Organic Farming as a Commons for Protecting Water Resources / L’agriculture biologique comme bien commun pour protéger la ressource en eau

Today, organic farming is also a provider of public goods, promoted by an increasing number of actors. It may be seen as a “commons”, that has to be shaped and developed by new types of collective commitments to study. Two French experiences in that perspective aiming to protect water resources and led by local authorities have been analyzed. The study shows that the local authority behaves as a facilitator of territorial development plan. It acts through two complementary levers, the control of supply (land and ownership) and demand (institutional catering). Whereas environmental efficiency remains to be proved, the projects rely on an increasing collective mobilization and develop according to their ability for budding and territorial rooting. New modes of governance appear, that raise the questions of a local authority positioning in such plans and the invention of mixed institutional arrangements

SCATTERING MECHANISM ANALYSIS USING MULTI-ANGULAR POLARIMETRIC RADARSAT-2 DATASETS

International audienceThe objective of this study is to analyze scattering mecha- nisms using multi-incidence angle observations over agri- cultural fields. Radarsat-2 datasets acquired in the end of March / beginning of April with four different ranges of incidence angle are explored using polarimetric decom- position methodology. The results show that single scat- tering is always the dominant scattering mechanism over test sites, although single scattering occurs on bare sur- face is significantly stronger than that occurs in vegeta- tion canopy. As incidence angle increases, single scatter- ing decreases, and volumetric scattering increase as ex- pected. Therefore, lower incidence angle acquisition is appropriate to characterize soil moisture over bare sur- face due to the limited effect of roughness, while higher incidence angle is suitable for surface roughness iden- tification over bare surface and plant height description over vegetation canopy. Nevertheless, as the incidence angle increases towards 4

SOIL MOISTURE CHARACTERIZATION USING MULTI-ANGULAR POLARIMETRIC RADARSAT-2 DATASETS

International audienceThe use of multi-angular polarimetric datasets instead of the standard single-angular data is considered to be a solution to improve the effectiveness of bare soil char- acterization. However, the potential of polarimetric pa- rameters derived from the multi-angular SAR datasets was studied little, particularly for the C band polarimet- ric datasets. In this study, the sensitivity of polarimetric descriptors from single and multiple incidence angle acquisitions is investigated against in situ soil moisture and surface roughness. The behaviours of polarimetric descriptors are compared with the simulations using integral equation model (IEM). The results show that the variation of polarimetric descriptors in term of soil moisture as well as surface roughness is in accordance with the IEM simulations; even though the variation scale is different between the real data and simulation (The simulation is more sensitive than the real data). The polarimetric sensitivity found in this study provides additional evidences for the potential utilization of multi-angular polarimetric SAR datasets for bare sur- face characterization

FBXW7/hCDC4 controls glioma cell proliferation in vitro and is a prognostic marker for survival in glioblastoma patients

BACKGROUND: In the quest for novel molecular mediators of glioma progression, we studied the regulation of FBXW7 (hCDC4/hAGO/SEL10), its association with survival of patients with glioblastoma and its potential role as a tumor suppressor gene in glioma cells. The F-box protein Fbxw7 is a component of SCF(Fbxw7), a Skp1-Cul1-F-box E3 ubiquitin ligase complex that tags specific proteins for proteasome degradation. FBXW7 is mutated in several human cancers and functions as a haploinsufficient tumor suppressor in mice. Any of the identified targets, Cyclin E, c-Myc, c-Jun, Notch1/4 and Aurora-A may have oncogenic properties when accumulated in tumors with FBXW7 loss. RESULTS: We tested the expression of FBXW7 in human glioma biopsies by quantitative PCR and compared the transcript levels of grade IV glioma (glioblastoma, G-IV) with those of grade II tumors (G-II). In more than 80% G-IV, expression of FBXW7 was significantly reduced. In addition, levels of FBXW7 were correlated with survival indicating a possible implication in tumor aggressiveness. Locus 4q31.3 which carries FBXW7 was investigated by in situ hybridization on biopsy touchprints. This excluded allelic loss as the principal cause for low expression of FBXW7 in G-IV tumors. Two targets of Fbxw7, Aurora-A and Notch4 were preferentially immunodetected in G-IV biopsies. Next, we investigated the effects of FBXW7 misregulation in glioma cells. U87 cells overexpressing nuclear isoforms of Fbxw7 lose the expression of the proliferation markers PCNA and Ki-67, and get counterselected in vitro. This observation fits well with the hypothesis that Fbxw7 functions as a tumor suppressor in astroglial cells. Finally, FBXW7 knockdown in U87 cells leads to defects in mitosis that may promote aneuploidy in progressing glioma. CONCLUSION: Our results show that FBXW7 expression is a prognostic marker for patients with glioblastoma. We suggest that loss of FBXW7 plays an important role in glioma malignancy by allowing the accumulation of multiple oncoproteins and that interfering with Fbxw7 or its downstream targets would constitute a new therapeutic advance

Seguridad de las aplicaciones web

Conferencia "Seguridad de las aplicaciones web" impartida en la Escuela Politécnica Nacional (Quito, Ecuador) el 22 de mayo de 2014

40S hnRNP particles are a novel class of nuclear biomolecular condensates.

