We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Unconformity-related uranium deposits, which represent a significant high-grade uranium resource, are systematically surrounded by a host-rock alteration halo enriched in clay minerals. Illite is often the major clay mineral component of the halo and it displays a variable crystal structure. New data are provided on the crystal structure and the chemistry of illite encountered within and outside of the alteration halo surrounding the Shea Creek deposit. Two illite populations were distinguished using textural and structural criteria: samples rich in the tv-1M polytype display thin (sub-micrometer) and ‘hairy’ shapes, while samples richer in the cv-1M polytype contain illites with rigid lath-like shapes several micrometers wide. In barren ‘regional’ sandstone, the trends with depth of the textural and microstructural properties of illite particles are: (1) an increase of particle size, (2) an evolution to a more isometric form, and (3) a dominance of the cv-1M polytype over the tv-1M polytype. These trends record diagenetic processes under conditions of deep burial and differ from those observed in altered sandstone around the uranium mineralization. The altered sandstone is characterized by enrichment in the tv-1M polytype near the unconformity and/or brittle structural features. This tv-1M illitization took place in response to structurally-controlled infiltration of basement rocks by diagenetic brines which were further recycled after interaction into the overlying basin. Variations of the illite structural and textural properties may result from nucleation/growth kinetics and may be indicative of a change in the flow regime, and/or a change of saturation state of the fluid vs. illite. The tv-1M illite may be favored in environments characterized by a high fluid/rock ratio and a high supersaturation state of the fluids in proximity to mineralization.
The spatial distribution of the dominant matrix minerals present in the middle-Proterozoic Athabasca Group sandstone (kaolin, illite, sudoite, dravite, hematite) was studied at a regional scale in the Shea Creek region (Saskatchewan, Canada), in which two epigenetic unconformity-type uranium deposits have been discovered. 3D models of matrix mineral distribution were derived from normative mineral calculations and 3D interpolation using whole-rock geochemical analyses of sandstone samples collected from both mineralized and barren areas. The calculations were constrained by information obtained from petrographic and crystal-chemical clay mineralogical studies on representative samples. The 3D mineral distribution models were compared to the lithostratigraphy and structural features of the Athabasca Group sandstone to ascertain the source and mobility of the main elements involved in the sandstone host-rock alteration processes related to the U mineralization. The distribution of Al is conformable with the lithostratigraphy throughout the studied area, regardless of proximity to basement-rooted structures and U ore bodies. The distribution of illite displays similar features, but the intensity of the illitization of kaolin decreases with increasing distance from the structures and U ore bodies. Hematite bleaching and neoformation of sudoite and dravite were restricted to the vicinity of the fault zones above the U ore bodies. The spatial configurations of the mineral anomalies show that syn-ore fluids flowed from the basement towards the sandstone cover via the fault zones, as described in current metallogenic models. Although Al remained immobile (mass transfer), the anomalous K, B and Mg present in the host-rock alteration haloes were probably imported from the basement rocks (mass transport). Unlike B and Mg, K migrated laterally at least several kilometers from the basement-rooted faults. The mineral distribution models were used to quantify the volume of altered sandstone (10−2−10−1 km3) and the amounts of K, Mg and B which were imported to the alteration haloes above the Shea Creek U ore bodies: 186,000 t of K, 66,000 t of Mg, and 11,000 t of B above the Anne ore body, and 24,000 t of K, 185,000 t of Mg, and a similar 11,000 t of B above the Colette ore body.
The 2022 update of the Canadian Stroke Best Practice Recommendations (CSBPR) for Acute Stroke Management, 7th edition, is a comprehensive summary of current evidence-based recommendations, appropriate for use by an interdisciplinary team of healthcare providers and system planners caring for persons with an acute stroke or transient ischemic attack. These recommendations are a timely opportunity to reassess current processes to ensure efficient access to acute stroke diagnostics, treatments, and management strategies, proven to reduce mortality and morbidity. The topics covered include prehospital care, emergency department care, intravenous thrombolysis and endovascular thrombectomy (EVT), prevention and management of inhospital complications, vascular risk factor reduction, early rehabilitation, and end-of-life care. These recommendations pertain primarily to an acute ischemic vascular event. Notable changes in the 7th edition include recommendations pertaining the use of tenecteplase, thrombolysis as a bridging therapy prior to mechanical thrombectomy, dual antiplatelet therapy for stroke prevention,1 the management of symptomatic intracerebral hemorrhage following thrombolysis, acute stroke imaging, care of patients undergoing EVT, medical assistance in dying, and virtual stroke care. An explicit effort was made to address sex and gender differences wherever possible. The theme of the 7th edition of the CSBPR is building connections to optimize individual outcomes, recognizing that many people who present with acute stroke often also have multiple comorbid conditions, are medically more complex, and require a coordinated interdisciplinary approach for optimal recovery. Additional materials to support timely implementation and quality monitoring of these recommendations are available at www.strokebestpractices.ca.
