WorldWideScience

Sample records for depolarization electronic resource

  1. Selection of Electronic Resources.

    Science.gov (United States)

    Weathers, Barbara

    1998-01-01

    Discusses the impact of electronic resources on collection development; selection of CD-ROMs, (platform, speed, video and sound, networking capability, installation and maintenance); selection of laser disks; and Internet evaluation (accuracy of content, authority, objectivity, currency, technical characteristics). Lists Web sites for evaluating…

  2. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  3. The effect of depolarization fields on the electronic properties of two-dimensional materials

    Science.gov (United States)

    Shin, Young-Han; Kim, Hye Jung; Noor-A-Alam, Mohammad

    2015-03-01

    Graphene is a two-dimensional semimetal with a zero band gap. By weakening the sp2 covalent bonding of graphene with additional elements such as hydrogen or fluorine, however, it is possible to make it insulating. We can expect that the band gap converges to that of a three-dimensional analogue by repeating such two-dimensional layers along the normal to the layer. If we control the position of additional elements to make a dipole monolayer, the system will have an intrinsic internal field decreases as the number of layers increases. But, for two-dimensional bilayers, depolarization field is so strong that its electronic properties can be much different from its monolayer analogue. In this presentation, we show that the internal fields induced by dipole moments can change electronic properties of two-dimensional materials such as graphene-like structures and complex metal oxides. This work was supported by the National Research Foundation of Korea Grant by the Ministry of Education, Science, and Technology (2009-0093818, 2012-014007, 2014M3A7B4049367)

  4. Electronic Resource Management and Design

    Science.gov (United States)

    Abrams, Kimberly R.

    2015-01-01

    We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

  5. Electronic Resource Management and Design

    Science.gov (United States)

    Abrams, Kimberly R.

    2015-01-01

    We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

  6. High-Precision Calibration of Electron Beam Energy from the Hefei Light Source Using Spin Resonant Depolarization

    Science.gov (United States)

    Lan, Jie-Qin; Xu, Hong-Liang

    2014-12-01

    The electron beam energy at the Hefei Light Source (HLS) in the National Synchrotron Radiation Laboratory is highly precisely calibrated by using the method of spin resonant depolarization for the first time. The spin tune and the beam energy are determined by sweeping the frequency of a radial rf stripline oscillating magnetic field to artificially excite a spin resonance and depolarize the beam. The resonance signal is recognized by observing the sudden change of the Touschek loss counting rate of the beam. The possible systematic errors of the experiment are presented and the accuracy of the calibrated energy is shown to be about 10-4. A series of measurements show that the energy stability of the machine is of the order of 9 × 10-3.

  7. Measurement of the depolarizing (vector)pe cross section using co-moving electrons

    Energy Technology Data Exchange (ETDEWEB)

    Oellers, Dieter [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany)

    2008-07-01

    In order to perform experiments with polarised antiprotons (PAX-Collaboration) one needs an effective way to produce a stored polarized antiproton beam. FILTEX showed that an unpolarised proton beam is polarised when travelling through a polarised hydrogen target. For this result there exist two competing theoretical explanations. One with a strong contribution from electrons while the other sees an almost exact cancellation of all electron effects. New calculations by Walcher and Arenhoevel suggest a very large cross section for the spin-exchange between protons and electrons of left angle {sigma}P{sub zz} right angle {approx}2.10{sup 13} barn at small relative velocities T{approx} 1.7 keV. First results of a depolarising measurement at these low energies are shown in this talk.

  8. Managing electronic resources a LITA guide

    CERN Document Server

    Weir, Ryan O

    2012-01-01

    Informative, useful, current, Managing Electronic Resources: A LITA Guide shows how to successfully manage time, resources, and relationships with vendors and staff to ensure personal, professional, and institutional success.

  9. Electronic Resources Management Project Presentation 2012

    KAUST Repository

    Ramli, Rindra M.

    2012-11-05

    This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration is to consolidate all electronic resources into a single and centralized location. This would allow for better information sharing among library staff.

  10. Implementing CORAL: An Electronic Resource Management System

    Science.gov (United States)

    Whitfield, Sharon

    2011-01-01

    A 2010 electronic resource management survey conducted by Maria Collins of North Carolina State University and Jill E. Grogg of University of Alabama Libraries found that the top six electronic resources management priorities included workflow management, communications management, license management, statistics management, administrative…

  11. Implementing CORAL: An Electronic Resource Management System

    Science.gov (United States)

    Whitfield, Sharon

    2011-01-01

    A 2010 electronic resource management survey conducted by Maria Collins of North Carolina State University and Jill E. Grogg of University of Alabama Libraries found that the top six electronic resources management priorities included workflow management, communications management, license management, statistics management, administrative…

  12. Resource Letter: TE-1: Teaching electronics

    Science.gov (United States)

    Henry, Dennis C.

    2002-01-01

    This Resource Letter examines the evolution, roles, and content of courses in electronics in the undergraduate physics curriculum, and provides a guide to resources for faculty teaching such courses. It concludes with a brief section addressing problems of electromagnetic interference in electronic systems, and provides an introduction to the literature and practice of electromagnetic compatibility. I have included textbooks, reference books, articles, collections of laboratory experiments and projects, sources of equipment and parts, software packages, videos, and websites.

  13. Electronic Resources Management System: Recommendation Report 2017

    KAUST Repository

    Ramli, Rindra M.

    2017-05-01

    This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system as potential replacements namely: Proquest 360 Resource Manager, Ex Libris Alma and Open Source CORAL ERMS. After comparing and trialling the systems, it was decided to go for Proquest 360 Resource Manager.

  14. Library Training to Promote Electronic Resource Usage

    DEFF Research Database (Denmark)

    Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

    2017-01-01

    Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...

  15. Reviewing the Electronic Resources & Libraries Conference

    Science.gov (United States)

    Tijerina, Bonnie

    2008-01-01

    The third Electronic Resources & Libraries (ER&L) conference gathered at Georgia Institute of Technology's Global Learning and Conference Center in Atlanta, Georgia, March 18-21, 2008. Over 360 attendees, from six countries and from 80% of the United States, represented their libraries and organizations resulting in a diverse and…

  16. Making sense of the electronic resource marketplace: trends in health-related electronic resources.

    Science.gov (United States)

    Blansit, B D; Connor, E

    1999-07-01

    Changes in the practice of medicine and technological developments offer librarians unprecedented opportunities to select and organize electronic resources, use the Web to deliver content throughout the organization, and improve knowledge at the point of need. The confusing array of available products, access routes, and pricing plans makes it difficult to anticipate the needs of users, identify the top resources, budget effectively, make sound collection management decisions, and organize the resources effectively and seamlessly. The electronic resource marketplace requires much vigilance, considerable patience, and continuous evaluation. There are several strategies that librarians can employ to stay ahead of the electronic resource curve, including taking advantage of free trials from publishers; marketing free trials and involving users in evaluating new products; watching and testing products marketed to the clientele; agreeing to beta test new products and services; working with aggregators or republishers; joining vendor advisory boards; benchmarking institutional resources against five to eight competitors; and forming or joining a consortium for group negotiating and purchasing. This article provides a brief snapshot of leading biomedical resources; showcases several libraries that have excelled in identifying, acquiring, and organizing electronic resources; and discusses strategies and trends of potential interest to biomedical librarians, especially those working in hospital settings.

  17. Electronic resource management systems a workflow approach

    CERN Document Server

    Anderson, Elsa K

    2014-01-01

    To get to the bottom of a successful approach to Electronic Resource Management (ERM), Anderson interviewed staff at 11 institutions about their ERM implementations. Among her conclusions, presented in this issue of Library Technology Reports, is that grasping the intricacies of your workflow-analyzing each step to reveal the gaps and problems-at the beginning is crucial to selecting and implementing an ERM. Whether the system will be used to fill a gap, aggregate critical data, or replace a tedious manual process, the best solution for your library depends on factors such as your current soft

  18. Electronic Resource Management System. Vernetzung von Lizenzinformationen

    Directory of Open Access Journals (Sweden)

    Michaela Selbach

    2014-12-01

    Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

  19. Utilization of electronic information resources by academic staff at ...

    African Journals Online (AJOL)

    Utilization of electronic information resources by academic staff at Makerere University. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... It examined the academic staff awareness of the resources available, the types ...

  20. Bipartite depolarizing maps

    Science.gov (United States)

    Lami, Ludovico; Huber, Marcus

    2016-09-01

    We introduce a 3-parameter class of maps (1) acting on a bipartite system which are a natural generalisation of the depolarizing channel (and include it as a special case). Then, we find the exact regions of the parameter space that alternatively determine a positive, completely positive, entanglement-breaking, or entanglement-annihilating map. This model displays a much richer behaviour than the one shown by a simple depolarizing channel, yet it stays exactly solvable. As an example of this richness, positive partial transposition but not entanglement-breaking maps is found in Theorem 2. A simple example of a positive yet indecomposable map is provided (see the Remark at the end of Section IV). The study of the entanglement-annihilating property is fully addressed by Theorem 7. Finally, we apply our results to solve the problem of the entanglement annihilation caused in a bipartite system by a tensor product of local depolarizing channels. In this context, a conjecture posed in the work of Filippov [J. Russ. Laser Res. 35, 484 (2014)] is affirmatively answered, and the gaps that the imperfect bounds of Filippov and Ziman [Phys. Rev. A 88, 032316 (2013)] left open are closed. To arrive at this result, we furthermore show how the Hadamard product between quantum states can be implemented via local operations.

  1. Effectiveness Analysis of Electronic Resources at the Hacettepe University

    OpenAIRE

    2011-01-01

    It is important to collect and analyze the usage data of electronic databases and periodicals in order to make policies regarding the composition, improvement and more extensive utilization of electronic resources of libraries. The aim of this study is to investigate how efficiently the full text accessible electronic resources of Hacettepe University Libraries are used. For this purpose the usage data obtained from COUNTER Software regarding the electronic databases to which Hacettepe Univer...

  2. The Study of Analytical Model of Library Electronic Resources Usage-A Case of Medical Electronic Resources

    OpenAIRE

    Chung-Yen Yu; Jiann-Cherng Shieh

    2014-01-01

    With the advents of internet, the importance of electronic resources is growing. Due to the increasing expensiveness of electronic resources, university libraries normally received budgets from parent institutions annually. They necessarily applied effective and systematic methods for decision making in electronic resources purchase or re-subscription. However, there are some difficulties in practices: First of all, libraries are unable to receive user records; second, the COUNTER statistics ...

  3. The Role of the Acquisitions Librarian in Electronic Resources Management

    Science.gov (United States)

    Pomerantz, Sarah B.

    2010-01-01

    With the ongoing shift to electronic formats for library resources, acquisitions librarians, like the rest of the profession, must adapt to the rapidly changing landscape of electronic resources by keeping up with trends and mastering new skills related to digital publishing, technology, and licensing. The author sought to know what roles…

  4. Electronic resources preferred by pediatric hospitalists for clinical care.

    Science.gov (United States)

    Beck, Jimmy B; Tieder, Joel S

    2015-10-01

    There is little research on pediatric hospitalists' use of evidence-based resources. The aim of this study was to determine the electronic resources that pediatric hospitalists prefer. Using a web-based survey, the authors determined hospitalists' preferred electronic resources, as well as their attitudes toward lifelong learning, practice, and experience characteristics. One hundred sixteen hospitalists completed the survey. The most preferred resource for general information, patient handouts, and treatment was UpToDate. Online search engines were ranked second for general information and patient handouts. Pediatric hospitalists tend to utilize less rigorous electronic resources such as UpToDate and Google. These results can set a platform for discussing the quality of resources that pediatric hospitalists use.

  5. Cataloging and Indexing of Electronic Information Resources

    Science.gov (United States)

    2003-04-01

    digital library, but it facilitates the exchange of these objects among digital libraries . METS provides an XML DTD that can point to metadata in other...International Federation of Library Associations and Institutions (IFLA). (2002). Digital Libraries : Metadata Resources. Retrieved May 3, 2002 from the

  6. Adoption and use of electronic information resources by medical ...

    African Journals Online (AJOL)

    ... were analysed with descriptive Statistics(Simple percentage and frequency count). ... for doing assignment, Google search, for personal development, and getting ... major problems encountered when using electronic Information Resources.

  7. Euler European Libraries and Electronic Resources in Mathematical Sciences

    CERN Document Server

    The Euler Project. Karlsruhe

    The European Libraries and Electronic Resources (EULER) Project in Mathematical Sciences provides the EulerService site for searching out "mathematical resources such as books, pre-prints, web-pages, abstracts, proceedings, serials, technical reports preprints) and NetLab (for Internet resources), this outstanding engine is capable of simple, full, and refined searches. It also offers a browse option, which responds to entries in the author, keyword, and title fields. Further information about the Project is provided at the EULER homepage.

  8. Building an electronic resource collection a practical guide

    CERN Document Server

    Lee, Stuart D

    2004-01-01

    This practical book guides information professionals step-by-step through building and managing an electronic resource collection. It outlines the range of electronic products currently available in abstracting and indexing, bibliographic, and other services and then describes how to effectively select, evaluate and purchase them.

  9. Why and How to Measure the Use of Electronic Resources

    Directory of Open Access Journals (Sweden)

    Jean Bernon

    2008-11-01

    Full Text Available A complete overview of library activity implies a complete and reliable measurement of the use of both electronic resources and printed materials. This measurement is based on three sets of definitions: document types, use types and user types. There is a common model of definitions for printed materials, but a lot of questions and technical issues remain for electronic resources. In 2006 a French national working group studied these questions. It relied on the COUNTER standard, but found it insufficient and pointed out the need for local tools such as web markers and deep analysis of proxy logs. Within the French national consortium COUPERIN, a new working group is testing ERMS, SUSHI standards, Shibboleth authentication, along with COUNTER standards, to improve the counting of the electronic resources use. At this stage this counting is insufficient and its improvement will be a European challenge for the future.

  10. Access to electronic resources by visually impaired people

    Directory of Open Access Journals (Sweden)

    Jenny Craven

    2003-01-01

    Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

  11. The Study of Analytical Model of Library Electronic Resources Usage-A Case of Medical Electronic Resources

    Directory of Open Access Journals (Sweden)

    Chung-Yen Yu

    2014-10-01

    Full Text Available With the advents of internet, the importance of electronic resources is growing. Due to the increasing expensiveness of electronic resources, university libraries normally received budgets from parent institutions annually. They necessarily applied effective and systematic methods for decision making in electronic resources purchase or re-subscription. However, there are some difficulties in practices: First of all, libraries are unable to receive user records; second, the COUNTER statistics does not include details about users and their affiliation. As a result, one cannot conduct advanced user analysis based on the usage of users, institutions, and departments. To overcome the difficulties, this study presents a feasible model to analyze electronic resource usage effectively and flexibly. We set up a proxy server to collect actual usage raw data. By analyzing items in internet browsing records, associated with original library automatic system, this study aims at exploring how to use effective ways to analyze big data of website log data. We also propose the process of how original data to be transformed, cleared, integrated, and demonstrated. This study adopted a medical university library and its subscription of medical electronic resources as a case. Our data analysis includes (1 year of subscription,(2 title of journal, (3 affiliation, (4 subjects, and (5 specific journal requirements, etc. The findings of the study are contributed to obtain further understanding in policy making and user behavior analysis. The integrated data provides multiple applications in informatics research, information behavior, bibliomining, presenting diverse views and extended issues for further discussion.

  12. Practical guide to electronic resources in the humanities

    CERN Document Server

    Dubnjakovic, Ana

    2010-01-01

    From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

  13. Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

    Directory of Open Access Journals (Sweden)

    Sanna Torma

    2004-01-01

    Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

  14. Providing Access to Electronic Information Resources in Further Education

    Science.gov (United States)

    Banwell, Linda; Ray, Kathryn; Coulson, Graham; Urquhart, Christine; Lonsdale, Ray; Armstrong, Chris; Thomas, Rhian; Spink, Sin; Yeoman, Alison; Fenton, Roger; Rowley, Jennifer

    2004-01-01

    This article aims to provide a baseline for future studies on the provision and support for the use of digital or electronic information services (EIS) in further education. The analysis presented is based on a multi-level model of access, which encompasses access to and availability of information and communication technology (ICT) resources,…

  15. ANALYTICAL REVIEW OF ELECTRONIC RESOURCES FOR THE STUDY OF LATIN

    Directory of Open Access Journals (Sweden)

    Olena Yu. Balalaieva

    2014-04-01

    Full Text Available The article investigates the current state of development of e-learning content in the Latin language. It is noted that the introduction of ICT in the educational space has expanded the possibility of studying Latin, opened access to digital libraries resources, made it possible to use scientific and educational potential and teaching Latin best practices of world's leading universities. A review of foreign and Ukrainian information resources and electronic editions for the study of Latin is given. Much attention was paid to the didactic potential of local and online multimedia courses of Latin, electronic textbooks, workbooks of interactive tests and exercises, various dictionaries and software translators, databases and digital libraries. Based on analysis of the world market of educational services and products the main trends in the development of information resources and electronic books are examined. It was found that multimedia courses with interactive exercises or workbooks with interactive tests, online dictionaries and translators are the most widely represented and demanded. The noticeable lagging of Ukrainian education and computer linguistics in quantitative and qualitative measures in this industry is established. The obvious drawback of existing Ukrainian resources and electronic editions for the study of Latin is their noninteractive nature. The prospects of e-learning content in Latin in Ukraine are outlined.

  16. Electronic Commerce Resource Centers. An Industry--University Partnership.

    Science.gov (United States)

    Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

    1999-01-01

    Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

  17. Student Satisfaction with Electronic Library Resources at Wayne State University

    Science.gov (United States)

    Holley, Robert P.; Powell, Ronald R.

    2004-01-01

    This paper reports the results of a survey of student satisfaction with electronic library resources other than the online catalog at Wayne State University. Undertaken in Fall Term 2000 as a class project for a marketing course, a student team designed, administered, and analyzed a survey of a random sample of students. Almost 40% of the…

  18. Electronic Commerce Resource Centers. An Industry--University Partnership.

    Science.gov (United States)

    Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

    1999-01-01

    Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

  19. Technical Communicator: A New Model for the Electronic Resources Librarian?

    Science.gov (United States)

    Hulseberg, Anna

    2016-01-01

    This article explores whether technical communicator is a useful model for electronic resources (ER) librarians. The fields of ER librarianship and technical communication (TC) originated and continue to develop in relation to evolving technologies. A review of the literature reveals four common themes for ER librarianship and TC. While the…

  20. Providing Access to Electronic Information Resources in Further Education

    Science.gov (United States)

    Banwell, Linda; Ray, Kathryn; Coulson, Graham; Urquhart, Christine; Lonsdale, Ray; Armstrong, Chris; Thomas, Rhian; Spink, Sin; Yeoman, Alison; Fenton, Roger; Rowley, Jennifer

    2004-01-01

    This article aims to provide a baseline for future studies on the provision and support for the use of digital or electronic information services (EIS) in further education. The analysis presented is based on a multi-level model of access, which encompasses access to and availability of information and communication technology (ICT) resources,…

  1. Evaluating the appropriateness of electronic information resources for learning.

    Science.gov (United States)

    Saparova, Dinara; Nolan, Nathanial S

    2016-01-01

    Current US medical students have begun to rely on electronic information repositories-such as UpToDate, AccessMedicine, and Wikipedia-for their pre-clerkship medical education. However, it is unclear whether these resources are appropriate for this level of learning due to factors involving information quality, level of evidence, and the requisite knowledgebase. This study evaluated appropriateness of electronic information resources from a novel perspective: amount of mental effort learners invest in interactions with these resources and effects of the experienced mental effort on learning. Eighteen first-year medical students read about three unstudied diseases in the above-mentioned resources (a total of fifty-four observations). Their eye movement characteristics (i.e., fixation duration, fixation count, visit duration, and task-evoked pupillary response) were recorded and used as psychophysiological indicators of the experienced mental effort. Post reading, students' learning was assessed with multiple-choice tests. Eye metrics and test results constituted quantitative data analyzed according to the repeated Latin square design. Students' perceptions of interacting with the information resources were also collected. Participants' feedback during semi-structured interviews constituted qualitative data and was reviewed, transcribed, and open coded for emergent themes. Compared to AccessMedicine and Wikipedia, UpToDate was associated with significantly higher values of eye metrics, suggesting learners experienced higher mental effort. No statistically significant difference between the amount of mental effort and learning outcomes was found. More so, descriptive statistical analysis of the knowledge test scores suggested similar levels of learning regardless of the information resource used. Judging by the learning outcomes, all three information resources were found appropriate for learning. UpToDate, however, when used alone, may be less appropriate for first

  2. MODEL OF AN ELECTRONIC EDUCATIONAL RESOURCE OF NEW GENERATION

    Directory of Open Access Journals (Sweden)

    Anatoliy V. Loban

    2016-01-01

    Full Text Available The mathematical structure of the modular architecture of an electronic educational resource (EER of new generation, which allows to decompose the process of studying the subjects of the course at a hierarchically ordered set of data (knowledge and procedures for manipulating them, to determine the roles of participants of process of training of and technology the development and use of EOR in the study procrate.

  3. Evaluating increased resource use in fibromyalgia using electronic health records

    Directory of Open Access Journals (Sweden)

    Margolis JM

    2016-11-01

    Full Text Available Jay M Margolis,1 Elizabeth T Masters,2 Joseph C Cappelleri,3 David M Smith,1 Steven Faulkner4 1Truven Health Analytics, Life Sciences, Outcomes Research, Bethesda, MD, 2Pfizer Inc, Outcomes & Evidence, New York, NY, 3Pfizer Inc, Statistics, Groton, CT, 4Pfizer Inc, North American Medical Affairs, Medical Outcomes Specialists, St Louis, MO, USA Objective: The management of fibromyalgia (FM, a chronic musculoskeletal disease, remains challenging, and patients with FM are often characterized by high health care resource utilization. This study sought to explore potential drivers of all-cause health care resource utilization and other factors associated with high resource use, using a large electronic health records (EHR database to explore data from patients diagnosed with FM. Methods: This was a retrospective analysis of de-identified EHR data from the Humedica database. Adults (≥18 years with FM were identified based on ≥2 International Classification of Diseases, Ninth Revision codes for FM (729.1 ≥30 days apart between January 1, 2008 and December 31, 2012 and were required to have evidence of ≥12 months continuous care pre- and post-index; first FM diagnosis was the index event; 12-month pre- and post-index reporting periods. Multivariable analysis evaluated relationships between variables and resource utilization. Results: Patients were predominantly female (81.4%, Caucasian (87.7%, with a mean (standard deviation age of 54.4 (14.8 years. The highest health care resource utilization was observed for the categories of “medication orders” and “physician office visits,” with 12-month post-index means of 21.2 (21.5 drug orders/patient and 15.1 (18.1 office visits/patient; the latter accounted for 73.3% of all health care visits. Opioids were the most common prescription medication, 44.3% of all patients. The chance of high resource use was significantly increased (P<0.001 26% among African-Americans vs Caucasians and for patients

  4. Online Electronic Resources and Slovenian Bibliography: a Case Study

    Directory of Open Access Journals (Sweden)

    Daniela Škerget

    2014-09-01

    Full Text Available AbstractConsidering the fact that the number of publications available online only is growing, the question whether to include online electronic resources into the Slovenian bibliography, and if so, in which way, and what are the requirements for the inclusion, is raised. To answer these questions, the research on the growth of the Slovenian online scientific production in comparison with production in printed form was conducted in the case of original scientific articles. Results showed a rapid growth of the number of original scientific articles available online only, which indicates the necessity to form a separate Slovenian bibliography of online resources. The selection criteria for the Slovenian bibliography of online resources are also presented. This kind of bibliography would, along with the informational value, add to the historical value of intellectual production in a given time frame, enriched with a link to the resource preserved in another location (archive, repository, in case of unavailability of the resource on its original location.

  5. Journals, Data and Abstracts Make an Integrated Electronic Resource

    Science.gov (United States)

    Boyce, P.

    1996-12-01

    Astronomy now has an integrated, Web-based information resource for research papers, data and bibliographic information. The major scholarly research journals, a comprehensive abstract service and the astronomical data centers are now linked together to provide an information resource which is not available to most other scientific disciplines. As of January, 1997, the Astrophysical Journal joins the ApJ Letters on the Web. Astronomy and Astrophysics Supplements now has a page image version. Elsevier's electronic journal New Astronomy has recently made its appearance. Over forty percent of the new peer-reviewed, astronomical literature is now available electronically. The main Astronomy and Astrophysics journal, the Astronomical Journal and others will be available by 1998, at which point ninety percent of the literature will be available electronically, a figure not approached by any other scientific discipline. With so many different sources, one of the challenges has been to integrate the on-line, peer-reviewed literature into a resource which serves the astronomical community in a unified and coherent manner. Following the lead of the AAS, the major publishers have chosen to rely upon the NASA-supported Astrophysics Data System (ADS) and the astronomical data centers to provide the means by which the various separate journals can interoperate. The data centers and the ADS have developed unique identification codes for journal articles. By adopting the existing standard "bibcodes" and integrating them into their WWW links, each of the major astronomical journals are able to link to the abstracts of most of the referenced articles. Since the ADS also serves as an on-line repository for page images of the past twenty years of the major astronomical journals, the full text of many of the referenced articles are available, too. The articles in the ADS have recently been linked through their references, both forward and backward in time. With the "bibcode" providing

  6. Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

    Science.gov (United States)

    Shao, Fang

    The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

  7. Resources

    Science.gov (United States)

    ... resources Alzheimer's - resources Anorexia nervosa - resources Arthritis - resources Asthma and allergy - resources Autism - resources Blindness - resources BPH - resources Breastfeeding - resources Bulimia - resources Burns - resources Cancer - resources Cerebral ...

  8. Discipline, Availability of Electronic Resources and the Use of Finnish National Electronic Library-- FinELib

    Science.gov (United States)

    Törmä, Sanna; Vakkari, Pertti

    2004-01-01

    This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib), Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic…

  9. Electric field enhancement of depolarization of excited states

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, M.H.; Hillard, G.B.; Glab, W.L.

    1985-12-01

    Our calculations show that an external dc electric field can enhance by many orders of magnitude the depolarization cross section of highly excited atoms by charged particles. The enhancement is due to the fact that the electric field extends and shifts the electronic charge distribution along its direction, thus effectively creating a giant electric dipole in the atom.

  10. End-of-life resource recovery from emerging electronic products

    DEFF Research Database (Denmark)

    Parajuly, Keshav; Habib, Komal; Cimpan, Ciprian

    2016-01-01

    of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial......Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case...... at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best...

  11. Electronic Resources and Mission Creep: Reorganizing the Library for the Twenty-First Century

    Science.gov (United States)

    Stachokas, George

    2009-01-01

    The position of electronic resources librarian was created to serve as a specialist in the negotiation of license agreements for electronic resources, but mission creep has added more functions to the routine work of electronic resources such as cataloging, gathering information for collection development, and technical support. As electronic…

  12. Effects of Electronic Information Resources Skills Training for Lecturers on Pedagogical Practices and Research Productivity

    Science.gov (United States)

    Bhukuvhani, Crispen; Chiparausha, Blessing; Zuvalinyenga, Dorcas

    2012-01-01

    Lecturers use various electronic resources at different frequencies. The university library's information literacy skills workshops and seminars are the main sources of knowledge of accessing electronic resources. The use of electronic resources can be said to have positively affected lecturers' pedagogical practices and their work in general. The…

  13. Electronic Document Management: A Human Resource Management Case Study

    Directory of Open Access Journals (Sweden)

    Thomas Groenewald

    2004-11-01

    Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

  14. Electronic Safety Resource Tools -- Supporting Hydrogen and Fuel Cell Commercialization

    Energy Technology Data Exchange (ETDEWEB)

    Barilo, Nick F.

    2014-09-29

    The Pacific Northwest National Laboratory (PNNL) Hydrogen Safety Program conducted a planning session in Los Angeles, CA on April 1, 2014 to consider what electronic safety tools would benefit the next phase of hydrogen and fuel cell commercialization. A diverse, 20-person team led by an experienced facilitator considered the question as it applied to the eight most relevant user groups. The results and subsequent evaluation activities revealed several possible resource tools that could greatly benefit users. The tool identified as having the greatest potential for impact is a hydrogen safety portal, which can be the central location for integrating and disseminating safety information (including most of the tools identified in this report). Such a tool can provide credible and reliable information from a trustworthy source. Other impactful tools identified include a codes and standards wizard to guide users through a series of questions relating to application and specific features of the requirements; a scenario-based virtual reality training for first responders; peer networking tools to bring users from focused groups together to discuss and collaborate on hydrogen safety issues; and a focused tool for training inspectors. Table ES.1 provides results of the planning session, including proposed new tools and changes to existing tools.

  15. Controlling user access to electronic resources without password

    Science.gov (United States)

    Smith, Fred Hewitt

    2015-06-16

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

  16. The Internet School of Medicine: use of electronic resources by medical trainees and the reliability of those resources.

    Science.gov (United States)

    Egle, Jonathan P; Smeenge, David M; Kassem, Kamal M; Mittal, Vijay K

    2015-01-01

    Electronic sources of medical information are plentiful, and numerous studies have demonstrated the use of the Internet by patients and the variable reliability of these sources. Studies have investigated neither the use of web-based resources by residents, nor the reliability of the information available on these websites. A web-based survey was distributed to surgical residents in Michigan and third- and fourth-year medical students at an American allopathic and osteopathic medical school and a Caribbean allopathic school regarding their preferred sources of medical information in various situations. A set of 254 queries simulating those faced by medical trainees on rounds, on a written examination, or during patient care was developed. The top 5 electronic resources cited by the trainees were evaluated for their ability to answer these questions accurately, using standard textbooks as the point of reference. The respondents reported a wide variety of overall preferred resources. Most of the 73 responding medical trainees favored textbooks or board review books for prolonged studying, but electronic resources are frequently used for quick studying, clinical decision-making questions, and medication queries. The most commonly used electronic resources were UpToDate, Google, Medscape, Wikipedia, and Epocrates. UpToDate and Epocrates had the highest percentage of correct answers (47%) and Wikipedia had the lowest (26%). Epocrates also had the highest percentage of wrong answers (30%), whereas Google had the lowest percentage (18%). All resources had a significant number of questions that they were unable to answer. Though hardcopy books have not been completely replaced by electronic resources, more than half of medical students and nearly half of residents prefer web-based sources of information. For quick questions and studying, both groups prefer Internet sources. However, the most commonly used electronic resources fail to answer clinical queries more than half

  17. Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

    Science.gov (United States)

    Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

    2014-01-01

    This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

  18. Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

    Science.gov (United States)

    Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

    2014-01-01

    This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

  19. Electronic resource management practical perspectives in a new technical services model

    CERN Document Server

    Elguindi, Anne

    2012-01-01

    A significant shift is taking place in libraries, with the purchase of e-resources accounting for the bulk of materials spending. Electronic Resource Management makes the case that technical services workflows need to make a corresponding shift toward e-centric models and highlights the increasing variety of e-formats that are forcing new developments in the field.Six chapters cover key topics, including: technical services models, both past and emerging; staffing and workflow in electronic resource management; implementation and transformation of electronic resource management systems; the ro

  20. Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

    Science.gov (United States)

    Hulseberg, Anna; Monson, Sarah

    2009-01-01

    Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

  1. Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

    Science.gov (United States)

    Hulseberg, Anna; Monson, Sarah

    2009-01-01

    Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

  2. The Relevancy of Graduate Curriculum to Human Resource Professionals' Electronic Communication.

    Science.gov (United States)

    Hoell, Robert C.; Henry, Gordon O.

    2003-01-01

    Electronic communications of human resource professionals and the content of 23 university human resource management courses were categorized using the Human Resource Certification Institute's body of knowledge. Differences between proportion of topics discussed and topics covered in curricula suggest some topics are over- or undertaught.…

  3. A Depolarizing Electrogenic Pump in Frog Muscle

    Science.gov (United States)

    1975-08-01

    mw copy AFRRI SR75-20 AUGUST 1975 AFRRI SCIENTIFIC REPORT O ■ to A DEPOLARIZING ELECTROGENIC PUMP IN FROG MUSCLE D. Geduldig D. R...Academy of Sciences - National Research Council. AFRRI SR75-20 August 1975 A DEPOLARIZING ELECTROGENIC PUMP IN FROG MUSCLE D. GEDULDIG* D. R...INTRODUCTION When Na-enriched frog muscles are bathed in Na- and K-free saline, the small amount of potassium which could accumulate outside of the membrane

  4. 2015 Utilization of Electronic Information Resources in Ramat ...

    African Journals Online (AJOL)

    intensely powerful and has permeated all segments and ... Web (WWW) and the internet to make information more accessible. On the other ... access points on the campus and computer literacy is till .... resources are often faster to consult than.

  5. Remote Electronic Resources and the OPAC: Illustrated by the Unisa Library Experience.

    Science.gov (United States)

    Van der Merwe, Ina; Van Eeden, Welna; Hartzer, Sandra

    This paper describes the Unisa (University of South Africa) Library's experience with cataloging remote electronic resources, including electronic journals, electronic text files, online databases, digital images, Unisa campus Web sites, and mailing list discussions. The first section discusses the decision to add bibliographic references for…

  6. Controlling user access to electronic resources without password

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Fred Hewitt

    2017-08-22

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

  7. Proximity to Intrinsic Depolarizing Resonances with a Partial Siberian Snake

    Science.gov (United States)

    Crandell, D. A.; Alexeeva, L. V.; Anferov, V. A.; Blinov, B. B.; Chu, C. M.; Caussyn, D. D.; Courant, E. D.; Gladycheva, S. E.; Hu, S.; Krisch, A. D.; Nurushev, T. S.; Phelps, R. A.; Ratner, L. G.; Varzar, S. M.; Wong, V. K.; Derbenev, Ya. S.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E. J.; von Przewoski, B.; Baiod, R.; Russell, A. D.; Ohmori, C.; Sato, H.

    1996-05-01

    Partial Siberian snakes are effective in overcoming imperfection depolarizing resonances, but they may also change the crossing energy for intrinsic depolarizing resonances. We experimentally investigated the effect of a partial Siberian snake near intrinsic depolarizing resonances with stored 140 MeV and 160 MeV polarized proton beams. Using various partial Siberian snake strengths up to 30%, depolarization was observed; this may be due to a change in the spin precession frequency which moves the energy of nearby intrinsic depolarizing resonances.

