Search

Gully erosion is widespread in central China's ecologically fragile loess plateau. However, research on the monitoring and evaluation of large-scale fine erosion is scarce. Here, we use the sentinel-1A imagery during a rainy season, using the small baseline subset synthetic aperture radar interferometry (SBAS-InSAR) technology to calculate gully erosion for the largest loess plateau in China, the Dongzhiyuan tableland. The results showed that the average and cumulative subsidence rates of the whole study area are 9 mm/year and 6 mm/year respectively, while the subsidence within the gullies reached 160 mm/year and 70 mm/year, which was mainly caused by rainfall and landslides formed by groundwater softening slopes. In addition, erosion was more severe at the bottom of the gully closer to the lower reaches of the watershed, which may be related to the concentrated runoff downstream during rainfall. Interestingly, the erosion deformation was more intense on slopes 20m above the gully bottom caused by groundwater seepage. The results demonstrated the reliable capability of the SBAS-InSAR method in accurately assessing large-scale erosion deformation.

Papillary thyroid carcinoma (PTC) is a common thyroid malignancy. Circular RNAs (circRNAs) have been implicated in the development of PTC. Here, we explored the function and mechanism of circRNA family with sequence similarity 53, member B (circ_FAM53B) in PTC pathogenesis. Circ_FAM53B, microRNA (miR)-183-5p and coiled-coil domain containing 6 (CCDC6) levels were gauged by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or Western blotting. The direct relationship between miR-183-5p and circ_FAM53B or CCDC6 was verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Our data showed that circ_FAM53B expression was reduced in PTC tissues and cells. Circ_FAM53B expression restrained proliferation, migration, and invasion and triggered apoptosis of PTC cells, as well as hindered HUVEC tube formation. Circ_FAM53B repressed miR-183-5p expression. MiR-183-5p re-expression reversed the effects of circ_FAM53B on cell behaviors. MiR-183-5p targeted and inhibited CCDC6, and circ_FAM53B upregulated CCDC6 through miR-183-5p competition. MiR-183-5p knockdown repressed cell proliferation, migration, invasion, and tube formation and facilitated apoptosis by upregulating CCDC6. Furthermore, circ_FAM53B reduced tumor growth in vivo. Collectively, our findings suggest that circ_FAM53B affects PTC cell biological behaviors via the miR-183-5p-CCDC6 axis.

This article presents a dual fast marching tree algorithm that consists of constrained fast marching tree planning in a Cartesian space (C_FMT∗) and human-like fast marching tree planning in self-motion manifolds (H_FMT∗) for human-like motion planning for anthropomorphic arms with task constraints. The key idea of the proposal is to exploit dual sampling in a Cartesian space and self-motion manifolds to explore the entire configuration space. The C_FMT∗ reduces the constrained planning problem to the unconstrained instance by sampling in the obstacle-free Cartesian space and satisfying the task constraints; it can solve most of these constrained path planning tasks quickly and obtain lower cost solutions compared to the existing techniques. In addition, a validity checking method of Cartesian sampling points based on self-motion manifolds is introduced to ensure the probabilistic completeness of the new planner. By analyzing musculoskeletal models of the human arm and the muscle strength property, a torque effort criterion was deduced to generate biomimetic motion for anthropomorphic arms. Then, an H_FMT∗ that incorporates the FMT∗ algorithm with the torque effort criterion is also proposed and used to bias the tree growth toward human-like movements in the self-motion manifolds of the obtained path. Finally, the proposed approach has been illustrated with several real examples executed with a humanoid robot. The obtained results show that the paths obtained with the proposed approach are quicker and more human-like.

Recent studies have provided some evidence supporting that cycling specialization (CS) may be positively related to successful aging (SA) among elderly adults. However, there is a gap regarding the examination of the role of loneliness in the relationship between CS and SA. A hypothetical model was proposed to test the relationship between CS, SA, and loneliness. For this purpose, this study randomly conducted a questionnaire survey among 395 cycling participants over the age of 60 in China. The results showed that behavior, cognition, and affect had negative effects on loneliness. Behavior, cognition, and affect were positively associated with SA. Loneliness was negatively related to SA. Furthermore, behavior, cognition, and affect had positive and indirect effects on SA through loneliness. These results offered some new insights for understanding the relationship between CS and SA, especially considering the indirect effect of loneliness. The limitations and implications of the findings were discussed.

