Continental drainage in north america during the phanerozoic from Nd isotopes

Neodymium (Nd) isotopic data show consistent patterns in the sources of sedimentary rocks in North America at a continental scale. Between 600 and 450 million years ago (Ma), ancient continental shield sources dominated. Around 450 Ma, detritus from the Caledonian-Appalachian mountains overwhelmed sediment from all older sources, and is documented over large areas of the southern, western, and northern margins of North America. This material continued to dominate the sediment supply until about 150 Ma, probably due to cannibalistic recycling of sedimentary rocks formed earlier. Around 150 Ma, the rising western Cordillera delivered new and different detritus to the sedimentary system.     

Comparison of inoculation regimes for the experimental production of swine erysipelas arthritis: I Clinical, pathological and bacteriological findings

The arthritic form of swine erysipelas was induced in pigs by multiple intravenous inoculation of 2 strains of Erysipelothrix rhusiopathiae. The strains differed significantly in their arthritogenicity but not in the number of cases of lameness induced. The use of 3 intravenous inoculations instead of 5 did not significantly affect the outcome. In a second trial, the more arthritogenic strain was injected in ten-fold dilutions from 5 x 10(9) to 5 x 10(4) organisms. Pigs receiving the lower doses showed high variability in their arthritic responses that precluded sensitive analysis of the dose effects on the number of arthritic and infected joints. However, slaughter weights showed a significant negative correlation with dose. Mean slaughter weights in treatment groups varied by 14.6 kg per pig, an average weight loss of 3 kg per pig for each ten-fold rise in dose of the highly virulent strain, and significantly correlated with the number of arthritic and infected joints. Culture of homogenised synovial membrane through selective horse meat-serum broth containing kanamycin, neomycin and vancomycin identified 66% and 59% more infected joints than primary blood agar culture of synovial fluid or synovial membrane homogenate, respectively.     

Chlamydial infection in a colony of captive koalas

Forty three koalas in a captive colony were investigated for the presence of Chlamydia psittaci infection and associated disease. Swabs were taken from conjunctivae and urogenital sites for cell culture isolation of C psittaci and for cytological examination (direct smears) for chlamydial inclusions and evidence of inflammation. On the basis of cell culture isolation, 28 samples from 25 koalas were positive for C psittaci (that is, infected). Three koalas were positive from both sites, 5 from conjunctivae alone and 17 from urogenital sites alone. Seven of the 8 koalas with positive conjunctival swabs had overt signs of conjunctivitis, but only 3 of the 20 koalas with positive urogenital swabs had overt signs of 'wet bottom' (continual urine soiling due to cystitis) or purulent discharge. However, 5 of the 20 with positive urogenital swabs had past episodes of 'wet bottom'. Moreover, examination of direct cytological smears showed evidence of inflammation (neutrophils) in 7 of 8 koalas with positive conjunctival swabs and 17 of 20 with positive urogenital swabs. Chlamydial inclusions were rarely identified with surety on direct cytological smears. In the 18 koalas without chlamydia, one had overt conjunctivitis while 2 had past episodes of conjunctivitis. The koala with conjunctivitis at the time of sampling had a prior history of 'wet bottom'. Examination of direct cytological smears revealed 2 of the chlamydial negative koalas had high numbers of neutrophils in urogenital smears. It was concluded that C psittaci infection may cause overt or sub-clinical disease, with the former developing when the koalas were stressed through management procedures or concomitant disease.     

Survey of intramammary infections in ewes on the New England Tableland of New South Wales

Samples of mammary secretion were collected aseptically from 1093 ewes in 8 separate flocks. Most of the ewes were suckling lambs 4 to 6 weeks old. Standard bacteriological tests were carried out on the samples to identify the organisms involved in intramammary infections. Data on age, breed, lactational status and clinical status of the gland and its secretion were recorded at the time of sampling. The prevalence of intramammary infection was 14% of ewes (8% of glands). There was a tendency for prevalence of intramammary infection to be positively correlated with age of the ewe (two-year-old and six-year-old ewes had, respectively, 4.4% and 14.0% of glands infected). This relationship was highly significant for Border Leicester x Merino ewes. There were also significant differences in infection prevalence between breeds. infected glands had a higher prevalence of clinical abnormalities of udder, teat and secretion than did non-infected glands. Staphylococcus aureus was overwhelmingly the most frequently isolated bacterium being responsible for 40% of all intramammary infections.     

