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Perturbative and non-perturbative approaches to string sigma-models in AdS/CFTVescovi, Edoardo 12 October 2016 (has links)
Diese Doktorarbeit behandelt quantentheoretische Aspekte von Typ II Superstringtheorien in AdS5xS5- und AdS4xCP3-Hintergründen für die AdS/CFT Korrespondenz. Dabei werden perturbative Methoden und Verfahren der Gitterfeldtheorie benutzt. Die Konstruktion des Supercoset-Sigma-Modell für Strings im AdS5xS5wird skizziert, während die generelle Quantendynamik des Superstring in AdS4xCP3 mit Hilfe einer dimensionaler Reduktion der Supermembrane-Wirkung in AdS4xS7 beschrieben wird. Ein manifest kovarianter Formalismus zur semi-klassischen Quantisierung von Strings um beliebige Minimalflächen in AdS5xS5 wird präsentiert, der durch die Darstellung der Fluktuationsoperatoren in Form von intrinsischen und extrinsischen Varianten der Hintergrundgeometrie erreicht wird. Eine Verallgemeinerung der Lame-Differentialgleichung zur 4. Ordnungwird mit Hilfe der Spektralmethode exakt gelöst. Dadurch konnten in 1-Schleifennäherung die Energie des String im SU(2)-Sektor, im Grenzfall beschrieben durch ein Quantum-Landau-Lifshitz-Modell, und der bosonische Beitrag zur Energie des in AdS5 und S5 rotierenden String bestimmt werden. In ähnlicher Weise erhält man in 1-Schleifennäherung den ¼-BPS-Latitude Wilson-Loop in N=4-SYM-Theorie normiert durch den ½-BPS-Loop. Das Regularisierungsschema reproduziert die Vorhersage aus supersymmetrischer Lokalisierung bis auf einen Rest, welcher diskutiert wird. Außerdem wird die Wirkung des AdS4xCP3-String, entwickelt um den null-cusp Hintergrund, studiert und die Cusp-Anomalie in 2-Schleifennäherung berechnet. Das Ergebnis stimmt mit dem vermuteten exakten Ausdruck, der ABJM-Interpolationsfunktion, überein. Schließlich wird die AdS5xS5-Superstringtheorie in AdS-Lichtkegel-Eichung diskretisiert und mit Monte-Carlo-Algorithmen Gittersimulationen bei endlicher Kopplung durchgeführt. Dabei werden die Stringwirkung, aus der mit Hilfe von AdS/CFT die null-cusp anomale Dimension von N=4 SYM extrahiert werden kann, und die Masse einer AdS Anregung bestimmt. / This thesis discusses quantum aspects of type II superstring theories in AdS5xS5 and AdS4xCP3 backgrounds relevant for the AdS/CFT correspondence, using perturbative methods at large string tension and lattice field theory techniques inspired by a work of Roiban and McKeown. We review the construction of the supercoset sigma-model for strings in the AdS5xS5 background, whereas the general quantum dynamics of the superstring in AdS4xCP3 is described by a double dimensional reduction of the supermembrane action in AdS4xS7. We present a manifestly covariant formalism for semiclassical quantization of strings around arbitrary minimal-area surfaces in AdS5xS5, expressing the fluctuation operators in terms of intrinsic and extrinsic invariants of the background geometry. We exactly solve the spectral problem for a fourth-order generalization of the Lame'' differential equation with doubly periodic coefficients in a complex variable. This calculates the one-loop energy of the (J1,J2)-string in the SU(2) sector in the limit described by a quantum Landau-Lifshitz model and the bosonic contribution to the energy of the (S,J)-string rotating in AdS5 and S5. Similar techniques calculate the 1/4-BPS latitude Wilson loops in N=4 SYM theory at one loop, normalized to the 1/2-BPS circular loop. Our regularization scheme reproduces the next-to-leading order predicted by supersymmetric localization, up to a remainder function that we discuss upon. We also study the AdS4xCP3 string action expanded around the null cusp background and compute the cusp anomaly up to two loops. This agrees with an all-loop conjectured expression of the ABJM interpolating function. We finally discretize the AdS5xS5 superstring theory in the AdS light-cone gauge and perform lattice simulations at finite coupling with a Monte Carlo algorithm. We measure the string action, from which we extract the null cusp anomalous dimension of N=4 SYM as derived from AdS/CFT, as well as the mass of an AdS excitation.
