基于QUEST决策树兼容多源数据的淡水沼泽湿地信息提取

以三江平原东北部为例,探讨了中国典型淡水沼泽湿地信息的提取方法.利用TM卫星影像数据,基于半方差分析和z检验方法对比研究区典型地物不同尺度的各种纹理特征,从而遴选最优的窗口大小、纹理特征及其派生波段以提高地物之间的可分性.采用快速、无偏、高效统计树(quick,unbiased,and efficient statistical tree,QUEST)算法集成遥感影像的光谱特征、多尺度纹理特征和地学辅助数据建立研究区湿地信息提取的决策树模型.基于实测的GPS样本点采用混淆矩阵的方法对分类结果进行精度验证,并与传统的最大似然监督分类方法(maximum likelihood classification,MLC)进行对比.结果表明,基于QUEST的决策树分类结果的总精度和Kappa系数分别为84.58%和0.816,分类精度较MLC监督分类方法有明显提高,是内陆淡水沼泽湿地信息提取的有效手段.     

西安市典型区域城市生态单元空间格局研究

综合利用遥感(RS)与地理信息系统(GIS)技术手段,选取西安市南郊城乡结合部为研究区,采用室内遥感影像判读、野外考察验证与室内机助制图相结合的方式,根据城市生态单元分类体系,在GIS的支持下建立了研究区城市生态单元数据库,并在此基础上,通过计算研究区城市生态单元的平均面积、形状指数、分形分维数、稳定性指数、MoranI指数这五项指数,对城市生态单元空间格局进行定量化研究.结果表明,城市生态单元主类斑块数量和斑块总面积基本保持正比例关系,形状指数和分形分维数之间、稳定性指数和MoranI指数之间均存在着正相关关系.     

沙质荒漠化土地景观分类与制图—以毛乌素沙地为例

对景观分类理论和方法进行了探索,并以毛乌素沙地为研究对象,提出了一套适用于农牧交错区沙质荒漠化土地景观分类与制图的方法。由于沙丘分布广泛,与地带性植被和土壤的分布相迭加,增加了地表景观的破碎程度,使农牧交错区沙地的主要景观要素类型在结构上具有复合性。为了更好地描述沙地景观的复合性特征,作者提出景观基本结构组分的概念。首先确定景观基本结构组分,根据景观基本结构组分的不同组合确定景观要素类型;然后在野外调查的基础上,通过对遥感数据的解译和判读进行景观要素类型的划分;最后在GIS支持下成图。该方法对我国北方农牧交错区沙质荒漠化土地具有普遍意义。     

基于多时相无人机遥感影像优化河口湿地景观分类

河口湿地具有丰富的生物多样性和高度异质化的景观格局。针对河口湿地景观的复杂性,采用传统的基于单幅遥感影像的分类方法并不能得到较好的分类结果。本研究采用多时相无人机遥感影像参与分类,以优化河口湿地景观自动分类结果。选择天目湖上游平桥河河口湿地为研究区,选取4个季节的无人机影像为基础数据源,采用面向对象与决策树相结合的分类方法,针对不同季节组合的影像进行分类。结果表明:采用多时相无人机影像能显著提升分类效果,且参与分类的时相越多,效果越好;单季影像中,春季是最适合进行景观分类的季节,分类总体精度为62.7%,Kappa系数为0.59;当4个季节获取的影像同时参与分类时,分类总体精度为91.7%,Kappa系数为0.90;参与分类的时相光谱特征差异越大,分类效果提升越明显。本研究可为河口湿地景观分类提供技术支持,并提出了一种利用可见光无人机遥感影像进行湿地景观分类的新思路。     

纵向岭谷区不同景观类型的服务价值

基于2001年纵向岭谷区的遥感影像,将研究区划分为森林、草地、农田、湿地、水体、城镇、冰川7个一级景观类型,根据气候带、植被及地貌划分了26个二级景观类型,并利用中国陆地生态系统服务价值的研究成果,在GIS技术的支持下,对纵向岭谷区各景观类型的服务价值进行了研究.结果表明：纵向岭谷区总服务价值为5 302.35×10⁸ yuan·a^-1,占中国总服务价值的9.47%;在研究区提供的年服务价值中,土壤形成与保护的服务价值所占比例最高,占18.50%,其次是气体调节和生物多样性保护的服务价值;受景观类型分布广度和单位面积服务强度的综合影响,占研究区总面积66.11%的森林景观对区域总服务价值的贡献最大,贡献率达85.34%,其次为草地和农田景观.     

