Filtering out irrelevant documents and classifying the relevant ones into topical categories is a de facto task in many applications. However, supervised learning solutions require extravagant human efforts on document labeling. In this paper, we propose a novel seed-guided topic model for dataless short text classification and filtering, named SSCF. Without using any labeled documents, SSCF takes a few “seed words” for each category of interest, and conducts short text filtering and classification in a weakly supervised manner. To overcome the issues of data sparsity and imbalance, the short text collection is mapped to a collection of pseudodocuments, one for each word. SSCF infers two kinds of topics on pseudo-documents: category-topics and general-topics. Each category-topic is associated with one category of interest, covering the meaning of the latter. In SSCF, we devise a novel word relevance estimation process based on the seed words, for hidden topic inference. The dominating topic of a short text is identified through post inference and then used for filtering and classification. On two real-world datasets in two languages, experimental results show that our proposed SSCF consistently achieves better classification accuracy than state-of-the-art baselines. We also observe that SSCF can even achieve superior performance than the supervised classifiers supervised latent dirichlet allocation (sLDA) and support vector machine (SVM) on some testing tasks.
Xiu-Quan Shi, Wei Yan, Ke-Yue Wang, Qi-Yuan Fan and Yan Zou
We tested the hypothesis that dietary fi bre (DF) has protective effects against manganese (Mn)-induced neurotoxicity. Forty-eight one-month old Sprague-Dawley rats were randomly divided into six groups: control, 16 % DF, Mn (50 mg kg-1 body weight), Mn+ 4 % DF, Mn+ 8 % DF, and Mn+ 16 % DF. After oral administration of Mn (as MnCl2) by intragastric tube during one month, we determined Mn concentrations in the blood, liver, cerebral cortex, and stool and tested neurobehavioral functions. Administration of Mn was associated with increased Mn concentration in the blood, liver, and cerebral cortex and increased Mn excretion in the stool. Aberrations in neurobehavioral performance included increases in escape latency and number of errors and decrease in step-down latency. Irrespective of the applied dose, the addition of DF in forage decreased tissue Mn concentrations and increased Mn excretion rate in the stool by 20 % to 35 %. All neurobehavioral aberrations were also improved. Our fi ndings show that oral exposure to Mn may cause neurobehavioral abnormalities in adult rats that could be effi ciently alleviated by concomitant supplementation of DF in animal feed.
Qi Lu, Chun-xia Zhao, Kun-ling Shen, Wen-bo Xu, Yan Zhang, Jia-lin Yu and Xi-qiang Yang
Objective Fusion protein is a subunit of the human respiratory syncytial virus (HRSV) and a potential vaccine candidate. Thus, a study on the genetic characteristics of F protein was considered important for further investigations in this field. The aim of this study was to determine the prevalence and genetic diversity of the F gene of HRSV infections in hospitalized pediatric patients in Beijing with acute lower respiratory tract infections and to compare the circulating genotypes that are currently found worldwide.
Methods HRSV particles were amplified by RT-PCR and the PCR products were purified for sequencing. Further analysis was carried out by Bioedit and MEGA 3.0 biological software programs.
Results Seventy-six samples (23.1%) were positive for HRSV. The percentage of cases in patients younger than 1 year was 84.21%. Among the six Beijing isolates, four belonged to subgroup A, whose respective F genes shared 97.0%-97.4% nucleotide sequence identity and 92.1%-93.0% amino acid sequence identity. The other two isolates belonged to subgroup B. Here, 97.3% and 98.2% sequence identity were found at nucleotide and amino acid levels, respectively.
Conclusions Phylogenetic analysis of nucleotide sequences revealed that those four isolates within subgroup A were monophyletic and closely related to each other, but those two within subgroup B distributed in two distinct clusters. Subgroup A and B strains co-circulated, indicating that two different transmission chains occurred in Beijing from 2003-2004.
Shi-Fan Han, Rui-Fang Zhu, Jia Xue, Qi Yu, Yan-Bing Su and Xiu-Juan Wang
This study proposes the establishment of a knowledge-system ontology in the nursing field. It uses advanced data mining techniques, digital publishing technologies, and new media concepts to comprehensively integrate and deepen nursing knowledge and to aggregate sources of knowledge in specialized technical fields. This study applies all forms of media and transmission channels, such as personal computers and mobile devices, to establish a knowledge-transmission system that provides knowledge services such as knowledge search, update retrieval, evaluation, questions and answers (Q&As), online viewing, information subscription, expert services, push notifications, review forums, and online learning. In doing so, this study creates an authoritative and foundational knowledge service engine for the nursing field, which provides convenient, flexible, and comprehensive knowledge services to members of the nursing industry in a digital format.
Cui Guan, Zhi Jiang Zeng, Zi Long Wang, Wei Yu Yan and Qi Zhong Pan
The queen and worker bees have the same genetic makeup. However, the queen differs dramatically from the workers in anatomy, physiology, behavior, and lifespan. Three genes (sir2, ash2, and hdac1) have been shown to be associated with histone methylation and acetylation as well as longevity in worms and flies. The relative expression level of these genes was examined in the heads of queens and workers at different developmental stages. The sir2, ash2, and hdac1 expression levels in newly emerged queens, egg-laying queens, and egg-laying workers were significantly higher than those in newly emerged workers, nurses, and foragers. We conclude that these genes are possibly “queen-like” genes.
Lian Fei Cao, Huo Qing Zheng, Qi Yan Shu, Fu Liang Hu and Zi Wei Xu
China is the largest producer and exporter of royal jelly in the world. The high production of royal jelly in China is mainly attributed to a high royal jelly-producing lineage of honeybees (Apis mellifera) (HRJB). However, few studies have been conducted on the genetic characterization of HRJB. In this study, the mitochondrial DNA intergenic region between cytochrome oxidase I and II (COI-COII) and the mitochondrial NADH dehydrogenase subunit 2 sequences (ND2) were determined for 90 HRJB colonies, collected from the regions of China where HRJB originated, and 25 unimproved A. m. ligustica colonies from China. COI-COII sequence analysis revealed two mitotypes (C1 and C2d) in HRJB colonies and one mitotype (C1) in unimproved A. m. ligustica colonies. The main mitotype (C1) in HRJB accounted for 93% of the colonies. Based on ND2 sequences, four and two mitotypes were found in HRJB and unimproved A. m. ligustica colonies, respectively. Sequence alignment showed that nucleotides in three positions of the ND2 sequence were different between the main mitotype of HRJB and that of unimproved A. m. ligustica. Our study suggested that HRJB was bred from A. m. ligustica and possibly had genetic characteristics different from unimproved A. m. ligustica.