The identification of sulfide oxidation as a potential metabolism driving primary production on late Noachian Mars.

The transition of the martian climate from the wet Noachian era to the dry Hesperian (4.1-3.0 Gya) likely resulted in saline surface waters that were rich in sulfur species. Terrestrial analogue environments that possess a similar chemistry to these proposed waters can be used to develop an understanding of the diversity of microorganisms that could have persisted on Mars under such conditions. Here, we report on the chemistry and microbial community of the highly reducing sediment of Colour Peak springs, a sulfidic and saline spring system located within the Canadian High Arctic. DNA and cDNA 16S rRNA gene profiling demonstrated that the microbial community was dominated by sulfur oxidising bacteria, suggesting that primary production in the sediment was driven by chemolithoautotrophic sulfur oxidation. It is possible that the sulfur oxidising bacteria also supported the persistence of the additional taxa. Gibbs energy values calculated for the brines, based on the chemistry of Gale crater, suggested that the oxidation of reduced sulfur species was an energetically viable metabolism for life on early Mars.

Multidisciplinary managed care networks-Life-saving interventions for hepatitis C patients.

Successful hepatitis C virus (HCV) therapy depends on effective pathways of care. Over two decades, we have developed four sequential models of care latterly using a multidisciplinary managed care network to improve HCV testing, care and treatment. This was a cohort study to evaluate the effectiveness of care pathways, carried out using all HCV antibody-positive individuals tested in a geographical region between 1994 and 2014. The study involved 3122 HCV-positive patients. They were divided into four subgroups representing different care pathways defined by their date of HCV antibody diagnosis. The number who accessed treatment services within 1 year of diagnosis increased from 77 of 292 (26.3%) to 521 of 821 (72.9%). The rate of treatment starts within 1 year of diagnosis increased from 6 of 292 (2.0%) to 133 of 821 (16.2%), and the sustained viral response rate improved from 61.6% to 77.4%. All-cause mortality decreased from 232 of 688 (33.7%) in subgroup A to 55 of 1207 (4.5%) in subgroup D, and multivariate analysis showed that pathway type was an independent predictor of mortality irrespective of age, sex, SVR status or HIV co-infection with pathway in D having an odds ratio of 0.53(0.40-0.77; P<.001) compared to pathway in A. At study end, 78% (3122) of an estimated 4000 HCV positive had been diagnosed. In total, 97.5% of HCV caseload was referred to specialist services and 89% attended for assessment. The introduction of a managed care network increased access to care and reduced all-cause mortality.