645 research outputs found
Eddy Current Corner Crack Inspection
The purpose of this paper is to report on the development of an eddy current (EC) measurement model applicable to corner crack inspections. Naturally, corner cracks are more difficult to detect than those on flat surfaces, because the specimen edge itself gives a large response to the EC probe. The flaw signal, if any, tends to be obscured by the large edge signal. Thus, probe impedance should be determined more accurately than usual in order to extract flaw signals out of the background. Experimentally, this requires high-accuracy impedance measurements with rigid control over probe motion. In modeling point of view, this means that predictions should be made from an exact model, or at least from a model which can achieve the required level of accuracy [1–3]
Changes in STI and HIV testing and testing need among men who have sex with men during the UK's COVID-19 pandemic response.
OBJECTIVES: We examined the impact of COVID-19-related restrictions on sexual behaviours, STI and HIV testing and testing need among men who have sex with men (MSM) in the UK. METHODS: We used social media and dating applications to recruit to three cross-sectional surveys (S1-S3) during the UK's pandemic response (S1: 23 June-14 July 2020; S2: 23 November-12 December 2020; S3: 23 March-14 April 2021). Surveys included lookback periods of around 3-4 months (P1-P3, respectively). Eligible participants were UK resident men (cisgender/transgender) and gender-diverse people assigned male at birth (low numbers of trans and gender-diverse participants meant restricting these analyses to cisgender men), aged ≥16 years who reported sex with men (cisgender/transgender) in the last year (S1: N=1950; S2: N=1463; S3: N=1487). Outcomes were: recent STI/HIV testing and unmet testing need (new male and/or multiple condomless anal sex partners without a recent STI/HIV test). Crude and adjusted associations with each outcome were assessed using logistic regression. RESULTS: Participants' sociodemographic characteristics were similar across surveys. The proportion reporting a recent STI and/or HIV test increased between P1 and P2 (25.0% to 37.2% (p<0.001) and 29.7% to 39.4% (p<0.001), respectively), then stabilised in P3 (40.5% reporting HIV testing). Unmet STI testing need increased across P1 and P2 (26.0% to 32.4%; p<0.001), but trends differed between groups, for example, unmet STI testing need was higher in bisexually-identifying (vs gay-identifying) MSM across periods (adjusted OR (aOR): P1=1.64; P2=1.42), but declined in HIV-positive (vs HIV-negative/unknown) MSM (aOR: P1=2.06; P2=0.68). Unmet HIV testing need increased across P1 and P2 (22.9% to 31.0%; p<0.001) and declined in P3 (25.1%; p=0.001). During P3, MSM reporting a low life-satisfaction level (vs medium-very high) had greater unmet need (aOR: 1.44), while from P2 onwards HIV pre-exposure prophylaxis users (vs non-users) had lower unmet need (aOR: P2=0.32; P3=0.50). CONCLUSION: Considerable unmet STI/HIV testing need occurred among MSM during COVID-19-related restrictions, especially in bisexually-identifying men and those reporting low life satisfaction. Improving access to STI/HIV testing in MSM is essential to prevent inequalities being exacerbated
Sexual behaviour, STI and HIV testing and testing need among gay, bisexual and other men who have sex with men recruited for online surveys pre/post-COVID-19 restrictions in the UK.
OBJECTIVES: We examined sexual behaviour, sexually transmitted infection (STI) and HIV testing and testing need, and identified associated factors, among gay, bisexual and other men who have sex with men (GBMSM) in the UK after COVID-19 restrictions ended, and compared these with 'pre-pandemic' estimates. METHODS: We analysed survey data from GBMSM (N=1039) recruited via social media and Grindr in November-December 2021. We then compared Grindr-recruited 2021 participants (N=437) with those from an equivalent survey fielded in March-May 2017 (N=1902). Questions on sexual behaviour and service use had lookback periods of 3-4 months in both surveys. Unmet testing need was defined as reporting any new male and/or multiple condomless anal sex (CAS) partners without recent STI/HIV testing. Participants were UK residents, GBMSM, aged ≥16 years who reported sex with men in the last year. Multivariable logistic regression identified associated sociodemographic and health-related factors with unmet STI/HIV testing need in 2021, and then for 2017/2021 comparative analyses, adjusting for demographic differences. RESULTS: In 2021, unmet STI and HIV testing need were greater among older GBMSM (aged ≥45 years vs 16-29 years; adjusted OR (aOR): 1.45 and aOR: 1.77, respectively), and lower for pre-exposure prophylaxis (PrEP) users (vs non-PrEP users; aOR: 0.32 and aOR: 0.23, respectively). Less unmet STI testing need was observed among HIV-positive participants (vs HIV-negative/unknown; aOR: 0.63), and trans and non-binary participants (vs cisgender male; aOR: 0.34). Between 2017 (reference) and 2021, reported sexual risk behaviours increased: ≥1 recent new male sex partner (72.1%-81.1%, aOR: 1.71) and ≥2 recent CAS partners (30.2%-48.5%, aOR: 2.22). Reporting recent STI testing was greater in 2021 (37.5%-42.6%, aOR: 1.34) but not recent HIV testing, and there was no significant change over time in unmet STI (39.2% vs 43.7%) and HIV (32.9% vs 39.0%) testing need. DISCUSSION: Comparable community surveys suggest that UK resident GBMSM may have engaged in more sexual risk behaviours in late 2021 than pre-pandemic. While there was no evidence of reduced STI/HIV service access during this time, there remained considerable unmet STI/HIV testing need
Difficulty accessing condoms because of the COVID-19 pandemic reported by gay, bisexual and other men who have sex with men in the UK: findings from a large, cross-sectional, online survey.
