Influence of Ectomycorrhizal Hyphae on Phosphate Fractions and Dissolution of Phosphate Rock in Rhizosphere Soils of Pinus radiata

A study was conducted to determine the effect of ectomycorrhizal hyphae on phosphate rock dissolution and soil properties in the rhizosphere of one-year-old Pinus radiata D. Don seedlings established on an allophanic soil (Andosol) in the field. High and low ectomycorrhizal hyphal activities were produced in soils inside the lower compartments of rhizosphere study containers by using either 26 μm or < 10 μ m pore-size nylon mesh(es) at the interfaces between the lower and upper compartments. The meshes at the interfaces allowed (26 μm) or reduced (< 10 μ m) hyphae penetration into the lower compartment. Pairs of containers, one with 26 μ m mesh and the other with < 10 μ m mesh, were buried under Pinus radiata seedlings for 10 months in a forest plantation. The effect of ectomycorrhizal (ECM) hyphal activity on phosphate rock dissolution and soil properties was determined. The increased ECM hyphal activity induced increased soil acidification and promoted greater production of acid phosphatase enzyme, causing greater changes in phosphorus (P) fractions in the rhizosphere soils. The increased ECM hyphal activity also stimulated higher dissolution of phosphate rock and mobilization of soil organic P. The results suggest that ECM hyphal strand has a significant role in mobilizing low-solubility P forms and soil organic P for utilization by the tree.     

Variation in budding and flowering-time of commercial cultivars of Antirrhinum majus

Seven F1 hybrids of Antirrhinum majus were grown in a range of environments and measurements were made of the time from sowing to budding and of the time from budding to flowering. The time to budding of all cultivars varied with environment, but was always longer for late-flowering types. The time from budding to flowering changed with environment in the early-flowering cultivars. This period was shorter and apparently independent of environment in the late-flowering types.The possibility of selecting types which combine the short vegetative phase of the early-flowering cultivars with the lower time for inflorescence development of the late ones is discussed.     

Macrozamia toxicosis in a dog

A case of Macrozamia riedlei seed poisoning is described in a young Dachshund. Vomiting and depression commenced within 6 h of ingestion; other signs that developed included severe hepatopathy, jaundice, abdominal pain that was unresponsive to analgesics, severe gastro-intestinal haemorrhage and thrombocytopenia as well as crystalluria and marrow dyserythropoiesis. The dog was euthanased 6 days after ingestion of the seeds.     

Diagnostic ultrasound in veterinary practice: How safe is it?

This paper provides information on the safety of ultrasonic diagnostic procedures as currently used in veterinary practice. The known mechanisms of action are described and selected literature on biological effects of ultrasound is reviewed. Current international consensus is presented on the safety of medical ultrasound with respect to thermal effects. To date, there is no independently verified clinical evidence that the level of exposure delivered to the tissues during scanned grey-scale (‘B-mode’) imaging has any adverse effects. Lung haemorrhage has been observed in animal experiments using diagnostic exposures, but the effects have not been reported in the foetus. Equipment that uses pulsed Doppler transmits higher acoustic outputs in a stationary beam, and can produce temperature increases that may have significant biological consequences. When considering sonographic and pulsed Doppler examinations of the prenatal animal, the safety margins are small and the operator should be aware of the acoustic output of the equipment, the exposure time, and the sensitivity of target tissues.     

Mechanisms underlying Phalaris aquatica "sudden death" syndrome in sheep

Twenty outbreaks of Phalaris aquatica "sudden death" syndrome in sheep were investigated between 1981 and 1991. Four were confirmed and one was suspected, to be a cardiac disorder; 5 were confirmed and 3 were suspected, to be a polioencephalomalacic disorder; the aetiology of the remaining 7 outbreaks could not be determined. Potentially toxic levels of hydrocyanic acid (20 to 36 mg/100 g) were measured in the 3 toxic phalaris pastures tested. The measurement of potentially toxic levels of nitrate nitrogen (2920 micrograms/g) in toxic phalaris pastures by others, was noted. It is suggested that phalaris "sudden death" syndrome could have as many as 4 different underlying mechanisms, and that these might reflect the presence in the plant of a cardio-respiratory toxin, a thiaminase and amine co-substate, cyanogenic compounds, and nitrate compounds.     

Use of clomipramine in the treatment of anxiety-related and obsessive-compulsive disorders in cats

Objective To evaluate the efficacy and tolerance of a treatment protocol for anxiety-related and obsessive-compulsive disorders in cats.
Design A study was undertaken to assess the clinical response in cats diagnosed with anxiety-related or obsessive-compulsive disorders to a treatment regimen that included clomipramine and behaviour modification.
Procedure The study group of 11 cats was acquired through referral. A detailed behavioural and clinical history was obtained. Presenting signs were urine spraying in seven cases, overgrooming in three and excessive vocalisation in one. Clomipramine was administered orally once daily. The mean starting dose was 0.4 mg/kg. If necessary, the dose was adjusted according to the clinical response of each cat. A behaviour modification program was designed and the owner instructed on its implementation. Cats were to continue on medication for at least 1 month after clinical signs disappeared, then medication withdrawal was to be attempted by decreasing the clomipramine dose progressively at weekly intervals while the behaviour modification program continued.
Results In all cases the presenting clinical sign was largely improved or disappeared. One cat was removed from the study by the owner. Four cats became lethargic at higher doses, but this resolved when the clomipramine dose was reduced. The average maintenance dosage was 0.3 mg/kg once daily. Clomipramine withdrawal was attempted in two cases: the behaviour returned in one case and the medication was reinstated at 0.3 mg/kg twice daily.
Conclusion Clomipramine was effective in controlling the signs of anxiety-related and obsessive-compulsive disorders in 10 of 10 assessable cases when used in combination with behaviour modification. Clomipramine was well tolerated.