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The relationships between two lipophilic pterocarpanoid phytoalexins, phaseollin and phaseollidin, were studied. Concentrations of these two compounds in infection-droplets were influenced by host cultivar, fungal species and length of incubation phase. In most experiments with the host cultivar Red Kidney Selection W245, phaseollin was the major component. The addition of cycloheximide and several other metabolic inhibitors to conidial inoculum and to monilicolin A solutions markedly altered the normal phaseollin/phaseollidin relationship. Two newly observed phenolic compounds were detected in diffusate solutions and in extracts from in vitro studies. These compounds were isolated and shown to be C20H18O5 and C20H20O5 and appear to be fungal hydroxylation products of phaseollin and phaseollidin respectively. The dynamic nature of the relationships between phaseollin and phaseollidin and the importance of evaluating, in quantitative terms, both the chemical concentrations and the biological activity of individual antifungal compounds in multicomponent phytoalexin systems is discussed.

A comparison is reported of fineness results obtained for 27 lots of scoured wool by the projection-microscope and air-flow methods. The sampling of the scoured wool was done by core-boring, and the cores were hand-carded before air-flow tests were made. The sub-samples for projection-microscope measurement were cut into snippets 1 mm long in order to obtain a length-biassed sample. The air-flow apparatus was calibrated with reference tops in five different forms. The results show that there exists a systematic difference between the air-flow and projection-microscope mean diameters of scoured wool when the air-flow instrument is calibrated with reference tops in the original state. A better agreement results by hand-carding the test samples of the reference tops, but the closest agreement is obtained by cutting, washing, and hand-carding these test samples so that their condition is similar to that of the core sample being tested. Provided that this kind of calibration were applied, the mean diameter of ...

The antifungal activity towards Monilinia fructicola of some naturally occurring pterocarpans and a number of related compounds obtained by substitution, degradation and partial synthesis has been examined. Compounds that were effective as antifungal agents had ED 50 values around 2 × 10 −5 M. A structure-activity relationship is proposed.

In studies where regular analyses of sow's milk are being made in an effort to evaluate the total energy content of the milk from sows at different dietary levels, once the composition trends of the milk have been assessed, the number of analyses can be considerably reduced and a greater number of samples handled. Satisfactory calorific values can be obtained from the estimated composition requiring analyses for fat and total solids only.

An extraction-titration method is described for the determination of free fatty acids in small samples of fresh milk.Recoveries of fatty acids added to milk ranged from 63% for butyric acid to 97% for stearic acid. For a composite sample approximating milk fat in fatty acid composition the recovery was 83%.Interference from citric and lactic acids was not significant for reasonably fresh samples.The method gives a higher recovery of the lower molecular weight fatty acids than is possible by earlier methods.For titrating very dilute solutions of fatty acids α-naphtholphthalein was shown to be a more accurate indicator than phenolphthalein; it also provides a better defined endpoint.

1. Improvements are described in the methods for the extraction and colorimetric estimation of metals in dairy produce, using the carbamate reagent for copper and thiocyanate for iron.2. A combined filtration procedure has been developed to enable both metals to be determined on the same sample, and with slight modifications this procedure has been applied to the analysis of samples of butter, cream, buttermilk and whey.3. The wet-ashing technique has also been improved to enable it to be used for the estimation of both metals on the same digest.4. Comparisons show that the combined filtration method is capable of giving results which agree very well with those yielded by wet-ashing.5. The results of many analyses show that the majority of creamery butter samples have a satisfactorily low content of both copper and iron.6. Many whey butter samples have a rather high metallic content.7. Notes are given on the results obtained when the methods described are applied to other dairy produce.

1. The composition has been studied of the milk of forty-four sows in the course of sixty-eight lactations. The milk was obtained by machine milking following intravenous injection of oxytocin.2. Definite lactational trends have been observed for all the major constituents, and the third week seems a critical stage for most of the milk components.3. The mean values for the milk, based on the analyses of over 450 samples from the seventh to fifty-sixth day of the lactation were: fat 9·58 %, protein 6·11 %, lactose 4·62 %, ash 0·92%. Such figures are considered to be rather meaningless for most practical purposes, in view of the marked changes over the course of lactation.4. The day-to-day variation in the composition of sow's milk has been studied. Whereas the fat value changes considerably, the non-fat constituents show a less marked variation. Difficulties in securing a representative sample of the weekly milk have been overcome by preparing a composite sample from three milMngs within the week.5. Some preliminary work has been done on variation in the composition during the process of milking. Sequential samples show an erratic fat content, especially during the early part of the lactation. When calculated on a fat-free basis, the protein, lactose and ash contents are relatively constant during the process of milking.

