Forty years of struggle in North Carolina: Workplace segregation and fatal occupational injury rates.

OBJECTIVE: To assess workplace segregation in fatal occupational injury from 1992 to 2017 in North Carolina. METHODS: We calculated occupational fatal injury rates within categories of occupation, industry, race, age, and sex; and estimated expected numbers of fatalities among Black and Hispanic male workers had they experienced the rates of White male workers. We also estimated the contribution of workforce segregation to disparities by estimating the expected number of fatalities among Black and Hispanic male workers had they experienced the industry and occupation patterns of White male workers. We assessed person-years of life-lost, using North Carolina life expectancy estimates. RESULTS: Hispanic workers contributed 32% of their worker-years and experienced 58% of their fatalities in construction. Black workers were most overrepresented in the food manufacturing industry. Hispanic males experienced 2.11 (95% CI: 1.86-2.40) times the mortality rate of White males. The Black-White and Hispanic-White disparities were widest among workers aged 45 and older, and segregation into more dangerous industries and occupations played a substantial role in driving disparities. Hispanic workers who suffered occupational fatalities lost a median 47 life-years, compared to 37 among Black workers and 36 among White workers. CONCLUSIONS: If Hispanic and Black workers experienced the workplace safety of their White counterparts, fatal injury rates would be substantially reduced. Workforce segregation reflects structural racism, which also contributes to mortality disparities. Root causes must be addressed to eliminate disparities.

Twenty-five year occupational homicide mortality trends in North Carolina: 1992-2017.

INTRODUCTION: Determining industry of decedents and victim-perpetrator relationships is crucial to inform and evaluate occupational homicide prevention strategies. In this study, we examine occupational homicide rates in North Carolina (NC) by victim characteristics, industry and victim-perpetrator relationship from 1992 to 2017. METHODS: Occupational homicides were identified from records of the NC Office of the Chief Medical Examiner system and the NC death certificates. Sex, age, race, ethnicity, class of worker, manner of death, victim-perpetrator relationship and industry were abstracted. Crude and age-standardised homicide rates were calculated as the number of homicides that occurred at work divided by an estimate of worker-years (w-y). Rate ratios and 95% CIs were calculated, and trends over calendar time in occupational homicide rates were examined overall and by industry. RESULTS: 456 homicides over 111 573 049 w-y were observed. Occupational homicide rates decreased from 0.82 per 100 000 w-y for the period 1992-1995 to 0.21 per 100 000 w-y for the period 2011-2015, but increased to 0.32 per 100 000 w-y in the period 2016-2017. Fifty-five per cent (252) of homicides were perpetrated by strangers. Taxi drivers experienced an occupational homicide rate that was 110 times (95% CI 76.52 to 160.19) the overall occupational homicide rate in NC; however, this rate declined by 76.5% between 1992 and 2017. Disparities were observed among workers 65+ years old, racially and ethnically minoritised workers and self-employed workers. CONCLUSION: Our findings identify industries and worker demographics that experienced high occupational homicide fatality rates. Targeted and tailored mitigation strategies among vulnerable industries and workers are recommended.

25-Year fatal workplace suicide trends in North Carolina: 1992-2017.

BACKGROUND: Suicide is a serious public health problem in the United States, but limited evidence is available investigating fatal suicides at work. There is a substantial need to characterize workplace suicides to inform suicide prevention interventions and target high-risk settings. This study aims to examine workplace suicide rates in North Carolina (NC) by worker characteristics, means of suicide used, and industry between 1992 and 2017. METHODS: Fatal workplace suicides were identified from records of the NC Office of the Chief Medical Examiner system and the NC death certificate. Sex, age, race, ethnicity, class of worker, manner of death, and industry were abstracted. Crude and age-standardized homicide rates were calculated as the number of suicides that occurred at work divided by an estimate of worker-years (w-y). Rate ratios and 95% confidence intervals (CIs) were calculated, and trends over calendar time for fatal workplace suicides were examined overall and by industry. RESULTS: 81 suicides over 109,464,430 w-y were observed. Increased rates were observed in workers who were male, self-employed, and 65+ years old. Firearms were the most common means of death (63%) followed by hanging (16%). Gas service station workers experienced the highest fatal occupational suicide rate, 11.5 times (95% CI: 3.62-36.33) the overall fatal workplace suicide rate, followed by Justice, Public Order, and Safety workers at 3.23 times the overall rate (95% CI: 1.31-7.97). CONCLUSION: Our findings identify industries and worker demographics that were vulnerable to workplace suicides. Targeted and tailored mitigation strategies for vulnerable industries and workers are recommended.

