55 research outputs found
Enrichment of fusobacteria in sea surface oil slicks from the deepwater horizon oil spill
The Deepwater Horizon (DWH) oil spill led to rapid microbial community shifts in the Gulf of Mexico, including the formation of unprecedented quantities of marine oil snow (MOS) and of a massive subsurface oil plume. The major taxa that bloomed in sea surface oil slicks during the spill included Cycloclasticus, and to a lesser extent Halomonas, Alteromonas, and Pseudoalteromonas—organisms that grow and degrade oil hydrocarbons aerobically. Here, we show that sea surface oil slicks at DWH contained obligate and facultative anaerobic taxa, including members of the obligate anaerobic phylum Fusobacteria that are commonly found in marine sediment environments. Pyrosequencing analysis revealed that Fusobacteria were strongly selected for when sea surface oil slicks were allowed to develop anaerobically. These organisms have been found in oil-contaminated sediments in the Gulf of Mexico, in deep marine oil reservoirs, and other oil-contaminated sites, suggesting they have putative hydrocarbon-degrading qualities. The occurrence and strong selection for Fusobacteria in a lab-based incubation of a sea surface oil slick sample collected during the spill suggests that these organisms may have become enriched in anaerobic zones of suspended particulates, such as MOS. Whilst the formation and rapid sinking of MOS is recognised as an important mechanism by which a proportion of the Macondo oil had been transported to the sea floor, its role in potentially transporting microorganisms, including oil-degraders, from the upper reaches of the water column to the seafloor should be considered. The presence of Fusobacteria on the sea surface—a highly oxygenated environment—is intriguing, and may be explained by the vertical upsurge of oil that provided a carrier to transport these organisms from anaerobic/micro-aerophilic zones in the oil plume or seabed to the upper reaches of the water column. We also propose that the formation of rapidly-sinking MOS may have re-transported these, and other microbial taxa, to the sediment in the Gulf of Mexico
Preserving the palaeoenvironmental record in Drylands: Bioturbation and its significance for luminescence-derived chronologies
Luminescence (OSL) dating has revolutionised the understanding of Late Pleistocene dryland activity. However,
one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been
preserved intact, enabling their use as proxy indicators of past changes. This relies on stabilisation or burial
soon after deposition and a mechanism to prevent any subsequent re-mobilisation. As well as a dating
technique OSL, especially at the single grain level, can be used to gain an insight into post-depositional
processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences.
This paper explores the possible impact of bioturbation (the movement of sediment by flora and fauna) on
luminescence derived chronologies from Quaternary sedimentary deposits in Texas and Florida (USA) which
have both independent radiocarbon chronologies and archaeological evidence. These sites clearly illustrate the
ability of bioturbation to rejuvenate ancient weathered sandy bedrock and/or to alter depositional stratigraphies
through the processes of exhumation and sub-surface mixing of sediment. The use of multiple OSL replicate
measurements is advocated as a strategy for checking for bioturbated sediment. Where significant OSL
heterogeneity is found, caution should be taken with the derived OSL ages and further measurements at the
single grain level are recommended. Observations from the linear dunes of the Kalahari show them to have no
bedding structure and to have OSL heterogeneity similar to that shown from the bioturbated Texan and Florida
sites. The Kalahari linear dunes could have therefore undergone hitherto undetected post-depositional sediment
disturbance which would have implications for the established OSL chronology for the region
Cosolvent flushing for the remediation of PAHs from former manufactured gas plants
Cosolvent flushing is a technique that has been proposed for the removal of hydrophobic organic contaminants in the subsurface. Cosolvents have been shown to dramatically increase the solubility of such compounds compared to the aqueous solubility; however, limited data are available on the effectiveness of cosolvents for field-contaminated media. In this work, we examine cosolvent flushing for the removal of polycyclic aromatic hydrocarbons (PAHs) in soil from a former manufactured gas plant (FMGP). Batch studies confirmed that the relationship between the soil-cosolvent partitioning coefficient (Ki) and the volume fraction of cosolvent (fc) followed a standard log-linear equation. Using methanol at an fc of 0.95, column studies were conducted at varying length scales, ranging from 11.9 to 110 cm. Removal of PAH compounds was determined as a function of pore volumes (PVs) of cosolvent flushed. Despite using a high fc, rate and chromatographic effects were observed in all the columns. PAH effluent concentrations were modeled using a common two-site sorption model. Model fits were improved by using MeOH breakthrough curves to determine fitted dispersion coefficients. Fitted mass-transfer rates were two to three orders of magnitude lower than predicted values based on published data using artificially contaminated sands
Effective interactions, Fermi-Bose duality, and ground states of ultracold atomic vapors in tight de Broglie waveguides
Derivation of effective zero-range one-dimensional (1D) interactions between
atoms in tight waveguides is reviewed, as is the Fermi-Bose mapping method for
determination of exact and strongly-correlated states of ultracold bosonic and
fermionic atomic vapors in such waveguides, including spin degrees of freedom.
