900 resultados para Research on terrorism : trends, achievements, and failures
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In this work, we introduce a necessary sequential Approximate-Karush-Kuhn-Tucker (AKKT) condition for a point to be a solution of a continuous variational inequality, and we prove its relation with the Approximate Gradient Projection condition (AGP) of Garciga-Otero and Svaiter. We also prove that a slight variation of the AKKT condition is sufficient for a convex problem, either for variational inequalities or optimization. Sequential necessary conditions are more suitable to iterative methods than usual punctual conditions relying on constraint qualifications. The AKKT property holds at a solution independently of the fulfillment of a constraint qualification, but when a weak one holds, we can guarantee the validity of the KKT conditions.
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The aim of this degree thesis is to see what research says about the use of computer and video games to support upper elementary pupils’ development in English reading comprehension in Swedish schools. Other goals are to see how online and offline gaming can be integrated in the Swedish schools and what attitudes teachers have towards gaming. The method used is a systematic literature review and the purpose is to analyze chosen articles and to find relevant content that answers the research questions. Five articles were chosen from different databases and were systematically analyzed in this thesis. The results show that online gaming as support for education can be rewarding for some upper elementary pupils in English learning. However, in English reading comprehension there is not much research found which means that more research needs to be made within this area. Moreover, involving online gaming in English language learning seems to be a challenge for teachers mostly because of their lack of knowledge about the subject, even though they are positive to gaming. The lack of knowledge about the subject could be altered with more education and courses in the area.
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International assessments indicate that Swedish students achieve high results in reading, writing and understanding English. However, this does not mean that the students display oral proficiency, despite an emphasis on functional and communicative language skills in the current English Syllabus. While a previous literature study by this researcher has shown that authentic texts are a way to increase these skills, most of the results shown are from an international viewpoint. Thus an empirical study was conducted within Sweden with the aim to examine the use of authentic texts in the Swedish EFL upper elementary classroom. Twelve teachers have answered a questionnaire on how they use authentic texts in their language teaching, as well as their opinions about these as a teaching tool. Additionally, 37 students have answered a questionnaire on their attitudes about authentic texts. Results indicate that all of the teachers surveyed see authentic texts as an effective way to increase students’ communicative competence and English language skills; however, only a few use them with any frequency in language teaching. Furthermore, this seems to affect the students’ attitudes, since many say that they read authentic texts in their free time, but prefer to learn English out of a textbook at school. These findings are based on a small area of Sweden. Therefore, further research is needed to learn if these opinions hold true for the entire country or vary dependent upon region or other factors not taken into consideration in this study.
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This Thesis is the result of my Master Degree studies at the Graduate School of Economics, Getúlio Vargas Foundation, from January 2004 to August 2006. am indebted to my Thesis Advisor, Professor Luiz Renato Lima, who introduced me to the Econometrics' world. In this Thesis, we study time-varying quantile process and we develop two applications, which are presented here as Part and Part II. Each of these parts was transformed in paper. Both papers were submitted. Part shows that asymmetric persistence induces ARCH effects, but the LMARCH test has power against it. On the other hand, the test for asymmetric dynamics proposed by Koenker and Xiao (2004) has correct size under the presence of ARCH errors. These results suggest that the LM-ARCH and the Koenker-Xiao tests may be used in applied research as complementary tools. In the Part II, we compare four different Value-at-Risk (VaR) methodologies through Monte Cario experiments. Our results indicate that the method based on quantile regression with ARCH effect dominates other methods that require distributional assumption. In particular, we show that the non-robust method ologies have higher probability to predict VaRs with too many violations. We illustrate our findings with an empirical exercise in which we estimate VaR for returns of São Paulo stock exchange index, IBOVESPA, during periods of market turmoil. Our results indicate that the robust method based on quantile regression presents the least number of violations.
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O objetivo deste trabalho de pesquisa é investigar a oferta de crédito comercial durante períodos de crise financeira em seis países diferentes: Brasil, França, Alemanha, Itália, Espanha e Reino Unido, foram utilizadas informações de empresas de capital aberto entre 2000 e 2011. A literatura internacional documenta que durante o pico de crises financeiras a oferta de crédito comercial aumenta pois as companhias usam o crédito comercial como substituto e/ou complemento ao crédito bancário, apesar de após o momento de pico esta oferta diminui significantemente porque as empresas enfrentam problemas de liquidez causado por escassez de crédito. Mesmo que somente existam evidências pontuais de que a oferta de crédito comercial aumentou durante a crise financeira global de 2008, o efeito pós-crise é perceptível durante a crise Europeia de 2011, pois as empresas europeias diminuíram a oferta de crédito comercial, também evidenciando que estas companhias estavam confrontando problemas de administração de liquidez. Em relação ao uso de crédito comercial como ferramenta de transmissão de capital, nenhuma evidência foi encontrada para provar sua existência em tempo de crise financeira.
