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1. chinaXiv:202002.00066 [pdf]

新型冠状病毒肺炎疫情的动力学分析和预测

诸葛昌靖; 张东艳; 杨武岳; 彭梁榕; 洪柳
Subjects: Mathematics >> Modeling and Simulation

基于经典动力学模型和模型参数自动优化算法, 本文分析了全国当前累计确诊感染病例数大于100(截止到2020年2月16日)的24个省市自治区, 以及湖北省除神农架以外的16个地市从2020年1月20日至2月16日的累计确诊病例数, 并对相应省市地区疫情可能的结束时间和总感染人数的进行了长期预测. 我们的研究表明, 在目前严防严控措施下, 全国大部分省市的疫情将于2月底前基本结束, 而湖北省内疫情也有望于3月中旬结束, 但是武汉市的疫情可能要持续到4月初. 通过对比公开数据与预测值, 我们建议加强对黑龙江、河北、江西、安徽、贵州和四川六省, 以及湖北省内武汉、荆州、鄂州、随州、天门和恩施六个地市的的监控, 以防疫情死灰复燃. 此外, 分析结果提示, 在疫情发展前期, 天津、河北、重庆、四川、海南和广西等省, 以及湖北省下辖多个地市可能存在着聚集性感染, 这有待于疫后进一步的流行病学调查确认.

submitted time 2020-02-25 Hits144Downloads109 Comment 0

2. chinaXiv:202002.00009 [pdf]

一种新型冠状病毒肺炎(COVID-19)药物与天然产物快速发现的计算药理学方法

全源; 梁峰吉; 熊江辉
Subjects: Biology >> Virology

新发传染病爆发流行期间,亟需提出候选药物功效与机制的科学假说。疫苗或新药研发均需要一定时间,因而药物重定位(老药新用)策略有其独特价值。但是新发疾病其病原体、宿主反应的临床数据不充分,制约了候选药物假设的提出。此阶段常根据病人临床特征进行广谱抗病毒药物的尝试。本文借鉴人工智能领域常见的启发式搜索思路,提出一种新方法(aCODE),基于前期有一定疗效提示的广谱抗病毒药,获得其宿主靶蛋白集合,在全基因组尺度上搜索与之相关性最高的基因模块组合,进而对候选化合物(如已批准上市药物、天然产物)进行模式匹配与统计检验排序。本方法可根据临床实践的进展更新输入药物,迭代输出更精准结果,输出的天然产物或中药、药食同源成分结合其它信息后可实施快速测试,形成敏捷研发测试闭环。本方法的第二版更新及其与文献证据的比对分析请参考:http://chinaxiv.org/abs/202002.00024。

submitted time 2020-02-21 Hits2408Downloads668 Comment 0

3. chinaXiv:202002.00033 [pdf]

Decoding evolution and transmissions of novel pneumonia coronavirus using the whole genomic data

Yu, Wen-Bin; Tang, Guang-Da; Zhang, Li; Corlett, Richard T.
Subjects: Biology >> Virology
Subjects: Biology >> Genetics

Background. The outbreak of COVID-19 started in mid-December 2019 in Wuhan, Central China. Up to February 18, 2020, SARS-CoV-2 has infected more than 70,000 people in China, and another 25 countries across five continents. In this study, we used 93 complete genomes of SARS-CoV-2 from the GISAID EpiFluTM database to decode the evolution and human-to-human transmissions of SARS-CoV-2 in the recent two months. Methods. Alignment of coding-regions was conducted haplotype analyses using DnaSP. Substitution sites were analyzed in codon. Evolutionary analysis of haplotypes used NETWORK. Population size changes were estimated using both DnaSP and Arlequin. Expansion date of population size was calculated based on the expansion parameter tau (τ) using the formula t=τ/2u. Findings. Eight coding-regions have 120 substitution sites, including 79 non-synonymous and 40 synonymous substitutions. Forty-two non-synonymous substitutions changed the biochemical property of amino acids. No evident combination was found. Fifty-eight haplotypes were classified as five groups, and 31 haplotypes were found in samples from both China and other countries, respectively. The rooted network suggested H13 and H35 to be ancestral haplotypes, and H1 (and its descendent haplotypes including all samples from the Hua Nan market) was derived H3 haplotype. Population size of SARS-CoV-2 were estimated to have a recent expansion on 6 January 2020, and an early expansion on 8 December 2019. Interpretation. Genomic variations of SARS-CoV-2 are still low in comparisons with published genomes of SARS-CoV and MERS-CoV. Phyloepidemiologic analyses indicated the SARS-CoV-2 source at the Hua Nan market should be imported from other places. The crowded market boosted SARS-CoV-2 rapid circulations in the market and spread it to the whole city in early December 2019. Furthermore, phyloepidemiologic approaches have recovered specific direction of human-to-human transmissions, and the import sources of international infectious cases.

