Timing the evolution of antioxidant enzymes in cyanobacteria

How early photosynthesizers managed oxidative stress remains relatively unresolved. Analyses of enzymes dealing with reactive oxygen species traces the evolutionary history of superoxide dismutases and finds evidence of CuZnSOD in the ancestor of all cyanobacteria, dating back to the Archaean

The evolution and spread of sulfur cycling enzymes reflect the redox state of the early Earth

Funding: K.M. was supported by the Dean of the College Office at Carleton College. This work was performed by the Virtual Planetary Laboratory team, a member of the NASA Nexus for Exoplanet System Science, funded via NASA Astrobiology Program grant no. 80NSSC18K0829 to R.A. Financial support for this publication also results from a Scialog program sponsored jointly by Research Corporation for Science Advancement and the Heising-Simons Foundation and includes a grant (no. 28109) to Carleton College by RCSA. E.S. and J.B. acknowledge funding from a NERC Frontiers grant (NE/V010824/1).The biogeochemical sulfur cycle plays a central role in fueling microbial metabolisms, regulating the Earth's redox state, and affecting climate. However, geochemical reconstructions of the ancient sulfur cycle are confounded by ambiguous isotopic signals. We use phylogenetic reconciliation to ascertain the timing of ancient sulfur cycling gene events across the tree of life. Our results suggest that metabolisms using sulfide oxidation emerged in the Archean, but those involving thiosulfate emerged only after the Great Oxidation Event. Our data reveal that observed geochemical signatures resulted not from the expansion of a single type of organism but were instead associated with genomic innovation across the biosphere. Moreover, our results provide the first indication of organic sulfur cycling from the Mid-Proterozoic onwards, with implications for climate regulation and atmospheric biosignatures. Overall, our results provide insights into how the biological sulfur cycle evolved in tandem with the redox state of the early Earth.Publisher PDFPeer reviewe

Evolution in Cardiovascular Care for Elderly Patients With Non–ST-Segment Elevation Acute Coronary Syndromes: Results From the CRUSADE National Quality Improvement Initiative

OBJECTIVES This study evaluated the impact of age on care and outcomes for non-ST-segment elevation acute coronary syndromes (NSTE ACS). BACKGROUND Recent clinical trials have expanded treatment options for NSTE ACS, now reflected in guidelines. Elderly patients are at highest risk, yet have previously been shown to receive less care than younger patients. METHODS In 56,963 patients with NSTE ACS at 443 U.S. hospitals participating in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines (CRUSADE) National Quality Improvement Initiative from January 2001 to June 2003, we compared use of guidelines-recommended care across four age groups: <65, 65 to 74, 75 to 84, and ≥85 years. A multivariate model tested for age-related differences in treatments and outcomes after adjusting for patient, provider, and hospital factors. RESULTS Of the study population, 35% were ≥75 years old, and 11% were ≥85 years old. Use of acute anti-platelet and anti-thrombin therapy within the first 24 h decreased with age. Elderly patients were also less likely to undergo early catheterization or revascularization. Whereas use of many discharge medications was similar in young and old patients, clopidogrel and lipid-lowering therapy remained less commonly prescribed in elderly patients. In-hospital mortality and complication rates increased with advancing age, but those receiving more recommended therapies had lower mortality even after adjustment than those who did not. CONCLUSIONS Age impacts use of guidelines-recommended care for newer agents and early in-hospital care. Further improvements in outcomes for elderly patients by optimizing the safe and early use of therapies are likely

Identificaction and quantificationof proteins from Methylophaga Thiooxidans and Methylocella Silvestris using label-free LC/MS

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2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011

On the trail of iron uptake in ancestral Cyanobacteria on early Earth

Cyanobacteria oxygenated Earth's atmosphere ~2.4 billion years ago, during the Great Oxygenation Event (GOE), through oxygenic photosynthesis. Their high iron requirement was presumably met by high levels of Fe(II) in the anoxic Archean environment. We found that many deeply branching Cyanobacteria, including two Gloeobacter and four Pseudanabaena spp., cannot synthesize the Fe(II) specific transporter, FeoB. Phylogenetic and relaxed molecular clock analyses find evidence that FeoB and the Fe(III) transporters, cFTR1 and FutB, were present in Proterozoic, but not earlier Archaean lineages of Cyanobacteria. Furthermore Pseudanabaena sp. PCC7367, an early diverging marine, benthic strain grown under simulated Archean conditions, constitutively expressed cftr1, even after the addition of Fe(II). Our genetic profiling suggests that, prior to the GOE, ancestral Cyanobacteria may have utilized alternative metal iron transporters such as ZIP, NRAMP, or FicI, and possibly also scavenged exogenous siderophore bound Fe(III), as they only acquired the necessary Fe(II) and Fe(III) transporters during the Proterozoic. Given that Cyanobacteria arose 3.3–3.6 billion years ago, it is possible that limitations in iron uptake may have contributed to the delay in their expansion during the Archean, and hence the oxygenation of the early Earth.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Royal Society of Biology http://dx.doi.org/10.13039/100012361University of Bristol http://dx.doi.org/10.13039/501100000883https://osf.io/7x598/?view_only=715cd38c378446ba8c3f6c924f9be9f

High resolution, wide field of view, ptychographic imaging of a biological sample using a high harmonic generation source

We present coherent diffractive imaging with broadband radiation generated from a high harmonic source around 29nm wavelength to image neuron tissue from the mouse hypothalamus to 80nm resolution over a 40nm field of view