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Biomedical subjects

J Nixon

Publications and source records attributed to J Nixon.

101 records · Page 6Linked to original sources
PubMed1975

Discriminating symptoms in schizophrenia. A report from the international pilot study of schizophrenia.

Schizophrenia is recognized by the presence of one or more clinical syndromes, but there is disagreement as to how far the boundaries of the concept should be extended. During the course of a World Health Organization study, using the Present State Examination and a computerized classification program, a nuclear schizophrenic syndrome was nearly always (95.1%) associated with a diagnosis of schizophrenic or paranoid psychosis. The only substantial exception was that 13 out of 79 patients diagnosed as manic were said to show the nuclear syndrome. The computer classification was concordant with a clinical diagnosis of schizophrenic or paranoid psychosis, manic psychosis, or depressive disorder, in 90% of cases. If appropriate precautions are taken, many of the sources of noncomparability in epidemiological, therapeutic, and prognostic studies can be brought under control.

Adjustment Disorders↗
PubMed1972

Underwater audiogram of the California sea lion by the conditioned vocalization technique.

Conditioning techniques were developed demonstrating that pure tone frequencies under water can exert nearly perfect control over the underwater click vocalizations of the California sea lion (Zalophus californianus). Conditioned vocalizations proved to be a reliable way of obtaining underwater sound detection thresholds in Zalophus at 13 different frequencies, covering a frequency range of 250 to 64,000 Hz. The audiogram generated by these threshold measurements suggests that under water, the range of maximal sensitivity for Zalophus lies between one and 28 kHz with best sensitivity at 16 kHz. Between 28 and 36 kHz there is a loss in sensitivity of 60 dB/octave. However, with relatively intense acoustic signals (> 38 dB re 1 mub underwater), Zalophus will respond to frequencies at least as high as 192 kHz. These results are compared with the underwater hearing of other marine mammals.

Animals↗
PubMedDate not supplied

A molecular to molar analysis of communicative and problem behaviors.

Few studies have examined the relationship between communicative and problem behaviors that are already present in a behavioral repertoire. In this study, a detailed microanalysis of the antecedents and consequences of aggressive and communicative behavior of a 7-year-old boy was conducted. By using both descriptive and experimental methodologies, the data suggested that problem and communicative behavior were maintained on thin concurrent schedules of social negative reinforcement. A molar analysis of the descriptive data showed that the relative amount of time allocated to each behavior was a function of the relative amount of reinforcement that each behavior accrued. The implications of these findings are discussed in terms of conducting descriptive analyses and for enhancing the efficacy of interventions for problem behavior.

Child↗
PubMedDate not supplied

Freshwater drowning and near-drowning accidents involving children: a five-year total population study.

A large total population study of childhood fresh water immersion accidents is reported. The study was undertaken in the City of Brisbane over the five-year period 1971 to 1975 inclusive, and 111 fresh water immersion accidents involving children were studied and analysed. The childhood fresh water immersion accident rate, including drowning and near-drownings, of 10-43 per year per 100,000 at risk (fatality rate of 5-17) is the highest reported. If an unsupervised child gets into difficulties in fresh water and loses consciousness he has a 50% chance of dying. The immersion accident rate has doubled over the last six years. Age-specific immersion accident rates have been calculated, and have revealed that, in the toddler group (12 months to 23 months), the fresh water immersion accident rate is 50-01 per 100,000 (fatality rate of 22-55). Rates for drowning and near-drowning accidents after a fresh water immersion, by site, age and outcome (survival versus fatality), are also presented for the first time. Swimming pools produce 6-20 immersion accidents per year per 100,000 children at risk, and the domestic family bath tub produces 1-78. Possible factors explaining the high incidence are discussed, and comparisons of drowning rates from other centres are made.

Accidents↗
PubMedDate not supplied

Computerised tomography scans of the head in a district general hospital.

We report the results of a retrospective study of all computerised tomography (CT) brain scans of adult patients carried out over a 10-week period, based on radiological and clinical records. The commonest scan results were normal (51%) and stroke (26%), with an overall diagnostic accuracy of 43/80 (54%). On the basis of a retrospective blind survey by a neurologist, 42% of scans were thought not to be indicated. The results indicate the need for: guidelines on the use of CT scanning in stroke. Emphasis of current guidelines on the use of CT scanning in head injury. Neurological assessment of some suspected diagnoses before scanning.

Adult↗