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ABSTRACT In the last decade, increases in both soil temperature and active layer thickness have been observed in the central Lena River basin, an area located in the centre of continuous permafrost in the Eurasian continent. Increased soil temperatures have been accompanied by corresponding increases in soil moisture within the active layer at many sites throughout the region. These underground hydro-thermal changes are believed to be primarily due to perennially wet climate conditions, rather than the atmospheric warming alone that has resulted in abnormally large amounts of winter snow accumulation and late summer rainfall in the Lena River basin. This study aimed to clarify the linkage between atmospheric and land surface variations in regions of continuous permafrost in eastern Siberia based on in situ observation and atmospheric climatic data analyses. These wet conditions in 2004-2008 were likely caused by the enhancement of cyclones over the Arctic Ocean and eastward propagation of storm activity during late summer and early winter. Water vapour flux was enhanced in conjunction with the manifestation of precipitation in eastern Siberia. As a result, consecutive positive anomalies of winter snow accumulation and precipitation during the subsequent summers effectively humidified land surfaces in the permafrost region from 2005 onwards, which resulted in abrupt soil warming and wetting of both the active layer and the upper part of the permafrost. The positive effects on increasing soil temperatures of both snowfall in winter and rainfall in summer have been observed in eastern Siberia since the 1990s, and have also been demonstrated through land surface simulation. Results of these hydro-climatic changes indicated that the near-surface permafrost in eastern Siberia is vulnerable to the climatic conditions that have arisen due to the acceleration of the hydrological cycle that has resulted from the aforementioned period of warming. [ABSTRACT FROM AUTHOR]

Rice lodging causes a loss of yield and leads to lower-quality rice. In Japan, Koshihikari is the most popular rice variety, and it has been widely cultivated for many years despite its susceptibility to lodging. Reducing basal fertilizer is recommended when the available nitrogen in soil (SAN) exceeds the optimum level (80–200 mg N kg−1). However, many commercial farmers prefer to simultaneously apply one-shot basal fertilizer at transplant time. This study investigated the relationship between the rice lodging and SAN content by assessing their spatial distributions from unmanned aircraft system (UAS) images in a Koshihikari paddy field where one-shot basal fertilizer was applied. We analyzed the severity of lodging using the canopy height model and spatially clarified a heavily lodged area and a non-lodged area. For the SAN assessment, we selected green and red band pixel digital numbers from multispectral images and developed a SAN estimating equation by regression analysis. The estimated SAN values were rasterized and compiled into a 1 m mesh to create a soil fertility map. The heavily lodged area roughly coincided with the higher SAN area. A negative correlation was observed between the rice inclination angle and the estimated SAN, and rice lodging occurred even within the optimum SAN level. These results show that the amount of one-shot basal fertilizer applied to Koshihikari should be reduced when absorbable nitrogen (SAN + fertilizer nitrogen) exceeds 200 mg N kg−1. [ABSTRACT FROM AUTHOR]

The article presents a study on the disappearance of snow in Eastern Siberia and its relationship to atmospheric influences. It examines the Lena River Basin in Eastern Siberia and the variations of snow disappearance in a fifteen-year period. The study mentions that snow disappearance moved northward from April to June. It also found that the melting of snow occurred within thirty days of snow disappearance. The study also relates increased air temperature and water vapor during snow melting with temperature change in the air and increased water vapor in the Lena River Basin.

One mechanism for the reappearance of G protein-coupled receptors after agonist activation is microtubule-based transport. In pressure-overload cardiac hypertrophy, there is downregulation of G protein-coupled receptors and the appearance of a densified microtubule network extensively decorated by a microtubule-associated protein, MAP 4. Our hypothesis is that overdecoration of a dense microtubule network with this structural protein, as in hypertrophied myocardium, would impede receptor recovery. We tested this hypothesis by studying muscarinic acetylcholine receptor (mAChR) internalization and recovery after agonist stimulation in neuroblastoma cells. Exposure of cells to carbachol, a muscarinic receptor agonist, decreased membrane receptor binding activity. After carbachol withdrawal, receptor binding recovered toward the initial value. When microtubules were depolymerized before carbachol withdrawal, mAChR recovery was only 44% of that in intact cells. Cells were then infected with an adenovirus containing MAP 4 cDNA. MAP 4 protein decorated the microtubules extensively, and receptor recovery upon carbachol withdrawal was reduced to 54% of control. Thus muscarinic receptor recovery after agonist exposure is microtubule dependent, and MAP 4 decoration of microtubules inhibits receptor recovery. [ABSTRACT FROM AUTHOR]

