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Article ; Online: Analysis of vegetation dynamics in the Qinling-Daba Mountains region from MODIS time series data

Yan Bai

Ecological Indicators, Vol 129, Iss , Pp 108029- (2021)

2021

Abstract: The Qinling-Daba Mountains region (Qinba) is an important geographical transitional zone across the north and south of China. To comprehensively understand the ecological transition in the Qinba over past two decades, this study assessed and predicted ... ...

Abstract	The Qinling-Daba Mountains region (Qinba) is an important geographical transitional zone across the north and south of China. To comprehensively understand the ecological transition in the Qinba over past two decades, this study assessed and predicted the spatiotemporal variations of vegetation comparatively, using 250-m time series MODIS NDVI and EVI products. From 2000 to 2019, remarkable increases were observed both in annual and seasonal NDVI and EVI (P < 0.05), and the increasing rate of NDVI was higher than that of EVI for all temporal scales, except summer. Compared to NDVI, larger areas of no significant change were obtained in annual, autumn, and winter EVI, primarily distributed in the high-altitude regions of western Qinba. All assessed vegetation types increased significantly during past two decades except alpine vegetation and marsh, however, the seasons in which the significant increase in NDVI and EVI occurred varied for different vegetation types. Hurst exponent analysis suggested that inconsistent characteristics of vegetation dynamic trends were stronger in the future across Qinba. The area proportion of unfavorable trends, identified mainly covered with cultivated vegetation and scrub, was much larger than that of favorable trends, especially detected by EVI. Areas likely to experience vegetation variation of unfavorable and undetermined trends deserve high focus.
Keywords	Vegetation indices ; Spatiotemporal variation ; Trend analysis ; Vegetation types ; MODIS ; Qinling-Daba Mountains region ; Ecology ; QH540-549.5
Subject code	910
Language	English
Publishing date	2021-10-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: A Combinatorial Optimization Strategy for Performance Improvement of Stratum Ventilation Considering Outdoor Weather Changes and Metabolic Rate Differences

Yan Bai / Zhuo Wei

Sustainability, Vol 15, Iss 2804, p

Energy Consumption and Sensitivity Analysis

2023 Volume 2804

Abstract: Since occupants spend most of their time indoors, an energy-saving and comfortable indoor environment are particularly important. The differences in the metabolic rate of occupants make them have different requirements for their thermal environment. To ... ...

Abstract	Since occupants spend most of their time indoors, an energy-saving and comfortable indoor environment are particularly important. The differences in the metabolic rate of occupants make them have different requirements for their thermal environment. To save energy under the comprehensive needs of occupants for thermal environment, the combinatorial optimization strategy based on NSGA-II and improved the TOPSIS method is proposed in this study. Firstly, the physical model of the CFD simulation is verified by experiments. Secondly, the specific operation cases corresponding to combinations of different levels of factors are determined via the RSM method, and the ventilation performance prediction model considering the metabolic rate differences and outdoor weather changes is established. Thirdly, supply air velocities and temperatures are optimized by using Pareto-based NSGA-II; the Pareto optimal solution set under different outdoor temperatures is obtained. Finally, based on the Pareto optimal solutions at different outdoor temperatures, the optimal strategy under dynamic outdoor air temperature is obtained by improved TOPSIS by the CRITIC method. The optimization of ventilation parameters significantly improved the ventilation performance, and the results show that the predicted mean vote, energy consumption, vertical air temperature difference between head and ankle levels and the local mean age of air for different metabolic rates decrease by 64.1%, 4.74%, 24.83% and 7.39% on average, respectively. Moreover, the relative energy saving rate increases as the metabolic rate increases, and the strategy facilitates adaptation to outdoor weather changes and meets the individual needs of occupants for the indoor environment. This has important implications for achieving the global goal of energy efficiency and emission reduction.
Keywords	HVAC ; optimization strategy ; indoor thermal environment ; energy consumption ; metabolic rate ; outdoor air temperatures ; Environmental effects of industries and plants ; TD194-195 ; Renewable energy sources ; TJ807-830 ; Environmental sciences ; GE1-350
Subject code	690
Language	English
Publishing date	2023-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Structurally diverse brefeldin A derivatives as potent and selective acetylcholinesterase inhibitors from an endophytic fungus Penicillium brefeldianum F4a

Yan Bai / Duo Ren / Xinlei Xue / Weixian Gao / Jiangchun Hu / Huaqi Pan

Arabian Journal of Chemistry, Vol 17, Iss 1, Pp 105388- (2024)

1481

Abstract: Nine previously undescribed brefeldin A (BFA) derivatives (1–9), together with one known compound 4-epi-brefeldin A (10), were isolated from an endophytic fungus Penicillium brefeldianum F4a. The chemical structures were elucidated using NMR and HRESIMS. ...

