Outbreak of immature paramphistomosis in Nellore Jodipi sheep.

An outbreak of immature paramphistomosis in Nellore Jodipi sheep was recorded in Nellore district of Andhra Pradesh in 158 sheep during the months of April-June-2012. The condition is diagnosed as immature paramphistomosis on the basis of symptoms, dung sample examination and necropsy findings. The infected sheep exhibited symptoms like persistent foetid, blackish diarrhoea, sub maxillary edema, dehydration and death. Necropsy findings include hemorrhagic thickening and necrosis of proximal duodenal mucosa, ascites, gelatinization of subcutaneous and renal fat. Duodenal scrapings revealed large number of immature paramphistomes under low power microscopy. Recovery of ailing sheep was observed after oral treatment of niclosamide @ of 100 mg/kg bwt along with supportive therapy.

In vitro and in vivo studies of biodegradable fine grained AZ31 magnesium alloy produced by equal channel angular pressing.

The objective of the present work is to investigate the role of different grain sizes produced by equal channel angular pressing (ECAP) on the degradation behavior of magnesium alloy using in vitro and in vivo studies. Commercially available AZ31 magnesium alloy was selected and processed by ECAP at 300°C for up to four passes using route Bc. Grain refinement from a starting size of 46µm to a grain size distribution of 1-5µm was successfully achieved after the 4th pass. Wettability of ECAPed samples assessed by contact angle measurements was found to increase due to the fine grain structure. In vitro degradation and bioactivity of the samples studied by immersing in super saturated simulated body fluid (SBF 5×) showed rapid mineralization within 24h due to the increased wettability in fine grained AZ31 Mg alloy. Corrosion behavior of the samples assessed by weight loss and electrochemical tests conducted in SBF 5× clearly showed the prominent role of enhanced mineral deposition on ECAPed AZ31 Mg in controlling the abnormal degradation. Cytotoxicity studies by MTT colorimetric assay showed that all the samples are viable. Additionally, cell adhesion was excellent for ECAPed samples particularly for the 3rd and 4th pass samples. In vivo experiments conducted using New Zealand White rabbits clearly showed lower degradation rate for ECAPed sample compared with annealed AZ31 Mg alloy and all the samples showed biocompatibility and no health abnormalities were noticed in the animals after 60days of in vivo studies. These results suggest that the grain size plays an important role in degradation management of magnesium alloys and ECAP technique can be adopted to achieve fine grain structures for developing degradable magnesium alloys for biomedical applications.

Brassinosteroid control of sex determination in maize.

Brassinosteroids (BRs) are plant hormones that regulate growth and development. They share structural similarities with animal steroids, which are decisive factors of sex determination. BRs are known to regulate morphogenesis and environmental stress responses, but their involvement in sex determination in plants has been only speculative. We show that BRs control sex determination in maize revealed through characterization of the classical dwarf mutant nana plant1 (na1), which also feminizes male flowers. na1 plants carry a loss-of-function mutation in a DET2 homolog--a gene in the BR biosynthetic pathway. The mutant accumulates the DET2-specific substrate (24R)-24-methylcholest-4-en-3-one with a concomitant decrease of downstream BR metabolites. Treatment of wild-type maize plants with BR biosynthesis inhibitors completely mimicked both dwarf and tasselseed phenotypes of na1 mutants. Tissue-specific na1 expression in anthers throughout their development supports the hypothesis that BRs promote masculinity of the male inflorescence. These findings suggest that, in the monoecious plant maize, BRs have been coopted to perform a sex determination function not found in plants with bisexual flowers.