Iron Deposition and Distribution Across the Hippocampus Is Associated with Pattern Separation and Pattern Completion in Older Adults at Risk for Alzheimer's Disease

Elevated iron deposition in the brain has been observed in older adult humans and persons with Alzheimer's disease (AD), and has been associated with lower cognitive performance. We investigated the impact of iron deposition, and its topographical distribution across hippocampal subfields and segments (anterior, posterior) measured along its longitudinal axis, on episodic memory in a sample of cognitively unimpaired older adults at elevated familial risk for AD (N = 172, 120 females, 52 males; mean age = 68.8 ± 5.4 years). MRI-based quantitative susceptibility maps were acquired to derive estimates of hippocampal iron deposition. The Mnemonic Similarity Task was used to measure pattern separation and pattern completion, two hippocampally mediated episodic memory processes. Greater hippocampal iron load was associated with lower pattern separation and higher pattern completion scores, both indicators of poorer episodic memory. Examination of iron levels within hippocampal subfields across its long axis revealed topographic specificity. Among the subfields and segments investigated here, iron deposition in the posterior hippocampal CA1 was the most robustly and negatively associated with the fidelity memory representations. This association remained after controlling for hippocampal volume and was observed in the context of normal performance on standard neuropsychological memory measures. These findings reveal that the impact of iron load on episodic memory performance is not uniform across the hippocampus. Both iron deposition levels as well as its spatial distribution, must be taken into account when examining the relationship between hippocampal iron and episodic memory in older adults at elevated risk for AD.

What drives job satisfaction among community pharmacists? An application of relative importance analysis

Background

Pharmacy employers want to improve pharmacists' job satisfaction, but ratings of job satisfaction are highly subjective, as evaluating job satisfaction involves weighing simultaneously the importance of multiple correlated determinants that are often perceived unequally.

Objectives

To 1) describe the application of relative importance analysis in estimating the predictive ability of correlated determinants of job satisfaction, and to rank the determinants in order of relative importance, and 2) explore how the perceived relative importance of job satisfaction predictors may vary across community pharmacists' age, gender, and work setting categories.

Methods

Data were obtained from the 2019 National Pharmacy Workforce Survey administered to 96,110 licensed U.S. pharmacists. Multiple regression analysis (MR) and relative weight analysis (RWA) were used to assess the predictive ability of determinants to explain pharmacists' job satisfaction. Subgroup analyses were performed to explore variations in the perceived relative importance of predictors across pharmacists' age, gender and work setting categories.

Results

Over the entire sample of community pharmacists, no personal experience of workplace discrimination [RW = 0.0613, rank = 1] and less reported engagement in advanced dispensing activities [RW = 0.0235, rank = 2] were most associated with greater job satisfaction, as both predictors jointly accounted for 67.5% of the predicted criterion variance (R ²). Pharmacists' compensation was observed to have the lowest perceived relative importance for predicting job satisfaction [RW = 0.0005, rank = 6], accounting for 0.5% of R ². Between-group comparisons showed that, no personal experience of workplace discrimination had the highest perceived relative importance for job satisfaction across pharmacists' age groups, among women, and across most work settings except small chain pharmacies. Within-group comparisons showed that pharmacists' compensation was significantly more important than professional interactions (Δ_RW(PC-PPI) 0.2900 [0.0637, 0.5360]) for job satisfaction among pharmacists in large chain pharmacies, while patient-care services was significantly more important than compensation for job satisfaction in independent (Δ_RW(PPS-PC) 0.1761 [0.0017, 0.5980]) and health system retail pharmacists (Δ_RW(PPS-PC) 0.4190 [0.0444, 0.8303]).

Conclusions

Relative importance analysis corroborated multiple regression and provided a more interpretable presentation of variable influence on community pharmacists job satisfaction as the importance of personal and workplace characteristics in how pharmacists evaluate their job satisfaction varied across age, gender and work setting categories.

Too Committed to Switch Off-Capturing and Organizing the Full Range of Work-Related Rumination from Detachment to Overcommitment

Work-related thoughts during off-job time have been studied extensively in occupational health psychology and related fields. We provide a focused review of the research on overcommitment-a component within the effort-reward imbalance model-and aim to connect this line of research to the most commonly studied aspects of work-related rumination. Drawing on this integrative review, we analyze survey data on ten facets of work-related rumination, namely (1) overcommitment, (2) psychological detachment, (3) affective rumination, (4) problem-solving pondering, (5) positive work reflection, (6) negative work reflection, (7) distraction, (8) cognitive irritation, (9) emotional irritation, and (10) inability to recover. First, we apply exploratory factor analysis to self-reported survey data from 357 employees to calibrate overcommitment items and to position overcommitment within the nomological net of work-related rumination constructs. Second, we apply confirmatory factor analysis to self-reported survey data from 388 employees to provide a more specific test of uniqueness vs. overlap among these constructs. Third, we apply relative weight analysis to assess the unique criterion-related validity of each work-related rumination facet regarding (1) physical fatigue, (2) cognitive fatigue, (3) emotional fatigue, (4) burnout, (5) psychosomatic complaints, and (6) satisfaction with life. Our results suggest that several measures of work-related rumination (e.g., overcommitment and cognitive irritation) can be used interchangeably. Emotional irritation and affective rumination emerge as the strongest unique predictors of fatigue, burnout, psychosomatic complaints, and satisfaction with life. Our study is intended to assist researchers in making informed decisions on selecting scales for their research and paves the way for integrating research on the effort-reward imbalance and work-related rumination.

