ETHYLENE OXIDE STERILIZATION OF TISSUE CULTURE MEDIA

Liquid ethylene oxide, which kills bacteria, yeasts, and molds, was added to a tissue culture medium instead of the usual antibiotics. With some limitations, the use of ethylene oxide sterilization of tissue culture medium has been shown feasible. Data indicate that this method can be used in experiments involving the sterilization of test chemicals and components of the medium used for mammalian cells in culture.     

Spatial analysis of forage parameters using geographic information system and image-analysis techniques

In efficient agricultural systems high production and high quality is expected throughout the year, but spatial and seasonal variation of biophysical variables can have a significant impact on the yield and quality of production. The yield and quality component of a forage field was monitored using statistical and Geographical Information System (GIS) techniques. The display of yield and forage quality in a spatial context proved to be very useful to the farmer since it allowed him to determine where in the field he obtained the best and worst production and whether such performance was consistent over the entire growing season. GIS is considered a new management tool that allows the spatial evaluation and presentation of production information in a new and innovative manner. Examples are provided to assist farmers in production accounting, to determine cause and effect relationships between management and production, to forecast production and to modify management to account for differences within the field.     

Tarichatoxin: isolation and purification

The potent neurotoxin occurring in the embryos of the California newt, Taricha torosa, has been obtained in crystalline form. With a lethal subcutaneous dose of approximately 0.14 micrograms for a 20-gram mouse, it is, along with saxitoxin and tetrodotoxin, one of the most toxic nonprotein substances known.     

Frost action in clay soils. I. A temperature-step and equilibrate differential scanning calorimeter technique for unfrozen water content determinations below 0°C

A modified differential scanning calorimeter procedure was used to determine the relationship between temperature and unfrozen water content (UWC) in seven clays between 0°C and – 15°C to – 24°C. The procedure, which involved nucleation by a cooling followed by a rapid warming to – 0.l°C, avoided the difficulty of supercooling. Problems caused by temperature lag between the sample and its holder and by slowness of water movement within the sample, important even when cooling clay samples of about 17 mm³ at a rate of 0.31 K min^?1, were overcome by cooling in a stepwise fashion which allowed time for equilibration between each temperature step. The clays studied included sodium and calcium Wyoming bentonites, < 1 μm and 1–2 pm fractions of St Austell kaolinite and three subsoil clays from England. After nucleation and as temperature fell below OT, water froze in two stages in most of the clays. UWCs at the minimum temperatures reached were up to 38% for the bentonites, between 9% and 20% for the subsoil clays and <4% for the kaolinites.     

Frost action in clay soils. II. Ice and water location and suction of unfrozen water in clays below 0°C

The relation between temperature, unfrozen water content (UWC) and shrinkage of a number of clays, and the distribution of ice and water within the clays, was studied. The clays included sodium and calcium Wyoming bentonites, < 1 μm and 1–2 μm kaolinite and three English subsoil clays. On freezing blocks of these clays (initial size up to approximately 1 cm³) over a period of months, they shrank progressively with reduction in temperature studied except for the < 1 μm and 1–2 μm kaolinites, which ceased shrinking at – 0.24°C and – 0.73°C respectively. During shrinkage, the water in the clay blocks migrated to freeze outside the blocks where ice was already nucleated. After equilibration for a month at – 0.19°C and at – 0.73°C, the water contents of the finer clays, excluding ice bands, equalled the UWCs measured previously using a differential scanning calorimeter. Two stages of ice formation were apparent in the curves of UWC vs temperature and were attributed to the different locations of the ice in the clays. Initially, ice formed in bands outside the clay matrix, accompanied by clay shrinkage (Stage 1). After a shrinkage limit had been reached ice began to form within the pores of the clay (Stage 2). Comparisons of the results of these freezing experiments with conventional moisture-release curves showed that the suction of the unfrozen water in clays was, within experimental error, as predicted by the Schofield equation. Results are also discussed in terms of ice-water and air-water interfacial tensions.     