Abstract	Nine previously undescribed brefeldin A (BFA) derivatives (1–9), together with one known compound 4-epi-brefeldin A (10), were isolated from an endophytic fungus Penicillium brefeldianum F4a. The chemical structures were elucidated using NMR and HRESIMS. ECD analysis and Mosher's method were used to confirm the absolute configurations of 1–9. The inhibitory activity of all isolated BFA derivatives (1–10) on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was evaluated in vitro. The bioassay results suggested that neobrefeldin (1) and brefeldin H (2) exhibited higher potent and selective AChE inhibitory activity (IC50 = 0.12 and 0.28 μM) than the therapeutic drug galantamine for Alzheimer's disease (AD) (IC50 = 0.66 µM), whereas only neobrefeldin (1) displayed weak inhibitory activity against BuChE (IC50 = 175.04 µM). Moreover, a molecular docking analyses was performed and showed compounds 1 and 2 were dual binding site AChE inhibitors. It is worth noting that neobrefeldin (1) showed a better binding affinity with the peripheral anionic site through the hydrogen bonding interaction with Tyr124 than brefeldin H (2), resulting in better AChE inhibitory activity. These findings not only provide a promising AChE inhibitor neobrefeldin (1) for developing agents against early AD, but also provide a valuable perspective for better understanding its AChE inhibition activity.
Keywords	Cholinesterase inhibitors ; Endophytic fungi ; Penicillium brefeldianum ; Brefeldin A derivatives ; Molecular docking ; Chemistry ; QD1-999
Subject code	540
Language	English
Publishing date	2024-01-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Response of stomatal conductance to plant water stress in buffalograss seed production

Chu Wang / Kai Zhu / YanYan Bai / ChenYan Li / Maona Li / Yan Sun

Agricultural Water Management, Vol 292, Iss , Pp 108661- (2024)

Observation with UAV thermal infrared imagery

2024

Abstract: Stomatal conductance (gs) is an indicator that allows for direct evaluation of plant water status, but it is challenging to achieve rapid monitoring in large-scale fields due to limitations in observation methods. Here this study was conducted to ... ...

Abstract	Stomatal conductance (gs) is an indicator that allows for direct evaluation of plant water status, but it is challenging to achieve rapid monitoring in large-scale fields due to limitations in observation methods. Here this study was conducted to identify the thresholds of gs with different target yields and develop a gs-based water stress diagnostic model for buffalograss (Buchloe dactyloides (Nutt.) Engelm.) using UAV thermal infrared imagery for buffalograss in 2022 and 2023. The results of the field experiment demonstrated that the gs rapidly response to changes in the water stress status of buffalograss. The thresholds of gs were 403 and 385 mmol m−2 s−1 for the vegetative and reproductive growth stages, respectively, with the target seed yield of 1224 kg ha−1. The gs values were classified into three levels for the vegetative growth and four levels for the in reproductive growth stage of buffalograss, respectively. The canopy temperature depression response to water stress is consistent with the gs. Based on this relationship, this study developed a gs-based diagnostic model with a random forest algorithm for buffalograss. Furthermore, a spital map of gs was created using UAV thermal infrared imagery. The modification test results indicated that the model made a good estimation of gs were good with normalized root mean square errors of 15% in the vegetative stage and 11% in the reproductive stage, respectively. Therefore, it is feasible to use thermal infrared imagery for monitoring gs and evaluating the water stress of plants in buffalograss fields.
Keywords	Turfgrass ; Seed yields ; Canopy temperature depression ; Threshold ; Piecewise function ; Water stress ; Agriculture (General) ; S1-972 ; Agricultural industries ; HD9000-9495
Subject code	580
Language	English
Publishing date	2024-03-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Research progress in calculating net community production of marine ecosystem by remote sensing

Yingqi Wang / Kui Wang / Yan Bai / Di Wu / Hao Zheng

Frontiers in Marine Science, Vol

2023 Volume 10

Abstract: Net community production (NCP) is defined as the difference between gross primary production (GPP) and total community respiration (R). NCP indicates the balance between the production and consumption of community organic carbon, therefore making it a ... ...