Seasonal differences in the longwave radiation balance, diurnal cycles of humidity and cloudiness, and ambient winds during the warm season were evaluated to determine their effect on the nocturnal cooling processes of a high mountain hollow in central Japan. This hollow is located at an elevation of 2230 m at the bottom, having a depth of 50-200 m with a diameter of approximately 1 km. One of the most marked seasonal changes in the atmosphere is a reduction in the downward longwave radiation from summer to autumn due to reduced water vapor. This reduction is larger than that of the upward longwave radiation due to a reduced surface temperature. This radiation balance resulted in larger (smaller) potential intensity of radiative cooling during autumn (summer). A composite analysis of diurnal variation for days in summer and autumn showed that the humidity and cloud conditions, differing between the seasons, determined the initial timing and development of nocturnal cooling. During summer (July and August), increased downward longwave radiation in the evening caused by a combination of increased water vapor and cloud cover over the mountains, suppresses and delays cooling. In contrast, dry and fair weather conditions throughout early autumn (September and October) causes strong and continuous cooling. Despite the high potential for radiative cooling during late autumn (after mid-October), nocturnal cooling was frequently disturbed by strong ambient winds exceeding 3.6 m s[sup -1]. The weak winds during summer and early autumn have a minor effect in determining the actual cooling intensity. [ABSTRACT FROM AUTHOR]

Surface water monitoring with fine spatiotemporal resolution in the subarctic is important for understanding the impact of climate change upon hydrological cycles in the region. This study provides dynamic water mapping with daily frequency and a moderate (500 m) resolution over a heterogeneous thermokarst landscape in eastern Siberia. A combination of random forest and conditional generative adversarial networks (pix2pix) machine learning (ML) methods were applied to data fusion between the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Microwave Scanning Radiometer 2, with the addition of ancillary hydrometeorological information. The results show that our algorithm successfully filled in observational gaps in the MODIS data caused by cloud interference, thereby improving MODIS data availability from 30.3% to almost 100%. The water fraction estimated by our algorithm was consistent with that derived from the reference MODIS data (relative mean bias: −2.43%; relative root mean squared error: 14.7%), and effectively rendered the seasonality and heterogeneous distribution of the Lena River and the thermokarst lakes. Practical knowledge of the application of ML to surface water monitoring also resulted from the preliminary experiments involving the random forest method, including timing of the water-index thresholding and selection of the input features for ML training. [ABSTRACT FROM AUTHOR]

In recent years, extreme cold air outbreak events (COEs) in winter have tended to occur more frequently over the mid‐latitudes of Eurasia, including Mongolia, despite marked warming across the continent. In the 2000s, an increase in COEs contributed to huge losses of livestock throughout Mongolia, causing socioeconomic stagnation. This study diagnosed the interdecadal variability of the frequency of COEs during cold season (November–March) using observations from 70 meteorological stations in Mongolia by contrasting a past period (PP:1981–1999) and a recent period (RP:2000–2016). Then, this analysis was extended to characterize the synoptic pattern of each period using ERA‐Interim reanalysis data in terms of the ridge and trough system and cold advection. We defined a COE as an event having at least five continuous days with a daily average air temperature lower than minus one standard deviation from the daily climatology during cold season in 1981–2016. The results revealed that totally 112 COEs could be identified over Mongolia during 1981–2016 with a higher number of events (59) during the RP. Regionally, a slight increase in COEs was observed in the north, whereas no clear change was evident in the south. Composite analyses for each period demonstrated that a trough in the central Eurasian mid‐troposphere was deepened and southwestward advection of cold air enhanced during the RP, in comparison with the PP, which changed the wind direction over northern Mongolia from westerly to northwesterly. In addition, the number of snow cover days have increased slightly in the RP in northern Mongolia, likely acting as a favourable condition for low air temperatures with intensifying surface cooling. These findings suggest that a deepened trough over central Eurasia, strengthened northerly cold advection into Mongolia, and cooling from the snow‐covered surface are most likely to have resulted in the increased frequency of COEs overnorthern Mongolia in the RP. [ABSTRACT FROM AUTHOR]

