Cone-restricted kernel subspace methods Kobayashi, T; Yoshikawa, F; Otsu, N
2010 IEEE International Conference on Image Processing,
2010-Sept.
Conference Proceeding
Odprti dostop
We propose cone-restricted kernel subspace methods for pattern classification. A cone is mathematically defined in a manner similar to a linear subspace with a nonnegativity constraint. Since the ...angles between vectors (i.e., inner products) are fundamental to the cone, kernel tricks can be directly applied. The proposed methods approximate the distribution of sample patterns by using the cone in kernel feature space via kernel tricks, and the classification is more accurate than that of the kernel subspace method. Due to the nonlinearity of kernel functions, even a single cone in the kernel feature space can can cope with multi-modal distributions in the original input space. In the experimental results on person detection and motion detection, the proposed methods exhibit the favorable performances.
On a grading system for beef marbling Yoshikawa, Fumito; Toraichi, Kazuo; Wada, Koichi ...
Pattern recognition letters,
11/2000, Letnik:
21, Številka:
12
Journal Article
Recenzirano
This paper presents an automatic grading system for beef marbling which is composed of discriminant threshold selection method and run length processing. From the experimental results, it has been ...confirmed that the proposed system enables high quality grading of beef marbling, and robust region segmentation of the actual beef rib-eye image into lean and fat regions.
This paper presents a Fluency Image Coding System of beef rib-eye images for Beef Marbling Evaluation. This is the second in a series of cooperative researches with the Japan Livestock Technology ...Association under an initiative to construct an Automated Online Beef Marbling Grading Support System by image analysis techniques. Our first cooperative research was on a Beef Marbling Grading Method, and was published in this journal in Pattern Recognition Lett. 21 (12) (2000) 1037–1050. This second cooperative research focuses on a binary image coding system that supports remote observation of beef marbling structure from a database of coded beef rib-eye images by users including meat graders, livestock producers, and researchers. Image encoding is by a novel automatic contour compression method based on function approximation via interpolation using the Fluency Compactly Supported Sampling Functions of degree 2. Image decoding, based on interpolation of the encoded data by the similar functions, enables the web-browser based decoder to reconstruct the original fat contours smoothly even on Affine-transformed enlargement. Experimental results showing, respectively, size and image quality comparisons with other formats that support binary images and several enlargement schemes are included for evaluation.
We propose methods for segmenting a motion sequence into motion primitives, taking into account temporal constraints (continuity along the time axis). In the proposed methods, dynamic programming ...(DP) is used on a motion feature sequence to allow for the effects of these constraints on the results of the segmentation. The methods do not require such a running window along the time axis, as is typical for the usual methods, and thus they can be applied to the segmentation of transient motions. The results of comparative experiments using several motion features and segmentation methods on weightlifting motion data demonstrate the effectiveness of the proposed methods.
Free viewpoint browsing of live soccer games Kameda, Y.; Koyama, T.; Mukaigawa, Y. ...
2004 IEEE International Conference on Multimedia and Expo (ICME) (IEEE Cat. No.04TH8763),
2004, Letnik:
1
Conference Proceeding
We present a new video browsing method for multiple videos that are taken at large-scale space for live 3D events such as soccer games. By our method, multiple viewers over a computer network can ...browse a live 3D event from any viewpoint and each viewer can move his/her viewpoint freely. Our algorithm consists of five steps. Our system first captures videos from multiple cameras, then extracts texture segments from the videos, selects appropriate segments according to a viewpoint which is given by user dynamically, transmits them to users, and lays out the segments in virtual space so that each viewer can see the segments in a virtual environment as if the viewers were in the event. Our 3D video display system requires 10 Mbps at most to browse a soccer game. We conducted experiments at two real soccer stadiums and succeeded in realizing live realistic visualization with free viewpoint at about 26 fps
Abstract
Designer receptor activated by designer drugs (DREADDs) techniques are widely used to modulate the activities of specific neuronal populations during behavioural tasks. However, ...DREADDs-induced modulation of histaminergic neurons in the tuberomamillary nucleus (HA
TMN
neurons) has produced inconsistent effects on the sleep–wake cycle, possibly due to the use of Hdc-Cre mice driving Cre recombinase and DREADDs activity outside the targeted region. Moreover, previous DREADDs studies have not examined locomotor activity and aggressive behaviours, which are also regulated by brain histamine levels. In the present study, we investigated the effects of HA
TMN
activation and inhibition on the locomotor activity, aggressive behaviours and sleep–wake cycle of Hdc-Cre mice with minimal non-target expression of Cre-recombinase. Chemoactivation of HA
TMN
moderately enhanced locomotor activity in a novel open field. Activation of HA
TMN
neurons significantly enhanced aggressive behaviour in the resident–intruder test. Wakefulness was increased and non-rapid eye movement (NREM) sleep decreased for an hour by HA
TMN
chemoactivation. Conversely HA
TMN
chemoinhibition decreased wakefulness and increased NREM sleep for 6 h. These changes in wakefulness induced by HA
TMN
modulation were related to the maintenance of vigilance state. These results indicate the influences of HA
TMN
neurons on exploratory activity, territorial aggression, and wake maintenance.
