Rotational Inerfia of Continents: A Proposed Link between Polar Wandering and Plate Tectonics

A mechanism is proposed whereby displacement between continents and the earth's pole of rotation (polar wandering) gives rise to latitudinal transport of continental plates (continental drift) because of their relatively greater rotational inertia. When extended to short-term polar wobble, the hypothesis predicts an energy change nearly equivalent to the seismic energy rate.     

Genesis of acetate and methane by gut bacteria of nutritionally diverse termites

The evolution of different feeding guilds in termites is paralleled by differences in the activity of their gut microbiota. In wood-feeding termites, carbon dioxide-reducing acetogenic bacteria were found to generally outprocess carbon dioxide-reducing methanogenic bacteria for reductant (presumably hydrogen) generated during microbial fermentation in the hindgut. By contrast, acetogenesis from hydrogen and carbon dioxide was of little significance in fungus-growing and soil-feeding termites, which evolved more methane than their wood- and grass-feeding counterparts. Given the large biomass of termites on the earth and especially in the tropics, these findings should help refine global estimates of carbon dioxide reduction in anoxic habitats and the contribution of termite emissions to atmospheric methane concentrations.     

Novel Colloidal Interactions in Anisotropic Fluids

Small water droplets dispersed in a nematic liquid crystal exhibit a novel class of colloidal interactions, arising from the orientational elastic energy of the anisotropic host fluid. These interactions include a short-range repulsion and a long-range dipolar attraction, and they lead to the formation of anisotropic chainlike structures by the colloidal particles. The repulsive interaction can lead to novel mechanisms for colloid stabilization.     

Comparison of HgO and CuSO4/TiO2 as catalysts in manual Kjeldahl digestion for determination of crude protein in animal feed: collaborative study

Because of environmental concerns about HgO, and because of lengthy digestion requirements for HgO and CuSO4, interest in alternative catalysts for the Kjeldahl determination of animal feeds remains high. A digestion system using a mixed CuSO4/TiO2 catalyst has been found to reduce digestion times to 40 min. A collaborative study was carried out to compare this system to the official AOAC HgO method, 7.015. Thirty-eight samples, consisting of blind duplicates of closely matched pairs and 2 standard materials, were analyzed once by each method. Results were received from 13 laboratories. Means and standard deviations of individual samples were comparable, with an overall difference of grand means of 0.005% protein. With only one exception, analyses of variance showed no significant method difference at the 95% confidence level. The CuSO4/TiO2 method has been approved interim official first action as an alternative method for determination of crude protein in animal feed.     

土壤对磷的吸附与解吸及需磷量探讨

本文探讨了不同质地土壤对磷的吸附与解吸。根据Langmuir方程式求出不同土壤对磷的最大吸附量。影响磷吸附的土壤理化性质主要为粘粒含量、碳酸盐含量和有效磷含量。以Freundhich方程式X=ac^b中的c值为每克土中含P0.2μg时而计算出的X量可做为施磷量的依据。     

Seroprevalence of leptospiral antibodies among dairy cattle kept in communal corrals in periurban areas of Bamako, Mali, West Africa

Sera obtained from dairy cattle in communal corral herds located near the city of Bamako in Mali, West Africa were sceeened using the microscopic agglutination test against 26 serovars representing 15 serogroups of Leptospira interrogans. Forty five percent (44.8%; 288/642) were positive to one or more serovars. This seroprevalence rate likely reflects infection since vaccination against leptospiral infection has not been practiced i Mali. The rate was higher among females. The most common titers were against antigens of serovars cynopteri (14.7%), hardjo (13.3%), pomona (9.2%), nona (8.1%), kambale (6.5%), grippotypyosa (6.4%), hebdomadis (6.2%), and pyrogenes (5.2%).