Chronobiology of sleep in humans

Periodic circadian (24-h) cycles play an important role in daily hormonal and behavioural rhythms. Usually our sleep/wake cycle, temperature and melatonin rhythms are internally synchronized with a stable phase relationship. When there is a desynchrony between the sleep/wake cycle and circadian rhythm, sleep disorders such as advanced and delayed sleep phase syndrome can arise as well as transient chronobiologic disturbances, for example from jet lag and shift work. Appropriately timed bright light is effective in re-timing the circadian rhythm and sleep pattern to a more desired time, ameliorating these disturbances. Other less potent retiming effects may also be obtained from the judicious use of melatonin and exercise.     

Internal interactions within the human circadian system: the masking effect

Summary In the realm of human circadian rhythms, the masking effect is defined as the change in the course of deep body temperature induced by changes in the degree of physical activity, or by the alteration between sleep and wake. This effect is particularly obvious during internal desynchronization where the rhythms of deep body temperature, and the sleep-wake sleep-wake sleep cycle — i.e. one of the masking factors — run with different periods.Every sleep onset is accompanied by a rapid drop, and wake onset by a rapid rise in deep body temperature, each one with an overshoot of about 50% of the steady state variations. When rhythms are calculated, with the dominant temperature period as the screening period, exclusively from data obtained during sleep episodes, on the one hand, and from those obtained exclusively during wake, on the other, two average cycles emerge: the sleep temperature curve and the wake temperature curve. Both run in parallel but are separated by the masking effcct. As derived from many experiments, the mean masking effect amounts to 0.28±0.06°C. The masking effect also depends to some extent on the phase of the temperature rhtthm; it is larger than average around the temperature maximum and during the descending phase of the temperature cycle, where the alertness commonly is highest and the probability to sleep, in general, and the REM sleep propensity, in particular, are smaller than average. This also can be interpreted to indicate that the sleep temperature curve is phase advanced relative to the wake temperature curve; this, on the average, by 0.9±0.3 h.If the individually determined amount of masking is added to the temperature data obtained during sleep, or substracted from the temperature data obtained during wake, a temperature curve emerges that can be though of as being purified of the masking effect. Analyses of this artificial curve allow estimation of that part of the internal interactions uninfluenced by the masking effect. On the average, about half of the amount of interaction between the rhythm of sleep-wake and that of deep body temperature is explained by the masking effect, whereas the other half is oscillatory interaction. Both types of interaction are inherent and inseparable parts of the circadian clock mechanism, as can be deduced from model considerations.     

基于网络的睡眠监护与分析系统设计

介绍了基于网络的睡眠监护与分析系统的软硬件设计方案．对系统设计中需要解决的网络数据传输．图形实时显示．以及数据库管理等一些关键性的问题．提出了解决方法．基于这些方法进行了初步的系统实验．取得了较为满意的效果．本系统可望成为未来数字化家庭的重要医疗单元和今后进一步开展远程医疗研究的基础．     

登陆广东热带气旋统计及个例的对比分析

热带气旋造成的危害与其登陆时强度、登陆点及登陆后维持的时间长短有直接关系。根据1949—1988年《台风年鉴》和1989—2001年《热带气旋年鉴》的资料，对登陆广东沿岸的热带气旋作了登陆点及登陆后维持时间等的分类统计。另外，在统计分析的基础上，选取了一对登陆月份、登陆时强度、登陆地点相近，但登陆后维持时间不同的台风——9309号和9908号热带气旋进行对比分析。结果表明，季风槽、副高的活动、西南季风的活跃程度、准静止锋云系的发展，以及高空辐散场的建立对热带气旋登陆后的水汽输送和维持时间长短有重要影响。     

固定收入债券利率风险管理中的持续期度量方法

首先指出对有固定收入的债券进行投资也存在着风险，其中主要为利率风险，而持续期以及以其为基础建立的持续期分析则是进行利率风险管理的重要方法．然后在对传统的利率持续期模型进行评介的基础上，进一步分析了学者们对传统持续期模型的发展，详细介绍了包含债券收益率曲线非平行移动的持续期模型和在不同利率期限结构假设下所推导的持续期模型．     

桥梁施工的工序时间与投入资源的经济学分析

针对桥梁工程施工进度计划编制及工期成本优化中所涉及的工序作业时间和费用确定问题，以工序作业时间的定额计算法为基础，应用经济学中的“边际收益递减规律”，分析工序投入资源量与产量和直接费用的关系，提出根据最佳资源投入量及最大资源投入量，计算工序正常作业时间及正常费用、临界作业时间及临界费用的方法。结果表明；该计算模型是确定工序作业时间及费用的一种较简便可行的方法，使施工进度计划编制与工期成本优化的结果更加可靠。     

甘肃黄土地区地震动持续时间预测研究

在阐述地震动持时的含义及特征的基础上，分析研究了黄土地区与非黄土地区地震动衰减的差异，建立了甘肃省黄土地区地震动衰减规律，提出一种解决与给定超越概率水平相匹配的地震动持时的概率预测方法，给出了甘肃省黄土主要分布地区50年超越概率10％的地震动持时区划结果。     

基于体动射频信号的睡眠分期

为了减轻传统接触式睡眠生理监测系统对人体造成的负担,设计了一种基于微波技术的非接触式睡眠生理信号采集与分析系统,提出一种基于体动射频信号的睡眠分期识别算法.通过小波变换对射频运动传感器(RFMS)采集的体动信号进行预处理,再计算出体动信号的能量值,最后通过判别式处理和阈值法实现了睡眠分期:醒觉期、浅睡期、中睡期、深睡期.实验采集分析了8个实验者为期46天的睡眠生理信号,同时同步采集视频信息、TANITA水床睡眠信息、接触式呼吸脉搏信号.与视频结果比较发现醒觉期正确率达到90%;与TANITA水床睡眠结果相比,本系统的结果与其吻合程度达到70%;与不同睡眠状态下呼吸率、心率的变化相比,本系统的结果吻合度达到80%.     

Interspecific differences in early life‐history traits in crested newts (Triturus cristatus superspecies,Caudata, Salamandridae) from the Balkan Peninsula

We studied intraspecific and interspecific variations of early life‐history traits for four crested newt species with different habitat preferences. Although we found considerable variation in size and growth rate between offspring of conspecific females, the species effect appeared to be much more pronounced. The crested newt species we examined differed in egg size, size of larvae at hatching and growth rate. Triturus dobrogicus appeared to be the outlier species among these species, and showed (1) the smallest egg size, (2) the smallest larval size at hatching and (3) the longest larval period, resulting in the largest metamorphosed juveniles.     

基于时延Petri网的房地产业工期计划管理

分析目前用于工期计划管理的主要方法,并结合房地产开发项目的特点,提出基于时延Petri网(Timed Petri Net,TPN)的工期计划管理方法。该方法具有传统方法的特点,且解决了传统方法不能实时了解工期进展状况的缺点。论文最后通过模拟房地产开发项目验证了该方法在房地产开发工期计划管理中的适用性和有效性。