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Biomedical subjects

C D Ferguson

Publications and source records attributed to C D Ferguson.

8 recordsLinked to original sources
PubMed2003

Ergodic dynamics in a natural threshold system.

Numerical simulations suggest that certain driven, dissipative mean-field threshold systems, including earthquake models, can be characterized by statistical properties often associated with ergodic dynamics, in the same sense as stochastic Brownian motion. We applied a fluctuation metric proposed by Thirumalai and Mountain [Phys. Rev. E 47, 479 (1993)]] for statistically stationary systems and find that the natural earthquake fault system in California demonstrates similar ergodic dynamics.

Computer Simulation↗
PubMed1999

Spinodals, scaling, and ergodicity in a threshold model with long-range stress transfer.

We present both theoretical and numerical analyses of a cellular automaton version of a slider-block model or threshold model that includes long-range interactions. Theoretically we develop a coarse-grained description in the mean-field (infinite range) limit and discuss the relevance of the metastable state, limit of stability (spinodal), and nucleation to the phenomenology of the model. We also simulate the model and confirm the relevance of the theory for systems with long- but finite-range interactions. Results of particular interest include the existence of Gutenberg-Richter-like scaling consistent with that found on real earthquake fault systems, the association of large events with nucleation near the spinodal, and the result that such systems can be described, in the mean-field limit, with techniques appropriate to systems in equilibrium.

Journal Article↗
PubMed1986

Endodontics. Diagnostic, treatment planning, and prognostic considerations.

An efficient systematic approach to proper diagnosis of pulpal and periradicular disease is presented. Then treatment planning considerations that determine if a tooth can be endodontically treated, if it has strategic value to be treated, and if the patient really wants the treatment are discussed. The long-term success rate of endodontic treatment is also discussed along with the predictability of emergency treatment for the patient being treated for urgent care.

Acute Disease↗
PubMed1983

Local dental anesthesia with epinephrine. Minimal effects on the sympathetic nervous system or on hemodynamic variables.

To define the hemodynamic effects of local dental anesthesia, we measured the mean arterial pressure (MAP), heart rate, and plasma catecholamine responses for 60 minutes following an inferior alveolar nerve block with epinephrine-and nonepinephrine-containing lidocaine hydrochloride anesthesia in 14 men using a randomized double-blind crossover trial. Lidocaine alone caused no significant change in MAP or heart rate and only slight, transient changes in plasma catecholamine concentrations when compared with baseline values. Lidocaine with epinephrine caused significant, sustained (60 minutes) increases in plasma epinephrine concentrations (mean +/- SEM, 27 +/- 4 to 94 +/- 13 pg/mL) and a slight, but transient (two-minute) increase in heart rate from 68 +/- 3 to 70 +/- 3 beats per minute. Lidocaine with epinephrine caused no significant change in MAP. There is no significant hemodynamic response to lidocaine dental anesthesia (with or without epinephrine) in healthy young men.

Anesthesia, Dental↗
PubMedDate not supplied

Current dental concepts in antibiotic prophylaxis for total joint replacement patients.

The subject of antibiotic prophylaxis has evoked controversy and much debate over the validity of such practice. In July 1997, the American Dental Association and American Academy of Orthopedic Surgeons issued an advisory statement concerning the use of antibiotic prophylaxis for patients with total joint replacements. A historical perspective of the subject is presented, with a review of the recommendation for total joint replacement antibiotic prophylaxis, a discussion of the new decision-making responsibility for the dentist, and medicolegal ramifications of this change.

Adult↗