Knowlesgay1412

Productivity-poor oligotrophic environments are plentiful on earth. Yet it is not well-understood how organisms maintain population sizes under these extreme conditions. Most scenarios consider the adaptation of a single microorganism (isogenic) at the cellular level, which increases their fitness in such an environment. However, in oligotrophic environments, the adaptation of microorganisms at population level - that is, the ability of living cells to differentiate into subtypes with specialized attributes leading to the coexistence of different phenotypes in isogenic populations - remains a little-explored area of microbiology research. In this study, we performed experiments to demonstrate that an isogenic population differentiated to two sub-populations under low energy-flux in chemostats. Fluorescence cytometry and turnover rates revealed that these sub-populations differ in their nucleic acid content and metabolic activity. A mechanistic modeling framework for the dynamic adaptation of microorganisms with the consideration of their ability to switch between different phenotypes was experimentally calibrated and validated. Simulation of hypothetical scenarios suggests that responsive diversification upon a change in energy availability offers a competitive advantage over homogenous adaptation for maintaining viability and metabolic activity with time. This article is protected by copyright. All rights reserved.Aim Extended hours haemodialysis is associated with superior survival to standard hours. However, residual confounding limits the interpretation of this observation. We aimed to determine the effect of a period of extended hours dialysis on long-term survival among participants in the ACTIVE Dialysis trial. Methods Two-hundred maintenance haemodialysis recipients were randomized to extended hours dialysis (median 24 h/wk) or standard hours dialysis (median 12 h/wk) for 12 months. Further pre-specified observational follow up occurred at 24, 36 and 60 months. Vital status and modality of renal replacement therapy were ascertained. Results Over the 5 years, 38 participants died, 30 received a renal transplant, and 6 were lost to follow up. Total weekly dialysis hours did not differ between standard and extended groups during the follow-up period (14.1 hours [95%CI 13.4-14.8] vs 14.8 hours [95%CI 14.1-15.6]; P = .16). There was no difference in all-cause mortality (hazard ratio for extended hours 0.91 [95%CI 0.48-1.72]; P = .77). Similar results were obtained after censoring participants at transplantation, and after adjusting for potential confounding variables. Subgroup analysis did not reveal differences in treatment effect by region, dialysis setting or vintage (P-interaction .51, .54, .12, respectively). Conclusion Twelve months of extended hours dialysis did not improve long-term survival nor affect dialysis hours after the intervention period. An urgent need remains to further define the optimal dialysis intensity across the broad range of dialysis recipients.Reproductive isolation is a necessary condition for plant domestication in their domestication centre where crops co-occur with their wild progenitors. However, the identification of reproductive barriers and their relative contribution to reproductive isolation have been overlooked in plants under domestication. We assessed pre- and post-pollination reproductive barriers and their relative contribution to reproductive isolation between wild and domesticated chaya (Cnidoscolus aconitifolius) in its domestication centre. We found that wild and domesticated chaya both exhibit a high degree of reproductive isolation. However, the reproductive isolation barriers exhibited some asymmetry while pre-pollination barriers (differential pollen production and pollinator specificity) were only detected in wild plants, post-pollination barriers (pollen-pistil incompatibility and/or failure to set fruit) were observed in both wild and domesticated plants. We conclude that complete reproductive isolation has evolved in sympatry in co-occurring domesticated and wild chaya.Nitrate ( NO 3 - ) and nitrite ( NO 2 - ) ions are naturally occurring inorganic ions that are part of the nitrogen cycle. High doses of these ions in drinking water impose a potential risk to public health. In this work, molecular dynamics simulations are carried out to study the passage of nitrate and nitrite ions from water through graphene nanosheets (GNS) with hydrogen-functionalized narrow pores in presence of an external electric field. The passage of ions through the pores is investigated through calculations of ion flux, and the results are analyzed through calculations of various structural and thermodynamic properties such as the density of ions and water, ion-water radial distribution functions, two-dimensional density distribution functions, and the potentials of mean force of the ions. Current simulations show that the nitrite ions can pass more in numbers than the nitrate ions in a given time through GNS hydrogen-functionalized pore of different geometry. It is found that the nitrite ions can permeate faster than the nitrate ions despite the former having higher hydration energy in the bulk. This can be explained in terms of the competition between the number density of the ions along the pore axis and the free energy barrier calculated from the potential of mean force. Also, an externally applied electric field is found to be important for faster permeation of the nitrite over the nitrate ions. The current study suggests that graphene nanosheets with carefully created pores can be effective in achieving selective passage of ions from aqueous solutions.Aim Catheter dislocation is an important cause of technique failure for peritoneal dialysis (PD). Aim of this study is to evaluate the effect of intramural trait configuration on this outcome. Methods We considered 240 swan neck, double-cuffed catheters positioned in adult patients in our Centre with mini-laparotomy technique partitioned, according with the intramural segment design, in a standard technique group (ST) (n. 199) oblique passage of the catheter through the rectus sheath in the craniocaudal direction, and in a modified technique group (MT) (n. 41) anterior fascia lanced 3 cm cranially to the deep cuff to let catheter out. The primary end-point was dialysis failure due to tip migration. Secondary end-points were any other causes of catheter removal. H3B-6527 mw Results Incidence of catheter removal for non-responsive tip migration was 14.3% in MT and 6.1% in ST. Neither this difference nor the catheter survival rate for this outcome was statistically significant. PD interruption for refractory exit site/tunnel infection (ESI) was in favour of ST (4% ST, 35.