Electroencephalogram Signal Correlations between Default Mode Network and Attentional Functioning

Attentional issues may affect acquiring new information, task performance, and learning. Cortical network activities change during different functional brain states, including the default mode network (DMN) and attention network. We investigated the neural mechanisms underlying attentional functions and correlations between DMN connectivity and attentional function using the Trail-Making Test (TMT)-A and -B. Electroencephalography recordings were performed by placing 19 scalp electrodes per the 10 - 20 system. The mean power level was calculated for each rest and task condition. Non-parametric Spearman’s rank correlation was used to examine the correlation in power levels between the rest and TMT conditions. The most significant correlations during TMT-A were observed in the high gamma wave, followed by theta and beta waves, indicating that most correlations were in the parietal lobe, followed by the frontal, central, and temporal lobes. The most significant correlations during TMT-B were observed in the beta wave, followed by the high and low gamma waves, indicating that most correlations were in the temporal lobe, followed by the parietal, frontal, and central lobes. Frontoparietal beta and gamma waves in the DMN may represent attentional functions.

Factors Associated with Antiretroviral Therapy Defaulting among Adult Patients Receiving Care at Chikankata Mission Hospital, Chikankata District, Zambia

Background: Defaulting on antiretroviral therapy has been identified as the most important factor contributing to the antiretroviral therapy failure rate. This study aimed to investigate factors associated with defaulting on antiretroviral therapy among adult patients receiving care at Chikankata Mission Hospital antiretroviral therapy clinic. Method: Cross-sectional analytical study on 385 participants selected by a computer generated random numbers technique of simple random sampling from among the patients receiving antiretroviral therapy at Chikankata Mission Hospital. Data collected were processed and analysed using Statistical Package for Social Science version 27. Univariate and backward multivariable logistic regression analysis was performed to identify factors associated with antiretroviral therapy defaulting. The level of significance was set at 5% with a confidence level of 95%. Results: Over half (58.4%) of the study participants defaulted on antiretroviral therapy. About 65.8% of study participants indicated improved health as the reason they defaulted on antiretroviral therapy. Most participants indicated that it was important to always go for antiretroviral therapy services (Adjusted Odds Ratio 1.95;95% Confidence Interval: [1.14 - 3.33], p = 0.015). Very few participants indicated poor family support for antiretroviral therapy services (Adjusted Odds Ratio 4.08;95% Confidence Interval: [2.02 - 8.23], p Conclusion: Defaulting on antiretroviral therapy continues to be a significant problem and needs to be addressed as a matter of priority. More counselling and awareness-raising programmes are required to improve knowledge and understanding on the importance of attending scheduled antiretroviral therapy clinics and services as well as the consequences of defaulting on antiretroviral therapy.

Adverse selection,loan access and default behavior in the Chilean consumer debt market

Why do households use different types of loans?Which factors cause borrowers to default?Using a comprehensive survey dataset from Chile,I estimate a partial information model of consumer debt access,lender choice,loan amount and default.The model consists of a first-stage multinomial logit that explains the choice across the five loan types,plus the options of no access to debt due to credit constraints and a no wish for consumer debt.In the second and third stages,the model assumes a log-linear regression of the debt amount and a logit regression of the default behavior,accounting for the loan type selection probability.Identification is obtained using factors measured at different time periods for the default and the loan type choices.I find that households choose different lenders based on income,education and labor risks.Higher income and education decrease the probability of credit constraints,while increasing bank lending and debt amounts.Unemployment risk and household size increase the chances of all the loan types;however,unemployment decreases the debt amount.Age and wage volatility reduce the probability of all loans.Default decreases with income,education and age,whereas it increases with indebtedness,unemployment,household size,health shocks,and paying previous loans.Counterfactual exercises demonstrate that pension reform,higher requirements for borrowers’capacities,and financial literacy programs could substantially reduce default risk.Financial literacy could greatly reduce arrears,households with credit constraints,the number of debtors and the aggregate debt amounts,especially for non-bank lending.Highlights Chilean borrowers present heterogeneous adverse selection across lender types.No Debt Access decreases with income,age,education,but it increases with risk.Default is associated with income,unemployment,indebtedness and demographics.Paying past loans and health needs are associated with indebtedness and default.Financial literacy programs may be a powerful policy to improve the debt market.

