128 research outputs found
Produtos agropecuários: para quem exportar?
The paper discussed the main factors that explain the Brazilian agricultural exports. In order to achieve this goal, the paper applied a gravity model that includes fixed and random effects estimations, besides the Ordinary Least Squares (OLS) approach. Distance, trade partners´ GDP, and geographical localization were the significant variables. Moreover, puzzle effects are associated to exchange rate, partners´ agricultural exports profile and the partners´ agricultural share in GDP. Finally, this study highlights the potential change of the relevant variables because of specific characteristics of each commercial Brazilian partner.exports, gravity model, agricultural sector., Agribusiness, Q17, F13,
Spatial dynamics of labor markets in Brazil
There was substantial spatial variation in labor market outcomes in Brazil over the 1990s. In 2000, about one-fifth of workers lived in apparently economically stagnant municipios where real wages declined but employment increased faster than the national population growth rate. More than one-third lived in apparently dynamic municipios, experiencing both real wage growth and faster-than-average employment growth. These areas absorbed more than half of net employment growth over the period. To elucidate this spatial variation, the authors estimate spatial labor supply and demand equations describing wage and employment changes of Brazilian municipios. They use Conley's spatial GMM technique to allow for instrumental variable estimation in the presence of spatially autocorrelated errors. The main findings include: (1) a very strong influence of initial workforce educational levels on subsequent wage growth (controlling for possibly confounding variables such as remoteness and climate); (2) evidence of positive spillover effects of own-municipio growth onto neighbors'wage and employment levels; (3) an exodus from farming areas; (4) relatively elastic response of wages to an increase in labor supply; and (5) evidence of a local multiplier effect from government transfers.Labor Markets,Economic Theory&Research,Economic Growth,Municipal Financial Management,Achieving Shared Growth
Determinants of City Growth in Brazil
In this paper, we examine the determinants of Brazilian city growth between 1970 and 2000. We consider a model of a city, which combines aspects of standard urban economics and the new economic geography literatures. For the empirical analysis, we constructed a dataset of 123 Brazilian agglomerations, and estimate aspects of the demand and supply side as well as a reduced form specification that describes city sizes and their growth. Our main findings are that increases in rural population supply, improvements in inter-regional transport connectivity and education attainment of the labor force have strong impacts on city growth. We also find that local crime and violence, measured by homicide rates impinge on growth. In contrast, a higher share of private sector industrial capital in the local economy stimulates growth. Using the residuals from the growth estimation, we also find that cities who better administer local land use and zoning laws have higher growth. Finally, our policy simulations show that diverting transport investments from large cities towards secondary cities do not provide significant gains in terms of national urban performance.
Determinants of city growth in Brazil
The authors examine the determinants of Brazilian city growth between 1970 and 2000. They consider a model of a city that combines aspects of standard urban economics and the new economic geography literatures. For the empirical analysis, the authors construct a dataset of 123 Brazilian agglomerations and estimate aspects of the demand and supply side, as well as a reduced form specification that describes city sizes and their growth. Their main findings are that increases in rural population supply, improvements in interregional transport connectivity, and education attainment of the labor force have strong impacts on city growth. They also find that local crime and violence, measured by homicide rates, impinge on growth. In contrast, a higher share of private sector industrial capital in the local economy stimulates growth. Using the residuals from the growth estimation, the authors also find that cities that better administer local land use and zoning laws have higher growth. Finally, their policy simulations show that diverting transport investments from large cities toward secondary cities does not provide significant gains in terms of national urban performance.Economic Theory&Research,City Development Strategies,Municipal Financial Management,Achieving Shared Growth,Economic Growth
Caracterização eletrofisiológica da toxina TF1a purificada da peçonha do escorpião Tityus fasciolatus