  8. An Evaluation of Electronic Product Design Education Using Hypermedia-Resourced Learning Environments

    Science.gov (United States)

    Page, Tom; Thorsteinsson, Gisli

    2006-01-01

    The work outlined here provides a comprehensive report and formative observations of the development and implementation of hypermedia resources for learning and teaching used in conjunction with a managed learning environment (MLE). These resources are used to enhance teaching and learning of an electronics module in product design at final year…

  9. A Study on Developing Evaluation Criteria for Electronic Resources in Evaluation Indicators of Libraries

    Science.gov (United States)

    Noh, Younghee

    2010-01-01

    This study aimed to improve the current state of electronic resource evaluation in libraries. While the use of Web DB, e-book, e-journal, and other e-resources such as CD-ROM, DVD, and micro materials is increasing in libraries, their use is not comprehensively factored into the general evaluation of libraries and may diminish the reliability of…

  10. Managing Selection for Electronic Resources: Kent State University Develops a New System to Automate Selection

    Science.gov (United States)

    Downey, Kay

    2012-01-01

    Kent State University has developed a centralized system that manages the communication and work related to the review and selection of commercially available electronic resources. It is an automated system that tracks the review process, provides selectors with price and trial information, and compiles reviewers' feedback about the resource. It…

  11. Where Do Electronic Books Fit in the College Research Arsenal of Resources?

    Science.gov (United States)

    Barbier, Patricia

    2007-01-01

    Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

  12. Where Do Electronic Books Fit in the College Research Arsenal of Resources?

    Science.gov (United States)

    Barbier, Patricia

    2007-01-01

    Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

  13. Neutron Depolarization in Submicron Ferromagnetic Materials

    NARCIS (Netherlands)

    Rekveldt, M.Th.

    1989-01-01

    The neutron depolarization technique is based on the loss of polarization of a polarized neutron beam after transmission through ferromagnetic substances. This loss, caused by Larmor precession in individual domains, determines the mean domain size, the mean square direction cosines of the domains a

  14. Depolarization of UCN stored in material traps

    CERN Document Server

    Serebrov, A; Lasakov, M; Rudnev, Y; Krasnoschekova, I A; Geltenbort, P; Butterworth, J; Bowles, T; Morris, C; Seestrom, S; Smith, D; Young, A R

    2000-01-01

    Depolarization of ultra-cold neutrons (UCN) stored in material traps was first observed. The probability of UCN spin flip per reflection depends on the trap material and varies from 7x10 sup - sup 6 (beryllium) to 10 sup - sup 4 (glass).

  15. Spreading depolarization may link migraine and stroke.

    Science.gov (United States)

    Eikermann-Haerter, Katharina

    2014-01-01

    Migraine increases the risk of stroke, particularly in young and otherwise healthy adults. Being the most frequent neurological condition, migraine prevalence is on a par with that of other common stroke risk factors, such as diabetes or hypertension. Several patterns of association have emerged: (1) migraine and stroke share a common association (eg, vasculopathies, patent foramen ovale, or pulmonary A-V malformations); (2) injury to the arterial wall such as acute arterial dissections can present as migraine aura attacks or stroke; (3) strokes rarely develop during a migraine attack, as described for "migrainous stroke." Increasing experimental evidence suggests that cerebral hyperexcitability and enhanced susceptibility to spreading depolarization, the electrophysiologic event underlying migraine, may serve as a mechanism underlying the migraine-stroke association. Mice carrying human vascular or neuronal migraine mutations exhibit an enhanced susceptibility to spreading depolarization while being particularly vulnerable to cerebral ischemia. The severe stroke phenotype in migraine mutant mice can be prevented by suppressing spreading depolarization. If confirmed in the clinical setting, inhibiting spreading depolarization might protect migraineurs at stroke risk as well as decrease attacks of migraine. © 2014 American Headache Society.

  16. MULER: Building an Electronic Resource Management (ERM Solution at York University

    Directory of Open Access Journals (Sweden)

    Aaron August Lupton

    2012-01-01

    Full Text Available Many university libraries now utilize an Electronic Resource Management (ERM system to assist with operations related to electronic resources. An ERM is a relational database containing information such as suppliers, costs, holdings, and renewal dates for electronic resources, both at the database and title levels. While commercial ERM products are widely available, some institutions are custom building their own ERM in- house. This article describes how York University in Toronto, Canada, did just that by building a system called Managing University Library Electronic Resources (MULER. The article details the background and history of how electronic resources were managed pre-MULER; why a new ERM was needed; the planning process; the current and innovative functions of MULER, including integration of MULER data into York University Libraries search and discovery layer, Vufind; subject tagging in MULER; new functions to be added; and lessons learned from the project. Positive and negative implications of choosing an in-house project over paying for a commercial product are also discussed.

  17. Spreading convulsions, spreading depolarization and epileptogenesis in human cerebral cortex

    DEFF Research Database (Denmark)

    Dreier, Jens P; Major, Sebastian; Pannek, Heinz-Wolfgang

    2012-01-01

    Spreading depolarization of cells in cerebral grey matter is characterized by massive ion translocation, neuronal swelling and large changes in direct current-coupled voltage recording. The near-complete sustained depolarization above the inactivation threshold for action potential generating...

  18. Energy transfer and depolarization in the photoluminescence of a plasmonic molecule.

    Science.gov (United States)

    Yin, Tingting; Jiang, Liyong; Dong, Zhaogang; Yang, Joel K W; Shen, Ze Xiang

    2017-02-02

    We report a comprehensive experimental study of the polarization dependence between excitation and photoluminescence (PL) emission from single dolmen-like metallic nanostructures that exhibit both Fano-like and Lorentz-like plasmon resonances. Though the PL spectra of this plasmonic "molecule" also exhibit the Fano and Lorentz signature, the emitted photons do not maintain the same polarization as the excitation. Surprisingly, the degree of depolarization correlates closely to the resonant excitation of the constituent atoms (single nanorod). More specifically, the excitation of a transverse plasmon mode results in a depolarized emission through the longitudinal plasmon modes of the constituent nanorods. In view of the recent evidence of on-resonant plasmon induced excitations in generating hot electrons, our results suggest that depolarized PL emissions could be enhanced through hot-electron decay. Both macroscopic and microscopic mechanisms are proposed to well-understand the excitation wavelength dependent depolarized photoluminescence behaviors in the plasmonic molecule. Our results lay a foundation for applying the depolarized photoluminescence of complex plasmonic nanostructures in polarization engineering.

  19. The National Site Licensing of Electronic Resources: An Institutional Perspective

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhu

    2011-06-01

    Full Text Available While academic libraries in most countries are struggling to negotiate with publishers and vendors individually or collaboratively via consortia, a few countries have experimented with a different model, national site licensing (NSL. Because NSL often involves government and large-scale collaboration, it has the potential to solve many problems in the complex licensing world. However, not many nations have adopted it. This study uses historical research approach and the comparative case study research method to explore the seemingly low level of adoption. The cases include the Canadian National Site Licensing Project (CNSLP, the United Kingdom’s National Electronic Site Licensing Initiative (NESLI, and the United States, which has not adopted NSL. The theoretical framework guiding the research design and data collection is W. Richard Scott’s institutional theory, which utilizes three supporting pillars—regulative, normative, and cultural-cognitive—to analyze institutional processes. In this study, the regulative pillar and the normative pillar of NSL adoption— an institutional construction and change—are examined. Data were collected from monographs, research articles, government documents, and relevant websites. Based on the analysis of these cases, a preliminary model is proposed for the adoption of NSL. The factors that support a country’s adoption of NSL include the need for new institutions, a centralized educational policy-making system and funding system, supportive political trends, and the tradition of cooperation. The factors that may prevent a country from adopting NSL include decentralized educational policy and funding, diversity and the large number of institutions, the concern for the “Big Deal,” and the concern for monopoly.

  20. Recording, analysis, and interpretation of spreading depolarizations in neurointensive care

    DEFF Research Database (Denmark)

    Dreier, Jens P; Fabricius, Martin; Ayata, Cenk

    2016-01-01

    recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy...... electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can...

  1. Depolarization in the ILC Linac-to-Ring Positron Beamline

    CERN Document Server

    Riemann, Sabine

    2012-01-01

    To achieve the physics goals of future Linear Colliders, it is important that electron and positron beams are polarized. The positron source planned for the International Linear Collider (ILC) is based on a helical undulator system and can deliver a polarised beam with positron polarization of 60%. To ensure that no significant polarization is lost during the transport of the electron and positron beams from the source to the interaction region, spin tracking has to be included in all transport elements which can contribute to a loss of polarization. These are the positron source, the damping ring, the spin rotators, the main linac and the beam delivery system. In particular, the dynamics of the polarized positron beam is required to be investigated. The results of positron spin tracking and depolarization study at the Positron-Linac-To-Ring (PLTR) beamline are presented.

  2. Analytical Study of Usage of Electronic Information Resources at Pharmacopoeial Libraries in India

    Directory of Open Access Journals (Sweden)

    Sunil Tyagi

    2014-02-01

    Full Text Available The objective of this study is to know the rate and purpose of the use of e-resource by the scientists at pharmacopoeial libraries in India. Among other things, this study examined the preferences of the scientists toward printed books and journals, electronic information resources, and pattern of using e-resources. Non-probability sampling specially accidental and purposive technique was applied in the collection of primary data through administration of user questionnaire. The sample respondents chosen for the study consists of principle scientific officer, senior scientific officer, scientific officer, and scientific assistant of different division of the laboratories, namely, research and development, pharmaceutical chemistry, pharmacovigilance, pharmacology, pharmacogonosy, and microbiology. The findings of the study reveal the personal experiences and perceptions they have had on practice and research activity using e-resource. The major findings indicate that of the total anticipated participants, 78% indicated that they perceived the ability to use computer for electronic information resources. The data analysis shows that all the scientists belonging to the pharmacopoeial libraries used electronic information resources to address issues relating to drug indexes and compendia, monographs, drugs obtained through online databases, e-journals, and the Internet sources—especially polices by regulatory agencies, contacts, drug promotional literature, and standards.

  3. Connecting knowledge resources to the veterinary electronic health record: opportunities for learning at point of care.

    Science.gov (United States)

    Alpi, Kristine M; Burnett, Heidi A; Bryant, Sheila J; Anderson, Katherine M

    2011-01-01

    Electronic health records (EHRs) provide clinical learning opportunities through quick and contextual linkage of patient signalment, symptom, and diagnosis data with knowledge resources covering tests, drugs, conditions, procedures, and client instructions. This paper introduces the EHR standards for linkage and the partners-practitioners, content publishers, and software developers-necessary to leverage this possibility in veterinary medicine. The efforts of the American Animal Hospital Association (AAHA) Electronic Health Records Task Force to partner with veterinary practice management systems to improve the use of controlled vocabulary is a first step in the development of standards for sharing knowledge at the point of care. The Veterinary Medical Libraries Section (VMLS) of the Medical Library Association's Task Force on Connecting the Veterinary Health Record to Information Resources compiled a list of resources of potential use at point of care. Resource details were drawn from product Web sites and organized by a metric used to evaluate medical point-of-care resources. Additional information was gathered from questions sent by e-mail and follow-up interviews with two practitioners, a hospital network, two software developers, and three publishers. Veterinarians with electronic records use a variety of information resources that are not linked to their software. Systems lack the infrastructure to use the Infobutton standard that has been gaining popularity in human EHRs. While some veterinary knowledge resources are digital, publisher sites and responses do not indicate a Web-based linkage of veterinary resources with EHRs. In order to facilitate lifelong learning and evidence-based practice, veterinarians and educators of future practitioners must demonstrate to veterinary practice software developers and publishers a clinically-based need to connect knowledge resources to veterinary EHRs.

  4. Improving access to information – defining core electronic resources for research and wellbeing

    Directory of Open Access Journals (Sweden)

    Kristiina Hormia-Poutanen

    2007-11-01

    Full Text Available Research and innovation are listed as the key success factors for the future development of Finnish prosperity and the Finnish economy. The Finnish libraries have developed a scenario to support this vision. University, polytechnic and research institute libraries as well as public libraries have defined the core electronic resources necessary to improve access to information in Finland. The primary aim of this work has been to provide information and justification for central funding for electronic resources to support the national goals. The secondary aim is to help with the reallocation of existing central funds to better support access to information.

  5. Elektronik Bilgi Kaynaklarının Seçimi / Selection of Electronic Information Resources

    Directory of Open Access Journals (Sweden)

    Pınar Al

    2003-04-01

    Full Text Available For many years, library users have used only from the printed media in order to get the information that they have needed. Today with the widespread use of the Web and the addition of electronic information resources to library collections, the use of information in the electronic environment as well as in printed media is started to be used. In time, such types of information resources as, electronic journals, electronic books, electronic encyclopedias, electronic dictionaries and electronic theses have been added to library collections. In this study, selection criteria that can be used for electronic information resources are discussed and suggestions are provided for libraries that try to select electronic information resources for their collections.

  6. Storage ring lattice calibration using resonant spin depolarization

    Directory of Open Access Journals (Sweden)

    K. P. Wootton

    2013-07-01

    Full Text Available This paper presents measurements of the GeV-scale electron beam energy for the storage rings at the synchrotron light source facilities Australian Synchrotron (AS and SPEAR3 at SLAC. Resonant spin depolarization was employed in the beam energy measurement, since it is presently the highest precision technique and an uncertainty of order 10^{-6} was achieved at SPEAR3 and AS. Using the resonant depolarization technique, the beam energy was measured at various rf frequencies to measure the linear momentum compaction factor. This measured linear momentum compaction factor was used to evaluate models of the beam trajectory through combined-function bending magnets. The main bending magnets of both lattices are rectangular, horizontally defocusing gradient bending magnets. Four modeling approaches are compared for the beam trajectory through the bending magnet: a circular trajectory, linear and nonlinear hyperbolic cosine trajectories, and numerical evaluation of the trajectory through the measured magnetic field map. Within the uncertainty of the measurement the momentum compaction factor is shown to agree with the numerical model of the trajectory within the bending magnet, and disagree with the hyperbolic cosine approximation.

  7. Differential description and irreversibility of depolarizing light-matter interactions

    CERN Document Server

    Fade, Julien

    2016-01-01

    The widely-used Jones and Mueller differential polarization calculi allow non-depolarizing deterministic polarization interactions, known to be elements of the $SO^+(1,3)$ Lorentz group, to be described in an efficient way. In this Letter, a stochastic differential Jones formalism is shown to provide a clear physical insight on light depolarization, which arises from the interaction of polarized light with a random medium showing fluctuating anisotropic properties. Based on this formalism, several "intrinsic" depolarization metrics naturally arise to efficiently characterize light depolarization in a medium, and an irreversibility property of depolarizing transformations is finally established.

  8. Using Electronic Information Resources Centers by Faculty Members at University Education: Competencies, Needs and Challenges

    Science.gov (United States)

    Abouelenein, Yousri

    2017-01-01

    This study aimed at investigating the factual situation of electronic information resources centers to faculty members at university education. Competencies that faculty members should possess regarding this issue were determined. Also their needs for (scientific research skills and teaching) were assessed. In addition, problems that hinder their…

  9. Localising versus standardising electronic human resource management: complexities and tensions between HRM and IT departments

    NARCIS (Netherlands)

    Tate, Mary; Furtmueller, E.; Wilderom, C.P.M.

    2013-01-01

    In this paper, we provide an analysis of the complexities involved during global e-HRM (Electronic Human Resource Management) implementation. We present findings from a case study on the challenge of global integration versus local responsiveness of e-HRM systems. We take a local site lens, analysin

  10. Use of Electronic Information Resources among Research Scholars in the Islamia University of Bahawalpur, Pakistan

    Science.gov (United States)

    Amjad, Anam; Ahmed, Shamshad; Bin Naeem, Salman

    2013-01-01

    This study examined the use of electronic resources among academic scholars of The Islamia University of Bahawalpur (IUB), Punjab, Pakistan. A quantitative survey was found most convenient and useful for this study. The total population of the study was 169 research students in IUB. The response rate was 79% and 133 utilizable responses were coded…

  11. The Acquisition and Management of Electronic Resources: Can Use Justify Cost?

    Science.gov (United States)

    Koehn, Shona L.; Hawamdeh, Suliman

    2010-01-01

    As library collections increasingly become digital, libraries are faced with many challenges regarding the acquisition and management of electronic resources. Some of these challenges include copyright and fair use, the first-sale doctrine, licensing versus ownership, digital preservation, long-term archiving, and, most important, the issue of…

  12. 电子资源的编目策略%Cataloging Strategies of Electronic Resources

    Institute of Scientific and Technical Information of China (English)

    王亚林

    2012-01-01

    Compared with traditional paper resources, electronic resources have following characteristics which determine different cataloging strategies from paper resources. These characteristics are huge quantity, updating rapidly, coexistence of a variety of manifestations. The source data of electronic resources is usually provided by the database agent. The cataloging of electronic resources is based on the Chapter IX of Anglo-American Cataloging Rules, Library of Congress Rule Interpretations and rules of Cooperative Online Serials. There are two major cataloging methods for electronic resources abroad, they are single record approach and separate record approach. Peking University Library chooses the latter method and batches cataloging automatically using the source data.%电子资源吲传统纸质资源相比,具有数量大、更新快、多种载体表现并行等特点,且大部分出版机构能够提供数据源数据。这些特点决定了.电子资源应采取与纸质文献不同的编目策略。电子资源编日的主要依据是《英美编日条例》的第9章、美国《国会图书馆条例解释》及全美期刊合作编目计划的规定。对于电子资源的编目,国外有单一记录编目法和分散记录编目法。北京大学图书馆采用后者,同时利用数据源数据批舒自动编目。

  13. Power resource management and low-power remote wireless RF electronics

    Science.gov (United States)

    Jannson, Tomasz; Forrester, Thomas; Degrood, Kevin; Lee, Kang; Gans, Eric; Walter, Kevin

    2009-05-01

    Battery power resource management becomes a critical issue in the case of self-powered remote wireless RF electronics, where the basic parameter is time of system operation before battery recharging or battery replacement. In such cases, very often related to physical protection against antitampering (AT), proper theoretical modeling of a battery driven power supply in the context of a given digital electronic system is of utmost importance. Such modeling should include various types of batteries (primary and secondary), various self-discharge processes in different temperatures, and even energy harvesting, the latter to supply power for long-term content, low-power electronic subsystems. In this paper we analyze simple modeling of resource power management, including variations of all of these parameters and energy harvesting.

  14. Identifying and evaluating electronic learning resources for use in adult-gerontology nurse practitioner education.

    Science.gov (United States)

    Thompson, Hilaire J; Belza, Basia; Baker, Margaret; Christianson, Phyllis; Doorenbos, Ardith; Nguyen, Huong

    2014-01-01

    Enhancing existing curricula to meet newly published adult-gerontology advanced practice registered nurse (APRN) competencies in an efficient manner presents a challenge to nurse educators. Incorporating shared, published electronic learning resources (ELRs) in existing or new courses may be appropriate in order to assist students in achieving competencies. The purposes of this project were to (a) identify relevant available ELR for use in enhancing geriatric APRN education and (b) to evaluate the educational utility of identified ELRs based on established criteria. A multilevel search strategy was used. Two independent team members reviewed identified ELR against established criteria to ensure utility. Only resources meeting all criteria were retained. Resources were found for each of the competency areas and included formats such as podcasts, Web casts, case studies, and teaching videos. In many cases, resources were identified using supplemental strategies and not through traditional search or search of existing geriatric repositories. Resources identified have been useful to advanced practice educators in improving lecture and seminar content in a particular topic area and providing students and preceptors with additional self-learning resources. Addressing sustainability within geriatric APRN education is critical for sharing of best practices among educators and for sustainability of teaching and related resources. © 2014.

  15. Library Electronic Resource Sharing Among Liberal Arts Colleges: ACS Palladian Alliance Project

    Directory of Open Access Journals (Sweden)

    Wenxian Zhang

    1997-03-01

    Full Text Available 無Effective electronic resource sharing is critical to library information services of the 1990s. Explosion of data and increased cost of information force libraries to work together, and technological advancements present the library service profession a platform for resource sharing. The Palladian Alliance Project of the Associated Colleges of the South is designed to provides ACS member institutions an effective means to enhance information access for their faculty and students, and achieve significant cost containment in the years to come.

  16. Availability, Level of Use and Constraints to Use of Electronic Resources by Law Lecturers in Public Universities in Nigeria

    Science.gov (United States)

    Amusa, Oyintola Isiaka; Atinmo, Morayo

    2016-01-01

    (Purpose) This study surveyed the level of availability, use and constraints to use of electronic resources among law lecturers in Nigeria. (Methodology) Five hundred and fifty-two law lecturers were surveyed and four hundred and forty-two responded. (Results) Data analysis revealed that the level of availability of electronic resources for the…

  17. Spreading depolarization monitoring in neurocritical care of acute brain injury.

    Science.gov (United States)

    Hartings, Jed A

    2017-04-01

    Spreading depolarizations are unique in being discrete pathologic entities that are well characterized experimentally and also occur commonly in patients with substantial acute brain injury. Here, we review essential concepts in depolarization monitoring, highlighting its clinical significance, interpretation, and future potential. Cortical lesion development in diverse animal models is mediated by tissue waves of mass spreading depolarization that cause the toxic loss of ion homeostasis and limit energy substrate supply through associated vasoconstriction. The signatures of such deterioration are observed in electrocorticographic recordings from perilesional cortex of patients with acute stroke or brain trauma. Experimental work suggests that depolarizations are triggered by energy supply-demand mismatch in focal hotspots of the injury penumbra, and depolarizations are usually observed clinically when other monitoring variables are within recommended ranges. These results suggest that depolarizations are a sensitive measure of relative ischemia and ongoing secondary injury, and may serve as a clinical guide for personalized, mechanistically targeted therapy. Both existing and future candidate therapies offer hope to limit depolarization recurrence. Electrocorticographic monitoring of spreading depolarizations in patients with acute brain injury provides a sensitive measure of relative energy shortage in focal, vulnerable brains regions and indicates ongoing secondary damage. Depolarization monitoring holds potential for targeted clinical trial design and implementation of precision medicine approaches to acute brain injury therapy.

  18. Abnormal depolarizing patterns in three patients with filarial infection.

    Science.gov (United States)

    Crespo, S; Palacios, G; Scott, S; Lago, M; Puente, S; Martínez, M; Baquero, M; Subirats, M

    2004-05-01

    Several authors have described a particular potential of automated depolarization analysis in detecting malaria infection as part of the routine full blood count (FBC) performed by the Cell-Dyn 4000 analyzer. In these cases, abnormal depolarizing patterns are due to the presence of leukocyte-associated malaria hemozoin, a pigment which depolarizes the laser light. In this report we describe samples from three individual patients who did not have malaria infection but showed abnormal depolarizing events. Further investigation determined that these samples were from patients infected by the nematode Mansonella perstans. The observed depolarizing pattern consisted of a normal depolarizing eosinophil population and in addition an abnormal depolarizing population that showed a close "linear" relationship between "granularity" (90 degrees depolarization) and "lobularity" (90 degrees polarization). This atypical population was smaller than normal leukocytes and thus clearly different from the patterns associated with malaria infection. Abnormal depolarization patterns of M. perstans clearly do not reflect leukocyte-associated malaria hemozoin. It is possible however that the erythrocyte-lysing agent used to facilitate leukocyte analysis by the instrument may have caused microfilaria fragmentation and thus the distinctive "straight-line" features of the abnormal scatter plots

  19. Potential resource and toxicity impacts from metals in waste electronic devices.

    Science.gov (United States)

    Woo, Seung H; Lee, Dae Sung; Lim, Seong-Rin

    2016-04-01

    As a result of the continuous release of new electronic devices, existing electronic devices are quickly made obsolete and rapidly become electronic waste (e-waste). Because e-waste contains a variety of metals, information about those metals with the potential for substantial environmental impact should be provided to manufacturers, recyclers, and disposers to proactively reduce this impact. This study assesses the resource and toxicity (i.e., cancer, noncancer, and ecotoxicity) potentials of various heavy metals commonly found in e-waste from laptop computers, liquid-crystal display (LCD) monitors, LCD TVs, plasma TVs, color cathode ray tube (CRT) TVs, and cell phones and then evaluates such potentials using life cycle impact-based methods. Resource potentials derive primarily from Cu, Sb, Ag, and Pb. Toxicity potentials derive primarily from Pb, Ni, and Hg for cancer toxicity; from Pb, Hg, Zn, and As for noncancer toxicity; and from Cu, Pb, Hg, and Zn for ecotoxicity. Therefore, managing these heavy metals should be a high priority in the design, recycling, and disposal stages of electronic devices.

  20. Model of e-learning with electronic educational resources of new generation

    Directory of Open Access Journals (Sweden)

    A. V. Loban

    2017-01-01

    Full Text Available Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with electronic educational resource of new generation is developed, conditionally decomposed into three basic components: the formalization model of the course in the form of the thesaurusclassifier (“Author of e-resource”, the model of learning as management (“Coordination. Consultation. Control”, the learning model with the thesaurus-classifier (“Student”. Model “Author of e-resource” allows the student to achieve completeness, high degree of didactic elaboration and structuring of the studied material in triples of variants: modules of education information, practical task and control tasks; the result of the student’s (author’s of e-resource activity is the thesaurus-classifier. Model of learning as management is based on the principle of personal orientation of learning in computer environment and determines the logic of interaction between the lecturer and the student when determining the triple of variants individually for each student; organization of a dialogue between the lecturer and the student for consulting purposes; personal control of the student’s success (report generation and iterative search for the concept of the class assignment in the thesaurus-classifier before acquiring the required level of training. Model “Student” makes it possible to concretize the learning tasks in relation to the personality of the student and to the training level achieved; the assumption of the lecturer about the level of training of a

  1. [Cortical spreading depolarization: a new pathophysiological mechanism in neurological diseases].

    Science.gov (United States)

    Sánchez-Porras, Renán; Robles-Cabrera, Adriana; Santos, Edgar

    2014-05-20

    Cortical spreading depolarization is a wave of almost complete depolarization of the neuronal and glial cells that occurs in different neurological diseases such as migraine with aura, subarachnoid hemorrhage, intracerebral hemorrhage, head trauma and stroke. These depolarization waves are characterized by a change in the negative potential with an amplitude between -10 and -30mV, duration of ∼1min and changes in the ion homeostasis between the intra- and extracellular space. This results in neuronal edema and dendritic distortion. Under pathologic states of hypoperfusion, cortical spreading depolarization can produce oxidative stress, worsen hypoxia and induce neuronal death. This is due to intense arterial vasoconstriction produced by an inverse response called spreading ischemia. Only in the last years there has been an electrophysiological confirmation of cortical spreading depolarization in human brains. Occurrence of cortical spreading depolarization has been associated with worse outcome in patients. Currently, increased knowledge regarding the pathophysiologic mechanisms supports the hypothetical correlation of cortical spreading depolarization with brain damage in humans. There are diverse therapeutic alternatives that promise inhibition of cortical spreading depolarization and subsequent better outcomes. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  2. Depolarization Lidar Determination of Cloud-Base Microphysical Properties

    NARCIS (Netherlands)

    Donovan, D.P.; Klein Baltink, H.; Henzing, J.S.; Roode, S. de; Siebesma, A.P.

    2016-01-01

    The links between multiple-scattering induced depolarization and cloud microphysical properties (e.g. cloud particle number density, effective radius, water content) have long been recognised. Previous efforts to use depolarization information in a quantitative manner to retrieve cloud microphysical

  3. [Use of internet and electronic resources among Spanish intensivist physicians. First national survey].

    Science.gov (United States)

    Gómez-Tello, V; Latour-Pérez, J; Añón Elizalde, J M; Palencia-Herrejón, E; Díaz-Alersi, R; De Lucas-García, N

    2006-01-01

    Estimate knowledge and use habits of different electronic resources in a sample of Spanish intensivists: Internet, E-mail, distribution lists, and use of portable electronic devices. Self-applied questionnaire. A 50-question questionnaire was distributed among Spanish intensivists through the hospital marketing delegates of a pharmaceutical company and of electronic forums. A total of 682 questionnaires were analyzed (participation: 74%). Ninety six percent of those surveyed used Internet individually: 67% admitted training gap. Internet was the second source of clinical consultations most used (61%), slightly behind consultation to colleagues (65%). The pages consulted most were bibliographic databases (65%) and electronic professional journals (63%), with limited use of Evidence Based Medicine pages (19%). Ninety percent of those surveyed used e-mail regularly in the practice of their profession, although 25% admitted that were not aware of its possibilities. The use of E-mail decreased significantly with increase in age. A total of 62% of the intensivists used distribution lists. Of the rest, 42% were not aware of its existence and 32% admitted they had insufficient training to handle them. Twenty percent of those surveyed had portable electronic devices and 64% considered it useful, basically due to its rapid consultation at bedside. Female gender was a negative predictive factor of its use (OR 0.35; 95% CI 0.2-0.63; p=0.0002). A large majority of the Spanish intensivists use Internet and E-mail. E-mail lists and use of portable devices are still underused resources. There are important gaps in training and infrequent use of essential pages. There are specific groups that require directed educational policies.

  4. Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

    Science.gov (United States)

    Friege, Henning

    2012-09-01

    For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

  5. Aufwand und Nutzen des Electronic Resource Management Systems RMS an der UB Kassel

    Directory of Open Access Journals (Sweden)

    Tobias Pohlmann

    2016-03-01

    The university library of Kassel therefore uses SemperTool’s web-based electronic resource management system RMS. This paper presents the functionality of this system and makes an estimate of the expenditure of work necessary to enter all relevant information about licensed databases, e-book and e-journal packages with the corresponding individual resources. It also describes existing and projected tools for analysis and evaluation, which are decisive for the usefulness of such a system, and concludes with the satisfaction reached at the university library of Kassel. These experiences may help other libraries to decide whether or not to introduce RMS or a comparable system.

  6. NK-3 receptor activation depolarizes and induces an after-depolarization in pyramidal neurons in gerbil cingulate cortex

    DEFF Research Database (Denmark)

    Rekling, Jens C

    2004-01-01

    The involvement of tachykinins in cortical function is poorly understood. To study the actions of neurokinin-3 (NK3) receptor activation in frontal cortex, whole cell patch clamp recordings were performed from pyramidal neurons in slices of cingulate cortex from juvenile gerbils. Senktide (500n......M), a selective NK3 receptor agonist, induced a transient increase in spontaneous EPSPs in layer V pyramidal neurons, accompanied by a small depolarization ( approximately 4 mV). EPSPs during senktide had a larger amplitude and faster 10-90% rise time than during control. Senktide induced a transient...... depolarization in layer II/III pyramidal neurons, which often reached threshold for spikes. The depolarization ( approximately 6 mV) persisted in TTX, and was accompanied by an increase in input resistance. Senktide also transiently induced a slow after-depolarization, which appeared following a depolarizing...

  7. ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

    Directory of Open Access Journals (Sweden)

    Maria D. Tukalo

    2013-09-01

    Full Text Available This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions to enhance the creative potential of students in a modern learning environment.

  8. Teachers' Link to Electronic Resources in the Library Media Center: A Local Study of Awareness, Knowledge, and Influence

    Science.gov (United States)

    Williams, Teresa D.; Grimble, Bonnie J.; Irwin, Marilyn

    2004-01-01

    High school students often use online databases and the Internet in the school library media center (SLMC) to complete teachers' assignments. This case study used a survey to assess teachers' awareness of electronic resources, and to determine whether their directions influence student use of these resources in the SLMC. Participants were teachers…

  9. Impact of Knowledge Resources Linked to an Electronic Health Record on Frequency of Unnecessary Tests and Treatments

    Science.gov (United States)

    Goodman, Kenneth; Grad, Roland; Pluye, Pierre; Nowacki, Amy; Hickner, John

    2012-01-01

    Introduction: Electronic knowledge resources have the potential to rapidly provide answers to clinicians' questions. We sought to determine clinicians' reasons for searching these resources, the rate of finding relevant information, and the perceived clinical impact of the information they retrieved. Methods: We asked general internists, family…

  10. Reducing Clinical Trial Monitoring Resource Allocation and Costs Through Remote Access to Electronic Medical Records

    Science.gov (United States)

    Uren, Shannon C.; Kirkman, Mitchell B.; Dalton, Brad S.; Zalcberg, John R.

    2013-01-01

    Purpose: With electronic medical records (eMRs), the option now exists for clinical trial monitors to perform source data verification (SDV) remotely. We report on a feasibility study of remote access to eMRs for SDV and the potential advantages of such a process in terms of resource allocation and cost. Methods: The Clinical Trials Unit at the Peter MacCallum Cancer Centre, in collaboration with Novartis Pharmaceuticals Australia, conducted a 6-month feasibility study of remote SDV. A Novartis monitor was granted dedicated software and restricted remote access to the eMR portal of the cancer center, thereby providing an avenue through which perform SDV. Results: Six monitoring visits were conducted during the study period, four of which were performed remotely. The ability to conduct two thirds of the monitoring visits remotely in this complex phase III study resulted in an overall cost saving to Novartis. Similarly, remote monitoring eased the strain on internal resources, particularly monitoring space and hospital computer terminal access, at the cancer center. Conclusion: Remote access to patient eMRs for SDV is feasible and is potentially an avenue through which resources can be more efficiently used. Although this feasibility study involved limited numbers, there is no limit to scaling these processes to any number of patients enrolled onto large clinical trials. PMID:23633977

  11. Electronic theses and dissertations: a review of this valuable resource for nurse scholars worldwide.

    Science.gov (United States)

    Goodfellow, L M

    2009-06-01

    A worldwide repository of electronic theses and dissertations (ETDs) could provide worldwide access to the most up-to-date research generated by masters and doctoral students. Until that international repository is established, it is possible to access some of these valuable knowledge resources. ETDs provide a technologically advanced medium with endless multimedia capabilities that far exceed the print and bound copies of theses and dissertations housed traditionally in individual university libraries. CURRENT USE: A growing trend exists for universities worldwide to require graduate students to submit theses or dissertations as electronic documents. However, nurse scholars underutilize ETDs, as evidenced by perusing bibliographic citation lists in many of the research journals. ETDs can be searched for and retrieved through several digital resources such as the Networked Digital Library of Theses and Dissertations (http://www.ndltd.org), ProQuest Dissertations and Theses (http://www.umi.com), the Australasian Digital Theses Program (http://adt.caul.edu.au/) and through individual university web sites and online catalogues. An international repository of ETDs benefits the community of nurse scholars in many ways. The ability to access recent graduate students' research electronically from anywhere in the world is advantageous. For scholars residing in developing countries, access to these ETDs may prove to be even more valuable. In some cases, ETDs are not available for worldwide access and can only be accessed through the university library from which the student graduated. Public access to university library ETD collections is not always permitted. Nurse scholars from both developing and developed countries could benefit from ETDs.

