Helplessness and depression in end-stage renal disease.

45 dialysis and 25 posttransplant patients (mean age 40.6 yrs) participated in interviews and were administered a battery of tests, including the Beck Depression Inventory, Health Locus of Control Scale, Rotter's Internal–External Locus of Control Scale, and Self-Esteem Inventory. Separate ratings made by hospital staff and family were also obtained. Analyses revealed that perceived control over nontreatment life dimensions was importantly related to depression, although data failed to provide strong support for a reformulated helplessness theory. (58 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical comparison of kalman filter algorithms: Orbit determination case study

Numerical characteristics of various Kalman filter algorithms are illustrated with a realistic orbit determination study. The case study of this paper highlights the numerical deficiencies of the conventional and stabilized Kalman algorithms. Computational errors associated with these algorithms are found to be so large as to obscure important mismodeling effects and thus cause misleading estimates of filter accuracy. The positive result of this study is that the U-D covariance factorization algorithm has excellent numerical properties and is computationally efficient, having CPU costs that differ negligibly from the conventional Kalman costs. Accuracies of the U-D filter using single precision arithmetic consistently match the double precision reference results. Numerical stability of the U-D filter is further demonstrated by its insensitivity to variations in the a priori statistics.     

A Modern-Day Parable.

Presents a parable adapted from a story by L. Tolstoy. The parable involves a highly respected psychometrician professor, statistical methods, and the methods and techniques necessary for publications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monitoring the information-processing demands of attention switching.

Examined demands on information-processing capacity in 3 experiments with 48 Ss by combining auditory digit-tasks involving attention switching with the secondary task of pursuit tracking. Secondary task scores in 2 experiments were lower for tracking segments involving signalled switches between digit-tasks and between input channels, respectively. These results could not be accounted for by a trade-off between digit-task and tracking performance. When the attended channel was defined by voice quality in a 3rd experiment, tracking performance was not affected by switches between input channels. A comparison of the present results and those of related studies indicates that switching attention per se between input channels does not constitute the primary demand for central processing capacity in dichotic tasks. The increased demand appears to be related instead to the concomitant changes required in the input processing and to the processing of signals to switch the focus of attention. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new role for psychologists—Hospital Ethics Committees.

Over the past decade psychology has begun to appreciate that it represents more than "merely mental health care" and has become increasingly involved in the generic health care arena. The participation of psychologists in Hospital Ethics Committees (HECs) is presented as a professional activity for which psychologists are particularly well suited. The clinical mission of HECs, the historical importance of ethical considerations to psychology, and the field's specific training and psycho-social expertise suggest valuable contributions that psychologists can make in this particular area. Further, as psychology actively increases its participation in HECs, other professional disciplines outside of the mental field will systematically have the opportunity to become more familiar with psychology and its clinical and research expertise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-help or hype? Comments on psychology's failure to advance self-care.

Demonstrates that self-help programs are experiencing explosion growth; that psychologists are to be credited with a substantial body of research dating back to the 1970s; that this research demonstrates the potential of self-help programs; that some psychologists have failed to heed the results of studies by rushing to market with exaggerated product claims; and that the American Psychological Association has itself set a poor example and failed to advance clear standards. These points are not intended as a criticism of self-help. Rather, they serve as an observation of psychology's failure to advance self-care. Psychologists are encouraged to meet the challenge that self-care presents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Component Overpressure Growth and Characterization of High-Resistivity CdTe Crystals for Radiation Detectors

Spectrometer-grade CdTe single crystals with resistivities higher than 10⁹ Ω cm have been grown by the modified Bridgman method using zone-refined precursor materials (Cd and Te) under a Cd overpressure. The grown CdTe crystals had good charge-transport properties (μτ _e = 2 × 10⁻³ cm² V⁻¹, μτ _h = 8 × 10⁻⁵ cm² V⁻¹) and significantly reduced Te precipitates compared with crystals grown without Cd overpressure. The crystal growth conditions for the Bridgman system were optimized by computer modeling and simulation, using modified MASTRAPP program, and applied to crystal diameters of 14 mm (0.55′′), 38 mm (1.5′′), and 76 mm (3′′). Details of the CdTe crystal growth operation, structural, electrical, and optical characterization measurements, detector fabrication, and testing using ²⁴¹Am (60 keV) and ¹³⁷Cs (662 keV) sources are presented.     

Microstructural Developments and Dielectric Properties of Rapid Thermally Processed PZT Thin Films Derived by Metallo-organic Decomposition

Microstructural developments and dielectric properties of lead zirconate titanate thin films (0.22 4mUm) with the composition Pb(Zr_0.53Ti_0.47)O₃ were studied. The films were prepared by metallo-organic decomposition (MOD) and rapid thermal processing (RTP) in the temperature range 475–825°C for 2 min in an oxygen gas flow with and without post-annealing. An amorphous–pyrochlore–perovskite phase transformation is indicated at or below 525°C RTF temperatures while a direct amorphous-to-perovskite phase transformation is indicated at higher RTP temperatures. A decrease in grain size with increasing temperature is correlated with an increase in and dominance of nucleation of perovskite sites. The best dielectric and fatigue properties were exhibited by films processed in the temperature range 725–775°C. Hysteresis loops tended toward squareness and polarization charges increased with increased temperature. Furthermore, 45% of the initial charge remained after 10⁹switching reversals. A degradation, however, was observed in both properties at higher temperatures.     

Properties of large area diamond membranes for X ray lithography

Over the past 20 years a wide variety of materials have been evaluated for use as x-ray mask support membrane. Reference 1 presents a comprehensive list of materials investigated to date. Besides x-ray and optical transparency an important requisite for a mask material is dimensional stability. Since the Young's modulus of elasticity is a measure of the atomic bond strength, the covalently bonded refractory materials such as BN or SiC, and diamond, which have large moduli, are more stable than polymers or metals. BN has been the material of choice for x-ray masks in the United States and Europe for the past 10 years; however, CVD BN contains a significant amount of hydrogen in the as-deposited state and is not sufficiently stable under prolonged x-ray exposure. On the other hand, it has been shown by nuclear reaction analysis that diamond films contain less than 1% hydrogen, despite being synthesized in a predominantly hydrogen gas mixture. The low residual hydrogen content, combined with diamond's other unique characteristics such as high mechanical stiffness and high x-ray transparency, makes it an attractive candidate for an x-ray mask material.