Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

중국인 한국어 학습자의 어휘 학습전략 요인 연구

학위논문 (석사) -- 서울대학교 대학원 : 사범대학 국어교육과(한국어교육전공), 2020. 8. 김호정.본 연구는 중국인 한국어 학습자의 어휘 학습전략 요인을 분석하여 그 특성을 밝히고 어휘 학습전략과 학습자 요인과의 관계 분석을 통해 어휘 학습전략의 효과적인 교수·학습 방향을 탐색하는 것을 목적으로 한다. 그 동안 어휘 교수는 필요성을 인정받지 못하고 학습자 개인의 문제로 여겨져 왔다. 중국인 학습자들은 새로운 어휘를 접할 때 어휘 학습전략을 효과적으로 사용하지 못하여 외국어 학습 자체에 흥미를 잃기가 쉽다. 중국인 학습자들이 한국어 어휘 학습 시에 무작정 단어를 암기하는 데 수많은 시간을 투자하였음에도 불구하고 어휘의 정확한 쓰임새를 파악하지 못하는 경우가 이에 해당한다. 본 연구는 이와 같은 문제점을 인식하고 중국인 한국어 학습자의 주도적인 학습에 유용한 어휘 학습전략에 대한 연구를 진행하였다. 먼저, Ⅰ장에서는 연구 목적 및 필요성과 어휘 학습전략에 관한 제2언어교육과 한국어교육에서의 선행연구를 검토하였다. Ⅱ장에서는 기존의 연구를 토대로 한국어 어휘에 관한 개념과 어휘교육의 위상, 언어 학습전략과 어휘 학습전략에 관한 개념 및 분류 체계를 살피고 어휘 학습전략에 영향을 미치는 학습자 요인을 선정하였다. Ⅲ장에서는 중국인 한국어 학습자의 특성에 맞는 어휘 학습전략 측정을 위한 도구를 개발하여 의미 발견 전략과 기억 강화 전략 두 개 범주와 상위전략 6개, 하위전략 61개로 구성된 설문문항을 만들어 중국인 한국어 학습자 577명을 대상으로 조사를 실시하였다. 조사 결과는 요인분석(Factor analysis), 기술 통계, 독립표본 t-검정(independent samples t-test), 일원변량분석(One-way AVOVA), 상관분석(Correlation analysis), 다중회귀분석(Multiple regression analysis) 등의 방법으로 분석을 실시하였다. 그 결과 Ⅳ장에서는 다음과 같은 연구 결과를 도출하였다. 먼저, 어휘 학습에 대한 인식 조사 결과 학습자들은 어휘 학습의 중요성과 필요성을 크게 인식하고 있음을 확인하였다. 이어서 요인분석을 통해, 중국인 한국어 학습자의 특성을 밝힐 수 있는 의미 발견 전략과 기억 강화 전략 두 개 범주 내 상위전략 7개와 하위전략 30개를 도출할 수 있었다. 상위전략으로는 의미 발견 전략에 속하는 어휘 의미 강화 전략과 사회적 요청 전략, 기억 강화 전략에 속하는 연관성을 활용한 기억 전략, 자기 주도적 인지 조절 전략, 선택적인 반복 전략, 어휘 정보 활용 전략, 정의적(심리적) 불안 조절 전략의 7개 상위전략으로 개념화가 가능하였다. 중국인 한국어 학습자의 어휘 학습전략의 사용 양상을 범주별로 살펴본 결과, 의미 발견 전략을 기억 강화 전략보다 더 많이 선호하는 것을 알 수 있었다. 구체적으로 7개의 상위전략별로 살펴보면 어휘 정보 활용 전략 > 선택적인 반복 전략 > 연관성을 활용한 기억 전략> 정의적(심리적) 불안 조절 전략 > 자기 주도적 인지 전략 > 사회적 요청 전략 > 어휘 의미 강화 전략의 순으로 나타났다. 또한, 학습자 요인에 따른 어휘 학습전략의 차이분석을 한 결과 성별에 따라 여성이 남성에 비해 전략을 더 많이 사용함을 알 수 있었다. 학습자 연령에 따르면 20대 초반(20~24세) 학습자와 20대 후반 (25~29세) 학습자 간 차이가 유의미하게 나타났다. 숙달도에 따른 차이 분석에서는 전반적으로 초급, 중급 학습자들이 고급 학습자에 비해 전략 활용도가 높았다. 학습자의 제1외국어(영어, 한국어)에 따라서는 유의미한 차이를 보이지 않았고 학습 기간에 따라 4년 이상 학습자와 1년 미만인 학습자 간에 유의미한 차이를 확인할 수 있었다. 다음으로 연령, 숙달도와 어휘 학습전략 간의 상관관계를 살펴 본 결과, 숙달도와 어휘 학습전략 간의 상관관계가 유의미하게 나타났다. 이로 인해 숙달도별 하위전략 사용의 순위는 어휘 의미 강화 전략의 핵심어를 활용한 전략이나 사회적 요청 전략의 모국어로 번역을 부탁하는 전략이 숙달도가 낮을수록 상관관계가 높았다. 그리고 어휘 정보 활용 전략에 속하는 글의 문맥 또는 전후 관계를 통해 의미를 추측하는 전략이 중국인 한국어 학습자의 숙달도 향상에 도움을 줄 수 있는 전략임을 확인하였다. 또한, 학습자의 숙달도에 영향을 미치는 어휘 학습전략을 분석한 결과, 어휘 정보 활용 전략의 글의 문맥 또는 전후 관계를 통해 의미를 추측하는 전략과 정의적(심리적) 불안 조절 전략의 어떤 경우에 어떤 어휘를 사용 할지를 잘 아는 전략은 학습자의 숙달도에 긍정적인 영향을 미치고 어휘 의미 강화 전략중에서 다른 사람에게 퀴즈를 통해 어휘를 기억하는 전략은 긍정적인 영향을 미치지 못하였다는 것이 확인되었다. 이상과 같이, 본 연구는 중국인 학습자의 특성을 밝힐 수 있는 어휘 학습 전략의 범주와 세부 전략을 추출하여 고찰하였다. 이러한 연구 결과는 중국인 학습자들을 대상으로 하는 어휘 학습 교육 방안을 강구하는 데 유용한 기초 자료를 제공할 수 있다는 점에서 의의를 찾을 수 있을 것이다.The purpose of this study is to analyze the factors of the vocabulary learning strategy of Chinese Korean learners, reveal their characteristics, and explore the effective teaching and learning direction of the vocabulary learning strategy by analyzing the vocabulary learning strategy and its relationship with the learner factor. Until now, vocabulary teaching and its necessity has been largely disregarded and considered a personal problem for learners. However, Chinese learners are likely to lose interest in foreign language learning itself because they do not use vocabulary learning strategies effectively when they