  12. A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources.

    Science.gov (United States)

    Oguchi, Masahiro; Murakami, Shinsuke; Sakanakura, Hirofumi; Kida, Akiko; Kameya, Takashi

    2011-01-01

    End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection methods were suggested for equipment types that currently have no specific collection systems in Japan, particularly for video games, notebook computers, and mid-size ICT and audio/video equipment.

  13. From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

    KAUST Repository

    Ramli, Rindra M.

    2017-05-17

    An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables and challenges as well as lessons learnt by the Project Team.

  14. Depolarization of D-T plasmas by recycling in material walls

    Energy Technology Data Exchange (ETDEWEB)

    Greenside, H.S.; Budny, R.V.; Post, D.E.

    1984-02-01

    The feasibility of using polarized deuterium (D) and tritium (T) plasmas in fusion reactors may be seriously affected by recycling in material walls. Theoretical and experimental results are reviewed which show how the depolarization rates of absorbed D and T depend on first wall parameters such as the temperature, the bulk and surface diffusivities, the density of electronic states at the Fermi surface, the spectral density of microscopic fluctuating electric field gradients, and the concentration of paramagnetic impurities. Nuclear magnetic resonance (NMR) spectroscopy of hydrogenated and deuterated amorphous semiconductors suggests that low-Z nonmetallic materials may provide a satisfactory first wall or limiter coating under reactor conditions with characteristic depolarization times of several seconds. Experiments are proposed to test the consequences of our analysis.

  15. Neutron depolarization imaging of the hydrostatic pressure dependence of inhomogeneous ferromagnets

    Science.gov (United States)

    Schulz, M.; Neubauer, A.; Böni, P.; Pfleiderer, C.

    2016-05-01

    The investigation of fragile and potentially inhomogeneous forms of ferromagnetic order under extreme conditions, such as low temperatures and high pressures, is of central interest for areas such as geophysics, correlated electron systems, as well as the optimization of materials synthesis for applications where particular material properties are required. We report neutron depolarization imaging measurements on the weak ferromagnet Ni3Al under pressures up to 10 kbar using a Cu:Be clamp cell. Using a polychromatic neutron beam with wavelengths λ ≥ 4 Å in combination with 3He neutron spin filter cells as polarizer and analyzer, we were able to track differences of the pressure response in inhomogeneous samples by virtue of high resolution neutron depolarization imaging. This provides spatially resolved and non-destructive access to the pressure dependence of the magnetic properties of inhomogeneous ferromagnetic materials.

  16. Neuronal Depolarization Drives Increased Dopamine Synaptic Vesicle Loading via VGLUT.

    Science.gov (United States)

    Aguilar, Jenny I; Dunn, Matthew; Mingote, Susana; Karam, Caline S; Farino, Zachary J; Sonders, Mark S; Choi, Se Joon; Grygoruk, Anna; Zhang, Yuchao; Cela, Carolina; Choi, Ben Jiwon; Flores, Jorge; Freyberg, Robin J; McCabe, Brian D; Mosharov, Eugene V; Krantz, David E; Javitch, Jonathan A; Sulzer, David; Sames, Dalibor; Rayport, Stephen; Freyberg, Zachary

    2017-08-30

    The ability of presynaptic dopamine terminals to tune neurotransmitter release to meet the demands of neuronal activity is critical to neurotransmission. Although vesicle content has been assumed to be static, in vitro data increasingly suggest that cell activity modulates vesicle content. Here, we use a coordinated genetic, pharmacological, and imaging approach in Drosophila to study the presynaptic machinery responsible for these vesicular processes in vivo. We show that cell depolarization increases synaptic vesicle dopamine content prior to release via vesicular hyperacidification. This depolarization-induced hyperacidification is mediated by the vesicular glutamate transporter (VGLUT). Remarkably, both depolarization-induced dopamine vesicle hyperacidification and its dependence on VGLUT2 are seen in ventral midbrain dopamine neurons in the mouse. Together, these data suggest that in response to depolarization, dopamine vesicles utilize a cascade of vesicular transporters to dynamically increase the vesicular pH gradient, thereby increasing dopamine vesicle content. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. The continuum of spreading depolarizations in acute cortical lesion development

    DEFF Research Database (Denmark)

    Hartings, Jed A; Shuttleworth, C William; Kirov, Sergei A;

    2017-01-01

    A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão's historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum...... of spreading mass depolarizations, a concept that is central to understanding their pathologic effects. Within minutes of acute severe ischemia, the onset of persistent depolarization triggers the breakdown of ion homeostasis and development of cytotoxic edema. These persistent changes are diagnosed....... The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion...

  18. Scattering and Depolarization of Electromagnetic Waves--Full Wave Solutions.

    Science.gov (United States)

    1984-01-01

    Analysis," Proceedings of the International Union of Radio Science URSI Conference at Ciudad Universitaria , Madrid, August 1983, in press. . . 13...rough land and seat3 J. The full wave approach was also used to determine the scattering and depolarization of radio waves in irregular spheroidal struc...Full Wave Solutions," Radio Science, Vol. 17, No. 5, September-October 1982, pp. 1055-1066. 4. "Scattering and Depolarization by Rough Surfaces: Full

  19. Electronic tracking of human resource skills and knowledge, just in time training, manageable due diligence

    Energy Technology Data Exchange (ETDEWEB)

    Kolodziej, M.A. [Quick Test International Inc., (Canada). Canadian Technology Human Resource Board; Baker, O. [KeySpan Energy Canada, Calgary, AB (Canada)

    2001-06-01

    KeySpan Energy Canada is in the process of obtaining recognition of various occupational profiles including pipeline operators, inspectors, and field and plant operators from various certifying organizations. The process of allowing individuals to obtain certification is recognized by Canadian Technology Human Resources Board as a step towards national standards for technologists and technicians. Proven competency is a must for workers in todays oil industry in response to increasingly stringent government safety regulations, environmental concerns and high public scrutiny. Quick Test international Inc. has developed a management tool in collaboration with end users at KeySpan Energy Canada. It is an electronic, Internet based competency tool for tracking personal competencies and maintaining continued competency. Response to the tool has been favourable. 2 refs., 4 figs.

  20. [HYGIENIC REGULATION OF THE USE OF ELECTRONIC EDUCATIONAL RESOURCES IN THE MODERN SCHOOL].

    Science.gov (United States)

    Stepanova, M I; Aleksandrova, I E; Sazanyuk, Z I; Voronova, B Z; Lashneva, L P; Shumkova, T V; Berezina, N O

    2015-01-01

    We studied the effect of academic studies with the use a notebook computer and interactive whiteboard on the functional state of an organism of schoolchildren. Using a complex of hygienic and physiological methods of the study we established that regulation of the computer activity of students must take into account not only duration but its intensity either. Design features of a notebook computer were shown both to impede keeping the optimal working posture in primary school children and increase the risk offormation of disorders of vision and musculoskeletal system. There were established the activating influence of the interactive whiteboard on performance activities and favorable dynamics of indices of the functional state of the organism of students under keeping optimal density of the academic study and the duration of its use. There are determined safety regulations of the work of schoolchildren with electronic resources in the educational process.

  1. Medical Image Resource Center--making electronic teaching files from PACS.

    Science.gov (United States)

    Lim, C C Tchoyoson; Yang, Guo Liang; Nowinski, Wieslaw L; Hui, Francis

    2003-12-01

    A picture archive and communications system (PACS) is a rich source of images and data suitable for creating electronic teaching files (ETF). However, the potential for PACS to support nonclinical applications has not been fully realized: at present there is no mechanism for PACS to identify and store teaching files; neither is there a standardized method for sharing such teaching images. The Medical Image Resource Center (MIRC) is a new central image repository that defines standards for data exchange among different centers. We developed an ETF server that retrieves digital imaging and communication in medicine (DICOM) images from PACS, and enables users to create teaching files that conform to the new MIRC schema. We test-populated our ETF server with illustrative images from the clinical case load of the National Neuroscience Institute, Singapore. Together, PACS and MIRC have the potential to benefit radiology teaching and research.

  2. Electronic Human Resource Management (e-HRM of Hotel Business in Phuket

    Directory of Open Access Journals (Sweden)

    Kitimaporn Choochote

    2015-04-01

    Full Text Available This research aims to study the pattern of the electronic human resources management (e-HRM of the hotel business in Phuket. The study is conducted with the implementation of field data and in-depth interview of hotels’ HR managers. In consequence, the study reveals that the hotel business has applied the use of the e-HRM varying in job recruitment (15 percent, employee engagement (55 percent, organizational file structure (10 percent, idea and creativity exchanges (38 percent and assessment system (6 percent. However, considered as 100 percent, the hotel business has not prepared to apply the use of the e-HRM in salary system, learning and training program, welfare allocation and career development.

  3. Using mobile electronic devices to deliver educational resources in developing countries.

    Science.gov (United States)

    Mazal, Jonathan Robert; Ludwig, Rebecca

    2015-01-01

    Developing countries have far fewer trained radiography professionals than developed countries, which exacerbates the limited access to imaging services. The lack of trained radiographers reflects, in part, limited availability of radiographer-specific educational resources. Historically, organizations that provided such resources in the developing world faced challenges related to the limited stock of current materials as well as expenses associated with shipping and delivery. Four mobile electronic devices (MEDs) were loaded with educational content (e-books, PDFs, and digital applications) spanning major radiography topics. The MEDs were distributed to 4 imaging departments in Ghana, India, Nepal, and Nigeria based on evidence of need for radiography-specific resources, as revealed by survey responses. A cost comparison of postal delivery vs digital delivery of educational content was performed. The effectiveness of delivering additional content via Wi-Fi transmission also was evaluated. Feedback was solicited on users' experience with the MEDs as a delivery tool for educational content. An initial average per e-book expense of $30.05, which included the cost of the device, was calculated for the MED delivery method compared with $15.56 for postal delivery of printed materials. The cost of the MED delivery method was reduced to an average of $10.05 for subsequent e-book deliveries. Additional content was successfully delivered via Wi-Fi transmission to all recipients during the 3-month follow-up period. Overall user feedback on the experience was positive, and ideas for enhancing the MED-based method were identified. Using MEDs to deliver radiography-specific educational content appears to be more cost effective than postal delivery of printed materials on a long-term basis. MEDs are more efficient for providing updates to educational materials. Customization of content to department needs, and using projector devices could enhance the usefulness of MEDs for

  4. Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

    Science.gov (United States)

    Rios, Pedro; Stuart, Julie Ann; Grant, Ed

    2003-12-01

    Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

  5. SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

    Directory of Open Access Journals (Sweden)

    Sheri L Lewis

    Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

  6. On The Depolarization Asymmetry Seen in Giant Radio Lobes

    CERN Document Server

    Bell, M B

    2012-01-01

    The depolarization asymmetry seen in double-lobed radio sources, referred to as the Laing-Garrington (L-G) effect where more rapid depolarization is seen in the lobe with no visible jet as the wavelength increases, can be explained either by internal differences between the two lobes, or by an external Faraday screen that lies in front of only the depolarized lobe. If the jet one-sidedness is due to relativistic beaming the depolarization asymmetry must be due to an intervening Faraday screen. If it is intrinsic the depolarization asymmetry must be related to internal differences in the lobes. We assume in this paper that the speed in the outer jet of several Fanaroff-Riley Class 1 (FRI) sources exhibiting the L-G effect is close to the 0.1c reported by several other investigators. For these sources we find that the jet one-sidedness cannot be explained by beaming and therefore must be intrinsic. In these FRI sources the L-G effect must be due to differences that originate inside the lobes themselves. Althoug...

  7. Spreading depolarizations in patients with spontaneous intracerebral hemorrhage

    DEFF Research Database (Denmark)

    Helbok, Raimund; Schiefecker, Alois Josef; Friberg, Christian;

    2017-01-01

    Pathophysiologic mechanisms of secondary brain injury after intracerebral hemorrhage and in particular mechanisms of perihematomal-edema progression remain incompletely understood. Recently, the role of spreading depolarizations in secondary brain injury was established in ischemic stroke......, subarachnoid hemorrhage and traumatic brain injury patients. Its role in intracerebral hemorrhage patients and in particular the association with perihematomal-edema is not known. A total of 27 comatose intracerebral hemorrhage patients in whom hematoma evacuation and subdural electrocorticography...... patients (67%), a total of 650 spreading depolarizations were observed. Spreading depolarizations were more common in the initial days with a peak incidence on day 2. Median electrocorticography depression time was longer than previously reported (14.7 min, IQR, 9-22 min). Postoperative perihematomal-edema...

  8. Depolarization and attenuation effects of radomes at 20 GHz

    Science.gov (United States)

    Hendrix, Charles E.; McNally, James E.; Monzingo, Robert A.

    1989-03-01

    The problem of describing the attenuation and depolarization effects of a wet radome on a transmitted signal is considered by experiments carried out with two commonly used radome materials, ESSCOLAM-6 and ESSCOLAM-8. The results suggest that a two-component model of depolarization is required to account for the observed results. Predictions for the behavior of a complete radome are obtained, but full-scale testing with an operating radome to compare predicted and actual results remains to be done. An important conclusion is that, while highly water-repellent radome materials are desirable from the point of view of attenuation, they are not so desirable in terms of the degree of depolarization introduced between orthogonally polarized signal components in frequency-reuse systems.

  9. Enhanced Spin Depolarization and Storage Time in a Rb Vapor

    Institute of Scientific and Technical Information of China (English)

    QI Yue-Rong; GAO Hong; ZHANG Shou-Gang

    2009-01-01

    The experiment of measuring the spin depolarized time and light storage time in a Rb vapor under different conditions is performed. Typically, these measurements are accomplished in three different containers: atoms in a bare glass ceil, atoms in a buffer gas cell, and atoms in a tetracontane (C40H82) coating cell. The increasing depolarization and storage times are observed in both the buffer gas ceil and the tetracontane coating cell. In the latter case, a storage time greater than 400 μs is obtained.

  10. Nonspherical nanoparticles characterization by partially depolarized dynamic light scattering

    Science.gov (United States)

    Levin, Alexander D.; Shmytkova, Ekaterina A.

    2015-06-01

    The realization of improved depolarized dynamic light scattering method is presented. This technique supports measurement of non-spherical nanoparticals dimensions in liquids. The relations between translational and rotational diffusion coefficients and autocorrelation function of scattered light with polarized and depolarized components in various proportions are derived. Thus measurement of very weak cross-polarized component can be avoided. This improvement permits to reduce measurement time, to improve signal to noise ratio and results precision. The technique was applied for sizing of gold nanorods and multiwalled carbon nanotubes in liquids.

  11. Observation of wide rf induced synchrotron sideband depolarizing resonances.

    Science.gov (United States)

    Bychkov, M. A.; Anferov, V. A.; Blinov, B. B.; Courant, E. D.; Crandell, D. A.; Derbenev, Ya. S.; Kaufman, W. A.; Krisch, A. D.; Lorenzon, W.; Nurushev, T. S.; Phelps, R. A.; Wong, V. K.; Caussyn, D. D.; Chu, C. M.; Ellison, T. J. P.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E. J.; von Przewoski, B.; Ohmori, C.; Minty, M. G.; Russell, A. D.

    1997-04-01

    In a recent experiment with a stored 104.1 MeV vertically polarized proton beam at the IUCF Cooler Ring, we depolarized the beam using an rf solenoid with a magnetic field of about 1.3\\cdot10-3T\\cdotm. We observed the two expected rf depolarizing resonances centered around the protons' 1.5 MHz circulation frequency as in previous experiments. Near each of these resonances, we also found synchrotron sidebands which are caused by the proton's energy oscillations. The strengths and widths of the synchrotron resonances were quite different for the sidebands above and below the circulation frequency.

  12. Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

    Science.gov (United States)

    Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

    2015-01-01

    The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

  13. Utilization of Electronic Information Resources by Undergraduate Students of University of Ibadan: A Case Study of Social Sciences and Education

    Science.gov (United States)

    Owolabi, Sola; Idowu, Oluwafemi A.; Okocha, Foluke; Ogundare, Atinuke Omotayo

    2016-01-01

    The study evaluated utilization of electronic information resources by undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan. The study adopted a descriptive survey design with a study population of 1872 undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan, from which a…

  14. Numerical simulation study on spin resonant depolarization due to spin-orbit coupling

    Institute of Scientific and Technical Information of China (English)

    Lan Jie-Qin; Xu Hong-Liang

    2012-01-01

    The spin polarization phenomenon in lepton circular accelerators had been known for many years.It provides a new approach for physicists to study the spin feature of fundamental particles and the dynamics of spin-orbit coupling,such as spin resonances.We use numerical simulation to study the features of spin under the modulation of orbital motion in an electron storage ring.The various cases of depolarization due to spin-orbit coupling through an emitting photon and misalignment of magnets in the ring are discussed.

  15. Canals beyond Mars: Beam depolarization in radio continuum maps of the warm ISM

    CERN Document Server

    Haverkorn, M

    2004-01-01

    Multi-frequency radio polarimetric observations of the diffuse Galactic synchrotron background enable us to study the structure of the diffuse ionized gas via rotation measure maps. However, depolarization will introduce artifacts in the resulting rotation measure, most notably in the form of narrow, elongated ``depolarization canals''. We use numerical models of a non-emitting Faraday rotating medium to study the RM distribution needed to create depolarization canals by depolarization due to a finite beam width, and to estimate the influence of this depolarization mechanism on the determination of RM. We argue that the depolarization canals indeed can be caused by beam depolarization, which in turn is a natural consequence when observing a turbulent medium with limited resolution. Furthermore, we estimate that beam depolarization can induce an additional error of about 20% in RM determinations, and considerably less in regions that are not affected by depolarization canals.

  16. Primary afferent depolarization evoked by a painful stimulus.

    Science.gov (United States)

    Vyklický, L; Rudomin, P; Zajac, F E; Burke, R E

    1969-07-11

    Pulses of intense radiant heat applied to the plantar pad of unanesthetized spinal cats produced negative dorsal root potentials, increased excitability of cutaneous A fibers, and marked activation of ipsilateral flexor motoneurons. The same effects were obtained during cold block of A fiber conduction in the appropriate peripheral nerve. We conclude that adequate noxious activation of cutaneous C fibers depolarizes cutaneous A fibers.

  17. Decavanadate induces mitochondrial membrane depolarization and inhibits oxygen consumption.

    Science.gov (United States)

    Soares, S S; Gutiérrez-Merino, C; Aureliano, M

    2007-05-01

    Decavanadate induced rat liver mitochondrial depolarization at very low concentrations, half-depolarization with 39 nM decavanadate, while it was needed a 130-fold higher concentration of monomeric vanadate (5 microM) to induce the same effect. Decavanadate also inhibits mitochondrial repolarization induced by reduced glutathione in vitro, with an inhibition constant of 1 microM, whereas no effect was observed up to 100 microM of monomeric vanadate. The oxygen consumption by mitochondria is also inhibited by lower decavanadate than monomeric vanadate concentrations, i.e. 50% inhibition is attained with 99 M decavanadate and 10 microM monomeric vanadate. Thus, decavanadate is stronger as mitochondrial depolarization agent than as inhibitor of mitochondrial oxygen consumption. Up to 5 microM, decavanadate does not alter mitochondrial NADH levels nor inhibit neither F(O)F(1)-ATPase nor cytochrome c oxidase activity, but it induces changes in the redox steady-state of mitochondrial b-type cytochromes (complex III). NMR spectra showed that decameric vanadate is the predominant vanadate species in decavanadate solutions. It is concluded that decavanadate is much more potent mitochondrial depolarization agent and a more potent inhibitor of mitochondrial oxygen consumption than monomeric vanadate, pointing out the importance to take into account the contribution of higher oligomeric species of vanadium for the biological effects of vanadate solutions.

  18. Magnetic correlations in oxides: Neutron diffraction and neutron depolarization study

    Indian Academy of Sciences (India)

    S M Yusuf

    2008-10-01

    We have studied magnetic correlations in several oxide materials that belong to colossal magnetoresistive, naturally occurring layered oxide showing low-dimensional magnetic ordering, solid oxide fuel cell interconnect materials, and magnetic nanoparticles using neutron diffraction and neutron depolarization techniques. In this paper, an overview of some of these results is given.

  19. Migraine prophylaxis, ischemic depolarizations, and stroke outcomes in mice.

    Science.gov (United States)

    Eikermann-Haerter, Katharina; Lee, Jeong Hyun; Yalcin, Nilufer; Yu, Esther S; Daneshmand, Ali; Wei, Ying; Zheng, Yi; Can, Anil; Sengul, Buse; Ferrari, Michel D; van den Maagdenberg, Arn M J M; Ayata, Cenk

    2015-01-01

    Migraine with aura is an established stroke risk factor, and excitatory mechanisms such as spreading depression (SD) are implicated in the pathogenesis of both migraine and stroke. Spontaneous SD waves originate within the peri-infarct tissue and exacerbate the metabolic mismatch during focal cerebral ischemia. Genetically enhanced SD susceptibility facilitates anoxic depolarizations and peri-infarct SDs and accelerates infarct growth, suggesting that susceptibility to SD is a critical determinant of vulnerability to ischemic injury. Because chronic treatment with migraine prophylactic drugs suppresses SD susceptibility, we tested whether migraine prophylaxis can also suppress ischemic depolarizations and improve stroke outcome. We measured the cortical susceptibility to SD and ischemic depolarizations, and determined tissue and neurological outcomes after middle cerebral artery occlusion in wild-type and familial hemiplegic migraine type 1 knock-in mice treated with vehicle, topiramate or lamotrigine daily for 7 weeks or as a single dose shortly before testing. Chronic treatment with topiramate or lamotrigine reduced the susceptibility to KCl-induced or electric stimulation-induced SDs as well as ischemic depolarizations in both wild-type and familial hemiplegic migraine type 1 mutant mice. Consequently, both tissue and neurological outcomes were improved. Notably, treatment with a single dose of either drug was ineffective. These data underscore the importance of hyperexcitability as a mechanism for increased stroke risk in migraineurs, and suggest that migraine prophylaxis may not only prevent migraine attacks but also protect migraineurs against ischemic injury. © 2014 American Heart Association, Inc.

  20. The collisional depolarization of OH(A (2)Σ(+)) and NO(A (2)Σ(+)) with Kr.

    Science.gov (United States)

    Chadwick, H; Brouard, M; Chang, Y-P; Eyles, C J; McCrudden, G; Perkins, T; Seamons, S A; Kłos, J; Alexander, M H; Dagdigian, P J; Herráez-Aguilar, D; Aoiz, F J

    2014-02-01

    Quantum beat spectroscopy has been used to measure rate coefficients at 300 K for collisional depolarization for NO(A (2)Σ(+)) and OH(A (2)Σ(+)) with krypton. Elastic depolarization rate coefficients have also been determined for OH(A) + Kr, and shown to make a much more significant contribution to the total depolarization rate than for NO(A) + Kr. While the experimental data for NO(A) + Kr are in excellent agreement with single surface quasiclassical trajectory (QCT) calculations carried out on the upper 2A(') potential energy surface, the equivalent QCT and quantum mechanical calculations cannot account for the experimental results for OH(A) + Kr collisions, particularly at low N. This disagreement is due to the presence of competing electronic quenching at low N, which requires a multi-surface, non-adiabatic treatment. Somewhat improved agreement with experiment is obtained by means of trajectory surface hopping calculations that include non-adiabatic coupling between the ground 1A(') and excited 2A(') states of OH(X/A) + Kr, although the theoretical depolarization cross sections still significantly overestimate those obtained experimentally.

  1. Human resource requirements for quality-assured electronic data capture of the tuberculosis case register

    Directory of Open Access Journals (Sweden)

    Hoa Nguyen B

    2012-01-01

    Full Text Available Abstract Background The tuberculosis case register is the data source for the reports submitted by basic management units to the national tuberculosis program. Our objective was to measure the data entry time required to complete and double-enter one record, and to estimate the time for the correction of errors in the captured information from tuberculosis case registers in Cambodia and Viet Nam. This should assist in quantifying the additional requirements in human resources for national programs moving towards electronic recording and reporting. Methods Data from a representative sample of tuberculosis case registers from Cambodia and Viet Nam were double-entered and discordances resolved by rechecking the original case register. Computer-generated data entry time recorded the time elapsed between opening of a new record and saving it to disk. Results The dataset comprised 22,732 double-entered records of 11,366 patients (37.1% from Cambodia and 62.9% from Viet Nam. The mean data entry times per record were 97.5 (95% CI: 96.2-98.8 and 66.2 (95% CI: 59.5-73.0 seconds with medians of 90 and 31 s respectively in Cambodia and in Viet Nam. The percentage of records with an error was 6.0% and 39.0% respectively in Cambodia and Viet Nam. Data entry time was inversely associated with error frequency. We estimate that approximately 118-person-hours were required to produce 1,000 validated records. Conclusions This study quantifies differences between two countries for data entry time for the tuberculosis case register and frequencies of data entry errors and suggests that higher data entry speed is partially offset by requiring revisiting more records for corrections.

  2. Temporal coding at the immature depolarizing GABAergic synapse

    Directory of Open Access Journals (Sweden)

    Guzel Valeeva

    2010-07-01

    Full Text Available In the developing hippocampus, GABA exerts depolarizing and excitatory actions and contributes to the generation of neuronal network driven Giant Depolarizing Potentials (GDPs. Here, we studied spike time coding at immature GABAergic synapses and its impact on synchronization of the neuronal network during GDPs in the neonatal (postnatal days P2-6 rat hippocampal slices. Using extracellular recordings, we found that the delays of action potentials (APs evoked by synaptic activation of GABA(A receptors are long (mean, 65 ms and variable (within a time window of 10-200 ms. During patch-clamp recordings, depolarizing GABAergic responses were mainly subthreshold and their amplification by persistent sodium conductance was required to trigger APs. AP delays at GABAergic synapses shortened and their variability reduced with an increase in intracellular chloride concentration during whole-cell recordings. Negative shift of the GABA reversal potential (EGABA with low concentrations of bumetanide, or potentiation of GABA(A receptors with diazepam reduced GDPs amplitude, desynchronized neuronal firing during GDPs and slowed down GDPs propagation. Partial blockade of GABA(A receptors with bicuculline increased neuronal synchronization and accelerated GDPs propagation. We propose that spike-timing at depolarizing GABA synapses is determined by intracellular chloride concentration. At physiological levels of intracellular chloride GABAergic depolarization does not reach the action potential threshold and amplification of GABAergic responses by non-inactivating sodium conductance is required for postsynaptic AP initiation. Slow and variable excitation at GABAergic synapse determines the level of neuronal synchrony and the rate of GDPs propagation in the developing hippocampus.

  3. Temporal coding at the immature depolarizing GABAergic synapse.

    Science.gov (United States)

    Valeeva, Guzel; Abdullin, Azat; Tyzio, Roman; Skorinkin, Andrei; Nikolski, Evgeny; Ben-Ari, Yehezkiel; Khazipov, Rustem

    2010-01-01

    In the developing hippocampus, GABA exerts depolarizing and excitatory actions and contributes to the generation of neuronal network driven giant depolarizing potentials (GDPs). Here, we studied spike time coding at immature GABAergic synapses and its impact on synchronization of the neuronal network during GDPs in the neonatal (postnatal days P2-6) rat hippocampal slices. Using extracellular recordings, we found that the delays of action potentials (APs) evoked by synaptic activation of GABA(A) receptors are long (mean, 65 ms) and variable (within a time window of 10-200 ms). During patch-clamp recordings, depolarizing GABAergic responses were mainly subthreshold and their amplification by persistent sodium conductance was required to trigger APs. AP delays at GABAergic synapses shortened and their variability reduced with an increase in intracellular chloride concentration during whole-cell recordings. Negative shift of the GABA reversal potential (E(GABA)) with low concentrations of bumetanide, or potentiation of GABA(A) receptors with diazepam reduced GDPs amplitude, desynchronized neuronal firing during GDPs and slowed down GDPs propagation. Partial blockade of GABA(A) receptors with bicuculline increased neuronal synchronization and accelerated GDPs propagation. We propose that spike timing at depolarizing GABA synapses is determined by intracellular chloride concentration. At physiological levels of intracellular chloride GABAergic depolarization does not reach the action potential threshold and amplification of GABAergic responses by non-inactivating sodium conductance is required for postsynaptic AP initiation. Slow and variable excitation at GABAergic synapse determines the level of neuronal synchrony and the rate of GDPs propagation in the developing hippocampus.

  4. Use and Cost of Electronic Resources in Central Library of Ferdowsi University Based on E-metrics

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Davarpanah

    2012-07-01

    Full Text Available The purpose of this study was to investigate the usage of electronic journals in Ferdowsi University, Iran based on e-metrics. The paper also aimed to emphasize the analysis of cost-benefit and the correlation between the journal impact factors and the usage data. In this study experiences of Ferdowsi University library on licensing and usage of electronic resources was evaluated by providing a cost-benefit analysis based on the cost and usage statistics of electronic resources. Vendor-provided data were also compared with local usage data. The usage data were collected by tracking web-based access locally, and by collecting vender-provided usage data. The data sources were one-year of vendor-supplied e-resource usage data such as Ebsco, Elsevier, Proquest, Emerald, Oxford and Springer and local usage data collected from the Ferdowsi university web server. The study found that actual usage values differ for vendor-provided data and local usage data. Elsevier has got the highest usage degree in searches, sessions and downloads. Statistics also showed that a small number of journals satisfy significant amount of use while the majority of journals were used less frequent and some were never used at all. The users preferred the PDF rather than HTML format. The data in subject profile suggested that the provided e-resources were best suited to certain subjects. There was no correlation between IF and electronic journal use. Monitoring the usage of e-resources gained increasing importance for acquisition policy and budget decisions. The article provided information about local metrics for the six surveyed vendors/publishers, e.g. usage trends, requests per package, cost per use as related to the scientific specialty of the university.

  5. Use and User Perception of Electronic Information Resources: A Case Study of Siva Institute of Frontier Technology, India

    Directory of Open Access Journals (Sweden)

    Velmurugan Chandran

    2013-12-01

    Full Text Available The present study aims to explore the use and user perception of electronic resources in Siva Institute of Frontier Technology, India. A total number of 123 users were taken into account for the study through a questionnaire-based survey method. A well-structured questionnaire was designed and distributed to the selected 200 students and staff members. 123 copies of the questionnaires were returned dully filled in and the overall response rate was 61.50 percent. The questionnaire contained both open- and close-ended questions. The collected data were classified, analyzed, and tabulated by using simple statistical methods. This study covers the impact of electronic resources on students and faculty in their academic pursuit.

  6. Spreading depolarizations increase delayed brain injury in a rat model of subarachnoid hemorrhage

    NARCIS (Netherlands)

    Hamming, Arend M.; Wermer, Marieke J H; Umesh Rudrapatna, S.; Lanier, Christian; Van Os, Hine J A; Van Den Bergh, Walter M.; Ferrari, Michel D.; van der Toorn, A; Van Den Maagdenberg, Arn M J M; Stowe, Ann M.; Dijkhuizen, Rick M.

    2016-01-01

    Spreading depolarizations may contribute to delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage, but the effect of spreading depolarizations on brain lesion progression after subarachnoid hemorrhage has not yet been assessed directly. Therefore, we tested the hypothesis that

  7. Spreading depolarizations increase delayed brain injury in a rat model of subarachnoid hemorrhage

    NARCIS (Netherlands)

    Hamming, Arend M.; Wermer, Marieke J. H.; Rudrapatna, S. Umesh; Lanier, Christian; van Os, Hine J. A.; van den Bergh, Walter M.; Ferrari, Michel D.; van der Toorn, Annette; van den Maagdenberg, Arn M. J. M.; Stowe, Ann M.; Dijkhuizen, Rick M.

    Spreading depolarizations may contribute to delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage, but the effect of spreading depolarizations on brain lesion progression after subarachnoid hemorrhage has not yet been assessed directly. Therefore, we tested the hypothesis that

  8. How Human Resource Professionals Use Electronic Channels to Communicate CSR : A case study focused on Solvay's French industrial sites

    OpenAIRE

    Fournet, Clara; Pauly, Marissa

    2015-01-01

    Corporate Social Responsibility (CSR) has become a large concern for many companies with the rise of globalization. Oftentimes, companies are encouraged to communicate CSR externally, but not internally. This research focuses upon the internal communication of CSR, specifically how Human Resource (HR) professionals use electronic channels to communicate to employees. The scope of this research is focused solely upon HR professionals within Solvay’s French industrial sites, which produce chemi...

  9. Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

    Directory of Open Access Journals (Sweden)

    Soto Giselle

    2008-11-01

    Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

  10. Tracking the Flow of Resources in Electronic Waste - The Case of End-of-Life Computer Hard Disk Drives.

    Science.gov (United States)

    Habib, Komal; Parajuly, Keshav; Wenzel, Henrik

    2015-10-20

    Recovery of resources, in particular, metals, from waste flows is widely seen as a prioritized option to reduce their potential supply constraints in the future. The current waste electrical and electronic equipment (WEEE) treatment system is more focused on bulk metals, where the recycling rate of specialty metals, such as rare earths, is negligible compared to their increasing use in modern products, such as electronics. This study investigates the challenges in recovering these resources in the existing WEEE treatment system. It is illustrated by following the material flows of resources in a conventional WEEE treatment plant in Denmark. Computer hard disk drives (HDDs) containing neodymium-iron-boron (NdFeB) magnets were selected as the case product for this experiment. The resulting output fractions were tracked until their final treatment in order to estimate the recovery potential of rare earth elements (REEs) and other resources contained in HDDs. The results further show that out of the 244 kg of HDDs treated, 212 kg comprising mainly of aluminum and steel can be finally recovered from the metallurgic process. The results further demonstrate the complete loss of REEs in the existing shredding-based WEEE treatment processes. Dismantling and separate processing of NdFeB magnets from their end-use products can be a more preferred option over shredding. However, it remains a technological and logistic challenge for the existing system.

  11. The impact of electronic healthcare associated infection surveillance software on infection prevention resources: A systematic review of the literature.