The 2020 update of the Canadian Stroke Best Practice Recommendations (CSBPR) for the Secondary Prevention of Stroke includes current evidence-based recommendations and expert opinions intended for use by clinicians across a broad range of settings. They provide guidance for the prevention of ischemic stroke recurrence through the identification and management of modifiable vascular risk factors. Recommendations address triage, diagnostic testing, lifestyle behaviors, vaping, hypertension, hyperlipidemia, diabetes, atrial fibrillation, other cardiac conditions, antiplatelet and anticoagulant therapies, and carotid and vertebral artery disease. This update of the previous 2017 guideline contains several new or revised recommendations. Recommendations regarding triage and initial assessment of acute transient ischemic attack (TIA) and minor stroke have been simplified, and selected aspects of the etiological stroke workup are revised. Updated treatment recommendations based on new evidence have been made for dual antiplatelet therapy for TIA and minor stroke; anticoagulant therapy for atrial fibrillation; embolic strokes of undetermined source; low-density lipoprotein lowering; hypertriglyceridemia; diabetes treatment; and patent foramen ovale management. A new section has been added to provide practical guidance regarding temporary interruption of antithrombotic therapy for surgical procedures. Cancer-associated ischemic stroke is addressed. A section on virtual care delivery of secondary stroke prevention services in included to highlight a shifting paradigm of care delivery made more urgent by the global pandemic. In addition, where appropriate, sex differences as they pertain to treatments have been addressed. The CSBPR include supporting materials such as implementation resources to facilitate the adoption of evidence into practice and performance measures to enable monitoring of uptake and effectiveness of recommendations.
Improvements in management of transient ischemic attack (TIA) have decreased stroke and mortality post-TIA. Studies examining trends over time on a provincial level are limited. We analyzed whether efforts to improve management have decreased the rate of stroke and mortality after TIA from 2003 to 2015 across an entire province.
Methods:
Using administrative data from the Canadian Institute for Health Information’s (CIHI) databases from 2003 to 2015, we identified a cohort of patients with a diagnosis of TIA upon discharge from the emergency department (ED). We examined stroke rates at Day 1, 2, 7, 30, 90, 180, and 365 post-TIA and 1-year mortality rates and compared trends over time between 2003 and 2015.
Results:
From 2003 to 2015 in Ontario, there were 61,710 patients with an ED diagnosis of TIA. Linear regressions of stroke after the index TIA showed a significant decline between 2003 and 2015, decreasing by 25% at Day 180 and 32% at 1 year (p < 0.01). The 1-year stroke rate decreased from 6.0% in 2003 to 3.4% in 2015. Early (within 48 h) stroke after TIA continued to represent approximately half of the 1-year event rates. The 1-year mortality rate after ED discharge following a TIA decreased from 1.3% in 2003 to 0.3% in 2015 (p < 0.001).
Interpretation:
At a province-wide level, 1-year rates of stroke and mortality after TIA have declined significantly between 2003 and 2015, suggesting that efforts to improve management may have contributed toward the decline in long-term risk of stroke and mortality. Continued efforts are needed to further reduce the immediate risk of stroke following a TIA.
The objective of this analysis was to evaluate the short- (8 weeks) and long-term (24 weeks) efficacy of three fixed doses of venlafaxine extended release (ER) and placebo on the social adjustment of patients with generalised anxiety disorder (GAD). We analysed data from 544 outpatients who participated in a 24-week, double-blind, multicentre, parallel-group, placebo-controlled study conducted at 55 centres in five countries. All patients meet the DSM-IV criteria for GAD and were randomly assigned to receive venlafaxine ER 37.5, 75, and 150 mg or matched placebo administered orally once daily. Social adjustment was measured using the Social Adjustment Scale-Self Report, which explores social adaptation in the areas of work, social and leisure, extended family, primary relationship (marital), parental, and family unit. At baseline, the GAD patients had a high level of social dysfunction. Venlafaxine ER showed a dose-related improvement in social impairment during short-term treatment and in sustaining this improvement over the long-term. In the most severely socially impaired subgroup, placebo remission rates on the HAM-A were low, and the magnitude of the venlafaxine-placebo difference on the mean HAM-A total score was high, reaching more than 7 points. The benefits of venlafaxine ER treatment of GAD extend beyond that of improvement of anxiety symptoms to a significant improvement in the impairment of functioning that is associated with the illness.
