Variations in phototroph communities on the ablating bare-ice surface of glaciers on Brøggerhalvøya, Svalbard

During the summer ablation season, Arctic glacier surfaces host a wealth of microbial life. Here, the phototroph communities on the ablating bare-ice surface of three valley glaciers on Brøggerhalvøya, Svalbard were investigated. The communities mainly comprised seven taxa of green algae and cyanobacteria, which have been commonly reported on Arctic glaciers. Although the geographical and glaciological settings of the three studied glaciers are similar, there were differences in total phototroph biomass. The community structure was also distinctive among the glaciers: high dominance of a single taxon of green algae (Ancylonema nordenskiöldii) for Midtre Lovénbreen, abundant cyanobacteria for Austre Brøggerbreen, and diverse green algae for Pedersenbreen. The major soluble ions in the surface ice showed that there was no significant difference in meltwater nutrient conditions between the glaciers, but there were lower concentrations of mineral-derived ions on Midtre Lovénbreen. Consequently, the glacier-specific mineral loading and surface hydrology are inferred to explain the contrast in bare ice algal communities between the glaciers. We hypothesize that local, glacier-specific conditions affect algal communities and the associated influences on carbon cycling and ice-surface albedo

Microbial genomics amidst the Arctic crisis

The Arctic is warming – fast. Microbes in the Arctic play pivotal roles in feedbacks that magnify the impacts of Arctic change. Understanding the genome evolution, diversity and dynamics of Arctic microbes can provide insights relevant for both fundamental microbiology and interdisciplinary Arctic science. Within this synthesis, we highlight four key areas where genomic insights to the microbial dimensions of Arctic change are urgently required: the changing Arctic Ocean, greenhouse gas release from the thawing permafrost, 'biological darkening' of glacial surfaces, and human activities within the Arctic. Furthermore, we identify four principal challenges that provide opportunities for timely innovation in Arctic microbial genomics. These range from insufficient genomic data to develop unifying concepts or model organisms for Arctic microbiology to challenges in gaining authentic insights to the structure and function of low-biomass microbiota and integration of data on the causes and consequences of microbial feedbacks across scales. We contend that our insights to date on the genomics of Arctic microbes are limited in these key areas, and we identify priorities and new ways of working to help ensure microbial genomics is in the vanguard of the scientific response to the Arctic crisis

Storage and export of microbial biomass across the western Greenland Ice Sheet

The Greenland Ice Sheet harbours a wealth of microbial life, yet the total biomass stored or exported from its surface to downstream environments is unconstrained. Here, we quantify microbial abundance and cellular biomass flux within the near-surface weathering crust photic zone of the western sector of the ice sheet. Using groundwater techniques, we demonstrate that interstitial water flow is slow (~10−2 m d−1), while flow cytometry enumeration reveals this pathway delivers 5 × 108 cells m−2 d−1 to supraglacial streams, equivalent to a carbon flux up to 250 g km−2 d−1. We infer that cellular carbon accumulation in the weathering crust exceeds fluvial export, promoting biomass sequestration, enhanced carbon cycling, and biological albedo reduction. We estimate that up to 37 kg km−2 of cellular carbon is flushed from the weathering crust environment of the western Greenland Ice Sheet each summer, providing an appreciable flux to support heterotrophs and methanogenesis at the bed

Monoclonal gammopathy of renal significance (MGRS): Real-world data on outcomes and prognostic factors

Monoclonal gammopathy of renal significance (MGRS) is a recognized clinical entity. Literature regarding treatment and its outcomes in MGRS is sparse due to the rarity and misdiagnosis of MGRS. We retrospectively analyzed 280 adults with an MGRS diagnosis from 2003 to 2020 across 19 clinical centers from 12 countries. All cases required renal biopsy for the pathological diagnosis of MGRS. Amyloidosis-related to MGRS (MGRS-A) was present in 180 patients; nonamyloidosis MGRS (MGRS-NA), including a broad spectrum of renal pathologies, was diagnosed in 100 patients. The median overall survival in the studied cohort was 121.0 months (95% CI: 105.0–121.0). Patients with MGRS-A had a shorter overall survival than patients with MGRS-NA (HR = 0.41, 95%CI: 0.25–0.69; p = 0.0007). Both hematologic and renal responses were associated with longer survival. Achievement of ≥VGPR was generally predictive of a renal response (OR = 8.03 95%CI: 4.04–115.96; p < 0.0001), one-fourth of patients with ≥VGPR were renal nonresponders. In MGRS-A, factors associated with poor prognosis included elevated levels of creatinine, beta-2-microglobulin, and hemodialysis at diagnosis. In MGRS-NA, only age >65 years was associated with increased risk of death. Treatments provided similar hematologic response rates in both types of MGRS. Autologous stem cell transplantation led to better response than other treatments. This multicenter and international effort is currently the largest report on MGRS

Possible interactions between bacterial diversity, microbial activity and supraglacial hydrology of cryoconite holes in Svalbard

The diversity of highly active bacterial communities in cryoconite holes on three Arctic glaciers in Svalbard was investigated using terminal restriction fragment length polymorphism (T-RFLP) of the 16S rRNA locus. Construction and sequencing of clone libraries allowed several members of these communities to be identified, with Proteobacteria being the dominant one, followed by Cyanobacteria and Bacteroidetes. T-RFLP data revealed significantly different communities in holes on the (cold) valley glacier Austre Brøggerbreen relative to two adjacent (polythermal) valley glaciers, Midtre Lovénbreen and Vestre Brøggerbreen. These population compositions correlate with differences in organic matter content, temperature and the metabolic activity of microbial communities concerned. No within-glacier spatial patterns were observed in the communities identified over the 2-year period and with the 1 km-spaced sampling. We infer that surface hydrology is an important factor in the development of cryoconite bacterial communities