Separation and Purification of Four Stilbenes from Vitis vinifera L. cv. Cabernet Sauvignon Roots Through High-speed Counter-current Chromatography

A method for preparative separation and purification of trans-resveratrol, δ-viniferin, ε-viniferin and trans-vitisin B from the roots of Vitis vinifera L. cv. Cabernet Sauvignon was successfully established and is reported on in this paper. The four important stilbenes were purified by high-speed counter-current chromatography (HSCCC) with a suitable quaternary solvent system composed of chloroform–methanol–n-butanol–water (4:3:0.05:2, v/v). A total of 7.1 mg ± 0.2 mg of trans-resveratrol, 1.1 mg ± 0.1 mg of δ-viniferin, 18.7 mg ± 0.5 mg of ε-viniferin, and 12.2 mg ± 0.2 mg of trans-vitisin B, with purities of 97.89%, 90.61%, 94.37% and 78.38% respectively, were obtained from 241 mg of crude sample in a one-step HSCCC separation. The chemical structures of trans-resveratrol and δ-viniferin were further confirmed with the retention time using the method of standard addition, while the structural identification of ε-viniferin and trans-vitisin B was performed with LC-ESI/MS, 1H-NMR, and 13C-NMR

Modeling redistribution of α-HCH in Chinese soil induced by environment factors

This study explores long-term environmental fate of alpha-HCH in China from 1952 to 2007 using ChnGPERM (Chinese Gridded Pesticide Emission and Residue Model). The model captures well the temporal and spatial variations of alpha-HCH concentration in Chinese soils by comparing with a number of measured data across China in different periods. The results demonstrate alpha-HCH grasshopping effect in Eastern China and reveal several important features of the chemical in Northeast and Southeast China. It is found that Northeast China is a prominent sink region of alpha-HCH emitted from Chinese sources and alpha-HCH contamination in Southwest China is largely attributed to foreign sources. Southeast China is shown to be a major source contributing to alpha-HCH contamination in Northeast China, incurred by several environmental factors including temperature, soil organic carbon content, wind field and precipitation. (C) 2011 Elsevier Ltd. All rights reserved.This study explores long-term environmental fate of alpha-HCH in China from 1952 to 2007 using ChnGPERM (Chinese Gridded Pesticide Emission and Residue Model). The model captures well the temporal and spatial variations of alpha-HCH concentration in Chinese soils by comparing with a number of measured data across China in different periods. The results demonstrate alpha-HCH grasshopping effect in Eastern China and reveal several important features of the chemical in Northeast and Southeast China. It is found that Northeast China is a prominent sink region of alpha-HCH emitted from Chinese sources and alpha-HCH contamination in Southwest China is largely attributed to foreign sources. Southeast China is shown to be a major source contributing to alpha-HCH contamination in Northeast China, incurred by several environmental factors including temperature, soil organic carbon content, wind field and precipitation. (C) 2011 Elsevier Ltd. All rights reserved

SwG-former: Sliding-window Graph Convolutional Network Integrated with Conformer for Sound Event Localization and Detection

Sound event localization and detection (SELD) is a joint task of sound event detection (SED) and direction of arrival (DoA) estimation. SED mainly relies on temporal dependencies to distinguish different sound classes, while DoA estimation depends on spatial correlations to estimate source directions. To jointly optimize two subtasks, the SELD system should extract spatial correlations and model temporal dependencies simultaneously. However, numerous models mainly extract spatial correlations and model temporal dependencies separately. In this paper, the interdependence of spatial-temporal information in audio signals is exploited for simultaneous extraction to enhance the model performance. In response, a novel graph representation leveraging graph convolutional network (GCN) in non-Euclidean space is developed to extract spatial-temporal information concurrently. A sliding-window graph (SwG) module is designed based on the graph representation. It exploits sliding-windows with different sizes to learn temporal context information and dynamically constructs graph vertices in the frequency-channel (F-C) domain to capture spatial correlations. Furthermore, as the cornerstone of message passing, a robust Conv2dAgg function is proposed and embedded into the SwG module to aggregate the features of neighbor vertices. To improve the performance of SELD in a natural spatial acoustic environment, a general and efficient SwG-former model is proposed by integrating the SwG module with the Conformer. It exhibits superior performance in comparison to recent advanced SELD models. To further validate the generality and efficiency of the SwG-former, it is seamlessly integrated into the event-independent network version 2 (EINV2) called SwG-EINV2. The SwG-EINV2 surpasses the state-of-the-art (SOTA) methods under the same acoustic environment

Rhizosphere soil nutrients and bacterial community diversity of four broad-leaved trees planted under Chinese fir stands with different stocking density levels

