“Retreating ice fronts (as a result of awarming climate) expose large expanses of deglaciated forefield, which become colonized by microbes and plants. There has been increasing interest in characterizing the biogeochemical development of these ecosystems
using a chronosequence approach. Prior to the establishment of plants, microbes use autochthonously produced and allochthonously delivered nutrients for growth. The microbial community composition is largely made up of heterotrophic microbes (both bacteria and fungi), autotrophic microbes and nitrogen-fixing diazotrophs. Microbial activity is thought to be responsible for the initial build-up of labile nutrient pools, facilitating the growth of higher order plant life in developed soils. However, it is unclear to what extent these ecosystems rely on external sources of nutrients such as
ancient carbon pools Selleck PCI-34051 and periodic nitrogen deposition. Furthermore, the seasonal variation of chronosequence dynamics and the effect of winter are largely unexplored. Modelling this ecosystem will provide a quantitative evaluation of the key processes and could guide the focus of future research. Year-round datasets combined with novel metagenomic techniques will help answer some of the Pexidartinib research buy pressing questions in this relatively new but rapidly expanding field, which is of growing interest in the context of future large-scale ice retreat.”
“Background: Nevirapine is an important component of paediatric combination HIV therapy. Adequate SB273005 in vivo drug exposure is necessary in order to achieve long-lasting viral suppression.\n\nObjectives: To study the influence of age, drug dose and formulation type, nutritional status and CYP2B6 516G>T polymorphism on blood concentrations of nevirapine in children
treated with generic antiretroviral drugs.\n\nMethods: A multicentre study was conducted at four sites in India. HIV-infected children receiving generic nevirapine-based fixed-dose combinations were recruited. Trough and 2 h nevirapine plasma concentrations were determined by HPLC. Characterization of the CYP2B6 gene polymorphism was performed using direct sequencing. Clinical and nutritional status was recorded. Groups were compared using the Mann-Whitney U-test and multivariable logistic regression analysis was performed to identify factors contributing to low drug levels.\n\nResults: Ninety-four children of median age 78 months were studied; 60% were undernourished or stunted. Stunted children had a significantly lower 2 h nevirapine concentration compared with non-stunted children (P<0.05); there were no significant differences in trough concentrations between different nutritional groups. Nevirapine levels were significantly higher in children with TT compared with GG and GT CYP2B6 genotypes (P<0.01). Children <= 3 years had a 3.2 (95% confidence interval 1.07-9.45) times higher risk of having sub-therapeutic nevirapine concentrations.