Networking personal computers

Network technology allows more convenient delivery of computer-aided learning programs. Software and peripheral devices such as printers may be shared between all workstations. The network provides an expedient environment for the development of software, and eradicates the logistic problems of software dispersal via floppy discs. The system can easily be tailored for individual courses, and facilitates more rapid updating of course and revision material. Linking computers from departmental research and administrative groups allows the use of electronic mail and sharing of expensive peripherals such as laser printers, plotters and further links to external networks and computer systems.     

Sugar residues on proteins

Glycoproteins have become increasingly important in the structure and function of many different mammalian systems; for example, membrane glycoproteins and glycoprotein hormones. It is, therefore, important to understand their chemistry, which would include an understanding of both the carbohydrate and protein parts of the molecule. Since the chemical characterization of the protein moiety has been extensively examined and the techniques for its characterization are well worked out, only the carbohydrate portion of glycoproteins will be reviewed in this article. The chemical nature of the carbohydrate moiety of glycoproteins will be examined. First, the types of monosaccharides present in animal systems, especially those in the mammalian systems, will be described. Next, various types of simple and complex carbohydrate chains will be discussed to establish the diversity, size, and number of chains present in the carbohydrate units in different glycoproteins. Then, the type of linkages of the carbohydrate to the protein will be examined to determine if the primary sequence of protein is important in determining the size and type of carbohydrate chains present in glycoproteins. Finally, the current methods of structural elucidation such as monosaccharide sequence, intersugar bonds, and anomeric linkages in the carbohydrate moiety of glycoproteins will be reviewed. These methods include the techniques of periodate oxidation, methylation, partial acid hydrolysis, and specific glycosidase digestion of glycoproteins, as well as the latest techniques using micromethods of carbohydrate quantitation and characterization involving gas chromatography and mass spectrometry. The function of the carbohydrate in glycoproteins will also be considered. First, hormone glycoproteins will be discussed in their relationship to the immunological and biological function of the glycoprotein when the carbohydrate is sequentially removed. Next, the function of the carbohydrate in the turnover of glycoproteins will be discussed. These topics will be considered in order to develop an understanding of a specific function(s) of the carbohydrate in glycoproteins.     

Neuronal network analyses: premises, promises and uncertainties

Neuronal networks assemble the cellular components needed for sensory, motor and cognitive functions. Any rational intervention in the nervous system will thus require an understanding of network function. Obtaining this understanding is widely considered to be one of the major tasks facing neuroscience today. Network analyses have been performed for some years in relatively simple systems. In addition to the direct insights these systems have provided, they also illustrate some of the difficulties of understanding network function. Nevertheless, in more complex systems (including human), claims are made that the cellular bases of behaviour are, or will shortly be, understood. While the discussion is necessarily limited, this issue will examine these claims and highlight some traditional and novel aspects of network analyses and their difficulties. This introduction discusses the criteria that need to be satisfied for network understanding, and how they relate to traditional and novel approaches being applied to addressing network function.     