encounter new vocabulary. This evident when Chinese learners, after spending a lot of time memorizing Korean vocabulary recklessly, do not know the exact usage of words. Recognizing these problems, this study conducted research on vocabulary learning strategies useful for Chinese Korean language learners. To achieve this, this study first explains the goals and needs of the study, as well as reviewing second language education and prior research in Korean language education in relation to vocabulary learning strategies in Chapter I. Based on the existing research, Chapter II examined the concept of Korean vocabulary, the status of vocabulary education, the concepts and classification systems of language learning strategies in addition to vocabulary learning strategies, and selected learners' factors that affect vocabulary learning strategies. In Chapter III, 577 Chinese Korean language learners were surveyed by developing tools for measuring vocabulary learning strategies tailored to the characteristics of Chinese Korean language learners; creating a questionnaire consisting of two categories of semantic discovery strategies and memory enhancement strategies, six higher-level strategies and 61 lower-level strategies. The results of the survey were analyzed through Factor analysis, descriptive statistics, independent sample T-Test, one-way AVOVA, Correlation analysis, and Multiple regression analysis.  The findings of the study were produced in Chapter IV, and are as follows. Firstly, the perception survey of vocabulary learning found that learners were highly aware of the importance and necessity of vocabulary learning. Through the factor analysis assessment, we were able to derive seven higher-level strategies and 30 lower-level strategies in two categories: meaning discovery strategies and memory enhancement strategies tailored to the characteristics of Chinese Korean language learners. These strategies were further categorized into seven strategies: strengthening vocabulary and meaning, social request strategies, memory strategy using association, self-directed cognitive control strategies, selective iterative strategies, vocabulary information utilization strategies, and affective (psychological) anxiety control strategies. After looking at the usage patterns of vocabulary learning strategies of Chinese Korean language learners by category, we can see that they prefer semantic discovery strategies to memory enhancement strategies. Specifically, if you look at each of the seven top strategies, it appears in the order of vocabulary information utilization strategies > selective iterative strategies > memory strategy using association > affective (psychological) anxiety control strategy > self-directed cognitive control strategies > social request strategy > strengthening vocabulary and meaning strategy. In addition, a difference analysis of vocabulary learning strategies based on learner factors showed that women use strategies more than men. According to the Natural Learning Ordinance, there was a significant difference between learners in their early 20s (ages 20 to 24) and learners in their late 20s (ages 25 to 29). Overall, beginner and