Forty-year trends in fatal occupational injuries in North Carolina.

BACKGROUND: We describe progress in the control of deaths on-the-job due to fatal occupational injury in North Carolina over the period 1978-2017. METHODS: Forty years of information on fatal occupational injuries in North Carolina has been assembled from medical examiners' reports and death certificates, supplemented by newspaper and police reports. Cases were defined as unintentional fatal occupational injuries among adults. Annual estimates of the population at risk were derived from US Census data, and rates were quantified using Poisson regression methods. RESULTS: There were 4434 eligible deaths. The unintentional fatal occupational injury rate at the beginning of the study period was more than threefold the rate at the end of the study. The fatal occupational injury rate among men declined from 9.6 per 100,000 worker-years in the period 1978-1982 to 3.1 per 100,000 worker-years in the period 2013-2017. The fatal occupational injury rate among women declined from 0.3 per 100,000 worker-years in the period 1978-1981 to 0.1 per 100,000 worker-years in the period 2013-2017. Declines in rates were observed for young adults as well as older workers and were observed across all major industry categories. Average annual declines in rates were greatest in those industries and occupations that had the highest fatal injury rates at the start of the study period. CONCLUSIONS: The substantial decline in fatal injury rates underscores the importance of injury prevention and demonstrates the ability to make meaningful reductions in unintentional fatal injury.

Fatal occupational injuries in North Carolina, 1992-2017.

OBJECTIVES: After declining for several decades, fatal occupational injury rates have stagnated in the USA since 2009. To revive advancements in workplace safety, interventions targeting at-risk worker groups must be implemented. Our study aims to identify these at-risk populations by evaluating disparities in unintentional occupational fatalities occurring in North Carolina (NC) from 1992 to 2017. METHODS: Our retrospective cohort study drew on both the NC Office of the Chief Medical Examiner system and the NC death certificate data system to identify unintentional fatal occupational injuries occurring from 1992 to 2017. Unintentional fatal occupational injury rates were reported across industries, occupations and demographic groups, and rate ratios were calculated to assess disparities. RESULTS: Among those aged 18 and older, 2645 unintentional fatal occupational injuries were identified. Fatal occupational injury rates declined by 0.82 injuries/100 000 person-years over this period, falling consistently from 2004 to 2009 and increasing from 2009 to 2017. Fatal injury rates were highest among Hispanic workers, who experienced 2.75 times the fatal injury rate of non-Hispanic White workers (95% CI 2.42 to 3.11) and self-employed workers, who experienced 1.44 times the fatal injury rate of private workers (95% CI 1.29 to 1.60). We also observed that fatal injury rates increased with age group and were higher among male relative to female workers even after adjustment for differential distributions across occupations. CONCLUSIONS: The decline in unintentional fatal occupational injury rates over this period is encouraging, but the increase in injury rate after 2009 and the large disparities between occupations, industries and demographic groups highlight the need for additional targeted safety interventions.

Disparities in Fatal Occupational Injury Rates in North Carolina, 1978-2017: Comparing Nonmanagerial Employees to Managers.

BACKGROUND: We examined fatal occupational injuries among private-sector workers in North Carolina during the 40-year period 1978-2017, comparing the occurrence of fatal injuries among nonmanagerial employees to that experienced by managers. METHODS: We estimated a standardized fatal occupational injury ratio by inverse probability of exposure weighting, taking nonmanagerial workers as the target population. When this ratio measure takes a value greater than unity it signals settings in which nonmanagerial employees are not provided as safe a work environment as that provided for managers. RESULTS: Across all industries, nonmanagerial workers in North Carolina experienced fatal occupational injury rates 8.2 (95% CI = 7.0, 10.0) times the rate experienced by managers. Disparities in fatal injury rates between managers and the employees they supervise were greatest in forestry, rubber and metal manufacturing, wholesale trade, fishing and extractive industries, and construction. CONCLUSIONS: The results may help focus discussion about workplace safety between labor and management upon equity, with a goal of providing a work environment for nonmanagerial employees as safe as the one provided for managers.

Association of Traumatic Knee Injury With Radiographic Evidence of Knee Osteoarthritis in Military Officers.

