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41.
With the view that visual cue could be taken as a kind of stimulus, the study of the mechanism in the visual perception process by using visual cues in their probabilistic representation eventually leads to a class of statistical Integration of multiple visual cues (IMVC) methods which have been applied widely in perceptual grouping, video analysis, and other basic problems in computer vision. In this paper, a survey on the basic ideas and recent advances of IMVC methods is presented, and much focus is on the models and algorithms of IMVC for video analysis within the framework of Bayesian estimation. Furthermore, two typical problems in video analysis, robust visual tracking and “switching problem” in muIti-targèt tracking (MTT) are taken as test beds to verify a series of Bayesian-based IMVC methods proposed by the authors. Furthermore, the relations between the statistical IMVC and the visual perception process, as well as potential future research work for IMVC, are discussed.  相似文献   
42.
为探索雌二醇(E2)对应激性胃溃疡发生的影响及机制,以电剌激束缚雄性小鼠口唇部1h诱发胃溃疡,用阿尔新兰—氯化镁洗脱法测定胃壁粘蛋白。结果表明,肌肉注射(im)E244μg·kg-1后1h电刺激束缚应激(ERS)或imE2176μg·kg-1后立即ERS可明显加剧胃溃疡,并使胃壁粘蛋白量显著减少。侧脑室注射非惊厥剂量(0.08μg/5μl/只)印防己毒素(Pic)或惊厥剂量(0.3μg/5μl/只)均可完全消除E2的加剧效应,安定、异丙肾上腺素和阿托品都不能影响E2的加剧效应。表明外源性E2进入体内后可削弱胃粘液屏障,加剧电刺激束缚应激胃溃疡,此效应可能是E2随血液循环透过血—脑屏障,通过作用脑中GABAA受体实现的  相似文献   
43.
The relationships between anxiety/stress, possible endogenous ligands for benzodiazepine receptors and the behavioral modification by drugs are discussed in this short review, including the specific characteristics of elements involved in those interactions, e.g. ones concerning the aversiveness of the stressful situation and the nature of the organism under investigation. These are important factors when considering aversive tasks, insofar as they may involve stressful conditions which differ in intensity and in the degree of control afforded the subject. These characteristics may well lead to differing functional effects on GABA-gated chloride channels or, in other words, to an incongruous balance between endogenous benzodiazepine receptor agonist and inverse agonist activity. This is not surprising, as it is well known that different forms of stressors often actually produce divergent behavioral, physiological and biochemical effects. This review also illustrates the necessity of taking into account the variable effects of stressors and/or drugs on animals differing in reactivity or emotionality, even in the case of non-selected stocks. The implication is made that, by genetic and/or environmental manipulation of the emotional state of the animals used, it will be possible to obtain more clearly definable results in neuropharmacological and psychopharmacological studies.  相似文献   
44.
将聚乙二醇(SH-PEG)修饰在单层MoS 2纳米片表面并进一步接枝聚乙烯亚胺(PEI),用以连接透明质酸(HA),从而构建一种新的HA-PEI-LA-MoS 2-SH-PEG纳米药物递送系统。用透射电镜、傅里叶变换红外光谱仪、紫外可见分光光度计、Zeta电位分析仪、动态光散射仪等仪器表征材料的形貌及理化性质。使用盐酸阿霉素(DOX)作为模型药物,研究复合物HA-PEI-LA-MoS 2-SH-PEG@DOX的体外药物释放行为。同时,在二硫化钼纳米复合物上负载一种新型的光热剂黑色素(Mel),研究其体外光热效果。结果表明:制备的纳米复合材料HA-PEI-LA-MoS 2-SH-PEG@(DOX/Mel)具有pH和近红外光(NIR)双重刺激响应药物释放的性能;黑色素的加载显著提高了MoS 2纳米复合物的光热效果,具有应用于肿瘤化学光热协同治疗的前景。  相似文献   
45.
46.
We investigated the effect of low spatial frequency (SF) filtering on neural substrates underlying global and local processing in the peripheral vision by measuring hemodynamic responses with functional magnetic resonance imaging (fMRI). Subjects identified global or local shapes of compound letters that were either broadband in spatialfrequency spectrum or contrast balanced (CB) to removed low SFs and displayed randomly in the left or right visual fields. Attention to both broadband and CB global shapes generated stronger activation over the medial occipital cortex relative to local attention. Lateralized activations in association with global processing were observed over the right temporal-parietal junction for broadband stimuli whereas over the right fusiform gyrns for CB stimuli. Attention to CB local shapes resulted in activations in the medial frontal cortex, bilateral inferior frontal and superior temporal cortices.The results were discussed in terms of the competition between global and local information in determining brain activations in association with global/local processing of compound stimuli.  相似文献   
47.
机能的改善依赖于内自身适应于训练刺激产生的生化反应,然而,循环性训练受益更大,周而复始,从产生训练刺激到体内恢复,自始至终保持犊循环间歇性去形成一个由“刺激”与“恢复”的循环结构,循环性的主要目的就是最大限度利用训练刺激和提供体内的恢复,没有这一过程就不能真正的存在训练程序,建立一套这样的结构包括明确的运动刺激和明确的恢复期使之达到最佳的训练效果,来导致机能最大比率的改善。  相似文献   
48.
Summary Subjects followed rhythmic acoustical sequences by finger-tapping. Tapping onset preceded stimulus onset by a value close to 30 ms. It is suggested that this temporal difference might correspond to one cycle of a hypothetical timing mechanism in the brain which has been observed with other experimental paradigms.This work was supported by DFG, Po 121/13.  相似文献   
49.
传统交流故障字典法通过施加不同频率的正弦激励,以获得对待测电路中频率敏感元件更高的故障覆盖率。为减少多次对待测电路施加激励的时间开销,该文提出可将多个不同频率激励进行叠加,得到非正弦的激励信号作为待测电路激励。在此背景下,讨论了产生一个非正弦激励信号,使之能够包含所需测试频率分量的方法。并分析了在施加非正弦激励下情形下,对待测电路响应中不同频率分量进行解耦,识别各分量交流参数的可行性和需要解决的问题。结果表明:在已知叠加前波形频域特征时,可以反推出叠加前各个原始波形的特征参数。因此,可以在实现压缩传统交流故障字典法测试时间的同时,达到与传统方法相近的诊断能力。  相似文献   
50.
稳态体感诱发电位的提取与分析   总被引:1,自引:0,他引:1  
对人体施加较高频率的电流刺激可以引起稳态体感诱发电位。为了诱发并提取出稳态体感诱发电位,该文设计并实现了一种可由计算机精确控制刺激电流的强度和频率等参数的新型体感诱发电位刺激器,给出了提取稳态体感诱发电位的检测方法,还讨论了能够在实验过程中减少刺激伪迹的措施。同时,给出了一种可在较短时间及噪声环境下提取出稳态体感诱发电位的频域分析方法,并与提取瞬态诱发电位采用的叠加平均方法进行了比较。理论分析与实验结果表明,该方法可以在较短时间内用头皮电极提取出稳态体感诱发电位,可以用在术中监护受试者的神经传导水平,而且其幅值的分布能够反映大脑对体感刺激的响应。  相似文献   
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