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[en] TECHNICAL EFFICIENCY IN DAIRY FARMS: RESEARCH SYNTHESIS AND AN APPLICATION IN THE SOUTH OF BRAZIL / [pt] EFICIÊNCIA TÉCNICA EM EXPLORAÇÕES LEITEIRAS: SÍNTESE DE PESQUISA E UMA APLICAÇÃO NO SUL DO BRASILTACIANA MARETH 01 December 2016 (has links)
[pt] O número de publicações sobre Eficiência Técnica (TE) de explorações leiteiras vem crescendo nos últimos tempos devido à relevância política, econômica e social do tema, bem como ao seu apelo acadêmico. O objetivo desta tese é duplo: apresentar uma síntese de pesquisa sobre a TE em explorações leiteiras, desenvolvendo tanto uma análise de meta-síntese quanto uma análise de meta-regressão; apresentar um estudo empírico com o objetivo de mensurar e compreender os fatores que afetam a TE em propriedades leiteiras nos municípios selecionados no Sul do Brasil. A síntese de pesquisa (análise de meta-síntese e análise de meta-regressão) abrange 103 artigos publicados entre 1987 e 2014 em 54 fontes diferentes usando uma abordagem rigorosa e reprodutível para selecionar estudos. Esta síntese complementa e amplia as revisões de literatura anteriores apresentando um quadro de síntese (contexto e determinantes, entradas, saídas e técnicas de mensuração da TE) por meio da análise de conteúdo. Em seguida, a meta-regressão foi aplicada para analisar os efeitos que as diferentes metodologias e que as características específicas de cada estudo têm sobre a média da TE (modelos I ao IV – subseção 3.1.3). Os resultados da análise de meta-síntese indicam que não há um acordo entre os autores sobre o contexto e os determinantes da TE. A análise dos determinantes levou a proposições de pesquisa verificáveis. Os principais determinantes da TE são: a localização geográfica (altitude, qualidade do solo, clima), o tamanho da propriedade, os investimentos em cuidados veterinários, alimentação e práticas de ordenha, modelo de estimativa da TE, políticas públicas, e gestão relacionada com as variáveis. Os resultados da análise de meta-regressão (total de 531 distribuições do índice de TE em explorações leiteiras baseado nos 103 artigos da amostra) são discutidos e têm-se duas contribuições importantes: (i) o estudo atualiza e compara trabalhos anteriores sobre a TE em fazendas leiteiras e (ii) acrescenta duas dimensões das explorações leiteiras: tamanho (número de vacas e hectares de terra) e o desenvolvimento econômico. A variação nos índices de TE relatados na literatura pode ser explicada pela metodologia das estimativas (método de estimação, forma funcional, dimensionalidade do modelo), pela localização geográfica das fazendas e pelo tamanho da propriedade. Além disso, os resultados sugerem que, dado o estado da tecnologia predominante em cada região no momento em que os estudos sobre TE foram realizados, os produtores de leite na amostra poderiam aumentar a sua produção de leite em 20,1 porcento (nível de ineficiência), em média, se eles produzirem em suas fronteiras de eficiência. Implicações para os produtores de leite e para pesquisas futuras é validar essa síntese de pesquisa. A partir dessa síntese de pesquisa, algumas proposições e hipóteses que emergiram foram testadas usando os dados obtidos em uma pesquisa realizada em municípios selecionados no Sul do Brasil. Este estudo empírico mensurou a TE para cada propriedade de leite e identificou aquelas que apresentam as melhores práticas (benchmarks). A mensuração do nível de TE combinada com a análise das melhores práticas auxilia os produtores a melhorar seu grau de eficiência. Em seguida, utilizando outros dois modelos de meta-regressão (V e VI – subseção 3.2.3), o estudo empírico auxiliou no entendimento dos principais fatores que afetam essa TE, derramando novas luzes empíricas na literatura acadêmica. / [en] There is a growing number of publications on Technical Efficiency (TE) of dairy farms, due to the political, economic and social relevance of the theme as well as to its academic appeal. The goal of this thesis is two fold: first, it presents a research synthesis on TE in dairy farms conducting both a meta-synthesis and a meta-regression analysis and, second, an empirical study aiming at measuring and understanding the factors affecting