263 research outputs found
Latent classes of childhood maltreatment, adult sexual assault, and revictimization in men: Differences in masculinity, anger, and substance use.
Male sexual abuse has been associated with a number of maladaptive outcomes; however, there is a dearth of research on male revictimization, that is, experiences of victimization in both childhood and adulthood. The current study examined different patterns of victimization based on five types of childhood maltreatment and characteristics of adult sexual assault via latent class analysis. Further, the present study assessed differences across these latent classes in the domains of masculinity, anger, and substance use. A community sample of 294 men ranging in age from 18 to 66 years (M = 32.71; SD = 9.73) was recruited via Amazon Mechanical Turk, an online research forum. The latent class analysis identified four classes, namely, revictimization (10.9%), adult substance-related victimization (4.8%), childhood maltreatment (23.8%), and low victimization (60.5%). Differential patterns emerged for masculinity, anger, and substance use, with the revictimization and childhood maltreatment classes differing significantly from the adult substance-related victimization and low victimization classes. Compared with the low victimization class, the three victimization classes were elevated on multiple facets of masculinity; the revictimization class was higher on anger and alcohol- and drug use. Results provide evidence that research examining childhood or adulthood victimization experiences in isolation may fail to capture the full range of victimization experiences in men. Findings provide important implications for understanding patterns of victimization among men and how interventions may be targeted to address psychological and behavioral outcomes. (PsycINFO Database Record (c) 2019 APA, all rights reserved
Discovering the Elite Hypervolume by Leveraging Interspecies Correlation
Evolution has produced an astonishing diversity of species, each filling a
different niche. Algorithms like MAP-Elites mimic this divergent evolutionary
process to find a set of behaviorally diverse but high-performing solutions,
called the elites. Our key insight is that species in nature often share a
surprisingly large part of their genome, in spite of occupying very different
niches; similarly, the elites are likely to be concentrated in a specific
"elite hypervolume" whose shape is defined by their common features. In this
paper, we first introduce the elite hypervolume concept and propose two metrics
to characterize it: the genotypic spread and the genotypic similarity. We then
introduce a new variation operator, called "directional variation", that
exploits interspecies (or inter-elites) correlations to accelerate the
MAP-Elites algorithm. We demonstrate the effectiveness of this operator in
three problems (a toy function, a redundant robotic arm, and a hexapod robot).Comment: In GECCO 201
Properties of Nucleon Resonances by means of a Genetic Algorithm
We present an optimization scheme that employs a Genetic Algorithm (GA) to
determine the properties of low-lying nucleon excitations within a realistic
photo-pion production model based upon an effective Lagrangian. We show that
with this modern optimization technique it is possible to reliably assess the
parameters of the resonances and the associated error bars as well as to
identify weaknesses in the models. To illustrate the problems the optimization
process may encounter, we provide results obtained for the nucleon resonances
(1230) and (1700). The former can be easily isolated and thus
has been studied in depth, while the latter is not as well known
experimentally.Comment: 12 pages, 10 figures, 3 tables. Minor correction
Dominance Based Crossover Operator for Evolutionary Multi-objective Algorithms
In spite of the recent quick growth of the Evolutionary Multi-objective Optimization (EMO) research field, there has been few trials to adapt the general variation operators to the particular context of the quest for the Pareto-optimal set. The only exceptions are some mating restrictions that take in account the distance between the potential mates - but contradictory conclusions have been reported. This paper introduces a particular mating restriction for Evolutionary Multi-objective Algorithms, based on the Pareto dominance relation: the partner of a non-dominated individual will be preferably chosen among the individuals of the population that it dominates. Coupled with the BLX crossover operator, two different ways of generating offspring are proposed. This recombination scheme is validated within the well-known NSGA-II framework on three bi-objective benchmark problems and one real-world bi-objective constrained optimization problem. An acceleration of the progress of the population toward the Pareto set is observed on all problems
Analysis of objectives relationships in multiobjective problems using trade-off region maps
