Augmented 2D-TAN: A Two-stage Approach for Human-centric Spatio-Temporal Video Grounding

We propose an effective two-stage approach to tackle the problem of language-based Human-centric Spatio-Temporal Video Grounding (HC-STVG) task. In the first stage, we propose an Augmented 2D Temporal Adjacent Network (Augmented 2D-TAN) to temporally ground the target moment corresponding to the given description. Primarily, we improve the original 2D-TAN from two aspects: First, a temporal context-aware Bi-LSTM Aggregation Module is developed to aggregate clip-level representations, replacing the original max-pooling. Second, we propose to employ Random Concatenation Augmentation (RCA) mechanism during the training phase. In the second stage, we use pretrained MDETR model to generate per-frame bounding boxes via language query, and design a set of hand-crafted rules to select the best matching bounding box outputted by MDETR for each frame within the grounded moment.Comment: Best Paper Award at the 3rd Person in Context (PIC) Challenge CVPR Workshop 202

Design, synthesis and biological evaluation of isochroman-4-one hybrids bearing piperazine moiety as antihypertensive agent candidates

7,8 Dihydroxy 3 methyl isochromanone 4 XJP is a polyphenolic natural product with moderate antihypertensive activity. T o obtain new agents with stronger potency and safer profile , we employed XJP and naftopidil as the lead compound s t o design and synth esize a novel class of hybrids as antihypertensive candidates, In the present study, a series of hybrids ( 6a r ) of XJP bearing arylpiperazine moiety, which is identified as the pharmacophore of naftopidil, were designed and synthesized as novel α 1 adrenergic receptor antagonists. The biological evaluation showed that target compounds 6c , 6e , 6f , 6g , 6h , 6m and 6q possessed potent in vitro vasodilation potency and α 1 adrenergic receptor antagonistic activity . Furthermore, the most potent compound 6e significantly reduced the systolic and diastolic blood pressure in spontaneously hypertensive rats (SHRs),which was comparable to that of naftopidil, and it had no observable effects on the basal heart rate, suggesting that 6e deserves to be further investigated as a potential clinical candidate for the treatment of hypertension

Design, synthesis, biological evaluation and docking study of 4-isochromanone hybrids bearing N-benzyl pyridinium moiety as dual binding site acetylcholinesterase inhibitors (part II)

A series of novel 4-isochromanone compounds bearing N-benzyl pyridinium moiety were designed and synthesized as acetylcholinesterase (AChE) inhibitors. The biological evaluation showed that most of the target compounds exhibited potent inhibitory activities against AChE. Among them, compound 1q possessed the strongest anti-AChE activity with an IC50 value of 0.15 nM and high AChE/BuChE selectivity (SI >5000). Moreover, compound 1q had low toxicity in normal nerve cells and was relatively stable in rat plasma. Together, the current finding may provide a new approach for the discovery of novel anti-Alzheimer’s disease agents

Design, synthesis, biological evaluation and docking study of 4-isochromanone hybrids bearing N-benzyl pyridinium moiety as dual binding site acetylcholinesterase inhibitors (part II)

A series of novel 4-isochromanone compounds bearing N-benzyl pyridinium moiety were designed and synthesized as acetylcholinesterase (AChE) inhibitors. The biological evaluation showed that most of the target compounds exhibited potent inhibitory activities against AChE. Among them, compound 1q possessed the strongest anti-AChE activity with an IC50 value of 0.15 nM and high AChE/BuChE selectivity (SI >5000). Moreover, compound 1q had low toxicity in normal nerve cells and was relatively stable in rat plasma. Together, the current finding may provide a new approach for the discovery of novel anti-Alzheimer’s disease agents

乾燥地におけるマルチスケールでの蒸発散量に関する研究

博士(理学)doctoral創造科学技術大学院静岡大学甲第786号ET

Reconstruction of Global Long-Term Gap-Free Daily Surface Soil Moisture from 2002 to 2020 Based on a Pixel-Wise Machine Learning Method

Global, long-term, gap-free, high quality soil moisture products are extremely important for hydrological monitoring and climate change research. However, soil moisture products produced from satellite observations have data gaps due to the limited capabilities of satellite orbit/swath and retrieval algorithms, which limit the regional and global applications of soil moisture data in hydrology and agriculture studies. To solve this problem, we proposed a gap-filling method to reconstruct a global gap-free surface soil moisture product by applying the machine learning (Random Forest) algorithm on a pixel-by-pixel basis, taking into account the nonlinear relationship between surface soil moisture and the related surface environmental variables. The gap-filling method was applied to the NN-SM surface soil moisture product, which has a fraction of data gaps of around 50% globally on a multi-year average. A global daily gap-free surface soil moisture dataset from 2002 to 2020 was then generated. The reconstructed values of several sub-regions after manually eliminating the original values were cross-verified with the original data, and this clearly demonstrated the reliability of the reconstruction method with the correlation coefficient (R) ranging between 0.770 and 0.918, the Root Mean Square Error (RMSE) between 0.057 and 0.082 m3/m3, the unbiased Root Mean Square Error (ubRMSE) between 0.053 and 0.081 m3/m3, and Bias between −0.012 and 0.008 m3/m3. The accuracy of the reconstructed surface soil moisture dataset was evaluated using in situ observations of surface soil moisture at 12 sites from the International Soil Moisture Network (ISMN) and the Long-Term Agroecosystem Research (LTAR) network, and the results showed good accuracy in terms of R (0.610), RMSE (0.067 m3/m3), ubRMSE (0.045 m3/m3) and Bias (0.031 m3/m3). Overall, the reconstructed surface soil moisture dataset retained the characteristics of the NN-SM product, such as high accuracy and good spatiotemporal pattern. However, with the advantage of continuous spatiotemporal coverage, it is more suitable for further applications in the analysis of global surface soil moisture trends, land surface hydrological processes, and land-atmosphere energy and water exchanges, etc

