Sitka spruce (Picea sitchensis (Bong.) Carr), white spruce (P. glauca (Moench) Voss) and Engelmann spruce (P. engelmanni (Parry)) plantations in British Columbia (B.C.), Canada, have come under serious attack from the white pine weevil, Pissodes strobi (Peck) (Coleoptera: Curculionidae). This pest attacks and destroys the terminal leader of the tree, causing serious growth losses and stem deformities. Since 1993, we have conducted a series of screening trials to search for spruce with resistance to the white pine weevil. Spruce tree selections from across the range of the species have been planted in several replicated trials. At 12 of these trial sites, in order to accelerate the screening process, local insect populations were augmented by adding reared weevils to the site. Results from our two oldest trials, at Jordan River and Cowichan Lake (planted in 1994), both on Vancouver Island, B.C., indicate that screening for weevil resistance can be effectively accomplished by using the weevil population augmentation method. Consistent selections could be obtained in trials with as few as 10 replicates per family. If weevil attack rates of 50% cumulative attack are obtained, then consistent selections may be obtained in as little as 4 years, which is a fairly quick turn-around time for studying resistance in trees.

Stand susceptibility to defoliation by spruce budworm, Choristoneura fumiferana (Clem.), was examined in the Fort Nelson area of the Prince George Forest Region of British Columbia. In a retrospective study, defoliation maps of the study area were overlaid onto British Columbia Ministry of Forests cover type maps using a geographic information system. Analysis of the combined data identified forest characteristics associated with increased susceptibility to defoliation by spruce budworm. These were stands where the leading species was white spruce (Picea glauca (Moench) Voss), or where spruce was associated with aspen (Populus tremuloides Michx. and P. balsamifera L.) in mixed stands. Susceptibility to defoliation also was related to site quality, level of crown closure and stand age. Spruce stands on medium quality sites (site index 15 to 25m, at reference breast height age 50 years) were more susceptible than stands on both poor- and high-quality sites. When spruce was mixed with aspen, stands on higher quality sites were more susceptible to budworm attack than poor sites. Open stands, where crown closure was <50%, were more susceptible to attack by spruce budworm than closed canopy stands. Older stands (120–199 years) were more susceptible to budworm attack than younger stands (40–110 years). In defoliated plots monitored for 6 years, tree mortality and top-kill reached a maximum of 30.4 and 47.2%, respectively. The losses varied with level of defoliation and were reduced by applications of the biological pesticide Bacillus thuringiensis.

Cracking of ring joint style flanges has been a recurring problem in the petrochemical industry, particularly in high-pressure hydrogen processing vessels. The cracking of the ring joint groove region is an inherent problem with the design. The ring groove is subjected to high stresses from the wedging action of the gasket and the ring groove radii are not substantial enough to effectively reduce the stress concentrating effect. A fitness for service assessment was conducted for a hydrogen processing vessel containing cracks in the ring groove radius region of a ring joint style flange. The flange was forged 2-1/4Cr-1Mo material with a Type 347 SS overlay. Results of an elastic-plastic numerical fracture mechanics assessment showed that the driving force for crack propagation was high for a very localized region near the ring groove radius. However, the driving force decreased significantly for deeper cracks as the crack tip became removed from the very localized high stress region of the ring groove. The assessment also showed that the highest stresses occurred during the bolt-up operation. Metallurgical tests were performed on a small sample removed from the flange. The chemistry, grain size, microstructure, and hardness of the material indicated that the probability that this material had very low resistance to hydrogen-assisted crack growth during downtime was quite small and that the resistance to crack advance during service was good. Therefore, the combined results of the fracture assessment and metallurgical testing were used to justify continued operation without repair of the cracks present in the flange. [S0094-9930(00)01901-6]

Presents an empirical example of a strongly cooperative manipulation system (the pusher/steerer system), whose capabilities derive from the redistribution of resources typically used in a single robot system. The authors define strongly cooperative strategies to be, intuitively, those which are not trivially serializable. In the authors' system, one robot steers, and the other pushes; the object lies between them. The steerer is the only agent that has information about the path, while the pusher exerts the necessary motive force, and rotates to follow changes in the object's orientation. The system is asynchronous, with no explicit communication between the robots. The authors are interested in studying manipulation systems of this type, because they are strongly cooperative; that is, the two robots must act in concert to achieve the goal. The authors have performed over one hundred pusher/steerer manipulation experiments with two of their mobile robots, TOMMY and LILY. As the authors' analysis predicts, they have found that their system allows a wide variety of paths and manipulable objects for these robots.

