1000 resultados para Comparative embryology
Resumo:
The main objective of the paper is to assess the impact of fiscal variables on private investment comparing some Latin-American economies to other advanced ones. For such purposes, the authors carry out an econometric analysis for the period 1990-2008. They make use of two dynamic panel models in which they group countries with similar characteristics and development levels. In one of them, they include Mexico, Brazil, Chile, Colombia and Uruguay; whereas in the second one the countries accounted for are the U.S., Canada, Spain, Korea, Ireland and Japan. They specify in both models an investment function using as arguments a wide range of variables, including those related with fiscal policy. From their results the authors infer that governments can, with higher spending, boost up the economy even when they finance spending with higher taxes. In Latin America, where income concentration is enormous, a proposal to boost up the economy through higher government expenditure financed with a progressive income tax, is even more justified.
Resumo:
The aim of this paper is to analyze the relation between economic growth and labor market dynamics in Brazil between 1981 and 2009, making a comparison with the United States. Among the findings, one can mention that economic growth in Brazil has been related to a massive incorporation of labor force in labor intensive activities, whereas, in the United States, to a substantial improvement of labor productivity in high-technology activities. Despite the favorable economic context in the 2000s, huge inequalities between these countries have widened since the structure of the Brazilian labor market remained with few or no changes.
Resumo:
The record of successful developmental states in East Asia and the partial successes of developmental states in Latin America suggest several common preconditions for effective state intervention including a Weberian bureaucracy, monitoring of implementation, reciprocity (subsidies in exchange for performance), and collaborative relations between government and business. Although Brazil failed to develop the high technology manufacturing industry and exports that have fueled sustained growth in East Asia, its developmental state had a number of important, and often neglected, successes, especially in steel, automobiles, mining, ethanol, and aircraft manufacturing. Where Brazil's developmental state was less successful was in promoting sectors like information technology and nuclear energy, as well as overall social and regional equality. In addition, some isolated initiatives by state governments were also effective in promoting particular local segments of industry and agriculture. Comparisons with East Asia, highlight the central role of state enterprises in Brazil that in effect internalized monitoring and reciprocity and bypassed collaboration between business and government (that was overall rarer in Brazil).
Resumo:
We study the phonon dispersion, cohesive and thermal properties of raxe gas solids Ne, Ar, Kr, and Xe, using a variety of potentials obtained from different approaches; such as, fitting to crystal properties, purely ab initio calculations for molecules and dimers or ab initio calculations for solid crystalline phase, a combination of ab initio calculations and fitting to either gas phase data or sohd state properties. We explore whether potentials derived with a certain approaxih have any obvious benefit over the others in reproducing the solid state properties. In particular, we study phonon dispersion, isothermal ajid adiabatic bulk moduli, thermal expansion, and elastic (shear) constants as a function of temperatiue. Anharmonic effects on thermal expansion, specific heat, and bulk moduli have been studied using A^ perturbation theory in the high temperature limit using the neaxest-neighbor central force (nncf) model as developed by Shukla and MacDonald [4]. In our study, we find that potentials based on fitting to the crystal properties have some advantage, particularly for Kr and Xe, in terms of reproducing the thermodynamic properties over an extended range of temperatiures, but agreement with the phonon frequencies with the measured values is not guaranteed. For the lighter element Ne, the LJ potential which is based on fitting to the gas phase data produces best results for the thermodynamic properties; however, the Eggenberger potential for Ne, where the potential is based on combining ab initio quantum chemical calculations and molecular dynamics simulations, produces results that have better agreement with the measured dispersion, and elastic (shear) values. For At, the Morse-type potential, which is based on M0ller-Plesset perturbation theory to fourth order (MP4) ab initio calculations, yields the best results for the thermodynamic properties, elastic (shear) constants, and the phonon dispersion curves.
Resumo:
In this study, methods of media literacy instruction including analytic activities, production activities, and a combination of analytic and production activities were compared to determine their influence on grade 8 students' knowledge, attitudes, and behaviours towards commercials. The findings showed that media literacy instruction does improve media literacy skills. Specifically, activities that included an analytic component or an analytic and production component were significantly better than activities that included a production component. Participants that completed analytic or analytic and production activities were able to discern media-related terms, target audience, selling techniques, social values, and stereotypes in commercials better than participants that completed only production activities. The research findings also showed obstacles when teaching media literacy. When engaged in analytic activities, the difficulties included locating suitable resources, addressing the competition from commercials, encouraging written reflection, recognizing social values, and discussing racial stereotypes. When engaged in production activities, the difficulties were positioning recording stations, managing group work, organizing ideas, filming the footage, computer issues, and scheduling time. Strategies to overcome these obstacles are described.
Resumo:
Four staircase lakes occupying a single watershed located in the Algoma District, north of Lake Superior were chosen for this study. I examined the subfossil diatom assemblage in the top twenty centimeters of the surface sediments in each of these four lakes in an attempt to reconstruct their respective past pH history. From these analyses it was possible to test the hypothesis that the rate of change of diatom inferred pH was not significantly different in lakes located one below the other in a single "staircase" within a single watershed system. My results indicated that the four Z lakes had been acid for at least the last century. The water color of the three upper Z lakes (Z1, Z2 and Z3) was brown (>30 Pt Co units). The bottom lake (Z4) was the only clear water lake in the system «5 Pt Co units). This bottom staircase lake had no muskeg development around its shoreline. The alkaliphilous diatoms in the Z watershed system were important in determining the diatom inferred pH of the four Z lakes. The centric diatoms were extremely rare in the clearwater bottom lake (Z4). The ecology of the Eupodiscales is perhaps important in the interpretation of sediment in the more acid environment. Lake Z4 was the only one that had a progressive as well as a significant decrease in its downcore diatom inferred pH since the early 1960's. This lead me to speculate that the humic substances present in the upper three brown water lakes (Z1, Z2 and Z3) were perhaps Important in buffering them against a further decrease in water pH even though they were located within an area which was sensitive to acid precipitation.