Differential optogenetic excitation of the auditory midbrain in freely moving behaving mice

In patients with severe sensory impairment due to compromised peripheral function, partial restoration can be achieved by implantation of sensory prostheses for the electrical stimulation of the central nervous system. However, these state of the art approaches suffer from the drawback of limited spectral resolution. Electrical field spread depends on the impedance of the surrounding medium, impeding spatially focused electrical stimulation in neural tissue. To overcome these technical limitations, optogenetic excitation could be applied in such prostheses to achieve enhanced resolution through precise and differential stimulation of nearby neuronal ensembles within the central sensory pathway. Previous experiments have provided a first proof for behavioral detectability of optogenetic excitation in the rodent auditory system. However, little is known about the generation of complex and behaviorally relevant sensory patterns involving differential excitation. In this study, we developed an optogenetic implant to excite two spatially separated points along the tonotopy of the murine central inferior colliculus (ICc). Using a newly-devised reward-based operant Go/No-Go paradigm for the evaluation of optogenetic excitation of the auditory midbrain in freely moving, behaving mice, we demonstrate that differential optogenetic excitation of a sub-cortical sensory pathway is possible and efficient. Here we demonstrate how animals which were previously trained in a frequency discrimination paradigm a) rapidly generalize between sound and optogenetic excitation, b) generally detect optogenetic excitation at two different neuronal ensembles, and c) discriminate between them. Our results demonstrate for the first time that optogenetic excitation at different points of the ICc tonotopy elicits a stable response behavior over time periods of several months. With this study, we provide the first proof of principle for sub-cortical differential stimulation of sensory systems using complex artificial cues in freely moving animals.

Research on Finger Vein Image Segmentation and Blood Sampling Point Location in Automatic Blood Collection

In the fingertip blood automatic sampling process, when the blood sampling point in the fingertip venous area, it will greatly increase the amount of bleeding without being squeezed. In order to accurately locate the blood sampling point in the venous area, we propose a new finger vein image segmentation approach basing on Gabor transform and Gaussian mixed model (GMM). Firstly, Gabor filter parameter can be set adaptively according to the differential excitation of image and we use the local binary pattern (LBP) to fuse the same-scale and multi-orientation Gabor features of the image. Then, finger vein image segmentation is achieved by Gabor-GMM system and optimized by the max flow min cut method which is based on the relative entropy of the foreground and the background. Finally, the blood sampling point can be localized with corner detection. The experimental results show that the proposed approach has significant performance in segmenting finger vein images which the average accuracy of segmentation images reach 91.6%.

Weber Texture Local Descriptor for Identification of Group-Housed Pigs

The individual identification of group-housed pigs plays an important role in breeding process management and individual behavior analysis. Recently, livestock identification methods based on the side view or face image have strict requirements on the position and posture of livestock, which poses a challenge for the application of the monitoring scene of group-housed pigs. To address the issue above, a Weber texture local descriptor (WTLD) is proposed for the identification of group-housed pigs by extracting the local features of back hair, skin texture, spots, and so on. By calculating the differential excitation and multi-directional information of pixels, the local structure features of the main direction are fused to enhance the description ability of features. The experimental results show that the proposed WTLD achieves higher recognition rates with a lower feature dimension. This method can identify pig individuals with different positions and postures in the pig house. Without limitations on pig movement, this method can facilitate the identification of individual pigs with greater convenience and universality.

Copy Move Forgery Detection Through Differential Excitation Component-Based Texture Features

Copy-move forgery (CMF) is an established process to copy an image segment and pastes it within the same image to hide or duplicate a portion of the image. Several CMF detection techniques are available; however, better detection accuracy with low feature vector is always substantial. For this, differential excitation component (DEC) of Weber Law descriptor in combination with the gray level co-occurrence matrix (GLCM) approach of texture feature extraction for CMFD is proposed. GLCM Texture features are computed in four directions on DEC and this acts as a feature vector for support vector machine classifier. These texture features are more distinguishable and it is validated through other two proposed methods based on discrete wavelet transform-GLCM (DWT-GLCM) and GLCM. Experimentation is carried out on CoMoFoD and CASIA databases to validate the efficacy of proposed methods. Proposed methods exhibit resilience against many post-processing attacks. Comparative analysis with existing methods shows the superiority of the proposed method (DEC-GLCM) with regard to detection accuracy.

Polarized evanescent waves reveal trochoidal dichroism

Matter’s sensitivity to light polarization is characterized by linear and circular polarization effects, corresponding to the system’s anisotropy and handedness, respectively. Recent investigations into the near-field properties of evanescent waves have revealed polarization states with out-of-phase transverse and longitudinal oscillations, resulting in trochoidal, or cartwheeling, field motion. Here, we demonstrate matter’s inherent sensitivity to the direction of the trochoidal field and name this property trochoidal dichroism. We observe trochoidal dichroism in the differential excitation of bonding and antibonding plasmon modes for a system composed of two coupled dipole scatterers. Trochoidal dichroism constitutes the observation of a geometric basis for polarization sensitivity that fundamentally differs from linear and circular dichroism. It could also be used to characterize molecular systems, such as certain light-harvesting antennas, with cartwheeling charge motion upon excitation.

Seismic Analysis of Structures Subjected to Spatially Varying Earthquake Using POD Vectors: Experimental and Analytical Studies

Structures, such as bridges, pipelines which are supported at multiple places, will be subjected to differential excitation. A significant change in the correlation of the motions between the two supports is due to the combined effects of wave passage, coherency loss and local soil conditions. In the classical formulation, the response is divided into quasi-static and dynamic components and the latter is usually evaluated by time history methods or modal analysis for a linear system. In this work, the feasibility of Proper Orthogonal Decomposition (POD) vectors as a replacement for the conventional eigenvectors has been discussed. The performance of POD modes has been assessed for the uncoupled system, system having closely spaced modes. The null space vectors of the POD modes generated from the response of the structure subjected to correlated input motion were able to predict the responses of the structures subjected to spatially varying input motions. The efficiency of using the POD vectors has also been verified with the help of an experiment conducted on a steel control and safety rod drive mechanism (CSRDM) which is an example of multi-supported and differentially excited structure.