4,855 research outputs found
Representation Learning with Fine-grained Patterns
With the development of computational power and techniques for data
collection, deep learning demonstrates a superior performance over most of
existing algorithms on benchmark data sets. Many efforts have been devoted to
studying the mechanism of deep learning. One important observation is that deep
learning can learn the discriminative patterns from raw materials directly in a
task-dependent manner. Therefore, the representations obtained by deep learning
outperform hand-crafted features significantly. However, those patterns are
often learned from super-class labels due to a limited availability of
fine-grained labels, while fine-grained patterns are desired in many real-world
applications such as visual search in online shopping. To mitigate the
challenge, we propose an algorithm to learn the fine-grained patterns
sufficiently when only super-class labels are available. The effectiveness of
our method can be guaranteed with the theoretical analysis. Extensive
experiments on real-world data sets demonstrate that the proposed method can
significantly improve the performance on target tasks corresponding to
fine-grained classes, when only super-class information is available for
training
Quantification of the influence of drugs on zebrafish larvae swimming kinematics and energetics
The use of zebrafish larvae has aroused wide interest in the medical field for its potential role in the development of new therapies. The larvae grow extremely quickly and the embryos are nearly transparent which allows easy examination of its internal structures using fluorescent imaging techniques. Medical treatment of zebrafish larvae can directly influence its swimming behaviours. These behaviour changes are related to functional changes of central nervous system and transformations of the zebrafish body such as muscle mechanical power and force variation, which cannot be measured directly by pure experiment observation. To quantify the influence of drugs on zebrafish larvae swimming behaviours and energetics, we have developed a novel methodology to exploit intravital changes based on observed zebrafish locomotion. Specifically, by using an in-house MATLAB code to process the recorded live zebrafish swimming video, the kinematic locomotion equation of a 3D zebrafish larvae was obtained, and a customised Computational Fluid Dynamics tool was used to solve the fluid flow around the fish model which was geometrically the same as experimentally tested zebrafish. The developed methodology was firstly verified against experiment, and further applied to quantify the fish internal body force, torque and power consumption associated with a group of normal zebrafish larvae vs. those immersed in acetic acid and two neuroactive drugs. As indicated by our results, zebrafish larvae immersed in 0.01% acetic acid display approximately 30% higher hydrodynamic power and 10% higher cost of transport than control group. In addition, 500 μM diphenylhydantoin significantly decreases the locomotion activity for approximately 50% lower hydrodynamic power, whereas 100 mg/L yohimbine has not caused any significant influences on 5 dpf zebrafish larvae locomotion. The approach has potential to evaluate the influence of drugs on the aquatic animal’s behaviour changes and thus support the development of new analgesic and neuroactive drugs
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