A study of the use of vibration and stress wave sensing for the detection of bearing failure

Results from an experimental study of vibrations and stress waves emitted from ball bearings are presented. Fatique tests were run with both high quality bearings and man faulted bearings, all of one size. Tests were instrumented with different sensors to detect the noises from 10 Hz to 1 MHz. Frequency spectrum plots are presented. The modulation characteristics of the ultrasonic noises were analyzed, and acoustic emission type measurements were conducted. Results are presented which show that there are usable acoustic signal levels even beyond 500 KHz. These signal levels are modulated by a low frequency carrier which is a function of the stress loading and acoustic transmissibility. The results were correlated to fault size in the bearings. The correlation shows that the sensor used for signals from 100 KHz to 1 MHz gave the best sensitivity and detected the generation of very small spalls or pits

A New Kind of Joy

A 1979 print of miscellaneous sports items by C. Don Ensor.https://scholarworks.moreheadstate.edu/university_art_collection/1136/thumbnail.jp

Impact of health financing policies in Cambodia: a 20 year experience

Improving financial access to services is an essential part of extending universal health coverage in low resource settings. In Cambodia, high out of pocket spending and low levels of utilisation have impeded the expansion of coverage and improvement in health outcomes. For twenty years a series of health financing policies have focused on mitigating costs to increase access particularly by vulnerable groups. Demand side financing policies including health equity funds, vouchers and community health insurance have been complemented by supply side measures to improve service delivery incentives through contracting. Multiple rounds of the Cambodia Socio-Economic Survey are used to investigate the impact of financing policies on health service utilisation and out of pocket payments both over time using commune panel data from 1997 to 2011 and across groups using individual data from 2004 to 2009. Policy combinations including areas with multiple interventions were examined against controls using difference-in-difference and panel estimation. Widespread roll-out of financing policies combined with user charge formalisation has led to a general reduction in health spending by the poor. Equity funds are associated with a reduction in out of pocket payments although the effect of donor schemes is larger than those financed by government. Vouchers, which are aimed only at reproductive health services, has a more modest impact that is enhanced when combined with other schemes. At the aggregate level changes are less pronounced although there is evidence that policies take a number of years to have substantial effect. Health financing policies and the supportive systems that they require provide a foundation for more radical extension of coverage already envisaged by a proposed social insurance system. A policy challenge is how disparate mechanisms can be integrated to ensure that vulnerable groups remain protected

A national certification programme for academic degrees in cyber security

With a growing need for cyber security skills, there has been a notable increase in the number of academic degrees targeting this topic area, at both undergraduate and postgraduate levels. However, with a widening and varied choice available to them, prospective students and employers require a means to identify academic degrees that offer appropriate and high-quality education in the subject area. This paper presents a case study of the establishment and operation of a certification programme for academic degrees in cyber security. It describes the means by which appropriate topic themes and subject areas for relevant degrees were identified and defined, leading to a certification programme that addresses degrees in general cyber security as well as notable specialisations including digital forensics and network security. The success of the programme is evidenced by 25 degrees across 19 universities having been certified to date, and a continued response to new calls for certification

What factors affect patients’ access to healthcare? Protocol for an overview of systematic reviews

Background The importance of access to healthcare for all is internationally recognised as a global goal, high on the global agenda. Yet inequalities in health exist within and between countries which are exacerbated by inequalities in access to healthcare. In order to address these inequalities, we need to better understand what drives them. While there exists a wealth of research on access to healthcare in different countries and contexts, and for different patient groups, to date no attempt has been made to bring this evidence together through a global lens. This study aims to address that gap by bringing together evidence of what factors affect patients’ access to healthcare and exploring how those factors vary in different countries and contexts around the world. Methods An overview of reviews will be conducted using a comprehensive search strategy to search four databases: Medline, Embase, Global Health and Cochrane Systematic Reviews. Additional searches will be conducted on the Gates Foundation, the World Health Organisation (WHO) and World Bank websites. Titles and abstracts will be screened against the eligibility criteria and full-text articles will be obtained for all records that meet the inclusion criteria or where there is uncertainty around eligibility. A data extraction table will be developed during the review process and will be piloted and refined before full data extraction commences. Methodological quality/risk of bias will be assessed for each included study using the AMSTAR 2 tool. The quality assessment will be used to inform the narrative synthesis, but a low-quality score will not necessarily lead to study exclusion. Discussion Factors affecting patients’ ability to access healthcare will be identified and analysed according to different country and context characteristics to shed light on the importance of different factors in different settings. Results will be interpreted accounting for the usual challenges associated with conducting such reviews. The results may guide future research in this area and contribute to priority setting for development initiatives aimed at ensuring equitable access to healthcare for all

