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Climate stabilization remains elusive, with increased greenhouse gas concentrations already increasing global average surface temperatures 1.1°C above pre-industrial levels (World Meteorological Organization 2019). Carbon dioxide (CO2) emissions from fossil fuel use, deforestation, and other anthropogenic sources reached ~ 43 billion metric tonnes in 2019 (Friedlingstein et al 2019, Jackson et al 2019). Storms, floods, and other extreme weather events displaced a record 7 million people in the first half of 2019 (IDMC 2019). When global mean surface temperature four million years ago was 2°C–3°C warmer than today (a likely temperature increase before the end of the century), ice sheets in Greenland and West Antarctica melted and parts of East Antarctica’s ice retreated, causing sea levels to rise 10–20 m (World Meteorological Organization 2019). Methane (CH4) emissions have contributed almost one quarter of the cumulative radiative forcings for CO2, CH4, and N2O (nitrous oxide) combined since 1750 (Etminan et al 2016). Although methane is far less abundant in the atmosphere than CO2, it absorbs thermal infrared radiation much more efficiently and, in consequence, has a global warming potential (GWP) ~86 times stronger per unit mass than CO2 on a 20-year timescale and 28- times more powerful on a 100-year time scale (IPCC 2014). Global average methane concentrations in the atmosphere reached ~1875 parts per billion (ppb) at the end of 2019, more than two-and-a-half times preindustrial levels (Dlugokencky 2020). The largest methane sources include anthropogenic emissions from agriculture, waste, and the extraction and use of fossil fuels as well as natural emissions from wetlands, freshwater systems, and geological sources (Kirschke et al 2013, Saunois et al 2016a, Ganesan et al 2019). Here, we summarize new estimates of the global methane budget based on the analysis of Saunois et al (2020) for the year 2017, the last year of the new Global Methane Budget and the most recent year data are fully available. We compare these estimates to mean values for the reference ‘stabilization’ period of 2000–2006 when atmospheric CH4 concentrations were relatively stable. We present data for sources and sinks and provide insights for the geographical regions and economic sectors where emissions have changed the most over recent decades.

Quantifying the fluxes of carbon dioxide (CO2 ) between the atmosphere and terrestrial ecosystems in all their diversity, across the continents, is important and urgent for implementing effective mitigating policies. Whereas much is known for Europe and North America for instance, in comparison, South Asia, with 1.6 billion inhabitants and considerable CO2 fluxes, remained terra incognita in this respect. We use regional measurements of atmospheric CO2 aboard a Lufthansa passenger aircraft between Frankfurt (Germany) and Chennai (India) at cruise altitude, in addition to the existing network sites for 2008, to estimate monthly fluxes for 64-regions using Bayesian inversion and transport model simulations. The applicability of the model's transport parameterization is confirmed using SF6 , CH4 and N2 O simulations for the CARIBIC datasets. The annual amplitude of carbon flux obtained by including the aircraft data is twice as large as the fluxes simulated by a terrestrial ecosystem model that was applied to prescribe the fluxes used in the inversions. It is shown that South Asia sequestered carbon at a rate of 0.37 ± 0.20 Pg C yr-1 (1 Pg C = 1015 g of carbon in CO2 ) for the years 2007 and 2008. The seasonality and the strength of the calculated monthly fluxes are successfully validated using independent measurements of vertical CO2 profiles over Delhi and spatial variations at cruising altitude over Asia aboard Japan Airlines passenger aircraft.

