Phyletic trends in uppermost Triassic (Rhaetian) Radiolaria: Two examples from Queen Charlotte Islands, British Columbia, Canada

Risella Carter and Laxtorum Blome, two genera from the diverse Rhaetian fauna of the Sandilands Formation, Queen Charlotte Islands, are used to illustrate phyletic trends in latest Triassic Radiolaria. Several distinct morphotypes constituting a lineage are recognized for each genus. These lineages are homogenous, evolved in situ, and show a continuum of variation through time. The evolution of Risella takes place entirely in the Rhaetian and all species disappear at the end of the Triassic. Earliest species of Laxtorum appear in the upper Norian and evolve rapidly in the Rhaetian. All Rhaetian species go extinct at the end of the Triassic but the genus survives marginally into the Lower Jurassic. Morphological transformations in Risella (a paronaellid) are manifest in the external/cortical shell as the shape changes from triangular to three-rayed. In Laxtorum, distal post abdominal chambers become constricted and eventually develop a terminal tube while, at the same time, an increase in size and sphericity is coupled with a reduction in the number of post abdominal chambers. Evolutionary transitions in the Risella lineage probably represent a reversion of the normal hypothesized trend for paronaellid radiolarians. In the Laxtorum lineage, comparisons with other groups and species displaying similar homeomorphies suggest the evolutionary trends are fundamental and occur repeatedly in faunas of all ages.

Lower Triassic bryozoan beds from Ellesmere Island, High Arctic, Canada

In the Sverdrup Basin (Canadian Arctic), the Lower Triassic Blind Fiord Formation, comprising siltstone and shale, overlies various Middle to Late Permian (post-Wordian) sedimentary units. This formation is subdivided into three members: the Confederation Point, Smith Creek and Svartfjeld members of, respectively, Griesbachian-Dienerian, Smithian-Spathian and Spathian ages. Lower Triassic bryozoan beds are known from many sections of Ellesmere Island, but have never been studied in detail. During the Early Triassic biotic recovery interval, immediately following the Permian/Triassic extinction event, only one new bryozoan genus evolved in the Boreal region: Arcticopora. The first lower Triassic bryozoan bed appears in the upper part of the Confederation Point Member, and is dated as late Dienerian. Succeeding bryozoan levels occur in the upper Smith Creek Member, and are late Smithian-early Spathian in age. Bryozoan beds occupy a similar stratigraphic position in Spitsbergen. There, they occur scattered in silt to coarse sandstone beds, but also in bryozoan-dominated packstone beds resembling the packstone units in the uppermost part of the Confederation Point Member of Ellesmere Island. Previously, bryozoan-rich beds of Triassic age have not been reported, and the present work fills an important time gap in the bryozoan carbonate database

Erosion and channel change as factors of landslides and valley formation in Champlain sea clays: The Chacoura river, Quebec, Canada

The Champlain Sea clays of Eastern Canada are incised by numerous rivers. Their slopes have been modified by landslides: on the Chacoura River near Trois-Rivières (Quebec), several large landslide scars, more or less recent, are visible. The role of erosion (channel incision, lateral channel migration and erosion of slopes due to agricultural drainage) as a trigger of these landslides is important. The aim of this study is to understand how erosion and landslides are related to valley development. From a detailed analysis of aerial photographs and DEMs, a map of the phenomena has been drawn by identifying various elements such as landslides, limits of the slope, position of the channel, and the area covered by forest. It is shown that channel change and erosion are strongly linked to landslides by the fact that they change the bank morphology in an unstable way. A slide in itself is a natural way for the slope to achieve stability. But when it occurs in a stream, it creates a disturbance to the stream flow enhancing local erosion which may change the river path and generate more erosion downstream or upstream resulting in more slides. Cross-valley sections and a longitudinal profile show that landslides are a major factor of valley formation. It appears that the upper part of the Chacoura River valley is still unaffected by landslides and has V-shaped sections. The lower part has been subject to intense erosion and many landslide scars can be seen. This shows that the valley morphology is transient, and that future activity is more likely to occur in the upper part of the river. Therefore the identification of areas prone to erosion will help determine the possible location of future large landslides just like the ones that occurred in the lower part.

Interet de la double voie d'abord dans les blepharoplasties superieures associees aux malpositions palpebrales. [Advantages of a double approach to upper blepharoplasty associated with eyelid malpositions]

During upper blepharoplasty, myocutaneous excess and fat pads are treated using an anterior approach. Eyelid malpositions such as involutional ptosis or lid retraction could be associated and should be treated with associated procedures. Aponeurotic surgery on the levator muscle can make use of the same anterior approach, with the major difficulty of dosage. In cases of ptosis with a positive epinephrine test or minor muscular retraction, the Muller muscle-conjunctival surgery via a posterior approach seems to be more reproducible. Double-approach techniques are described.

