An outpatient unit for early pregnancy. Establishment and effects on the pattern of hospital admissions

We report on a 67-year-old woman with acute lymphoblastic leukemia (ALL) who was supposed to have a variant Philadelphia (Ph) translocation identified by conventional cytogenetic techniques. Fluorescence in situ hybridization (FISH) analysis demonstrated the presence of an amplification of BCR-ABL rearrangement at locus 22q11. This is the first observation, to our knowledge, of a duplicated BCR-ABL chimeric gene within the derived chromosome 22 in ALL. Our observation supports the possibility of detecting a variant Ph chromosome at the single-cell level by FISH analysis.     

Application of the Wigner distribution to nonlinear systems

A new way to study nonlinear oscillations is presented, based on Time—Frequency Analysis, a technique that allows the representation and study of the instantaneous spectral content of a signal. The investigation of nonlinear oscillations is an interesting subject in many areas of physics and engineering, especially in nonlinear optics where this phenomenon arises directly from the interaction of electromagnetic waves and matter. Here it is shown how Time—Frequency Analysis can clarify the nature of a free nonlinear oscillation, which is proven to have a peculiar yet physically reasonable instantaneous spectrum.     

Intentional changes in sound pressure level and rate: their impact on measures of respiration, phonation, and articulation

The purpose of the study was to compare the effects of changing sound pressure level (SPL) and rate on respiratory, phonatory, and articulatory behavior during sentence production. Ten subjects, 5 men and 5 women, repeated the sentence, "I sell a sapapple again," under 5 SPL and 5 rate conditions. From a multi-channel recording, measures were made of lung volume (LV), SPL, fundamental frequency (F0), semitone standard deviation (STSD), and upper and lower lip displacements and peak velocities. Loud speech led to increases in LV initiation, LV termination, F0, STSD, and articulatory displacements and peak velocities for both lips. Token-to-token variability in these articulatory measures generally decreased as SPL increased, whereas rate increases were associated with increased lip movement variability. LV excursion decreased as rate increased. F0 for the men and STSD for both genders increased with rate. Lower lip displacements became smaller for faster speech. The interspeaker differences in velocity change as a function of rate contrasted with the more consistent velocity performance across speakers for changes in SPL. Because SPL and rate change are targeted in therapy for dysarthria, the present data suggest directions for future research with disordered speakers.     

一种基于信息熵离散化算法的研究

该文研究连续属性的离散化问题。首先,详细介绍了基于熵的离散化算法(EBD),并对其存在的问题进行了分析。随后,给出了用于度量区间密度的定义;接着,在自适应思想的启发下,对EBD算法进行了改进,提出了基于熵的变阀值离散化算法,区间密度的引入使得该算法能够随样本集在区间上密度的变化适当调整熵的阀值。实验结果表明,与EBD算法相比,改进算法不仅保持简单性、一致性和精确性,而且容易操作。     

Is a low leptin concentration, a low resting metabolic rate, or both the expression of the "thrifty genotype"? Results from Mexican Pima Indians

BACKGROUND: The high prevalence of obesity and type 2 diabetes in some populations is believed to be the expression of a "thrifty genotype," which conferred survival advantages during periods of harsh environmental conditions, but has become a liability in industrialized environments of abundance. Low plasma leptin concentrations and a low metabolic rate may be the phenotypic expression of this genotype. OBJECTIVE: We hypothesized that plasma leptin concentrations and resting metabolic rate would be lower in Mexican Pima Indians not yet exposed to an affluent lifestyle than in non-Pima Mexicans living in the same environment. DESIGN: We studied 208 nondiabetic Pima Indians (105 women and 103 men) living a traditional lifestyle in a remote, mountainous area of northwest Mexico and 183 nondiabetic non-Pima Mexicans (90 women and 93 men) living in the same environment. A subset of 40 (17 women and 23 men) Pima Indians and 40 (19 women and 21 men) non-Pima Mexicans was selected for studies of energy metabolism with a ventilated-hood system. RESULTS: Leptin concentrations were strongly correlated with percentage body fat in both groups (r = 0.83, P < 0.0001). There was no significant difference in plasma leptin concentration between groups in absolute value (P = 0.90) or after adjustment for percentage body fat, waist circumference, age, and sex (P = 0.40). Similarly, there was no significant difference in resting metabolic rate between groups in absolute value (P = 0.27) or after adjustment for fat-free mass (P = 0.32). CONCLUSIONS: These results do not support the hypothesis that hypoleptinemia, a relatively low resting metabolic rate, or both are expressions of the thrifty genotype.     

