Long term effects of preplant fumigation of potato fields

The application of nematicides resulted in increased potato yields, and populations ofPratylenchus penetrans were lower for 3 years after application; but longevity of benefits of fumigating potato fields varied with the kind and amount of nematicide, application methods and with growing conditions after fumigation. Fumigation of two fields in the fall of 1965 with Vorlex, Telone, D-D, and mixtures of chloropicrin with Telone or D-D resulted in 70% to 90% control of the meadow nematode,P. penetrans, after two crops in one field, and 50% to 70% control after three crops in another. Yield increases of Kennebec potatoes averaged 42% and 16% in successive crops in the first field and yield increases of Katahdin potatoes averaged 13%, 22% and 16% in three successive crops in the other field. Fumigation resulted in 30 to 70% less vascular browning in tubers in the first two crops but there was no effect in the third crop. There was no effect on black scurf in any crop. Root injury varied proportionally with populations ofP. penetrans in roots in 1967. Populations ofP. penetrans regained injurious levels in three other fields after one crop when abundant root growth in moist 1967 followed spring fumigation with Telone and D-D. Under poor conditions for sealing of the soil following fumigation in the spring of 1968, counts ofP. penetrans collected at different soil depths after fumigation showed excellent kill below 3 inches and poorer kill in the upper 2 inches of soil.     

Diagnosis of sporotrichosis in a donkey using direct fluorescein-labeled antibody testing.

A 4-year-old female donkey residing in an open field in Indiana was admitted for evaluation of facial lesions of 2 years duration. Cytologic and histologic examination of exudate and tissue from the lesions revealed a pyogranulomatous inflammatory reaction with numerous yeasts. Sporothrix schenckii was suspected to be the infectious agent; however, multiple culture attempts did not provide positive identification of the organism. Serologic examination supported infection with S. schenckii. A specific direct immunofluorescent antibody test performed on paraffin-embedded tissue sections confirmed the organism as S. schenckii. Clinical signs resolved after appropriate iodide therapy.     

The Use of Economic Instruments and Green Taxes to Complement an Environmental Regulatory Regime

In 1999, some countries are developing and effectively applying economic instruments for environmental protection and natural resource management, whilst others are relying on command and control regulatory procedures under-enforced by sometimes inadequately trained and motivated enforcement officers. This paper considers the current and future role of economic instruments as policy instruments for use by governments. In many developed countries, past over-regulation allied to a serious shortfall of experienced environmental enforcers required regulatory regimes to be supplemented by well targeted economic instruments and green taxes. Their application to countries which do not have developed environmental control systems is more questionable. The purported threats of the longer term effects of global warming, damage to the ozone layer and an apparent loss of biodiversity have led environmentalists to adopt the so-called precautionary principle. Sustainable development has added to the pressures for further national and transfrontier legislation. The challenge facing policymakers, therefore, is to design policies to enable market forces to operate in the environmental sphere, for example through a system of pollution charges, principally intended to promote greater environmental efficiency. These charging systems can be of many kinds but their main defining feature is their reliance on markets and the price mechanism to internalise environmental externalities, thereby attempting to make polluters pay through facing the full social costs of their activities. Some of the applications of these charging systems, financial and fiscal instruments and tradable emission systems are explained and illustrated.     

The use of haemoglobin, packed-cell volume and serum sorbitol dehydrogenase as indicators of the development of fascioliasis in sheep

Haemoglobin, packed-cell volume and serum sorbitol dehydrogenase activity were studied in 8 groups of 3 Corriedale weaner wethers artificially infected with a range of fluke burdens. Data from haemoglobin and packed-cell volume measurements were analysed using regression procedures. All parasitised groups exhibited a decrease in haemoglobin and packed-cell volume compared with the control group. The rate of this decrease was approximately linear, and dependent on the size of the fluke burden. Prediction equations for the rates of decrease of haemoglobin and packed-cell volume in fluke-infected sheep are presented. Death occurred when haemoglobin fell below 5 g 100 ml-1, and packed-cell volume to 15%. Anaemia became profound in sheep infected with more than 346 flukes and these sheep died 56-63 days after infection. Serum sorbitol dehydrogenase activity exhibited several peaks, before and after Week 12 post-infection, when flukes should have been present in the bile ducts. Reason for the activity later than Week 12 was not clear, although stress or immune responses may contribute. Haemoglobin and packed-cell volume may be useful in predicting the size of fluke burdens when the duration of the infection is known, and may indicate that time of death of infected sheep. Sorbitol dehydrogenase is an unreliable indicator of the size or the duration of fluke burdens.     

