Modelling the behaviour of a large landslide with respect to hydrogeological and geomechanical parameter heterogeneity

Thanks to a sophisticated transient hydrogeological modelling allowing the determination of the pore pressure fields in La Frasse landslide mass during a crisis, it has been possible to model the mechanical behaviour of the slide and obtain results that prove to be similar to the monitored data, in terms of peak velocity, distribution of velocity with time and space and total displacements. Such results are reached only when appropriate constitutive modelling laws are used, and when geotechnical tests supply all the required parameters. The main results concern the potential effect of a drainage system during a crisis, like the one experienced in 1994. It can include vertical boreholes equipped with pumps or drains drilled from a gallery. The draining system reduces horizontal displacements down to 5% of the values modelled during the crisis. This effect, which appears to extend over a large width, will be even more significant if the boreholes discharge the drained water into the gallery, due to its extension in the presently stabilised landslide mass below the active zone. The modelling tools developed for La Frasse landslide thus provide all the necessary information to optimise the drainage schem

Spécificités hydrogéologiques des hautes vallées alpines: Exemple de la Haute-Sarine (Suisse)

Resume.: La vallée alpine de la Haute-Sarine est à plus d'un titre représentative des aquifères alluviaux de montagne, de par son environnement comme ses caractéristiques hydrogéologiques. Les investigations et les analyses réalisées dans le cadre de cette étude nous ont permis d'améliorer les connaissances sur le remplissage quaternaire meuble de cette vallée, ainsi que de mettre en évidence l'alimentation préférentielle de la nappe non seulement par l'infiltration de la rivière et des précipitations mais aussi par les apports souterrains des karsts évaporitiques. Nous avons également pu constater la richesse des ressources en eaux souterraines de la Haute-Sarine, tant au point de vue qualitatif qu'au point de vue quantitatif. La connaissance de ces caractéristiques typiques des nappes alluviales de haute altitude a par la suite permis l'élaboration d'un concept de gestion et de protection des eaux souterraines adéquat qui s'inscrit dans une politique de développement durable des ressources dans le contexte alpi

Surgical and regional treatments for colorectal cancer metastases in older patients: A systematic review and meta-analysis

Objective The present study explored the existing literature to describe the outcomes of surgical and regional treatments for colorectal cancer metastases (mCRC) in older patients. Methods A literature search was conducted in PubMed, EMBASE, Cochrane and ClinicalTrials.gov for studies published since 2000 that investigated the short- and long-term outcomes of regional treatments (surgical or non-surgical) for mCRC in patients aged >= 65 years. Pooled data analyses were conducted by calculating the risk ratio (RR), mean differences (MD) and hazard ratio (HR) between older and younger patients or between two different approaches in older patients. Results After screening 266 articles, 29 were included in this review. These studies reported the outcomes of surgery (n = 19) and non-surgical local ablation treatments (n = 3) for CRC metastases in older vs. younger patients or compared the outcomes of different interventions in older patients (n = 7). When comparing older vs. younger patients undergoing liver surgery for mCRC, pooled data analysis showed higher postoperative mortality [RR = 2.53 (95%CI: 2.00-3.21)] and shorter overall survival [HR = 1.17 (95%CI: 1.07-1.18)] in older patients, whereas no differences in operative outcomes, postoperative complications and diseasefree survival were found. When comparing laparoscopy vs. open surgery for liver resection in older mCRC patients, laparoscopy was associated with fewer postoperative complications [RR = 0.27 (95%CI: 0.10-0.73)]. Conclusion Liver resection for mCRC should not be disregarded a priori in older patients, who show similar operative and postoperative outcomes as younger patients. However, clinicians should consider that they are at increased risk of postoperative mortality and have a worse overall survival, which may reflect comorbidities and frailty