University of Nebraska–Lincoln

About: University of Nebraska–Lincoln is a education organization based out in Lincoln, Nebraska, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 28059 authors who have published 61544 publications receiving 2139104 citations. The organization is also known as: Nebraska & UNL.

An Empirical Test of Crisis, Social Selection, and Role Explanations of the Relationship Between Marital Disruption and Psychological Distress: A Pooled Time‐Series Analysis of Four‐Wave Panel Data

Abstract: Although a higher level of psychological distress has been found in many studies of divorced compared with married individuals, explanations for this difference remain elusive. Three basic theoretical explanations have been proposed. Social role theory maintains that the role of being divorced is inherently more stressful than that of being married; crisis theory attributes the higher stress to role transitions and transient stressors of the disruption process, and social selection theory claims that the higher stress levels among the divorced result from the selection of people with poor mental health into divorce. Some empirical support is available for each of these approaches, but all three have not been tested simultaneously in a longitudinal study. This research empirically evaluates the efficacy of these theories in a pooled time-series analysis of a four-wave panel of married persons followed over 12 years. The pooledtime series random effects model was used to es timate the effects of social roles, crisis, and social selection. The results provide evidence that the higher stress levels of the divorced primarily reflect the effect of social role with selection and crisis effects making small contributions only. Key Words: divorce adjustment, panel study, psychological distress. A number of previous studies clearly show that the divorced report higher levels of psychological distress than do the married (Booth & Amato, 1991; Coombs, 1991; Gove, Hughes, & Briggs, 1983; Mastekaasa, 1994; Ross, 1995; Waite, 1995). Empirical studies have not been as definitive about the factors that account for this relationship. Each of the three explanations that have been proposed have some empirical support. A social selection explanation maintains that persons with high psychological distress and mental disorders are disproportionately selected into divorce and less likely to remarry, yielding higher distress scores among the currently divorced (Aseltine & Kessler, 1993). According to crisis theory, the disruption process and resultant role transitions temporarily elevate distress (Booth & Amato). Role theory attributes the greater psychological distress reported by the divorced to the more difficult life circumstances they experience (Ross). An adequate simultaneous test of these competing explanations in a single study has been limited by small sample sizes, cross-sectional designs, limited duration of panel studies, lack of measures of distress pre- and postdisruption, and analysis design limitations. The purpose of this study is to overcome some of these limitations by testing these explanations with pooled-time series models in a large nationally representative fourwave panel sample extending over a 12-year period. Measures used include psychological distress both pre- and postmarital disruptions. NOTE This is a revised version of a paper presented at the International Conference on Social Stress Research in Paris, France, in 1996. We would like to thank Alan Booth and Paul Amato for their comments on an earlier draft. This study was supported in part by National Institute on Aging Grant R01 AG4146. [Reference] REFERENCES Allison, P D. (1994). Using panel data to estimate the effects of events. Sociological Methods & Research, 23, 174-199. Amato, P, & Partridge, S. (1987). Widows and divorcees with dependent children: Material, personal, family, and social well-being. Family Relations, 36, 316-320. Aseltine, R. H., Jr., & Kessler, R. C. (1993). Marital disruption and depression in a community sample. Journal of Health and Social Behavior, 34, 237-251. Avison, W. R. (1999). Family structure and processes. In A. V. Horwitz & I L. Scheid (Eds.), A handbook for the studY of mental health: Social contexts, theories, and systems (pp. 228-240). New York: Cambridge University Press. Berman, W. …

Combining unit-level symbolic execution and system-level concrete execution for testing nasa software

Abstract: We describe an approach to testing complex safety critical software that combines unit-level symbolic execution and system-level concrete execution for generating test cases that satisfy user-specified testing criteria. We have developed Symbolic Java PathFinder, a symbolic execution framework that implements a non-standard bytecode interpreter on top of the Java PathFinder model checking tool. The framework propagates the symbolic information via attributes associated with the program data. Furthermore, we use two techniques that leverage system-level concrete program executions to gather information about a unit's input to improve the precision of the unit-level test case generation. We applied our approach to testing a prototype NASA flight software component. Our analysis helped discover a serious bug that resulted in design changes to the software. Although we give our presentation in the context of a NASA project, we believe that our work is relevant for other critical systems that require thorough testing.

Internal and near‐surface electromagnetic fields for a spherical particle irradiated by a focused laser beam

Abstract: Theoretical expressions for the internal and external electromagnetic fields for an arbitrary electromagnetic beam incident upon a homogeneous spherical particle are derived, and numerical calculations based upon this theoretical development are presented. In particular, spatial distributions of the internal and near‐surface electric field magnitude (source function) for a focused fundamental (TEM00 mode) Gaussian beam of 1.06 μm wavelength and 4 μm beam waist diameter incident upon a 5‐μm‐diam water droplet in air are presented as a function of the location of the beam focal point relative to the sphere center. The calculations indicate that the internal and near‐surface electric field magnitude distribution can be strongly dependent upon relative focal point positioning and may differ significantly from the corresponding electric field magnitude distribution expected from plane‐wave irradiation.

Search for supersymmetry at the LHC in events with jets and missing transverse energy

Abstract: A search for events with jets and missing transverse energy is performed in a data sample of pp collisions collected at sqrt(s) = 7 TeV by the CMS experiment at the LHC. The analyzed data sample corresponds to an integrated luminosity of 1.14 inverse femtobarns. In this search, a kinematic variable, alphaT, is used as the main discriminator between events with genuine and misreconstructed missing transverse energy. No excess of events over the standard model expectation is found. Exclusion limits in the parameter space of the constrained minimal supersymmetric extension of the standard model are set. In this model, squark masses below 1.1 TeV are excluded at 95% CL. Gluino masses below 1.1 TeV are also ruled out at 95% CL for values of the universal scalar mass parameter below 500 GeV.