The air-flow technique for the measurement of wool-fibre fineness has advantages over other methods because of its speed and convenience of testing. However, if the wool being tested is in the form of washed corings from greasy bales or corings from scoured bales rather than tops, the sample may contain impurities such as vegetable matter or sand and dust, and, although it is possible for such impurities to be removed, the treatment requires time and the continuous attention and judgement of a trained operator. The effect of the presence of impurities on the indicated mean diameter of wool fibres is therefore a matter of some importance, and an account is given in this paper of an investigation undertaken to study this effect. The theoretical basis of the influence of impurities on the indicated diameter is given, and it is shown that the experimental results are, in general, in agreement with the predicted values. Provided that the amount of vegetable matter present does not exceed 5% and coarse, sandy d...

1. Detailed analyses for the major constituents of the colostrum and milk of four sows are reported. In all cases the initial colostrum is characterized by a very high protein, and a low lactose and fat content. As with the colostrum of other species, the transition to milk occurs progressively during the course of about 4–7 days.2. Analyses for mineral constituents, calcium, magnesium, phosphorus and chloride are reported on a range of samples covering the whole lactation of two sows. In contrast to the ash of the colostrum of most other species, the ash of the colostrum of the sow is lower than that of normal milk, and as lactation is established there is a rise in the total ash content, and in its main constituents, calcium and phosphorus.

The isolation and partial characterization of a polypeptide (mol.wt. ca 8,000) designated as monilicolin A is reported from mycelium of Monilinia fructicola . Monilicolin A is a sulphur-containing, highly water soluble peptide with ca 65 amino acid residues. No evidence for the presence of non amino acid groups was obtained. Monilicolin A is active as a phytoalexin-inducing agent at very low concentrations (ED50 = 8 × 10−9 M). Its action appears to be specific for phaseollin-induction in as far as it has been assayed at present. It is neither phytotoxic nor fungitoxic. The use of monilicolin A in studies on the induction of phaseollin biosynthesis is briefly discussed.

The gross energy content of the milk of the cow, sow, ewe, goat and of human milk has been determined by bomb calorimeter, and compared with results obtained using conversion factors and chemical analysis.Correction for non-protein nitrogen content led to values agreeing within 0·5–1·0% for the milk of all species. For human colostrum other factors may be involved, and a closer estimate of gross energy value of human milk was obtained by treating all nitrogenous constituents as being protein.

1. The composition of the milk of six low-plane and six high-plane ewes has been studied. Definite lactational trends have been observed for all the major constituents.2. For all the ewes the initial colostrum was characterized by very high protein and fat contents and by low lactose content.3. Analyses of the mineral constituents—calcium, magnesium, sodium, potassium, phosphorus, and chloride—are reported covering the whole lactation of twelve sheep. The colostrum of the low-plane animals was higher in total mineral content than that of the high-plane animals.The author wishes to thank Mr L. J. Lambourne for providing the milk samples and Mr J. E. Allen for the spectographic analyses.

