Sodicity‐induced land degradation and its sustainable management: problems and prospects

Currently at least 20 per cent of the world's irrigated land is salt‐affected. However, projections of global population growth, and of an increased demand for food and fibre, suggest that larger areas of salt‐affected soil will need to be cropped in the future. About 60 per cent of salt‐affected soils are sodic, and much of this land is farmed by smallholders. Ameliorating such soils requires the application of a source of calcium (Ca²⁺), which replaces excess sodium (Na⁺) at the cation exchange sites. The displaced Na⁺ is then leached from the root zone through excess irrigation, a process that requires adequate flows of water through the soil. However, it must now be recognized that we can no longer conduct sodic soil amelioration and management solely with the aim of achieving high levels of crop productivity. The economic, social, and environmental impacts of different soil‐amelioration options must also be considered. A holistic approach is therefore needed. This should consider the cost and availability of the inputs needed for amelioration, the soil depth, the level to which sodicity needs to be reduced to allow cropping, the volume and quality of drainage water generated during amelioration, and the options available for drainage‐water disposal or reuse. The quality and cost of water available for post‐amelioration crops, and the economic value of the crops grown during and after amelioration should also be taken into account, as should farmers' livelihoods, the environmental implications of amelioration (such as carbon sequestration), and the long‐term sustainable use of the ameliorated site (in terms of productivity and market value). Consideration of these factors, with the participation of key stakeholders, could sustainably improve sodic soil productivity and help to transform such soils into a useful economic resource. Such an approach would also aid environmental conservation, by minimizing the chances of secondary sodicity developing in soils, particularly under irrigated agriculture. Copyright © 2006 John Wiley & Sons, Ltd.     

Preparation and use of amine-functionalized glycidyl methacrylate-g-poly(ethylene terephthalate) fibers for removal of chromium(VI) from aqueous solution

Poly(ethylene terephthalate) (PET) fibers were grafted with glycidyl methacrylate (GMA) using benzoyl peroxide as initiator. 1,6-diaminohexane (HMDA) was then covalently attached to this GMA grafted PET fibers. Variations of time, temperature, initiator and monomer concentrations were investigated. HMDA-GMA-g-PET fibers were used as a new sorbent for removal of Cr(VI) ions from aqueous solutions through batch adsorption method. Effects of various parameters such as pH, treatment time, and initial ions concentration on the adsorption amount of ions onto reactive fibers were investigated. The adsorption rates of Cr(VI) ions were much higher on the HMDA-GMA-g-PET fiber than on GMA-g-PET and ungrafted PET fiber. Within 60 min, at pH 3, Cr(VI) was removed by 98 % while the initial concentration of ions was at 25 mg/l and by 94 % at 400 mg/l. The Cr(VI) ions adsorbed were easily desorbed by treating with 1M KOH within 10 min.     

The Prevalence of Bovine Hypodermosis in Kars Province,Turkey

A total of 1276 cattle from 76 farms in 8 villages were examined by palpation of the skin for evidence of hypodermosis. The effects of age, sex, breed, and colour of cattle on hypodermosis were investigated. The overall prevalence was 31.9%. The mean number of warble fly larvae on infested animals was 8.46. Hypodermosis infestations were encountered in all the villages visited. Within a herd, the intensity of infestion decreased with the age of cattle. Infestation rates of warble fly larvae were lower in native cattle, in females, and in piebald animals.     

Detection of rabies viral antigens in non-autolysed and autolysed tissues by using an immunoperoxidase technique

The objectives of this study were to determine the potential of an immunoperoxidase technique involving the avidin-biotin complex (ABC) stain for the diagnosis of rabies in fresh tissues and compare it with other standard methods, including the fluorescent antibody test (FAT), haematoxylin and eosin and Seller's stain, and to investigate its capacity to detect rabies antigen in autolysed tissues. Samples of non-autolysed brain from 81 domestic and wild animals suspected of having rabies were examined. Rabies antigen was detected by FAT in 41 of these samples and Negri bodies were detected in 40 (97.6 per cent) of them by the immunoperoxidase technique, in 25 by haematoxylin and eosin and in 22 by Seller's stain. The sensitivity of the immunoperoxidase technique decreased as the tissues were left to autolyse; after two days it was 91.2 per cent, after four days 70.6 per cent, and after seven days 11.8 per cent.     

