致病性耶尔森氏菌PCR扩增多态性的研究

目的为了解不同来源的鼠疫耶尔森氏菌和不同血清型的小肠结肠炎耶尔森氏菌及假结核耶尔森氏菌（ＰＴＢ３）的遗传学差异。方法使用随机引物扩增多态ＤＮＡ（ＲＡＰＤ）技术。结果鼠疫耶尔森氏菌和假结核耶尔森氏菌的扩增主带型相似，而与小肠结肠炎耶尔森氏菌的差异较大；不同来源的鼠疫耶尔森氏菌株ＲＡＰＤ图谱亦有细微差别。小肠结肠炎耶尔森氏菌不同血清型的菌株以及同一血清型不同来源株的ＲＡＰＤ亦有较大差异。这为耶尔森氏菌更进一步的分型提供了一种新方法。此外，还根据小肠结肠炎耶尔森氏菌肠毒素基因设计了一对引物，将７个血清型６６株小肠结肠炎耶尔氏菌分成两组，一组的扩增为预期的２８９ｂｐ片段，另一组为约２００ｂｐ的片段。结论实验表明，鼠疫菌和假结核菌可以通过ＲＡＰＤ和其它生物学技术相结合加以区分。使用ＲＡＰＤ技术可对同一血清型不同来源的小肠结肠炎耶尔森氏菌进行更进一步分型。上述方法可用于分子流行病学调查。     

Mating Is Random

ABSTRACT: Human leukocyte antigen (HLA) typing was undertaken in 151 unrelated blood donors and in 35 normal couples having at least two living children. We compared observed and expected sharing of HLA antigens at four loci in normal couples. We also compared the observed sharing in couples with the expected sharing in unrelated blood donors if taken two by two and with the sharing observed after 1000 “synthetic matings” of normal couples. No statistically significant difference in HLA sharing appeared between these groups. Furthermore no differences were observed in the probabilities of sharing individual HLA antigens among the different groups. We thus conclude that the observed HLA sharing in normal couples is governed by chance alone and that mating is random in our population.     

Random mating revisited

Procedures are recommended for testing for the existence of the populational phenomenon commonly referred to as random mating. Some reasons for caution are emphasized, especially whether knowledge about the genetic homogeneity of the population being analyzed is adequate.C.T.F. supported by N.I.H. Grant HE09011. L.E. is the recipient of U.S. Public Health Service Research Career Award 2KO3-HD09033-08.     

任意分组标记法在cDNA微阵列图像分析中的应用

获取cDNA微阵列点的颜色数据，是实现cDNA微阵列图像分析的基本前提，cDNA微阵列的构成是多种多样的，主要表现在具有不同的点阵密度和不同的分布形状等方面，通用、方便和快捷的数据点颜色值获取方法，将有助于扩大计算机分析系统的数据处理速度和应用范围，本文介绍了任意分组标记法的基本原理及其在cDNA微阵列图像分析系统中的应用。     

Random amplified polymorphic DNA analysis of clinically and environmentally isolated Cryptococcus neoformans in Nagasaki.

We examined clinical (pulmonary cryptococcosis and cryptococcal meningitis) and environmental (pigeon excreta) isolates of Cryptococcus neoformans var. neoformans (serotype A) in the southern Japanese prefecture of Nagasaki. The random amplified polymorphic DNA profiles obtained by using three primers revealed six patterns among 21 clinical isolates and three patterns among 8 environmental isolates. Pattern I was the most common (18 of 29 isolates) and was found among isolates obtained throughout the entire Nagasaki Prefecture. Patterns I, III, and IV were found among both clinical and environmental isolates. Patterns I and IV had a characteristic distribution, and in particular, pattern IV was isolated exclusively (five of six isolates) from isolates from Nagasaki City. Two environmental isolates from two locations associated strongly with two patients revealed identical random amplified polymorphic DNA patterns (patterns I and IV) for isolates from each patient. Our results suggest that clinical and environmental isolates belong to the same pool of C. neoformans isolates and that these isolates have certain geographic locations, although the number of isolated strains was limited.     

Design of Random and Semi‐Random Conjugated Polymers for Organic Solar Cells

Significant effort has been devoted to the improvement of organic solar cell performance via the optimization of polymer structure. The expanding scope of conjugated polymer design extends from novel monomers to side‐chain and backbone engineering. These efforts target desired properties for optimal organic photovoltaic performance, including electronic aspects such as optical band gaps, frontier orbital levels, and charge carrier mobilities, as well as physical aspects such as surface energy. Perfectly alternating, donor‐acceptor copolymers represent the state‐of‐the‐art, having low band gaps and demonstrating record efficiencies. However, recent reports indicate significant potential by introducing some degree of randomization to donor‐acceptor copolymers. Specifically, semi‐random copolymers have demonstrated promising photovoltaic performance through incorporation of small ratios of acceptor monomers into a donor‐dominant polymer backbone. Semi‐random polymers have also been found uniquely suited to the optimization of ternary blend solar cells, which benefit from highly tunable randomized structures by means of energy level matching, complementary optical absorption, and directed polymer‐polymer miscibility via surface energy tuning. In this trend article the scope of random and semi‐random polymers, many based on poly(3‐hexyl thiophene), is explored, primarily in the context of solar cell applications. Distinctions between regimes of random copolymers are also defined and discussed.     