Three-dimensional slope stability analysis of South Peak, Crowsnest Pass, Alberta, Canada

South Peak is a 7-Mm3 potentially unstable rock mass located adjacent to the 1903 Frank Slide on Turtle Mountain, Alberta. This paper presents three-dimensional numerical rock slope stability models and compares them with a previous conceptual slope instability model based on discontinuity surfaces identified using an airborne LiDAR digital elevation model (DEM). Rock mass conditions at South Peak are described using the Geological Strength Index and point load tests, whilst the mean discontinuity set orientations and characteristics are based on approximately 500 field measurements. A kinematic analysis was first conducted to evaluate probable simple discontinuity-controlled failure modes. The potential for wedge failure was further assessed by considering the orientation of wedge intersections over the airborne LiDAR DEM and through a limit equilibrium combination analysis. Block theory was used to evaluate the finiteness and removability of blocks in the rock mass. Finally, the complex interaction between discontinuity sets and the topography within South Peak was investigated through three-dimensional distinct element models using the code 3DEC. The influence of individual discontinuity sets, scale effects, friction angle and the persistence along the discontinuity surfaces on the slope stability conditions were all investigated using this code.

Terrestrial Lidar investigation of the 2004 rockslide along Petit Champlain Street, Québec City (Quebec, Canada)

Au cours des 240 dernières années, 53 mouvements de versant se sont produits le long du promontoire de Québec, causant la mort de 88 personnes principalement lors de chutes de blocs. En octobre 2004, un petit éboulement a atteint la route dans une zone proche de l'éboulement de 1889 qui a tué 35 personnes et blessé 30 autres. Une image 3D a été créée par l'utilisation d'un scanner Lidar terrestre (SLT). Les sept familles de joints identifiées sont en accord avec les mesures effectuées dans de précédentes études. L'imagerie SLT a aussi permit d'estimer les volumes des instabilités passées et d'en analyser le mécanisme : un glissement rocheux qui affecte des blocs débités en parallélépipèdes par d'autres familles de joints. De plus la zone étudiée montre qu'elle est favorable aux chutes de blocs.

Approche des oedèmes du membre supérieur liés à une occlusion de la veine sous-clavière située en aval d'une fistule artério-veineuse [Approach to upper limb edema secondary to subclavian vein occlusion situated distal to an arteriovenous fistula]

AIM OF THE STUDY: To analyse the course of upper limb edema in patients with an arteriovenous fistula used for dialysis and to analyse the available therapeutic options. STUDY DESIGN: Retrospective study of patients with this type of edema, who were treated in our institution from 1992 to 1996. PATIENTS AND METHODS: Seven consecutive patients with an arterioveinous fistula treated for edema of the upper extremity, were reviewed. The fistula was created at the elbow in 6 patients and at the forearm in 1. The edema appeared immediately after operation in 4 patients and after a delay in 3 patients. Stenosis (3 patients) or occlusion (2 patients) of the subclavian vein was documented in 5 patients who were investigated by angiography. RESULTS: The edema regressed spontaneously in 4 patients because collaterals developed in 3 patients, and the fistula thrombosed in 1 patient. Surgical intervention allowed regression of the edema in the other 3 patients: excessive output of the fistula was reduced in 2 patients and an axillojugular bypass was performed in 1 patient. The fistula remained effective in 6 patients. Another fistula was performed on the contralateral arm in 1 patient. CONCLUSION: Non-operative management is recommended in patients who develop edema immediately after creation of the fistula, because spontaneous regression is likely. Measures aimed at reducing the output of the fistula or enhancing the venous capacities of the arm are required when edema appears at a later stage. The fistula can be saved in the majority of cases.

Is the diagnostic yield of upper GI endoscopy improved by the use of explicit panel-based appropriateness criteria?

BACKGROUND: Increasing the appropriateness of use of upper gastrointestinal (GI) endoscopy is important to improve quality of care while at the same time containing costs. This study explored whether detailed explicit appropriateness criteria significantly improve the diagnostic yield of upper GI endoscopy. METHODS: Consecutive patients referred for upper GI endoscopy at 6 centers (1 university hospital, 2 district hospitals, 3 gastroenterology practices) were prospectively included over a 6-month period. After controlling for disease presentation and patient characteristics, the relationship between the appropriateness of upper GI endoscopy, as assessed by explicit Swiss criteria developed by the RAND/UCLA panel method, and the presence of relevant endoscopic lesions was analyzed. RESULTS: A total of 2088 patients (60% outpatients, 57% men) were included. Analysis was restricted to the 1681 patients referred for diagnostic upper GI endoscopy. Forty-six percent of upper GI endoscopies were judged to be appropriate, 15% uncertain, and 39% inappropriate by the explicit criteria. No cancer was found in upper GI endoscopies judged to be inappropriate. Upper GI endoscopies judged appropriate or uncertain yielded significantly more relevant lesions (60%) than did those judged to be inappropriate (37%; odds ratio 2.6: 95% CI [2.2, 3.2]). In multivariate analyses, the diagnostic yield of upper GI endoscopy was significantly influenced by appropriateness, patient gender and age, treatment setting, and symptoms. CONCLUSIONS: Upper GI endoscopies performed for appropriate indications resulted in detecting significantly more clinically relevant lesions than did those performed for inappropriate indications. In addition, no upper GI endoscopy that resulted in a diagnosis of cancer was judged to be inappropriate. The use of such criteria improves patient selection for upper GI endoscopy and can thus contribute to efforts aimed at enhancing the quality and efficiency of care. (Gastrointest Endosc 2000;52:333-41).