intermediate learners were more likely to use strategies than advanced learners in the analysis of differences in proficiency. The experience of learning a first foreign language did not show any significant difference, and significant differences could be identified in the period of learning, particularly between learners of more than four years and learners of less than one year. According to the difference analysis results, the correlation between age, proficiency, learning period, and vocabulary learning strategy was significant. As a result, the lower the level of mastery, the higher the correlation between strategies utilizing the core words of the strengthening vocabulary and meaning strategy through the ranking of the use of sub-strategies by mastery, or strategies that ask others to translate vocabulary into Chinese through quizzes and social request strategies. Also, the strategy of guessing the meaning through context, or by analyzing previous parts of text after finding unknown words was identified as a strategy that could help improve the proficiency of Chinese Korean language learners. In addition, an analysis of vocabulary learning strategies affecting learners' proficiency confirmed that strategies to guess meanings through contexts or contexts of vocabulary information utilization strategies, and strategies to know what vocabulary to use through affective (psychological) anxiety control strategy, had a positive impact on learners' proficiency and a strategy to remember vocabulary through quizzes to others in strengthening vocabulary and meaning strategy, did not have a positive impact. To conclude, this study identified and considered the detailed categories of vocabulary learning strategies that could reveal the characteristics of Chinese Korean language learners. These findings may be meaningful in that they can provide basic data useful for the development of lexicon learning teaching methods for Chinese learners.Ⅰ. 서론 1 1. 연구 목적 및 필요성 1 2. 선행연구 5 2.1. 제2언어교육에서의 어휘 학습전략 5 2.2. 한국어교육에서의 어휘 학습전략 10 3. 연구 대상 및 연구 방법 16 Ⅱ. 어휘 학습전략의 이론적 배경 19 1. 어휘의 개념과 어휘교육 19 1.1. 어휘의 개념 19 1.2. 어휘교육의 위상 21 2. 어휘교육에서의 어휘 학습전략 24 2.1. 언어 학습전략의 개념 24 2.2. 어휘 학습전략의 개념 26 3. 어휘 학습전략의 분류 28 3.1. 의미 발견 전략 35 3.2. 기억 강화 전략 37 4. 어휘 학습전략에 영향을 미치는 학습자 요인 41 Ⅲ. 어휘 학습전략의 분석 방법 및 절차 45 1. 연구 대상 및 자료 수집 방법 45 1.1. 연구 대상 45 1.2. 자료 수집 방법 47 2. 어휘 학습전략의 측정 도구 47 2.1. 도구 개발 절차 47 2.2. 도구 개발 과정 50 3. 예비 실험 62 3.1. 예비 실험 참여자 62 3.2. 예비 실험 절차 및 결과 63 4. 본 실험 64 4.1. 신뢰도 검증 64 4.2. 타당도 검증 65 5. 자료 분석 방법 및 절차 66 Ⅳ. 어휘 학습전략의 분석 결과 68 1. 어휘 학습에 대한 인식 양상 68 2. 어휘 학습전략의 요인분석 70 3. 어휘 학습전략 요인별 연관성 분석 75 4. 어휘 학습전략의 사용 양상 80 4.1. 의미 발견 전략별 사용 양상 87 4.1.1. 어휘 정보 활용 전략의 사용 양상 87 4.1.2. 사회적 요청 전략의 사용 양상 89 4.2. 기억 강화 전략별 사용 양상 90 4.2.1. 어휘 의미 강화 전략의 사용 양상 90 4.2.2. 연관성을 활용한 기억 전략의 사용 양상 92 4.2.3. 자기 주도적 인지 조절 전략의 사용 양상 93 4.2.4. 선택적인 반복 전략의 사용 양상 94 4.2.5. 정의적(심리적) 불안 조절 전략의 사용 양상 96 5. 학습자 요인에 따른 어휘 학습전략의 차이 분석 97 5.1. 성별에 따른 어휘 학습전략의 차이 97 5.2. 연령에 따른 어휘 학습전략의 차이 105 5.3. 숙달도에 따른 어휘 학습전략의 차이 117 5.4. 학습자의 제1외국어에 따른 어휘 학습전략의 차이 128 5.5. 학습 기간에 따른 어휘 학습전략의 차이 130 6. 어휘 학습전략과 학습자 요인의 상관관계 134 7. 논의 및 교육적 함의 147 Ⅴ. 결론 150 *참고문헌 155 *부 록 1 167 *부 록 2 171 *ABSTRACT 177Maste

