A Spatial Comparison of Short and Long Term Migration Trends in China

China’s floating population, those individuals who have migrated between counties or provinces for a period of longer than 6 months, account for 79 million individuals. If intracounty migration is also included, the number jumps to 145 million individuals or over 11% of the total population. This study examines the geographical differences in short and long term migration using ArcGIS to manipulate the spatial GIS data. The study shows that both short and long term migration (in absolute numbers) occurs more frequently near cities and in coastal regions. However, by normalizing the data by population size, the study eliminates the problems of population size on the size of the migrants. Using this normalized data, the study finds that western and northern counties have a large number of migrants present relative to the size of the population. Determining where this floating population migrates helps explain regional inequalities in employment opportunities.

Aftermarket short covering in ipos and long-term stock liquidity

This study investigates the effect of the aftermarket short covering (ASC) carried out by the underwriter during the price stabilization period on stock long-term liquidity. Because the ASC increases liquidity during the stabilization period and liquidity is a persistent characteristic of stocks, the ASC can increase long-term liquidity. In fact, we show that the ASC has a positive effect on liquidity over the 6 months subsequent to the stabilization period. This positive relation holds true even after controlling for many variables found important to explain liquidity by previous authors and the instrumentalization of the ASC.

Forecasting electricity load demand: analysis of the 2001 rationing period in Brazil

This paper studies the electricity load demand behavior during the 2001 rationing period, which was implemented because of the Brazilian energetic crisis. The hourly data refers to a utility situated in the southeast of the country. We use the model proposed by Soares and Souza (2003), making use of generalized long memory to model the seasonal behavior of the load. The rationing period is shown to have imposed a structural break in the series, decreasing the load at about 20%. Even so, the forecast accuracy is decreased only marginally, and the forecasts rapidly readapt to the new situation. The forecast errors from this model also permit verifying the public response to pieces of information released regarding the crisis.

Efeitos da baixa liquidez em posições compradas em relação às posições vendidas sobre o desempenho de fundos long short em situação de crise sistêmica (2008)

Diversos estudos sobre investimentos em Ações e Fundos de Investimentos no Brasil, mais especificamente sobre Fundos Multimercados Long-Short, focam em sua neutralidade em relação ao Ibovespa bem como na performance de seus gestores e de suas respectivas estratégias, como Penna (2007) e Gomes e Cresto (2010). Com ênfase na comparação entre a liquidez da posição comprada e a da posição vendida em ações, foi verificado o comportamento de fundos long-short em situações normais e de crise, do período que vai de 2007 a 2009. Foram encontrados fortes indícios de que houve perda maior em momentos de estresse por parte de fundos que carregavam ações menos líquidas em suas carteiras na posição comprada em relação a posição vendida, apesar do número reduzido de fundos estudados e também de ter sido utilizado periodicidade mensal. Encontrou-se um retorno médio em 2008 de 11,1% para uma carteira formada por fundos com ações mais líquidas na posição comprada do que na posição vendida e 5,4% para uma carteira com posição inversa. Uma análise de risco-retorno feita com o Índice de Sharpe (IS) corrobora o estudo, pois a carteira composta por fundos com posição mais líquida na posição vendida apresentou IS de -1,5368, bem inferior ao IS de -0,3374 da carteira de posição inversa (mais líquida na posição comprada). Foi também utilizado o Modelo Índice, como em Bodie, Kane e Marcus (2005), para verificar se esses fundos, separados em carteiras divididas entre mais líquidos na posição comprada do que na posição vendida e vice-versa, tinham desempenho melhor que o mercado (IBOVESPA) de maneira sistemática (alpha=α) e a exposição dessas carteiras ao risco de mercado (Beta = β), além do Modelo de Fatores. As regressões realizadas para os modelos citados encontram coeficientes e respectivas inferências estatísticas que respaldam a hipótese acima, apesar de baixo número de observações utilizado.

