细解美国硬木的等级

Bob Sabistina先生是全美硬木板材协会前首席检验官,现任全美硬木板材协会（NHLA）和美国阔叶木外销委员会（AHEC）国际分等规则顾问。他为全球多家媒体撰写的分等规则文章,被认为是对NHLA分等规则的最权威解读。     

Value-added products from forest biotechnology

The three major components of forest biotechnology addressed in this paper are asexual propagation, genomics and genetic engineering (GE). Forest biotechnology offers potential that cannot be realized from conventional breeding because of the long life of forest trees and because of the long time required to make genetic gains through tree improvement programs. Most of the biotechnology research in forest trees has concentrated on genetically variable traits that give a relative quick return on investment: growth, form, insect, disease and herbicide resistance, and wood properties. In the long run, other modified traits should have greater value than is obtained solely from timber management. At the tree or forest level, some of those traits will address carbon sequestration, bioenergy, bioremediation, biopulping and species restoration. At the gene level within a tree, the types of potential gains will include pharmaceuticals, resins, latexes, oils, flavonoids, and foodstuff, inclusive of increased fruit quantity and quality and the sugars and starches embedded in the cell walls. With the advent of nanotechnology, trees of the future will be dissected to form every wood product that is now commercially available and, in addition, a multitude of new products will appear.     

Onion yield and quality response to two irrigation scheduling strategies

Irrigation technologies that conserve water are necessary to assure the economic and environmental sustainability of commercial agriculture. This study was conducted in the Rio Grande Valley in Texas to evaluate yield and quality of subsurface drip irrigated onions (Allium cepa L.) using different scheduling strategies and water stress levels. One strategy consisted of initiating irrigation when the reading of a granular matrix sensors (Watermark^{® 1} soil moisture sensor, Irrometer, Co., Riverside, CA) installed at 0.2 m depth reached −20 kPa (optimum), −30 kPa and −50 kPa. The second strategy was to replace 100%, 75%, and 50% of crop evapotranspiration (ETc) weekly. Higher total yields, and jumbo onion size yields were obtained when the soil moisture was kept above −30 kPa. Yields were not affected when water applications were reduced from 100% to 75% ETc and from −20 to −30 kPa. The ETc strategies of 100%, and 75% ETc resulted in similar water usage to the soil moisture monitoring strategies of initiating irrigation at −20 and −30 kPa. Total yields dropped significantly when soil water stress increased below −50 kPa. For the ET based strategy yields also dropped with the 50% ETc treatment. Onion bulb pungency and brix were unaffected by water level.     

Effective use of tea to limit dietary iron available to starlings (Sturnus vulgaris).

Wild-caught starlings (Sturnus vulgaris) were fed an iron-enriched diet, with or without supplemental black tea leaves, to determine whether tea-derived tannins would prevent intestinal iron absorption. Hepatic biopsies were obtained to determine hepatic iron concentrations by atomic absorption spectroscopy. Hepatic iron concentrations increased significantly (P = 0.04) in 21 birds that consumed only the iron-enriched diet for 6 mo but not in the 20 birds that consumed the iron-enriched diet with tea leaf supplementation for the same time period.