基于优化矩不变特征的鲜切菜在线分级技术

由于矩不变特征具有平移、旋转和缩放不变性,在物体形状识别领域得到了广泛的应用。在鲜切菜分级领域,鲜切菜的尺度是分级的重要指标之一,但是矩不变特征具有尺度不变性,不能区分不同尺度的鲜切菜。几何特征可以很好的描述物体的尺度,但是不具备旋转不变性。因此,本文将矩不变特征的平移、旋转不变性与几何特征优秀的尺度表达能力融合,提出了一种基于优化矩不变特征模型的鲜切菜在线分级方法。首先提取标准鲜切菜的几何特征和矩不变特征,并利用其统计信息建立数学模型,然后提取待分级的鲜切菜的几何特征和矩不变特征,最后计算待分级的鲜切菜特征与标准鲜切菜特征模型的相似度,完成鲜切菜的在线分级。本文以鲜切土豆丁为例,试验结果表明,本文方法能准确地将鲜切菜分级,实时性和鲁棒性高,具有很好的工程应用前景。     

求具有公共对称轴线的二圆锥曲线的公切线

本文论述了用尺规作图规则［１］求具有公共对称轴线的两条圆锥曲线公切线的几何作图问题。     

Electroencephalography findings in healthy and Finnish Spitz dogs with epilepsy: visual and background quantitative analysis

BACKGROUND: Qualitative and quantitative electroencephalography (EEG) parameters of healthy and Finnish Spitz dogs with epilepsy have not been determined. OBJECTIVE: To determine if EEG can provide specific characteristics to distinguish between healthy dogs and dogs with epilepsy. ANIMALS: Sixteen healthy and 15 Finnish Spitz dogs with epilepsy. METHODS: A prospective clinical EEG study performed under medetomidine sedation. Blinded visual and quantitative EEG analyses were performed and results were compared between study groups. RESULTS: Benign epileptiform transients of sleep and sleep spindles were a frequent finding in a majority of animals from both groups. The EEG analysis detected epileptiform activity in 3 Finnish Spitz dogs with epilepsy and in 1 healthy Finnish Spitz dog. Epileptiform activity was characterized by spikes, polyspikes, and spike slow wave complexes in posterior-occipital derivation in dogs with epilepsy and with midline spikes in control dog. The healthy dogs showed significantly less theta and beta activity than did the dogs with epilepsy (P < .01), but the only significant difference between healthy dogs and dogs with untreated epilepsy was in the alpha band (P < .001). Phenobarbital treatment increased alpha, beta (P < .001), and theta (P < .01), and decreased delta (P < .001) frequency bands compared with dogs with untreated epilepsy. CONCLUSIONS AND CLINICAL IMPORTANCE: Benign epileptiform transients of sleep could be easily misinterpreted as epileptiform activity. Epileptiform activity in Finnish Spitz dogs with epilepsy seems to originate from a posterior-occipital location. The EEG of dogs with epilepsy exhibited a significant difference in background frequency bands compared with the control dogs. Phenobarbital treatment markedly influenced all background activity bands. Quantitative EEG analysis, in addition to visual analysis, seems to be a useful tool in the examination of patients with epilepsy.     

基于纹理特征和支持向量机的玉米病害的识别

针对玉米病害叶片彩色纹理图像的特点，提出一种将支持向量机和色度矩分析应用于玉米病害识别的方法。首先利用色度矩提取玉米病害叶片纹理图像的特征向量，然后将支持向量机分类方法应用于病害的识别。玉米病害纹理图像识别实验结果表明：支持向量机分类方法对于病害分类训练样本较少时，具有良好的分类能力和泛化能力，适合于玉米病害的分类。不同分类核函数的相互比较分析表明，径向基核函数最适合于玉米病害的分类识别。     

Roost availability may constrain shorebird distribution: Exploring the energetic costs of roosting and disturbance around a tropical bay

High tides force shorebirds from their intertidal feeding areas to refuges known as roosts. This paper explores the energetic costs of roost disturbance of great knot (Calidris tenuirostris) and red knot (C. canutus) at Roebuck Bay, North-western Australia, assessing disturbance levels at different roost sites through direct observation and automatic radio-telemetry, and applying physiological equations and predictive roost choice models to estimate energetic costs of disturbance through a complete tidal cycle. The study area had a variety of roosts, but use of each was constrained by conditions of tide and time. The roost most suitable for shorebirds on daytime high tides of intermediate height experienced high levels of disturbance from both natural sources (birds of prey) and humans. Flight costs caused by disturbance at this site exceeded the costs of flying to and roosting at the nearest alternative roost, 25 km away. However, shorebirds did not roost at the alternate site, possibly because of the risk of heat stress in a prolonged flight in tropical conditions. Increases in disturbance levels at just one of the roost sites of Roebuck Bay would increase energetic costs substantially, and could easily reach the point at which feeding areas accessed from this roost cannot be used without incurring a net energy deficit. Roost availability can therefore limit access to feeding areas and hence limit population size. Adequate provision and management of roost sites is accordingly an important consideration in conservation of sites used by coastal shorebirds.     

