Diversité des logiques de travail dans les exploitations maraîchères en circuits courts

Les circuits courts alimentaires font aujourd'hui l'objet d'une attention grandissante, aussi bien de la part des producteurs que des consommateurs. Fondés sur une réduction du nombre d'intermédiaires marchands, ces modes de commercialisation répondent à une forte demande de consommation locale et seraient susceptibles de constituer une voie de dynamisation de l'économie agricole locale. Ces systèmes participeraient de plus à un processus de revalorisation économique et sociale du métier d'agriculteur, notamment au travers des liens qu'ils induisent avec les consommateurs et de l'indépendance qu'ils confèrent aux producteurs dans l'exercice de leur activité. Cependant, une des principales limites de ces systèmes de commercialisation serait celle liée à l'organisation du travail et à la gestion du temps sur l'exploitation. Il est en effet souvent souligné que la gestion de la commercialisation combinée à la maitrise d'un système d'exploitation souvent complexe et diversifié entraine une surcharge de travail pour le producteur. Dans cette communication, nous nous intéresserons à la dimension " travail " dans les exploitations maraichères en circuits courts. Nous montrerons que les résultats en termes de temps de travail et de chiffres d'affaire des exploitations semblent dépendre du rapport que les agriculteurs entretiennent avec leur travail, au-delà du fait de commercialiser en circuits courts. Cette notion de rapport au travail sera d'abord vue comme une grille de lecture permettant de mieux cerner la diversité des exploitations maraichères en circuits courts. Elle nous permettra ensuite de mettre en évidence les différentes logiques de travail pouvant expliquer la variabilité des résultats technico-économiques et de soulever les principales problématiques liées à l'organisation du travail dans ces exploitations

Influence of fillers on mechanical properties of ATH filled EPDM during ageing by gamma irradiation

International audienceThe presence of a significant content of fillers accelerates the degradation of ATH filled EPDM subjected to gamma irradiation at room temperature. Above the melting temperature of the EPDM, this induces a decrease in the apparent mechanical reinforcement of the fillers. This also promotes de-cohesion mechanisms which leads to an increase in the strain at break with irradiation dose. It is not clear whether the use of a filler treatment attenuates this accelerating effect or not; however, part of this treatment remains efficient at a high dose and seems also to delay but not suppress the occurrence of de-cohesion mechanisms at large strain. Moreover, at room temperature, i.e. below the melting temperature, all the consequences of ageing by gamma irradiation are strongly attenuated by the presence of a semicrystalline microstructure, the morphology of which is not too strongly modified by irradiation. (C) 2010 Elsevier Ltd. All rights reserved

An in vitro network of intermolecular interactions between viral RNA segments of an avian H5N2 influenza A virus: comparison with a human H3N2 virus.

International audienceThe genome of influenza A viruses (IAV) is split into eight viral RNAs (vRNAs) that are encapsidated as viral ribonucleoproteins. The existence of a segment-specific packaging mechanism is well established, but the molecular basis of this mechanism remains to be deciphered. Selective packaging could be mediated by direct interaction between the vRNA packaging regions, but such interactions have never been demonstrated in virions. Recently, we showed that the eight vRNAs of a human H3N2 IAV form a single interaction network in vitro that involves regions of the vRNAs known to contain packaging signals in the case of H1N1 IAV strains. Here, we show that the eight vRNAs of an avian H5N2 IAV also form a single network of interactions in vitro, but, interestingly, the interactions and the regions of the vRNAs they involve differ from those described for the human H3N2 virus. We identified the vRNA sequences involved in five of these interactions at the nucleotide level, and in two cases, we validated the existence of the interaction using compensatory mutations in the interacting sequences. Electron tomography also revealed significant differences in the interactions taking place between viral ribonucleoproteins in H5N2 and H3N2 virions, despite their canonical '7 + 1' arrangement

Metastatic Melanomas Express Inhibitory Low Affinity Fc Gamma Receptor and Escape Humoral Immunity

Our research, inspired by the pioneering works of Isaac Witz in the 1980s, established that 40% of human metastatic melanomas express ectopically inhibitory Fc gamma receptors (FcγRIIB), while they are detected on less than 5% of primary cutaneous melanoma and not on melanocytes. We demonstrated that these tumoral FcγRIIB act as decoy receptors that bind the Fc portion of antimelanoma IgG, which may prevent Fc recognition by the effector cells of the immune system and allow the metastatic melanoma to escape the humoral/natural immune response. The FcγRIIB is able to inhibit the ADCC (antibody dependent cell cytotoxicity) in vitro. Interestingly, the percentage of melanoma expressing the FcγRIIB is high (70%) in organs like the liver, which is rich in patrolling NK (natural killer) cells that exercise their antitumoral activity by ADCC. We found that this tumoral FcγRIIB is fully functional and that its inhibitory potential can be triggered depending on the specificity of the anti-tumor antibody with which it interacts. Together these observations elucidate how metastatic melanomas interact with and potentially evade humoral immunity and provide direction for the improvement of anti-melanoma monoclonal antibody therapy

Actinomadura meyerae osteitis following wound contamination with hay in a woman in France: a case report

<p>Abstract</p> <p>Introduction</p> <p>Mycetoma is a chronic granulomatous infection caused by environmental fungi or bacteria. It affects dermal and subcutaneous tissues, with putative contiguous extension to muscles or bones. While common in tropical and subtropical areas, mycetoma is rare in Europe.</p> <p>Case presentation</p> <p>We describe a case of <it>Actinomadura meyerae </it>osteitis in a 49-year-old Caucasian woman who suffered a tibia open fracture contaminated with hay; to the best of our knowledge the first case of autochthonous <it>A. meyerae </it>infection reported in France. The bacterium was cultivated from a bone biopsy. Following surgical osteosynthesis and six months of treatment with cotrimoxazole, our patient made a full recovery.</p> <p>Conclusion</p> <p>Our case report suggests that <it>A. meyerae </it>is a potential agent of wound infection in farm workers in contact with hay.</p