    Science.gov (United States)

    Russo, Philip L; Shaban, Ramon Z; MacBeth, Deborough; Carter, Abigail; Mitchell, Brett G

    2017-09-08

    Surveillance of healthcare-associated infections is fundamental for infection prevention. The methods and practices for surveillance have evolved as technology becomes more advanced. The availability of electronic surveillance software (ESS) has increased, and yet adoption of ESS is slow. It is argued that ESS deliver savings through automation, particularly in terms of human resourcing and infection prevention (IP) staff time. This paper describes the findings of a systematic review on the impact of ESS on IP resources. A systematic search was conducted of electronic databases Medline and the Cumulative Index to Nursing and Allied Health Literature published between 1st January 2006 and 31(st) December 2016 with analysis using Newcastle-Ottawa Scale. 2832 articles were reviewed of which 16 studies met the inclusion criteria. IP resources were identified as time undertaken on surveillance. A reduction in IP staff time to undertake surveillance was demonstrated in 13 studies. The reduction proportion ranged from 12.5% - 98.4% (mean 73.9%). The remaining three did not allow for any estimation of the effect in terms of IP staff time. None of the studies demonstrated an increase in IP staff time. The results of this review demonstrate that adopting ESS yield considerable dividends in IP staff time relating to data collection and case ascertainment whilst maintaining high levels of sensitivity and specificity. This has the potential to enable reinvestment into other components of IP to maximise efficient use of scare IP resources. Copyright © 2017. Published by Elsevier Ltd.

  12. HELP (INFORMATION ELECTRONIC RESOURCE "CHRONICLE OF ONU: DATES, FACTS, EVENTS": HISTORY OF UNIVERSITY IN INFORMATION SPACE

    Directory of Open Access Journals (Sweden)

    А. М. Гавриленко

    2016-03-01

    Object of research is the help information resource "The chronicle of the Odessa national university of I. I. Mechnikov: dates, facts, events". The main objective of our article – to state the main methodological bases of creation of information resource. One of advantages of information resource is possibility of continuous updating and replenishment by new information. Main objective of creation of this information resource is systematization of material on stories of the Odessa national university of I. I. Mechnikov from the date of his basis to the present, ensuring interactive access to information on the main dates, the most significant events in life of university. The base of research are sources on the history of university, chronology of historical development, formation of infrastructure, cadres and scientific researches. In information resource the main stages of development, functioning and transformation of the Odessa University are analyzed, information on its divisions is collected. For creation of this information resource in Scientific library the method of work was developed, the main selection criteria of data are allocated. This information resource have practical value for all who is interested in history of university, historians, scientists-researchers of history of science and the city of Odessa.

  13. Overcoming Depolarizing Resonances with Dual Helical Partial Siberian Snakes

    Science.gov (United States)

    Huang, H.; Ahrens, L. A.; Bai, M.; Brown, K.; Courant, E. D.; Gardner, C.; Glenn, J. W.; Lin, F.; Luccio, A. U.; Mackay, W. W.; Okamura, M.; Ptitsyn, V.; Roser, T.; Takano, J.; Tepikian, S.; Tsoupas, N.; Zelenski, A.; Zeno, K.

    2007-10-01

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is challenging. In a medium energy accelerator, the depolarizing spin resonances are strong enough to cause significant polarization loss but full Siberian snakes cause intolerably large orbit excursions and are also not feasible since straight sections usually are too short. Recently, two helical partial Siberian snakes with double pitch design have been installed in the Brookhaven Alternating Gradient Synchrotron (AGS). With a careful setup of optics at injection and along the energy ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances otherwise encountered during acceleration to maintain a high intensity polarized beam in medium energy synchrotrons. The observation of partial snake resonances of higher than second order will also be described.

  14. Unexpectedly wide rf-induced synchrotron sideband depolarizing resonances

    Science.gov (United States)

    Chu, C. M.; Ellison, T. J.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; von Przewoski, B.; Anferov, V. A.; Blinov, B. B.; Bychkov, M. A.; Caussyn, D. D.; Courant, E. D.; Crandell, D. A.; Derbenev, Ya. S.; Kaufman, W. A.; Krisch, A. D.; Lorenzon, W.; Nurushev, T. S.; Phelps, R. A.; Ratner, L. G.; Wong, V. K.; Ohmori, C.; Minty, M. G.; Martin, P. S.; Russell, A. D.; Sivers, D. W.

    1998-10-01

    Using an rf solenoid magnet, we studied the depolarization of a stored 104.1 MeV vertically polarized proton beam. The two primary rf depolarizing resonances were properly centered around the protons' circulation frequency fc, at fc(3-νs) and fc(νs-1), where νs is the spin tune; moreover, each resonance was roughly consistent with the expected width of about 720 Hz. Each primary rf resonance had two synchrotron sideband resonances at the expected frequencies. The two νs-1 sidebands were deep dips while the two 3-νs sidebands were very shallow; this was not expected. Moreover, all four sideband resonances were unexpectedly wider than the two primary resonances.

  15. Overcoming depolarizing resonances with dual helical partial Siberian snakes.

    Science.gov (United States)

    Huang, H; Ahrens, L A; Bai, M; Brown, K; Courant, E D; Gardner, C; Glenn, J W; Lin, F; Luccio, A U; Mackay, W W; Okamura, M; Ptitsyn, V; Roser, T; Takano, J; Tepikian, S; Tsoupas, N; Zelenski, A; Zeno, K

    2007-10-12

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is challenging. In a medium energy accelerator, the depolarizing spin resonances are strong enough to cause significant polarization loss but full Siberian snakes cause intolerably large orbit excursions and are also not feasible since straight sections usually are too short. Recently, two helical partial Siberian snakes with double pitch design have been installed in the Brookhaven Alternating Gradient Synchrotron (AGS). With a careful setup of optics at injection and along the energy ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances otherwise encountered during acceleration to maintain a high intensity polarized beam in medium energy synchrotrons. The observation of partial snake resonances of higher than second order will also be described.

  16. Spreading Depolarizations Have Prolonged Direct Current Shifts and Are Associated with Poor Outcome in Brain Trauma

    Science.gov (United States)

    2011-01-01

    prognosis . Keywords: cortical spreading depression; electroencephalography; craniotomy; signal processing; acute brain injury Introduction Cortical...GCS =Glasgow coma scale. differed from normality and Kruskai-Wallis tests were used for non-parametric analysis of variance. Data are reported as...graded prognosis corresponding to 100% (isoelectric depolarizations), 60% (depolarizations with de- pression periods) and 23% (no depolarizations) of

  17. Muscarinic depolarization of layer II neurons of the parasubiculum.

    Directory of Open Access Journals (Sweden)

    Stephen D Glasgow

    Full Text Available The parasubiculum (PaS is a component of the hippocampal formation that sends its major output to layer II of the entorhinal cortex. The PaS receives strong cholinergic innervation from the basal forebrain that is likely to modulate neuronal excitability and contribute to theta-frequency network activity. The present study used whole cell current- and voltage-clamp recordings to determine the effects of cholinergic receptor activation on layer II PaS neurons. Bath application of carbachol (CCh; 10-50 µM resulted in a dose-dependent depolarization of morphologically-identified layer II stellate and pyramidal cells that was not prevented by blockade of excitatory and inhibitory synaptic inputs. Bath application of the M1 receptor antagonist pirenzepine (1 µM, but not the M2-preferring antagonist methoctramine (1 µM, blocked the depolarization, suggesting that it is dependent on M1 receptors. Voltage-clamp experiments using ramped voltage commands showed that CCh resulted in the gradual development of an inward current that was partially blocked by concurrent application of the selective Kv7.2/3 channel antagonist XE-991, which inhibits the muscarine-dependent K(+ current I M. The remaining inward current also reversed near EK and was inhibited by the K(+ channel blocker Ba(2+, suggesting that M1 receptor activation attenuates both I M as well as an additional K(+ current. The additional K(+ current showed rectification at depolarized voltages, similar to K(+ conductances mediated by Kir 2.3 channels. The cholinergic depolarization of layer II PaS neurons therefore appears to occur through M1-mediated effects on I M as well as an additional K(+ conductance.

  18. Muscarinic Depolarization of Layer II Neurons of the Parasubiculum

    Science.gov (United States)

    Glasgow, Stephen D.; Chapman, C. Andrew

    2013-01-01

    The parasubiculum (PaS) is a component of the hippocampal formation that sends its major output to layer II of the entorhinal cortex. The PaS receives strong cholinergic innervation from the basal forebrain that is likely to modulate neuronal excitability and contribute to theta-frequency network activity. The present study used whole cell current- and voltage-clamp recordings to determine the effects of cholinergic receptor activation on layer II PaS neurons. Bath application of carbachol (CCh; 10–50 µM) resulted in a dose-dependent depolarization of morphologically-identified layer II stellate and pyramidal cells that was not prevented by blockade of excitatory and inhibitory synaptic inputs. Bath application of the M1 receptor antagonist pirenzepine (1 µM), but not the M2-preferring antagonist methoctramine (1 µM), blocked the depolarization, suggesting that it is dependent on M1 receptors. Voltage-clamp experiments using ramped voltage commands showed that CCh resulted in the gradual development of an inward current that was partially blocked by concurrent application of the selective Kv7.2/3 channel antagonist XE-991, which inhibits the muscarine-dependent K+ current IM. The remaining inward current also reversed near EK and was inhibited by the K+ channel blocker Ba2+, suggesting that M1 receptor activation attenuates both IM as well as an additional K+ current. The additional K+ current showed rectification at depolarized voltages, similar to K+ conductances mediated by Kir 2.3 channels. The cholinergic depolarization of layer II PaS neurons therefore appears to occur through M1-mediated effects on IM as well as an additional K+ conductance. PMID:23520542

  19. Susceptibility of Primary Sensory Cortex to Spreading Depolarizations

    OpenAIRE

    Bogdanov, VB; Middleton, NA; Theriot, JJ; Parker, PD; Abdullah, OM; Ju, YS; Hartings, JA; Brennan, KC

    2016-01-01

    Spreading depolarizations (SDs) are recognized as actors in neurological disorders as diverse as migraine and traumatic brain injury (TBI). Migraine aura involves sensory percepts, suggesting that sensory cortices might be intrinsically susceptible to SDs. We used optical imaging, MRI, and field potential and potassium electrode recordings in mice and electrocorticographic recordings in humans to determine the susceptibility of different brain regions to SDs. Optical imaging experiments in mi...

  20. Transparent Depolarizing Organic and Inorganic Films for Optics and Sensors.

    Science.gov (United States)

    Hiratani, Takayuki; Hamad, Wadood Y; MacLachlan, Mark J

    2017-04-01

    Fabrication of novel organic and inorganic depolarizing films derived from quasinematic cellulose nanocrystal (CNC) organization is demonstrated. These films convert linearly polarized and circularly polarized light into unpolarized light over the entire visible region. Patterning of the quasinematic CNCs on top of a chiral nematic film gives latent images that are revealed only upon observation through the circularly polarizing filters. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Effect of Access to an Electronic Medical Resource on Performance Characteristics of a Certification Examination: A Randomized Controlled Trial.

    Science.gov (United States)

    Lipner, Rebecca S; Brossman, Bradley G; Samonte, Kelli M; Durning, Steven J

    2017-09-05

    Electronic resources are increasingly used in medical practice. Their use during high-stakes certification examinations has been advocated by many experts, but whether doing so would affect the capacity to differentiate between high and low abilities is unknown. To determine the effect of electronic resources on examination performance characteristics. Randomized controlled trial. Medical certification program. 825 physicians initially certified by the American Board of Internal Medicine (ABIM) who passed the Internal Medicine Certification examination or sat for the Internal Medicine Maintenance of Certification (IM-MOC) examination in 2012 to 2015. Participants were randomly assigned to 1 of 4 conditions: closed book using typical or additional time, or open book (that is, UpToDate [Wolters Kluwer]) using typical or additional time. All participants took the same modified version of the IM-MOC examination. Primary outcomes included item difficulty (how easy or difficult the question was), item discrimination (how well the question differentiated between high and low abilities), and average question response time. Secondary outcomes included examination dimensionality (that is, the number of factors measured) and test-taking strategy. Item response theory was used to calculate question characteristics. Analysis of variance compared differences among conditions. Closed-book conditions took significantly less time than open-book conditions (mean, 79.2 seconds [95% CI, 78.5 to 79.9 seconds] vs. 110.3 seconds [CI, 109.2 to 111.4 seconds] per question). Mean discrimination was statistically significantly higher for open-book conditions (0.34 [CI, 0.32 to 0.35] vs. 0.39 [CI, 0.37 to 0.41] per question). A strong single dimension showed that the examination measured the same factor with or without the resource. Only 1 electronic resource was evaluated. Inclusion of an electronic resource with time constraints did not adversely affect test performance and did not change

  2. Depolarization properties of the femtosecond supercontinuum generated in condensed media

    Science.gov (United States)

    Kumar, R. Sai Santosh; Deepak, K. L. N.; Rao, D. Narayana

    2008-10-01

    In this paper, we present a study of depolarization of a supercontinuum across its spectral range as a function of the femtosecond laser pump intensity for an anisotropic crystalline condensed medium, potassium-dihydrogen-phosphate (KDP) crystal, and compare our results with commonly used supercontinuum generation (SCG) materials, namely borosilicate glass Schott (BK-7) glass (representing isotropic amorphous condensed media) and BaF2 (isotropic crystalline condensed media). Our results show that at higher input powers, depolarization in the continuum increases for BK-7, BaF2 , and along the direction of the optic axis of the KDP crystal. However, in the case of KDP crystal, we observe that the depolarization properties are strongly dependent on (i) the plane of polarization of incident light and (ii) the orientation of the crystal with respect to the incident light. Our studies also confirm that one can achieve SCG in a KDP crystal that maintains the same state of input polarization even at high input intensities when proper orientation of the crystal is used.

  3. Cellular contraction precedes membrane depolarization in Vorticella convallaria

    Science.gov (United States)

    Shiono; Naitoh

    1997-01-01

    Application of a mechanical stimulus to the cell body of the peritrich ciliate Vorticella convallaria evoked an all-or-nothing membrane depolarization, the large pulse. This was always accompanied by an all-or-nothing cellular contraction, and simultaneous recordings of the two events revealed that the large pulse was always preceded by the cellular contraction. A smaller graded membrane depolarization (the medium pulse) was sometimes produced in response to a weaker mechanical stimulus. The medium pulse was accompanied by a small, graded, localized contraction of the cell body and was occasionally followed by a large pulse. When a large pulse occurred during a medium pulse, it reached the same peak level as that of a large pulse evoked without a preceding medium pulse. When a medium pulse occurred during a medium pulse, summation of the two pulses was observed. Sustained contraction causes V. convallaria to become rounded, and in this state a mechanical stimulus stronger than that used to evoke the large pulse evoked a graded depolarizing mechanoreceptor potential in the cell. We conclude that both the large and medium pulses are caused by an inward receptor current that is activated mechanically following contraction of the cell body. A localized contraction evokes a small mechanoreceptor current, causing a medium pulse. An all-or-nothing contraction evokes a saturated, all-or-nothing mechanoreceptor current, causing a large pulse.

  4. Elastodynamic metasurface: Depolarization of mechanical waves and time effects

    Energy Technology Data Exchange (ETDEWEB)

    Boutin, Claude, E-mail: claude.boutin@entpe.fr [Ecole Nationale des Travaux Publics de l' Etat, Université de Lyon, LGCB, UMR CNRS 5513, Vaulx-en-Velin (France); Schwan, Logan [Acoustics Research Center, University of Salford, Newton Building, Salford M5 4WT (United Kingdom); Dietz, Matthew S. [Department of Civil Engineering, University of Bristol, Queen' s Building, Bristol BS8 1TR (United Kingdom)

    2015-02-14

    We report the concept of microstructured surfaces with inner resonance in the field of elastodynamics, so-called elastodynamic metasurfaces. Such metasurfaces allow for wavefield manipulation of mechanical waves by tuning the boundary conditions at specific frequencies. In particular, they can be used to depolarize elastic waves without introducing heterogeneities in the medium itself; the physical means to do so in homogeneous elastic media used to remain, surprisingly, an open question while depolarization is commonplace in electromagnetism. The principle relies on the anisotropic behaviour of a subwavelength array of resonators: Their subwavelength configuration confines the Bragg interferences scattered by resonators into a boundary layer. The effective behaviour of the resonating array is expressed with homogenization as an unconventional impedance, the frequency-dependence, and anisotropy of which lead to depolarization and time effects. The concept of the elastodynamic metasurface is tested experimentally and results bear testament to its efficacy and robustness. Elastodynamic metasurfaces are easily realized and analytically predictable, opening new possibilities in tomography techniques, ultrasonics, geophysics, vibration control, materials and structure design.

  5. Understanding intention to use electronic information resources: A theoretical extension of the technology acceptance model (TAM).

    Science.gov (United States)

    Tao, Donghua

    2008-11-06

    This study extended the Technology Acceptance Model (TAM) by examining the roles of two aspects of e-resource characteristics, namely, information quality and system quality, in predicting public health students' intention to use e-resources for completing research paper assignments. Both focus groups and a questionnaire were used to collect data. Descriptive analysis, data screening, and Structural Equation Modeling (SEM) techniques were used for data analysis. The study found that perceived usefulness played a major role in determining students' intention to use e-resources. Perceived usefulness and perceived ease of use fully mediated the impact that information quality and system quality had on behavior intention. The research model enriches the existing technology acceptance literature by extending TAM. Representing two aspects of e-resource characteristics provides greater explanatory information for diagnosing problems of system design, development, and implementation.

  6. Building and Managing Electronic Resources in Digital Era in India with Special Reference to IUCAA and NIV, Pune: A Comparative Case Study

    Science.gov (United States)

    Sahu, H. K.; Singh, S. N.

    2015-04-01

    This paper discusses and presents a comparative case study of two libraries in Pune, India, Inter-University Centre for Astronomy and Astrophysics and Information Centre and Library of National Institute of Virology (Indian Council of Medical Research). It compares how both libraries have managed their e-resource collections, including acquisitions, subscriptions, and consortia arrangements, while also developing a collection of their own resources, including pre-prints and publications, video lectures, and other materials in an institutional repository. This study illustrates how difficult it is to manage electronic resources in a developing country like India, even though electronic resources are used more than print resources. Electronic resource management can be daunting, but with a systematic approach, various problems can be solved, and use of the materials will be enhanced.

  7. Print and Electronic Resources: Usage Statistics at Guru Gobind Singh Indraprastha University Library

    Science.gov (United States)

    Kapoor, Kanta

    2010-01-01

    Purpose: The purpose of this paper is to quantify the use of electronic journals in comparison with the print collections in the Guru Gobind Singh Indraprastha University Library. Design/methodology/approach: A detailed analysis was made of the use of lending services, the Xerox facility and usage of electronic journals such as Science Direct,…

  8. Print and Electronic Resources: Usage Statistics at Guru Gobind Singh Indraprastha University Library

    Science.gov (United States)

    Kapoor, Kanta

    2010-01-01

    Purpose: The purpose of this paper is to quantify the use of electronic journals in comparison with the print collections in the Guru Gobind Singh Indraprastha University Library. Design/methodology/approach: A detailed analysis was made of the use of lending services, the Xerox facility and usage of electronic journals such as Science Direct,…

  9. What Is the Hidden Depolarization Mechanism in Low-luminosity AGNs?

    Science.gov (United States)

    Bower, Geoffrey C.; Dexter, Jason; Markoff, Sera; Rao, Ramprasad; Plambeck, R. L.

    2017-07-01

    Millimeter-wavelength polarimetry of accreting black hole systems can provide a tomographic probe of the accretion flow on a wide range of linear scales. We searched for linear polarization in two low-luminosity active galactic nuclei (LLAGNs), M81 and M84, using the Combined Array for Millimeter Astronomy and the Submillimeter Array. We find upper limits of ˜1%-2% averaging over the full bandwidth and with a rotation measure (RM) synthesis technique. These low polarization fractions, along with similarly low values for LLAGNs M87 and 3C 84, suggest that LLAGNs have qualitatively different polarization properties than radio-loud sources and Sgr A*. If the sources are intrinsically polarized and then depolarized by Faraday rotation, then we place lower limits on the RM of a few times {10}7 {rad} {{{m}}}-2 for the full bandwidth case and ˜ {10}9 {rad} {{{m}}}-2 for the RM synthesis analysis. These limits are inconsistent with or marginally consistent with expected accretion flow properties. Alternatively, the sources may be depolarized by cold electrons within a few Schwarzschild radii from the black hole, as suggested by numerical models.

  10. Energy and Beam-Offset dependence of the Luminosity weighted depolarization for CLIC

    CERN Document Server

    Esberg, Jakob; Uggerhoj, Ulrik; Dalena, Barbara

    2011-01-01

    We report on simulations of e+e- depolarization due to beam-beam effects. These effects are studied for CLIC at 3 TeV, using GUINEA PIG++. We find a strong energy dependence of the luminosity weighted depolarization. In the luminosity peak at CLIC the total luminosity weighted depolarization remains below the one per-mil level. The effect of a vertical offset on the energy dependent depolarization is investigated. The depolarization in the luminosity peak remains below per-cent level even for 5sy offsets.

  11. Intention to use and actual use of electronic information resources: further exploring Technology Acceptance Model (TAM).

    Science.gov (United States)

    Tao, Donghua

    2009-11-14

    Following up a previous study that examined public health students' intention to use e-resources for completing research paper assignments, the present study proposed two models to investigate whether or not public health students actually used the e-resources they intended to use and whether or not the determinants of intention to use predict actual use of e-resources. Focus groups and pre- and post-questionnaires were used to collect data. Descriptive analysis, data screening, and Structural Equation Modeling (SEM) techniques were used for data analysis. The study found that the determinants of intention-to-use significantly predict actual use behavior. Direct impact of perceived usefulness and indirect impact of perceived ease of use to both behavior intention and actual behavior indicated the importance of ease of use at the early stage of technology acceptance. Non-significant intention-behavior relationship prompted thoughts on the measurement of actual behavior and multidimensional characteristics of the intention construct.

  12. MendelWeb: An Electronic Science/Math/History Resource for the WWW.

    Science.gov (United States)

    Blumberg, Roger B.

    This paper describes a hypermedia resource, called MendelWeb that integrates elementary biology, discrete mathematics, and the history of science. MendelWeb is constructed from Gregor Menders 1865 paper, "Experiments in Plant Hybridization". An English translation of Mendel's paper, which is considered to mark the birth of classical and…

  13. QR Codes as Finding Aides: Linking Electronic and Print Library Resources

    Science.gov (United States)

    Kane, Danielle; Schneidewind, Jeff

    2011-01-01

    As part of a focused, methodical, and evaluative approach to emerging technologies, QR codes are one of many new technologies being used by the UC Irvine Libraries. QR codes provide simple connections between print and virtual resources. In summer 2010, a small task force began to investigate how QR codes could be used to provide information and…

  14. Electronic resources at the University of Sharjah medical library: an investigation of students' information-seeking behavior.

    Science.gov (United States)

    Boumarafi, Behdja

    2010-10-01

    Electronic information is becoming prevalent worldwide, and its use is growing exponentially as more and more users are recognizing the potential that it offers in terms of access and delivery. However, with the introduction of new tools for e-information searching and retrieval, users have to readjust their information-seeking behavior to cope with the corresponding changes. The University of Sharjah library is steadily increasing its investment in e-resources to offer ubiquitous access to the growing body of literature in areas that interest the community it serves. This study reports the findings of a survey conducted to investigate the information-seeking behavior of medical students at the medical library. Results showed evidence of use of e-resources, but they did not explicitly establish that some of the major problems mentioned by participants did hinder the information searches of the respondents. An extensive literature review sets the background for the study.

  15. 图书馆电子信息资源利用效果评价研究%Study on Utilization Effect Evaluation of Library Electronic Information Resources

    Institute of Scientific and Technical Information of China (English)

    晋晓强; 贺培风; 何忠印

    2012-01-01

    This paper discusses utilization effect of electronic information resources combining with the characteristics of electronic information resources, makes evaluation system of library electronic information resource utilization effect from three aspects : the library, the users and the data providers, hoping for providing valuable reference for the efficient use of library electronic resources.%本文结合电子信息资源的特性对电子信息资源的利用进行初步探讨,从图书馆、用户和数据服务商三个角度构建图书馆电子信息资源利用效果的评价体系,希望能为图书馆电子信息资源的高效利用提供参考。

  16. Spreading depolarizations and late secondary insults after traumatic brain injury

    DEFF Research Database (Denmark)

    Hartings, Jed A; Strong, Anthony J; Fabricius, Martin

    2009-01-01

    -contusional cortex in 32 patients who underwent surgical treatment for TBI. Prospective electrocorticography was performed during neurointensive care with retrospective analysis of hourly nursing chart data. Recordings were 84 hr (median) per patient and 2,503 hr in total. In 17 patients (53%), 280 spreading...... temperatures suggests that the labile balance of energy supply and demand is an important determinant of their occurrence. Monitoring of depolarizations might serve as a functional measure to guide therapeutic efforts and their blockade may provide an additional line of defense against the effects of secondary...

  17. Integral decomposition and polarization properties of depolarizing Mueller matrices.

    Science.gov (United States)

    Ossikovski, Razvigor; Arteaga, Oriol

    2015-03-15

    We show that, by suitably defining the integral decomposition of a depolarizing Mueller matrix, it becomes possible to fully interpret the polarization response of the medium or structure under study in terms of mean values and variances-covariances of a set of six integral polarization properties. The latter appear as natural counterparts of the elementary (differential) polarization properties stemming from the differential decomposition of the Mueller matrix. However, unlike the differential decomposition, the integral one is always mathematically and physically realizable and is furthermore unambiguously defined inasmuch as a nondepolarizing estimate of the initial Mueller matrix is secured. The theoretical results are illustrated on an experimental example.

  18. Faraday ghosts depolarization canals in the Galactic radio emission

    CERN Document Server

    Shukurov, A M; Shukurov, Anvar; Berkhuijsen, Elly M.

    2003-01-01

    Narrow, elongated regions of very low polarized intensity -- so-called canals -- have recently been observed by several authors at decimeter wavelengths in various directions in the Milky Way, but their origin remains enigmatic. We show that the canals arise from depolarization by differential Faraday rotation in the interstellar medium and that they represent level lines of Faraday rotation measure RM, a random function of position in the sky. Statistical properties of the separation of canals depend on the autocorrelation function of RM, and so provide a useful tool for studies of interstellar turbulence.

  19. Characterizing the Depolarizing Quantum Channel in Terms of Riemannian Geometry

    CERN Document Server

    Cafaro, Carlo

    2011-01-01

    We explore the conceptual usefulness of Riemannian geometric tools induced by the statistical concept of distinguishability in quantifying the effect of a depolarizing channel on quantum states. Specifically, we compare the geometries of the interior of undeformed and deformed Bloch spheres related to density operators on a two-dimensional Hilbert space. We show that randomization emerges geometrically through a smaller infinitesimal quantum line element on the deformed Bloch sphere while the uniform contraction manifests itself via a deformed set of geodesics where the spacial components of the deformed four-Bloch vector are simply the contracted versions of the undeformed Bloch vector components.

  20. An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

    KAUST Repository

    Ramli, Rindra M.

    2017-05-03

    An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

  1. Eavesdropping on Electronic Guidebooks: Observing Learning Resources in Shared Listening Environments.

    Science.gov (United States)

    Woodruff, Allison; Aoki, Paul M.; Grinter, Rebecca E.; Hurst, Amy; Szymanski, Margaret H.; Thornton, James D.

    This paper describes an electronic guidebook, "Sotto Voce," that enables visitors to share audio information by eavesdropping on each others guidebook activity. The first section discusses the design and implementation of the guidebook device, key aspects of its user interface, the design goals for the audio environment, the eavesdropping…

  2. Electronic Resources in a Next-Generation Catalog: The Case of WorldCat Local

    Science.gov (United States)

    Shadle, Steve

    2009-01-01

    In April 2007, the University of Washington Libraries debuted WorldCat Local (WCL), a localized version of the WorldCat database that interoperates with a library's integrated library system and fulfillment services to provide a single-search interface for a library's physical and electronic content. This brief will describe how WCL incorporates a…

  3. Equalizing Access to Electronic Networked Resources: A Model for Rural Libraries in the United States.

    Science.gov (United States)

    Senkevitch, Judith J.; Wolfram, Dietmar

    1994-01-01

    Provides an overview of the current state of networking technology in rural libraries and describes a model for educating rural librarians in accessing electronic networks. Topics discussed include information needs in rural libraries; telecommunications technology access in rural areas; and examples of services to enhance information access.…

  4. Preference and Use of Electronic Information and Resources by Blind/Visually Impaired in NCR Libraries in India

    Directory of Open Access Journals (Sweden)

    Shailendra Kumar

    2013-06-01

    Full Text Available This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

  5. Depolarizing actions of hydrogen sulfide on hypothalamic paraventricular nucleus neurons.

    Directory of Open Access Journals (Sweden)

    C Sahara Khademullah

    Full Text Available Hydrogen sulfide (H2S is a novel neurotransmitter that has been shown to influence cardiovascular functions as well and corticotrophin hormone (CRH secretion. Since the paraventricular nucleus of the hypothalamus (PVN is a central relay center for autonomic and endocrine functions, we sought to investigate the effects of H2S on the neuronal population of the PVN. Whole cell current clamp recordings were acquired from the PVN neurons and sodium hydrosulfide hydrate (NaHS was bath applied at various concentrations (0.1, 1, 10, and 50 mM. NaHS (1, 10, and 50 mM elicited a concentration-response relationship from the majority of recorded neurons, with almost exclusively depolarizing effects following administration. Cells responded and recovered from NaHS administration quickly and the effects were repeatable. Input differences from baseline and during the NaHS-induced depolarization uncovered a biphasic response, implicating both a potassium and non-selective cation conductance. The results from the neuronal population of the PVN shed light on the possible physiological role that H2S has in autonomic and endocrine function.

  6. Overcoming horizontal depolarizing resonances with multiple tune jumps

    Science.gov (United States)

    Huang, H.; Ahrens, L. A.; Bai, M.; Brown, K. A.; Dutheil, Y.; Gardner, C.; Glenn, J. W.; Lin, F.; MacKay, W. W.; Meot, F.; Poblaguev, A.; Ranjbar, V.; Roser, T.; Schoefer, V.; Tepikian, S.; Tsoupas, N.; Yip, K.; Zelenski, A.; Zeno, K.

    2014-08-01

    In a medium energy proton synchrotron, strong enough partial Siberian snakes can be used to avoid both imperfection and vertical intrinsic depolarizing resonances. However, partial snakes tilt the stable spin direction away from vertical, which generates depolarizing resonances associated with horizontal tune. The relatively weak but numerous horizontal intrinsic resonances are the main source of the residual polarization losses. A pair of horizontal tune jump quads have been used in the Brookhaven Alternating Gradient Synchrotron to overcome these weak resonances. The locations of the two quads have to be chosen such that the disturbance to the beam optics is minimum. The emittance growth has to be mitigated for this method to work. In addition, this technique needs very accurate jump timing. Using two partial Siberian snakes, with vertical tune inside the spin tune gap and 80% polarization at the Alternating Gradient Synchrotron injection, polarized proton beam had reached 1.5×1011 proton per bunch with 65% polarization. With the tune jump timing optimized and emittance preserved, more than 70% polarization with 2×1011 protons per bunch has been achieved. The polarization transport efficiency is close to 90%.

  7. Overcoming horizontal depolarizing resonances with multiple tune jumps

    Directory of Open Access Journals (Sweden)

    H. Huang

    2014-08-01

    Full Text Available In a medium energy proton synchrotron, strong enough partial Siberian snakes can be used to avoid both imperfection and vertical intrinsic depolarizing resonances. However, partial snakes tilt the stable spin direction away from vertical, which generates depolarizing resonances associated with horizontal tune. The relatively weak but numerous horizontal intrinsic resonances are the main source of the residual polarization losses. A pair of horizontal tune jump quads have been used in the Brookhaven Alternating Gradient Synchrotron to overcome these weak resonances. The locations of the two quads have to be chosen such that the disturbance to the beam optics is minimum. The emittance growth has to be mitigated for this method to work. In addition, this technique needs very accurate jump timing. Using two partial Siberian snakes, with vertical tune inside the spin tune gap and 80% polarization at the Alternating Gradient Synchrotron injection, polarized proton beam had reached 1.5×10^{11} proton per bunch with 65% polarization. With the tune jump timing optimized and emittance preserved, more than 70% polarization with 2×10^{11} protons per bunch has been achieved. The polarization transport efficiency is close to 90%.

  8. Depolarization of a piezoelectric film under an alternating current field

    Science.gov (United States)

    Kwok, K. W.; Cheung, M. K.; Chan, H. L. W.; Choy, C. L.

    2007-03-01

    In this article, we demonstrate that a sol-gel-derived niobium-doped lead zirconate titanate film can be depolarized by the application of alternating current (ac) fields of diminishing amplitude and we explain the phenomenon based on the concept of the Preisach model. The amplitude of the ac fields is decreased from 20 to 2 MV/m in ten steps. The observed piezoelectric coefficient of the film decreases after each ac field step. Depending on the initial polarization and the direction of the ac fields, the piezoelectric coefficient can decrease to a very small value indicating the complete depolarization of the film. Our results reveal the existence of a distribution of the switching fields in the microdomains (Preisach dipolar units), and that because of mutual interactions the magnitudes of the switch-up and switch-down fields for each microdomain are not necessarily the same. Our results also suggest that the sputter deposition of the top electrode can induce more "down-state" microdomains, thus giving rise to an initial polarization in the film. Because of interactions with other microdomains or other effects, part of these microdomains exhibit very high switching fields.

  9. Collaboration in electronic resource provision in university libraries: SHEDL, a Scottish case study

    OpenAIRE

    Kidd, T

    2009-01-01

    This case study examines the growth of collaboration among Scottish higher education institutions. Following a summary of the work of the Scottish Confederation of University and Research Libraries (SCURL), more detailed information is provided on collaboration in the fields of acquisition, licensing, selection, and purchasing. Some of the UK background is outlined, relating to NESLi2 in particular, in order to illuminate the options within Scotland. The origins of negotiations on electronic ...

  10. Internet and electronic resources for inflammatory bowel disease: a primer for providers and patients.

    Science.gov (United States)

    Fortinsky, Kyle J; Fournier, Marc R; Benchimol, Eric I

    2012-06-01

    Patients with inflammatory bowel disease (IBD) are increasingly turning to the Internet to research their condition and engage in discourse on their experiences. This has resulted in new dynamics in the relationship between providers and their patients, with misinformation and advertising potentially presenting barriers to the cooperative patient-provider partnership. This article addresses important issues of online IBD-related health information and social media activity, such as quality, reliability, objectivity, and privacy. We reviewed the medical literature on the quality of online information provided to IBD patients, and summarized the most commonly accessed Websites related to IBD. We also assessed the activity on popular social media sites (such as Facebook, Twitter, and YouTube), and evaluated currently available applications for use by IBD patients and providers on mobile phones and tablets. Through our review of the literature and currently available resources, we developed a list of recommended online resources to strengthen patient participation in their care by providing reliable, comprehensive educational material.