CYP3A5 polymorphisms and their effects on tacrolimus exposure in an ethnically diverse South African renal transplant population

Background. Tacrolimus forms the cornerstone for immunosuppression in solid-organ transplantation. It has a narrow therapeutic window with wide inter- and intra-patient variability (IPV). Cytochrome P-450 3A5 (CYP3A5) is the main enzyme involved in tacrolimus metabolism, and rs776746A>G is the most frequently studied polymorphism in the CYP3A5 gene. The rs776746A>G (i.e. CYP3A5*3) single-nucleotide polymorphism in CYP3A5 alters tacrolimus predose trough concentration (C0) and may also affect IPV, which may lead to immune- and/or drug-mediated allograft injury. CYP3A5*3 may result in absent (*3/*3), partial (*1/*3) or normal (*1/*1) CYP3A5 expression. The effect of CYP3A5*3 on tacrolimus exposure and variability has not been examined in South African (SA) transplant recipients.Objectives. To determine the frequencies and effect of CYP3A5 and adenosine triphosphate-binding cassette subfamily B member 1 (ABCB1) polymorphisms on tacrolimus C0/dose ratios in different ethnic groups attending a tertiary renal transplant clinic in SA, and other factors that may explain inter- and IPV in tacrolimus C0.Methods. All consenting stable renal transplant recipients on tacrolimus at the Livingstone Hospital Renal Unit in Port Elizabeth, SA, were included. Tacrolimus concentrations were obtained using a microparticle enzyme immunoassay method (ARCHITECT analyser, Abbott Laboratories). Polymerase chain reaction/restriction fragment length polymorphism was used to genotype for CYP3A5*3 and *6 allelic variants.Results. There were 43 participants (35% black African, 44% mixed ancestry and 21% white), with a mean age of 44.5 years, median duration post-transplant of 47 months and median (interquartile range) creatinine and estimated glomerular filtration rate levels of 118 (92 - 140) µmol/L and 62 (49 - 76) mL/min at study inclusion. The mean tacrolimus C0 in the study was 6.7 ng/mL, with no difference across the different ethnic groups. However, the mean total daily dose of tacrolimus required was 9.1 mg (0.12 mg/kg), 7.2 mg (0.09 mg/kg) and 4.3 mg (0.06 mg/kg) in black, mixed-ancestry and white patients, respectively (p=0.017). The frequencies for CYP3A5 expressors (i.e. CYP3A5*1/*1 + CYP3A5*1/*3 genotypes) were 72%, 100%, 76% and 12% for all patients combined and black, mixed-ancestry and white patients, respectively. The frequencies for CYP3A5 non-expressors (i.e. CYP3A5*3/*3 genotypes) were 0%, 24% and 88% among the black, mixed-ancestry and white patients, respectively. None of the patients carried the CYP3A5*6 allele. CYP3A5*1/*1 and CYP3A5*1/*3 genotype carriers required a two-fold increase in dose compared with the non-expressor genotype carriers, CYP3A5*3/*3 (p<0.05). CYP3A5*3/*3 carriers also demonstrated higher IPV than CYP3A5*1/*1 and *1/*3 carriers (18.1% v. 14.2%; p=0.125).Conclusions. Compared with global transplant populations, SA renal transplant recipients demonstrated a very high rate of CYP3A5 expression, with a significant impact on tacrolimus pharmacokinetics. Genetic variation in CYP3A5 expression affects tacrolimus dosing requirements, and knowing the CYP3A5 genotype of transplant patients may allow better dose prediction compared with current standard dosing recommendations in a multi-ethnic population. Overall, black African patients required higher doses of tacrolimus than their white counterparts. While further prospective studies are needed to better evaluate dosing algorithms, it would appear that the starting dose of tacrolimus should be higher in black and mixed-race patients.