Anaerobic ammonium oxidation (anammox) is important for converting bioavailable nitrogen into dinitrogen gas, particularly in carbon-poor environments. However, the diversity and prevalence of anammox bacteria in the terrestrial subsurface-a typically oligotrophic environment-are little understood. To determine the distribution and activity of anammox bacteria across a range of aquifer lithologies and physicochemistries, we analyzed 16S rRNA genes and quantified hydrazine synthase genes and transcripts sampled from 59 groundwater wells and metagenomes and metatranscriptomes from an oxic-to-dysoxic subset.
View Article and Find Full Text PDFThere has been a growing trend in recent years towards the attribution of adult-like syntactic categories to young language-learning children. This is based, at least in part, on studies which claim to have found positive evidence for syntactic phrase structure categories in young children's speech. However, these claims contradict the findings of previous research which suggest that the categories underlying children's early multi-word speech are much more limited in scope.
View Article and Find Full Text PDFNucleic Acids Res
February 1986
The physical organization of eight Tetrahymena genes active during conjugation (meiosis) was examined in the somatic (macro-) and germinal (micro-) nuclei of this organism. Three of these genes make transcripts that are only detected during meiotic prophase. Southern blot analyses indicated that all genes examined were present in both nuclei.
View Article and Find Full Text PDFInsulin aggregation remains a fundamental obstacle to the long-term application of many insulin infusion systems. We here report the effects of physiologic and nonphysiologic compounds on the aggregation behavior of crystalline zinc insulin (CZI) solutions. Under conditions chosen to simulate the most severe that would be encountered in delivery systems (presence of air, continuous motion, and elevated temperature), both highly purified and regular CZI at 5 U/ml formed turbid gels in 5 days.
View Article and Find Full Text PDFA selection of neutral insulin formulations from commercially available vials was examined by quasi-elastic light scattering. In preliminary investigation, significant differences in the particulate nature of insulins from different manufacturers were apparent. Some preparations contained only small diameter species believed to be insulin hexamer while others showed evidence of larger aggregates and microcrystals.
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