Genetics of Body Color in Tilapia mossambica

Gold, bronze, and black (normal pigmentation) body colors in Tilapia mossambica are controlled by a single autosomal gene with incomplete dominant gene action: GG fish are black gg fish are gold; Gg fish are bronze. Because gold body color is produced by the recessive genotype, it is easy to produce and to maintain a truebreeding population of gold T. mossambica for commercial purposes. If all other colors are culled, the population will breed true, because gold × gold will always produce 100% gold offspring. The G gene will be a valuable genetic marker for many genetic studies, such as the production of gynogenetic T. mossambica .     

Inhibin and reproduction. First communication: changes to inhibin level in Barki ewes after artificial infection with bluetongue virus

Bluetongue virus type 16, isolated from sheep in Egypt, was injected to 4 normally cycling Barki ewes and caused high levels of inhibin. This was assayed by a biological method, using suppression of the luteinising hormone (LH) of castrated rats. Albumin (fraction 2) was injected to normally cycling ewes. The sera of injected ewes were investigated 1 day after injection and weekly up to the 4th one injection. There was a gradual decrease of LH (4.8 +/- 0.52 I.U./ml serum) until the minimum level (1.17 +/- 0.25 I.U./ml serum) was reached, in comparison to the control serum LH which was 5.26 +/- 0.52 I.U./ml serum during the dioestrous phase.     

Chromosome localisation of genes for resistance to Heterodera schachtii, Cercospora beticola and Polymyxa betae using sets of Beta procumbens and B. patellaris derived monosomic additions in B. vulgaris

Beet cyst nematodes (BCN, Heterodera schachtii), Cercospora beticola, and rhizomania, caused by the beet necrotic yellow vein virus (BNYVV) and vectored by the soil-borne fungus Polymyxa betae, are the most serious diseases of sugar beet ( Beta vulgaris subsp. vulgaris). The wild Beta species of section Procumbentes are known to be completely resistant to H. schachtii, C. beticola and P. betae. Alien monosomic additions (2n=19), plants of cultivated beet (2n=18) carrying different individual chromosomes of B. procumbens (2n=18) or B. patellaris (2n=36), were tested in greenhouse experiments for resistance to these pathogens. Gene(s) conferring full resistance to the beet cyst nematode in B. patellaris are located on chromosome 1.1, and the other tested chromosomes of B. patellaris are not involved in the expression of resistance. Artificial inoculation under greenhouse conditions, with in vitro produced inoculum of C. beticola and spot-percentage rating of the disease intensity, showed that the high level of resistance that was observed in the wild species B. procumbens and B. patellaris was not found in any of the monosomic additions tested. It was suggested that genes on various chromosomes of the wild species are needed to express full resistance, and that the chromosomes of group 7 of B. patellaris and chromosome 7 of B. procumbens have the largest effect. The greenhouse tests for resistance to P. betae in B. patellaris derived monosomic additions showed that the addition families of group 4.1 have a strong partial resistance, while the addition families of group 8.1 appeared to be completely resistant to the pathogen. Resistance to P. betae in the two wild species as well as in the two resistant addition types did not exclude infection with BNYVV, but resulted in a considerable reduction of the virus concentration. It was concluded that resistance to the vector would complement virus resistance, and may provide a more effective and durable control of rhizomania. This revised version was published online in July 2006 with corrections to the Cover Date.     

Copper functionalization of polypropylene fabric surface in order to use in fog collectors

Polypropylene fabrics were coated with copper particles using electroless plating, screen printing and wire arc spray coating techniques. Surface morphology of the fabrics was studied using optical and scanning electron microscopes (SEM). Furthermore, tensile strength, electrical conductivity, thermal conductivity, air permeability, water contact angle and fog collection efficiency of the coated fabrics were measured and the obtained results were analyzed. SEM micrographs showed that a very thin and uniform layer of copper deposited on the surface of the electroless plated polypropylene fibers. In the printed or spray coated fabrics the copper particles filled the spaces between yarns and fibers. The polypropylene electroless copper plated fabrics showed higher tensile strength, electrical conductivity, air permeability and thermal conductivity when compared with the fabrics coated with copper screen printed and copper spray coated fabrics. Finally, the obtained results showed that copper electroless plating could increase the fog collection efficiency of polypropylene fabrics considerably. As a conclusion, the surface modified copper electroless polypropylene fabrics are good candidates for fog collection in appropriate regions which need further investigations.     