Random number generation and creativity

A previous paper suggested that humans can generate genuinely random numbers. I tested this hypothesis by repeating the experiment with a larger number of highly numerate subjects, asking them to call out a sequence of digits selected from 0 through 9. The resulting sequences were substantially non-random, with an excess of sequential pairs of numbers and a deficit of repeats of the same number, in line with previous literature. However, the previous literature suggests that humans generate random numbers with substantial conscious effort, and distractions which reduce that effort reduce the randomness of the numbers. I reduced my subjects' concentration by asking them to call out in another language, and with alcohol - neither affected the randomness of their responses. This suggests that the ability to generate random numbers is a 'basic' function of the human mind, even if those numbers are not mathematically 'random'. I hypothesise that there is a 'creativity' mechanism, while not truly random, provides novelty as part of the mind's defence against closed programming loops, and that testing for the effects seen here in people more or less familiar with numbers or with spontaneous creativity could identify more features of this process. It is possible that training to perform better at simple random generation tasks could help to increase creativity, through training people to reduce the conscious mind's suppression of the 'spontaneous', creative response to new questions.     

Random sampling for evaluating treatment plans

We analyze the influence of sampling technique on the accuracy of estimating irradiated volumes, dose-volume histograms and tumor control and normal tissue complication probabilities. The sampling techniques we consider are uniform distribution of points on a regular Cartesian grid and random selection of points. For three-dimensional treatment planning, random sampling leads to a significant reduction in estimation error and/or in the number of calculation points necessary to achieve a required accuracy. We discuss advantages and drawbacks of random sampling, as compared to sampling on a regular grid. It is suggested that, in practical situations, at least 50 times fewer randomly sampled points per organ/volume of interest are needed for fast estimation of complication probability with the same accuracy, i.e., not exceeding 5% (within 95% confidence limits) in the worst case.     

Random transposon mutagenesis of Campylobacter jejuni

Genetic studies of Campylobacter jejuni have been limited due to the lack of a transposon mutagenesis method. Here, we describe a novel technique for random transposon mutagenesis using a mariner-based transposon into C. jejuni strain 480. Insertions were random, as demonstrated by Southern blot analysis and insertional junction sequencing. We have demonstrated, for the first time, random in vivo transposon mutagenesis of C. jejuni.     

Random visual noise impairs object-based attention

Object-based visual attention is observed when the benefit of attending to one element in a display extends to other elements that are part of the same perceptual object. Apperceptive agnosia is an object identification deficit in which spatial attention is preserved but object-based attention is impaired. Some debate exists regarding the extent to which the object-based impairment can be attributed to perceptual mechanisms that are specifically involved in grouping and segmentation of a scene, as opposed to early sensory processes. In the present paper we show that random visual noise is sufficient to eliminate the object benefit, a result inconsistent with the view that grouping mechanisms are responsible for the effect. The results have implications for an understanding of apperceptive agnosia, and for an understanding of object-based attention more generally.     

DNA Data Storage Gets Random Access

正Researchers have devised a system to recover targeted files from 200 megabytes of data encoded in DNA.Random access is a key for a practical DNA-based memory,but until now,researchers have been able to achieve it with only up to 0.15 megabytes of data.DNA data storage involves translating the binary 0s and 1s of digital data into sequences of the four bases A,C,G,and T that make up DNA.     

Random output selector for the laboratory

A random selector, whose output is in the form of switch closures, is described. On each activation one of N outputs is selected and remains closed until the next activation. Each output is equally probable and independent of the previously selected output. The selector can be constructed from the off-the-shelf components of one manufacturer in approximately 1 hr.     

Random ensemble learning for EEG classification

Real-time detection of seizure activity in epilepsy patients is critical in averting seizure activity and improving patients’ quality of life. Accurate evaluation, presurgical assessment, seizure prevention, and emergency alerts all depend on the rapid detection of seizure onset. A new method of feature selection and classification for rapid and precise seizure detection is discussed wherein informative components of electroencephalogram (EEG)-derived data are extracted and an automatic method is presented using infinite independent component analysis (I-ICA) to select independent features. The feature space is divided into subspaces via random selection and multichannel support vector machines (SVMs) are used to classify these subspaces. The result of each classifier is then combined by majority voting to establish the final output. In addition, a random subspace ensemble using a combination of SVM, multilayer perceptron (MLP) neural network and an extended k-nearest neighbors (k-NN), called extended nearest neighbor (ENN), is developed for the EEG and electrocorticography (ECoG) big data problem. To evaluate the solution, a benchmark ECoG of eight patients with temporal and extratemporal epilepsy was implemented in a distributed computing framework as a multitier cloud-computing architecture. Using leave-one-out cross-validation, the accuracy, sensitivity, specificity, and both false positive and false negative ratios of the proposed method were found to be 0.97, 0.98, 0.96, 0.04, and 0.02, respectively. Application of the solution to cases under investigation with ECoG has also been effected to demonstrate its utility.