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Biomedical subjects

L Sax

Publications and source records attributed to L Sax.

5 recordsLinked to original sources

Characteristics of spatiotemporal integration in the priming and rewarding effects of medial forebrain bundle stimulation.

Only the function relating the required pulse frequency to the interburst interval discriminates between the priming effect and the rewarding effect: Separating two short bursts of pulses has no effect on their combined rewarding effect, but it enhances their priming effect. There are significant nonscalar differences between animals in the number-current and charge-duration functions for priming and reward, but there are no significant differences in these functions between effects within animals. Substantially more electrical-stimulation is required to produce good priming than to produce a reward that sustains maximum possible levels of performance. These findings suggest that the priming effect is a transient excitement generated by the receipt of one or more very large rewards. The discussion elaborates a model that reconciles this hypothesis with the earlier finding that the rewarding effect may be blocked pharmacologically without blocking priming.

Animals

Pesticide poisoning surveillance through regional poison control centers.

The purpose of this study is to describe pesticide exposure in the population of callers to Minnesota Regional Poison Centers. Case files from 1988 reporting pesticide exposure to humans were identified in cooperation with the Minnesota Center for Health Statistics. Data analysis was conducted by computer using SAS statistical package. Of the 1,428 case files indicating pesticide as the primary substance of exposure to Minnesota residents, a mean age of 5 years (range, one month to 85 years) was identified; 50 percent of all cases were below age 3 years. Males accounted for 1.3 times as many cases as females. Insecticide was identified in the largest percentage of case files (74 percent) followed by herbicide (12 percent), rodenticide (11 percent) and fungicide-nonmedicinal (3 percent). Ingestion was the most common route of exposure; 85 percent of all calls originated from a residence. While insecticides are still the most common types of pesticide call, herbicide has surpassed insecticide in production and sales in the US. In this study, herbicide type exposure calls present a much different picture than other pesticide types. The usefulness of poison control centers for examination of pesticide poisoning is explored. Since reporting occurs coincidental with the exposure and its associated symptoms, each pesticide poisoning report could potentially serve as a true sentinel health event.

Adolescent

Yohimbine does not affect fat distribution in men.

Forty-seven men with a mean age of 42 years were assigned in random, double-blind fashion to treatment with either placebo or high-dose yohimbine (peak dose, 43 mg/day). Thirty-three subjects completed the six-month program. Variables assessed throughout the study included: body weight and body mass index; total cholesterol and HDL; body fat; and fat distribution as measured both by waist-to-hip ratio and by CT scan. Treatment with yohimbine had no effect on any variable in comparison with the control group.

Adipose Tissue

Unsupervised waveform classification for multi-neuron recordings: a real-time, software-based system. I. Algorithms and implementation.

We describe a new, mostly software-based device for the sorting of waveforms in an extracellular multi-neuron recording situation. The sorting algorithm is largely unattended, and, after an initial 'learning' process, works in real time. Shape comparisons are based on up to 8 time points in the waveform; these points (the reduced feature set) are chosen automatically by analyzing the current incoming data stream. A feasibility version has been implemented on a LSI-11/2 system, using FORTRAN for set-up calculations and assembler for the real-time operations. Detailed comparisons with performance of other sorting devices are presented in the companion paper.

Algorithms