The step cycle organization of infant walkers

To walk independently, the human infant must coordinate its multisegmented body to achieve both postural stability and forward mobility. In this experiment, we sought evidence of the form this coordination takes in infants who have been walking 3 to 10 months. Using the Philippson phases to represent the step cycle, we analyzed film records of infants and adults walking at speeds from 2 to 4 km/hr. Our results reveal a clear relationship between walking speed and the F and E(3) Philippson phases of the step cycle in both the young walkers and the adults. Indeed, across all four phases of the step cycle, the infants exhibited an organization that was almost identical to that of the mature walkers.     

Comparability of peer-assessment measures: A multitrait-multimethod and selection analytic approach

This research attempted to assess the relationship among the Pupil Evaluation Inventory (PEI), sociometric nominations, and sociometric ratings in terms of (1) a multitrait-multimethod analysis, (2) selection agreement indices of extreme individuals, and (3) stability over an 8-week period. Subjects were members of four second-grade classrooms at a regional school serving a diverse population of children. While stability estimates for measures were adequate and evidence for convergent validity was reasonably good, evidence for divergent validity was weaker. Selection agreement analyses yielded highly variable results, indicating that different samples of children tend to be selected by different instruments despite the similarity in dimensions being tapped. Methodological and theoretical implications of these findings are discussed.This work was based on the first author's M.S. thesis under the direction of the second author.     

The influence of medical and legal authorities on deaths facilitated by physicians.

This study investigated whether two widely publicized cases of deaths facilitated by physicians were followed by significant peaks in mortality. In March, 1991, Timothy Quill, MD, published a controversial editorial describing the physician-assisted suicide (PAS) of his 45-year-old, female leukemia patient. In a landmark decision in December 1990, the Missouri Supreme Court allowed removal of life support for Nancy Cruzan, a comatose accident victim. Correcting for trends and seasonal fluctuations, the authors examined: (1) U.S. leukemia mortality in the period centered on Quill's editorial, and (2) mortality from accident/coma combinations in the period centered on the Missouri Supreme Court's decision on Cruzan. Female leukemia deaths rose 11.3% above the expected rate (p < .01) just after Quill's article was published. The more closely the decedent matched Quill's patient, the greater the peak, with the largest peak (33.9%) evident for female leukemia patients in their 40s, who were long-term residents of smaller communities (p < .05). Five possible explanations for the findings were assessed, leading to the conclusion that Quill's editorial elicited an increase in mortality. The involvement of physicians in this increase is supported by analysis of the Cruzan case. This showed a mortality peak of 57% for accident/coma patients following the court decision.