Recurrent Neural Network Training with Dark Knowledge Transfer

Recurrent neural networks (RNNs), particularly long short-term memory (LSTM), have gained much attention in automatic speech recognition (ASR). Although some successful stories have been reported, training RNNs remains highly challenging, especially with limited training data. Recent research found that a well-trained model can be used as a teacher to train other child models, by using the predictions generated by the teacher model as supervision. This knowledge transfer learning has been employed to train simple neural nets with a complex one, so that the final performance can reach a level that is infeasible to obtain by regular training. In this paper, we employ the knowledge transfer learning approach to train RNNs (precisely LSTM) using a deep neural network (DNN) model as the teacher. This is different from most of the existing research on knowledge transfer learning, since the teacher (DNN) is assumed to be weaker than the child (RNN); however, our experiments on an ASR task showed that it works fairly well: without applying any tricks on the learning scheme, this approach can train RNNs successfully even with limited training data.Comment: ICASSP 201

Optimization of Protein-Protein Interaction Measurements for Drug Discovery Using AFM Force Spectroscopy

Increasingly targeted in drug discovery, protein-protein interactions challenge current high throughput screening technologies in the pharmaceutical industry. Developing an effective and efficient method for screening small molecules or compounds is critical to accelerate the discovery of ligands for enzymes, receptors and other pharmaceutical targets. Here, we report developments of methods to increase the signal-to-noise ratio (SNR) for screening protein-protein interactions using atomic force microscopy (AFM) force spectroscopy. We have demonstrated the effectiveness of these developments on detecting the binding process between focal adhesion kinases (FAK) with protein kinase B (Akt1), which is a target for potential cancer drugs. These developments include optimized probe and substrate functionalization processes and redesigned probe-substrate contact regimes. Furthermore, a statistical-based data processing method was developed to enhance the contrast of the experimental data. Collectively, these results demonstrate the potential of the AFM force spectroscopy in automating drug screening with high throughput

Expression and Clinical Significance of SHP2 in the Tumor Tissues of Smokers with Lung Cancer

Background and objective It has been proved that protein phosphorylation and dephosphorylation were important mechanisms in lung cancer development, and tobacco smoking is an important risk factor of lung cancer. The aim of this study is to investigate the expression and clinical significance of protein tyrosine phosphatase SHP2 in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC); the relationship between tobacco smoking and the expression of SHP2 is also studied. Methods Immunohistochemistry (Invision) and fluorescence in situ hybridization (FISH) were used to detect the expression of SHP2 and the augment of SHP2 mRNA in the 53 lung cancer specimens. Results The weak positive rate of SHP2 was 80% (which was also the total positive rate) in normal bronchial epithelium. The weak, moderate and strong positive rates were 35.4%, 43.8% and 6.2% (total positive rate was 85.4%) in 48 NSCLC patients, 0%, 80% and 20% (total positve rate was 100%) in 5 SCLC patients, 40.7%, 37.4% and 3.7% (total positive rate was 81.5%) in the tumor tissues of 27 NSCLC patients who didn’t smoke and 23.8%, 71.4% and 4.7% (total positive rate was 100%) in the tumor tissues of 21 NSCLC patients whose smoking indexes were ≥400. Significant differences of SHP2 expression were observed between tumor tissues and normal bronchial epithelium, NSCLC and SCLC, and between different smoking indexes (P < 0.05). Conclusion The enhancement of SHP2 expression in the tumor tissues of NSCLC patients who smoke may be correlated with tobacco smoking; SHP2 may play certain role in the development of lung cancer; SHP2 prospectively provides new ideas for the drug research and development of lung cancer treatment

Phylogenetic structure and formation mechanism of shrub communities in arid and semiarid areas of the Mongolian Plateau

The mechanisms of species coexistence within a community have always been the focus in ecological research. Community phylogenetic structure reflects the relationship of historical processes, regional environments, and interactions between species, and studying it is imperative to understand the formation and maintenance mechanisms of community composition and biodiversity. We studied the phylogenetic structure of the shrub communities in arid and semiarid areas of the Mongolian Plateau. First, the phylogenetic signals of four plant traits (height, canopy, leaf length, and leaf width) of shrubs and subshrubs were measured to determine the phylogenetic conservation of these traits. Then, the net relatedness index (NRI) of shrub communities was calculated to characterize their phylogenetic structure. Finally, the relationship between the NRI and current climate and paleoclimate (since the Last Glacial Maximum, LGM) factors was analyzed to understand the formation and maintenance mechanisms of these plant communities. We found that desert shrub communities showed a trend toward phylogenetic overdispersion; that is, limiting similarity was predominant in arid and semiarid areas of the Mongolian Plateau despite the phylogenetic structure and formation mechanisms differing across habitats. The typical desert and sandy shrub communities showed a significant phylogenetic overdispersion, while the steppified desert shrub communities showed a weak phylogenetic clustering. It was found that mean winter temperature (i.e., in the driest quarter) was the major factor limiting steppified desert shrub phylogeny distribution. Both cold and drought (despite having opposite consequences) differentiated the typical desert to steppified desert shrub communities. The increase in temperature since the LGM is conducive to the invasion of shrub plants into steppe grassland, and this process may be intensified by global warming

On the Concepts of Subject, Object, Subjectivity and Objectivity 2

This article gives Prof. Zhiyong Dong’s own definitions to the concepts of Subject, Object, Subjectivity and Objectivity.