Abstract	Net community production (NCP) is defined as the difference between gross primary production (GPP) and total community respiration (R). NCP indicates the balance between the production and consumption of community organic carbon, therefore making it a key parameter for evaluating the efficiency of carbon sequestration using the biological pump (BP). It is difficult to quantify NCP directly via satellite, because there are complex processes in community production and respiration. We reviewed previous research on satellite-based NCP and classified the methods into two primary categories: empirical methods and semi-analytical methods. The former category was established based on numerical relationships between NCP and satellite-based proxies, while the latter was developed by utilizing mechanistic analysis to establish quantitative expressions linking NCP to such proxies. Although satellite-based calculations of NCP have been attempted, they still suffer from significant uncertainties. Future research should focus on the precise calculation of satellite-based NCP by investigating the underlying processes and mechanisms that regulate NCP, developing regional models, and increasing the resolution of satellite sensors, as well as applying satellite lidar and coordinated multi-sensor observation technology.
Keywords	remote sensing ; net community production ; carbon export efficiency ; biological pump ; net primary production ; Science ; Q ; General. Including nature conservation ; geographical distribution ; QH1-199.5
Subject code	710
Language	English
Publishing date	2023-06-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Evolutionary Robust Clustering Over Time for Temporal Data.

Zhao, Qi / Yan, Bai / Yang, Jian / Shi, Yuhui

IEEE transactions on cybernetics

2023 Volume 53, Issue 7, Page(s) 4334–4346

Abstract: In many clustering scenes, data samples' attribute values change over time. For such data, we are often interested in obtaining a partition for each time step and tracking the dynamic change of partitions. Normally, a smooth change is assumed for data to ...

Abstract	In many clustering scenes, data samples' attribute values change over time. For such data, we are often interested in obtaining a partition for each time step and tracking the dynamic change of partitions. Normally, a smooth change is assumed for data to have a temporal smooth nature. Existing algorithms consider the temporal smoothness as an a priori preference and bias the search toward the preferred direction. This a priori manner leads to a risk of converging to an unexpected region because it is not always the case that a reasonable preference can be elicited given the little prior knowledge about the data. To address this issue, this article proposes a new clustering framework called evolutionary robust clustering over time. One significant innovation of the proposed framework is processing the temporal smoothness in an a posteriori manner, which avoids unexpected convergence that occurs in existing algorithms. Furthermore, the proposed framework automatically infers the a posteriori preference to temporal smoothness without data's affinity matrix and predefined parameters, which holds better applicability and efficiency. The effectiveness and efficiency of the proposed framework are confirmed by comparing with state-of-the-art algorithms on both synthetic and real datasets.
MeSH term(s)	Algorithms ; Cluster Analysis
Language	English
Publishing date	2023-06-15
Publishing country	United States
Document type	Journal Article
ISSN	2168-2275
ISSN (online)	2168-2275
DOI	10.1109/TCYB.2022.3167711
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Article ; Online: Exploring VIIRS Night Light Long-Term Time Series with CNN/SI for Urban Change Detection and Aerosol Monitoring

Changyong Cao / Bin Zhang / Frank Xia / Yan Bai

Remote Sensing, Vol 14, Iss 3126, p

2022 Volume 3126

Abstract: There is a great need to study the decadal long-term time series of urban night-light changes since the launch of Suomi NPP, NOAA-20, to future JPSS-2, 3, and 4 in the next decades. The recently recalibrated and reprocessed Suomi NPP VIIRS/DNB dataset ... ...

Abstract	There is a great need to study the decadal long-term time series of urban night-light changes since the launch of Suomi NPP, NOAA-20, to future JPSS-2, 3, and 4 in the next decades. The recently recalibrated and reprocessed Suomi NPP VIIRS/DNB dataset overcomes a number of limitations in the operational data stream for time series studies. However, new methodologies are desirable to explore the large volume of historical data to reveal long-term socio-economic and environmental changes. In this study, we introduce a novel algorithm using convolutional neural network similarity index (CNN/SI) to rapidly and automatically identify cloud-free observations for selected cities. The derived decadal clear sky mean radiance time series allows us to study the urban night light changes over a long period of time. Our results show that the radiometric changes for some metropolitan areas changed on the order of 29% in the past decade, while others had no appreciable change. The strong seasonal variation in the mean radiance appears to be highly correlated with seasonal aerosol optical thickness. This study will facilitate the use of recalibrated/reprocessed data, and improve our understanding of urban night light changes due to geophysical, climatological, and socio-economic factors.
Keywords	Suomi NPP VIIRS ; recalibrated/reprocessed historical radiance data ; CNN/SI ; urban night light long-term time series ; urban growth ; aerosols ; Science ; Q
Language	English
Publishing date	2022-06-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Physical Activity and Mortality in Patients With Chronic Kidney Disease

