112

0307-4412(94)E0035-M

M o n i t o r

ARTHUR C ROBINSON

Department o f Biological Sciences Napier University Edinburgh EHIO 5DT, Scotland

Faust, C B and Jasseal, S S Lipids -- A Consumer's Guide. Education in Chemistry, 30 (January issue), 15-17, 1993

This is a clear and succinct article which focuses on lipids of current 'consumer' interest: the sterols (particularly cholesterol), the triglycerides and the phospholipids. The text is accompanied by clear, simple diagrams. Different lipids are covered under the sub-headings 'bodily functions', 'food fats', 'health issues', and 'treatments'. Under 'bodily functions', the role of cholesterol as a constituent of cell membranes and as precursor of many hormones is stressed. Triacylglyerols are shown to act as the major reservoir of fatty acids as an energy source, and essential fatty acids are defined. The "food fats' section depicts the triacyglycerol compositions of animal and plant fats, the difference between unsaturated and saturated fats and oils, the measurement of overall unsaturation by the 'iodine number' , and the chemical basis of hydrolytic rancidity and oxidative rancidity. Under 'health issues" the classification of lipoproteins is described, together with the correlation between high concen- trations of serum lipids (particularly LDL and cholesterol) and coronary heart disease. The article closes with a brief discussion of dietary and drug-based treatments for the reduction of undesirably-high circulating lipid levels. In conclusion, this is a straightforward coverage which would serve as an elementary introduction to lipid biochemistry.

[Loughborough Grammar School, and Bridge St Medical Centre, Loughborough, UK]

Schmidt, H G, van der Arend, A, Moust, J H C, Koxx, I and Boon, L lnfhtence of Tutors' Subject-matter Expertise on Student Effort and Achievement in Problem-based Learning. Academic Medicine 68, 784-791 (1993)

It has been suggested by some that the task of a tutor in a problem-based tutorial should be to facilitate the learning of students rather than to convey knowledge. According to Barrows (Problem-based Learning Springer Publishing, New York, 1981J), these "process-facilitation' skills are more import- ant than subject-matter expertise. Such a point of view has, perhaps not surprisingly, evoked considerable controversy. The purpose of the educational research described in this article by Schmidt et al was to investigate the effect of tutors' subject- matter expertise on student's levels of academic achievement and study effort during a problem-based health sciences course. Differences in tutors' behaviours, and the influence of these differences on students" performances were also studied.

A review of the literature on the effects of tutors' content expertise on student learning suggested to Schmidt and colleagues that previous results were generally inconclusive and ambiguous. Strenous attempts were therefore made to avoid the pitfalls of earlier work. First, a tutor's content expertise was defined relative to the content of the unit in which he or she tutored (something that was not always done in earlier studies). Second, data involving an entire problem-based curriculum with more than 150 tutors were analyzed. Third, attempts were made to measure differences in behaviour between expert and non- expert tutors, and the consequences of this for student learning.

The results of these studies indicated that Barrows" assertion is not entirely justificd, at least not with regard to thc health scicnccs curriculum analyzed herc. Students guided b5 subject- matter experts were shown to spend more time on self-directed study, and their marks were better than those achieved by students guided by non-expert tutors. The positive effect of subject-matter expcrtisc on achievement was found to be strongest in the first curriculum year. suggesting that novice students arc more dependent on their tutors" expertise than are more advanced students. Furthermore, the content-expert tutors made more extensive use of their subject-matter knowledge to guide students. In other words, using one's subject-matter knowledge adequately is directly related to being able to facilitate the learning process. The authors state: "In hindsight, this finding is not earth-shakingly surprising. Facilitating the learning process of students cannot simply be a matter of knowing how to ask questions; a tutor also needs to know what to ask." Isn't it comforting to know that we are needed after all!

[Department of Education and Research, University of Limburg, PO Box 616, 621}0MD Maastricht, The Netherlands[

Tao, B Y Biological Engineering." a New Discipline J?>r the Next Centuo'. J Nat Resour Life Sci Educ 22, 34-38 (1993)

Although biological engineering applications currently concen- trate on the food processing and pharmaceutical industries, the advent of molecular biological tools means that new engineering applications will be developed increasingly in agriculture, medicine, ecology and environmental studies. New engineering programmes are therefore needed to teach the scientific prin- ciples, the associated engineering technology, the ethical use of new developments in biotechnology, and their potential effects on society.

The author highlights current efforts to re-define engineering curricula to embrace the life sciences and summarises the guidelines that were drawn up during recent workshops on biological engineering. A set of core courses was developed, which included engineering topics in biology, biophysics, and biomaterials. The first year of the course would cover structure, function, and energy transformation in biosystems at the cellular, organism and population levels. The second year would concentrate on fundamental aspects of measurement systems, emphasising the sensors and transducers which can be used in agricultural, biological and environmental applications. In the third year, the terminology and definitions of engineering properties of biological materials, and the interactions between living and non-living components of biological systems would be studied. Further work would focus on the interactions of organisms with their environments. A fourth year would bc devoted to computer simulation as a tool for understanding, designing and testing biotechnological systems.

The author also presents in detail the curriculum and objectives of Purdue University's current Biochemical and Food Process Engineering (BFPE) Programme as an example of a biological engineering course. The important point is made that, given public anxiety about the potential of biotechnology. biological engineers will be expected to demonstrate very high standards of professional ethics and social responsibility. In addition to the technical aspects of the craft, all biological engineering courses should therefore include discussions and assignments which focus on the social and ethical issues involved in the implementation of engineering projects.

[Department of Agricultural Engineering, Purduc University, W Lafayette, IN 47907, USA]

B I O C H E M I C A L E D U C A T I O N 22(2) 1994