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The collaborative cross mouse for studying the effect of host genetic background on memory impairments due to obesity and diabetes 被引量:1
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作者 Avia Paz Kareem Midlej +2 位作者 Osayd Zohud Iqbal MLone Fuad A.Iraqi 《Animal Models and Experimental Medicine》 2025年第1期126-141,共16页
Background:Over the past few decades,a threefold increase in obesity and type 2 diabetes(T2D)has placed a heavy burden on the health-care system and society.Previous studies have shown correlations between obesity,T2D... Background:Over the past few decades,a threefold increase in obesity and type 2 diabetes(T2D)has placed a heavy burden on the health-care system and society.Previous studies have shown correlations between obesity,T2D,and neurodegenera-tive diseases,including dementia.It is imperative to further understand the relation-ship between obesity,T2D,and cognitive deficits.Methods:This investigation tested and evaluated the cognitive impact of obesity and T2D induced by high-fat diet(HFD)and the effect of the host genetic background on the severity of cognitive decline caused by obesity and T2D in collaborative cross(CC)mice.The CC mice are a genetically diverse panel derived from eight inbred strains.Results:Our findings demonstrated significant variations in the recorded phenotypes across different CC lines compared to the reference mouse line,C57BL/6J.CC037 line exhibited a substantial increase in body weight on HFD,whereas line CC005 ex-hibited differing responses based on sex.Glucose tolerance tests revealed significant variations,with some lines like CC005 showing a marked increase in area under the curve(AUC)values on HFD.Organ weights,including brain,spleen,liver,and kidney,varied significantly among the lines and sexes in response to HFD.Behavioral tests using the Morris water maze indicated that cognitive performance was differentially affected by diet and genetic background.Conclusions:Our study establishes a foundation for future quantitative trait loci map-ping using CC lines and identifying genes underlying the comorbidity of Alzheimer's disease(AD),caused by obesity and T2D.The genetic components may offer new tools for early prediction and prevention. 展开更多
关键词 collaborative cross mouse DIABETES host genetic background memory impairments OBESITY
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Construction and characteristic analysis of background error covariance coupled with land surface temperature 被引量:1
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作者 Qihang Yang Yaodeng Chen +4 位作者 Luyao Qin Yuanbing Wang Deming Meng Xusheng Yan Xinyao Qian 《Atmospheric and Oceanic Science Letters》 2025年第3期7-12,共6页
Land surface temperature(LST)is the key variable in land-atmosphere interaction,having an important impact on weather and climate forecasting.However,achieving consistent analysis of LST and the atmosphere in assimila... Land surface temperature(LST)is the key variable in land-atmosphere interaction,having an important impact on weather and climate forecasting.However,achieving consistent analysis of LST and the atmosphere in assimilation is quite challenging.This is because there is limited knowledge about the cross-component background error covariance(BEC)between LST and atmospheric state variables.This study aims to clarify whether there is a relationship between the error of LST and atmospheric variables,and whether this relationship varies spatially and temporally.To this end,the BEC coupled with atmospheric variables and LST was constructed(LST-BEC),and its characteristics were analyzed based on the 2023 mei-yu season.The general characteristics of LST-BEC show that the LST is mainly correlated with the atmospheric temperature and the correlation decreases gradually with a rise in atmospheric height,and the error standard deviation of the LST is noticeably larger than that of the low-level atmospheric temperature.The spatiotemporal characteristics of LST-BEC on the heavy-rain day and light-rain day show that the error correlation and error standard deviation of LST and low-level atmospheric temperature and humidity are closely related to the weather background,and also have obvious diurnal variations.These results provide valuable information for strongly coupled land-atmosphere assimilation. 展开更多
