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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.
161

Comportamento de B, Zn, Cu, Mn e Pb em solo contaminado sob cultivo de plantas e adição de fontes de matéria orgânica como amenizantes do efeito tóxico / Behavior of B, Zn, Cu, Mn e Pb in contaminated soil under plant cultivation and organic matter addition for metal toxicity amelioration

Santos, Gláucia Cecília Gabrielli dos 10 November 2005 (has links)
Foram conduzidos dois experimentos em casa-de-vegetação com solo contaminado acidentalmente com metais pesados. No primeiro deles objetivou-se avaliar o potencial das espécies vegetais Brassica juncea, Raphunus sativus L., Hybiscus cannabinus e Amaranthus crentus em absorver, translocar e acumular zinco, cobre, manganês, chumbo e boro na parte aérea e assim atuarem na recuperação do solo estudado. No segundo experimento avaliou-se a aplicação dos materiais orgânicos: Solomax, turfa e concentrado húmico mineral como amenizantes de toxidez dos elementos citados para Brassica juncea. Em um terceiro experimento em laboratório, avaliou-se a capacidade de retenção de zinco pelos materiais orgânicos estudados. As variáveis avaliadas foram: produção de material vegetal; quantidades absorvida e acumulada de Zn, Cu, Mn, Pb e B; índices de translocação e remoção desses elementos pelas plantas. No solo foram determinados os teores total e disponível (DTPA e CaCl2 0,01 mol L-1) de Zn, Cu, Mn e Pb. No extrato de saturação foram determinados os teores solúvel (ICP-OES) e livre (eletroforese capilar) dos elementos citados, que também foram determinados na parte aérea da Brassica juncea. Resultados das determinações analíticas também foram introduzidos no programa de especiação iônica MINTEQ. Foram avaliados ainda os efeitos dos materiais orgânicos na distribuição dos metais pesados nas frações do solo. No ajuste dos dados do experimento de retenção de zinco foi a empregado o modelo de Freundlich e calculado o coeficiente de distribuição Kd. Embora as espécies tenham sido capazes de acumular quantidades elevadas dos elementos na parte aérea, elas não puderam ser consideradas hiperacumuladoras. O Amaranthus crentus e a Brassica juncea apresentaram os maiores índices de remoção para Zn, Mn e B. Os materiais orgânicos apresentaram valores elevados de Kd refletindo a alta afinidade do zinco pela fase sólida e elevada capacidade dos materiais orgânicos em imobilizar o elemento. Os elevados coeficientes de correlação obtidos para as isotermas de adsorção indicam que o modelo Freundlich pode ser utilizado para descrever a adsorção do Zn pelos materiais. A quantidade de Zn removida pelos materiais, em termos percentuais variou com o material e com o pH, sendo favorecida nos valores mais elevados. A turfa e o concentrado húmico reduziram os teores de metais extraídos por DTPA e CaCl2 sendo esta redução refletida nos teores acumulados pela Brassica juncea, contudo esta redução não foi suficiente para impedir os efeitos fitotóxicos dos elementos. A especiação dos metais mostrou que o Zn e o Mn encontraram-se principalmente na forma livre, enquanto que o Cu e o Pb apresentaram-se complexados à matéria orgânica dissolvida. Não foram observadas correlações significativas entre os teores dos metais determinados diretamente por eletroforese capilar e indiretamente pelo programa de especiação. O fracionamento seqüencial dos metais indicou que grande parte dos metais está ligada a frações pouco disponíveis do solo. Conclui-se que a aplicação da turfa e do concentrado húmico mineral juntamente com o cultivo do Amaranthus crentus e da Brassica juncea podem auxiliar na recuperação a longo prazo de solos contaminados com Zn, Mn Pb e B. / Two pot trials were carried out using a heavy metal accidentally contaminated soil. In the first one it was evaluated the plant absorbing, translocating and accumulating power for zinc, copper, manganese, lead and boron by the following vegetal species: Brassica juncea, Raphunus sativus L., Hybiscus cannabinus and Amaranthus crentus, so they could help in the rehabilitation of the studied soil. In the second pot trial it was evaluated the application of the following organic materials: Solomax, peat, and humic mineral concentrate for heavy metal toxicity amelioration for Brassica juncea. In a laboratory experiment it was evaluated the zinc retention capacity for the above mentioned organic materials. The measured variables were plant dry matter yield, absorbed and accumulated amounts of Zn, Cu, Mn, Pb and B; the translocation index and the removal index of metal by the mentioned plant species. The total and available (DTPA and CaCl2 001 mol L-1) content of Zn, Cu, Mn and Pb, were determined in soil samples. Concerning the soil saturation extract, the soluble and free forms of the mentioned elements were determined by ICPOES and capillary electrophoresis respectively. The same metals were also determined in the plant tissue of Brassica juncea. Analytical results were introduced in the chemical equilibrium program MINTEQ in order to calculate the concentration of the free forms of Zn, Cu, Mn, and Pb. A fractioning scheme for metals in soil was carried out in order to evaluate the effect of adding sources of organic carbon. The Freundlich model was used to account for zinc adsorption by the studied organic materials and the distribution coefficient Kd was also calculated. Although the plant species were able to accumulate high amounts of metal in the aerial part, that could not be considered as a hipper-accumulation process. The highest metal removal indexes were observed for Brassica juncea and Amaranthus crentus. Organic materials showed high values of Kd, reflecting its high affinity for zinc and a great capacity of zinc immobilization as well. Freundlich model was very effective in describing the adsorption isotherms as indicated by the high determination coefficients. Zinc retention was affected by the organic material type and pH, being favored by the highest studied pH values. Peat and humic mineral concentrate reduced the amounts of metals extracted by DTPA and CaCl2 in soil but the reduction was not great enough to avoid toxic effects in plants. Zn and Mn were present mostly as free cations in soil saturation extract while Pb and Cu were complexed by dissolved organic matter. It was not detected any significant correlation between free metal contents directly determined by capillary electrophoresis and those estimated by MINTEQ. Metal sequential extraction showed that most of them occurred in the least available fractions of soil. Peat and humic mineral concentrate application to soil associated with Amaranthus crentus and Brassica juncea cultivation may be used in long term amelioration of soils contaminated with Zn, Mn, Pb and B.
162

