A twin registry study of familial and individual risk factors for trauma exposure and posttraumatic stress disorder.

This study examines the association of individual and familial risk factors with exposure to trauma and posttraumatic stress disorder (PTSD) in male twins (N = 6744) from the Vietnam Era Twin Registry. Independent reports of familial psychopathology from co-twins were used to avoid the potential biases of the family history method. Risk for exposure to traumatic events was increased by service in Southeast Asia, preexisting conduct disorder, preexisting substance dependence, and a family history of mood disorders whose effects appear to be partly genetic.

Pilot study of spirituality and mental health in twins.

Objective: The goal of this study was to investigate associations between empirically defined dimensions of spirituality, personality variables, and psychiatric disorders in Vietnam era veterans.

Method: One hundred pairs of male twins from the Vietnam Era Twin Registry were administered the self-report Spiritual Well-Being Scale and a pilot Index of Spiritual Involvement. Correlation analyses were supplemented with regression analyses that examined the relative influence of genetic and environmental factors on aspects of spirituality.

Fencerows, Edges, and Implications of Changing Connectivity Illustrated by Two Contiguous Ohio Landscapes.

We evaluated the amounts and implications of changes in habitat connectivity on rural land-scapes by modeling the colonization success and subsequent habitat colonization of a model edge organism within real landscapes. We first inventoried the changes in the fencerow and forest-edge network of two contiguous Ohio (U.S.

Foundations of Metrology.

The theory of measurement has attracted the attention of a number of philosphers whose works remain largely unknown to metrologists. Recent work in the development of Measurement Assurance Programs has demonstrated the power of this theory as a tool for guiding the development of measurement systems. The elements of the theory, especially that of Carnap and its applications to metrology, are developed as an aid to program planning and evaluation.