517 research outputs found

    Fecal coliform decay and regrowth kinetics in an anaerobic dairy wastewater environment

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    The kinetics of fecal coliforms (FC) decay and regrowth were analyzed under laboratory conditions using filtered dairy wastewater under anaerobic conditions. The mean specific growth rates during the regrowth phase, µr , in the batch study were 1.79, 1.46, and 1.27d-1 for initial organic carbon concentrations of 478, 235 and 127 mg/L COD, respectively. The substrate concentrations had a significant impact on the FC regrowth. A maximum specific growth rate (mmax) of 1.92 d-1, and half-saturated coefficient (ks) of 60.92mg/L were determined from these data. The mean dark FC decay rate coefficients, kd , at 35oC in the batch study were 2.19, 2.52 and 3.29 d-1 for organic carbon concentrations of 478, 235 and 127 mg/L COD, respectively. The effect of substrate concentrations on the FC dark decay rate coefficient was significant (P-value=0.0004). A simple linear regression equation of kd= 3.460-0.00497 *S was obtained for the batch study. The decay rate coefficients of FC, determined from non-steady state data, for hydraulic retention times of 1.7, 3.5, and 6.9days at 25oC were 1.34, 1.57, and1.38 d-1, respectively. The mean µr values in the CSTR at 35oC were 0.83, 2.85, 2.68, 2.29, 2.11 d-1 for the hydraulic retention times of 1.7, 3.5 (Trial 1), 3.5 (Trial 2), 3.5 (Trial 3) and 6.9days, respectively. mmax of 4.00d-1, and ks of 275.12mg/L were obtained for the CSTR studies. mmax of 3.03 d-1, and ks of 169.01mg/L was obtained for the combined data from batch and CSTR studies. The mean kd-ìd values determined from the non-steady state data for hydraulic retention times of 1.7, 3.5 (Trial 1), 3.5(Trial 2), 3.5 (Trial 3), and 6.9days at 35oC were 4.67, 1.72, 0.72, 1.63, and 5.87d-1, respectively. These results indicate that the 3.5days hydraulic retention time reactors were near steady state conditions

    Isolation and Characterization of New 24 Microsatellite DNA Markers for Golden Cuttlefish (Sepia esculenta)

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    Twenty-four microsatellite DNA markers were isolated and characterized for golden cuttlefish (Sepia esculenta) from a (GT)13—enriched genomic library. Loci were tested in 48 individuals from Jiaozhou bay of China. The numbers of alleles per locus ranged from two to 25 with an average of 10.3. The observed and expected heterozygosities ranged from 0.063 to 0.896 and from 0.137 to 0.953, with averages of 0.519 and 0.633, respectively. Six loci significantly deviated from Hardy-Weinberg equilibrium after Bonferroni’s correction and no significant linkage disequilibrium between loci pairs was detected. These microsatellite markers would be useful for analyzing the population genetic structure to make conservation and management decisions for S. esculenta

    Population genetic structure and demographic history of small yellow croaker, Larimichthys polyactis (Bleeker, 1877), from coastal waters of China

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    Small yellow croaker, Larimichthys polyactis (Bleeker, 1877), a commercially important benthopelagic fish, is widely distributed in the Bohai, Yellow and East China Seas. To evaluate the population genetic structure and demographic history of L. polyactis, we sequenced the complete mitochondrial deoxyribonucleic acid (mtDNA) control region (798 to 801 bp) in 127 individuals sampled from seven localities throughout its distribution region in China. A total of 136 polymorphic sites were detected, which defined 125 haplotypes. High haplotype diversity (1.000 ± 0.013 to 1.000 ± 0.034) and moderate nucleotide diversity (0.0112 ± 0.0061 to 0.0141 ± 0.0075) were detected in the species. The neighbor-joining tree of haplotypes was assigned into two closely related clades, but did not appear to have any geographic genealogic structure. Hierarchical molecular variance analysis (AMOVA), pair wise FST comparisons and the nearest-neighbor statistic (Snn) showed no significant genetic differences among populations in the Bohai, Yellow and East China Seas. The demographic history of L. polyactis was examined by using neutrality tests and mismatch distribution analysis, which revealed that the species had undergone a Pleistocene population expansion. The results based on the complete mtDNA control region sequences analysis indicate that within its distribution range, L. polyactis constituted a panmictic mtDNA gene pool. Factors such as dispersal capacity, ocean currents and insufficient evolution time could be responsible for the lack of population genetic differentiation in L. polyactis.Keywords: Larimichthys polyactis, mitochondrial control region, population genetic structure, demographi

