RELATION OF SEVERAL PEDOLOGICAL CHARACTERISTICS TO ENGINEERING QUALITIES OF SOIL

An attempt to predict engineering qualities which are needed in soil evaluation and to enhance nonagricultural use of soil survey data was made. Data from a variety of soils were subjected to simple correlation and multiple regression analyses to relate three pedologic characteristics: clay content, cation-exchange capacity (CEC), and organic matter content to two engineering qualitites: plasticity index, and optimum moisture. Simple correlation coefficients showed that clay content and CEC correlated significantly with the engineering determinations. The relationship between organic matter content and these engineering determinations was weaker. Multiple regression analyses showed that the three pedologic characteristics accounted for most of the variation in each of the engineering qualities, and that prediction was feasible.     

Electrophoretic evidence of the integrity of humic substances separated by means of electrofocusing

The alkaline extracts of an andic soil, a Bhir horizon of a spodic soil and leonardite which, after electrofocusing, displayed bands in the neutral region of the pH gradient, were fractionated by electrophoresis in phosphate buffer at pH 6.5. The non-migrated fraction gave an electrofocusing profile containing only bands focused at pH values above that of the electrophoretic separation. Electrophoresis in sodium acetate buffer pH 4.8 of humic substances extracted from peat permitted isolation of bands focusing above pH4.8. The distribution of metals after electrophoresis suggests that a great part of humic substances which originate bands above pH 6.5 consists of negatively charged Fe and Al complexes. Addition of EDTA to solutions of humic substances extracted from the samples resulted in the disappearance of bands in the neutral region of the pH gradient in the electrofocusing profile of the Bhir sample, while a consistent lessening of these bands was observed in the leonardite and andic soil samples.     

ADSORPTION OF PHOSPHATE BY VARIOUS OXIDES: THEORETICAL TREATMENT OF THE ADSORPTION ENVELOPE

An explanation is put forward for the shape of adsorption envelopes found for phosphate adsorption by various metallic oxides. The equation x_m= C₁ (μH₃PO⁴⁺μ∑anions) is proposed, where μH₃pO₄ is the chemical potential of undissociated H₃PO₄; μ∑anions is the chemical potential of all phosphate anions considered as one. component; C₁ is a constant that includes influences of surface charge, chemical affinity of the metal for phosphate, specific surface area, etc., and x_mis the calculated Langmuir maximum adsorption of P at each pH. The dependence of C₁ on the metal present in the oxide is shown.     

Kinetic and stoichiometric assessment of the antioxidant activity of flavonoids by electron spin resonance spectroscopy

There is current interest in the use of naturally occurring flavonoids as antioxidants for the preservation of foods and the prevention of diseases such as atherosclerosis and cancers. To establish the molecular characteristics required for maximum antioxidant activity, electron spin resonance (ESR) spectroscopy has been used to determine the stoichiometry and kinetics of the hydrogen-donating ability of 15 flavonoids and d-alpha-tocopherol to galvinoxyl, a resonance-stabilized, sterically protected aryloxyl radical. The second-order reaction rates, which will be governed by O-H bond dissociation energies, were myricetin > morin > quercetin > fisetin approximately catechin > kaempferol approximately luteolin > rutin > d-alpha-tocopherol > taxifolin > tamarixetin > myricetin 3',4',5'-trimethyl ether > datiscetin > galangin > hesperitin approximately apigenin. Reactivity is highly dependant on the configuration of OH groups on the flavonoid B and C rings, there being little contribution from the A ring to antioxidant effectiveness. Highest reaction rates and stoichiometries were observed with flavonols capable of being oxidized to orthoquinones or extended paraquinones. However, rates and stoichiometries did not always correlate and the data suggest that kinetic factors may be of greater importance within a biological context.     

A Case of Bovine Linear Keratosis

Résumé— Cet article décrit un cas de nevus épidermique linéaire unilatéral chez un veau de six mois. Histologiquement, les lésions consistaient en une alternance de zones d'hiper et de parakératose avec une inflammation dermique distincte. Le diagnostic de nevus linéaire inflammatoire a été posé sur la base des lésions macro et microscopiques. [Deprez, P., De Coole, H., Sustronk, B., Muille, E., Ducatelle, R. A case of bovine linear keratosis (A propos d'un cas de kératose linéaire chez un bovin).
Resumen— En este artículo se describe un caso de nevos epidérmicos lineares unilaterales en un bo vino de seis meses de edad. Las lesiones histológicas consistian zonas donde se alternaba hiper i paraqueratosis, mientras que la dermis presentaba una marcada inflamación. Se diagnosticó un nevo epidérmico verrucoso linear e inflamatorio a partir de las lesiones clinicas e histopatológicas [A case of bovine linear keratosis (Un caso de queratosis linear bovina).
Abstract— This report describes a case of unilateral linear epidermal nevi in a 6-month-old bovine. Histologicalli, the lesions consisted of alternating areas of hiper- and parakeratosis with a distinct dermal inflammation. A diagnosis of inflammatori linear verrucous epidermal nevus was made based on the clinical and histopathological lesions.     

A genetic description of two selected strains of rabbits

Two strains of rabbits (strains 1077 and 2066) have been selected since 1974 for increased litter size. Each strain is split into a fixed number of reproduction groups. The mating scheme is similar to random non-sib herd mating. The number of animals per generation is higher in strain 1077 (28 mated bucks and 104 mated does) than in strain 2066 (17 and 59, respectively). The increase of the inbreeding coefficient is higher in strain 2066 than in strain 1077 (27 and 21%, respectively, at generation 20). The mean standard deviation of the individual inbreeding coefficients per generation is low (less than 4%) in both strains. Short-term inbreeding is stable over generations. The observed inbreeding effective size Ne _f and the observed familial structure effective size Ne _h converge to the same value. The number of founder genomes still present in the genetic pool of the generation decreases regularly: from 5.6 to 2.4 between G6 and G20 for strain 1077. It is a bit lower over time for strain 2066 (from 5.7 to 1.9 between G6 and G20). The effective number of founders is nearly twice as small as the total number: 30 for strain 1077 and 15 for strain 2066. The effective number of major ancestors decreases slightly in strain 1077 (13.6 in G6 and 12.9 in G20) and regularly in strain 2066 (13.8 in G6 and 9.4 in G20).     

Bioavailability and pharmacokinetics of phenylbutazone in the cow

Phenylbutazone was administered orally and intravenously at a dose of 5 mg/kg to healthy cows and to cows positive for bovine leukaemia virus (BLV). Pharmacokinetic parameters and bioavailability were investigated. No differences were seen in the parameters between the healthy and BLV positive animals. The biological half-lives ranged from 31.4 to 82.1 h after intravenous administration and from 38.6 to 78.2 h after oral administration. The mean value of the apparent volume of distribution was 0.09 litres/kg. Total body clearance ranged from 0.78 to 1.94 ml/kg/h. The average systemic availability was 67.5% with a wide variation among the animals (range 41.9–95.5%). Based on the disposition kinetics and on the therapeutic concentration range suggested in man, an oral loading dose ranging from 10 to 20 mg/kg and a daily maintenance dose ranging from 2.5 to 5 mg/kg can be proposed.