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71.
R Ottman JH Lee WA Hauser S Hong D Hesdorffer N Schupf TA Pedley ML Scheuer 《Canadian Metallurgical Quarterly》1993,43(12):2526-2530
Methods for standardized classification of epileptic seizures are important for both clinical practice and epidemiologic research. In this study, we developed a strategy for standardized classification using a semistructured telephone interview and operational diagnostic criteria. We interviewed 1,957 adults with epilepsy ascertained from voluntary organizations. To confirm and expand the seizure history, we also interviewed a first-degree relative for 67% of subjects and obtained medical records for 59%. Three lay reviewers used all available information to classify seizures. To assess reliability, each reviewer classified a sample of subjects assigned to the others. In addition, an expert physician classified a sample of subjects assigned to two of the reviewers. Agreement was "moderate-substantial" for generalized-onset seizures, both for the comparisons between pairs of lay reviewers and for the neurologist versus lay reviewers. Agreement was "substantial-almost perfect" for partial-onset seizures, both for pairs of lay reviewers and for the neurologist versus lay reviewers. These results suggest that seizures can be reliably classified by lay reviewers, using operational criteria applied to symptoms ascertained in a semistructured telephone interview. 相似文献
72.
The relative effect of protozoan and bacterial predators on the survival of Escherichia coli in estuarine water samples was examined. Predacious protozoa exerted their major influence on E. coli destruction during the first 2 days of a 10-day-decline period. Inhibition of protozoa after day 2 had little effect on E. coli survival. Bacterial predators also contributed to E. coli destruction but in natural estuarine water samples were maintained at lower levels due to "grazing" by predacious protozoa. 相似文献
73.
The serum of some patients with insulin-resistant "diabetes" contains antibodies that bind to and block the cell membrane receptors for insulin. In this report, we have characterized the effects of the antireceptor antibodies on the interaction of (125)I-insulin with its receptor on the human lymphoblastoid cell line IM-9. Up to 95% of specific insulin binding can be inhibited by pretreatment of the cells with these immunoglobulins. The onset of the inhibitory effect is time- and temperature-dependent, and the effect is reversed extremely slowly if the cells are suspended in a large excess of antibody-free buffer. These features of antibody binding can be easily distinguished from those for insulin binding to its receptor. The inhibitory effect of the antibodies can be reversed by exposure of the cells to conditions known to elute surface immunoglobulins. The three antireceptor sera studied appear to alter the insulin-receptor interaction in different ways. Two antisera markedly reduce receptor affinity through combined effects on the insulin association and dissociation rates, and, additionally, have smaller effects on available receptor number. A third antiserum primarily affects available receptor number and has little effect on receptor affinity. All three antisera inhibit the capacity of insulin to promote negatively cooperative site-site interactions among insulin receptors. The data suggest that these autoantibodies to the insulin receptor bind to different determinants on the receptor and may therefore be useful as unique probes of insulin receptor structure and function. 相似文献
74.
Making complex decisions in real world problems often involves assigning values to sets of interdependent variables where an expressive dependency structure among these can influence, or even dictate, what assignments are possible. Commonly used models typically ignore expressive dependencies since the traditional way of incorporating non-local dependencies is inefficient and hence leads to expensive training and inference. The contribution of this paper is two-fold. First, this paper presents Constrained Conditional Models (CCMs), a?framework that augments linear models with declarative constraints as a way to support decisions in an expressive output space while maintaining modularity and tractability of training. The paper develops, analyzes and compares novel algorithms for CCMs based on Hidden Markov Models and Structured Perceptron. The proposed CCM framework is also compared to task-tailored models, such as semi-CRFs. Second, we propose CoDL, a?constraint-driven learning algorithm, which makes use of constraints to guide semi-supervised learning. We provide theoretical justification for CoDL along with empirical results which show the advantage of using declarative constraints in the context of semi-supervised training of probabilistic models. 相似文献
75.