COUNTER DIFFUSION OF Rb86 AND Sr89 IN COMPACTED SOIL

Counter-diffusion coefficients of Rb⁸⁶ and Sr⁸⁹ counter diffusing against H⁺ ions were measured in Dundee silt loam and Sharkey clay soils at differing soil bulk-densities. The cation exchange complex of each soil was saturated with either Rb⁺, Sr⁺⁺, or H⁺ and washed free of salts before making diffusion measurements. The water content of the soil on an oven-dry weight basis was maintained at a constant value for all bulk-densities; 14.2 and 28.0 per cent for the Dundee and Sharkey soils respectively. These moisture contents correspond to a tension of 2/3 bar for sieved soil. The diffusion coefficients were dependent upon concentration. Average counter-diffusion coefficients were calculated and related to soil bulk-density. Soil compaction of Dundee silt loam had little or no effect upon the counter diffusion of Rb⁸⁶. The average counter-diffusion coefficients of Sr⁸⁹ in Dundee silt loam and Sharkey clay were significantly and linearly related to bulk-density; as bulk-density increased the average counter-diffusion coefficients increased. The average counter-diffusion coefficients were approximately 0.5–0.75 of the corresponding self-diffusion coefficients measured previously in these soils. The applicability of counter- and self-diffusion data to practical field problems are discussed.     

Heritability of epileptic seizures in the Belgian tervueren

Survey data were collected on the Incidence of epileptic seizures In 997 Belgian tervuerens. The herltabllity of this disorder was estimated as 0–77 (with a 95 per cent confidence Interval spanning from 0–65 to 0–88) using a Bayesian analysis In an ordered categorical threshold model. Single locus models do not appear adequate as an explanation for this Inherited seizure disorder. The high heritabllity estimate suggests that breeders can wage a successful battle against this disorder by breeding unaffected Individuals, particularly those from familles with no history of seizures.     

Renewing Canada's Manufacturing Economy: A Regional Comparison, 1973‐1996

ABSTRACT Regional economies are continually undergoing adjustment as their firm populations react to changing tastes, technologies, and the challenges of outside competition. Adjustment typically takes place as the stock of jobs is renewed in each industry. This micro‐dynamic process of renewal has a substantial impact on the structure of national and regional economies. The primary objective of this paper is to measure the degree of renewal within the Canadian manufacturing economy as whole and within individual provinces. Using a longitudinal micro‐data set—which covers the population of manufacturing plants in Canada from 1973 to 1996—the study shows that the manufacturing sector experienced considerable job renewal. Two‐thirds of jobs in 1996 were newly created since 1973. There was considerable variation in provincial renewal rates. A decomposition analysis suggests this variation is not purely an artifact of the types of industries found in provinces, but reflects other characteristics of provincial economies.     

Shadow Europe: Alternative European Financial Geographies

ABSTRACT This paper sets out to trace some major points of convergence between an emerging literature on the political geographies of corruption¹ and current attempts to develop a renewed research agenda in the geographies of global finance—in this case in a specifically European context. In particular, we offer some preliminary observations on the need to elaborate an alternative geography of Europe's financial architecture that could incorporate the role of flows of illegal and informal finance as major driving forces behind the way in which that architecture currently constitutes itself. This is an inherently complex task due to the intrinsically hidden nature of these flows and the difficulties involved in their accurate measurement; nevertheless, they are too important to be ignored, as is too frequently the case at present. In the paper we offer some necessarily preliminary, and deliberately provocative, reflections on how to take forward such a re‐conceptualisation. Ultimately, our analysis revolves around the identification of an uneasy tension between the demand for deregulated financial markets and the increasing integration of those markets, and the international momentum towards finding ways of dealing with the (apparently) ever‐increasing problems of corruption, money laundering, and the financing of terrorism through new forms of financial regulation and control.