A non-Gaussian continuous state space model for asset degradation

The degradation model plays an essential role in asset life prediction and condition based maintenance. Various degradation models have been proposed. Within these models, the state space model has the ability to combine degradation data and failure event data. The state space model is also an effective approach to deal with the multiple observations and missing data issues. Using the state space degradation model, the deterioration process of assets is presented by a system state process which can be revealed by a sequence of observations. Current research largely assumes that the underlying system development process is discrete in time or states. Although some models have been developed to consider continuous time and space, these state space models are based on the Wiener process with the Gaussian assumption. This paper proposes a Gamma-based state space degradation model in order to remove the Gaussian assumption. Both condition monitoring observations and failure events are considered in the model so as to improve the accuracy of asset life prediction. A simulation study is carried out to illustrate the application procedure of the proposed model

Structural reliability prediction of a steel bridge element using dynamic object oriented Bayesian Network (DOOBN)

Different from conventional methods for structural reliability evaluation, such as, first/second-order reliability methods (FORM/SORM) or Monte Carlo simulation based on corresponding limit state functions, a novel approach based on dynamic objective oriented Bayesian network (DOOBN) for prediction of structural reliability of a steel bridge element has been proposed in this paper. The DOOBN approach can effectively model the deterioration processes of a steel bridge element and predict their structural reliability over time. This approach is also able to achieve Bayesian updating with observed information from measurements, monitoring and visual inspection. Moreover, the computational capacity embedded in the approach can be used to facilitate integrated management and maintenance optimization in a bridge system. A steel bridge girder is used to validate the proposed approach. The predicted results are compared with those evaluated by FORM method

Peer influence as a driver of technological innovation in the UK National Health Service: a qualitative study of clinicians’ experiences and attitudes

Background Accelerating innovation to improve quality is a key policy target for healthcare systems around the world. Effectively influencing individuals’ behaviour is crucial to the success of innovation initiatives. This study explores UK clinicians’ lived experiences of, and attitudes towards, clinical peers endorsing healthcare innovations. Methods Qualitative interviews with UK-based clinicians in one of two groups: (1) clinicians working in ‘front-line’ service provision and (2) clinicians in strategic leadership roles within health institutions. Participants were identified through purposive sampling, and participated in semistructured telephone interviews. Thematic analysis was used to identify and analyse themes in the data. Results 17 participants were recruited: eight clinicians from front-line UK healthcare settings and nine clinicians in leadership roles. Two major themes were identified from the interviews: power and trust. Participants recognised and valued peers’ powerful influence, exerted in person via social networks and routine work-related activities. Peers were implicitly trusted, although often on condition of their credibility and deservingness of respect, supporting evidence and absence of conflict of interest. While the groups shared similar views, they diverged on the subject of institutions, felt to be powerful by strategic leaders yet scarcely mentioned by front-line clinicians. Conclusions UK clinicians view peers as a powerful and trustworthy source to promote innovative technologies. Policies that aim to support this process should seek to control the wider conditions that nurture peer-to-peer influence. Further research into interpersonal influence in health settings may improve implementation of change initiatives

Association Between Obesity and Asthma among Adults: A Hospital Based Case-Control Study

The aim is to study the association between obesity and asthma among adults by gender. The prevalences of both asthma and obesity have increased substantially in recent decades, leading to speculation that obese individuals might be at risk of asthma. However, the evidence of a relationship between obesity and asthma is not fully conclusive among adults. Hence we investigate the association between obesity and asthma among men and women using both measured weight and height and self-reported weight and height while controlling for the effects of the demographic and environmental factors. This case-control study involves a total of 159 adults; 53 cases and 106 controls enrolled in the month of July 2009 at PSG Hospitals. Body Mass Index (BMI) was calculated based on measured weight and height. The Odds Ratio (OR) with 95% confidence interval for obese individuals was estimated using logistic regression analysis with SPSS 11.5 for windows software (SPSS Inc., Chicago, Illinois). Multivariate logistic regression model was used to adjust all risk estimates for covariates. Obese women were found to have 9.14 times the risk of asthma than non obese women (95% confidence interval (CI):1.38, 35.68) after adjusting for covariates, such as age, education, environmental tobacco smoke and pet keeping. No significant association was observed among men although the direction of association is positive; adjusted odds ratio was 1.06 (95% CI: 0.12, 9.70). No significant association was observed between self-reported prevalence of obesity and asthma; among women, adjusted odds ratio = 4.33 (95% CI: 0.69, 27.37); and among men, adjusted odds ratio = 0.89 (95% CI: 0.11, 7.12). The study indicates a strong positive association between obesity and asthma among adult Indian women. The causal links between obesity and asthma by gender need to be further examined using prospective cohort studies

Illuminating Choices for Library Prep: A Comparison of Library Preparation Methods for Whole Genome Sequencing of Cryptococcus neoformans Using Illumina HiSeq.

