Important GABAergic mechanism within the NTS and the control of sympathetic baroreflex in SHR

Inhibitory neurotransmission has an important role in the processing of sensory afferent signals in the nucleus of the solitary tract (NTS), particularly in spontaneously hypertensive rats (SHR). In the present study, we tested the hypothesis that gamma-aminobutyric acid (GABA) mediated neurotransmission within the NTS produces an inhibition of the baroreflex response of splanchnic sympathetic nerve discharge (sSND). In urethane-anesthetized, artificially ventilated and vagotomized male SHR and Wistar Kyoto (WKY) rats we compared baroreflex-response curves evoked after bilateral injections into the NTS of the GABA-A antagonist bicuculline (25 pmol/50 nl) or the GABA-B antagonist CGP 35348 (5 nmol/50 nl). Baseline MAP in SHR was higher than the WKY rats (SHR: 153+/-5, vs. WKY: 112+/-6 mm Hg, p<0.05). Bilateral injection of bicuculline or CGP 35348 into the NTS induced a transient (5 min) reduction in MAP (Delta = -26+/-4 and -41+/-6 mm Hg, respectively vs. saline Delta = +4+/-3 mm Hg, p<0.05) and sSND (Delta = -21+/-13 and -78+/-7%, respectively vs. saline: Delta = +6+/-4% p<0.05). Analysis of the baroreceptor curve revealed a decrease in the lower plateau (43+/-11 and 15+/-5%, respectively vs. saline: 78+/-6%, p<0.05) and an increase in the sympathetic gain of baroreflex (6.3+/-0.3, 7.2+/-0.8% respectively vs. saline: 4.2+/-0.4%, p<0.05). Bicuculline or CGP35348 into the NTS in WKY rats did not change MAP, sSND and sympathetic baroreflex gain. These data indicate that GABAergic mechanisms within the NTS act tonically reducing sympathetic baroreflex gain in SHR. Crown Copyright (C) 2010 Published by Elsevier By. All rights reserved.

Contribution of excitatory amino acid receptors of the retrotrapezoid nucleus to the sympathetic chemoreflex in rats

In the present study, we evaluated the role of glutamatergic mechanisms in the retrotrapezoid nucleus (RTN) in changes of splanchnic sympathetic nerve discharge (sSND) and phrenic nerve discharge (PND) elicited by central and peripheral chemoreceptor activation. Mean arterial pressure (MAP), sSND and PND were recorded in urethane-anaesthetized, vagotomized, sino-aortic denervated and artificially ventilated male Wistar rats. Hypercapnia (10% CO(2)) increased MAP by 32 +/- 4 mmHg, sSND by 104 +/- 4% and PND amplitude by 101 +/- 5%. Responses to hypercapnia were reduced after bilateral injection of the NMDA receptor antagonist D,L-2-amino-5-phosphonovalerate (AP-5; 100mm in 50 nl) in the RTN (MAP increased by 16 +/- 3 mmHg, sSNDby 82 +/- 3% and PND amplitudeby 63 +/- 7%). Bilateral injection of the non-NMDA receptor antagonist 6,7-dinitro-quinoxaline-2,3-dione(DNQX; 100 mm in 50 nl) and the metabotropic receptor antagonist (+/-)-alpha-methyl-4-carboxyphenylglycine (MCPG; 100mm in 50 nl) in the RTN did not affect sympathoexcitatory responses induced by hypercapnia. Injection of DNQX reduced hypercapnia-induced phrenic activation, whereas MCPG did not. In animals with intact carotid chemoreceptors, bilateral injections of AP-5 and DNQX in the RTN reduced increases in MAP, sSND and PND amplitude produced by intravenous injection of NaCN (50 mu g kg(-1)). Injection of MCPG in the RTN did not change responses produced by NaCN. These data indicate that RTN ionotropic glutamatergic receptors are involved in the sympathetic and respiratory responses produced by central and peripheral chemoreceptor activation.

p38 alpha MAP Kinase Controls IL-17 Synthesis in Vogt-Koyanagi-Harada Syndrome and Experimental Autoimmune Uveitis