BACKGROUND: COVID-19 restrictions severely reduced face-to-face sexual health services, an important access point for condoms. We examine whether gay, bisexual and other men who have sex with men (GBMSM) in the UK had difficulty accessing condoms during the first year of the pandemic, and if so, which groups were most affected. METHODS: Questions about difficulty accessing condoms were asked as part of a short, online cross-sectional survey of GBMSM undertaken November/December 2021, recruited via social media and Grindr. Eligible participants were UK-resident GBMSM (cis/trans/gender-diverse person assigned male at birth [AMAB]), aged ≥16 years who were sexually active (reported sex with men in the last year). Multivariable logistic regression was used to examine if and how reporting this outcome varied by key sociodemographic, health and behavioural factors independent of the potential confounding effect of numbers of new male sex partners. RESULTS: Of all participants (N = 1039), 7.4% (n = 77) reported difficulty accessing condoms due to the pandemic. This was higher among younger GBMSM (aged 16-29 years vs. ≥45; 12.8% vs. 4.9%; aOR: 2.78); trans/gender-diverse AMAB participants (vs. cis gender males; 24.4% vs. 6.6%; aOR = 4.86); bisexually-identifying participants (vs. gay-identifying; 11.1% vs. 6.5%; aOR = 1.78); and those without degree level education (vs. having a degree; 9.8% vs. 5.6%; aOR = 2.01). CONCLUSIONS: A minority of sexually active GBMSM reported difficulty accessing condoms because of the pandemic, however, this was more common amongst those who already experience a disproportionate burden of poor sexual health. Interventions are needed to address these inequalities in accessing this important primary STI/HIV prevention measure
COVID-19 infection and vaccination uptake in men and gender-diverse people who have sex with men in the UK: analyses of a large, online community cross-sectional survey (RiiSH-COVID) undertaken November-December 2021.
BACKGROUND: Men and gender-diverse people who have sex with men are disproportionately affected by health conditions associated with increased risk of severe illness due to COVID-19 infection. METHODS: An online cross-sectional survey of men and gender-diverse people who have sex with men in the UK recruited via social networking and dating applications from 22 November-12 December 2021. Eligible participants included self-identifying men, transgender women, or gender-diverse individuals assigned male at birth (AMAB), aged ≥ 16, who were UK residents, and self-reported having had sex with an individual AMAB in the last year. We calculated self-reported COVID-19 test-positivity, proportion reporting long COVID, and COVID-19 vaccination uptake anytime from pandemic start to survey completion (November/December 2021). Logistic regression was used to assess sociodemographic, clinical, and behavioural characteristics associated with SARS-CoV-2 (COVID-19) test positivity and complete vaccination (≥ 2 vaccine doses). RESULTS: Among 1,039 participants (88.1% white, median age 41 years [interquartile range: 31-51]), 18.6% (95% CI: 16.3%-21.1%) reported COVID-19 test positivity, 8.3% (95% CI: 6.7%-10.1%) long COVID, and 94.5% (95% CI: 93.3%-96.1%) complete COVID-19 vaccination through late 2021. In multivariable models, COVID-19 test positivity was associated with UK country of residence (aOR: 2.22 [95% CI: 1.26-3.92], England vs outside England) and employment (aOR: 1.55 [95% CI: 1.01-2.38], current employment vs not employed). Complete COVID-19 vaccination was associated with age (aOR: 1.04 [95% CI: 1.01-1.06], per increasing year), gender (aOR: 0.26 [95% CI: 0.09-0.72], gender minority vs cisgender), education (aOR: 2.11 [95% CI: 1.12-3.98], degree-level or higher vs below degree-level), employment (aOR: 2.07 [95% CI: 1.08-3.94], current employment vs not employed), relationship status (aOR: 0.50 [95% CI: 0.25-1.00], single vs in a relationship), COVID-19 infection history (aOR: 0.47 [95% CI: 0.25-0.88], test positivity or self-perceived infection vs no history), known HPV vaccination (aOR: 3.32 [95% CI: 1.43-7.75]), and low self-worth (aOR: 0.29 [95% CI: 0.15-0.54]). CONCLUSIONS: In this community sample, COVID-19 vaccine uptake was high overall, though lower among younger age-groups, gender minorities, and those with poorer well-being. Efforts are needed to limit COVID-19 related exacerbation of health inequalities in groups who already experience a greater burden of poor health relative to other men who have sex with men
A methodology for automated feature engineering in training of shallow neural networks for prediction of multi-linear growth failures (“Nova Algorithm”)
Deep learning requires a large data set. When working with smaller data sets we need an automated approach for feature learning as a pre-processing step to create the training set for a shallow neural network with one hidden layer. The outcome of the neural net classifier is filtered using post-processing rules over a defined wait and quiet period to create an ensemble prediction with higher quality. This gives us the benefits of deep learning, but with a smaller data set.