Forest fires significantly impact permafrost degradation in the subarctic regions. However, interannual and seasonal variations in surface deformation due to permafrost thawing in burned areas were poorly understood. Measuring the ground surface displacement in fire scars helps us understand the freeze‐thaw dynamics of near‐surface ground and predict the future state, particularly in ice‐rich permafrost regions. This study used the L‐ and C‐band interferometric synthetic aperture radar technique to reveal interannual subsidence and seasonal thaw settlement/frost heave in a fire scar near Mayya, Sakha Republic in Eastern Siberia burned in 2013. We found that the cumulative subsidence was up to 7 cm between 2014 and 2020, most of which had occurred by 2016. The magnitude of seasonal thaw settlement and frost heave varied each year from 2017 to 2020 after the fire, but the interannual change in frost heave corresponded to the temporal variation in precipitation during the thawing season from 2017 to 2020. This suggests that the precipitation amount during the thawing season is related to the magnitude of segregation‐ice formation in the sediments, which determines the frost heave amount. The observed seasonal displacements could not be quantitatively explained by models inferred from the Stefan's equation and volume changes associated with ice‐water phase change. This implies that other models associated with segregated ice (ice lens) formation/thaw are required to explain the observed seasonal displacement. Plain Language Summary: Forest fires in permafrost regions significantly affect regional landscape changes and ecosystems through permafrost degradation and subsequent ground deformation. However, the number of observations of post forest fire surface displacement is extremely limited. We calculated surface displacement in a fire scar in Eastern Siberia from spaceborne radar images captured using interferometric synthetic aperture radar. Our observed data will help us understand permafrost degradation processes in forest fire scars. Key Points: Ground subsidence was primarily associated with the severity of forest fires, and slope orientation was likely an additional factorSeasonal frost heave measured by interferometric synthetic aperture radar was correlated to precipitation amount in thawing seasonExisting phase change model could not explain observed seasonal displacement quantitatively [ABSTRACT FROM AUTHOR]

Highlights: [•] Soil moisture affected evapotranspiration and GPP. [•] Evapotranspiration and GPP dropped after waterlogging. [•] Droplet of evapotranspiration occurred 1-year earlier than that of GPP. [ABSTRACT FROM AUTHOR]

With a view to creating images of the interior of snow and detection of an object buried in show, an under-snow radar has been fabricated and tested using microwave holography. Since the accumulated snow consists of numerous layers and is not uniform, conventional microwave holography exhibits poor resolution in the distance direction due to unwanted reflection from the interior and hence it is difficult to detect a buried object. To rectify this situation, a multifrequency hologram is used so that the resolution in the distance direction is improved and a clearer image is obtained. In this system, data collection and processing are carried out with a microcomputer and, as a result, a flexible and quasi-real time numerical image reconstruction is possible compared to the optical processing. In the experiment with this system, a metal object less than 1 mm long can be detected in the snow. Thus, the feasibility of the image reconstruction of the object in the snow is demonstrated. Further, the snow surface and the ground surface under the snow can be detected and hence the amount of snow accumulation may be determined. However, it is still necessary to estimate various parameters such as the dielectric constant of the accumulated snow. The problem of reconstruction in a multiple medium is left unsolved. [ABSTRACT FROM AUTHOR]

• Using time-lapse images enabled us to determine quantitative grazing intensity (GI). • Grazing consistently decreased aboveground biomass of grasslands. • CO2 and soil parameters declined as GI increased, but increased when GI was low. • Values of GI at which the grazing effect shifted from plus to minus were obtained. Grazing is a key factor in grassland disturbance that affects plant biomass, soil properties, and carbon exchange in grasslands. The objective of this study was to quantitatively evaluate the effects of grazing on grassland ecosystems in Mongolia. To this end, we developed a new method for determining the actual and quantitative livestock effects. Fenced (ungrazed) plots were established in two nomadically grazed grasslands in Mongolia, Bayan-Unjuul (BU) and Baganuur (BN), and time-lapse cameras were installed at the plots for photographing outside the fences (grazed area) every 10 min. Using images collected for 3 years (2016 − 2018), we counted the number of livestock animals by species and calculated grazing intensity (GI). In addition, we investigated plant biomass; CO 2 fluxes including gross primary production and ecosystem respiration; and soil properties during mid-August at the BU and BN sites. Our new method enabled us to quantitatively assess the seasonal and interannual variations and spatial differences in GI. Livestock used the BU site mainly in spring but the BN site in summer. Using the seasonal GIs, we performed linear regressions to examine grazing effects on plant biomass, CO 2 exchanges, and soil properties. Our results indicated that, among the livestock species we monitored, grazing by goats most strongly affects the grassland function and structures. GI negatively correlated with aboveground biomass (AGB), CO 2 fluxes, soil organic carbon (SOC), and total nitrogen (TN), suggesting that these parameters decreased with increasing GI. The effect size of grazing on AGB was negative for all years and sites, indicating that grazing consistently decreased AGB, whereas CO 2 fluxes, SOC, and TN were positive when the GI was low. By using our new method, we obtained the certain values of GI at which the grazing effect shifted from positive to negative. [ABSTRACT FROM AUTHOR]

