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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.
131

Utilização de altas diluições na produção orgânica de repolho, brócolis e couve-flor / Use of high dilutions for organic production of cabbage, broccoli, and cauliflower

Rueda, Edwin Ernesto Pulido 05 February 2013 (has links)
Made available in DSpace on 2016-12-08T16:44:44Z (GMT). No. of bitstreams: 1 PGPV13MA109.pdf: 557511 bytes, checksum: d2cb3e9e50b7e2f27e43a1b3f1a189c1 (MD5) Previous issue date: 2013-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The family of Brassicaceae plays an important role in Brazilian horticulture, having the species of cabbage, broccoli, and cauliflower the higher at consumption by the population. The aim of this study was to evaluate the use of high dilutions preparation for production under organic system of cabbage, broccoli, and cauliflower. Experiments were conducted in the greenhouse and under fields conditions. For greenhouse, the experimental design was completely randomized. For field experiments the experiment design were randomized complete block design. Both designs were with four replications and nine treatments. For greenhouse, trays had of 64 plants from with 20 plant were taken as experiment plot. Each plot consisted of 20 plants for each specie and repetition. Ten plants distributed in double line was the plot in the field experiment. The treatments consisted of homeopathic preparations of Arnica montana, Silicea terra, Carbo vegetabilis, and Sulphur at 6CH and 30CH. For control water was used. The experiments were conducted separately for each species. In greenhouse, the treatments were applied every four days until transplanting (seven applications). Under field conditions, the treatments were applied every fifteen days until harvest (four applications). Shoot fresh mass, root fresh mass, shoot dry mass, root dry mass, plant height, root length, and stem diameter for seedlings were evaluated. For field, shape index, rate of the length of the heart and longitudinal diameter (C / D) for cabbage field crop were evaluated. Plant height and stem diameter for broccoli were evaluated. Fresh mass and dry mass of cabbage heads and broccoli inflorescences were also evaluated. The disease incidence of black-rot and alternaria and the occurrence of cabbage aphid and damage caused by diamondback moth were evaluated. The preparations of Sulphur at 6CH increased the shoot dry mass, root dry mass for seedlings and production of cabbage heads. The preparations of Sulphur at 6CH increased the plant height, root length, and stem diameter for broccoli. Silicea terra at 30CH increased the fresh mass and dry mass of broccoli inflorescences. Sulphur at 6CH reduced the aphid occurrence for cabbage and diamondback moth damage percentage for broccoli. Sulphur at 30CH increased the shoot dry mass, root dry mass, and height for cabbage seedlings. Sulphur at 30CH increased the shoot dry mass, root dry mass, and stem diameter. Aphid occurrence, alternaria; and black rot incidence were decreased when broccoli was treated by Sulphur at 30CH. Silicea terra at 30CH increased the shoot dry mass, root dry mass, height plant, stem diameter, and root length for broccoli seedlings. Silicea terra at 30CH also increased the shoot dry mass, root dry mass, and stem diameter of cauliflower seedlings. The preparations of Silicea terra at 30CH increased the production of cabbage heads and reduced the black rot incidence for broccoli. The high dilution preparations have influence on the yield and management of pests and diseases of cabbage, broccoli, and cauliflower growth under organic production system / A família Brassicaceae ocupa papel destacado na olericultura brasileira, sendo as espécies de repolho, brócolis e couve-flor de maior consumo pela população. O objetivo deste trabalho foi avaliar o uso de preparados em altas diluições na produção em sistemas orgânicos de repolho, brócolis e couve-flor. Os experimentos com repolho, brócolis e couve-flor foram realizados em casa de vegetação e a campo na Epagri e na comunidade de Pedras Brancas, Lages, SC. O delineamento foi inteiramente casualizado em casa de vegetação e de blocos ao acaso, a campo. Ambos os delineamentos foram com quatro repetições e nove tratamentos. Em casa de vegetação, as bandejas foram constituídas por 64 plantas por parcela para cada hortaliça. A parcela útil foi composta por 20 plantas centrais das 64 plantas da parcela. A campo, cada parcela de repolho e brócolis foi constituída por 10 plantas distribuídas em dupla linha. Os tratamentos utilizados, tanto para casa de vegetação como para campo, foram os preparados homeopáticos de Arnica montana, Silicea terra, Carbo vegetabilis e Sulphur na 6CH e 30CH; e água como testemunha. Os experimentos foram delineados em separado para cada uma das hortaliças e conduzidos em duplo cego. Em casa de vegetação, os tratamentos foram aplicados a cada quatro dias, sobre as mudas até seu transplante, totalizando sete aplicações. No campo, após o transplante das mudas, os tratamentos foram aplicados a cada quinze dias, sobre as plantas até sua colheita, totalizando quatro aplicações. Foram avaliadas, em mudas, características de massa fresca e seca da parte aérea e radicular, altura da planta, comprimento de raiz e diâmetro do caule. A campo, no momento da colheita, foram avaliadas as características de índice de formato, a relação do comprimento do coração e do diâmetro longitudinal (C/D) para repolho; para o brócolis, altura da planta e diâmetro do caule. Massa fresca e seca das cabeças em repolho e das inflorescências de brócolis também foram avaliadas. A incidência de alternariose e podridão-negra, bem como, a ocorrência do pulgão e dos danos da traça-das-crucíferas foram avaliadas em repolho e brócolis. O preparado de Sulphur na 6CH aumentou a massa seca da parte aérea e radicular em mudas e a produção de cabeças de repolho, bem como o incremento da massa fresca e seca das inflorescências em brócolis. O preparado de Sulphur na 6CH reduziu também a ocorrência do pulgão em plantas de repolho e brócolis e o percentual de danos da traça-das-crucíferas em brócolis.O preparado de Sulphur na 30CH aumentou a massa seca da parte aérea e radicular e altura da plântula em mudas de repolho, bem como o incremento da massa seca da parte aérea e radicular e diâmetro do caule em mudas de couve-flor. A ocorrência do pulgão, a incidência da alternariose e a podridão-negra foram reduzidas quando tratadas como o preparado de Sulphur na 30CH em plantas de brócolis. O preparado de Silicea terra na 30CH incrementou a massa seca da parte aérea e radicular, altura da plântula, comprimento de raiz e diâmetro do caule, em mudas de brócolis, bem como a massa seca da parte aérea e radicular e diâmetro do caule em mudas de couve-flor. O preparado de Silicea terra na 30CH aumentou a produção de cabeças de repolho e reduziu a incidência da podridão-negra em plantas de brócolis. Conclui- se que preparados em altas diluições influenciam na produção e no manejo de insetos-praga e doenças de plantas de repolho, brócolis e couve-flor, sob sistema orgânico
132

