ABSTRACT
A cross-correlation method for recording spinal myotatic reflexes has been developed to meet the need for brief test periods in babies and children and subjects with central neurological pathology. In normal adult subjects the method has been validated by comparing excitatory and inhibitory reflexes obtained with cross-correlation with those obtained with conventional signal averaging. In the cross-correlation method a pseudo-random binary sequence of 64 brief tendon taps was delivered in <1.5 s, and in the averaging method 20-150 taps at one per second. The reflexes were expressed as unit impulse responses to enable direct, quantitative comparisons to be made. With cross-correlation the responses were slightly expanded in time, had lower peak amplitudes, and onset latencies advanced by 10 ms, the clock period of the pseudo-random binary sequence. The amplitude of biceps phasic stretch reflex increased with muscle contraction in a similar manner with both methods. In tests for stationarity the amplitude of biceps phasic stretch reflex varied <10% in the first six repeats of the pseudo-random binary sequence. The tap force required at threshold for cross-correlation was approximately half that for averaging, but with both methods the magnitude of biceps phasic stretch reflex varied linearly with tap force over the range of one to two times threshold. The validity of responses obtained with cross-correlation was assessed by a statistical procedure. In conclusion, the cross-correlation method is robust and gives similar results to those obtained with averaging.
Subject(s)
Reflex, Stretch/physiology , Adult , Diagnostic Techniques, Neurological/instrumentation , Diagnostic Techniques, Neurological/statistics & numerical data , Electromyography/methods , Female , Humans , Male , Middle Aged , Muscle Contraction/physiology , Regression Analysis , Statistics as TopicABSTRACT
The relationship between various measures of traffic speed, under free flow conditions, and accident rate is investigated for two groups of sites, one in the Tyne and Wear county of the UK and the other in Bahrain. The effect of speed limits on traffic speed is estimated for both groups of sites. In Bahrain, there is statistically significant evidence of an association between mean speed and accident rate. In Tyne and Wear the statistical evidence is weaker, and points to a stronger relationship between accidents and the variability of traffic speeds. In both areas, there is an apparent decrease in accident rate if the percentage of heavy vehicles increases, with the speed distribution held constant. In both areas the effect of speed limits is to reduce the mean speed of traffic by at least one quarter. Higher speeds are associated with longer trips.
Subject(s)
Accidents, Traffic/statistics & numerical data , Automobile Driving , Bahrain , Humans , Models, Statistical , United KingdomABSTRACT
The 109 female survivors of a mental hospital population surveyed in 1965 for facial dyskinesia were followed up 16 years later. The 99 survivors with non-organic brain syndromes were analysed. Prevalence of dyskinesia had risen from 18.4% to 46.5% during follow-up and its development was significantly associated with neuroleptic dosage. Enlarged ventricles on brain scans were significantly associated with dyskinesia, cognitive impairment and neuroleptic prescribing.
Subject(s)
Antipsychotic Agents/adverse effects , Dyskinesia, Drug-Induced/etiology , Facial Muscles/drug effects , Affective Disorders, Psychotic/drug therapy , Affective Disorders, Psychotic/psychology , Aged , Antipsychotic Agents/administration & dosage , Brain/pathology , Chlorpromazine/administration & dosage , Chlorpromazine/adverse effects , Dose-Response Relationship, Drug , Female , Fluphenazine/administration & dosage , Fluphenazine/adverse effects , Fluphenazine/analogs & derivatives , Follow-Up Studies , Humans , Neurocognitive Disorders/drug therapy , Neurocognitive Disorders/psychology , Neurologic Examination , Neuropsychological Tests , Psychotic Disorders/drug therapy , Psychotic Disorders/psychology , Risk Factors , Schizophrenia/drug therapy , Schizophrenic Psychology , Tomography, X-Ray ComputedABSTRACT
We compared the social, professional, and occupational characteristics of nurses employed by area health authorities and nurses employed by general practitioners by interviewing random samples of 153 nurses in 113 practices situated in four rural and five urban area health authorities in England. The two kinds of nurse were similar in most professional respects but differed in their social characteristics, career patterns, and terms and conditions of employment. They also differed in the singleness of their commitment and the hours they worked in the study practices.
Subject(s)
Family Practice , Nursing Staff , Educational Measurement , Employment , England , Humans , Nursing Staff/education , Social Class , WorkforceABSTRACT
We compared the nursing and medical activities and the opinions of nurses employed by area health authorities and nurses employed by general practitioners by interviewing a random sample of 153 nurses in 113 practices, situated in four rural and five urban area health authorities in England. The availability of a treatment room profoundly affected the work of both kinds of nurse and there were differences between them in the balance between ;caring' and ;technical' activities which may be largely attributed to the circumstances of their employment. However, their occupational histories and choices of employer appear to reflect both differences in their training and differences in their values about career and marriage.
