Daniel P. Johnson

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Human cooperation is held to be an evolutionary puzzle because people voluntarily engage in costly cooperation, and costly punishment of non-cooperators, even among anonymous strangers they will never meet again. The costs of such cooperation cannot be recovered through kin-selection, reciprocal altruism, indirect reciprocity, or costly signaling. A number(More)
Starting in adolescence and continuing through adulthood, women are twice as likely as men to experience depression. According to the response styles theory (RST), gender differences in depression result, in part, from women's tendency to ruminate more than men. A meta-analysis was performed to evaluate gender differences in rumination in adults (k = 59; N(More)
Ex press ions a re d eriv e d for th e volum e of a n a pproxim a te s p he re in te rm s of mea s ure d breadth , the di s ta nce be tw een pa ra ll e l pla nes ta nge nt to opposit e s id es. Th e diffe rence in volum e of a ball a nd a tru e s ph e re of th e sam e ave rage breadth is s how n to be of seco nd ord e r , a nd mu c h s ma ll e r th a n th e(More)
The association between stressful life events and depression has been consistently supported in the literature; however, studies of the developmental trajectories of these constructs and the nature of their association over time are limited. We examined trajectories of depressive symptoms and negative dependent life events and the associations between these(More)
This study examined the extent to which rumination and depression share genetic and environmental influences in a community sample of adult twins (N=663). Twins completed multiple rumination questionnaires, a depressive symptoms questionnaire and a diagnostic interview. Rumination was moderately heritable (h2=.37-.41 for the latent variable) and(More)
Scheduling of refineries is a hard hybrid problem. Application of the Constrained Envelope Scheduling (CES) approach required development of the Gradient Constraint Equation Subdivision (GCES) algorithm, a novel global feasibility solver for the large system of quadratic constraints that arise as sub-problems. We describe the implemented solver and its(More)
To examine the efficacy and overall tolerability of the simultaneous initiation of treatment (coinitiation) with triiodothyronine (T3) and a selective serotonin reuptake inhibitor (SSRI) for major depressive disorder (MDD). Sources of date were Medline/Pubmed, EMBASE, the Cochrane database, and program syllabi from major psychiatric meetings held since(More)
We examined the magnitude of genetic and environmental influences on observed negative emotionality at age 14, 20, and 24 months. Participants were 403 same-sex twin pairs recruited from the Longitudinal Twin Study whose emotional responses to four different situations were coded by independent raters. Negative emotionality showed significant consistency(More)
In previous work, we have presented a novel global feasibility solver for the large system of quadratic constraints that arise as subproblems in the solving of hard hybrid problems, such as the scheduling of refineries. In this paper we present the Gradient Optimal Constraint Equation Subdivision (GOCES) algorithm, which incorporates a standard NLP solver(More)
This multiwave longitudinal study tested two quantitative genetic developmental models to examine genetic and environmental influences on exposure to negative dependent and independent life events. Participants (N = 457 twin pairs) completed measures of life events annually from ages 9 to 16. The same genetic factors influenced exposure to dependent events(More)