Arctic Sun

The muskox and reindeer are the only ruminants that have evolved to survive in harsh Arctic environments. However, the genetic basis of this Arctic adaptation remains largely unclear. Here, we compared a de novo assembled muskox genome with reindeer and other ruminant genomes to identify convergent amino acid substitutions, rapidly evolving genes and positively selected genes among the two Arctic ruminants. We found these candidate genes were mainly involved in brown adipose tissue (BAT) thermogenesis and circadian rhythm...

Cardiorespiratory arrest due to severe hypothermia may require prolonged cardiopulmonary resuscitation whilst the patient is rewarmed. There are reported cases of successful resuscitation with good neurological outcomes after prolonged arrests and resuscitation up to 9 h. However, in the majority of these cases, extracorporeal life support was used to maintain perfusion and rewarm the patient. Here, we report a case of successful cardiopulmonary resuscitation lasting 6.5 h, following cardiac arrest secondary to severe hypothermia, with rewarming using an Arctic Sun™ 5000...

Climate warming causes permafrost thaw predicted to increase toxic methylmercury (MeHg) and greenhouse gas [i.e., methane (CH4 ), carbon dioxide (CO2 ), and nitrous oxide (N2 O)] formation. A microcosm incubation study with Arctic tundra soil over 145 days demonstrates that N2 O at 0.1 and 1 mM markedly inhibited microbial MeHg formation, methanogenesis, and sulfate reduction, while it slightly promoted CO2 production. Microbial community analyses indicate that N2 O decreased the relative abundances of methanogenic archaea and microbial clades implicated in sulfate reduction and MeHg formation...

The accurate representation of variability of isotopic composition of modern precipitation based on long-term continuous monitoring is vital for interpreting hydrological and climatic processes. Based on measurements of δ2 H and δ18 O of 353 precipitation samples from five stations in the Alpine Mountains of Central Asia (ACA) during 2013-2015, the spatiotemporal variability of isotopic composition of precipitation and its controlling factors under multiple timescales were explored. Results showed that (1) the stable isotopes in precipitation at multiple timescales displayed an obviously inconsistent trend, especially in winter...

Recent rapid warming has caused uneven impacts on the composition, structure, and functioning of northern ecosystems. It remains unknown how climatic drivers control linear and non-linear trends in ecosystem productivity. Based on a plant phenology index (PPI) product at a spatial resolution of 0.05° over 2000-2018, we used an automated polynomial fitting scheme to detect and characterize trend types (i.e., polynomial trends and no-trends) in the yearly-integrated PPI (PPIINT ) for northern (> 30°N) ecosystems and their dependence on climatic drivers and ecosystem types...

Nucleocytoplasmic large DNA viruses (NCLDVs) infect various marine eukaryotes. However, little is known about NCLDV diversity and their relationships with eukaryotic hosts in marine environments, the elucidation of which will advance the current understanding of marine ecosystems. This study characterizes the interplay between NCLDVs and the eukaryotic plankton community (EPC) in the sub-Arctic area using metagenomics and metabarcoding to investigate NCLDVs and EPC, respectively, in the Kongsfjorden ecosystem of Svalbard (Norway) in April and June 2018...

The rapid warming of Arctic is causing increased fire activities in the boreal Northern Hemisphere (NH), leading to unprecedent changes in the global carbon cycling, human health and ecosystems. Understanding the interaction between fire and climate in this far north region is crucial for predicting future changes of wildfires. However, fire records over geological time scales are still scarce in the high latitudes of NH to provide comprehensive pictures of the fire history in this region. Here, we used the flux of levoglucosan (Lev) and its isomers in a sediment profile YN from Svalbard, high Arctic, as proxies for the changes in biomass burning from ∼9-2 kyr BP (thousand years before present)...

Predicting climate anomalies months in advance is of tremendous socioeconomic value. Facing both theoretical and practical constraints, this realm of "seasonal prediction" progressed slowly in recent decades. Here we devise an innovative scheme that pushes the boundary of seasonal prediction by recognizing and isolating distinct spatiotemporal footprints left by modes of climate variability that cause varying annual cycles in response to the solar forcing. The predictive power harnessed from these spatiotemporal footprints results in a prediction skill surpassing existing models for seasonal forecasts of eastern China rainfall, which is one of the most challenging seasonal prediction problems...

Seasonal ice in lakes plays an important role for local communities and lake ecosystems. Here we use Large Ensemble simulations conducted with the Community Earth System Model version 2, which includes a lake simulator, to quantify the response of lake ice to greenhouse warming and to determine emergence patterns of anthropogenic lake ice loss. Our model simulations show that the average duration of ice coverage and maximum ice thickness are projected to decrease over the next 80 years by 38 days and 0.23 m, respectively...

Rising global temperatures are expected to increase reproductive costs for wildlife as greater thermoregulatory demands interfere with reproductive activities. However, predicting the temperatures at which reproductive performance is negatively impacted remains a significant hurdle. Using a thermoregulatory polygon approach, we derived a reproductive threshold temperature for an Arctic songbird-the snow bunting ( Plectrophenax nivalis ). We defined this threshold as the temperature at which individuals must reduce activity to suboptimal levels (i...

