Revealing the large nuclear dust structures in NGC 1068 with MIDI/VLTI

To understand the relation between the small "obscuring torus" and dusty structures at larger scales (5-10 pc) in NGC 1068, we use ESO's Mid-Infrared Interferometer (MIDI) with the 1.8 m Auxiliary Telescopes to achieve the necessary spatial resolution (~ 20-100 millarcsec). We use the chromatic phases in the data to improve the spatial fidelity of the analysis. We present interferometric data for NGC 1068 obtained in 2007 and 2012. We find no evidence of source variability. Many (u,v) points show non-zero chromatic phases indicating significant asymmetries. Gaussian model fitting of the correlated fluxes and chromatic phases provides a 3-component best fit with estimates of sizes, temperatures and positions of the components. A large, warm, off-center component is required at a distance approximately 90 mas to the north-west at a PA ~ -18 deg. The dust at 5-10 pc in the polar region contributes 4 times more to the mid-infrared flux at 12 um than the dust located at the center. This dust may represent the inner wall of a dusty cone. If similar regions are heated by the direct radiation from the nucleus, then they will contribute substantially to the classification of many Seyfert galaxies as Type 2. Such a region is also consistent in other Seyfert galaxies (the Circinus galaxy, NGC 3783 and NGC 424).Comment: 21 pages, 10 figures; Accepted for publication on A&

Topological mass generation to antisymmetric tensor matter field

We propose a mechanism to give mass to tensor matter field which preserve the U(1) symmetry. We introduce a complex vector field that couples with the tensor in a topological term. We also analyze the influence of the kinetic terms of the complex vector in our mechanism.Comment: 5 pages, to appear in Europhysics Letter

Decomposicao da evolucao da desigualdade de renda no Brasil em efeitos idade, periodo e coorte / Explaining income inequality in Brazil: age, period and cohort effects

A partir dos microdados da Pesquisa Nacional por Amostra de Domicílios (PNAD), este trabalho tem como objetivo contribuir para o entendimento da evolução da desigualdade de renda no Brasil, de 1981 a 2001, ao identificar, sob algumas hipóteses, os efeitos idade, período e coorte. O método de identificação utilizado, proposto por Deaton e Paxson (1994), permitiu estimar esses efeitos para indicadores de desigualdade Theil-T com base na renda familiar de todas as fontes e na renda familiar do trabalho principal para a amostra total dos chefes de família e por grupo de escolaridade. Os principais resultados encontrados mostram que: a) a desigualdade de renda aumenta para as gerações mais novas, sendo esse aumento mais acentuado para a medida de renda do trabalho principal; b) o efeito coorte não é significativo para famílias com chefes de mesma escolaridade, o que sugere que o crescimento da desigualdade de renda para as gerações mais novas possa refletir um aumento da escolaridade das gerações mais novas em relação às antigas; c) a desigualdade de rendimentos do trabalho principal cresce acentuadamente com a idade, sobretudo para os grupos de maior escolaridade, o que é compatível com implicações da teoria do capital humano; d) a desigualdade de renda de todas as fontes tende a se reduzir após uma certa idade para os grupos de menor escolaridade; e e) há um efeito período significativo de aumento da desigualdade de renda observado em 1989 e 1993, períodos de aguda aceleração inflacionária. / Using Brazilian household survey data, this paper aims to contribute for a better understanding of the income inequality evolution from 1981 to 2001. This is done by decomposing the time evolution of the income inequality among Brazilian households into age, time and cohort effects. Identification of these effects follows as an application of the method proposed by Deaton and Paxson (1994) to a series of Theil-T inequality indexes of overall family income and earnings for the whole sample of household heads, as well as for schooling groups. The main results are: a) income and, more pronouncedly, earnings, are more unevenly distributed among families belonging to the youngest generations; b) the cohort effect is not important among families whose heads have similar levels of schooling, which suggests that the rise in inequality among younger cohorts is a result of the increase in schooling levels along the last decades; c) large positive age effects are present, especially for groups with higher schooling levels; d) income inequality tends to decrease after a certain age for groups with low education; and e) peaks in income inequality were observed in 1989 and 1993, probably due to sharp increases in inflation

The role of attitudinal factors in mathematical on-line assessments: a study of undergraduate STEM students

This study explores student attitudes to the use of substantive on-line assessments that require mathematical answers. Our goal is to learn what are the important aspects in a design of more effective e-assessments that support learning of mathematical subjects in a higher education setting. To that end we analyse the effects of a variety of attitudinal factors towards such assessments amongst a cross-section of 1st year students in an English University. These students were all previously exposed to on-line assessments containing substantial mathematical work, including testing of and feedback on the algebraic structure of their answers. They were provided with detailed online feedback, and we therefore specifically examine the effect of formative feedback on the usage of educational technology. Our results suggest that students find on-line feedback more enjoyable and useful than traditional feedback. 'Attitude' and 'Enjoyment' are the two most important factors influencing their usage intention. Our results also show that, even for this digital generation, confidence in using computers and the availability of support for using information technology are important factors in making effective use of on-line assessments

Informações técnicas para o cultivo do feijoeiro-comum na Região Central-Brasileira: 2012-2014.

