Temperature sensitivity of the mineral permafrost feedback at the continental scale.

Oxidative weathering of sulfide minerals in sedimentary rocks releases carbon dioxide (CO) into the atmosphere. In permafrost zones, this could be a positive feedback on climate change if it increases with warming, yet sulfide oxidation rates and their temperature response remain unknown over large spatial and temporal scales. We analyze a 60-year sulfate concentration dataset from catchments across the Mackenzie River Basin.

Aquatic biomass is a major source to particulate organic matter export in large Arctic rivers.

Arctic rivers provide an integrated signature of the changing landscape and transmit signals of change to the ocean. Here, we use a decade of particulate organic matter (POM) compositional data to deconvolute multiple allochthonous and autochthonous pan-Arctic and watershed-specific sources. Constraints from carbon-to-nitrogen ratios (C:N), δC, and ΔC signatures reveal a large, hitherto overlooked contribution from aquatic biomass.

An Abrupt Aging of Dissolved Organic Carbon in Large Arctic Rivers.

Permafrost thaw in Arctic watersheds threatens to mobilize hitherto sequestered carbon. We examine the radiocarbon activity (FC) of dissolved organic carbon (DOC) in the northern Mackenzie River basin. From 2003-2017, DOC-FC signatures (1.

Mercury Export from Arctic Great Rivers.

Land-ocean linkages are strong across the circumpolar north, where the Arctic Ocean accounts for 1% of the global ocean volume and receives more than 10% of the global river discharge. Yet estimates of Arctic riverine mercury (Hg) export constrained from direct Hg measurements remain sparse. Here, we report results from a coordinated, year-round sampling program that focused on the six major Arctic rivers to establish a contemporary (2012-2017) benchmark of riverine Hg export.

Reversal of cognitive decline in Alzheimer's disease.

Alzheimer's disease is one of the most significant healthcare problems nationally and globally. Recently, the first description of the reversal of cognitive decline in patients with early Alzheimer's disease or its precursors, MCI (mild cognitive impairment) and SCI (subjective cognitive impairment), was published [1]. The therapeutic approach used was programmatic and personalized rather than monotherapeutic and invariant, and was dubbed metabolic enhancement for neurodegeneration (MEND).