Adjustment For Control Variables Research Articles

Association Between Partisan Affiliation of State Governments and State Mortality Rates Before and During the COVID-19 Pandemic.

Increasing polarization of states reached a high point during the COVID-19 pandemic, when the party affiliation of elected officials often predicted their policy response. The health consequences of these divisions are unclear. Prior studies compared mortality rates based on presidential voting patterns, but few considered the partisan orientation of state officials. This study examined whether the partisan orientation of governors or legislatures was associated with mortality outcomes during the COVID-19 pandemic. Data on deaths and the partisan orientation of governors and legislators were obtained from the Centers for Disease Control and Prevention and the National Conference of State Legislatures, respectively. Linear regression was used to measure the association between Republican representation (percentage of seats held) in legislatures and (1) age-adjusted, all-cause mortality rates (AAMRs) in 2015-2021 and (2) excess death rates during three phases of the COVID-19 pandemic, controlling for median household income, the prevalence of four risk factors (obesity, chronic obstructive pulmonary disease, heart attack, stroke), and state policy orientation. Associations between excess death rates and the governor's party were also examined. States with Republican governors or greater Republican representation in legislatures experienced higher AAMRs during 2015-2021, lower excess death rates during Phase 1 of the COVID-19 pandemic (weeks ending March 28, 2020, through June 13, 2020), and higher excess death rates in Phases 2 and 3 (weeks ending June 20, 2020, through April 30, 2022; p < 0.05). Most associations lost statistical significance after adjustment for control variables. Mortality was higher in states with Republican governors and greater Republican legislative representation before and during much of the pandemic. Observed associations could be explained by the adverse effects of policy choices, reverse causality (e.g., popularity of Republican candidates in states with lower socioeconomic and health status), or unmeasured factors that predominate in states with Republican leaders.

The mediating role of self-efficacy between workplace violence and PTSD among nurses in Liaoning Province, China: A cross-sectional study.

Nurses are at high risk for workplace violence, which can lead to psychological problems. The purpose of this study was to determine the relationship between workplace violence, self-efficacy, and PTSD, and to further explore whether self-efficacy mediates the relationship between workplace violence and PTSD among Chinese nurses. This cross-sectional study was conducted in Liaoning Province, China in 2020. A total of 1,017 valid questionnaires were returned. Each questionnaire included the Workplace Violence Scale, the General Self-Efficacy Scale, the Post-traumatic Stress Disorder Scale (PTSS-10), and demographics information. A hierarchical multiple regression approach was used to explore the mediating role of self-efficacy in the relationship between workplace violence and PTSD. The mediation model was then tested by the PROCESS macro in SPSS. A total of 1,017 nurses were included in this study, and the average score of PTSD among Chinese nurses was 26.85 ± 13.13 (mean ± SD). After further adjustment for control variables, workplace violence was positively associated with PTSD, explaining 13% of the variance. High self-efficacy was associated with low PTSD, explaining 18% of the variance. Self-efficacy partially mediated the role of workplace violence and PTSD. The high scores of PTSD among Chinese nurses demand widespread attention. Workplace violence is an important predictor of PTSD in nurses. Self-efficacy is a significant factor in improving PTSD in nurses and mediates the relationship between workplace violence and PTSD. Measures and strategies to improve self-efficacy may mitigate the effects of workplace violence on PTSD in nurses.

An iterative optimization algorithm for posture and geometric parameters of grinding wheel based on cross-section sensitivity and matching constraints of solid end mills