关键词 background error covariance Land surface temperature Error correlation Error standard deviation Data assimilation
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Association of the glycemic background patterns and the diabetes management efficacy in poorly controlled type 2 diabetes
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作者 Ayşe N Erbakan Müzeyyen Arslan Bahadır +6 位作者 FatoşN Kaya Büşra Güleç MiraçVural Keskinler Ümmügülsüm AktemurÇelik Özge Faydalıel Banu Mesçi Aytekin Oğuz 《World Journal of Diabetes》 SCIE 2025年第1期74-90,共17页
BACKGROUND Inadequate glycemic control in patients with type 2 diabetes(T2DM)is a major public health problem and a significant risk factor for the progression of diabetic complications.AIM To evaluate the effects of ... BACKGROUND Inadequate glycemic control in patients with type 2 diabetes(T2DM)is a major public health problem and a significant risk factor for the progression of diabetic complications.AIM To evaluate the effects of intensive and supportive glycemic management strategies over a 12-month period in individuals with T2DM with glycated hemoglobin(HbA1c)≥10%and varying backgrounds of glycemic control.METHODS This prospective observational study investigated glycemic control in patients with poorly controlled T2DM over 12 months.Participants were categorized into four groups based on prior glycemic history:Newly diagnosed,previously well controlled with recent worsening,previously off-target but now worsening,and HbA1c consistently above 10%.HbA1c levels were monitored quarterly,and patients received medical,educational,and dietary support as needed.The analysis focused on the success rates of good glycemic control and the associated factors within each group.RESULTS The study showed significant improvements in HbA1c levels in all participants.The most significant improvement was observed in individuals newly diagnosed with diabetes:65%achieved an HbA1c target of≤7%.The results varied between participants with different glycemic control histories,followed by decreasing success rates:39%in participants with previously good glycemic control,21%in participants whose glycemic control had deteriorated compared to before,and only 10%in participants with persistently poor control,with mean HbA1c levels of 6.3%,7.7%,8.2%,and 9.7%,respectively.After one year,65.2%of the“newly diagnosed patients”,39.3%in the“previously controlled group”,21.9%in the“previously off-target but now worsened'”group and 10%in the“poorly controlled from the start”group had achieved HbA1c levels of 7 and below.CONCLUSION In poorly controlled diabetes,the rate at which treatment goals are achieved is associated with the glycemic background characteristics,emphasizing the need for tailored strategies.Therefore,different and comprehensive treatment approaches are needed for patients with persistent uncontrolled diabetes. 展开更多
关键词 Type 2 diabetes mellitus Glycated hemoglobin Glycemic control Patient-centered care Diabetes management glycemic background
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Comparison of Simulated Backgrounds with In-orbit Observations for HXI Onboard ASO-S
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作者 Hao-Xiang Wang Zhe Zhang +4 位作者 Wei Liu Xian-Kai Jiang Deng-Yi Chen Yi-Ming Hu Yang Su 《Research in Astronomy and Astrophysics》 2025年第3期141-153,共13页