Dissertação (mestrado)—Fundação Universidade de Brasília, Programa de Pós-Graduação em Biologia Animal, 2018.Os escorpiões, pertencentes ao filo Arthropoda, representam aproximadamente 1,5% das espécies presentes na classe dos aracnídeos. No Brasil, existem diversas espécies de escorpiões presentes em todas as regiões, dentre eles os que mais se destacam são os pertencentes ao gênero Tityus devido à sua grande distribuição geográfica e importância médica. Dentre eles, uma espécie que se destaca é o Tityus fasciolatus mais presente na região central do Brasil. Essa espécie de escorpião, assim como as outras, possui uma peçonha extremamente complexa formada por uma série de compostos, e dentre eles estão os peptídeos conhecidos como neurotoxinas capazes de interagir e afetar o funcionamento dos canais de sódio dependentes de voltagem, responsáveis pela iniciação e propagação dos potenciais de ação. A peçonha do escorpião Tityus fasciolatus foi coletada e submetida ao fracionamento utilizando a técnica de cromatografia líquida de alta eficiência em fase reversa (RP-HPLC). As frações obtidas foram analisadas em espectrômetro de massa (MALDI-TOF) a fim de identificar o peptídeo de interesse, que teve sua sequência determinada e sua atividade testada nos sete subtipos de canais de sódio de mamíferos e em canais de sódio de inseto e aracnídeo por meio da técnica de patch-clamp em configuração voltage clamp. O peptídeo purificado denominado Tf1a foi capaz de alterar a cinética de todos os subtipos de canais de mamífero e, ainda, agir sobre os canais de inseto e de aranha modificando também seu funcionamento. O efeito observado permite classificar a toxina Tf1a como uma β-toxina escorpiônica do tipo like. Sendo assim esse trabalho foi capaz de descrever uma nova neurotoxina purificada da peçonha de um escorpião e caracterizar a sua atividade em diversos tipos de canais iônicos, colaborando assim com o entendimento da ação destes peptídeos.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).Scorpions, belonging to the Arthropoda phylum, represent approximately 1.5% of the species present in the Arachnidae class. There are several species of scorpions present in all regions of Brazil, among them the ones that stand out most are those belonging to the genus Tityus thanks to its great geographic distribution and medical importance. Between them, one species that stands out is the Tityus fasciolatus most present in the central region of Brazil. This species of scorpion, like the others, has an extremely complex venom formed by a several compounds. Among them are the peptides also known as neurotoxins capable of interacting and affect the functioning of the voltagegated sodium channels, responsible for the initiation and propagation of the action potential. The venom of the scorpion Tityus fasciolatus was collected and submitted to fractionation using reverse phase high performance liquid chromatography (RP-HPLC) technique. The fractions obtained were analyzed by mass spectrometer (MALDI-TOF) to identify the peptide of interest, which had its sequence determined and its activity tested on the seven subtypes of mammalian sodium channels and on insect and arachnid sodium channels by the use of the patch-clamp technique in voltage clamp configuration. The purified peptide named Tf1a was able to change the kinetics of all subtypes of mammalian channels and also act on the insect and arachnid channels, modifying their normal functioning. The effects caused allows us to classify the toxin Tf1a as a β-like scorpion toxin. Thus, this work was able to describe a new neurotoxin purified from the venom of a scorpion and characterize its activity in several types of ion channels, thus collaborating with the understanding of the action of these peptides
Caracterização eletrofisiológica das toxinas moduladoras de canais de sódio (Tst1 e Tst3) purificadas da peçonha do escorpião Tityus stigmurus
Tese (doutorado) — Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, Programa de Pós-Graduação em Biologia Molecular, 2022.imadamente 1,5% das espécies de aracnídeos existentes. Dentro do
território brasileiro, são encontradas diversas espécies de escorpiões, estando
presente em todos os estados do país. Dentre as espécies de maior importância
e abundância estão os animais pertencentes ao gênero Tityus, tendo em vista o
grande número de acidentes e problemas graves causados. Uma espécie de
destaque é o Tityus stigmurus, espécie endêmica do Nordeste do Brasil. Essa
espécie se destaca por ser a maior causadora de picadas nesta região do país,
sendo responsável pelo grande número de casos acidentes graves,
desencadeando altos índices de internações e morte. A peçonha destes animais
é formada por diversos compostos diferentes, no qual os que mais se
sobressaem são peptídeos, também conhecidos como neurotoxinas. Essas
neurotoxinas são capazes de interagir e afetar o funcionamento de canais
iônicos dependentes de voltagem tais como potássio (Kv), cálcio (Cav) e sódio
(Nav), responsáveis pela propagação e iniciação de sinais nervosos. Neste
trabalho, a peçonha do escorpião Tityus stigmurus foi extraída e submetida ao
processo de fracionamento utilizando a técnica de Cromatografia Líquida de Alta
Eficiência em Fase Reversa (RP-HPLC). As frações coletadas foram analisadas
em Espectrômetro de Massa (MALDI-TOF) e as frações de interesse para este
trabalho foram separadas e sequenciadas de forma parcial pelo método de ISD.