  11. Depolarization of synchrotron radiation in a multilayer magneto-ionic medium

    CERN Document Server

    Shneider, Carl; Fletcher, Andrew; Shukurov, Anvar

    2014-01-01

    Depolarization of diffuse radio synchrotron emission is classified in terms of wavelength-independent and wavelength-dependent depolarization in the context of regular magnetic fields and of both isotropic and anisotropic turbulent magnetic fields. Previous analytical formulas for depolarization due to differential Faraday rotation are extended to include internal Faraday dispersion concomitantly, for a multilayer synchrotron emitting and Faraday rotating magneto-ionic medium. In particular, depolarization equations for a two- and three-layer system (disk-halo, halo-disk-halo) are explicitly derived. To both serve as a `user's guide' to the theoretical machinery and as an approach for disentangling line-of-sight depolarization contributions in face-on galaxies, the analytical framework is applied to data from a small region in the face-on grand-design spiral galaxy M51. The effectiveness of the multiwavelength observations in constraining the pool of physical depolarization scenarios is illustrated for a two-...

  12. Granulometric composition study of mineral resources using opto-electronic devices and Elsieve software system

    Directory of Open Access Journals (Sweden)

    Kaminski Stanislaw

    2016-01-01

    Full Text Available The use of mechanical sieves has a great impact on measurement results because occurrence of anisometric particles causes undercounting the average size. Such errors can be avoided by using opto-electronic measuring devices that enable measurement of particles from 10 μm up to a few dozen millimetres in size. The results of measurement of each particle size fraction are summed up proportionally to its weight with the use of Elsieve software system and for every type of material particle-size distribution can be obtained. The software allows further statistical interpretation of the results. Beam of infrared radiation identifies size of particles and counts them precisely. Every particle is represented by an electronic impulse proportional to its size. Measurement of particles in aqueous suspension that replaces the hydrometer method can be carried out by using the IPS L analyser (range from 0.2 to 600 μm. The IPS UA analyser (range from 0.5 to 2000 μm is designed for measurement in the air. An ultrasonic adapter enables performing measurements of moist and aggregated particles from 0.5 to 1000 μm. The construction and software system allow to determine second dimension of the particle, its shape coefficient and specific surface area. The AWK 3D analyser (range from 0.2 to 31.5 mm is devoted to measurement of various powdery materials with subsequent determination of particle shape. The AWK B analyser (range from 1 to 130 mm measures materials of thick granulation and shape of the grains. The presented method of measurement repeatedly accelerates and facilitates study of granulometric composition.

  13. Neutron depolarization measurements of magnetite in chiton teeth

    Science.gov (United States)

    Seifert, M.; Schulz, M.; Benka, G.; Pfleiderer, C.; Gilder, S.

    2017-06-01

    Magnetite constitutes one of the most abundant magnetic minerals in the Earth's crust. In the single domain state, magnetite often carries the magnetic remanence in rocks due to its stable and strong magnetic remanence. Hence it is of keen interest to paleomagnetists who study the ancient magnetic field preserved in the rock record. The extremely small size range and vulnerability to oxidation of single domain magnetite makes synthetization and preservation virtually impossible. Consequently, most experimental work on magnetite under pressure is carried out on multidomain magnetite. The radula of the marine mollusc chiton (Polyplacophora) is one of the few natural sources of single domain magnetite. We have performed a comparative study on samples of chiton radula in a vibrating sample magnetometer (VSM) and with the newly evolving neutron depolarization imaging (NDI) technique. Despite a constant offset between the VSM and NDI data in the coercivity we find a good agreement between the two techniques.

  14. Experimental verification of depolarization effects in bioelectrical impedance measurement.

    Science.gov (United States)

    Chen, Xiaoyan; Lv, Xinqiang; Du, Meng

    2014-01-01

    The electrode polarization effects on bioelectrical impedance measurement at low-frequency cannot be ignored. In this paper, the bioelectrical data of mice livers are measured to specify the polarization effects on the bio-impedance measurement data. We firstly introduce the measurement system and methodology. Using the depolarization method, the corrected results are obtained. Besides, the specific effects of electrode polarization on bio-impedance measurement results are investigated using comparative analysis of the previous and posterior correction results from dielectric spectroscopy, Cole-Cole plot, conductivity and spectroscopy of dissipation tangent. Experimental results show that electrode polarization has a significant influence on the characteristic parameters of mouse liver tissues. To be specific, we see a low-frequency limit resistance R0 increase by 19.29%, a reactance peak XP increase by 8.50%, a low-frequency limit conductivity Kl decrease by 17.65% and a dissipation peak tangent decrease by 160%.

  15. Inflections in threshold electrotonus to depolarizing currents in sensory axons.

    Science.gov (United States)

    Burke, David; Howells, James; Trevillion, Louise; Kiernan, Matthew C; Bostock, Hugh

    2007-12-01

    Threshold electrotonus involves tracking the changes in axonal excitability produced by subthreshold polarizing currents and is the only technique that allows insight into the function of internodal conductances in human subjects in vivo. There is often an abrupt transient reversal of the threshold change as excitability increases in response to conditioning depolarizing currents (S1 phase). In recordings from motor axons, it has been recently demonstrated that this notch or inflection is due to activation of low-threshold axons. We report that a notch is frequently seen in sensory recordings (in 33 of 50 healthy subjects) using the standard threshold electrotonus protocol. When large, the notch can distort subsequent phases of threshold electrotonus and could complicate quantitative measurements and modeling studies.

  16. Multiple Tune Jumps to Overcome Horizontal Depolarizing Resonances

    Science.gov (United States)

    Huang, H.; Ahrens, L. A.; Bai, M.; Brown, K. A.; Dutheil, Y.; Gardner, C.; Glenn, J. W.; Lin, F.; Mackay, W. W.; Meot, F.; Poblaguev, A.; Ranjbar, V.; Roser, T.; Schoefer, V.; Tepikian, S.; Tsoupas, N.; Yip, K.; Zelenski, A.; Zeno, K.

    2016-02-01

    Imperfection and vertical intrinsic depolarizing resonances have been overcome by the two partial Siberian snakes in the Alternative Gradient Synchrotron(AGS). The relatively weak but numerous horizontal resonances are the main source of polarization loss in the AGS. A pair of horizontal tune jump quads have been used to overcome these weak resonances. The locations of the two quads have to be chosen such that the disturbance to the beam optics is minimum. The emittance growth has to be mitigated for this method to work. In addition, this technique needs very accurate jump timing. Using two partial Siberian snakes, with vertical tune inside the spin tune gap and 80% polarization at AGS injection, polarized proton beam had reached 1.5 × 1011 proton per bunch with 65% polarization. With the tune jump timing optimized and emittance preserved, more than 70% polarization with 2 × 1011 protons per bunch has been achieved.

  17. Chloride regulates afferent arteriolar contraction in response to depolarization

    DEFF Research Database (Denmark)

    Hansen, P B; Jensen, B L; Skott, O

    1998-01-01

    . The results show that K+-induced contraction of smooth muscle cells in the afferent arteriole is highly sensitive to chloride, whereas neurotransmitter release and ensuing contraction is not dependent on chloride. Thus, there are different activation pathways for depolarizing vasoconstrictors......-Renal vascular reactivity is influenced by the level of dietary salt intake. Recent in vitro data suggest that afferent arteriolar contractility is modulated by extracellular chloride. In the present study, we assessed the influence of chloride on K+-induced contraction in isolated perfused rabbit...... afferent arterioles. In 70% of vessels examined, K+-induced contraction was abolished by acute substitution of bath chloride. Consecutive addition of Cl- (30, 60, 80, 100, 110, and 117 mmol/L) restored the sensitivity to K+, and half-maximal response was observed at 82 mmol/L chloride. The calcium channel...

  18. Modeling of PZT Ferroelectric Ceramic Depolarization Driven by Shock Stress

    Institute of Scientific and Technical Information of China (English)

    LAN Chao-Hui; PENG Yu-Fei; LONG Ji-Dong; WANG Qiang; WANG Wen-Dou

    2011-01-01

    @@ Shock-induced phase transition of ferroelectric ceramic PZT 95/5 causes elastic stiffening and depolarization,releasing stored electrostatic energy into the load circuit.We develop a model to describe the response of the PZT ferroelectric ceramic and implement it into simulation codes.The model is based on the phenomenological theory of phase transition dyynamics and takes into account the effects of the self-generated intensive electrical field and stress.Connected with the discharge model and external circuit, the whole transient process of PZT ceramic depoling can be investigated.The results show the finite transition velocity of the ferroelectric phase and the double wave structure caused by phase transition.Simulated currents are compared with the results from experiments with shock pressures varying from 0.4 to 2.8GPa.

  19. 试论图书馆电子资源与纸本资源的协调发展%The coordinated development of library electronic resources and paper resources

    Institute of Scientific and Technical Information of China (English)

    冯雷

    2012-01-01

      纸本资源和电子资源属于公共图书馆文献资源中两个非常重要的资源类型,纸本资源和电子资源的协调发展在图书馆的可持续发展过程中起着非常重要的作用。本文对如何实现图书馆电子资源和纸本资源之间的协调发展进行了探讨,希望能够为图书馆文献资源的管理提供一些参考。%  The paper and electronic resources are two very important types of literature resources of public libraries, the coordinated development of the paper and electronic resources play a very important role in the sustainable development process of the library. This article discusses how to realize the coordinated development of library electronic resources and paper resources, hope to provide some reference for library literature resource management.

  20. On the Development of Electronic Resources and Paper Resources%关于电子资源与纸本资源协调发展的思考和建议

    Institute of Scientific and Technical Information of China (English)

    王军武

    2012-01-01

    In recent years, a large number of electronic resources was introduced to the libraries, which has become an im- portant component of library resource system. However, there are also a lot of hot debates about the following issues, such as how to build a traditional paper resources, how to deal with the relationship between paper resources and electronic resources, how to build a library resources development system, etc. These problems also confused many librarians who are building resources in the library. With the combination with the opinions from some experts, research scholars, the paper proposed some guiding principles to deal with the relationship between electronic resources and paper resources. Taking all the aspects into consideration, such as the concepts of the library, the funding of the resources, the policies and structure of the library, cooperative development, the paper also proposes some measures for the development of electronic resources and paper resources.%在复合图书馆环境下,如何协调发展电子资源与纸本资源是图书馆界专家、学者研究和探讨的热点问题,也是许多图书馆工作者在文献资源建设实践中十分困惑的问题。文章结合有关专家、学者的研究成果及图书馆的相关案例,概述了电子资源与纸本资源协调发展应遵循的指导性原则,并从馆藏理念、经费投入、馆藏政策、馆藏结构、合作发展、服务利用等几个方面提出了协调发展电子资源与纸本资源的若干举措。

  1. Green Supply Chain Collaboration for Fashionable Consumer Electronics Products under Third-Party Power Intervention—A Resource Dependence Perspective

    Directory of Open Access Journals (Sweden)

    Jiuh-Biing Sheu

    2014-05-01

    Full Text Available Under third-party power intervention (TPPI, which increases uncertainty in task environments, complex channel power interplays and restructuring are indispensable among green supply chain members as they move toward sustainable collaborative relationships for increased viability and competitive advantage. From the resource dependence perspective, this work presents a novel conceptual model to investigate the influence of political and social power on channel power restructuring and induced green supply chain collaboration in brander-retailer bidirectional green supply chains of fashionable consumer electronics products (FCEPs. An FCEP refers to the consumer electronics product (e.g., personal computers, mobile phones, computer notebooks, and game consoles with the features of a well-known brand associated, a short product lifecycle, timely and fashionable design fit for market trends, and quick responsiveness to the variations of market demands. The proposed model is tested empirically using questionnaire data obtained from retailers in the FCEP brander-retailer distribution channels. Analytical results reveal that as an extension of political and social power, TPPI positively affects the reciprocal interdependence of dyadic members and reduces power asymmetry, thereby enhancing the collaborative relationship of dyadic members and leading to improved green supply chain performance. Therein, reciprocal interdependence underlying collaborative relationship is the key to reducing the external environmental uncertainties in the TPPI context.

  2. Cortical spreading depolarization increases adult neurogenesis, and alters behavior and hippocampus-dependent memory in mice.

    Science.gov (United States)

    Urbach, Anja; Baum, Eileen; Braun, Falko; Witte, Otto W

    2017-05-01

    Cortical spreading depolarizations are an epiphenomenon of human brain pathologies and associated with extensive but transient changes in ion homeostasis, metabolism, and blood flow. Previously, we have shown that cortical spreading depolarization have long-lasting consequences on the brains transcriptome and structure. In particular, we found that cortical spreading depolarization stimulate hippocampal cell proliferation resulting in a sustained increase in adult neurogenesis. Since the hippocampus is responsible for explicit memory and adult-born dentate granule neurons contribute to this function, cortical spreading depolarization might influence hippocampus-dependent cognition. To address this question, we induced cortical spreading depolarization in C57Bl/6 J mice by epidural application of 1.5 mol/L KCl and evaluated neurogenesis and behavior at two, four, or six weeks thereafter. Congruent with our previous findings in rats, we found that cortical spreading depolarization increases numbers of newborn dentate granule neurons. Moreover, exploratory behavior and object location memory were consistently enhanced. Reference memory in the water maze was virtually unaffected, whereas memory formation in the Barnes maze was impaired with a delay of two weeks and facilitated after four weeks. These data show that cortical spreading depolarization produces lasting changes in psychomotor behavior and complex, delay- and task-dependent changes in spatial memory, and suggest that cortical spreading depolarization-like events affect the emotional and cognitive outcomes of associated brain pathologies.

  3. A rotational diffusion coefficient of the 70s ribosome determined by depolarized laser light scattering

    NARCIS (Netherlands)

    Bruining, J.; Fijnaut, H.M.

    We have obtained a rotational diffusion coefficient of the 70S ribosome isolated from Escherichia-coli (MRE-600), from the depolarized light scattering spectrum measured by photon correlation spectroscopy. The intensity correlation function of depolarized scattered light contains contributions due

  4. A rotational diffusion coefficient of the 70s ribosome determined by depolarized laser light scattering

    NARCIS (Netherlands)

    Bruining, J.; Fijnaut, H.M.

    1975-01-01

    We have obtained a rotational diffusion coefficient of the 70S ribosome isolated from Escherichia-coli (MRE-600), from the depolarized light scattering spectrum measured by photon correlation spectroscopy. The intensity correlation function of depolarized scattered light contains contributions due t

  5. Modulation of electromagnetic fields by a depolarizer of random polarizer array

    DEFF Research Database (Denmark)

    Ma, Ning; Hanson, Steen Grüner; Wang, Wei

    2016-01-01

    The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers with ran...

  6. On Depolarization Lidar-Based Method for The Determination of Liquid-Cloud Microphysical Properties

    Directory of Open Access Journals (Sweden)

    Roy Gilles

    2016-01-01

    Full Text Available Under single scattering conditions, water droplets clouds do not depolarize the backscattered light. However, backscattered light from multiple scattering will be depolarized. The level of depolarization is a function of the droplets size, the cloud extinction coefficient value and profile; it has also an important dependency on the lidar field-of-view (FOV. The use of depolarization information to retrieve cloud microphysical properties, using Multiple-FOV has been the object of studies, [1], [2]. Recently the use of the depolarization, at a single FOV, has been studied for cloud with linear liquid water content profiles, [3], [4]. In this paper we present the mechanism leading to depolarization and identify the FOV values for which the information on particle size is high. Also Monte Carlo simulations for cloud with constant and ramp up profiles are presented. The degree of linear depolarization as a function of cloud penetration is significantly different for both cloud profiles. This suggests that the use of the degree of linear depolarization at a single FOV should be used with caution to determine clouds micro-physical parameters.

  7. Electronic medical record data to identify variables associated with a fibromyalgia diagnosis: importance of health care resource utilization

    Directory of Open Access Journals (Sweden)

    Masters ET

    2015-03-01

    Full Text Available Elizabeth T Masters,1 Jack Mardekian,1 Birol Emir,1 Andrew Clair,1 Max Kuhn,2 Stuart L Silverman,31Pfizer, Inc., New York, NY, 2Pfizer, Inc., Groton, CT, 3Cedars-Sinai Medical Center, Los Angeles, CA, USABackground: Diagnosis of fibromyalgia (FM is often challenging. Identifying factors associated with an FM diagnosis may guide health care providers in implementing appropriate diagnostic and management strategies.Methods: This retrospective study used the de-identified Humedica electronic medical record (EMR database to identify variables associated with an FM diagnosis. Cases (n=4,296 were subjects ≥18 years old with ≥2 International Classification of Diseases, Ninth Revision (ICD-9 codes for FM (729.1 ≥30 days apart during 2012, associated with an integrated delivery network, with ≥1 encounter with a health care provider in 2011 and 2012. Controls without FM (no-FM; n=583,665 did not have the ICD-9 codes for FM. Demographic, clinical, and health care resource utilization variables were extracted from structured EMR data. Univariate analysis identified variables showing significant differences between the cohorts based on odds ratios (ORs.Results: Consistent with FM epidemiology, FM subjects were predominantly female (78.7% vs 64.5%; P<0.0001 and slightly older (mean age 53.3 vs 52.7 years; P=0.0318. Relative to the no-FM cohort, the FM cohort was characterized by a higher prevalence of nearly all evaluated comorbidities; the ORs suggested a higher likelihood of an FM diagnosis (P<0.0001, especially for musculoskeletal and neuropathic pain conditions (OR 3.1 for each condition. Variables potentially associated with an FM diagnosis included higher levels of use of specific health care resources including emergency-room visits, outpatient visits, hospitalizations, and medications. Units used per subject for emergency-room visits, outpatient visits, hospitalizations, and medications were also significantly higher in the FM cohort (P<0

  8. Effects of extracellular calcium and sodium on depolarization-induced automaticity in guinea pig papillary muscle.

    Science.gov (United States)

    Katzung, B G

    1975-07-01

    Regenerative discharge of action potentials is induced in mammalian papillary muscles by passage of small depolarizing currents. In this paper, the effects of various extracellular calcium and sodium concentrations and of tetrodotoxin on this phenomenon were studied in guinea pig papillary muscles in a sucrose gap chamber. Phase 4 diastolic depolarization was found to be associated with an increase in membrane resistance. The slope of phase 4 depolarization was decreased by reductions in extracellular calcium or sodium concentration. The range of maximum diastolic potentials and the thresholds from which regenerative potentials arose were reduced, especially at the positive limit of potentials, by a reduction in either ion. It was concluded that both calcium and sodium influence diastolic depolarization and participate in the regenerative action potentials of depolarization-induced ventricular automaticity.

  9. Modulation of electromagnetic fields by a depolarizer of random polarizer array

    DEFF Research Database (Denmark)

    Ma, Ning; Hanson, Steen Grüner; Wang, Wei

    2016-01-01

    The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers with ran......The statistical properties of the electric fields with random changes of the polarization state in space generated by a depolarizer are investigated on the basis of the coherence matrix. The depolarizer is a polarizer array composed of a multitude of contiguous square cells of polarizers...... with randomly distributed polarization angles, where the incident fields experience a random polarization modulation after passing through the depolarizer. The propagation of the modulated electric fields through any quadratic optical system is examined within the framework of the complex ABCD matrix to show...

  10. "Spreading Depolarization" bei Migräneaura und Schlaganfall im menschlichen Gehirn

    Directory of Open Access Journals (Sweden)

    Dreier JP

    2013-01-01

    Full Text Available Neuere Studien belegen eine hohe Frequenz von „Spreading Depolarizations“ bei Patienten mit aneurysmatischer Subarachnoidalblutung, verzögerter zerebraler Ischämie nach Subarachnoidalblutung, malignem ischämischem Schlaganfall, spontaner intrazerebraler Blutung und Schädel-Hirn-Trauma. „Spreading Depolarization“ führt in der grauen Substanz zum zytotoxischen Ödem. Langandauernde „Spreading Depolarizations“ leiten im Tierexperiment Kaskaden ein, die zum Zelltod führen. Therapien, die „Spreading Depolarization“ verkürzen oder die pathologische, inverse neurovaskuläre Kopplung an „Spreading Depolarization“ aufheben, könnten eine interessante Option in der Behandlung der oben genannten Erkrankungen darstellen.

  11. Spreading depolarizations have prolonged direct current shifts and are associated with poor outcome in brain trauma

    DEFF Research Database (Denmark)

    Hartings, Jed A; Watanabe, Tomas; Bullock, M Ross

    2011-01-01

    Cortical spreading depolarizations occur spontaneously after ischaemic, haemorrhagic and traumatic brain injury. Their effects vary spatially and temporally as graded phenomena, from infarction to complete recovery, and are reflected in the duration of depolarization measured by the negative direct...... current shift of electrocorticographic recordings. In the focal ischaemic penumbra, peri-infarct depolarizations have prolonged direct current shifts and cause progressive recruitment of the penumbra into the core infarct. In traumatic brain injury, the effects of spreading depolarizations are unknown......, although prolonged events have not been observed in animal models. To determine whether detrimental penumbral-type depolarizations occur in human brain trauma, we analysed electrocorticographic recordings obtained by subdural electrode-strip monitoring during intensive care. Of 53 patients studied, 10...

  12. Survey on User Satisfaction of Electronic Resources in University Libraries%高校图书馆电子资源用户满意度调查

    Institute of Scientific and Technical Information of China (English)

    陈姚竹; 马东

    2011-01-01

    通过分析影响用户对图书馆电子资源利用的因素,以美国顾客满意度指数模型为基础,提出关于各个因素的测量指标,对高校图书馆电子资源用户满意度进行测量。%Through analyzing the influencing factors on utilizing library electronic resources, based on the model of American customer satisfaction index, the paper puts forward corresponding measurement indexes, and then measures the user satisfaction on electronic resources of university library

  13. Delayed ischaemic neurological deficits after subarachnoid haemorrhage are associated with clusters of spreading depolarizations.

    Science.gov (United States)

    Dreier, Jens P; Woitzik, Johannes; Fabricius, Martin; Bhatia, Robin; Major, Sebastian; Drenckhahn, Chistoph; Lehmann, Thomas-Nicolas; Sarrafzadeh, Asita; Willumsen, Lisette; Hartings, Jed A; Sakowitz, Oliver W; Seemann, Jörg H; Thieme, Anja; Lauritzen, Martin; Strong, Anthony J

    2006-12-01

    Progressive ischaemic damage in animals is associated with spreading mass depolarizations of neurons and astrocytes, detected as spreading negative slow voltage variations. Speculation on whether spreading depolarizations occur in human ischaemic stroke has continued for the past 60 years. Therefore, we performed a prospective multicentre study assessing incidence and timing of spreading depolarizations and delayed ischaemic neurological deficit (DIND) in patients with major subarachnoid haemorrhage (SAH) requiring aneurysm surgery. Spreading depolarizations were recorded by electrocorticography with a subdural electrode strip placed on cerebral cortex for up to 10 days. A total of 2110 h recording time was analysed. The clinical state was monitored every 6 h. Delayed infarcts after SAH were verified by serial CT scans and/or MRI. Electrocorticography revealed 298 spreading depolarizations in 13 of the 18 patients (72%). A clinical DIND was observed in seven patients 7.8 days (7.3, 8.2) after SAH. DIND was time-locked to a sequence of recurrent spreading depolarizations in every single case (positive and negative predictive values: 86 and 100%, respectively). In four patients delayed infarcts developed in the recording area. As in the ischaemic penumbra of animals, delayed infarction was preceded by progressive prolongation of the electrocorticographic depression periods associated with spreading depolarizations to >60 min in each case. This study demonstrates that spreading depolarizations have a high incidence in major SAH and occur in ischaemic stroke. Repeated spreading depolarizations with prolonged depression periods are an early indicator of delayed ischaemic brain damage after SAH. In view of experimental evidence and the present clinical results, we suggest that spreading depolarizations with prolonged depressions are a promising target for treatment development in SAH and ischaemic stroke.

  14. Development of an electronic medical record based alert for risk of HIV treatment failure in a low-resource setting.

    Directory of Open Access Journals (Sweden)

    Nancy Puttkammer

    Full Text Available BACKGROUND: The adoption of electronic medical record systems in resource-limited settings can help clinicians monitor patients' adherence to HIV antiretroviral therapy (ART and identify patients at risk of future ART failure, allowing resources to be targeted to those most at risk. METHODS: Among adult patients enrolled on ART from 2005-2013 at two large, public-sector hospitals in Haiti, ART failure was assessed after 6-12 months on treatment, based on the World Health Organization's immunologic and clinical criteria. We identified models for predicting ART failure based on ART adherence measures and other patient characteristics. We assessed performance of candidate models using area under the receiver operating curve, and validated results using a randomly-split data sample. The selected prediction model was used to generate a risk score, and its ability to differentiate ART failure risk over a 42-month follow-up period was tested using stratified Kaplan Meier survival curves. RESULTS: Among 923 patients with CD4 results available during the period 6-12 months after ART initiation, 196 (21.2% met ART failure criteria. The pharmacy-based proportion of days covered (PDC measure performed best among five possible ART adherence measures at predicting ART failure. Average PDC during the first 6 months on ART was 79.0% among cases of ART failure and 88.6% among cases of non-failure (p<0.01. When additional information including sex, baseline CD4, and duration of enrollment in HIV care prior to ART initiation were added to PDC, the risk score differentiated between those who did and did not meet failure criteria over 42 months following ART initiation. CONCLUSIONS: Pharmacy data are most useful for new ART adherence alerts within iSanté. Such alerts offer potential to help clinicians identify patients at high risk of ART failure so that they can be targeted with adherence support interventions, before ART failure occurs.

  15. Depolarizing Effects of Daikenchuto on Interstitial Cells of Cajal from Mouse Small Intestine

    Science.gov (United States)

    Kim, Hyungwoo; Kim, Hyun Jung; Yang, Dongki; Jung, Myeong Ho; Kim, Byung Joo

    2017-01-01

    Background: Daikenchuto (DKT; TJ-100, TU-100), a traditional herbal medicineis used in modern medicine to treat gastrointestinal (GI) functional disorders. Interstitial cells of Cajal (ICCs) are the pacemaker cells of the GI tract and play important roles in the regulation of GI motility. Objective: The objective of this study was to investigate the effects of DKT on the pacemaker potentials (PPs) of cultured ICCs from murine small intestine. Materials and Methods: Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues. All experiments on ICCs were performed after 12 h of culture. The whole-cell patch-clamp configuration was used to record ICC PPs (current clamp mode). All experiments were performed at 30-32°C. Results: In current-clamp modeDKT depolarized and concentration-dependently decreased the amplitudes of PPs. Y25130 (a 5-HT3 receptor antagonist) or SB269970 (a 5-HT7 receptor antagonist) did not block DKT-induced PP depolarization, but RS39604 (a 5-HT4 receptor antagonist) did. Methoctramine (a muscarinic M2 receptor antagonist) failed to block DKT-induced PP depolarization, but pretreating 4-diphenylacetoxy-N-methylpiperidine methiodide (a muscarinic M3 receptor antagonist) facilitated blockade of DKT-induced PP depolarization. Pretreatment with an external Ca2+-free solution or thapsigargin abolished PPsand under these conditions, DKT did not induce PP depolarization. Furthermore Ginseng radix and Zingiberis rhizomes depolarized PPs, whereas Zanthoxyli fructus fruit (the third component of DKT) hyperpolarized PPs. Conclusion: These results suggest that DKT depolarizes ICC PPs in an internal or external Ca2+-dependent manner by stimulating 5-HT4 and M3 receptors. Furthermore, the authors suspect that the component in DKT largely responsible for depolarization is probably also a component of Ginseng radix and Zingiberis rhizomes. SUMMARY Daikenchuto (DKT) depolarized and concentration-dependently decreased the amplitudes of

  16. Thermally stimulated depolarization current studies of sulfonated polystyrene ionomers

    Science.gov (United States)

    Carvalho, Antonio José Felix; Viana, Vicente Galber Freitas; Faria, Roberto Mendonça

    2009-12-01

    A detailed study of thermally stimulated depolarization current (TSDC) was carried out to investigate dipolar relaxation and the charge storage phenomenon in films of sulfonated polystyrene (SPS) ionomers having lithium or potassium as counterions. Differential scanning calorimetry measurements were also applied as a complementary technique, mainly to follow the change of the glass transition temperature with the amount of sulfonated groups. It was observed that, since the glass transition does not change significantly with the amount of sulfonated groups, a cluster of multiplets is expected not to be formed in the range used in this work. TSDC of SPS samples polarized at temperatures higher than the glass transition temperature showed three peaks: one at lower temperature (peak β), an intermediate peak (peak α), and a third that appeared at a temperature coincident with the polarization temperature (peak ρ). Quantitative information about trapping-detrapping and dipolar relaxation and their corresponding activation energies was determined by fittings of the deconvoluted peaks with kinetic relaxation processes.

  17. Thermally stimulated depolarization current studies of sulfonated polystyrene ionomers

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Antonio Jose Felix [Universidade Federal de Sao Carlos, Laboratory of Polymers and Renewable Materials, Sorocaba, SP (Brazil); Viana, Vicente Galber Freitas [Universidade Federal do Piaui, Centro de Ciencias da Natureza, Teresina, PI (Brazil); Faria, Roberto Mendonca [USP, Instituto de Fisica de Sao Carlos, SP (Brazil)

    2009-12-15

    A detailed study of thermally stimulated depolarization current (TSDC) was carried out to investigate dipolar relaxation and the charge storage phenomenon in films of sulfonated polystyrene (SPS) ionomers having lithium or potassium as counterions. Differential scanning calorimetry measurements were also applied as a complementary technique, mainly to follow the change of the glass transition temperature with the amount of sulfonated groups. It was observed that, since the glass transition does not change significantly with the amount of sulfonated groups, a cluster of multiplets is expected not to be formed in the range used in this work. TSDC of SPS samples polarized at temperatures higher than the glass transition temperature showed three peaks: one at lower temperature (peak {beta}), an intermediate peak (peak {alpha}), and a third that appeared at a temperature coincident with the polarization temperature (peak {rho}). Quantitative information about trapping-detrapping and dipolar relaxation and their corresponding activation energies was determined by fittings of the deconvoluted peaks with kinetic relaxation processes. (orig.)

  18. Recording, analysis, and interpretation of spreading depolarizations in neurointensive care : Review and recommendations of the COSBID research group

    NARCIS (Netherlands)

    Dreier, Jens P; Fabricius, Martin; Ayata, Cenk; Sakowitz, Oliver W; William Shuttleworth, C; Dohmen, Christian; Graf, Rudolf; Vajkoczy, Peter; Helbok, Raimund; Suzuki, Michiyasu; Schiefecker, Alois J; Major, Sebastian; Winkler, Maren Kl; Kang, Eun-Jeung; Milakara, Denny; Oliveira-Ferreira, Ana I; Reiffurth, Clemens; Revankar, Gajanan S; Sugimoto, Kazutaka; Dengler, Nora F; Hecht, Nils; Foreman, Brandon; Feyen, Bart; Kondziella, Daniel; Friberg, Christian K; Piilgaard, Henning; Rosenthal, Eric S; Westover, M Brandon; Maslarova, Anna; Santos, Edgar; Hertle, Daniel; Sánchez-Porras, Renán; Jewell, Sharon L; Balança, Baptiste; Platz, Johannes; Hinzman, Jason M; Lückl, Janos; Schoknecht, Karl; Schöll, Michael; Drenckhahn, Christoph; Feuerstein, Delphine; Eriksen, Nina; Horst, Viktor; Bretz, Julia S; Jahnke, Paul; Scheel, Michael; Bohner, Georg; Rostrup, Egill; Pakkenberg, Bente; Heinemann, Uwe; Claassen, Jan; Carlson, Andrew P; Kowoll, Christina M; Lublinsky, Svetlana; Chassidim, Yoash; Shelef, Ilan; Friedman, Alon; Brinker, Gerrit; Reiner, Michael; Kirov, Sergei A; Andrew, R David; Farkas, Eszter; Güresir, Erdem; Vatter, Hartmut; Chung, Lee S; Brennan, K C; Lieutaud, Thomas; Marinesco, Stephane; Maas, Andrew Ir; Sahuquillo, Juan; Dahlem, Markus A; Richter, Frank; Herreras, Oscar; Boutelle, Martyn G; Okonkwo, David O; Bullock, M Ross; Witte, Otto W; Martus, Peter; van den Maagdenberg, Arn Mjm; Ferrari, Michel D; Dijkhuizen, Rick M; Shutter, Lori A; Andaluz, Norberto; Schulte, André P; MacVicar, Brian; Watanabe, Tomas; Woitzik, Johannes; Lauritzen, Martin; Strong, Anthony J; Hartings, Jed A

    2017-01-01

    Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly

  19. Low temperature dielectric relaxation of poly (L-lactic acid) (PLLA) by Thermally Stimulated Depolarization Current

    Science.gov (United States)

    Mishra Patidar, Manju; Jain, Deepti; Nath, R.; Ganesan, V.

    2016-10-01

    Poly (L-lactic acid) (PLLA) is a biodegradable and biocompatible polyester that can be produced by renewable resources, like corn. Being non-toxic to human body, PLLA is used in biomedical applications, like surgical sutures, bone fixation devices, or controlled drug delivery. Besides its application studies, very few experiments have been done to study its dielectric relaxation in the low temperature region. Keeping this in mind we have performed a low temperature thermally stimulated depolarization current (TSDC) studies over the temperature range of 80K-400K to understand the relaxation phenomena of PLLA. We could observe a multi modal broad relaxation of small but significant intensity at low temperatures while a sharp and high intense peak around glass transition temperature, Tg∼ 333K, of PLLA has appeared. The fine structure of the low temperature TSDC peak may be attributed to the spherulites formation of crystallite regions inter twinned with the polymer as seen in AFM and appear to be produced due to an isothermal crystallization process. XRD analysis also confirms the semicrystalline nature of the PLLA film.

  20. The BRIGHTEN Program: Implementation and Evaluation of a Program to Bridge Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking

    Science.gov (United States)

    Emery, Erin E.; Lapidos, Stan; Eisenstein, Amy R.; Ivan, Iulia I.; Golden, Robyn L.

    2012-01-01

    Purpose: To demonstrate the feasibility of the BRIGHTEN Program (Bridging Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking), an interdisciplinary team intervention for assessing and treating older adults for depression in outpatient primary and specialty medical clinics. The BRIGHTEN team collaborates "virtually"…

  1. The module of methodical support in system of electronic educational resources as the innovative element of the modern maintenance of formation

    Directory of Open Access Journals (Sweden)

    Ольга Николаевна Крылова

    2009-06-01

    Full Text Available The article introduces some results of research, which were devoted to evaluation of tearches' mobility to introduce innovations in the contents of education. The author considers innovative potential of modules of the methodical support for system of electronic educational resources.

