98 research outputs found

    The limits of life and the biosphere in earth’s interior

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    Fifty years of scientific ocean drilling have shown that microorganisms are widespread deep inside the ocean floor. Microbial populations exist in both organic-matter-rich and nutrient-poor sediments (Kallmeyer et al., 2012; D’Hondt et al., 2015), in sediments that are millions of years old and are buried to over a kilometer depth (Roussel et al., 2008; Ciobanu et al., 2014; Inagaki et al., 2015), and deep inside the basaltic oceanic crust (Orcutt et al., 2011; Lever et al., 2013). In these varied environments, metabolic activity is extraordinarily low (D’Hondt et al., 2009; Hoehler and Jørgensen 2013; Lever et al. 2015a), but microbial cells remain physiologically active (Morono et al., 2011) or survive in their dormant phases (Lomstein et al., 2012). The total amount of sub-surface biomass is still being debated (Hinrichs and Inagaki, 2012; Kallmeyer et al., 2012; Parkes et al., 2014) and the factors posing ultimate limits to deep life and the habitability of Earth remain to be resolved

    Interactions between temperature and energy supply drive microbial communities in hydrothermal sediment

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    Temperature and bioavailable energy control the distribution of life on Earth, and interact with each other due to the dependency of biological energy requirements on temperature. Here we analyze how temperature-energy interactions structure sediment microbial communities in two hydrothermally active areas of Guaymas Basin. Sites from one area experience advective input of thermogenically produced electron donors by seepage from deeper layers, whereas sites from the other area are diffusion-dominated and electron donor-depleted. In both locations, Archaea dominate at temperatures >45 °C and Bacteria at temperatures <10 °C. Yet, at the phylum level and below, there are clear differences. Hot seep sites have high proportions of typical hydrothermal vent and hot spring taxa. By contrast, high-temperature sites without seepage harbor mainly novel taxa belonging to phyla that are widespread in cold subseafloor sediment. Our results suggest that in hydrothermal sediments temperature determines domain-level dominance, whereas temperature-energy interactions structure microbial communities at the phylum-level and below

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    How will the ebola crisis impact the HIV epidemic?

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    10.1186/s12977-014-0110-zRetrovirology11111

    World AIDS Day: Together we will stop HIV transmission and conquer AIDS

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    10.1186/1742-4690-10-129Retrovirology10112

    Quantification of esophageal tumor motion on cine-magnetic resonance imaging

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    Contains fulltext : 136634.pdf (Publisher’s version ) (Closed access)PURPOSE: To quantify the movement of esophageal tumors noninvasively on cine-magnetic resonance imaging (MRI) by use of a semiautomatic method to visualize tumor movement directly throughout multiple breathing cycles. METHODS AND MATERIALS: Thirty-six patients with esophageal tumors underwent MRI. Tumors were located in the upper (8), middle (7), and lower (21) esophagus. Cine-MR images were collected in the coronal and sagittal plane during 60 seconds at a rate of 2 Hz. An adaptive correlation filter was used to automatically track a previously marked reference point. Tumor movement was measured in the craniocaudal (CC), left-right (LR), and anteroposterior (AP) directions and its relationship along the longitudinal axis of the esophagus was investigated. RESULTS: Tumor registration within the individual images was typically done at a millisecond time scale. The mean (SD) peak-to-peak displacements in the CC, AP, and LR directions were 13.3 (5.2) mm, 4.9 (2.5) mm, and 2.7 (1.2) mm, respectively. The bandwidth to cover 95% of excursions from the mean position (c95) was also calculated to exclude outliers caused by sporadic movements. The mean (SD) c95 values were 10.1 (3.8) mm, 3.7 (1.9) mm, and 2.0 (0.9) mm in the CC, AP, and LR dimensions. The end-exhale phase provided a stable position in the respiratory cycle, compared with more variety in the end-inhale phase. Furthermore, lower tumors showed more movement than did higher tumors in the CC and AP directions. CONCLUSIONS: Intrafraction tumor movement was highly variable between patients. Tumor position proved the most stable during the respiratory cycle in the end-exhale phase. A better understanding of tumor motion makes it possible to individualize radiation delivery strategies accordingly. Cine-MRI is a successful noninvasive modality to analyze motion for this purpose in the future

    Iron(III), nickel(II) and zinc(II) complexes based on acetophenone- S

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    New complexes, [Fe(L)Cl], [Ni(L)], and [Zn(L)C2H5OH] (1-3), were synthesized by template reaction of 2-hydroxy-acetophenone-S-methyl-thiosemicarbazone with 2-hydroxy-benzaldehyde. The compounds were characterized by elemental analysis, magnetic measurements, FT-IR, H-1 NMR, UV-visible, and ESI-MS spectra. In these complexes, the ligand is coordinated to the metal ion as dinegatively charged tetradentate chelating agents via the N2O2 donor set. The iron(III) and zinc(II) complexes exhibit square pyramidal geometry whereas the nickel(II) complex has a square planar geometry. The crystal structure of 1, determined by X-ray diffraction method, indicates that 1 crystallizes in the monoclinic space group P21/c with Z=4. Thermal decompositions of the compounds have been investigated using TGA in air
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