Understanding the relationships between objectives in many-objective optimisation problems is desirable in order to develop more effective algorithms. We propose a techniquefor the analysis and visualisation of complex relationships between many (three or more) objectives. This technique looks at conflicting, harmonious and independent objectives relationships from different perspectives. To do that, it uses correlation, trade-off regions maps and scatter-plots in a four step approach. We apply the proposed technique to a set of instances of the well-known multiobjective multidimensional knapsack problem. The experimental results show that with the proposed technique we can identify local and complex relationships between objectives, trade-offs not derived from pairwise relationships, gaps in the fitness landscape, and regions of interest. Such information can be used to tailor the development of algorithms
Synthesis and Characterization of Cobalt(II) N,N′‑Diphenylazodioxide Complexes
Removal of chloride from CoCl2 with TlPF6 in acetonitrile, followed by addition of excess nitrosobenzene, yielded the eight-coordinate cobalt(II) complex salt [Co{Ph(O)NN(O)- Ph}4](PF6)2, shown by single-crystal X-ray analysis to have a distorted tetragonal geometry. The analogous treatment of the bipyridyl complex Co(bpy)Cl2 yielded the mixed-ligand cobalt(II) complex salt [Co(bpy){Ph(O)NN(O)Ph}2](PF6)2, whose singlecrystal X-ray structure displays a trigonal prismatic geometry, similar to that of the iron(II) cation in the previously known complex salt [Fe{Ph(O)NN(O)Ph}3](FeCl4)2. The use of TlPF6 to generate solvated metal complex cations from chloride salts or chlorido complexes, followed by the addition of nitrosobenzene, is shown to be a useful synthetic strategy for the preparation of azodioxide complex cations with the noncoordinating, diamagnetic PF6 − counteranion. Coordination number appears to be more important than d electron count in determining the geometry and metal−ligand bond distances of diphenylazodioxide complexes
Mathematical Identification of Critical Reactions in the Interlocked Feedback Model
Dynamic simulations are necessary for understanding the mechanism of how biochemical networks generate robust properties to environmental stresses or genetic changes. Sensitivity analysis allows the linking of robustness to network structure. However, it yields only local properties regarding a particular choice of plausible parameter values, because it is hard to know the exact parameter values in vivo. Global and firm results are needed that do not depend on particular parameter values. We propose mathematical analysis for robustness (MAR) that consists of the novel evolutionary search that explores all possible solution vectors of kinetic parameters satisfying the target dynamics and robustness analysis. New criteria, parameter spectrum width and the variability of solution vectors for parameters, are introduced to determine whether the search is exhaustive. In robustness analysis, in addition to single parameter sensitivity analysis, robustness to multiple parameter perturbation is defined. Combining the sensitivity analysis and the robustness analysis to multiple parameter perturbation enables identifying critical reactions. Use of MAR clearly identified the critical reactions responsible for determining the circadian cycle in the Drosophila interlocked circadian clock model. In highly robust models, while the parameter vectors are greatly varied, the critical reactions with a high sensitivity are uniquely determined. Interestingly, not only the per-tim loop but also the dclk-cyc loop strongly affect the period of PER, although the dclk-cyc loop hardly changes its amplitude and it is not potentially influential. In conclusion, MAR is a powerful method to explore wide parameter space without human-biases and to link a robust property to network architectures without knowing the exact parameter values. MAR identifies the reactions critically responsible for determining the period and amplitude in the interlocked feedback model and suggests that the circadian clock intensively evolves or designs the kinetic parameters so that it creates a highly robust cycle
Observation of the Dynamic Beta Effect at CESR with CLEO
Using the silicon strip detector of the CLEO experiment operating at the
Cornell Electron-positron Storage Ring (CESR), we have observed that the
horizontal size of the luminous region decreases in the presence of the
beam-beam interaction from what is expected without the beam-beam interaction.
The dependence on the bunch current agrees with the prediction of the dynamic
beta effect. This is the first direct observation of the effect.Comment: 9 page uuencoded postscript file, postscritp file also available
through http://w4.lns.cornell.edu/public/CLNS, submitted to Phys. Rev.
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