Arthrographic Analysis of Communication between the Tarsometatarsal and Distal Intertarsal Joints of the Horse

The intra-articular anatomy of 103 equine tarsi was studied by contrast radiography with image intensification and computerized tomography. There was communication between the tarsometatarsal and distal intertarsal joints in 21 of 55 (38%) interpretable tarsometatarsal arthrograms, and in 11 of 48 (23%) interpretable distal intertarsal arthrograms. The difference was not significant. The volume of contrast agent and the pressure of injection did not correlate with communication. Forced injection caused subcutaneous leakage of contrast medium but not communication. Communication occurred via the tarsal canal and the space between the third and the combined first and second tarsal bones. Injection of the distal intertarsal joint from the dorsomedial aspect of the limb, distal to the palpable distal border of the medial branch of the tendon of the tibialis cranialis muscle and between the central, third, and combined first and second tarsal bones, provided reliable access except in the presence of severe periosteal proliferations.     

Specificity of polyclonal antibodies to different antigenic preparations of Pseudomonas syringae pv. pisi strain UQM551 and Pseudomonas syringae pv. syringae strain L

Polyclonal antibodies were produced against sonicated and heat-killed cells of Pseudomonas syringae pv. pisi strain UQM551 and Pseudomonas syringae pv. syringae strain L, and their specificities were compared. Evidence is presented that the serological specificity between these two pathovars lies in surface antigens. Of the surface antigens purified and tested, only flagella and lipopolysaccharide from the cell wall showed no cross-reactivity with heterologous antisera. Antisera to glutaraldehyde-fixed flagella of the two strains showed a high level of specificity. At a species or genus level, antisera prepared from heat-killed cells of P. syringae distinguished this species from all other bacterial species and genera tested, including strains of Pseudomonas fluorescens, Escherichia coli, Agrobacterium and Rhizobium.     

Silviculture of ash in southern England

In 1992 the Wessex Silvicultural Group held a number of meetingsto study the silviculture of ash, during which 16 sites throughoutcentral southern England were visited. Ash can produce valuabletimber on relatively short rotations, and to take full advantageof this potential stands must be carefully managed. The mainpoints to consider are: (1) site selection: ash is site demandingand grows best on moist calcareous barns of pH 6 to 7. Sitesprone to frost should be avoided. (2) Spacing: if timber productionis an important objective, ash should be established with atleast 2500 stems ha^-1 on bare land and 2000 stems ha^-1 on restockingsites. It is sensitive to exposure when young and requires sideshelter making it unsuitable for pure planting on exposed ground.(3) Weed control: this is essential for successful establishment.It is recommended that an area of at least 1 m² around eachtree should be kept weed free for at least 3 years. (4) Protection:the species is relatively free from squirrel damage but is palatableto voles, rabbits, hares and deer. Protection using appropriateindividual tree protection or fencing is essential. (5) Thinning:once a height of 6–7 m has been reached ash should havefrequent crown thinnings to maintain a live crown over at leastone-third the height of the tree. Under-thinning was by farthe most common fault in the stands visited.     

Partial Hepatectomy with Temporary Hepatic Vascular Occlusion in Dogs with Hepatic Arteriovenous Fistulas

A technique for temporary hepatic vascular occlusion during partial hepatectomy for hepatic arteriovenous (AV) fistulas in the dog is presented in seven dogs, and three additional cases of hepatic AV fistulas are reviewed. Hematologic, serum biochemical, radiologic, and nuclear scintigraphic parameters before and after surgery are discussed; abnormalities included anemia, hypoproteinemia, leukocytosis, increased liver function tests, retrograde filling of the portal vein during celiac angiography, and increased arteriovenous ratios during nuclear scintigraphy. Hemodynamic and pathologic findings are presented, and portal hypertension and secondary multiple portosystemic shunts are described. Clinical improvement was observed in four dogs with follow-up periods ranging from 5 months to 3 years.     

A review of black heart of ash (Fraxinus excelsior L.)

Black heart is a non-fungal stain of ash (Fraxinus excelsiorL.) which results in a price penalty compared with white wood.The formation of black heart varies within individual trees,between trees and on different sites; the evidence availablesuggests that it can be present in up to 45 per cent of treesat age 60. Once formed the proportion of cross-sectional areaaffected increases with age. Previous work has suggested thatblack heart has no effect on timber properties or strength butits occurrence has been linked with high soil moisture. Howeverthese studies were conducted in the 1950s and need to be confirmedusing more rigorous research methods. Scope exists for innovativemarketing of black heartwood to emphasize that it is a naturalfeature and can be visually pleasing; this may lead to betterreturns for the grower.     

集成定量方法用于同时监控密集型农业区域土壤侵蚀和非点源污染状况的研究

In China, some areas with intensive agricultural use are facing serious environmental problems caused by non-point source pollution（NPSP） as a consequence of soil erosion（SE）. Until now, simultaneous monitoring of NPSP and SE is difficult due to the intertwined effects of crop type, topography and management in these areas. In this study, we developed a new integrated method to simultaneously monitor SE and NPSP in an intensive agricultural area（about 6 000 km2） of Nanjing in eastern China, based on meteorological data,a geographic information system database and soil and water samples, and identified the main factors contributing to NPSP and SE by calculating the NPSP and SE loads in different sub-areas. The levels of soil total nitrogen（TN）, total phosphorus（TP）, available nitrogen（AN） and available phosphorus（AP） could be used to assess and predict the extent of NPSP and SE status in the study area.The most SE and NPSP loads occurred between April to August. The most seriously affected area in terms of SE and NPSP was the Jiangning District, implying that the effective management of SE and NPSP in this area should be considered as a priority. The sub-regions with higher vegetation coverage contributed to less SE and NPSP, confirming the conclusions of previous studies, namely that vegetation is an effective factor controlling SE and NPSP. Our quantitative method has both high precision and reliability for the simultaneous monitoring of SE and NPSP occurring in intensive agricultural areas.