Hoverflies of the Timon-David collection (Diptera, Syrphidae)

Hoverflies are among the most important insect pollinators and there is documented evidence of a recent decline in their populations. To trace the past distributions of hoverfly species, verified records of historical collections are essential.Here, we provide data on 1071 specimens of hoverflies collected or received by Jean Timon-David and hosted at the Marseille Natural History Museum, France. Most of the specimens were collected by Timon-David himself and come from south-eastern France, mainly from the Departments of Bouches-du-Rhône, Var and Hautes-Alpes. Most of these specimens were checked for the accuracy of their identification according to the latest identification keys. This resulted in 85 additions to the known fauna of the French Departments, mostly for Var and Bouches-du-Rhône. The taxonomy of all specimens was checked against the latest available checklists and updated names added whenever necessary. Specimens received from entomologists working in other continents may also be valuable, as these are historic testimonies of the fauna of their own respective regions of origin and may, therefore, also be used as reference material. One paratype specimen from Australia is present in the collection. The holotype of Cheilosia vangaveri Timon-David, 1937 is absent from the collection and should be considered as lost. All but two of the specimens with locality labels had their geographical coordinates of origin added in the dataset

Chelation-controlled regioselective alkylation of pyrimidine 2'-deoxynucleosides.

International audienceProtection-deprotection steps, which are usually needed for regioselective alkylation of pyrimidine deoxynucleosides, can be avoided by choosing the appropriate solvent. The combined effects of low dielectric constant and possible sodium chelation by pyrimidine nucleosides may account for the unexpected regioselectivity observed in THF

Hoverflies of the Timon-David collection (Diptera, Syrphidae)

Hoverflies are among the most important insect pollinators and there is documented evidence of a recent decline in their populations. To trace the past distributions of hoverfly species, verified records of historical collections are essential.Here we provide data on 1071 specimens of hoverflies collected or received by Jean Timon-David and hosted at the Marseille Natural History Museum, France. Most of the specimens were collected by Timon-David himself and come from south-eastern France, mainly from the departments of Bouches-du-Rhône, Var and Hautes-Alpes. Most of these specimens were checked for the accuracy of their identification according to the latest identification keys. This resulted in 85 additions to the known fauna of the French departments, mostly for Var and Bouches-du-Rhône. The taxonomy of all specimens was checked against the latest available checklists, and updated names added whenever necessary. Specimens received from entomologists working in other continents may also be valuable, as these are historic testimonies of the fauna of their own respective regions of origin, and may therefore also be used as reference material. One paratype specimen from Australia is present in the collection. The holotype of Cheilosia vangaveri Timon-David, 1937 is absent from the collection and should be considered as lost. All but two of the specimens with locality labels had their geographical coordinates of origin added in the data set

Solvent-controlled regioselective protection of 5'-O-protected thymidine.

International audienceThis paper describes an efficient procedure for selective 3'-O- or 3-N-protection of 5'-O-tert-butyldimethylsilylthymidine, depending on the use of aprotic polar solvents with low or high dielectric constant, respectively. These syntheses were activated by either ultrasound or microwaves. Several alkyl bromides offer a convenient route to prepare 3'-O- or 3-N-protected and functionalized thymidine derivatives

ETUDE « 4 POUR 1 000 » OUTRE-MER: Stocker du carbone dans les sols agricoles et forestiers ultramarins - Etat des connaissances et leviers d’actions dans les départements et régions d’Outre-mer

