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Atmospheric carbon dioxide concentration (pCO2) has increased by approximately 80 ppm from the Last Glacial Maximum (LGM) to the early Holocene. The change in this atmospheric greenhouse gas is recognized as a climate system response to gradual change in insolation. Previous modeling studies suggested that the deglacial increase in atmospheric pCO2 is primarily attributed to the release of CO2 from the ocean. Additionally, it has been suggested that abrupt change in the Atlantic meridional overturning circulation (AMOC) and associated interhemispheric climate changes are involved in the release of CO2. However, understanding remains limited regarding oceanic circulation changes and the factors responsible for changes in chemical tracers in the ocean during the last deglaciation and their impact on atmospheric pCO2. In this study, we investigate the evolution of the ocean carbon cycle during the last deglaciation (21 to 11 ka BP) using three-dimensional ocean fields from the transient simulation of the MIROC 4m climate model, which exhibits abrupt AMOC changes similar to those observed in reconstructions. We investigate the reliability of simulated changes in the ocean carbon cycle by comparing the simulated carbon isotope ratios with sediment core data, and we examine potential biases and overlooked or underestimated processes in the model. Qualitatively, the modeled changes in atmospheric pCO2 are consistent with ice core records. For example, during Heinrich Stadial 1 (HS1), atmospheric pCO2 increases by 10.2 ppm, followed by a reduction of 7.0 ppm during the Bølling–Allerød (BA) period and then by an increase of 6.8 ppm during the Younger Dryas (YD) period. However, the model underestimates the changes in atmospheric pCO2 during these events compared to values derived from ice core data. Radiocarbon and stable isotope signatures (Δ14C and δ13C) indicate that the model underestimates both the activated deep-ocean ventilation and reduced efficiency of biological carbon export in the Southern Ocean and the active ventilation in the North Pacific Intermediate Water (NPIW) during HS1. The relatively small changes in simulated atmospheric pCO2 during HS1 might be attributable to these underestimations of ocean circulation variation. The changes in Δ14C associated with strengthening and weakening of the AMOC during the BA and YD periods are generally consistent with values derived from sediment core records. However, although the data indicate continuous increase in δ13C in the deep ocean throughout the YD period, the model shows the opposite trend. It suggests that the model either simulates excessive weakening of the AMOC during the YD period or has limited representation of geochemical processes, including marine ecosystem response and terrestrial carbon storage. Decomposing the factors behind the changes in ocean pCO2 reveals that variations in temperature and alkalinity have the greatest impact on change in atmospheric pCO2. Compensation for the effects of temperature and alkalinity suggests that the AMOC changes and the associated bipolar climate changes contribute to the decrease in atmospheric pCO2 during the BA and the increase in atmospheric pCO2 during the YD period.

Abstract The T2K experiment presents new measurements of neutrino oscillation parameters using $$19.7(16.3)\times 10^{20}$$ 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional $$4.7\times 10^{20}$$ 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on $$\sin ^2\theta _{13}$$ sin 2 θ 13 and the impact of priors on the $$\delta _{\textrm{CP}}$$ δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of $$\sin ^2\theta _{23}$$ sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on $$\sin ^2\theta _{13}$$ sin 2 θ 13 from reactors, $$\sin ^2\theta _{23}=0.561^{+0.021}_{-0.032}$$ sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman–Cousins corrected intervals, and $$\varDelta {}m^2_{32}=2.494_{-0.058}^{+0.041}\times 10^{-3}~\text {eV}^2$$ Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant $$\varDelta \chi ^{2}$$ Δ χ 2 intervals. The CP-violating phase is constrained to $$\delta _{\textrm{CP}}=-1.97_{-0.70}^{+0.97}$$ δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman–Cousins corrected intervals, and $$\delta _{\textrm{CP}}=0,\pi $$ δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than $$2\sigma $$ 2 σ credible level using a flat prior in $$\delta _{\textrm{CP}},$$ δ CP , and just below $$2\sigma $$ 2 σ using a flat prior in $$\sin \delta _{\textrm{CP}}.$$ sin δ CP . When the external constraint on $$\sin ^2\theta _{13}$$ sin 2 θ 13 is removed, $$\sin ^2\theta _{13}=28.0^{+2.8}_{-6.5}\times 10^{-3},$$ sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Introduction: Myelodysplastic syndromes (MDS) are characterized by persistent of cytopenia, gene abnormalities, and dysplasia. Although the correlation between chronic inflammation and ineffective hematopoiesis is demonstrated in forming MDS pathogenesis, the detailed mechanisms remain unclear. Methods: Recently, we established a new MDS with low blasts (MDS-LB) model (CBLΔE8/9-RUNX1S291fs mice) , which recapitulates MDS-LB pathogenesis such as pancytopenia and chronic inflammation, by introducing these two mutations into murine hematopoietic stem and progenitor cells (HSC/Ps) . Results: MDS model mice exhibited excessive mitochondrial fragmentation due to Drp1 activation in HSC/Ps. Importantly, pharmacological inhibition of mitochondrial fragmentation rescued leukocytopenia and dysplasia formation in MDS mice by suppressing inflammatory signaling activation, suggesting that mitochondrial fragmentation could be a new therapeutic target of MDS. Given that mitochondrial fragmentation is related to MDS pathogenesis, we hypothesized that mitochondrial fragmentation can be used for morphological diagnosis of MDS. Differential diagnosis of patients with non-MDS cytopenia and MDS-LB has been challenging. We assessed mitochondrial morphology in bone marrow samples from 10 healthy individuals and 141 patients before disease-modifying therapy. The percentage of cells with mitochondrial fragmentation was significantly increased in patients with MDS-LB, compared with that in patients with cytopenia without dysplasia and gene abnormality (mean 50.7% vs 22.4%, P