Grinding wheel posture and geometric parameters are the key to optimizing the grinding process for helical grooves of solid end mills. However, the current envelope calculation models have not done enough research on the influence of the grinding wheel discretization method and grinding kinematics models mainly focus on helical grooves with constant core radius. Moreover, the matching error of the overall cross-section curve is ignored. These problems can reduce model generality, affect final calculation results, and cause inferior cutting performance. Therefore, a novel optimization algorithm for grinding wheel posture and geometric parameters is developed in this paper. Firstly, a parametric grinding wheel modeling method with adaptive adjustment of control variables is proposed, and a generalized grinding kinematics model for variable core radius is established. Then, by analyzing the sensitivity of cross-section parameters and the formation mechanism of the core radius, an iterative strategy based on parameter sets is established. Under the condition that the core radius is ensured in advance, the matching errors of rake angle, groove width, and overall cross-section curve are considered comprehensively to optimize the grinding wheel posture and geometric parameters. Finally, the proposed method is verified by simulation and machining. The results indicate that the proposed method can realize the envelope calculation of the helical groove with variable core radius, and optimize the grinding wheel posture and geometric parameters accurately and efficiently.

Incarceration exposure and prescription opioid use during pregnancy

BackgroundPrior research demonstrates a high prevalence of substance use, including opioid use, among those who have had personal or vicarious contact with the correctional system. Relatedly, alongside patterns of rising opioid use in general, opioid use during pregnancy is becoming a growing public health concern. Still, risk factors for prescription opioid use during pregnancy remain understudied. This study is the first to assess the connection between a women’s personal or vicarious exposure to incarceration in the 12 months prior to birth and patterns of prenatal opioid use. MethodsData are from the Pregnancy Risk Assessment Monitoring System (PRAMS) in 2019 (N = 17,551 mothers). Logistic and multinomial logistic regression are used to assess the association between incarceration exposure and patterns of opioid use during pregnancy. ResultsIncarceration-exposed women were more likely to use all eight types of prescription opioids assessed in this study (Hydrocodone, Codeine, Oxycodone, Tramadol, Hydromorphone/Meperidine, Oxymorphone, Morphine, and Fentanyl). After adjustment for control variables, incarceration-exposed women were significantly more likely to report any prescription opioid use during pregnancy (OR = 1.745, 95% CI = 1.194, 2.554). Furthermore, relative to no opioid use, incarceration exposure was also associated with illicit prescription opioid use (RRR = 2.979, 1.533, 5.791). ConclusionsIncarceration exposure in the year prior to birth is associated with higher odds of prescription opioid use. These findings add to the burgeoning literature that details a women’s exposure to incarceration is a risk marker for substance use and engagement in health risk behaviors that can jeopardize maternal and infant wellbeing.

Security assessment of electricity-gas-heat integrated energy systems based on the vulnerability index

Integrated energy systems (IES) realize the coupling of different energy flows and help to improve energy efficiency and increase renewable energy consumption. However, due to the coupling effect, variation of operation parameters in one energy flow can be propagated to other ones through the coupling equipment, which results in complex security problems of IES. Here, we propose a security assessment method based on the vulnerability index (VI) for electricity-gas-heat IES. The vulnerability index combines the current values of state variables, operation limits, and sensitivity factors between state variables and control variables simultaneously. Current values are obtained by the solution of the steady-state IES model by the decomposed Newton-Raphson method. Sensitivity factors are derived based on the Jacobian matrix in the IES model. VI matrixes for IES with different control modes are formulated and deduced. The vulnerable state variables and the key control variables are identified based on the VI matrixes. A case study is conducted to validate the proposed method. Vulnerable state variables and key control variables are identified by the absolute value of vulnerability index with the upward and downward adjustment of control variables. These results are verified by energy flow calculations, which show that vulnerable state variables and key control variables derived by vulnerability index are more accurate than those identified by sensitivity factors. In the situations of determining electricity based on heat and determining heat based on electricity, the method proposed herein is 1.73 and 22.45 times faster than energy flow calculations respectively.

