A study of the mechanical properties of egg shell

1. The mechanical behaviour of the egg shell of the domestic fowl was investigated by cutting strips from the shell and testing the flection either in a four‐point load test or in a cantilever beam test.

2. It was found that moisture content, temperature and load rate have important effects on shell properties ; both the strength and stiffness of the shell are greater in snapping‐inward tests than in snapping‐outward tests; residual stress exists in the egg shell; the correlation between failure moment and shell thickness was highly significant, on average about 0.9, and was dependent on the spread in the thickness data.

3. Estimates were made of the ultimate strength and Young's modulus of egg shell material and it is concluded that a substantial size effect exists in the egg shell.     

Lesions and pathogenesis of disease in young calves experimentally induced by a bovine adenovirus type 5 isolated from a calf with weak calf syndrome.

Lesions induced in each of 9 young colostrum-deprived calves closely resembled lesions seen in naturally occurring "weak calf syndrome" of eastern Idaho and southwestern Montana. The disease was experimentally induced by intravenous injection of bovine adenovirus type 5 that had been isolated from a calf with weak calf syndrome...     

Studies on effects of certain quinones: III. Photosynthetic 14CO2 incorporation by Rhodospirillum rubrum

Substituted naphthoquinones, 2,3,-dichloro-1,4-naphthoquinone, and 2-methyl-1,4-naphthoquinone produced marked changes in the pattern of ¹⁴C-distribution during ¹⁴CO₂-fixation by photosynthetic bacterium Rhodospirillum rubrum. The most obvious change in the labeling pattern during photoautotrophic ¹⁴CO₂-fixation was a several-fold increase in 3-phosphoglyceric acid accompanied with a decrease in the amount of glutamate. In photoheterotrophic cells, quinones caused an appreciable increase in ¹⁴C-glycolic acid and concomitant decrease, although not proportional, in the amount of ¹⁴C-sugar phosphate. The level of ¹⁴C-incorporated in poly-β-hydroxybutyrate and ether-extractable lipids was considerably decreased in photoautotrophic and photoheterotrophic cells treated with quinones. The ability of quinones to interfere with the synthesis of NADH and ATP, and their ability to interact with sulfhydryl enzymes and coenzymes appears to be responsible for the changes observed.     

Mercapturic acid formation in the metabolism of propachlor,CDAA, and fluorodifen in the rat

When [¹⁴C]F₃-fluorodifen (2,4′-dinitro-4-trifluoromethyl diphenylether), carbonyl-[¹⁴C]CDAA (N,N-diallyl-2-chloroacetamide), and carbonyl-¹⁴C-propachlor (2-chloro-N-isopropylacetanilide) were fed to rats, 57 to 86% of the ¹⁴C was excreted via the urine within 48 hr. Although very little radioactivity was excreted in the feces of CDAA-treated rats, 15–22% of the ¹⁴C was excreted in the feces of propachlor- of fluorodifentreated rats and an average of 8% of the ¹⁴C remained in these rats 48 hr after treatment. Oxidation of the ¹⁴C label to [¹⁴C]O₂ was not a major process in the metabolism of these herbicides. The only major radioactive metabolite present in the 24-h urine of fluorodifen-treated rats, 2-nitro-4-trifluoromethylphenyl mercapturic acid, accounted for 41% of the administered dose of ¹⁴C. In the metabolism of CDAA, the corresponding mercapturic acid accounted for 76% of the dose; it was the only major metabolite present in the 24-h urine. In contrast, three major metabolites were detected in the 24-h urine of propachlortreated rats, and the mercapturic acid accounted for only 20% of the dose. The mercapturic acid of each herbicide was identified by mass spectrometry.     

Antifungal mode of action of triforine

Rapidly growing mycelia of Aspergillus fumigatus treated with 10 μg/ml triforine (N,N′-bis-(1-formamido-2,2,2-trichloroethyl)-piperazine) showed little or no inhibition in dry weight increase prior to 2 h. By 2.5–3 h, triforine inhibited dry weight increase by 85%. The effects of triforine on protein, DNA, and RNA syntheses corresponded to the effect on dry weight increase both in time of onset and magnitude. Neither glucose nor acetate oxidation were inhibited by triforine.Ergosterol synthesis was almost completely inhibited by triforine even in the first hour after treatment. Inhibition of ergosterol synthesis was accompanied by an accumulation of the ergosterol precursors 24-methylenedihydrolanosterol, obtusifoliol, and 14α-methyl-Δ^{8, 24 (28)}-ergostadienol. Mycelia treated with 5 μg/ml of triarimol (α-(2,4-dichlorophenyl)-α-phenyl-5-pyrimidinemethanol) also accumulated the same sterols as well as a fourth sterol believed to be Δ^{5, 7}-ergostadienol.Identification of 4,4-dimethyl-Δ^{8, 24 (28)}-ergostadienol in untreated mycelia indicates that the C-14 methyl group is the first methyl group removed in the biosynthesis of ergosterol by A. fumigatus. The lack of detectable quantities of 4,4-dimethyl-Δ^{8, 24 (28)}-ergostadienol in triforine or triarimol-treated mycelia and the accumulation of C-14 methylated sterols in treated mycelia suggests that both fungicides inhibit sterol C-14 demethylation. The accumulation of Δ^{5, 7}-ergostadienol in triarimol-treated mycelia further implies that triarimol also inhibits the introduction of the sterol C-22(23) double bond.Two strains of Cladosporium cucumerinum tolerant to triforine and triarimol were also tolerant to the fungicide S-1358 (N-3-pyridyl-S-n-butyl-S′-p-t-butylbenzyl imidodithiocarbonate).     

Etude des phénomènes de sorption entre deux triazines herbicides et des acides humiques

A study of sorption phenomena between two triazine herbicides and humic acids Terbutryne is very readily adsorbed by humic acids while atrazine is only slightly adsorbed and this only in an acid environment. The influence of pH on adsorption and the competitive effect of the cations Ca²⁺, Al³⁺ and Fe³⁺ shows that the proton form of the molecules of the two herbicides can be adsorbed by an ion exchange-type mechanism; the neutral form of terbutryne molecules could be adsorbed by other mechanisms. Desorption of terbutryne is accompanied by a more marked hysteresis phenomenon in the case of neutral molecules, and, in an acid environment, calcium shows a weak capacity for displacement in relation lo the adsorbed herbicide.