Tartary buckwheat breeding (<Emphasis Type="Italic">Fagopyrum tataricum</Emphasis> L. Gaertn.) through hybridization with its Rice-Tartary type

Tartary buckwheat (Fagopyrum tataricum) is a highly nutritious crop that is widely grown in Asia, but the flour contains a large portion of the hull if it is ground with industrial processing since the hull is very hard to remove as it adheres to the testa layer of the groat. Rice-Tartary, a particular type of Tartary buckwheat, has seeds with a loose hull and the presence of splits on the sides of the seeds that make dehulling easily. The present study reports on the first attempt of crop improvement in Tartary buckwheat breeding through hybridization. Hybrids were obtained by hybridization of crosses between Tartary buckwheat and Rice-Tartary. Additional crosses were made among selected progenies of these crosses. Based on progeny analysis of the F₁, F₂, and F₃, the character of Rice-Tartary, as exhibited as the presence of splits on the sides of the seeds, is controlled by one gene which is homozygous recessive. A Tartary buckwheat breeding program has been conducted for 6 years based on these crosses. Advanced lines with easy dehull and yield potential are at the stage of ready for yield trials. Production of easy dehulling Tartary buckwheat in the future could boost Canada’s domestic and international markets.     

Adsorption—desorption and/or precipitation—dissolution processes of zinc in soils

The concentrations of trace and toxic metals in soil solutions are explained by several authors either in terms of adsorption—desorption or precipitation—dissolution reactions in soils. Data have been given for zinc to test the applicability of both concepts. The results show that the concentrations of zinc in equilibrium solutions with soil clay fractions and whole soil samples at pH values below 7 are determined exclusively by adsorption—desorption reactions for various pH's, contents of bound zinc and compositions of soils. At neutral to alkaline pH values precipitation—dissolution reactions of zinc may take place. There is some evidence that formation of zinc silicates may control the zinc concentration in solution provided natural complexing agents are absent, the affinity of the soil for zinc is low and the content of reaching zinc is high (> ～ 100 ppm). Even at pH values above 7, the formation of other zinc compounds is unlikely in most soils because additions of large amounts of zinc are required to ensure saturation of the adsorption sites of different soil components before the zinc concentration in the soil solution can increase sufficiently to bring about the precipitation of definite compounds. Model experiments in CaCO₃-buffered systems showed that the adsorption capacity for specifically adsorbed zinc (in μmole/g) by the following components increased in the order CaCO₃ (0.44), bentonite (44), humic acid (842), amorphous Fe- and Al-oxides (1190, 1310) and δ -MnO₂ (1540) and demonstrated the importance of Mn-, Fe-, and Al-oxides and humic substances for the binding of zinc in soils containing carbonates, and thus indicate the special role of these components in limiting precipitation reactions.     

A potential second messenger role for unsaturated fatty acids: activation of Ca2+-dependent protein kinase

Arachidonate and other unsaturated long-chain fatty acids were found to activate protein kinase C from human neutrophils. Kinase activation by arachidonate required calcium and was enhanced by diolein but did not require exogenous phosphatidylserine. Submaximal levels of arachidonate also enhanced the affinity of the kinase for calcium during activation by phosphatidylserine. Thus the release of arachidonate, which is triggered in many cell types by ligand-receptor interactions, could play a second messenger role in the regulation of cellular function by activation of protein kinase C.     

The mentality of crows: convergent evolution of intelligence in corvids and apes

Discussions of the evolution of intelligence have focused on monkeys and apes because of their close evolutionary relationship to humans. Other large-brained social animals, such as corvids, also understand their physical and social worlds. Here we review recent studies of tool manufacture, mental time travel, and social cognition in corvids, and suggest that complex cognition depends on a "tool kit" consisting of causal reasoning, flexibility, imagination, and prospection. Because corvids and apes share these cognitive tools, we argue that complex cognitive abilities evolved multiple times in distantly related species with vastly different brain structures in order to solve similar socioecological problems.     

The fall, recovery, orbit, and composition of the Tagish Lake meteorite: a new type of carbonaceous chondrite

The preatmospheric mass of the Tagish Lake meteoroid was about 200,000 kilograms. Its calculated orbit indicates affinity to the Apollo asteroids with a semimajor axis in the middle of the asteroid belt, consistent with a linkage to low-albedo C, D, and P type asteroids. The mineralogy, oxygen isotope, and bulk chemical composition of recovered samples of the Tagish Lake meteorite are intermediate between CM and CI meteorites. These data suggest that the Tagish Lake meteorite may be one of the most primitive solar system materials yet studied.