This article illustrates the controlling mechanism along with data transmission using optical camera communication in both line-of-sight and non-line-of sight (NLOS) environment. The transmitter of the system is mainly composite of microcontroller (Arduino Mega), DHT sensor, two LEDs, and four push button switches. Here, two LEDs are continuously transmitting the control and data signal. The control signal is operated through push button switches. We have used four different control signals that are transmitted from the LEDs and data transmission by collecting data from the surrounding through the temperature and humidity sensor. The entire transmitter operations are processed and controlled through arduino programming in a microcontroller. The COOK modulation technique is used for this system. For data reception, we have used laptop's camera that is controlled through five different exposure times and operated based on the rolling shutter effect of the camera. A logistic regression algorithm is applied to recognize the data transmitting LED from the normalized intensity of the stripe patterns. The receiver is capable to collect data under certain conditions, if the light source is obstructed by an object through deep neural network. Again, Generative Adversial Network (GAN) is used as a decoder to reduce the BER during moving scenario and NLOS conditions. Different activation functions are used in the GAN model to find the optimum solution for the system. However, we have archived the maximum 2.5 m communication distance with 10-4 BER. The receiver program is designed using Python 3.8.

Sedimentary 231Pa/230Th ratios provide clues to estimate the strength of past ocean circulation. For its estimation, understanding the processes controlling the distributions of 231Pa and 230Th in the ocean is important. However, simulations of dissolved and particulate 231Pa and 230Th in the modern ocean, recently obtained from the GEOTRACES project, remain challenging. Here we report a model simulation of 231Pa and 230Th in the global ocean with COCO ver4.0. Starting from the basic water-column reversible scavenging model, we also introduced the bottom scavenging and the dependence of scavenging efficiency on particle concentration. As demonstrated in a previous study, the incorporation of bottom scavenging improves the simulated distribution of dissolved 231Pa and 230Th in the deep ocean, which has been overestimated in models not considering the bottom scavenging. We further demonstrate that introducing the dependence of scavenging efficiency on particle concentration results in a high concentration of dissolved 230Th in the Southern Ocean as observed in the GEOTRACES data. Our best simulation can well reproduce not only the oceanic distribution of 231Pa and 230Th but also the sedimentary 231Pa/230Th ratios. Sensitivity analysis reveals that oceanic advection of 231Pa primarily determines sedimentary 231Pa/230Th ratios. On the other hand, 230Th advection and bottom scavenging have an opposite effect to 231Pa advection on the sedimentary 231Pa/230Th ratios, reducing their latitudinal contrast. Our best simulation shows the realistic residence times of 231Pa and 230Th, but simulation without bottom scavenging and dependence of scavenging efficiency on particle concentration significantly overestimates the residence times for both 231Pa and 230Th in spite of similar distribution of sedimentary 231Pa/230Th ratios to our best simulation.