the TE in dairy farms of selected municipalities in the South of Brazil. The research synthesis embraces 103 papers published between 1987 and 2014 in 54 sources using a rigorous and reproducible approach to select studies. This synthesis complements and extends previous literature reviews on TE in dairy farms, offering a synthesis framework (i.e., context and determinants, inputs, outputs and measurement techniques of TE) and analysing the effects of different methodologies and study-specific characteristics on Mean TE (MTE) through meta-regression. Findings point to no agreement among authors on context and determinants of TE. The analysis of determinants led to verifiable research propositions: the main determinants of TE are geographical location (altitude, quality of the soil, climate), farm size, investments in veterinary care, feeding and milking practice, TE model estimation techniques, public policy, and management-related variables. Results from the meta-regression analysis of the gathered papers totalling 531 TE observations in dairy farms worldwide are discussed and makes two important contributions: (i) it updates and compares previous works on frontier estimation of TE in dairy farms and (ii) it adds two dimensions of dairy farms, size (herd and land area) and economic development, to the known differentials of TE measurement. The variation in the MTE indexes reported in the literature can be explained by the methodology of estimations (method of estimation, functional form of frontier models, model dimensionality), farms geographical location and farm size. Additionally, the results suggest that, given the state of technology prevailing in each region at the time that the studies on TE were conducted, dairy farmers in the sample could increase milk output by 20.1 percent (level of inefficiency), on average, if they produce on their frontiers. Implications for dairy farmers and for future research close the research synthesis. The propositions and hypotheses emerged from the research synthesis and were tested using data obtained in a survey conducted in selected municipalities in the South of Brazil. The mensuration of level TE combined with benchmark analysis helps the producers improve the degree of efficiency. This empirical study measured and helped in the understanding of the main factors affecting the TE in dairy farms from these municipalities, shedding new empirical lights in the academic literature.
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Estudo da variação do determinante em sintagmas nominais possessivos na historia do Portugues / Study of determiner variation in possessive nominal phrases on Portuguese historyFloripi, Simone Azevedo 26 February 2008 (has links)
Orientador: Charlotte Marie Chambelland Galves / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-10T22:01:12Z (GMT). No. of bitstreams: 1
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Previous issue date: 2008 / Resumo: Esta tese tem por objetivo descrever e analisar, dentro de uma perspectiva diacrônica, a variação do uso do determinante em estruturas com sintagmas nominais (DP) possessivos em 23 textos de autores portugueses nascidos desde o século 16 ao século 19. No período investigado, o emprego do artigo mostrava-se variável, passando, no decorrer dos séculos, para uma obrigatoriedade que se manifesta nos dias de hoje nesse contexto. Esta pesquisa, buscará determinar os contextos afetados pela mudança e delinear uma análise para os fenômenos envolvidos. Como arcabouço teórico utilizaremos uma abordagem minimalista (Chomsky (1995), Kayne (1994) e Schoorlemmer (1998)), tendo como pressupostos teóricos o Modelo de Princípios e Parâmetros. Sobre as características do Português Europeu moderno, período final da mudança investigada, utilizaremos as investigações de Castro (2001, 2006), Castro e Costa (2002), Miguel (2002, 2004) e Brito (2001, 2007) sobre o sintagma possessivo. Os textos utilizados como base de investigação para esta pesquisa diacrônica foram selecionados do Corpus Anotado do Português Histórico Tycho Brahe que se encontram disponíveis na internet no site: www.ime.usp.br/~tycho/corpus. Para o levantamento de dados serão utilizados os textos disponíveis