Traceable P2P record exchange: a database-oriented approach

In recent years, peer-to-peer (P2P) technologies are used for flexible and scalable information exchange in the Internet, but there exist problems to be solved for reliable information exchange. It is important to trace how data circulates between peers and how data modifications are performed during the circulation before reaching the destination for enhancing the reliability of exchanged information. However, such lineage tracing is not easy in current P2P networks, since data replications and modifications are performed independently by autonomous peers—this creates a lack of reliability among the records exchanged. In this paper, we propose a framework for traceable record exchange in a P2P network. By managing historical information in distributed peers, we make the modification and exchange histories of records traceable. One of the features of our work is that the database technologies are utilized for realizing the framework. Histories are maintained in a relational database in each peer, and tracing queries are written in the datalog query language and executed in a P2P network by cooperating peers. This paper describes the concept of the framework and overviews the approach to query processing.     

Overexpression and elevated plasma level of tumor-associated antigen 90K/Mac-2 binding protein in colorectal carcinoma

The cancer cell secretome may contain potentially useful biomarkers. Previously, we have analyzed the colorectal carcinoma (CRC) cell secretome. In this study, tumor‐associated antigen 90K (TAA90K)/Mac‐2 binding protein (Mac‐2BP), one of the CRC cell secreted proteins, was chosen for evaluation as a potential CRC biomarker because its mRNA level was also found to be significantly elevated in CRC tissues and in a more metastatic CRC cell line from the analysis of two public domain array‐based datasets. Immunohistochemical analysis of 241 CRC specimens showed that TAA90K/Mac‐2BP was positively detected in 52.7% of the tumors, but weakly or not detected in over 95% of the adjacent nontumor epithelial cells. The plasma TAA90K/Mac‐2BP levels were significantly higher in CRC patients (N = 280) versus healthy controls (N = 147) (7.77 ± 3.49 vs. 5.72 ± 2.67 μg/mL, p<0.001). Moreover, combination of TAA90K/Mac‐2BP and carcinoembryonic antigen (CEA) could outperform CEA alone in discriminating CRC patients from healthy persons in this case‐control study. Our results collectively indicate that analysis of cancer cell secretome is a feasible strategy for identifying cancer biomarker candidates, and the TAA90K/Mac‐2BP may be a potential CRC biomarker.     

PLC高速计数模块在数控装置中的应用

本文主要介绍了PLC高速计数特殊功能模块在数控装置中的应用实例,分析了控制系统的基本原理,同时也对控制编程的要点进行了相应的介绍和分析,该实例具有一定参考价值。     

Influence of temperature on the liver circadian clock in the ruin lizard Podarcis sicula

Reptiles represent an interesting animal model to investigate the influence of temperature on molecular circadian clocks. The ruin lizard Podarcis sicula lives in a continental climate and it is subjected to wide range of environmental temperatures during the course of the year. As consequence, ruin lizard daily activity pattern includes either the hibernation or periods of inactivity determined by hypothermia. Here we showed the rhythmic expression of two clock genes, lPer2 and lClock, in the liver of active lizards exposed to summer photo-thermoperiodic conditions. Interestingly, the exposition of lizards to hypothermic conditions, typical of winter season, induced a strong dampening of clock genes mRNA rhythmicity with a coincident decrease of levels. We also examined the qualitative and quantitative distribution of lPER2 and lCLOCK protein in different cellular compartments during the 24-h cycle. In the liver of active lizards both proteins showed a rhythmic expression profile in all cellular compartments. After 3 days at 6 degrees C, some temporal fluctuations of the lCLOCK and lPER2 are still detectable, although, with some marked modifications in respect to the values detected in the liver of active lizards. Besides demonstrating the influence of low temperature on the lizard liver circadian oscillators, present results could provide new essential information for comparative studies on the influence of temperature on the circadian system across vertebrate classes.     