Histamine is synthesised from l-histidine through the catalysis of histidine decarboxylase (HDC). In the central nervous system (CNS), histamine is exclusively produced in histaminergic neurons ...located in the posterior hypothalamus and controls various CNS functions. Although histidine was known as a precursor of histamine, the impact of oral histidine intake on brain histamine concentration and brain function has not been fully elucidated. In the present study, we aimed to elucidate the importance of oral histidine supplementation in the histaminergic nervous system and working memory in stressful conditions. First, we confirmed that sleep deprivation by water-floor stress in male mice increased histamine consumption and resulted in histamine reduction and impaired working memory in the Y-maze test. This memory impairment was rescued by intracerebroventricular injection of histamine and histidine, indicating that oral histidine intake could also improve memory function. Next, we examined the impact of histidine intake on brain histamine concentration and neuronal activity. Histidine intake increased extracellular histamine concentration around the prefrontal cortex (PFC) and the basal forebrain (BF), leading to a robust increase in the number of c-fos-positive cells around these areas. Finally, we investigated the beneficial effects of histidine intake on working memory. Histidine supplementation alleviated impaired memory function induced by sleep deprivation. This beneficial effect of histidine on memory was cancelled by intracerebroventricular injection of the HDC inhibitor α-fluoromethylhistidine. These results demonstrate that oral histidine intake replenishes brain histamine and leads to the recovery of impaired working memory induced by sleep deprivation through histaminergic activation.
•Sleep deprivation (SD) by water-floor stress increased brain histamine consumption.•Prolonged SD resulted in histamine depletion and impaired working memory.•Oral histidine intake increases extraneuronal histamine concentration.•Neuronal activation in the PFC and BF was induced by oral histidine treatment.•Oral histidine intake improved the working memory of SD mice via histamine system.
Histamine clearance is an essential process for avoiding excessive histaminergic neuronal activity. Previous studies using rodents revealed the predominant role of astrocytes in brain histamine ...clearance. However, the molecular mechanism of histamine clearance has remained unclear. We detected histamine N‐methyltransferase (HNMT), a histamine‐metabolizing enzyme, in primary human astrocytes and the astrocytes of human brain specimens. Immunocytochemical analysis and subcellular fractionation assays revealed that active HNMT localized to the cytosol, suggesting that histamine transport into the cytosol is crucial for histamine inactivation. We showed that primary human astrocytes transported histamine in a time‐dependent manner. Kinetics analysis showed that two low‐affinity transporters were involved in histamine transport. Histamine uptake by primary human astrocytes was not dependent on the extracellular Na+/Cl− concentration. Histamine is reported to be a substrate for three low‐affinity and Na+/Cl−‐independent transporters: organic cation transporter 2 (OCT2), OCT3, and plasma membrane monoamine transporter (PMAT). RT‐PCR analysis revealed that OCT3 and PMAT were expressed in primary human astrocytes. Immunohistochemistry confirmed OCT3 and PMAT expression in the astrocytes of human brain specimens. Drug inhibition assays and gene knockdown assays revealed the major contribution of PMAT and the minor contribution of OCT3 to histamine transport. The present study demonstrates for the first time that the molecular mechanism of histamine clearance is by primary human astrocytes. These findings might indicate that PMAT, OCT3 and HNMT in human astrocytes play a role in the regulation of extraneuronal histamine concentration and the activities of histaminergic neurons.
L-histidine is one of the essential amino acids for humans, and it plays a critical role as a component of proteins. L-histidine is also important as a precursor of histamine. Brain histamine is ...synthesized from L-histidine in the presence of histidine decarboxylase, which is expressed in histamine neurons. In the present study, we aimed to elucidate the importance of dietary L-histidine as a precursor of brain histamine and the histaminergic nervous system. C57BL/6J male mice at 8 wk of age were assigned to 2 different diets for at least 2 wk: the control (Con) diet (5.08 g L-histidine/kg diet) or the low L-histidine diet (LHD) (1.28 g L-histidine/kg diet). We measured the histamine concentration in the brain areas of Con diet–fed mice (Con group) and LHD-fed mice (LHD group). The histamine concentration was significantly lower in the LHD group Con group vs. LHD group: histamine in cortex (means ± SEs): 13.9 ± 1.25 vs. 9.36 ± 0.549 ng/g tissue; P = 0.002. Our in vivo microdialysis assays revealed that histamine release stimulated by high K+ from the hypothalamus in the LHD group was 60% of that in the Con group (P = 0.012). However, the concentrations of other monoamines and their metabolites were not changed by the LHD. The open-field tests showed that the LHD group spent a shorter amount of time in the central zone (87.6 ± 14.1 vs. 50.0 ± 6.03 s/10 min; P = 0.019), and the light/dark box tests demonstrated that the LHD group spent a shorter amount of time in the light box (198 ± 8.19 vs. 162 ± 14.1 s/10 min; P = 0.048), suggesting that the LHD induced anxiety-like behaviors. However, locomotor activity, memory functions, and social interaction did not differ between the 2 groups. The results of the present study demonstrated that insufficient intake of histidine reduced the brain histamine content, leading to anxiety-like behaviors in the mice.
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