Socioeconomia; Exigências climáticas e épocas de semeadura; Manejo do solo; Correção e fertilização do solo; Fixação biológica de nitrogênio - FBN; Cultivares; Implantação da lavoura; Manejo de plantas daninhas; Manejo da irrigação; Manejo integrado de doenças; Manejo integrado de pragas; Colheita; Beneficiamento e armazenamento; Recomendações técnicas para a produção de sementes do feijoeiro-comum.bitstream/item/61388/1/seriedocumentos-272.pd

NGC 1068: No change in the mid-IR torus structure despite X-ray variability

Context. Recent NuSTAR observations revealed a somewhat unexpected increase in the X-ray flux of the nucleus of NGC 1068. We expect the infrared emission of the dusty torus to react on the intrinsic changes of the accretion disk. Aims. We aim to investigate the origin of the X-ray variation by investigating the response of the mid-infrared environment. Methods. We obtained single-aperture and interferometric mid-infrared measurements and directly compared the measurements observed before and immediately after the X-ray variations. The average correlated and single-aperture fluxes as well as the differential phases were directly compared to detect a possible change in the structure of the nuclear emission on scales of $\sim$ 2 pc. Results. The flux densities and differential phases of the observations before and during the X-ray variation show no significant change over a period of ten years. Possible minor variations in the infrared emission are $\lesssim$ 8 %. Conclusions. Our results suggest that the mid-infrared environment of NGC 1068 has remained unchanged for a decade. The recent transient change in the X-rays did not cause a significant variation in the infrared emission. This independent study supports previous conclusions that stated that the X-ray variation detected by NuSTAR observations is due to X-ray emission piercing through a patchy section of the dusty region.Comment: 6 pages, 5 figures, 3 tables. Accepted for publication on A&

Produção integrada do feijoeiro-comum.

O que é produção integrada (PI)? Quais são os fundamentos da PI? Quais são as técnicas que compõem a PI? Quais são os benefícios que a PI traz para o produtor/consumidor do feijão? Quais são os resultados práticos já observados no campo? Que custos a PI envolve? Como é possível obter informações sobre adesão à PI? Como é possível conseguir a certificação de PI? Como são definidas as instruções normativas sobre as certificações da PI? Como começou o Sapi no Brasil? Como começou o Sapi voltado para o cultivo do feijoeiro no Brasil? Para quais locais as Normas Técnicas Específicas para a Produção Integrada do Feijoeiro-Comum foram validadas? Quais os principais resultados obtidos quando comparados os sistemas de PI e de produção convencional (PC)?bitstream/item/123690/1/p241.pd

Public Perception on Corporate Social Responsibilities of Various Agricultural Industries in Claveria, Misamis Oriental, Philippines

Recent influx of multinational agri-companies (PMFT, Del Monte, Dole) has changed the socio-economic and agro-ecosystems dynamics of the municipality of Claveria, Misamis Oriental. Conventional cropping systems, such as vegetable and corn production, have been replaced by corporate-dictated commodities, namely, tobacco, pineapple, and banana. These firms operate with the corporate social responsibility (CSR) as the company’s commitment to contribute to sustainable economic development, working with employees, their families, the local community, and society at large to improve their quality of life. However, to have a real impact among locals, CSR must be thoroughly understood and local perception must be gauged. A series of focus group discussions involving key stakeholders and local officials and a survey involving more than 200 respondents within the study site were conducted. Survey questionnaires were translated to local dialect, pretested, and administered. Responses were collated and analyzed using central tendencies (mean, median, mode) and revalidated. Results show that the companies’ existence made a positive impression with the local government, but low to very low awareness on the issue of CSR within the general public was shown. Perceived awareness of any initiatives at improving social or environmental conditions in the community was indeed very low and most respondents claimed to have no idea at all. The community has not fully appreciated the efforts of these companies and failed to fully understand that the scope of corporate responsibility may operate beyond the companies’ normal commercial environment or traditional business operations and can thus benefit the community