ABSTRACT: Storm‐runoff quantity and quality were studied in three watersheds located near St. Paul in Ramsey County, Minnesota, from April 15 through September 15 of 1984, 1985, and 1986 to qualitatively determine the effects of precipitation and selected land uses on storm runoff. In respect to precipitation effects, differences in stormrunoff quantity between years in an urban watershed that lacks wetlands appear to be related to the average storm size (amount of precipitation) during the study period of each year. In contrast, the differences in storm‐runoff quantity from watersheds that contain wetlands appear to be related to total precipitation during study period of each year. In respect to land use, the differences in storm‐runoff quantity appear to be related to the amounts of impervious and wetland area. The watershed that contains the largest amount of impervious area and smallest amount of wetland area has the largest amount of storm runoff. Differences in storm‐runoff quality appear to be related to the amounts of wetland and lake area. The watershed that contains the largest amounts of wetland and lake area has the smallest storm‐runoff loading of suspended solids, phosphorus, and nitrogen. The wetland and lake areas likely retain the loading and, subsequently, lower the amount of storm‐runoff loading exported from a watershed.

The V5 ultraviolet auroral imager is one of a complement of experiments launched into polar orbit aboard the Swedish spacecraft Viking in February of 1986. The imager consists of two intensified wide‐angle f/1 cameras, identical except in passband, with electronic despinning providing exposure times of one second. Critical to electronic despinning is the use of tapered fiber optic bundles to remove distortions generated when the spherical focal surface of the Burch configuration camera is projected onto the plane of the charge coupled detector. Data acquired by V5 are telemetered to a ground station in Kiruna, Sweden for archiving and real time display using a VAX11/750 system.

The Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) defoliated Douglas-fir (Pseudotsuga menziesii var glauca [Beissn.] Franco), in British Columbia from 1981 to 1983. Forty-five defoliated and 16 non-defoliated (check) plots were monitored for defoliation and damage from 1982 to 1985. By 1985, cumulative mortality and top-kill in the defoliated plots averaged 51% (49% by volume) and 11%, respectively. Check plots sustained no mortality and less than 1% top-kill due to causes other than tussock moth defoliation. Mortality occurred very early in the outbreak, with 56% of the dead trees already dead by 1982, generally after 1 year, but at most after 2 years of defoliation. Mortality and top-kill were related to the number of seasons of defoliation and, particularly, to defoliation intensity. It was concluded that Douglas-fir tussock moth is an important depletion factor of Douglas-fir in British Columbia.

An urban wetland in the Minneapolis-St. Paul Metropolitan Area was found to retain sediment and nutrient loads in runoff routed through the wetland. Sediment and nutrient loads in runoff were measured during 1982 at the inlet and outlet of the 6.4-bectare urban wetland. Comparison of annual loads entering and leaving the wetland showed that retention of incoming loads in the wetland was 97 percent of nonvolatile suspended solids, 76 percent of volatile suspended solids, 48 percent of total phosphorus, 4 percent of dissolved phosphorus, 3 percent of dissolved nitrite plus nitrate nitrogen, 1 percent of total ammonia nitrogen, and 47 percent of total organic nitrogen. Flow volume was increased on an annual average basis by 5 percent between the wetland inlet and oulet. Most retention of sediment and nutrient loads occurred between late April and mid-July.

Meat and meat products are excellent sources of protein for the human dietary. There are, however, concerns that consumption of meat may not be in the best interests of health. These concerns date to the nineteenth century, at which time a number of "pure-food 'advocates'" equated the consumption of meat with a variety of conditions including dermatitis, arteriosclerosis, constipation, flatulence etc. and with moral laxness. In recent years, there has been concern that consumption of meat could lead to increased intake of cholesterol and saturated fatty acids which are thought to have an adverse effect on cardiovascular health. Examination of current knowledge suggests that dietary intake of cholesterol and saturated fatty acids are not primary aetiological agents for the development of atherosclerosis. There is a suggestion in the literature that meat proteins themselves may be atherogenic. The theory is that consumption of meats that are rich in methionine leads to the development of high circulating levels of homocysteine which causes atheromatous lesions to develop. Induction of homocysteinaemia by vitamin B6 deficiency did not result in the development of atherosclerosis, however, which sheds some doubt on the theory that meat proteins are atherogenic. A review of current literature reveals that there is no concrete reason to suspect that meat consumption poses any threat to human health. Key words: Meat, health, heart, fat, cholesterol

