First description of in situ chlorophyll fluorescence signal within East Antarctic coastal polynyas during fall and winter

Antarctic coastal polynyas are persistent and recurrent regions of open water located between the coast and the drifting pack-ice. In spring, they are the first polar areas to be exposed to light, leading to the development of phytoplankton blooms, making polynyas potential ecological hotspots in sea-ice regions. Knowledge on polynya oceanography and ecology during winter is limited due to their inaccessibility. This study describes i) the first in situ chlorophyll fluorescence signal (a proxy for chlorophyll-a concentration and thus presence of phytoplankton) in polynyas between the end of summer and winter, ii) assesses whether the signal persists through time and iii) identifies its main oceanographic drivers. The dataset comprises 698 profiles of fluorescence, temperature and salinity recorded by southern elephant seals in 2011, 2019-2021 in the Cape-Darnley (CDP;67˚S-69˚E) and Shackleton (SP;66˚S-95˚E) polynyas between February and September. A significant fluorescence signal was observed until April in both polynyas. An additional signal occurring at 130m depth in August within CDP may result from in situ growth of phytoplankton due to potential adaptation to low irradiance or remnant chlorophyll-a that was advected into the polynya. The decrease and deepening of the fluorescence signal from February to August was accompanied by the deepening of the mixed layer depth and a cooling and salinification of the water column in both polynyas. Using Principal Component Analysis as an exploratory tool, we highlighted previously unsuspected drivers of the fluorescence signal within polynyas. CDP shows clear differences in biological and environmental conditions depending on topographic features with higher fluorescence in warmer and saltier waters on the shelf compared with the continental slope. In SP, near the ice-shelf, a significant fluorescence signal in April below the mixed layer (around 130m depth), was associated with fresher and warmer waters. We hypothesize that this signal could result from potential ice-shelf melting from warm water intrusions onto the shelf leading to iron supply necessary to fuel phytoplankton growth. This study supports that Antarctic coastal polynyas may have a key role for polar ecosystems as biologically active areas throughout the season within the sea-ice region despite inter and intra-polynya differences in environmental conditions

Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

Peer reviewe

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

Background: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15–20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases. Methods: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded. Results: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5–528.7, P = 1.1 × 10−4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3–8.2], P = 2.1 × 10−4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1–2635.4], P = 3.4 × 10−3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3–8.4], P = 7.7 × 10−8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10−5). Conclusions: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old

The impact of protected areas on local economic development: The case of the Chaîne des Puys - Limagne Fault in France

International audienc

Analyse contrefactuelle des effets économiques des politiques de gestion et de valorisation. Le cas des politiques menées sur le site « Chaîne des puys -Faille de Limagne

Si les politiques de gestion de sites naturels sont destinées à préserver ces espaces, elles visent aussi souvent à promouvoir le développement économique local. Néanmoins, peu d'analyses d'impact économique de ces politiques ont été réalisées. Nous analysons ici l'impact de ces politiques mises en place pour le site de la Chaîne des puys-Faille de Limagne sur le développement économique des 464 communes du département du Puy-de-Dôme entre 2008 et 2018. A l'aide d'une méthode de doubles différences avec appariement préalable, nous évaluons les retombées générées sur quatre dimensions de l'économie locale : secteur touristique, autres secteurs économiques (commerce de détail, immobilier), conditions d'emplois, et attractivité résidentielle. Les résultats montrent des effets positifs sur l'offre touristique (lits et emplois), essentiellement limités aux communes de la métropole, et sur les dynamiques résidentielles (solde migratoire apparent, taux d'immigration), au niveau du département uniquement

High prevalence of SDHB mutations in head and neck paraganglioma in Belgium

BACKGROUND: Recent reports have found genetic mutations in up to one quarter of patients harbouring pheochromocytoma and/or paraganglioma. This high prevalence was mainly due to the discovery of the role of SDH genes. While SDHD has been more frequently associated with the pathogenesis of head and neck paragangliomas, SDHB mutations were mainly associated with malignant and/or extra-adrenal pheochromocytoma/paraganglioma. OBJECTIVE: To look for mutations in susceptibility genes and genotype-phenotype correlations in patients with pheochromocytoma and/or paraganglioma from Belgium. METHODS: Screening of the coding parts of SDH, VHL and RET genes was performed by SSCP in patients with pheochromocytoma and/or paraganglioma diagnosed at or referred to the Cliniques Universitaires Saint Luc from May 2003 to May 2006. RESULTS: Fifty-six unrelated patients were included (36 head and neck paragangliomas, including six familial cases and 30 sporadic cases; 18 abdominal pheochromocytoma/paraganglioma and two paraganglioma of the cauda equina). The overall prevalence of mutations was 41% (n = 23 including 19 head and neck paragangliomas and four abdominal pheochromocytoma/paraganglioma), mainly due to SDH mutations. While SDHD mutations were found in all patients with familial head and neck paragangliomas, in sporadic cases, the prevalence of SDHB mutations (n = 8, 27%) was twice that of SDHD mutations (n = 4, 13%). Patients harbouring SDHB mutations had unilateral late-onset head and neck tumours without evidence of recurrence or malignancy. CONCLUSION: This Belgian series confirms the elevated prevalence of predisposing mutations in patients with head and neck and extra-adrenal paragangliomas, but differs from previous reports by the high frequency of SDHB mutations associated with head and neck paragangliomas without evidence of recurrence or malignancy