Past efforts to synthesize and quantify the magnitude and change in carbon dioxide (CO2) fluxes in terrestrial ecosystems across the rapidly warming Arctic–boreal zone (ABZ) have provided valuable information but were limited in their geographical and temporal coverage. Furthermore, these efforts have been based on data aggregated over varying time periods, often with only minimal site ancillary data, thus limiting their potential to be used in large-scale carbon budget assessments. To bridge these gaps, we developed a standardized monthly database of Arctic–boreal CO2 fluxes (ABCflux) that aggregates in situ measurements of terrestrial net ecosystem CO2 exchange and its derived partitioned component fluxes: gross primary productivity and ecosystem respiration. The data span from 1989 to 2020 with over 70 supporting variables that describe key site conditions (e.g., vegetation and disturbance type), micrometeorological and environmental measurements (e.g., air and soil temperatures), and flux measurement techniques. Here, we describe these variables, the spatial and temporal distribution of observations, the main strengths and limitations of the database, and the potential research opportunities it enables. In total, ABCflux includes 244 sites and 6309 monthly observations; 136 sites and 2217 monthly observations represent tundra, and 108 sites and 4092 observations represent the boreal biome. The database includes fluxes estimated with chamber (19 % of the monthly observations), snow diffusion (3 %) and eddy covariance (78 %) techniques. The largest number of observations were collected during the climatological summer (June–August; 32 %), and fewer observations were available for autumn (September–October; 25 %), winter (December–February; 18 %), and spring (March–May; 25 %). ABCflux can be used in a wide array of empirical, remote sensing and modeling studies to improve understanding of the regional and temporal variability in CO2 fluxes and to better estimate the terrestrial ABZ CO2 budget. ABCflux is openly and freely available online (Virkkala et al., 2021b, https://doi.org/10.3334/ORNLDAAC/1934).

The contribution of soil heterotrophic respiration to the boreal–Arctic carbon (CO2) cycle and its potential feedback to climate change remains poorly quantified. We developed a remote-sensing-driven permafrost carbon model at intermediate scale (∼1 km) to investigate how environmental factors affect the magnitude and seasonality of soil heterotrophic respiration in Alaska. The permafrost carbon model simulates snow and soil thermal dynamics and accounts for vertical soil carbon transport and decomposition at depths up to 3 m below the surface. Model outputs include soil temperature profiles and carbon fluxes at 1 km resolution spanning the recent satellite era (2001–2017) across Alaska. Comparisons with eddy covariance tower measurements show that the model captures the seasonality of carbon fluxes, with favorable accuracy in simulating net ecosystem CO2 exchange (NEE) for both tundra (R>0.8, root mean square error (RMSE – 0.34 g C m−2 d−1), and boreal forest (R>0.73; RMSE – 0.51 g C m−2 d−1). Benchmark assessments using two regional in situ data sets indicate that the model captures the complex influence of snow insulation on soil temperature and the temperature sensitivity of cold-season soil heterotrophic respiration. Across Alaska, we find that seasonal snow cover imposes strong controls on the contribution from different soil depths to total soil heterotrophic respiration. Earlier snowmelt in spring promotes deeper soil warming and enhances the contribution of deeper soils to total soil heterotrophic respiration during the later growing season, thereby reducing net ecosystem carbon uptake. Early cold-season soil heterotrophic respiration is closely linked to the number of snow-free days after the land surface freezes (R=-0.48, p), i.e., the delay in snow onset relative to surface freeze onset. Recent trends toward earlier autumn snow onset in northern Alaska promote a longer zero-curtain period and enhanced cold-season respiration. In contrast, southwestern Alaska shows a strong reduction in the number of snow-free days after land surface freeze onset, leading to earlier soil freezing and a large reduction in cold-season soil heterotrophic respiration. Our results also show nonnegligible influences of subgrid variability in surface conditions on the model-simulated CO2 seasonal cycle, especially during the early cold season at 10 km scale. Our results demonstrate the critical role of snow cover affecting the seasonality of soil temperature and respiration and highlight the challenges of incorporating these complex processes into future projections of the boreal–Arctic carbon cycle.

