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Stand parameter extraction based on video point cloud data

Journal of Forestry Research 2021年第4期32卷 1553-1565页

作者： Ziyu Zhao Zhongke Feng Jincheng Liu Yudong Li Precision Forestry Key Laboratory of Beijing Beijing Forestry UniversityBeijing 100083People’s Republic of China College of Natural Resources and Environment Northwest A&F UniversityXian 712100People’s Republic of China

Monitoring sample plots is important for the sustainable management of forest ecosystems.Acquiring resource data in the field is labor-intensive,time-consuming and expensive.With the rapid development of hardware technology and photogrammetry,forest researchers have turned two-dimensional images into three-dimensional point clouds to obtain resource information.This paper presents a method of sample plot analysis using two charge-coupled device(CCD) cameras based on video photography.A handheld CCD camera was used to shoot the sample plot by surrounding a central tree.Video-based point clouds were used to detect and model individual tree trunks in the sample plots and the dbh of each was estimated.The experimental results were compared with field measurement data.The results show that the relative root mean squared error(rRMSE) of the dbh estimates of individual trees was 2.1-5.7%,acceptable for practical applications in traditional forest inventories.The rRMSE of height estimates was2.7-36.3%.Average dbh and heights,and tree density and volume were calculated.Video-based methods require compact observation instruments,involve low costs during field investigations,acquire data with high efficiency,and point cloud data can be processed automatically.Furthermore,this method can directly extract information on the relative position of trees,which is important to show distribution visually and provides a basis for researchers to regulate stand density.Additionally,video photography with its unique advantages is a technology warranting future attention for forest inventories and ecological construction.

关键词： Video photography Point cloud Forest Hough transform dbh

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Assessment of handheld mobile terrestrial laser scanning for estimating tree parameters

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Journal of Forestry Research 2021年第4期32卷 1503-1513页

作者： Cornelis Stal Jeff rey Verbeurgt Lars De Sloover Alain De Wulf Center for Applied Data Science University College GhentValentin Vaerwyckweg 19000 GhentBelgium Department of Geography 3D Data Acquisition Research UnitGhent UniversityKrijgslaan 2819000 GhentBelgium Department of Geography CartoGIS Research UnitGhent UniversityKrijgslaan 2819000 GhentBelgium

Sustainable forest management heavily relies on the accurate estimation of tree parameters.Among others,the diameter at breast height(dbh) is important for extracting the volume and mass of an individual tree.For systematically estimating the volume of entire plots,airborne laser scanning(ALS) data are used.The estimation model is frequently calibrated using manual dbh measurements or static terrestrial laser scans(STLS) of sample plots.Although reliable,this method is time-consuming,which greatly hampers its use.Here,a handheld mobile terrestrial laser scanning(HMTLS) was demonstrated to be a useful alternative technique to precisely and efficiently calculate dbh.Different data acquisition techniques were applied at a sample plot,then the resulting parameters were comparatively analysed.The calculated dbh values were comparable to the manual measurements for HMTLS,STLS,and ALS data sets.Given the comparability of the extracted parameters,with a reduced point density of HTMLS compared to STLS data,and the reasonable increase of performance,with a reduction of acquisition time with a factor of5 compared to conventional STLS techniques and a factor of3 compared to manual measurements,HMTLS is considered a useful alternative technique.

关键词： Forest inventory dbh Airborne laser scanning Terrestrial laser scanning Handheld mobile laser scanning Point cloud processing

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Carbon storage and sequestration rate assessment and allometric model development in young teak plantations of tropical moist deciduous forest, India

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Journal of Forestry Research 2015年第3期26卷 589-604页

作者： Kaushalendra Kumar Jha Technical Forestry Indian Institute of Forest ManagementPO Box No. 357 Nehru Nagar Bhopal 462 003 MP India