Invasive alien species (IAS) cause major environmental and economic damage worldwide, and also threaten human food security and health. The impacts of IAS are expected to rise with continued globalization, land use modification, and climate change. Developing effective strategies to deal with IAS requires a collaborative, interdisciplinary approach, in which scientists work co-operatively with social scientists and policy-makers. Higher education can contribute to this process by training professionals to balance the ecological, economic, and social dimensions of the IAS problem. We examined the extent of such training in Canada by reviewing undergraduate and graduate university curricula at all 94 member institutions of the Association of Universities and Colleges of Canada for IAS content. We found that degree and diploma programs focusing on IAS issues are lacking at Canadian post-secondary institutions. Furthermore, few courses are devoted solely to IAS, and those that are typically adopt an ecological perspective. We argue that the absence of interdisciplinary university curricula on IAS in Canada negatively affects our ability to respond to this growing global challenge. We present several international educational programs on IAS as case studies on how to better integrate training on invasive species into university curricula in Canada. RESUME Les especes exotiques envahissantes (EEE) sont a l’origine d’importants dommages ecologiques et economiques partout dans le monde, en plus de menacer la securite alimentaire et la sante humaine. On s’attend a ce que leurs eff ets prennent de l’ampleur devant la poursuite de la mondialisation, l’evolution de l’utilisation des sols et les changements climatiques. L’elaboration de strategies efficaces pour contrer les EEE exige une approche cooperative et interdisciplinaire, par laquelle des scientifiques travaillent en collaboration avec des specialists en sciences sociales et des responsables de l’elaboration de politiques. L’enseignement superieur peut y contribuer en formant des professionnels a trouver un equilibre entre les dimensions ecologiques, economiques et sociales du probleme des EEE. Nous avons etudie la portee d’une telle formation au Canada en revisant les programmes d’etudes universitaires des premier et second cycles de chacun des 94 etablissements membres de l’Association des universites et colleges du Canada. Nous en avons conclu que les programmes menant a un grade ou a un diplome et ciblant les problemes lies aux EEE font defaut aux etablissements postsecondaires canadiens. En outre, peu de cours se concentrent uniquement sur les EEE, et ceux qui le font adoptent habituellement une approche ecologique. Nous faisons valoir que le manque de programmes universitaires interdisciplinaires portant sur les EEE au Canada entrave notre capacite a aff ronter ce defi mondial croissant. Nous presentons plusieurs programmes educatifs internationaux sur les EEE, a titre d’etudes de cas pour mieux integrer la formation sur les especes envahissantes aux programmes universitaires du Canada.

In a study of the effect of some further biological, physical, and chemical factors on the formation of pisatin, the following points were demonstrated: (1) Pisatin formation following heat treatment (45°C) or anaerobic storage was dependent on the duration of the exposure period. Delayed inoculation, following some treatments, resulted in an increased capacity of the host to form pisatin. Pisatin concentration and host susceptibility were inversely related. (2) Pisatin formation was stimulated by several saprophytic fungal species. (3) Detached pea pod tissues retained their capacity to form or release pisatin for 20 days following inoculation. (4) Pisatin was stable in the tissues of Pisum sativum and mycelium of Ascochyta pisi. (5) Pisatin was localized in inoculated tissues and did not diffuse to neighbouring healthy tissues. The formation of pisatin in relation to alterations in host metabolism is briefly discussed.

The relationship between phase of normal respiration and reaction time (RT) was studied. Ss were required to respond by pressing a switch each time a simple auditory signal was presented. Averages of response times were calculated for signals occurring during each of three identifiable phases of normal respiration. It was found that mean RT for signals presented during the inhalation phase of respiration was significantly less than for signals presented during either the exhalation phase or the pause between exhalation and inhalation.

It has been shown that human milk, like cow's milk, increases in fat content during suckling. The increase is not associated with any systematic change in fat globule size distribution. Human milk fat globules, like those of the cow, have been shown to cluster at body temperature. These facts support the theory that the increase in fat content during suckling is due to the fine ducts filtering out the larger globule clusters.

THE presence of an antifungal ‘principle (or principles)’ produced by pods of Phaseolus vulgaris L. in response to infections with Sclerotinia fructicola (Wint.) Rhem. has been demonstrated on the basis of biological assays by Muller1,2. We now report the isolation of an antifungal compound produced in similar hypersensitivity studies using pods of Pisum sativum L., and describe some of its chemical, physical and biological properties.

IT is obvious that plants are resistant to attack by fungi that are non-pathogenic to them. However, until recently, the mechanism of this resistance has been obscure. Pisatin, a substance believed to be responsible for such resistance in the garden pea (Pisum sativum L.), has been recently isolated from pea pods inoculated with fungal spores1.

The qualitative formation of pisatin by 58 named cultivars and nine numbered lines of P. sativum andP. arvense and three other species of Pi.mm following inoculation by Moitilinia fructioola was established.