Global terrestrial ecosystems control the atmospheric CO2 concentration through gross primary production (GPP) and ecosystem respiration processes. Chlorophyll fluorescence is one of the energy release pathways of excess incident light in the photosynthetic process. Over the last 10 years, extensive studies have revealed that canopy-scale Sun-induced chlorophyll fluorescence (SIF), which potentially provides a direct pathway to link leaf-level photosynthesis to global GPP, can be observed from satellites. SIF is used to infer photosynthetic capacity of plant canopy; however, it is not clear how the leaf-level SIF emission contributes to the top-of-canopy directional SIF. Plant canopy radiative transfer models are useful tools to understand the mechanism of anisotropic light interactions such as scattering and absorption in plant canopies. One-dimensional (1-D) plane-parallel layer models (e.g., the Soil Canopy Observation, Photochemistry and Energy fluxes (SCOPE) model) have been widely used and are useful to understand the general mechanisms behind the temporal and seasonal variations in SIF. However, a 1-D model does not explain the complexity of the actual canopy structures. Three-dimensional models (3-D) have a potential to delineate the realistic directional canopy SIFs. Forest Light Environmental Simulator for SIF (FLiES-SIF) version 1.0 is a 3-D Monte Carlo plant canopy radiative transfer model to understand the biological and physical mechanisms behind the SIF emission from complex forest canopies. The FLiES-SIF model is coupled with leaf-level fluorescence and a physiology module so that users are able to simulate how the changes in environmental and leaf traits as well as canopy structure affect the observed SIF at the top of the canopy. The FLiES-SIF model was designed as three-dimensional model, yet the entire modules are computationally efficient: FLiES-SIF can be easily run by moderate-level personal computers with lower memory demands and public software. In this model description paper, we focused on the model formulation and simulation schemes, and showed some sensitivity analysis against several major variables such as view angle and leaf area index (LAI). The simulation results show that SIF increases with LAI then saturated at LAI>2–4 depending on the spectral wavelength. The sensitivity analysis also shows that simulated SIF radiation may decrease with LAI at a higher LAI domain (LAI>5). These phenomena are seen in certain Sun and view angle conditions. This type of nonlinear and nonmonotonic SIF behavior towards LAI is also related to spatial forest structure patterns. FLiES-SIF version 1.0 can be used to quantify the canopy SIF in various view angles including the contribution of multiple scattering which is the important component in the near-infrared domain. The potential use of the model is to standardize the satellite SIF by correcting the bidirectional effect. This step will contribute to the improvement of the GPP estimation accuracy through SIF.

The Arctic environment is undergoing rapid changes such as faster warming than the global average and exceptional melting of glaciers in Greenland. Black carbon (BC) particles, which are a short-lived climate pollutant, are one cause of Arctic warming and glacier melting. However, the sources of BC particles are still uncertain. We simulated the potential emission sensitivity of atmospheric BC present over the Arctic (north of 66∘ N) using the FLEXPART (FLEXible PARTicle) Lagrangian transport model (version 10.1). This version includes a new aerosol wet removal scheme, which better represents particle-scavenging processes than older versions did. Arctic BC at the surface (0–500 m) and high altitudes (4750–5250 m) is sensitive to emissions in high latitude (north of 60∘ N) and mid-latitude (30–60∘ N) regions, respectively. Geospatial sources of Arctic BC were quantified, with a focus on emissions from anthropogenic activities (including domestic biofuel burning) and open biomass burning (including agricultural burning in the open field) in 2010. We found that anthropogenic sources contributed 82 % and 83 % of annual Arctic BC at the surface and high altitudes, respectively. Arctic surface BC comes predominantly from anthropogenic emissions in Russia (56 %), with gas flaring from the Yamalo-Nenets Autonomous Okrug and Komi Republic being the main source (31 % of Arctic surface BC). These results highlight the need for regulations to control BC emissions from gas flaring to mitigate the rapid changes in the Arctic environment. In summer, combined open biomass burning in Siberia, Alaska, and Canada contributes 56 %–85 % (75 % on average) and 40 %–72 % (57 %) of Arctic BC at the surface and high altitudes, respectively. A large fraction (40 %) of BC in the Arctic at high altitudes comes from anthropogenic emissions in East Asia, which suggests that the rapidly growing economies of developing countries could have a non-negligible effect on the Arctic. To our knowledge, this is the first year-round evaluation of Arctic BC sources that has been performed using the new wet deposition scheme in FLEXPART. The study provides a scientific basis for actions to mitigate the rapidly changing Arctic environment.

