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Biomedical subjects

M J Ackerman

Publications and source records attributed to M J Ackerman.

47 records · Page 3Linked to original sources
PubMed1982

Shared-resource computing for small research labs.

A real time laboratory computer network is described. This network is composed of four real-time laboratory minicomputers located in each of four division laboratories and a larger minicomputer in a centrally located computer room. Off the shelf hardware and software were used with no customization. The network is configured for resource sharing using DECnet communications software and the RSX-11-M multi-user real-time operating system. The cost effectiveness of the shared resource network and multiple real-time processing using priority scheduling is discussed. Examples of utilization within a medical research department are given.

Computers↗
PubMed1976

Brain stimulation in rats exposed to hyperbaric environments.

Six rats were trained to make an operant response to receive brief trains of electrical current to the lateral hypothalamus (self-stimulation). All animals were then randomly exposed to pressures of 4.03, 5.51, 7.06, or 10.1 ATA breathing either compressed air or N2-O2 and 13.1 ATA (N2-O2 only). When the subjects breathed air at pressures of 7.06 and 10.1 ATA, rate of self-stimulation decreased by 32 and 43%, respectively. No differences were observed in rate of response at any pressure when the animals breathed N2-O2 with the partial pressure of oxygen maintained at 0.2 ATA. When an oxygen-nitrogen mixture was breathed at 3 ATA in which the PO2 was similar to compressed air at 10.1 ATA, self-stimulation rate was decreased by 40%; this suggests that PO2 is a critical variable influencing behavior mediated by brain stimulation. Results are discussed in terms of the use of self-stimulation as one tool for better understanding the neuronal mechanisms of behavior as they relate to breathing-gas mixtures at increased pressures.

Analysis of Variance↗
PubMed1975

Calculation of the relative speed of sound in a gas mixture.

Since the frequency spectrum of a voice signal is directly dependent on the velocity of sound, studies of speech spectra include the problem of calculating the speed of sound in the gas mixture being used. A computer program written in BASIC has been developed to calculate the speed of sound relative to air in various diving gas mixtures. In addition, a set of tables available as a separate technical report has been generated using this program. These tables are designed to provide a standard reference for reporting spectral shifts in speech due to different gas mixtures under normal diving conditions.

Computers↗
PubMedDate not supplied

Acquired QT prolongation associated with esophagitis and acute weight loss: how to evaluate a prolonged QT interval.

When the physician is confronted with a patient having significant QT prolongation, it is critical to determine whether the patient harbors a genetic defect and a transmissible form of long QT syndrome (LQTS) or whether the QT prolongation has an acquired cause. The distinction has profound ramifications for the type of care provided to the patient and family. We report the case of a previously healthy 14-year-old boy who presented with a 10-day history of painful swallowing, a 10-lb weight loss, and chest pain. A 12-lead electrocardiogram (ECG) showed marked QT prolongation. Endoscopy and culture identified a Herpes simplex esophageal ulcer. After treatment with acyclovir, the patient recovered completely. Three weeks after the resolution of his symptoms and recovery from his acute weight loss, a follow-up ECG showed complete normalization of the QT interval. This case illustrates yet another potential mechanism for acquired QT prolongation. We also provide a diagnostic algorithm for the careful evaluation of a prolonged QT interval.

Acyclovir↗
PubMedDate not supplied

The visible human male: a technical report.

The National Library of Medicine's Visible Human Male data set consists of digital magnetic resonance (MR), computed tomography (CT), and anatomic images derived from a single male cadaver. The data set is 15 gigabytes in size and is available from the National Library of Medicine under a no-cost license agreement. The history of the Visible Human Male cadaver and the methods and technology to produce the data set are described.

Adult↗