Optimal Control of Hybrid Energy Storage System of New Energy Power Generation System Based on Improved Particle Swarm Algorithm

In order to ensure the stability and reliability of power supply and realize day and night power generation, wind and solar complementary power generation systems are built in areas with abundant solar and wind energy resources. However, the system investment cost is too high. Because of this, there are wind, light intermittent, and non-intermittent power generation systems. For issues such as stability, an energy storage system needs to be configured to stabilize power fluctuations. This paper aims to study the optimization control of hybrid energy storage system of new energy power generation system based on improved particle swarm algorithm. In this paper, the application of particle swarm algorithm to power system reactive power optimization has been researched in two aspects. Through optimization methods, reasonable adjustment of control variables, full use of equipment resources of the power grid, to improve voltage quality and reduce system operation network to ensure the stability of the voltage system. In addition, this paper selects the IEEE30 node test system and simulation data analysis, takes the hybrid energy storage system as the optimization object, and optimizes the reactive power of the newly improved particle swarm algorithm. The experiments in this paper show that the improved algorithm has a good effect in reactive power optimization, increasing the performance of the hybrid energy storage system by 27.02%. MPSO algorithm is also better than basic PSO algorithm. It can be seen from the figure that in the PSO algorithm, the algorithm basically tends to be stable after more than 40 iterations, and finally the algorithm converges to 0.089.

Suicidality in Children with Elevated Autistic Traits.

By using a nationally representative school-based sample (4,816 children aged 8-14 years), we examined the risk of suicidality in children with elevated autistic traits and assessed the mediation of anxiety/depression and moderation effects of family function and academic performance. The Chinese version of the Social Responsiveness Scale (SRS-C) was used to measure autistic features. Logistic regression models were applied to assess associations between autistic traits and suicidality (suicidal ideation, suicide plans, and suicide attempts) for estimating the mediation effects of anxiety/depression and moderation effects of academic performance and family function after adjustment for control variables. Every 10-point increase in the SRS-C score was associated with a 1.3-1.4-fold increase in suicidality risk. Associations relating to suicide plans and attempts were fully mediated; however, the association with ideation was partially mediated by anxiety/depression. Academic performance and family function did not appear to moderate associations between autistic traits and suicidality. In conclusion, children with elevated autistic traits exhibited increased risk of suicidality, which could be generally attributed to symptoms of anxiety/depression. Because adequate family function and academic performance did not mitigate the link between elevated autistic traits and suicidality, in-depth exploration into specific protective factors in children with elevated autistic traits is warranted. LAY SUMMARY: By using a nationally representative school-based sample (4,816 children aged 8-14 years), we observed that the risk of suicidality increased in children with elevated autistic traits. This association was generally explained by increased levels of anxiety/depression. Furthermore, better family function and academic performance did not appear to mitigate the link between autistic traits and suicidality. Autism Res 2020, 13: 1811-1821. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

A novel hierarchical distributed framework for optimal reactive power dispatch based on a system of systems structure

Optimal reactive power dispatch is one of the major issues in operation of power systems which aims to minimize losses, voltage stability, voltage deviation, etc. through an optimal adjustment of control variables. Recently, some alterations have been involved in control procedures, management and scheduling of these systems due to the power systems restructure, electricity markets and smart grids. These changes are notable in methods used for optimal dispatch of reactive power as well. According to the hierarchical structure of the power grids, this paper presents a hierarchical distributed framework based on a System of Systems (SoS) concept. In this structure, every section of the grid is controlled by a smart agent. Agents are interconnected and exchange the required data via a telecommunication network. In this paper, the amounts of active and reactive power exchanged between agents are considered as boundary and common parameters. Our proposed method is implemented on the IEEE 118-bus network connected to 7 active power distribution networks. The results are compared to the ones obtained from a distributed method based on an Incident Command System (ICS) and a centralized control method. It turns out that the proposed method outperforms the other two competing methods.

