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Deep sea cold seeps are sites where hydrogen sulfide, methane, and other hydrocarbon-rich fluids vent from the ocean floor. They are an important component of Earth's carbon cycle in which subsurface hydrocarbons form the energy source for highly diverse benthic micro-and macro-fauna in what is otherwise vast and spartan sea scape. Passive continental margin cold seeps are typically attributed to the migration of hydrocarbons generated from deeply buried source rocks. Many of these seeps occur over salt tectonic provinces, where the movement of salt generates complex fault systems that can enable fluid migration or create seals and traps associated with reservoir formation. The elevated advective heat transport of the salt also produces a chimney effect directly over these structures. Here, we provide geophysical and geochemical evidence that the salt chimney effect in conjunction with diapiric faulting drives a subsurface groundwater circulation system that brings dissolved inorganic carbon, nutrient-rich deep basinal fluids, and potentially overlying seawater onto the crests of deeply buried salt diapirs. The mobilized fluids fuel methanogenic archaea locally enhancing the deep biosphere. The resulting elevated biogenic methane production, alongside the upward heat-driven fluid transport, represents a previously unrecognized mechanism of cold seep formation and regulation. [ABSTRACT FROM AUTHOR]

Mer tyrosine kinase (MerTK) is a receptor tyrosine kinase that mediates non-inflammatory, homeostatic phagocytosis of diverse types of cellular debris. Highly expressed on the surface of microglial cells, MerTK is of importance in brain development, homeostasis, plasticity and disease. Yet, involvement of this receptor in the clearance of protein aggregates that accumulate with ageing and in neurodegenerative diseases has yet to be defined. The current study explored the function of MerTK in the microglial uptake of alpha-synuclein fibrils which play a causative role in the pathobiology of synucleinopathies. Using human primary and induced pluripotent stem cell-derived microglia, the MerTK-dependence of alpha-synuclein fibril internalization was investigated in vitro. Relevance of this pathway in synucleinopathies was assessed through burden analysis of MERTK variants and analysis of MerTK expression in patient-derived cells and tissues. Pharmacological inhibition of MerTK and siRNA-mediated MERTK knockdown both caused a decreased rate of alpha-synuclein fibril internalization by human microglia. Consistent with the non-inflammatory nature of MerTK-mediated phagocytosis, alpha-synuclein fibril internalization was not observed to induce secretion of pro-inflammatory cytokines such as IL-6 or TNF, and downmodulated IL-1β secretion from microglia. Burden analysis in two independent patient cohorts revealed a significant association between rare functionally deleterious MERTK variants and Parkinson's disease in one of the cohorts (P = 0.002). Despite a small upregulation in MERTK mRNA expression in nigral microglia from Parkinson's disease/Lewy body dementia patients compared to those from non-neurological control donors in a single-nuclei RNA-sequencing dataset (P = 5.08 × 10−21), no significant upregulation in MerTK protein expression was observed in human cortex and substantia nigra lysates from Lewy body dementia patients compared to controls. Taken together, our findings define a novel role for MerTK in mediating the uptake of alpha-synuclein fibrils by human microglia, with possible involvement in limiting alpha-synuclein spread in synucleinopathies such as Parkinson's disease. Upregulation of this pathway in synucleinopathies could have therapeutic values in enhancing alpha-synuclein fibril clearance in the brain. [ABSTRACT FROM AUTHOR]

Nova Scotia has potential for undiscovered hydrocarbon reservoirs in the deep-water portion of the Scotian Margin. However, exploration in these environments involves major challenges and geological risks. As the presence, [...]

The natural microbial community composition of ocean floor sediments for the Scotian Margin has yet to be fully resolved. Such an environmental baseline study can be conducted by genomic and [...]

The ocean floor surface sediments of the Scotian Slope, Nova Scotia are host to a complex network of microbially mediated reactions that knit together the carbon, sulfur, and nitrogen biogeochemical [...]

A novel Bayesian technique is developed to identify those frames within an ensemble of coherently collected imagery that reduced the likelihood of the composite ensemble. The resulting binary weighted motion-compensated frame average is compared to the unweighted average by using simulated data collected from a fielded laser vision system. The image resolution is found to be enhanced.

There is growing consensus that Canada needs to "do more" in the Indo-Pacific region as it becomes the centre of gravity in a changing international landscape—a landscape challenging several traditional assumptions about the nature and configuration of global power which Canadian foreign policy has rested upon for decades, specifically due to the emergence of Sino-American rivalry. It is clear Canada needs a regional approach which is rooted in and better informed by geopolitical considerations, but there remains an absence of analytical frameworks to compare and evaluate alternative approaches. In addressing this void, this paper sketches out and compares four possible orientations Canada could pursue towards the Indo-Pacific region: Minimal Engagement, US-Aligned Confrontation, Regional Multilateralism, and Selective Minilateralism. Remaining agnostic about which one(s) Canada should choose, the paper is designed to highlight the stark trade-offs Canada must increasingly confront as it navigates this uncertain environment. [ABSTRACT FROM AUTHOR]