Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

Intérêt des bioprothèses dans le traitement des insuffisances mitrales fonctionnelles

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Letter: Reintervention for a failed surgical aortic bioprosthesis. Percutaneous or surgical treatment: should we look at the short- or long-term perspective?

International audienc

Zones humides et pouvoirs territoriaux

Issu d’une journée d’études organisée en association entre le RUCHE (Réseau de Chercheurs en Histoire Environnementale) et le GHZH (Groupe d’Histoire des Zones Humides), le dossier « Zones humides et pouvoirs territoriaux » interroge les jeux de pouvoirs noués autour de la gestion des zones humides dans des territoires aussi différents que la Russie soviétique, les Îles Shetland et la France moderne. Comment les pouvoirs territoriaux administrent-ils les zones humides ? Observe-t-on des pratiques spécifiques ? En effet, les modalités d’exploitation, qu’elles soient intensives ou extensives, mais aussi la volonté de préserver des espaces fragiles, révèlent les logiques de pouvoir à l’œuvre sur un territoire donné. Les projets d’aménagement des marais et tourbières participent pleinement de l’affirmation d’une autorité politique dont relèvent les droits et les outils nécessaires pour les mener à bien. Plus avant, ce dossier montre comment les zones humides pouvaient être instrumentalisées par les pouvoirs. Ce questionnement historique s’ancre dans les dynamiques environnementales actuelles. Au cours des quarante dernières années, les zones humides sont passées du statut de territoires répulsifs à celui de rempart de la biodiversité. Ce changement mobilise toute une chaîne de pouvoirs : de celui que détiennent encore les propriétaires à celui des États et des institutions internationales. « Wetlands and territorial powers » is a thematic issue based on a workshop organized by both RUCHE (Réseau de Chercheurs en Histoire Environnementale) and GHZH (Groupe d’Histoire des Zones Humides). These articles question the power games developed and induced by the governance of wetlands in such different areas as USSR, Early Mondern Shetland Islands and France. How territorial powers governed wetlands? Did they enforce specific modalities? Exploitation conditions, whether intensive or extensive, but also the will to preserve those revealed logics of power at force on a specific area. Development projects of marshes and peatlands contributed to affirm political powers which detained rights and tools involved to achieve it. Moreover, these articles show how wetlands could be used by authorities. This historical inquiry is fully anchored in current environmental dynamics. Wetlands statute has deeply changed since the beginning of the 1970s. They are no longer seen as repulsive areas and have been erected as bulwark of the biodiversity. This change mobilizes a chain of powers: from the landowners to States and international organizations

Les pautes del poblament dels Ceretans, Oppida secundaris

International audienc

Dual-Phase 99mTc Sestamibi Scintigraphy With Neck and Thorax SPECT/CT in Primary Hyperparathyroidism: a Single-Institution Experience

International audiencePurpose: To assess the diagnostic value of dual-phase 99mTc sestamibi scintigraphy with neck and thorax single-photon emission computed tomography/computed tomography (SPECT/CT) in patients with primary hyperparathyroidism, and to analyze the relationships between SPECT/CT data and serum calcium or parathyroid hormone (PTH) concentrations.Materials and Methods: 99mTc sestamibi scintigraphy was performed in 94 consecutive patients. Images included early and delayed planar neck images and delayed neck and thorax SPECT/CT. Scintigraphy was scored positive or negative.Results: Fifty-nine sestamibi studies (63%) were positive. SPECT/CT demonstrated a single focus in 56 patients, in usual parathyroid sites in 80% of cases and in unusual sites in the remaining 20% (retrotracheal area, 7%; intrathyroidal, 9%; mediastinum, 4%), and double foci in 3. Serum calcium values were higher in patients with a positive scintigraphy than in those with a negative scintigraphy (2.80 vs. 2.66 mmol/L, P = 0.001) with similar figures for serum PTH values (129 vs. 107 pg/mL, P = 0.0649). In patients with a measurable parathyroid adenoma on integrated CT scan (n = 43), the greatest axial diameter of the adenoma was correlated to serum calcium (r = 0.405, P < 0.0071) or PTH concentrations (r = 0.589, P < 0.0001). Fifty-four patients underwent surgery, 45 with a positive, and 9 with a negative preoperative scintigraphy, resulting in a sensitivity of 92% (95% CI: 80-98) and a specificity of 83% (95% CI: 36-100).Conclusions: Dual-phase 99mTc sestamibi scintigraphy with SPECT/CT enables to identify a parathyroid adenoma in about two-thirds of patients with primary hyperparathyroidism and allows the surgeon to plan appropriate surgery. The likelihood of scintigraphy to be positive is affected by calcium or PTH concentrations

