Discrimination between alternative binary response models.
Explore the source record for details and available documents.
Biometry↗
Biomedical subjects
D R Cox
Publications and source records attributed to D R Cox.
A simple example of a comparison involving quantal data.
Explore the source record for details and available documents.
Biometry↗
Comparative chromosome mapping of a conserved homoeo box region in mouse and human.
Specific genes are assumed to regulate pattern formation in the mammalian embryo, but as yet none has been identified unequivocally. It is possible that such genes in mammals may be identified by virtue of a conserved coding sequence, because many of the Drosophila melanogaster homoeotic and segmentation genes, which have crucial roles in the regulation of segmental pattern formation during embryonic development, contain a 180-base pair (bp) DNA sequence, the homoeo box, and that sequences homologous to the Drosophila homoeo box are also present in 6-10 copies in higher animals, including mammals. Although the assumption that the homoeo box identifies genes responsible for pattern formation in mammals remains to be validated, it is a particularly attractive hypothesis given the strong conservation of homoeo boxes over vast evolutionary distances. Here we report the localization of a human homoeo box region, previously cloned and shown to contain two homoeo boxes within a sequence of 5-kilobases (kb), to the long arm of chromosome 17. We show that two single-copy homoeo box-flanking probes derived from this region strongly hybridize to single-copy restriction fragments in mouse genomic DNA and that these conserved homoeo box-flanking sequences map to mouse chromosome 11. This may be significant as several genes that map to chromosome 17 in human also map to chromosome 11 in the mouse, implying that a segment of mouse chromosome 11 is homologous to a region of human chromosome 17. Taken together, these data suggest that the homoeo box region detected with our probes is highly conserved in human and mouse.
Animals↗
Incubation period of AIDS in patients infected via blood transfusion.
Temporal trends in the prevalence of HIV (human immunodeficiency virus) infection are uncertain because of the reluctance of most governments to embark on large-scale programmes of serological surveillance. In the absence of such data, attempts have been made to relate the number of reported cases of AIDS (acquired immune deficiency syndrome) in a defined population to the proportion of that population infected with the virus as a specified time point. One crucial determinant of this relationship is the probability distribution of the incubation period of the disease, with the period defined as the time interval from infection to diagnosis. Recent statistical analysis suggests a mean incubation period of 4.5 years with wide confidence limits, whereas a more heuristic study reports a mean of 15 years. Here we report on a new analysis which reveals age-related differences in the mean (and median) incubation period: 1.97 (1.90) years for children (0-4 yrs old at infection), 8.23 (7.97) years for adults (5-59 yrs old), 5.50 (5.44) years for elderly patients (60 yrs and older).
Acquired Immunodeficiency Syndrome↗
Exercise training in healthy type A middle-aged men: effects on behavioral and cardiovascular responses.
Thirty-six healthy Type A men (means = 44.4 years) were randomly assigned to either an aerobic exercise training group or a strength and flexibility training group. Subjects completed a comprehensive psychological assessment battery before and after the exercise programs consisting of behavioral, psychometric, and psychophysiological testing. The behavioral assessment consisted of repeated Type A interviews that were videotaped for subsequent component analyses. The psychometric testing included two self-report questionnaires to assess Type A behavior. The psychophysiological test consisted of a standard behavioral challenge, a mental arithmetic task, performed while cardiovascular responses were monitored. Aerobic exercise (AE) training consisted of 12 weeks of continuous walking or jogging at an intensity of at least 70% of subjects' initial maximal oxygen consumption (VO2max) as determined by an initial treadmill test. Strength and flexibility (SF) training consisted of 12 weeks of circuit Nautilus training with no aerobic exercise. After 12 weeks of exercise, the AE group increased their VO2max by 15%, while the SF group did not change. Both groups experienced decreases in overt behavioral manifestations of the Type A behavior pattern and self-reported Type A traits. However, the AE group showed an attenuation of heart rate, systolic and diastolic blood pressure, and estimated myocardial oxygen consumption (MVO2) during the task and had lower blood pressure, heart rate, and (MVO2) during recovery. In contrast, the SF group showed a significant reduction only in DBP during the task, which was likely due to habituation. These results support the use of aerobic exercise as a method for reducing cardiovascular risk among healthy Type A men.
Adult↗
The delayed neurobehavioural sequelae of traumatic brain injury.
This is a comprehensive review of the late-occurring effects of traumatic brain injury (TBI). It appears that TBI increases the risk over basal rates for the general population, to this degree: for depression, by a factor of five or 10; for seizures, by two to five; for psychotic disorders, by the same factor; and for dementia, by four or five. Severe TBI, or injuries with special characteristics, may increase the risk of delayed sequelae even further. One is not able, at this point, to estimate the relative occurrence of a newly described entity--delayed amnesia. An initial TBI increases the risk for subsequent TBI, by a factor of two. A second TBI increases the risk of yet another TBI eightfold.
Amnesia↗
Proceedings of the Symposium on Designs for Clinical Cancer Research. Summary views: A statistician's perspective.
This paper outlines some broad issues concerning the role of statistical methods, and argues for flexibility of approach. It reviews the controversies concerning historical versus concurrent controls, and randomization versus extensive balancing. Finally, it proposes directions in which further developments of statistical technique would be desirable.
Forecasting↗