Carbon （C） sequestration through plantations is one of the important mitigation measures for rising levels of carbon dioxide and other greenhouse gases in the atmosphere. This study aimed to assess C stocks and their sequestration rate, and to develop allometric models for estimation of C stocking in age-series young teak （Tectona grandis） planta- tions （1, 5, 11, 18, 24 and 30 years） by using biomass and productivity estimation and regression, respectively. These plantations were raised in tropical moist deciduous forests of Kumaun Himalayan tarai. Total C stocks estimated for these plantations were 1.6, 15.8, 35.4, 39.0, 61.5 and 73.2 Mg ha-1, respectively. Aboveground and belowground C storage in- creased with increasing plantation age; however, the range of their percentage contribution showed little variation （87.8-88.2 and 11.7-12.7 %, respectively）, The rate of C sequestration for these respective plantations was 1.06, 6.95, 5.46, 5.42, 3.39 and 5.37 Mg ha-1 a-1. Forty percent of the aboveground annual storage was retained in the tree while 60 % was released in the form of foliage, twigs, and fruit litter. In the case of total （tree） annual production, 43 % was retained while 57 % was released as litter including root. C stock, C sequestration rate, accumulation ratio （1.4-18.1）, root：shoot C ratio （0.61--0.13） and production efficiency （0.01-0.18） were comparable to some previous reports for other species and forests. These data could be useful in deciding the harvesting age for young teak with respect to C storage and sequestrationrate. Four allometric models using linear regression equations were developed between biomass （twice the C stock） and diameter, girth, and height of the tree at different ages. The diameter model was found more suitable for C stock predic- tion in similar areas.

关键词： Age series Biomass Carbon budget dbh Productivity Production ratios Regression equations -Tectona grandis

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Stem CO_(2) efflux of Abies fabri in subalpine forests in the Gongga Mountains,Eastern Tibetan Plateau

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Journal of Plant Ecology 2017年第6期10卷 1001-1011页

作者： Guang Zhao Gangcai Liu Wanze Zhu Jixia Zhao Xuemei Wang Yaoyao Wang Min Jia Institute of Mountain Hazards and Environment Chinese Academy of Sciences and Ministry of Water Resources#.9Block 4Renminnanlu RoadChengdu 610041China University of Chinese Academy of Sciences 19A YuquanluBeijing 100039China

Aims Despite the importance of stem cO_(2)efflux(Es)in ecosystem carbon cycling and energy balance,little is known about temporal variation in the temperature coefficient(Q10)and sapwood nitrogen concen-trations([N])and their intrinsic links with Es.The objectives of this study were:(i)to examine the response of Es to temperature in a subalpine region and(ii)to explore the influence of stem diameter and[N]on Es.Also,we will test the hypothesis that(i)Es in trees has thermal acclimation and(ii)Es will be well correlated with diameter at breast height(dbh)and[N].Methods Here,a horizontally oriented soil chamber technique was applied to measure Es of Abies fabri in two subalpine forest stands in Southwestern china from May to December 2014.We also exam-ined the variability in Es,Q10 and[N]in trees and monitored the relationship between temperature,[N],dbh and Es.Important Findings During the measurement period,Es showed an apparent seasonal trend,following the change in air temperature,increasing from May and peaking in July,then continuously decreasing until December.The mean Es for the growing and dormant seasons were 1.45 and 0.25μmol·m^(−2)·s^(−1),respectively,and Es in the mature forest was sig-nificantly higher than in the immature forest.The area-based Es was positively correlated with dbh and sapwood width(SW),while volume-based Es showed negative relationship with dbh and SW.Across the five diameter classes,69.8-89.0%of the variation in Es could be explained by air temperature.The temperature sensitiv-ity(Q10)of Es ranged from 2.98 to 5.61 during the measurement period,with a higher Q10 appearing in the growing season than in the dormant season.There was a significant linear relationship(P<0.01)between[N]and Es(expressed based on two different units).Additionally,exponential models of Es against[N]and air temperature were applied to estimate Es.

关键词： stem cO_(2)efflux Q10 dbh sapwood nitrogen contents subalpine forests

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Age structure in neutral theory resolves inconsistencies related to reproductive-size threshold

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Journal of Plant Ecology 2012年第1期5卷 64-71页

作者： James Rosindell Patrick A.Jansen Rampal S.Etienne Institute of Integrative and Comparative Biology Faculty of Biological SciencesUniversity of LeedsLeeds LS29JTWest YorkshireUK Institute of Bioinformatics and Evolutionary Studies University of IdahoMoscowID 83844USA Center for Tropical Forest Science Smithsonian Tropical Research InstitutePO Box 0843-03092BalboaAnconRepublic of Panama Centre of Ecosystem Studies Wageningen UniversityPO Box 476700 AA Wageningenthe Netherlands Community and Conservation Ecology Centre for Ecological and Evolutionary StudiesUniversity of GroningenPO Box 111039700 CC Groningenthe Netherlands