Uncertainty and Well-Being amongst Homeworkers in the COVID-19 Pandemic: A Longitudinal Study of University Staff

The COVID-19 pandemic heightened uncertainties in people's lives-and was itself a source of fresh uncertainty. We report a study of homeworkers on whether such uncertainties, and particularly those related to their work environment, are associated with lower levels of well-being and whether this association is exacerbated by prior poor well-being. We focus on five uncertainties surrounding the pandemic and employment-the virus, the job quality, workload, logistics of work lives, and support from the employer. Our empirical tests show that uncertainties around the virus, employer support, and their job quality have the strongest negative associations with well-being. These are based on data collected over three time periods in the first year of the pandemic from a sample of university staff (academics and non-academics) and well-being is measured on two continua, anxiety-contentment and depression-enthusiasm. The effects of uncertainties around workload and logistics are less pronounced, but more apparent among employees with better (not poorer) past well-being, at various times of the recession. The study adds to our understanding of the pandemic and highlights the need to link uncertainty to mental health more than it has in the past.

Direct and Indirect Associations of Widespread Individual Differences in Brain White Matter Microstructure With Executive Functioning and General and Specific Dimensions of Psychopathology in Children

BACKGROUND

Executive functions (EFs) are important partly because they are associated with risk for psychopathology and substance use problems. Because EFs have been linked to white matter microstructure, we tested the prediction that fractional anisotropy (FA) and mean diffusivity (MD) in white matter tracts are associated with EFs and dimensions of psychopathology in children younger than the age of widespread psychoactive substance use.

METHODS

Parent symptom ratings, EF test scores, and diffusion tensor parameters from 8588 9- to 10-year-olds in the ABCD Study (Adolescent Brain Cognitive Development Study) were used.

RESULTS

A latent factor derived from EF test scores was significantly associated with specific conduct problems and attention-deficit/hyperactivity disorder problems, with dimensions defined in a bifactor model. Furthermore, EFs were associated with FA and MD in 16 of 17 bilateral white matter tracts (range: β = .05; SE = .17; through β = -.31; SE = .06). Neither FA nor MD was directly associated with psychopathology, but there were significant indirect associations via EFs of both FA (range: β = .01; SE = .01; through β = -.09; SE = .02) and MD (range: β = .01; SE = .01; through β = .09; SE = .02) with both specific conduct problems and attention-deficit/hyperactivity disorder in all tracts except the forceps minor.

CONCLUSIONS

EFs in children are inversely associated with diffusion tensor imaging measures in nearly all tracts throughout the brain. Furthermore, variance in diffusion tensor measures that is shared with EFs is indirectly shared with attention-deficit/hyperactivity disorder and conduct problems.

Not All Transformational Leadership Behaviors Are Equal: The Impact of Followers’ Identification With Leader and Modernity on Taking Charge

This study investigates how each dimension of transformational leadership directly and indirectly influences followers’ change-oriented behaviors. Using a sample of 329 independent leader–follower dyads from a wide range of Chinese organizations, we examine followers’ identification with leader as an intervening variable between the four dimensions of transformational leadership (“core” transformational behaviors, high-performance expectations, individualized support, and intellectual stimulation) and followers’ taking charge behaviors. Results showed that intellectual stimulation had the highest relative effect size that was largely due to its direct effect on taking charge. Individualized support only exerted a significant indirect effect. Additionally, the negative direct and positive indirect effects of high-performance expectations rendered its total effect nonsignificant. Furthermore, the direct, indirect, and total effects of “core” transformational behaviors were nonsignificant. We also found that followers’ value of modernity moderated the effect of identification with leader on taking charge. The indirect effects of intellectual stimulation, individualized support, and high-performance expectations were significant when modernity was high but nonsignificant when it was low. Implications for theory, practice, and future research are discussed.

The ABC for Studying the Too-Much-of-a-Good-Thing Effect

The too-much-of-a-good-thing (TMGT) effect occurs when an initially positive relation between an antecedent and a desirable outcome variable turns negative when the underlying ordinarily beneficial antecedent is taken too far, such that the overall relation becomes nonmonotonic. The presence of the TMGT effect incites serious concerns about the validity of linearly specified empirical models. Recent research posited that the TMGT effect is omnipresent, due to an overarching meta-theoretical principle. Drawing on the competitive mediation approach, the authors of the present study suggest an antecedent-benefit-cost (ABC) framework that explains the TMGT effect as a frequent but not omnipresent issue in empirical research and integrates a variety of linear and nonlinear relationships. The ABC framework clarifies important conceptual and empirical issues surrounding the TMGT effect and facilitates the choice between linear and curvilinear models. To avoid serious methodological pitfalls, future studies with desirable outcome variables such as, for example, task performance, job performance, firm performance, satisfaction, team innovation, leadership effectiveness, or individual creativity should consider the ABC framework.

On Johnson's (2000) Relative Weights Method for Assessing Variable Importance: A Reanalysis

This article provides a reanalysis of J. W. Johnson's (2000) "relative weights" method for assessing variable importance in multiple regression. The primary conclusion of the reanalysis is that the derivation of the method is theoretically flawed and has no more validity than the discredited method of Green, Carroll, and DeSarbo (1978) on which it is based. By means of 2 examples, supplemented by other results from the literature, it is also shown that the method can result in materially distorted inferences when it is compared with another widely used importance metric, namely, general dominance (Azen & Budescu, 2003; Budescu, 1993). Our primary recommendation is that J. W. Johnson's (2000) relative weights method should no longer be used as a variable importance metric for multiple linear regression. In the final section of the article, 2 additional recommendations are made based on our analysis, examples, and discussion.