On delay-derivative-dependent stability of systems with fast-varying delays

Stability of linear systems with uncertain bounded time-varying delays is studied under the assumption that the nominal delay values are not equal to zero. An input-output approach to stability of such systems is known to be based on the bound of the L₂-norm of a certain integral operator. There exists a bound on this operator norm in two cases: in the case where the delay derivative is not greater than 1 and in the case without any constraints on the delay derivative. In the present note we fill the gap between the two cases by deriving a tight operator bound which is an increasing and continuous function of the delay derivative upper bound d?1. For d→∞ the new bound corresponds to the second case and improves the existing bound. As a result, for the first time, delay-derivative-dependent frequency domain and time domain stability criteria are derived for systems with the delay derivative greater than 1.     

Nonsmooth optimization for multiband frequency domain control design

Multiband frequency domain synthesis consists in the minimization of a finite family of closed-loop transfer functions on prescribed frequency intervals. This is an algorithmically difficult problem due to its inherent nonsmoothness and nonconvexity. We extend our previous work on nonsmooth H_∞ synthesis to develop a nonsmooth optimization technique to compute local solutions to multiband synthesis problems. The proposed method is shown to perform well on illustrative examples.     

A parametric bootstrap approach for ANOVA with unequal variances: Fixed and random models

This article is about testing the equality of several normal means when the variances are unknown and arbitrary, i.e., the set up of the one-way ANOVA. Even though several tests are available in the literature, none of them perform well in terms of Type I error probability under various sample size and parameter combinations. In fact, Type I errors can be highly inflated for some of the commonly used tests; a serious issue that appears to have been overlooked. We propose a parametric bootstrap (PB) approach and compare it with three existing location-scale invariant tests—the Welch test, the James test and the generalized F (GF) test. The Type I error rates and powers of the tests are evaluated using Monte Carlo simulation. Our studies show that the PB test is the best among the four tests with respect to Type I error rates. The PB test performs very satisfactorily even for small samples while the Welch test and the GF test exhibit poor Type I error properties when the sample sizes are small and/or the number of means to be compared is moderate to large. The James test performs better than the Welch test and the GF test. It is also noted that the same tests can be used to test the significance of the random effect variance component in a one-way random model under unequal error variances. Such models are widely used to analyze data from inter-laboratory studies. The methods are illustrated using some examples.     

The electrooxidation of sulfur-containing compounds at boron-doped diamond electrode

The electrooxidation of homocysteine, glutathione (GSH), 2-mercapto ethanesulfonic acid and cephalexin at boron-doped diamond (BDD) electrodes and glassy carbon (GC) electrodes was investigated by cyclic voltammetry. The oxidation of these sulfur-containing compounds exhibited well-defined irreversible responses. This preliminary study has shown that BDD has better sensitivity than GC. Concentration dependence has been studied and indicated the promise of using BDD electrodes for quantitative determination. All of the compounds displayed recognizable oxidation peaks at BDD electrodes at millimolar concentration levels. Scan rate dependence of GSH has been examined. It was shown that there was no adsorption on the surface of the BDD electrode for the low concentration.     

基于人类视觉感知特性的一种纹理图象分割方法

在纹理图象分割的研究领域中,基于人类视觉感知特性的图象分割方法是一个重要的新方向,本文给出了一种纹理图象分割的方法,设计了一组参数不同的2D最佳正交极可分方向滤波器来提取图象特征,然后经过四叉树平滑,用模糊C－均值聚类对图象进行分类,最后进行边缘确定,实验结果表明,这种方法能获得较好的分割效果。     

基于MPLS的区分服务技术

传统的Internet只能提供尽力传送服务,但这种没有任何保证、不可预测的服务已不能满足许多应用的需要。IETF提出的Intserv/RSVP方案从技术角度可以提供灵活的服务质量,满足各种应用的需要,但该方案要求每个路由器保存每个连接的状态,复杂化了核心路由器的处理,因此实现 和配置是非常困难的。IETF提出的Diffserv将各种复杂的接入控制、每个连接的管理交给边界路由器处理,核心路由器只处理流量聚合,因而具有更好的伸缩性和鲁棒性。MPLS是一种可以在多种第二层媒质上进行标签交换的网络技术,将探讨如何结合Diffserv和MPLS两种技术,提供各种服务质量,特别是VPN。