Daily physical activity assessment: what is the importance of upper limb movements vs whole body movements?

OBJECTIVE: The movement of the upper limbs (eg fidgeting-like activities) is a meaningful component of nonexercise activity thermogenesis (NEAT). This study examined the relationship between upper limb movements and whole body trunk movements, by simultaneously measuring energy expenditure during the course of the day. DESIGN: A cross-sectional study consisting of 88 subjects with a wide range in body mass index (17.3-32.5 kg/m(2)). The energy expenditure over a 24-h period was measured in a large respiratory chamber. The body movements were assessed by two uniaxial-accelerometers during daytime, one on the waist and the other on the dominant arm. The accelerometry scores from level 0 (=immobile) up to level 9 (=maximal intensity) were recorded. The activities of subjects were classified into eight categories: walking at two speeds on a horizontal treadmill (A & B), ambling (C), self-care tasks (D), desk work (E), meals (F), reading (G), watching TV (H). RESULTS: There was a significant relationship between the accelerometry scores from the waist (ACwaist) and that from the wrist (ACwrist) over the daytime period (R(2)=0.64; P<0.001). The ACwrist was systematically higher than the ACwaist during sedentary activities, whereas it was the reverse for walking activities. ACwrist to ACwaist ratio of activities E-H were above 1.0 and for walking activities (A-C) were below 1.0. A multiple regression analysis for predicting daytime energy expenditure revealed that the explained variance improved by 2% only when the ACwrist was added as a second predictor in addition to the ACwaist. This indicates that the effect of the ACwrist for predicting energy expenditure was of limited importance in our conditions of measurement. CONCLUSIONS: The acceleration of the upper limbs which includes fidgeting is more elevated than that of the whole body for sitting/lying down activities. However, their contribution to energy expenditure is lower than whole body trunk movements, thus indicating that the weight-bearing locomotion activities may be a key component of NEAT. However, its contribution may depend on the total duration of the upper limb movements during the course of the day.

Underutilization of upper gastrointestinal endoscopy.

BACKGROUND & AIMS: Efforts to reduce costs in health care may raise concerns about underuse of medical procedures. This study prospectively assessed underuse of upper gastrointestinal endoscopy in a cohort of patients in whom we have recently published data on overuse of endoscopy. METHODS: Underuse was identified by formal necessity criteria for endoscopy, obtained by an explicit panel process. Outpatients were consecutively included in two clinical settings. Setting A consisted of 20 primary care physicians and 7215 patient visits that occurred within 1 month. Setting B consisted of 920 visits that occurred during 3 weeks at an outpatient clinic. RESULTS: During these 8135 visits, 611 patients complained of upper digestive symptoms; 63 of them underwent endoscopy. Underuse was identified in 72 patients (11.8%). The two clinical situations mainly responsible for underuse of endoscopy were uninvestigated peptic symptoms resistant to treatment and dysphagia. At first follow-up, 29 of the patients with initial underuse still fulfilled criteria of necessity (underuse rate, 4.7%). One-year follow-up showed underuse of endoscopy in 5 patients. CONCLUSIONS: This prospective evidence shows that underuse of a medical procedure exists. The estimated overuse and underuse of endoscopy in this cohort were approximately equal (5%). Improving quality of care will require reductions of both overuse and underuse of medical procedures.

Tectonic evolution of the High Himalaya in upper Lahul (NW Himalaya, India)

The Upper Lahul region in the NW Himalaya is located in the transition zone between the High Himalayan Crystalline (HHC) to the SW and the Tethyan Zone sedimentary series to the NE. The tectonic evolution of these domains during the Himalayan Orogeny is the consequence of a succession of five deformation events. An early D1 phase corresponds to synmetamorphic, NE verging folding. This deformation created the Tandi Syncline, which consists of Permian to Jurassic Tethyan metasediments cropping out in the core of a large-scale synformal fold within the HHC paragneiss. This tectonic event is interpreted as related to a NE directed nappe stacking (Shikar Beh Nappe), probably during the late Eocene to the early Oligocene. A subsequent D2a phase caused SW verging folding in the HHC. This deformation is interpreted as contemporaneous with late Oligocene to early Miocene SW directed thrusting along the Main Central Thrust. In the Tethyan Zone, a D2b phase is marked by a decollement thrust, a system of reverse faults, and gentle folds, associated with SW directed tectonic movements. This deformation is related to an imbricate structure, characteristic of a shallow structural level, and developed in the frontal part of a nappe affecting the Tethyan Zone units of SE Zanskar (Nyimaling-Tsarap Nappe). A later D3 phase generated the Chandra Dextral Shear Zone (CDSZ), a large-scale, ductile, dextral strike-slip shear zone, located in the transition zone between the HHC and the Tethyan Himalaya. The CDSZ most likely represents a part of a system of early Miocene extensional and/or dextral, strike-slip shear zones-observed at the HHC-Tethyan Zone contact along the entire Himalaya. A final D4 phase induced large-scale doming and NE:verging back folding.