Effect of dalapon-sodium on nitrification and denitrification in a tropical loam soil

A loamy soil treated with dalapon-sodium was incubated under aerobic or anaerobic conditions with added ammonium or nitrate nitrogen respectively. The incubated dalapon-sodium treated soil and controls were analysed periodically for NH₄+N and NO₃^-N. Results indicated that the herbicide retarded nitrification and denitrification by up to 8 and 12 weeks respectively. Effet du dalapon-sodium sur la nitrification et la dénitrification dans un sol de limon tropical Un sol de limon traité avec du dalapon-sodium a été mis en incubation dans des conditions aérobies ou anaérobies avec addition d'azote ammoniacal ou nitrique respectivement. Le sol traité avec du dalapon-sodium et mis en incubation a été analysé périodiquement, ainsi que les témoins, pour NH₄^+N et NO₃^-N. Les résultats ont montré que l'herbicide retardait la nitrification et la dénitrification respectivement jusqu’à 8 et 12 semaines. Wirkung von Dalapon-Na auf Nitrifikation und Denitrifikation in einem tropischen Lehmboden Einem mit Dalapon-Na behandelten Lehmboden wurde Ammon- bzw. Nitratstickstoff zugesetzt und unter aeroben bzw. anaeroben Bedingungen gelagert. Der mit Dalapon-Na behandelte Boden und die entsprechenden Kontrollen wurden periodisch auf NH₄⁺- und NO₃^--Stickstoff untersucht. Die Ergebnisse zeigten, dass das Herbizid die Nitrifikation um bis zu 8 und die Denitrifikation bis zu 12 Wochcn verzögerte.     

Eye diseases in Siberian husky dogs

A full ophthalmic examination was performed on 40 Siberian husky dogs using direct and indirect ophthalmoscopy, gonloscopy and nasolacrimal cannulation. Eight (20%) of the dogs were found to have distichia, 10 (25%) had excessive medial caruncular hairs, 8 (20%) had absence, displacement, or narrowing of the nasolacrimal puncta, 2 (5%) had bilateral corneal crystalline opacities, and 2 (5%) had unilateral areas of lateral corneal lipidosis. Fifty percent of the dogs had some abnormality of the iridocorneal (drainage) angle. However, in only one of these was the deformity severe enough to require glaucoma prophylaxis. An association between blue iris colour and malformation of the iridocorneal angle was noted.     

"Coulomb Staircase" at Room Temperature in a Self-Assembled Molecular Nanostructure

Double-ended aryl dithiols [alpha,alpha'-xylyldithiol (XYL) and 4,4'-biphenyldithiol] formed self-assembled monolayers (SAMs) on gold(111) substrates and were used to tether nanometer-sized gold clusters deposited from a cluster beam. An ultrahigh-vacuum scanning tunneling microscope was used to image these nanostructures and to measure their current-voltage characteristics as a function of the separation between the probe tip and the metal cluster. At room temperature, when the tip was positioned over a cluster bonded to the XYL SAM, the current-voltage data showed "Coulomb staircase" behavior. These data are in good agreement with semiclassical predictions for correlated single-electron tunneling and permit estimation of the electrical resistance of a single XYL molecule (approximately18 ± 12 megohms).     

Vaccinia dermal infection and methylcholanthrene in cortisone-treated mice

Cortisone-treated mice were inoculated with vaccinia virus, and then five paintings of methylcholanthrene were applied over the site of inoculation. In 70 percent of the mice, tumors developed at the site of inoculation, and 35 percent of the mice, with and without skin tumors, also developed lymphomas. Identically treated control mice that were vacciniaimmune developed a significantly lower incidence (38 percent) of both skin tumors and lymphomas     

Radiographic and Histologic Changes After Thoracolumbar Disc Curettage

Forty-eight thoracolumbar disc spaces were approached by a dorsolateral muscle-separating technique in six mature dogs. Twenty-four of the discs were fenestrated and curetted, and the changes were followed radiographically and histologically for 16 weeks. Disc space collapse was visible radiographically immediately after the surgical procedure, and those disc spaces remained narrow throughout the observation period. Histologically, there was evidence of chondrocyte activation within 2 weeks in the excavated disc spaces. By 16 weeks, fibrocartilage had filled the void in the curetted disc spaces.     

Congenital hypothyroidism in Scottish Deerhound puppies

Two Scottish Deerhound puppies had clinical and pathological features consistent with the diagnosis of congenital non-goitrous hypothyroidism. They were from separate litters, but were the progeny of the same sire and dam. The puppies were smaller, had shorter limbs and shorter, broader heads than their littermates. They also had histories of weakness, difficulty in walking and somnolence. A characteristic radiographic feature was the absence of epiphyseal growth centres. Both had depressed serum thyroxine (T4) levels and one did not respond to exogenous thyroid stimulating hormone. On necropsy, the thyroid glands were small, the follicles varied in size and contained little or no colloid. The adenohypophysis contained many cells with markedly vacuolated cytoplasm. It is suggested that the clinicopathological pattern is the result of a primary thyroid abnormality. Possible mechanisms include either primary thyroid hypoplasia or an unresponsiveness to thyroid stimulating hormone.