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Biomedical subjects

M Gagnon

Publications and source records attributed to M Gagnon.

At least 127 records · Page 7Linked to original sources
PubMed1980

[Dynamic characteristics of alternate strides in cross-country skiing].

Seven instructors in cross-country skiing were filmed during the performance of the alternate stride at three different velocities: maximal, medium and slow. The dynamic characteristics of the movement were analyzed. On the basis of spatio-temporal analyses, it was found that the alternate stride is a motion essentially propulsive with the predominance of the superior limbs to propulsion. The skier maintains or increases his velocity at the beginning of the glide which is possibly attributed to the transfer of momentum of the recovery leg. A decrease in horizontal velocity is observed at the end of the glide. At maximal speed, the asynchronous character of the actions by the superior and inferior limbs is more important; there is a reduced emphasis in the actions by the superior limbs. At medium speed, the following characteristics are observed: a reduced importance in the asynchronous actions, a larger preponderance to the gliding phase and a smaller elevation of the skier's center of gravity.

Adult↗
PubMedDate not supplied

Ecological diversity and community ecology in the Fayum sequence (Egypt).

The Jebel Qatrani sequence found in the Fayum region of Egypt samples the richest Paleogene mammalian fauna of Africa, including some of the earliest anthropoid primates. The paleoecology of the Fayum has been interpreted as either a woodland bushland or a lowland evergreen tropical forest, although the issue of changing ecological conditions through time has never been investigated. The Fayum fossils can be grouped into four successive and stratigraphically distinct faunal assemblages. Each of these mammalian assemblages is compared with modern mammal communities. Six communities from modern African forest habitats and six communities from woodland bushland habitats are used to produce typical models of ecological diversity. An ecological spectrum for each modern community is generated by assigning mammal species to categories of taxonomic, diet, and body size diversity. Modern forest communities have a higher diversity of rodents and primates, a high diversity of frugivores, low diversity of grazers, and show a steep gradient in body size distribution from a high diversity of small species towards a low diversity of large species. Woodland-bushland communities have a higher diversity of ungulates and carnivores, a low diversity of frugivores but a high diversity of grazers, and a more even body size distribution. Diversity spectra from the four successive Fayum fossil assemblages are compared with the models derived from the modern mammal communities. The Fayum assemblages show similarities to modern forest habitats in patterns of diet diversity and to modern woodland bushland habitats in body size diversity. More detailed analyses of taxonomic diversity suggest that the lowermost assemblages were different in ecological structure from modern habitats, while the uppermost assemblage shows strong resemblances to modern humid tropical forests.

Animals↗
PubMedDate not supplied

Effect of glucose and peripheral glucose regulation on memory in the elderly.

We examined changes in cognitive performance following the intake of a glucose (50 g) or saccharin solution (50 mg) in fasted elderly male and female subjects. Glucoregulation was estimated using a recovery index that was used to categorize subjects within each sex as having poor or good recovery. Elderly males with poor recovery performed worse on the Logical Memory subtest of the Wechsler Memory Scale and on the free recall or recognition parts of a work list task. The item analysis of the Logical Memory subtest showed that male subjects with poor recovery remembered less of the last items of the paragraphs after drinking saccharin while the first items were equally remembered by both groups. Glucose improved the performance of the males with good regulation for the first seven items while the performance of males with poor regulation decreased for those items under glucose. The present study support the notion that peripheral glucoregulation can influence memory performance and that the ingestion of glucose can influence certain aspects of memory functioning.

Aged↗
PubMedDate not supplied

CytoView. A prototype computer image-based Papanicolaou smear proficiency test.

OBJECTIVE: To develop and assess CytoView, a prototype computer image-based cytology proficiency testing (PT) system, as an alternative to glass-slide cervical cytology PT. STUDY DESIGN: The computer-based PT consists of 10 cases taken from 10 Pap smears, each of which had received a consensus Clinical Laboratory Improvement Amendments-category diagnosis from three pathologists. Each CytoView "case" was the digital representation of > 8,000 microscopic fields, captured from a selected 5 x 10-mm rectangle of a Pap smear. The 5 x 10-mm capture rectangle was selected from the slide's most representative area for its diagnostic category. The CytoView project team developed each case through a multistep process that included image capture, image alignment, correlation of 10x and 40x images, and image display. The 10-slide CytoView PT prototype was then assessed by groups of cytopathologists and cytotechnologists. RESULTS: The CytoView prototype PT system was developed and assessed. CONCLUSION: Preliminary evaluation of CytoView indicated potential for this format as a valid and logistically feasible alternative to the traditional glass slide PT format.

Evaluation Studies as Topic↗