    Effect of Eucommia ulmoides extract on osteoblast proliferation

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    Purpose: To evaluate the effect of Eucommia ulmoides extract (EUE) on osteoblast proliferation as well as investigate its probable mechanisms of action.Methods: EUE was pharmacologically evaluated at three doses. Osteoblast cells were divided as follows: Group I: negative control; groups II–IV: received EUE (180, 360 and 540 μg/ml, respectively). We performed 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay to determine osteoblast viability following treatment. Alkaline phosphatase (ALP), osteocalcin, and collagen I levels in osteoblasts were quantified using commercially available kits. Thereafter, mRNA and protein expression of ALP, collagen I, osteocalcin, transforming growth factor-β1 (TGF-β1) were measured using real-time quantitative PCR (qPCR) and western blot, respectively.Results: EUE significantly (p < 0.01) promoted osteoblast proliferation at three treatment doses (180, 360, and 540 μg/mL). Furthermore, ALP, osteocalcin, collagen I and TGF-β1 expression at both mRNA and protein levels increased significantly (all p < 0.05) following EUE treatment.Conclusion: The results suggest that EUE may promote osteoblast cell proliferation and that ALP, osteocalcin, collagen I and TGF-β1 gene expression may be involved in the mechanism of action.Keywords: qPCR, collagen I, Bone, Liver, Eucommia ulmoides extrac

    Expression and localization of estrogenic type 12 17β-hydroxysteroid dehydrogenase in the cynomolgus monkey

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    BACKGROUND: We have recently discovered that human type 12 17β-HSD (h17β-HSD12), a homolog of type 3 17β-HSD, is a new estrogen-specific 17β-hydroxysteroid dehydrogenase involved in the production of estradiol (E2). To further characterize this estradiol-producing enzyme, we have isolated the corresponding cDNA in the cynomolgus monkey (Macaca fascicularis), characterized its enzymatic activities and performed cellular localization using in situ hybridization. RESULTS: Using HEK-293 cells stably expressing Macaca fascicularis type 12 17β-HSD (mf17β-HSD12), we have found that the mf17β-HSD12 catalyzes efficiently and selectively the transformation of El into E2, in analogy with the h17β-HSD12. We have also quantified the mf17β-HSD12 mRNA expression levels in a series of Macaca fascicularis tissues using Quantitative RealTime PCR. The Macaca fascicularis 17β-HSD12 mRNA is widely expressed with the highest levels tissues found in the cerebellum, spleen and adrenal with moderate level observed in all the other examined, namely the testis, ovary, cerebral cortex, liver, heart, prostate, mammary gland, myometrium, endometrium, skin, muscle and pancreas. To gain knowledge about the cellular localization of the mf17β-HSD12 mRNA expression, we performed in situ hybridization using a (35)S-labeled cRNA probe. Strong labeling was observed in epithelial cells and stromal cells of the mammary gland. In the uterus, the labeling is detected in epithelial cells and stromal cells of the endometrium. CONCLUSION: These results strongly suggest that the Macaca fascicularis 17β-HSD12 is an essential partner of aromatase in the biosynthesis of estradiol (E2). It strongly suggests that in the estradiol biosynthesis pathway, the step of 17-ketoreduction comes after the step of the aromatization (the aromatization of 4-androstendione to estrone followed by the conversion of estrone into estradiol by estrogen specific l7β-HSDs) which is in contrast with the hypothesis suggesting that 4-androstenedione is converted to testosterone followed by the aromatization of testosterone
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