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Biomedical subjects

R K Jones

Publications and source records attributed to R K Jones.

At least 55 records · Page 3Linked to original sources
PubMed1982

Inhalation toxicology of diesel exhaust particles.

Our present knowledge of the health effects of diesel exhaust particles can be summarized as follows: 1. Diesel exhaust particles are very small in size and consist of a carbonaceous core with a myriad of adsorbed hydrocarbon compounds that are readily extracted with organic solvents. 2. The particle extracts are cytotoxic and mutagenic in in vitro bacterial and mammalian cell cultures. 3. The particle extracts area carcinogenic when painted on mouse skin along with a suitable promoter. 4. Inhaled particles readily deposit in the respiratory tract, a portion is rapidly cleared and a substantial portion is retained for long periods of time (over 100 days) in the lung. 5. Adsorbed hydrocarbon compounds slowly dissociate from the particles in biological media and presumably in the lung. 6. Detoxification mechanisms act on the hydrocarbon compounds released from the particles to minimize effects in in vitro systems and presumably in vivo.

Air Pollutants↗
PubMed1981

Why two eyes are better than one: the two views of binocular vision.

Despite centuries of research on the topic, the answer to the question "'Are two eyes significantly better than one, independent of stereopsis?" is still uncertain. In this investigation, steps are taken toward answering the question in a behavioral context. Three sets of experiments are reported in which human binocular and monocular performance are compared in a variety of exteroceptive and visuomotor tasks. In all of the experiments, two eyes facilitated performance. The findings suggest that the binocular system is able to detect the matching information, that is, the concordance, in the monocular optic arrays and to use that information to increase visual efficiency. Furthermore, stereopsis was not found to be important in the performance of visuomotor skills in three dimensions when the subjects were free to move their heads. Thus, the results indicate that an important ecological benefit of binocular frontal vision is having binocular concordance, rather than having binocular disparity.

Adult↗
PubMed1981

Feasibility of an alcoholism health insurance benefit.

The present study examined the impact of alcoholism treatment upon the subsequent utilization of health care services. Information gathered on a sample of 2,362 alcoholic clients at time of admission and six months later, was utilized to compare the savings in medical care expenses with the costs of alcoholism treatment. For the first year following treatment, costs exceeded savings by an average of $263 per client (benefit-cost ratio = 0.63:1). However, if the savings were sustained, the benefits would exceed costs within two years of the treatment period. These findings support the notion that alcoholism treatment produces a reduction in medical costs and provides some economic justification for an alcoholism insurance benefit.

Adult↗
PubMed1980

Psychiatric morbidity in prisons.

Faced with the recommendation by an outside consultant to construct a large hospital for the criminally insane, the Oklahoma legislature approved a proposal by the state mental health department to study the mental health treatment needs of the prison population. Through a variety of assessment techniques, the authors found the inmates had a spectrum of disorders needing different treatment approaches. Approximately 78 per cent of the inmates are diagnosable. Thirty-five per cent require treatment other than brief intervention, and 10 per cent are seriously ill. It is estimated that 20 per cent may be resistive and may require involuntary treatment.

Adult↗
PubMed1979

Treatment outcome for alcoholics as a function of therapeutic effort.

The association between therapeutic effort measured in terms of reimbursements for services and several treatment outcome variables was examined. A sample of clients regarded as definitely alcoholic was grouped into five categories according to the amount of money reimbursed for treatment in a fee-for-service arrangement. A systematic positive relationship was found between the amount of treatment measured in dollars and therapeutic outcome measured by remission rate and income. The data suggest that there may be an optimal cutoff for resource investment, above which no further treatment gains are achieved. Such information can provide a basis for program management decisions and suggests important implications for assumptions regarding alcoholism.

Adult↗
PubMed1978

A distinctive characteristic of pictorial perception: the zoom effect.

To investigate the role of flat surface information for the plane of projection in pictorial perception, three studies were designed in which varying amounts of such information were made available to adult subjects. The first study tested preferences for true or modified linear perspective under conditions of presence or absence of surface texture cues for the plane of projection. In the second and third studies, the absence of texture cues for the plane was coupled with the addition of motion parallax and binocular information respectively. It was found that adults showed a consistent preference for parallel perspective in pictures when the flat-surface information was provided either by visible texture or by motion parallax; but no consistent preference for either true or modified perspective in the absence of all three sources of flatness information or when the flat surface information was given only by binocular cues in the absence of visible surface texture of visible surface texture or head motion.

Cues↗
PubMed1978

Gasoline vapor exposure during bulk handling operations.

The survey evaluated gasoline vapor concentrations in the employees, breathing zone at five bulk handling facilities. Charcoal tube samples were analyzed by a special GLC/flame ionization/flasher technique which coupled with a computer program identified up to 142 constituents. A time-weighted limit of 240 ppm/10-hour day was only exceeded for five percent of the time at one location.

Air Pollution↗
PubMed1977

Towards a definition of living systems: a theory of ecological support for behavior.

It is proposed that the Darwinian theoretical approach and account of living systems has not yet been clearly given. A first approximation to this is attempted, focussing on behavior in evolving environments. A theoretical terminology is defined emphasizing the mutuality of organism and environment and the existence of biologically theoretical entities.

Animals↗
PubMed1977

Topographic impairment of night vision related to exercise.

We observed impaired night vision in the lower visual fields of long distance runners. We reduplicated our field observations by studying four vigorously exercising men, aged 26 to 52 years, under controlled laboratory conditions. Results of our observations showed impaired night vision did occur in the inferior visual fields of all four subjects.

Adult↗
PubMed1976

Inflammatory sequences in acute pulmonary radiation injury.

The histopathologic events in the developing acute pulmonary inflammatory reaction to inhaled particles of Yttrium 90 are detailed. In animals that died or were sacrificed during the first year after inhalation exposure, microscopic findings of acute inflammation predominated and included vascular congestion; stasis, focal hemorrhage; edema; various inflammatory cell infiltrates; cytolysis and desquamation of bronchiolar and alveolar epithelium followed by regeneration; vascular injury and repair; and the eventual development of pulmonary fibrosis. Accumulation of alveolar fibrin deposits was an additional characteristic, though not a constant feature of the early stages of radiation pneumonitis. In addition to the direct effects of radiation on pulmonary cell populations, the histopathologic findings were suggestive of diverse activation of various cellular and humoral mediation systems in their pathogenesis. The potential interrelationships of systems responsible for increased vascular permeability, coagulation and fibrinolysis, chemotaxis, and direct cellular injury were discussed and related to the pathogenesis of the microscopic findings characteristic of early pulmonary radiation injury.

Aerosols↗