Joint contrast optimization and object segmentation in active polarimetric images

International audienceWe present a method for automatic target detection based on the iterative interplay between an active polarimetric imager with adaptive capabilities and a snake-based image segmentation algorithm. It successfully addresses the difficult situations where the target and the background differ only by their polarimetric properties. This method illustrates the benefits of integrating digital processing algorithms at the heart of the image acquisition process rather than using them only for postprocessing

Asylum Seekers in Small Villages: Spatial Proximity and Integration in Italian and French Villages

What happens when asylum seekers from African or Middle Eastern countries are resettled by authorities in small European villages? When they arrive, are they welcomed, or on the contrary, rejected by villagers? Generally speaking, overseas migrants usually wish to be resettled in large European cities. As for European villagers, they tend to form communities closed on themselves, so one might expect a rather cold reception. However, fieldwork in Italian and French villages where asylum-seeking migrants were resettled shows that this is not necessarily the case. Having observed resettlement experiences in the Italian region of Molise and the French region of Alsace, we discovered that, wherever migrants are hosted within the confines of a village, villagers get frequent opportunities to meet them, learn to communicate with them, and spontaneously offer help, especially to children, women, and whole families. The lack of a common language does not prevent day-to-day iwnteractions or development of interpersonal relations. Children go to school and are keen to learn the host society’s language; adult migrants receiving help want to reciprocate by working for free, thus allowing them to quickly learn European ways and skills. If most asylum seekers eventually leave for larger cities, the months spent in a village prove to be a useful step preparing them for further resettlement

A vingança do curso de ação contra a ilusão cientificista = Courses of action’s revenge against the scientistic illusion

O nascimento e desenvolvimento da sociologia acadêmica foi facilitada enormemente pela crença cientificista compartilhada pela maioria dos seus fundadores, especialmente Comte e Durkheim e revitalizada pelo estruturalismo de Bourdieu, da possibilidade das ciências da sociedade não serem substancialmente diferentes das outras ciências, ou seja, das ciências naturais. Contudo, não há nenhuma ação auto-determinada a ser encontrada na natureza, nenhum curso de ação direcionado para algum objetivo ou para convicções fortes (valores); não há nenhum sujeito de ação no mundo da física. Entretanto, a fim de defender uma crença que embora falsa fez tanto e ainda faz muito para consolidar o status científico da sociologia, seus principais autores foram e permaneceram relutantes em considerar como fez Weber que os cursos de ação individuais ao longo do tempo constituem o elemento central na produção e mudança de sociedades modernas. E cinquenta anos após o nascimento do construtivismo, estes autores ainda encaram com grande suspeita o único método empírico que permite reconstruir cursos individuais de ação (situada), a entrevista narrativa ou história de vida. Não que este método faça milagres; mas se tomado seriamente, pode mudar a maneira como sociólogos olham para as sociedades: não como sistemas estáticos, mas como conjuntos dinâmicos e sempre em transformaçã

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics

Visually narrating post-colonial lives: ghosts of war and empire

This paper is about two journeys: the first through the memories of an old soldier captured by the Japanese in the Second World War; the second through the present life to which this past gave rise, in which the old soldier tends the graves of his fellow soldiers as part of his current navigation by bus and taxi of the post-colonial landscape of Hong Kong

Polymorphism of Plasmodium falciparum Na+/H+ exchanger is indicative of a low in vitro quinine susceptibility in isolates from Viet Nam

<p>Abstract</p> <p>Background</p> <p>The <it>Plasmodium falciparum </it>NA+/H+ exchanger (<it>pfnhe1</it>, gene PF13_0019) has recently been proposed to influence quinine (QN) susceptibility. However, its contribution to QN resistance seems to vary geographically depending on the genetic background of the parasites. Here, the role of this gene was investigated in <it>in vitro </it>QN susceptibility of isolates from Viet Nam.</p> <p>Method</p> <p>Ninety-eight isolates were obtained from three different regions of the Binh Phuoc and Dak Nong bordering Cambodia provinces during 2006-2008. Among these, 79 were identified as monoclonal infection and were genotyped at the microsatellite <it>pfnhe1 </it>ms4760 locus and <it>in vitro </it>QN sensitivity data were obtained for 51 isolates. Parasite growth was assessed in the field using the HRP2 immunodetection assay.</p> <p>Results</p> <p>Significant associations were found between polymorphisms at <it>pfnhe1 </it>microsatellite ms4760 and susceptibility to QN. Isolates with two or more DNNND exhibited much lower susceptibility to QN than those harbouring zero or one DNNND repeats (median IC₅₀of 682 nM <it>versus </it>median IC₅₀of 300 nM; <it>p </it>= 0.0146) while isolates with one NHNDNHNNDDD repeat presented significantly reduced QN susceptibility than those who had two (median IC₅₀of 704 nM <it>versus </it>median IC₅₀of 375 nM; p < 0.01). These QNR associated genotype features were mainly due to the over representation of profile 7 among isolates (76.5%). The majority of parasites had <it>pfcrt76T </it>and wild-type <it>pfmdr1 </it>(> 95%) thus preventing analysis of associations with these mutations. Interestingly, area with the highest median QN IC₅₀showed also the highest percentage of isolates carrying the <it>pfnhe1 </it>haplotype 7.</p> <p>Conclusions</p> <p>The haplotype 7 which is the typical Asian profile is likely well-adapted to high drug pressure in this area and may constitute a good genetic marker to evaluate the dissemination of QNR in this part of the world.</p

Quinine-Resistant Malaria in Traveler Returning from Senegal, 2007

We describe clinical and parasitologic features of in vivo and in vitro Plasmodium falciparum resistance to quinine in a nonimmune traveler who returned to France from Senegal in 2007 with severe imported malaria. Clinical quinine failure was associated with a 50% inhibitory concentration of 829 nmol/L. Increased vigilance is required during treatment follow-up

A Escuta de Jovens em Filmes de Pesquisa

Apresenta-se trajetória de um grupo de pesquisa dedicado à produção de conhecimento sobre jovens de espaços populares no contexto de produção de filmes de pesquisa. Dois filmes são descritos e interpretados com especial destaque aos dispositivos utilizados para colocar em diálogo as narrativas de si e contextos de vida e sociabilidade de jovens através de imagens e sons. A representação fílmica não se confunde com um retrato do real, mas, em vez disso, é reconstituição através da seleção, tradução e montagem do produto que se quer compartilhar com o público. As entrevistas narrativas concebidas em bases dialógicas são elementos estruturantes da produção dos filmes que buscam apresentar o ser-jovem em sua complexidade

Basic skills and transitions to adulthood

This article reports on the findings of a qualitative research project conducted in the North East of England. This project involved interviews with 55 young adults in an attempt to explore the impact of poor basic skills on transitions to adulthood. Poor basic skills have been identifued across Europe as a problem facing nation states, groups and individuals. But apart from large-scale survey-based studies (Bynner and Parsons, 2001), previous youth research has neglected the process through which basic skills play a role in transitions to adulthood. Proposing a social theory of situated basic skills as communal and individual resources, the authors develop an approach that is sensitive to both structure and agency in theorizing the role of literacy, numeracy and oracy in transitions. They claim that the mobilization of basic skills resources and their role across the life-course can best be understood by using a conceptualization of agency that recognizes the importance of reflexivity as a mediating link between subjective (agential) and objective (structural) dimensions of transition