Earth Observations-Based Evapotranspiration in Northeastern Thailand

Thailand is characterized by typical tropical monsoon climate, and is suffering serious water related problems, including seasonal drought and flooding. These issues are highly related to the hydrological processes, e.g., precipitation and evapotranspiration (ET), which are helpful to understand and cope with these problems. It is critical to study the spatiotemporal pattern of ET in Thailand to support the local water resource management. In the current study, daily ET was estimated over Thailand by ETMonitor, a process-based model, with mainly satellite earth observation datasets as input. One major advantage of the ETMonitor algorithm is that it introduces the impact of soil moisture on ET by assimilating the surface soil moisture from microwave remote sensing, and it reduces the dependence on land surface temperature, as the thermal remote sensing is highly sensitive to cloud, which limits the ability to achieve spatial and temporal continuity of daily ET. The ETMonitor algorithm was further improved in current study to take advantage of thermal remote sensing. In the improved scheme, the evaporation fraction was first obtained by land surface temperature—vegetation index triangle method, which was used to estimate ET in the clear days. The soil moisture stress index (SMSI) was defined to express the constrain of soil moisture on ET, and clear sky SMSI was retrieved according to the estimated clear sky ET. Clear sky SMSI was then interpolated to cloudy days to obtain the SMSI for all sky conditions. Finally, time-series ET at daily resolution was achieved using the interpolated spatio-temporal continuous SMSI. Good agreements were found between the estimated daily ET and flux tower observations with root mean square error ranging between 1.08 and 1.58 mm d−1, which showed better accuracy than the ET product from MODerate resolution Imaging Spectroradiometer (MODIS), especially for the forest sites. Chi and Mun river basins, located in Northeast Thailand, were selected to analyze the spatial pattern of ET. The results indicate that the ET had large fluctuation in seasonal variation, which is predominantly impacted by the monsoon climate

Optimizing Window Length for Turbulent Heat Flux Calculations from Airborne Eddy Covariance Measurements under Near Neutral to Unstable Atmospheric Stability Conditions

Airborne eddy covariance (EC) is one of the most effective ways to directly measure turbulent flux at a regional scale. This study aims to find the optimum spatial window length for turbulent heat fluxes calculation from airborne eddy covariance measurements under near neutral to unstable atmospheric stability conditions, to reduce the negative influences from mesoscale turbulence, and to estimate local meaningful turbulent heat fluxes accurately. The airborne flux measurements collected in 2008 in the Netherlands were used in this study. Firstly, the raw data was preprocessed, including de-spike, segmentation, and stationarity test. The atmospheric stability conditions were classified as near neutral, moderately unstable, or very unstable; the stable condition was excluded. Secondly, Ogive analysis for turbulent heat fluxes from all available segmentations of the airborne measurements was used to determine the possible window length range. After that, the optimum window length for turbulent heat flux calculations was defined based on the analysis of all possible window lengths and their uncertainties. The results show that the choice of the optimum window length strongly depends on the atmospheric stability conditions. Under near neutral conditions, local turbulence is mixed insufficiently and vulnerable to heterogeneous turbulence. A relatively short window length is needed to exclude the influence of mesoscale turbulence, and we found the optimum window length ranges from 2000 m to 2500 m. Under moderately unstable conditions, the typical scale of local turbulence is relative large, and the influence of mesoscale turbulence is relatively small. We found the optimum window length ranges from 3900 m to 5000 m. Under very unstable conditions, large convective eddies dominate the transmission of energy so that the window length needs to cover the large eddies with large energy transmission. We found the optimum window length ranges from 4500 m to 5000 m. This study gives a comprehensive methodology to determine the optimizing window length in order to compromise a balance between the accuracy and the surface representativeness of turbulent heat fluxes from airborne EC measurements

A New Evapotranspiration-Based Drought Index for Flash Drought Identification and Monitoring

Flash droughts, a type of extreme event characterized by the sudden onset and rapid intensification of drought conditions with severe impacts on ecosystems, have become more frequent in recent years due to global warming. The drought index is an effective way to monitor drought and mitigate its negative impact on human production and life. This study presents a new flash drought identification and monitoring method based on the evapotranspiration-based drought index, i.e., the evaporative stress percentile (ESP). This ESP-based method considers both the rate of the rapid intensification and each phase of flash drought development, which allows it to be used quantitative assessment of flash drought characteristics including detailed information on the onset, development, termination, and intensity. The ESP is evaluated using the soil moisture percentile (SMP) derived from the GLDAS-Noah soil moisture data. The results show that there was good agreement between the ESP and SMP across most of China, with correlation coefficient values above 0.8 and MAE values below 10 percentile/week. The ESP was then used to identify flash droughts in China and compared with the Precipitation Anomaly Percentage (PAP) and the SMP for three cases of typical flash drought events in three different regions and years with different land covers. It demonstrates the robustness of the ESP for detecting flash droughts in different geographical regions, for different land cover types, and for different climatic characteristics. This method is applied to characterize historical flash droughts in 1979–2018 in China, and the results show that flash droughts in China occur most frequently in the transitional climate zone between humid and arid regions in Northern China. This study contributes to a better understanding of flash drought development and supports to decision-makers in providing early warnings for flash droughts