24 research outputs found
Racking Performance of Plasterboard-Clad Steel Stud Walls
It is recognised that structural design efficiency in domestic and similar structures can be improved when the composite behaviour and contribution of all materials in the permanent structure can be fully recognised in the structural design of the frame. The ability to achieve this Improvement is currently limited by the need 10 rely on empirical test results for standardised building elements when considering the composite behaviour of the entire structure. The existing test methodology for determining the shear strength of plasterboard lined steel stud walls leads to an excessively conservative design of the complete structure. Since the test configuration is for isolated test panels, the absence of continuity of the plasterboard lining around a set corner is not included in the test procedure. A test program has been devised and carried out to explore the effect of the set corner on the performance of shear test panels. A dramatic improvement in both diaphragm shear strength and shear stiffness has been achieved in these tests supporting a proposal to amend the standard lest methodology to Include set corners
Determinants of carotid microembolization
AbstractPurpose: Earlier studies have highlighted risk factors for perioperative stroke after carotid endarterectomy, such as female sex, preoperative symptoms, and cerebral infarction. In this study, we investigated the relationship between these factors and perioperative microembolization. Methods: A total of 235 patients were entered in the study at two centers. Transcranial Doppler ultrasound scanning was possible in 190 patients (81%) and was performed for 1 hour preoperatively and continuously intraoperatively as a means of detecting microemboli and monitoring mean middle cerebral artery velocity. The findings of transcranial Doppler ultrasound scanning were related to perioperative risk factors by means of univariate analysis. Results: Microemboli were detected in 28 (15%), 79 (42%), and 98 (52%) patients preoperatively, during carotid artery dissection, and after closure of the artery, respectively. Having 10 or more emboli after carotid artery closure was more common in women (P =.04) and in patients with symptomatic carotid artery disease (P =.04) and was demonstrated in three of the six patients who had a perioperative stroke. These three patients also had preoperative evidence of cerebral infarction and an intraoperative middle cerebral artery velocity less than 40 cm/s. Conclusion: In this study, perioperative microembolization was more common in women and patients with symptomatic carotid artery disease. These findings may explain the increased risk of carotid surgery in these patients. (J Vasc Surg 2001;34:1060-4.
Whole-genome sequencing of a quarter-century melioidosis outbreak in temperate Australia uncovers a region of low-prevalence endemicity
This study was funded by the National Health and Medical Research Council via awards 1046812 and 1098337, and the Wellcome Trust Sanger Institute via award 098051. S.J.P. receives funding from the NIHR Cambridge Biomedical Research Centre.Melioidosis, caused by the highly recombinogenic bacterium Burkholderia pseudomallei, is a disease with high mortality. Tracing the origin of melioidosis outbreaks and understanding how the bacterium spreads and persists in the environment are essential to protecting public and veterinary health and reducing mortality associated with outbreaks. We used whole-genome sequencing to compare isolates from a historical quarter-century outbreak that occurred between 1966 and 1991 in the Avon Valley, Western Australia, a region far outside the known range of B. pseudomallei endemicity. All Avon Valley outbreak isolates shared the same multilocus sequence type (ST-284), which has not been identified outside this region. We found substantial genetic diversity among isolates based on a comparison of genome-wide variants, with no clear correlation between genotypes and temporal, geographical or source data. We observed little evidence of recombination in the outbreak strains, indicating that genetic diversity among these isolates has primarily accrued by mutation. Phylogenomic analysis demonstrated that the isolates confidently grouped within the Australian B. pseudomallei clade, thereby ruling out introduction from a melioidosis-endemic region outside Australia. Collectively, our results point to B. pseudomallei ST-284 being present in the Avon Valley for longer than previously recognized, with its persistence and genomic diversity suggesting long-term, low-prevalence endemicity in this temperate region. Our findings provide a concerning demonstration of the potential for environmental persistence of B. pseudomallei far outside the conventional endemic regions. An expected increase in extreme weather events may reactivate latent B. pseudomallei populations in this region.Publisher PDFPeer reviewe
Middle to Late Devensian glaciation of north-east Scotland: implications for the north-eastern quadrant of the last British-Irish ice sheet
We present a review of over 175 years of research into the Middle to Late Devensian (Weichselian) glaciation of north-east Scotland based crucially on both its lithostratigraphic and geomorphic records. The location of the region, and surrounding seabed, makes this unusually detailed record significant for deciphering the former interactions and dynamics of Scottish and Scandinavian ice within the North Sea Basin (NSB), which continue to be controversial. A twelve-stage event stratigraphy is proposed based on a parsimonious interpretation of stratigraphic relationships, till lithology and regional clast fabrics, striae, subglacial bedforms, ice-marginal features and published geochronometry at critical sites. The record of regional glaciation supports converging evidence that the north-eastern quadrant of the last British and Irish Ice Sheet (BIIS) reached its maximum spatial extent in the late Middle- to early Late Devensian and later re-expanded following widespread internal glacial reorganisations, marine transgression and partial retreat from the central NSB. Retreat was interrupted by several glacial readvances of limited extent. Field-captured data helps identify important events that are not clearly resolved from remote sensing alone, particularly regarding growth phases of the last glaciation
Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease
BACKGROUND:
Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes.
METHODS:
We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization.
RESULTS:
During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events.
CONCLUSIONS:
Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)
Influence of penicillin allergy on antibiotic prescribing patterns and costs
Antibiotic treatment for patients with community- acquired pneumonia (CAP) and previous history of penicillin allergy varies widely and can be more costly than for those with no history of penicillin allergy. Aim: To assess the influence of documented penicillin allergy on antibiotic prescribing for patients with CAP in an Australian hospital, and the clinical and financial consequences arising from changes to prescribing patterns. Method: The medical records of all patients 18 years and older admitted with CAP over a 15 week period were reviewed. The severity of patients' penicillin allergies was assessed through interview using a structured questionnaire and two groups formed: those with and without penicillin allergy. The antibiotic selections and treatment costs (drug plus accommodation costs) were then compared for the two groups. Results: 155 patients were reviewed (84 females, 71 males) with a mean age of 68 years (SD 18). Of these, 27 (17%) had documented penicillin allergies, of which 12 were classified as Severity 1 (anaphylaxis, urticaria), 12 as Severity 2 (rash, itch) and 3 as intolerance (gastrointestinal upset). Patients with a penicillin allergy were more likely to receive a cephalosporin, a macrolide and/or an aminoglycoside. This approach was in accordance with the recommendations of the Therapeutic Guidelines: Antibiotic (published in 2000), however the choice of cephalosporin in all cases was not. A history of penicillin allergy increased length of stay (p=0.054) and total cost of admission (p=0.051). Conclusion: Adherence of antibiotic prescribing to the Therapeutic Guidelines: Antibiotic for patients with penicillin allergies is variable. Patients labelled with penicillin allergy had greater drug costs and total admission costs. Thorough history taking to identify patients with true allergy versus intolerance may increase appropriate use of penicillins and reduce the use of more costly and potentially toxic alternative antibiotics