三江平原桦南县景观格局时序变化与驱动因素研究

基于RS和GIS技术,集成地形图与遥感影像(MSS、TM)数据,对1954～2005年三江平原桦南县景观格局动态变化特征与驱动力进行分析。结果表明,过去50年间,桦南县景观格局发生了剧烈变化,耕地和林地是研究区面积最大的2种景观类型,1986年以后,耕地成为研究区面积最大的景观类型。1954～1976年期间耕地面积增加速率较大,主要是草地、湿地大面积被开垦为耕地;1976～1986年期间,有大面积湿地、林地转化为耕地;1986年以后,各景观类型面积变化趋势变缓。景观指数在过去几十年期间都发生了重大变化,农业的大规模开发与以上景观指数的变化规律存在密切关系。气候变暖和人类活动的增强共同作用于区域景观格局。     

3S技术在哈尔滨市郊景观生态规划中的应用

利用哈尔滨市遥感数据资料,在RS、GIS 和GPS技术支持下,获取哈尔滨市郊景观格局现状及哈尔滨数字高程模型(DEM).选取平均斑块面积、景观优势度、平均坡度、平均海拔和破碎度因子对其进行综合分析,并借助 DEM 模型进行景观生态规划.结果表明,3S技术为典型景观类型的确定提供了科学依据;建立了市郊景观类型数据库,并生成景观类型专题图;土地利用现状和景观空间分布以及地形地貌和土地利用类型相结合.DEM和遥感影像的叠加,从大尺度上定性刻画市郊的景观生态规划,而景观生态规划和DEM 的叠加,更加直观地反映了市郊的景观结构,为提高区域生态功能,促进城乡一体化的健康发展提供科学依据.     

基于不同决策树的面向对象林区遥感影像分类比较

面向地理对象影像分析技术(GEOBIA)是影像分辨率越来越高的背景下的产物.如何提高高分辨率影像分类精度和分类效率是影像处理的重要议题之一.本研究对QuickBird影像多尺度分割后的对象进行分类,分析了C5.0、C4.5、CART决策树算法在林区面向对象分类中的效率,并与kNN算法的分类精度进行比较.利用eCognition软件对遥感影像进行多尺度分割,分析得到最佳尺度为90和40.在90尺度下分离出植被和非植被后,在40尺度下提取不同类别植被的光谱、纹理、形状等共21个特征,并利用C5.0、C4.5、CART决策树算法分别对其进行知识挖掘,自动建立分类规则.最后利用建立的分类规则分别对植被区域进行分类,并比较分析其精度.结果表明: 基于决策树的分类精度均高于传统的kNN法.其中,C5.0方法的精度最高,其总体分类精度为90.0%,Kappa系数0.87.决策树算法能有效提高林区树种分类精度,且C5.0决策树的Boosting算法对该分类效果具有最明显的提升.     

利用GIS对吉林针阔混交林TM遥感图像分类方法的初探

为提高林区TM遥感图像自动分类识别精度,在GIS技术辅助下,以吉林省汪清林业局针阔混交林TM遥感图像为例,对研究区DEM、坡向等地理因子和土壤类型等环境因子与森林植被分布之间的内在规律进行了定量分析,并结合对遥感图像预分类的定性分析,形成分类知识库,建立了适用于针阔混交林的自动分类识别专家系统.分类试验证明,该系统能比较明显地削弱混合像元和地形阴影的影响,分类精度较无监督分类法提高了14.22%,Kappa指数为0.7556,达到区别森林类型的分类目的.将GIS数据引入专家系统,应用先验知识建立推理机制,可以解决遥感图像中云区和云阴影区由于不能接收到正确的光谱值而无法进行分类的问题.     

吉林省镇赉县近10年景观格局变化

以吉林省镇赉县2000年、2005年、2009年三期TM遥感影像为信息源,在小尺度下通过RS解译,对GIS建立的空间数据模型叠加分析和景观特征指数计算,结合自然与人文要素,具体分析镇赉县土地利用景观格局的变化情况。分析结果表明:近10a间研究区景观斑块面积和斑块的数量发生明显变化,水体景观类型斑块数量呈现大幅度增加,研究区各景观面积动态度变化显著,耕地面积大幅度增加,而草地和未利用土地面积大幅度减少。研究区景观破碎化程度较低、景观分维数较小且变化不大、景观异质性低,景观较为完整,该地区生态表现出明显的脆弱性和易恢复性。自然环境的制约、人为活动的干扰、政策的导向等因素决定和影响了该地区景观格局的变化趋势。     

