A general inspection and opportunistic replacement policy for one-component systems of variable quality

We model the influence of opportunities in a hybrid inspection and replacement policy. The base policy has two phases: an initial inspection phase in which the system is replaced if found defective; and a later wear-out phase that terminates with replacement and during which there is no inspection. The efficacy of inspection is modelled using the delay time concept. Onto this base model, we introduce events that arise at random and offer opportunities for cost-efficient replacement, and we investigate the efficacy of additional opportunistic replacements within the policy. Furthermore, replacements are considered to be heterogeneous and of variable quality. This is a natural policy for heterogeneous systems. Our analysis suggests that a policy extension that allows opportunities to be utilised offers benefit, in terms of cost-efficiency. This benefit is significant compared to those offered by age-based inspection or preventive replacement. In addition, opportunistic replacement may simplify maintenance planning

Delay-time modelling of a critical system subject to random inspections

We model the inspection-maintenance of a critical system in which the execution of inspections is random. The models we develop are interesting because they mimic realities in which production is prioritised over maintenance, so that inspections might be impeded or they might be opportunistic. Random maintenance has been modelled by others but there is little in the literature that relates to inspection of a critical system. We suppose that the critical system can be good, defective or failed, and that failure impacts on production, so that a failure is immediately revealed, but a defect does not. A defect, if revealed at inspection, is a trigger for replacement. We compare the cost and reliability of random inspections with scheduled periodic inspections and discuss the implications for practice. Our results indicate that inspections that are performed opportunistically rather than scheduled periodically may offer an economic advantage provided opportunities are sufficiently frequent and convenient. A hybrid inspection and replacement policy, with inspections subject to impediments, is robust to departure from its inspection schedule. Keywords: Maintenance; reliability; random inspection; production; qualit

Efficacy of coping mechanisms used during COVID-19 as reported by parents of children with autism

The COVID-19 pandemic’s alterations to daily life have been especially challenging for families with Autism Spectrum Disorder (ASD), worsening the core features of ASD and overall mental health. With the increased need for effective coping, the current retrospective study used data from a survey regarding parent reports of how often their child with ASD used certain coping strategies (frequency), as well as the extent to which they felt their child benefitted from their use (efficacy) in mitigating stress during the pandemic. This retrospective study Repeated measures ANOVAs were conducted to evaluate whether there were significant differences in both frequency and efficacy ratings for each coping strategy, for the entire sample as well as for three children’s age groups. Using Spearman’s rank-order correlations, correlation coefficients between the frequency and efficacy of each coping strategy were explored. Results revealed that maladaptive strategies were used more frequently than adaptive strategies, while parent routine as the most frequently used and efficacious for all age groups. Additionally, for adaptive strategies, humor and focusing on the positive had the strongest correlations between frequency and efficacy ratings amongst all age groups. Of the maladaptive strategies, repetitive behaviors, rumination, and isolation had the strongest correlations for the youngest, middle, and oldest age groups, respectively. Further, for each age group, the adaptive coping strategies had stronger correlations between frequency and efficacy than the maladaptive ones. It is our hope that the results of this study will lay the foundation for developing adaptive coping strategies to alleviate stress in children with ASD. Further investigations using a larger cohort are warranted to determine effective coping strategies for individuals with ASD across a range of situations, including acute stressors (such as future public health emergencies and natural disasters), as well as common daily stressors

2, 3-Di-O-sulfo glucuronic acid: an unmodified and unusual residue in a highly sulfated chondroitin sulfate from Litopenaeus vannamei

The occurrence of a natural and unmodified highly sulfated chondroitin sulfate from Litopenaeus vannamei heads (sCS) is herein reported. Its partial digestion by Chondroitinases AC and ABC together with its electrophoretic migration profile revealed it as a highly sulfated chondroitin sulfate despite its average molecular weight being similar to CSA. Using orthogonal 1D/2D NMR experiments, the anomeric signals (δ 4.62/106.0) corresponding to unusual 2,3-di-O-Sulfo-GlcA (∼36%), U33S (δ 4.42/84.1, ∼63%) and U22S (4.12/80.1, ∼50%) substitutions were confirmed. In addition, non-sulfated GlcA (δ 4.5/106.3) linked to 4-O- (A14S, 36%) or 6-O-Sulfo (A16S, 28%) GalNAc (δ 4.64/103.5) was observed. Although the biological role of sCS in shrimp is unknown, its influence on hemostasis was also demonstrated. The sCS identification brings to light new questions about the hierarchical model of GAGs biosynthesis and contributes to the better understanding of the subtle relationship between GAGs structure and function

Prevalence of fibromyalgia in a low socioeconomic status population

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to estimate the prevalence of fibromyalgia, as well as to assess the major symptoms of this syndrome in an adult, low socioeconomic status population assisted by the primary health care system in a city in Brazil.</p> <p>Methods</p> <p>We cross-sectionally sampled individuals assisted by the public primary health care system (n = 768, 35–60 years old). Participants were interviewed by phone and screened about pain. They were then invited to be clinically assessed (304 accepted). Pain was estimated using a Visual Analogue Scale (VAS). Fibromyalgia was assessed using the Fibromyalgia Impact Questionnaire (FIQ), as well as screening for tender points using dolorimetry. Statistical analyses included Bayesian Statistics and the Kruskal-Wallis Anova test (significance level = 5%).</p> <p>Results</p> <p>From the phone-interview screening, we divided participants (n = 768) in three groups: No Pain (NP) (n = 185); Regional Pain (RP) (n = 388) and Widespread Pain (WP) (n = 106). Among those participating in the clinical assessments, (304 subjects), the prevalence of fibromyalgia was 4.4% (95% confidence interval [2.6%; 6.3%]). Symptoms of pain (VAS and FIQ), feeling well, job ability, fatigue, morning tiredness, stiffness, anxiety and depression were statically different among the groups. In multivariate analyses we found that individuals with FM and WP had significantly higher impairment than those with RP and NP. FM and WP were similarly disabling. Similarly, RP was no significantly different than NP.</p> <p>Conclusion</p> <p>Fibromyalgia is prevalent in the low socioeconomic status population assisted by the public primary health care system. Prevalence was similar to other studies (4.4%) in a more diverse socioeconomic population. Individuals with FM and WP have significant impact in their well being.</p