Activation of SC during electrical stimulation of LGN: retinal antidromic stimulation or corticocollicular activation?

We have recently used combined electrostimulation, neurophysiology, microinjection and functional magnetic resonance imaging (fMRI) to study the cortical activity patterns elicited during stimulation of cortical afferents in monkeys. We found that stimulation of a site in lateral geniculate nucleus (LGN) increases the fMRI signal in the regions of primary visual cortex receiving input from that site, but suppresses it in the retinotopically matched regions of extrastriate cortex. Intracortical injection experiments showed that such suppression is due to synaptic inhibition. During these experiments, we have consistently observed activation of superior colliculus (SC) following LGN stimulation. Since LGN does not directly project to SC, the current study investigated the origin of SC activation. By examining experimental manipulations inactivating the primary visual cortex, we present here evidence that the robust SC activation, which follows the stimulation of LGN, is due to the activation of corticocollicular pathway.     

Multiparametric Analysis of Vocal Fold Vibrations in Healthy and Disordered Voices in High-Speed Imaging

Objectives

The aim of this study was to look for visual subjective and objective parameters of vocal fold dynamics being capable of differentiating healthy from pathologic voices in daily clinical practice applying endoscopic high-speed digital imaging (HSI).

Study Design and Methods

Four hundred ninety-six datasets containing 80 healthy and 416 pathologic subjects (232 functional dysphonia (FD), 13 bilateral, and 171 unilateral vocal fold nerve paralysis) were analyzed retrospectively. Videos at 4000 Hz (256 × 256 pixel) were recorded during sustained phonation. Subjective parameters were visually evaluated and complemented by an analysis of objective parameters. Visual subjective parameters were mucosal wave, glottal closure type, glottal closure insufficiency (GI), asymmetries of the vocal folds, and phonovibrogram (PVG) symmetry. After image segmentation, objective parameters were computed: closed quotient, perturbation measures (PMs) of glottal area, and left-right asymmetry values.

Results

HSI evaluation enabled to distinguish healthy from pathologic voices. For visual subjective parameters, GI, symmetrical behavior, and PVG symmetry exhibited statistical significant differences. For 95% of the data, objective parameters could be computed. Among objective parameters, closed quotient, jitter, shimmer, harmonic-to-noise ratio, and signal-to-noise ratio for the glottal area function differentiated statistically significant normal from pathologic voices. Applying linear discriminant analysis by combining visual subjective and objective parameters, accurate classifications were made for 63.2% of the female and 87.5% of the male group for the three-class problem (healthy, FD, and unilateral vocal fold nerve paralysis).

Conclusion

Actual acoustically applied PMs can be transferred to clinical beneficial HSI analysis. Combining visual subjective and objective basic parameters succeeds in differentiating pathologic from healthy voices. The presented evaluation can easily be included into everyday clinical practice. However, further research is needed to broaden our understanding of the variability within and across healthy and pathologic vocal fold vibrations for diagnosing voice disorders and therapy control.     

《大学物理实验》试题库系统的设计与实现

介绍了采用Visual Basic语言和Access数据库开发而成的大学物理实验试题库系统,该系统利用Word作为存储试题的容器,解决了物理试题录入中存在的公式、图片、表格等非文本数据的存储与修改的技术性问题。     

Can we really ‘read’ art to see the changing brain? A review and empirical assessment of clinical case reports and published artworks for systematic evidence of quality and style changes linked to damage or neurodegenerative disease

The past three decades have seen multiple reports of people with neurodegenerative disorders, or other forms of changes in their brains, who also show putative changes in how they approach and produce visual art. Authors argue that these cases may provide a unique body of evidence, so-called ‘artistic signatures’ of neurodegenerative diseases, that might be used to understand disorders, provide diagnoses, be employed in treatment, create patterns of testable hypotheses for causative study, and also provide unique insight into the neurobiological linkages between the mind, brain, body, and the human penchant for art-making itself. However—before we can begin to meaningfully build from such emerging findings, much less formulate applications—not only is such evidence currently quite disparate and in need of systematic review, almost all case reports and artwork ratings are entirely subjective, based on authors' personal observations or a sparse collection of methods that may not best fit underlying research aims. This leads to the very real question of whether we might actually find patterns of systematic change if fit to a rigorous review—Can we really ‘read’ art to illuminate possible changes in the brain? How might we best approach this topic in future neuroscientific, clinical, and art-related research? This paper presents a review of this field and answer to these questions. We consider the current case reports for seven main disorders—Alzheimer's and Parkinson's disease, frontotemporal and Lewy body dementia, corticobasal degeneration, aphasia, as well as stroke—consolidating arguments for factors and changes related to art-making and critiquing past methods. Taking the published artworks from these papers, we then conduct our own assessment, employing computerized and human-rater-based approaches, which we argue represent best practice to identify stylistic or creativity/quality changes. We suggest, indeed, some evidence for systematic patterns in art-making for specific disorders and also find that case authors showed rather high agreement with our own assessments. More important, through opening this topic and past evidence to a systematic review, we hope to open a discussion and provide a theoretical and empirical foundation for future application and research on the intersection of art-making and the neurotypical, the changed, and the artistic brain.     