Polypeptide Alteration During The Cold Stratification In Mazzard Seed

Many seeds of woody plants require low temperature for germination and that’s called seed dormancy has been investigated for relations of proteins by several researchers. We determined polypeptide profiles of cold-stratified Mazzard seeds. Seeds were studied in five different periods: seeds in dormancy (none stratified), 30, 60, 90 and 120 days cold-stratified. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) of the soluble protein fractions from stratified and none stratified seeds was utilized for determination of changes in polypeptides. SDS-PAGE revealed a decrease in the concentrations of 14 polypeptides and appearance of four low-molecular weight (15.1, 16.3, 17.8 and 19.4?kDa) polypeptides were determined in 90 and 120 day stratified seeds. The study results exhibited the evidences of the involvement of protein changes in response of Mazzard seeds during cold stratification.     

An optimised protocol for molecular identification of Eimeria from chickens

Molecular approaches supporting identification of Eimeria parasites infecting chickens have been available for more than 20 years, although they have largely failed to replace traditional measures such as microscopy and pathology. Limitations of microscopy-led diagnostics, including a requirement for specialist parasitological expertise and low sample throughput, are yet to be outweighed by the difficulties associated with accessing genomic DNA from environmental Eimeria samples. A key step towards the use of Eimeria species-specific PCR as a sensitive and reproducible discriminatory tool for use in the field is the production of a standardised protocol that includes sample collection and DNA template preparation, as well as primer selection from the numerous PCR assays now published. Such a protocol will facilitate development of valuable epidemiological datasets which may be easily compared between studies and laboratories. The outcome of an optimisation process undertaken in laboratories in India and the UK is described here, identifying four steps. First, samples were collected into a 2% (w/v) potassium dichromate solution. Second, oocysts were enriched by flotation in saturated saline. Third, genomic DNA was extracted using a QIAamp DNA Stool mini kit protocol including a mechanical homogenisation step. Finally, nested PCR was carried out using previously published primers targeting the internal transcribed spacer region 1 (ITS-1). Alternative methods tested included sample processing in the presence of faecal material, DNA extraction using a traditional phenol/chloroform protocol, the use of SCAR multiplex PCR (one tube and two tube versions) and speciation using the morphometric tool COCCIMORPH for the first time with field samples.     

Directing gonadal differentiation in bluegill, Lepomis macrochirus (Rafinesque), and black crappie, Pomoxis nigromaculatus (Lesueur), by periodic estradiol-17β immersions

We investigated the feminization of bluegill and black crappie by short periodic immersions in an aqueous estradiol‐17β (E₂) solution. Bluegill fry (13.8 mm) were immersed in a 1 mg L^?1 E₂ solution every 5 days on three occasions over an 11‐day period. In the positive control treatment, the same cohort of fry was fed 200 mg kg^?1 E₂ diet for 45 days. Two different size (26.1 and 20.1 mm) but the same age (45 days old) black crappie fry were immersed in the same concentration of E₂ solution for 5 h a day every 3–5 days on 10 occasions between 45 and 86 days post hatch. Both modes of E₂ administration were effective to induce feminization in bluegill. Feeding fry E₂ impregnated diet for 45 days yielded 99.3% female populations from a 38.8% female experimental population. Only three short‐time E₂ immersions of fry over a much shorter treatment period also produced 76.9% female populations. E₂ immersions had no effect on sex ratios of larger black crappie fry and produced variable levels of feminization (60–82% female) in smaller black crappie fry. Results of the present study showed that feminization in both species can be achieved by periodic immersions of fry in a 1 mg L^?1 E₂ solution with no adverse effects on survival. Yet, further researches on timing and intensity of immersion treatments are still needed for optimization of the procedures.     

Determination of chemical profile, antioxidant, DNA damage protection and antiamoebic activities of Teucrium polium and Stachys iberica

This work deals with the evaluation of in vitro antioxidant, DNA preventing and antiamoebic activities of the water extracts of Teucrium polium and Stachys iberica. In all systems, T. polium extract exhibited excellent activity potential than that of S. iberica. The amount of total phenolics and flavonoids were high in this extract. In the presence of 40 mg/ml T. polium extract, a significant protection was observed for native super coiled DNA of pBR322 plasmid DNA. In the presence of 32 mg/ml of T. polium extract, no trophozoite was after the 24th hour.