Leadership in Organizations-A Book Review

Book Revie

Measuring Chronic Food Insecurity with Food Bank User Data: Implications for Gender Disparities in Chronic Health

Food insecurity is a key social determinant of health and an important risk factor in numerous health conditions. Evidence indicates that food insecurity impacts men and women differently with women experiencing higher rates of reported food insecurity and a higher correlation of that insecurity with chronic health conditions like diabetes and obesity. One possible explanation for this difference could be that women are more likely to find themselves in a chronic, predictable state of food insecurity while the male experience is more likely to be unpredictable and transient. Yet, the traditional reliance of food security research on the Census Bureau’s Current Population Survey Food Security Supplement has limited the investigation of these temporal dynamics. Using food bank usage as a proxy for food insecurity, the cumulative number of food bank appearances and the average interval between appearances were compared between men and women. Multivariate ordinary least squares regression analyses were performed, and after controlling for family size and composition, access to food bank services, and socio-economic estimates, households headed by women were found to have significantly longer average intervals, and after controlling for average interval length, more cumulative visits to the food bank. Taken together, these facts suggest that female-headed households are more likely to experience chronic food insecurity

Fitting Nonlinear Ordinary Differential Equation Models with Random Effects and Unknown Initial Conditions Using the Stochastic Approximation Expectation–Maximization (SAEM) Algorithm

The past decade has evidenced the increased prevalence of irregularly spaced longitudinal data in social sciences. Clearly lacking, however, are modeling tools that allow researchers to fit dynamic models to irregularly spaced data, particularly data that show nonlinearity and heterogeneity in dynamical structures. We consider the issue of fitting multivariate nonlinear differential equation models with random effects and unknown initial conditions to irregularly spaced data. A stochastic approximation expectation–maximization algorithm is proposed and its performance is evaluated using a benchmark nonlinear dynamical systems model, namely, the Van der Pol oscillator equations. The empirical utility of the proposed technique is illustrated using a set of 24-h ambulatory cardiovascular data from 168 men and women. Pertinent methodological challenges and unresolved issues are discussed

Impaired Endothelial Function in Coronary Heart Disease Patients With Depressive Symptomatology

OBJECTIVES The purpose of this study was to assess whether depressive symptomatology was associated with vascular endothelial dysfunction in patients with coronary heart disease (CHD). BACKGROUND In patients with CHD, the presence of depression is associated with a two to four times increased risk of mortality, but the disease pathways involved are uncertain. Endothelial dysfunction is an established risk factor for cardiovascular events in patients with CHD. METHODS Flow-mediated dilation (FMD) of the brachial artery, a measure of endothelial function, was assessed in 143 patients (99 men, 44 women), ages 40 to 84 years (mean age, 63 ± 10 years), with documented CHD. RESULTS Patients with significant depressive symptomatology, as indicated by a Beck Depression Inventory (BDI) score ≥10 (n = 47) showed attenuated FMD (p = 0.001) compared with patients that were not depressed (BDI <10 n = 96). The use of antidepressant medication was associated with improved FMD (p < 0.05). CONCLUSIONS The increased risk of cardiovascular events in CHD patients with elevated symptoms of depression may be mediated, in part, by endothelial dysfunction

Opportunities for Bio-Based Solvents Created as Petrochemical and Fuel Products Transition towards Renewable Resources

The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids) will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents

Neutrino Radiation Transport and Other Topics in High Energy Density Astrophysics

Neutron star mergers and the collapse of massive stars result in some of the universe’s most violet explosions. However, the detailed mechanisms behind all of these astrophysical explosions remain elusive. Their strongly nonlinear and complicated nature makes them difficult and expensive to simulate, and the properties of matter in these extreme conditions are poorly constrained. I use a variety of computational tools to understand the detailed mechanisms behind both types of events. I describe my relativistic time-independent multidimensional Monte Carlo neutrino radiation transport code Sedonu that provides an accurate account of the neutrino radiation fields and the interaction with neutrinos and background fluid. Though Sedonu calculations are time-independent, I demonstrate their utility in dynamical general relativistic variable Eddington tensor radiation hydrodynamics simulations. I apply Sedonu to simulations of accretion disks following neutron star mergers to demonstrate that more realistic disk cooling and neutrino-driven mass ejection rates are larger than is predicted using approximate transport methods. I also reinforce that neutrino pair annihilation from these disk configurations is unlikely to be able to energize a gamma-ray burst jet. I subject Sedonu to the first thorough comparison of Boltzmann neutrino radiation transport methods in multiple spatial dimensions in the context of core-collapse supernovae. The comparisons with the other highly accurate discrete ordinates-based transport scheme show remarkably similar results, verifying the accuracy of both methods and underscoring the importance of numerical fidelity. I perform the first broad parameter study on how different descriptions of dense nuclear matter and star rotation rates influence the dynamics of, and hence gravitational waves from, the bounce and early post-bounce phase of rapidly rotating core collapse supernovae. Using the results of 1824 two-dimensional general relativistic core-collapse simulations, I demonstrate that the equation of state is unlikely to be constrained by LIGO observations. I show that the effect of the equation of state on the gravitational wave frequency can be described by a single universal relation. Finally, I use results of three-dimensional general relativistic magnetohydrodynamics simulations of rapidly rotating core collapse to demonstrate that the polar magnetic structures that form are destroyed by a magnetohydrodynamic kink instability.</p

Hemodynamics and Vascular Hypertrophy in African Americans and Caucasians With High Blood Pressure

BACKGROUND: Hypertension in African Americans is characterized by greater systemic vascular resistance (SVR) compared with Caucasian Americans, but the responsible mechanisms are not known. The present study sought to determine if peripheral vascular hypertrophy is a potential mechanism contributing to elevated SVR in African Americans with high blood pressure (BP). METHODS: In a biracial sample of 80 men and women between the ages of 25 and 45 years, with clinic BP in the range 130/85-160/99mm Hg, we assessed cardiac output and SVR, in addition to BP. Minimum forearm vascular resistance (MFVR), a marker of vascular hypertrophy, also was assessed. RESULTS: SVR was elevated in African Americans compared with Caucasians (P < 0.001). Regression models indicated that age, body mass index, 24-hour diastolic BP, and ethnicity were significant predictors of SVR. There was also a significant interaction between ethnicity and MFVR in explaining SVR in the study sample. In particular, there was a significant positive association between MFVR and SVR among African Americans (P = 0.002), whereas the association was inverse and not statistically significant among Caucasians (P = 0.601). CONCLUSION: Hypertrophy of the systemic microvasculature may contribute to the elevated SVR that is characteristic of the early stages of hypertension in African American compared with Caucasians

'It has a bleak future': The effects of job loss on regional and rural journalism in Australia

Severe contractions in the Australian media landscape have led to a loss of jobs in major metropolitan newsrooms. In 2015, those cuts spread significantly to regional and rural newsrooms in Australia. This paper explores the effect of job loss on rural and regional journalism through a survey of 31 journalists working at rural and regional media organisations whose positions were made redundant from 2012 to 2015. As well as providing accounts of their own personal redundancy experiences, this paper explores the participants’ opinions of regional and rural journalism. It concludes that those whose positions in local journalism have become redundant are concerned about the resources of local newsrooms, and the quality of journalism these newsrooms can subsequently produce