ObjectiveRhizosphere soil nutrients and bacterial diversity of four broad-leaved tree species underplanted in Chinese fir plantation with different stand density levels were analyzed to reveal characteristics of the rhizosphere soil environment and selection of suitable underplanted tree species. MethodsChinese fir plantation with three density levels (900, 1,200, and 1,875 stems ha(-1), respectively) were selected and underplanted with Michelia macclurei, Schima superba, Phoebe zhennan, and Tsoongiodendron odorum. The rhizosphere soil nutrients and bacterial community of the broad-leaved tree species were determined after 4 years. ResultsSignificant differences in rhizosphere nutrient content were detected among different tree density levels, where the contents of total K, available K and available P in 900 stems ha(-1) stands were significantly higher than the other stocking density levels. There were also significant differences in the contents of total C, total N, total K, available K and available P in the rhizosphere soils of the four trees species, while there were no significant differences in pH and total P. Rhizosphere soil nutrient contents were higher under S. superba and M. macclurei than under P. zhennan and T. odorum. The rhizosphere soil nutrient contents and bacterial diversity decreased with the increase of stand density, and the bacterial diversity showed significant differences in the rhizosphere soils of P. zhennan, T. odorum and S. superba when underplanted in different stand densities. The bacterial diversity was positively correlated with the available P content of rhizosphere soils, suggesting that soil available P content plays an important role in shaping the structure of bacterial community. ConclusionThe nutrient contents and bacterial diversity of rhizosphere soils of underplated broad-leaved species decreased with increasing stand density of Chinese fir plantation. Rhizosphere soils of M. macclurei and S. superba were rich in nutrient contents and bacterial diversity. Thus, low density of Chinese fir plantation (900 stems ha(-1)) underplanted with M. macclurei and S. superba is suitable for the establishment of mixed forest, which will facilitate better tree growth and maintaining soil fertility to realize sustainable management of forests

Dual consistent pseudo label generation for multi-source domain adaptation without source data for medical image segmentation

IntroductionUnsupervised domain adaptation (UDA) aims to adapt a model learned from the source domain to the target domain. Thus, the model can obtain transferable knowledge even in target domain that does not have ground truth in this way. In medical image segmentation scenarios, there exist diverse data distributions caused by intensity in homogeneities and shape variabilities. But multi source data may not be freely accessible, especially medical images with patient identity information.MethodsTo tackle this issue, we propose a new multi-source and source-free (MSSF) application scenario and a novel domain adaptation framework where in the training stage, we only get access to the well-trained source domain segmentation models without source data. First, we propose a new dual consistency constraint which uses domain-intra and domain-inter consistency to filter those predictions agreed by each individual domain expert and all domain experts. It can serve as a high-quality pseudo label generation method and produce correct supervised signals for target domain supervised learning. Next, we design a progressive entropy loss minimization method to minimize the class-inter distance of features, which is beneficial to enhance domain-intra and domain-inter consistency in turn.ResultsExtensive experiments are performed for retinal vessel segmentation under MSSF condition and our approach produces impressive performance. The sensitivity metric of our approach is highest and it surpasses other methods with a large margin.DiscussionIt is the first attempt to conduct researches on the retinal vessel segmentation task under multi-source and source-free scenarios. In medical applications, such adaptation method can avoid the privacy issue. Furthermore, how to balance the high sensitivity and high accuracy need to be further considered

Study on the Evolution Mechanism of Lane Change Decision in Urban Expressway Diversion Area

Urban expressway is the artery of modern urban traffic network, and the vehicle operation at off-ramp and diverging area affects the operation efficiency of the whole traffic system. The lane-changing game behavior between off ramp vehicles and going straight vehicles is very important in the whole driving behavior, and the lane-changing behavior between vehicles is easy to cause traffic accidents and stopping phenomena. To improve the driving efficiency in the diversion area and reduce the accident risk, by analyzing the process of the lane-changing behavior at off-ramp, this paper establishes a two-vehicle game model, solves the replicator dynamic equation according to the Dynamic Evolutionary Game Theory, uses MATLAB to calculate the evolution process and evolution speed based on different payoff factors, explores the influence of safety and speed on the stability of turn-out, and judges the evolutionary equilibrium point according to the determinant and trail of the Jacobi matrix. We build a realistic turn-out scenario and simulate it using the micro-traffic simulation software SUMO and it is found that: (1) The speed of different evolutionary equilibrium points based on speed payoff increased by 8.3% and 4.4% respectively compared with the speed of initial point. (2) The number of conflicts at the evolutionary equilibrium point based on the security payoff reduced to 22% of the initial point. (3) Compared with the initial point, the speed of the evolutionary stable point based on comprehensive payoff increased by 10.3%, and the number of conflicts reduced to 11% of the initial point. The simulation results show that the strategy of stable point of the evolutionary game model can effectively reduce the accident rate and improve the road operation efficiency

Effectiveness of Green Olympic Initiatives on Reasons Affecting Residents’ Actions to Support the Olympic Movement