The majority of aerosol data are obtained from daytime measurements, and there are few datasets available for studying nighttime aerosol characteristics. In order to estimate the aerosol optical depth (AOD) and the precipitable water vapor (PWV) during the nighttime using the moon as a light source, a sky radiometer (POM-02, Prede Ltd., Japan) was modified. The amplifier was adjusted so that POM-02 could measure lower levels of input irradiance. In order to track the moon based on the calculated values, a simplified formula was incorporated into the firmware. A new position sensor with a four-quadrant detector to adjust the tracking of the Sun and moon was also developed. The calibration constant, which is the sensor output for the extraterrestrial solar and lunar irradiance at the mean Earth–Sun distance, was determined by using the Langley method. The measurements for the Langley calibration were conducted at the National Oceanic and Atmospheric Administration/Mauna Loa Observatory (NOAA/MLO) from 28 September 2017 to 7 November 2017. By assuming that the correct reflectance is proportional to the reflectance estimated by the Robotic Lunar Observatory (ROLO) irradiance model, the calibration constant for the lunar direct irradiance was successfully determined using the Langley method. The ratio of the calibration constant for the moon to that of the Sun was often greater than 1; the value of the ratio was 0.95 to 1.18 in the visible and near-infrared wavelength regions. This indicates that the ROLO model often underestimates the reflectance. In addition, this ratio depended on the phase angle. In this study, this ratio was approximated by a quadratic equation of the phase angle. By using this approximation, the reflectance of the moon can be calculated to within an accuracy of 1 % or less. In order to validate the estimates of the AOD and PWV, continuous measurements with POM-02 were conducted at the Japan Meteorological Agency/Meteorological Research Institute (JMA/MRI) from January 2018 to May 2018, and the AOD and PWV were estimated. The results were compared with the AOD and PWV obtained by independent methods. The AOD was compared with that estimated by the National Institute for Environmental Studies (NIES) High Spectral Resolution Lidar measurements (wavelength: 532 nm), and the PWV was compared with the PWV obtained from a radiosonde and the Global Positioning System. In addition, the continuity of the AOD (PWV) before and after sunrise and sunset in Tsukuba was examined, and the AOD (PWV) of AERONET and that of POM-02 at MLO were compared. In the results, the daytime and nighttime AOD (PWV) measurements are shown to be statistically almost equivalent. The AODs (PWVs) during the daytime and nighttime for POM-02 are presumed to have the same degree of precision and accuracy within the measurement uncertainty.

We calibrated the JSBACH model with six different stomatal conductance formulations using measurements from 10 FLUXNET coniferous evergreen sites in the boreal zone. The parameter posterior distributions were generated by the adaptive population importance sampler (APIS); then the optimal values were estimated by a simple stochastic optimisation algorithm. The model was constrained with in situ observations of evapotranspiration (ET) and gross primary production (GPP). We identified the key parameters in the calibration process. These parameters control the soil moisture stress function and the overall rate of carbon fixation. The JSBACH model was also modified to use a delayed effect of temperature for photosynthetic activity in spring. This modification enabled the model to correctly reproduce the springtime increase in GPP for all conifer sites used in this study. Overall, the calibration and model modifications improved the coefficient of determination and the model bias for GPP with all stomatal conductance formulations. However, only the coefficient of determination was clearly improved for ET. The optimisation resulted in best performance by the Bethy, Ball–Berry, and the Friend and Kiang stomatal conductance models. We also optimised the model during a drought event at a Finnish Scots pine forest site. This optimisation improved the model behaviour but resulted in significant changes to the parameter values except for the unified stomatal optimisation model (USO). Interestingly, the USO demonstrated the best performance during this event.

