"Redesenhando margens para que a água limpa comece a chegar" : imaginários sociotécnicos e o processo de reparação ambiental da bacia do rio Doce

Este estudo analisa os imaginários sociotécnicos presentes no processo de reparação ambiental da bacia do Rio Doce relacionado ao rompimento da barragem de Fundão. No dia 5 de novembro de 2015, a barragem de Fundão, de propriedade da empresa Samarco (Vale S.A. e BHP Billiton) rompe, estabelecendo um dos maiores desastres sociotécnicos do mundo. Em março de 2016, com a intenção de liderar e mediar o processo reparatório, é criada a Fundação Renova. Nesse contexto, esta pesquisa buscou compreender – com base nos futuros imaginados pelos técnicos da Renova – como a ciência e a técnica produzem e reordenam a vida social a partir da reparação. O estudo encontra-se inserido no campo de pesquisa denominado como Estudos Sociais das Ciências e Tecnologias, sendo que se tomou como ponto de partida teórico a abordagem coproducionista, como descrita por Jasanoff (2004), tendo como principal marco analítico o conceito de imaginários sociotécnicos, desenvolvido pela mesma autora e Sang Hyun Kim (2009; 2015). As análises foram realizadas com dados contidos em documentos, os quais estruturam e institucionalizam a reparação, nos dados coletados por meio de entrevistas, realizadas com um grupo de técnicos da Renova, bem como em dados que surgiram no processo de observação. Considerando as formalizações que atravessam os três principais acordos jurídicos (TTAC; TAP; e TACG), os quais contribuem para a institucionalização do processo reparatório, é possível inferir que a reparação – da forma como é disposta originalmente – coproduz e reflete um imaginário sociotécnico que traduz a ciência como agente principal para a recuperação de um mundo que foi destruído. Foi possível desenhar, a partir dos resultados, que os imaginários que produzem a reparação estão vinculados à projeção de uma situação anterior ao desastre, a qual visa balizar as ações de reparação. Tais ações, por sua vez, devem respeitar as consequências produzidas pelo evento. Contudo, a partir da agência dos técnicos envolvidos, é possível perceber que a situação anterior não deve, necessariamente, servir como ideal para a reparação. Mesmo assim, os imaginários compartilham uma confiança sobre a capacidade da ciência e da tecnologia para a produção de um futuro ideal para a bacia do Rio Doce.This study analyzes the sociotechnical imaginaries present in the environmental repair process of the Rio Doce basin, related to the rupture of the Fundão dam. On November 5, 2015, the Fundão dam, owned by the company Samarco (Vale S.A. and BHP Billiton) breaks, establishing one of the largest sociotechnical disasters in the world. In March 2016, with the intention of leading and mediating the reparatory process, the Renova Foundation is created. In this context, this research sought to understand – based on the future imagined by Renova technicians – how science and technique produce and reorder social life based on reparation. The study is inserted in the research field called Science and Technology Studies, taking the coproductionist approach as theoretical starting point, as described by Jasanoff (2004), having as main analytical concept the concept of sociotechnical imaginaries developed by the same author and Sang-Hyun Kim (2009; 2015). The analyzes were performed with data contained in documents, which structure and institutionalize the repair, in the data collected through interviews, carried out with a group of technicians from Renova, as well as data that emerged in the observation process. Considering the formalizations that go through the three main legal agreements (TTAC; TAP; and TACG), which contribute to the institutionalization of the reparatory process, it is possible to infer that the repair - as originally arranged – co-produces and reflects a sociotechnical imaginary that translates science as the main agent for the recovery of a world that has been destroyed. It was possible to draw, from the results, that the imaginary that produce the repair are linked to the projection of a situation prior to the disaster, which aims to guide the repair actions. Such actions, in turn, must respect the consequences produced by the event. However, from the agency of the technicians involved, it is possible to realize that the previous situation should not necessarily serve as an ideal for repair. Even so, the imaginary shares a confidence in the ability of science to produce an ideal future for the Doce River basin

Comparison of Two Self-organization and Hierarchical Routing Protocols for Ad Hoc Networks

International audienceIn this article, we compare two self-organization and hierarchical routing protocols for ad hoc networks. These two protocols apply the reverse approach from the classical one, since they use a reactive routing protocol inside the clusters and a proactive routing protocol between the clusters. We compare them regarding the cluster organization they provide and the routing that is then performed over it. This study gives an idea of the impact of the use of recursiveness and of the partition of the DHT on self-organization and hierarchical routing in ad hoc networks

Dipole Interactions and Electrical Polarity in Nanosystems -- the Clausius-Mossotti and Related Models