PURPOSE. Interleukin (IL)-17, which is responsible for the initial influx of leukocytes into the target tissue, was recently described as the main cytokine involved in autoimmune diseases. Vogt-Koyanagi-Harada (VKH) syndrome is a significant cause of noninfectious blindness in the world. Herein the authors aimed at unraveling the involvement of IL-17 in VKH and in experimental autoimmune uveitis, focusing on the signaling pathways involved in IL-17 synthesis. METHODS. Mice were immunized with 161-180 peptide and pertussis toxin. Draining lymph node cells, harvested 21 days after immunization, were cultured in the presence or absence of p38 alpha mitogen-activated protein kinase (MAPK) inhibitor (SB203580) and assayed for cytokine production and quantification of CD4(+)IL-17(+) cells. Mice received intraocular injections of SB203580, and disease severity was evaluated by histologic examination of the enucleated eyes at day 21. CD4(+) lymphocytes from MSK-1/2-deficient mice, human CD4(+) cells silenced with MSK1 siRNA, or peripheral blood mononuclear cells (PBMCs) from VKH patients were cultured in the presence or absence of p38 alpha MAPK inhibitor and then assayed for IL-17, IFN-gamma, and IL-4 production. RESULTS. The inhibition of p38 alpha MAPK fully blocked the synthesis of IL-17 by PBMCs from VKH patients and lymphocytes from EAU mice. The absence of the msk1/2 gene resulted in failure to produce IL-17 by murine and human lymphocytes. Interestingly, intraocular injections of SB203580 in EAU mice did not suppress development of the disease. CONCLUSIONS. These data show that p38 alpha MAPK-MSK1/2 is involved in the control of IL-17 synthesis by CD4(+) T cells and that inhibition of p38 alpha MAPK in vitro suppresses IL-17 synthesis but that inhibition of this kinase in vivo did not protect from EAU. (Invest Ophthalmol Vis Sci. 2010;51:3567-3574) DOI: 10.1167/iovs.09-4393

Essays on firm dynamics in the Swedish wholesale trade sector

This thesis consists of a summary and five self-contained papers addressing dynamics of firms in the Swedish wholesale trade sector. Paper [1] focuses upon determinants of new firm formation in the Swedish wholesale trade sector, using two definitions of firms’ relevant markets, markets defined as administrative areas, and markets based on a cost minimizing behavior of retailers. The paper shows that new entering firms tend to avoid regions with already high concentration of other firms in the same branch of wholesaling, while right-of-the-center local government and quality of the infrastructure have positive impacts upon entry of new firms. The signs of the estimated coefficients remain the same regardless which definition of relevant market is used, while the size of the coefficients is generally higher once relevant markets delineated on the cost-minimizing assumption of retailers are used. Paper [2] analyses determinant of firm relocation, distinguishing between the role of the factors in in-migration municipalities and out-migration municipalities. The results of the analysis indicate that firm-specific factors, such as profits, age and size of the firm are negatively related to the firm’s decision to relocate. Furthermore, firms seems to be avoiding municipalities with already high concentration of firms operating in the same industrial branch of wholesaling and also to be more reluctant to leave municipalities governed by right-of-the- center parties. Lastly, firms seem to avoid moving to municipalities characterized with high population density. Paper [3] addresses determinants of firm growth, adopting OLS and a quantile regression technique. The results of this paper indicate that very little of the firm growth can be explained by the firm-, industry- and region-specific factors, controlled for in the estimated models. Instead, the firm growth seems to be driven by internal characteristics of firms, factors difficult to capture in conventional statistics. This result supports Penrose’s (1959) suggestion that internal resources such as firm culture, brand loyalty, entrepreneurial skills, and so on, are important determinants of firm growth rates. Paper [4] formulates a forecasting model for firm entry into local markets and tests this model using data from the Swedish wholesale industry. The empirical analysis is based on directly estimating the profit function of wholesale firms and identification of low- and high-return local markets. The results indicate that 19 of 30 estimated models have more net entry in high-return municipalities, but the estimated parameters is only statistically significant at conventional level in one of our estimated models, and then with unexpected negative sign. Paper [5] studies effects of firm relocation on firm profits of relocating firms, employing a difference-in-difference propensity score matching. Using propensity score matching, the pre-relocalization differences between relocating and non-relocating firms are balanced, while the difference-in-difference estimator controls for all time-invariant unobserved heterogeneity among firms. The results suggest that firms that relocate increase their profits significantly, in comparison to what the profits would be had the firms not relocated. This effect is estimated to vary between 3 to 11 percentage points, depending on the length of the analyzed period. 

Dwelling in possibility: aestheticizing identity in African American women's fiction

African American women writers define aesthetics through their negotiation of identity in the politicized loci of space, place and voice. In the balkanization of such issues of voice and space, we can see the ways that the emergent selfis embodied and aestheticized in literature. To do so creates a more tactile and "artfull" representation of the self rather than a representation of identity as a mere abstract concept. To use written language to express the self is to carry processes of selfdefinition for black women into the realm of creative production. For women, especially black women, who are a politically and socially compromised element of society, the written word is a way of expressing the politically and the socially critical voice that is suppressed in other forums of expression. Using theories on "writing in difference" as a skeleton key, this project seeks to outline some of the ways that black women writers use aesthetic elements in their art to express the potential for self-examination, discovery, and emancipation.

Consumption smoothing in Latin America: an empirical assessment of present value models

The study aims to assess the empirical adherence of the permanent income theory and the consumption smoothing view in Latin America. Two present value models are considered, one describing household behavior and the other open economy macroeconomics. Following the methodology developed in Campbell and Schiller (1987), Bivariate Vector Autoregressions are estimated for the saving ratio and the real growth rate of income concerning the household behavior model and for the current account and the change in national cash ‡ow regarding the open economy model. The countries in the sample are considered separately in the estimation process (individual system estimation) as well as jointly (joint system estimation). Ordinary Least Squares (OLS) and Seemingly Unrelated Regressions (SURE) estimates of the coe¢cients are generated. Wald Tests are then conducted to verify if the VAR coe¢cient estimates are in conformity with those predicted by the theory. While the empirical results are sensitive to the estimation method and discount factors used, there is only weak evidence in favor of the permanent income theory and consumption smoothing view in the group of countries analyzed.

Restrição ao crédito educacional e investimentos em capital humano no Brasil: evidências através dos retornos à educação

Este artigo procura identificar o papel de restrição ao crédito sobre a decisão de investimento em capital humano no Brasil. Para tanto é usada a hipótese de que custos diretos e de oportunidade de estudar afetam pessoas restritas e não restritas por crédito de forma diferente. Enquanto o custo de oportunidade afeta a todos de forma similar, o custo direto afeta mais fortemente aqueles restritos ao crédito. A partir da estimação de taxas de retorno à educação com o uso de diferentes variáveis instrumentais é possível lançar luz sobre o papel da restrição ao crédito sobre escolaridade. Ao comparar as taxas de retorno utilizando como instrumento a oferta relativa de professores (Proxy dos custos diretos) e salário mediano dos jovens (variável de custo de oportunidade), encontramos uma acentuada diferença no ponto estimado, indicando a existência de efeito da restrição sobre escolaridade. Entretanto, o mau desempenho do segundo instrumento no segundo estágio torna problemática a comparação.

State–society cycles and political pacts in a national–dependent society: Brazil

The history of independent Brazil may be divided into three major state–society cycles, and, after 1930, five political pacts or class coalitions can be identified. These pacts were nationalist; only in the 1990s did the Brazilian elites surrender to the neoliberal hegemony. Yet, since the mid-2000s they have been rediscovering the idea of the nation. The main claim of the essay is that Brazilian elites and Brazilian society are “national–dependent”, that is, they are ambivalent and contradictory, requiring an oxymoron to define them. They are dependent because they often see themselves as “European” and the mass of the people as inferior. But Brazil is big enough, and there are enough common interests around its domestic market, to make the Brazilian nation less ambivalent. Today Brazil is seeking a synthesis between the last two political cycles – between social justice and economic development in the framework of democracy.

The impact of structured teaching methods on the quality of education

This paper estimates the impact of the use of structured methods on the quality of education of the students in primary public school in Brazil. Structure methods encompass a range of pedagogical and managerial instruments applied to the education system. In recent years, several municipalities in the State of São Paulo have contracted out private educational providers to implement these structured methods in their schooling system. Their pedagogical proposal involves structuring curriculum contents, elaboration and use of teachers and students textbooks, and training and supervision of the teachers and instructors. Using a difference in differences estimation strategy, we find that the fourth and eighth grader students in the municipalities with structured methods performed better in Portuguese and Math than students in municipalities not exposed to the methods. We find no differences in approval rates. However, a robustness check is not able to discard the possibility that unobserved municipal characteristics may affect the results.