Increasing numbers of research papers about information retrieval for Health Technology Assessments (HTA), systematic reviews and other evidence syntheses are being published. It is time-consuming for information specialists to keep up-to-date with the latest developments in the field. To help searchers with this challenge, the Interest Group on Information Retrieval (IRG) of Health Technology Assessment International (HTAi) has compiled the best available research evidence on information retrieval aspects into an open-access web resource: Summarized Research in Information Retrieval for HTA (SuRe Info). The resource can be accessed at http://www.sure-info.org
METHODS:
The Sure Info team run topic-specific search strategies in selected relevant databases to identify information retrieval methods publications that fulfil the SuRe Info inclusion criteria. Eligible publications receive a structured abstract containing a brief critical appraisal. Key messages for search practice based on the appraisals and accepted best practice are summarized into topic-specific chapters.
RESULTS:
SuRe Info currently offers fourteen chapters, with more in development. SuRe Info chapters fall into two categories: (i) chapters about general search methods that are used across all types of research, such as how to develop search strategies and the availability and use of search filters, and (ii) chapters summarizing the methods to use when searching for specific aspects of HTA (as defined in the European Network for HTA (EUnetHTA) HTA Core Model®), including searching for evidence on clinical effectiveness and safety, and identifying economic evaluations. References at the end of each chapter are linked to appraisals of publications that have been used to develop each chapter. Links to the full-text of the publications are provided when freely available. The SuRe Info chapters are reviewed every six months and updated if new evidence is identified or if resources change.
CONCLUSIONS:
SuRe Info is a unique resource, identifying and summarizing current best research evidence on information retrieval aspects for HTA. It supports the timely uptake of potential efficiencies arising from new evidence that may be incorporated into the evidence identification processes of HTA organizations.
Key pathophysiology of sickle cell anaemia includes compensatory erythropoiesis, vascular injury and chronic inflammation, which divert amino acids from tissue deposition for growth/weight gain and muscle formation. We hypothesised that sickle mice maintained on an isoenergetic diet with a high percentage of energy derived from protein (35 %), as opposed to a standard diet with 20 % of energy derived from protein, would improve body composition, bone mass and grip strength. Male Berkeley transgenic sickle mice (S; n 8–12) were fed either 20 % (S20) or 35 % (S35) diets for 3 months. Grip strength (BIOSEB meter) and body composition (dual-energy X-ray absorptiometry scan) were measured. After 3 months, control mice had the highest bone mineral density (BMD) and bone mineral content (BMC) (P < 0·005). S35 mice had the largest increase in grip strength. A two-way ANOVA of change in grip strength (P = 0·043) attributed this difference to genotype (P = 0·025) and a trend in type of diet (P = 0·067). l-Arginine (l-Arg) supplementation of the 20 % diet was explored, as a possible mechanism for improvement obtained with the 35 % diet. Townes transgenic sickle mice (TS; n 6–9) received 0·8, 1·6, 3·2 or 6·4 % l-Arg based on the same protocol and outcome measures used for the S mice. TS mice fed 1·6 % l-Arg for 3 months (TS1.6) had the highest weight gain, BMD, BMC and lean body mass compared with other groups. TS3.2 mice showed significantly more improvement in grip strength than TS0·8 and TS1.6 mice (P < 0·05). In conclusion, the high-protein diet improved body composition and grip strength. Outcomes observed with TS1.6 and TS3.2 mice, respectively, confirm the hypothesis and reveal l-Arg as part of the mechanism.
We investigated whether a higher number of fast-food outlets in an individual’s home neighbourhood is associated with increased prevalence of type 2 diabetes mellitus and related risk factors, including obesity.
Design
Cross-sectional study.
Setting
Three UK-based diabetes screening studies (one general population, two high-risk populations) conducted between 2004 and 2011. The primary outcome was screen-detected type 2 diabetes. Secondary outcomes were risk factors for type 2 diabetes.
Subjects
In total 10 461 participants (mean age 59 years; 53 % male; 21 % non-White ethnicity).
Results
There was a higher number of neighbourhood (500 m radius from home postcode) fast-food outlets among non-White ethnic groups (P<0·001) and in socially deprived areas (P<0·001). After adjustment (social deprivation, urban/rural, ethnicity, age, sex), more fast-food outlets was associated with significantly increased odds for diabetes (OR=1·02; 95 % CI 1·00, 1·04) and obesity (OR=1·02; 95 % CI 1·00, 1·03). This suggests that for every additional two outlets per neighbourhood, we would expect one additional diabetes case, assuming a causal relationship between the fast-food outlets and diabetes.
Conclusions
These results suggest that increased exposure to fast-food outlets is associated with increased risk of type 2 diabetes and obesity, which has implications for diabetes prevention at a public health level and for those granting planning permission to new fast-food outlets.
