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Biomedical subjects

T L Williams

Publications and source records attributed to T L Williams.

At least 55 records · Page 3Linked to original sources
PubMed1989

A strategy for curriculum integration of information skills instruction.

The ever increasing need of health professionals for information and the inclusion of active learning experiences in the medical school curriculum require that students learn the effective use of health information tools. Curriculum integration is gaining acceptance as an effective approach to teaching information skills in this setting. At the University of Miami School of Medicine, information skills components taught by library faculty are integrated into the Freshman Orientation Program and two sophomore curriculum courses. Beginning with a core set of skills and basic information management tools, more complex and subject-specific skills are introduced sequentially throughout the basic sciences curriculum. During the first two years, a wide range of information skills are taught, and students receive many opportunities to seek and identify information using both printed sources and computerized bibliographic databases. This paper describes how curriculum integration of information skills instruction was achieved and the many benefits of this approach. Included are a description of the information skills components, evaluation data, and future plans.

Computer Systems↗
PubMed1988

Fictive locomotion in the lamprey; a comparison using bicarbonate and HEPES buffers.

Fictive locomotion in the lamprey, elicited by N-methyl-DL-aspartate or D-glutamate, was compared in two buffer solutions, one using bicarbonate, the other using HEPES. No differences were observed in burst proportion, cycle length, or phase lag per segment between these buffers solutions. These data indicate that HEPES-buffered artificial cerebrospinal fluid, which does not require gassing with carbon dioxide to maintain pH, may be a suitable alternative to bicarbonate-buffered artificial cerebrospinal fluid.

Animals↗
PubMed1988

Kynurenic acid and AP5 distinguish between NMDA receptor agonists.

Quantitative analysis of responses to amino acids in mouse cortical slices has indicated that the antagonists kynurenate and 2-amino-5-phosphonopentanoic acid distinguish between ibotenate and both N-methyl-D-aspartate (NMDA) and quinolinate. This result is consistent with the existence of NMDA-receptor subtypes.

2-Amino-5-phosphonovalerate↗
PubMed1988

Amino acid pharmacology in neocortical slices: evidence for bimolecular actions from an extension of the Hill and Gaddum-Schild equations.

1. The equivalent circuit of the cortical slice preparation has been analysed to show that the measured d.c. voltages can be used to estimate the Hill coefficient for ligands acting on the pyramidal cell bodies. 2. The Gaddum-Schild equation for agonist-antagonist interactions has been modified for applications in which the Hill coefficient is not equal to 1. 3. The equations obtained have been applied to recent data of Burton et al. (1988). The results provide evidence for a bimolecular action of the agonists N-methyl-D-aspartate (NMDA) and quinolinic acid and the antagonists kynurenic acid and 2-amino-5-phosphono-pentanoic acid at NMDA receptors on mouse neocortical pyramidal cells.

2-Amino-5-phosphonovalerate↗
PubMed1988

The economics of academic health sciences libraries: cost recovery in the era of big science.

With launching of Sputnik by the Soviet Union in the late 1950s, science and technology became a high priority in the United States. During the two decades since, health sciences libraries have experienced changes in almost all aspects of their operations. Additionally, recent developments in medical care and in medical education have had major influences on the mission of health science libraries. In the unending struggle to keep up with new technologies and services, libraries have had to support increasing demands while they receive a decreasing share of the health care dollar. This paper explores the economic challenges faced by academic health sciences libraries and suggests measures for augmenting traditional sources of funding. The development of marketing efforts, institutional memberships, and fee-based services by the Louis Calder Memorial Library, University of Miami School of Medicine, is presented as a case study.

Direct Service Costs↗
PubMed1987

Inhibitory synaptic input to edge cells during fictive locomotion.

Edge cells are stretch receptors with receptive fields in the lateral margin of the lamprey spinal cord. Their activity may entrain the spinal central pattern generator (CPG). We have recorded intracellularly from edge cells during short episodes of fictive locomotion. Every cell tested exhibited numerous chloride-sensitive IPSPs. We have therefore provided evidence that edge cell sensitivity is modulated by the activity of the spinal CPG.

Animals↗
PubMed1986

The internal polyadenylate tract of yeast killer virus M1 double-stranded RNA is variable in length.

The 1.8-kbp M1 double-stranded (ds) RNA from type 1 killer strains of Saccharomyces cerevisiae contains an internal 200-bp adenine- and uracil-rich region. We have previously demonstrated that this region consists primarily of adenine residues on the plus strand of M1 dsRNA and on the full-length, in vitro synthesized (+) transcript (denoted m) of M1 dsRNA, neither of which contains 3'-terminal polyadenylate. We now show that there is variability in the length of the polyadenylate tracts of m transcripts synthesized in vitro by virions purified from either of the K1 diploid killer strains A364A X S7 or A364A X 1384. This variability reflects size differences seen in the corresponding M1 dsRNA genomes which, along with other data presented, localizes the variability in the length of M1 dsRNA to the adenine- and uracil-rich region.

