Learning "O" Helps for Learning More: Handling the Concealed Entity Problem for Class-incremental NER

As the categories of named entities rapidly increase in real-world applications, class-incremental learning for NER is in demand, which continually learns new entity classes while maintaining the old knowledge. Due to privacy concerns and storage constraints, the model is required to update without any annotations of the old entity classes. However, in each step on streaming data, the "O" class in each step might contain unlabeled entities from the old classes, or potential entities from the incoming classes. In this work, we first carry out an empirical study to investigate the concealed entity problem in class-incremental NER. We find that training with "O" leads to severe confusion of "O" and concealed entity classes, and harms the separability of potential classes. Based on this discovery, we design a rehearsal-based representation learning approach for appropriately learning the "O" class for both old and potential entity classes. Additionally, we provide a more realistic and challenging benchmark for class-incremental NER which introduces multiple categories in each step. Experimental results verify our findings and show the effectiveness of the proposed method on the new benchmark

Did the 2008 Wenchuan earthquake trigger a change in the conduct of research on seismic risk?

This study aims to address how the 2008 Wenchuan Earthquake influenced knowledge generation and diffusion compared to the research stemming from the 1989 Loma Prieta Earthquake in the United States and the 1995 Hanshin Awaji Earthquake in Japan, for the three countries are exposed to high seismic risk. The findings show that (1) regarding research quantity, the influence of the Wenchuan Earthquake on disaster-related knowledge generation is just beginning compared with the gradual decreases in research on the other earthquakes; (2) regarding disciplinary development, the proportion of studies relating to the Wenchuan Earthquake in natural sciences and engineering technology is gradually decreasing, while the proportion of studies in medical science, social sciences and economics is increasing; (3) the quantity of earthquake-related studies is not solely related to the influence of a specific disaster but associated with the national financial support offered by the affected country. One reason why China experiences the high research output is that Chinese national finance strongly supports such research, similar to the United States and Japan. This phenomenon corresponds with the fact that the major research institutions in China are national institutions rather than universities. Finally, (4) interdisciplinary research on the Wenchuan Earthquake mainly involves interactions between natural sciences and engineering technology. Interactions between other disciplines need to be enhanced. Thus, this research argues that, although disaster knowledge generation and diffusion is imbalanced, the multidimensional nature of earthquakes has been recognized in the literature

The Synaptic Vesicle Protein 2A Interacts With Key Pathogenic Factors in Alzheimer's Disease: Implications for Treatment

Alzheimer’s disease (AD), a serious neurodegenerative disease, is pathologically characterized by synaptic loss and dysfunction. Synaptic vesicle protein 2A (SV2A) is an indispensable vesicular protein specifically expressed in synapses and can be used as a biomarker for synaptic density. We found that the expression of SV2A was down-regulated in the hippocampus of AD patients, yet the relation of SV2A to other hallmarks of AD pathology such as amyloid precursor protein (APP), β-amyloid (Aβ), and Tau protein is not thoroughly clear. In addition, SV2A colocalized with APP and was down-regulated at Aβ deposition. Moreover, we found that SV2A deficiency leads to a simultaneous increase in Aβ and Tau hyperphosphorylation, while SV2A overexpression was associated with downregulation of β-site APP cleaving enzyme 1 and apolipoprotein E genes. In addition, evidence gained in the study points to the phosphatidylinositol 3-kinase signaling pathway as a possible mediator in SV2A regulation influencing the incidence and development of AD. With limited effective diagnostic methods for AD, a close interplay between SV2A and AD-related proteins demonstrated in our study may provide novel and innovative diagnostic and therapeutic opportunities.ISSN:2296-634

Comparative Analysis of Bat Genomes Provides Insight into the Evolution of Flight and Immunity

Bats are the only mammals capable of sustained flight and are notorious reservoir hosts for some of the world’s most highly pathogenic viruses, including Nipah, Hendra, Ebola and SARS. To identify genetic changes associated with the development of bat-specific traits, we performed whole genome sequencing and comparative analyses of two distantly related bat species, fruit bat Pteropus alecto and insectivorous Myotis davidii. We discovered an unexpected concentration of positively selected genes in the DNA damage checkpoint and NF-κB pathways that may be related to the origin of flight, as well as expansion and contraction of important gene families. Comparison of bat genomes with other mammalian species has provided new insights into bat biology and evolution