We present an ongoing survey with the Nançay Radio Telescope at L-band. The targeted area is 74° ≲ l < 150° and 3.5° < |b| < 5°. This survey is characterized by a long integration time (18 min), large bandwidth (512 MHz) and high time and frequency resolution (64 μs and 0.5 MHz) giving a nominal sensitivity limit of 0.055 mJy for long period pulsars. This is about 2 times better than the mid-latitude HTRU survey, and is designed to be complementary with current large scale surveys. This survey will be more sensitive to transients (RRATs, intermittent pulsars), distant and faint millisecond pulsars as well as scintillating sources (or any other kind of radio faint sources) than all previous short-integration surveys.
In this work, hydrophobic mesostructured organosilica thin films, exhibiting isolated mesopores (~ 7 nm), have been successfully deposited by spin-coating using different polystyrene-block-polyethylene oxide copolymers (PS-b-PEO) as structure-directing agents and methyltriethoxysilane (MTES) as organosilica precursor. Different ordered mesostructures (Face Centered Cubic, 2D or 3D Hexagonal and Body Centered Cubic) can be achieved by controlling different synthesis parameters. X-Ray Diffraction (XRD) and Grazing Incidence Small Angle X-Ray Scattering (GISAXS) techniques were used to investigate the mesostructure evolution through thermal and UV treatments. Swelling and shrinkage were evidenced by in-situ XRD and X-Ray Reflectivity measurements during the thermal removal of the meso-templates. Infrared spectroscopy and 29Si NMR were additionally used to investigate the microstructure evolution. The film porosity was estimated thanks to Ellipsometry Porosimetry (EP). Correlation between mechanical properties through nanoindentation measurements and the mesostructure ordering is discussed as well as assessments of the dielectric constant k by mercury contact probe.
We give a general theorem stating that transversely intersecting regular stratified sets have regularly stratified intersection (and union) for a large class of regularity conditions. Such a result was previously known only for Whitney regular stratified sets and for weakly Whitney stratified sets.
Introduction
It is often useful to know that the transverse intersection of two regularly stratified sets is again regular. That the transverse intersection of two Whitney regular stratified sets is again Whitney regular was apparently first published in 1976 by Chris Gibson [10] in the Liverpool notes on the topological stability of smooth mappings. In their book “Stratified Morse Theory” [11], perhaps following Teissier's account for complex analytic varieties in his La Rabida notes [19] where Teissier attributes the detailed proof given there to Denis Chéniot, Mark Goresky and Robert MacPherson cite the 1972 Comptes Rendus note by Chéniot [6] for a proof of this result, which is a mistake, as Chéniot does not prove the Whitney regularity of intersections or even discuss it; he is concerned with the frontier condition in the case of a complex variety, and moreover only for intersections with a smooth complex submanifold. This mistake in attribution has unfortunately been copied by many authors.
That the transverse intersection of two weakly Whitney regular stratified sets is again weakly Whitney regular was proved by Karim Bekka in his thesis [1] and published in [3].
An examination was made of urinary catecholamine and metabolite outputs in 28 unipolar depressed patients and 25 normal controls. The total group of depressed patients had significantly higher urinary outputs of norepinephrine (NE) and its metabolite normetanephrine (NM), and significantly lower urinary outputs of the dopamine metabolite dihydroxyphenylacetic acid (DOPAC), than controls. Patients who met DSM-III criteria for a major depressive episode with melancholia (N = 8) had significantly higher urinary outputs of normetanephrine than controls, whereas patients with a major depressive episode without melancholia (N = 7) and dysthymic disorder patients (N = 8) had levels comparable with controls. We postulate that the higher urinary outputs of norepinephrine and its metabolite, normetanephrine, reflect dysregulation of the sympathetic nervous system in depression.
La compression de poudre céramique nécessite l'incorporation de molécules organiques assurant la cohésion des grains entre eux. Comprimer des poudres céramiques formulées revient à leur fournir une certaine énergie. En fonction de la formulation de la poudre, on peut mesurer l'énergie stockée par unité de masse, caractéristique de la poudre. Récemment, une technique employée dans la métallurgie des poudres, la Compaction Grande Vitesse (CGV), a été utilisée pour la mise en forme d'objets céramiques. Cette méthode apporte des particularités au niveau des propriétés physiques des comprimés, notamment en terme d'homogénéité par rapport au pressage uniaxial dit conventionnel. Des comprimés issus des deux méthodes de mise en forme, et élaborés à partir de poudres formulées différemment, seront comparés en terme de comportement à la compression et via l'utilisation d'un modèle mathématique.
Le développement d'un modèle permettant la prédiction des dimensions de la couche de réaction formée lors de l'élaboration d'assemblages acier–aluminium par mouillage réactif TIG est présenté. La croissance de la phase Fe2Al5 formée à l'interface est régie par les transferts de chaleur au sein de la structure générés par l'apport d'énergie du procédé TIG. Une modélisation du procédé couplée avec la loi de croissance de la phase constituant la couche de réaction permet alors de prédire l'épaisseur et la largeur de cette couche.