  2. Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

    Science.gov (United States)

    Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

    2013-01-01

    In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

  3. The BRIGHTEN Program: Implementation and Evaluation of a Program to Bridge Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking

    Science.gov (United States)

    Emery, Erin E.; Lapidos, Stan; Eisenstein, Amy R.; Ivan, Iulia I.; Golden, Robyn L.

    2012-01-01

    Purpose: To demonstrate the feasibility of the BRIGHTEN Program (Bridging Resources of an Interdisciplinary Geriatric Health Team via Electronic Networking), an interdisciplinary team intervention for assessing and treating older adults for depression in outpatient primary and specialty medical clinics. The BRIGHTEN team collaborates "virtually"…

  4. Electronic Information Resources (EIR Adoption in Private University Libraries: The Moderating Effect of Productivity and Relative Advantage on Perceived Usefulness

    Directory of Open Access Journals (Sweden)

    Izuagbe, Roland

    2016-03-01

    Full Text Available The study tested a hybrid model with constructs drawn from the Technology Acceptance Model (TAM and Diffusion of Innovation (DOI theory in order to examine the moderating effect of productivity and relative advantage (RA on perceived usefulness (PU vis-à-vis electronic information resources (EIR adoption in private university libraries in Ogun and Osun States of Nigeria. The descriptive research design was adopted in the study. The population consisted of 61 (55.0% librarians and 50 (45.0% library officers (totaling 116—100% in Babcock University, Bells University, Covenant University, Bowen University, Oduduwa University, and Redeemer's University. Purposive sampling procedure was adopted after which total enumeration was used since the total population is small. The questionnaire was used for data collection. Of the 116 copies of the questionnaire administered, 111 (95.7% were found usable. The instrument was structured based on a 4-point Likert agreement scale of Strongly Agree, Agree, Disagree, and Strongly Disagree. Data were analyzed using descriptive statistics like tables of frequency counts and percentage. The findings revealed that productivity and relative advantage are significant moderators of perceived usefulness of EIR adoption in private university libraries in Ogun and Osun States, Nigeria.

  5. Characterization of homogenous depolarizing media based on Mueller matrix differential decomposition.

    Science.gov (United States)

    Arteaga, Oriol; Kahr, Bart

    2013-04-01

    In a depolarizing medium in which the optical properties are uniformly distributed, the logarithm of the Mueller matrix can be used to calculate the differential Mueller matrix. From the differential Mueller matrix, the 10 optical properties of a homogeneous depolarizing medium are recovered. A modified calculation is introduced for media showing small time-irreversal depolarization events. The benefits of this method are illustrated in the determination of circular dichroism and circular birefringence of a nickel sulfate hexahydrate crystal from spectroscopic Mueller matrix measurements.

  6. Statistical meaning of the differential Mueller matrix of depolarizing homogeneous media.

    Science.gov (United States)

    Ossikovski, Razvigor; Arteaga, Oriol

    2014-08-01

    By applying the statistical definition of a depolarizing Mueller matrix we formally derive and physically interpret the differential matrix of a depolarizing homogeneous medium. The depolarization phenomenon being a direct consequence of the fluctuations of the six elementary polarization properties of the medium, the differential matrix contains the mean values and the variances of the properties, thus fully describing those from a statistical viewpoint. Similarly, the reduced coherency matrix associated with the G-symmetric component of the differential matrix has an immediate physical interpretation as being the covariance matrix of the three basic groups of polarization properties. The formal developments are illustrated on experimental examples.

  7. Coherence and polarization speckle generated by a rough-surfaced retardation plate depolarizer

    DEFF Research Database (Denmark)

    Ma, Ning; Hanson, Steen Grüner; Takeda, Mitsuo

    2015-01-01

    The coherence and polarization of polarization speckle, arising from a stochastic electromagnetic field with random change of polarization, modulated by a depolarizer are examined on the basis of the coherence matrix. The depolarizer is a rough-surfaced retardation plate with a random function...... of position introducing random phase differences between the two orthogonal components of the electric vector. Under the assumption of Gaussian statistics with zero mean, the surface model for the depolarizer of the rough-surfaced retardation plate is obtained. The propagation of the modulated fields through...

  8. Study of Depolarization Field Influence on Ferroelectric Films Within Transverse Ising Model

    Institute of Scientific and Technical Information of China (English)

    TAO Yong-Mei; SHI Qin-Fen; JIANG Qing

    2005-01-01

    An improved transverse Ising model is proposed by taking the depolarization field effect into account.Within the framework of mean-field theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg-Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.

  9. Redox-active nanoceria depolarize mitochondrial membrane of human colon cancer cells

    Science.gov (United States)

    Jana, Saikat Kumar; Banerjee, Priyanka; Das, Soumen; Seal, Sudipta; Chaudhury, Koel

    2014-06-01

    Nanotherapeutics is emerging as a promising option to the various limitations and side effects associated with conventional chemotherapy. The present study investigates the cytotoxic effect of redox-active cerium oxide nanoparticles (nanoceria) on human colorectal adenocarcinoma-derived cell line (HCT 15). Exposure of these cells to nanoceria for 24 h with concentration ranging between 10 and 100 μM resulted in a significant reduction of cell viability in a dose-dependent manner. Further, at a concentration of 10 µM, nanoceria exhibited time-dependent cytotoxic effect when exposed to the cells for 24, 48, and 72 h. Upon treatment of the cells with nanoceria, reactive oxygen species (ROS) and lipid peroxidation which are indicators of oxidative stress and cytotoxicity increased significantly, in a dose-dependent manner. Nanoceria was also found to depolarize the mitochondrial membrane, thereby collapsing the membrane potential and leading to initiation of apoptosis. Scanning electron microscopic study of nanoceria-treated HCT 15 cells showed morphological changes and loss of filopodia and lamellipodia, indicating arrest of metastatic spread. Summarizing, when cultured HCT 15 cells are exposed to nanoceria, a dose-dependent cytotoxic effect mediated by ROS generation is observed.

  10. Light depolarization induced by metallic tips in apertureless near-field optical microscopy and tip-enhanced Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gucciardi, P G [CNR-Istituto per i Processi Chimico-Fisici, sezione Messina, Salita Sperone, Contrada Papardo, I-98158 Faro Superiore, Messina (Italy); Lopes, M; Deturche, R; Julien, C; Barchiesi, D; Chapelle, M Lamy de la [Institut Charles Delaunay-CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de Technologie de Troyes, 12 rue Marie Curie, BP2060, 10010 Troyes (France)

    2008-05-28

    We have investigated the depolarization effects of light scattered by sharp tips used for apertureless near-field optical microscopy. Dielectric and metal coated tips have been investigated and depolarization factors between 5 and 30% have been measured, changing as a function of the incident light polarization and of the tip shape. The experimental results are in good agreement with theoretical calculations performed by the finite element method, giving a near-field depolarization factor close to 10%. The effect of depolarization has been investigated in polarized tip-enhanced Raman spectroscopy (TERS) experiments; the depolarization gives rise to forbidden Raman modes in Si crystals.

  11. Aerosol Properties over Southeastern China from Multi-Wavelength Raman and Depolarization Lidar Measurements

    Directory of Open Access Journals (Sweden)

    Heese Birgit

    2016-01-01

    Full Text Available A dataset of particle optical properties of highly polluted urban aerosol over the Pearl River Delta, Guangzhou, China is presented. The data were derived from multi-wavelengths Raman and depolarization lidar PollyXT and AERONET sun photometer measurements. The measurement campaign was conducted from Nov 2011 to June 2012. High aerosol optical depth was observed in the polluted atmosphere over this megacity, with a mean value of 0.54 ± 0.33 and a peak value of even 1.9. For the particle characterization the lidar ratio and the linear particle depolarization ratio, both at 532 nm, were used. The mean values of these properties are 48.0 sr ± 10.7 sr for the lidar ratio and 4%+-4% for the particle depolarization ratio, which means most depolarization measurements stayed below 10%. So far, most of these results indicate urban pollution particles mixed with particles arisen from biomass and industrial burning.

  12. Aerosol Properties over Southeastern China from Multi-Wavelength Raman and Depolarization Lidar Measurements

    Science.gov (United States)

    Heese, Birgit; Althausen, Dietrich; Baars, Holger; Bohlmann, Stephanie; Deng, Ruru

    2016-06-01

    A dataset of particle optical properties of highly polluted urban aerosol over the Pearl River Delta, Guangzhou, China is presented. The data were derived from multi-wavelengths Raman and depolarization lidar PollyXT and AERONET sun photometer measurements. The measurement campaign was conducted from Nov 2011 to June 2012. High aerosol optical depth was observed in the polluted atmosphere over this megacity, with a mean value of 0.54 ± 0.33 and a peak value of even 1.9. For the particle characterization the lidar ratio and the linear particle depolarization ratio, both at 532 nm, were used. The mean values of these properties are 48.0 sr ± 10.7 sr for the lidar ratio and 4%+-4% for the particle depolarization ratio, which means most depolarization measurements stayed below 10%. So far, most of these results indicate urban pollution particles mixed with particles arisen from biomass and industrial burning.

  13. Depolarization properties of cirrus clouds from polarization lidar measurements over Hefei in spring

    Institute of Scientific and Technical Information of China (English)

    Zhenzhu Wang; Ruli Chi; Bo Liu; Jun Zhou

    2008-01-01

    @@ A new polarization lidar has been developed for detecting depolarization characteristics of aerosol and cirrus over Hefei (31.90°N, 117.16°E), China. The fundamental principle of polarization lidar is briefly introduced.

  14. Preliminary evidence that ketamine inhibits spreading depolarizations in acute human brain injury

    DEFF Research Database (Denmark)

    Sakowitz, Oliver W; Kiening, Karl L; Krajewski, Kara L

    2009-01-01

    by the noncompetitive N-methyl-d-aspartate receptor antagonist ketamine. This restored electrocorticographic activity. CONCLUSIONS: These anecdotal electrocorticographic findings suggest that ketamine has an inhibitory effect on spreading depolarizations in humans. This is of potential interest for future...

  15. Detection of spreading depolarization with intraparenchymal electrodes in the injured human brain

    DEFF Research Database (Denmark)

    Jeffcote, Toby; Hinzman, Jason M; Jewell, Sharon L

    2014-01-01

    BACKGROUND: Spreading depolarization events following ischemic and traumatic brain injury are associated with poor patient outcome. Currently, monitoring these events is limited to patients in whom subdural electrodes can be placed at open craniotomy. This study examined whether these events can ...... for craniotomy. The method provides a new investigative tool for the evaluation of the contribution of these events to secondary brain injury in human patients.......BACKGROUND: Spreading depolarization events following ischemic and traumatic brain injury are associated with poor patient outcome. Currently, monitoring these events is limited to patients in whom subdural electrodes can be placed at open craniotomy. This study examined whether these events can...... for traumatic brain injury or aneurysmal subarachnoid hemorrhage were monitored for depolarization events in an intensive care setting with concurrent strip (subdural) and depth (intra-parenchymal) electrode recordings. RESULTS: (1) Depolarization events can be reliably detected from intra-cortically placed...

  16. A unified numerical model of collisional depolarization and broadening rates due to hydrogen atom collisions

    CERN Document Server

    Derouich, M; Barklem, P S

    2015-01-01

    Interpretation of solar polarization spectra accounting for partial or complete frequency redistribution requires data on various collisional processes. Data for depolarization and polarization transfer are needed but often missing, while data for collisional broadening are usually more readily available. Recent work by Sahal-Br\\'echot and Bommier concluded that despite underlying similarities in the physics of collisional broadening and depolarization processes, relationships between them are not possible to derive purely analytically. We aim to derive accurate numerical relationships between the collisional broadening rates and the collisional depolarization and polarization transfer rates due to hydrogen atom collisions. Such relationships would enable accurate and efficient estimation of collisional data for solar applications. Using earlier results for broadening and depolarization processes based on general (i.e. not specific to a given atom), semi-classical calculations employing interaction potentials...

  17. Sensitivity of laser light depolarization analysis for detection of malaria in blood samples.

    Science.gov (United States)

    Padial, Manuel Martínez; Subirats, Mercedes; Puente, Sabino; Lago, Mar; Crespo, Santiago; Palacios, Gonzalo; Baquero, Margarita

    2005-05-01

    Automated light depolarization analysis could be a useful tool for diagnosing malarial infections. This work discusses the results of a diagnostic efficacy study on 411 samples from patients with suspected malaria infection performed with a Cell-Dyn 4000 analyser. Light dispersed at 90 degrees and depolarized can be used for identifying and counting eosinophils. However, other cell populations with depolarizing capacity occur in malarial samples; these result from leukocytes ingesting haemozoin that is derived from the degradation of the haem group of haemoglobin performed by the parasite. A sensitivity of 72 % and specificity of 98 % were recorded, with positive and negative predictive values of 78 % and 97 %, respectively. Although the sensitivity level of the automated light depolarization analysis is not adequate to replace the existing methods for the diagnosis of parasitic diseases, it could alert clinicians to unsuspected infections by parasites, particularly those from the genus Plasmodium.

  18. Efficient depolarization-loss-compensation of solid state lasers using only a Glan-Taylor polarizer

    Science.gov (United States)

    Mondal, S.; Singh, S. P.; Hussain, K.; Choubey, A.; Upadhyay, B. N.; Datta, P. K.

    2013-02-01

    A novel scheme for reducing the depolarization loss resulting from thermally induced stress birefringence of a free running flash-lamp pumped single Nd: YAG rod is reported here and measured under resonator configuration with the use of a Glan-Taylor polarizer only. The depolarization loss has been systematically investigated and compared with the quarter wave-plate scheme. The Glan-Taylor polarizer is given two rotations with respect to two perpendicular axes for obtaining Brewster's effect as well as phase retardation inside a stable resonator. This single optical element optimally reduces depolarization loss to ˜18% and performs better than quarter wave-plate in combination with a polarizer. Using Jones-vector formulation, we analyzed the effect of tilting of Glan-Taylor polarizer and accounted the measured data of depolarization loss.

  19. Isomerization and fluorescence depolarization of merocyanine 540 in polyacrylic acid. Effect of H

    Indian Academy of Sciences (India)

    Dipankar Sukul; Sobhan Sen; Partha Dutta; Kankan Bhattacharyya

    2002-10-01

    Dynamics of isomerization and fluorescence depolarization of merocyanine 540 (MC540) in an aqueous solution of polyacrylic acid (PAA) have been studied using picosecond time resolved fluorescence spectroscopy. It is observed that the dynamics of isomerization and depolarization are sensitive enough to monitor the uncoiling of PAA at high H (> 6). At low H (< 3), when the polymer remains in a hypercoiled form, polymer bound MC540 experiences very high microscopic friction and, hence, the isomerization and depolarization processes are very slow. At high H (> 6) a polyanion is formed and the polymer assumes an extended configuration due to electrostatic repulsion. At high H (> 6), the anionic probe MC540 is expelled from the polyanion to bulk water and the dynamics of isomerization and fluorescence depolarization become faster by 12 and 5 times respectively, compared to those at low H.

  20. Recurrent Spontaneous Spreading Depolarizations Facilitate Acute Dendritic Injury in the Ischemic Penumbra

    OpenAIRE

    Risher, W Christopher; Ard, Deborah; Yuan, Jianghe; Kirov, Sergei A.

    2010-01-01

    Spontaneous spreading depolarizations (SDs) occur in the penumbra surrounding ischemic core. These SDs, often referred to as peri-infarct depolarizations, cause vasoconstriction and recruitment of the penumbra into the ischemic core in the critical first hours after focal ischemic stroke; however, the real-time spatiotemporal dynamics of SD-induced injury to synaptic circuitry in the penumbra remain unknown. A modified cortical photothrombosis model was used to produce a square-shaped lesion ...

  1. Three-Signal Method for Accurate Measurements of Depolarization Ratio with Lidar

    Science.gov (United States)

    Reichardt, Jens; Baumgart, Rudolf; McGee, Thomsa J.

    2003-01-01

    A method is presented that permits the determination of atmospheric depolarization-ratio profiles from three elastic-backscatter lidar signals with different sensitivity to the state of polarization of the backscattered light. The three-signal method is insensitive to experimental errors and does not require calibration of the measurement, which could cause large systematic uncertainties of the results, as is the case in the lidar technique conventionally used for the observation of depolarization ratios.

  2. On the Use of Radar Depolarization Ratios for Estimating Shapes of Ice Hydrometeors in Winter Clouds.

    Science.gov (United States)

    Matrosov, Sergey Y.; Reinking, Roger F.; Kropfli, Robert A.; Martner, Brooks E.; Bartram, B. W.

    2001-03-01

    An approach is suggested to relate measurements of radar depolarization ratios and aspect ratios of predominant hydrometeors in nonprecipitating and weakly precipitating layers of winter clouds. The trends of elevation angle dependencies of depolarization ratios are first used to distinguish between columnar-type and plate-type particles. For the established particle type, values of depolarization ratios observed at certain elevation angles, for which the influence of particle orientation is minimal, are then used to estimate aspect ratios when information on particle effective bulk density is assumed or inferred from other measurements. The use of different polarizations, including circular, slant-45° linear, and two elliptical polarizations, is discussed. These two elliptical polarizations are quasi-circular and quasi-linear slant-45° linear, and both are currently achievable with the National Oceanic and Atmospheric Administration Environmental Technology Laboratory's Ka-band radar. In comparison with the true circular and slant-45° linear polarizations, the discussed elliptical polarizations provide a stronger signal in the `weak' radar receiver channel; however, it is at the expense of diminished dynamic range of depolarization ratio variations. For depolarization measurements at the radar elevation angles that do not show much sensitivity to particle orientations, the available quasi-circular polarization provides a better depolarization contrast between nonspherical and spherical particles than does the available quasi-linear slant-45°polarization. The use of the proposed approach is illustrated with the experimental data collected during a recent field experiment. It is shown that it allows successful differentiation among pristine planar crystals, rimed planar crystals, long columns, blocky columns, and graupel. When a reasonable assumption about particle bulk density is made, quantitative estimates of particle aspect ratios from radar depolarization

  3. Dibucaine mitigates spreading depolarization in human neocortical slices and prevents acute dendritic injury in the ischemic rodent neocortex.

    Directory of Open Access Journals (Sweden)

    W Christopher Risher

    Full Text Available Spreading depolarizations that occur in patients with malignant stroke, subarachnoid/intracranial hemorrhage, and traumatic brain injury are known to facilitate neuronal damage in metabolically compromised brain tissue. The dramatic failure of brain ion homeostasis caused by propagating spreading depolarizations results in neuronal and astroglial swelling. In essence, swelling is the initial response and a sign of the acute neuronal injury that follows if energy deprivation is maintained. Choosing spreading depolarizations as a target for therapeutic intervention, we have used human brain slices and in vivo real-time two-photon laser scanning microscopy in the mouse neocortex to study potentially useful therapeutics against spreading depolarization-induced injury.We have shown that anoxic or terminal depolarization, a spreading depolarization wave ignited in the ischemic core where neurons cannot repolarize, can be evoked in human slices from pediatric brains during simulated ischemia induced by oxygen/glucose deprivation or by exposure to ouabain. Changes in light transmittance (LT tracked terminal depolarization in time and space. Though spreading depolarizations are notoriously difficult to block, terminal depolarization onset was delayed by dibucaine, a local amide anesthetic and sodium channel blocker. Remarkably, the occurrence of ouabain-induced terminal depolarization was delayed at a concentration of 1 µM that preserves synaptic function. Moreover, in vivo two-photon imaging in the penumbra revealed that, though spreading depolarizations did still occur, spreading depolarization-induced dendritic injury was inhibited by dibucaine administered intravenously at 2.5 mg/kg in a mouse stroke model.Dibucaine mitigated the effects of spreading depolarization at a concentration that could be well-tolerated therapeutically. Hence, dibucaine is a promising candidate to protect the brain from ischemic injury with an approach that does not rely on

  4. A Study on the Model for Resources Matching of Electronic Bartering%电子易货资源匹配模型研究

    Institute of Scientific and Technical Information of China (English)

    吴剑云; 张嵩

    2012-01-01

    By exchanging idle goods and services, electronic bartering can help enterprises solve dull sale problems, shortage of funds, overstocks and other problems without sufficient cash. Relying on the Internet and the e-commerce platform, electronic bartering removes the traditional bartering limitations, greatly expands the trading object and range, improves the transaction efficiency, and provides additional channels for economic development. How to promote more successful barters among multiple barterers? A key factor is the matching of barter resources. Focusing on the automatic matching of resources in the electronic barter, this paper proposes a network model to help maximize resources matching and provide recommendation information for barter participants, thereby raising the transaction rate and making the barter market prosperous.According to the type and quantity of barter resources, barter market can be divided into two types. In the first type, the supply and demand of the barter market is related to the same type of resources and each barterer owns only one type of resource. In the second type, the supply and demand of the barter market is linked to many types of resources and each barterer owns multiple resources to be exchanged. The first case has been resolved in the relevant document by using the graph theory to solve digraph circuits. This paper is interested in studying the second type of barter. Suppose the barter market has m barterers and n resources. Each barterer owns diverse types of barter resources, and is interested in other types of resources. The barterer a will provide other barterers his own resources only if he gets the resources he needs from the barterer b. Note that each of the bartered resource is regarded as having equal value to any other resources. The main objective is to maximize the number of resources that are bartered.Next, this paper proposes a math model of automatic resources matching by systematically analyzing resource

  5. The Use and Maintenance of University Library Electronic Resources%浅议大学图书馆电子资源的利用与维护

    Institute of Scientific and Technical Information of China (English)

    马鹏飞; 熊豫玲

    2011-01-01

    随着科学技术的飞速发展,高新信息技术的广泛应用,大学图书馆的工作内容和方法也面临新的挑战,为了使用户更好的利用大学图书馆的电子资源,提高电子资源利用率,实现大学图书馆数字化,本文主要从电子资源的利用和维护方面进行探讨。%With the rapid development of science and technology,the extensive application of high-tech information technology, University of content and methods of library work is also facing new challenges in order to make better use of university library users to electronic resources,improve the utilization of electronic resources to achieve the University Library digital,paper, from the use of electronic resources and maintenance were discussed.

  6. Barriers to electronic access and delivery of educational information in resource constrained public schools: a case of Greater Tubatse Municipality

    CSIR Research Space (South Africa)

    Pholotho, T

    2016-05-01

    Full Text Available Information and Communication Technologies (ICTs) are capable of expanding access to quality education, educational resources and provide teachers with new skills. Nevertheless, a majority of rural public schools have limited ICTs, mainly due...

  7. Electronic Grey Literature in Accelerator Science and Its Allied Subjects : Selected Web Resources for Scientists and Engineers

    CERN Document Server

    Rajendiran, P

    2006-01-01

    Grey literature Web resources in the field of accelerator science and its allied subjects are collected for the scientists and engineers of RRCAT (Raja Ramanna Centre for Advanced Technology). For definition purposes the different types of grey literature are described. The Web resources collected and compiled in this article (with an overview and link for each) specifically focus on technical reports, preprints or e-prints, which meet the main information needs of RRCAT users.

  8. Mechanism of blue-light-induced plasma-membrane depolarization in etiolated cucumber hypocotyls

    Science.gov (United States)

    Spalding, E. P.; Cosgrove, D. J.

    1992-01-01

    A large, transient depolarization of the plasma membrane precedes the rapid blue-light (BL)-induced growth suppression in etiolated seedlings of Cucumis sativus L. The mechanism of this voltage transient was investigated by applying inhibitors of ion channels and the plasma-membrane H(+)-ATPase, by manipulating extracellular ion concentrations, and by measuring cell input resistance and ATP levels. The depolarizing phase was not affected by Ca(2+)-channel blockers (verapamil, La3+) or by reducing extracellular free Ca2+ by treatment with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA). However, these treatments did reduce the rate of repolarization, indicating an inward movement of Ca2+ is involved. No effects of the K(+)-channel blocker tetraethylammonium (TEA+) were detected. Vanadate and KCN, used to inhibit the H(+)-ATPase, reduced or completely inhibited the BL-induced depolarization. Levels of ATP increased by 11-26% after 1-2 min of BL. Input resistance of trichrome cells, measured with double-barreled microelectrodes, remained constant during the onset of the depolarization but decreased as the membrane voltage became more positive than -90 mV. The results indicate that the depolarization mechanism initially involves inactivation of the H(+)-ATPase with subsequent transient activation of one or more types of ion channels.

  9. 电子资源许可使用的发展与创新%The Development and Innovation of the Use of the Electronic Resource License

    Institute of Scientific and Technical Information of China (English)

    王军

    2012-01-01

      电子资源许可使用在我国发展时间较短,在其建立过程中还存在许可定价、购买模式、馆际互借以及电子资源的长期保存许可方式等难题。电子资源许可使用的发展与创新,需要根据用户需求制定发展战略,建立图书馆的读者监督管理制度和数字化资源服务制度,规范文献编目制度等,以提高电子信息资源与图书馆信息资源的使用效果和广泛的使用需求%  It's been a short time since the use of electronic resource licenses has developed in China; in addition, many problems ap-pear in the establishment process in terms of license pricing, purchase pattern, inter-library loan and long-term preservation ways of electronic resources. In order to develop and innovate the use of the license, libraries should develop strategies in accordance with the users' needs, establish a reader supervision system and a digital resource service system, and normalize the document cataloging sys-tem to enhance the utilization effect and meet the extensive demand for electronic and library information resources.

  10. GABA depolarizes immature neurons and inhibits network activity in the neonatal neocortex in vivo.

    Science.gov (United States)

    Kirmse, Knut; Kummer, Michael; Kovalchuk, Yury; Witte, Otto W; Garaschuk, Olga; Holthoff, Knut

    2015-07-16

    A large body of evidence from in vitro studies suggests that GABA is depolarizing during early postnatal development. However, the mode of GABA action in the intact developing brain is unknown. Here we examine the in vivo effects of GABA in cells of the upper cortical plate using a combination of electrophysiological and Ca(2+)-imaging techniques. We report that at postnatal days (P) 3-4, GABA depolarizes the majority of immature neurons in the occipital cortex of anaesthetized mice. At the same time, GABA does not efficiently activate voltage-gated Ca(2+) channels and fails to induce action potential firing. Blocking GABA(A) receptors disinhibits spontaneous network activity, whereas allosteric activation of GABA(A) receptors has the opposite effect. In summary, our data provide evidence that in vivo GABA acts as a depolarizing neurotransmitter imposing an inhibitory control on network activity in the neonatal (P3-4) neocortex.

  11. Assessment of lidar depolarization uncertainty by means of a polarimetric lidar simulator

    Science.gov (United States)

    Bravo-Aranda, Juan Antonio; Belegante, Livio; Freudenthaler, Volker; Alados-Arboledas, Lucas; Nicolae, Doina; José Granados-Muñoz, María; Guerrero-Rascado, Juan Luis; Amodeo, Aldo; D'Amico, Giusseppe; Engelmann, Ronny; Pappalardo, Gelsomina; Kokkalis, Panos; Mamouri, Rodanthy; Papayannis, Alex; Navas-Guzmán, Francisco; José Olmo, Francisco; Wandinger, Ulla; Amato, Francesco; Haeffelin, Martial

    2016-10-01

    Lidar depolarization measurements distinguish between spherical and non-spherical aerosol particles based on the change of the polarization state between the emitted and received signal. The particle shape information in combination with other aerosol optical properties allows the characterization of different aerosol types and the retrieval of aerosol particle microphysical properties. Regarding the microphysical inversions, the lidar depolarization technique is becoming a key method since particle shape information can be used by algorithms based on spheres and spheroids, optimizing the retrieval procedure. Thus, the identification of the depolarization error sources and the quantification of their effects are crucial. This work presents a new tool to assess the systematic error of the volume linear depolarization ratio (δ), combining the Stokes-Müller formalism and the complete sampling of the error space using the lidar model presented in Freudenthaler (2016a). This tool is applied to a synthetic lidar system and to several EARLINET lidars with depolarization capabilities at 355 or 532 nm. The lidar systems show relative errors of δ larger than 100 % for δ values around molecular linear depolarization ratios (˜ 0.004 and up to ˜ 10 % for δ = 0.45). However, one system shows only relative errors of 25 and 0.22 % for δ = 0.004 and δ = 0.45, respectively, and gives an example of how a proper identification and reduction of the main error sources can drastically reduce the systematic errors of δ. In this regard, we provide some indications of how to reduce the systematic errors.

  12. Number of independent parameters in the Mueller matrix representation of homogeneous depolarizing media.

    Science.gov (United States)

    Arteaga, Oriol

    2013-04-01

    In general the transmission of polarized light through a homogeneous depolarizing sample has motion-reversal symmetry because the response remains the same for light traveling in the opposite direction. As a consequence, the optical properties of a sample, characterized by the differential Mueller matrix, must be invariant upon motion reversal. This Letter shows that the 16 parameters of the differential Mueller matrix must therefore obey six conditions to satisfy this symmetry. This limits the number of independent parameters to 10. The 10 elementary optical properties of a depolarizing homogeneous medium are defined and discussed.

  13. Coupled mode theory approach to depolarization associated with propagation in turbulent media

    Science.gov (United States)

    Crosignani, B.; di Porto, P.; Clifford, Steven F.

    1988-06-01

    Marcuse's (1974) coupled-mode theory is invoked in the present consideration of the problem of light depolarization in a turbulent atmosphere, in order to allow the evaluation of the depolarization ratio for a plane wave and comparison of its expression with that obtained in the frame of two distinct approaches predicting different behaviors. It is found that both approaches yield the same result when calculated to the same order in both of the relevant smallness parameters, thereby resolving a long-standing controversy.

  14. Coherence and Polarization of Polarization Speckle Generated by Depolarizers and Their Changes through Complex ABCD Matrix

    DEFF Research Database (Denmark)

    Ma, Ning; Hanson, Steen Grüner; Lee, Tim K.;

    2015-01-01

    of special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree...... of coherence (DoC). and degree of polarization (DoP) P. The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory....

  15. To a Method of Polarization-Depolarization Currents for Diagnosis of Dielectric Isolation

    Science.gov (United States)

    Ambrozevich, S. A.; Sibatov, R. T.; Uchaikin, D. V.; Morozova, E. V.

    2016-01-01

    Fractional derivative formalism is proposed as the mathematical foundation of the polarization-depolarization current method for the diagnosis of dielectric isolation. Physical basis of the new approach is the observed deviation of the long-term relaxation from the Debye exponential law. We found that this behavior is consistent with the solution of the fractional differential equation: exponential behavior turns into the power dependence in the long-time asymptotics, and this part of the relaxation curve is more sensitive to the material state. The results of calculations for the polarization-depolarization currents in an oil-paper capacitor are in agreement with the specially performed experiments.

  16. Clinician‐selected Electronic Information Resources do not Guarantee Accuracy in Answering Primary Care Physicians’ Information Needs. A review of: McKibbon, K. Ann, and Douglas B. Fridsma. “Effectiveness of Clinician‐selected Electronic Information Resources for Answering Primary Care Physicians’ Information Needs.” Journal of the American Medical Informatics Association 13.6 (2006: 653‐9.

    Directory of Open Access Journals (Sweden)

    Martha Ingrid Preddie

    2008-03-01

    Full Text Available Objective – To determine if electronic information resources selected by primary care physicians improve their ability to answer simulated clinical questions.Design – An observational study utilizing hour‐long interviews and think‐aloud protocols.Setting – The offices and clinics of primary care physicians in Canada and the United States.Subjects – Twenty‐five primary care physicians of whom 4 were women, 17 were from Canada, 22 were family physicians,and 24 were board certified.Methods – Participants provided responses to 23 multiple‐choice questions. Each physician then chose two questions and looked for the answers utilizing information resources of their own choice. The search processes, chosen resources and search times were noted. These were analyzed along with data on the accuracy of the answers and certainties related to the answer to each clinical question prior to the search.Main results – Twenty‐three physicians sought answers to 46 simulated clinical questions. Utilizing only electronic information resources, physicians spent a mean of 13.0 (SD 5.5 minutes searching for answers to the questions, an average of 7.3(SD 4.0 minutes for the first question and 5.8 (SD 2.2 minutes to answer the second question. On average, 1.8 resources were utilized per question. Resources that summarized information, such as the Cochrane Database of Systematic Reviews, UpToDate and Clinical Evidence, were favored 39.2% of the time, MEDLINE (Ovid and PubMed 35.7%, and Internet resources including Google 22.6%. Almost 50% of the search and retrieval strategies were keyword‐based, while MeSH, subheadings and limiting were used less frequently. On average, before searching physicians answered 10 of 23 (43.5% questions accurately. For questions that were searched using clinician‐selected electronic resources, 18 (39.1% of the 46 answers were accurate before searching, while 19 (42.1% were accurate after searching. The difference of

  17. Conceived on the City Electronic Waste Resource Mana oement Model%城市电子废弃物资源化管理模式构想

    Institute of Scientific and Technical Information of China (English)

    熊贵琍; 余涛

    2012-01-01

    Investigated e- waste collection system the investigation, the whereabouts and electronic waste disposal in Httizhou city, the paper analyzed the Huizhou city e- waste collection and disposal of a series of problems, combined with the actual, conceived urban electronic waste resources management mode.%通过对惠州市电子废弃物收集体系组成、去向以及电子废弃物处置方式的调查,分析惠州市电子废弃物收集和处置存在的一系列问题,结合实际提出了城市电子废弃物资源化管理模式的初步构想。

  18. Kv1.1 channelopathy abolishes presynaptic spike width modulation by subthreshold somatic depolarization.

    Science.gov (United States)

    Vivekananda, Umesh; Novak, Pavel; Bello, Oscar D; Korchev, Yuri E; Krishnakumar, Shyam S; Volynski, Kirill E; Kullmann, Dimitri M

    2017-02-28

    Although action potentials propagate along axons in an all-or-none manner, subthreshold membrane potential fluctuations at the soma affect neurotransmitter release from synaptic boutons. An important mechanism underlying analog-digital modulation is depolarization-mediated inactivation of presynaptic Kv1-family potassium channels, leading to action potential broadening and increased calcium influx. Previous studies have relied heavily on recordings from blebs formed after axon transection, which may exaggerate the passive propagation of somatic depolarization. We recorded instead from small boutons supplied by intact axons identified with scanning ion conductance microscopy in primary hippocampal cultures and asked how distinct potassium channels interact in determining the basal spike width and its modulation by subthreshold somatic depolarization. Pharmacological or genetic deletion of Kv1.1 broadened presynaptic spikes without preventing further prolongation by brief depolarizing somatic prepulses. A heterozygous mouse model of episodic ataxia type 1 harboring a dominant Kv1.1 mutation had a similar broadening effect on basal spike shape as deletion of Kv1.1; however, spike modulation by somatic prepulses was abolished. These results argue that the Kv1.1 subunit is not necessary for subthreshold modulation of spike width. However, a disease-associated mutant subunit prevents the interplay of analog and digital transmission, possibly by disrupting the normal stoichiometry of presynaptic potassium channels.