一种DEFAULT密码算法抵抗差分故障攻击新方法

针对DEFAULT轻量级分组密码算法无法抵抗差分故障攻击的问题,利用横向混淆和线性码提出一种抵抗差分故障攻击的方法。该方法在算法实现冗余部分针对算法结构使用横向混淆(或纵向隐藏)的方式实现,并结合[10,4,6]线性码的1 bit纠错和4 bit检错能力对每个S盒进行防护。研究结果表明,该方法不仅提供了对算法半字节的纠错和所有比特位的检测能力,而且仅需要约25.08%的额外软件实现性能消耗。相较于已有的防护方法,该方法在通用性、故障检测效果及实现代价方面均有明显优势。

Supply-Side Structural Reform, Digital Economy and Corporate Default Risk

In recent years, a lot of corporate defaults have had an impact on the capital market. How to prevent corporate default risks has become an important topic of concern for the academic community, enterprises and the government. We took China’s A-share listed companies from 2012 to 2018 as a sample, and used the double difference method to analyze the impact of supply-side structural reforms on corporate default risks. We found that supply-side structural reforms have reduced the risk of corporate default, and the inhibitory effect has gradually increased. In the relationship between supply-side structural reforms and corporate default risks, corporate financing capabilities have played an intermediary role. Supply-side structural reforms can improve the company’s endogenous financing capabilities, thereby reducing the risk of corporate default. However, we also found that the mediating effect of a company’s exogenous financing capability is not significant. At the same time, the regression results show that the digital economy can play a regulatory role. It can not only actively regulate the relationship between supply-side structural reforms and corporate default risks, but also mediate the mediating effect of corporate endogenous financing capabilities. The results of this article provide some evidence for the synergy between supply-side structural reforms and the digital economy.

The default mode network is affected in the early stage of simian immunodeficiency virus infection:a longitudinal study

Acquired immune deficiency syndrome infection can lead to cognitive dysfunction represented by changes in the default mode network.Most recent studies have been cross-sectional and thus have not revealed dynamic changes in the default mode network following acquired immune deficiency syndrome infection and antiretroviral therapy.Specifically,when brain imaging data at only one time point are analyzed,determining the duration at which the default mode network is the most effective following antiretroviral therapy after the occurrence of acquired immune deficiency syndrome.However,because infection times and other factors are often uncertain,longitudinal studies cannot be conducted directly in the clinic.Therefore,in this study,we performed a longitudinal study on the dynamic changes in the default mode network over time in a rhesus monkey model of simian immunodeficiency virus infection.We found marked changes in default mode network connectivity in 11 pairs of regions of interest at baseline and 10 days and 4 weeks after virus inoculation.Significant interactions between treatment and time were observed in the default mode network connectivity of regions of interest pairs area 31/V6.R and area 8/frontal eye field(FEF).L,area 8/FEF.L and caudal temporal parietal occipital area(TPOC).R,and area 31/V6.R and TPOC.L.ART administered 4 weeks after infection not only interrupted the progress of simian immunodeficiency virus infection but also preserved brain function to a large extent.These findings suggest that the default mode network is affected in the early stage of simian immunodeficiency virus infection and that it may serve as a potential biomarker for early changes in brain function and an objective indicator for making early clinical intervention decisions.

基于XGBoost的中国上市公司违约风险预测模型

准确预测上市公司的违约风险,是企业信用风险评价的关键,也是金融机构信贷决策的重要依据。通过线性回归模型的信息量AIC遴选违约判别能力最大的指标组合,采用粒子群优化算法构建基于XGBoost的违约预测模型。选取中国A股3425家上市公司不同时间窗口的数据为样本进行违约预测,将所构建的PSO-XGBoost模型与逻辑回归、支持向量机等13种预测模型对比,验证所建模型的有效性。通过UCI数据库中的3个公开信用数据集,利用Friedman检验,验证所建模型的稳健性。研究表明:使用上市公司数据与13种模型对比,PSO-XGBoost模型提高了预测精度G-mean;使用3个公开信用数据集,在多个评价指标上,PSO-XGBoost模型的平均预测性能显著优于对比模型;通过指标对预测结果的贡献获得指标重要性得分,增强了预测模型的可解释性。研究发现:“资产负债率”“流动比率”“长期资本负债率”等财务指标对违约预测的影响最大,“行业景气指数”“社会消费品零售总额增长率”“流通中现金(M0)供应量同比增长率”等指标是影响违约预测的重要指标。本研究可以为提高违约风险预测的准确性提供有效的方法和实证证据,有助于加强上市公司违约风险的预警和防范,降低违约风险监管成本,为企业管理者、债权人及投资者提供良好的决策支持。

