22,325 research outputs found
Two surveys of the needs of engineering schools in the field of biomechanical and human factors engineering education
Surveys of engineering school needs in field of biomechanical and human factors engineering educatio
Coarse-grained simulation of polymer translocation through an artificial nanopore
The translocation of a macromolecule through a nanometer-sized pore is an
interesting process with important applications in the development of
biosensors for single--molecule analysis and in drug delivery and gene therapy.
We have carried out a molecular dynamics simulation study of electrophoretic
translocation of a charged polymer through an artificial nanopore to explore
the feasibility of semiconductor--based nanopore devices for ultra--fast DNA
sequencing. The polymer is represented by a simple bead--spring model designed
to yield an appropriate coarse-grained description of the phosphate backbone of
DNA in salt--free aqueous solution. A detailed analysis of single translocation
event is presented to assess whether the passage of individual ions through the
pore can be detected by a nanoscale field--effect transistor by measuring
variations in electrostatic potential during polymer translocation. We find
that it is possible to identify single events corresponding to the passage of
counterions through the pore, but that discrimination of individual ions on the
polymer chain based on variations in electrostatic potential is problematic.
Several distinct stages in the translocation process are identified,
characterized by changes in polymer conformation and by variations in the
magnitude and direction of the internal electric field induced by the
fluctuating charge distribution. The dependence of the condensed fraction of
counterions on Bjerrum length leads to significant changes in polymer
conformation, which profoundly affect the dynamics of electrophoresis and
translocation.Comment: 37 pages Revtex, 11 postscript figure
Nutrition and food technology for a Controlled Ecological Life Support System (CELSS)
Food technology requirements and a nutritional strategy for a Controlled Ecological Life Support System (CELSS) to provide adequate food in an acceptable form in future space missions are discussed. The establishment of nutritional requirements, dietary goals, and a food service system to deliver acceptable foods in a safe and healthy form and the development of research goals and priorities were the main objectives of the study
Report of the Stanford Linked Data Workshop
The Stanford University Libraries and Academic Information Resources (SULAIR) with the Council on Library and Information Resources (CLIR) conducted at week-long workshop on the prospects for a large scale, multi-national, multi-institutional prototype of a Linked Data environment for discovery of and navigation among the rapidly, chaotically expanding array of academic information resources. As preparation for the workshop, CLIR sponsored a survey by Jerry Persons, Chief Information Architect emeritus of SULAIR that was published originally for workshop participants as background to the workshop and is now publicly available. The original intention of the workshop was to devise a plan for such a prototype. However, such was the diversity of knowledge, experience, and views of the potential of Linked Data approaches that the workshop participants turned to two more fundamental goals: building common understanding and enthusiasm on the one hand and identifying opportunities and challenges to be confronted in the preparation of the intended prototype and its operation on the other. In pursuit of those objectives, the workshop participants produced:1. a value statement addressing the question of why a Linked Data approach is worth prototyping;2. a manifesto for Linked Libraries (and Museums and Archives and …);3. an outline of the phases in a life cycle of Linked Data approaches;4. a prioritized list of known issues in generating, harvesting & using Linked Data;5. a workflow with notes for converting library bibliographic records and other academic metadata to URIs;6. examples of potential “killer apps” using Linked Data: and7. a list of next steps and potential projects.This report includes a summary of the workshop agenda, a chart showing the use of Linked Data in cultural heritage venues, and short biographies and statements from each of the participants
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