We redesigned our intermediate-level organismal physiology laboratory course to center on student-designed experiments in plant and human physiology. Our primary goals were to improve the ability of students to design experiments and analyze data. We assessed these abilities at the beginning and end of the semester by giving students an evaluation tool consisting of an experimental scenario, data, and four questions of increasing complexity. To control for nontreatment influences, the improvement scores (final minus initial score for each question) of students taking both the laboratory and the companion lecture course were compared with those of students taking the lecture course only. The laboratory + lecture group improved more than the lecture-only group for the most challenging question. This evidence suggests that our inquiry-based curriculum is achieving its primary goals. The evaluation tool that we developed may be useful to others interested in measuring experimental analysis abilities in their students.

Abstract. In order to determine the composition of the IX174 coat, 4X particles labeled in most of the amino acids have been dissociated, and the proteins separated by electrophoresis on polyacrylamide gels. The molar ratios of the four proteins calculated from the fraction of radioactivity in each peak and the molecular weights of the individual proteins suggest that the capsid is composed of 60 molecules of the 48,000 daltons protein and that each of the 12 spikes is composed of one molecule of the 36,000 daltons protein and five each of the 19,000 and 5,000 daltons proteins.Introduction.-DX174 is a small bacteriophage about 230 A in diameter1 with a molecular weight of 6.2 X 106. About three fourths of this, or 4.3 X 106, is protein.2 Electron microscopy reveals anl icosahedral particle with mushroomshaped appendages or spikes protruding from the twelve axes of five-fold svmmetry.1' 3' 4 Although the first work on the phage coat indicated that it was composed primarily of one type of protein with a molecular weight of 23,000 daltons,5 later physical and chemical studies' have demonstrated that it is considerably more complicated than this. In addition, genetic studies indicate that four cistrons code for phage structural proteins.8Edgell, Hutchison, and Sinsheimer4 were able to separate the spike proteins from the DNA-containing inner capsid after treatment with 4 M\I urea and study the two fractions by electrophoresis on polyacrylamide gels in 9 MI urea. They found that the capsid is composed of only one type of protein and that the spikes probably consist of three proteins. While they usually observed only two spike protein bands on gels, they saw three bands with one particular mutant and argued that in the case of wild-type 4X two of the proteins moved to the same position in their gels.A variety of evidence implies that the spikes are responsible for adsorption of the phage to susceptible hosts. Both the 4 At urea-treated particles and the defective particles formed by mutants in one of the spike cistrons (II) are unable to initiate infection, even though they contain infective DNA. Also, mutants in at least one spike gene fail to make the serum-blocking power antigen under

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Two RNA polymerases have been purified from the slime mold Physarum polycephalum, one sensitive and one resistant to a-amanitin. Both enzymes are more active with denatured DNA than native DNA as a template and prefer Mn++ rather than Mg++ as a divalent cation. The a-amanitin-sensitive enzyme shows maximum activity at 0.15 M KCI, whereas the resistant enzyme is most active at very low ionic strength. Analysis of the resistant enzyme on polyacrylamide gels containing sodium dodecyl sulfate shows two subunits present in a 1:1 ratio with molecular weights of 205,000 and 125,000.By now, multiple species of RNA polymerase have been isolated from a number of eukaryotes (1-5), including simple ones such as yeast and slime molds. The enzymes from a particular organism or tissue generally differ in the salt concentration at which they elute from DEAE-cellulose columns, their sensitivity to the mushroom toxin a-amanitin, and the ionic strength and divalent cation required for maximum activity. RNA polymerase I, which is not inhibited by aamanitin, is localized in the nucleolus and is generally believed to be responsible for ribosomal RNA synthesis. Polymerase II, on the other hand, is completely inhibited by small amounts of a-amanitin and is localized in the nucleoplasm. Some organisms have a third RNA polymerase, which is also localized in nucleoplasm but insensitive to a-amanitin (6). In this report we will describe the purification and some of the properties of two RNA polymerases from the plasmodial stage of the slime mold Physarum polycephalum. METHODSOrganism. Physarum polycephalum, strain M3c, was obtained from Dr. Joyce Mohberg and grown either as microplasmodia shaken in liquid medium or as macroplasmodia on filter paper in rocker pans (7). In either case, it is necessary to harvest cells in early logarithmic phase in order to obtain maximum RNA polymerase activity.Nuclei were prepared according to Procedure B of Mohberg and Rusch (8), with MgCl2 in the homogenizing medium and omission of the final wash. They were resuspended in an equal volume of 50%O glycerol in 0.05 M Tris (pH 7.9)-5 mM MgCl2-0.1 mM EDTA-1 mM dithiothreitol and stored at -80°until use. Nucleoli were prepared as described in this same reference. All operations were performed at 0-4'.Enzyme Assay. The standard RNA polymerase assay contained, in 0.2 ml, 0.05 M Tris, pH 7.9, 0.075 mg/ml of heatdenatured calf-thymus DNA (Worthington), 0.6 mM each ATP, CTP, and GTP (P-L Biochemicals), 2 ,Ci of [8H]UTP, 27 Ci/mmol (New England Nuclear Corp.), 40 sg/ml of pyruvate kinase (Calbiochem), 2.5 mM phosphoenol pyruvate, 1 mM dithiothreitol, 1 mM MnCl2, and 0.1 M KCl. The UTP concentration in the assay was only 0.4 uM in order to increase the sensitivity of the assay by maintaining a high specific activity. The reaction mixture was incubated for 30 min at 30°, chilled, and precipitated with 5% trichloroacetic acid containing 5 mM sodium pyrophosphate. The precipitate was collected on a glass-fiber filter, washed with 2% trichloroacetic acid, dried, a...