Effect of ambient storage of wheat samples on their nutritive value for chickens

1. Two wheat cultivars (Abbott and Equinox) were grown using the same crop husbandry conditions. Batches of each cultivar were stored at ambient temperature (AT) for 0, 6, 12, 18 or 24 weeks. Those stored at AT for less than 24 weeks were then stored at -20 degrees C up to the end of the storage period. The 24 week (AT) samples were divided into two lots and one lot was frozen to -20 degrees C for 24 h. 2. Each of the 12 wheat samples was included (650 g/kg) in a nutritionally complete diet and fed to broiler chickens from 7 to 21 d of age. The apparent metabolisable energy (AME) of each sample was determined using a rapid bioassay with adult cockerels. 3. The Equinox cultivar sample had a high proportion (92/1000) of visibly sprouted grains and had a low Hagberg falling number (high amylase activity) and high content of free sugars compared to the Abbott sample. There were no major changes in dry matter, free sugar content, water extract viscosity or Hagberg falling number due to the different times of ambient storage of either of the two wheat cultivar samples. 4. The chickens fed on the Abbott cultivar wheat had a greater weight gain, although there were no differences in the determined AME of the two wheat cultivars. 5. The Abbott sample stored at ambient temperature for 6 weeks had a greater AME than the sample given no ambient storage and the samples given 18 and 24 weeks ambient storage. There were no significant differences between the Equinox cultivar samples. There were no effects of storage time on the growth performance of the broiler chickens. 6. The AME of the unfrozen Abbott cultivar was greater than the frozen (for 24 h) sample but there was no effect on broiler growth performance. This study suggests that, in some wheat samples, there may be a benefit in avoiding freezing during storage.     

Chemical composition and the nutritive quality of different wheat cultivars for broiler chickens

1. Different wheat cultivar samples were grown in replicated trials on a single site in three harvest years. A total of 23 wheat samples were harvested. Nutritionally complete, meal-form diets that included each wheat sample at 650 g/kg were used to compare broiler growth performance and determine apparent metabolisable energy (AME). The relationships were examined between these variables of nutritive value for broilers and the chemical composition and tests of quality on the wheat samples. 2. The total starch contents of the wheat samples ranged from 594 to 732 g/kg dry matter (DM). The mean total non-starch polysaccharide (NSP) content was 100g/kg DM comprising 73.5 g/kg DM of insoluble material. Endosperm hardness ranged between 10 and 77 relative units and Beaver was the softest cultivar in two of the batches of samples. The AME of the wheat-based diets had a maximum range of 0.5 MJ/kg within each of the three batches of wheat that were tested. 3. Endosperm hardness of the wheat grains, within a harvest year, was positively correlated with broiler weight gain and the 1000-grain weight was negatively correlated with feed conversion efficiency (FCE). Starch content and gross energy were positively correlated with determined AME, and DM, 1000-grain weight and water holding capacity were negatively correlated with AME. 4. A step-wise regression technique indicated that endosperm hardness and ash content of the wheat were the explanatory variables that, within harvest years, significantly reduced the unexplained variation in broiler growth rate, feed intake and FCE. The contents of total starch, crude protein and ether extract were the explanatory variables that, within harvest years, significantly reduced the unexplained variation in AME.     

Pharmacokinetics of cephalexin in cats after oral administration of the antibiotic in tablet and paste preparations

Objective To determine the bioequivalence of a paste formulation of cephalexin with that of the tablet form.
Design A two-way cross-over study.
Animals Ten adult cats of mixed breed.
Procedure The cats, randomly allocated to two groups, received either the paste preparation or the tablet orally at 12-hour intervals for 48 h before a 12-hour blood collection period. Two weeks later the treatments were reversed and the blood sampling repeated. The serum concentrations of the antibiotic were determined. The pharmacokinetic factors were analysed using a computer.
Results There were no significant differences between the peak concentration of cephalexin, or the other pharmacokinetic factors obtained from the tablet and paste formulations. The serum profiles of cephalexin following four 12-hourly doses of each formulation were similar with the peak serum values occurring at approximately 2 h after administration.
Conclusion The paste formulation and the tablet form are bioequivalent.