Highlights • Unusual perennial excess soil water enhanced growth of understory vegetation of larch forest. • Through wet years and following drying years understory GPP and ER increased, while no trend was found in ecosystem fluxes. • Declined overstory larch led to preferable light condition and enhanced turbulent mixing for understory fluxes. • The understory growth and remaining deeper soil water compensated for the declined larch contribution to all ecosystem fluxes. Abstract This study investigated the CO 2 exchange over a 10-year period (2005–2014) inside and above a larch-dominant forest in the central Lena river basin, eastern Siberia. A wet-soil condition, such as that found in the active layer (seasonally thawed soil layer of upper permafrost), containing unusually high soil water close to saturation and partial surface waterlogging, was prolonged during the warm season of 2005–2009. In later years, the soil layer closer to the ground surface became dry (∼10% volumetric water content), although the deeper part remained relatively wet (∼30%). We quantitatively compared the whole forest and the understory CO 2 exchanges to detect the separate effects of excessive soil waters on the overstory and understory vegetation. The conventional light and temperature response functions for half-hourly CO 2 fluxes, that is, the net ecosystem exchange of daytime and night-time, respectively, were applicable to the understory observations. Comparison of the fitting parameters of the light response function at two levels revealed a smaller maximum net ecosystem exchange (NEE) under light saturation with a steep response under weak light conditions for the understory. The CO 2 exchanges at the understory increased from the wet-soil period to the drying soil period by 46% (1.3 g C m−2 d−1) of gross primary production (GPP) and 29% (1.2 g C m−2 d−1) of ecosystem respiration (ER), while no trend was found in the ecosystem scale fluxes. These increases were due to an increasing understory biomass, changes in plentiful light and soil water in the inside-canopy environments, and enhanced turbulent mixing. The decline in the larch contribution could be compensated for by the understory growth and the remaining wetness of the active layer, which indicated that the interactions between the larch and the understory supported the stability of carbon cycles in this forest ecosystem. [ABSTRACT FROM AUTHOR]

The Arctic freshwater budget is critical for understanding the climate in the northern regions. However, the hydrology of the Arctic circumpolar tundra region (ACTR) and the largest pan-Arctic rivers are still not well understood. In this paper, we analyze the spatiotemporal variations in the terrestrial water storage (TWS) of the ACTR and three of the largest pan-Arctic river basins (Lena, Mackenzie, Yukon). To do this, we utilize monthly Gravity Recovery and Climate Experiment (GRACE) data from 2002 to 2016. Together with global land reanalysis, and river runoff data, we identify declining TWS trends throughout the ACTR that we attribute largely to increasing evapotranspiration driven by increasing summer air temperatures. In terms of regional changes, large and significant negative trends in TWS are observed mainly over the North American continent. At basin scale, we show that, in the Lena River basin, the autumnal TWS signal persists until the spring of the following year, while in the Mackenzie River basin, the TWS level in the autumn and winter has no significant impact on the following year. As expected global warming is expected to be particularly significant in the northern regions, our results are important for understanding future TWS trends, with possible further decline. [ABSTRACT FROM AUTHOR]