Une analyse multivariée de la longue mémoire et des changements de régime de Markov dans les rendements boursiers

Aguessy, Michael Nelson January 2011 (has links)
La littérature existante sur la façon d'estimer et d'anticiper les rendements boursiers est très diversifiée. En effet, de nombreux auteurs estiment que les modèles linéaires tels que les processus de longue mémoire expliquent mieux les fluctuations sur les marchés boursiers. D'autres estiment plutôt que les modèles non linéaires sont plus adaptés, car les fluctuations sont plutôt déterminées par des chocs structurels. Ainsi un modèle non linéaire tel que celui faisant usage des changements de régimes de Markov serait préférable Notre étude qui est une application empirique des travaux de Haldrup et al (2010), cherche à estimer simultanément ces aspects linéaires et non linéaires, pour les rendements des indices boursiers de Londres (FTSE100), New York (S&P500), Tokyo (NIKKEI225) et Toronto (SPTSX). S'effectuant sur une période de 1984-2010, elle considérera également l'intérêt marginal que pourrait apporter une spécification multivariée plutôt qu'univariée à la prévision des rendements. L'estimation des paramètres de longue mémoire et des changements de régimes de Markov dans les rendements boursiers, confirme les conclusions de nos prédécesseurs. Cependant, suite à la réalisation des prévisions, nous obtiendrons que les modèles Vecteur Autorégressif avec changement de régime de Markov présentent de meilleures propriétés en terme de prévision que les modèles Vecteur Autorégressif avec Longue Mémoire et ceux avec Vecteur Autorégressif avec Changement de Régime de Markov et Longue Mémoire.
133

On the Specification of Local Models in a Global Vector Autoregression: A Comparison of Markov-Switching Alternatives

