1,976 research outputs found

    O-cell Testings Case Histories Demonstrate the Importance of Bored Pile (Drilled Shaft) Construction Technique

    Get PDF
    Herein we review the Osterberg Cell, or O-cell, method for performing large capacity load tests on bored piles (drilled shafts), and demonstrate how it provides a new opportunity to assess the effects of construction technique. A sampling of 8 case histories, 7 with comparative testing, illustrates the impact of poor technique and thus demonstrates the importance of good construction technique. The poor techniques include inadequate bottom cleanout, failure to use drilling fluids, poor concrete placement, failure to roughen sides, and improper drilling tools. We conclude with a brief description of a recent, world record, 133 MN (15,000 tons) O-cell load test

    Physiological responses to wearing the space shuttle launch and entry suit and the prototype advanced crew escape suit compared to the unsuited condition

    Get PDF
    The launch and entry suit (LES) is a life support suit worn during Orbiter ascent and descent. The impact of suit weight and restricted mobility on egress from the Orbiter during an emergency is unknown. An alternate suit - the advanced crew escape suite (ACES) - is being evaluated. The physiological responses to ambulatory exercise of six subjects wearing the LES and ACES were measured and compared to those measurements taken while unsuited. Dependent variables included heart rate and metabolic response to treadmill walking at 5.6 km/h (3.5 mph), and also bilateral concentric muscle strength about the knee, shoulder, and elbow. No significant (p greater than 0.06) differences in heart rate or metabolic variables were measured in either suit while walking at 5.6 km/h. Significant (p less than 0.05) decreases in all metabolic variables were remarked when both suits were compared to the unsuited condition. There were no significant (p greater than 0.05) differences among the three suit conditions at 30 or 180 deg/s for muscles about the elbow and knee; however, about the shoulder, a significant (p = 0.0215) difference between the ACES and the unsuited condition was noted. Therefore, wearing a life support suit while performing Orbiter egress imposes a significant metabolic demand on crewmembers. Selective upper body strength movements may be compromised

    Measuring International Competitiveness in the Beef Sector

    Get PDF
    Beef is a heterogenous commodity, which makes it difficult to compare beef prices on an international level. This article evaluates several methods of comparing beef prices for use in measuring both comparative advantage and the rate of protection. The most suitable method is one that compares the prices of wholesale cuts, adjusted for transportation costs.

    Crotalus atrox venom preconditioning increases plasma fibrinogen and reduces perioperative hemorrhage in a rat model of surgical brain injury.

    Get PDF
    Perioperative bleeding is a potentially devastating complication in neurosurgical patients, and plasma fibrinogen concentration has been identified as a potential modifiable risk factor for perioperative bleeding. The aim of this study was to evaluate preconditioning with Crotalus atrox venom (Cv-PC) as potential preventive therapy for reducing perioperative hemorrhage in the rodent model of surgical brain injury (SBI). C. atrox venom contains snake venom metalloproteinases that cleave fibrinogen into fibrin split products without inducing clotting. Separately, fibrinogen split products induce fibrinogen production, thereby elevating plasma fibrinogen levels. Thus, the hypothesis was that preconditioning with C. atrox venom will produce fibrinogen spilt products, thereby upregulating fibrinogen levels, ultimately improving perioperative hemostasis during SBI. We observed that Cv-PC SBI animals had significantly reduced intraoperative hemorrhage and postoperative hematoma volumes compared to those of vehicle preconditioned SBI animals. Cv-PC animals were also found to have higher levels of plasma fibrinogen at the time of surgery, with unchanged prothrombin time. Cv-PC studies with fractions of C. atrox venom suggest that snake venom metalloproteinases are largely responsible for the improved hemostasis by Cv-PC. Our findings indicate that Cv-PC increases plasma fibrinogen levels and may provide a promising therapy for reducing perioperative hemorrhage in elective surgeries

    The long-term impact of the MEMA kwa Vijana adolescent sexual and reproductive health intervention: effect of dose and time since intervention exposure.

    Get PDF
    BACKGROUND: Despite recent decreases in HIV incidence in many sub-Saharan African countries, there is little evidence that specific behavioural interventions have led to a reduction in HIV among young people. Further and wider-scale decreases in HIV require better understanding of when behaviour change occurs and why. The MEMA kwa Vijana adolescent sexual and reproductive health intervention has been implemented in rural Mwanza, Tanzania since 1999. A long-term evaluation in 2007/8 found that the intervention improved knowledge, attitudes to sex and some reported risk behaviours, but not HIV or HSV2 prevalence. The aim of this paper was to assess the differential impact of the intervention according to gender, age, marital status, number of years of exposure and time since last exposure to the intervention. METHODS: In 2007, a cross-sectional survey was conducted in the 20 trial communities among 13,814 young people (15-30 yrs) who had attended intervention or comparison schools between 1999 and 2002. Outcomes for which the intervention had an impact in 2001 or 2007 were included in this subgroup analysis. Data were analysed using cluster-level methods for stratified cluster-randomised trials, using interaction tests to determine if intervention impact differed by subgroup. RESULTS: Taking into account multiplicity of testing, concurrence with a priori hypotheses and consistency within the results no strong effect-modifiers emerged. Impact on pregnancy knowledge and reported attitudes to sex increased with years of exposure to high-quality intervention. CONCLUSIONS: The desirable long-term impact of the MEMA kwa Vijana intervention did not vary greatly according to the subgroups examined. This suggests that the intervention can have an impact on a broad cross-section of young people in rural Mwanza. TRIAL REGISTRATION: ClinicalTrials.gov NCT00248469

    An automated quasi-continuous capillary refill timing device

    Get PDF
    Capillary refill time (CRT) is a simple means of cardiovascular assessment which is widely used in clinical care. Currently, CRT is measured through manual assessment of the time taken for skin tone to return to normal colour following blanching of the skin surface. There is evidence to suggest that manually assessed CRT is subject to bias from ambient light conditions, a lack of standardisation of both blanching time and manually applied pressure, subjectiveness of return to normal colour, and variability in the manual assessment of time. We present a novel automated system for CRT measurement, incorporating three components: a non-invasive adhesive sensor incorporating a pneumatic actuator, a diffuse multi-wavelength reflectance measurement device, and a temperature sensor; a battery operated datalogger unit containing a self contained pneumatic supply; and PC based data analysis software for the extraction of refill time, patient skin surface temperature, and sensor signal quality. Through standardisation of the test, it is hoped that some of the shortcomings of manual CRT can be overcome. In addition, an automated system will facilitate easier integration of CRT into electronic record keeping and clinical monitoring or scoring systems, as well as reducing demands on clinicians. Summary analysis of volunteer (n = 30) automated CRT datasets are presented, from 15 healthy adults and 15 healthy children (aged from 5 to 15 years), as their arms were cooled from ambient temperature to 5°C. A more detailed analysis of two typical datasets is also presented, demonstrating that the response of automated CRT to cooling matches that of previously published studies
    • …
    corecore