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“The near ubiquitous distribution of nifH genes in sediments sampled from 14 high-temperature (48.0-89.0 degrees C) and acidic (pH 1.90-5.02) geothermal springs in Yellowstone National Park suggested a role for the biological reduction of dinitrogen (N-2) to ammonia (NH3) (e.

g. nitrogen fixation or diazotrophy) in these environments. nifH genes from these environments formed three unique phylotypes that were distantly related to acidiphilic, mesophilic diazotrophs. Acetylene reduction assays and N-15(2) tracer studies in microcosms containing sediments sampled from acidic and high-temperature environments where nifH genes were detected confirmed the potential for biological N-2 reduction in these environments. Rates of acetylene Rabusertib order reduction by sediment-associated populations were positively correlated with the concentration of NH4+, suggesting a potential relationship between NH4+ consumption and N-2 fixation activity. Amendment of microcosms with NH4+ resulted in increased lag times in acetylene reduction assays. Manipulation of

incubation temperature and pH in acetylene reduction assays indicated that diazotrophic populations are specifically adapted to local conditions. Incubation of sediments in the presence of a N-2 headspace yielded a highly enriched culture containing a single nifH phylotype. This phylotype was detected in all 14 geothermal spring sediments examined and its abundance find more ranged from similar to 780 to similar to 6800 copies (g dry weight sediment)(-1), suggesting that this organism may contribute N to the ecosystems. Collectively, these results for the first time demonstrate NU7026 datasheet thermoacidiphilic N-2 fixation in the natural environment and extend the upper temperature for biological N-2 fixation in terrestrial systems.”
“Purpose To assess whether use of recombinant human bone morphogenetic protein-2 (rhBMP-2) during lumbar spinal fusion surgery affects subsequent risk of pancreatic cancer.\n\nMethods Using US Medicare claims data, we performed a retrospective cohort study of patients who underwent lumbar spinal fusion surgery

between October 2003 and December 2005. The study population, all > 66 years, was identified from procedure codes for lumbar fusion. Claims for a bone morphogenetic protein (BMP) served as a proxy for rhBMP-2 exposure (another BMP product shared the same code). Pancreatic cancer was identified from claims indicating this diagnosis and cancer-specific therapy. We used Cox proportional hazard regression to estimate hazard ratios (HRs) and 95%CIs.\n\nResults Of the 93 654 patients in the study, the mean age was 75 years, and 16.5% had claims for BMP. During a mean 1.4 years of follow-up, 91 patients were diagnosed with pancreatic cancer (eight in the BMP- and 83 in the non-BMP cohort). Consistent with previous research, pancreatic cancer was associated with older age, male gender, black race, and diabetes mellitus.