Otimização de alavancagem e gestão de risco em estratégias long-short

Alavancagem em hedge funds tem preocupado investidores e estudiosos nos últimos anos. Exemplos recentes de estratégias desse tipo se mostraram vantajosos em períodos de pouca incerteza na economia, porém desastrosos em épocas de crise. No campo das finanças quantitativas, tem-se procurado encontrar o nível de alavancagem que otimize o retorno de um investimento dado o risco que se corre. Na literatura, os estudos têm se mostrado mais qualitativos do que quantitativos e pouco se tem usado de métodos computacionais para encontrar uma solução. Uma forma de avaliar se alguma estratégia de alavancagem aufere ganhos superiores do que outra é definir uma função objetivo que relacione risco e retorno para cada estratégia, encontrar as restrições do problema e resolvê-lo numericamente por meio de simulações de Monte Carlo. A presente dissertação adotou esta abordagem para tratar o investimento em uma estratégia long-short em um fundo de investimento de ações em diferentes cenários: diferentes formas de alavancagem, dinâmicas de preço das ações e níveis de correlação entre esses preços. Foram feitas simulações da dinâmica do capital investido em função das mudanças dos preços das ações ao longo do tempo. Considerou-se alguns critérios de garantia de crédito, assim como a possibilidade de compra e venda de ações durante o período de investimento e o perfil de risco do investidor. Finalmente, estudou-se a distribuição do retorno do investimento para diferentes níveis de alavancagem e foi possível quantificar qual desses níveis é mais vantajoso para a estratégia de investimento dadas as restrições de risco.

Alterations in muscular enzymes of horses competing long-distance endurance rides under tropical climate

Estudaram-se as alterações de atividade das enzimas musculares creatino quinase (CK), lactato desidrogenase (LDH) e aspartato aminotransferase (AST) em um grupo de cavalos que utilizados em provas de enduro de 70 e 100km de distância, em cinco competições. Os valores (U/l) basais (antes da largada) foram 245,13±9,84 para CK, 496,61±14,76 para LDH e 328,95±8,65 para AST. Todas as atividades das enzimas decresceram no primeiro momento das provas (~30km). Valores de pico, significativamente diferentes, foram alcançados para CK (413,59±50,75) imediatamente após 70km de distância; 24 horas após para LDH (628,61±33,30); e 48 horas após as provas para AST (389,89±16,96). A monitoração do período de recuperação revelou diferente comportamento entre as concentrações enzimáticas com CK retornando aos valores basais 24 horas pós-provas (279,61 ± 23,05). LDH e AST retornaram aos valores basais, 72 horas pós-provas (505,25±33,78 e 359,35±24,90, respectivamente). Os dados obtidos revelaram diferentes alterações na concentração de enzimas musculares de cavalos de enduro, diretamente relacionadas com a duração do esforço.

Long-term stability studies on protection against Newcastle disease by commercial live vaccine used in Brazil

The thermostability (TS) and efficacy offered by live vaccines against Newcastle disease strains B 1, La Sota, VG-GA and Ulster, produced or imported by four Brazilian laboratories, were evaluated during their validity period. Kinetic profiles were obtained from samples conserved in refrigerators during 0, 4, 8, 12, 16, 20 and 24 months after their manufacturing. The statistical analysis of the vaccine titre effect obtained by the fresh air (FA) method showed that the vaccine profiles were parallel and coincident, presenting a significant descending trend. The vaccine titres and efficiency proofs at the end of the validity period were above the level of legislation requirements and showed an average loss in titre of 0.40 and 0.66 log(10), within the first and second validity years, respectively. The titre obtained by TS, within the month after manufacturing, had no significant difference from the titre obtained by FA within 24 months after manufacturing, being their pairs of observations positively correlated (r = 0,49, p = 0.0003), showing that the TS method, which anticipates the vaccines' performance at the end of the validity period, can substitute the FA method 24 months after manufacturing. (C) 2009 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