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The question posed by Theme 4 of this workshop is indeed a very broad one and would demand a thorough research on the topics involved. I am afraid I did not have the proper time to think it over and I would not be able to provide a wide ranging answer to this question. Thus, I will be selective and I will present the following issues that need to be addressed to support Brazilian development: i) competition among banks; ii) high rate of interest on liquidity; iii) approval by the Congress of a Complementary Law to regulate the financial sector as required by the 1988 Brazilian Constitution; iv) exploitation of workers through the governance of the Job Time Guarantee Fund (FGTS) and iv) state-owned versus government owned enterprises.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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High soil acidity influences the availability of mineral nutrients and increases that of toxic aluminium (Al), which has a jeopardizing effect on plant growth. The objective of this research was to evaluate the effects of soil liming on the development of guava (Psidium guajava L.) plants, on soil chemical characteristics, and on fruit yield. The experiment was carried out at the Bebedouro Citrus Experimental Station, state of São Paulo, Brazil, in a Typic Hapludox soil, from August 1999 to March 2003. The treatments consisted of limestone dose: D0 = zero; D1 = half dose; D2 = total dose; D3 = 1.5 times the dose, and D4 = 2 times the dose to raise the V value to 70%. The doses corresponded to zero, 1.85, 3.71, 5.56, and 7.41tha(-1) applied to the upper soil layer (0-30cm deep) before planting. The results showed that liming caused an improvement in the evaluated soil chemical characteristics up to a depth of 60cm in soil samples both in the line and between lines. The highest fruit yields were obtained when the base saturation reached a value of 55% in the line and 62% between the lines. Foliar levels of calcium (Ca) and magnesium (Mg) were 8.8 and 2.5gkg-1, respectively. The highest limestone dose maintained the soil base saturation (at the layer of 0-20cm) in the line close to 55% during at least 40 months after the incorporation of limestone.
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The bronze bug Thaumastocoris peregrinus Carpintero & Dellape (Hemiptera: Thaumastocoridae) was detected infesting Eucalyptus trees in Brazil in 2008, in the states of São Paulo, Rio Grande do Sul and Minas Gerais and in 2009 was found in the state of Espirito Santo, Mato Grosso do Sul, Rio de Janeiro and Parana. Details about geographical spread, means of introduction, impact in Eucalyptus plantations and natural enemies observed in the field are discussed.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Stressful experiences appear to have a strong influence on susceptibility to drug taking behavior. Cross-sensitization between stress and drug-induced locomotor response has been found. Locomotor response to novelty or cocaine (10 mg/kg, i.p.), cyclic AMP-dependent protein kinase (PKA) activity in the nucleus accumbens and basal corticosterone levels were evaluated in male adult rats exposed to acute and chronic predictable or unpredictable stress. Rats exposed to a 14-day predictable stress showed increased locomotor response to novelty and to cocaine, whereas rats exposed to chronic unpredictable stress demonstrated increased cyclic AMP-dependent PKA activity in the nucleus accumbens. Both predictable and unpredictable stress increased basal corticosterone plasma levels. These experiments demonstrated that stress-induced early cocaine sensitization depends on the stress regime and is apparently dissociated from stress-induced changes in cyclic AMP-dependent PKA activity and corticosterone levels. (C) 2002 Elsevier B.V. B.V. All rights reserved.
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One of the most interesting alternatives for replacement of hard chrome plating is tungsten carbide thermal spray coating applied by the high velocity oxy-fuel (HVOF) process which presents a safer, cleaner and less expensive alternative to chromium plating. The objective of this research is to compare the influence of the tungsten carbide-17cobalt (WC- 17Co) coating applied by high velocity oxy fuel (HVOF) process with that of hard-chromium electroplating on the fatigue strength and abrasive wear of AISI 4340 steel.
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Diets rich in saturated fatty acids are one of the most important causes of atherosclerosis in men, and have been replaced with diets rich in unsaturated fatty acids (UFA) for the prevention of this disorder. However, the effect of UFA on myocardial performance, metabolism and morphology has not been completely characterized. The objective of the present investigation was to evaluate the effects of a UFA-rich diet on cardiac muscle function, oxidative stress, and morphology. Sixty-day-old male Wistar rats were fed a control (N = 8) or a UFA-rich diet (N = 8) for 60 days. Myocardial performance was studied in isolated papillary muscle by isometric and isotonic contractions under basal conditions after calcium chloride (5.2 mM) and ss-adrenergic stimulation with 1.0 mu M isoproterenol. Fragments of the left ventricle free wall were used to study oxidative stress and were analyzed by light microscopy, and the myocardial ultrastructure was examined in left ventricle papillary muscle. After 60 days the UFA-rich diet did not change myocardial function. However, it caused high lipid hydroperoxide (176 +/- 5 vs 158 +/- 5, P < 0.0005) and low catalase (7 +/- 1 vs 9 +/- 1, P < 0.005) and superoxide-dismutase (18 +/- 2 vs 27 +/- 5, P < 0.005) levels, and discrete morphological changes in UFA-rich diet hearts such as lipid deposits and mitochondrial membrane alterations compared to control rats. These data show that a UFA-rich diet caused myocardial oxidative stress and mild structural alterations, but did not change mechanical function.
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The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. on day 21 of pregnancy, the adult rats (weighing approximately 250 ± 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 ± 0.2) and SOD (G3 = 223.0 ± 84.7; G4 = 146.1 ± 40.8), and decreased fetal CAT activity (G3 = 22.4 ± 10.6; G4 = 34.4 ± 14.1) and GSH-t (G3 = G4 = 0.3 ± 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 ± 0.2 and SOD = 274.1 ± 80.3; fetal CAT = 92.6 ± 82.7 and GSH-t = 0.6 ± 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days).
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)