Aims Neutral theory consists of a suite of models that assume ecological equivalence among individual organisms.They have been most commonly applied to tropical forest tree communities either as null models or as approximations.Neutral models typically only include reproductive adults;therefore,fitting to empirical tree community data requires defining a reproductive-size threshold,which for trees is usually set arbitrarily to a diameter at breast height(dbh)of 100 mm.The inevitable exclusion of some reproductive adults and inclusion of some saplings cause a non-random sampling bias in neutral model fits.Here,we investigate this problem and resolve it by introducing simple age structure into a neutral model.Methods We compared the performance and sensitivity of dbh threshold of three variants of a spatially explicit neutral model:the traditional model,a model incorporating random sampling and a model with two distinct age classes—reproductive adults and saplings.In the age-structured model,saplings are offspring from adults that disperse according to a Gaussian dispersal kernel around the adults.The only extra parameter is the ratio of adults to saplings,which is not a free parameter but directly measurable.We used species–area relationships(SARs)to explore the predicted effect of saplings on the species richness at different scales in our model.We then evaluated the three model variations to find the parameters required to maintain the observed level of species richness in the 50-ha plot on Barro Colorado Island(BCI).We repeated our analysis filtering the data at different minimum tree-size thresholds in order to find the effect this threshold has on our results.Lastly,we used empirical species–individual relationships(SIRs)to test the pre-existing hypothesis that environmental filtering is the primary cause of differences between the assemblage of saplings and that of adults on BCI.Important Findings Our age-structured neutral model was characterized by SARs that were insensitive to the presence of saplings at

关键词： neutral theory age structure sampling dbh

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High frequency loss of heterozygosity in the region of the dbh locus in bladder cancer

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Chinese Medical Journal 2000年第2期113卷 21-23页

作者：杨晓峰申鹏飞姚开泰米振国刘尚莹张泓王东文刘春刘红耀 China 030001 China 410078 China 410078

Objective To determine the location of a putative tumor suppressor gene (TSG), and evaluate the frequency loss of heterozygosity (LOH) of the long arm of chromosome 9 (9q) in bladder cancer Methods We analyzed 25 patients with bladder cancer for LOH of 9q using 25 high density microsatellite markers Results Twenty three samples (92%) showed LOH at least at one locus on 9q We identified that the commonly deleted region were at 9q12 q21, 9q22, and 9q34 The rate of LOH was 44 0%, 22 7%, 22 7%, 16 0%, 12 0% on dbh, D9S15, D9S1815, D9S1831, D9S176 locus, respectively, and was not significantly related with grades and stages of tumor Conclusion These data suggest that alteration of a TSG at dbh of 9q may play an important role in the development of bladder cancer

关键词： bladder cancer loss of heterozygosity dbh

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Gene Regulation of Catecholamine Biosynthetic Enzymes by Nitric Oxide in PC12 Cells

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Open Journal of Endocrine and Metabolic Diseases 2014年第4期4卷 77-84页

作者： Dominique Ansell Julie Grandbois T. C. Tai Medical Sciences Division Northern Ontario School of Medicine Sudbury Canada

Nitric oxide (NO) regulates a wide range of physiological processes. Recent studies show that NO can regulate the release of catecholamines (CA) from the adrenal medulla. In the current study, the PC12 cell line was used to examine the effect of NO on the regulation of the CA biosynthetic enzymes: tyrosine hydroxylase (TH), dopamine-β-hydroxylase (dbh) and phenylethanolamine Nmethyltransferase (PNMT). Treatment of PC12 cells with the NO donor, sodium nitroprusside (SNP) for 6 hours significantly increased TH, dbh and PNMT mRNA levels. In addition, NO potentiates the regulation of gene expression of all three CA biosynthetic enzymes by glucocorticoids and cholinergic agonists. The signaling pathways involved in NO regulation of CA biosynthetic enzymes were investigated with the use of specific kinase activators and inhibitors, with results supporting a contributing role of PKA, PKC and PKG in SNP-mediated induction for all three CA genes (p < 0.01). In addition, inhibitors of transcription and translation inhibited SNP-mediated induction of all three genes (p < 0.001) suggesting that both transcriptional and translational mechanisms may be involved in CA gene regulation by NO. Results from this study show that in addition to regulating CA biosynthetic enzymes, NO can also potentiate cholinergic and glucocorticoid activation of CA genes.