Gender and Health Status Response to Long-Term Oxygen Therapy in COPD Patients

Introduction: The association of gender with health status (HS) response to long-term oxygen therapy (LTOT) in very severe COPD is unclear. The aims of this study were: (1) to compare dyspnea perception and HS between male and female with very severe COPD at baseline and (2) to provide a prospective assessment of HS response to LTOT, according to gender.Patients and methods: Hypoxemic COPD (n =97, age: 65.5 +/- 9.6 years, 53% males) were enrolled in a prospective longitudinal study over 12 months or until death. St. George's Respiratory Questionnaire (SGRQ) and baseline dyspnea index (BDI) were assessed.Results: At baseline, HS impairment and dyspnea sensation were similar between genders. After 12 months of LTOT, women presented improvement in symptom (64.1 +/- 120.6 versus 40.6 +/- 122.9; P < 0.0001) and total SGRQ scores. Men also showed improvement in symptoms after 12 months (62.7 +/- 23.3 versus 49.6 +/- 22.8; P < 0.0005); however, they presented deterioration of activity, impact and total scores during the study period, with markedly decline of activity domain (68.5 +/- 20.0 versus 75.9 +/- 16.9; P = 0.008). BDI did not show significant difference by gender over the study period.Conclusions: Our results show that the HS course in very severe COPD patients differs according to gender, as females show greater response longitudinally to LTOT. (C) 2010 SEPAR. Published by Elsevier Espana, S.L. All rights reserved.

Comparison between RT-PCR and the mouse inoculation test for detection of rabies virus in samples kept for long periods under different conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Gluconeogenesis and P-enolpyruvate carboxykinase in liver and kidney of long-term fasted quails

The activity of cytoplasmic and mitochondrial phosphoenolpyruvate carboxykinase (PEPCK) in kidney and liver, and in vivo gluconeogenic activity, were determined during different phases of prolonged fasting in quails. The fasting-induced changes in the activity of kidney cytoplasmic PEPCK were positively correlated with the changes in gluconeogenesis. Both activities increased at the initial phase (I) of fasting to levels 65% to 100% higher than fed values, and decreased during the protein-sparing period (phase II), although remaining higher than in fed birds. At the catabolic final phase (III) both kidney cytoplasmic PEPCK activity and gluconeogenesis increased markedly, attaining levels 115% to 150% higher than fed values. The activity of liver cytoplasmic PEPCK, present in appreciable amounts in quails, did not change during phases I and II of fasting, but increased to levels 60% higher than fed values at the final phase (III). Plasma glucose levels at phase III did not differ significantly from those at phases I and II. In both kidney and liver the activity of the mitochondrial PEPCK was not significantly affected by fasting. The data suggest that the kidney cytoplasmic PEPCK is the main enzyme responsible for gluconeogenesis adjustments during food deprivation in quails, and that this function is complemented at the final phase by enzyme present in liver cytosol.

Propolis: Effect of different concentrations, extracts and intake period on seric biochemical variables

Propolis is a resinous substance produced by honeybees that possesses many biological activities, such as antitumor, antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory, among others. The purpose of the present study was to investigate the biochemical profile of propolis-treated rats to observe whether propolis might lead to side effects after administration. Three different treatments were analyzed: (1) rats were treated with different concentrations of propolis (1, 3 and 6 mg/kg/day) during 30 days; (2) rats were treated with I mg/kg/day of ethanolic or water extracts of propolis (EEP, WEP) during 30 days; (3) rats were treated with I mg/kg/day of ethanolic extract of propolis during 90 and 150 days. Our results demonstrated no alterations in the seric levels of cholesterol, HDL-cholesterol, total lipids, triglycerides and in the specific activity of aminotransferases (AST) and lactic dehydrogenase (LDH) of propolis-treated groups when compared to controls. on the basis of our findings, since propolis does not induce any significant change in seric parameters, it is claimed that long-term administration of propolis might not have any cardiac injury. (c) 2005 Elsevier B.V.. All rights reserved.

Serum electrolyte and total protein alterations in Pantaneiro horse during long distance exercise

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Manipulation of Rest Period Length Induces Different Causes of Fatigue in Vertical Jumping

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Long-term physical training increases liver IGF-I in diabetic rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Long-term inhibition of 5-alpha reductase and aromatase changes the cellular and extracellular compartments in gerbil ventral prostate at different postnatal ages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)