p-Type CaFe2O4 semiconductor nanorods controllably synthesized by molten salt method

Pure phase, regular shape and well crystallized nanorods of p-type semiconductor CaFe2O4 have been fabricated for the first time by a facile molten salt assisted method, as confirmed by XRD, TEM, SEM and HRTEM. UV-vis diffuse reflectance spectra and Mott-Schottky plots show that the band structure of the CaFe2O4 nanorods is narrower than that of the CaFe2O4 nanoparticles synthesized by conventional method. The enhancement of the visible-light absorption is due to narrowness of the band gap in CaFe2O4 nanorods. The appropriate ratio between the molten salt and the CaFe2O4 precursors plays an important role in inhibiting the growth of the crystals along the (201) plane to give the desired nanorod morphology. This work not only demonstrates that highly pure p-type CaFe2O4 semiconductor with tunable band structure and morphology could be obtained using the molten salt strategy, but also affirms that the bandgap of a semiconductor may be tunable by monitoring the growth of a particular crystal plane. Furthermore, the facile eutectic molten salt method developed in this work may be further extended to fabricate some other semiconductor nanomaterials with a diversity of morphologies. (C) 2016 Science Press and Dalian Institute of Chemical Physics. All rights reserved

Effect of Dietary Supplemented with Mulberry Leaf Powder on Growth Performance, Serum Metabolites, Antioxidant Property and Intestinal Health of Weaned Piglets

