Comparing traditional and Rasch analyses of the Mississippi PTSD Scale: revealing limitations of reverse-scored items

This study examined whether Rasch analysis could provide more information than true score theory (TST) in determining the usefulness of reverse-scored items in the Mississippi Scale for Posttraumatic Stress Disorder (M-PTSD). Subjects were 803 individuals in inpatient PTSD units at 10 VA sites. TST indicated that the M-PTSD performed well and could be improved slightly by deleting one item. Factor analysis using raw scores indicated that the reverse-scored items formed the second factor and had poor relationships with normally scored items. However, since item-total correlations supported their usefulness, they were kept. The subsequent Rasch analysis indicated that five of the seven worst fitting items were reverse-scored items. We concluded that using reversed items with disturbed patients can cause confusion that reduces reliability. Deleting them improved validity without loss of reliability. The study supports the use of Rasch analysis over TST in health research since it indicated ways to reduce respondent burden while maintaining reliability and improving validity.     

JIDE: a new software for computer-aided design of hip prosthesis

This work is aimed at developing an innovative simulation environment supporting and improving the design of standard joint implants (JPD integrated design environment (JIDE)). The conceptual workflow starts from the design of a new implant, by using conventional CAD programmes and completes with the generation of a report that summarises the goodness for a new implant against a database of human bone anatomies. For each dataset in the database, the JPD application calculates a set of quantitative indicators that will support the designer in the evaluation of its design on a statistical basis. The resulting system is thus directed to prostheses manufacturers and addresses a market segment that appears to have a steady growth in the future.     

Frequency dispersion of electro-optical properties over a wide range by means of time-response analysis

We show that a Z-transform-based time-response analysis of the electro-optical response of a crystal to a step voltage with a short rise time allows one to obtain the dispersion of the electro-optical coefficients over a wide frequency range. We describe the method employed and present the results obtained for the main electroptic coefficients (r22, r61, and rc) of a standard LiNbO3 crystal. We also show that this method is able to provide even small values of the electro-optic coefficient as well as the dispersion within a wide frequency range, which is limited only by the rise time of the step voltage.     

Filaments for Incandescent Lamps with Energy Conserving Envelopes

The design considerations for filaments in energy conserving incandescent lamps are described. Such lamps require compact high emissivity filaments to absorb infrared radiation reflected from heat mirrored focusing envelopes. The relationships between the electrical parameters in the radiation returning environment and in the clear surroundings are developed. Efficiency experiments with filaments of various geometries under conditions of radiation return were performed. A highly compact coiled coil filament seems most promising for development. A calculation is presented of the filament emissivity as a function of spacing of the windings in a coil. Measurements of the emissivity as a function of the pitch of a coiled coil filament agree with the calculation.     

Evaluating robustness in a two layer simulated robot architecture

Many two layer robot architectures have been proposed and implemented. While justification for the design can be well argued, how does one know it is really a good idea? In this paper, one describes a two layer architecture (reinforcement learning in the bottom layer and POMDP planning at the top) for a simulated robot and summarize a set of three experiments in which one evaluated the design. To address the many difficulties of evaluating robot architectures, one advocates an experimental approach in which design criteria are elucidated and then form the basis for the evaluation experiments. In our case, one tests the implementation for its reliability and generalization (our design criteria) by comparing our architecture to one in which a key component is substituted; in these experiments, one demonstrates significant performance gains on the design criteria for our architecture.     

A functional polymeric material based on hybrid electrochemically controlled junctions

A thin film polymeric junction was fabricated which yields a molecular electronic device functionally able to learn, i.e. to respond coherently to an external training signal. The fabricated structure is based upon electrochemical control of electronic current in a conducting polymer in contact with a solid electrolyte polymer. This functional behavior bears some resemblance to simple cases of biological learning processes. We report a comprehensive electronic characterization of the device function. Additional study was performed in order to estimate the possibility of the integration of such kinds of devices in statistical adaptive networks.     

RS-102221: a novel high affinity and selective, 5-HT2C receptor antagonist

The 5-HT2C receptor is one of three closely related receptor subtypes in the 5-HT2 receptor family. 5-HT2A and 5-HT2B selective antagonists have been described. However, no 5-HT2C selective antagonists have yet been disclosed. As part of an effort to further explore the function of 5-HT2C receptors, we have developed a selective 5-HT2C receptor antagonist, RS-102221 (a benzenesulfonamide of 8-[5-(5-amino-2,4-dimethoxyphenyl) 5-oxopentyl]-1,3,8-triazaspiro[4.5]decane-2,4-dione). This compound exhibited nanomolar affinity for human (pKi = 8.4) and rat (pKi = 8.5) 5-HT2C receptors. The compound also demonstrated nearly 100-fold selectivity for the 5-HT2C receptor as compared to the 5-HT2A and 5-HT2B receptors. RS-102221 acted as an antagonist in a cell-based microphysiometry functional assay (pA2 = 8.1) and had no detectable intrinsic efficacy. Consistent with its action as a 5-HT2C receptor antagonist, daily dosing with RS-102221 (2 mg/kg intraperitoneal) increased food-intake and weight-gain in rats. Surprisingly, RS-102221 failed to reverse the hypolocomotion induced by the 5-HT2 receptor agonist 1-(3-chlorophenyl)piperazine (m-CPP). It is concluded that RS-102221 is the first selective, high affinity 5-HT2C receptor antagonist to be described.     

Academic intrinsic motivation in young elementary school children.

Two studies, 1 longitudinal and 1 cross-sectional, demonstrate that for young elementary school children, academic intrinsic motivation is a reliable, valid, and significant construct. It was positively related to achievement, IQ, and perception of competence, and inversely related to anxiety. Academic intrinsic motivation at age 9 was significantly predicted by motivation measured 1 and 2 years earlier, above and beyond the contribution of IQ and achievement. Children with higher academic intrinsic motivation at ages 7 and 8 were more likely to show higher motivation at age 9. Whereas young children could reliably distinguish between subject areas of academic intrinsic motivation, only math motivation showed consistently specific relations to other math criteria. Findings are discussed with regard to developmental theories of intrinsic motivation and the significance of academic intrinsic motivation for children's education. (PsycINFO Database Record (c) 2010 APA, all rights reserved)