Search

[Objective] The effects of plant fiber sand barriers, cattle and sheep dung barriers, and sand barriers comprised of cattle and sheep dung combined with plant fiber were studied in order to create effective sand barriers for the restoration of desertified grassland in the alpine area at Maqu County, Gansu Province. [Methods] Sand barriers made of plant fiber, cattle and sheep dung, and cattle and sheep dung combined with plant fiber were installed in the alpine area at Maqu County. Plant and soil characteristics in the grassland before and after installing the sand barriers were compared. [Results] ① Sand barriers made of cattle and sheep dung, and made of cattle and sheep dung combined with plant fiber produced good effects with regard to vegetation restoration. The average plant community cover grew from 7.28% to 48.21% and 58.29%, respectively, and the number of species increased from 4 to 11. Plants grew taller, increasing from an average of 6.67 cm to 35.17 cm and 30.70 cm, respectively. Average plant dry weight increased from 4.46 g/m2 to 81.17 g/m2 and 80.70 g/m2, respectively. The plant dieback rate dropped from 9.55% to 7.0% and 6.80%, respectively; ② Cattle and sheep dung sand barriers as well as cattle and sheep dung sand barriers combined with plant fiber greatly boosted soil nutrients at the 5 cm depth. Total nitrogen increased from 0.154 g/kg to 0.370 g/kg and 0.491 g/kg, respectively. Soil alkaline hydrolyzed nitrogen rose from 4.78 mg/kg to 13.99 mg/kg and 19.78 mg/kg, respectively. Available phosphorus increased from 1.64 mg/kg to 5.54 mg/kg and 6.20 mg/kg, respectively. Available potassium increased from 21.07 mg/kg to 55.37 mg/kg and 56.90 mg/kg, respectively. [Conclusion] Considering the vegetation restoration effects, costs, and degradation factors, cattle and sheep dung sand barriers are the ideal technique for vegetation restoration of desertified grassland in alpine area of Maqu County.

Mountain bike (MTB) racing is a highly intensive physical activity and requires a high degree of technical ability to perform at the elite athlete level, which might compromise mental well-being, increasing symptoms of anxiety and depression through overtraining, injury, and burnout. Yoga Pranayama is the key to bringing about psychosomatic integration and harmony. This study aimed to explore the effects of yoga pranayama practices (YPP) on elite mountain bikers' burnout. This is a single-arm pilot study. Twenty-seven subjects practiced 30 sessions of YPP seven times a week for 1 month. The outcomes measured were blood biochemical parameters accompanied by complete blood count and athlete burnout score. Cubital vein blood test and burnout questionnaire were conducted at baseline and after 1 month. Test results showed a significant decrease in cortisol (CO) (P = 0.001) and urea nitrogen (P < 0.001) and an increase in testosterone: CO ratio (P = 0.001). This study indicates that YPP might improve burnout in elite mountain bikers.

This article studies a stealthy attack strategy design for distributed state estimation from the perspective of an attacker in cyber‐physical systems, where both internal and external attack scenarios are considered simultaneously. To enhance robustness against outliers and reduce communication burden, a distributed fusion estimator is developed by fusing the innovation residuals of neighboring smart sensor nodes without any attack. Based on the designed distributed fusion estimator, the evolution of the distributed estimation error covariance is analyzed, and its lower and upper bounds are obtained. Moreover, a stealthy attack framework embedding adjustable parameter is designed to weaken the estimation performance, where the constraints of the adjustable parameter are provided based on the desired attack effect. Finally, a simulation example is provided to manifest the validity of the main results. [ABSTRACT FROM AUTHOR]

AbstractGaussian smoothing (GS) is extensively employed in GRACE(-FO) data processing. However, it suffers from significant signal leakage problems along coastlines, which greatly complicate the estimation of GRACE(-FO) coastal ocean mass changes. To reduce the leakage error in coastal regions, we have developed a partial Gaussian smoothing (pGS) function that performs smoothing operations only within homogeneous ocean or land signals. A simulation experiment reveals that the pGS function could effectively reduce leakage issues along the coastlines. We evaluate the performance of the pGS function for actual GRACE (-FO) data by applying it directly to unsmoothed gridded data and incorporating it as a regularization constraint matrix in the fast mascon method. For the annual signal and long-term trend components, the consistency levels of the pGS results and the JPLM model demonstrate a substantial improvement in comparison to the GS function. Additionally, comparisons with external data indicate that the pGS outcomes exhibit a significantly greater degree of consistency with inferred ocean mass changes than other GRACE(-FO) solutions. These findings emphasize the outstanding performance of the pGS function in reducing leakage errors between the land and ocean signals, thereby contributing to the precise determination of coastal ocean mass changes. [ABSTRACT FROM AUTHOR]

BackgroundMuch research has been devoted to understanding cognitive correlates of elementary mathematics performance, but little such research has been done for advanced mathematics (e.g., modern algebra, statistics, and mathematical logic).AimsTo promote mathematical knowledge among college students, it is necessary to understand what factors (including cognitive factors) are important for acquiring advanced mathematics.SamplesWe recruited 80 undergraduates from four universities in Beijing.MethodsThe current study investigated the associations between students' performance on a test of advanced mathematics and a battery of 17 cognitive tasks on basic numerical processing, complex numerical processing, spatial abilities, language abilities, and general cognitive processing.ResultsThe results showed that spatial abilities were significantly correlated with performance in advanced mathematics after controlling for other factors. In addition, certain language abilities (i.e., comprehension of words and sentences) also made unique contributions. In contrast, basic numerical processing and computation were generally not correlated with performance in advanced mathematics.ConclusionsResults suggest that spatial abilities and language comprehension, but not basic numerical processing, may play an important role in advanced mathematics. These results are discussed in terms of their theoretical significance and practical implications.

The Gravity Recovery and Climate Experiment (GRACE) and its successor, GRACE Follow-On (GRACE-FO), have revolutionized the approach to monitoring global mass variations. However, the presence of several gaps, notably the continuous 11-month gap between the two missions, has generated a disruption in observations and hindered the analysis and application of the data. To address this problem, we have proposed a spectral domain gap-filling approach based on principal component analysis (PCA). Our simulation experiments demonstrate that the PCA gap-filling technique has significant potential to successfully reconstruct global mass variation and accurately capture real signals for most basins with an accuracy of less than 2 cm. When applied to actual missing data, our methodology delivers highly consistent results with previously published filling approaches, such as singular spectrum analysis and improved multichannel singular spectrum analysis method, for most of the global basins. Noteworthy, in the case of the Nelson basin, our PCA gap-filling method outperforms other methods in capturing seasonal signals and the return to a normal level of the terrestrial water storage changes in 2018. A comparison in the spectral domain indicates that the accuracy of the PCA-filling output is comparable to the original GRACE(-FO) data. Moreover, our method exhibits high generality, allowing for direct application to continuous GRACE(-FO) data without other additional data processing and without differentiating the types of missing data. Therefore, the proposed PCA gap-filling method offers exciting opportunities to guarantee the continuity of global mass change observations and benefit subsequent applications that require continuous data records. [ABSTRACT FROM AUTHOR]