A parallel programming interface for out-of-core cluster applications

Clusters of workstations are a practical approach to parallel computing that provide high performance at a low cost for many scientific and engineering applications. In order to handle problems with increasing data sets, methods supporting parallel out-of-core computations must be investigated. Since writing an out-of-core version of a program is a difficult task and virtual memory systems do not perform well in some cases, we have developed a parallel programming interface and the support library to provide efficient and convenient access to the out-of-core data. This paper focuses on how these components extend the range of problem sizes that can be solved on the cluster of workstations. Execution time of Jacobi iteration when using our interface, virtual memory and PVFS are compared to characterize the performance for various problem sizes, and it is concluded that our new interface significantly increases the sizes of problems that can be efficiently solved. Jianqi Tang received B.Sc. and M.Sc. from Harbin Institute of Technology in 1997 and 1999 respectively, both in computer application. Currently, she is a Ph.D. candidate at the Department of Computer Science and engineering, Harbin Institute of Technology. She has participated in several National research projects. Her research interests include parallel computing, parallel I/O and grid computing. Binxing Fang received M.Sc. in 1984 from Tsinghua University and Ph.D. from Harbin Institute of Technology in 1989, both in computer science. From 1990 to 1993 he was with National University of Defense Technology as a postdoctor. Since 1984, he is a faculty member at the Department of Computer Science and engineering of Harbin Institute of Technology, where he is presently a Professor. He is a Member of the National Information Expert Consultant Group and a Standing Member of the Council of Chinese Society of Communications. His research efforts focus on parallel computing, computer network and information security. Professor Fang has implemented over 30 projects from the state and ministry/province. Mingzeng Hu was born in 1935. He has been with the Department of Computer Science and engineering in Harbin Institute of Technology since 1958, where he is currently a Professor. He was a visiting scholar in the Siemens Company, Germany from 1978 to 1979, a visiting associate professor in Chiba University, Japan from 1984 to 1985, and a visiting professor in York University, Canada from 1989 to 1995. He is the Director of the National Key Laboratory of Computer Information Content Security. He is also a Member of 3rd Academic Degree Committee under the State Council of China. Professor Hu’s research interests include high performance computer architecture and parallel processing technology, fault tolerant computing, network system, VL design, and computer system security technology. He has implemented many projects from the state and ministry/province and has won several Ministry Science and Technology Progress Awards. He published over 100 papers in core journals home and abroad and one book. Professor Hu has supervised over 20 doctoral students. Hongli Zhang received M.Sc in computer system software in 1996 and Ph.D. in computer architecture in 1999 from Harbin Institute of Technology. Currently, she is an Associate Professor at the Department of Computer Science and engineering, Harbin Institute of Technology. Her research interests include computer network security and parallel computing.     

Personal computer-based visualization of molecular models by available ray-tracing software

Developed primarily for the graphic arts, ray-tracing algorithms offer a high level of flexibility with reference to photorealistic and surrealistic image rendering. The utility of these programs is further enhanced by portability (i.e., compatibility with a number of operating systems), accessibility through various sources, and low cost. This report documents, through the use of existing software, the application of these ray-tracing attributes to molecular graphics on a desktop computer. This application is especially pertinent in view of rapid speed enhancements in personal computers (PCs), which have enabled molecular modeling and dynamics on these systems. In this regard, ray tracing on a PC provides enhanced capabilities for molecular graphics rendering that are potentially equivalent to those achieved by workstations.     

The Relational Basis of Molecular Codes

Molecular codes can be considered a special type of mapping among molecular species in biochemical systems. The formalization of molecular codes allows to identify these in network models of real world systems. Analyzing algorithmically identified codes leads to the observation that codes does not necessarily stand alone, but that we can identify certain relations among codes. In this paper I will define two types of relations that can occur among codes, (1) code linkage and (2) code nesting, and will discuss implications of this finding.     

GeneView: multi-language human gene mapping library with a graphical user interface

GeneView is a newly developed human gene mapping library systemthat works on an X-Window platform. This system is designedfor researchers who routinely utilize gene mapping data in thelaboratory but are unfamiliar with computer technology. GeneViewoffers various features, including friendly user interface,fast operation and visualization facility. Genetic loci aredisplayed graphically with an idiogram. This system can be operatedin multiple languages. A current version supports Japanese andEnglish, and can be easily expanded to include other languages.A prototype of GeneView is now installed on a SPARC (Sun4) workstation.Because of the X-Window platform, GeneView should be compatiblewith various types of workstations.     