Histamine in Canadian wines was determined by U.V. absorption of an ortho-phthaldialdehyde derivative using high performance liquid chromatography. Canadian wines average 1.84 and range between 0.09 and 6.11 mg histamine per liter of wine. For similar vinifications there was no significant difference between American hybrids, French-American hybrids and vinifera wines. Differences were noted, after amelioration, bentonite fining, and hot pressing.

AbstractRegression equations expressing reflectance of incidentlight from the upper (adaxial) surface of single leaves as a function of their relative turgidity and water content were developed. Reflectance at the 1.45‐ and 1.93‐µ water absorption bands was significantly related (p = 0.01) to the leaf relative turgidity or water content. However, because of variations in internal leaf structure associated with the availability of water during leaf development, the ability to predict the leaf water status from reflectance easurements was poor. With cotton (Gossypium hirsutum L.) the greatest change in reflectance occurs when the relative turgidity is below 70% and the leaves are visibly wilted. Within the relative turgidity range, 70 to 80%, reflectance changes are small and may not be definable for predictive purposes because of variation among leaves of field‐grown cotton caused by age differences and osmotic stresses.

The influence of the level of energy and ascorbate supplementation on hydroxyproline excretion in swine was studied in a 3 × 3 factorial experiment using 36 weanling, male Yorkshire swine. There were three levels of energy, 140, 240 and 340 kcal per kg W 0.75 of metabolizable energy (ME) per day and three levels of ascorbate, nil, 500 and 1000 mg per day. An apparent complex interaction between energy level and level of ascorbate supplementation on hydroxyproline excretion was found. When ascorbate intake levels were increased to 1000 mg per day, there was a significant increase in total hydroxyproline excretion per kg of body weight with increased energy intake. This was not observed at ascorbate levels of 0 and 500 mg per day. When the influence of ascorbate supplementation within energy groups was examined, it was found that hydroxyproline excretion decreased significantly when the animals received 240 kcal per kg W 0.75 of ME per day, and increased when the level of energy intake was 340 kcal per kg W 0.75 of ME per day. Since urinary hydroxyproline is derived mainly from bone, these data suggest that 1000-mg levels of ascorbate, when combined with a high level of energy, in this case 340 kcal per kg W 0.75 , may increase the catabolism of bone matrix; on the other hand, when energy is limited, supplementary ascorbate may increase polymerization of precursor collagen into stable forms.

Three trials, involving a total of 160 Yorkshire SPF pigs, were conducted to evaluate the effect of the addition of copper (Cu) and/or raw ground soybeans (RGS) to diets of market pigs. The addition of RGS to pig diets resulted in decreased feed consumption and slower growth rate when pigs were fed ad libitum. When feed intake was restricted, rate of gain was not influenced by RGS. Dietary Cu supplementation resulted in an improved rate of gain and feed consumption when fed ad libitum, with a greater response exhibited by pigs fed diets containing RGS. Prediction of rate of gain for a constant feed intake suggested that a portion of the Cu effect is due to increased feed intake. Copper supplementation resulted in increased liver Cu, and decreased liver iron. Increased levels of dietary RGS resulted in decreased liver iron. An RGS × Cu interaction was observed in kidney Cu, in which higher dietary levels of both RGS and Cu were accompanied by decreased kidney Cu content. Increased levels of dietary RGS caused a decrease in nitrogen digestibility.

Abstract Cabbage yields were significantly related to the frequency of irrigation, evapotranspiration (ET) and the rate of N fertilization. Irrigating when the mean soil water suction in the upper 24 inches of soil approached 1.6 bars insured an adequate supply of soil water. The N-ET-marketable cabbage yield surface showed that yields did not change greatly for many combinations of ET and N. Yield isoquants suggest possible combinations of N and ET which will produce the same yield.