CCR4-Associated Factor CAF1 Is an Essential Factor for Spermatogenesis

The CCR4-associated protein CAF1 has been demonstrated to play several roles in the control of transcription and of mRNA decay. To gain further insight into its physiological function, we generated CAF1-deficient mice. They are viable, healthy, and normal in appearance; however, mCAF1(−/−) male mice are sterile. The crossing of mCAF1(+/−) mice gave a Mendelian ratio of mCAF1(+/+), mCAF1(+/−), and mCAF1(−/−) pups, indicating that haploid mCAF1-deficient germ cells differentiate normally. The onset of the defect occurs during the first wave of spermatogenesis at 19 to 20 days after birth, during progression of pachytene spermatocytes to haploid spermatids and spermatozoa. Early disruption of spermatogenesis was evidenced by Sertoli cell vacuolization and tubular disorganization. The most mature germ cells were the most severely depleted, but progressively all germ cells were affected, giving Sertoli cell-only tubes, large interstitial spaces, and small testes. This phenotype could be linked to a defect(s) in germ cells and/or to inadequate Sertoli cell function, leading to seminiferous tubule disorganization and finally to a total disappearance of germ cells. The mCAF1-deficient mouse provides a new model of failed spermatogenesis in the adult that may be relevant to some cases of human male sterility

Prosthesis–Patient Mismatch in Small Aortic Annuli: Self-Expandable vs. Balloon-Expandable Transcatheter Aortic Valve Replacement

International audienceProsthesis–patient mismatch (PPM) is associated with worse outcomes following surgical aortic valve replacement (SAVR). PPM has been identified in a significant proportion of TAVR, particularly in patients with small aortic annuli. Our objective was to evaluate the hemodynamic performances of balloon-expandable (BE) (Sapiens 3TM) versus two different self-expandable (SE) (Evolut ProTM, Accurate NeoTM) TAVR devices in patients with small aortic annulus defined by a computed tomography aortic annulus area (AAA) between 330 and 440 mm2. We enrolled 131 consecutive patients corresponding to 76 Sapiens 3 23 mm (58.0%), 26 Evolut Pro (19.9%) and 29 Accurate Neo (22.1%). Mean age was 82.5 ± 7.06 years, 22.9% of patients were male and mean Euroscore was 4.0%. Mean AAA was 374 ± 27 mm2 for Sapiens 3, 383 ± 29 mm2 for Corevalve Evolut Pro and 389 ± 25 mm2 for Accurate Neo. BE devices were associated with significantly higher rates of PPM (39.5%) as compared to SE devices (15.4% for Corevalve Evolut Pro and 6.9% for Accurate Neo) (p < 0.0001). Paravalvular leaks ≥ 2/4 were more often observed in SE devices (15.4% for Corevalve Evolut Pro and 17.2% for Accurate Neo) than in BE devices (2.6%) (p = 0.007). In conclusion, SE TAVR devices did achieve better hemodynamic results despite higher rates of paravalvular leaks. Therefore, SE TAVI devices could be considered as first choice in small aortic anatomy

Prosthesis-patient mismatch is an independent predictor of congestive heart failure after transcatheter aortic valve replacement

International audienc