The world faces major environmental challenges that affect the well-being of human beings, plants, and wildlife. The Olympic Games, one of the most influential sport events, should pay special attention to environmental issues. In 1996, the environmental element became a central factor of the International Olympic Committee’s (IOC) (IOC, 2009). To scientifically and comprehensively evaluate the impact of the Olympics on the host city, the IOC launched the Olympic Games Global Impact (OGGI) study in 2003 (IOC, 2006). This study begins two years before the host city is selected, and terminates two years after hosting the Games (IOC, 2006). One of the reasons to do an 11-year OGGI study is likely because the social, economic, and environmental impact of the Games may vary throughout the whole process. To a great extent, these technical reports remain internal to the IOC. A majority of previous studies on mega sport events have focused on the economic impact (Twynam & Johnston, 2004). Few studies have emphasized the environmental aspect of major sport events. It would be constructive to investigate the environmental impact of the Beijing Games over eight years, from the moment of being named as the host city to one year after hosting the event. Based on the environmental measures applied in Beijing, there were five critical time periods that should be considered in order to comprehensively understand the effectiveness of the Beijing Green Olympic initiatives, including July 2001 (Time 1) when Beijing was named as the host city for the 2008 Olympic Games, August 2007(Time 2) when it was one year before the Games, August 2008 (Time 3) when it was during the Games, December 2008 (Time 4) when it covered close-out and summary period of the Games, and December 2009 (Time 5) when it was one year after the Games. Research has suggested that local residents play an important role in achieving successful and sustainable impact of mega sport events (Deccio & Baloglu, 2002). Therefore, the purpose of this study was to examine residents’ perceived effectiveness of Beijing Green Olympic initiatives, by investigating their awareness, perception, attitude, intention, and actual behavior through conducting a time-series analysis. Based on a comprehensive review of literature, a questionnaire was developed that included the following sections: awareness, perception, attitude, behavior intention, and actual behavior associated with Beijing Green Olympics initiatives. All items were phrased in a 7-point scale (1 = “strongly disagree” to 7 = “strongly agree”). The questionnaire was phrased into five versions, corresponding with the five key time periods. Each version had a different leading statement and, to increase recall accuracy, a historical scenario/picture reflecting a specific time period. Five sets of pictures depicting significant events that happened in China during each time periods were collected and their accuracy of time representation was verified by two professors and three graduate students in sport social science from a leading Chinese university. Items within each time period were put in a random order to reduce carry-over effect in the repeated measure research design. The questionnaire was then double-translated to ensure translation accuracy. A community intercept approach was adopted and data were collected at shopping centers, city libraries, parks, restaurants, municipal offices, and transportation centers in Beijing, China. A total of 119 subjects, who were 18 years or older in 2001 and considered Beijing as his/her primary residential location since 2001, were included in the study. A doubly repeated measure MANOVA was conducted, which revealed that the vector mean scores of the Green Olympics’ effectiveness variables (i.e., awareness, perception, attitude, behavior intention, and actual behaviour) were significantly (p \u3c .05) different over the five time periods. The research findings indicate that the perceived environmental impact by residents had been formed, developed, and altered as a result of different environmental efforts applied in Beijing. To a great extent, these reflected the effectiveness of the Green Olympic programs across five key periods of the Games. Further discussions are conducted on expanding environmental programs and policies beyond 2008 and the city of Beijing, and moving China toward environmentally sustainable development

Traffic Multiresolution Modeling and Consistency Analysis of Urban Expressway Based on Asynchronous Integration Strategy

The paper studies multiresolution traffic flow simulation model of urban expressway. Firstly, compared with two-level hybrid model, three-level multiresolution hybrid model has been chosen. Then, multiresolution simulation framework and integration strategies are introduced. Thirdly, the paper proposes an urban expressway multiresolution traffic simulation model by asynchronous integration strategy based on Set Theory, which includes three submodels: macromodel, mesomodel, and micromodel. After that, the applicable conditions and derivation process of the three submodels are discussed in detail. In addition, in order to simulate and evaluate the multiresolution model, “simple simulation scenario” of North-South Elevated Expressway in Shanghai has been established. The simulation results showed the following. (1) Volume-density relationships of three submodels are unanimous with detector data. (2) When traffic density is high, macromodel has a high precision and smaller error and the dispersion of results is smaller. Compared with macromodel, simulation accuracies of micromodel and mesomodel are lower but errors are bigger. (3) Multiresolution model can simulate characteristics of traffic flow, capture traffic wave, and keep the consistency of traffic state transition. Finally, the results showed that the novel multiresolution model can have higher simulation accuracy and it is feasible and effective in the real traffic simulation scenario

Third-order nonlinearity in Ge–Sb–Se glasses at mid-infrared wavelengths

International audienceThe optical properties of Ge–Sb–Se glasses have been extensively studied at telecom wavelengths in recent years. However, the understanding of nonlinearity in Ge–Sb–Se glasses at mid-infrared wavelengths still remains limited. In this work, a series of Ge20SbxSe80−x (x = 0, 5, 10) glasses were prepared by conventional melt–quenching method. The absorption spectra and the refractive index of glasses were recorded. The third order nonlinearity, n2, and nonlinear absorption coefficient were measured for Ge–Sb–Se glass samples at the wavelengths of 1550, 2000 and 2500 nm by Z-scan technique, respectively. With the increasing of Sb contents, the linear refractive index of glass increased. Among the three operating wavelengths, all the three glass samples have a highest n2 at 2000 nm. By using the figure of merit (FOM) to evaluate the studied three glasses, the Ge20Sb10Se70 glass shows the greatest potential for mid-IR all optical switching device