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[en] The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 μg/mL of PBDEs was added followed by incubation under 30 deg. C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.
[en] Functional loss of the Ataxia Telangiectasia-Mutated (ATM) gene product leads to a pleiotropic phenotype, with radiation hypersensitivity as one of the most widely studied events. We have recently reported that treatment of LNCaP human prostate cancer cells with the Protein Kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA) with radiation initiated an apoptotic response via activation of the enzyme ceramide synthase (CS) and de novo synthesis of the sphingolipid ceramide (Garzotto M et. al. 1999), while radiation alone failed to induce apoptosis in these cells. Recent studies in our laboratory showed that the CS pathway is activated in response to DNA damage and that this activation is regulated by the ATM gene product (Liao W-C et. al. 1999). Here, we show that TPA reduces the ATM protein level in both LNCaP and CWR22-Rv1 cells. Radiation alone had no significant effect on ATM levels in these prostate cancer cell lines, nor when applied together with TPA. TPA-induced reduction of ATM protein correlated with increased apoptosis in these cell lines. Quantitative RT-PCR showed a 50% reduction of ATM mRNA between 8-16 h of TPA treatment. Gel-shift analysis showed a significant reduction in the amount of Sp-1 transcription factor binding to the ATM promoter, as early as 4 h post TPA-treatment for LNCaP, but with slower kinetics for CWR22-Rv1. The use of morpholino-antisense ATM replaced the TPA effects by significantly reducing the levels of ATM protein present, and conferred intense XRT-induced activation of CS, ceramide and apoptosis. These data demonstrate that in some human prostate cell lines, transcription of ATM can be attenuated by TPA treatment, enhancing sensitivity to ionizing radiation through a CS-mediated pathway. This investigation defines a new approach to overcome radiation resistance in human prostate cancer cells in a cell-type specific manner
[en] Four Taiwanese native Miscanthus floridulus lines, collected at altitudes of 260, 500, 1000, and 1500 m were cultivated in 2009 and 2010. The plant height and tiller numbers of four M. floridulus lines increased gradually along with the growing time. These M. floridulus lines had the tallest plant height and most tiller number after these species were planted 210 days. Line 3, which was collected at the altitude of 1000 m, had the ability to grow at low temperature. Line 3 M. floridulus had the highest plant height, tiller number, fresh and dry yields than other three lines. Fresh and dry yields of Line 3 were positively correlated to the plant height, tiller number, and leaf width, but showed no correlation with the leaf length. The correlation between agronomic traits and climatic data was also studied. Results can be used as a model for developing a non-food crop-based energy production system in the future. -- Highlights: → Miscanthus floridulus collected at 1000 m altitude had the highest plant height, tiller number, fresh and dry yields. → Fresh and dry yields of were positively correlated to the plant height, tiller number, and leaf width. → Fresh and dry yields showed no correlation with the leaf length. → The accumulative rainfall, temperature, radiation, and exposure time to radiation were positively correlated to the plant height, leaf length and leaf width.
[en] A new modeling concept to evaluate the effects of cadmium and copper on heterotrophic growth rate constant (μH) and lysis rate constant (bH) in activated sludge was introduced. The oxygen uptake rate (OUR) was employed to measure the constants. The results indicated that the μH value decreased from 4.52 to 3.26 d-1 or by 28% when 0.7 mg L-1 of cadmium was added. Contrarily the bH value increased from 0.31 to 0.35 d-1 or by 11%. When adding 0.7 mg L-1 of copper, the μH value decreased to 2.80 d-1 or by 38%. The bH value increased to 0.42 d-1 or by 35%. After regression, the inhibitory effect was in a good agreement with non-competitive inhibition kinetic. The inhibition coefficient values for cadmium and copper were 1.82 and 1.21 mg L-1, respectively. The relation between the bH values and heavy metal concentrations agreed with exponential type well. The heavy metal would enhance bH value. Using these data, a new kinetic model was established and used to simulate the degree of inhibition. It was evident that not only the inhibitory effect on μH but also that the enhancement effect on bH should be considered when heavy metal presented.