Depolarization ratio (δ) of backscattered light is an applicable parameter for distinguishing the sphericity of particles in real time, which has been widely adopted by ground-based lidar observation systems. In this study, δ values of particles and chemical compositions in both PM2.5 (aerodynamic diameter less than 2.5 µm) and PM10 (aerodynamic diameter less than 10 µm) were concurrently measured on the basis of a bench-top optical particle counter with a polarization detection module (POPC) and a continuous dichotomous aerosol chemical speciation analyzer (ACSA-14) from November 2016 to February 2017 at an urban site in Beijing megacity. In general, measured δ values depended on both size and sphericity of the particles. During the observation period, mass concentrations of NO3- in PM2.5 (fNO3) were about an order of magnitude higher than that in PM2.5−10 (cNO3) with a mean fNO3∕cNO3 ratio of 14±10. A relatively low fNO3∕cNO3 ratio (∼5) was also observed under higher relative humidity conditions, mostly due to heterogeneous processes and particles in the coarse mode. We found that δ values of ambient particles in both PM2.5 and PM2.5−10 obviously decreased as mass concentration of water-soluble species increased at unfavorable meteorological conditions. This indicated that the morphology of particles was changed as a result of water-absorbing processes. The particles with optical size (Dp) of Dp = 5 µm were used to represent mineral dust particles, and its δ values (δDp=5) decreased by 50 % as the mass fraction of cNO3 increased from 2 % to 8 % and ambient relative humidity increased up to 80 %, suggesting that mineral dust particles were likely to be spherical during humid pollution episodes. During the observation, relative humidity inside the POPC measuring chamber was stable at 34±2 %, lower than the ambient condition. Its influence on the morphology was estimated to be limited and did not change our major conclusion. This study highlights the evident alteration of non-sphericity of mineral dust particles during their transport owing to a synergistic effect of both pollutant coatings and hygroscopic processes, which plays an important role in the evaluation of its environmental effect.

East Asia is suffering from severe air pollution problems due to intensive anthropogenic emissions and natural mineral dust aerosols. During transport, the aerosol particles undergo complex mixing processes, resulting in great impacts on regional air quality, human health and climate. In this study, we conducted a long-term observation using an optical particle counter equipped with a polarization detection module (POPC) at an urban site in Beijing. Mass concentrations of both PM2.5 and PM10 estimated from POPC compared well with ground-based measurements. The results revealed that the observed depolarization ratio (δ, termed as the ratio of the intensity of the s-polarized signal to the intensity of the 120∘ backward scattering signal [s/(s+p)]) for aerosol particles in the fine mode was generally much lower in summer than that in spring as a result of predominance of different aerosol types. Mineral dust particles in the coarse mode normally had a large δ value (0.3±0.05) owing to their nonspherical shape; however, particles in the fine mode mostly had water-soluble compositions, which led to an apparent decrease of their δ values in particular high relative humidity (RH) conditions. Because the observation site was subject to the impact of frequent dust events in spring, the δ value of particle at 1 µm was almost twice as high as that (0.07±0.01) in summer. Based on size-resolved δ values, anthropogenic pollutants, mineral dust and polluted mineral dust particles and their contribution to local air quality could be well distinguished. About 26.7 % of substandard days (daily averaged PM2.5 concentration larger than 75 µg m−3) in Beijing featured high atmospheric loading of coarse-mode particles in winter and springtime. In particular, during severe pollution episodes in winter, the δ values of coarse-mode particles decreased by 13 %, which implies a high possibility of dust-related heterogeneous processes in pollution formation. During dust events, δ values of particles with optical size (Dp) of 5 µm evidently decreased, with an increase of the PM2.5 ∕ PM10 ratio as well as RH, indicating the morphological changes of mineral dust. This study confirmed that high RH tends to promote water absorption processes on the dust surface as well as the coating of soluble compounds, and suggested that remote sensing techniques for aerosols may underestimate the impact of dust particles due to the complex mixing of dust and anthropogenic particles in urban areas, and the interaction between dust particles and pollutants should be considered well by the optical model.