Background: The study aimed to explore the effect of mulberry leaf powder (MP) on the performance, serum metabolites and antioxidant property, as well as intestinal health, of weaned piglets. A total of 120 healthy piglets weighing 8.43 ± 1.91 kg (Duroc × (Landrace × Yorkshire); weaned at 28 d) were chosen and classified into four treatments with three replicates of 10 piglets each based on a randomized complete block design (barrow:gilt = 1:1). The diet treatments were a corn–soybean meal basal diet added with 0% (Ctrl), 2% (MP_2), 4% (MP_4) and 6% MP (MP_6), respectively. The feeding experiment was 28 days in total. The feeding period lasted for 28 days in total. Results: The diet supplemented with 2% MP had no detrimental effects on the growth performance, immunity, enzyme capacity and inflammatory factors, as well as intestinal barrier function. MP_2 is capable of decreasing the levels of serum D-lactic acid and lactate dehydrogenase, enhancing the superoxide dismutase capacity in the liver and diminishing the potential pathogenic bacteria Allisonella in the colon. However, compared with MP_2, MP_6 had unfavorable effects on the average daily gain and average daily feed intake; the concentration of serum non-esterified fatty acids; the activities of superoxide dismutase and glutathione peroxidase and the capacity of lipase and amylase, as well as the intestinal barrier function-related mRNA expression of occludin, claudin-1 and mucin-2 in piglets. Conclusion: Taken together, piglets fed with 2% MP had no adverse effect and was capable of improving the serum metabolites, enhancing the antioxidant capacity (SOD) and lowering the potential pathogenic bacteria of the hindgut (Allisonella). However, the highest concentration of MP (6%) may cause detrimental effects for piglets, which are probably associated with the higher antinutritional factors and fiber. Therefore, the dietary supplementation of 2% MP for piglets may be advisable

Splice form dependence of β-neurexin/neuroligin binding interactions

Alternatively spliced β-neurexins (β-NRXs) and neuroligins (NLs) are thought to have distinct extracellular binding affinities, potentially providing a β-NRX/NL synaptic recognition code. We utilized surface plasmon resonance to measure binding affinities between all combinations of alternatively spliced β-NRX 1-3 and NL 1-3 ectodomains. Binding was observed for all β-NRX/NL pairs. The presence of the NL1 B splice insertion lowers β-NRX binding affinity by ∼2-fold, while β-NRX splice insertion 4 has small effects that do not synergize with NL splicing. New structures of glycosylated β-NRXs 1 and 2 containing splice insertion 4 reveal that the insertion forms a new β strand that replaces the β10 strand, leaving the NL binding site intact. This helps to explain the limited effect of splice insert 4 on NRX/NL binding affinities. These results provide new structural insights and quantitative binding information to help determine whether and how splice isoform choice plays a role in β-NRX/NL-mediated synaptic recognition

Survival outcomes of abdominal radical hysterectomy, laparoscopic radical hysterectomy, robot-assisted radical hysterectomy and vaginal radical hysterectomy approaches for early-stage cervical cancer: a retrospective study

Abstract Background This study compared the survival outcomes of abdominal radical hysterectomy (ARH) (N = 32), laparoscopic radical hysterectomy (LRH) (N = 61), robot-assisted radical hysterectomy (RRH) (N = 100) and vaginal radical hysterectomy (VRH) (N = 45) approaches for early-stage cervical cancer to identify the surgical approach that provides the best survival. Methods Disease-free survival (DFS) and overall survival (OS) were calculated using the Kaplan–Meier method, and survival curves were compared using the log-rank test. Results The volume of intraoperative blood loss was greater in the ARH group than in the LRH group, the RRH group or the VRH group [(712.50 ± 407.59) vs. (224.43 ± 191.89), (109.80 ± 92.98) and (216.67 ± 176.78) ml, respectively; P < 0.001]. Total 5-year OS was significantly different among the four groups (ARH, 96.88%; LRH, 82.45%; RRH, 94.18%; VRH, 91.49%; P = 0.015). However, no significant difference in 5-year DFS was observed among the four groups (ARH, 96.88%; LRH, 81.99%; RRH, 91.38%; VRH, 87.27%; P = 0.061). Conclusion This retrospective study demonstrated that ARH and RRH achieved higher 5-year OS rates than LRH for early-stage cervical cancer