, indicating a preference for less dense environments, in agreement with previous work. Studying the separations as a function of cluster richness, there was a change in quasars lying closer to poorer clusters for z < 0.2 (Lietzen et al. 2009) to lying closer to richer clusters for 0.2 < z < 0.4, though more clusters at low redshifts will be needed to confirm this. There is no obvious relation between the orientation angle between a quasar and the major axis of the closest galaxy cluster and 2D projected separations. Using faint (Mr > −23.0 mag) and bright (Mr < −23.0 mag) quasars, there is no difference between the two magnitude samples for the 2D separations or the cluster richness, in contrast to Strand et al. (2008) who found brighter quasars lying in denser environments than dimmer quasars. These is no change with redshift (over 0 < z < 1.2) in the positions of the quasars with respect to the cluster or the cluster richness as a function of absolute quasar magnitude. There is also no preferred orientation between the quasar and the cluster major axis for bright or faint quasars. Spectra of a selection of 680 star forming galaxies, red galaxies, and AGN were taken by Luis Campusano and Ilona S¨ochting and 515 redshifts calculated. Though few of these galaxies turned out to be cluster members as was originally intended, it was possible to use these galaxies to study the environments of quasars with respect to star-forming galaxies and galaxy clusters. The objects were classified (33 classed as AGN), and star formation rates calculated and compared. Three AGN and 10 star forming galaxies lie at the same redshift (z = 0.29) as three galaxy clusters. The three galaxy clusters have the same orientation angle and may be part of a filament along with the star forming galaxies and AGN. Further study will investigate the relation between AGN positions and filaments of structure. A sample of quasar spectra taken by Lutz Haberzettl using Hectospec on the MMT were taken to increase the number of quasars used in this study. However, when studying the spectra, a number of high redshift quasars showed evidence of ultra-strong UV Feii emission in their spectra. The redshifts of these quasars were too high to be included in the main body of the study. However, a significantly large number of ultra-strong UV Feii emitting quasars have been found in the direction of three LQGs in the redshift range 1.1 < z < 1.6, including the Clowes-Campusano Large Quasar Group (CCLQG). Ly� fluorescence can increase the UV Feii emission. However, Ly� emission from other quasars was found to be negligible compared to emission from the quasar’s central source. Though there has been no previous indication that the LQG environment is unique, the high level of iron emission may indicate a difference in environment. Plans for future work based on these results are outlined.
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Investigating the democratic effects of state-sponsored youth participation in Russia : Nashi and the Young Guard of United RussiaAtwal, Maya January 2011 (has links)
This study investigates the relative impact of state sponsorship on the democratic effects of participation in the case of two Russian youth organisations – Nashi and the Young Guard, which were established with Kremlin support in 2005. In doing so this study questions the assumption that state involvement necessarily has a corrosive influence on participation and asserts the value of studying state-sponsored participatory initiatives. It concludes that the potential democratic effects of state-sponsored participation should not be disregarded solely on the basis of state involvement for two reasons: Firstly, the impact of state sponsorship on the democratic effects of participation is shaped by other factors, including the socio-political environment and the agency of participants. The state may have a vested interest in supporting some positive democratic effects of participation to further its own aims. Secondly, there are limits to the state‘s power to determine the democratic effects of participation. In particular, the state is unable to control the significance attached to participation by those involved. Without rejecting scholarly work on the Kremlin‘s questionable democratic credentials or on the pro-regime youth movements‘ numerous negative tendencies, this study contends that there is much more to these Kremlin-sponsored youth movements than existing portrayals allow.
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Discovering patterns on financial data streams. / CUHK electronic theses & dissertations collection / ProQuest dissertations and thesesJanuary 2010 (has links)
Then, we consider the patterns between news stream and time series indices stream. We first transform the news stream into a set of bursty feature (keywords) time series streams and propose three technique to study their relationship to time series index. First, we explore a Non-homogeneous Hidden Markov Model (NHMM) to predict the stock market process which takes both stock prices and news articles into consideration. Second, we propose a risk analytical model to predict the volatility of price indices by integrating news information. Finally, we devise an algorithm to detect the priming event from text and a time series index. The evaluation on real world dataset suggests the significant correlation exists between news stream and time series stream and our pattern discover algorithm can detect promising patterns from this relationship to support real world applications effectively. / We start from investigating the co-movement relationship of multiple time series. We propose techniques to study two aspects of this problem. First, we propose a co-movement model for constructing financial portfolio by analyzing and mining the co-movement patterns among two time series. Second, we presents an efficient streaming algorithm to discover leaders from multiple time series stream. Both of the algorithms are evaluated using real time series indices data and the result proves that co-movement patterns and detected leaders are promising and can support various applications including portfolio management, high frequency trading and risk management. / With the increasing amount of data in financial market, there are two types of data streams attracting a lot of research and studies, time series index stream and related news stream. In this thesis, we focus on discovering patterns from these data streams and try to answer the following challenging questions, (I) given two co-evolving time series indices, what is the co-movement dependency between them. (II) given a set of evolving time series, could we detect some leaders from them whose rise or fall impacts the behavior of many other time series? (III) could we integrate the news stream information into stock price prediction? (IV) could we integrate the news stream information into stock risk analysis? and (V) could we detect what are those events that trigger time series index movement. For each of the question, we design algorithms and address three technique issues (I) how to detect promising patterns from the noisy financial data; (II) how to update the old patterns when new data arrives in high frequency; (III) how to use the pattern to support the financial applications. / Wu, Di. / Adviser: Jeffrey Xu Pu. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 124-131). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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Zhodnocení finanční situace společnosti SAND TEAM, spol. s r. o. / Evaluation of SAND TEAM, Ltd Financial StandingOpálková, Andrea January 2010 (has links)
The evaluation of financial situation and financial health of the company SAND TEAM, spol. s r. o. with using the financial analysis' methods and its instruments (the chosen indexes of profit ratio, activity, liquidity and indebtedness). The position determination at the market, due to comparison of the financial analysis' data. The formulation of suggestions and recommendation regarding to the suitable managing of the company, which lead to the improvement of the situation, e.g. keeping the financial health and the powerful position at the market.