Immunoglobulin A myeloma in a cat with pleural effusion and serum hyperviscosity

Immunoglobulin A myeloma, serum hyperviscosity, and septic pleuritis were diagnosed in a cat with pleural and peritoneal effusions. Serum hyperviscosity was determined by use of a WBC pipette, and clinical manifestations included retinopathy and cardiac changes. The presence of Salmonella typhimurium in the pleural fluid may have resulted from increased susceptibility to infection. Postmortem examination revealed plasma cell infiltration of the pleura, mesenteric lymph nodes, and the serosa of the intestine, liver, and spleen. This case represents an unusual form of myeloma in the cat.     

Influence of genetic type, slaughter weight and sex on ovine muscle fiber and fat-cell development

Histological properties from the longissimus (LD) and semimembranosus (SM) muscles of 51 wether and ewe lambs from Hampshire rams and two ewe genetic types (SR, 1/2 Suffolk and 1/2 Rambouillet, and FS, 1/2 Finnish Landrace and 1/2 Southdown) and three slaughter live weights (32, 41 and 50 kg) were compared. Fibers in both muscles were classified as beta R (red), alpha R (intermediate) or alpha W (white). All LD muscle fiber types from FS ewe lambs increased in diameter from 32 to 41 kg, but decreased in diameter from 41 to 50 kg. Also, this quadratic effect with slaughter weight was found in alpha R and alpha W fibers from the SM muscle of FS wether and ewe lambs. However, diameters of alpha R and alpha W fibers from SR wether and ewe lambs and beta R fibers from SR ewe lambs increased linearly in the SM muscle with increasing slaughter weight. As slaughter weight increased, the proportion of alpha R fibers decreased in both the LD and SM muscles for SR wether and FS wether and ewe lambs. Concurrent with the increase in slaughter weight and decrease in alpha R fiber percentage, the proportion of alpha W fibers increased in the LD muscle of SR wether lambs, the SM muscle of SR ewe lambs and both muscles of FS wether and ewe lambs. Genetic type and sex groups, except SR ewe lambs, support the theory of transformation of alpha R to alpha W fibers with increasing slaughter weights. Fat-cell diameters increased in both muscles of SR wether and FS ewe lambs with increasing slaughter weights. Increases in fat traits of lamb carcasses were related to increases in red-fiber size. Alpha red fiber numbers were inversely related (P less than .05) to alpha W fiber numbers in both the LD and SM muscles (r = -.83 and -.79). The proportion of alpha R to alpha W fibers might be used as an indicator of physiological maturity for lambs.     

Severe respiratory disease in dairy cattle in New York State associated with bovine respiratory syncytial virus infection

Severe respiratory disease associated with bovine respiratory syncytial virus (BRSV) infection has been identified in dairy cattle in New York State. The cases identified occurred in dairy calves and heifers. The disease was characterized in 4 animals by pathologic changes including interstitial pneumonia, necrotizing bronchiolitis with multinucleated syncytial epithelial cells and interstitial emphysema. BRSV antigen was demonstrated in lung samples or was isolated in tissue culture in all 4 cases. A retrospective survey of 6279 bovine diagnostic accessions between 1977 and 1982 revealed 66 cases of interstitial pneumonia, often with concurrent bronchiolitis. In this 5 year period, only 1 case in 1981 had interstitial pneumonia and bronchiolitis with pathologic features consistent with BRSV infection. It is concluded that pathogenic BRSV has entered New York State and that it is contributing to clinical respiratory disease in dairy cattle.