do Corpus Tycho Brahe, pois, assim, poderemos tratar quantitativamente de objetos mais complexos, tanto do ponto de vista do fenômeno envolvido quanto do período considerado; e, com base nesse tratamento quantitativo, faremos uma análise qualitativa sustentável / Abstract: The aim of this thesis is to describe and investigate, within a diachronic perspective, the use of the determiner in possessive noun phrases in 23 Portuguese authors born between the 16th and the 19th century. During the period considered, the use of the article was variable, becoming obligatory at some point, as it can be observed nowadays in European Portuguese. This research will try to verify the contexts affected by the change and to propose an analysis for the observed facts. We adopt a minimalist approach based on Chomsky (1995), Kayne (1994) and Schoorlemmer (1998) within the Principles and Parameters Model. In order to explore the modern European Portuguese characteristics, corresponding to the last stage of the change investigated, we use the analyses by Castro (2001, 2006), Castro e Costa (2002), Miguel (2002, 2004) and Brito (2001, 2007). For our description and analysis, we use literary texts drawn from the Corpus Anotado do Português Histórico Tycho Brahe, which are freely available at www.ime.usp.br/~tycho/corpus / Doutorado / Linguistica / Doutor em Linguística
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Utilização do método de Gauss-Jordan no ensino médioVasconcellos, Luiz Fernando Nascimento 18 March 2014 (has links)
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Previous issue date: 2014-03-18 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho é voltado para professores e alunos do Ensino Médio. Tem como objetivo
mostrar a utilização do Método da Eliminação de Gauss-Jordan para a resolução de sistemas
de equações lineares, cálculo de matrizes inversas e cálculo de determinantes. A motivação
para a escolha desse tema é que, cada vez mais, o estudo das matrizes, dos determinantes e,
consequentemente, dos sistemas de equações lineares vem sendo deixado de lado no Ensino
Médio. Inicialmente, é feito um pequeno apanhado sobre o que são matrizes equivalentes
e operações elementares, além de se falar sobre cofator de um elemento de uma matriz
e sobre matriz adjunta, necessária para o cálculo da inversa utilizando-se determinantes.
Apresenta-se um pouco da história de Gauss e de Jordan e, logo em seguida, o método
propriamente dito. Também é visto o que acontece com o método quando as matrizes não
são invertíveis, os sistemas são possíveis e indeterminados ou os sistemas são impossíveis.
Quanto aos determinantes, são apresentadas suas propriedades e mostrada a eficácia do
método para determinantes de ordem n 3 e, além disso, é mostrada a aplicação dos
determinantes no cálculo de inversas e na resolução de sistemas de equações pela Regra de
Cramer. Finalmente, são apresentadas sugestões de exercícios com uma breve resolução. / This work is oriented to teachers and students in the high school. It aims to show the usage
of Gauss-Jordan’s Elimination Method to solve systems of linear equations, calculation of
inverse matrices and determinants. The motivation behind the selection of this topic is
that, more and more, the study of matrices, determinants, and consequently, systems of
linear equations has been ignored in the high school. Firstly, an abridgement is done on
what equivalent matrices and elementary operations are. Secondly, it explains about the
cofactor of an element of a matrix and about adjoint matrices, needed for the calculation
of the inverse matrix using determinants. A little introduction of Gauss and Jordan’s
histories is made, and then, the method itself. It is also shown what happens with the
method when the matrices are not invertible, the systems are possible but undetermined,
or, the systems are not possible. Concerning determinants, their properties are presented
and the method’s efficacy for determinants of order n 3 is shown and furthermore, it
is shown the application of the determinants in the calculation of inverse matrices and
resolutions of systems using Cramer’s Rule. Finally, some suggestions for exercises are
presented with brief resolutions.