The Hard X-ray Imager(HXI)payload,a component of China’s Advanced Space-based Solar Observatory satellite,is designed to observe solar X-ray emissions in the 30-200 keV range,with the aim of investigating nonthermal ... The Hard X-ray Imager(HXI)payload,a component of China’s Advanced Space-based Solar Observatory satellite,is designed to observe solar X-ray emissions in the 30-200 keV range,with the aim of investigating nonthermal physical processes during solar flares.Before launch,Geant4 simulations were employed to assess the onorbit background of the HXI instrument,evaluating its performance and potential to achieve its scientific objectives.This study addresses issues identified in previous simulations and conducts further analyses to examine the distribution of background counts across the 99 detectors.The results demonstrate alignment between simulations and observations at low and medium geomagnetic latitudes;however,challenges persist at high geomagnetic latitudes due to limitations in the current albedo photon model.This investigation provides insights into background sources from various particles,enhances understanding of space background characteristics,and offers guidance for background subtraction in imaging processes. 展开更多
关键词 instrumentation detectors-Sun X-rays gamma-rays-(cosmology )cosmic background radiation-gamma-rays diffuse background
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Enhanced suppression of background in capture reaction measurements with LAMBDA-Ⅱin ground laboratories
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作者 Lu-Yang Song Lin Wang +22 位作者 Jun Su Li-Yong Zhang Jian-Jun He Shi-Lun Jin Fei Lu Yang-Ping Shen Jun-Feng Chen Yao-De Sheng Xin Chen Shen Lin Zhi-Wei Qin Zi-Ming Li Hao Zhang Luo-Huan Wang Yin-Ji Chen Xin-Zhi Jiang Zhi-Lin Shen Xin-Yue Li Feng-Cheng Liu Yi-Tong Huang Si-Ze Chen Bing Guo Wei-Ping Liu 《Nuclear Science and Techniques》 2025年第11期273-282,共10页
The precise determination of cross sections for key nuclear reactions within the Gamow window is crucial for advancing the study of stellar evolution and nucleosynthesis.However,extremely low reaction yields combined ... The precise determination of cross sections for key nuclear reactions within the Gamow window is crucial for advancing the study of stellar evolution and nucleosynthesis.However,extremely low reaction yields combined with the cosmic-ray-induced background make these measurements highly challenging,particularly for capture reactions.This work demonstrates the second configuration of the large-scale modular BGO detection array(LAMBDA-Ⅱ)designed to capture reaction measurements and introduces a method for suppressingγ-ray detection background in ground laboratories.By employing active and passive shielding,the background of LAMBDA-Ⅱwas significantly reduced by approximately two orders of magnitude,reaching 8.1×10^(-3)and 1.0×10^(-3)keV^(-1)h^(-1)in the 6-11 and 11-20 MeV energy ranges,respectively.When combined with a mA-scale intensity beam,this reduced background enables the investigation of several capture reactions of astrophysical interest in ground laboratories. 展开更多
关键词 Nuclear astrophysics Capture reaction background Summing technique γdetector array SHIELDING
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Study on the Correction Method of Radiant Temperature Measurement of Turbine Blades Under the Background of High-Temperature Dynamics
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作者 Shengnan Liu Liwei Chen 《Instrumentation》 2025年第2期80-90,共11页
The turbine blades operate under high temperature and high pressure conditions,and when using radiation thermometry,the influence of radiation from surrounding blades leads to measurement errors.To address this issue,... The turbine blades operate under high temperature and high pressure conditions,and when using radiation thermometry,the influence of radiation from surrounding blades leads to measurement errors.To address this issue,this paper develops a three-dimensional discretized dynamic radiation transfer model based on the blade shape of the turbine.The relationship between the radiation angle coefficient of the surrounding blades and the rotation angle of the blade under test is