关键词： NO PC12 Cells TH dbh PNMT Catecholamines

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多巴胺β－羟化酶缺乏症

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临床心血管病杂志 1994年第6期10卷 372-374页

作者：李莉张永珍闫西艴河南医科大学第一附属医院内科

多巴胺β－羟化酶缺乏症李莉，张永珍，闫西艴多巴胺β－羟化酶（ＤＢＨ）缺乏症是一种先天性疾病。１９８６年首次被认识［１］，此后陆续有报道［２～６］。多数患者成年才被发现，对婴幼儿患者由于缺乏认识。往往造成死亡［６］，应... 详细信息

多巴胺β－羟化酶缺乏症李莉，张永珍，闫西艴多巴胺β－羟化酶（ＤＢＨ）缺乏症是一种先天性疾病。１９８６年首次被认识［１］，此后陆续有报道［２～６］。多数患者成年才被发现，对婴幼儿患者由于缺乏认识。往往造成死亡［６］，应引起高度重视。本文对近年来ＤＢＨ缺...

关键词：多巴胺 β-羧化酶缺乏 dbh

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电针颧髎穴和尾部电流致痛后c—fos在大鼠中枢脑桥延髓内dbh阳性神经元中的表达

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中国组织化学与细胞化学杂志 1993年第2期2卷 114-118,180页

作者：周重人周敬修上海医科大学神经生物学教研室上海200032

本研究在大鼠上分别用电针大鼠面部颧髎穴和尾部电流刺激致痛后,报道dbh阳性神经元与c—fos蛋白在中枢神经系统中的共存。实验在雄性SD大鼠上进行。刺激后2小时,经心脏用4％多聚甲醛磷酸缓冲液灌注固定,脑组织作冰冻冠状切片。在同一切... 详细信息

本研究在大鼠上分别用电针大鼠面部颧髎穴和尾部电流刺激致痛后,报道dbh阳性神经元与c—fos蛋白在中枢神经系统中的共存。实验在雄性SD大鼠上进行。刺激后2小时,经心脏用4％多聚甲醛磷酸缓冲液灌注固定,脑组织作冰冻冠状切片。在同一切片上顺序进行Fos抗体—ABC—DABni和dbh抗体—PAP—DAB双免疫细胞化学方法染色,并以不刺激动物作对照,结果表明:针组和痛组动物均可在脑干若干核团内观察到Fos样免疫阳性(FLI)显示神经元在细胞核上,星紫黑色。光镜下在A_1、A_2、A_3蓝斑与蓝斑下核处有dbh样免疫阳性(DLI)在细胞体、突起和终末上,呈棕黄色,但胞核不染。光镜下出现三种形式神经元:1.仅有FLI胞核染色。2.仅有DLI胞质、突起和终末染色。3.FLI胞核存在DLI胞体中(即共存)。统计分析表明。在脑干部位,FLI在网状外侧核(RL)、孤束核(nts)、延髓头端腹侧区(RVM)和导水管周围灰质的腹侧、腹外侧和外侧部位(PAG)针组显著多于痛组。共存神经元仅在A_1部位针组显著地多于痛组,A_2、A_5及蓝斑部位。针组与痛组的共存数差异不显著。

关键词： c—fos 电针髎颧穴 dbh 免疫细胞化学双重标记鼠尾电流致痛刺激

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阳离子表面活性剂应用于防老剂dbh的相转移催化反应的研究

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精细化工 1990年第4期7卷 68-71页

作者：王金娣祁国珍华东化工学院专用化学品研究所上海zip200237

对苯二酚二苄醚又叫防老剂dbh,是中等程度的防老剂,不污染、不变色。适用于乳胶,海绵制品及浅色橡胶中。作者选择了阳离子表面活性剂通过相转移催化反应新工艺,合成了上述产品。革除了反应溶剂,缩短了反应时间,简化了工艺。讨论了不同... 详细信息

对苯二酚二苄醚又叫防老剂dbh,是中等程度的防老剂,不污染、不变色。适用于乳胶,海绵制品及浅色橡胶中。作者选择了阳离子表面活性剂通过相转移催化反应新工艺,合成了上述产品。革除了反应溶剂,缩短了反应时间,简化了工艺。讨论了不同的阳离子表面活性剂对反应的影响。

关键词：橡胶防老剂 dbh 表面活性剂催化

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