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Scanner data and the construction of price indices.Ivancic, Lorraine, Economics, Australian School of Business, UNSW January 2007 (has links)
This thesis explores whether scanner data can be used to inform Consumer Price Index (CPI) construction, with particular reference to the issues of substitution bias and choice of aggregation dimensions. The potential costs and benefits of using scanner data are reviewed. Existing estimates of substitution bias are found to show considerable variation. An Australian scanner data set is used to estimate substitution bias for six different aggregation methods and for fixed base and superlative indexes. Direct and chained indexes are also calculated. Estimates of substitution bias are found to be highly sensitive to both the method of aggregation used and whether direct or chained indexes were used. The ILO (2004) recommends the use of dissimilarity indexes to determine the issue of when to chain. This thesis provides the first empirical study of dissimilarity indexes in this context. The results indicate that dissimilarity indexes may not be sufficient to resolve the issue. A Constant Elasticity of Substitution (CES) index provides an approximate estimate of substitution-bias-free price change, without the need for current period expenditure weights. However, an elasticity parameter is needed. Two methods, referred to as the algebraic and econometric methods, were used to estimate the elasticity parameter. The econometric approach involved the estimation of a system of equations proposed by Diewert (2002a). This system has not been estimated previously. The results show a relatively high level of substitution at the elementary aggregate level, which supports the use a Jevons index, rather than Carli or Dutot indexes, at this level. Elasticity parameter estimates were found to vary considerably across time, and statistical testing showed that elasticity parameter estimates were significantly different across estimation methods. Aggregation is an extremely important issue in the compilation of the CPI. However, little information exists about 'appropriate' aggregation methods. Aggregation is typically recommended over 'homogenous' units. An hedonic framework is used to test for item homogeneity across four supermarket chains and across all stores within each chain. This is a novel approach. The results show that treating the same good as homogenous across stores which belong to the same chain may be recommended.
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Relation of nutritional status, immunity, hemoglobinopathy and <i>falciparum</i> malaria infectionNyakeriga, Alice January 2005 (has links)
<p>The interaction between nutritional status and malaria disease is complex and often controversial. Nutritional deficiencies (macro- or micro-nutrient) are thought to lead to malnutrition with subsequent susceptibility to malaria infection. On the other hand severe malaria or repeated malaria infections lead to malnutrition. While the cause and effect are difficult to attribute, micronutrient deficiencies such as iron deficiency and malaria infection often co-exist and show complex interactions leading to mutually reinforced detrimental clinical effects.</p><p>That iron deficiency has adverse effects on human health is widely recognized. Iron plays a crucial role in processes of growth and cell division and in the transport of oxygen throughout the body. It is also important for the proliferation of cells of the immune system as well as for microorganisms including the malaria parasite. Iron deficiency results in a decrease in hemoglobin concentrations and subsequent anemia. However, the etiology of anemia is multi-factorial and may be affected, in addition, by several factors including malaria and host factors, especially hemoglobinopathies such as alpha-thalassemia and sickle cell trait. These hemoglobinopathies are also common in malaria endemic areas.</p><p>In this thesis, we have investigated the relationship between nutritional status, immunity, hemoglobinopathies and <i>falciparum</i> malaria in a cohort of children less than 8 years old living on the coast of Kenya. We have found that malaria was associated with malnutrition in an age-dependent fashion. Malaria was associated with subsequent underweight or stunting in children under the age of 2 years, but this effect was not there in older children. Also, we observed that iron deficiency was associated with protection of children against clinical malaria. Children who were iron deficient had a lower incidence of malaria episodes as compared to those who were iron replete.</p><p>While studies on the effects of single micronutrient deficiencies on components of the immune system are difficult to design and interpret, there is ample evidence that micronutrient deficiencies, in general, affect all components of immunity. In line with this, we found that nutritional iron status was associated with certain malaria-specific immunoglobulins and interleukin-4 mRNA levels. Iron deficient children had lower levels of malaria-specific IgG2 and IgG4 but higher expression levels of IL-4 mRNA as compared to the iron replete children. Finally, we observed a tendency towards a higher prevalence of iron deficiency in children carrying either alpha-thalassemia or sickle cell trait.</p>
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