Zur Theorie der lateralen Inhibition

Summary Recently it was shown (Reichardt 1961) that lateral neural inhibition, such as was found in the lateral eye of Limulus polyphemus by Hartline and Ratliff, can in principle compensate for the dioptric apparatus of the eye. The model of lateral inhibition in Limulus developed there is here considered further, with emphasis on the changes in the effective structure of the nerve network (and the associated vector transformation) resulting from the forced inactivity of fibers whose inhibition exceeds their excitation. The stability of the network model as a function of the inhibition coefficients is studied and two theorems regarding the stability are proven. The dependence of the properties of the network on the pattern of receptor excitation are investigated and it is shown by examples that the network could be used for form discrimination. This model's relationship to previously known pattern recognition systems is discussed and its possible application in computer technology is mentioned.     

Getting the Data Flowing: Lessons Learned from Existing Reporting Systems in the Forestry Sector in Indonesia for REDD+ MRV

In the context of REDD+, Measurement, Reporting and Verification (MRV) is one way to manage forest change information. A national carbon and non-carbon database will be used in REDD+ to negotiate compensation schemes with the international community. Much of this data will be collected at the local level, thus a reporting system that can integrate these locally collected data into the national database is crucial. In this paper we compare and draw lessons from three existing local to national reporting systems that include the participation of local communities: 1) the government extension services, 2) the government owned forestry company, and 3) a private logging company in Indonesia, and provide recommendations for REDD+ reporting systems. The results suggest that the main desired conditions for effective data flow are: benefits to motivate local participation, based on contributions to reporting activities; simple data format and reporting procedures to allow local participation in the reporting process, and to support data aggregation at the national level; a facilitator to mediate data aggregation at the village level to ensure data consistency, completeness and accuracy; and a transparent and clear data flow. Under these conditions, continuous, accountable and consistent data flow from the local level will reach the national level where it can be fully utilized.     

Decision support for clinical laboratory capacity planning

The design of a decision support system for capacity planning in clinical laboratories is discussed. The DSS supports decisions concerning the following questions: how should the laboratory be divided into job shops (departments/sections), how should staff be assigned to workstations and how should samples be assigned to workstations for testing. The decision support system contains modules for supporting decisions at the overall laboratory level (concerning the division of the laboratory into job shops) and for supporting decisions at the job shop level (assignment of staff to workstations and sample scheduling). Experiments with these modules are described showing both the functionality and the validity.     

Scaling of differentiation in networks: nervous systems,organisms, ant colonies,ecosystems, businesses,universities, cities,electronic circuits,and Legos

Nodes in networks are often of different types, and in this sense networks are differentiated. Here we examine the relationship between network differentiation and network size in networks under economic or natural selective pressure, such as electronic circuits (networks of electronic components), Legos (networks of Lego pieces), businesses (networks of employees), universities (networks of faculty), organisms (networks of cells), ant colonies (networks of ants), and nervous systems (networks of neurons). For each of these we find that (i) differentiation increases with network size, and (ii) the relationship is consistent with a power law. These results are explained by a hypothesis that, because nodes are costly to build and maintain in such "selected networks", network size is optimized, and from this the power-law relationship may be derived. The scaling exponent depends on the particular kind of network, and is determined by the degree to which nodes are used in a combinatorial fashion to carry out network-level functions. We find that networks under natural selection (organisms, ant colonies, and nervous systems) have much higher combinatorial abilities than the networks for which human ingenuity is involved (electronic circuits, Legos, businesses, and universities). A distinct but related optimization hypothesis may be used to explain scaling of differentiation in competitive networks (networks where the nodes themselves, rather than the entire network, are under selective pressure) such as ecosystems (networks of organisms).     

