Glacial drainage development controls temporal and spatial fluctuations of sediment flux in Mont Blanc’s North face.

21 pagesInternational audiencePresent-day global warming raises important issues regarding sediment flux from glaciated catchments. The detrital export from such environments results from erosion processes operating in three geomorphic domains: the supraglacial rockwalls, the ice-covered substratum and the proglacial area, downstream from the glacier. The dominant process controlling present-day sediment export from glaciated catchments remains debated with most studies underlining the paraglacial dynamics in the glacier forefront. This study nuances these observations by quantifying the contribution from each geomorphic domain to the export of a glaciated catchment in the North face of Mont-Blanc (France). High resolution hydro-sedimentary flux data were acquired during eight years in two proglacial streams with contrasting glacio-hydrological characteristics, Bossons and Crosette streams. In the Bossons stream catchment, the sediment response highlights the initiation of the dendritic drainage network beneath the glacier, the short-lived evacuation of an annual storage during the early melt-season and its subsequent steadier regime. In addition, three years exhibit late melt season exports which are uncorrelated with temperature or rainfall. The evolution of the drainage network throughout the melt season explains the evacuation of the annual and pluri-annual subglacial sediment stocks. In addition, glacial retreat in link with higher melt rate allows for exporting a pluri-annual sediment stock stored beneath the glacier. To conclude, the present-day sediment response in Bossons catchment displays distinct components with characteristic timescales and is dampened by intermediate storage controlled by drainage development and extreme events in the glacial and proglacial domains

Renal arteriovenous fistula in a renal transplant recipient: a case report and literature review

Renal arteriovenous fistula (rAVF) is a rare complication after a total nephrectomy, with only 72 cases reported in the last literature review published in 1997. AVF has never been described in a renal transplant recipient, and the possible consequences of hemodetournement on the graft function are unknown

Characterizing habitat suitability for a central-place forager in a dynamic marine environment

Characterizing habitat suitability for a marine predator requires an understanding of the environmental heterogeneity and variability over the range in which a population moves during a particular life cycle. Female California sea lions (Zalophus californianus) are central-place foragers and are particularly constrained while provisioning their young. During this time, habitat selection is a function of prey availability and proximity to the rookery, which has important implications for reproductive and population success. We explore how lactating females may select habitat and respond to environmental variability over broad spatial and temporal scales within the California Current System. We combine near-real-time remotely sensed satellite oceanography, animal tracking data (n = 72) from November to February over multiple years (2003-2009) and Generalized Additive Mixed Models (GAMMs) to determine the probability of sea lion occurrence based on environmental covariates. Results indicate that sea lion presence is associated with cool (<14°C), productive waters, shallow depths, increased eddy activity, and positive sea-level anomalies. Predictive habitat maps generated from these biophysical associations suggest winter foraging areas are spatially consistent in the nearshore and offshore environments, except during the 2004-2005 winter, which coincided with an El Niño event. Here, we show how a species distribution model can provide broadscale information on the distribution of female California sea lions during an important life history stage and its implications for population dynamics and spatial management. © 2018 Published by John Wiley & Sons Ltd