Model Predictive Control of GTAW Weld Pool Penetration

Weld pool penetration is a major indicator of weld integrity but it is not directly measurable. The key to solving this issue is to find or create observable phenomena that can be used to derive the penetration. An innovative method has recently been proposed/developed to derive the penetration from the reflection of projected laser from an oscillating weld pool surface. However, in addition to the penetration, the oscillation, thus the reflection determined by it, also depends on the pulse amplitude of the current, which needs to be adjusted as the control variable to feedback control the penetration as the output. This dependence imposes a constraint on the control algorithm such that the adjustment of the control variable must be relatively slow to minimize additional sources that affect the oscillation/sensor. This restriction on the control variable adjustment also brings challenges to the identification of the dynamic model of the weld process to be controlled, which has to apply a varying control signal to stimulate the dynamics. To solve these issues, this letter proposes using a low order model to catch the dominant dynamics such that a high speed variation in the control signal can be avoided when choosing the model predictive control algorithm. This allows use of relatively poor models to determine the adjustment on the pulsing amplitude, and still achieves relatively accurate control. Experimental results verified the effectiveness of the resultant penetration control system despite the restrictions imposed by the penetration sensor, which affect the identification of high order dynamics and free adjustments of control variables.

Socioeconomic status, stressful life situations and mental health problems in children and adolescents: Results of the German BELLA cohort-study.

AimChildren and adolescents with low socioeconomic status (SES) suffer from mental health problems more often than their peers with high SES. The aim of the current study was to investigate the direct and interactive association between commonly used indicators of SES and the exposure to stressful life situations in relation to children’s mental health problems.MethodsThe prospective BELLA cohort study is the mental health module of the representative, population-based German National Health Interview and Examination Survey for children and adolescents (KiGGS). Sample data include 2,111 participants (aged 7–17 years at baseline) from the first three measurement points (2003–2006, 2004–2007 and 2005–2008). Hierarchical multiple linear regression models were conducted to analyze associations among the SES indicators household income, parental education and parental unemployment (assessed at baseline), number of stressful life situations (e.g., parental accident, mental illness or severe financial crises; 1- and 2-year follow-ups) and parent-reported mental health problems (Strength and Difficulties Questionnaire; 2-year follow-up).ResultsAll indicators of SES separately predicted mental health problems in children and adolescents at the 2-year follow-up. Stressful life situations (between baseline and 2-year follow-up) and the interaction of parental education and the number of stressful life situations remained significant in predicting children’s mental health problems after adjustment for control variables. Thereby, children with higher educated parents showed fewer mental health problems in a stressful life situation. No moderating effect was found for household income and parental employment. Overall, the detected effect sizes were small. Mental health problems at baseline were the best predictor for mental health problems two years later.ConclusionsChildren and adolescents with a low SES suffer from multiple stressful life situations and are exposed to a higher risk of developing mental health problems. The findings suggest that the reduction of socioeconomic inequalities and interventions for families with low parental education might help to reduce children’s mental health problems.

The importance of sexuality, changes in erectile functioning and its association with self-esteem in men with localized prostate cancer: data from an observational study

BackgroundTreatment for localized prostate cancer (PCa) can cause long-term changes in erectile functioning. However, data on the importance of sexuality and possible consequences of altered erectile functioning on self-esteem in men with localized PCa are lacking.MethodsSelf-report questionnaires were completed by 292 men with PCa, initially managed with active surveillance (AS) or radical prostatectomy (RP). Independent t-tests were conducted to evaluate group differences. A sequential multiple regression model was fitted to analyze the associations between the importance of sexuality, changes in erectile functioning and impairment of self-esteem. Interaction effects were tested using simple slope analyses.ResultsParticipants were 70 ± 7.2 years old and 66.5% rated sex as being “rather/very important”. The two groups differed markedly in changes in erectile functioning, importance of sexuality and impairment of self-esteem (p < .001), with higher values in RP patients. Regression analysis showed that after adjustment for control variables and importance of sexuality, changes in erectile functioning were still associated with impairment of self-esteem (B = .668, SE = .069, p < .001). The interaction of changes in erectile functioning and importance of sexuality reached significance (B = .318, SE = .062, p < .001).ConclusionsRP patients report more changes in erectile functioning than AS patients. Moreover, in men with localized PCa, erectile functioning and self-esteem are closely related. Sexuality seems to be important for the majority of these men. Physicians should address the possibility of erectile dysfunction and its potential effects on psychological well-being before the treatment decision.