Protective Effects of Interleukin-4 on Tissue Destruction and Morphological Changes of Bovine Nasal Chondrocytes in vitro

Background: Previous studies have shown that some cytokines have protective effects on cartilage in joint diseases. In the current study, effects of IL-4 against morphological changes and tissue degradation induced by IL-1α on bovine nasal cartilage (BNC) explants were investigated. Methods: Fresh BNC samples were prepared from a slaughterhouse under sterile conditions. BNC explants culture was treated with both IL-lα (10 ng/ml) and IL-4 (50 ng/ml) at the same time for 28 days. The morphological characteristics of explants were assessed by using histology techniques and invert microscopy. Matrix metalloproteinase-1 (MMP-1) production was assessed within different days by using Western blotting. Results: IL-lα induced prominent cartilage morphology degradation. The pro and active form of MMP-1 band substantially increased at day 21 of culture. In the presence of both IL-lα and IL-4, chondrocytes preserved their ordinary normal phenotype with intact extracellular matrix. In addition, a significant reduction in pro-MMP-1and inhibition of active MMP-1 was seen. Conclusion: In conclusion, IL-4 could be regarded as a potential candidate in cartilage protecting against the degradation changes of IL-lα. It seems that the preservation effect of IL-4 is associated with significant reduction of MMP-1. Key Words: Chondrocyte, Interleukin-1α, Interleukin-4, Matrix metalloproteinase-1, Bovine nasal cartilage     

Acidulated activation of phosphate rock enhances release,lateral transport and uptake of phosphorus and trace metals upon direct-soil application

Phosphate rock (PR) was activated via acidulation with HCl, EDTA, and oxalic acid to enhance its reactivity. The release, lateral transport, and uptake of phosphorus (P) along with trace metals from pristine and activated PRs were investigated in a soil micro-block system over a period of 27 days, using wheat (Triticum aestivum L.) plants. Significantly (p < 0.05) higher amounts of available soil P, Fe, Mn, and Zn were released from all the PRs after application to soil within first 9 days of seedling transplantation, while the release of other trace metals (Cd, Co, Cr, Cu, Ni, and Pb) was minimal (<1.2 mg kg^?1). On cumulative basis, APR-O (oxalic acid activated PR) was the most efficient amendment releasing 164% more available P, followed by APR-E (EDTA activated PR) releasing 130% more available P, compared to the pristine PR. Similar results were also observed in the release of available Fe, Mn, Zn, and other trace metals. The highest diffusive mass fluxes for available P, Mn, Fe, and Zn in soil were observed after 3 days of seedling transplantation, which reduced subsequently. The uptake of P, Fe, Mn, and Zn by wheat plants was increased by 394%, 715%, 92%, and 91%, respectively, in APR-O application compared to the pristine PR, while it was increased by 280%, 188%, 16%, and 27%, respectively, in APR-E application compared to the pristine PR. Subsequently, APR-O and APR-E amendments resulted in enhanced shoot lengths, root lengths, shoot dry matter, and root dry matter contents of wheat plants. Hence, it was concluded that activation of PR with oxalic acid and EDTA prior to direct soil application may enhance the reactivity of PR and could serve as a cost-effect fertilization strategy for higher wheat crop production.     