Production of arsine and methylarsines in soil and in culture

Arsenate, arsenite, monomethylarsonate, and dimethylarsinate were added to different soils, and evolution of gaseous arsenical products was determined over 3 weeks. Arsine was produced in all three soils from all substrates, whereas methylarsine and dimethylarsine were produced only from methylarsonate and dimethylarsinate, respectively. At least three times more arsine than dimethylarsine was produced in soil incubated with dimethylarsinate. Resting cell suspensions of Pseudomonas and Alcaligenes produced arsine as the sole product when incubated anaerobically in the presence of arsenate or arsenite. In all instances, no trimethylarsine was observed, nor could any evidence be shown for the methylation of any arsenical substrate in soil or in culture. It was concluded that reduction to arsine, not methylation to trimethylarsine, was the primary mechanism for gaseous loss of arsenicals from soil.     

Degradation and conversion of somatostatin in normal and diabetic rats in vivo and in vitro

Plasma somatostatin-like immunoreactivity in the portal and jugular veins of streptozotocin diabetic rats was compared with that in normal control rats. In the diabetic group, somatostatin levels in the portal (p less than 0.05) and jugular (p less than 0.01) veins were both elevated compared with those in the control group. Moreover, the degree of elevation was greater in the jugular vein than in the portal vein. To further investigate the role of the liver in the clearance of somatostatin-28 in vivo, 2 micrograms of somatostatin-28 was administered as a bolus into the external jugular vein of intact and functionally hepatectomized rats. The mean half-time of somatostatin-28 was significantly longer in intact diabetic rats than in controls (p less than 0.05). The functional hepatectomy did not cause a significant difference in the half-time in diabetic rats but made it longer in control rats. These results suggest that the longer half-time of somatostatin-28 in diabetic rats in vivo is due to its slower hepatic clearance. The hepatic clearance of somatostatin-28 and somatostatin-14 was further studied in vitro using a recirculating liver perfusion method. The hepatic clearance of 1.2 nM of either somatostatin-28 or somatostatin-14 was significantly lower in diabetic rats than in controls (p less than 0.01). This indicates that elevated plasma somatostatin levels in diabetic rats are caused at least in part by decreased hepatic clearance of somatostatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Activity of native and dextran-modified hyaluronidase in in vitro and in vivo systems

Modified hyaluronidase derivatives have been obtained. Covalent coupling of the enzyme with aldehyde dextran results in 65-85% protein binding to the carrier, residual catalytic activity accounting for 90-100% of the baseline. Modified hyaluronidase is more thermostable than the native enzyme. The data on intravenous drug distribution in the mouse organs are promising and ensure effective use of modified hyaluronidase for the treatment of pulmonary diseases.     

Importance of guanine nitration and hydroxylation in DNA in vitro and in vivo

Guanine (Gua) modification by nitrating and hydroxylating systems was investigated in DNA. In isolated calf thymus DNA, 8-NO(2)-Gua and 8-oxo-Gua were dose-dependently formed with peroxynitrite, and 8-NO(2)-Gua was released in substantial amounts. Myeloperoxidase (MPO) with H(2)O(2) and NO(2)(-) reacted with calf thymus DNA to form 8-NO(2)-Gua dose dependently without release of 8-NO(2)-Gua. The frequency of strand breaks was higher than the sum of 8-NO(2)-Gua and 8-oxo-Gua, particularly in the MPO-treated DNA, indicating the importance of other types of damage. The activation of human neutrophils and lymphocytes with phorbol ester did not induce 8-NO(2)-Gua and 8-oxo-Gua in their nuclear DNA. However, 8-NO(2)-Gua was found in calf thymus DNA co-incubated with activated neutrophils in the presence of NO(2)(-). No significant formation of 8-NO(2)-Gua was found in liver DNA from mice treated with Escherichia coli lipopolysaccharide. The incubation of peroxynitrite or MPO-H(2)O(2)-NO(2)(-)-treated DNA with formamidopyrimidine glycosylase (Fpg) released 8-oxo-Gua, but not 8-NO(2)-Gua, indicating that 8-NO(2)-Gua is not a substrate for Fpg. Although 8-NO(2)-Gua was generated in isolated DNA by different nitrating systems, other types of damage were formed in abundance, and the lesion could not be found reliably in nuclear DNA, suggesting that the biological importance is limited.     