Odd-wave 1D interactions derived from 3D p-wave scattering are included as well
as the usual even-wave interactions derived from 3D s-wave scattering, with
emphasis on the role of 3D Feshbach resonances for selectively enhancing s-wave
or p-wave interactions. A duality between 1D fermions and bosons with
zero-range interactions suggested by Cheon and Shigehara is shown to hold for
the effective 1D dynamics of a spinor Fermi gas with both even and odd-wave
interactions and that of a spinor Bose gas with even and odd-wave interactions,
with even(odd)-wave Bose coupling constants inversely related to odd(even)-wave
Fermi coupling constants. Some recent applications of Fermi-Bose mapping to
determination of many-body ground states of Bose gases and of both magnetically
trapped, spin-aligned and optically trapped, spin-free Fermi gases are
described, and a new generalized Fermi-Bose mapping is used to determine the
phase diagram of ground-state total spin of the spinor Fermi gas as a function
of the even and odd-wave coupling constants.Comment: 16 pages, 3 figures. Submitted to Optics Communications for special
issue "Degenerate Quantum Gases
Modifying Lax equations and the second Hamiltonian structure
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46607/1/222_2005_Article_BF01394252.pd
Degradation of lignosulfonic and tannic acids by ligninolytic soil fungi cultivated under icroaerobic conditions
The artificial intelligence-based model ANORAK improves histopathological grading of lung adenocarcinoma
The introduction of the International Association for the Study of Lung Cancer grading system has furthered interest in histopathological grading for risk stratification in lung adenocarcinoma. Complex morphology and high intratumoral heterogeneity present challenges to pathologists, prompting the development of artificial intelligence (AI) methods. Here we developed ANORAK (pyrAmid pooliNg crOss stReam Attention networK), encoding multiresolution inputs with an attention mechanism, to delineate growth patterns from hematoxylin and eosin-stained slides. In 1,372 lung adenocarcinomas across four independent cohorts, AI-based grading was prognostic of disease-free survival, and further assisted pathologists by consistently improving prognostication in stage I tumors. Tumors with discrepant patterns between AI and pathologists had notably higher intratumoral heterogeneity. Furthermore, ANORAK facilitates the morphological and spatial assessment of the acinar pattern, capturing acinus variations with pattern transition. Collectively, our AI method enabled the precision quantification and morphology investigation of growth patterns, reflecting intratumoral histological transitions in lung adenocarcinoma
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
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
Mineral prospectivity of the King Leopold Orogen and Lennard Shelf: analysis of potential field data in the west Kimberley region
The mineral potential of the west Kimberley region was investigated following interpretation of regional gravity and magnetic data. Emphasis was placed on identifying geological structures that may have importance for the mineral potential of the region. Subsurface structure was constrained through combined gravity and magnetic modelling along three transects. Crustal-scale faults were interpreted and investigated to determine their depth extent, because they may act as fluid conduits that localize mineralization. Crustal-scale features bound regions of different geological and geophysical character and may also control the formation of the oldest geological units. The Artesian Fault, identified during this study, is interpreted to extend from the Paperbark Supersuite into the Kimberley Basin. \ud
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The potential field interpretations and section models were linked to tectonic events and mineralization episodes in order to map the distribution of economically important regions using a knowledge-driven mineral systems approach to mineral prospectivity mapping. The mineral systems considered were 1) magmatic nickel sulfide, 2) carbonate-hosted base metals, 3) orogenic and epithermal gold, 4) sediment-hosted stratiform base metals, 5) intrusion-related base metals (including tin–tungsten, iron oxide– copper–gold and copper–gold porphyry deposits). Prospectivity modelling shows that a geologically complex belt in the south of the Kimberley Basin, at the boundary with the King Leopold Orogen, is prospective for magmatic-related and hydrothermal mineral systems. In addition, a structural high on the Lennard Shelf is prospective for carbonate-hosted base metals, and parts of the King Leopold Orogen are prospective for sediment-hosted stratiform base metals. These results show that knowledge-driven modelling of mineral systems can be effective in identifying prospectivity in regional studies of underexplored areas
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