Point polarizable molecules at fixed spatial positions have solvable electrostatic properties in classical approximation, the most familiar being the Clausius-Mossotti (CM) formula. This paper generalizes the model and imagines various applications to nanosystems. The behavior is worked out for a sequence of octahedral fragments of simple cubic crystals, and the crossover to the bulk CM law is found. Some relations to fixed moment systems are discussed and exploited. The one-dimensional dipole stack is introduced as an important model system. The energy of interaction of parallel stacks is worked out, and clarifies the diverse behavior found in different crystal structures. It also suggests patterns of self-organization which polar molecules in solution might adopt. A sum rule on the stack interaction is found and tested. Stability of polarized states under thermal fluctuations is discussed, using the one-dimensional domain wall as an example. Possible structures for polar hard ellipsoids are considered. An idea is formulated for enhancing polarity of nanosystems by intentionally adding metallic coatings.Comment: 18 pages (includes 6 embedded figures and 3 tables). New references, and other small improvements. Scheduled for publication by J. Chem. Phys., Jan. 200

First spatial resolution of the stellar components of the interacting binary CH Cygni

We report the first resolved bispectrum speckle interferometry of the symbiotic binary CH Cyg. The measured component separation, $\rho=42 \pm 2$ mas, is consistent with the one derived from the known spectroscopic orbit and distance. In particular, our result implies a total mass of the binary of M_{\rm t}=M_{\rm g}+M_{\rm wd}=3.7^{+3.5}_{-1.7} \rm M_{\sun}, which is in good agreement with the value M_{\rm t}=2.7^{+1.2}_{-0.6} \rm M_{\sun} derived from the spectroscopic orbit solution for the red giant and evolutionary contraints. We also show that the radio jets and the bipolar outflow are not orthogonal to the orbital plane of the binary system.Comment: 5 pages, 4 figures, submitted to MNRA

Qualidade da madeira de sumauma Ceiba pentandra plantada em ecossistemas de varzea e terra firme e em diferentes sistemas de plantios.

Correlacao, por meio de parametros fisicos, da qualidade da madeira de arvores nativas adultas com madeiras de arvores jovens plantadas em varzea e terra firme e em diferentes sistemas de plantio em Manaus-AM (Brasil). Com base em resultados preliminares, pode-se observar que o plantio de sumauma em diferentes ecossistemas nao alterou a densidade media das arvores na altura do DAP, apesar da tendencia a um pequeno aumento da densidade nos plantios de terra firme (monocultivo e SAFs); estatisticamente nao houve diferenca entre as medias ao nivel de 5% de probabilidade pelo Teste de Tukey. Com esses resultados, e' possivel afirmar que o aumento das taxas de crescimento e o local de plantio da sumauma nao tiveram influencia sobre a densidade da madeira. Comparando a variacao media da densidade aparente no sentido medula-casca para as diversas condicoes de plantio, notou-se que a especie nativa apresentou a menor variacao e o plantio em monocultivo, a maior. Com excecao do planti em varzea (Caldeirao), todos os ambientes apresentaram um grande aumento na densidade aparente proximo a casca. Uma possivel explicacao para o aumento radial da densidade, seja o fato de que especies de crescimento rapido podem sobreviver mais tempo no dossel da floresta e produzirem madeira mais resistente quando maduras, como, por emsemplo, a transicao da sumauma de uma especie de colonizadora de rapido crescimento, produzindo madeira de densidade menor que 0,10 g/cm3, para uma especie colonizadora do dossel com densidade maior que 0,40 g/cm3

Does socioeconomic status matter? The fertility transition in a northern Italian village (marriage cohorts 1900‒1940)

Background: The paper explores the mechanisms of the European fertility transition in northern Italy by social group. Objective: Our objective is to understand when and in which sectors of a rural society the reduction of family size began. We focus on Emilia-Romagna, a region that in the 1990s had the lowest fertility level in Italy. The core purpose of this paper is the analysis of socioeconomic status (SES) fertility differentials, especially between rural sharecroppers and landless rural workers, as well as other non-agricultural groups. Methods: Our analysis focuses on the reproductive histories of marriage cohorts in the years 1900‒1940. We perform a micro-level statistical analysis of legitimate births of parity 1+. Results: In this period fertility decline has just begun, and shows a strong decline in the post-WWI marriage cohorts. Although nonagricultural groups lead the downward trend in family size, the role of socioeconomic status means that the path of sharecropper households is atypical. Conclusions: The fertility transition proceeds by means of spacing and stopping, testifying to a new attitude towards birth control, which agricultural and nonagricultural social groups adopted in different ways. Usually, the decline in fertility progresses from nonagricultural to rural classes. In the rural world the path is inverted, going from the lower to the upper groups. Contribution: The paper contributes to the debate on the links between socioeconomic status and fertility transition in Italy. It shows that the link between household economy and control of fertility is specific to SES groups, which can follow atypical paths, compared to the known reference model. The use of microdemographic data provides evidence for the hypothesis that the fertility transition can be shaped by the specific social and economic characteristics of population subgroups

Alcohol, tobacco and breast cancer – collaborative reanalysis of individual data from 53 epidemiological studies, including 58 515 women with breast cancer and 95 067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58 515 women with invasive breast cancer and 95 067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19–1.45, P<0.00001) for an intake of 35–44 g per day alcohol, and 1.46 (1.33–1.61, P<0.00001) for ⩾45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5–8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98–1.07, and for current smokers=0.99, 0.92–1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver