20 research outputs found

    Habitat selection by an avian top predator in the tropical megacity of Delhi: human activities and socio-religious practices as prey-facilitating tools

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    Research in urban ecology is growing rapidly in response to the exponential growth of the urban environment. However, few studies have focused on tropical megacities, and on the interplay between predators’ habitat selection and human socio-economic aspects, which may mediate their resilience and coexistence with humans. We examined mechanisms of breeding habitat selection by a synanthropic raptor, the Black Kite Milvus migrans, in Delhi (India) where kites mainly subsist on: (1) human refuse and its associated prey-fauna, and (2) ritualised feeding of kites, particularly practised by Muslims. We used mixed effects models to test the effect of urban habitat configuration and human practices on habitat selection, site occupancy and breeding success. Kite habitat decisions, territory occupancy and breeding success were tightly enmeshed with human activities: kites preferred areas with high human density, poor waste management and a road configuration that facilitated better access to resources provided by humans, in particular to Muslim colonies that provided ritual subsidies. Furthermore, kites bred at ‘clean’ sites with less human refuse only when close to Muslim colonies, suggesting that the proximity to ritual-feeding sites modulated the suitability of other habitats. Rather than a nuisance to avoid, as previously portrayed, humans were a keenly-targeted foraging resource, which tied a predator’s distribution to human activities, politics, history, socio-economics and urban planning at multiple spatio-temporal scales. Many synurbic species may exploit humans in more subtle and direct ways than was previously assumed, but uncovering them will require greater integration of human socio-cultural estimates in urban ecological research

    The Influence of CO<sub>2</sub> Admixtures on the Product Composition in a Nitrogen-Methane Atmospheric Glow Discharge Used as a Prebiotic Atmosphere Mimic

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    This work extends our previous experimental studies of the chemistry of Titan’s atmosphere by atmospheric glow discharge. The Titan’s atmosphere seems to be similarly to early Earth atmospheric composition. The exploration of Titan atmosphere was initiated by the exciting results of the Cassini-Huygens mission and obtained results increased the interest about prebiotic atmospheres. Present work is devoted to the role of CO2 in the prebiotic atmosphere chemistry. Most of the laboratory studies of such atmosphere were focused on the chemistry of N2 + CH4 mixtures. The present work is devoted to the study of the oxygenated volatile species in prebiotic atmosphere, specifically CO2 reactivity. CO2 was introduced to the standard N2 + CH4 mixture at different mixing ratio up to 5 % CH4 and 3 % CO2. The reaction products were characterized by FTIR spectroscopy. This work shows that CO2 modifies the composition of the gas phase with the detection of oxygenated compounds: CO and others oxides. There is a strong influence of CO2 on increasing concentration other products as cyanide (HCN) and ammonia (NH3)

    Proteomic Analysis of Differentially Expressed Proteins in Peripheral Cholangiocarcinoma

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    Cholangiocarcinoma is an adenocarcinoma of the liver which has increased in incidence over the last thirty years to reach similar levels to other liver cancers. Diagnosis of this disease is usually late and prognosis is poor, therefore it is of great importance to identify novel candidate markers and potential early indicators of this disease as well as molecules that may be potential therapeutic targets. We have used a proteomic approach to identify differentially expressed proteins in peripheral cholangiocarcinoma cases and compared expression with paired non-tumoral liver tissue from the same patients. Two-dimensional fluorescence difference gel electrophoresis after labeling of the proteins with cyanines 3 and 5 was used to identify differentially expressed proteins. Overall, of the approximately 2,400 protein spots visualised in each gel, 172 protein spots showed significant differences in expression level between tumoral and non-tumoral tissue with p < 0.01. Of these, 100 spots corresponding to 138 different proteins were identified by mass spectrometry: 70 proteins were over-expressed whereas 68 proteins were under-expressed in tumoral samples compared to non-tumoral samples. Among the over-expressed proteins, immunohistochemistry studies confirmed an increased expression of 14-3-3 protein in tumoral cells while α-smooth muscle actin and periostin were shown to be overexpressed in the stromal myofibroblasts surrounding tumoral cells. α-Smooth muscle actin is a marker of myofibroblast differentiation and has been found to be a prognostic indicator in colon cancer while periostin may also have a role in cell adhesion, proliferation and migration and has been identified in other cancers. This underlines the role of stromal components in cancer progression and their interest for developing new diagnostic or therapeutic tools
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