analyzed.The radiation angle coefficient is calculated using the triangular element method,and temperature inversion is performed based on the effective emissivity to compute the measurement error.The results show that under dynamic high temperature conditions,the temperature measurement error caused by reflection at the selected 60%leaf height point varies with the rotation angle,and the maximum reaches 25.58K.The angular coefficient exhibits periodic fluctuations with changes in rotation angle,and the maximum effective emissivity increases as the rotation angle increases.As the blade height increases,the impact of reflected radiation on radiometric temperature measurement errors shows a decreasing trend.This study provides a reference for radiation thermometry in dynamic high-temperature environments. 展开更多
关键词 radiation temperature measurement dynamic background turbine blades effective emissivity ERROR
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Identification of QTL-by-environment interaction by controlling polygenic background effect
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作者 Fuping Zhao Lixian Wang Shizhong Xu 《Journal of Genetics and Genomics》 2025年第7期915-926,共12页
The quantitative trait loci(QTL)-by-environment(Q × E) interaction effect is hard to detect because there are no effective ways to control the genomic background. In this study, we propose a linear mixed model th... The quantitative trait loci(QTL)-by-environment(Q × E) interaction effect is hard to detect because there are no effective ways to control the genomic background. In this study, we propose a linear mixed model that simultaneously analyzes data from multiple environments to detect Q × E interactions. This model incorporates two different kinship matrices derived from the genome-wide markers to control both main and interaction polygenic background effects. Simulation studies demonstrate that our approach is more powerful than the meta-analysis and inclusive composite interval mapping methods. We further analyze four agronomic traits of rice across four environments. A main effect QTL is identified for 1000-grain weight(KGW), while no QTL are found for tiller number. Additionally, a large QTL with a significant Q × E interaction is detected on chromosome 7 affecting grain number, yield, and KGW. This region harbors two important genes, PROG1 and Ghd7. Furthermore, we apply our mixed model to analyze lodging in barley across six environments. The six regions exhibiting Q × E interaction effects identified by our approach overlap with the SNPs previously identified using EM and MCMC-based Bayesian methods, further validating the robustness of our approach. Both simulation studies and empirical data analyses show that our method outperforms all other methods compared. 展开更多
关键词 Q×E interaction Main effect META-ANALYSIS Mixed model Polygenic background
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High summer background O_(3)levels in the desert of northwest China
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作者 Xinbing Ren Fang Wang +8 位作者 Bayi Wu Shaoting Zhang Lei Zhang Xingjun Zhou Yuanzhe Ren Yongjing Ma Feng Hao Yongli Tian Jinyuan Xin 《Journal of Environmental Sciences》 2025年第5期516-528,共13页
Generally speaking,the precursors of ozone(O_(3)),nitrogen oxides and volatile organic compounds are very low in desert areas due to the lack of anthropogenic emissions and natural emissions,and thus O_(3)concentratio... Generally speaking,the precursors of ozone(O_(3)),nitrogen oxides and volatile organic compounds are very low in desert areas due to the lack of anthropogenic emissions and natural emissions,and thus O_(3)concentrations are relatively low.However,high summer background concentrations of about 100μg/m^(3)or 60 ppb were found in the Alxa Desert in the highland of northwest China based on continuous summer observations from 2019 to 2021,which was higher than the most of natural background areas or clean areas in world for