城市生态系统的动力学演化模型研究进展

从系统分析出发,对城市生态系统的动力学演化模型的发展历程、建模的方法和步骤过程、软件开发方法和目前的模型软件等进行了总结。归纳了城市生态系统的动力学演化建模的方法,主要包括模型定义、模拟、实现、验证、分析和应用等六大步骤。目前国内外用于城市生态系统动力学演化模型的主要方法有：基于数理模型的方法、生态控制论和灵敏度模型、系统动力学模型、多目标规划法等。已经开发的用于城市生态系统的动力学模拟的软件可以划分为两类：基于土地利用和交通规划的专业模型和基于系统动力学和灵敏度模型的一般软件。总结了常用的城市演化模型软件,讨论了模型的研究对象和应用范围。分析了城市生态系统的动力学演化模型建模的不确定性的来源,并指出：向宏观和微观两极化发展是城市生态系统动力学演化模型的发展趋势之一,而与人工智能和地理信息系统等新方法的集成是发展的另一趋势。城市生态系统动力学演化模型的开发前景在于对不确定性问题的定性、定量分析,而多模型的耦合和集成是发展的必然趋势。     

Uncovering mechanisms of bistability in biological systems

As the systems biology era progresses, theoreticians and experimentalists continue uncovering the molecular mechanisms that underlie the regulation of complex cellular phenomena, including those governing proliferation, differentiation, and death. The discovery of bistability in cellular responses and their signaling pathways has become a recurring theme, and prompted strong interest in understanding both the design and function of these networks. Modeling these systems has been crucial in assisting experimentalists to better understand how this and other types of behavior can emerge from a subset of regulators, and also to analyze and identify systems-level characteristics that would otherwise be difficult to intuit. In this review, recent advances in both theoretical and experimental work investigating the mechanistic as well as biological basis for bistability will be presented. These will include the role of positive feedback loops, the potential function of dual phosphorylation cycles, and substrate competition as a means of generating ultrasensitivity.     

Topological estimation of electronic absorption bands of arene absorption spectra as a tool for modeling their toxicity and environmental pollution

A novel application of distance-based topological indices : Wiener (W)-, Szeged (Sz)-, Padmakar-Ivan (PI)-, and Sadhana (Sd)-indices in modeling electronic absorption bands of arene absorption spectra has been described. It is demonstrated that all these indices correlate linearly with the logarithm of beta and para electronic absorption bands in several series of arene systems. The results have shown that our methodology is best suited for the estimation--lnlambda(beta), while comparatively less significant results are obtained in case of the estimation of lnlambda(p). The statistical analysis of the data have shown that PI index gives better results for modeling lnlambda(beta); while Sz index proved better for modeling lnlambda(p). The results are critically discussed on the basis of regression parameters and quality of correlation. Such a study will be useful as a tool for modeling toxicity of arene system as well as their environmental pollution.     

NEURAL METHODS OF CALIBRATION OF SENSORS FOR GAS MEASUREMENTS AND AROMA IDENTIFICATION SYSTEM

The article presents the neural methods of calibration of gas sensors for use in an artificial electronic nose for gas measurements. Different neural network solutions will be presented and compared. They include the classical multilayer perceptron, neuro-fuzzy networks and support vector machines. The other aspect illustrated in the article is the introductory preprocessing of the measured sensor signals in order to attain the highest possible efficiency of the gas measuring system. The theoretical considerations will be supported by the numerical experiments concerning the application of the electronic nose. The first practical aspect is concerned with the application of the developed system for classification problems and will be illustrated in the examples of the recognition of the biocomponents in the gasoline and the recognition of smells of cosmetic cream at the aging process. The second one belongs to the estimation problem and is concerned with the determination of the concentration of the particular gas components in the mixture of gases.

PRACTICAL APPLICATIONS

The results presented in the article may find practical application for calibration of the electronic nose in gas measurements. The electronic nose is widely used for smell recognition. It may find practical application in the petroleum, cosmetics or food industry for the assessment of the quality of their products. Military application is also of great interest.     

Free molecular biological software available from the EMBL file server

A new service provided by EMBL (EMBL Softsvare File Server)is described that will make free molecular biology softwareavailable to anyone with computer network access. MS–DOS,Apple Macintosh and VAX/VMX are supported at the moment. Theprograms will be delivered by normal electronic mail; conversionmechanisms will transfor binary files to ASCII to allow mailtransfer. This service will also help authors to distributetheir software conveniently.