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Aplicacao de determinante: area de poligono convexo e volume de piramide / Determinants of application: convex polygon area and volume of pyramidAraujo, Elismar Jose de 17 June 2015 (has links)
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Previous issue date: 2015-06-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work will concentrate on making a rereading of the theories that surround the
procedures for calculating the area of a convex polygon, as well as the volume of a
pyramid whose base is a polygon convex, with its vertices properly represented in a
coordinate system, in the plan or in space, respectively. Addresses some topics on arrays
and determinant and some of its applications, in particular the study of polygon area
and the volume of the pyramid. Based on applying a decisive factor for the calculation
of the area of a triangle with its vertices represented in a coordinate system, presents
a new theorem to calculate the area of any polygon convex, as well as, a new formula
to calculate the volume of any pyramid with convex basis as a direct application of the
volume of the tetrahedron with its vertices represented in an orthogonal system. For
both, it was essential to the concept of coordinates in the plane and in space, vectors in
the plane and in space, and some of its properties, being essential for the demonstrate
the volume of the tetrahedron and the area of the triangle, using determinant.
Keywords: Volume. Area. Convex polygon. Pyramid. Triangle. Tetrahedron / O presente trabalho versar a em fazer uma releitura das teorias que circundam os
procedimentos de c alculo da area de um pol gono convexo, assim como, do volume de
uma pir^amide cuja base e um pol gono convexo, com seus v ertices devidamente representados
em um sistema de coordenadas, no plano ou no espa co, respectivamente.
Aborda alguns t opicos sobre matrizes e determinante e algumas de suas aplica c~oes, em
especial o estudo de area de pol gonos e o volume de pir^amide. Baseado na aplica c~ao
de determinante para o c alculo da area de um tri^angulo com seus v ertices representados
em um sistema de coordenadas, apresenta um novo teorema para o c alculo da
area de qualquer pol gono convexo, assim como, uma nova f ormula para calcular o volume
de qualquer pir^amide com base convexa como uma aplica c~ao direta do volume do
tetraedro com seus v ertices representados em um sistema ortogonal. Para tanto, foi imprescind
vel abordar o conceito de coordenadas no plano e no espa co, vetores no plano
e no espa co e algumas de suas propriedades, sendo fundamentais para a demonstrar o
volume do tetraedro e a area do tri^angulo, usando determinante.
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The role of taxation in attracting foreign direct investments to South Africa : a BRICS comparisonTerhoeven, Janine 09 March 2012 (has links)
Foreign direct investment in South Africa is expected to increase economic growth thereby alleviating poverty. With technology offering a global trade arena it has become increasingly important for countries to compete for the attention of international investors. Through studies conducted to identify the matters international investors take into consideration in deciding where to invest, tax policies were identified as an area considered by foreign investors. Although research has been performed on the tax policies applied by countries and the effect thereof on foreign direct investment, limited attention has been afforded to the tax policies of South Africa. With its recent inclusion in BRICS, South Africa will be competing with these expected future economic giants. Determining whether South Africa’s tax policies are competitive with these countries would provide useful insight for the marketing of the country. The study discusses and compares the foreign direct investment determinants identified as having an impact on investors’ decisions in investing outside local borders before focusing on taxation in particular. Based on the literature reviewed and the comparison performed, the study concludes that South Africa’s tax policies are competitive with those offered by BRICS countries AFRIKAANS : Die verwagting is dat buitelandse direkte belegging in Suid-Afrika na ekonomiese groei sal lei en sodoende armoede verlig. Met tegnologie wat 'n globale handel arena aanbied, word dit al hoe belangriker vir lande om te kompeteer vir die aandag van internasionale beleggers. Deur middel van studies wat gedoen is om die