Description: Journal of Proteome Research DOI: 10.1021/acs.jproteome.5b00148

Description: Background: Lung nodules caused by mycobacteria can resemble lung cancer on chest imaging. The advent of lung cancer screening with low-dose Computed Tomography is accompanied by high false-positive rates, making it necessary to establish criteria to differentiate malignant from benign nodules. Methods: We conducted a retrospective case–control study of 52 patients with mycobacterial lung nodules and 139 patients with lung cancer, diagnosed between 2010 and 2012. We compared clinical and radiographic characteristics to identify predictors of disease by univariate and multivariate analysis. The discriminatory power of maximum Standardized Uptake Values from Positron-Emission-Tomography was also evaluated. Results: Several variables were correlated with a diagnosis of mycobacterial infection or lung cancer on univariate analysis. Such variable include smoking status and history, lesion size and imaging evidence of tree-in-bud opacities, lymphadenopathy or emphysema on computed tomography. Upon author consensus, the most clinically-relevant variables were selected to undergo multivariate analysis. A history of current or former smoking [OR 4.4 (95 % CI 1.2–15.6) and 2.7 (95 % CI 1.1–6.8), respectively P = 0.04] was correlated with diagnoses of lung cancer. Contrarily, the presence of tree-in-bud opacities was less likely to be correlated with a diagnosis of malignancy [OR 0.04 (95 % CI 0.0–1.0), P = 0.05]. Additionally, higher maximum standardized uptake values from positron emission tomography were associated with malignancy on multivariate analysis [OR 1.1 (95 % CI 1.0–1.2), P = 0.04]; but the accuracy of the values in differentiating between diseases was only 0.67 as measured by the area under the curve. Lesion size was not independently associated with diagnosis [OR 0.5 (95 % CI 0.2–1.2), (P = 0.12)]. Conclusions: Establishing the likelihood of malignancy for lung nodules based on isolated clinical or radiographic criteria is difficult. Using the variables found in this study may allow clinicians to stratify patients into groups of high and low risk for malignancy, and therefore establish efficient diagnostic strategies.

Description: Over the last two decades sea bed drilling technology has proven to provide a valuable complement to the services of classical drill ships. Especially for shallow drillings up to 200 mbsf and when working in remote areas difficult to access, sea bed drill rigs are a cost-effective alternative. Recent developments especially concerning borehole logging techniques add to the capabilities of sea bed drilling technology. The MARUM-MeBo is a robotic drilling system that is developed since 2004 at the MARUM Center for Marine Environmental Sciences at the University of Bremen (Freudenthal and Wefer, 2013). The drill rig is deployed on the sea bed and remotely controlled from the vessel. It is used for core drilling in soft sediments as well as hard rocks in the deep sea. Especially since an upgrade in 2007/2008 for the use of wireline drilling technique, the first-generation drill rig MARUM-MeBo70 with a drilling capacity of about 70 m was successfully deployed on more than 15 research expeditions. Since 2014 the second-generation drill rig MARUM-MeBo200 with an increased drilling capacity of up to 200 m below sea floor is successfully in operation. In this presentation we focus on results of three recent drilling campaigns, exemplifying the exploitation of the potential of the sea bed drilling technology: In early 2017 the MeBo70 was deployed from the ice breaking vessel RV POLARSTERN on the West Antarctic shelf (Gohl et al., 2017), an area difficult to access by a drill ship. We were able to recover a sedimentary sequence of the upper Cretaceous time period as one of the very few terrigenous records from this time in Antarctica. This sequence indicates that about 92 to 83 Mio years ago at a paleolatitude of about 82°S this area was covered by a temperate coastal rain forest, making any Antarctic ice sheet formation at this time period unlikely (Klages et al., in press). Also, in 2017 the MeBo70 was deployed in the Arctic off Svalbard. Next to coring a temperature probe was used to assess in situ temperatures and local geothermal gradients (Riedel et al. 2018). Combining these temperature data with the porewater geochemistry of the drilled cores Wallmann et al (2018) were able to prove the effect of isostatic rebound after deglaciation on gas hydrate dissociation. In late 2017 the MeBo200 was deployed in the Black Sea. Geophysical borehole log data of P-wave velocity, electrical resistivity, and spectral gamma ray were combined with core-derived physical properties of porosity, magnetic susceptibility, and bulk density and compared with seismic data of the region (Riedel et al., in press). This study shows the potential of core-log seismic integration for shallow drilling campaigns conducted with a sea bed drill rig. References: Freudenthal, T and Wefer, G (2013) Geoscientific Instrumentation, Methods and Data Systems, 2(2). 329-337. doi:10.5194/gi-2-329-2013 Gohl, K, et al. (2017) Geochemistry, Geophysics, Geosystems, 18, 4235–4250. https://doi.org/10.1002/2017GC007081 Klages, JP et al. (in press) Nature, 2019-10-14805B Riedel, M et al. (2018) Geochemistry, Geophysics, Geosystems, 19, 1165–1177. doi:10.1002/2017GC007288 Riedel, M et al. (in press) Marine and Petroleum Geology, doi.org/10.1016/j.marpetgeo.2019.104192 Wallmann, K et al. (2018) Nature Communications, 9:83, DOI: 10.1038/s41467-017-02550-9

Description: This paper is not subject to U.S. copyright. The definitive version was published in Geochimica et Cosmochimica Acta 108 (2013): 184–201, doi:10.1016/j.gca.2013.01.022.

Description: Sulfate-dependent anaerobic oxidation of methane (AOM) is the key sedimentary microbial process limiting methane emissions from marine sediments and methane seeps. In this study, we investigate how the presence of low-organic content sediment influences the capacity and efficiency of AOM at Bullseye vent, a gas hydrate-bearing cold seep offshore of Vancouver Island, Canada. The upper 8 m of sediment contains 〈0.4 wt.% total organic carbon (OC) and primarily consists of glacially-derived material that was deposited 14,900–15,900 yrs BP during the retreat of the late Quaternary Cordilleran Ice Sheet. We hypothesize this aged and exceptionally low-OC content sedimentary OM is biologically refractory, thereby limiting degradation of non-methane OM by sulfate reduction and maximizing methane consumption by sulfate-dependent AOM. A radiocarbon-based dissolved inorganic carbon (DIC) isotope mass balance model demonstrates that respired DIC in sediment pore fluids is derived from a fossil carbon source that is devoid of 14C. A fossil origin for the DIC precludes remineralization of non-fossil OM present within the sulfate zone as a significant contributor to pore water DIC, suggesting that nearly all sulfate is available for anaerobic oxidation of fossil seep methane. Methane flux from the SMT to the sediment water interface in a diffusion-dominated flux region of Bullseye vent was, on average, 96% less than at an OM-rich seep in the Gulf of Mexico with a similar methane flux regime. Evidence for enhanced methane oxidation capacity within OM-poor sediments has implications for assessing how climate-sensitive reservoirs of sedimentary methane (e.g., gas hydrate) will respond to ocean warming, particularly along glacially-influenced mid and high latitude continental margins.

Description: Partial support for this research was provided by Interagency Agreements DE-FE0002911 and DE-NT0006147 between the US Geological Survey Gas Hydrates Project and the US Department of Energy’s Methane Hydrates Research and Development Program.