Composite finger metacarpophalangeal joint reconstruction in combined second and third free toe-to-hand transfers

Composite metacarpophalangeal joint reconstruction using the toe proximal phalanx and the metacarpal head, with a capsular repair, is an option during free toe transfer procedures for absent fingers. Eleven composite metacarpophalangeal finger joint reconstructions were performed in four patients concurrent with combined second and third toe-to-hand transfer. The average follow-up period was 5 years. Postoperative assessment included range of motion, stability, radiographic changes, and pain. The average range of motion was 52 degrees, average ulnar stress deviation was 14 degrees. No patients complained of pain. Composite metacarpophalangeal joint reconstruction should be considered in free toe-to-hand procedures when metacarpal head articular cartilage is preserved.     

Temperature and modulation characteristics of resonant-cavitylight-emitting diodes

Resonant-cavity light-emitting diodes (RCLED) are novel, high-efficiency light-emitting diodes which employ optical microcavities. These diodes have higher intensities and higher spectral purity as compared to conventional LEDs. Analytical formulas are derived for the enhancement of the spontaneous emission along the optical axis of the cavity. The design rules for high-efficiency operation of RCLEDs are established. The temperature dependence of the emission intensity is analyzed in the range 20-80° and it is described by an exponential dependence with a characteristic temperature of 112 K. The modulation characteristics of RCLEDs exhibit 3 dB frequencies of 580 MHz. Eye diagrams at transmission rates of 622 Mb/s are wide open indicating the suitability of RCLEDs for high-speed data transmission     

Polarisation insensitive semiconductor optical amplifier withintegrated electroabsorption modulators

The authors demonstrate a 1.55 μm wavelength multiquantum well semiconductor optical amplifier, integrated with bulk layer electroabsorption modulators and passive waveguide beam expanders at the input and output ports. The device has a fibre to fibre gain of 9 dB, an extinction ratio of 15 dB per modulator, a spectral range >35 nm, and polarisation sensitivity <1 dB     

A 16-Kbit Θ-search associative memory

The design of a high-capacity Θ-search associative memory (Θ∈{<,>,⩽,⩾,=≠}) is presented. PSPICE simulation and layouts show that the proposed Θ-search associative memory chip consisting of 256 words, each 64-b long, can fit on a 13.5-mm×9.5-mm chip. It can perform maskable Θ-search operations over its contents in 110 ns     

Adaptive detection of DS/CDMA signals in fading channels

This paper examines the behavior of the minimum mean-squared error (MMSE) receiver in frequency-nonselective-fading channels. It is noted that the MMSE receiver will often lose phase lock on the desired signal when the desired signal dips into a deep fade. A modification to the MMSE receiver is presented which is demonstrated to function quite nicely in flat-fading channels. Analytical results for the modified MMSE receiver are presented and found to agree very well with simulation results. These analytical results are then compared to the theoretical performance of the conventional (i.e., correlator) receiver in terms of both bit-error rate (BER) and capacity. As expected, the modified MMSE receiver was found to offer a substantial improvement in both BER and capacity. Finally, a simple empirically derived formula is given which will give a good approximation to the BER of the modified MMSE receiver in a Rayleigh-fading environment. This formula can also be used to determine the number of users a given system can support. It is noted that as E_b/N₀ grows, it is quite feasible to approach 100% channel utilization with the MMSE receiver, whereas a conventional receiver is typically limited to a utilization of 10%-20%     

Psychopharmacotherapy for addictive and comorbid disorders: current studies

Proper diagnosis of comorbid disorders is crucial in treatment planning for the dually diagnosed. Since psychoactive substance use can obfuscate the diagnosis, special care must be taken to exclude organically based syndromes. Adequate periods of abstinence should first be achieved and subsequently the patient re-examined for residual symptoms compatible with a nonaddictive, nonsubstance-induced psychiatric disorder. The integration of concurrent treatment of both the mental and the addictive disorders appears to be the best approach for treatment of comorbid psychiatric and addictive disorders. An abstinence-based model that typically utilizes a 12-step group therapy is often employed for the addictive illnesses. Other forms of psychosocial therapies such as case managers are being used as well. Presently, physicians' prescribing practices for comorbid addicted patients are based on traditional approaches to use of medications in psychiatric patients, and their attitudes towards addictive disorders may play a significant role in determining the overall success of treatment.     

Measuring perceived mutuality in close relationships: Validation of the Mutual Psychological Development Questionnaire.

In an initial validation study of the Mutual Psychological Development Questionnaire (MPDQ), a measure of perceived mutuality in close relationships, 345 respondents completed the scale for spouse or partner and friend relationships. Results indicated high interitem reliability. Construct and concurrent validity were demonstrated. MPDQ ratings were correlated with adequacy of social support, relationship satisfaction, and cohesion. Ratings correlated negatively with depression. Low spouse or partner mutuality was predictive of significant depressive symptoms in women but not in men. In a 2nd study, 81 respondents completed the scale at 2 time points. Test–retest reliability was satisfactory, and high interitem consistency was replicated. The substantive meaning of these findings, gender differences, and possible future research applications of the MPDQ are disscussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A DBR laser tunable by resistive heating

A distributed Bragg reflector (DBR) laser tuned by resistive heating is presented. It has a tuning range greater than 10 nm with only a 33% reduction in output power and a 10% increase in linewidth. Its behavior is easily modeled, agreeing well with simple theory     

A Maximum Entropy Approach for Collaborative Filtering

Collaborative filtering (CF) involves predicting the preferences of a user for a set of items given partial knowledge of the user's preferences for other items, while leveraging a database of profiles for other users. CF has applications e.g. in predicting Web sites a person will visit and in recommending products. Fundamentally, CF is a pattern recognition task, but a formidable one, often involving a huge feature space, a large data set, and many missing features. Even more daunting is the fact that a CF inference engine must be capable of predicting any (user-selected) items, given any available set of partial knowledge on the user's other preferences. In other words, the model must be designed to solve any of a huge (combinatoric) set of possible inference tasks. CF techniques include memory-based, classification-based, and statistical modelling approaches. Among these, modelling approaches scale best with large data sets and are the most adept at handling missing features. The disadvantage of these methods lies in the statistical assumptions (e.g. feature independence), which may be unjustified. To address this shortcoming we propose a new model-based CF method, based on the maximum entropy principle. For the MS Web application, the new method is demonstrated to outperform a number of CF approaches, including naive Bayes and latent variable (cluster) models, support vector machines (SVMs), and the (Pearson) correlation method.