summer O_(3)background concentrations.The high O_(3)background concentrations were related to surface features and altitude.Heavy-intensity anthropogenic activity areas in desert areas can cause increased O_(3)concentrations or pollution,but also generated O_(3)depleting substances such as nitrous oxide,which eventually reduced the regional O_(3)baseline values.Nitrogen dioxide(NO2)also had a dual effect on O_(3)generation,showing promotion at low concentrations and inhibition at high concentrations.In addition,sand-dust weather reduced O_(3)clearly,but O_(3)eventually stabilized around the background concentration values and did not vary with sand-dust particulate matter. 展开更多
关键词 Alxa Desert O_(3)background concentration Anthropogenic effect Sand-dust weather Northwest China
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Rogue waves on a periodic background in the reduced Maxwell–Bloch system
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作者 YiJie Zhao Zhaqilao Niqi Ao 《Communications in Theoretical Physics》 2025年第8期25-34,共10页
In this paper,the nonlinearization of the Lax pair and the Darboux transformation method are used to construct the rogue wave on the elliptic function background in the reduced Maxwell–Bloch system,which is described... In this paper,the nonlinearization of the Lax pair and the Darboux transformation method are used to construct the rogue wave on the elliptic function background in the reduced Maxwell–Bloch system,which is described by four component nonlinear evolution equations(NLEEs).On the background of the Jacobian elliptic function,we obtain the admissible eigenvalues and the corresponding non-periodic eigenfunctions of the model spectrum problem.Then,with the help of the one-fold Darboux transformation and two-fold Darboux transformation,rogue waves on a dn-periodic background and cn-periodic background are derived,respectively.Finally,the corresponding complex dynamical properties and evolutions of the four components are illustrated graphically by choosing suitable parameters. 展开更多
关键词 Jacobian elliptic function Darboux transformation reduced Maxwell–Bloch system rogue waves on a periodic background
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A Preliminary Study on the Background of the Formation of the Meng Yao Zheng Dian
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作者 Hongying Wu Bao Long 《Journal of Clinical and Nursing Research》 2025年第2期93-101,共9页
Meng Yao Zheng Dian is one of the three classics of Mongolian medicine.It was written by Zhanbra Dorje,who was a famous Mongolian physician.The book was not only related to the author's origin,education and learni... Meng Yao Zheng Dian is one of the three classics of Mongolian medicine.It was written by Zhanbra Dorje,who was a famous Mongolian physician.The book was not only related to the author's origin,education and learning experience,but also closely related to the social development,cultural exchanges between Mongolian and Tibetan,and people's demand for Mongolian medicine at that time.The book in four languages indicates the name of Mongolian medicinal herbs,Mongolian of China,Tibetan of China,Chinese,Manchu medicine academic and cultural exchanges played a positive role in promoting the cultural exchanges,is a vivid embodiment of the cultural exchanges between Chinese nationalities and exchanges and mingling. 展开更多
关键词 Zhanbra Dorje Meng Yao Zheng Dian background of the book
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Interactions of the Background State and Eddies in Shaping Aleutian Low Variations
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作者 Nan LIN Tuantuan ZHANG +3 位作者 Qiaoling REN Ho-Nam CHEUNG Chang-Hoi HO Song YANG 《Advances in Atmospheric Sciences》 2025年第8期1548-1565,共18页