aangeleenthede wat internasionale beleggers in ag neem en die besluit waar om te belê, te identifiseer, is die belastingbeleid geïdentifiseer as 'n gebied wat oorweeg word deur buitelandse beleggers. Hoewel navorsing uitgevoer is op die belastingbeleid wat toegepas word deur die lande en die uitwerking daarvan op buitelandse direkte belegging, is daar beperkte aandag verleen aan die belastingbeleid van Suid-Afrika. Met Suid-Afrika se onlangse opname in BRICS sal die land meeding met hierdie verwagte toekomstige ekonomiese reuse. Om vas te stel of Suid-Afrika se belastingbeleid mededingend is met hierdie lande, sal nuttige insig verskaf word vir die bemarking van die land. Die studie bespreek en vergelyk die buitelandse direkte belegging determinante wat verwag word om 'n uitwerking te hê op beleggers se besluite om te belê buite hul plaaslike grense voor daar gefokus word op belasting in die besonder. Op grond van die literatuur en die vergelyking uitgevoer, het die studie tot die gevolgtrekking gekom dat Suid-Afrika se belastingbeleid mededingend is met dié wat deur BRICS lande beskikbaar gemaak word. Copyright 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Terhoeven, J 2011, The role of taxation in attracting foreign direct investments to South Africa : a BRICS comparison, MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-03092012-122234 / > F12/4/168/gm / Dissertation (MCom)--University of Pretoria, 2012. / Taxation / unrestricted
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Community-based forest management institutions in Cameroon: dynamics and compliance determinantsKimengsi, Jude Ndzifon, Ndikebeng, Kometa Raoul, Mukong, Alfred Kechia 06 June 2024 (has links)
Changes linked to forest management institutions in diverse communities and cultural settings continue to attract research interest. However, comparative insights on their manifestations are lacking in Former British and Former French Cameroon. We trace the evolution of forest management institutions in the Kilum-Ijim and Santchou landscapes of Cameroon and analyse their compliance determinants, using key informant interviews (n = 12), focus group discussions (n = 6) and household surveys (n = 150). The results revealed a fairly stable culturally embedded institutional landscape in Kilum-Ijim, and a significant multiplication of structural institutions for Santchou. The logistic regression showed that perception and compliance with forest management institutions substantially depend on educational attainment, migration, membership in organisations, length of stay in the area and proximity of respondents to protected areas. The conclusion drawn is that landscapes which came under British colonial influence have fairly stable culturally embedded institutions, when compared to those that came under French influence. These site-specific traits shed light on the complexities linked to embedded institutions and their evolution. It further edifies theoretical perspectives on critical institutionalism. Studies on the source and content of the ‘last vestiges’ of these institutions are required.
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Socijalno-medicinski aspekti depresivnih poremećaja u Vojvodini / Socio-medical aspects of depressive disorders in VojvodinaHarhaji Sanja 28 October 2016 (has links)
<p>Depresija je jedan od najčešćih mentalnih poremećaja u opštoj populaciji širom sveta i prema podacima Svetske zdravstvene organizacije se nalazi na trećem mestu globalnog opterećenja bolestima. Cilj ovog istraživanja je bio da se utvrdi prevalencija depresije u populaciji odraslog stanovništva Vojvodine, da se identifikuju kategorije stanovništva pod najvećim rizikom i da se utvrdi povezanost depresije sa determinantama zdravlja, zdravstvenim stanjem i korišćenjem zdravstvene zaštite. Istraživanje je sprovedeno kao studija preseka na reprezentativnom uzorku stanovništva Vojvodine starosti 15 i više godina, kao deo nacionalne studije „Istraživanje zdravlja stanovništva Srbije“ koju je sprovelo Ministarstvo zdravlja Republike Srbije 2013. godine. Kao instrument istraživanja su korišćeni upitnici konstruisani u skladu sa upitnikom Evropskog istraživanja zdravlja. Prisustvo depresivnih simptoma je analizirano primenom PHQ-8 upitnika (Patient Health Questionnaire-8) a vrednost PHQ-8 skora 10 i više je ukazivala na prisustvo depresivne epizode (depresije). Istraživanjem je obuhvaćeno 3550 ispitanika prosečne starosti 50,2 godine. Prevalencija depresije je iznosila 4,8%. Primenom multivarijantne regresije