氟苯尼考在三疣梭子蟹(Portunus trituberculatus)疾病模型内的代谢动力学

为了解健康和疾病条件下药物在三疣梭子蟹(Portunus trituberculatus)体内的代谢差异,在构建三疣梭子蟹溶藻弧菌疾病模型的基础上,按25mg/kg剂量分别给健康和患病三疣梭子蟹单次口灌氟苯尼考后,采用高效液相色谱法测定了其肝胰腺、肌肉和血浆中的药物浓度,药时数据应用3P97药代动力学软件拟合。结果显示:氟苯尼考在健康和患病条件下三疣梭子蟹相同组织中的药时曲线形态相似,三种组织的药时数据均符合带时滞的一级吸收二室开放模型;肝胰腺吸收药物最快,肌肉次之,血浆最慢;与健康组相比,患病蟹肝胰腺、肌肉、血浆三种组织对氟苯尼考的吸收和消除速度明显减慢,达峰时间推迟,半衰期延长,清除率减低,最高药物浓度下降,表观分布容积和药时曲线下总面积变大。说明疾病使氟苯尼考在三疣梭子蟹体内的吸收、分布、代谢和消除均发生了显著变化,建议患病三疣梭子蟹口服氟苯尼考的休药期至少10d。     

社交网络不良信息传播模型研究

当前社交网络的信息传播模型主要是对病毒SIR模型的改进而形成的,因其主体不同而具有不完善性,为更好地揭示不良信息在社交网络中的传播规律,从而寻找预防和控制不良信息传播的最优方法。根据社交网络中信息传播的方式和特点,与传染病动力学理论结合构建出SEIR模型来研究不良信息在社交网络中的传播。模型定义了4种传播规则,分析不良信息在不同状态用户之间的传播过程,并且应用扩散核函数和空间协方差方程对相关参数进行了分析。最后通过对比实验说明调节控制率γ的大小对虚假信息在网络中的传播有一定的控制作用。     

Mapping the distribution of the main host for plague in a complex landscape in Kazakhstan: An object-based approach using SPOT-5 XS,Landsat 7 ETM+, SRTM and multiple Random Forests

Plague is a zoonotic infectious disease present in great gerbil populations in Kazakhstan. Infectious disease dynamics are influenced by the spatial distribution of the carriers (hosts) of the disease. The great gerbil, the main host in our study area, lives in burrows, which can be recognized on high resolution satellite imagery. In this study, using earth observation data at various spatial scales, we map the spatial distribution of burrows in a semi-desert landscape.The study area consists of various landscape types. To evaluate whether identification of burrows by classification is possible in these landscape types, the study area was subdivided into eight landscape units, on the basis of Landsat 7 ETM+ derived Tasselled Cap Greenness and Brightness, and SRTM derived standard deviation in elevation.In the field, 904 burrows were mapped. Using two segmented 2.5 m resolution SPOT-5 XS satellite scenes, reference object sets were created. Random Forests were built for both SPOT scenes and used to classify the images. Additionally, a stratified classification was carried out, by building separate Random Forests per landscape unit.Burrows were successfully classified in all landscape units. In the ‘steppe on floodplain’ areas, classification worked best: producer's and user's accuracy in those areas reached 88% and 100%, respectively. In the ‘floodplain’ areas with a more heterogeneous vegetation cover, classification worked least well; there, accuracies were 86 and 58% respectively. Stratified classification improved the results in all landscape units where comparison was possible (four), increasing kappa coefficients by 13, 10, 9 and 1%, respectively.In this study, an innovative stratification method using high- and medium resolution imagery was applied in order to map host distribution on a large spatial scale. The burrow maps we developed will help to detect changes in the distribution of great gerbil populations and, moreover, serve as a unique empirical data set which can be used as input for epidemiological plague models. This is an important step in understanding the dynamics of plague.     

Choosing Geographic Units for Choropleth Rate Maps,with an Emphasis on Public Health Applications

Choropleth maps are the most widely used map type for mapping rates, such as those involving disease, crime, and socioeconomic indicators. The essential step of choosing a geographic unit to map is often made in an ad hoc manner. Among the desirable characteristics of choropleth mapping units are high degree of resolution, homogeneity of population size, homogeneity of land area, observation of minimum population thresholds and land area thresholds, temporal stability and currency, compactness of shape, audience familiarity, data availability, and the functional relevance of the unit to the phenomena mapped. Because of the uneven distribution of human populations, no single geographic unit can meet all of these characteristics in practice, and a well designed choropleth map necessarily involves some compromise. We present guidelines for choosing geographic units that take into account the above criteria, considering 12 geographic units ranging from census blocks to states. Even allowing for differences in scale and purpose, some units confer clear advantages over others.     

A spatial data model design for feature-based geographical information systems

Abstract

In state-of-the-art GIS, geographical features are represented as geometric objects with associated topological relations and classification attributes. Semantic relations and intrinsic interrelations of the features themselves are generally neglected. In this paper, a feature-based model that enhances the representation of geographical features is described. Features, as the fundamental depiction of geographical phenomena, encompass both real world entities and digital representation. A feature-based object incorporates both topological relations among geometric elements and non-topological (semantic) relations among features. The development of an object-oriented prototype feature-based GIS that supports relations between feature attributes and feature classes is described. Object-oriented concepts such as class inheritance and polymorphism facilitate the development of feature-based GTS.     