submitted time 2020-02-21 Hits68432Downloads15595 Comment 0

4. chinaXiv:202002.00036 [pdf]

社会行为的效价信息对注意捕获的影响:基于帮助和阻碍行为的探讨

郑旭涛; 郭文姣; 陈满; 金佳; 尹军
Subjects: Psychology >> Cognitive Psychology

采用学习-测验两任务范式,通过三项实验探讨了社会行为的效价信息对注意捕获的影响。在学习阶段,被试观看具有积极效价的帮助行为(某智能体帮助另一智能体爬山)和消极效价的阻碍行为(某智能体阻碍另一智能体爬山),以及与各自运动特性匹配的无社会交互行为,其目的为建立不同智能体颜色与社会行为效价信息的联结关系。在测验阶段,则分别检验社会行为中的施动方(帮助者和阻碍者)颜色和受动方(被帮助者和被阻碍者)颜色的注意捕获效应。结果发现,消极社会行为中施动方颜色和受动方颜色均更容易捕获注意,而积极社会行为效价信息并没有改变联结特征值的注意捕获效应;且相比于受动方,与消极社会行为效价建立联结的施动方颜色的注意捕获效应更强。该结果提示,存在消极社会行为效价驱动的注意捕获,且消极的效价信息与卷入社会行为所有个体的特征建立联结,但该联结中施动方物理特征具有更高的注意优先性。这一发现暗示,声誉信息与对社会交互行为的整体表征可能综合作用于对社会交互事件的注意选择。

submitted time 2020-02-20 Hits184Downloads63 Comment 0

5. chinaXiv:202002.00028 [pdf]

新型冠状病毒(2019-nCoV)时空数据集及其典型应用

林浩; 鲍君雅
Subjects: Survey & Drawing Science and Technology >> Photogrammetry and Remote Sensing
Subjects: Statistics >> Biomedical Statistics

目前,新型冠状病毒(2019-nCoV)疫情正受到全球各科研工作者的广泛关注。然而,当前尚没有一个官方的渠道对2019-nCoV疫情数据进行实时开源,为了促进本次疫情相关的科研工作,本研究旨在为广大科研工作者提供权威的、开放的和多尺度的新型冠状病毒(2019-nCoV)时空数据集,为疫情监测、防控、预测和预警提供重要的数据来源。此外,该数据集还能应用于2019-nCoV疫情的多尺度、多时相制图和可视化,为疫情的空间分布、演化、趋势分析和模拟预测提供指导。

submitted time 2020-02-19 Hits2377Downloads384 Comment 0

6. chinaXiv:202002.00028 [pdf]

新型冠状病毒(2019-nCoV)时空数据集及其典型应用

林浩; 鲍君雅
Subjects: Survey & Drawing Science and Technology >> Photogrammetry and Remote Sensing
Subjects: Statistics >> Biomedical Statistics

目前,新型冠状病毒(2019-nCoV)疫情正受到全球各科研工作者的广泛关注。然而,当前尚没有一个官方的渠道对2019-nCoV疫情数据进行实时开源,为了促进本次疫情相关的科研工作,本研究旨在为广大科研工作者提供权威的、开放的和多尺度的新型冠状病毒(2019-nCoV)时空数据集,为疫情监测、防控、预测和预警提供重要的数据来源。此外,该数据集还能应用于2019-nCoV疫情的多尺度、多时相制图和可视化,为疫情的空间分布、演化、趋势分析和模拟预测提供指导。

submitted time 2020-02-17 Hits201Downloads130 Comment 0

7. chinaXiv:202002.00019 [pdf]

计算模型在道德认知研究中的应用

张银花; 李红; 吴寅
Subjects: Psychology >> Cognitive Psychology

道德认知关注道德心理背后的信息加工。近年来,研究者开始将计算模型应用于道德认知研究,以探索道德认知如何在大脑中实现。但目前研究者对道德认知进行计算建模的研究处于起步阶段。计算模型(漂移扩散模型、效用模型、强化学习模型和分层高斯过筛器模型)在道德认知行为和生理研究上的运用量化了道德决策、道德判断和道德推理背后的认知过程和神经机制。此外,这一新进展对理解反社会行为和精神障碍等有所助益。最后,计算建模有待完善,未来研究需要关注其潜在的问题。

submitted time 2020-02-12 Hits136Downloads42 Comment 0

8. chinaXiv:202001.00081 [pdf]

