Comparison of the Johne''s absorbed EIA and the complement-fixation test for the diagnosis of Johne''s disease in cattle

A commercially available absorbed ELISA for the diagnosis of Johne's disease (JD) (paratuberculosis) in cattle, the Johne's Absorbed EIA, was compared with the conventional complement-fixation test (CFT) used in Australia. Stored plasma from 3 Victorian dairy herds with a history of JD, sera from specimens submitted from animals showing clinical signs of JD and sera from the US National Repository for Paratuberculosis Specimens were used to determine the sensitivity of each test. The EIA detected 48.8% of 43 Australian animals with subclinical JD, while the CFT detected only 12 (21.4%) of 56 subclinically affected cattle. Of 150 subclinically infected US cattle, the EIA detected 47.3% and the CFT detected 52.0%. The EIA detected 59.7% of animals which at the time of sampling were shedding Mycobacterium paratuberculosis in their faeces, but showed no clinical signs of JD, while the CFT detected 57.3%. The EIA correctly identified 88.2% of 136 histologically confirmed clinical cases, and the CFT detected 83.4%. The specificity of each test was determined by testing sera collected at slaughter from animals residing in a known JD-free area of Australia, and from samples from the US National Repository of Paratuberculosis Specimens collected from certified-free herds in Wisconsin. The EIA was found to have a specificity of 99.8% when 998 Australian animals were used as the test population, and 99.0% when 196 US animals were used. The specificity of the CFT using Australian samples was 96.9% and 95.2% using American samples.     

Technical Aspects of Laparoscopic Ovarian Autograft in Ewes After Cryopreservation by Slow-Cooling Protocol

Iatrogenic ovarian failure and infertility are long term‐term side effects of anticancerous gonadotoxic treatments in children or women of reproductive year. Ovarian cortex cryopreservation can be a solution to preserve immature germinal cells before gonadotoxic treatment, for later transplantation. The aim of our study was to prove the efficiency of a laparoscopic technique for orthotopic graft after a slow‐freezing/thawing protocol, and to evaluate the effect of ovarian cryopreservation and autograft on the primordial follicle survival rate. Experimental surgical study was performed on 6‐ to 12‐month‐old ewes. The study was approved by the ethic committee of the Lyon‐veterinary‐school. The left ovary was removed by laparoscopy and cut in half, and medulla was excised. In group 1 (n = 6), autograft was performed immediately on the right ovary, and in group 2 (n = 6), graft was performed after a slow‐freezing/thawing protocol. The second hemi‐ovary served as an ungrafted control fragment. A polypropylene/polyglactin mesh was included between graft and base to separate the two structures, to help histological analysis. The mean graft performance time was 71 ± 8 min in the first group and 57 ± 10 min in the second. Freezing did not affect the number of primordial follicles. In the ungraft control fragments, the global anomaly rate (cytoplasm plus nuclear anomaly) increased after freezing (p < 0.05). Others results did not reach signification. Pelvic adhesion occurred only once. The post‐graft primordial follicle survival rate was 5.1 ± 2.8% in the non‐frozen group vs. 6.3 ± 2.3% after freezing/thawing. Kruskal–Wallis and Wilkoxon non‐parametric tests were used for statistical analysis. Laparoscopy seems to be a well‐adapted technique for ovarian tissue orthotopic autograft. The main follicle loss occurs before graft revascularization. Our orthotopic graft’s procedure has to be improved to obtain a better graft’s neovascularization, and to have a better long‐term post‐graft primordial follicle survival rate.     

Ultrasonic shear wave velocities of MgSiO3 perovskite at 8 GPa and 800 K and lower mantle composition

Ultrasonic interferometric measurements of the shear elastic properties of MgSiO3 perovskite were conducted on three polycrystalline specimens at conditions up to pressures of 8 gigapascals and temperatures of 800 kelvin. The acoustic measurements produced the pressure (P) and temperature (T) derivatives of the shear modulus (G), namely ( partial differentialG/ partial differentialP)T = 1.8 +/- 0.4 and ( partial differentialG/ partial differentialT)P = -2.9 +/- 0.3 x 10(-2) gigapascals per kelvin. Combining these derivatives with the derivatives that were measured for the bulk modulus and thermal expansion of MgSiO3 perovskite provided data that suggest lower mantle compositions between pyrolite and C1 carbonaceous chondrite and a lower mantle potential temperature of 1500 +/- 200 kelvin.     

Agronomic and environmental implications of enhanced s‐triazine degradation

Novel catabolic pathways enabling rapid detoxification of s‐triazine herbicides have been elucidated and detected at a growing number of locations. The genes responsible for s‐triazine mineralization, i.e. atzABCDEF and trzNDF, occur in at least four bacterial phyla and are implicated in the development of enhanced degradation in agricultural soils from all continents except Antarctica. Enhanced degradation occurs in at least nine crops and six crop rotation systems that rely on s‐triazine herbicides for weed control, and, with the exception of acidic soil conditions and s‐triazine application frequency, adaptation of the microbial population is independent of soil physiochemical properties and cultural management practices. From an agronomic perspective, residual weed control could be reduced tenfold in s‐triazine‐adapted relative to non‐adapted soils. From an environmental standpoint, the off‐site loss of total s‐triazine residues could be overestimated 13‐fold in adapted soils if altered persistence estimates and metabolic pathways are not reflected in fate and transport models. Empirical models requiring soil pH and s‐triazine use history as input parameters predict atrazine persistence more accurately than historical estimates, thereby allowing practitioners to adjust weed control strategies and model input values when warranted. Published in 2010 by John Wiley & Sons, Ltd.     

Indigofera spicata (creeping indigo) poisoning of three ponies

Three ponies continuously grazed a pasture containing an estimated 24% Indigofera spicata (wet weight basis) for 4–6 weeks in April and May 2004. They developed ataxia, paresis, depression, muscle fasciculations, dysphagia, ptyalism and halitosis. Two also developed corneal opacity. One pony recovered with supportive treatment, but the other two were euthanased and necropsied. Neuropathology was not present in either case, but both livers had periacinar and periportal lymphocytic infiltrations and hydropic degeneration of mid‐zonal hepatocytes, with mild to moderate periacinar necrosis also evident in one. The I. spicata contained 2.66 mg 3‐nitropropionic acid (3‐NPA)/g dry matter and 1.5 mg indospicine/g dry matter. Indospicine, but not 3‐NPA, was detected in serum from both of the euthanased ponies and indospicine was detected in heart, liver and muscle from the one pony in which this assay was performed. The clinical syndrome closely resembled ‘Birdsville horse disease’ caused by I. linnaei and was similar to that reported in horses poisoned by the closely related species I. hendecaphylla and to 3‐NPA poisoning of other animals, including humans. 3‐NPA is thought to cause this neurological syndrome. To our knowledge, this is the first authenticated report of I. spicata poisoning in grazing animals. We also report here the first published evidence that 3‐NPA and indospicine exist in naturalised I. spicata in Australia and of the formation of indospicine residues in tissues of animals grazing paddocks infested with I. spicata.