山东黄河冲积平原区地氟病与地球化学环境相关性研究

山东黄河冲积平原区是山东省地氟病的重病区,危害严重。选择其中的郓城、嘉祥、博兴3县进行土壤氟含量、饮水氟含量、儿童尿氟、儿童氟斑牙检出率、氟斑牙指数、成人尿氟、成人氟骨症检出率等指标进行调查,结果表明区内土壤、饮水氟含量和群体的尿氟含量普遍较高,高氟的危害和地方性氟中毒病情十分严重。在分析氟元素在土壤、饮水中的分布及变化规律的基础上,开展地方性氟中毒病与生态地球化学环境相关性研究,认为地方性氟中毒病与土壤中氟含量、饮水氟含量呈正相关关系。     

西沙群岛造礁石珊瑚主要疾病调查与初步研究

记录了2010年5-10月及2011年4-8月在西沙群岛海域开展珊瑚疾病调查的结果,发现普哥滨珊瑚(Porites pukoensis)、扁枝滨珊瑚(Porites andrewsi)、蔷薇珊瑚(Montipora spp.)、杯形珊瑚(Pocillopora spp.)、鹿角珊瑚(Acropora spp.) 、菊花珊瑚(Goniastrea spp.)、澄黄滨珊瑚(Porites lutea)和滨珊瑚(Porites spp.)等共14种珊瑚主要出现了白化、白斑病、黑化、黄色炎症样病症、粉红颗粒状综合症等9种不同症状的疾病,目前该海域为珊瑚疾病的频发区。其中,普哥滨珊瑚的黄色炎症样病症和扁枝滨珊瑚的白化最为常见。普哥滨珊瑚黄色炎症样病症主要出现在永兴岛附近海区,患病部位存在大量黄色脓样分泌物,患病部位水螅体生长正常、萎缩或缺失,有时骨骼部分缺失,患病部位面积一般为0.02~12.00 cm2;该疾病由机械损伤或其他原因引起,因机械损伤引起的伤口一般在2~3个月可以恢复,其中小面积伤口的黄色物质可在10~20d内消失、伤口基本恢复正常,而其他原因产生的黄色物质需1~3个月才能消失,有的甚至在观察期内无明显变化。扁枝滨珊瑚的白化出现在七连屿一带的扁枝滨珊瑚分布区,该病存在整枝完全白化、局部大面积白化、散布白色斑点3种情况,白化部位水螅体缺失。本文为我国西沙海域珊瑚疾病的首次报道,可为今后开展西沙珊瑚疾病研究提供参考。     

多层螺旋CT在烟雾病诊断中的应用

目的探讨16排螺旋CT血管造影(MSCTA)及其重建在烟雾病诊断与治疗中的应用价值.材料与方法分析15例烟雾病病例.受检者均行颅脑CT平扫和MSCTA检查.在ADW4.2工作站上作容积再现(VR)、最大密度投影(MIP)和多平面重建(MPR).结果多层螺旋CT血管造影均清晰显示发生狭窄、闭塞的颈内动脉、Wills环血管近侧端以及明显增多、扩张的脑底部侧支血管影,其中双侧颈内动脉闭塞6例,单侧颈内动脉伴同侧大脑后动脉狭窄1例,单侧大脑中动脉8例,其中1例同时动脉瘤.所有CTA图像均可评价侧支血管情况,表现为相应血管及其分支的粗大、增多、迂曲延长.VR重建图像有利于显示狭窄段与周围骨性结构空间关系,但在显示、评价脑底增生小血管和侧支血管方面不及MIP和MPR重建.结论综合运用多种重建技术,多层螺旋CT血管造影不仅可以清晰显示狭窄血管,还可以评价狭窄远端血管和侧支血管等情况,直观显示病变周围空间结构关系,从而为治疗提供重要的参考依据.     

胸部CT对COPD合并肺动脉高压分级诊断价值

目的:结合多普勒超声心动图对比分析胸部CT平扫在慢性阻塞性肺病(COPD)合并肺动脉高压(PAH)分级上的诊断价值。方法:回顾性分析100例经多普勒超声心动图检查确诊、分级的COPD合并PAH患者的胸部CT平扫资料,测量CT所示的主肺动脉直径、右肺动脉直径及左肺动脉直径,并与30例未发生PAH的COPD患者的上述胸部CT平扫资料对比,分析它们与PAH分级的关系,并进行统计学分析。结果:100例COPD并PAH患者中,经超声心动图确诊为轻度PAH57人,中度PAH27例,重度PAH16例。上述三组PAH患者CT上所测量的主肺动脉直径,方差分析得出三者间的差别有统计学意义,两两比较发现:轻度组PAH的主肺动脉直径与中度组PAH的主肺动脉直径有统计学差异(P=0.017);轻度组PAH的主肺动脉直径与重度组PAH的主肺动脉直径有统计学差异(P=0.000);中度组PAH的主肺动脉直径与重度组PAH的主肺动脉直径有统计学差异(P=0.031);轻度组PAH的主肺动脉直径<中度组PAH的主肺动脉直径<重度组PAH的主肺动脉直径。轻度PAH的主肺动脉直径约为29.71mm±3.57mm,最佳诊断阈值是29.11mm;中度PAH的主肺动脉直径约为31.77mm±3.44mm,最佳诊断阈值是30.53mm;重度PAH的主肺动脉直径约为34.28mm±4.14mm,最佳诊断阈值是32.00mm。结论:胸部CT平扫通过测量主肺动脉直径对COPD并PAH的分级具有一定的诊断价值。