Neurodegeneration induced by ß-synuclein in the context of the neurotransmitter dopamine

Raina, Anupam 08 April 2019 (has links)
No description available.
163

Neurodegeneration induced by ß-synuclein in the context of the neurotransmitter dopamine

Raina, Anupam 08 April 2019 (has links)
No description available.
164

Non-offending guardian support and protection in cases of child sexual abuse : the role of risk perception

Oliver, Caroline January 2012 (has links)
Research has shown that the reaction of the non-offending guardian following disclosure of child sexual abuse (CSA) is an important factor related to the adjustment of the victim. However, to date, comparatively little research has examined the characteristics of non-offending guardians, specifically factors related to their ability to support and protect their child in the aftermath of disclosure. A systematic review of the existing literature, specifically primary studies of intervening variables for guardian belief, support and protection, or various combinations thereof, is firstly presented. Here, the lack of consensus within the literature over definition of ‘guardian support’ is highlighted, a situation that has confounded the drawing of firm conclusions regarding associated factors. Secondly, an empirical study is presented where this area of research is broadened out to include a general population of mothers and female carers, and to specifically examine perception of future sex offending risk through the use of vignettes. It is postulated that risk perception is a mediating variable between a guardian’s belief in the occurrence of CSA and subsequent support and protection, a variable that has yet to be examined within the literature as it relates to non-offending guardians. Results showed that mothers tended to over-estimate risk of re-offending, although of concern was that, in general terms, younger offenders with male victims (rated as ‘high risk’ according to a widely-used actuarial measure of sex offender risk) were regarded to be the least risky. Finally, an existing measure of guardian support is critically appraised. It is hypothesised that this type of instrument, that only measures a narrow aspect of a non-offending guardian’s post-disclosure functioning, might be usefully employed within an overall ‘risk of failure to protect’ assessment framework. Drawing upon the current findings, a model upon which to base this type of assessment is outlined in the discussion.
165

Comportamento de B, Zn, Cu, Mn e Pb em solo contaminado sob cultivo de plantas e adição de fontes de matéria orgânica como amenizantes do efeito tóxico / Behavior of B, Zn, Cu, Mn e Pb in contaminated soil under plant cultivation and organic matter addition for metal toxicity amelioration