Fan Zhang / Hui Wang / Liuyan Huang / Yan Bai

Frontiers in Medicine, Vol

A Protocol for Systematic Review and Dose-Response Meta-Analysis

2022 Volume 9

Abstract: ObjectiveTo examine the dose-response associations between total physical activity, different intensity of physical activity, and all-cause mortality in patients with chronic kidney disease (CKD).Methods and AnalysisPubMed, Embase, Web of Science, and ... ...

Abstract	ObjectiveTo examine the dose-response associations between total physical activity, different intensity of physical activity, and all-cause mortality in patients with chronic kidney disease (CKD).Methods and AnalysisPubMed, Embase, Web of Science, and the Cochrane library will be searched from inception to June 2022. Only cohort studies assessing physical activity associations with all-cause mortality among CKD patients will be considered for inclusion. The quality of included cohort studies will be evaluated according to the Newcastle-Ottawa Scale (NOS). The robust error meta-regression (REMR) model will be used to establish dose-response relationships between physical activity and mortality. Additional statistical analysis including Egger's test, subgroup analysis, sensitivity analysis. The strengths of evidence will be evaluated with the Grading of Recommendation, Assessment, Development, and Evaluation approach.Ethics and DisseminationEthics approval is not required as no private information from individuals is collected.PROSPERO Registration NumberCRD 42021283630.
Keywords	physical activity ; chronic kidney disease ; mortality ; dose-response ; meta-analysis ; Medicine (General) ; R5-920
Subject code	310
Language	English
Publishing date	2022-04-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Gridless Evolutionary Approach for Line Spectral Estimation With Unknown Model Order.

Yan, Bai / Zhao, Qi / Zhang, Jin / Zhang, J Andrew / Yao, Xin

IEEE transactions on cybernetics

2024 Volume 54, Issue 2, Page(s) 935–947

Abstract: Gridless methods show great superiority in line spectral estimation. These methods need to solve an atomic ... ...

Abstract	Gridless methods show great superiority in line spectral estimation. These methods need to solve an atomic l
Language	English
Publishing date	2024-01-17
Publishing country	United States
Document type	Journal Article
ISSN	2168-2275
ISSN (online)	2168-2275
DOI	10.1109/TCYB.2022.3179378
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: A global land cover map produced through integrating multi-source datasets

Min Feng / Yan Bai

Big Earth Data, Vol 3, Iss 3, Pp 191-

2019 Volume 219

Abstract: In the past decades, global land cover datasets have been produced but also been criticized for their low accuracies, which have been affecting the applications of these datasets. Producing a new global dataset requires a tremendous amount of efforts; ... ...

Abstract	In the past decades, global land cover datasets have been produced but also been criticized for their low accuracies, which have been affecting the applications of these datasets. Producing a new global dataset requires a tremendous amount of efforts; however, it is also possible to improve the accuracy of global land cover mapping by fusing the existing datasets. A decision-fuse method was developed based on fuzzy logic to quantify the consistencies and uncertainties of the existing datasets and then aggregated to provide the most certain estimation. The method was applied to produce a 1-km global land cover map (SYNLCover) by integrating five global land cover datasets and three global datasets of tree cover and croplands. Efforts were carried out to assess the quality: 1) inter-comparison of the datasets revealed that the SYNLCover dataset had higher consistency than these input global land cover datasets, suggesting that the data fusion method reduced the disagreement among the input datasets; 2) quality assessment using the human-interpreted reference dataset reported the highest accuracy in the fused SYNLCover dataset, which had an overall accuracy of 71.1%, in contrast to the overall accuracy between 48.6% and 68.9% for the other global land cover datasets.
Keywords	global land cover ; data integration ; accuracy evaluation ; Geography. Anthropology. Recreation ; G ; Geology ; QE1-996.5
Language	English
Publishing date	2019-07-01T00:00:00Z
Publisher	Taylor & Francis Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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