“
“We still lack full mechanistic understanding of how the temperature history affects the future decomposition rate of litter and soil organic matter. To explore that, we used the GLUE modelling framework together with the Q-model and data from a needle litter incubation experiment to compare a differential temperature response of litter qualities to a temperature-dependent decomposer efficiency. The needle litter incubation
was a full factorial design with the initial and final temperatures 5, 15 and 25 degrees C. Samples were moved from the initial to the final temperature when approximately 12% of the initial carbon had been respired and the experiment terminated when an additional 12% had been lost. We used four variations of the Q-model; the litter was described as having one or two initial quality values and the decomposer efficiency was either fixed or allowed to vary with temperature. click here All variations were calibrated with good fits to the data subsets with equal initial and final temperatures. Evaluation against temperature shift subsets also showed good results, except just after the change in temperature where all variations
predicted a smaller response than observed. The effects of having one or two initial litter quality values (fixed decomposer efficiency) on end-of-experiment litter quality and respiration were marginal. Letting decomposer efficiency vary with temperature resulted in a decrease in efficiency between 5 and 15 degrees C but no change between 15 and 25 degrees C and in EPZ 6438 substantial differences in litter quality at the end of the initial incubation in response to incubation temperature. The temperature response of decomposition through temperature dependent decomposer efficiency proved, therefore, to be more important than the differential response to different substrate qualities. These results suggests that it may be important to consider other factors (e. g. microbial efficiency, changing substrate composition) than the temperature sensitivity coupled
to substrate quality when evaluating effects of temperature changes on soil organic matter stability.”
“Background: find more About 70% of human breast cancers express estrogen receptor alpha (ER alpha) and in this kind of breast cancer estrogen plays an important role. Estrogen independent growth has been reported to promote resistance to one of the selective estrogen receptor modulators (SERMs) tamoxifen which is clinically the first line treatment for patients with ER alpha-positive breast cancer. The resistance of tamoxifen is a major problem in the clinical management of breast cancer. Methods: We used MCF-7 cells with ectopic expression of MDTH in this study. MTT, clone formation and tumor formation in nude mice methods were utilized to confirm the role of MTDH in estrogen-independent growth and tamoxifen resistance.