Abstract Background The reason why the osteotomy line in the sagittal view should be parallel to the medial tibial posterior slope in open wedge high tibial osteotomy (OWHTO) remains unclear. In addition, previous study reported that a posterolateral hinge position led to an increase in tibial posterior slope (TPS) after OWHTO. Our aims were to examine the relationships between angles among the tibial plateau and osteotomy planes or the hinge point and the change in TPS, and the location of the hinge position after OWHTO using three-dimensional computed tomography (3DCT). We hypothesized that the sagittal angle between the tibial plateau and osteotomy planes with an anterior-widening proximal tibial fragment resulted in increased TPS, and the hinge position located posterolaterally. Methods Preoperative planning anticipated a weight-bearing line ratio of 62% on the radiograph. The anterior gap was 67% of the posterior gap in OWHTO. We identified the tibial plateau and upper and lower osteotomy planes on 3DCT of 82 patients with symptomatic medial osteoarthritic knee after OWHTO. The osteotomy plane angles between the tibial plateau and upper osteotomy planes, and opening gap angles between both osteotomy planes in the coronal and sagittal views were measured. The anteroposterior (AP) and lateral hinge position was displayed as a percentage on the upper osteotomy plane. We assessed the relationships among them. Results The TPS significantly increased after OWHTO (p = 0.002). There was no significant difference between the sagittal osteotomy plane angle and the change in TPS. The sagittal opening gap angle and the AP hinge position ratio were significantly correlated with the change in the TPS (r = 0.477 p

Taiga–tundra boundary ecosystems are affected by climate change. Methane (CH4) emissions in taiga–tundra boundary ecosystems have sparsely been evaluated from local to regional scales. We linked in situ CH4 fluxes (2009–2016) with vegetation cover, and scaled these findings to estimate CH4 emissions at a local scale (10 × 10 km) using high-resolution satellite images in an ecosystem on permafrost (Indigirka lowland, north-eastern Siberia). We defined nine vegetation classes, containing 71 species, of which 16 were dominant. Distribution patterns were affected by microtopographic height, thaw depth and soil moisture. The Indigirka lowland was covered by willow-dominated dense shrubland and cotton-sedge-dominated wetlands with sparse larch forests. In situ CH4 emissions were high in wetlands. Lakes and rivers were CH4 sources, while forest floors were mostly neutral in terms of CH4 emission. Estimated local CH4 emissions (37 mg m−2 d−1) were higher than those reported in similar studies. Our results indicate that: (i) sedge and emergent wetland ecosystems act as hot spots for CH4 emissions, and (ii) sparse tree coverage does not regulate local CH4 emissions and balance. Thus, larch growth and distribution, which are expected to change with climate, do not contribute to decreasing local CH4 emissions.

Albedo and fraction of absorbed photosynthetically active radiation (FAPAR) determine the shortwave radiation balance and productivity of forests. Currently, the physical link between forest albedo and productivity is poorly understood, yet it is crucial for designing optimal forest management strategies for mitigating climate change. We investigated the relationships between boreal forest structure, albedo and FAPAR using a radiative transfer model called Forest Reflectance and Transmittance model FRT and extensive forest inventory data sets ranging from southern boreal forests to the northern tree line in Finland and Alaska (N = 1086 plots). The forests in the study areas vary widely in structure, species composition, and human interference, from intensively managed in Finland to natural growth in Alaska. We show that FAPAR of tree canopies (FAPARCAN) and albedo are tightly linked in boreal coniferous forests, but the relationship is weaker if the forest has broadleaved admixture, or if canopies have low leaf area and the composition of forest floor varies. Furthermore, the functional shape of the relationship between albedo and FAPARCAN depends on the angular distribution of incoming solar irradiance. We also show that forest floor can contribute to over 50 % of albedo or total ecosystem FAPAR. Based on our simulations, forest albedos can vary notably across the biome. Because of larger proportions of broadleaved trees, the studied plots in Alaska had higher albedo (0.141–0.184) than those in Finland (0.136–0.171) even though the albedo of pure coniferous forests was lower in Alaska. Our results reveal that variation in solar angle will need to be accounted for when evaluating climate effects of forest management in different latitudes. Furthermore, increasing the proportion of broadleaved trees in coniferous forests is the most important means of maximizing albedo without compromising productivity: based on our findings the potential of controlling forest density (i.e., basal area) to increase albedo may be limited compared to the effect of favoring broadleaved species.

