Miniaturised optical encoder for ultra precision metrology systems

We report here on a novel high resolution optical encoder, which can be employed within ultra precision metrology systems. Microsystems techniques have been used to monolithically integrate the discrete components of an encoder onto a single compound semiconductor chip, thereby radically reducing the footprint and cost of assembly. Gratings manufactured at the wafer level by standard photo-lithography, allow for the simultaneous alignment of many devices in a single process step. This development coupled with a unique photodiode configuration not only significantly increases performance but also improves the alignment tolerances in both manufacture and set-up, which substantially reduces the required set-up time. The optical encoder chip has been successfully demonstrated under test conditions on a 4 μm pitch scale: alignment tolerances have been increased with DC to AC ratios of the order of 7:1 and signal-to-noise ratios greater than 40:1.     

Chemical sensing with micromolded plastic microcantilevers

This paper describes microcantilever sensors produced via injection molding. The injection mold design is novel in that it employs one floating and one fixed mold half, hence only necessitating high flatness on two surfaces (e.g., the mating surfaces of the mold), whereas the remainder of the mold can be machined to only moderate tolerances. The mold holds a sub-100 nanometer flatness error over the entire mold mating surfaces, needed to produce micro- and nanoscale parts. Micrometer-scale cantilevers are produced and characterized as a test case. Microcantilevers are fabricated from three different polymeric materials and have exceptional repeatability as evidenced by their measured first-mode bending resonant frequencies. As a precursor to biological sensing, gold-thiol chemical sensing results obtained with the injection-molded cantilevers are also presented and show values that agree with the literature. As a whole, this work shows that the polymeric microcantilever parts fabricated via injection molding are mechanical and functional equivalents to their silicon-type counterparts, and are cheaper and easier to manufacture. [1483].     

Elemental diet in the treatment of pneumatosis coli

BACKGROUND: Pneumatosis cystoides coli (PCC) is a rare condition characterized by gas-filled cysts in the bowel wall. Our aim was to assess the response of PCC to treatment with an elemental diet. METHODS: Two patients with PCC were treated with an elemental diet. Both patients had experienced debilitating symptoms for at least a year and were unresponsive to other therapies. Elemental 028 comprises readily absorbed amino acids, fats, simple sugars, minerals, vitamins, and trace elements. After colonoscopically documented resolution at 2 weeks, low-residue foods were gradually added to the diet. RESULTS: Both patients' symptoms disappeared within 3-4 days of commencing the diet, and colonoscopy at 2 weeks confirmed complete resolution of the cysts. One patient relapsed with the introduction of high-residue foods and was again controlled within days by recommencing the elemental diet. CONCLUSION: An elemental diet can successfully treat both the initial presentation of PCC and any subsequent relapse.     

Assessment of attention: relationship between psychological testing and information processing approaches

Examined the relationship between the psychological testing and information processing approaches in assessing attention. Eighty-seven subjects (57 females, 30 males) undertook eight psychological tests of attention and a visual-spatial reaction-time task. Using the cognitive-correlate method (Posner & McLeod, 1982), it was found that three components of attention (viz., visual-motor scanning, sustained selective processing, and visual/auditory spanning) derived from the psychological tests could be significantly predicted by specific, yet different, combinations of six indices of information processing (mean reaction time (RT), mean movement time (MT), feature extraction, identification, response selection, and motor adjustment): (a) mean RT and mean MT were found to be the most important indices for predicting performance on visual-motor scanning; (b) the motor-adjustment stage was found to be the most important index for predicting performance on sustained selective processing; (c) the response-selection stage was found to be the most important index for predicting performance on visual/auditory spanning. These relationships are important for supporting the construct-related validity of the psychological tests of attention and for extending the generality and applicability of the RT task.     

Impact of causal attributions on affective reactions to success and failure.

Assessed the impact of outcome (success vs failure) and attribution (internal vs external) on affect in an achievement setting. Following the theorizing of B. Weiner et al (1978, 1979), it was anticipated that the outcome manipulation would determine general positive and negative affective reactions, whereas the attribution manipulation would influence affects related to self-esteem. 53 female undergraduates received success or failure feedback on a social accuracy test and were induced to attribute their performance to either an internal (ability) or an external cause (characteristics of the task). A factor analysis revealed 3 dimensions: Negative Affect, Positive Affect, and Self-Esteem. ANOVA indicated that the nature of the attribution influenced all 3 forms of affective reactions. Success produced greater positive affect, less negative affect, and higher self-esteem than failure only when ability attributions were induced. Although additional analyses offered some support for the presence of affects influenced solely by outcome, the majority of analyses supported the notion that attributions are the primary determinants of affective reactions to success and failure. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implementation of neuropsychiatric research programs.

"This paper presents a philosophy of the research service unit's approach toward implementing neuropsychiatric research." The philosophy was developed at the Palo Alto VA Hospital and is being applied at the Chicago VA Research Hospital. A research service unit is an administrative staff developed to serve, train, and encourage the research efforts of the entire professional hospital staff or of a division. A basic rationale is indicated. 8 pressing problems encountered in carrying out psychiatric research are listed. Major topics are "Attitude of Personnel and Time Allotted for Research," "Presentation and Discussion of New Developments," "Methods of Training," "Assistance of Library for Up-To-Date Information," "Expenditures for Personnel and Equipment," "Effective and Efficient Research Design," "Aid of Volunteer Help," and "Preparation and Publication of Research Reports." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simulation analysis of passive solar heated buildings—Preliminary results

Solar gains through windows, walls, modified walls, skylights, clerestory windows, and roof sections provide an opportunity to dramatically reduce the total heating energy requirements of a building. Many such passive solar heating elements are currently available to a designer presenting a large number of possible system designs. A computer simulation analysis has been employed to aid in the selection of components. The results indicate that a performance comparable to that of a conventional active solar heating system should be achievable in an optimized design passive solar heating system. The placement and type of thermal storage is crucial to good performance. Movable insulation of the window increases the performance. When used in conjunction with a conventional heating system, temperature variations in the building can be reduced to those normally experienced.     

Classical conditioning of hippocampal theta patterns in the rat.

Electrical stimulation (88 Hz) of the lateral hypothalamus elicited a sustained theta response at hippocampal recording sites in 11 male Sprague-Dawley rats immobilized with succinylcholine. By pairing this UCS with a 10-sec presentation of a light, conditioned theta responses were demonstrated in as few as 40 trials. Spectral analysis of hippocampal bioelectric patterns during acquisition, extinction, and reconditioning indicated that the earliest change as a result of conditioning was a loss of power in EEG frequency below 8 Hz, followed by the development of a peak at 8 Hz with further conditioning. Extinction was associated with an increase in power of the frequencies below 8 Hz. When the conditioned Ss were tested in the absence of the neuromuscular blocking agent, the CS elicited a theta response that was associated with slow motor activity on 70% of the trials. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)