Factors controlling the water quality of rock glacier springs in European and American mountain ranges

Rock glaciers (RGs) provide significant water resources in mountain areas under climate change. Recent research has highlighted high concentrations of solutes including trace elements in RG-fed waters, with negative implications on water quality. Yet, sparse studies from a few locations hinder conclusions about the main drivers of solute export from RGs. Here, in an unprecedented effort, we collected published and unpublished data on rock glacier hydrochemistry around the globe. We considered 201 RG springs from mountain ranges across Europe, North and South America, using a combination of machine learning, multivariate and univariate analyses, and geochemical modeling. We found that 35 % of springs issuing from intact RGs (containing internal ice) have water quality below drinking water standards, compared to 5 % of springs connected to relict RGs (without internal ice). The interaction of ice and bedrock lithology is responsible for solute concentrations in RG springs. Indeed, we found higher concentrations of sulfate and trace elements in springs sourcing from intact RGs compared to water originating from relict RGs, mostly in specific lithological settings. Enhanced sulfide oxidation in intact RGs is responsible for the elevated trace element concentrations. Challenges for water management may arise in mountain catchments rich in intact RGs, and where the predisposing geology would make these areas geochemical RG hotspots. Our work represents a first comprehensive attempt to identify the main drivers of solute concentrations in RG water

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Mid-term Results after Endovascular Repair of the Atherosclerotic Descending Thoracic Aortic Aneurysm

AbstractIntroduction. Thoracic aortic aneurysms (TAA) are the most common condition of the thoracic aorta requiring surgical treatment. Despite significant improvement in anesthetic, surgical techniques and postoperative care, the mortality and morbidity rate in TAA-repair remains high. The aim of this study was to assess the morbidity and mortality rate after endovascular stent-graft treatment of atherosclerotic (non-dissecting) TAAs.Methods. Thirty-one patients, ASA-classification III–IV, with symptomatic or expanding atherosclerotic TAAs underwent endovascular stent-graft repair between May 1997 and August 2003. Procedures were performed on an emergency basis in 13 patients and elective in 18 patients. Patients were assessed postoperatively by routine CT-scan within 48 h. Further follow up investigations were performed after 3, 6, 12 months and annually thereafter.Results. Stent-graft placement was successful in all but one patient in whom the stent-graft procedure had to be postponed due severe hemodynamic instability. Perioperative mortality rate was 19% including three haemorrhages, two cardiac events and one respiratory failure (6/31). Technical success rate was 55% (17/31). Completion CT scans performed in 30 patients within 2 days of stent-graft procedure showed type I leaks in seven patients (23%), type II leaks in four patients (13%) and type III leaks in two patients (6%). Further complications included one stroke, one paralysis, one spinalis anterior syndrome and five relevant access related complications. New onset endoleaks, all type I, were observed in seven patients (23%) occurring after 3, 4, 7, 8, 17, 25 and 26 months. Mean follow-up was 15 months (range 2–69 months).Conclusion. Thoracic aortic atherosclerotic aneurysm stent-grafting is feasible but not without significant morbidity and mortality