Coordonnée par le Cirad en partenariat avec INRAE et l’IRD, l’étude « 4 pour 1000 » Outre-mer dresse un bilaninédit des stocks de carbone du sol des territoires ultramarins. Les auteurs formulent des recommandationsopérationnelles et de recherche pour préserver ces stocks élevés et répondre aux grands enjeux actuels del’agriculture face au changement climatique au niveau national et territorial.Si le potentiel des sols métropolitains a fait l’objet d’une évaluation en 2019, celui des territoires ultramarins étaitjusqu’ici méconnu. Dans le cadre de la présente étude, les auteurs dressent pour la première fois un état deslieux des connaissances pour la Guadeloupe, la Martinique, la Guyane, La Réunion, Mayotte, Saint-Martinet Saint-Barthélémy. Deux constats majeurs sont dressés.En matière de stocks de carbone dans les sols, les territoires ultramarins jouent un rôle important malgré leurfaible superficie (15 % de celle de l’hexagone) : ils équivalent à environ 20 % des stocks de carbone du sol demétropole. Cela s’explique essentiellement par la minéralogie originale de ces sols développés sur roches volcaniques, mais également l’impact de leurs usages (forêt, prairie, canne à sucre …).Autre constat : les données existantes sur le carbone du sol dans ces territoires sont incomplètes. Les sols de laGuadeloupe, de la Martinique, de Guyane et de La Réunion sont documentés de façon conséquente maisparcellaire. En revanche, aucune information n’existe encore pour Mayotte, Saint-Barthélémy et Saint-Martin.En outre, du fait de l’importance de la forêt guyanaise (équivalant à 46 % de la superficie forestière métropolitaine),le carbone stocké dans la biomasse aérienne a spécifiquement été étudié dans le cadre de cette étude.Il en ressort qu’il équivaut à 120 % du carbone aérien des forêts métropolitaines.Les auteurs formulent une série de recommandations.PREMIÈREMENT, il faut préserver les stocks élevés de carbone du sol et de la biomasse aérienne dans les territoires ultramarins et en limiter leur diminution :• Intégrer dans la Politique Agricole Commune la rémunération des services écosystémiques associés auxpratiques agricoles et forestières préservant les stocks des sols ;• Lutter contre la spéculation et la rétention de foncier agricole ;• Promouvoir les pratiques agroécologiques grâce à des mesures incitatives et à la communication ;• Faciliter l’accès aux moyens nécessaires à la mise en oeuvre des bonnes pratiques : investissement, Coopérative d’utilisation de matériel agricole et formations ;• Transposer le Label « bas-carbone » pour contribuer à l’adoption de pratiques stockant du carbone parune incitation économique. DEUXIÈMEMENT, des actions de recherche doivent être menées pour mettre en oeuvre efficacement les recommandations précédentes :• Accroître les connaissances des stocks de carbone du sol dans ces territoires pour mesurer les retombéesdes politiques publiques ;• Adapter les méthodes de quantification des capacités de stockage du carbone dans les sols pour transposerle Label « bas-carbone » ;• Accentuer les travaux sur la dimension sociale pour favoriser les innovations et l’adoption de bonnespratiques ;• Développer des approches co-construites d’évaluation de scénarios agroécologiques à l’échelle dechaque territoire ultramarin ;• Créer davantage de lien entre science et politique et mieux intégrer les territoires d’Outre-mer dans lesengagements français et européen en matière de lutte contre le changement climatique

High Risk of Anal and Rectal Cancer in Patients With Anal and/or Perianal Crohn’s Disease

International audienceBackground & AimsLittle is known about the magnitude of the risk of anal and rectal cancer in patients with anal and/or perineal Crohn’s disease. We aimed to assess the risk of anal and rectal cancer in patients with Crohn’s perianal disease followed up in the Cancers Et Surrisque Associé aux Maladies Inflammatoires Intestinales En France (CESAME) cohort.MethodsWe collected data from 19,486 patients with inflammatory bowel disease (IBD) enrolled in the observational CESAME study in France, from May 2004 through June 2005; 14.9% of participants had past or current anal and/or perianal Crohn’s disease. Subjects were followed up for a median time of 35 months (interquartile range, 29–40 mo). To identify risk factors for anal cancer in the total CESAME population, we performed a case-control study in which participants were matched for age and sex.ResultsAmong the total IBD population, 8 patients developed anal cancer and 14 patients developed rectal cancer. In the subgroup of 2911 patients with past or current anal and/or perianal Crohn’s lesions at cohort entry, 2 developed anal squamous-cell carcinoma, 3 developed perianal fistula–related adenocarcinoma, and 6 developed rectal cancer. The corresponding incidence rates were 0.26 per 1000 patient-years for anal squamous-cell carcinoma, 0.38 per 1000 patient-years for perianal fistula–related adenocarcinoma, and 0.77 per 1000 patient-years for rectal cancer. Among the 16,575 patients with ulcerative colitis or Crohn’s disease without anal or perianal lesions, the incidence rate of anal cancer was 0.08 per 1000 patient-years and of rectal cancer was 0.21 per 1000 patient-years. Among factors tested by univariate conditional regression (IBD subtype, disease duration, exposure to immune-suppressive therapy, presence of past or current anal and/or perianal lesions), the presence of past or current anal and/or perianal lesions at cohort entry was the only factor significantly associated with development of anal cancer (odds ratio, 11.2; 95% CI, 1.18-551.51; P = .03).ConclusionsIn an analysis of data from the CESAME cohort in France, patients with anal and/or perianal Crohn’s disease have a high risk of anal cancer, including perianal fistula–related cancer, and a high risk of rectal cancer