Andersson, Sebastian January 2014 (has links)
In this paper, focus is on the global vector autoregressive (GVAR) model. Its attractiveness stems from an ability to incorporate global interdependencies when modeling local economies. The model is based on a collection of local models, which in general are estimated as regular VAR models. This paper examines alternative specifications of the local models by estimating them as regime-switching VAR models, where transition probabilities between different states are studied using both constant and time-varying settings. The results show that regime-switching models are appealing as they yield inferences about the states of the economy, but these inferences are not guaranteed to be reasonable from an economic point of view. Furthermore, the global solution of the model is in some cases non-stationary when local models are regime-switching. The conclusion is that the regime-switching alternatives, while theoretically reasonable, are sensitive to the exact specification used. At the same time, the issue of specifying the regime-switching models in such a way that they perform adequately speaks in favor of the simpler, yet functional, basic GVAR model.
134

Essays on oil price shocks and financial markets

Wang, Jiayue January 2012 (has links)
This thesis is composed of three chapters, which can be read independently. The first chapter investigates how oil price volatility affects the investment decisions for a panel of Japanese firms. The model is estimated using a system generalized method of moments technique for panel data. The results are presented to show that there is a U-shaped relationship between oil price volatility and Japanese firm investment. The results from subsamples of these data indicate that this U-shaped relationship is more significant for oil-intensive firms and small firms. The second chapter aims to examine the underlying causes of changes in real oil price and their transmission mechanisms in the Japanese stock market. I decompose real oil price changes into three components; namely, oil supply shock, aggregate demand shock and oil-specific demand shock, and then estimate the dynamic effects of each component on stock returns using a structural vector autoregressive (SVAR) model. I find that the responses of aggregate Japanese real stock returns differ substantially with different underlying causes of oil price changes. In the long run, oil shocks account for 43% of the variation in the Japanese real stock returns. The response of Japanese real stock returns to oil price shocks can be attributed in its entirety to the cash flow variations. The third chapter tests the robustness of SVAR and investigates the impact of oil price shocks on the different U.S. stock indices. I find that the responses of real stock returns of alternate stock indices differ substantially depending on the underlying causes of the oil price increase. However, the magnitude and length of the effect depends on the firm size. The response of U.S. stock returns to oil price shocks can be attributed to the variations of expected discount rates and expected cash flows.
135

Weighting schemes in global VAR modelling: a forecasting exercise

Martin, Florian, Crespo Cuaresma, Jesus 03 1900 (has links) (PDF)
We provide a comprehensive analysis of the out-of-sample predictive accuracy of different global vector autoregressive (GVAR) specifications based on alternative weighting schemes to address global spillovers across countries. In addition to weights based on bilateral trade, we entertain schemes based on different financial variables and geodesic distance. Our results indicate that models based on trade weights, which are standard in the literature, are systematically outperformed in terms of predictive accuracy by other specifications. We find that, while information on financial linkages helps improve the forecasting accuracy of GVAR models, averaging predictions by means of simple predictive likelihood weighting does not appear to systematically lead to lower forecast errors.
136

The Impact of Oil Prices on Macroeconomic Indicators in Azerbaijan and Georgia / The Impact of Oil Prices on Macroeconomic Indicators in Azerbaijan and Georgia

Karimov, Farhad January 2015 (has links)
Using a multivariate vector autoregression (VAR) approach, this paper investigates the relationships between oil price and macroeconomic indicators of closely interrelated developing economies of oil exporting Azerbaijan and oil importing Georgia based on monthly time series from January 2001 to November 2012. The model is estimated for each country separately and the results are object for comparison. The empirical evidence suggests that oil price has significant effects on macroeconomy in both countries. In particular, these effects are positive for all 3 macroeconomic variables on the example of Azerbaijan. On the example of Georgia, these effects are positive for GDP and inflation rate, and, negative for exchange rate. On the other hand, macroeconomic indicators of Azerbaijan fail to affect oil price level.
137