Gláucia Cecília Gabrielli dos Santos 10 November 2005 (has links)
Foram conduzidos dois experimentos em casa-de-vegetação com solo contaminado acidentalmente com metais pesados. No primeiro deles objetivou-se avaliar o potencial das espécies vegetais Brassica juncea, Raphunus sativus L., Hybiscus cannabinus e Amaranthus crentus em absorver, translocar e acumular zinco, cobre, manganês, chumbo e boro na parte aérea e assim atuarem na recuperação do solo estudado. No segundo experimento avaliou-se a aplicação dos materiais orgânicos: Solomax, turfa e concentrado húmico mineral como amenizantes de toxidez dos elementos citados para Brassica juncea. Em um terceiro experimento em laboratório, avaliou-se a capacidade de retenção de zinco pelos materiais orgânicos estudados. As variáveis avaliadas foram: produção de material vegetal; quantidades absorvida e acumulada de Zn, Cu, Mn, Pb e B; índices de translocação e remoção desses elementos pelas plantas. No solo foram determinados os teores total e disponível (DTPA e CaCl2 0,01 mol L-1) de Zn, Cu, Mn e Pb. No extrato de saturação foram determinados os teores solúvel (ICP-OES) e livre (eletroforese capilar) dos elementos citados, que também foram determinados na parte aérea da Brassica juncea. Resultados das determinações analíticas também foram introduzidos no programa de especiação iônica MINTEQ. Foram avaliados ainda os efeitos dos materiais orgânicos na distribuição dos metais pesados nas frações do solo. No ajuste dos dados do experimento de retenção de zinco foi a empregado o modelo de Freundlich e calculado o coeficiente de distribuição Kd. Embora as espécies tenham sido capazes de acumular quantidades elevadas dos elementos na parte aérea, elas não puderam ser consideradas hiperacumuladoras. O Amaranthus crentus e a Brassica juncea apresentaram os maiores índices de remoção para Zn, Mn e B. Os materiais orgânicos apresentaram valores elevados de Kd refletindo a alta afinidade do zinco pela fase sólida e elevada capacidade dos materiais orgânicos em imobilizar o elemento. Os elevados coeficientes de correlação obtidos para as isotermas de adsorção indicam que o modelo Freundlich pode ser utilizado para descrever a adsorção do Zn pelos materiais. A quantidade de Zn removida pelos materiais, em termos percentuais variou com o material e com o pH, sendo favorecida nos valores mais elevados. A turfa e o concentrado húmico reduziram os teores de metais extraídos por DTPA e CaCl2 sendo esta redução refletida nos teores acumulados pela Brassica juncea, contudo esta redução não foi suficiente para impedir os efeitos fitotóxicos dos elementos. A especiação dos metais mostrou que o Zn e o Mn encontraram-se principalmente na forma livre, enquanto que o Cu e o Pb apresentaram-se complexados à matéria orgânica dissolvida. Não foram observadas correlações significativas entre os teores dos metais determinados diretamente por eletroforese capilar e indiretamente pelo programa de especiação. O fracionamento seqüencial dos metais indicou que grande parte dos metais está ligada a frações pouco disponíveis do solo. Conclui-se que a aplicação da turfa e do concentrado húmico mineral juntamente com o cultivo do Amaranthus crentus e da Brassica juncea podem auxiliar na recuperação a longo prazo de solos contaminados com Zn, Mn Pb e B. / Two pot trials were carried out using a heavy metal accidentally contaminated soil. In the first one it was evaluated the plant absorbing, translocating and accumulating power for zinc, copper, manganese, lead and boron by the following vegetal species: Brassica juncea, Raphunus sativus L., Hybiscus cannabinus and Amaranthus crentus, so they could help in the rehabilitation of the studied soil. In the second pot trial it was evaluated the application of the following organic materials: Solomax, peat, and humic mineral concentrate for heavy metal toxicity amelioration for Brassica juncea. In a laboratory experiment it was evaluated the zinc retention capacity for the above mentioned organic materials. The measured variables were plant dry matter yield, absorbed and accumulated amounts of Zn, Cu, Mn, Pb and B; the translocation index and the removal index of metal by the mentioned plant species. The total and available (DTPA and CaCl2 001 mol L-1) content of Zn, Cu, Mn and Pb, were determined in soil samples. Concerning the soil saturation extract, the soluble and free forms of the mentioned elements were determined by ICPOES and capillary electrophoresis respectively. The same metals were also determined in the plant tissue of Brassica juncea. Analytical results were introduced in the chemical equilibrium program MINTEQ in order to calculate the concentration of the free forms of Zn, Cu, Mn, and Pb. A fractioning scheme for metals in soil was carried out in order to evaluate the effect of adding sources of organic carbon. The Freundlich model was used to account for zinc adsorption by the studied organic materials and the distribution coefficient Kd was also calculated. Although the plant species were able to accumulate high amounts of metal in the aerial part, that could not be considered as a hipper-accumulation process. The highest metal removal indexes were observed for Brassica juncea and Amaranthus crentus. Organic materials showed high values of Kd, reflecting its high affinity for zinc and a great capacity of zinc immobilization as well. Freundlich model was very effective in describing the adsorption isotherms as indicated by the high determination coefficients. Zinc retention was affected by the organic material type and pH, being favored by the highest studied pH values. Peat and humic mineral concentrate reduced the amounts of metals extracted by DTPA and CaCl2 in soil but the reduction was not great enough to avoid toxic effects in plants. Zn and Mn were present mostly as free cations in soil saturation extract while Pb and Cu were complexed by dissolved organic matter. It was not detected any significant correlation between free metal contents directly determined by capillary electrophoresis and those estimated by MINTEQ. Metal sequential extraction showed that most of them occurred in the least available fractions of soil. Peat and humic mineral concentrate application to soil associated with Amaranthus crentus and Brassica juncea cultivation may be used in long term amelioration of soils contaminated with Zn, Mn, Pb and B.
166