Análise de resultados intermediários das políticas de bônus em escolas públicas estaduais brasileiras

Programas de bônus para servidores de escolas públicas, visando estimular a melhoria da aprendizagem dos alunos, foram adotados por diferentes estados brasileiros entre 2008 e 2011. A presente pesquisa teve como objetivo avaliar o impacto desses programas em três dimensões: 1. práticas pedagógicas dos professores; 2. absenteísmo e rotatividade dos professores ou visão do diretor ou professor sobre a assiduidade e rotatividade do professor; 3. interlocução com familiares para garantir a frequência dos alunos. A coleta de dados foi feita a partir dos questionários da Prova Brasil, respondidos por diretores, professores e alunos das escolas do grupo de tratamento e do grupo controle. Foram considerados na análise: a variação no ano de implementação dos programas (dose), seus diferentes desenhos (tipo) e a série/ano dos alunos (série) que responderam a Prova Brasil. A abordagem metodológica adotada para a análise proposta foi a de pareamento pelo escore de propensão, seguido do cálculo de diferenças em diferenças, entre os Estados que implementaram a política e os que não adotaram. Os resultados variam de acordo com a série e dose, havendo impacto positivo para algumas categorias de análise na dimensão 1, relacionado à frequência com que professores corrigem o dever de casa. Na dimensão 2, os resultados apontam para uma redução de preocupação dos diretores com a rotatividade dos professores e aumento da percepção de que o absenteísmo dos docentes é um problema na realidade escolar pública brasileira. Quanto à dimensão 3, os dados revelam, de modo geral, ausência de impacto. Permanece a dúvida sobre a eficiência e a eficácia do estímulo financeiro para produzir mudanças no comportamento dos professores e diretores que possam promover resultados intermediários na melhoria da aprendizagem dos alunos.

Caracterização funcional de dois cDNAs de cana-de- açúcar : PKCI e SHAGGY

Flowering is controlled by several environmental and endogenous factors, usually associated with a complex network of metabolic mechanisms. The gene characterization in Arabidopsis model has provided much information about the genetic and molecular mechanisms that control flowering process. Some of these genes had been found in rice and maize. However, in sugarcane this processe is not well known. It is known that early flowering may reduce its production up to 60% at northeast conditions. Considering the impact of early flowering in sugarcane production, the aim of this work was to make the gene characterization of two cDNAs previously identified in subtractive cDNA libraries: scPKCI and scSHAGGY. The in silico analysis showed that these two cDNAs presented both their sequence and functional catalytic domains conserved. The results of transgenic plants containing the overexpression of the gene cassette scPKCI in sense orientation showed that this construction had a negative influence on the plant development as it was observed a decrease in plant height and leaf size. For the scPKCI overexpression in antisense orientation it was observed change in the number of branches from T1 transgenic plants, whereas transgenic T2 plants showed slow development during germination and initial stages of development. The other cDNA analyzed had homology to SHAGGY protein. The overexpression construct in sense orientation did not shown any effect on development. The only difference observed it was an increase in stigma structure. These results allowed us to propose a model how these two genes may be interact and affect floweringdevelopment.

Validation of the Deardorff model for estimating energy balance components for a sugarcane crop

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

Role of Locus coeruleus noradrenergic neurons in cardiorespiratory and thermal control during hypoxia

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

Accelerated ageing test to evaluate seed vigor in pumpkin and zucchini seeds

The accelerated ageing (AA) test is widely used to evaluate seed vigor in various species including vegetable crops. The objective of this work was to study procedures for conducting AA to evaluate seed vigor of pumpkin and zucchini seed lots. Five seed lots of commercially acceptable quality (germination) standards were selected from both cv. `Menina Brasileira' (zucchini) and `Barbara' Hybrid (pumpkin). The following tests were conducted: standard germination, the first count of germination, and AA with and without saline solution (periods of 48, 72 and 96 hours). For each combination of temperature and ageing period, seeds were placed in a single layer on a screen in a germination plastic box with either 40 mL deionized water or 40g NaCl/100mL of water. Both AA methods identified lots 2 and 5 of `Menina Brasileira' and lot 10 of `Barbara' hybrid as having the lowest physiological quality. The temperature 41 C promoted a more drastic reduction in germination than did 38 C. This observation was more marked after 96 hours. Based on the results obtained, it can be concluded that the combination 41 degrees C/96 hours should be used to evaluate the physiological potential of pumpkin and zucchini seeds; however, additional studies are necessary to evaluate other combinations and confirm this indication.

Barium uptake by maize plants as affected by sewage sludge in a long-term field study

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