THE ECONOMICS OF DISEASE AND ITS CONTROL

The beneficial effects which can arise from disease control and eradication are described. The point is made that many diseases are zoonotic and the fringe benefits arising from the eradication of such diseases as tuberculosis and brucellosis are discussed. Examples are chosen from parasitological diseases to show that eradication is impossible with many of them and that many factors have to be considered before embarking on a control programme which might be uneconomic. Bovine mastitis is singled out as the most important cause of loss to the dairy industry and the cost and benefits of mastitis control are described. The point is made that disease control opens the way for animals to reach a high potential provided advantage is taken of the disease free situation.     

The Nutrient Composition of Fresh Fiddlehead Greens

Fiddlehead greens of the ostrich fern, Matteuccia struthiopteris, var. Penn., from two separate locations were analyzed for their nutrlent composition. Greens contained (in %) 87 water, 1.12 fiber, 4.23 crude protein, 4.02 ash, 3.06 carbohydrate and 0.5 fat. The fatty acid composition consisted mostly of palmitate, linoleate and linolenate. Unsaturated fatty acids account for approximately 65% of the fatty acids associated with fiddlehead lipids. Niacin, riboflavin, thiamin, vitamin C, and vitamin A were present at concentration ranges (based on wet weight) of 4.07–5.57, 0.15–0.24, 0.018–0.024, 19.00–32.69 mg/lOOg greens and 2175-2709 I.U./lOOg, respectively. Spectrochemical analysis identified 17 minerals with potassium, phosphorus, magnesium and calcium being the most prominent. The low sodium content (0.5 mg/lOOg greens) should be noted. The high potassium to sodium ratio could make fiddlehead greens an integral part of the diet of persons requiring low intakes of sodium.     

THE OPTIMAL DESIGN OF DRAINAGE SYSTEMS

This paper derives from a research project investigating the systematic use of formal optimization techniques in computer aided building design. A comprehensive model of drainage design suitable for optimization is developed. After limited success with a very powerful general purpose optimization program based upon the Geometric Programming technique, a problem dependent algorithm is developed based upon Dynamic Programming. The latter technique is shown in actual designs to produce optimal drainage designs simply and cheaply.     

Cyclic voltammetry and potentiodynamic polarization studies of chalcopyrite concentrate in glycine medium

Cyclic voltammetry and potentiodynamic polarization analyses were utilized to investigate the mechanism and kinetics of glycine leaching reactions for chalcopyrite. The effects of pH (9–12), temperature (30–90 °C) and glycine concentration (0–2 mol/L) on corrosion current density, corrosion potential and cyclic voltammograms were investigated using chalcopyrite concentrate–carbon paste electrodes. Results showed that an increase in the glycine concentration from 0 to 2 mol/L led to an increased oxidation peak current density. Under the same conditions, corrosion current density was found to change from approximately 28 to 89 μA/cm^bwhereas corrosion potential was decreased from –80 to –130 mV. Elevated temperatures enhanced the measured current densities up to 60 °C; however, above this level, current density was observed to decrease. A similar current density behavior was determined with pH. A pH change from 9 to 10.5 resulted in an increase in current density and pH higher than 10.5 gave rise to a reduced current density. In addition, the thermodynamic stability of copper and iron oxides was found to increase at higher temperatures.     

THE EFFECT OF ULTRAVIOLET IRRADIATION ON SHELF-LIFE AND RIPENING OF PEACHES AND APPLES

“Loring” and “Elberta” peaches and “Golden Delicious” apples were irradiated with UV (254nm) to doses of 0.84 × 10⁴ to 40 × 10⁴ erg/mm² then stored. “Loring” were stored 10 days and “Elberta” 20 days at 12°C. “Golden Delicious” were stored 30 days at 20–25°C in a dark room. Fruit were examined and differences in percentage rot and in physical-chemical properties determined. Percentage rot decreased with increasing UV dose. Fruit were firmer, pH and soluble solids lower and acidity higher for UV-treated than for nontreated peaches; pH was lower and acidity and ascorbic acid higher in UV treated than in nontreated apples. Percentage weight loss was less for UV-treated apples. The results indicated that UV treatment not only reduced storage rots but also delayed ripening of peaches and apples.     

Amino Acids in the American Groundnut (Apios americana)

The amino acid composition of groundnut (Apios americana Medikus) was analyzed using ion-exchange column chromatography. Aspartic and glutamic acids were the predominant amino acids in both seeds and tubers. Other amino acids present in significant quantities were leucine, histidine and proline. The most abundant free amino acids, other than aspartic and glutamic acids, were arginine and leucine in the seeds and histidine and serine in the tubers.     

Evaluation of Heated Frying Oils Containing Added Fatty Acids

Frying oils (corn, lightly and highly hydrogenated soybean and tallow) were heated 24 hr at 200°C and acid value and percentage polar compounds measured. Fatty acids (stearic, oleic and linoleic) were added to the oils at 1 and 5% levels to determine their effect on oil quality. Corn oil formed acidic and polar compounds at faster rates than the other oils. With 5% fatty acids added, acid value decreased because acidic compounds evaporated faster than they were formed. Polar compound formation generally increased with fatty acid addition in corn oil and lightly hydrogenated soybean oil and decreased in highly hydrogenated soybean oil and tallow.