OBJECTIVE: The association between knee injury and knee osteoarthritis (OA) is understudied relative to its importance, particularly in younger populations. This study was undertaken to examine the association of knee injury with radiographic features of knee OA in military officers, who have a physically demanding profession and high rates of knee injury. METHODS: Participants were recruited in 2015-2017 from an existing program that enrolled 6,452 military officers during 2004-2009. Officers with a history of knee ligament or meniscal injuries (n = 117 via medical record review) were compared to officers with no history of knee injury (n = 143). Bilateral posteroanterior knee radiographs were obtained using a standardized fixed-flexion positioning frame. All images were read for Kellgren/Lawrence (K/L) grade, osteophyte (OST), and joint space narrowing (JSN) scores. Data were analyzed using linear-risk regression models with generalized estimating equations. RESULTS: Injured and noninjured participants were similar (mean age 28 years, mean body mass index 25 kg/m2 , ~40% female). The mean time from first knee injury to imaging among injured participants was 9.2 years. Compared with noninjured knees, greater prevalence of radiographic OA (K/L grade ≥ 2), OST (grade ≥ 1), and JSN (grade ≥ 1) was observed among injured knees, with prevalence differences of +16% (95% confidence interval [95% CI] 10%, 22%), +29% (95% CI 20%, 38%), and + 17% (95% CI 10%, 24%), respectively. Approximately 1 in 6 officers with prior knee injury progressed to radiographic OA by age 30 years. CONCLUSION: At the midpoint of a projected 20-year military career, officers with a history of traumatic knee injury have a markedly increased prevalence of knee radiographic OA compared to officers without injury.

Therapeutic strategies for refractory variceal bleeding due to percutaneous liver biopsy: A case report.

INTRODUCTION AND IMPORTANCE: Variceal bleeding due to intrahepatic arterioportal fistula is an unusual complication of percutaneous liver biopsy. As majority of variceal bleeding are cirrhotic in origin, the rare occurrence of an acquired intrahepatic arterioportal fistula presents a therapeutic dilemma. CASE PRESENTATION: We report the case of a 57-year-old female with refractory variceal bleeding that occurred six years after a percutaneous liver biopsy. As part of the workup for placement of Transjugular Intrahepatic Portosystemic Shunt, a computed tomography hepatic arteriography was performed. This revealed a large arterioportal fistula in left lobe of liver. Variceal bleeding was controlled following successful embolisation of the arterioportal fistula. CLINICAL DISCUSSION: Persistent intrahepatic arterioportal fistula can result in portal hypertension and variceal bleeding. This is a rare complication of percutaneous liver biopsy that warrants consideration as an aetiology of portal hypertension with variceal bleeding. The therapeutic strategy for refractory bleeding due to intrahepatic arterioportal fistula is different from cirrhotic portal hypertension and requires trans-arterial embolisation of the fistula. CONCLUSION: This case highlights the need to consider arterioportal fistula as an aetiology of portal hypertension as therapeutic strategy in refractory variceal bleeding is different from cirrhotic portal hypertension.

Measurement of Early Childhood Oral Health for Research Purposes: Dental Caries Experience and Developmental Defects of the Enamel in the Primary Dentition.

Epidemiological investigations of early childhood oral health rely upon the collection of high-quality clinical measures of health and disease. However, ascertainment of valid and accurate clinical measures presents unique challenges among young, preschool-age children. The paper presents a clinical research protocol for the conduct of oral epidemiological examinations among children, implemented in ZOE 2.0, a large-scale population-based genetic epidemiologic study of early childhood caries (ECC). The protocol has been developed for the collection of information on tooth surface-level dental caries experience and tooth-level developmental defects of the enamel in the primary dentition. Dental caries experience is recorded using visual criteria modified from the International Caries Detection and Assessment System (ICDAS), and measurement of developmental defects is based upon the modified Clarkson and O'Mullane Developmental Defects of the Enamel Index. After a dental prophylaxis (toothbrushing among all children and flossing as needed), children's teeth are examined by trained and calibrated examiners in community locations, using portable dental equipment, compressed air, and uniform artificial light and magnification conditions. Data are entered directly onto a computer using a custom Microsoft Access-based data entry application. The ZOE 2.0 clinical protocol has been implemented successfully for the conduct of over 6000 research examinations to date, contributing phenotype data to downstream genomics and other "omics" studies of ECC and DDE, as well as traditional clinical and epidemiologic dental research.

