Novel facultative Methylocella strains are active methane consumers at terrestrial natural gas seeps

Natural gas seeps contribute to global climate change by releasing substantial amounts of the potent greenhouse gas methane and other climate-active gases including ethane and propane to the atmosphere. However, methanotrophs, bacteria capable of utilising methane as the sole source of carbon and energy, play a significant role in reducing the emissions of methane from many environments. Methylocella-like facultative methanotrophs are a unique group of bacteria that grow on other components of natural gas (i.e. ethane and propane) in addition to methane but a little is known about the distribution and activity of Methylocella in the environment. The purposes of this study were to identify bacteria involved in cycling methane emitted from natural gas seeps and, most importantly, to investigate if Methylocella-like facultative methanotrophs were active utilisers of natural gas at seep sites

Location and Level of Etk Expression in Neurons Are Associated with Varied Severity of Traumatic Brain Injury

Much recent research effort in traumatic brain injury (TBI) has been devoted to the discovery of a reliable biomarker correlating with severity of injury. Currently, no consensus has been reached regarding a representative marker for traumatic brain injury. In this study, we explored the potential of epithelial/endothelial tyrosine kinase (Etk) as a novel marker for TBI.TBI was induced in Sprague Dawley (SD) rats by controlled cortical impact. Brain tissue samples were analyzed by Western blot, Q-PCR, and immunofluorescence staining using various markers including glial fibrillary acidic protein, and epithelial/endothelial tyrosine kinase (Etk). Results show increased Etk expression with increased number and severity of impacts. Expression increased 2.36 to 7-fold relative to trauma severity. Significant upregulation of Etk appeared at 1 hour after injury. The expression level of Etk was inversely correlated with distance from injury site. Etk and trauma/inflammation related markers increased post-TBI, while other tyrosine kinases did not.The observed correlation between Etk level and the number of impacts, the severity of impact, and the time course after impact, as well as its inverse correlation with distance away from injury site, support the potential of Etk as a possible indicator of trauma severity

Corresponding Functional Dynamics across the Hsp90 Chaperone Family: Insights from a Multiscale Analysis of MD Simulations

Understanding how local protein modifications, such as binding small-molecule ligands, can trigger and regulate large-scale motions of large protein domains is a major open issue in molecular biology. We address various aspects of this problem by analyzing and comparing atomistic simulations of Hsp90 family representatives for which crystal structures of the full length protein are available: mammalian Grp94, yeast Hsp90 and E.coli HtpG. These chaperones are studied in complex with the natural ligands ATP, ADP and in the Apo state. Common key aspects of their functional dynamics are elucidated with a novel multi-scale comparison of their internal dynamics. Starting from the atomic resolution investigation of internal fluctuations and geometric strain patterns, a novel analysis of domain dynamics is developed. The results reveal that the ligand-dependent structural modulations mostly consist of relative rigid-like movements of a limited number of quasi-rigid domains, shared by the three proteins. Two common primary hinges for such movements are identified. The first hinge, whose functional role has been demonstrated by several experimental approaches, is located at the boundary between the N-terminal and Middle-domains. The second hinge is located at the end of a three-helix bundle in the Middle-domain and unfolds/unpacks going from the ATP- to the ADP-state. This latter site could represent a promising novel druggable allosteric site common to all chaperones

Numerical modelling of rectangular footing on a sand embankment over mine tailings

Ullah, S ORCiD: 0000-0002-5522-53413D finite element simulations are conducted to better understand the soil-structure interaction of rectangular foundations resting on a sand embankment over soft mine tailings. To account for large strains, an updated Lagrangian formulation is used in which the stiffness matrix is updated with the non-linear change of the soil geometry. The sand is modelled using a modified Mohr-Coulomb (MMC) soil model where the friction and dilation angles are varied with deviatoric plastic strains. It is shown that failure over a moderate slope angle of 22° and normalised sand embankment height (H/B) of 0.26 (H is the embankment height and B is the footing width) involves a deep seated circular slip plane, involving the sand and clay layers, where the foundation was close to the crest of the embankment. The failure pattern turns gradually to typical punch-through with an inclined sand shear plane as the distance of the footing edge exceeds 1.13B from the crest. The results of this study agree well with those from model centrifuge experiments, and can be utilised in developing better analytical models and equipment capable of live monitoring of slope deformation. © 2020, Springer Nature Singapore Pte Ltd

Investigating the Impact of Social Media Commerce Constructs on Social Trust and Customer Value Co-creation: A Theoretical Analysis

Social media commerce has been one of the fastest-growing areas over recent years. However, only a limited number of studies have addressed the related issues of social media commerce. It was also noticed that extant literature did not explore or link the impact of social commerce constructs on social trust and how this could impact the customer value co-creation. Hence, the current research aims to identify this gap and to propose a conceptual framework that highlights the linkage between social commerce constructs, social trust, and customer value co-creation. In line with this, a number of exploratory interviews were conducted to gain further understanding about how the customer’s perception of customer value co-creation and social trust could be affected by the role of social commerce. Accordingly, the current model proposes that social commerce constructs (second-order; ratings and reviews, recommendations and referrals, and forums and communities) impact social trust, which in turn affects customer value co-creation dimensions (functional value, hedonic value, and social value) in social network sites (SNSs). Theoretical and practical implications are provided

The Asymmetric Binding of PGC-1α to the ERRα and ERRγ Nuclear Receptor Homodimers Involves a Similar Recognition Mechanism

Background: PGC-1a is a crucial regulator of cellular metabolism and energy homeostasis that functionally acts togetherwith the estrogen-related receptors (ERRa and ERRc) in the regulation of mitochondrial and metabolic gene networks.Dimerization of the ERRs is a pre-requisite for interactions with PGC-1a and other coactivators, eventually leading totransactivation. It was suggested recently (Devarakonda et al) that PGC-1a binds in a strikingly different manner to ERRcligand-binding domains (LBDs) compared to its mode of binding to ERRa and other nuclear receptors (NRs), where itinteracts directly with the two ERRc homodimer subunits.Methods/Principal Findings: Here, we show that PGC-1a receptor interacting domain (RID) binds in an almost identicalmanner to ERRa and ERRc homodimers. Microscale thermophoresis demonstrated that the interactions between PGC-1aRID and ERR LBDs involve a single receptor subunit through high-affinity, ERR-specific L3 and low-affinity L2 interactions.NMR studies further defined the limits of PGC-1a RID that interacts with ERRs. Consistent with these findings, the solutionstructures of PGC-1a/ERRa LBDs and PGC-1a/ERRc LBDs complexes share an identical architecture with an asymmetricbinding of PGC-1a to homodimeric ERR.Conclusions/Significance: These studies provide the molecular determinants for the specificity of interactions betweenPGC-1a and the ERRs, whereby negative cooperativity prevails in the binding of the coactivators to these receptors. Ourwork indicates that allosteric regulation may be a general mechanism controlling the binding of the coactivators tohomodimers