Images Landsat : guide d'utilisation et source d'information géologiques pour la région de Rouyn-Norande

Bases d'un guide d'utilisation des images landstat en géologie -- Exemple d'utilisation de la méthode pour la région de Rouyn-Noranda

Images Landsat: exemple d'utilisation géologique pour la région de Val D'Or, Québec

Méthodologie et matériel utilisé -- Secteurs tectoniques -- Géologie générale de la région et potentiel économique -- Analyse statistique des linéaments -- Analyse ponctuelle des grandes structures

Images Landsat: analyse sectorielle des linéaments et interprétation des grandes structures dans la région de Rouyn-Noranda, Québec

Analyse sectorielle des linéaments -- Grandes structures -- informations supplémentaires suite aux travaux de terrain

Damages to Residential Buildings Related to Pyritic Rockfills: Field Results of an Investigation on the South Shore of Montréal, Québec, Canada

Numerous cases of garage and basement concrete slab distress at various levels of heaving and deterioration were noticed early after construction in the Montreal south-shore area (Canada). The use of clayey sedimentary rock containing pyrite as aggregates for granular subbase is responsible for most of the observed distress. The heaving of the slabs is related to the oxidation process of the pyrite, followed by sulphate crystallization causing the swelling of the compacted granular subbase. A first inspection survey was carried out in the summer of 1999 in an attempt to assess the extent and magnitude of the damage caused by pyritic rockfills. More than 200 houses showing distress associated with pyrite were investigated in three localities. Damage of the garage floor slab seems to occur earlier after construction and to be more severe likely due to the subbase thickness and to the lower quality of the rockfill. Five houses at various stages of reaction process were monitored. The results suggest that the rockfill swelling is quite fast and continuous. The heaving rate of some garage slabs might be as high as 1.2 mm/month.Key words: pyrite, shales, swelling rockfill, oxidation, sulphate attack, damage. </jats:p

Efficacy of a Device to Narrow the Coronary Sinus in Refractory Angina

BACKGROUND Many patients with coronary artery disease who are not candidates for revascularization have refractory angina despite standard medical therapy. The balloon-expandable, stainless steel, hourglass-shaped, coronary-sinus reducing device creates a focal narrowing and increases pressure in the coronary sinus, thus redistributing blood into ischemic myocardium. METHODS We randomly assigned 104 patients with Canadian Cardiovascular Society (CCS) class III or IV angina (on a scale from I to IV, with higher classes indicating greater limitations on physical activity owing to angina) and myocardial ischemia, who were not candidates for revascularization, to implantation of the device (treatment group) or to a sham procedure (control group). The primary end point was the proportion of patients with an improvement of at least two CCS angina classes at 6 months. RESULTS A total of 35% of the patients in the treatment group (18 of 52 patients), as compared with 15% of those in the control group (8 of 52), had an improvement of at least two CCS angina classes at 6 months (P = 0.02). The device was also associated with improvement of at least one CCS angina class in 71% of the patients in the treatment group (37 of 52 patients), as compared with 42% of those in the control group (22 of 52) (P = 0.003). Quality of life as assessed with the use of the Seattle Angina Questionnaire was significantly improved in the treatment group, as compared with the control group (improvement on a 100-point scale, 17.6 vs. 7.6 points; P = 0.03). There were no significant between-group differences in improvement in exercise time or in the mean change in the wall-motion index as assessed by means of dobutamine echocardiography. At 6 months, 1 patient in the treatment group had had a myocardial infarction; in the control group, 1 patient had died and 3 had had a myocardial infarction. CONCLUSIONS In this small clinical trial, implantation of the coronary-sinus reducing device was associated with significant improvement in symptoms and quality of life in patients with refractory angina who were not candidates for revascularization

Relation between the sagittal pelvic and lumbar spine geometries following surgical correction of adolescent idiopathic scoliosis

Sagittal spinopelvic relations have been reported in adolescent idiopathic scoliosis (AIS), but there is little information on their effect following surgery. The objective of this study is to evaluate the relation between the pelvic and lumbar spine geometries following posterior spinal instrumentation and fusion (PSIF). Sixty patients with AIS undergoing PSIF were studied retrospectively. Thoracic kyphosis (TK), lumbar lordosis (LL), LL within and below fusion, pelvic incidence (PI), sacral slope (SS) and pelvic tilt (PT) were measured on preoperative and postoperative standing lateral radiographs. Significant postoperative correlations were found between PI and LL (r = 0.67), SS and LL (r = 0.90), PI and LL below fusion (r = 0.40), SS and LL below fusion (r = 0.48). Pelvic parameters did not influence LL within fusion. A strong correlation was found between LL below and within fusion (r = −0.76). The close interdependence between lumbar lordosis and pelvic geometry preoperatively is maintained postoperatively following PSIF. In the planning of surgery for AIS, it may be helpful to evaluate the sagittal pelvic morphology (PI) in addition to the spinal curves. Preoperative evaluation of the pelvic morphology could be used to optimize intraoperative positioning of the patient and to determine the optimal amount of LL that needs to be restored or preserved by the instrumentation, so that LL remains congruent with the pelvic morphology