Probing the origin of the dark material on Iapetus

Among the icy satellites of Saturn, Iapetus shows a striking dichotomy between its leading and trailing hemispheres, the former being significantly darker than the latter. Thanks to the VIMS imaging spectrometer on-board Cassini, it is now possible to investigate the spectral features of the satellites in Saturn system within a wider spectral range and with an enhanced accuracy than with previously available data. In this work, we present an application of the G-mode method to the high resolution, visible and near infrared data of Phoebe, Iapetus and Hyperion collected by Cassini/VIMS, to search for compositional correlations. We also present the results of a dynamical study on the efficiency of Iapetus in capturing dust grains travelling inward in Saturn system to evaluate the viability of Poynting-Robertson drag as the physical mechanism transferring the dark material to the satellite. The results of spectroscopic classification are used jointly with the ones of the dynamical study to describe a plausible physical scenario for the origin of Iapetus' dichotomy. Our work shows that mass transfer from the outer Saturnian system is an efficient mechanism, particularly for the range of sizes hypothesised for the particles composing the newly discovered outer ring around Saturn. Both spectral and dynamical data indicate Phoebe as the main source of the dark material. However, we suggest a multi-source scenario where now extinct prograde satellites and the disruptive impacts that generated the putative collisional families played a significant role in supplying the original amount of dark material.Comment: 20 pages, 4 tables, 11 figures, major revision (manuscript extended and completed, figures added and corrected, new results added), minor revision and finalization of author list, moderate revision (update of the manuscript following reviewer's feedback and discovery of the new Saturnian outer ring

Population dynamics of common thrips in marigold crop

Damages produced by the pest insects can be very big, thus care must be taken about some aspects concerning the incidence in samples, dynamics and evolution of one of the most important insect pests of the flowers, such as Thysanoptera. Due to the relatively high incidence of Thrips tabaci in the samples collected from the experimental field of marigold, the species presented a real economic importance. To obtain a high production and superior quality it was necessary to choose the best moment for treatments by applying in function of population dynamics of those pests. In case of population dynamics of adults and larva of Thrips tabaci from the crop of Calendula officinalis L., the maximal values in all local populations taken in study were in increase in the second decade of June, and reached the maximum level in the third decade of June. It was followed by an obvious decrease in July - their number started to decrease to the end of the collecting period, until the second decade of August, thanks to the end of vegetation period of the flowers. In function of population dynamics, the best time for applying treatments in the crop flowers was during the period 15.06.2011- 26.06.2011

Instituição de Ensino Superior sob Avaliação da Comunidade Empresarial

Em se tratando de marketing mesmo o maior esforço implementado por uma instituição pode ter nenhum valor se a ação implementada não for percebida pelo público-alvo. Neste sentido, este estudo visa investigar qual a percepção da comunidade empresarial de Rondonópolis em relação às ações de divulgação e de administração de imagem da FAIR/UNIR, instituição de ensino superior do sul do estado de Mato Grosso