The globalisation of the Chinese financial sector

Reyisha, Ahemaitijiang January 2015 (has links)
In this thesis we have studied China's financial sector globalisation by analysing the determinants of Chinese banking sector profitability, and the relationship between GDP growth and FDI inflows. For estimating the Chinese banking sector profitability, we applied system GMM estimation on the annual data of 56 banks currently in China. The time period of the data is from 2002-2011. We found out that both internal and external factors have impact on the Chinese banking sector profitability. As we have expected financial sector globalisation has positive impact on the profitability of banking industry. For analysing the impacts of financial sector globalisation in terms of FDI contribution to the Chinese economy, we have tested the relationship between FDI and GDP by running the VAR model on the macro data over the time period of 1987-2011. We have found that GDP growth explains the rapid development of FDI, and FDI indirectly influences the GDP growth by influencing the domestic investments.
138

The sustainability of European Monetary Union : evidence from business cycle synchronisation, monetary policy effectiveness and the Euro fiscal dividend

Zhang, H. E. January 2014 (has links)
EMU as the only functioning single currency area has been criticised as a non-optimal currency area since the Treaty on European Union was signed. Despite this, it has been seen as, probably, the most complete economic project that has ever been conducted by any group of governments. Through Dynamic Factor model and Panel VAR method, we are focusing on the issues of business cycle synchronisation, effectiveness of ECB monetary policy and the euro fiscal dividend, thus to advances the current studies on EMU through assessing whether it can be a sustainable system. For example, whether economic fluctuations can be effectively managed by implementing a single ECB monetary policy and financial market can be relied upon as a monitoring and enforcing device to discipline fiscal behaviour of Eurozone countries. Overall, we concluded that EMU could be more sustainable if it was just formed by its core members, leaving the periphery outside the single currency area. However, since the EU has recently conducted many rescue measures to save the Eurozone, we are unlikely to see those troubled countries to quit EMU, at least, at the present time. The sustainability of the current EMU can be improved if more intra-trade can be promoted to enhance business cycle convergence; hence, it will be more likely to have a union-wide appropriate monetary policy. This will also reduce the requirement of depending upon using fiscal measures to compensate the loss of monetary sovereignty. Moreover, fiscal activities can also be better monitored/enforced since the financial market has begun to adequately adjust the long-term interest rates on Eurozone government bonds according to the development in those countries fiscal stance.
139

Global Factors Driving Inflation and Monetary Policy: A Global VAR Assessment

Feldkircher, Martin, Lukmanova, Elizaveta, Tondl, Gabriele 08 1900 (has links) (PDF)
In this paper, we examine international linkages in inflation and short-term interest rates using a global sample of OECD and emerging economies. Using a Bayesian global vector autoregression (GVAR) model, we show that for short-term interest rates both movements in inflation and output play an important role. In advanced countries, however, international factors such as foreign interest rates appear as an important driver of local interest rates. For inflation, we also find evidence for the importance of global factors, such as price developments in other countries, oil prices and the exchange rate. Again, this impact of global factors appears predominately in advanced countries. / Series: Department of Economics Working Paper Series
140

Invasão por Pinus spp. em fisionomias campestres do Cerrado, no estado de São Paulo / Pine invasion in open physiognomies of the Cerrado in São Paulo state