不同样本数量下土壤属性空间预测比较

【目的】通过不同样本数量情形下土壤属性空间预测精度的对比,探讨样本数对预测精度的影响。【方法】以土壤有机质、土壤质量含水量、土壤速效钾和土壤有效锰4个土壤属性作为研究对象,采用矩量法（MoM）和有限最大似然法（REML）两种变异函数计算方法,对比分析在不同样本数情形下各土壤属性空间预测精度。【结果】（1）不论是利用MoM法还是REML法计算变异函数,样本点数从50增加到70,各土壤变量预测精度都有了明显提高;样本数从70逐步增加到150过程中,预测精度没有明显提高;（2）在不同样本数情形下,REML法相对于MoM法的预测精度的提高率具有明显的变化,而且在有些情况下,REML法的预测精度比MoM低,而且对于不同土壤变量,表现结果也不相同。【结论】样本数对土壤空间预测准确性具有显著影响,在本研究区域尺度下,当样本数小于70个时,无论用哪种变异函数计算方法进行预测,预测结果的可信度都比较低。     

Curcumin promotes proliferation and migration of neural stem cells in cerebral ischemic rats by regulating Notch signaling

AIM: To investigate the proliferation and migration of neural stem cells (NSCs) in the subventricular zone (SVZ) on focal cerebral ischemia with curcumin treatment, and to explore the relationship between these effects and Notch signaling. METHODS: The animal model was established by an intraluminal suture method to induce middle cerebral artery occlusion in rats. The rats were randomly divided into sham group, cerebral ischemia/reperfusion (I/R) group, and I/R+curcumin group. The animals were given curcumin for 7 d intraperitoneally. One hour after the model was successfully established, the rats were sacrificed. Immunofluorescence was used to label the NSCs by BrdU and BrdU/DCX, and the migration tendency was observed. The expression of Notch intracellular domain (NICD, the Notch signaling pathway intermediate product) was detected by Western blotting. RESULTS: Compared with I/R group, BrdU-positive and BrdU/DCX double positive cells in I/R+curcumin group were significantly higher than those in I/R group (P<0.05), and more positive cells were on the way of migration to the ischemic lesion zone. The expression level of NICD in I/R+curcumin group was significantly higher than that in I/R group (P<0.05). CONCLUSION: Curcumin promotes NSC proliferation and migration in SVZ after focal cerebral ischemia. The possible mechanism may be that curcumin activates Notch signaling.     

Role of focal adhesion kinase expression in renal tissues of type 2 diabetic rats

AIM：To explore the dynamic change of focal adhesion kinase (FAK) in renal tissues of rats with type 2 diabetes mellitus (T2DM), and to investigate its role in the pathogenesis of diabetic nephropathy (DN). METHODS：The rat model of T2DM was established and the diabetic rats were randomly divided into 8-week DM (DM8), 12-week DM (DM12) and 16-week DM (DM16) groups. Meanwhile, normal control (NC) and high-fat high-sucrose control (HC) groups were also established. The protein expression of FAK, transforming growth factor β1 (TGF-β1), extracellular signal-regulated kinase 1/2 (ERK1/2), p-ERK1/2 and fibronectin (FN) was detected by immunohistochemical staining. The protein levels of FAK and p-FAK (Tyr397) were detected by Western blotting. The mRNA level of FAK in the renal cortex was examined by RT-PCR. RESULTS：The expression of FAK protein in renal tubular epithelial cells in DM12 and DM16 groups was significantly higher than that in NC, HC and DM8 groups (P<0.05). Moreover, TGF-β1, p-ERK1/2 and FN protein expression in DM groups was significantly increased compared with NC and HC groups (P<0.05). The levels of FAK and p-FAK (Tyr397) in the renal cortex in DM12 and DM16 groups were significantly up-regulated compared with NC, HC and DM8 groups (P<0.05), and the expression trend of p-FAK in different groups was in accordance with that of total FAK. The FAK protein expression was positively correlated with the expression of TGF-β1, p-ERK1/2 and FN proteins (P<0.01). Compared with NC, HC and DM8 groups, the expression of FAK mRNA increased remarkably in DM12 and DM16 groups (P<0.05). CONCLUSION: There is a possibility that FAK is activated as a downstream effector of TGF-β1 in T2DM, which enhances the expression of FN protein through activating ERK1/2, and therefore plays an important role in the pathogenesis of type 2 diabetic nephropathy.     

一种最小化边界圆周补偿机制的形状图像检索算法

基于最小化边界圆周补偿机制的形状图像检索方法,提取了目标区域的特征,补偿了目标最小化边界圆周下的背景区域特征,较仅基于目标区域的检索算法取得了更好的查准率和查全率。     

莲心碱对大鼠脑缺血再灌注损伤血清中IL-1、TNFa的影响

目的:观察莲心碱对大鼠局灶性脑缺血/再灌注损伤血清中白介素-1(IL-1)和肿瘤坏死因子a(TNFa)活性的影响,探讨其对大鼠脑缺血再灌注损伤保护作用的机制。方法:线栓法阻塞大鼠大脑中动脉2h/再灌注24h制备大鼠脑缺血再灌注损伤动物模型。将24只SD雄性大鼠,随机分为3组:假手术组、缺血再灌注组和莲心碱3mg·kg-1组,分别于术前30min、再灌注后、再灌注12h舌静脉注射莲心碱3mg·kg-1;再灌注24h后大鼠断头取血,分离血清,采用双抗体夹心ELISA法测定血清IL-1和TNFa的吸光度。结果:大鼠脑缺血2h,再灌注24h后,血清中IL-1和TNFa活性显著增加,莲心碱可显著降低缺血再灌注损伤大鼠血清IL-1和TNFa活性。结论:莲心碱可能通过降低IL-1和TNFa活性而发挥脑缺血的保护作用。