The kinetic disposition and dosage regimen for carbenicillin in buffalo calves

The distribution half-life, elimination half-life, apparent volume of distribution and total body clearance of carbenicillin in healthy buffalo calves following a single intravenous administration (50 mg/kg) were 0.057±0.005 h, 1.688±0.11 h, 0.185±0.021 L kg^-1 and 75.97±6.519 ml kg^-1 h^-1 respectively. A satisfactory dosage regimen for carbenicillin in buffalo calves was calculated to be 56 mg/kg followed by 52 mg/kg body weight repeated at 6 h intervals.     

Soil Carbon and Nitrogen Stocks Under Plantations in Gambo District,Southern Ethiopia

The effect of six plantation species in comparison to natural forest (NF) on soil organic carbon (SOC) and total nitrogen (TN) stocks, depth-wise distribution, biomass carbon (C), and N was investigated on plantations and cultivated lands on an Andic paleudalf soil in Southern Ethiopia. The SOC, N, and bulk density were determined from samples taken in 4 replicates from 10-, 20-, 40-, 60-, and 100-cm depth under each site. Similarly, the biomass C and N of the plantation species and understory vegetation were also determined. The SOC and N were concentrated in the 0- to 10-cm depth and decreased progressively to the 1-m depth. Next to the NF, Juniperous procera accrued higher SOC and N in all depths than the corresponding plantations. No evidence of significant difference on SOC and N distribution among plantations was observed below the 10-cm depth with minor exceptions. The plantations accrue from 133.62 to 213.73 Mg ha^–1 or 59.1 to 94.5% SOC, 230.4 to 497.3 Mg ha^–1 or 6.9 to 14.9% TBC and 420.37 to 672.80 Mg ha^–1 or 12.5 to 20% total C-pool of that under the NF. The N stock under Juniperous procera was the highest, while the lowest was under Eucalyptus globulus and Cupressus lusitanica. We suggest that SOC and N sequestration can be enhanced through mixed cropping and because the performance of the native species Juniperous procera is encouraging, it should be planted to restock its habitat.     

Influence of Melatonin Treatments on Fruit Quality and Storage Life of Sweet Cherry cv. ‘Sweetheart’

The study was carried out to determine the effect of melatonin on quality and postharvest life of sweet cherries (Prunus avium L.) cv. ‘Sweetheart’ during storage. The fruits were dipped at different concentrations of melatonin (0, 250, 500 and 1000?µmol l^?1 for 10?min) and distilled water as control. The changes of sweet cherries were assessed at 7?day intervals by evaluating the following quality parameters: firmness, soluble solids content, titratable acidity, respiration rate, color values (L* and chroma), ascorbic acid content, total anthocyanin content, total phenolic content, and antioxidant activity. The results showed that increasing the dose to 1000?µmol l^?1 melatonin had a remarkable effect on maintaining the quality of sweet cherry. 1000?µmol l^?1 and 500?µmol l^?1 melatonin treatments significantly inhibited the decrease in firmness, ascorbic acid, total phenols, total anthocyanin, antioxidant content and reduced color changes and respiration rate. However, the total soluble solids content and titratable acidity of the fruit were not influenced by melatonin applications. These findings indicate that melatonin treatment may be effective in maintaining quality and bioactive compounds of sweet cherry fruit.

     

Haploidy in tomato (Lycopersicon esculentum Mill.): a critical review

Results on the induction of haploidy in tomato via both gynogenesis and microspore embryogenesis in vitro are far from satisfactory. The number of reports available on the gynogenic induction via in vitro non-fertilized ovary culture, wide hybridization and the use of irradiated pollen are limited. The main reason for this may be the difficulty experienced in working with this species. Therefore, many failed attempts have not been reported. Non-fertilized ovary culture and wide hybridization using Solanum sisymbriifolium Lam. as the male parent seem to be promising (Bal and Abak, Pak J Biol Sci 6:745–749, 2003a, b). Further efforts in this line may improve results obtained earlier. Several reports (Gresshoff and Doy, Planta 107:161–170, 1972; Sharp et al., Planta 104:357–361, 1972; Zamir et al., Plant Sci Lett 17:353–361, 1980; Chlyah and Taarji, Proc. Int. Symp. Plant tissue and cell culture application to crop improvement. 24–29 Sept. 1984; Jaramillo and Summers, J Amer Soc Hort Sci 115:1047–1050, 1990, HortScience 26:915–916, 1991; Summers et al., HortScience 27:838–840, 1992) are available on anther culture of tomato but a working protocol is yet to be developed. For the induction of anther callus, anthers carrying microspores at the meiotic stages appear to be the most responsive. However, the callus and the regenerants obtained were mainly of somatic origin. Somatic tissues of tomato anthers carrying the meiotic stages are highly responsive to tissue culture manipulations in comparison to anther tissues of the later stages. Therefore, reports on the induction of callus from anthers carrying early microspore stages should be met with caution. If culturing young anthers is of any help then it may be that the anther tissues are nursing the microspores and bringing them to the responsive uninucleate stage. Following the first report by Sharp et al. (Planta 104:357–361, 1972) on the induction of microspore embryogenesis, using a modified version of the microspore culture, reports concentrated only on anther culture (reviewed by Chlyah et al., Haploids in crop improvement I. Biotechnology in agriculture and forestry 12. Springer-Verlag, Berlin, 1990). Based on findings reported by Yinnan et al. (J Agric Biotechnol, , 1999) and Bal and Abak (Biotechnol Biotechnol Equip 19:35–42, 2005) on the induction of symmetrical division of microspore nuclei from uninucleate microspores, the formation of multicellular structures and globular embryos, it is likely that the future of tomato haploidy lies in the technique of isolated microspore culture.     

Mitosis and Differentiation in Roots Treated with Actinomycin

In the presence of actinomycin D (90 microg/ml), mitosis in root meristem of Allium cepa L. ceases after a delay of 36 hours. The block occurs at interphase. Differentiation of prevascular tissue is suppressed, and the evidence suggests it begins to fail before mitosis stops. Autoradiograms of roots treated with tritiated uracil show that synthesis of ribonucleic acid is blocked after mitosis fails. The effects of the antibiotic are reversible.