企业资源配置战略与债券信用评级

企业战略作为企业全局性、长期性资源配置的重要规划,对企业经营活动具有重要影响,也必然会影响企业的融资行为。本文从企业战略视角出发,以2008—2020年中国A股上市公司为研究对象,运用固定效应模型探究了企业资源配置战略对债券信用评级的影响。研究发现:相对于经营主导型企业,投资主导型企业的债券信用评级更低,并且该结论在处理内生性问题和进行一系列稳健性检验后依然成立。异质性分析发现,企业资源配置战略对债券信用评级的影响在非国有企业和分析师跟踪人数多的企业中更明显。中介效应检验结果表明,企业资源配置战略通过作用于企业违约风险而影响债券信用评级。本文的研究结论对发债企业、信用评级机构和债券市场投资者具有重要启示意义。

基于独立成分分析重症肌无力患者的静息态默认网络的功能连接改变及其与认知障碍的相关性

目的研究重症肌无力(myasthenia gravis,MG)患者大脑默认网络(default mode network,DMN)功能连接的改变,以及DMN和认知功能的关系。方法前瞻性纳入2020年1月至2022年12月就诊于苏州大学附属第一医院神经内科的MG患者39例,另选取同期性别、年龄、受教育年限、种族与MG患者匹配的40名健康志愿者作为健康对照组。对所有受试者进行神经心理学测试、情绪评估及静息态磁共振功能扫描。采用独立成分分析技术评估受试者大脑DMN的功能连接变化。采用Spearman相关性分析MG患者差异脑区的DMN的功能连接值与认知功能的相关性。结果MG组整体认知功能〔简易精神状态量表(MMSE)和蒙特利尔认知评估量表(MoCA)评分〕、言语学习和记忆能力(Rey听觉词语学习测验、词语流畅性测试)、视空间功能(钟表测试)评分均较对照组降低(均P<0.01);在执行能力测试方面,MG组连线功能测试完成时间长于对照组(P<0.01);MG组汉密尔顿焦虑量表和汉密尔顿抑郁量表评分均高于对照组(P<0.01)。独立成分分析结果显示,MG患者的DMN内功能连接在左后扣带回比对照组减弱(P<0.05,经过FDR校正)。MG患者的DMN内左后扣带回功能连接值与MMSE评分、数字符号转换测验评分呈正相关(P<0.05),而与连线测验A和B时间呈负相关(P<0.05)。结论MG患者在整体认知功能、言语学习和记忆力、视空间功能和执行功能方面下降,在左后扣带回的DMN内功能连接减弱,差异脑区在DMN内功能连接值与认知评分存在相关性,提示MG患者的认知功能损害可能与中枢神经系统受累有关。

地区失信环境与企业现金持有——来自失信被执行人的经验证据

构建相互信任的营商环境是经济高质量发展的基础。基于最高人民法院公布的失信被执行法人数据,实证检验地区失信环境对企业现金持有水平的影响并揭示其主要作用机制。研究发现:企业所在地区的失信被执行人越多,其现金持有水平越高;机制检验发现,失信环境能够加剧企业融资约束程度、增加费用支出和降低经营绩效,内外部资金来源受限以及增加的费用支出迫使企业出于预防性动机持有更高水平的现金;进一步检验发现,当企业的会计信息质量较差、规模较小时,失信环境中的企业需持有更多的现金以应对潜在风险。这些结论从现金持有的角度丰富了对失信环境经济后果的研究,为持续优化营商环境和完善社会信用体系提供了借鉴思路。

