Necrotizing typhlocolitis associated with a spirochete in rheas (Rhea americana).

Necrotizing typhlocolitis was diagnosed in 13 juvenile common rheas (Rhea americana) from three separate of geographically isolated Ohio flocks, with mortality ranging from 25% to 80%. At postmortem examination, a diphtheritic membrane covered ulcerated cecal mucosa. Histologically, cecal sections showed necrosis and granulomatous-to-suppurative inflammation that extended into the submucosa and often surrounded large eosinophilic colonies of bacteria. Warthin-Starry staining showed these colonies to be composed of entangled spirochetes that invaded the submucosa and frequently were present transmurally. Similar organisms were identified by Warthin-Starry staining in the cecum of a juvenile rhea from a fourth flock that histologically had mild lymphocytic typhlitis. Scanning and transmission electron microscopy demonstrated the presence of a spirochete in the ceca. Anaerobic culture yielded a gram-negative, beta-hemolytic spirochete. Coccidia, histomonads, and Salmonella spp. were consistently absent.     

Energy resources available to the United States, 1985 to 2000

Energy and the gross national product have grown hand in hand at 3 to 3(1/2) percent a year for almost 40 years. Our energy growth is slowing down and will sentially level off in the 1990's. Our production of oil and gas passed a peak in the early 1970's, and there is no resource base to justify predictions of increased yields. Coal is the only fossil fuel capable of increased production. There are serious doubts that our uranium resources can support a large light-water reactor program. Finding rates for petroleum, natural gas, and uranium are less than half of what they were 20 years ago.     

Movement rules for juvenile steelhead: dynamic linking of movement behaviour to habitat and density

We incorporated explanatory factors including stream habitat type and fish density into individual‐based models with dynamic connections among adjacent habitat units to infer dispersal behaviour of juvenile steelhead Oncorhynchus mykiss in a Great Lakes watershed. We used mark–recapture data and an inverse modelling approach to estimate daily probability of steelhead moving out of a habitat unit, P(move), according to four competing models. The models used included (i) a null model where all fish had equal movement probability; (ii) a habitat‐dependent model where P(move) depended on the habitat type; (iii) a density‐dependent model of P(move); and (iv) a model where P(move) depended on both density and habitat type. The habitat‐dependent model provided the most parsimonious fit to the observed data according to Akaike's information criteria (AICc). In the null model, P(move) averaged 0.70, whereas P(move) averaged 0.75 in pools, 0.68 in riffles and 0.73 in runs in the habitat‐dependent model.     

Solitary extramedullary plasmacytoma of the canine larynx

An 11-year-old, female, spayed cocker spaniel was presented with dysphonia caused by a solitary laryngeal mass. Excisional biopsy was performed, and a diagnosis of plasmacytoma was made on the basis of histological examination. Further investigations showed no signs of systemic involvement. Coarse fractionated radiation therapy failed to control the tumour. Therapy was successfully instituted with a conventional combination chemotherapy protocol over a period of 14 months. The dog remains disease free 30 months after diagnosis. Most solitary, extramedullary plasmacytomas in dogs arise in the gastrointestinal tract, with fewer reports in other sites. The larynx is an uncommon sight of involvement in any species, and to the authors' knowledge, this is the first report of this tumour type in the canine larynx. In contrast to the therapeutic benefits reported in humans, the combination of surgery and radiation therapy was unsuccessful in this case, although sustained remission was gained following chemotherapy.     

Crop water requirements for rainfed and irrigated grain corn in China

A basic parametric crop water use model (WATER) that employes climatic and environmental data to calculate temporal and spatial water consumption for a variety of major corps was applied specifically for grain corn to the region of China and Korea to investigate the evapotranspiration (ET) demand on grain corn and the associated irrigation water applications necessary for optimal crop production. A network of 241 stations provided the seasonal climatic input. The climatic input consisted of data averaged over approximately a 20 year period. Among the results, highest ET under full irrigation (first harvest) occurred in the northwestern inland sections of China, whereas least ET was found for the southeast. Under rainfed conditions, the relationship became nearly inverse. In order to achieve optimum crop yields, about 1000 mm of irrigation water was needed in the northwest, contrasted with none required in the south and east of China. A sensitivity analysis was applied to determine the degree of error introduced by faulty or uncertain environmental input data.     

THE INFLUENCE OF PHOSPHATE AND LIME ON THE GROWTH AND N FIXATION OF LOTUS ULIGINOSUS AND TRIFOLIUM REPENS UNDER GREENHOUSE CONDITIONS

Shoot dry weight, leaf area, leaf lamina dry weight and N-fixation of L. uliginosus cv. Grasslands 4705 were compared with those of T. repens S184 over a 90-day period frotn sowing, in pots in a greenhouse. Three P and three pH levels were imposed and there were three destructive harvests at 30-day intervals. N-fixation was estimated by the acetylene reduction technique prior to the last harvest. L. uliginosus had higjier means than T. repens for all characters measured under all treatments at all harvests. Large increases in shoot weight and leaf area were associated with addition of P, particularly with the first increment of P to L. uliginosus. High P reduced the contribution of lamina to total shoot weight in T. repens more than in L. uliginosus at the second harvest. Raising pH increased shoot weight and leaf area in both species. N-fixation was low in both species at low pH and low P. This was increased by addition of P, a smaller quantity being necessary for the same response in L. uliginosus compared with T. repens. At the higher P levels, the high pH gave rise to lower N-fixation than at the medium pH. Results are discussed in relation to field trials of other workers and the possible suitability of L. uliginosus for low fertility upland conditions.