Molecular Weight↗
PubMed1984

Fictive locomotion in the lamprey spinal cord in vitro compared with swimming in the intact and spinal animal.

A comparison has been made of the patterns of muscle activity during swimming in the intact and spinal lamprey, and the patterns of ventral root activity in the in vitro preparation of the lamprey spinal cord. Electromyographic (e.m.g.) activity was recorded with intramuscular bipolar electrodes from three segmental levels in intact lampreys swimming in a swim-mill at a range of swimming speeds. The patterns of activity obtained were similar to those seen in elasmobranch and teleost fish. After high spinal transection, lampreys could be induced to swim continuously for a period of several minutes in the swim-mill by a light initial mechanical stimulation of the tail or dorsal fin. The patterns of e.m.g. activity obtained from spinal animals at a range of swimming speeds were similar to those obtained in the intact state. Portions of spinal cord were isolated encompassing those segments from which e.m.g. recordings had been made and ventral root recordings were made in vitro of the rhythmic activity induced by bath application of D-glutamate. In all experiments the mean duration of the bursts of activity at any segmental level was directly proportional to the mean cycle duration, and the constant of proportionality (about 0.36) was similar for all three types of preparation. In all preparations the mean time delay for the activation of segments in the rostral-caudal direction was proportional to the cycle duration and to the number of segments between recording positions. The proportionality constant, or phase lag per segment, was approximately equal to 0.01 in all three types of preparation.

Action Potentials↗
PubMed1981

Experimental analysis of the gait and frequency of locomotion in the tortoise, with a simple mathematical description.

1. Voluntary locomotion of the tortoise Testudo graeca was investigated over a range of experimental conditions. 2. The swing and stance intervals of the step cycles of individual limbs and the interlimb intervals were shown to depend only upon the locomotor cycle duration independent of experimental conditions. 3. The gait is described by four simple equations, valid for all animals and conditions tested, with locomotor cycle duration as the only independent variable. 4. The observed frequency of locomotion was shown to be related to body weight, cloacal temperature, and walking surface ina manner which can be described by a single equation. 5. The implications of these findings for vertebrate locomotion are discussed.

Animals↗
PubMed1979

Effect of 2-deoxyglucose on [32P] phosphate and insulin release from perifused rat pancreatic islets.

The effect of 2-deoxyglucose on glucose mediated insulin and [32P]phosphate release was studied by perifusion of isolated rat pancreatic islets. When islets were perifused with media containing 2.8 mmol/l glucose and 20 mmol/l 2-deoxyglucose for 60 minutes and then exposed to media containing 8.3 or 16.7 mmol/l glucose and 20 mmol/l 2-deoxyglucose for the next 15 minutes, insulin release at either glucose concentration was prompt but blunted. Similarly, islets preincubated (90 min) with [32P] orthophosphate, then perifused with 20 mmol/l 2-deoxyglucose for 75 min and stimulated by either 8.3 or 16.7 mmol/l glucose for the final 15 minutes or 2-deoxyglucose exposure demonstrated obtundation of [32P]phosphate release. Perifusion of islets with 20 mmol/l 2-deoxyglucose alone induced no heightened 32P efflux. These studies suggest that 2-deoxyglucose affects initial events in stimulus-secretion coupling of glucose mediated insulin release.

Animals↗
PubMed1979

A dual effect of formaldehyde on the inwardly rectifying potassium conductance in skeletal muscle.

1. The inwardly rectifying potassium conductance of the membrane of frog sartorius muscle fibres is greatly reduced by treatment of muscles for 30 min with a solution containing formaldehyde (10 mM). 2. A transient increase in the conductance of the inward rectifier is observed early during formaldehyde action. 3. Analysis of the biphasic time course of the conductance changes, as determined under controlled voltage conditions, suggests that treatment with formaldehyde alters simultaneously, but in opposite ways, two factors that determine the conductance of the inward rectifier. 4. The linear component of the current-voltage relation, which dominates the relation at strongly positive potentials, is not affected while the above changes occur. But on prolonged exposure to formaldehyde the leak conductance increases. 5. The effects of formaldehyde on the inward rectifier are reversible on prolonged superfusion with normal Ringer solution. 6. The slight inward rectification remaining after most of the extracellular K is replaced by Rb, is similarly reduced by treatment with formaldehyde. 7. The results are interpreted in terms of the chemical properties of formaldehyde and present views of the mechanisms of inward rectification.

Animals↗