C. A. Luengo J. G. Huber M. B. Maple M. Roth 《Journal of Low Temperature Physics》1975,21(1-2):129-151
Detailed measurements of the specific heat jump C at the superconducting transition temperatureT
c as a function ofT
c are reported for several (La, Th)Ce systems. The measurements document the continuous demagnetization of the Ce impurity ions which proceeds with increasing Th concentration, and provide a critical test of a theory recently developed by Müller-Hartmann and Zittartz for the superconducting behavior of matrix-impurity systems which simultaneously exhibit both superconductivity and the Kondo effect.Research supported by the U.S. Air Force Office of Scientific Research, Grant No. AF-AFOSR-71-2073.Research supported by the University of Chile-University of California Cooperative Program sponsored by the Ford Foundation. 相似文献
76.
TA Reader 《Canadian Metallurgical Quarterly》1976,50(1):11-30
The structure and function of the digestive gland of the gastropod mollusc, Bithynia tentaculata, was investigated using ultrastructural, histochemical, and cytochemical techniques. The digestive gland was shown to be composed of two main cell types, the "digestive" cells and "secretory" cells. The digestive cells appeared to be concerned with the absorption and digestion of nutrients, while secretory cells produced digestive enzymes and calcareous concretions. Undifferentiated cells were scattered between these two main cell types. The pathological effects of larval digeneans on the digestive gland were also investigated, at the ultrastructural level. In such infected snails the digestive gland appeared to be degenerating. The significance of this tissue destruction was briefly discussed. 相似文献
77.
78.
The oxidative erosion of seven types of graphite has been investigated by heating in air at temperatures between 600 and 1000 K. The specimens include pyrolytic graphite, fine-grain graphites, carbon-fibre composites (CFC), and graphites doped with Si and Ti. The weight loss was measured using a microbalance, the surface morphology by scanning electron microscopy, and the composition of the surface layer by MeV ion beam techniques. Pyrolytic graphite is least affected by erosion, while pure and Si-doped CFCs erode particularly fast. Typical erosion rates for specimens with a surface area of ?4 cm2 are below 0.2 μg/m2 s at 600 K for all graphite types, and at 900 K range from 0.34 mg/m2 s for pyrolytic graphite to about 9 mg/m2 s for the strongest eroding types. The temperature dependence of the erosion rate of all types of graphite studied is well described by an activation energy of 1.7 eV. The erosion rates of these graphites are by far lower than the removal rates for deposited amorphous hydrocarbon layers. In contrast to all other types, the Ti-doped graphite absorbs a significant amount of oxygen reaching up to ?5% of its original mass. Once the oxygen uptake is saturated, it erodes with rates similar to those of the strongest eroding types. 相似文献
79.
F. Staufenbiel G. Schiwietz K. Czerski M. Roth P.L. Grande 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2005,230(1-4):426-430
High resolution Auger-electron spectroscopy has been applied to the interaction of swift heavy ions with atomically clean metallic solids. Spectra have been taken for fast projectile electrons and for charge-state equilibrated ions at normal incidence on microcrystalline beryllium samples, Al(1 0 0) single crystals and several metallic glasses (Al87La7Ni5Zr1, Ni78B14Si8, Co66Si16B12Fe4Mo2). From the energy shift and from the Auger-line width we have extracted ion-track potentials and also electron temperatures inside ion tracks. A first determination of the angular distribution of multiple-ionization lines is presented as well. 相似文献
80.
PDF417二维条码肖像图片压缩编码的优化算法研究 总被引:1,自引:0,他引:1
针对PDF417二维条码存储空间有限的问题,提出了一种基于小波变换的有损图像压缩算法,通过这个算法,可以将静态图片信息加入PDF417条码中,并能够满足在指定字节数情况下保证高质量地压缩图像,该文在分析小波变换等算法理论的基础上,详细介绍了PDF417二维条码肖像图片压缩编码的优化算法及该算法的实验结果与美国Symbol公司的PC2VQ算法结果对比。 相似文献