Methanogen populations in the rumen and in model rumen systems (operated over a 240-h period) were studied using the small subunit (SSU) rRNA phylogenetic framework for group-specific enumerations. ...Representatives of the family Methanobacteriaceae were the most abundant methanogen population in the rumen, accounting for 89.3% (+/- 1.02%) of total archaea in the rumen fluid and 99.2% (+/- 1.8%) in a protozoal fraction of rumen fluid. Their percentage of archaca in the model rumen systems declined from 84% (+/- 8.5%) to 54% (+/- 7.8%) after 48 h of operation, correlated with loss of protozoa from these systems. The Methanomicrobiales, encompassed by the families Methanomicrobiaceac, Methanocorpusculaceae, and Methanospirillaceae were the second most abundant population and accounted for 12.1% (+/-2.15%) of total SSU rRNA in rumen fluid. Additionally this group was shown to be essentially free living, since only a negligible hybridization signal was detected with the ruminal protozoal fraction. This group constituted a more significant proportion of total archaea in whole rumen fluid, 12.1% ( +/- 2.1%) and model rumen fluid containing no protozoa (26.3 +/- 7.7%). In contrast, the Methanosarcinales, generally considered the second most abundant population of rumen methanogens, accounted for only 2.8% (+/-0.3%) of total archaeal SSU rRNA in rumen fluid.
Predicting the response of cardiac output to volume administration remains an ongoing clinical challenge. The objective of our study was to compare the ability to predict volume responsiveness of ...various functional measures of cardiac preload. These included pulse pressure variation (PPV), stroke volume variation (SVV), and the recently launched automated respiratory systolic variation test (RSVT) in patients after major surgery.
In this prospective study, 24 mechanically ventilated patients after major surgery were enrolled. Three consecutive volume loading steps consisting of 300 ml 6% hydroxyethylstarch 130/0.4 were performed and cardiac index (CI) was assessed by transpulmonary thermodilution. Volume responsiveness was considered as positive if CI increased by >10%.
In total 72 volume loading steps were analysed, of which 41 showed a positive volume response. Receiver operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.70 for PPV, 0.72 for SVV and 0.77 for RSVT. Areas under the curves of all variables did not differ significantly from each other (P>0.05). Suggested cut-off values were 9.9% for SVV, 10.1% for PPV, and 19.7° for RSVT as calculated by the Youden Index.
In predicting fluid responsiveness the new automated RSVT appears to be as accurate as established dynamic indicators of preload PPV and SVV in patients after major surgery. The automated RSVT is clinically easy to use and may be useful in guiding fluid therapy in ventilated patients.
Summary
Ammonia‐oxidizing bacteria (AOB) play an important role in nitrogen cycling in estuaries, but little is known about AOB diversity, distribution and activity in relation to the chemical and ...physical changes encountered in estuary systems. Although estuarine salinity gradients are well recognized to influence microbial community structure, few studies have examined the influence of varying salinity on the diversity and stability of AOB populations. To investigate these relationships, we collected sediment samples from low‐, mid‐ and high‐salinity sites in Plum Island Sound estuary, MA, during spring and late summer over 3 years. Ammonia‐oxidizing bacteria distribution and diversity were assessed by terminal restriction fragment length polymorphism (TRFLP) analysis of the ammonia monooxygenase (amoA) gene, and fragments were identified by screening amoA clone libraries constructed from each site. Most striking was the stability and low diversity of the AOB community at the high‐salinity site, showing little variability over 3 years. Ammonia‐oxidizing bacteria at the high‐salinity site were not closely related to any cultured AOB, but were most similar to Nitrosospira spp. Ammonia‐oxidizing bacteria at the mid‐ and low‐salinity sites were distributed among Nitrosospira‐like sequences and sequences related to Nitrosomonas ureae/oligotropha and Nitrosomonas sp. Nm143. Our study suggests that salinity is a strong environmental control on AOB diversity and distribution in this estuary.
Transcriptomic imputation approaches combine eQTL reference panels with large-scale genotype data in order to test associations between disease and gene expression. These genic associations could ...elucidate signals in complex genome-wide association study (GWAS) loci and may disentangle the role of different tissues in disease development. We used the largest eQTL reference panel for the dorso-lateral prefrontal cortex (DLPFC) to create a set of gene expression predictors and demonstrate their utility. We applied DLPFC and 12 GTEx-brain predictors to 40,299 schizophrenia cases and 65,264 matched controls for a large transcriptomic imputation study of schizophrenia. We identified 413 genic associations across 13 brain regions. Stepwise conditioning identified 67 non-MHC genes, of which 14 did not fall within previous GWAS loci. We identified 36 significantly enriched pathways, including hexosaminidase-A deficiency, and multiple porphyric disorder pathways. We investigated developmental expression patterns among the 67 non-MHC genes and identified specific groups of pre- and postnatal expression.
The lattice Boltzmann numerical method is applied to model blood flow (plasma and platelets) and clotting in intracranial aneurysms at a mesoscopic level. The dynamics of blood clotting (thrombosis) ...is governed by mechanical variations of shear stress near wall that influence platelets–wall interactions. Thrombosis starts and grows below a shear rate threshold, and stops above it. Within this assumption, it is possible to account qualitatively well for partial, full or no occlusion of the aneurysm, and to explain why spontaneous thrombosis is more likely to occur in giant aneurysms than in small or medium sized aneurysms.
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