Atmospheric CO2 inversions estimate surface carbon fluxes from an optimal fit to atmospheric CO2 measurements, usually including prior constraints on the flux estimates. Eleven sets of carbon flux estimates are compared, generated by different inversions systems that vary in their inversions methods, choice of atmospheric data, transport model and prior information. The inversions were run for at least 5 yr in the period between 1990 and 2010. Mean fluxes for 2001-2004, seasonal cycles, interannual variability and trends are compared for the tropics and northern and southern extra-tropics, and separately for land and ocean. Some continental/basin-scale subdivisions are also considered where the atmospheric network is denser. Four-year mean fluxes are reasonably consistent across inversions at global/latitudinal scale, with a large total (land plus ocean) carbon uptake in the north (-3.4 Pg C yr-1 (±0.5 Pg C yr-1 standard deviation), with slightly more uptake over land than over ocean), a significant although more variable source over the tropics (1.6 ± 0.9 Pg C yr-1 ) and a compensatory sink of similar magnitude in the south (-1.4 ± 0.5 Pg C yr-1 ) corresponding mainly to an ocean sink. Largest differences across inversions occur in the balance between tropical land sources and southern land sinks. Interannual variability (IAV) in carbon fluxes is larger for land than ocean regions (standard deviation around 1.06 versus 0.33 Pg C yr-1 for the 1996-2007 period), with much higher consistency among the inversions for the land. While the tropical land explains most of the IAV (standard deviation ~ 0.65 Pg C yr-1 ), the northern and southern land also contribute (standard deviation ~ 0.39 Pg C yr-1 ). Most inversions tend to indicate an increase of the northern land carbon uptake from late 1990s to 2008 (around 0.1 Pg C yr-1 , predominantly in North Asia. The mean seasonal cycle appears to be well constrained by the atmospheric data over the northern land (at the continental scale), but still highly dependent on the prior flux seasonality over the ocean. Finally we provide recommendations to interpret the regional fluxes, along with the uncertainty estimates.

Traditional Global Navigation Satellite System-Acoustic (GNSS-A) positioning assumes the Layered Model in the sound speed structure, and any of horizontal perturbation of seawater degrades its accuracy. However, the use of the Gradient Model analytically demonstrated that the horizontal gradient of the sound speed structure and displacement can simultaneously be solved using multiple transponders for each of ping. We applied this technique to our observed data and found it unsuitable for real data. We confirmed that a horizontal perturbation with wavelength shorter than the horizontal extent of the transponder array significantly violates the linear approximation in the Gradient Model. Our vertical 2D numerical simulation of internal waves (IWs) forced by tidal oscillation showed that such small-scale IWs could effectively be generated by nonlinear cascade from large-scale IWs of the major tidal constituents. In addition, a small-scale IW in deep water typically has a period of 3–4 h, which degrades positioning accuracy significantly, whereas an IW of much shorter period in shallow water has less effect after removal of the fluctuation by time averaging within a typical observation period. Apparent array position obtained in the synthetic test based on the simulated IW-derived sound speed structure showed features quite similar to that observed in real surveys. To incorporate such deeper perturbation, we proposed a Disturbance Model using dual sea surface platforms, that can solve time-varying perturbation in the vicinity of each transponder.

Grasslands are important ecosystems containing unique biodiversity. It has been reported that some herbaceous species inhabiting grassland reduced its number and became extremely rare. Restoring these species as well as maintaining the grassland are key issues. Light environment is crucial for plant growth and survival. It is particularly important to evaluate light environment of microsite for herbaceous vegetation. In this paper, NDVI, vegetation biomass and gap fraction were estimated using time-series UAV data, and compared to photosynthetic photon flux density (PPFD), solar radiation and gap fraction measured by traditional ground-based techniques to validate its utility in accessing light environment for herbaceous vegetation in semi-natural grassland. The results showed that UAV derived variables displayed overall good correlations with ground derived variables: relative PPFD, relative solar radiation and gap fraction. Analysis of time-series UAV data revealed that UAV derived NDVI and vegetation biomass were not suitable for evaluating light environment when vegetation attains its maturity. UAV derived gap fraction was most resilient to change of vegetation growth. UAV derived methods have advantage in evaluating light environment in microsite without disturbing valuable plants and would help restoring semi-natural grassland.

Purpose: Exercise-induced hypoalgesia (EIH) is a reduction in pain sensitivity that occurs following a single bout of exercise. However, little research has compared the EIH effects of exercise at different intensities, including low intensity, in the same participant. It is unclear as to which exercise intensities demonstrate EIH more effectively. The aim of this study was to examine and compare the effect of different intensities of exercise on pain sensitivity in the same participant. Methods: We included 73 healthy young adult volunteers (35 female and 38 male) in this experimental cross-over study. Each participant completed four experimental sessions of 30 min, consisting of aerobic exercise at 30% heart rate reserve (HRR), aerobic exercise at 50% HRR, aerobic exercise at 70% HRR, and quiet rest. EIH was assessed using the pressure pain threshold (PPT) and temporal summation of pain (TSP) in the quadriceps, biceps, and trapezius. Results: Low- and moderate-intensity exercise increased the multisegmental PPT and reduced TSP (all P < 0.05). High-intensity exercise increased the multisegmental PPT (all P < 0.05), but decreased TSP in only the quadriceps and biceps (P < 0.05), not the trapezius (P = 0.13). We found no difference in relative PPT and TSP changes between exercise intensities (P > 0.05) except for relative PPT change at the quadriceps (P < 0.05). Conclusion: Our results show that not only moderate- and high-intensity exercise, but also low-intensity exercise can produce a hypoalgesic response. Keywords: exercise intensity, exercise-induced hypoalgesia, aerobic exercise, pressure pain threshold, temporal summation of pain

