PubMed Health⌕ Search

Biomedical subjects

B T Jones

Publications and source records attributed to B T Jones.

30 records · Page 2Linked to original sources
PubMed1989

Fourier transform atomic absorption flame spectrometry with continuum source excitation.

The design and performance of a Fourier transform atomic absorption flame spectrometer (FT-AAS) is presented. A 300-W xenon arc continuum source and a Michelson interferometer are used. A signal to noise disadvantage arising from the multiplex feature of FT-AAS is demonstrated by varying the photon flux at the detector without changing the exciting radiation. A grating is used for dispersion of the radiation before the interferometer to reduce the spectral window at the photomultiplier tube. Detection limits for several elements are generally an order of magnitude poorer than those obtained by continuum atomic absorption methods using echelle-grating spectrometers. Line profiles and absorption spectra, within the region of the spectral window selected by the grating, can be obtained with this method. Standard curves for sodium were constructed to extend the linear calibration range, by using absorbances measured at the absorption maximum and 0.022 nm off-line.

Fourier Analysis↗
PubMed1986

Reversibility of serotonin irritation syndrome with atmospheric anions.

Clinical reports and animal studies support the existence of a "serotonin irritation syndrome." This is a putative anxiety state caused by a rise in atmospheric cations and reversed by a corresponding rise in anions. Volunteers were exposed to generated ambient cations and anions under controlled conditions. Cations were found to increase anxiety, excitement, and suspicion. Anions reversed the effects of cations and, in addition, reduced suspicion and excitement to levels below those occurring before cationization. Implications of these findings and the possible mediation of effects by serotonin are discussed.

Air Ionization↗
PubMed1981

Association of blood pressure and polychlorinated biphenyl levels.

The geometric mean serum level of polychlorinated biphenyls (PCBs) of 458 persons in a communitywide study was 17.2 microgram/L, with 80% to 90% having levels within the range found in other community groups. As a dependent variable, PCB levels were found to be positively related to age, even when controlled for all other variables associated with PCB level: sex, local fish consumption, obesity, serum cholesterol level, and alcohol consumption. No major point source of PCB contamination was found, and fish taken in the drainage of a major population center had mean PCB levels below the current enforceable Food and Drug Administration tolerance of 5 mg/kg. As an independent variable, serum PCB levels were positively associated with gamma-glutamyl transpeptidase level, serum cholesterol level, and measured blood pressure. The PCB-blood pressure association, which was independent of age, sex, body mass index, and social class, must be confirmed in other exposed populations.

Alabama↗
PubMed1981

Cross-sectional study of a community with exceptional exposure to DDT.

The geometric mean level of total DDT in serum samples (76.2 ng/mL) from 499 persons living downstream from a defunct DDT-manufacturing plant was several times the national geometric mean (15.0 ng/mL). DDE isomers, metabolites of DDT, accounted for an average of 86.7% of total DDT. Total DDT levels increased with age, even when controlled for other independent variables also significantly associated with DDT: race, sex, fish consumption, years of residence, socioeconomic status, alcohol consumption, and serum triglyceride levels. Fish consumption, the second strongest determinant of DDT level, had one third the predictive power of age. Total DDT levels were not associated with specific illness or ill health. However, total DDT levels were positively associated with levels of serum cholesterol, triglyceride, and gamma-glutamyl transpeptidase. The finding that serum DDE levels increase with age suggests that no equilibrium in body burden has been reached or that pharmacokinetics or serum/adipose partition may vary with age.

Adolescent↗
PubMed1980

The role of context in the perception of orientation by the rat.

Two experiments are reported which demonstrate the role of contextual factors in the rat's perception of orientation. Designed to eschew criticisms of an earlier study by McGonigle and Jones, the first experiment shows that the rat's perception of linear Gestalten is conditional upon the set of alternative patterns within which the (linear) pattern is embedded. The second experiment shows that the ecological framework of an orientational cue (rather than its position relative to retinocortical coordinates) determines the rat's perception of vertical and horizontal stimuli.

Animals↗
PubMed1978

Levels of stimulus processing by the squirrel monkey: relative and absolute judgements compared.

Nine squirrel monkeys were required to select from various sets of stimuli-differing in size or brightness-either in terms of relational criteria or on an absolute stimulus basis. The level of information processing required by each task was assessed by means of stimulus transformation techniques, variations in set size, and by the elimination of the visible context. It was found that some relational judgements make fewer processing demands on the subject than do absolute stimulus judgements; the 'middle' relation, however, appears much more difficult to use than selection of a stimulus on an absolute basis and may be beyond the competence of the squirrel monkey. The results are seen as support for the thesis as advanced by McGonigle and Jones that the criteria of judgement, when varied, change the depth of stimulus processing by monkey as well as man.

Animals↗
PubMed1977

Judgemental criteria and the perception of structure.

We repudiate Dodwell's claim that his relational model is predictively more accurate than our Garner-based treatment of AT. We claim instead, that his case is based on a fundamental misunderstanding of the essentials of Garner's complex thesis, together with a misreading of our own report. Rather than accept his notion of a single continuum of salience as providing for the genesis of structure, we argue instead that his 'single' continuum' compounds and confounds at least two continua which may be understood only where the criteria of judgement are made explicit.

Discrimination, Psychological↗
PubMedDate not supplied

Anxiogenic effects of generated ambient cations--a preliminary study.

The existence of the putative "serotonin irritation syndrome" (SIS) was tested in a human population. Volunteers were exposed to a highly cationized environment for two hours. Symptoms of anxiety and excitement significantly increased. During the time of exposure serum serotonin levels also increased significantly. These results support the existence of SIS as a clinical entity.

Adult↗
PubMedDate not supplied

Building nursing expert systems using automated rule induction.

Previous articles in this journal testify that nursing expert systems have become a feature of nursing information technology and nursing theory. Regretfully, experts' knowledge is not easy to elicit and computer systems are not easy to program. Fortunately, expert system shells bypass most of the problems associated with programming expert systems. Lesser known but with no less impact are shells that bypass the other difficult phase of expert system construction, namely knowledge elicitation. The major aim of this article is to provide a nontechnical description of such a shell and the use to which we have put it within three quite different areas of nursing. In addition, the article introduces expert systems in nursing as a potentially unifying development in a profession rapidly undergoing specialization.

Expert Systems↗