1,269 research outputs found
New Descriptor for Glomerulus Detection in Kidney Microscopy Image
Glomerulus detection is a key step in histopathological evaluation of
microscopy images of kidneys. However, the task of automatic detection of
glomeruli poses challenges due to the disparity in sizes and shapes of
glomeruli in renal sections. Moreover, extensive variations of their
intensities due to heterogeneity in immunohistochemistry staining are also
encountered. Despite being widely recognized as a powerful descriptor for
general object detection, the rectangular histogram of oriented gradients
(Rectangular HOG) suffers from many false positives due to the aforementioned
difficulties in the context of glomerulus detection.
A new descriptor referred to as Segmental HOG is developed to perform a
comprehensive detection of hundreds of glomeruli in images of whole kidney
sections. The new descriptor possesses flexible blocks that can be adaptively
fitted to input images to acquire robustness to deformations of glomeruli.
Moreover, the novel segmentation technique employed herewith generates high
quality segmentation outputs and the algorithm is assured to converge to an
optimal solution. Consequently, experiments using real world image data reveal
that Segmental HOG achieves significant improvements in detection performance
compared to Rectangular HOG.
The proposed descriptor and method for glomeruli detection present promising
results and is expected to be useful in pathological evaluation
Force Rendering and Its Evaluation of a Friction-based Walking Sensation Display for a Seated User
Most existing locomotion devices that represent the sensation of walking
target a user who is actually performing a walking motion. Here, we attempted
to represent the walking sensation, especially a kinesthetic sensation and
advancing feeling (the sense of moving forward) while the user remains seated.
To represent the walking sensation using a relatively simple device, we focused
on the force rendering and its evaluation of the longitudinal friction force
applied on the sole during walking. Based on the measurement of the friction
force applied on the sole during actual walking, we developed a novel friction
force display that can present the friction force without the influence of body
weight. Using performance evaluation testing, we found that the proposed method
can stably and rapidly display friction force. Also, we developed a virtual
reality (VR) walk-through system that is able to present the friction force
through the proposed device according to the avatar's walking motion in a
virtual world. By evaluating the realism, we found that the proposed device can
represent a more realistic advancing feeling than vibration feedback
Aflatoxins in Rice Artificially Contaminated with Aflatoxin-producing Aspergillus flavus under Natural Storage in Japan
Aflatoxin (AFT) contamination is frequent in foods grown in tropical regions, including rice. Although AFTs are generally not found in temperate-region foods, global warming has affected typical temperate-region climates, potentially permitting the contamination of foods with AFT-producing Aspergillus flavus (A. flavus). Here we investigated the AFT production in rice during storage under natural climate conditions in Japan. We examined AFTs in brown rice and rough rice artificially contaminated with A. flavus for 1 year in Japan, and we subjected AFTs in white rice to the same treatment in airtight containers and examined the samples in warm and cold seasons, simulating the storage of white rice in general households. In the brown rice, AFTs increased after 2 months (March) and peaked after 9 months (October). The AFT contamination in the rough rice was minimal. After the polishing and cooking of the brown rice, AFTs were undetectable. In the white rice stored in airtight containers, AFTs increased after 1 month (August) and peaked after 2 months (September). Minimal AFTs were detected in the cold season. Thus, AFT contamination in rice may occur in temperate regions following A. flavus contamination. The storage of rice as rough rice could provide be useful for avoiding AFT contamination
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