The Aleutian Low(AL)is a dominant feature of the mean circulation in the North Pacific during the winter season.The background stationary wave,air-sea interaction,and transient eddies over the North Pacific exert dist... The Aleutian Low(AL)is a dominant feature of the mean circulation in the North Pacific during the winter season.The background stationary wave,air-sea interaction,and transient eddies over the North Pacific exert distinct impacts on the interannual variations of the AL intensity and position.In this study,we adopt the quasi-geostrophic geopotential tendency equation to investigate the roles of various physical processes in the maintenance and interannual variations of this system.The results show that absolute vorticity advection plays the most important role in the formation and maintenance of AL intensity,while high-frequency transient eddies contribute most to the meridional and zonal shifts of the AL.The high-frequency transient eddy vorticity forcing affects the AL through the barotropic energy conversion process,and,in turn,the AL enhances the high-frequency transient eddies through the baroclinic energy conversion process,forming a positive feedback.The associated high-frequency eddy kinetic energy anomalies exhibit an eastward movement toward the east coast of North America in the years of an intensified AL,which explains why a strengthened AL is often accompanied by an eastward movement.Furthermore,the energy conversion terms of high-frequency transient eddies are mostly located over the extratropical eastern North Pacific,leading to asymmetric features in the zonal movement of the AL. 展开更多
关键词 Aleutian Low interannual variations interactions between eddies and the background flow
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Gravitational Wave Background from Extreme-Mass-Ratio Inspirals
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作者 Haoyu Zhao Yuanhao Zhang +1 位作者 Xilong Fan Wenbiao Han 《Chinese Physics Letters》 2025年第5期239-247,共9页
The gravitational wave background(GWB) produced by extreme-mass-ratio inspirals(EMRIs) serves as a powerful tool for probing the astrophysical and dynamical processes in galactic centers. EMRI systems are a primary ta... The gravitational wave background(GWB) produced by extreme-mass-ratio inspirals(EMRIs) serves as a powerful tool for probing the astrophysical and dynamical processes in galactic centers. EMRI systems are a primary target for the space-based detector laser interferometer space antenna due to their long-lived signals and high signal-to-noise ratios. This study explores the statistical properties of the GWB from EMRI, focusing on the calculation methods for the GWB, the astrophysical distribution of EMRI sources, and the influence of key parameters, including the spin of supermassive black holes(SMBHs) and the masses of compact objects(COs). By analyzing these factors, we determine the distribution range of the characteristic strain of the GWB from EMRIs. We find that the final eccentricity distributions appear to have negligible effect on the intensity of the GWB due to rapid circularization before they become detectable and the spin of the SMBH enhances the gravitational wave characteristic strain by approximately 1% compared to cases without spin effects. The masses of COs can also significantly affect the characteristic strain of the GWB from EMRIs, with black hole as CO producing a gravitational wave signal intensity that is approximately one order of magnitude higher compared to cases where neutron star or white dwarf are the COs. 展开更多
关键词 probing astrophysical dynamical processes galactic centers astrophysical distribution extreme mass ratio inspirals laser interferometer space antenna gravitational wave background calculation methods characteristic strain Laser Interferometer Space Antenna
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深化医改背景下基于岗位胜任力的静脉治疗专科护理培训对护士专科能力的影响
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作者 余海霞 王波 +2 位作者 孟利霞 冯珊珊 郭炜炜 《齐鲁护理杂志》 2026年第2期149-151,共3页