Climate change is rapidly altering the Arctic environment. Although long-term environmental observations have been made at a few locations in the Arctic, the incomplete coverage from ground stations is a main limitation to observations in these remote areas. Here we present a wind and sun powered multi-purpose mobile observatory (ARC-MO) that enables near real time measurements of air, ice, land, rivers, and marine parameters in remote off-grid areas. Two test units were constructed and placed in Northeast Greenland where they have collected data from cabled and wireless instruments deployed in the environment since late summer 2021...

Mercury has become a ubiquitous hazardous element even ending up in pristine areas such as the Arctic, where it biomagnifies and leaves especially top predators vulnerable to potential health effects. Here we investigate total mercury (THg) concentrations and dietary proxies for trophic position and habitat foraging (δ15 N and δ13 C, respectively) in fur of 30 Arctic wolves collected during 1869-1998 in the Canadian High Arctic and Greenland. Fur THg concentration (mean ± SD) of 1.46 ± 1.39 μg g -1 dry weight is within the range of earlier reported values for other Arctic terrestrial species...

BACKGROUND: Targeted temperature management (TTM) has been shown to improve neurological outcomes and survival in patients resuscitated from cardiac arrest; however, the cost effectiveness of multiple TTM methods is not well studied. OBJECTIVE: This study aimed to evaluate the cost effectiveness of intravascular temperature management (IVTM) using Thermogard XP compared with surface cooling methods after cardiac arrest in the England from the perspectives of the UK national health service and Personal Social Services...

Vulpes are widely distributed throughout the world and have undergone drastic physiological and phenotypic changes in response to their environment. However, little is known about the underlying genetic causes of these traits, especially Vulpes corsac . In this study, RNA-Seq was used to obtain a comprehensive dataset for multiple pooled tissues of corsac fox, and selection analysis of orthologous genes was performed to identify the genes that may be influenced by the low-temperature environment. More than 6...

We investigated pigment and mycosporine-like amino acid (MAA) concentrations of phytoplankton and Northern krill ( Thysanoessa sp.) in sub-Arctic Kongsfjorden. Chlorophyll a (Chl-a) concentrations in the surface and middle-layer water were 0.44 μg L-1 (±0.17 μg L-1 ) and 0.63 μg L-1 (±0.25 μg L-1 ), respectively. Alloxanthin (Allo, a marker of cryptophytes) was observed at all stations, and its mean values for surface and middle-layer water were 0.09 μg L-1 (±0.05 μg L-1 ) and 0.05 (±0.02 μg L-1 ), respectively...

Recent global warming is profoundly and increasingly influencing the Arctic ecosystem. Understanding how microeukaryote communities respond to changes in the Arctic Ocean is crucial for understanding their roles in the biogeochemical cycles of nutrients and elements. Between July 22 and August 19, 2016, during cruise ARA07, seawater samples were collected along a latitudinal transect extending from the East Sea of Korea to the central Arctic Ocean. Environmental RNA was extracted and the V4 hypervariable regions of the reverse transcribed SSU rRNA were amplified...

The possibility that Arctic sea ice loss weakens mid-latitude westerlies, promoting more severe cold winters, has sparked more than a decade of scientific debate, with apparent support from observations but inconclusive modelling evidence. Here we show that sixteen models contributing to the Polar Amplification Model Intercomparison Project simulate a weakening of mid-latitude westerlies in response to projected Arctic sea ice loss. We develop an emergent constraint based on eddy feedback, which is 1.2 to 3 times too weak in the models, suggesting that the real-world weakening lies towards the higher end of the model simulations...

Rabies is a serious public health issue in China, with over 95% of human infections transmitted by dogs. As part of a routine surveillance carried out in the Inner Mongolia Autonomous Region (IMAR) between 2019 and 2021, 80 of 95 suspected rabies cases in domestic animals (dogs, livestock) and wild carnivores (foxes, badgers, a raccoon dog) were confirmed as rabies virus (RABV) positive. Phylogenetic analysis of RABVs of the 80 cases based on complete N genes showed that 97.5% (78/80) of the virus strains belonged to the Cosmopolitan (steppe-type) clade, with one in each of Arctic-related (AL2) and Asian (SEA1) clades...

Based on 16S rRNA gene analyses, the same bacterial operational taxonomic units (OTUs) are common to both the Arctic and Antarctic oceans, supporting the concept 'everything is everywhere'. However, whether the same OTUs from both poles have identical genomes, i.e. whether 'everything is still everywhere' at the genomic level has not yet been examined systematically. Here, we isolated, sequenced and compared the genomes of 45 culturable marine bacteria belonging to three genera of Salinibacterium, Psychrobacter and Pseudoalteromonas from both polar oceans...

The concentration of n-alkanes (C17 -C35 ) and sterols in marine particulate matter were investigated to trace the origin of organic carbon in Kongsfjorden in early spring (April). The spatial distributions of environmental factors (seawater temperature, salinity, density, turbidity, chlorophyll a (chl. a) and particulate organic carbon (POC) concentrations) and the cell density of phytoplankton differed between the inner and outer fjord regions. In addition, brassicasterol, diatom biomarker, showed a high concentration in the outer fjord and positive correlations with the chl...