  19. Electroanatomic Correlates of Depolarization Abnormalities in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

    NARCIS (Netherlands)

    Tanawuttiwat, Tanyanan; Te Riele, Anneline S J M; Philips, Binu; James, Cynthia A; Murray, Brittney; Tichnell, Crystal; Sawant, Abhishek C; Calkins, Hugh; Tandri, Harikrishna

    2016-01-01

    BACKGROUND: Epsilon waves and other depolarization abnormalities in the right precordial leads are thought to represent delayed activation of the right ventricular outflow tract in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). However, no study has directly correlated cardiac e

  20. Membrane depolarization and carbamoylcholine stimulate phosphatidylinositol turnover in intact nerve terminals

    Energy Technology Data Exchange (ETDEWEB)

    Audigier, S.M.P.; Wang, J.K.T.; Greengard, P.

    1988-04-01

    Synaptosomes, purified from rat cerebral cortex, were prelabeled with (/sup 3/H)inositol to study phosphatidylinositol turnover in nerve terminals. Labeled synaptosomes were either depolarized with 40 mM K/sup +/ or exposed to carbamoylcholine (carbachol). K/sup +/ depolarization increased the level of inositol phosphates in a time-dependent manner. The inositol bisphosphate level also increased rapidly, but its elevated level was sustained during continued depolarization. The elevated level of inositol bisphosphate was reversed upon repolarization of the synaptosomes. The level of inositol monophosphate increased slowly to 120-130% of control. These effects of K/sup +/ depolarization depended on the presence of Ca/sup 2 +/ in the incubation medium. Carbachol stimulated the turnover of phosphatidylinositol in a dose- and time-dependent manner. The level of inositol bisphosphate increased to 210% of control, and this maximal response was seen from 15 to 60 min. Accumulation of inositol monophosphate was larger than that of inositol bisphosphate, but its time course was slower. Atropine and pirenzepine inhibited the carbachol effect with high affinities. These data show that both Ca/sup 2 +/ influx and M/sub 1/ muscarinic receptor activation stimulate phospholipase C activity in synaptosomes, suggesting that phosphatidylinositol turnover may be involved in regulating neurotransmitter release from nerve terminals.

  1. Normal chemotaxis in Dictyostelium discoideum cells with a depolarized plasma membrane potential

    NARCIS (Netherlands)

    Duijn, Bert van; Vogelzang, Sake A.; Ypey, Dirk L.; Molen, Loek G. van der; Haastert, Peter J.M. van

    1990-01-01

    We examined a possible role for the plasma membrane potential in signal transduction during cyclic AMP-induced chemotaxis in the cellular slime mold Dictyostelium discoideum. Chemotaxis, cyclic GMP and cyclic AMP responses in cells with a depolarized membrane potential were measured. Cells can be

  2. Weaver mutant mouse cerebellar granule cells respond normally to chronic depolarization

    DEFF Research Database (Denmark)

    Bjerregaard, Annette; Mogensen, Helle Smidt; Hack, N;

    1997-01-01

    We studied the effects of chronic K(+)-induced membrane depolarization and treatment with N-methyl-D-aspartate (NMDA) on cerebellar granule cells (CGCs) from weaver mutant mice and non-weaver litter-mates. The weaver mutation is a Gly-to-Ser substitution in a conserved region of the Girk2 G prote...

  3. Two-body depolarized cils spectra of krypton and xenon at 295 K

    Science.gov (United States)

    Zoppi, M.; Moraldi, M.; Barocchi, F.; Magli, R.; Bafile, U.

    1981-10-01

    We have experimentally determined the two-body depolarized CILS spectra of krypton and xenon at room temperature between 2 and 120 cm-1. Comparison of the first three even experimental moments of the spectra with theoretical calculations shows, as in argon, the necessity of introducing a short-range negative contribution to the induced pair polarizability.

  4. Measurement of distinctive features of cortical spreading depolarizations with different MRI contrasts

    NARCIS (Netherlands)

    Umesh Rudrapatna, S.; Hamming, Arend M.; Wermer, Marieke J H; van der Toorn, A; Dijkhuizen, Rick M.

    2015-01-01

    Growing clinical evidence suggests critical involvement of spreading depolarizations (SDs) in the pathophysiology of neurological disorders such as migraine and stroke. MRI provides powerful tools to detect and assess co-occurring cerebral hemodynamic and cellular changes during SDs. This study

  5. Role of astrocytes in depolarization-coupled release of glutamate in cerebellar cultures

    DEFF Research Database (Denmark)

    Bak, Lasse K; Waagepetersen, Helle S; Schousboe, Arne

    2004-01-01

    Release of preloaded D-[3H]aspartate in response to depolarization induced by high potassium, N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) or the endogenous agonist glutamate was studied using cultured glutamatergic cerebellar granule neurons, cerebell...

  6. Molecular anisotropy effects in carbon K-edge scattering: depolarized diffuse scattering and optical anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Kevin H.

    2014-07-14

    Some polymer properties, such as conductivity, are very sensitive to short- and intermediate-range orientational and positional ordering of anisotropic molecular functional groups, and yet means to characterize orientational order in disordered systems are very limited. We demonstrate that resonant scattering at the carbon K-edge is uniquely sensitive to short-range orientation correlations in polymers through depolarized scattering at high momentum transfers, using atactic polystyrene as a well-characterized test system. Depolarized scattering is found to coexist with unpolarized fluorescence, and to exhibit pronounced anisotropy. We also quantify the spatially averaged optical anisotropy from low-angle reflectivity measurements, finding anisotropy consistent with prior visible, x-ray absorption, and theoretical studies. The average anisotropy is much smaller than that in the depolarized scattering and the two have different character. Both measurements exhibit clear spectral signatures from the phenyl rings and the polyethylene-like backbone. Discussion focuses on analysis considerations and prospects for using this depolarized scattering for studies of disorder in soft condensed matter.

  7. Measurement of distinctive features of cortical spreading depolarizations with different MRI contrasts

    NARCIS (Netherlands)

    Umesh Rudrapatna, S.; Hamming, Arend M.; Wermer, Marieke J H; van der Toorn, A; Dijkhuizen, Rick M.

    2015-01-01

    Growing clinical evidence suggests critical involvement of spreading depolarizations (SDs) in the pathophysiology of neurological disorders such as migraine and stroke. MRI provides powerful tools to detect and assess co-occurring cerebral hemodynamic and cellular changes during SDs. This study repo

  8. Molecular anisotropy effects in carbon K-edge scattering: Depolarized diffuse scattering and optical anisotropy

    Science.gov (United States)

    Stone, Kevin H.; Kortright, Jeffrey B.

    2014-09-01

    Some polymer properties, such as conductivity, are very sensitive to short- and intermediate-range orientational and positional ordering of anisotropic molecular functional groups, and yet means to characterize orientational order in disordered systems are very limited. We demonstrate that resonant scattering at the carbon K edge is uniquely sensitive to short-range orientation correlations in polymers through depolarized scattering at high momentum transfers, using atactic polystyrene as a well-characterized test system. Depolarized scattering is found to coexist with unpolarized fluorescence and to exhibit pronounced anisotropy. We also quantify the spatially averaged optical anisotropy from low-angle reflectivity measurements, finding anisotropy consistent with prior visible, x-ray absorption, and theoretical studies. The average anisotropy is much smaller than that in the depolarized scattering and the two have different character. Both measurements exhibit clear spectral signatures from the phenyl rings and the polyethylenelike backbone. Discussion focuses on analysis considerations and prospects for using this depolarized scattering for studies of disorder in soft condensed matter.

  9. Weaver mutant mouse cerebellar granule cells respond normally to chronic depolarization

    DEFF Research Database (Denmark)

    Bjerregaard, Annette; Mogensen, Helle Smidt; Hack, N

    1997-01-01

    We studied the effects of chronic K(+)-induced membrane depolarization and treatment with N-methyl-D-aspartate (NMDA) on cerebellar granule cells (CGCs) from weaver mutant mice and non-weaver litter-mates. The weaver mutation is a Gly-to-Ser substitution in a conserved region of the Girk2 G prote...

  10. Accessibility and Use of Web-Based Electronic Resources by Physicians in a Psychiatric Institution in Nigeria

    Science.gov (United States)

    Oduwole, Adebambo Adewale; Oyewumi, Olatundun

    2010-01-01

    Purpose: This study aims to examine the accessibility and use of web-based electronic databases on the Health InterNetwork Access to Research Initiative (HINARI) portal by physicians in the Neuropsychiatric Hospital, Aro--a psychiatry health institution in Nigeria. Design/methodology/approach: Collection of data was through the use of a three-part…

  11. The retrieval of the Asian dust depolarization ratio in Korea with the correction of the polarization-dependent transmission

    Science.gov (United States)

    Shin, Sungkyun; Müller, Detlef; Kim, Y. J.; Tatarov, Boyan; Shin, Dongho; Seifert, Patric; Noh, Young Min

    2013-01-01

    The linear particle depolarization ratios were retrieved from the observation with a multiwavelength Raman lidar at the Gwangju Institute of Science and Technology (GIST), Korea (35.11°N, 126.54°E). The measurements were carried out in spring (March to May) 2011. The transmission ratio measurements were performed to solve problems of the depolarization-dependent transmission at a receiver of the lidar and applied to correct the retrieved depolarization ratio of Asian dust at first time in Korea. The analyzed data from the GIST multiwavelength Raman lidar were classified into three categories according to the linear particle depolarization ratios, which are pure Asian dust on 21 March, the intermediate case which means Asian dust mixed with urban pollution on 13 May, and haze case on 10 April. The measured transmission ratios were applied to these cases respectively. We found that the transmission ratio is needed to be used to retrieve the accurate depolarization ratio of Asian dust and also would be useful to distinguish the mixed dust particles between intermediate case and haze. The particle depolarization ratios of pure Asian dust were approximately 0.25 at 532 nm and 0.14 at 532 nm for the intermediate case. The linear particle depolarization ratios of pure Asian dust observed with the GIST multiwavelength Raman lidar were compared to the linear particle depolarization ratios of Saharan dust observed in Morocco and Asian dust observed both in Japan and China.

  12. Temperature modulation of cerebral depolarization during focal cerebral ischemia in rats: correlation with ischemic injury.

    Science.gov (United States)

    Chen, Q; Chopp, M; Bodzin, G; Chen, H

    1993-05-01

    The role of cerebral depolarizations in focal cerebral ischemia is unknown. We therefore measured the direct current (DC) electrical activity in the cortex of Wistar rats subjected to transient occlusion of the middle cerebral artery (MCA). Focal ischemia was induced for 90 min by insertion of an intraluminal filament to occlude the MCA. To modulate cell damage, we subjected the rats to hypothermic (30 degrees C, n = 4), normothermic (37 degrees C, n = 4), and hyperthermic (40 degrees C, n = 6) ischemia. Controlled temperatures were also maintained during 1 h of reperfusion. Continuous cortical DC potential changes were measured using two active Ag-AgCl electrodes placed in the cortical lesion. Animals were killed 1 week after ischemia. The brains were sectioned and stained with hematoxylin and eosin, for evaluation of neuronal damage, and calculation of infarct volume. All animals exhibited an initial depolarization within 30 min of ischemia, followed by a single depolarization event in hypothermic animals, and multiple periodic depolarization events in both normothermic and hyperthermic animals. Hyperthermic animals exhibited significantly more (p < 0.05) DC potential deflections (n = 6.17 +/- 0.67) than normothermic animals (n = 2.75 +/- 0.96). The ischemic infarct volume (% of hemisphere) was significantly different for the various groups; hypothermic animals exhibited no measurable infarct volume, while the ischemic infarct volume was 10.2 +/- 12.3% in normothermic animals and 36.5 +/- 3.4% in hyperthermic animals (p < 0.05). A significant correlation was detected between the volume of infarct and number of depolarization events (r = 0.90, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Contractile responses to rat urotensin II in resting and depolarized basilar arteries.

    Science.gov (United States)

    Porras-González, Cristina; Ureña, Juan; Egea-Guerrero, Juan José; Gordillo-Escobar, Elena; Murillo-Cabezas, Francisco; González-Montelongo, María del Carmen; Muñoz-Sánchez, María Angeles

    2014-03-01

    The effects of human urotensin II (hUII) on the vascular tone of different animal species has been studied extensively. However, little has been reported on the vasoactive effects of rat urotensin (rUII) in murine models. The aim of the present study was to investigate the effects of rUII on vasoreactivity in rat basilar arteries. Basilar arteries from adult male Wistar rats (300-350 g) were isolated, cut in rings, and mounted on a small vessel myograph to measure isometric tension. rUII concentrations were studied in both resting and depolarized state. To remove endothelial nitric oxide effects from the rUII response, we treated selected arterial rings with Nω-nitro-L-arginine methyl ester (L-NAME). 10 μM rUII produced a potent vasoconstrictor response in rat basilar arteries with intact endothelium, while isometric forces remained unaffected in arterial rings treated with lower rUII concentrations. Although L-NAME did not have a significant effect on 10 μM rUII-evoked contraction, it slightly increased arterial ring contraction elicited by 1 μM rUII. In depolarized arteries, dose-dependent rUII increased depolarization-induced contractions. This effect was suppressed by L-NAME. Our results show that the rat basilar artery has a vasoconstrictor response to rUII. The most potent vasoconstrictor effect was produced by lower doses of rUII (0.1 and 1 μM) in depolarized arteries with intact endothelium. This effect could facilitate arterial vasospasm in vascular pathophysiological processes such as subarachnoid hemorrhage and hypertension, when sustained depolarization and L-type Ca(2+) channel activation are present.

  14. Share and share alike: encouraging the reuse of academic resources through the Scottish electronic Staff Development Library

    Directory of Open Access Journals (Sweden)

    Lorna M. Campbell

    2001-12-01

    Full Text Available The Scottish electronic Staff Development Library (http://www.sesdl.scotcit.acuk is an ongoing collaborative project involving the Universities of Edinburgh, Paisley and Strathclyde which has been funded by SHEFC as part of their current ScotCIT Programme (http:llwww.scotcit.ac.uk. This project is being developed in response to the increasing demand for flexible, high-quality staff development materials.

  15. Mathematical analysis of depolarization block mediated by slow inactivation of fast sodium channels in midbrain dopamine neurons.

    Science.gov (United States)

    Qian, Kun; Yu, Na; Tucker, Kristal R; Levitan, Edwin S; Canavier, Carmen C

    2014-12-01

    Dopamine neurons in freely moving rats often fire behaviorally relevant high-frequency bursts, but depolarization block limits the maximum steady firing rate of dopamine neurons in vitro to ∼10 Hz. Using a reduced model that faithfully reproduces the sodium current measured in these neurons, we show that adding an additional slow component of sodium channel inactivation, recently observed in these neurons, qualitatively changes in two different ways how the model enters into depolarization block. First, the slow time course of inactivation allows multiple spikes to be elicited during a strong depolarization prior to entry into depolarization block. Second, depolarization block occurs near or below the spike threshold, which ranges from -45 to -30 mV in vitro, because the additional slow component of inactivation negates the sodium window current. In the absence of the additional slow component of inactivation, this window current produces an N-shaped steady-state current-voltage (I-V) curve that prevents depolarization block in the experimentally observed voltage range near -40 mV. The time constant of recovery from slow inactivation during the interspike interval limits the maximum steady firing rate observed prior to entry into depolarization block. These qualitative features of the entry into depolarization block can be reversed experimentally by replacing the native sodium conductance with a virtual conductance lacking the slow component of inactivation. We show that the activation of NMDA and AMPA receptors can affect bursting and depolarization block in different ways, depending upon their relative contributions to depolarization versus to the total linear/nonlinear conductance.

  16. VSOP/Hv1 proton channels sustain calcium entry, neutrophil migration, and superoxide production by limiting cell depolarization and acidification.

    Science.gov (United States)

    El Chemaly, Antoun; Okochi, Yoshifumi; Sasaki, Mari; Arnaudeau, Serge; Okamura, Yasushi; Demaurex, Nicolas

    2010-01-18

    Neutrophils kill microbes with reactive oxygen species generated by the NADPH oxidase, an enzyme which moves electrons across membranes. Voltage-gated proton channels (voltage-sensing domain only protein [VSOP]/Hv1) are required for high-level superoxide production by phagocytes, but the mechanism of this effect is not established. We show that neutrophils from VSOP/Hv1-/- mice lack proton currents but have normal electron currents, indicating that these cells have a fully functional oxidase that cannot conduct protons. VSOP/Hv1-/- neutrophils had a more acidic cytosol, were more depolarized, and produced less superoxide and hydrogen peroxide than neutrophils from wild-type mice. Hydrogen peroxide production was rescued by providing an artificial conductance with gramicidin. Loss of VSOP/Hv1 also aborted calcium responses to chemoattractants, increased neutrophil spreading, and decreased neutrophil migration. The migration defect was restored by the addition of a calcium ionophore. Our findings indicate that proton channels extrude the acid and compensate the charge generated by the oxidase, thereby sustaining calcium entry signals that control the adhesion and motility of neutrophils. Loss of proton channels thus aborts superoxide production and causes a severe signaling defect in neutrophils.

  17. 重庆高校图书馆电子文献资源建设现状及对策%The Present Situation and Countermeasure of Electronic Literature Resources Construction about Chongqing University Library

    Institute of Scientific and Technical Information of China (English)

    刘子辉; 彭渝; 陈强; 吴晓英

    2014-01-01

    In the information society, Electronic document resources are very important for library development and the school's teaching and research. The university library should pay more at ention to the construction of electronic document resources. Through the survey of the electronic document resources in Chongqing, We have mastered the distribution of electronic document resources, analyzed the existing problems in resource construction, and proposed the related countermeasure. We hope to provide reference for the electronic document resources construction.%在信息社会,电子文献资源对高校图书馆建设、学校的教学与科研都起到非常重要的作用,各高校图书馆应该更加重视电子文献资源的建设。通过对重庆高校图书馆电子文献资源建设情况进行调查,掌握了本地区电子文献资源的分布情况,分析了资源建设中存在的问题,并提出了相关对策,希望为本地区高校图书馆电子文献资源建设提供参考。

  18. General model of depolarization and transfer of polarization of singly ionized atoms by collisions with hydrogen atoms

    Science.gov (United States)

    Derouich, M.

    2017-02-01

    Simulations of the generation of the atomic polarization is necessary for interpreting the second solar spectrum. For this purpose, it is important to rigorously determine the effects of the isotropic collisions with neutral hydrogen on the atomic polarization of the neutral atoms, ionized atoms and molecules. Our aim is to treat in generality the problem of depolarizing isotropic collisions between singly ionized atoms and neutral hydrogen in its ground state. Using our numerical code, we computed the collisional depolarization rates of the p-levels of ions for large number of values of the effective principal quantum number n* and the Unsöld energy Ep. Then, genetic programming has been utilized to fit the available depolarization rates. As a result, strongly non-linear relationships between the collisional depolarization rates, n* and Ep are obtained, and are shown to reproduce the original data with accuracy clearly better than 10%. These relationships allow quick calculations of the depolarizing collisional rates of any simple ion which is very useful for the solar physics community. In addition, the depolarization rates associated to the complex ions and to the hyperfine levels can be easily derived from our results. In this work we have shown that by using powerful numerical approach and our collisional method, general model giving the depolarization of the ions can be obtained to be exploited for solar applications.

  19. Selection and Evaluation of Electronic Resources Elektronik Kaynakların Seçimi ve Değerlendirilmesi

    Directory of Open Access Journals (Sweden)

    Doğan Atılgan

    2009-12-01

    Full Text Available Publication boom and issues related to controlling and accession of printed sources have created some problems after World War II. Consequently, publishing industry has encountered the problem of finding possible solution for emerged situation. Industry of electronic publishing has started to improve with the rapid increase of the price of printed sources as well as the problem of publication boom. The first effects of electronic publishing were appeared on the academic and scholarly publications then electronic publishing became a crucial part of all types of publications. As a result of these developments, collection developments and service policies of information centers were also significantly changed. In this article, after a general introduction about selection and evaluation processes of electronic publications, the subscribed databases by a state and a privately owned university in Turkey and their usage were examined. İkinci dünya savaşından sonra görülen yayın patlaması, basılı kaynakların denetim ve erişiminde sorunlar yaşanmasına neden olmuştur. Bu da yayıncılık sektöründe yeni arayışlara yol açmıştır. 1980’li yıllardan sonra basılı yayın fiyatlarındaki hızlı artış da bu etmenlere eklenince elektronik yayıncılık sektörü gelişmeye başlamıştır. Öncelikle bilimsel ve akademik yayınlarla başlayan elektronik yayın günümüzde tüm yayın türlerini kapsamaktadır. Yayıncılıktaki bu gelişim bilgi merkezlerinin derme geliştirme ve hizmet politikalarını da önemli ölçüde değiştirmiştir. Bu çalışmada elektronik yayınların seçim, değerlendirme ve sağlama konularında genel bir girişten sonra bir devlet üniversitesinin bir de özel üniversitenin abone olduğu veritabanları ve bu veri tabanlarının kullanımının değerlendirilmesi yapılmaktadır.

  20. Depolarizing power and polarization entropy of light scattering media: experiment and theory

    CERN Document Server

    Puentes, G; Aiello, A; Woerdman, J P; Puentes, Graciana; Voigt, Dirk; Aiello, Andrea

    2004-01-01

    We experimentally investigate the depolarizing power and the polarization entropy of a broad class of scattering optical media. By means of polarization tomography, these quantities are derived from an effective Mueller matrix, which is introduced through a formal description of the multi-mode detection scheme we use, as recently proposed by Aiello and Woerdman (arXiv:quant-ph/0407234). This proposal emphasized an intriguing universality in the polarization aspects of classical as well as quantum light scattering; in this contribution we demonstrate experimentally that this universality is obeyed by a surprisingly wide class of depolarizing media. This, in turn, provides the experimentalist with a useful characterization of the polarization properties of any scattering media, as well as a universal criterion for the validity of the measured data.

  1. Generation of vector beams using a double-wedge depolarizer: Non-quantum entanglement

    Science.gov (United States)

    Samlan, C. T.; Viswanathan, Nirmal K.

    2016-07-01

    Propagation of horizontally polarized Gaussian beam through a double-wedge depolarizer generates vector beams with spatially varying state of polarization. Jones calculus is used to show that such beams are maximally nonseparable on the basis of even (Gaussian)-odd (Hermite-Gaussian) mode parity and horizontal-vertical polarization state. The maximum nonseparability in the two degrees of freedom of the vector beam at the double wedge depolarizer output is verified experimentally using a modified Sagnac interferometer and linear analyser projected interferograms to measure the concurrence 0.94±0.002 and violation of Clauser-Horne-Shimony-Holt form of Bell-like inequality 2.704±0.024. The investigation is carried out in the context of the use of vector beams for metrological applications.

  2. On the Sr I 4607 A Hanle depolarization signals in the quiet Sun

    CERN Document Server

    Almeida, J S

    2005-01-01

    The Hanle depolarization signals of Sr 4607 A have been used to estimate the unsigned magnetic flux and magnetic energy existing in the quiet Sun photosphere. However, the Sr 4607 A Hanle signals are not sensitive to the unsigned flux and energy. They only bear information on the fraction of photosphere occupied by magnetic field strengths smaller than the Hanle saturation, which do not contribute to the unsigned flux and energy. We deduce an approximate expression for the relationship between magnetic fill factor and Hanle signal. When applied to existing Hanle depolarization measurements, it indicates that only 40% of the quiet Sun is filled by magnetic fields with a strength smaller than 60 G. The remaining 60% of the surface has field strengths above this limit. Such constraint will be needed to determine the distribution of magnetic field strengths existing in the quiet Sun.

  3. Structure in the polarized Galactic synchrotron emission, in particular `depolarization canals'

    CERN Document Server

    Haverkorn, M; De Bruyn, A G

    2004-01-01

    The polarized component of the diffuse radio synchrotron emission of our Galaxy shows structure, which is apparently unrelated to the structure in total intensity, on many scales. The structure in the polarized emission can be due to several processes or mechanisms. Some of those are related to the observational setup, such as beam depolarization -- the vector combination and (partial) cancellation of polarization vectors within a synthesized beam --, or the insensitivity of a synthesis telescope to structure on large scales, also known as the 'missing short spacings problem'. Other causes for structure in the polarization maps are intrinsic to the radiative transfer of the emission in the warm ISM, which induces Faraday rotation and depolarization. We use data obtained with the Westerbork Synthesis Radio Telescope at 5 frequencies near 350 MHz to estimate the importance of the various mechanisms in producing structure in the linearly polarized emission. In the two regions studied here, which are both at posi...

  4. Diode-double-face-pumped Nd:YAG ceramic slab laser amplifier with low depolarization loss

    Science.gov (United States)

    Chen, Yanzhong; Fan, Zhongwei; Guo, Guangyan; Jia, Dan; He, Jianguo; Lang, Ye; Qiu, Jisi; Kang, Zhijun; Zhao, Tianzhuo; Lin, Weiran; Wang, Jiang; Xie, Tengfei; Li, Jiang; Kou, Huamin; Pan, Yubai

    2017-09-01

    A diode-double-face-pumped Nd:YAG ceramic slab laser amplifier with uniform gain distribution and low depolarization loss was presented. Energy storage of 2.6 J was achieved at 1064 nm with a repetition rate of 200 Hz and a pulse width of 200 us from a 140 mm × 40 mm × 7 mm ceramic slab at a total pump power of 1215 W, corresponding to an optical-to-optical efficiency of 42.8%. An average small signal gain of 5.45 was achieved with a standard deviation of only 0.09 in the cross section, which shown good concentration uniformity. An average depolarization loss of 2.6% at different positions of the slab was obtained due to small thermal gradient of the zigzag configuration.

  5. Resolving 4-D Nature of Magnetism with Depolarization and Faraday Tomography: Japanese SKA Cosmic Magnetism Science

    CERN Document Server

    Akahori, Takuya; Ichaki, Kiyotomo; Ideguchi, Shinsuke; Kudoh, Takahiro; Kudoh, Yuki; Machida, Mami; Nakanishi, Hiroyuki; Ohno, Hiroshi; Ozawa, Takeaki; Takahashi, Keitaro; Takizawa, Motokazu

    2016-01-01

    Magnetic fields play essential roles in various astronomical objects. Radio astronomy has revealed that magnetic fields are ubiquitous in our Universe. However, the real origin and evolution of magnetic fields is poorly proven. In order to advance our knowledge of cosmic magnetism in coming decades, the Square Kilometre Array (SKA) should have supreme sensitivity than ever before, which provides numerous observation points in the cosmic space. Furthermore, the SKA should be designed to facilitate wideband polarimetry so as to allow us to examine sightline structures of magnetic fields by means of depolarization and Faraday Tomography. The SKA will be able to drive cosmic magnetism of the interstellar medium, the Milky Way, galaxies, AGN, galaxy clusters, and potentially the cosmic web which may preserve information of the primeval Universe. The Japan SKA Consortium (SKA-JP) Magnetism Science Working Group (SWG) proposes the project "Resolving 4-D Nature of Magnetism with Depolarization and Faraday Tomography"...

  6. Presynaptic α2-GABAA Receptors in Primary Afferent Depolarization and Spinal Pain Control

    OpenAIRE

    2011-01-01

    Spinal dorsal horn GABAA receptors are found both postsynaptically on central neurons and presynaptically on axons and/or terminals of primary sensory neurons, where they mediate primary afferent depolarization (PAD) and presynaptic inhibition. Both phenomena have been studied extensively on a cellular level, but their role in sensory processing in vivo has remained elusive, due to inherent difficulties to selectively interfere with presynaptic receptors. Here, we address the contribution of ...

  7. Presynaptic {alpha}2-GABAA receptors in primary afferent depolarization and spinal pain control

    OpenAIRE

    2011-01-01

    Spinal dorsal horn GABA(A) receptors are found both postsynaptically on central neurons and presynaptically on axons and/or terminals of primary sensory neurons, where they mediate primary afferent depolarization (PAD) and presynaptic inhibition. Both phenomena have been studied extensively on a cellular level, but their role in sensory processing in vivo has remained elusive, due to inherent difficulties to selectively interfere with presynaptic receptors. Here, we address the contribution o...

  8. Seizures, refractory status epilepticus, and depolarization block as endogenous brain activities

    Science.gov (United States)

    El Houssaini, Kenza; Ivanov, Anton I.; Bernard, Christophe; Jirsa, Viktor K.

    2015-01-01

    Epilepsy, refractory status epilepticus, and depolarization block are pathological brain activities whose mechanisms are poorly understood. Using a generic mathematical model of seizure activity, we show that these activities coexist under certain conditions spanning the range of possible brain activities. We perform a detailed bifurcation analysis and predict strategies to escape from some of the pathological states. Experimental results using rodent data provide support of the model, highlighting the concept that these pathological activities belong to the endogenous repertoire of brain activities.

  9. In vivo cluster formation of nisin and lipid II is correlated with membrane depolarization.

    Science.gov (United States)

    Tol, Menno B; Morales Angeles, Danae; Scheffers, Dirk-Jan

    2015-01-01

    Nisin and related lantibiotics kill bacteria by pore formation or by sequestering lipid II. Some lantibiotics sequester lipid II into clusters, which were suggested to kill cells through delocalized peptidoglycan synthesis. Here, we show that cluster formation is always concomitant with (i) membrane pore formation and (ii) membrane depolarization. Nisin variants that cluster lipid II kill L-form bacteria with similar efficiency, suggesting that delocalization of peptidoglycan synthesis is not the primary killing mechanism of these lantibiotics.

  10. Structural relaxation mechanisms in liquid Eugenol. A depolarized light scattering study

    Science.gov (United States)

    Bezot, P.; Hesse-Bezot, C.; Roynard, D.; Jeanneaux, F.

    1988-07-01

    A depolarized light scattering study of liquid Eugenol, over a large temperature range including the supercooled region, is proposed. Comparisons with shear mechanical impedance measurements, obtained at lower frequencies, lead to more precise information on the viscoelastic parameters in the supercooled region. The structural relaxation process measurements by means of the photon correlation technique are compared to the dielectric and mechanical measurements. Molecular mechanisms are proposed.

  11. Modeling of thermally stimulated depolarization current (TSDC) using dipole–dipole interaction concept

    Indian Academy of Sciences (India)

    A E Kotp

    2011-04-01

    The study of thermally stimulated depolarization current (TSDC) using the dipole–dipole interaction model is described in this work. The dipole–dipole interactionmodel (DDIM) determines the TSDC peak successfully since it gives significant peak parameters (i.e. activation energy () and pre-exponential factor ($\\tau_{0}$)) in addition to the dipole–dipole interaction strength parameter ($d_{i}$). Application of this model to study the peak parameters of some polymeric systems is presented.

  12. Computational simulation: astrocyte-induced depolarization of neighboring neurons mediates synchronous UP states in a neural network.

    Science.gov (United States)

    Kuriu, Takayuki; Kakimoto, Yuta; Araki, Osamu

    2015-09-01

    Although recent reports have suggested that synchronous neuronal UP states are mediated by astrocytic activity, the mechanism responsible for this remains unknown. Astrocytic glutamate release synchronously depolarizes adjacent neurons, while synaptic transmissions are blocked. The purpose of this study was to confirm that astrocytic depolarization, propagated through synaptic connections, can lead to synchronous neuronal UP states. We applied astrocytic currents to local neurons in a neural network consisting of model cortical neurons. Our results show that astrocytic depolarization may generate synchronous UP states for hundreds of milliseconds in neurons even if they do not directly receive glutamate release from the activated astrocyte.

  13. Ferroelectric behavior of a lead titanate nanosphere due to depolarization fields and mechanical stresses

    Energy Technology Data Exchange (ETDEWEB)

    Andrade Landeta, J.; Lascano, I.

    2017-07-01

    A theorical model has been developed based on the theory of Ginzburg-Landau-Devonshire to study and predict the effects the decreasing of size particle in a nanosphere of PbTiO3 subjected to the action of depolarization fields and mechanical stress. It was considered that the nanosphere is surrounded by a layer of space charges on its surface, and containing 180° domains generated by minimizing free energy of depolarization. Energy density of depolarization, wall domain and electro-elastic energy have been incorporated into the free energy of the theory Ginzburg-Landau-Devonshire. Free energy minimization was performed to determine the spontaneous polarization and transition temperature system. These results show that the transition temperature for nanosphere is substantially smaller than the corresponding bulk material. Also, it has been obtained that the stability of the ferroelectric phase of nanosphere is favored for configurations with a large number of 180° domains, with the decreasing of thickness space charge layer, and the application of tensile stress and decreases with compressive stress. (Author)

  14. Large plasma-membrane depolarization precedes rapid blue-light-induced growth inhibition in cucumber

    Science.gov (United States)

    Spalding, E. P.; Cosgrove, D. J.

    1989-01-01

    Blue-light (BL)-induced suppression of elongation of etiolated Cucumis sativus L. hypocotyls began after a 30-s lag time, which was halved by increasing the fluence rate from 10 to 100 micromoles m-2 s-1. Prior to the growth suppression, the plasma-membrane of the irradiated cells depolarized by as much as 100 mV, then returned within 2-3 min to near its initial value. The potential difference measured with surface electrodes changed with an identical time course but opposite polarity. The lag time for the change in surface potential showed an inverse dependence on fluence rate, similar to the lag for the growth inhibition. Green light and red light caused neither the electrical response nor the rapid inhibition of growth. The depolarization by BL did not propagate to nonirradiated regions and exhibited a refractory period of about 10 min following a BL pulse. Fluence-response relationships for the electrical and growth responses provide correlational evidence that the plasma-membrane depolarization reflects an event in the transduction chain of this light-growth response.