The association of vitamin D deficiency and glucose control among diabetic patients

ObjectiveTo evaluate the association between the level of vitamin D and glycemic control among patients with diabetes. Research design and methodWe analyzed data collected from NHANES 2003–2006. We included only non-pregnant adult diabetic persons 18years or older. Participants who had vitamin D level less than 20ng/ml were considered as having vitamin D deficiency. Participants were considered to have a glucose control if the HbA1c level was less than 7% [53mmol/L]. We used student’s t test to compare the difference in HbA1c means between people with Diabetes with and without a vitamin D deficiency. We used a multivariate logistic regression model to predict the relationship between glucose control and vitamin D deficiency. We used race/ethnicity, BMI, age, gender, type of diabetic medication used, having health insurance or not, and comorbid conditions (hypertension, anemia, cholesterol, liver disease, and kidney disease) as control variables. ResultsThe study population included a total of 929 non-institutionalized, non-pregnant, diabetic adult persons. About 57% of patients with diabetes had a vitamin D deficiency. Blacks (non-Hispanic patients) with diabetes had the highest rate of vitamin D deficiency (79%). The unadjusted means of HbA1c were significantly different between diabetic patients with no vitamin D deficiency and those with a vitamin D deficiency (7.06% [54mmol/L], 7.56 % [59mmol/L], respectively, P<0.0001). Multivariate adjustment showed a small but not significant, increase in odds (11%) of having uncontrolled diabetes in patients with a vitamin D deficiency after adjustment for other factors. ConclusionVitamin D deficiency is very common in patients with diabetes. We found no significant association between vitamin D level and glycemic control in patients with diabetes after adjustment for control variables.

Particle Swarm Optimization Based Optimal Reactive Power Dispatch for Power Distribution Network with Distributed Generation

Reactive power dispatch plays a main role in order to provide good facility secure and economic operation in the power system. Optimal reactive power dispatch (ORPD) is a nonlinear optimization problem and has both equality and inequality constraints. ORPD is defined as the minimization of active power loss by controlling a number of variables. Due to complex characteristics of ORPD, heuristic optimization has become an efficient solver. In this paper, particle swarm optimization (PSO) algorithm and MATPOWER toolbox are applied to solve the ORPD problem for distribution system with distributed generating (DG) plant. The proposed method minimizes the active power loss in a practical power system as well as determines the optimal placement of a new installed DG. The practical 41-bus, 6-machine power distribution network of Myingyan area is used to evaluate the performance. The result shows that the adjustment of control variables of distribution power network with a new DG gives a better approach than adjustment only the control variables without DG.

Transit Use, Physical Activity, and Body Mass Index Changes: Objective Measures Associated With Complete Street Light-Rail Construction.

We assessed effects on physical activity (PA) and weight among participants in a complete street intervention that extended a light-rail line in Salt Lake City, Utah. Participants in the Moving Across Places Study resided within 2 kilometers of the new line. They wore accelerometers and global positioning system (GPS) loggers for 1 week before and after rail construction. Regression analyses compared change scores of participants who never rode transit with continuing, former, and new riders, after adjustment for control variables (total n = 537). New riders had significantly more accelerometer-measured counts per minute than never-riders (P < .01), and former riders had significantly fewer (P < .01). New riders lost (P < .05) and former riders gained (P < .01) weight. Former riders lost 6.4 minutes of moderate-to-vigorous PA (MVPA) per 10 hours of accelerometer wear (P < .01) and gained 16.4 minutes of sedentary time (P < .01). New riders gained 4.2 MVPA minutes (P < .05) and lost 12.8 (P < .05) sedentary minutes per 10 hours accelerometer wear. In light of the health benefits of transit ridership in the complete street area, research should address how to encourage more sustained ridership.

Insomnia in adults: the impact of earlier cigarette smoking from adolescence to adulthood.