Geometrical channel models for space-time systems

Based on the unified concept of space-time system field theory, a general space-time channel model can be constructed from the statistics of the space-time system field function (S-TSFF) for an arbitrary medium. This statistical characterization of the medium (channel) can be expressed in terms of the space-time correlation function, or, equivalently, the space-time power spectral density of the S-TSFF. The space-time correlation function of the S-TSFF generalizes the concept of the mutual coherence function (MCF) for a random electric field to an arbitrary space-time field. There are three different geometrical channel models depending on the choice of the coordinate systems, e.g. rectangular, cylindrical, and spherical. Using the notions of channel correlation time and correlation distance— i.e. doppler spread and delay spread—various geometrical tap-delay channel models are derived. From a system point of view, the space-time correlation parameters can be interpreted as a measure of the spatial and temporal memory of the channel. It is further demonstrated that the rectangular space-time channel model reduces to the two-dimensional randomly time-varying tap-delay line models introduced by Kailath (1961) and Bello (1963). A dual property for the S-TSFF is observed. This system duality principle shows that the channel response can manifest as a space-time filter put forth by linear system theory (convolution integral in space-time), or as a space-time aperture put forth by optics (convolution integral in space-time spectrum).     

Adaptive PID control of systems with unknown time delay

A new algorithm for the adaptive control of systems with unknown time delay is presented in which the underlying control law has the familiar PID structure. The design is based on a continuous-time approach. This algorithm can be applied to a class of high-order systems which can be modelled by either a second-order system with time delay or a first-order system with time delay. The parameters of the system including time delay are estimated recursively by a derivative-free least-squares algorithm. The controller settings are selected according to a set of analytical formulae derived from mean-square error criteria. The algorithm is tested on simulated examples as well as a laboratory-scale coupled-tank apparatus.     

求解多约束0-1背包问题的遗传算法的改进

提出对基本遗传算法(Genetic Algorithm,GA)的改进策略,并将其应用于多约束0-1背包问题(Multi-constrained 0-1Knapsack Problems,MKP)的求解。改进策略主要有:将线性规划松弛法求得的MKP的解作为初始解,另外为了避免种群多样化的丧失,将复杂的修复操作和局部优化操作应用于每一个最近产生的解。最后,对大规模测试数据的标准集进行实验,并将该算法与先前的方法进行比较,结果表明新的遗传算法在大多数时间能够更快速地收敛到较优解。     

可拓评价方法的改进及其应用研究

将可拓工程方法与高层建筑中对火灾风险有影响的因子相结合,建立了高层建筑火灾风险评估的可拓评价模型。首先在该模型中对原可拓评价方法进行了修正,提出了最大贴近度法与最大对比度法。其次在原可拓评价方法的基础上首次建立了多级可拓评价模型,解决了用可拓评价方法进行多因素评价的问题。最后对高层建筑火灾风险评估进行了实例分析,根据实际情况采用可拓方法选取权重,并与文献中已有的权重进行比较,结果表明在不同权重下的评价结果基本一致.     

TiNi形状记忆合金电阻钎焊接头微观组织分析

利用自行改制的数控交流电阻焊机，采用CuNi薄带钎料，配合改进型钎剂实现了TiNi形状记忆合金电阻钎焊连接。借助于光学显微镜、SEM及EDX对钎缝的组织进行了分析。结果表明，试验采用的电阻钎焊工艺对母材的热影响极小，接头中没有明显的热影响区；在钎缝中存在的Ti，Ni4化合物相是TiNi合金产生双程及全程形状记忆效应的主要因素。