In this article, a novel optical microelectromechanical systems (MEMS) accelerometer sensor based on a one-dimensional photonic crystals wavelength modulation system is proposed with a focus on optimizing the sensitivity of the high-frequency device. The proposed accelerometer consists of a sensitive optical system and a high-frequency mechanical structure, which have been studied by rigorous coupled wave analysis (RCWA) and finite element analysis (FEA). A very large bandwidth, excellent sensitivity to optical sensing and considerable resolution of the high-frequency device of the proposed sensor provide several attractive performance aspects. Through a rigorous theoretical argument, the following results are demonstrated: a photonic band gap (PBG) from 1.1 to 2.8 $\mu $ m, a bandwidth from 0 to 20 kHz, an optical system sensitivity of to 3.38, and an accelerometer sensitivity of 2.06 nm/g, with a measurement range of ± 217 g and a resolution of 4.850 mg. In view of these optimized performances, the proposed MEMS accelerometer can be used for all kinds of high frequency applications.

In the Bitcoin ecosystem, bitcoin miners play an indispensable role in maintaining the Bitcoin’s blockchain. As a consequence, they are also rewarded with newly-created bitcoins and transaction fees. However, there are very limited studies to fully understand the characteristics and behaviors of bitcoin miners. In this paper, we conduct a comprehensive measurement study to shed insights into the community of bitcoin miners. By analyzing over ten-year bitcoin transaction logs, we observe that the scale of bitcoin miners shrinks significantly in recent years, and a small fraction of miners received most of newly generated bitcoins. In the early stage of the Bitcoin ecosystem, the mining reward was evenly distributed among miners, but later became more concentrated to a few highly active miners. For most of miners, their active duration is less than one year, and the interval between consecutive mining actions is more than 100 days. By further examining the transaction flows, we find that a significant portion of bitcoins have been hoarded for over 5 years, and the hoarding phenomenon becomes intense in recent years. We also discuss the implications of our findings, and believe our measurements enable us to have a better understanding of the whole Bitcoin ecosystem.

Geometric reward function is proposed as an alternative choice to circumvent the problem of compounding. However, it’s not so desirable since no parties have incentives to participate in the consensus mechanism. In this paper, we tailor a new bonus reward function by adding random salts to the geometric reward function. The new reward function is a tradeoff between equitablity and incentive compatibility. We conclude that the quitability of the new reward function is optimal compared with others. Beyond that, we present Gini coefficients to fine-evaluate euqitability of reward functions. We propose a new metric (aka. reward ratio) to quantify the level of incentive compatibility. Our simulation results show that the new reward function performs better than others in both incentive compatibility and anti-compounding.

Evidence suggests that personality and subjective well-being (SWB) are related to leisure activity engagement among elder adults. However, evidence of the role of cycling specialization (CS) in the...

Purpose Excitatory amino acid transporters (EAATs) have an indispensable function in the reuptake of extracellular glutamate. To investigate the relationship and the expression of neuronal and astrocytic markers after brain ischemia, the temporal profile of glial EAATs in both peripheral and core regions of the cortex was examined. Methods Transient common carotid artery occlusion was used to induce unilateral transient forebrain ischemia of Mongolian gerbils, and post-ischemic brains (6 h to 2 w) were collected and prepared for immunohistochemical and Western blotting analysis of glutamine synthetase (GS), GLT-1, GLAST, S100β, and NeuN, and for Alizarin red staining of calcium deposits. Results The expression of GLAST and GLT-1 were significantly escalated at 6 h both in the core and periphery regions, while reduced from 12 h to 2 w in the core region post-ischemia. GS-positive cells increased at 6 h both in the core and periphery regions, while the density of Alizarin red-positive cells increased and peaked at 12 h in the ischemic cortex. The density of S100β-positive cells decreased in the ischemic core and increased in the periphery region. Immunofluorescence staining showed that S100β and TUNEL double-positive cells increased at 12 h in the core region. Conclusion The results of GLT-1 and GLAST expression in the cortex indicate that their up-regulation was time-dependent and occurred in the acute post-ischemia period, whereas their down-regulation was region-dependent and it is involved in the pathological progress of nerve cell and glial cell death, and has a series of cascade reactions.

Accumulating studies suggested that serious leisure qualities (SLQs) had an important correlate to leisure motivation (LM). However, the role of SLQs on LM remains ambiguous. This study aims to exp...