井工煤矿甲烷排放精准监测与核算

甲烷作为全球第二大温室气体,具有增温潜势高、寿命短的特点,主要来源于煤炭、油气生产、农业、畜牧业和废弃物处理等领域。积极稳妥有序控制甲烷排放,兼具减缓全球温升的气候效益、能源资源化利用的经济效益、协同控制污染物的环境效益和减少生产事故的安全效益。甲烷也是煤矿生产排放中最主要的温室气体,目前对煤矿甲烷的排放监测及其在煤矿三维立体空间内的浓度分布研究将成为我国甲烷排放控制行动的重点,对煤矿企业更好顺应国家战略具有重要意义。选取山西某高瓦斯矿井、陕西某低瓦斯矿井进行甲烷排放监测核算,以固定监测、手工监测、无人机监测及矿后活动监测等方式研究我国高低瓦斯矿井甲烷分布,并对其甲烷排放量开展分析。结果表明:①美国Climate TRACE网站公布的山西某高瓦斯矿井、陕西某低瓦斯矿井2022年度甲烷排放量与实测法计算的结果差异较大,其中公布的某低瓦斯矿井年度甲烷排放量为实测法计算结果的10.92倍,自上而下的监测核算方法准确性不足,无法为碳交易提供可靠的数据支持。②矿后活动监测核算发现,采用IPCC缺省值计算的矿后活动甲烷排放量是实测法计算的3~5倍,且不同粒径和暴露时间下煤样反馈的矿后活动排放量差异较大。亟需一套统一精准的测试标准,为未来碳市场交易提供公平准确的数据。

我国社会信用体系建设面临的主要挑战及对策建议

党的十八大以来,国家高度重视社会信用体系建设,在一些基础领域和关键环节取得了重要进展,总体社会信用状况得到明显改善。然而,社会信用体系建设是一项长期且极为复杂的系统工程,目前仍面临着理论研究和法治建设滞后,社会信用体系建设的目标定位和功能边界不够清晰,商务征信体系不健全、企业账款拖欠严重,以及其他发展不平衡不充分等问题。建议在系统总结前期经验教训的基础上,加强理论研究,厘清认识和实践误区,进一步明确社会信用体系建设的目标定位和功能边界,加快推进信用立法,健全商务信用体系,破解企业账款拖欠难题,大力发展信用经济,并做好面向公众的宣传引导工作。

静息态功能磁共振成像在血管性认知障碍患者默认网络研究中的应用进展

血管性认知障碍是由脑血管疾病导致的一种从轻度认知功能障碍至痴呆的综合征,由于缺乏敏感性和特异性生物标志物,早期不易鉴别和诊断。血管性认知障碍患者脑网络连接异常的脑区多位于默认网络,其异常变化的功能连接与患者的认知障碍程度相关。静息态功能磁共振成像技术是一种常用的检测静息态大脑内在活动的方法,应用静息态磁共振不同分析技术探索血管性认知障碍患者默认网络异常变化有助于深入研究血管性认知障碍的发病机制,并提供客观的影像依据。该文主要综述静息态功能磁共振成像技术在血管性认知障碍患者默认网络研究中的应用成果,为血管性认知障碍的精准诊断和评估提供新思路。

城门失火殃及池鱼吗?来自债券违约的分析

近年来,我国债券违约事件频发,对债券市场的平稳运行造成威胁。以2020年11月永煤债券违约为外部冲击,从地区、行业、评级机构与承销商四个层面,基于2020年债券市场日度数据,利用事件研究法与双重差分模型分析了AAA级国有企业债券违约对债券市场影响的溢出效应。研究发现,永煤债券违约事件导致债券一级市场发行规模缩小与发行成本提升,并显著提高了二级债券市场存续债券的回报。从短期市场反应来看,违约事件造成的负面溢出效应(异常回报提升)同时存在于地区、行业、评级机构与承销商层面;从长期影响来看,违约事件导致的存续债券收益率提升的负面冲击仅在地区和行业间存在。异质性分析表明,违约事件对低承付能力地区、低市场竞争程度行业、由内资背景机构评级以及低声誉机构承销的债券负面影响更加显著。进一步检验发现,上述短期负面溢出效应在高等级(AAA)债券组中更加显著,并且评级机构的评价标准并没有受到该违约事件的影响,说明信用评级膨胀问题仍然严重。因此,监管部门应加强对债券市场的引导,从债券市场信息中介(评级机构与承销商等)角度采取措施来防范与降低债券违约风险。

金融科技能够抑制企业过度负债吗?

本文以2011—2021年中国上市公司为研究样本,采用北京大学数字普惠金融指数度量金融科技发展水平,实证检验金融科技对企业过度负债的影响。研究结果表明,金融科技能够助力银行等金融机构提升事前的信息甄别能力和加强事后的债权人监督功能,继而抑制企业过度负债行为。进一步的研究显示,金融科技对企业过度负债行为的抑制作用在国有企业和产品市场竞争程度低的行业企业中更加显著,并且金融科技能够通过抑制过度负债而降低企业债务违约风险。本文不仅在理论上丰富了金融科技影响效应和企业过度负债缓解机制的文献,而且在实践上为利用金融技术进步推动微观企业优化资本结构,助力实体经济高质量发展提供了依据。

