Effect of algicides on urea fertilizer efficiency in transplanted rice

The effects of the algicides terbutryn and copper sulfate on the potential for reducing the gaseous loss of NH₃ from urea applied to rice were examined in experiments with 2 methods of N fertilizer management, 2 or 3 N rates, and 3 algicide treatments. The experiments were conducted during the 1986 dry and wet seasons in an experimental field at Pila, Laguna, Philippines.Copper sulfate had little effect as an algicide at the rate used, but terbutryn immediately reduced algal growth. The populations of species resistant to terbutryn probably increased, but terbutryn had no long-term effect on the total number of colony-forming units of algae. There was some evidence that terbutryn reduced photodependent N₂ fixation as estimated by acetylene reduction assay.Terbutryn, when applied with urea 10 days after transplanting, reduced the maximum floodwater pH by 0.9 units or more for 7 d in the DS and by about 0.5 units for 8 d in the WS. Terbutryn increased the ammoniacal-N (AN) concentration in the floodwater 100% or more in the DS and 60% in the WS. The combined effect of terbutryn on the floodwater pH and AN concentration was reduced photodependent NH₃ partial pressure (NH₃), about 25% in the DS and 38% in the WS. deceased     

Chemical trail marking and following by caterpillars ofMalacosoma neustria

Chemical trail marking and following by gregarious caterpillars,Malacosoma neustria L. (Lepidoptera: Lasiocampidae), was studied in the laboratory. As in other species ofMalacosoma, larvae deposit a trail pheromone from a sternal secretory site when searching the host for food. Larvae in the vanguard of foraging columns establish chemical trails as they explore new territory. Marking behavior diminishes as successive unfed foragers utilize the trail. These exploratory trails are subsequently overmarked by fed larvae returning to the tent. Other foragers follow the trails of fed larvae in preference to trails of unfed larvae. Thus, like the eastern tent caterpillar,M. americanum, successful foragers ofM. neustria recruit colony-mates to feeding sites. The chemical activity of both recruitment and exploratory trails degrades slowly, suggesting that the trail pheromone ofM. neustria is a nonvolatile substance. Caterpillars ofM. neustria readily follow the nonvolatile trail pheromone which has been identified fromM. americanum, 5-cholestane-3,24-dione.     

Evaluating Market Attractiveness: Individual Incentives Versus Industry Profitability

In this paper, we employ an agent-based industry simulation model to study the effects of the interplay between individual firms’ market evaluation strategies on the extent of product innovations and overall industry development. In particular, we show that a homogenous industry consisting of companies with focus on historical profits yields high overall industry profits but is very unstable. The introduction of a single firm oriented towards market growth rather than profits is sufficient to trigger a severe drop in profits and a transformation towards an industry with strong market growth orientation and a large number of marketed product innovations. Furthermore, we show that the degree of horizontal differentiation of product innovations from existing products is of significant importance for the individual incentives to adopt market growth orientation and the effects of such a development on overall industry profits.     

Insect hydrocarbons

Standard mono- and dimethyl-branched hydrocarbons were synthesized from substituted thiophenes for the purpose of comparing their mass spectra to those of hydrocarbons isolated from the tobacco hornworm,Manduca sexta L. The mass spectra of the standard compounds confirmed the structures of the partially characterized natural products.     

316L不锈钢粉真空松装烧结的研究

研究了３１６Ｌ不锈钢粉注射成形等低压成形工艺的粉末真空松装烧结行为及其影响因素。通过添加石墨实现脱氧控碳，分析比较了气，水雾化粉真空松装还原烧结行为的差异。     

Maximum likelihood estimation of parameters of several continuous and discrete failure distributions

A comprehensive quantitative treatment is presented for maximum-likelihood estimation of parameters of the following continuous and discrete failure distributions: (1) Exponential, (2) Gamma, (3) Weibull, (4) Normal, (5) Lognormal, (6) Extreme value, (7) Poisson, (8) Binomial and (9) Geometric.     

Variation of glucosinolates in vegetable crops of Brassica rapa L. ssp. pekinensis

Glucosinolates of Chinese cabbage (Brassica rapa L. ssp. pekinensis) from Korea were characterised to determine the total glucosinolate content and the diversity amongst glucosinolates; 24 varieties were analysed. The profiles of 14 glucosinolates identified from the leaves were subjected to principal component analysis (PCA) to evaluate the differences among varieties. The Kori, Sandun and e-Norang varieties separated from the others based on glucosinolate concentration. Genetically modified Chinese cabbage containing the bar gene could not be separated from non-genetically modified varieties. Glucobrassicanapin, 4-methoxyglucobrassicin, gluconapin and glucobrassicin in Chinese cabbage were confirmed as the main glucosinolate compounds. The Kori, Sandun and e-Norang varieties appear to be good candidates for future breeding programmes since they have a high glucosinolate content. The presence of indolic glucosinolates in all varieties should be studied more extensively because they are the precursor of indole-3-carbinol, a potent cancer chemopreventive agent.