Air-sea CO2 fluxes over the Pacific Ocean are known to be characterized by coherent large-scale structures that reflect not only ocean subduction and upwelling patterns, but also the combined effects of wind-driven gas exchange and biology. On the largest scales, a large net CO2 influx into the extratropics is associated with a robust seasonal cycle, and a large net CO2 efflux from the tropics is associated with substantial interannual variability. In this work, we have synthesized estimates of the net air-sea CO2 flux from a variety of products, drawing upon a variety of approaches in three sub-basins of the Pacific Ocean, i.e., the North Pacific extratropics (18-66° N), the tropical Pacific (18° S-18° N), and the South Pacific extratropics (44.5-18° S). These approaches include those based on the measurements of CO2 partial pressure in surface seawater (pCO2 sw), inversions of ocean-interior CO2 data, forward ocean biogeochemistry models embedded in the ocean general circulation models (OBGCMs), a model with assimilation of pCO2 sw data, and inversions of atmospheric CO2 measurements. Long-term means, interannual variations and mean seasonal variations of the regionally integrated fluxes were compared in each of the sub-basins over the last two decades, spanning the period from 1990 through 2009. A simple average of the long-term mean fluxes obtained with surface water pCO2 diagnostics and those obtained with ocean-interior CO2 inversions are -0.47 ± 0.13 Pg C yr-1 in the North Pacific extratropics, +0.44 ± 0.14 Pg C yr-1 in the tropical Pacific, and -0.37 ± 0.08 Pg C yr-1 in the South Pacific extratropics, where positive fluxes are into the atmosphere. This suggests that approximately half of the CO2 taken up over the North and South Pacific extratropics is released back to the atmosphere from the tropical Pacific. These estimates of the regional fluxes are also supported by the estimates from OBGCMs after adding the riverine CO2 flux, i.e., -0.49 ± 0.02 Pg C yr-1 in the North Pacific extratropics, +0.41 ± 0.05 Pg C yr-1 in the tropical Pacific, and -0.39 ± 0.11 Pg C yr-1 in the South Pacific extratropics. The estimates from the atmospheric CO2 inversions show large variations amongst different inversion systems, but their median fluxes are consistent with the estimates from climatological pCO2 sw data and pCO2 sw diagnostics. In the South Pacific extratropics, where CO2 variations in the surface and ocean interior are severely undersampled, the difference in the air-sea CO2 flux estimates between the diagnostic models and ocean-interior CO2 inversions is larger (0.18 Pg C yr-1 ). The range of estimates from forward OBGCMs is also large (-0.19 to -0.72 Pg C yr-1 ). Regarding interannual variability of air-sea CO2 fluxes, positive and negative anomalies are evident in the tropical Pacific during the cold and warm events of the El Niño-Southern Oscillation in the estimates from pCO2 sw diagnostic models and from OBGCMs. They are consistent in phase with the Southern Oscillation Index, but the peak-to-peak amplitudes tend to be higher in OBGCMs (0.40 ± 0.09 Pg C yr-1 ) than in the diagnostic models (0.27 ± 0.07 Pg C yr-1 ).

Grasslands are important ecosystems to provide various economic and ecological services. In Japan, grassland of Miscanthus sinensis, which is a tall, perennial grass species, has been one of the symbolic landscape and require efficient monitoring system for better management. In this study, canopy height and biomass of M. sinensis in semi-natural grassland are estimated using time-series UAV imagery and structure from motion (SfM) and multi-view stereo (MVS) technique. The effect of complex topography on estimation of the canopy height and biomass is analysed as well as monitoring growth of M. sinensis. The results showed that UAV derived maximum canopy height and biomass have significant correlation with vegetation survey data producing R2 value of 0.92 and 0.78, respectively. The effect of topographic landforms was found to be smallest on top of the hill, followed by slope. Valley-like sunken place was affected worst. Analysis using time-series UAV data revealed that growth of M. sinensis is different between the landforms, and the best time to estimate its biomass was different between them. In order to accurately estimate canopy height and biomass of tall grass species such as M. sinensis, it is important to take plant growth stage into consideration as well as topographic landforms.