Protocols, Methods, and Tools for Genome-Wide Association Studies (GWAS) of Dental Traits.

Oral health and disease are known to be influenced by complex interactions between environmental (e.g., social and behavioral) factors and innate susceptibility. Although the exact contribution of genomics and other layers of "omics" to oral health is an area of active research, it is well established that the susceptibility to dental caries, periodontal disease, and other oral and craniofacial traits is substantially influenced by the human genome. A comprehensive understanding of these genomic factors is necessary for the realization of precision medicine in the oral health domain. To aid in this direction, the advent and increasing affordability of high-throughput genotyping has enabled the simultaneous interrogation of millions of genetic polymorphisms for association with oral and craniofacial traits. Specifically, genome-wide association studies (GWAS) of dental caries and periodontal disease have provided initial insights into novel loci and biological processes plausibly implicated in these two common, complex, biofilm-mediated diseases. This paper presents a summary of protocols, methods, tools, and pipelines for the conduct of GWAS of dental caries, periodontal disease, and related traits. The protocol begins with the consideration of different traits for both diseases and outlines procedures for genotyping, quality control, adjustment for population stratification, heritability and association analyses, annotation, reporting, and interpretation. Methods and tools available for GWAS are being constantly updated and improved; with this in mind, the presented approaches have been successfully applied in numerous GWAS and meta-analyses among tens of thousands of individuals, including dental traits such as dental caries and periodontal disease. As such, they can serve as a guide or template for future genomic investigations of these and other traits.

Assessment of adhesive bond strength from ultrasonic tone-bursts.

A model for the amplitude and phase of ultrasonic tone-bursts incident on adherend-adhesive interfaces is developed for both reflected and transmitted waves. The model parameters include the interfacial stiffness constants, which characterize the elastic properties of idealized adherend-adhesive interfaces having a continuum of bonds. The ultrasonic model is linked to the more realistic physico-chemical model of adhesive bonding via a scaling equation that establishes the relationship between the interfacial stiffness constants of the ultrasonic model and the fraction of actual bonds in the physico-chemical model. The link to the physico-chemical model enables a quantitative assessment of the absolute bond strength. The ultrasonic model and scaling equation are applied to the simulation assessment of the absolute bond strength of two aluminum alloy adherends joined by an epoxy adhesive. Model input is obtained from the calculated phase of tone-bursts reflected from the adherend-adhesive interfaces as a function of the interfacial stiffness constants. The simulation shows that the reflected phase is dominated by the first interface encountered by the incident tone-burst with little contribution from the second interface. The simulation also shows that the accuracy in assessing the adhesive bond strength depends on the sensitivity of the reflected phase to variations in the interfacial stiffness constants, reflecting in part the nonlinearity of the scaling relationship.

Physical therapy vs. internet-based exercise training (PATH-IN) for patients with knee osteoarthritis: study protocol of a randomized controlled trial.

BACKGROUND: Physical activity improves pain and function among individuals with knee osteoarthritis (OA), but most people with this condition are inactive. Physical therapists play a key role in helping people with knee OA to increase appropriate physical activity. However, health care access issues, financial constraints, and other factors impede some patients from receiving physical therapy (PT) for knee OA. A need exists to develop and evaluate other methods to provide physical activity instruction and support to people with knee OA. This study is examining the effectiveness of an internet-based exercise training (IBET) program designed for knee OA, designed by physical therapists and other clinicians. METHODS/DESIGN: This is a randomized controlled trial of 350 participants with symptomatic knee OA, allocated to three groups: IBET, standard PT, and a wait list (WL) control group (in a 2:2:1 ratio, respectively). The study was funded by the Patient Centered Outcomes Research Institute, which conducted a peer review of the proposal. The IBET program provides patients with a tailored exercise program (based on functional level, symptoms, and current activity), video demonstrations of exercises, and guidance for appropriate exercise progression. The PT group receives up to 8 individual visits with a physical therapist, mirroring standard practice for knee OA and with an emphasis on a home exercise program. Outcomes are assessed at baseline, 4 months (primary time point) and 12 months (to assess maintenance of treatment effects). The primary outcome is the Western Ontario and McMaster Universities Osteoarthritis Index, and secondary outcomes include objective physical function, satisfaction with physical function, physical activity, depressive symptoms and global assessment of change. Linear mixed models will be used to compare both the IBET and standard PT groups to the WL control group, examine whether IBET is non-inferior to PT (a treatment that has an established evidence base for knee OA), and explore whether participant characteristics are associated with differential effects of IBET and/or standard PT. This research is in compliance with the Helsinki Declaration and was approved by the Institutional Review Board of the University of North Carolina at Chapel Hill. DISCUSSION: The IBET program could be disseminated widely at relatively low cost and could be an important resource for helping patients with knee OA to adopt and maintain appropriate physical activity. This trial will provide an important evaluation of the effectiveness of this IBET program for knee OA. TRIAL REGISTRATION: NCT02312713.

