Glaciers and small ice caps in the macro-scale hydrological cycle: an assessment of present conditions and future changes

Glacier and small ice cap melt water contributions to the global hydrologic cycle are an important component of human water supply and for sea level rise. This melt water is used in many arid and semi-arid parts of the world for direct human consumption as well as indirect consumption by irrigation for crops, serving as frozen reservoirs of water that supplement runoff during warm and dry periods of summer when it is needed the most. Additionally, this melt water reaching the oceans represents a direct input to sea level rise and therefore accurate estimates of this contribution have profound economic and geopolitical implications. It has been demonstrated that, on the scale of glacierized river catchments, land surface hydrological models can successfully simulate glacier contribution to streamflow. However, at global scales, the implementation of glacier melt in hydrological models has been rudimentary or non-existent. In this study, a global glacier mass balance model is coupled with the University of New Hampshire Water Balance/Transport Model (WBM) to assess recent and projected future glacier contributions to the hydrological cycle over the global land surface (excluding the ice sheets of Greenland and Antarctica). For instance, results of WBM simulations indicate that seasonal glacier melt water in many arid climate watersheds comprises 40 % or more of their discharge. Implicitly coupled glacier and WBM models compute monthly glacier mass changes and resulting runoff at the glacier terminus for each individual glacier from the globally complete Randolph Glacier Inventory including over 200 000 glaciers. The time series of glacier runoff is aggregated over each hydrological modeling unit and delivered to the hydrological model for routing downstream and mixing with non-glacial contribution of runoff to each drainage basin outlet. WBM tracks and uses glacial and non-glacial components of the in-stream water for filling reservoirs, transfers of water between drainage basins (inter-basin hydrological transfers), and irrigation along the global system of rivers with net discharge to the ocean. Climate scenarios from global climate models prepared for IPCC AR5 are used to explore an expected range of possible future glacier outflow variability to estimate the impacts on human use of these valuable waters and their poorly understood net contribution to sea level change

Improved siRNA/shRNA Functionality by Mismatched Duplex

siRNA (small interfering RNA) and shRNA (small hairpin RNA) are powerful and commonly used tools in biomedical research. Currently, siRNAs are generally designed as two 21 nt strands of RNA that include a 19 nt completely complementary part and a 2 nt overhang. However, since the si/shRNAs use the endogenous miRNA machinery for gene silencing and the miRNAs are generally 22 nt in length and contain multiple internal mismatches, we tested if the functionality can be increased by designing the si/shRNAs to mimic a miRNA structure. We systematically investigated the effect of single or multiple mismatches introduced in the passenger strand at different positions on siRNA functionality. Mismatches at certain positions could significantly increase the functionality of siRNAs and also, in some cases decreased the unwanted passenger strand functionality. The same strategy could also be used to design shRNAs. Finally, we showed that both si and miRNA structured oligos (siRNA with or without mismatches in the passenger strand) can repress targets in all individual Ago containing cells, suggesting that the Ago proteins do not differentiate between si/miRNA-based structure for silencing activity

Occult anal sphincter deficiency could be a common finding in dyschesic patients: a first approach by colpooystddefecography

268 colpo-cysto-défécographies réalisées sur une période d'un an comme exploration de routine chez des patientes dyschésiques ont été rétrospectivement relues afin d'évaluer la fréquence des signes radiologiques d'atteinte du sphincter anal : ils ont été relevés dans 37 % des cas. Ces signes étaient présents chez des patientes présentant surtout des ptoses et prolapsus des compartiments pelviens moyen et postérieur ainsi qu'une dyskinésie des muscles du plancher, sans trouble majeur d'exonération. La colpo-cysto-défécographie permettrait donc la mise en évidence de nombreuses atteintes sphinctériennes qui pourraient au moins en partie être responsables de dyschésie

Test-positive rate at CT colonography is increased by rectal bleeding and/orunexplained weight loss, unlike other common gastrointestinal symptoms

Purpose: We evaluated the rate of significant colonic and extra-colonic abnormalities at computed tomography colonography (CTC), accordingto symptoms and age. Materials and methods: We retrospectively evaluated 7361 consecutive average-risk subjects (3073 males, average age: 60.3 ± 13.9; range 18–96years) for colorectal cancer (CRC) who underwent CTC. They were divided into three groups according to clinical symptoms: 1343 asymptomaticindividuals (group A), 899 patients with at least one “alarm” symptom for CRC, including rectal bleeding and unexplained weight loss (groupC), and 5119 subjects with other gastrointestinal symptoms (group B). Diagnostic and test-positive rates of CTC were established using opticalcolonoscopy (OC) and/or surgery as reference standard. In addition, clinically significant extra-colonic findings were noted. Results: 903 out of 7361 (12%, 95% confidence interval (CI) 0.11–0.13) subjects had at least one clinically significant colonic finding at CTC. CTCtrue positive fraction and false positive fraction were respectively 637/642 (99.2%, 95%CI 0.98–0.99) and 55/692 (7.95%, 95%CI 0.05–0.09). Thepooled test-positive rate in group C (138/689, 20.0%, 95%CI 0.17–0.23) was significantly higher than in both groups A (79/1343, 5.9%, 95%CI0.04–0.07) and B (420/5329, 7.5%, 95%CI 0.07–0.08) (p < 0.001). Aging and male gender were associated to a higher test positive rate. The rateof clinically significant extra-colonic findings was significantly higher in group C (44/689, 6.4%, 95%CI 0.04–0.08) versus groups A (26/1343,1.9%, 95%CI 0.01–0.02) and B (64/5329, 1.2%, 95%CI 0.01–0.02) (p < 0.001).Conclusion: Both test-positive and significant extra-colonic finding rates at CTC are significantly increased in the presence of “alarm” gastroin-testinal symptoms especially in older patients

Implémentation d’une consultation de colonoscopie virtuelle

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Utilité d’un logiciel de détection automatique des candidats-polype (CAD) en colonoscopie virtuelle

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Le cancer colo-rectal en imagerie : dépistage, stadification et suivi post-opératoire immédiat. Rôle de l’imagerie médicale dans le dépistage du cancer colo-rectal.

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Colonoscopie virtuelle par scanner

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