This study examined the role of cigarette smoking beginning in adolescence and extending to the fifth decade of life on insomnia at an average age of 43 years in the Children and Adults in the Community Study. Participants were originally assessed in 1983 and came from a community-based random sample of individuals living in 2 upstate New York counties. Participants were assessed over 7 waves of data collection that spanned approximately 29 years, from mean ages 14.1 years (T2) to 42.9 years (T8). We classified the longitudinal trajectories of cigarette use. Five cigarette use trajectory groups were identified: heavy/continuous smokers, late starters, occasional smokers, quitters/decreasers, and nonsmokers. The result of the logistic regression analysis of adult insomnia for the Bayesian posterior probability of the heavy/continuous smokers when compared with the Bayesian posterior probability of nonsmokers was statistically significant-adjusted odds ratio of 3.35 [95% confidence interval (1.06-10.56; P < 0.05)]-after adjustment for control variables. The findings highlight the importance of heavy chronic smoking as contributing to insomnia. Clinicians should focus their efforts on smoking prevention and treatment of younger individuals, as well as promoting cessation among older adult smokers to decrease the likelihood of insomnia.

Mental health issues decrease diabetes-specific quality of life independent of glycaemic control and complications: findings from Australia’s living with diabetes cohort study

BackgroundWhile factors associated with health-related quality of life for people with chronic diseases including diabetes are well researched, far fewer studies have investigated measures of disease-specific quality of life. The purpose of this study is to assess the impact of complications and comorbidities on diabetes-specific quality of life in a large population-based cohort of type 2 diabetic patients.MethodsThe Living with Diabetes Study recruited participants from the National Diabetes Services Scheme in Australia. Data were collected via a mailed self-report questionnaire. Diabetes-specific quality of life was measured using the Audit of Diabetes-Dependent Quality of Life (ADDQoL) questionnaire. The analyses are for 3609 patients with type 2 diabetes. Regression models with adjustment for control variables investigated the association of complications and comorbidities with diabetes-specific quality of life. Next, the most parsimonious model for diabetes-specific quality of life after controlling for important covariates was examined.ResultsThe expected associations with better diabetes-specific quality of life were evident, such as increased income, not on insulin, better glycaemic control and older age. However, being single and having been diagnosed with cancer were also associated with better ADDQoL. Additionally, poorer diabetes-specific quality of life was strongly sensitive to the presence of diabetes complications and mental health conditions such as depression, anxiety and schizophrenia. These relationships persisted after adjustment for gender, age, duration of diabetes, treatment regimen, sampling region and other treatment and socio-demographic variables.ConclusionsA greater appreciation of the complexities of diabetes-specific quality of life can help tailor disease management and self-care messages given to patients. Attention to mental health issues may be as important as focusing on glycaemic control and complications. Therefore clinicians’ ability to identify and mange mental health issues and/or refer patients is critical to improving patients’ diabetes-specific quality of life.

Physician Wages Across Specialties

Disparities in remuneration between primary care and other physician specialties may impede health care reform by undermining the sustainability of a primary care workforce. Previous studies have compared annual incomes across specialties unadjusted for work hours. Wage (earnings-per-hour) comparisons could better inform the physician payment debate. In a cross-sectional analysis of data from 6381 physicians providing patient care in the 2004-2005 Community Tracking Study (adjusted response rate, 53%), we compared wages across broad and narrow categories of physician specialties. Tobit and linear regressions were run. Four broad specialty categories (primary care, surgery, internal medicine and pediatric subspecialties, and other) and 41 specific specialties were analyzed together with demographic, geographic, and market variables. In adjusted analyses on broad categories, wages for surgery, internal medicine and pediatric subspecialties, and other specialties were 48%, 36%, and 45% higher, respectively, than for primary care specialties. In adjusted analyses for 41 specific specialties, wages were significantly lower for the following than for the reference group of general surgery (wage near median, $85.98): internal medicine and pediatrics combined (-$24.36), internal medicine (-$24.27), family medicine (-$23.70), and other pediatric subspecialties (-$23.44). Wage rankings were largely impervious to adjustment for control variables, including age, race, sex, and region. Wages varied substantially across physician specialties and were lowest for primary care specialties. The primary care wage gap was likely conservative owing to exclusion of radiologists, anesthesiologists, and pathologists. In light of low and declining medical student interest in primary care, these findings suggest the need for payment reform aimed at increasing incomes or reducing work hours for primary care physicians.