The workshop was chaired by Jackie Landman and attended by about forty people. Its purpose was to report on the current activities of the Developing Countries Affairs section of the International Committee (ICONS) including the status of the Information Sheets and the support given to overseas members. Alan Jackson reported that the question of possible duplication between ICONS and the new International and Public Health Nutrition Group is being kept under review. For the moment both will continue as they are support and academic groups respectively. Alan also explained that the Nutrition Society is related to the International Union of Nutritional Sciences (IUNS) through the International Committee of the Royal Society. Alan, as Chair of ICONS, sits on this Committee. The Royal Society pays a contribution to IUNS on behalf of the UK's nutritional sciences and is considering reducing this. A reduced contribution would mean that the UK would be in a lower category of IUNS. Council has agreed to supplement the contribution if necessary in order to maintain our status, although Alan wondered whether this would be good value for money. There was considerable disquiet among European delegates to the IUNS 1993 Adelaide Conference about the longevity of membership of the Council and Committees of IUNS. The procedure for changing members is slow, but the UK is now a member of the nominating committee. An offer by ICONS to IUNS to assist in increasing the impact of IUNS has not so far been taken up. Philip James suggested that the Nutrition Society, through the Federation of Nutrition Societies (FENS) network, make an analytical assessment of IUNS and concrete proposals for change. John Waterlow remarked that similar dissatisfaction had been voiced at the 1989 IUNS Conference in Korea but nothing had happened. Barrie Margetts reported that Council has agreed the conditions under which overseas Nutrition Societies can affiliate with the Nutrition Society and that application forms are available from the Executive Secretary. The Nutrition Association of Kenya has become the first affiliated society and other societies have expressed interest. ICONS currently has funds to assist societies with the affiliation fee. It was suggested that the opportunity for affiliation be publicized in publications which are read overseas. Ann Burgess reported on the progress of the Information Sheets since the last workshop. Sheet 1 (Low cost newsletters) has been published in Food and Nutrition Bulletin (1994) 15,92-94 and is now being brought up to date. The Sheets (nos. 2 and 3)

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The workshop was chaired by Barrie Margetts and attended by about twenty people. The purpose was to share information about the International Committee of The Nutrition Society (ICONS) and the progress of the Information Sheets, and to discuss other ways of supporting overseas members. Barrie outlined the structure and role of ICONS which has taken over the functions of the Task Force on Overseas Members. The Chairman is Alan Jackson who sits on Council and who represents Council on the International Relations Committee of the Royal Society, the United Kingdom body on the International Union of Nutritional Sciences. The role of ICONS is to deal with the international affairs of The Nutrition Society and it has two main areas of responsibility, namely European Affairs and Developing Country Affairs. Under the latter, the following activities are taking place: (1) organizing workshops, symposia, etc. at Nutrition Society meetings; this is facilitated through the ICONS member on the Programmes Committee, Barrie Margetts. (2) exploring the feasibility of starting a Group on International Nutrition, for which Catherine Geissler has responsibility. (3) providing information for overseas members. At present this is being done through a series of Information Sheets which are coordinated by Ann Burgess.