The source and sinks of carbon dioxide (CO2) and methane (CH4) due to anthropogenic and natural biospheric activities were estimated for the South Asian region (Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka). Flux estimates were based on top-down methods that use inversions of atmospheric data, and bottom-up methods that use field observations, satellite data, and terrestrial ecosystem models. Based on atmospheric CO2 inversions, the net biospheric CO2 flux in South Asia (equivalent to the Net Biome Productivity, NBP) was a sink, estimated at −104 ± 150 Tg C yr−1 during 2007–2008. Based on the bottom-up approach, the net biospheric CO2 flux is estimated to be −191 ± 193 Tg C yr−1 during the period of 2000–2009. This last net flux results from the following flux components: (1) the Net Ecosystem Productivity, NEP (net primary production minus heterotrophic respiration) of −220 ± 186 Tg C yr−1 (2) the annual net carbon flux from land-use change of −14 ± 50 Tg C yr−1, which resulted from a sink of −16 Tg C yr−1 due to the establishment of tree plantations and wood harvest, and a source of 2 Tg C yr−1 due to the expansion of croplands; (3) the riverine export flux from terrestrial ecosystems to the coastal oceans of +42.9 Tg C yr−1; and (4) the net CO2 emission due to biomass burning of +44.1 ± 13.7 Tg C yr−1. Including the emissions from the combustion of fossil fuels of 444 Tg C yr−1 for the 2000s, we estimate a net CO2 land–atmosphere flux of 297 Tg C yr−1. In addition to CO2, a fraction of the sequestered carbon in terrestrial ecosystems is released to the atmosphere as CH4. Based on bottom-up and top-down estimates, and chemistry-transport modeling, we estimate that 37 ± 3.7 Tg C yr−1 were released to atmosphere from South Asia during the 2000s. Taking all CO2 and CH4 fluxes together, our best estimate of the net land–atmosphere CO2-equivalent flux is a net source of 334 Tg C yr−1 for the South Asian region during the 2000s. If CH4 emissions are weighted by radiative forcing of molecular CH4, the total CO2-equivalent flux increases to 1148 Tg C yr−1 suggesting there is great potential of reducing CH4 emissions for stabilizing greenhouse gases concentrations.

Purpose: Knee osteoarthritis (KOA) is a degenerative disease with inflammation, becoming persistent as it progresses, resulting in reduced quality of life. Exercise is the recommended treatment for KOA; however, the extent of pain reduction with exercise is heterogeneous and the prognostic implications of baseline factors in patients undergoing exercise are still unknown. This study examined the association between the response to exercise therapy and clinical outcomes, radiologic severity, and pain sensitization, and investigated the optimal predictive value for the effectiveness of exercise. Patients and Methods: Demographics, radiologic severity, pressure pain threshold (PPT), and temporal summation of pain (TSP) at the knee, tibia, and forearm were assessed at baseline. The pain numeric rating scale (NRS) was assessed before and after 12 weeks of exercise. Patients were divided into responder/non-responder groups according to recommended criteria: responder, [greater than or equal to]30% reduction in pain; non-responder, <30% reduction in pain, and each variable was compared between the groups. The area under the curve (AUC) and cutoff points were determined by receiver operating characteristic curve analysis. Results: Sixty-five patients were categorized as responders and 26 as non-responders. In the non-responder group, baseline NRS (P<0.01), pain duration (P<0.01), and TSP at the knee (P<0.001) and tibia (P<0.05) were significantly higher, and PPT at the knee (P<0.001), tibia (P<0.001), and forearm (P<0.001) were significantly lower, than those in the responder group; however, no significant differences between groups were found in other demographics and radiologic severity. The variables that showed moderate or better predictive ability (AUC>0.7) were PPT at the knee (cutoff points: 241.5 kPa), tibia (307.5 kPa), forearm (318.5 kPa), and TSP at the knee (15.5 mm). Conclusion: Our findings suggest that pain sensitization is associated with the response to exercise therapy. Furthermore, we provide clinically predictive values for PPT and TSP in predicting the outcome to exercise in KOA. Keywords: pressure pain threshold, temporal summation of pain, cutoff point, prognostic prediction