je utvrđeno da žene imaju za 40% veću šansu za depresiju u odnosu na muškarce (OR=1,4), a kao prediktori depresije su se pokazali i starija životna dob, razvod/razlaz ili udovstvo, niži nivo obrazovanja, nezaposlenost, ekonomska neaktivnost i niži materijalni status. Osobe koje su u mesecu koji je prethodio istraživanju bile izložene stresu su imale oko sedam puta veću šansu za depresiju (OR=6,8), a kod ispitanika sa lošom socijalnom podrškom šansa za depresiju je bila oko četiri puta veća nego kod ispitanika sa jakom socijalnom podrškom (OR=3,7). Multimorbiditet je bio značajno prisutniji među ispitanicima sa depresijom, a šansa za prisustvo dve ili više hroničnih bolesti je kod njih bila skoro pet puta veća (OR=4,6) u odnosu na ispitanike koji nisu imali depresivne simptome. Depresija se pokazala i kao značajan prediktor češćeg korišćenja usluga zdravstvene zaštite. Dobijeni rezultati su potvrdili javnozdravstveni značaj depresije i istovremeno obezbedili podatke koji se mogu koristiti kao osnova za buduća prospektivna istraživanja, kao i za kreiranje programa za prevenciju i kontrolu depresivnih poremećaja i unapređenje mentalnog zdravlja.</p> / <p>Depression is one of the most common mental disorders in the general population worldwide and according to the World Health Organization it is the third leading cause of the global burden of disease. The aim of this study was to determine the prevalence of depression in the adult population of Vojvodina, to identify groups at the greatest risk of depression and to determine the relationship of depression with health determinants, health status and use of health care services. The research was carried out as a cross-sectional study on a representative sample of the population of Vojvodina, aged 15 and over as part of the National Health Survey of Serbia which was conducted by the Ministry of Health of the Republic of Serbia in 2013. Data was gathered by using questionnaires designed in accordance to the European Health Interview Survey. The presence of depressive symptoms was analyzed using the PHQ-8 questionnaire (Patient Health Questionnaire-8) and the score of 10 or above indicated a presence of a depressive episode (depression). The study included 3550 examinees with an average age of 50.2 years. The prevalence of depression was 4.8%. Multivariate regression showed that women had a 40% greater chance to suffer from depression as compared to men (OR=1.4). Also, factors such as older age, divorce/separation or widowhood, lower level of education, economic inactivity and poor financial situation were predictors of depression. People who were exposed to stress in the month prior to the survey had about seven times greater odds of depression (OR=6.8), and in patients with poor social support the chance of depression was about four times higher than among those with a strong social support (OR=3.7). Multimorbidity was significantly more prevalent among respondents with depression and they had five times higher odds of the presence of two or more chronic diseases (OR=4.6) in comparison with those who did not show depressive symptoms. Depression has been revealed as a significant predictor of more frequent use of health care services. The results confirmed the importance of depression to public health and also provided the data that can be used as a basis for future prospective studies, as well as for the development of the programs for the prevention and control of depressive disorders and mental health improvement.</p>
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A regularized arithmetic Riemann-Roch theorem via metric degenerationDe Gaetano, Giovanni 14 June 2018 (has links)
Das Hauptresultat dieser Arbeit ist ein regularisierter arithmetischer Satz von Riemann-Roch für ein hermitesches Geradenbündel, die isometrisch zum Geradenbündel den Spitzenformen vom geraden Gewicht ist, auf eine arithmetische Fläche, deren komplexe Faser isometrisch zu einer hyperbolischen Riemannschen Fläche ohne elliptische Punkte ist.
Der Beweis des Resultats erfolgt durch metrische Degeneration: Wir regularisieren die betreffenden Metriken in einer Umgebung der Singularitäten, wenden dann den arithmetischen Riemann-Roch-Satz von Gillet und Soulé an und lassen schließlich den Parameter gegen Null gehen. Durch die metrische Degeneration entsteht auf beiden Seiten der Formel ein divergenter Term. Die asymptotische Entwicklung der Divergenz berechnet sich auf der einen Seite direkt aus der Definition der glatten arithmetischen Selbstschnittzahlen.
