976 research outputs found
The Demographic Transition and the Sexual Division of Labor
This paper presents a theory where increases in female labor force participation and reductions in the gender wage-gap are generated as part of a single process of demographic transition, characterized by reductions in mortality and fertility. The paper suggests a link between changes in mortality and transformations in the role of women in society that has not been identified before in the literature. Mortality reductions affect the incentives of individuals to invest in human capital and to have children. Particularly, gains in adult longevity reduce fertility, increase investments in market human capital, increase female labor force participation, and reduce the wage differential between men and women. Child mortality reductions, though reducing fertility, do not generate this same pattern of changes. The model reconciles the increase in female labor market participation with the timing of age-specific mortality reductions observed during the demographic transition. It generates changes in fertility, labor market attachment, and the gender wage-gap as part of a single process of social transformation, triggered by reductions in mortality.
Toward in vitro fertilization in Brachiaria spp.
Brachiaria are forage grasses widely cultivated in tropical areas. In vitro pollination was applied to accessions of Brachiaria spp. by placing pollen of non-dehiscent anthers on a solid medium near isolated ovaries. Viability and in vitro germination were tested in order to establish good conditions for pollen development. Comparing sexual to apomictic plants, apomictic pollen has more abortion after meiosis during the microspore stage and a lower viability and, of both types, only some plants have sufficient germination in a high sugar concentration. Using in vitro pollination with the sexual plant, the pollen tube penetrates into the nucellus and micropyle, but the embryo sac degenerates and collapses. In the apomictic B. decumbens, in vitro pollination leads to the transfer of the sperm nuclei into the egg cell and the central cell. The results are discussed according to normal fertilization and barriers in sexual and apomictic plants
Estudos estruturais das enzimas envolvidas com o mecanismo de produção de ácidos orgânicos da bactéria G. Diazotrophicus utilizando métodos computacionais.
Ga5DH é uma enzima que exerce um papel fundamental na regulação do fluxo das fontes de carbono e energia nas bactérias, e na produção de Ácidos Orgânicos, entre eles o 5-Ceto-D-Gluconato (5KGA) [1,2]. Devido à importância deste ácido na indústria química [3], há um grande interesse em sua estrutura. Isto nos leva a apresentar a estrutura teórica de Ga5DH de Gluconacetobacter diazotrophicus, obtida com Modelagem por Homologia. Dez modelos foram gerados no programa MODELLER [4], baseados na estrutura de Gluconate 5- dehydrogenase de Streptococcus suis (PDB 3cxr), a única proteína Ga5DH resolvida experimentalmente até então.Trabalho apresentado na V Mostra de Trabalhos de Estagiários e Bolsistas, Campinas, out. 2009
EVALUATION OF THE EFFECTS OF ILLUMINATION, TEMPERATURE AND PAINTING FINISH IN PSP TECHNIQUE
This paper reports the results of global pressure measurements on a NACA0012 profile, obtained with the Pressure Sensitive Paint technique (PSP), and compares them with conventional pressure tap measurements with the purpose of analyzing the influence of parameters as illumination efficiency and temperature variation of the air flow in the accuracy of the PSP experimental results. The experimental measurements were conducted in the Pilot Transonic Wind Tunnel (TTP) of the Instituto de Aeronáutica e Espaço (IAE) for Mach number values of 0.4, 0.6 and 0.8. The experiments showed that in a carefully prepared experiment, under appropriated operational conditions, and rigorous adjustments of the PSP components, the obtained results can be accurate. Moreover, even when the influence of temperature is significant and the illumination condition is not ideal, it was possible to estimate well the impact caused in the pressure distribution over the model surface
Determinação do tamanho e da virulência de variantes estáveis (Many Polyhedra) do vírus Anticarsia gemmatalis MNPV.
Medição de qualidade de sementes de canola com visão computacional e aprendizado de máquina.
Produtos originados dos grãos da canola, como óleo, farinha e biodiesel, são diretamente afetados pela qualidade desses grãos. O uso da tecnologia tem contribuído para a identificação dos grãos impuros ou em estágios diferentes de maturidade. A visão computacional em conjunto com o aprendizado de máquina pode gerar ferramentas capazes de avaliar a qualidade das sementes de forma não invasiva, sem destruir amostras e com baixo custo, uma vez que utiliza imagens digitais como insumo. O presente estudo propõe o uso de visão computacional e aprendizado não supervisionado de máquina para análise de sementes de canola a partir de imagens digitais, com o objetivo de contar, identificar cada semente e calcular o percentual de grãos maduros. Os resultados mostraram que o método K?Means pode ser usado para contar e identificar sementes de canola em fotografias com alta precisão. Na amostra, foram identificadas noventa e três sementes maduras, quatro verdes e três secas
Emerging biotechnologies: bioinformatics services applied to agriculture.