货币政策不确定性与企业债务成本

降低企业债务融资成本是促进实体经济高质量发展的重要举措。选取2007—2020年A股非金融上市公司数据,系统考察货币政策不确定性对企业债务成本的影响。研究结果表明,货币政策不确定性与企业债务成本显著正相关。影响机制分析发现,债务违约概率是货币政策不确定性影响企业债务成本的中间变量,即货币政策不确定性上升会增加企业债务违约概率,从而导致企业债务成本上升。异质性分析发现,货币政策不确定性对非国有企业、小规模企业及非周期性行业企业债务成本的正向影响更加明显。研究表明降低货币政策不确定性对于缓解企业债务成本压力具有重要作用。

学前儿童否定结构语用发展研究

基于默认语义学理论,采用自然观察法,考察不同年龄段汉语学前儿童否定结构的语用发展特征。结果表明,随着年龄的增长,儿童逐渐使用复杂的否定形式,较多将否定词“不”放在句首,常见否定词“不”放在句中,将否定词“不”放在句尾的情况罕见。否定词“不”的移动过程与儿童的心智认知水平、语境要素语言化能力发展水平和语境依赖度有关,体现了语言使用的经济原则;儿童否定结构的使用建立在预设基础上,其语义表征受不同因素的制约,呈现出不同的语用发展过程。本研究旨在探索儿童否定结构语用发展规律,为儿童否定结构学习与语用能力的发展提供借鉴。

《民法典合同编通则解释》违约责任制度的亮点与盲点

《民法典合同编通则解释》未固步自封、画地为牢,在解释之外也创新发展了《民法典》规则,尤其是违约方终止合同时点、替代交易、违约金酌减等违约责任制度呈现诸多亮点与盲点。在违约方终止合同时点问题上,司法部门犹若“摇晃的钟摆”,长期摇摆于通知解除与司法解除之间。解释的方案貌似折中调和,却违背违约方终止的司法解除性质,又产生与同属司法解除的情势变更规则不一致的“精神分裂症”。替代交易是“虚拟的强制履行”,该规则不意味着替代交易行为只能在合同解除后实施。替代交易规则受到合理性规则限制和减损规则制约,但替代交易本身并非义务。解释“以旧瓶装新酒”,实现了对违约金酌减规则的升级再造。特别是在违约金不得调整约定之效力、违约金酌减的计算基础与考量因素、违约金不得酌减之情形等几个方面积极作为,虽尚有探讨斟酌之处,但进取创新精神仍值赞许。

出资义务加速到期规则的解释论

面对注册资本完全认缴制所产生的问题,2023年修订后的《公司法》对有限责任公司改采了限期认缴制,并引入了催缴失权、加速到期等规则予以完善。《公司法》第54条规定,公司不能清偿到期债务的,公司或者已到期债权的债权人有权要求已认缴出资但未届出资期限的股东提前缴纳出资。该条款简明扼要,涵盖了加速到期条件、请求权主体、出资财产入库公司等三重面向。本条规定体现了立法机关的价值判断,实质上系对公司、股东、债权人利益的衡量安排,以公司利益为该制度构建的基点和本旨。该利益衡量方案契合公司法的价值体系,在构成上包括三项旨意:以停止支付而非支付不能为加速到期标准;以公司资本需求为本位允许公司要求加速到期;以入库规则为通道保障公平清偿债权。在规范适用上,出资义务加速到期规则衔接董事催缴义务和催缴失权制度,可以协同保障公司的资本需求和公司利益。

核电厂安全级数字化仪控系统故障缺省值的验证与确认

安全级数字化仪控系统中故障缺省值的设置对核电厂安全具有至关重要的作用,但其验证与确认的难点在于具体实施时缺乏明确的细则指导。基于IEEE Std 1012,结合对法规标准、缺省值设计原则及以往项目实施经验的分析,同时考虑到漳州核电一期项目数字化仪控系统平台及设计开发流程的特点,提出了一套针对安全级数字化仪控系统故障缺省值的验证与确认策略和方法。经过漳州核电一期的实践验证,这套策略和方法能够充分、高效地验证缺省值设计的正确性和完整性,有效缓解了验证与确认过程中缺乏详尽标准、理论及相关成熟经验可借鉴的困境。对于后续核电安全级数字化仪控系统故障缺省值的验证与确认工作,该策略和方法具有一定的参考价值。