Der divergente Term auf der anderen Seite ist die zeta-regularisierte Determinante des zu den regularisierten Metriken assoziierten Laplace-Operators, der auf den 1-Formen mit Werten in dem betrachteten hermitischen Geradenbündel operiert. Wir definieren und berechnen zuerst eine Regularisiereung des entsprechenden zu den singulären Metriken assoziierten Laplace-Operators; diese wird später im regularisierten Riemann-Roch-Satz auftauchen. Zu diesem Zweck passen wir Ideen von Jorgenson-Lundelius, D'Hoker-Phong und Sarnak auf die vorliegende Situation an und verallgemeinern diese.
Schließlich beweisen wir eine Formel für den zum betrachteten hermitischen Geradenbündel assoziierten Wärmeleitungskern auf der Diagonalen bei einer Modellspitze. Diese Darstellung steht im Zusammenhang mit einer Entwicklung nach zur Whittaker-Gleichung assoziierten Eigenfunktionen, die im Anhang bewiesen wird. Weitere Abschätzungen des zum betrachteten hermitischen Geradenbündel gehörigen Wärmeleitungskern auf der komplexe Faser der arithmetischen Fläche schließen den Beweis des Hauptresultats ab. / The main result of the dissertation is an arithmetic Riemann-Roch theorem for the hermitian line bundle of cusp form of given even integer weights on an arithmetic surface whose complex fiber is isometric to an hyperbolic Riemann surface without elliptic points.
The proof proceeds by metric degeneration: We regularize the metric under consideration in a neighborhood of the singularities, then we apply the arithmetic Riemann-Roch theorem of Gillet and Soulé, and finally we let the parameter go to zero. Both sides of the formula blow up through metric degeneration. On one side the exact asymptotic expansion is computed from the definition of the smooth arithmetic intersection numbers.
The divergent term on the other side is the zeta-regularized determinant of the Laplacian acting on 1-forms with values in the chosen hermitian line bundle associated to the regularized metrics. We first define and compute a regularization of the determinant of the corresponding Laplacian associated to the singular metrics, which will later occur int he regularized arithmetic Riemann-Roch theorem. To do so we adapt and generalize ideas od Jorgenson-Lundelius, D'Hoker-Phong, and Sarnak.
Then, we prove a formula for the on-diagonal heat kernel associated to the chosen hermitian line bundle on a model cusp, from which its behavior close to a cusp is transparent. This expression is related to an expansion in terms of eigenfunctions associated to the Whittaker equation, which we prove in an appendix. Further estimates on the heat kernel associated to the chosen hermitian line bundle on the complex fiber of the arithmetic surface prove the main theorem.
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Human capital constraints in South Africa : a firm level analysis / J.R. LabuschagneLabuschagne, Johannes Riaan January 2010 (has links)
This study examines human capital constraints in the South African economy, and
the austerity these constraints have on firms in the country. The first part of the study
identifies the main human capital constraints facing South Africa, and explains how
these constraints influence an economy. An inadequately educated workforce along
with restrictive labour regulations makes out the central components of these
constraints. The second part explores all the relevant constraints individually, and
determines the cause of their existence. The final part of this study consists of a firm
level analysis that describes human capital constraints experienced by firms in South
Africa. Regression analysis examines the determinants of increased output per
worker in manufacturing firms. These determinants also indicate the cause of growth
in output per worker. Human capital aspects such as education, labour regulation,
compensation and competition are all shown to have a considerable influence on
output per worker. Principal Component Analysis (PCA) on the explanatory variables
achieved similar results. For this analysis, latent variables that incorporated
education, training, region and Sector Education Training Authority (SETA) support
and effectiveness explained the highest percentage of the total variance. However,
this study found no evidence to suggest that human capital development initiatives
like training programmes and SETA support have a positive relationship with
increased levels of productivity. / Thesis (M.Com. (Economics))--North-West University, Potchefstroom Campus, 2011.
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