Abstract - Bioinformatics is an emergent biotechnological field of study marked by interdisciplinarity and complexity. It involves the application and development of computational tools to biological data in order to process, generate, and disseminate biological knowledge. Bioinformatics is characterized by an intense generation of data and information (configured as a context of big data and e-science), associated with the need for computational resources with high processing and storage capacities and highly qualified and interdisciplinary staff, often found only in academia. The objective of this paper is to describe the organizational model and collaborative innovation activities of the Bioinformatics Multi-user Laboratory (LMB, in the acronym in Portuguese). The LMB is a facility located at the Brazilian Agricultural Research Corporation (Embrapa), the main Brazilian agricultural research public institute, formed by 46 Research and Service Centers distributed throughout Brazil and by several laboratories and business offices abroad, in America, Africa, Asia and Europe. Its mission involves to contribute to the advance of the frontier of knowledge in bioinformatics by: incorporating new technologies and enabling efficient solutions to the demands related to this field; providing access to high performance computing infrastructure and developing human skills. Considering the importance of biotechnology in the context of agricultural research, Embrapa implemented the LMB in 2011, with the purpose of increasing the efficiency of the use of computational, human and technological resources of Embrapa by providing access to bioinformatics computational resources, offering research collaboration possibilities and consultation on project design and biological data analysis. A case-study was conducted based on documentary research and interviews. The main findings of this research are: the description of the organizational model of LMB, the management team and roles; theservices it provides; its access policies and procedures of customer service.Altec 2015
In vitro infectivity of Spodoptera frugiperda multiple nucleopolyhedrovirus to different insect cell lines.
<div><p>Abstract: The objective of this work was to evaluate the response of an in vitro host range to Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), a pathogenic virus to the fall armyworm (Spodoptera frugiperda, Lepidoptera: Noctuidae), for the further development of a biopesticide based on cell culture systems. The cell lines from Bombyx mori (BM-5), Lymantria dispar (IPLB-LD-625Y), Trichoplusia ni (BTI-Tn-5B1-4), Anticarsia gemmatalis (UFL-AG-286), and S. frugiperda (IPLB-SF-21AE and Sf9) were tested for their susceptibility to a highly-virulent Brazilian isolate of SfMNPV. The cytopathic effects induced by the virus, the production of viral particles, and the synthesis of viral polypeptides were examined and compared. Both S. frugiperda cell lines showed hypertrophy of cell nuclei and production of many polyhedra. The SDS-Page of radiolabed proteins showed that the cell protein synthesis was shutoff, while an intense band of about 30 kDa, recognized as polyhedrin, was synthesized. The other cell lines did not show polyhedra production, although some of them underwent morphological changes and protein synthesis shutdown in response to virus infection. The SF-21 and Sf9 cell lines are recommended for further in vitro production of SfMNPV.</p></div
Análise e caracterização do gene de osmotina em cupuaçuzeiro.
O cupuaçuzeiro, Theobroma grandiflorum (Willd. ex Spreng.) Schum., pertence à família Malvaceae e é nativo da região Amazônica. A cultura do cupuaçuzeiro é afetada pela doença vassoura-de-bruxa, causada pelo fungo Moniliophthora perniciosa, provocando uma grande redução na produção de frutos. O conhecimento molecular da interação planta-patógeno é essencial para o desenvolvimento de ferramentas para o controle da doença, como por exemplo, a identificação de genótipos resistentes. Genes expressos em resposta ao ataque de patógenos são alvos de estudos desta interação. O objetivo do presente trabalho foi caracterizar um deles, o gene de osmotina, em cupuaçuzeiro. Sequências anotadas do transcriptoma de frutos de cupuaçuzeiro foram avaliadas quanto à presença deste gene. Os genes identificados foram comparados ao de osmotina de cacau pelo programa BLAST. Além disso, a organização do gene foi analisada por Southern blot, utilizando DNA genômico de cupuaçu. Identificaram-se duas sequências tipo osmotina: uma de 381 pb e outra de 477 pb, que correspondem a aproximadamente 63% e 79%, respectivamente, da região codificadora da proteína madura de cacau (607 pb). A comparação destas duas sequências com o gene de osmotina de cacau revelou identidade de cerca de 70%. Quanto à organização genômica em cupuaçu, foi observado que o gene está presente em múltiplas cópias. Estudos posteriores são necessários para investigar o envolvimento deste gene com os fenótipos de resistência à vassoura-de-bruxa
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