Heterogenous nuclear ribonucleoproteins (hnRNPs) are abundant proteins implicated in various steps of RNA processing that assemble on nuclear RNA into larger complexes termed 40S hnRNP particles. Despite their initial discovery 55 years ago, our understanding of these intriguing macromolecular assemblies remains limited. Here, we report the biochemical purification of native 40S hnRNP particles and the determination of their complete protein composition by label-free quantitative mass spectrometry, identifying A-group and C-group hnRNPs as the major protein constituents. Isolated 40S hnRNP particles dissociate upon RNA digestion and can be reconstituted in vitro on defined RNAs in the presence of the individual protein components, demonstrating a scaffolding role for RNA in nucleating particle formation. Finally, we revealed their nanometer scale, condensate-like nature, promoted by intrinsically disordered regions of A-group hnRNPs. Collectively, we identify nuclear 40S hnRNP particles as novel dynamic biomolecular condensates

At-sea movements of wedge-tailed shearwaters during and outside the breeding season from four colonies in New Caledonia

International audienceThe wedge-tailed shearwater (WTS) population of New Caledonia is one of the largest in the world, yet its biology and foraging ecology are poorly known. We studied WTS from 4 colonies in New Caledonia. We examined foraging behaviour and habitats using GPS receivers and light sensors during and outside the breeding season, respectively, and compared our findings with those from other WTS populations worldwide. During breeding, New Caledonian WTS alternated short foraging trips close to the colony over the lagoon, or off the reef edge, with longer trips over distant, deep waters. Whereas neighboring colonies overlapped at sea, especially during short trips, there was a clear separation of foraging zones between the pairs of colonies located in the southern versus northwestern parts of New Caledonia. Although WTS actively foraged and commuted to foraging zones during the day, they mainly returned to the colony or rested at night, indicating that they feed mainly during the day. Active foraging did not take place in more productive areas, suggesting that it may instead be related to the presence of sub-surface predators. Outside the breeding season, birds from 3 colonies had similar trans-equatorial migratory behaviour. All left New Caledonia at the same time of the year with a fast, northeasterly movement and wintered over deep waters in the same sector of the northwestern tropical Pacific Ocean. At overwintering sites, they spent most of their non-foraging time presumably sitting on the water, especially at night, making a slow westward movement before returning to New Caledonia. WTS from New Caledonia forage over warm, oligotrophic deep waters throughout their life cycle, and the species appears to have a flexible foraging strategy adapted to the various environmental conditions encountered across its wide tropical range

First Human Model of In Vitro Candida albicans Persistence within Granuloma for the Reliable Study of Host-Fungi Interactions

BACKGROUND: The balance between human innate immune system and Candida albicans virulence signaling mechanisms ultimately dictates the outcome of fungal invasiveness and its pathology. To better understand the pathophysiology and to identify fungal virulence-associated factors in the context of persistence in humans, complex models are indispensable. Although fungal virulence factors have been extensively studied in vitro and in vivo using different immune cell subsets and cell lines, it is unclear how C. albicans survives inside complex tissue granulomas. METHODOLOGY/PRINCIPAL FINDING: We developed an original model of in vitro human granuloma, reproducing the natural granulomatous response to C. albicans. Persistent granulomas were obtained when the ratio of phagocytes to fungi was high. This in vitro fungal granuloma mimics natural granulomas, with infected macrophages surrounded by helper and cytotoxic T lymphocytes. A small proportion of granulomas exhibited C. albicans hyphae. Histological and time-lapse analysis showed that C. albicans blastoconidia were located within the granulomas before hyphae formation. Using staining techniques, fungal load calculations, as well as confocal and scanning electron microscopy, we describe the kinetics of fungal granuloma formation. We provide the first direct evidence that C. albicans are not eliminated by immunocompetent cells inside in vitro human granulomas. In fact, after an initial candicidal period, the remaining yeast proliferate and persist under very complex immune responses. CONCLUSIONS/SIGNIFICANCE: Using an original in vitro model of human fungal granuloma, we herein present the evidence that C. albicans persist and grow into immunocompetent granulomatous structures. These results will guide us towards a better understanding of fungal invasiveness and, henceforth, will also help in the development of better strategies for its control in human physiological conditions