Perspectives on community policing : a social constructivist and comparative analysis

García Chávez, Tania Guadalupe January 2012 (has links)
Community policing is one of the more significant recent developments in policing and the notion has been widely discussed and applied around the world. This thesis examines its various conceptions as discussed in the literature and in practice, with particular emphasis being given to the role of trust between police and citizens in this context. The investigation adopts a constructivist and qualitative comparative analysis based in two countries: Mexico and the UK (with two case studies in each country) and with data primarily collected through interviews with samples of police and citizens. Key findings are that: The variety of conceptions about community policing highlight the complex nature of the notion and the many factors shaping its varied practices. Police assumptions as to what constitutes good practice in community policing and what success might look like, deserve to be re-examined. The social constructions that police and citizens hold about community policing provide valuable sources of insight which challenge some of the conventional understandings regarding policing priorities. Trust is a vital ingredient for successful community policing and needs to be based as much on the police trusting citizens and communities as the other way round.
167

Fast Algorithms for Nearest Neighbour Search

Kibriya, Ashraf Masood January 2007 (has links)
The nearest neighbour problem is of practical significance in a number of fields. Often we are interested in finding an object near to a given query object. The problem is old, and a large number of solutions have been proposed for it in the literature. However, it remains the case that even the most popular of the techniques proposed for its solution have not been compared against each other. Also, many techniques, including the old and popular ones, can be implemented in a number of ways, and often the different implementations of a technique have not been thoroughly compared either. This research presents a detailed investigation of different implementations of two popular nearest neighbour search data structures, KDTrees and Metric Trees, and compares the different implementations of each of the two structures against each other. The best implementations of these structures are then compared against each other and against two other techniques, Annulus Method and Cover Trees. Annulus Method is an old technique that was rediscovered during the research for this thesis. Cover Trees are one of the most novel and promising data structures for nearest neighbour search that have been proposed in the literature.
168

Etude de l'effet de facteurs environnementaux sur les processus biogéochimiques de mobilisation du Pb, Zn, Cd, As et Hg dans les sols - Modélisation empirique de la mobilité et phytodisponibilité des ETM

