The medical librarian and computer-assisted instruction

The requirements for a computer-assisted instruction (CAI) system in terms of hardware, communications, software, and personnel are discussed, and unique characteristics of CAI are reviewed. Current CAI applications in the medical field include programs in undergraduate medical and dental education, training of nurses and physical therapists, units for interns and residents, and continuing education for physicians. Certain problems exist in the current state of the art, however, including unsatisfactory aspects of each of the system components. The potential role of the medical librarian as a member of a CAI personnel team is explored, and contributions he can make in program development, monitoring, and evaluation are suggested. Medical librarians may themselves have opportunities in the future to use CAI to develop library skills and special subject knowledge. It is proposed that introduction of CAI may have the additional benefit of encouraging increased use of on-line bibliographic retrieval systems.

Hydrolysis of glyceryl tri(1- 14 C)octanoate and glyceryl tri(1- 14 C)oleate monolayers by postheparin lipolytic activity

The hydrolysis of monomolecular films of glyceryl tri[1-(14)C]octanoate and glyceryl tri[1-(14)C]oleate has been demonstrated by measurement of the decrease in surface radio-activity that occurs in the presence of postheparin plasma. The hydrolysis displayed first order kinetics and was proportional to enzyme concentration over a 10-fold range. No hydrolysis was observed in the absence of enzyme, and only slight activity (1%) was found in plasma taken from subjects before heparin administration. The hydrolysis was stimulated to a variable extent by Ca(2+). The first product of hydrolysis of the monolayer was identified as 1,2-diglyceride, which was subsequently converted to 2-monoglyceride. Inhibition of triglyceride hydrolysis was observed when postheparin plasma was preincubated in 2 m NaCl, 10(-4) m protamine, 10 mm Na(4)P(2)O(7), and 0.1 m NaF. Monolayer techniques avoid some but not all of the problems associated with emulsified lipid substrates and appear to be applicable for study of post-heparin lipolytic activities.

Reproductive biology, breeding seasons, and growth of eastern chipmunks, Tamias striatus (Rodentia: Sciuridae) in Canada

Reproductive, age, and body-size data from 1403 museum specimens from Manitoba to Nova Scotia and data on live chipmunks studied in the field in southeastern Ontario were analyzed. Schedules of the major stages of reproduction and growth are summarized graphically. Most adult males are in breeding condition (with large testes in black scrotal sacs and macroscopic tubules in caudae epididymidon) from March to June. As females can breed in March–April and (or) June–July, eastern chipmunks are unique among hibernating sciurids in that they have two breeding seasons per year. These occur over much of the Canadian range, with distinct waves of young appearing above ground in June and September. Spring breeding is probably annual and ubiquitous but records are too few to reveal the local frequency of summer breeding. Young have emerged in four consecutive Septembers at Stanley Corners, Ontario. Litter sizes from embryo and scar counts averaged 4.8 and 4.9. Although the young attain adult size and dentition in 3 months, most do not breed until 11 months old. We have questioned or explained conflicting reports and conclude that the breeding habits of Canadian chipmunks are essentially similar to those described by some U.S. workers.

Effect of food and water consumption, liver function, and thyroid function on the spontaneous running activity of white rats

The spontaneous running activity of male white rats was recorded in standard revolving activity cages under constant conditions of light and temperature. There was no correlation between spontaneous activity and voluntary food and water consumption or body weight gain. Furthermore, spontaneous activity could not be correlated either with liver function or with thyroid function.