Migrações e Desenvolvimento Regional: delineando a conexão entre os fenômenos

Migrations have always been present in world history and today, with religious and political conflicts, are becoming more and more accentuated. In this context, and realizing that migrations can influence significant changes in the countries, this study aimed to gather concepts and create categories that are important to clarify the relationship between migration and development, through a bibliographical research. The research method was did characterized like a bibliographic survey, in which the data collection was of the secondary type and, consequently, the analysis was the content analysis. After analyzing the documents selected, four categories were did created that relate to the connection between migration and development: economic growth, remittances, demographic trends and exclusionary benefits. Finally, it can be concluded that migrations have positive benefits and help in the development process of the countries receiving and emitting migrants. Finally, after analyzing and achieving the objective proposed in this study, it  suggest that future research be developed that addresses the issue of migration and development from the perspective of the categories created, since there are few practical studies relating these two themes.Las migraciones siempre han estado presentes en la historia mundial. Los procesos migratorios han influido en la evolución de diversos territorios y están relacionados con su dinámica de desarrollo. Hoy, con los conflictos territoriales, religiosos y políticos, las migraciones cobran una fuerte dinámica. Con eso y comprendiendo que las migraciones pueden influir en cambios significativos en las economías de los países, este estudio tuvo como objetivo recopilar conceptos y crear categorías que son de importancia para aclarar la relación entre migración y desarrollo. El método de investigación se caracterizó como un levantamiento bibliográfico, en el que la recolección de datos fue de tipo secundario, en las principales plataformas académicas de investigación. Luego del análisis de los documentos seleccionados, se crearon cinco categorías en torno a la conexión entre migraciones y desarrollo, a saber: crecimiento económico, remesas, tendencias demográficas, beneficios excluyentes y diversidad cultural. Se puede concluir que las migraciones tienen beneficios positivos y ayudan en el proceso de desarrollo de los países receptores y emisores de migrantes. Se sugiere la elaboración de futuras investigaciones que aborden el tema de la migración y el desarrollo desde la perspectiva de las categorías creadas, ya que existen pocos estudios prácticos que relacionen estos dos temas.As migrações sempre se fizeram presente na história mundial. Os processos migratórios influenciaram a evolução de vários territórios e relacionam-se com a dinâmica de desenvolvimento destes. Hoje, com conflitos territoriais, religiosos e políticos, as migrações ganham forte dinâmica. Com isso e percebendo que as migrações podem influenciar mudanças significativas nas economias dos países, este estudo teve como objetivo reunir conceitos e criar categorias que sejam de importância para esclarecer a relação entre a migração e o desenvolvimento. O método de pesquisa caracterizou-se como um levantamento bibliográfico, no qual a coleta de dados foi do tipo secundária, nas principais plataformas de pesquisas acadêmicas. Após a análise nos documentos selecionados, foram criadas cinco categorias que dizem respeito a conexão entre as migrações e o desenvolvimento, são elas: crescimento econômico, remessas, tendências demográficas, benefícios excludentes e diversidade cultural. Pode-se concluir que as migrações possuem benefícios positivos e auxiliam no processo de desenvolvimento dos países receptores e emissores de migrantes. Sugere-se a elaboração de futuras pesquisas que abordem a questão da migração e do desenvolvimento a partir da ótica das categorias criadas, visto que há poucos estudos práticos relacionando essas duas temáticas

Evidências eletroquímicas da eficiência de proteção do álcool propargílico sobre o aço-carbono em soluções etanólicas, por medidas de condutividade elétrica

It is shown that electrical conductivity measurement is a good method to characterize corrosion processes that occur on low-carbon steel in ethanolic solutions. Different aggressive coonditions were tested by changing the water content in distilled ethanol and by adding acid. Propargyl a alcohol inhibits the corrosion reaction. The specific conductivity of the solution decreases in the presence of propargyl alcohol for varying levels of aggressiveness. In dilute acetic acid ethanolic solutions, the proyection efficiency was better in 1.0mM propargyl alcohol than in the other concentrations.Neste trabalho é apresentado que a medida da condutividade elétrica da solução é um bom método para caracterizar os processos de corrosão que ocorrem sobre o aço-carbono em meio etanólico. Diferentes condições agressivas foram testadas modificando-se o conteúdo de água no etanol destilado e, por adição de ácido acético. O álcool propargílico inibe a reação de corrosão. A condutividade específica da solução diminui na presença de álcool propargílico mesmo em diferentes níveis de agressividade. Em soluções etanólicas diluídas de ácido acético, a eficiência de proteção foi melhor em uma solução 1,0 mM de álcool propargílico, do que nas outras concentrações

The Controversial Clinicobiological Role of Breast Cancer Stem Cells

Breast cancer remains a leading cause of morbidity and mortality in women mainly because of the propensity of primary breast tumors to metastasize. Growing experimental evidence suggests that cancer stem cells (CSCs) may contribute to tumor progression and metastasis spread. However, despite the tremendous clinical potential of such cells and their possible therapeutic management, the real nature of CSCs remains to be elucidated. Starting from what is currently known about normal mammary stem/progenitor cells, to better define the cell that originates a tumor or is responsible for metastatic spread, this review will discuss experimental evidence of breast cancer stem cells and speculate about the clinical importance and implications of their evaluation