Miashike, Roseli Lika 22 June 2015 (has links)
No Brasil, foram introduzidas diversas espécies de Pinus e a espécie P. elliottii Engelm apresenta o comportamento invasor em unidades de conservação de Cerrado, no estado de São Paulo. O objetivo deste estudo foi comparar P. elliottii com outras duas espécies do mesmo gênero, P. caribaea Moret e P. oocarpa Shiede ex Schltdl, através de: viabilidade e germinabilidade das sementes, em laboratório; sobrevivência das plântulas logo após a germinação e acompanhamento de seu crescimento em estufa; germinabilidade em fisionomias campestres; e chuva de sementes dentro de talhões. Para P. elliottii, também foi verificada a distância de dispersão das sementes. As sementes utilizadas nos testes em laboratório foram coletadas em Águas de Santa Bárbara (Estação Ecológica de Santa Bárbara - EEcSB; Floresta de Águas de Santa Bárbara - FASB) e Itirapina (Estação Experimental de Itirapina - EExI). Primeiramente, as sementes foram colocadas em água para separação das sementes cheias das vazias (flutuabilidade). Em seguida, as sementes cheias foram testadas quanto à viabilidade por meio de sal de tetrazólio e quanto à germinabilidade. As sementes germinadas foram acompanhadas até os cotilédones ficarem visíveis e uma parte destas teve o crescimento acompanhado até a 24ª semana. A germinabilidade em fisionomias campestres foi realizada apenas na EEcSB, onde as sementes das três espécies foram semeadas em diferentes graus de umidade do solo. Coletores de sementes foram instalados dentro dos talhões de Pinus spp., tanto na EEcSB-FASB como na EExI, para quantificar a chuva de sementes. A distância de dispersão das sementes de P. elliottii foi avaliada apenas na EEcSB, durante o período de maior dispersão de sementes (março a maio), e teve como classes de distâncias em relação ao talhão: 10, 30, 60, 100, 150 e 250 m. Os resultados dos testes em laboratório mostraram que P. caribaea e P. elliottii apresentam as maiores proporções de sementes cheias (>70%) e P. oocarpa e P. elliottii, as maiores taxas de viabilidade (>90%) e germinabilidade (>90%). Dentre as sementes germinadas das três espécies, mais de 90% desenvolveram-se até o aparecimento dos cotilédones. Quanto ao crescimento, P. caribaea e P. oocarpa apresentaram maior vigor em relação a P. elliottii. Em campo, as três espécies apresentaram, de maneira similar, baixíssima porcentagem de germinação (<1,5% do total semeado), preferencialmente em solos mais úmidos. A chuva de sementes de P. elliottii dentro de talhões foi muito maior (pelo menos o dobro) em comparação com as outras duas espécies. A distância de dispersão das sementes de P. elliottii foi maior nos primeiros 30 m, mas chegou até os 150 m. Portanto, P. caribaea e P. oocarpa apresentaram condições de se tornarem invasores pela viabilidade de suas sementes, vigor de crescimento e germinação em campo, mas o fator determinante para o sucesso na invasão P. elliottii é, provavelmente, a pressão de propágulos, maior do que as outras duas espécies, causada pela sua alta produção de sementes e intenso plantio. / Several pine species of the genus Pinus have been introduced in Brazil, and P. elliottii Engelm is presently considered an invasive species in the Brazilian savanna (Cerrado) in São Paulo State. The aim of this study was to compare P. elliottii with two other Pinus species, P. caribaea Moret and P. oocarpa Shiede ex Schltdl according to: seed viability and germinability, in laboratory; survival of seedlings soon after germination and their growth, in greenhouse; germination at field conditions; and seed rain inside the plantation. The distance of seed distance dispersal was also verified for P. elliottii. The seeds for the laboratory tests were collected in Águas de Santa Bárbara (Santa Barbara Ecological Station - EEcSB; Águas de Santa Bárbara Forest - FASB) and Itirapina (Itirapina Experimental Station - EExI). First, the seeds were placed in water to separate the full from the empty seeds (flutuability). Then full seeds were tested by viability (tetrazolium) and germinability. Germinated seeds were monitored until the cotyledons were visible and some of those were monitored up the 24th week to verify their growth rate. In the EEcSB, seeds of the three species were sown at different levels of soil moisture to observe the germination in the field. In order to quantify the species seed rain seed collectors were installed inside the Pinus spp. stands, in both EEcSB-FASB and EExI. The distance of P. elliottii seed spread was evaluated only at the EEcSB, during the greater period of seed dispersion (March to May), at the distances of 10, 30, 60, 100, 150 and 250 m from the planted areas. The results of laboratory tests showed that P. caribaea and P. elliottii have the highest proportions of full seeds (> 70%) and P. oocarpa and P. elliottii, the highest viability (> 90%) and germination rates (> 90%). Among the germinated seeds of the three species more than 90% developed to seedling stage. Concerning seedling growth, P. caribaea and P. oocarpa showed greater vigor than P. elliottii. In the field, the three species showed similar and very low germination rates (<1.5% of the total sown), preferably in more humid soils. The seed rain of P. elliottii inside the plantation stand was much higher (at least twice) compared to the other two species. The dispersal distance of P. elliottii seeds was higher in the first 30 m, but reached 150 m. The results show that P. caribaea and P. oocarpa are able to become invaders due to their high values of seed viability and germination, and vigor growth, however, the determining factor for the invasive success of P. elliottii is probably its higher propagule pressure, caused by several human mediated introductions, and high production of seeds.

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