THE DETERMINANTS OF MIGRATION IN BRAZIL

In the present study, the neoclassic human capital model was used as the theoretical foundation for the analyses of the determinants of migration in Brazil. The empirical studies were carried on with the application of a multiple regression macro model based on the gravitational model and on the Poisson distribution. In the empirical model, the number of migrants between Brazilian mesoregions was the response variable. Many socioeconomic and criminal aspects of the origin and the destiny of the migrants were used as explanatory variables. The distance between these regions and many geographical dummies were also used as independent variables. This paper contains seven sections. The first one introduces some concepts that are related to the determinants of migration. The next section briefly shows some aspects of the Brazilian regional diversity. After this, some quantitative data about the process of migration is presented. The subsequent section discusses the theoretical models of the analysis, which is the human capital model, and presents some similar studies done by other authors. Then, is showed the methodology and the macro model of migration that were used in the empirical analysis. Finally, the main empirical results are shown and the final discussions and conclusions are presented.

The determinants of migration in Brazil

In the present study, the neoclassic human capital model was used as the theoretical foundation for the analyses of the determinants of migration in Brazil. The empirical studies were carried on with the application of a multiple regression macro model based on the gravitational model and on the Poisson distribution. In the empirical model, the number of migrants between Brazilian mesoregions was the response variable. Many socioeconomic and criminal aspects of the origin and the destiny of the migrants were used as explanatory variables. The distance between these regions and many geographical dummies were also used as independent variables. This paper contains seven sections. The first one introduces some concepts that are related to the determinants of migration. The next section briefly shows some aspects of the Brazilian regional diversity. After this, some quantitative data about the process of migration is presented. The subsequent section discusses the theoretical models of the analysis, which is the human capital model, and presents some similar studies done by other authors. Then, is showed the methodology and the macro model of migration that were used in the empirical analysis. Finally, the main empirical results are shown and the final discussions and conclusions are presented.

Influence of implant design, length, diameter, and anatomic region on implant stability: A randomized clinical trial

Objetivos: Avaliar a influência da geometria dos implantes e região anatómica na estabilidade implantar. Métodos: Foi realizado um ensaio clínico controlado aleatorizado em 45 pacientes, onde foram colocados 79 implantes: 40 implantes MIS C1 e 39 implantes MIS Seven. O coeficiente de estabilidade do implante foi medido através da análise de frequência de ressonância (RFA) imediatamente após a colocação do implante e 8 semanas depois, com Osstell Mentor. Resultados: Foram analisados 76 implantes. O coeficiente de estabilidade do implante registado para estabilidade secundária foi significativamente maior que o verificado para a estabilidade primária (68,7±8,6 e 65,2±10,3, p=0,023). Considerando a estabilidade primária, não foi encontrada diferença estatisticamente significativa entre os comprimentos de 8,0 mm, 10,0 mm, 11,0 mm e 11,5 mm (67,9±7,6, 63,9±10, 57,2±11,1 e 66,4±11,3, p=0,312). O mesmo foi verificado para a estabilidade secundária (68,4±9,4, 67,9±9,3, 74,7±1,5 e 69,2±7,9, p=0,504). Não se observou diferença estatisticamente significativa entre os diâmetros dos implantes de 3,75 e 4,20 mm e estabilidade primária (64,3±8,7 e 66,1±11,7, p=0,445) ou estabilidade secundária (68,8±8,2 e 68,7±9,1, p=0,930). Foi encontrada diferença estatisticamente significativa para a estabilidade secundária, favorecendo o implante MIS Seven (p=0,048). A localização intraoral foi estatisticamente significativa para a estabilidade primária e secundária, sendo maior na maxila anterior em relação à maxila e mandíbula posteriores (p<0,05). Conclusões: O diâmetro e o comprimento dos implantes estudados não influenciaram sua estabilidade. O tipo do implante parece influenciar a estabilidade secundária, enquanto a região anatómica aparenta ter um efeito relevante na estabilidade primária e secundária.info:eu-repo/semantics/publishedVersio

Sulfate reduction and alterability of sulfur species in sediments of an estuary with irregular hydrological regime

The irregular hydrological regime in Patos Lagoon estuary has been suggested as having a distinctive influence on sulfur speciation in sediments. We performed an investigation for different prolonged hydrological conditions focusing on the distribution of sulfides (acid volatile sulfide (AVS), chromium reducible sulfide (CRS), and Free-S2-) in sediment cores from salt marsh and non-vegetated shallow zone. Significant differences in sulfides content and distribution between the different hydrological periods were found. The predominance of more reducing conditions was observed during the freshwater period. It reflects a higher total reducible inorganic sulfur (TRIS) content in this period, with a great accumulation of AVS in sediments (&gt; 100 mg kg-1). In the maximum salinity period, more oxidizing conditions prevailed, which significantly decreased the concentrations of metastable sulfides. The intense bioirrigation process exerts control over sulfide formation and distribution, which is as important as that exerted by the variations of the hydrological regime

Preparation of the orgamomodified cellulose acetate membranes for adsorption of the ions Cu(II), Cd(II), Mn(II) AND Ni(II)

Cellulose acetate polymeric membranes had been prepared by a procedure of two steps, combining the method of phase inversion and the technique of hydrolysis-deposition. The first step was the preparation of the membrane, and together was organomodified with tetraethylortosilicate and 3-aminopropyltrietoxysilane. Parameters that exert influence in the complexation of the metallic ion, as pH, time of complexation, metal concentration, had been studied in laboratory using tests of metal removal. The membranes had presented resistance mechanics and reactivity to cations, being able to be an alternative for the removal, daily pay-concentration or in the study of the lability of metals complexed

Validação de metodologia analítica por cromatografia líquida de alta eficiência para quantificação de bupivacaína (S75-R25) em nanoesferas de poli(lactídeo-co-glicolídeo)

Bupivacaine (S75-R25, NovaBupi®) is an amide type local anesthetic widely used. The present work consists of the development and validation of analytical methodology for evaluation of NovaBupi® content in the poly-lactide-co-glycolide nanospheres (PLGA-NS) by high performance liquid chromatography. The separation was made using the reversed-phase column LC-18, acetonitrile/phosphate buffer 85:15 v/v as mobile phase and detection at 220 nm. The results obtained show that the analytical methodology is accurate, reproducible, robust and linear over the concentration range 10-220.0 g/mL of NovaBupi®. The method was applied to determine the encapsulation efficiency and evaluate the release profile of NovaBupi®, showing good results