Home  About us  Contact
 

System Makes (system + make)

Distribution by Scientific Domains
Life Sciences33%

Selected Abstracts

Concurrent workload mapping for multicore security systems

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 10 2009
Benfano Soewito
Abstract Multicore based network processors are promising components to build real-time and scalable security systems to protect the networks and systems. The parallel nature of the processing system makes it challenging for application developers to concurrently program security systems for high performance. In this paper we present an automatic programming methodology that considers application complexity, traffic variation, and attack signatures update. In particular, our mapping algorithm concurrently takes advantage of parallelism in the level of tasks, applications, and packets to achieve optimal performance. We present results that show the effectiveness of the analysis, mapping, and the performance of the model methodology. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Methodology for drawing up a Red List of threatened freshwater fish in France

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 2 2002
P. Keith
Abstract 1.In 1995, the IUCN implemented new definitions to be used when drawing up red lists. However, in addition to being imprecise for fish species, these remain difficult to apply. 2.This paper describes a more exhaustive method under the IUCN (1995) definitions based on six quantitative and qualitative criteria where scientific data are given the greatest possible weight, as compared with ,expert opinion'. This dual system makes it possible both to allocate an IUCN category to each species, and to rank each species within a particular category according to given scores, so that priorities can be determined. 3.The new Red List for French Freshwater Fish drawn up with this method contains 27 species, or 54% of the French native fauna. Three species are extinct (EX), four are critically endangered (CR), two are endangered (EN), 14 are vulnerable (VU), and four are at lower risk (LR). 4.Based on sounder scientific grounds, this list modifies and replaces the one drawn up in 1992. In effect, it makes it easier to argue for the presence of one species in one category rather than in another. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Do school accountability systems make it more difficult for low-performing schools to attract and retain high-quality teachers?

JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 2 2004
Charles T. Clotfelter
Administrative data from North Carolina are used to explore the extent to which that state's relatively sophisticated school-based accountability system has exacerbated the challenges that schools serving low-performing students face in retaining and attracting high-quality teachers. Most clear are the adverse effects on retention rates, and hence on teacher turnover, in such schools. Less clear is the extent to which that higher turnover has translated into a decline in the average qualifications of the teachers in the low-performing schools. Other states with more primitive accountability systems can expect even greater adverse effects on teacher turnover in low-performing schools. © 2004 by the Association for Public Policy Analysis and Management. [source]

Promoting complex systems learning through the use of conceptual representations in hypermedia

JOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 9 2009
Lei Liu
Abstract Studying complex systems is increasingly important in many science domains. Many features of complex systems make it difficult for students to develop deep understanding. Our previous research indicated that a function-centered conceptual representation is part of the disciplinary toolbox of biologists, suggesting that it is an appropriate representation to help students develop deep understanding. This article reports on the results of two experiments that investigate how hypermedia using a conceptual representation influences pre-service teachers' and middle school students' learning of a complex biological system, the human respiratory system. We designed two versions of instructional hypermedia based on the structure,behavior-function conceptual representation. One hypermedia was function-centered which emphasized the function and behavior of the system, whereas the other was focused on the structure of the system. We contrasted the instructional effectiveness of these two alternative conceptual representations. The results of both studies indicated that participants using the function-centered hypermedia developed deeper understanding than those using the structure-centered version. This proof-of-concept study suggests that the function-centered conceptual representation is a powerful way to promote complex systems understanding. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 1023,1040, 2009 [source]

Electrochemical Sensing of Explosives

ELECTROANALYSIS, Issue 4 2007
Joseph Wang
Abstract This article reviews recent advances in electrochemical sensing and detection of explosive substances. Escalating threats of terrorist activities and growing environmental concerns have generated major demands for innovative field-deployable tools for detecting explosives in a fast, sensitive, reliable and simple manner. Field detection of explosive substances requires that a powerful analytical performance be coupled to miniaturized low-cost instrumentation. Electrochemical devices offer attractive opportunities for addressing the growing explosive sensing needs. The advantages of electrochemical systems include high sensitivity and selectivity, speed, a wide linear range, compatibility with modern microfabrication techniques, minimal space and power requirements, and low-cost instrumentation. The inherent electroactivity of nitroaromatic, nitramine and nitroester compounds makes them ideal candidates for electrochemical detection. Recent activity in various laboratories has led to the development of disposable sensor strips, novel electrode materials, submersible remote sensors, and electrochemical detectors for microchip (,Lab-on-Chip') devices for on-site electrochemical detection of explosive substances. The attractive behavior of these electrochemical monitoring systems makes them very promising for addressing major security and environmental problems. [source]

Translational repression mechanisms in prokaryotes

MOLECULAR MICROBIOLOGY, Issue 5 2003
Paula Jean Schlax
Summary Translational repression results from a complex choreography of macromolecular interactions interfering with the formation of translational initiation complexes. The relationship between the rate and extent of formation of these interactions to form repressed mRNA complexes determines the extent of repression. A novel analysis of repression mechanisms is presented here and it indicates that the reversibility of repressed complex formation influences the steady state balance of the distribution of translationally active and inactive complexes and therefore has an impact on the efficiency of repression. Reviewed here is evidence for three distinct translational repression mechanisms, regulating expression of the transcription factor ,32, threonine tRNA synthetase and ribosomal proteins on the , operon in Escherichia coli. Efficient regulation of expression in these systems makes use of specific mRNA structures in quite different ways. [source]