Lomustine with or without reirradiation for first progression of glioblastoma, LEGATO, EORTC-2227-BTG:study protocol for a randomized phase III study

Background: Chemotherapy with lomustine is widely considered as standard treatment option for progressive glioblastoma. The value of adding radiotherapy to second-line chemotherapy is not known. Methods: EORTC-2227-BTG (LEGATO, NCT05904119) is an investigator-initiated, pragmatic (PRECIS-2 score: 34 out of 45), randomized, multicenter phase III trial in patients with first progression of glioblastoma. A total of 411 patients will be randomized in a 1:1 ratio to lomustine (110 mg/m2 every 6 weeks) or lomustine (110 mg/m2 every 6weeks) plus radiotherapy (35 Gy in 10 fractions). Main eligibility criteria include histologic confirmation of glioblastoma, isocitrate dehydrogenase gene (IDH) wild-type per WHO 2021 classification, first progression at least 6 months after the end of prior radiotherapy, radiologically measurable disease according to RANO criteria with a maximum tumor diameter of 5 cm, and WHO performance status of 0–2. The primary efficacy endpoint is overall survival (OS) and secondary endpoints include progression-free survival, response rate, neurocognitive function, health-related quality of life, and health economic parameters. LEGATO is funded by the European Union’s Horizon Europe Research program, was activated in March 2024 and will enroll patients in 43 sites in 11 countries across Europe with study completion projected in 2028. Discussion: EORTC-2227-BTG (LEGATO) is a publicly funded pragmatic phase III trial designed to clarify the efficacy of adding reirradiation to chemotherapy with lomustine for the treatment of patients with first progression of glioblastoma. Trial registration: ClinicalTrials.gov NCT05904119.</p

Lomustine with or without reirradiation for first progression of glioblastoma, LEGATO, EORTC-2227-BTG: study protocol for a randomized phase III study

Background Chemotherapy with lomustine is widely considered as standard treatment option for progressive glioblastoma. The value of adding radiotherapy to second-line chemotherapy is not known. Methods EORTC-2227-BTG (LEGATO, NCT05904119) is an investigator-initiated, pragmatic (PRECIS-2 score: 34 out of 45), randomized, multicenter phase III trial in patients with first progression of glioblastoma. A total of 411 patients will be randomized in a 1:1 ratio to lomustine (110 mg/m$^{2}$ every 6 weeks) or lomustine (110 mg/m$^{2}$ every 6weeks) plus radiotherapy (35 Gy in 10 fractions). Main eligibility criteria include histologic confirmation of glioblastoma, isocitrate dehydrogenase gene (IDH) wild-type per WHO 2021 classification, first progression at least 6 months after the end of prior radiotherapy, radiologically measurable disease according to RANO criteria with a maximum tumor diameter of 5 cm, and WHO performance status of 0–2. The primary efficacy endpoint is overall survival (OS) and secondary endpoints include progression-free survival, response rate, neurocognitive function, health-related quality of life, and health economic parameters. LEGATO is funded by the European Union’s Horizon Europe Research program, was activated in March 2024 and will enroll patients in 43 sites in 11 countries across Europe with study completion projected in 2028. Discussion EORTC-2227-BTG (LEGATO) is a publicly funded pragmatic phase III trial designed to clarify the efficacy of adding reirradiation to chemotherapy with lomustine for the treatment of patients with first progression of glioblastoma. Trial registration ClinicalTrials.gov NCT05904119. Registered before start of inclusion, 23 May 202

A supramolecular assembly formed by influenza A virus genomic RNA segments

The influenza A virus genome consists of eight viral RNAs (vRNAs) that form viral ribonucleoproteins (vRNPs). Even though evidence supporting segment-specific packaging of vRNAs is accumulating, the mechanism ensuring selective packaging of one copy of each vRNA into the viral particles remains largely unknown. We used electron tomography to show that the eight vRNPs emerge from a common ‘transition zone’ located underneath the matrix layer at the budding tip of the virions, where they appear to be interconnected and often form a star-like structure. This zone appears as a platform in 3D surface rendering and is thick enough to contain all known packaging signals. In vitro, all vRNA segments are involved in a single network of intermolecular interactions. The regions involved in the strongest interactions were identified and correspond to known packaging signals. A limited set of nucleotides in the 5′ region of vRNA 7 was shown to interact with vRNA 6 and to be crucial for packaging of the former vRNA. Collectively, our findings support a model in which the eight genomic RNA segments are selected and packaged as an organized supramolecular complex held together by direct base pairing of the packaging signals

Towards microbiota-based disease management: analysis of grapevine microbiota in plots with contrasted levels of downy mildew infection

Vineyards harbor a myriad of microorganisms that interact with each other and with the grapevines. Some microorganisms are plant pathogens, such as the oomycete Plasmopara viticola that causes grapevine downy mildew. Others, such as plant growth promoting bacteria and disease biocontrol agents, have a positive influence on vine health. The present study aims to (1) investigate whether vine-based culture media increase the cultivability of the grapevine microbiota, in comparison to standard culture media and (2) identify and isolate bacterial taxa naturally present in grapevine leaves and significantly more abundant in plots showing low susceptibility to downy mildew