The industry of next-generation sequencing is constantly evolving, with novel library preparation methods and new sequencing machines being released by the major sequencing technology companies annually. The Illumina TruSeq v2 library preparation method was the most widely used kit and the market leader; however, it has now been discontinued, and in 2013 was replaced by the TruSeq Nano and TruSeq PCR-free methods, leaving a gap in knowledge regarding which is the most appropriate library preparation method to use. Here, we used isolates from the pathogenic fungi Cryptococcus neoformans var. grubii and sequenced them using the existing TruSeq DNA v2 kit (Illumina), along with two new kits: the TruSeq Nano DNA kit (Illumina) and the NEBNext Ultra DNA kit (New England Biolabs) to provide a comparison. Compared to the original TruSeq DNA v2 kit, both newer kits gave equivalent or better sequencing data, with increased coverage. When comparing the two newer kits, we found little difference in cost and workflow, with the NEBNext Ultra both slightly cheaper and faster than the TruSeq Nano. However, the quality of data generated using the TruSeq Nano DNA kit was superior due to higher coverage at regions of low GC content, and more SNPs identified. Researchers should therefore evaluate their resources and the type of application (and hence data quality) being considered when ultimately deciding on which library prep method to use

Validity of self-reported height and weight and factors associated with errors in self-report

The aim of this investigation is to assess the validity of self-reported height and weight and to examine factors associated with errors in self-report. A cross-sectional study was conducted in Coimbatore, Tamil Nadu, South India, from June 20 to August 20, 2011. The study involved 389 men and 355 women aged 20 years and above. We found that self-reported height and weight were significantly correlated with measured height and weight for men and women [Pearson’s correlation coefficient(r) for men and women: 0.61 and 0.44 in height, 0.91 and 0.85 in weight, 0.76 and 0.64 in body mass index (BMI), respectively]. The prevalence of obesity based on self-reported height and weight were 7.9 and 15.8% for men and women, respectively, which was slightly smaller than that based on measured data 7.7 and 19.7%, respectively. Sensitivity and specificity of obesity based on self-report for both men and women were 97, 62% in men and 89, 64% in women, respectively. Participants with higher measured BMI significantly underestimated their weight compared to those with smaller BMI. It is also observed that among both men and women with measured BMI above 18.5 kg/m2 were likely to underestimate their weight and BMI below 18.5 kg/m2were likely to overestimate their weight. However, the presence of diabetes, hypertension and heart disease was not associated with the difference between measured and self-reported height and weight for both men and women. Our findings indicate that self-reported weight has an acceptable agreement with measured data, but self-reported height has only a moderate agreement with measured data. There were no significant differences by presence of chronic disease and educational level between the self-reported and measured height and weight in both men and women

STAT4 deficiency reduces obesity-induced insulin resistance and adipose tissue inflammation

Signal transducer and activator of transcription (STAT) 4 is one of the seven members of the STAT family. STAT4 has a prominent role in mediating interleukin-12-induced T-helper cell type 1 lineage differentiation. T cells are key players in the maintenance of adipose tissue (AT) inflammation. The role of STAT4 in obesity and AT inflammation is unknown. We sought to determine the role of STAT4 in AT inflammation in obesity-induced insulin resistance. We studied STAT4-null mice on the C57Bl6/J background. We have found that STAT4(-/-)C57Bl6/J mice develop high-fat diet-induced obesity (DIO) similar to wild-type controls, but that they have significantly improved insulin sensitivity and better glucose tolerance. Using flow cytometry and real-time PCR, we show that STAT4(-/-) mice with DIO produce significantly reduced numbers of inflammatory cytokines and chemokines in adipocytes, have reduced numbers of CD8(+) cells, and display increased alternative (M2) macrophage polarization. CD8(+) cells, but not CD4(+) cells, from STAT4(-/-) mice displayed reduced in vitro migration. Also, we found that adipocyte inflammation is reduced and insulin signaling is improved in STAT4(-/-) mice with DIO. We have identified STAT4 as a key contributor to insulin resistance and AT inflammation in DIO. Targeting STAT4 activation could be a novel approach to reducing AT inflammation and insulin resistance in obesity

Health behavior modification after electron beam computed tomography and physician consultation

This study aimed to determine whether participants reported altering health behaviors (physical activity, diet, and alcohol consumption) after seeing results from an electron-beam computed tomography (EBCT) scan for coronary artery calcium and reviewing these results with a physician. Clinicians attempt to motivate patients to control cardiovascular risk factors by adopting healthy behaviors and reducing harmful actions. Asymptomatic patients (N = 510) were evaluated by EBCT for the extent of coronary artery calcium. Information pertaining to demographics, health history, and lifestyle/health behaviors was obtained from each participant at the time of the EBCT scan. Patients were given their numerical calcium score, shown images of their coronary arteries, and counseled by a physician for lifestyle and medical risk modification based on their coronary artery calcium score. Approximately 6 years after the scan, participants completed a follow-up questionnaire related to lifestyle modifications. In multivariable analysis, the presence and extent of coronary artery calcium was significantly associated with beneficial health behavior modifications. Specifically, the greater a patient’s coronary artery calcium score, the more likely they were to report increasing exercise (odds ratio = 1.34, P = 0.02), changing diet (odds ratio = 1.40, P < 0.01), and changing alcohol intake (odds ratio = 1.46, P = 0.05). This study suggests that seeing and being counseled on the presence and extent of coronary artery calcium is significantly associated with behavior change