Abstract: Water vapor, energy fluxes, and environmental conditions were measured in an eastern Siberian larch forest for 7 water years, from 1998 to 2006, to understand the water-balance characteristics and interannual variation (IAV). The latent heat flux accounted for 38–67% of the sum of turbulent heat fluxes in June, July, and August, a relatively moderate fraction was compared to values measured at mid- and low latitudes. More than 70% of the annual precipitation evaporated during May to September. Annual evapotranspiration, including interception loss, was relatively steady at 169–220mm compared with the wide range in annual precipitation (111–347mmyear−1). The evapotranspiration rate was 1.49–2.30mmday−1 on a daily basis from May to September above a dry canopy. This feature is one of the remarkable characteristics of the water balance in eastern Siberian forests. The thawing depth of the permafrost has been rapidly deepening since 2004, such that the maximal thawing depth varied from 127cm before 2003 to over 200cm after 2004. At the same time, there was a very large increase in the moisture content of the surface soil. This increase could not be explained by the amount of annual precipitation alone and may have been due to inflow from the deeper thawing layer. The IAV of evapotranspiration was small, but the yearly evapotranspiration coefficient (the ratio of evapotranspiration to potential evaporation) ranged from 0.30 to 0.45. These results indicate that the IAV of evapotranspiration is controlled by regulation of the land surface rather than by atmospheric demand. Soil-moisture content was the most important variable among the factors determining the evapotranspiration coefficient at an interannual temporal scale. This result differs somewhat from previous satellite-based findings that air temperature was a major variable for plant activity. This difference might result from the fact that the IAV of soil water content did not correspond to that of the precipitation amount because of the presence of the permafrost. By contrast, the soil water content was strongly affected by precipitation in the previous summer. [Copyright &y& Elsevier]

We developed a 15 kW synchronous motor with a fixed superconducting field winding. It was 8-pole type. Each field coil was a racetrack-shaped single pancake wound with a YBCO superconducting tape. It was fabricated by IBAD-PLD method and 10 mm in width. The rotating armature was composed of a copper winding and an iron core. The field coils were conduction-cooled down to 20 to 30 K through a copper pipe attached to the copper coil flange, in which helium gas was forced-flowed. The completed motor was first tested in the Suzuka factory of Japan Motor and Generator Co. Ltd. before shipping as usual. Then it was moved to the test site of the Nagasaki shipyard of Mitsubishi Heavy Industry Ltd. and installed into a ship propulsion test system, which had a propeller with a diameter of 0.5 m. We verified the quite stable underwater operation and the output power of 15 kW-360 rpm as designed. [ABSTRACT FROM AUTHOR]

The concept of the plasticity or transdifferentiation of adult stem cells has been challenged by the phenomenon of cell fusion. In this work, we examined whether neonatal cardiomyocytes fuse with various somatic cells including endothelial cells, cardiac fibroblasts, bone marrow cells, and endothelial progenitor cells spontaneously in vitro. When cardiomyocytes were cocultured with endothelial cells or cardiac fibroblasts, they fused and showed phenotypes of cardiomyocytes. Furthermore, cardiomyocytes reentered the G2-M phase in the cell cycle after fusing with proliferative noncardiomyocytes. Transplanted endothelial cells or skeletal muscle-derived cells fused with adult cardiomyocytes in vivo. In the cryoinjured heart, there were Ki67-positive cells that expressed both cardiac and endothelial lineage marker proteins. These results suggest that cardiomyocytes fuse with other cells and enter the cell cycle by maintaining their phenotypes. [ABSTRACT FROM AUTHOR]

In large mammals there is a correlation between microtubule network densification and contractile dysfunction in severe pressureoverload hypertrophy. In small mammals there is a similar correlation for the shift to β-myosin heavy chain (MHC), a MHC isoform having a slower ATPase V[sub max]. In this study, murine left ventricular (LV) pressure overload invoked both mechanisms: microtubule network densification and β-MHC expression. Cardiac β-MHC was also augmented without altering tubulin levels by two load-independent means, chemical thyroidectomy and transgenesis. In hypertrophy, contractile function of the LV and its cardiocytes decreased proportionally; microtubule depolymerization restored normal cellular contraction. In hypothyroid mice having a complete shift from α-MHC to β-MHC, contractile function of the LV and its cardiocytes also decreased, but microtubule depolymerization had no effect on cellular contraction. In transgenic mice having a cardiac β-MHC increase similar to that in hypertrophy, contractile function of the LV and its cardiocytes was normal, and microtubule depolymerization had no effect. Thus, although both mechanisms may cause contractile dysfunction, for the extent of MHC isoform switching seen even in severe murine LV pressure-overload hypertrophy, microtubule network densification appears to have the more important role. [ABSTRACT FROM AUTHOR]

Examines the level of soluble Fas (sFas) in patients with myocarditis. Role of Fas system in regulating peripheral immune responses; Tests conducted to serum samples of the patients; Findings of the study.