Subharmonic generation, chaos, and subharmonic resurrection in an acoustically driven fluid-filled cavity.

Traveling wave solutions of the nonlinear acoustic wave equation are obtained for the fundamental and second harmonic resonances of a fluid-filled cavity. The solutions lead to the development of a non-autonomous toy model for cavity oscillations. Application of the Melnikov method to the model equation predicts homoclinic bifurcation of the Smale horseshoe type leading to a cascade of period doublings with increasing drive displacement amplitude culminating in chaos. The threshold value of the drive displacement amplitude at tangency is obtained in terms of the acoustic drive frequency and fluid attenuation coefficient. The model prediction of subharmonic generation leading to chaos is validated from acousto-optic diffraction measurements in a water-filled cavity using a 5 MHz acoustic drive frequency and from the measured frequency spectrum in the bifurcation cascade regime. The calculated resonant threshold amplitude of 0.2 nm for tangency is consistent with values estimated for the experimental set-up. Experimental evidence for the appearance of a stable subharmonic beyond chaos is reported.

Elastic constants of solids and fluids with initial pressure via a unified approach based on equations-of-state.

The second and third-order Brugger elastic constants are obtained for liquids and ideal gases having an initial hydrostatic pressure p1. For liquids the second-order elastic constants are C11=A+p1, C12=A-p1, and the third-order constants are C111=-(B+5A+3p1), C112=-(B+A-p1), and C123=A-B-p1, where A and B are the Beyer expansion coefficients in the liquid equation of state. For ideal gases the second-order constants are C11=p1γ+p1, C12=p1γ-p1, and the third-order constants are C111=-p1(γ(2)+4γ+3), C112=-p1(γ(2)-1), and C123=-p1 (γ(2)-2γ+1), where γ is the ratio of specific heats. The inequality of C11 and C12 results in a nonzero shear constant C44=(1/2)(C11-C12)=p1 for both liquids and gases. For water at standard temperature and pressure the ratio of terms p1/A contributing to the second-order constants is approximately 4.3×10(-5). For atmospheric gases the ratio of corresponding terms is approximately 0.7. Analytical expressions that include initial stresses are derived for the material 'nonlinearity parameters' associated with harmonic generation and acoustoelasticity for fluids and solids of arbitrary crystal symmetry. The expressions are used to validate the relationships for the elastic constants of fluids.

The role of interventional radiology in complications after paediatric liver transplantation.

Liver transplantation has become an established treatment in both adults and children for end-stage liver disease, acute hepatic failure and certain liver tumours. There is a significant rate of complications after all forms of liver transplantation. The interventional radiologist plays a critical role in the diagnosis and treatment of these complications. The use of image-guided, minimally invasive procedures reduces the need for surgical revision or retransplantation, and improves graft and patient survival rate. This article reviews some of the most common vascular and non-vascular complications after paediatric liver transplantation, and the interventional radiology techniques used to diagnose and treat them.

Envelope solitons in acoustically dispersive vitreous silica.

Acoustic radiation-induced static strains, displacements, and stresses are manifested as rectified or 'dc' waveforms linked to the energy density of an acoustic wave or vibrational mode via the mode nonlinearity parameter of the material. An analytical model is developed for acoustically dispersive media that predicts the evolution of the energy density of an initial waveform into a series of energy solitons that generates a corresponding series of radiation-induced static strains (envelope solitons). The evolutionary characteristics of the envelope solitons are confirmed experimentally in Suprasil W1 vitreous silica. The value (- 11.9 ± 1.43) for the nonlinearity parameter, determined from displacement measurements of the envelope solitons via a capacitive transducer, is in good agreement with the value (- 11.6 ± 1.16) obtained independently from acoustic harmonic generation measurements. The agreement provides strong, quantitative evidence for the validity of the model.