Optical volume and mass measurements show that mammalian cells swell during mitosis

International audienceThe extent, mechanism, and function of cell volume changes during specific cellular events, such as cell migration and cell division, have been poorly studied, mostly because of a lack of adequate techniques. Here we unambiguously report that a large range of mammalian cell types display a significant increase in volume during mitosis (up to 30%). We further show that this increase in volume is tightly linked to the mitotic state of the cell and not to its spread or rounded shape and is independent of the presence of an intact actomyosin cortex. Importantly, this volume increase is not accompanied by an increase in dry mass and thus corresponds to a decrease in cell density. This mitotic swelling might have important consequences for mitotic progression: it might contribute to produce strong pushing forces, allowing mitotic cells to round up; it might also, by lowering cytoplasmic density, contribute to the large change of physicochemical properties observed in mitotic cells

Modélisation de la répartition de la consoude bulbeuse (Symphytum bulbosum Schimp.) en vue de sa conservation dans les Alpes-Maritimes et le Var

CITATIONS 0 READS 33 4 authors: Some of the authors of this publication are also working on these related projects: Microrefugia and stepping stones-the role of microclimate in climate-driven range shifts View project Conservation of the rare and endangered flora of french Mediterranean basin View project Maëlle Le Berre Conservatoire botanique national méditerranéen de Porquerolle

How to hierarchise species to determine priorities for conservation action? A critical analysis

International audienceHierarchisation and prioritisation methods represent a crucial step to determine priorities and implement actions in conservation biology: they are required to determine how to allocate available resources to the different components of biodiversity. However, they are very heterogeneous in terms of targets and goals. The main differences are presented with a focus on hierarchisation methods targeting species. This paper reviews 40 studies using 24 different point-scoring or rule-based methods aiming to determine conservation concerns for species. Only the hierarchisation methods targeting species were compared and their differences where highlighted in terms of study area, taxa, criteria assessment and summa-risation. Then six different studies using the same hierarchisation method for species were compared as well. This study enables to analyse the different existing methods in order to perform more relevant methodological choices adapted to the objective and the context of each selection process. A consistent framework is designed to help managers to choose an appropriate method using well-defined goals, study areas and taxonomic targets, and take into account data availability

Prioritization of natural habitats: A methodological framework applied to the French Mediterranean

International audienceLong-term preservation of habitats has become a cornerstone of modern conservation policies. As resources allocated to conservation actions are often limited, developing relevant prioritizing methods is necessary. Although many studies have been published on species prioritization, habitats have been the subject of less research. This study aims to develop a simple prioritization method suitable for habitats and appropriate to any typology. We analyzed literature to select criteria that would be the most accurate to rank habitats. Our final method consists in calculating a score based on four criteria: legal obligation, territorial responsibility, conservation condition and an extra criterion designed to fit local interests and objectives. The method is applied on habitats listed in Annex I of the Habitats Directive (92/43/EEC) on the territory of RESEDA-Flore, a network of stakeholders involved in the conservation of Mediterranean flora. Results highlight that dune habitats show the highest conservation values, while rocky habitats and caves obtain relatively low scores. At the top of the ranking, Mediterranean temporary ponds (3170), Dunes with Pinus pinea and/or Pinus pinaster forests (2270) and Coastal dunes with Juniperus spp. (2250) appear to be a high priority. These results can be used to design and implement habitat conservation strategies in the French Mediterranean

Comparison of 2002 AECG and 2016 ACR/EULAR classification criteria and added value of salivary gland ultrasonography in a patient cohort with suspected primary Sjögren’s syndrome

Abstract Background The objective was to evaluate concordance between 2002 American-European Consensus Group (AECG) and 2016 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria for primary Sjögren’s syndrome (pSS) and to assess how salivary gland ultrasonography (SGUS) might improve the classification of patients. Methods Patients with suspected pSS underwent a standardised evaluation, including SGUS, at inclusion into the single-centre Brittany DIApSS cohort. Agreement between the two criteria sets was assessed using Cohen’s κ coefficient. Characteristics of discordantly categorised patients were detailed. Results We prospectively included 290 patients between 2006 and 2016, among whom 125 (43%) met ACR/EULAR criteria and 114 (39%) also met AECG criteria; thus, 11 (4%) patients fulfilled only ACR/EULAR, no patients AECG only, and 165 (57%) patients neither criteria set. Concordance was excellent (κ = 0.92). Compared to patients fulfilling both criteria sets, the 11 patients fulfilling only ACR/EULAR criteria had similar age and symptom duration but lower frequencies of xerophthalmia and xerostomia (p < 0.01 for each) and salivary gland dysfunction (p < 0.01); most had systemic involvement (91%), including three (27%) with no sicca symptoms; 91% had abnormal salivary gland biopsy and 46% anti-Sjögren's-syndrome-related antigen A (anti-SSA); 64% were diagnosed with pSS by the physician. SGUS was abnormal in 12% of the 165 patients fulfilling no criteria set. Including SGUS among the ACR/EULAR criteria increased sensitivity from 87.4% to 91.1% when physician diagnosis was the reference standard. Conclusions Agreement between AECG and ACR/EULAR criteria sets is excellent. ACR/EULAR criteria are slightly more sensitive and classified some patients without sicca symptoms as having pSS. Including SGUS in the ACR/EULAR criteria may further improve their sensitivity