Após o processo de purificação e identificação, as toxinas purificadas,
correspondente às toxinas Tst1 e Tst3, foram testadas em canais de sódio
dependentes de voltagem (subtipos Nav 1.1 a 1.7) utilizando a técnica de patchclamp no modo whole cell. A toxina Tst1 demonstrou uma atividade
característica da classe das β-toxinas, alterando o potencial de abertura dos
canais de sódio (Nav) e inibindo a corrente dos mesmos, tendo uma ação
superior no subtipo Nav 1.3. Já a toxina Tst3 manifestou uma atividade
característico das α-toxinas, alterando a inativação rápida dos canais de sódio,
sendo os subtipos Nav 1.3, 1.6 e 1.7 os mais comprometidos. Assim, as toxinas
Tst1 e Tst3 são as primeiras toxinas purificadas da peçonha de Tityus stigmurus
amplamente caracterizadas em diferentes isoformas de canais de sódio (Nav).Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) e Fundação de Apoio à Pesquisa do Distrito Federal (FAP/DF).Belonging to the Arthropoda phylum, scorpions represent approximately
1.5% of arachnid species. In Brazil several species of scorpions are found, being
present in all regions. Among them, the most important and abundant species
are the animals belonging to the genus Tityus, due to their great variety and
medical importance. One of the most important ones is Tityus stigmurus, an
endemic species from the Northeast region of Brazil. This species stands out for
the high number of accidents in the Northeast region of the country, being
responsible for a large number of accidents, leading to hospitalization and cases
of death. The venom of these animals is composed of several different
compounds, in which the most prominent are peptides, also known as
neurotoxins. These neurotoxins are able to interact and affect the functioning of
ion channels such as potassium (Kv), calcium (Cav), and voltage-gated sodium
channels (Nav), responsible for the propagation and initiation of nerve signals. In
this work, the venom of the scorpion Tityus stigmurus was extracted and
fractioned using Reverse Phase High-Performance Liquid Chromatography (RPHPLC) technique. The fractions collected were analyzed in a Mass Spectrometer
(MALDI-TOF) and the fractions of interest were separated and partially
sequenced using ISD method. After the purification and identification, the purified
toxins, corresponding to toxins Tst1 and Tst3, were tested in voltage-gated
sodium channels (Nav 1.1 to 1.7) using the patch-clamp technique in whole cell
mode. The toxin Tst1 demonstrated a characteristic activity of β-toxin, altering
the opening potential of sodium channels (Nav) and inhibiting current, having a
greater action on the Nav 1.3 subtype. The toxin Tst3 showed a characteristic of
α-toxins, altering the rapid inactivation of sodium channels, with subtypes Nav
1.3, 1.6, and 1.7 the most compromised ones. Tst1 and Tst3 toxins are the first
toxins purified from Tityus stigmurus venom widely characterized in different
isoforms of sodium channels (Nav)
Examining the growth patterns of Brazilian cities
The share of urban population in Brazil increased from 58 to 80 percent between 1970 and 2000 and all net population growth over the next 30 years is predicted to be in cities. This paper explores population growth and its implications for economic dynamics and income generation among 123 urban agglomerations. Incomes are higher in larger agglomerations and in the South, but there is some indication of regional convergence with higher rates of income growth in poorer areas. In particular, agglomerations in the North and Central-West are growing faster than the more established urban centers in the South. Economic dynamics point to a process of increased diversification among larger cities, and greater specialization among medium-sized agglomerations. In bigger centers there is a trend toward deconcentration toward the periphery. The paper provides a simple analysis of correlates of labor supply, as measured by population growth and economic productivity, which is proxied by changes in per capita income.
- …