An implementation of the coupled perturbed Kohn-Sham equations: perturbation due to nuclear displacements

The Coupled Perturbed Kohn-Sham equations have been implemented in the Amsterdam Density Functional program package. Our implementation differs from previous ones in many ways. This program uses density fitting to calculate the Coulomb and exchange integrals. Further, all matrix elements of the Fock type matrix and its derivatives are calculated by numerical integration. The frozen core approximation is also implemented. Our implementation is approximately 10 times faster than a finite difference algorithm, and the absolute CPU times also compare favorably with other reported implementations.     

The Evolution of Concurrent Programs

Process algebra are formal languages used for the rigorous specification and analysis of concurrent systems. By using a process algebra as the target language of a genetic programming system, the derivation of concurrent programs satisfying given problem specifications is possible. A genetic programming system based on Koza's model has been implemented. The target language used is Milner's CCS process algebra, and is chosen for its conciseness and simplicity. The genetic programming environment needs a few adaptations to the computational characteristics of concurrent programs. In particular, means for efficiently controlling the exponentially large computation spaces that are common with process algebra must be addressed. Experimental runs of the system successfully evolved a number of non–iterative CCS systems, hence proving the potential of evolutionary approaches to concurrent system development.     

Pseudospectral methods for optimal motion planning of differentially flat systems

The article presents some preliminary results on combining two new ideas from nonlinear control theory and dynamic optimization. We show that the computational framework facilitated by pseudospectral methods applies quite naturally and easily to Fliess' implicit state variable representation of dynamical systems. The optimal motion planning problem for differentially flat systems is equivalent to a classic Bolza problem of the calculus of variations. We exploit the notion that derivatives of flat outputs given in terms of Lagrange polynomials at Legendre-Gauss-Lobatto points can be quickly computed using pseudospectral differentiation matrices. Additionally, the Legendre pseudospectral method approximates integrals by Gauss-type quadrature rules. The application of this method to the two-dimensional crane model reveals how differential flatness may be readily exploited.     

Modeling frequency-dependent losses in ferrite cores

We suggest a practical approach for modeling frequency-dependent losses in ferrite cores for circuit simulation. Previous work has concentrated on the effect of eddy-current losses on the shape of the B--H loop, but in this paper we look at the problem from the perspective of energy loss and propose a different network for accurately modeling power loss in ferrite cores. In power applications, the energy loss across the frequency range can have a profound effect on the efficiency of the system, and a simple ladder network in the magnetic domain is not always adequate for this task. Simulations and measurements demonstrate the difference in this approach from the RL ladder network models both in the small-signal and large-signal contexts.     

Objectivity in the Eye of the Beholder: Divergent Perceptions of Bias in Self Versus Others.

Important asymmetries between self-perception and social perception arise from the simple fact that other people's actions, judgments, and priorities sometimes differ from one's own. This leads people not only to make more dispositional inferences about others than about themselves (E. E. Jones & R. E. Nisbett, 1972) but also to see others as more susceptible to a host of cognitive and motivational biases. Although this blind spot regarding one's own biases may serve familiar self-enhancement motives, it is also a product of the phenomenological stance of naive realism. It is exacerbated, furthermore, by people's tendency to attach greater credence to their own introspections about potential influences on judgment and behavior than they attach to similar introspections by others. The authors review evidence, new and old, of this asymmetry and its underlying causes and discuss its relation to other psychological phenomena and to interpersonal and intergroup conflict. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preparation and assessment of frozen-hydrated sections of mammalian tissue for electron microscopy and X-ray microprobe analysis

A system is described for preparing and examining frozen-hydrated sections of mammalian tissue, using commercially available equipment. An essential part of the system is a liquid nitrogen cooled vacuum transfer system. Minor modifications were required to interface the various manufacturers' equipment, and also to facilitate handling of specimens in the cryoultramicrotome. A variety of criteria indicates that our sections are truly frozen-hydrated, but negligible image contrast in the sections is a serious problem both for morphological work and X-ray microanalysis.     

The governance of psychological practice: Implications of American developments for Canadian psychology.

Describes 5 means of maintaining standards for psychological practice that are currently used in the US: (1) general and criminal law, (2) peer control, (3) federal regulations, (4) state boards of examiners in psychology, and (5) civil malpractice litigation. Their relevance to the Canadian context is discussed, especially with respect to the more restricted role of the Canadian federal government in professional affairs, the lower profile for civil rights, and the lower incidence of civil litigation in Canada. Recommendations made to ensure the exemplary practice of psychology include the increased use of peer control through peer review committees, increased organization of professional practice at the national level, and a closer liaison between professional associations and governing boards at the provincial level. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Groundwork for creative research.

Examines the nature of and importance of creativity in scientists and relates these to the training functions in the university. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gastric pacing improves emptying and symptoms in patients with gastroparesis

BACKGROUND & AIMS: No effective treatment is available for patients with gastroparesis refractory to standard medical therapy. The aim of this study was to investigate the effects of gastric pacing on gastric electrical activity, gastric emptying, and symptoms in patients with gastroparesis. METHODS: Nine patients with gastroparesis participated in this study. Four pairs of cardiac pacing wires were implanted on the serosa of the stomach. The protocol consisted of two portions: a temporary inpatient study period and an outpatient study for a period of 1 month or more. RESULTS: Gastric pacing entrained the gastric slow wave in all subjects and converted tachygastria in 2 patients into regular 3-cpm slow waves. Gastric emptying was significantly improved after the outpatient treatment with gastric pacing. The gastric retention at 2 hours was reduced from 77.0% +/- 3.3% to 56.6% +/- 8.6% (P < 0.05). Symptoms of gastroparesis were substantially reduced at the end of the outpatient treatment (1.51 +/- 0.46 vs. 2.84 +/- 0.61; P < 0.04). Eight of 9 patients no longer relied on jejunostomy tube feeding, and no adverse events were noted related to the pacing unit. CONCLUSIONS: Gastric pacing seems to be able to improve symptoms of gastroparesis and to accelerate gastric emptying in patients with gastroparesis. More controlled studies are necessary to further investigate the role of gastric pacing in clinical practice.