Development and comparison of in vivo and in vitro models for endometritis in cows and mares

In order to investigate pathogenic mechanisms of acute endometritis in cows and mares, we established an in vivo model in both species. Based on the results of an in vitro transmigration system, human recombinant interleukin-8 (rhIL-8; 1.25 microg per mare and 5 microg per cow in 50 ml phosphate-buffered saline) was used to attract polymorphonuclear neutrophil granulocytes (PMNs) into the uteri. Peak numbers of uterine neutrophils were attracted after 6h, in both cows and mares. On average, mares responded more sensitively than cows, with 15 times higher numbers of rhIL-8-attracted uterine neutrophils (72+/-8 x 10(7)cells). In contrast to in vitro studies, in vivo migrated neutrophils (uterine neutrophils) of both species displayed a significantly reduced MHC class I expression. Expression of the CD11a molecule was significantly enhanced on equine uterine neutrophils but downregulated on bovine cells. Compared with untreated autologous peripheral neutrophils, both uterine and in vitro migrated neutrophils showed no alteration of phagocytic capacity. The ability to generate reactive oxygen species (ROS) was significantly upregulated in bovine and equine uterine neutrophils. This was also observed after in vitro migration of equine neutrophils, whereas ROS generation by bovine neutrophils was significantly depressed. In summary, the concept of inducing endometritis directly by local application of human interleukin-8 has been reliably successful in cows and mares. The model permits the analysis of PMN migration into the uterus under defined and controlled conditions. The observed differences between cows and mares with respect to phenotypical and functional characteristics of in vivo attracted uterine cells point to species-related features of neutrophil migration. In vitro transmigrated bovine and equine cells partially differ in phenotype and function from uterine neutrophils. Therefore, the in vitro transmigration assay cannot completely represent the in vivo endometritis model described here.     

Biosynthesis of beta-glucuronides of retinol and of retinoic acid in vivo and in vitro

After the intraportal injection of retinol-6,7-(14)C to rats, the O-ether derivative of retinol, retinyl -glucosiduronate, appears in the bile. Both retinoyl -glucuronide and retinyl -glucosiduronate are also synthesized in vitro when washed rat liver microsomes are incubated with uridine diphosphoglucuronic acid (UDPGA) and either retinoic acid or retinol, respectively. The synthesis of retinoyl -glucuronide was also demonstrated in microsomes of the kidney and in particulate fractions of the intestinal mucosa. The glucuronides were characterized by their UV absorption spectra, by their quenching of UV light or fluorescence under it, by their thin-layer chromatographic behavior in two solvent systems, and by the identification of products released during their hydrolysis by -glucuronidase. With retinoic acid as the substrate, the UDP glucuronyl transferase of rat liver microsomes had a pH optimum of 7.0, a temperature optimum of 38 degrees C, and a marked dependence on the concentrations of both retinoic acid and UDPGA, but was unaffected by a number of possible inhibitors, protective agents, and competitive substrates. The conversion of retinal to retinoic acid and the synthesis of retinoyl -glucuronide from retinoic acid could not be detected in whole homogenates, cell fractions, or outer segments of the bovine retina.     

Interactions of cadmium and selenium in rat plasma in vivo and in vitro

⁷⁵Se and ¹⁰⁹Cd tracers were used to study the binding of Se and Cd to plasma proteins at various SeO₃^2? doses and times up to 24 h after the simultaneous subcutaneous administration of SeO₃^2? and CdCl₂ to adult male rats. The simultaneous injection of CdCl₂ and SeO₃^2? markedly increased both Se and Cd plasma levels over that in control animals. Gel permeation chromatography of plasma indicated that at all times up to 24 h Cd and Se were bound in an atomic ratio of approx. 1 : 1 in 330 000 and 130 000 dalton fractions. From 4 to 24 h, Cd and Se appeared in the 420 000 dalton fraction, also with an atomic ratio of approx. 1 : 1. The 330 000 dalton molecules appeared to have a maximal binding capacity for the Cd-Se complex at a concentration of approx. 30 μmol/ml of plasma, while the 130 000 and 420 000 dalton molecules show a higher binding capacity. Studies in vitro revealed that SeO₃^2? does not interact directly with Cd and plasma proteins. It is metabolized by erythrocytes to a form that interacts in an atomic ratio of 1 : 1 with Cd to form a protein-bound complex of 130 000 daltons.