Hydrocarbons in Seawater and Water Extract of Jarzouna-Bizerte Coastal of Tunisia (Mediterranean Sea): Petroleum Origin Investigation Around Refinery Rejection Place

In this study, the occurrence of toxic heavy metals (As, Cd, Cr, Cu, Pb, and Zn) and relative bioaccumulation in biota samples were investigated in a freshwater ecosystem, the Basento river, one of the main aquatic systems in the south of Italy, which over the last years has been transformed into a sink of urban and industrial wastes. Therefore, the levels of arsenic, cadmium, chromium, copper, lead, and zinc were determined in water, sediments, and tissues of some macroinvertebrate—which are natural assessment endpoints for the evaluation of ecological risk in aquatic systems. Accumulation factors, as a ratio between the concentration of a given contaminant in biota and the one in an abiotic medium, were considered in order to estimate heavy metal contamination loads in biota. Statistical analysis was performed for a comparative evaluation of bioaccumulation among various macroinvertebrates, according to different feeding guilds. The Tukey honestly significantly different test showed significant differences in the bioaccumulation of As, Cd, and Cr among the considered biological receptors (collector–gatherer, predator, and filterer), suggesting that the biological uptake from immediate contact with the sediment or solid substratum (collector–gatherer), instead of the bioconcentration from water (filterer) or biomagnification along the biotic food webs (predators), is the more effective biological sequestering pathway for these metals. Biota–sediment accumulation factors, commonly used for the evaluation of sediment’s role in aquatic systems contamination, were determined for the considered metals. A linear correlation between the concentrations of As, Cd, Cr, and Zn in macroinvertebrates and those in the sediments suggested that the metal uptake data in macroinvertebrates can provide useful information for the estimation of heavy metal exposure risk or bioavailability when making assessments of sediment toxicity in freshwater ecosystems.     

Effect of varying density and water level on the spawning response of African catfish Clarias gariepinus: Implications for seed production

The development of a reliable methodology for spawning of African catfish, Clarias gariepinus without the use of hormone injections would greatly improve the prospects of aquaculture in Africa. Earlier work has shown that it is possible to produce C. gariepinus fingerlings by subjecting the broodfish to a physical stress of reduced water depth and/or increased temperature. The hypothesis that C. gariepinus could be induced to spawn through a combined physical stress of lowered water level and increased stocking density was tested in concrete tanks. Three water levels (25, 50 and 75 cm) and three stocking densities (2, 4 and 6 pairs of broodfish at a 1:1 sex ratio in each hapa) were tested. Water depth in the tanks and brood fish density in the hapas affected spawning success. The percentage of spawning females was significantly higher when broodfish were stocked at 2 and 4 pairs in each hapa at water levels of 25 cm or 50 cm. There was no significant difference in spawning response between the 25 and 50 cm depths while a significant difference was seen between the 75 cm and both 25 and 50 cm depths. The results indicate optimum levels and densities for enhancing spawning success in C. gariepinus.     

Investigation of soil compaction on yield and agronomic traits of wheat under saline and non-saline soils

Inappropriate crop management and long-term use of heavy agricultural equipment can lead to soil compaction. On the other hand, soil and water salinity causes reduction in the plant yield in addition to adverse effects on plants tolerance to the various stresses. The aim of this study was to investigate the interaction between soil compaction and salinity on the macronutrients uptake and wheat yield as well as its agronomic traits. The pot experiment was carried out on the loamy soil in a completely randomized block design with three replications. The treatments consisted of two salinity types (saline, EC = 6 dS/m and non-saline soil) and five levels of compaction; control, 5%, 10%, 15% and 20%. The results showed that soil compaction had significant effect on the amount of N, P and K in wheat grain, so that the uptake of N, P and K by grain has been decreased by increasing the compaction level of soil. Soil salinity had significant effect on N, P and K content in grain that the content of N, P and K has been diminished in the saline treatments compared to non-saline treatments. Results on the agronomic traits and yield of wheat also revealed that soil compaction and salinity had significant effect (p < 0.01) on straw weight, number of ears, number of grain, and thousand grain weight which caused reduction in these parameters. The interaction between compaction and salinity had only significant correlation (p < 0.01) with thousand grain weight leading to the decrement of thousand grain weight with increasing compaction levels, particularly in the saline treatment.