Starting with a novel definition of divided differences, this essay derives and discusses the basic properties of, and facts about, (univariate) divided differences. “It belongs to the most beautiful I have been able to do.”[Newton 1676]

The role of stressful life events in the etiology of various disorders has been of interest to investigators attempting to establish a link between stressful life events and disorders. None of the available scales are relevant to service personnel. In the present study an attempt was made to construct a scale to measure stressful life events in service personnel. In the first stage of study ope...

Post-traumatic stress disorder (PTSD) is a serious mental illness that affects current and former military service members at a disproportionately higher rate than the civilian population. Prior studies have shown that PTSD symptoms follow multiple trajectories in civilians and military personnel. The current study examines whether the trajectories of PTSD symptoms of veterans separated from th...

Often, organizational psychologists use methods of classification to group individual jobs into larger groups that are then used for personnel-related functions. In classifying jobs, researchers and practitioners make several important considerations, such as deciding on the type of data collected and choosing the appropriate quantitative clustering method. We highlight some of these considerat...

OBJECTIVES We examined stress levels and other indicators of mental health in reservists and active-duty military personnel by deployment status. METHODS We used data from the Department of Defense Health-Related Behaviors surveys, which collect comprehensive, population-based data for reserve and active-duty forces. Data were collected from 18 ,342 reservists and 16, 146 active-duty personne...

OBJECTIVES Obstructive sleep apnea (OSA) is frequently diagnosed in U.S. military personnel. OSA is associated with sleepiness, poor sleep quality, and service-related illnesses of insomnia, depression, post-traumatic stress disorder, and traumatic brain injury. METHODS Observational study of active duty military personnel with OSA and adherence to positive airway pressure (PAP) assessed with...