Fine particulate matter exposure during pregnancy and infancy and incident asthma

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Figures of merit to compare distributed linear inverse solutions

Summary This paper introduces the concept of the resolution matrix as the basis for an objective theoretical comparison of distributed linear inverse solutions to the neuroelectromagnetic inverse problem. In particular, we describe how figures of merit derived from the resolution matrices can be represented graphically to evaluate merits and shortcomings of the different solutions. The use of the figures of merit is illustrated with two solutions that consider minimal a priori information about the generators: Classical Minimum Norm and Backus Gilbert. We recommend to start any analysis with the individual exploration of the resolution kernel for each grid point or at least for those points where the activity is likely to occur. This analysis might help in selecting the optimal inverse for the sources that are supposed to be active in the process under study.This work was supported by a grant from the Deutsche Forschungsgemeinschaft (Klinische Forschergruppe Biomagnetismus and Biosignalanalyse). Partial support was received from Swiss National Foundation grant 4038-044081/1.     

利用Snort构建DIDS

随着internet的发展,网络越来越复杂,网络安全越来越受到人们的关注。本文主要介绍了如何利用Snort在Linux平台上搭建分布式的入侵检测系统。     

南充市自发性脑出血发病与气温的相关性及滞后效应

目的分析南充市自发性脑出血（sICH）发病与气温的相关性及滞后关系。 方法收集南充市全市范围内二级以上医院2014年1月至2018年12月收治的sICH患者病例资料及同期气温数据,利用Spearman等级相关法确定最佳温度指标,将其组建分布滞后非线性模型,评估其与sICH日发病风险的暴露-剂量反应关系,分层分析各温度节点在性别及年龄组别的滞后-剂量反应关系。 结果共收集sICH患者资料13 952例。Spearman相关性分析揭示sICH日发病人数与日均气温呈非线性负相关（r=-0.324,P<0.05）。分布滞后非线性模型分析结果表明极低温和低温当天sICH的相对危险度为1.68（1.35~2.08）及1.47（1.24~1.72）,危害效应最大,其随着滞后天数增加而减弱,极低温滞后1~2 d,低温持续滞后1~10 d。低龄组（18~60岁）在极低温、低温下滞后2 d,高龄组（>60岁）在极低温下滞后10 d,低温下滞后24 d。不同性别组在极低温、低温下滞后效应趋势一致,随滞后天数增加风险下降。 结论低温增加sICH发病风险,早期呈明显急性影响,且具有滞后效应,老年人对低温反应更加滞后。     

兰州市日均气温对两所三甲医院门诊湿疹人次的影响

目的 探讨兰州市日均气温对门诊湿疹人次的影响.方法 收集2007年1月1日至2015年12月31日兰州地区两所三甲医院皮肤科门诊湿疹患者的资料和同时期气象数据,在控制长期趋势、星期几效应的基础上,采用分布滞后非线性模型,通过quasi-Poisson连接函数进行拟合,并根据季节、性别和年龄分层后分析日均气温对湿疹门诊人次的影响.结果 日均气温与湿疹门诊人次的暴露-反应关系大致呈“W”型.按照季节、性别、年龄分层后,日均气温改变对湿疹门诊人次的影响主要以秋、冬季为重,夏季次之,春季最弱.低温对湿疹的影响可能存在滞后作用、累积作用及持续作用,即在-9℃、滞后14d时,RR值为1.12(95％ CI:1.03～ 1.22),达到最大,且温度每降低1℃,男性、青少年、中年人群湿疹发病的风险分别增加16％(RR:1.16,95％ CI:1.05～ 1.27)、14％(RR:1.14,95％ CI:1.02 ～ 1.26)及13％(RR:1.13,95％ CI:1.02～1.25),均有统计学意义(P＜0.05);而在女性及老年人群中,低温对湿疹的影响均不具有统计学意义(P＞ 0.05).高温的影响效应在暴露当天即已出现,随着滞后日的推移其影响效应渐减弱,但这种效应无统计学意义(P＞ 0.05).结论 在兰州地区日均气温对湿疹门诊人次的影响以秋、冬季为重,日均气温的改变可能为湿疹患者的危险因素之一,且低温对湿疹的影响存在滞后作用,滞后时间约为14d.     