Smoking and Illicit Drug Use Associations With Early Versus Delayed Reproduction: Findings in a Young Adult Cohort of Australian Twins

This article examines relationships between reproductive onset and lifetime history of smoking, regular smoking, and nicotine dependence, and cannabis and other illicit drug use. Data were drawn from a young adult cohort of 3,386 female and 2,751 male Australian twins born between 1964 and 1971. Survival analyses were conducted using Cox proportional hazards regression models predicting age at first childbirth from history of substance use or disorder separately by substance class. Other substance use or disorder, including alcohol dependence, as well as sociodemographic characteristics, history of psychopathology, and family and childhood risks, were included as control variables in adjusted models. Regular smoking and nicotine dependence were associated with earlier reproduction, with pronounced effects for women. For women, use of cannabis was associated with early reproduction before age 20, and with delayed reproduction among women who have not reproduced by age 20 or 25. Adjustment for control variables only partially explained these associations. Consistent with research linking adolescent use with sexual risk taking predictive of early childbearing, regular smokers and nicotine-dependent individuals show earlier reproductive onset. In contrast, delays in childbearing associated with use of cannabis are consistent with impairments in reproductive ability and/or opportunities for reproduction. Continued research on risks both upstream and downstream of substance-use initiation and onset of substance-use disorder is needed for causal mechanisms to be fully understood.

Multiobjective optimal VAR dispatch considering control variable adjustment costs

In this paper, strength Pareto evolutionary algorithm (SPEA) is applied to solve the multiobjective optimal reactive power (VAR) dispatch problem. The optimal VAR dispatch problem is formulated as a non-linear constrained multiobjective optimisation problem where the real power loss and the control variable adjustment costs are to be optimised simultaneously. The proposed approach handles the problem as a true multiobjective optimisation problem. A hierarchical clustering algorithm is imposed to provide the decision-maker with a representative and manageable Pareto-optimal set. Moreover, fuzzy set theory is employed to extract the best compromise solution over the trade-off curve. The results demonstrate the capabilities of the proposed approach to generate true and well-distributed Pareto-optimal solutions of the multiobjective VAR dispatch problem in one single run. In addition, the effectiveness of the proposed approach and its potential to solve the multiobjective VAR dispatch problem are confirmed.

The association between smoking and subsequent suicide-related outcomes in the National Comorbidity Survey panel sample

Controversy exists about whether the repeatedly documented associations between smoking and subsequent suicide-related outcomes (SROs; ideation, plans, gestures and attempts) are due to unmeasured common causes or to causal effects of smoking on SROs. We address this issue by examining associations of smoking with subsequent SROs with and without controls for potential explanatory variables in the National Comorbidity Survey (NCS) panel. The latter consists of 5001 people who participated in both the 1990-2002 NCS and the 2001-2003 NCS follow-up survey. Explanatory variables include sociodemographics, potential common causes (parental history of mental-substance disorders; other respondent childhood adversities) and potential mediators (respondent history of Diagnostic and Statistical Manual of Mental Disorders, 3rd edn, revised mental-substance disorders). Small gross (that is, without controls) prospective associations are found between history of early-onset nicotine dependence and both subsequent suicide ideation and, among ideators, subsequent suicide plans. None of the baseline smoking measures, though, predicts subsequent suicide gestures or attempts among ideators. The smoking-ideation association largely disappear, but the association of early-onset nicotine dependence with subsequent suicide plans persists (odds ratio=3.0), after adjustment for control variables. However, the latter association is as strong with remitted as active nicotine dependence, arguing against a direct causal effect of nicotine dependence on suicide plans. Decomposition of the control variable effects, furthermore, suggests that these effects are due to common causes more than to mediators. These results refine our understanding of the ways in which smoking is associated with later SROs and for the most part argue against the view that these associations are due to causal effects of smoking.