Joubert, Antoine 12 March 2008 (has links) (PDF)
La pollution des sols par les Eléments Traces Métalliques est un problème majeur car, contrairement aux autres milieux, le sol possède une plus faible capacité à s'épurer. Les différents modèles empiriques exprimant la solubilité et le coefficient de distribution Kd de ces polluants inorganiques dans les sols ne tiennent pas compte de l'influence des facteurs environnementaux. Le travail de thèse a consisté à étudier l'effet de facteurs environnementaux, dits « sensibles au changement global », sur la mobilité de Cd, Pb, Zn, As et Hg dans les sols, à l'aide d'un plan factoriel fractionnaire 2^(4-1). Onze échantillons de sol représentatifs de 3 sites d'études industriels et agricoles des bassins de la Meuse et de l'Ebre ont été étudiés dans le cadre du projet européen AQUATERRA. Le comportement de As n'est pas significativement corrélé à la nature intrinsèque des échantillons de sol mais à l'augmentation de la température et à une condition anoxique. Ces facteurs stimulent les activités microbiennes de solubilisation de As tels que réduction dissolutive microbienne des oxyhydroxydes de Fe et la réduction de As(V). La forte implication de l'activité microbienne permet de modéliser la mobilité de As en fonction des facteurs environnementaux, pour l'ensemble des 11 échantillons de sol. A l'inverse, le comportement de Cd, Pb et particulièrement Zn, est très significativement corrélé à la nature des échantillons de sol et notamment le pH du sol. Enfin, la phytodisponibilité de Cd, Pb, Zn et As a été estimée, à l'aide d'un système à compartiment, et modélisée de manière empirique, afin de permettre une meilleure compréhension des phénomènes de transfert sol-plante.
169

Klaipėdos miesto šiaurinės dalies oro taršos tyrimai ir modeliavimas / Investigation and modeling of the ambient pollution in Klaipeda city northern part

Petrauskas, Linas 21 June 2006 (has links)
Particulate matters – affected air pollution and air pollution sources in the Northern part of Klaipeda are being analysed in the final work. The first part of the work focuses on the air pollution in Lithuania and worldwide, leteron methods and devices for measuring the concentration of the particulate matters in the air are being analysed. Earlier research works on this subject are being analysed together with various information sources. With the help of modern efficient air polution measurement devices, particulate matters – affected air pollution and air pollution causes in the Northern part of Klaipeda were examined. After collecting data on transport concentration in certain streets of the seaport, it was possible to do the modelling of segments of these streets. the resuls of the modelling are being compared with the results of the pre-existing research. The conclusions and recommendations of the final work are based on the analyses of the particulate matters – affected air pollution and itas spread in Klaipeda. the work consists of 8 parts; the Introduction, the Literature overview, the analyses of the air pollution estimation methods and devices, Particulate matters – affected air pollution analyses in Klaipeda city, the modelling of the particulate matters spread in the seaport, Conclusions, Suggestions and References. The volume of work is 119 p., excluding appendices, 56 illustrations, 17 Figures, 58 reference sources. Articles for publication and publications... [to full text]
170

The office of coroner, 1860-1926 : resistance, reluctance and reform

Prichard, Donald January 2001 (has links)
This study explores, analyses and seeks to explain the processes by which legislative changes were achieved to overcome the problems associated with the role and duties of the office of coroner from the mid nineteenth century to the 1920s. From time to time during the period, the office was exposed to political and public scrutiny that brought calls for reform. Despite that, and the general recognition that change was necessary, the process was extremely protracted and reform limited so that when the 1926 Act reached the statute book, it was greeted with a level of subdued dissatisfaction. Throughout the period, the coroners resisted change based on an appeal to their traditional links with the people and representing the office as an ancient institution rooted in long established custom and practice. Despite that, the coroners were unable to evade the impact of changes associated with developments in local and national government which had an indirect, though significant, effect on coroners' reform. For most of the period, the policy of successive governments was to have no policy on coroners. To fill that void,various groups with conflicting interests and ambitions proposed changes to meet their needs and attempted to influence the government to implement them. A slow, complex, haphazard, fragmented and undirected process evolved that had its own dynamic. There was no strategist, no over-riding driving force, no single source. Suggestions were adopted, modified or rejected to produce a 'policy' that was eventually accepted by the Home Office. From the detailed examination of the complex events, issues and stances adopted by the various bodies, including the Home Office, an explanation for the unusual, slow and tortuous process of reform emerges. Coroners' problems were a minor issue for the government and carried little weight in the wider scheme of politics. With such a low priority rating, the government was reluctant to intervene except under the pressure of public criticism when events created a crisis or near crisis. Eventually, a minimum legislative intervention brought closure, but left important problems unresolved. The coroners still investigated unexplained deaths on behalf of the Crown and retained intact their traditional authority, independence, common law powers and discretion.

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