Ground-based observation of the polarization properties of aerosol particles using a polarization optical particle counter (POPC) was made from 27 October 2013, to 31 December 2015, at a suburban site in the Kyushu area of Japan. We found that the depolarization ratio (DR, the fraction of s-polarized signal in the total backward light scattering signal) of aerosol particles showed prominent seasonal variability, with peaks in spring (0.21–0.23) and winter (0.19–0.23), and a minimum value (0.09–0.14) in summer. The aerosol compositions in both fine mode (aerodynamic diameter of particle, Dp Dp Dp > 1 µm) particles. Occurrence of substandard air quality days in Kyushu was closely related with mixed type (coexistence of anthropogenic pollutants and dust particles in the atmosphere), especially in winter and spring, indicating that dust events in the Asian continent played a key role in the cross-boundary transport of continental pollution. Backward trajectory analysis demonstrated that air masses originating from the western Pacific contained large amounts of spherical particles due to the influence of sea salt, especially in summer; however, for air masses from the Asian continent, the dependence of number fraction of spherical particles on air relative humidity was insignificant, indicating the predominance of less-hygroscopic substances (e.g., mineral dust), although the mass concentrations of anthropogenic pollutants were elevated.

Recent population increases in urban areas of Asian countries have extended artificial land cover, increased energy consumption, and caused various problems. Higher air temperatures over urban areas (heat islands) degrade residential environments and affect human health. In Jakarta, the largest city in Indonesia and the second largest city in Asia, previous studies have relied on only a few observation points and physically-based models. To study the thermal environment in Jakarta in more detail, we performed seven fixed-point temperature and humidity observations from the dry to the pre-monsoon season (from 16 September to 18 October) in 2012. Over densely urbanized areas, higher temperatures and lower humidity were observed around noon compared with the sparsely urbanized areas. The maximum differences in temperature and specific humidity were found to be around 3 °C and 0.005 kg/kg, respectively. The differences in temperature and humidity became smaller in the afternoon because of the penetration of sea breezes. At night, the differences became larger again because the sea breeze weakened. Then, a difference of around 3°C was observed, except in the early morning. Although the difference in daytime temperature was smaller between densely urbanized areas and suburban areas, similar tendency was also confirmed in the daily time series averaged for sunny days in dry season.

We present an efficient, low-cost implementation of time-hopping impulse radio that fulfills the spectral mask mandated by the FCC and is suitable for high-data-rate, short-range communications. Key features are (i) all-baseband implementation that obviates the need for passband components, (ii) symbol-rate (not chip rate) sampling, A/D conversion, and digital signal processing, (iii) fast acquisition due to novel search algorithms, and (iv) spectral shaping that can be adapted to accommodate different spectrum regulations and interference environments. Computer simulations show that this system can provide 110 Mbps at 7–10 m distance, as well as higher data rates at shorter distances under FCC emissions limits. Due to the spreading concept of time-hopping impulse radio, the system can sustain multiple simultaneous users, and can suppress narrowband interference effectively.

By monitoring coherent transition radiation (CTR) with a Michelson interferometer, bunch length measurement was investigated. Less-than-20-fs electron bunches were generated by a photocathode-based linear accelerator (linac) and a magnetic bunch compressor. From the femtosecond electron bunch of 2.1 pC and 32 MeV, CTR was measured using a Michelson interferometer that had two detectors with different spectral ranges, which enhanced the detection spectral range of CTR (ranging from 3 to 50 THz) and enabled us to determine the bunch length of the electron bunch. A model based on the interferometer’s frequency sensitivity was proposed and introduced to analyze the measured interferograms. The measured interferograms and the frequency spectra were explained using the model.

We have developed an initial-beam-loading compensation system by a new compensation method, where the system modulates the phase and amplitude of a low-level rf signal simultaneously, thereby optimizing a high-power rf waveform fed to an accelerating structure to compensate the beam energy spread. This compensation system is very compact and can easily be installed in and removed from a klystron system. This system was used in a beam test performed in the 125 MeV electron linac of the Laboratory for Electron Beam Research and Application in Nihon University. Experimental results demonstrate that this system effectively corrects the beam energy spread due to the initial-beam-loading effect. The new compensation method is expected to be effective in the compensation of energy spread in high-intensity and long-pulse beams in electron linacs.

Based on the "Preliminary report of comparative studies on the Agrico-Pastoral People in the South Western Eurasia", the results obtained by the research group from the Plant Germplasm Institute, Fac. Agr., Kyoto University are briefly presented. Collections and preliminary evaluations were made on Triticum monococcum, T. aestivum, Hordeum vulgare, Secale cereale, Avena sativa, Panicum milliaceum, Agropyron ssp., and weeds (Bromus secalinus, Lolium temulentum) associated with grain fields.