用于运动目标探测的多通道成象系统

本文提出了一种采用自聚焦(GRIN)透镜阵列对运动目标进行探测的多通道光学成象系统.与单孔径成象系统比较,多通道成象系统具有更宽的视场和更高的运动敏感度,使之更适合于对运动目标的捕获、跟踪以及对运动量的测定.本文根据复眼的视觉机制和自聚焦透镜的成象原理,对运动目标进行了成象与测定实验.此外,初步介绍了为提高图象分辨率而采用的并行多通道处理技术.     

Haze removal from single images based on a luminance reference model

Optical transmission estimation is a key procedure for removing haze from certain outdoor images. In this paper, we propose a novel transmission estimation model called the luminance reference model. We theoretically prove the validity of this model, which demonstrates that the transmission can be computed accurately given a correct estimate of luminance reference. We also design an experiment exploiting large quantities of nature images to study the statistical property of the luminance reference. By statistics we find out that the distribution of luminance references in natural haze-free images is intensive. Therefore, to keep the simplicity and efficiency of the algorithm, the luminance reference is fixed as a constant for a single image. By using a scene-dependent estimate of the luminance reference, our method can be applied to different types of images. We further propose a guided approach to rapid and robust computation of transmission maps. Our experimental results show that the proposed method is computationally efficient, while producing comparable visual results to the existing state-of-the-art, but more complex, methods.     

视觉估计显示器gamma在Internet网络上的应用

使用自行开发出的基于Web的gamma估计程序,分别通过Internet对CRT和LCD显示器在暗、微暗和办公环境三种观察环境下,进行了视觉估计显示器gamma精确度研究实验.实验得出：不同实验者估计偏差范围,对CRT和LCD显示器分别是0.13和0.20|估计与测量结果的平均误差范围,对CRT和LCD显示器分别是0.07和0.17|gamma估计基本与观察环境无关|观察视角对LCD显示器gamma值影响很大|显示器的“亮度”和“对比度”设置,不影响视觉估计结果.     

光学密度可见光区光谱特性的理论分析与实验研究

光学密度是评价光学影像材料的具有唯一性的指标。随着高分子影像等的发展,对光学密度的光谱特性的要求也逐渐提高。2001年ISO对光学密度的测量条件作了新的修改规定。按照ISO新标准的光谱特性要求设计了新国家光学透射密度基准装置的组件结构,提出了一种基于光谱特性的光学密度理论测量方案,并进行了实验研究,将光学密度的光谱不确定度提高到0.001 1(0<D<4.0)和0.003 1(4.0≤D<6.0),比国际先进水平有了大幅度提高。     

Time measurement-visual analysis of l-cysteine using the autocatalytic sodium sulfite/hydrogen peroxide reaction system and its application to length detection-flow analysis

Trace amounts of l-cysteine can function as a trigger, i.e., reaction initiator, in the autocatalytic sodium sulfite/hydrogen peroxide reaction system. Rapidly changing of pH after induction time is visually confirmed by color changing of bromothymol blue in this autocatalytic reaction. Based on this finding, μg L⁻¹ levels of l-cysteine were measured over time using the autocatalytic reaction system. The determination range using the above method was 5.0 × 10⁻⁸-2.5 × 10⁻⁶ M, the detection limit (3σ) was 1.8 × 10⁻⁸ M (1.94 μg L⁻¹), and the relative standard deviation was 2.41% at an l-cysteine concentration of 5 × 10⁻⁷ M (n = 5). This method was also applied to length detection-flow injection analysis. The determination range for the flow injection analysis was 2.0 × 10⁻⁷-1.0 × 10⁻⁵ M. The detection limit (3σ) was 1.4 × 10⁻⁷ M (17.0 μg L⁻¹), and the relative standard deviation was 0.91% at an initial l-cysteine concentration of 10⁻⁶ M (n = 5).