基于正则化方法的加权最小模估计在脑磁源成像中的应用

脑磁图 ( m agnetoencephalography,MEG)逆问题的研究 ,根据点源和分布源两种源模型 ,可分为偶极子定位和磁源成像两大类求逆方法。采用非参数的分布源模型 ,MEG逆问题转化为一个病态的欠定方程组的求解。本文系统地阐述了结合 Tikhonov正则技术的加权最小模磁源重建方法 ,着重介绍了深度归一化算法、低分辨率脑电磁断层成像技术、局部欠定系统解法、选择性最小模方法 ,此外还从广义的加权最小模估计角度对最大熵重建方法 ,融合其它脑功能成像技术的方法以及最大后验概率估计方法加以解释和分析。不同的磁源成像方法目的都是通过引入合适的约束条件 ,从算法公式本身及神经细胞活动的特性中加以修正 ,减少逆问题的不适定程度 ,因此均可认为是使用正则方法来约束解空间 ,从而获得与测量磁场数据相拟合的并具有神经生理学和解剖学意义下的最合理的解。基于正则化技术的加权最小模估计是 MEG逆问题研究中最早开展、并已被广泛应用的磁源分布图像重建方法 ,本文给出了一个较为完整的理论发展框架     

EXpectation Propagation LOgistic REgRession (EXPLORER): Distributed privacy-preserving online model learning

We developed an EXpectation Propagation LOgistic REgRession (EXPLORER) model for distributed privacy-preserving online learning. The proposed framework provides a high level guarantee for protecting sensitive information, since the information exchanged between the server and the client is the encrypted posterior distribution of coefficients. Through experimental results, EXPLORER shows the same performance (e.g., discrimination, calibration, feature selection, etc.) as the traditional frequentist logistic regression model, but provides more flexibility in model updating. That is, EXPLORER can be updated one point at a time rather than having to retrain the entire data set when new observations are recorded. The proposed EXPLORER supports asynchronized communication, which relieves the participants from coordinating with one another, and prevents service breakdown from the absence of participants or interrupted communications.     

全局频繁闭项目集挖掘算法研究

频繁闭项目集挖掘是数据挖掘研究中的一个重要研究课题.目前已有的频繁闭项目集挖掘算法主要针对单机环境,有关分布式环境下的全局频繁闭项目集挖掘算法的研究尚不多见.为此,本文提出了一种快速挖掘全局频繁闭项目集算法,并对其更新问题进行了研究;提出了一种相应的频繁闭项目集增量式更新算法,该算法将充分利用先前的挖掘结果来节省发现新的全局频繁闭项目集的时间开销.实验结果表明算法是有效的.     

A cross-platform model for secure Electronic Health Record communication

During the past decade, there have been many regional, national and European projects focused on the development of platforms for secure access and sharing of distributed patient information. A platform is needed because present local or enterprise-wide information systems are typically not intended for cross-organisational secure access of patient data. Most of the present secure platforms are local or regional. Commonly used platform types in the health care environment vary from secure point-to-point communication systems to internet-based portals. This paper defines an enhanced cross-security platform which makes it possible for different kinds of local, regional, and national health information systems to communicate in a secure way. The proposed evolutionary way interconnects regional or national security domains with the help of a cross-platform zone. A more revolutionary model based on peer-to-peer Grid like networks and dynamic security credentials is also discussed. The proposed evolutionary model uses cross-domain security and interoperability services to ensure secure communication and interoperability between different security domains. The platform supports both communication defined beforehand and adhoc dynamic access to distributed electronic health records (EHRs). The internet is proposed as the "glue" between different regional or national security domains.     

Clinical cognition and embodiment

I first identify two different distinctions: between Cartesian cognition and embodied cognition, and between calculative rationality and intuitive know-how. I then suggest that, in the nursing literature, these two distinctions are run together, to create an opposition between 'Cartesian rationality' and 'embodied know-how'. However, it is vital to keep the two distinctions apart, because 'embodied knowing' is very frequently rational. In separating the idea of embodied cognition from non-rational intuition, I show how 'embodiment' leads to the concepts of distributed cognition and distributed expertise. This has extensive and important implications for how we understand clinical cognition in nursing.