目的:探究深化医改背景下基于岗位胜任力的静脉治疗专科护理培训对护士专科能力的影响。方法:选取2023年3月—2024年9月90名在职护士为研究对象,按照随机数字表法分成观察组和对照组各45名,对照组实施常规护理培训,观察组在对照组基础... 目的:探究深化医改背景下基于岗位胜任力的静脉治疗专科护理培训对护士专科能力的影响。方法:选取2023年3月—2024年9月90名在职护士为研究对象,按照随机数字表法分成观察组和对照组各45名,对照组实施常规护理培训,观察组在对照组基础上实施深化医改背景下基于岗位胜任力的静脉治疗专科护理培训。观察比较两组护士岗位胜任力、患者满意度、临床应用能力。结果:观察组护士岗位胜任力、患者满意度、临床应用能力均高于对照组(P<0.01,P<0.05)。结论:采用基于岗位胜任力的静脉治疗专科护理培训,可提高护理人员的专科岗位胜任力、临床应用能力,从而提高患者满意度。 展开更多
关键词 深化医改背景 静脉治疗 专科护理培训 满意度
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Research on Background and Utilization of Germplasm Resources in Maize 被引量:3
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作者 杨培珠 钟国祥 +4 位作者 谢虹 陈少方 苏立生 刘惠娈 张旭 《Agricultural Science & Technology》 CAS 2011年第10期1464-1467,共4页
[Objective] The research aimed at introducing the background and utilization of germplasm resources in maize.[Method] The research progress on genetic background and utilization of maize germplasm resources was compre... [Objective] The research aimed at introducing the background and utilization of germplasm resources in maize.[Method] The research progress on genetic background and utilization of maize germplasm resources was comprehensively reviewed in this paper,including maize heterotic groups and heterotic patterns,their flexible application in breeding and the utilization of various types of original materials.[Result] The results show that germplasm resource is the premise and basis for maize breeding.In-depth understanding and a reasonable selection of germplasm resources can significantly improve the breeding efficiency and speed up the breeding process.At the same time,it is considered that the selection and construction of original materials in maize breeding can not be limited to the heterotic groups and heterotic patterns,but has to be used reasonablely according to different types of germplasm resources and individual breeding objective and idea as well.[Conclusion] This study had broadened the idea and provided inspiration for the maize breeding practice in China. 展开更多
关键词 MAIZE Germplasm resources Genetic background UTILIZATION
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REAL-TIME TRACKING FOR FAST MOVING OBJECT ON COMPLEX BACKGROUND 被引量:4
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作者 张超 王道波 Farooq M 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第4期321-325,共5页
A real-time tracking system for the fast moving object on the complex background is proposed.The Markov random filed(MRF)model based background subtraction algorithm is used to detect the changing pixels and track t... A real-time tracking system for the fast moving object on the complex background is proposed.The Markov random filed(MRF)model based background subtraction algorithm is used to detect the changing pixels and track the moving object.The prior probability of the segmentation mask is modeled by using MRF,and the object tracking task is translated into the maximum a-posterior(MAP)problem.Experimental results show that the method is efficient at both offline and online moving objects on simple and complex background. 展开更多
关键词 unmanned aerial vechicles real-time tracking Markov random field background subtraction
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Mitochondrial DNA D-loop Variation and Genetic Background of Brahman Cattle 被引量:1
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作者 亐开兴 吴桂生 +7 位作者 廖祥龙 金显栋 赵刚 杨国荣 袁希平 黄必志 文际坤 张亚平 《Zoological Research》 CAS CSCD 北大核心 2006年第6期615-620,共6页
The complete mitochondrial DNA D-loop sequences from 10 stud Brahman cattle were sequenced and analyzed. The results showed that the genetic diversity of Brahman cattle was rich ; the rate of nucleotide variation, hap... The complete mitochondrial DNA D-loop sequences from 10 stud Brahman cattle were sequenced and analyzed. The results showed that the genetic diversity of Brahman cattle was rich ; the rate of nucleotide variation, haplotype diversity and nucleotide diversity were 6.25%, 0.978± 0.054 and 0.014 30± 0.008 68, respectively. Nine haplotypes were defined and fell into two distinct lineages, suggesting that Brahman cattle have both Bos indicus (Zebu) and B. taurus genetic background. The