The regional variability in tundra and boreal carbon dioxide (CO2) fluxes can be high, complicating efforts to quantify sink‐source patterns across the entire region. Statistical models are increasingly used to predict (i.e., upscale) CO2 fluxes across large spatial domains, but the reliability of different modeling techniques, each with different specifications and assumptions, has not been assessed in detail. Here, we compile eddy covariance and chamber measurements of annual and growing season CO2 fluxes of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) during 1990–2015 from 148 terrestrial high‐latitude (i.e., tundra and boreal) sites to analyze the spatial patterns and drivers of CO2 fluxes and test the accuracy and uncertainty of different statistical models. CO2 fluxes were upscaled at relatively high spatial resolution (1 km2) across the high‐latitude region using five commonly used statistical models and their ensemble, that is, the median of all five models, using climatic, vegetation, and soil predictors. We found the performance of machine learning and ensemble predictions to outperform traditional regression methods. We also found the predictive performance of NEE‐focused models to be low, relative to models predicting GPP and ER. Our data compilation and ensemble predictions showed that CO2 sink strength was larger in the boreal biome (observed and predicted average annual NEE −46 and −29 g C m−2 yr−1, respectively) compared to tundra (average annual NEE +10 and −2 g C m−2 yr−1). This pattern was associated with large spatial variability, reflecting local heterogeneity in soil organic carbon stocks, climate, and vegetation productivity. The terrestrial ecosystem CO2 budget, estimated using the annual NEE ensemble prediction, suggests the high‐latitude region was on average an annual CO2 sink during 1990–2015, although uncertainty remains high.

The data suggest that the ethanol extracts of Artemisia asiatica exerted significant protection from alcohol-induced gastric mucosal injury through bio-regulation, which is essential for cytoprotection and anti-inflammation.

Abstract. We report on one year of high-precision direct hourly radon observations at King Sejong Station (King George Island) beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m −3 in late-summer to 44 mBq m −3 in late winter and early spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m −3 , were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47-53 • S), with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8-4.0 were estimated for the most terrestrially influenced (South American) air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

The Norwegian young sea ICE (N‐ICE2015) expedition was designed to investigate the atmosphere‐snow‐ice‐ocean interactions in the young and thin sea ice regime north of Svalbard. Radiosondes were launched twice daily during the expedition from January to June 2015. Here we use these upper air measurements to study the multiple cyclonic events observed during N‐ICE2015 with respect to changes in the vertical thermodynamic structure, moisture content, and boundary layer characteristics. We provide statistics of temperature inversion characteristics, static stability, and boundary layer extent. During winter, when radiative cooling is most effective, we find the strongest impact of synoptic cyclones. Changes to thermodynamic characteristics of the boundary layer are associated with transitions between the radiatively “clear” and “opaque” atmospheric states. In spring, radiative fluxes warm the surface leading to lifted temperature inversions and a statically unstable boundary layer. Further, we compare the N‐ICE2015 static stability distributions to corresponding profiles from ERA‐Interim reanalysis, from the closest land station in the Arctic North Atlantic sector, Ny‐Ålesund, and to soundings from the SHEBA expedition (1997/1998). We find similar stability characteristics for N‐ICE2015 and SHEBA throughout the troposphere, despite differences in location, sea ice thickness, and snow cover. For Ny‐Ålesund, we observe similar characteristics above 1000 m, while the topography and ice‐free fjord surrounding Ny‐Ålesund generate great differences below. The long‐term radiosonde record (1993–2014) from Ny‐Ålesund indicates that during the N‐ICE2015 spring period, temperatures were close to the climatological mean, while the lowest 3000 m were 1–3°C warmer than the climatology during winter.

The clinical outcome of symptomatic hepatitis A and the incidence and clinical characteristics of atypical presentation of hepatitis A were studied using prospective, multicenter design. The atypical presentation included delayed anti-hepatitis A virus (HAV) immunoglobulin M (IgM) seroconversion defined as positive anti-HAV IgM on the repeated test within 7 days of hospital admission after the initially negative result, prolonged cholestasis, and acute kidney injury (AKI). A total of 595 patients with symptomatic hepatitis A requiring hospital admission were enrolled prospectively from September 2006 to August 2008 in four major hospitals in a Korean city with a population of approximately 1 million. Clinical outcomes of symptomatic hepatitis A showed a case fatality rate of 0.2%, and fulminant hepatitis in 0.5%. Delayed anti-HAV IgM seroconversion was found in 6.4%, and was significantly associated with shorter intervals from symptom onset to hospital admission, higher body mass index, and lower alanine aminotransferase (ALT) level at admission. Prolonged cholestasis was found in 4.7% of patients, and could be predicted by preexisting chronic hepatitis B viral infection, prolonged prothrombin time, and higher total bilirubin level. AKI was complicated in 1.5%, which could be predicted by lower albumin level, higher ALT level, and higher white blood cell (WBC) count. More than half of the patients required hemodialysis. Substantial occurrence of delayed anti-HAV IgM seroconversion, prolonged cholestasis, and AKI was confirmed with various predictable factors, which could be helpful for accurate diagnosis and management of hepatitis A patients.