Distribution of thiobacillus ferrooxidans and leptospirillum ferrooxidans: implications for generation of acid mine drainage

Although Thiobacillus ferrooxidans and Leptospirillum ferrooxidans are widely considered to be the microorganisms that control the rate of generation of acid mine drainage, little is known about their natural distribution and abundance. Fluorescence in situ hybridization studies showed that at Iron Mountain, California, T. ferrooxidans occurs in peripheral slime-based communities (at pH over 1.3 and temperature under 30 degreesC) but not in important subsurface acid-forming environments (pH 0.3 to 0.7, temperature 30 degrees to 50 degreesC). Leptospirillum ferrooxidans is abundant in slimes and as a planktonic organism in environments with lower pH. Thiobacillus ferrooxidans affects the precipitation of ferric iron solids but plays a limited role in acid generation, and neither species controls direct catalysis at low pH at this site.     

Baseline hematologic, endocrine, and clinical chemistry values in ducks and roosters

Venous blood samples were collected at 3-day intervals for a total of six samples from each of five adult male pekin ducks and five adult Ross roosters. Twenty biochemical, six hematologic, and three endocrine determinations were performed on each blood or serum sample collected. The data obtained provide reference values for future studies of avian species and illustrate the utility of an automated clinical chemistry analyzer in assessing multiple serum biochemistry values in small sample volumes obtained from birds.     

Principles for the use of macrocyclic lactones to minimise selection for resistance

OBJECTIVE: To provide principles for the appropriate use of avermectin/milbemycin or macrocyclic lactone (ML) anthelmintics in sheep, to ensure effective worm control and to minimise selection for ML resistance. STRATEGY: The principles were based on an assessment of the information currently available. The MLs were categorised into three groups (ivermectin [IVM], abamectin [ABA] and moxidectin [MOX]) based on structural differences, persistence and efficacy against ML resistant strains. The reported order of activity or efficacy against ML resistant worm strains was IVM相似文献   

Serum thyroxine and triiodothyronine concentrations in canine pyoderma

In an effort to evaluate the effect of pyoderma on circulating iodothyronines, plasma triiodothyronine (T3) and thyroxine (T4) values were determined before and after thyroid stimulating hormone administration in 25 dogs with pyoderma and in 15 controls. Basal T4 values were increased in dogs with pyoderma, but neither stimulated T4 nor T3 values were altered by this condition. On the basis of low values for circulating iodothyronines, hypothyroidism was suspected in 3 dogs in the pyoderma group. The dog with the most involved lesions had extremely low T3 and T4 values as well as an autoimmune disease. It was concluded that most dogs with pyoderma do not have thyroid dysfunction.