经前期综合征与奖赏进程失调——来自脑电的证据

侯璐璐; 陈莅蓉; 周仁来
Subjects: Psychology >> Experimental Psychology

研究表明,经前期综合征(Premenstrual syndromes, PMS)女性的情绪平衡性存在问题,而现有研究多从负性情绪上升的角度考察PMS的发病机制,而对其正性情绪缺损的关注不足。鉴于正性情绪与奖赏进程密切相关,本研究试图从奖赏进程失调的角度考察PMS女性与健康女性的差异以及该差异是否存在阶段特异性的问题,以期从正性情绪缺损的角度揭示其发病机制。具体而言,分别选取PMS女性与健康女性23名和22名,考察两组被试在黄体晚期(即经前期)和卵泡早期(即经后期)正性情绪以及完成赌博任务时的脑电数据时域和频域的差异。主观问卷结果显示,PMS女性的愉快和平静情绪低于健康女性,并且情绪平衡性也低于健康女性,但无明显的阶段特异性。时域分析结果显示,PMS组在经前期收到奖赏反馈后奖赏正波(reward positivity, RewP)的波幅和差异波(即奖赏条件和惩罚条件下的差值)的波幅均低于健康女性,进一步的相关分析结果显示,对于PMS组来说,经前期奖赏条件下的RewP波幅和差异波波幅与经前期的情绪平衡性显著正相关。频域分析的结果则发现PMS组在经前期奖赏条件下的θ频段(4~7Hz, 250~400ms)能量低于健康组。研究表明,PMS女性在经前期的奖赏加工进程存在异常,表现为对奖赏反馈的预期增强,而在收到奖赏反馈后又出现了钝化反应,且奖赏进程的失调与情绪平衡性相关。本研究为理解PMS女性奖赏进程失调的动态加工时程和神经震荡特征及其与情绪平衡性的关系提供了初步的神经生理证据。

submitted time 2020-01-10 Hits225Downloads129 Comment 0

9. chinaXiv:202001.00075 [pdf]

基于大规模古文语料库的词典构建及分词技术研究

邢付贵; 朱廷劭
Subjects: Psychology >> Applied Psychology

古文献的研究有助于传统文化的继承与发扬,而古文分词则是利用自然语言处理技术对古文献进行分析的重要环节,但由于缺少规范的数据资料而没有像现代汉语分词取得突破性进展。当前互联网拥有大量古汉语文本和词典方面的数据资料,但是这些数据分散,没有得到有效地整合。本文提出采集互联网非结构化古汉语数据,经过数据清洗和预处理抽取出一个古汉语基础词典,然后再利用互信息、信息熵、位置成词概率相结合的新词发现方法从大规模古籍文本中抽取古汉语候补词典,最终将基础词典与候补词典融合,利用正向最大匹配实现对古文的分词。与开源的分词器甲言在基于词典的分词方面比较后F值提高了14%,取得了良好的效果,结果证明本文构建的分词器可以应用在古汉语文本分词上。

submitted time 2020-01-07 Hits1165Downloads155 Comment 0

10. chinaXiv:202001.00046 [pdf]

A general self-consistent framework for studying cumulative displacement damage in nanostructured metals based on parameter passing and structural feedback between atomic and coarse-grained techniques

Xiangyan Li; Yange Zhang; Yichun Xu; Xuebang Wu; Xianping Wang; B.C. Pan; C.S. Liu; Q.F. Fang; Jun-Ling Chen; G.-N. Luo; Zhiguang Wang; X. Liu
Subjects: Materials Science >> Materials Science (General)

Nano-crystalline metals (NCs) exhibit radiation-tolerance due to the sink of grain boundaries (GBs) for radiation-induced defects such as self-interstitial atoms (SIAs) and vacancies (Vs). However, the relevant mechanisms for the radiation damage accumulation and GB structural relaxation under high radiation field in NCs are still not well understood due to the lack of self-consistent across-scale techniques for simulating radiation-induced microstructures evolution. In this article, by combining coarse-grained and atomistic simulations, we proposed a coupling method to investigate the evolution of the microstructure and SIA/V-GB interaction under cumulative irradiation in NC iron. The SIA overloaded effect was revealed in iron GBs at a high radiation dose rate and/or low temperature. Two types of GB structural response were observed to cumulative irradiation. With the SIA accumulated at the GB, the new GB phase formed and then a critical concentration of the SIA at the GB transited to the small quantity of the V during the GB structural recovery, accompanied by the local GB motion. Consequently, the GB’s role for Vs nearby alternated between the trapping and annihilation center with radiation dose. Alternatively, GB developed to a disordered structure after trapping abundant SIAs. The GB response pattern to cumulative irradiation that is related to the SIA formation energy at the GB or the GB thermal stability is well manifested in the cumulative distribution function of the defects formation energy and its energy level density. The present work reveals the dynamic healing picture for radiation damage near the GB under cumulative irradiation.

submitted time 2020-01-07 Hits995Downloads98 Comment 0

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