A partial implementation of this methodology was used for a pilot release for prediction of Common Previsioning Group (CPG) growth failures in 3PAR storage devices, using a trained neural net model with additional derived attributes, pre-processing rules and post-processing steps, applied to 90 days history of logical disk free space for each CPG on the storage device
Growing old, yet staying young: The role of telomeres in bats' exceptional longevity
Understanding aging is a grand challenge in biology. Exceptionally long-lived animals have mechanisms that underpin extreme longevity. Telomeres are protective nucleotide repeats on chromosome tips that shorten with cell division, potentially limiting life span. Bats are the longest-lived mammals for their size, but it is unknown whether their telomeres shorten. Using >60 years of cumulative mark-recapture field data, we show that telomeres shorten with age inRhinolophus ferrumequinumandMiniopterus schreibersii, but not in the bat genus with greatest longevity,Myotis. As in humans, telomerase is not expressed inMyotis myotisblood or fibroblasts. Selection tests on telomere maintenance genes show thatATMandSETX, which repair and prevent DNA damage, potentially mediate telomere dynamics inMyotisbats. Twenty-one telomere maintenance genes are differentially expressed inMyotis, of which 14 are enriched for DNA repair, and 5 for alternative telomere-lengthening mechanisms. We demonstrate how telomeres, telomerase, and DNA repair genes have contributed to the evolution of exceptional longevity inMyotisbats, advancing our understanding of healthy aging
Effect of vitamin D supplementation on bone health parameters of healthy young Indian women
Summary There is a huge prevalence of hypovitaminosis D in the Indian population. We studied the efficacy and safety of oral vitamin D supplementation in apparently healthy adult women. Monthly cholecalciferol given orally, 60,000 IU/month during summers and 120,000 IU/month during winters, safely increases 25-hydroxyvitamin D (25 (OH)D) levels to near normal levels. Introduction There is a huge burden of hypovitaminosis D in the Indian population. The current recommendation for vitamin D supplementation is not supported by sufficient evidence. Methods Study subjects included 100 healthy adult women of reproductive age group from hospital staff. They wer
The impact of vitamin D status on changes in bone mineral density during treatment with bisphosphonates and after discontinuation following long-term use in post-menopausal osteoporosis
BACKGROUND: It is still unclear whether addition of calcium/vitamin D supplements leads to an incremental benefit in patients taking bisphosphonates and whether achievement of serum level of 25 (OH) vitamin D of at least 70 nmol/L has an impact on the skeletal response to bisphosphonates. Moreover the maintenance of BMD after bisphosphonates withdrawal with the continuation of calcium/vitamin D supplements only, remains uncertain. The aims were to assess the impact of vitamin D status on changes in bone mineral density (BMD) in firstly patients with post-menopausal osteoporosis on bisphosphonates and secondly following discontinuation of bisphosphonates after long-term use. METHODS: Two patient groups were recruited. The first study population comprised of 112 women treated with a bisphosphonate. The second study population consisted of 35 women who had been on bisphosphonates for > 5 years in whom the treatment agent was discontinued. Baseline BMD, changes in BMD following treatment, duration of treatment, serum 25 (OH) vitamin D, parathyroid hormone (PTH), urine C-terminal telopeptides of type 1 collagen (CTX) were obtained on the study participants. RESULTS: In the first study group, subjects with serum vitamin D concentrations (> 70 nmol/L) had a significantly lower serum PTH level (mean [SEM] 41 [2] ng/L). PTH concentrations of 41 ng/L or less was associated with a significantly higher increase in BMD at the hip following treatment with bisphosphonates compared to patients with PTH > 41 ng/L (2.5% [0.9] v/s -0.2% [0.9], P = 0.04). In the second study group, discontinuation of bisphosphonate for 15 months after long-term treatment did not result in significant bone loss at the lumbar spine and total hip, although a trend towards gradual decline in BMD at the femoral neck was observed. CONCLUSION: the data suggest that optimal serum 25 (OH) vitamin D concentration may lead to further reduction in bone loss at the hip in patients on bisphosphonates. A prospective controlled trial is needed to evaluate whether the response to bisphosphonates is influenced by vitamin D status. BMD is preserved at the lumbar spine and total hip following discontinuation of bisphosphonate for a short period following long-term treatment, although a gradual loss occurs at the femoral neck
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