taurine haplotypes were predominant at 90% and only Brah-6 belonged to the Asian zebu mthaplotype. This indicates that Brahman cattle was one of the zebu breeds and inherited the excellent characteristics of both the Asian zebu and European beef cattle, such as easy calf delivery, high quality beef, heat tolerance and resistance to various parasites. Breeders introduced Brahman cattle to improve the productivity and adaptability of native cattle. The Zebu has evidently frequently introgressed into the modem taurine breeds. As for modem zebu breeds, B. taurus also highly contributed to their formation, except for the Asian zebu. Furthermore our results also confirm the hypothesis that B. indicus has undergone a separate domestication event and originated from the Indian subcontinent. 展开更多
关键词 Brahman cattle mtDNA D-loop polymorphism genetic background
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碳酸盐岩发育土壤重金属高背景:形成因素和风险特征
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作者 李雅男 夏学齐 +2 位作者 杨忠芳 卢新哲 黄春雷 《中国环境科学》 北大核心 2026年第1期11-19,共9页
从空间分布、元素组合、高背景范围、元素富集程度的控制因素,以及形成原因和风险特征等方面,系统梳理碳酸盐岩有关的土壤重金属高背景研究进展.当前普遍认为,该类高背景形成的主要因素是母岩风化过程中的“次生富集”,即钙等常量元素... 从空间分布、元素组合、高背景范围、元素富集程度的控制因素,以及形成原因和风险特征等方面,系统梳理碳酸盐岩有关的土壤重金属高背景研究进展.当前普遍认为,该类高背景形成的主要因素是母岩风化过程中的“次生富集”,即钙等常量元素淋失造成镉等微量元素的相对富集,在此过程中,铁锰矿物对这些元素的原地富集发挥了重要作用.从宏观角度,湿热的气候更有利于形成更高的背景含量.总体上,碳酸盐岩残积背景下镉等元素具有“高背景,低活性”特征,而在以其为物源的冲积区,存在酸溶态较高的现象,在土壤酸化等特定条件下,存在被活化风险.在中小尺度空间变异复杂的情况下,如何对该类高背景下自然背景与人为污染进行区分,开展相关风险定量识别,以及制定相关管控措施,是未来研究的重要方向. 展开更多
关键词 土壤 重金属 地质高背景 碳酸盐岩 形成原因 风险特征
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脂代谢与噪声下言语识别困难风险的孟德尔随机化分析
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作者 曹扬 吴萧男 +2 位作者 李丹阳 王洪阳 王秋菊 《中华耳科学杂志》 北大核心 2026年第1期20-25,共6页
目的探讨脂代谢指标与噪声下言语识别困难之间的因果关系,并评估其在听力损失早期阶段的作用。方法基于孟德尔随机化(Mendelian randomization,MR)设计,利用英国生物银行和全球脂质遗传学联盟两个大型全基因组关联分析数据库的数据,评... 目的探讨脂代谢指标与噪声下言语识别困难之间的因果关系,并评估其在听力损失早期阶段的作用。方法基于孟德尔随机化(Mendelian randomization,MR)设计,利用英国生物银行和全球脂质遗传学联盟两个大型全基因组关联分析数据库的数据,评估高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、低密度脂蛋白胆固醇、甘油三酯等脂代谢指标与噪声下言语识别困难之间的因果关联。采用逆方差加权方法作为主要分析方法,并通过多变量MR进一步验证脂代谢指标的独立贡献。结果两样本MR分析表明,HDL-C与噪声下言语识别困难具有显著的保护性因果关系(英国生物银行数据集:OR=0.993,95%CI:0.987~0.999,P=0.014),这一关联在多变量分析中保持稳健(OR=0.992,95%CI:0.984~1.000,P=0.045)。相比之下,其他脂代谢指标未显示出显著的独立因果效应。此外,全球脂质遗传学联盟数据集中HDL-C的保护作用虽然显示出类似趋势,但未达到统计学显著性(OR=0.994,95%CI:0.987~1.000,P=0.054),多变量MR结果(OR=0.992,95%CI:0.983~1.000,P=0.064)。结论HDL-C在噪声下言语识别困难中具有保护作用,HDL-C水平的改善可能通过抑制炎症、抗氧化和改善微循环等机制对听力健康产生积极影响。 展开更多
关键词 脂代谢 孟德尔随机化 高密度脂蛋白 噪声下言语识别困难 听力损失
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NBL-REF桥接法在长白山区地下水水质阈值确定中的应用
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作者 崔庚 姜颢睿 +3 位作者 苏伟奇 刘言 姜明 佟守正 《地理科学》 北大核心 2026年第2期326-336,共11页
地下水污染对生态环境与人类健康造成严重威胁,明确地下水水质阈值已成为开展地下水保护的核心前提。长白山区是中国重要的生态屏障与水源涵养区,地下水水质状况直接关系到区域生态安全与居民用水安全。因此,科学界定地下水水质阈值对... 地下水污染对生态环境与人类健康造成严重威胁,明确地下水水质阈值已成为开展地下水保护的核心前提。长白山区是中国重要的生态屏障与水源涵养区,地下水水质状况直接关系到区域生态安全与居民用水安全。因此,科学界定地下水水质阈值对该区具有重要意义。本研究基于地下水水质监测数据,综合运用概率图法、2-σ迭代计法和分布函数法确定地下水自然背景值,并结合自然背景值-参考值(Natural Background Level-Reference Value,NBL-REF)桥接法,界定长白山地区20项地下水水质指标的阈值。结果显示,虽然区内地下水受一定人为干扰,但大多数指标的自然背景值小于参考值,整体水质仍处于较好状态。然而,NO_(3)-N和Al的背景值高于参考值,DO、NH_(3)-N和Fe则略低于参考值,需加强治理与监管。阈值结果不仅反映了区域地下水的本底状况,也可用于水质约束管理,为长白山区地下水资源保护提供科学依据,并具有在其他山区及平原区推广应用的潜力。 展开更多
关键词 长白山 地下水 自然背景值 NBL-REF桥接法 水质阈值
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高管团队异质性对企业数字化转型的倒U型影响——创业导向的中介效应
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作者 郝喜玲 陈榕冰 +1 位作者 苟亚萍 杜晶晶 《工业技术经济》 北大核心 2026年第1期90-99,共10页
随着数字经济的深度发展与快速演进,企业数字化转型成为关乎可持续发展的战略决策。作为企业战略决策的核心主体,高管团队的异质性特征对企业数字化转型存在显著影响。本文以2010~2024年沪深A股上市公司为样本,将创业导向纳入分析框架,... 随着数字经济的深度发展与快速演进,企业数字化转型成为关乎可持续发展的战略决策。作为企业战略决策的核心主体,高管团队的异质性特征对企业数字化转型存在显著影响。本文以2010~2024年沪深A股上市公司为样本,将创业导向纳入分析框架,系统剖析高管团队异质性作用于企业数字化转型的内在路径。结果显示:高管团队的教育、职能及海外背景异质性与企业数字化转型之间呈倒U型关系,创业导向在高管团队教育和海外背景异质性与企业数字化转型之间发挥中介作用。研究成果不仅为高管团队异质性影响数字化转型的内在机制提供新视角,也为企业优化团队结构、推动数字化转型实践提供管理启示。 展开更多
关键词 高管团队 高管团队异质性 创业导向 数字化转型 高阶梯队理论 教育背景异质性 职能背景异质性 海外背景异质性
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