  15. Parkin Sensitizes toward Apoptosis Induced by Mitochondrial Depolarization through Promoting Degradation of Mcl-1

    Directory of Open Access Journals (Sweden)

    Richard G. Carroll

    2014-11-01

    Full Text Available Mitochondrial depolarization promotes Parkin- and PTEN-induced kinase 1 (PINK1-dependent polyubiquitination of multiple proteins on mitochondrial outer membranes, resulting in the removal of defective mitochondria via mitophagy. Because Parkin mutations occur in Parkinson’s disease, a condition associated with the death of dopaminergic neurons in the midbrain, wild-type Parkin is thought to promote neuronal survival. However, here we show that wild-type Parkin greatly sensitized toward apoptosis induced by mitochondrial depolarization but not by proapoptotic stimuli that failed to activate Parkin. Parkin-dependent apoptosis required PINK1 and was efficiently blocked by prosurvival members of the Bcl-2 family or knockdown of Bax and Bak. Upon mitochondrial depolarization, the Bcl-2 family member Mcl-1 underwent rapid Parkin- and PINK1-dependent polyubiquitination and degradation, which sensitized toward apoptosis via opening of the Bax/Bak channel. These data suggest that similar to other sensors of cell stress, such as p53, Parkin has cytoprotective (mitophagy or cytotoxic modes (apoptosis, depending on the degree of mitochondrial damage.

  16. Thermal Stress-Induced Depolarization Loss in Conventional and Panda-Shaped Photonic Crystal Fiber Lasers

    Science.gov (United States)

    Mousavi, Seyedeh Laleh; Sabaeian, Mohammad

    2016-10-01

    We report on the modeling of the depolarization loss in the conventional and panda-shaped photonic crystal fiber lasers (PCFLs) due to the self-heating of the fiber, which we call it thermal stress-induced depolarization loss (TSIDL). We first calculated the temperature distribution over the fiber cross sections and then calculated the thermal stresses/strains as a function of heat load per meter. Thermal stress-induced birefringence (TSIB), which is defined as | n x - n y |, in the core and cladding regions was calculated. Finally, TSIDL was calculated for the conventional and panda-shaped PCFLs as a function of fiber length and, respectively, saturated values of 22 and 25 % were obtained which were independent of heat load per meter. For panda-shaped PCFLs, prior to being saturated, an oscillating and damping behavior against the fiber length was seen where in some lengths reached 35 %. The results are close to an experimental value of 30 % reported for a pulsed PCFL (Limpert et al., Opt Express 12:1313-1319, 2004) where the authors reported a degree of polarization of 70 % (i.e., a depolarization of 30 %). The most important result of this work is a saturation behavior of TSIDL at long-enough lengths of the fiber laser which is independent of heat load per meter. To our knowledge, this the first report of TSIBL for PCFLs.

  17. Cortical hyperpolarization-activated depolarizing current takes part in the generation of focal paroxysmal activities

    Science.gov (United States)

    Timofeev, Igor; Bazhenov, Maxim; Sejnowski, Terrence; Steriade, Mircea

    2002-01-01

    During paroxysmal neocortical oscillations, sudden depolarization leading to the next cycle occurs when the majority of cortical neurons are hyperpolarized. Both the Ca2+-dependent K+ currents (IK(Ca)) and disfacilitation play critical roles in the generation of hyperpolarizing potentials. In vivo experiments and computational models are used here to investigate whether the hyperpolarization-activated depolarizing current (Ih) in cortical neurons also contributes to the generation of paroxysmal onsets. Hyperpolarizing current pulses revealed a depolarizing sag in ≈20% of cortical neurons. Intracellular recordings from glial cells indirectly indicated an increase in extracellular potassium concentration ([K+]o) during paroxysmal activities, leading to a positive shift in the reversal potential of K+-mediated currents, including Ih. In the paroxysmal neocortex, ≈20% of neurons show repolarizing potentials originating from hyperpolarizations associated with depth-electroencephalogram positive waves of spike-wave complexes. The onset of these repolarizing potentials corresponds to maximal [K+]o as estimated from dual simultaneous impalements from neurons and glial cells. Computational models showed how, after the increased [K+]o, the interplay between Ih, IK(Ca), and a persistent Na+ current, INa(P), could organize paroxysmal oscillations at a frequency of 2–3 Hz. PMID:12089324

  18. Single ice crystal measurements during nucleation experiments with the depolarization detector IODE

    Directory of Open Access Journals (Sweden)

    M. Nicolet

    2008-12-01

    Full Text Available In order to determine the efficiency of aerosol particles of several types to nucleate ice, an Ice Optical DEpolarization detector (IODE was developed to distinguish between water droplets and ice crystals in ice nucleation chambers. A laser beam polarized linearly (power: 50 mW, wavelength: 407 nm is directed through the chamber. The scattered light intensity from particles is measured at a scattering angle of Θ=175° in both polarization components (parallel and perpendicular. The ratio between the perpendicular intensity over the total one gives the depolarization ratio δ. Single particle detection is possible, using a peak detection algorithm. For high particle concentrations, a real-time signal averaging method can also be run simultaneously. The IODE detector was used in connection with the Zurich ice nucleation chamber during the ICIS 2007 workshop where ice nucleation experiments were performed with several aerosol types. In presence of ice crystals, peaks were detected in both channels, generating depolarization signals. Mean values of δ ranged from 0.24 to 0.37.

  19. Single ice crystal measurements during nucleation experiments with the depolarization detector IODE

    Directory of Open Access Journals (Sweden)

    M. Nicolet

    2010-01-01

    Full Text Available In order to determine the efficiency of different aerosol particles to nucleate ice, an Ice Optical DEpolarization detector (IODE was developed to distinguish between water droplets and ice crystals in ice nucleation chambers. A laser beam polarized linearly (power: 50 mW, wavelength: 407 nm is directed through the chamber. The scattered light intensity from particles is measured at a scattering angle of Θ=175° in both polarization components (parallel and perpendicular. The ratio between the perpendicular intensity over the total one yields the depolarization ratio δ. Single particle detection is possible, using a peak detection algorithm. For high particle concentrations, a real-time signal averaging method can also be run simultaneously.

    The IODE detector was used in connection with the Zurich ice nucleation chamber during the ICIS 2007 workshop where ice nucleation experiments were performed with several aerosol types. In presence of ice crystals, a depolarization ratio could be measured on a particle-by-particle basis. Mean values of δ ranged from 0.24 to 0.37 and agree well with theoretical calculations.

  20. Single ice crystal measurements during nucleation experiments with the depolarization detector IODE

    Science.gov (United States)

    Nicolet, M.; Stetzer, O.; Lüönd, F.; Möhler, O.; Lohmann, U.

    2010-01-01

    In order to determine the efficiency of different aerosol particles to nucleate ice, an Ice Optical DEpolarization detector (IODE) was developed to distinguish between water droplets and ice crystals in ice nucleation chambers. A laser beam polarized linearly (power: 50 mW, wavelength: 407 nm) is directed through the chamber. The scattered light intensity from particles is measured at a scattering angle of Θ=175° in both polarization components (parallel and perpendicular). The ratio between the perpendicular intensity over the total one yields the depolarization ratio δ. Single particle detection is possible, using a peak detection algorithm. For high particle concentrations, a real-time signal averaging method can also be run simultaneously. The IODE detector was used in connection with the Zurich ice nucleation chamber during the ICIS 2007 workshop where ice nucleation experiments were performed with several aerosol types. In presence of ice crystals, a depolarization ratio could be measured on a particle-by-particle basis. Mean values of δ ranged from 0.24 to 0.37 and agree well with theoretical calculations.

  1. Postsynaptic Depolarization Enhances GABA Drive to Dorsomedial Hypothalamic Neurons through Somatodendritic Cholecystokinin Release.

    Science.gov (United States)

    Crosby, Karen M; Baimoukhametova, Dinara V; Bains, Jaideep S; Pittman, Quentin J

    2015-09-23

    Somatodendritically released peptides alter synaptic function through a variety of mechanisms, including autocrine actions that liberate retrograde transmitters. Cholecystokinin (CCK) is a neuropeptide expressed in neurons in the dorsomedial hypothalamic nucleus (DMH), a region implicated in satiety and stress. There are clear demonstrations that exogenous CCK modulates food intake and neuropeptide expression in the DMH, but there is no information on how endogenous CCK alters synaptic properties. Here, we provide the first report of somatodendritic release of CCK in the brain in male Sprague Dawley rats. CCK is released from DMH neurons in response to repeated postsynaptic depolarizations, and acts in an autocrine fashion on CCK2 receptors to enhance postsynaptic NMDA receptor function and liberate the retrograde transmitter, nitric oxide (NO). NO subsequently acts presynaptically to enhance GABA release through a soluble guanylate cyclase-mediated pathway. These data provide the first demonstration of synaptic actions of somatodendritically released CCK in the hypothalamus and reveal a new form of retrograde plasticity, depolarization-induced potentiation of inhibition. Significance statement: Somatodendritic signaling using endocannabinoids or nitric oxide to alter the efficacy of afferent transmission is well established. Despite early convincing evidence for somatodendritic release of neurohypophysial peptides in the hypothalamus, there is only limited evidence for this mode of release for other peptides. Here, we provide the first evidence for somatodendritic release of the satiety peptide cholecystokinin (CCK) in the brain. We also reveal a new form of synaptic plasticity in which postsynaptic depolarization results in enhancement of inhibition through the somatodendritic release of CCK.

  2. Enhancement of light depolarization by random ensembles of titania-based low-dimensional nanoparticles

    Science.gov (United States)

    Zimnyakov, D. A.; Zdrajevsky, R. A.; Yuvchenko, S. A.; Ushakova, O. V.; Angelsky, O. V.; Yermolenko, S. B.

    2015-02-01

    Depolarization peculiarities of the light scattered by the random ensembles of titania-based low-dimensional nanoparticles are studied during the experiments with aqueous suspensions of potassium polytitanate nanoplatelets and nanoribbons. The obtained experimental results are compared with the theoretical data obtained for the random systems of oblate and prolate flattened ellipsoidal nanoparticles with various values of the shape factor and dielectric function corresponding the parent material (titanium dioxide). The possibility to recover the effective dielectric function from the depolarization ratio spectra using the ellipsoidal shape model is considered. Ellipsoidal approximation is appropriate for both the nanoplatelets and nanoribbons in the spectral region for which the real part of nanoparticles permittivity is sufficiently negative and the near-resonant excitation of longitudinal mode of charge oscillations in nanoparticles occurs. Also, ellipsoidal approximation is appropriate for nanoplatelets in the region of sufficiently po sitive real part of permittivity but gives remarkably underestimated values of the depolarization ratio for nanoribbons in the region. This is presumably caused by considerable difference in the light-induced charge distributions for nanoribbons and prolate flattened ellipsoidal nanoparticles with the decreasing efficiency in longitudinal mode excitation. The recovered values of nanoparticle permittivity exhibit the red shift with respect to the permittivity values of the parent material due to its modification in the course of nanoparticles synthesis.

  3. Utility of the electronic information resource UpToDate for clinical decision-making at bedside rounds.

    Science.gov (United States)

    Phua, J; See, K C; Khalizah, H J; Low, S P; Lim, T K

    2012-02-01

    Clinical questions often arise at daily hospital bedside rounds. Yet, little information exists on how the search for answers may be facilitated. The aim of this prospective study was, therefore, to evaluate the overall utility, including the feasibility and usefulness of incorporating searches of UpToDate, a popular online information resource, into rounds. Doctors searched UpToDate for any unresolved clinical questions during rounds for patients in general medicine and respiratory wards, and in the medical intensive care unit of a tertiary teaching hospital. The nature of the questions and the results of the searches were recorded. Searches were deemed feasible if they were completed during the rounds and useful if they provided a satisfactory answer. A total of 157 UpToDate searches were performed during the study period. Questions were raised by all ranks of clinicians from junior doctors to consultants. The searches were feasible and performed immediately during rounds 44% of the time. Each search took a median of three minutes (first quartile: two minutes, third quartile: five minutes). UpToDate provided a useful and satisfactory answer 75% of the time, a partial answer 17% of the time and no answer 9% of the time. It led to a change in investigations, diagnosis or management 37% of the time, confirmed what was originally known or planned 38% of the time and had no effect 25% of the time. Incorporating UpToDate searches into daily bedside rounds was feasible and useful in clinical decision-making.

  4. Depolarization thresholds for hippocampal damage, ischemic preconditioning, and changes in gene expression after global ischemia in the rat.

    Science.gov (United States)

    Halaby, Issam A; Takeda, Yoshimasa; Yufu, Katsumi; Nowak, Thaddeus S; Pulsinelli, William A

    2004-11-30

    Induced ischemic tolerance in rat hippocampus was investigated in a forebrain ischemia model of repeated 4-vessel occlusion (4-VO). Ischemic insult variability was reduced by the use of dc potential measurements to determine the duration of ischemic depolarization in hippocampus. The results demonstrate a depolarization threshold for ischemic injury to CA1 neurons of 4-6 min and a window for optimal preconditioning of 2.5-3.5 min. Levels of induced mRNAs encoding hsp72 and several immediate-early genes were also shown to vary with depolarization interval. Immediate-early genes were maximally induced after depolarization periods inducing optimal preconditioning, while hsp72 expression increased with insult severity over the range leading to neuron loss. These results are similar to those obtained in gerbil studies indicating that preconditioning does not require large increases in hsp72 expression, and demonstrate the fundamental comparability of rodent global ischemia models when monitored by this approach.

  5. General model of depolarization and transfer of polarization of singly ionized atoms by collisions with hydrogen atoms

    CERN Document Server

    Derouich, Moncef

    2016-01-01

    Simulations of the generation of the atomic polarization is necessary for interpreting the second solar spectrum. For this purpose, it is important to rigorously determine the effects of the isotropic collisions with neutral hydrogen on the atomic polarization of the neutral atoms, ionized atoms and molecules. Our aim is to treat in generality the problem of depolarizing isotropic collisions between singly ionized atoms and neutral hydrogen in its ground state. Using our numerical code, we computed the collisional depolarization rates of the $p$-levels of ions for large number of values of the effective principal quantum number $n^{*}$ and the Uns\\"old energy $E_p$. Then, genetic programming has been utilized to fit the available depolarization rates. As a result, strongly non-linear relationships between the collisional depolarization rates, $n^{*}$ and $E_p$ are obtained, and are shown to reproduce the original data with accuracy clearly better than 10\\%. These relationships allow quick calculations of the ...

  6. Possible role of GABAergic depolarization in neocortical neurons in generating hyperexcitatory behaviors during emergence from sevoflurane anesthesia in the rat

    Directory of Open Access Journals (Sweden)

    Byung‑Gun Lim

    2014-04-01

    Full Text Available Hyperexcitatory behaviors occurring after sevoflurane anesthesia are of serious clinical concern, but the underlying mechanism is unknown. These behaviors may result from the potentiation by sevoflurane of GABAergic depolarization/excitation in neocortical neurons, cells implicated in the genesis of consciousness and arousal. The current study sought to provide evidence for this hypothesis with rats, the neocortical neurons of which are known to respond to GABA (γ-aminobutyric acid with depolarization/excitation at early stages of development (i.e., until the second postnatal week and with hyperpolarization/inhibition during adulthood. Employing behavioral tests and electrophysiological recordings in neocortical slice preparations, we found: (1 sevoflurane produced PAHBs (post-anesthetic hyperexcitatory behaviors in postnatal day (P1–15 rats, whereas it failed to elicit PAHBs in P16 or older rats; (2 GABAergic PSPs (postsynaptic potentials were depolarizing/excitatory in the neocortical neurons of P5 and P10 rats, whereas mostly hyperpolarizing/inhibitory in the cells of adult rats; (3 at P14–15, <50% of rats had PAHBs and, in general, the cells of the animals with PAHBs exhibited strongly depolarizing GABAergic PSPs, whereas those without PAHBs showed hyperpolarizing or weakly depolarizing GABAergic PSPs; (4 bumetanide [inhibitor of the Cl− importer NKCC (Na+–K+–2Cl− cotransporter] treatment at P5 suppressed PAHBs and depolarizing GABAergic responses; and (5 sevoflurane at 1% (i.e., concentration <1 minimum alveolar concentration potentiated depolarizing GABAergic PSPs in the neurons of P5 and P10 rats and of P14–15 animals with PAHBs, evoking action potentials in ≥50% of these cells. On the basis of these results, we conclude that sevoflurane may produce PAHBs by potentiating GABAergic depolarization/excitation in neocortical neurons.

  7. Faraday isolator based on a TSAG single crystal with compensation of thermally induced depolarization inside magnetic field

    Science.gov (United States)

    Snetkov, Ilya; Palashov, Oleg

    2015-04-01

    A Faraday isolator based on a terbium scandium aluminum garnet (TSAG) single crystal with compensation of thermally induced depolarization inside magnetic field was demonstrated. An isolation ratio of 32 dB at 350 W cw laser radiation power was achieved. Thermally induced depolarization and thermal lens were studied and compared with similar thermal effects arising in the widely used terbium gallium garnet crystal (TGG) for the first time.

  8. Observations of the spectral dependence of linear particle depolarization ratio of aerosols using NASA Langley airborne High Spectral Resolution Lidar

    Science.gov (United States)

    Burton, S. P.; Hair, J. W.; Kahnert, M.; Ferrare, R. A.; Hostetler, C. A.; Cook, A. L.; Harper, D. B.; Berkoff, T. A.; Seaman, S. T.; Collins, J. E.; Fenn, M. A.; Rogers, R. R.

    2015-12-01

    Linear particle depolarization ratio is presented for three case studies from the NASA Langley airborne High Spectral Resolution Lidar-2 HSRL-2). Particle depolarization ratio from lidar is an indicator of non-spherical particles and is sensitive to the fraction of non-spherical particles and their size. The HSRL-2 instrument measures depolarization at three wavelengths: 355, 532, and 1064 nm. The three measurement cases presented here include two cases of dust-dominated aerosol and one case of smoke aerosol. These cases have partial analogs in earlier HSRL-1 depolarization measurements at 532 and 1064 nm and in literature, but the availability of three wavelengths gives additional insight into different scenarios for non-spherical particles in the atmosphere. A case of transported Saharan dust has a spectral dependence with a peak of 0.30 at 532 nm with smaller particle depolarization ratios of 0.27 and 0.25 at 1064 and 355 nm, respectively. A case of aerosol containing locally generated wind-blown North American dust has a maximum of 0.38 at 1064 nm, decreasing to 0.37 and 0.24 at 532 and 355 nm, respectively. The cause of the maximum at 1064 nm is inferred to be very large particles that have not settled out of the dust layer. The smoke layer has the opposite spectral dependence, with the peak of 0.24 at 355 nm, decreasing to 0.09 and 0.02 at 532 and 1064 nm, respectively. The depolarization in the smoke case may be explained by the presence of coated soot aggregates. We note that in these specific case studies, the linear particle depolarization ratio for smoke and dust-dominated aerosol are more similar at 355 nm than at 532 nm, having possible implications for using the particle depolarization ratio at a single wavelength for aerosol typing.

  9. Possible Role of GABAergic Depolarization in Neocortical Neurons in Generating Hyperexcitatory Behaviors during Emergence from Sevoflurane Anesthesia in the Rat

    Directory of Open Access Journals (Sweden)

    Byung-Gun Lim

    2014-03-01

    Full Text Available Hyperexcitatory behaviors occurring after sevoflurane anesthesia are of serious clinical concern, but the underlying mechanism is unknown. These behaviors may result from the potentiation by sevoflurane of GABAergic depolarization/excitation in neocortical neurons, cells implicated in the genesis of consciousness and arousal. The current study sought to provide evidence for this hypothesis with rats, the neocortical neurons of which are known to respond to GABA (γ-aminobutyric acid with depolarization/excitation at early stages of development (i.e., until the second postnatal week and with hyperpolarization/inhibition during adulthood. Employing behavioral tests and electrophysiological recordings in neocortical slice preparations, we found: (1 sevoflurane produced PAHBs (post-anesthetic hyperexcitatory behaviors in postnatal day (P1–15 rats, whereas it failed to elicit PAHBs in P16 or older rats; (2 GABAergic PSPs (postsynaptic potentials were depolarizing/excitatory in the neocortical neurons of P5 and P10 rats, whereas mostly hyperpolarizing/inhibitory in the cells of adult rats; (3 at P14–15, <50 % of rats had PAHBs and, in general, the cells of the animals with PAHBs exhibited strongly depolarizing GABAergic PSPs, whereas those without PAHBs showed hyperpolarizing or weakly depolarizing GABAergic PSPs; (4 bumetanide [inhibitor of the Cl− importer NKCC (Na+ -K+−2Cl− cotransporter] treatment at P5 suppressed PAHBs and depolarizing GABAergic responses; and (5 sevoflurane at 1 % (i.e., concentration <1 minimum alveolar concentration potentiated depolarizing GABAergic PSPs in the neurons of P5 and P10 rats and of P14–15 animals with PAHBs, evoking action potentials in ≥50% of these cells. On the basis of these results, we conclude that sevoflurane may produce PAHBs by potentiating GABAergic depolarization/excitation in neocortical neurons.

  10. 图书馆纸质资源与电子资源投入比例研究%The research of ratio between traditional and electronics resources in library

    Institute of Scientific and Technical Information of China (English)

    王以婧; 李明

    2012-01-01

    With the popularization of electronic product development,library is no longer the paper-based resources into a single information carrier the pattern,but has formed a paper resource and electronic resources coexist in the new situation.Because the library types of our country,the proportion of input between paper-based resources and other kinds of resources exist difference.This paper will discuss the relationship between the traditional and electronics resources,and also points out the existing problems and the countermeasures.%随着电子产品的普及发展,图书馆已不再以纸质资源为唯一的信息载体,而是形成了纸质资源和电子资源并存的新局面。由于国内图书馆类型的不同,纸质资源与电子资源的配比也会存在差异。通过讨论二者的关系,指出存在的问题及应对之策。

  11. Is Spreading Depolarization Characterized by an Abrupt, Massive Release of Gibbs Free Energy from the Human Brain Cortex?

    Science.gov (United States)

    Dreier, Jens P.; Isele, Thomas; Reiffurth, Clemens; Offenhauser, Nikolas; Kirov, Sergei A.; Dahlem, Markus A.; Herreras, Oscar

    2012-01-01

    In the evolution of the cerebral cortex, the sophisticated organization in a steady state far away from thermodynamic equilibrium has produced the side effect of two fundamental pathological network events: ictal epileptic activity and spreading depolarization. Ictal epileptic activity describes the partial disruption, and spreading depolarization describes the near-complete disruption of the physiological double Gibbs–Donnan steady state. The occurrence of ictal epileptic activity in patients has been known for decades. Recently, unequivocal electrophysiological evidence has been found in patients that spreading depolarizations occur abundantly in stroke and brain trauma. The authors propose that the ion changes can be taken to estimate relative changes in Gibbs free energy from state to state. The calculations suggest that in transitions from the physiological state to ictal epileptic activity to spreading depolarization to death, the cortex releases Gibbs free energy in a stepwise fashion. Spreading depolarization thus appears as a twilight state close to death. Consistently, electrocorticographic recordings in the core of focal ischemia or after cardiac arrest display a smooth transition from the initial spreading depolarization component to the later ultraslow negative potential, which is assumed to reflect processes in cellular death. PMID:22829393

  12. There is a Relationship between Resource Expenditures and Reference Transactions in Academic Libraries. A Review of: Dubnjakovic, A. (2012. Electronic resource expenditure and the decline in reference transaction statistics in academic libraries. Journal of Academic Librarianship, 38(2, 94-100. doi:10.1016/j.acalib.2012.01.001

    Directory of Open Access Journals (Sweden)

    Annie M. Hughes

    2013-03-01

    Full Text Available Objective – To provide an analysis of the impact of expenditures on electronic resourcesand gate counts on the increase or decrease in reference transactions.Design – Analysis of results of existing survey data from the National Center for Educational Statistics (NCES 2006 Academic Library Survey(ALS.Setting – Academic libraries in the United States.Subjects – 3925 academic library respondents.Methods – The author chose to use survey data collected from the 2006 ALS conducted bythe NCES. The survey included data on various topics related to academic libraries, but in the case of this study, the author chose to analyze three of the 193 variables included. The three variables: electronic books expenditure, computer hardware and software, and expenditures on bibliographic utilities, were combined into one variable called electronic resource expenditure. Gate counts were also considered as a variable. Electronic resource expenditure was also split as a variable into three groups: low, medium, and high. Multiple regression analysis and general linear modeling, along with tests of reliability, were employed. Main Results – The author determined that low, medium, and high spenders with regard to electronic resources exhibited differences in gate counts, and gate counts have an effect on reference transactions in any given week. Gate counts tend to not have much of an effect on reference transactions for the higher spenders, and higher spenders tend to have a higher number of reference transactions overall. Low spenders have lower gate counts and also a lower amount of reference transactions.Conclusion – The findings from this study show that academic libraries spending more on electronic resources also tend to have an increase with regard to reference transactions. The author also concludes that library spaces are no longer the determining factor with regard to number of reference transactions. Spending more on electronic resources is

  13. Ca2+ sparks evoked by depolarization of rat ventricular myocytes involve multiple release sites

    Institute of Scientific and Technical Information of China (English)

    ZANGWei-Jin; YUXiao-Jiang; ZANGYi-Min

    2003-01-01

    AIM:To investigate the fundamental nature of calcium release events (Ca2+‘sparks’) evoked in rat ventricular myocytes during excitation-contraction (E-C) coupling. METHODS: High-resolution line-scan confocal imaging with the fluorescent calcium indicator and patch-clamp techniques were used to study the spontaneous Ca2+ sparks and sparks evoked by depolarization. RESULTS: 1)Line scans oriented along the length of the cell showed that both spontaneous sparks and sparks evoked by depolarization to -35mV appeared to arise at single sites spacing about 1.80μm apart (ie, the sarcomere length), and measurements of their longitudinal spread (full-width at halfmaximal amplitude:FWHM) followed single Gaussian distributions with means of 2.6μm. 2)Different to this,transverse line scans often revealed spontaneous and evoked sparks that appeared to arise near-synchronously from paired sites. Measurements of transverse FWHM of both spontaneous and evoked sparks showed bimodal distributions, which were fit well by the sums of two Gaussian curves with means of 1.8 and 2.9μm for spontaneous sparks and ith means of 1.9 and 3.1 μm for evoked sparks. Relative areas under the two Gaussian curves were 1.73:1 and 1.85:1, respectively, for spontaneous and evoked sparks. CONCLUSIONS: Ca2+ sparks evoked by depolarization are not ′unitary′ events, but often involve multiple sites of origin along Z-lines, as previously shown for spontaneous sparks. Thus, Ca2+ released during sparks directly triggered by influx through L-type Ca2+ channels may, in turn, trigger neighboring sites. The restricted involvement of only a few transverse release sites preserves the essential feature of the ‘local control’ theory of E-C coupling.

  14. Depolarizing actions of GABA in immature neurons depend neither on ketone bodies nor on pyruvate.

    Science.gov (United States)

    Tyzio, Roman; Allene, Camille; Nardou, Romain; Picardo, Michel A; Yamamoto, Sumii; Sivakumaran, Sudhir; Caiati, Maddalena D; Rheims, Sylvain; Minlebaev, Marat; Milh, Mathieu; Ferré, Pascal; Khazipov, Rustem; Romette, Jean-Louis; Lorquin, Jean; Cossart, Rosa; Khalilov, Ilgam; Nehlig, Astrid; Cherubini, Enrico; Ben-Ari, Yehezkel

    2011-01-05

    GABA depolarizes immature neurons because of a high [Cl(-)](i) and orchestrates giant depolarizing potential (GDP) generation. Zilberter and coworkers (Rheims et al., 2009; Holmgren et al., 2010) showed recently that the ketone body metabolite DL-3-hydroxybutyrate (DL-BHB) (4 mM), lactate (4 mM), or pyruvate (5 mM) shifted GABA actions to hyperpolarizing, suggesting that the depolarizing effects of GABA are attributable to inadequate energy supply when glucose is the sole energy source. We now report that, in rat pups (postnatal days 4-7), plasma D-BHB, lactate, and pyruvate levels are 0.9, 1.5, and 0.12 mM, respectively. Then, we show that DL-BHB (4 mM) and pyruvate (200 μM) do not affect (i) the driving force for GABA(A) receptor-mediated currents (DF(GABA)) in cell-attached single-channel recordings, (2) the resting membrane potential and reversal potential of synaptic GABA(A) receptor-mediated responses in perforated patch recordings, (3) the action potentials triggered by focal GABA applications, or (4) the GDPs determined with electrophysiological recordings and dynamic two-photon calcium imaging. Only very high nonphysiological concentrations of pyruvate (5 mM) reduced DF(GABA) and blocked GDPs. Therefore, DL-BHB does not alter GABA signals even at the high concentrations used by Zilberter and colleagues, whereas pyruvate requires exceedingly high nonphysiological concentrations to exert an effect. There is no need to alter conventional glucose enriched artificial CSF to investigate GABA signals in the developing brain.

  15. Atropine-resistant depolarization in the guinea-pig small intestine.

    Science.gov (United States)

    Bywater, R A; Holman, M E; Taylor, G S

    1981-07-01

    1. Junction potentials were recorded from the circular muscle cells of the guinea-pig ileum following transmural stimulation in the presence of atropine at 30 degrees C.2. Single stimuli produced a transient hyperpolarization, the inhibitory junction potential (i.j.p.). At high stimulus strengths the i.j.p. was followed by a post-stimulus depolarization (PSD).3. During repetitive stimulation the magnitude of the hyperpolarization decreased; however, at the end of the stimulus period the PSD was enhanced and often reached threshold for the generation of action potentials. Thus, the size of the PSD was not directly related to the degree of the preceding hyperpolarization.4. Hyperpolarization of the circular muscle cells was produced by the application of anodal current using large external electrodes. Rapid cessation of the applied current produced a transient after-depolarization which was shorter in time course than the PSD following the i.j.p. If the applied anodal current was reduced slowly (at a rate which mimicked the decrease in the hyperpolarization during repetitive nerve stimulation) no after-depolarization was observed.5. Conditioning hyperpolarization of the circular muscle cells reduced the amplitude of the i.j.p. The i.j.p. was reversed at membrane potentials greater than approximately -90 mV.6. The PSD did not appear to be due to the extracellular accumulation of potassium ions following the i.j.p. since the PSD persisted even when the i.j.p. was reversed.7. The neurotoxin apamin reversibly abolished the i.j.p. and unmasked a transient excitatory junction potential (e.j.p.) with a variable latency (350-900 ms).

  16. Vanadate induces necrotic death in neonatal rat cardiomyocytes through mitochondrial membrane depolarization.

    Science.gov (United States)

    Soares, Sandra Sofia; Henao, Fernando; Aureliano, Manuel; Gutiérrez-Merino, Carlos

    2008-03-01

    Besides the well-known inotropic effects of vanadium in cardiac muscle, previous studies have shown that vanadate can stimulate cell growth or induce cell death. In this work, we studied the toxicity to neonatal rat ventricular myocytes (cardiomyocytes) of two vanadate solutions containing different oligovanadates distribution, decavanadate (containing decameric vanadate, V 10) and metavanadate (containing monomeric vanadate and also di-, tetra-, and pentavanadate). Incubation for 24 h with decavanadate or metavanadate induced necrotic cell death of cardiomyocytes, without significant caspase-3 activation. Only 10 microM total vanadium of either decavanadate (1 microM V 10) or metavanadate (10 microM total vanadium) was needed to produce 50% loss of cell viability after 24 h (assessed with MTT and propidium iodide assays). Atomic absorption spectroscopy showed that vanadium accumulation in cardiomyocytes after 24 h was the same when incubation was done with decavanadate or metavanadate. A decrease of 75% of the rate of mitochondrial superoxide anion generation, monitored with dihydroethidium, and a sustained rise of cytosolic calcium (monitored with Fura-2-loaded cardiomyocytes) was observed after 24 h of incubation of cardiomyocytes with decavanadate or metavanadate concentrations close to those inducing 50% loss of cell viability produced. In addition, mitochondrial membrane depolarization within cardiomyocytes, monitored with tetramethylrhodamine ethyl esther or with 3,3',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide, were observed after only 6 h of incubation with decavanadate or metavanadate. The concentration needed for 50% mitochondrial depolarization was 6.5 +/- 1 microM total vanadium for both decavanadate (0.65 microM V 10) and metavanadate. In conclusion, mitochondrial membrane depolarization was an early event in decavanadate- and monovanadate-induced necrotic cell death of cardiomyocytes.

  17. Depolarization corrections to the coercive field in thin-film ferroelectrics

    CERN Document Server

    Dawber, M; Littlewood, P B; Scott, J F

    2003-01-01

    Empirically, the coercive field needed to reverse the polarization in a ferroelectric increases with decreasing film thickness. For ferroelectric films of 100 mu m to 100 nm in thickness the coercive field has been successfully described by a semi-empirical scaling law. Accounting for depolarization corrections, we show that this scaling behaviour is consistent with field measurements of ultrathin ferroelectric capacitors down to one nanometre in film thickness. Our results also indicate that the minimum film thickness, determined by a polarization instability, can be tuned by the choice of electrodes, and recommendations for next-generation ferroelectric devices are discussed. (letter to the editor)

  18. Flux lattice behavior in high- T sub c materials studied by neutron depolarization

    Energy Technology Data Exchange (ETDEWEB)

    Crow, M.L.; Goyette, R.J.; Nunes, A.C.; Pickart, S.J. (University of Rhode Island, Kingston, Rhode Island 02881 (USA)); McGuire, T.R.; Shinde, S.; Shaw, T.M. (IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (USA))

    1990-05-01

    The depolarization of a neutron beam passing through a sample of the high-{ital T}{sub {ital c}} superconductor YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} has been measured as a function of temperature and applied field. The difference in behavior between field-cooled and zero-field-cooled states, the observation of hysteresis correlated with {ital H}{sub {ital c}1}, and the disappearance of the effect near 55 K (below {ital T}{sub {ital c}}) suggest an explanation in terms of vortex line lattice formation with possible connection to recently proposed flux line entanglement and melting.

  19. CHARACTERIZATION TESTING AND ANALYSIS OF SINGLE CELL SO2 DEPOLARIZED ELECTROLYZER

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J; Timothy Steeper, T

    2006-09-15

    This document reports work performed at the Savannah River National Laboratory (SRNL) that further develops the use of a proton exchange membrane or PEM-type electrochemical cell to produce hydrogen via SO{sub 2}-depolarized water electrolysis. This work was begun at SRNL in 2005. This research is valuable in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The HyS Process is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the acid decomposition portion of the cycle. The focus of this work was to conduct single cell electrolyzer tests in order to prove the concept of SO{sub 2}-depolarization and to determine how the results can be used to evaluate the performance of key components of the HyS Process. A test facility for conducting SO{sub 2}-depolarized electrolyzer (SDE) testing was designed, constructed and commissioned. The maximum cell current is 50 amperes, which is equivalent to a hydrogen production rate of approximately 20 liters per hour. Feed to the anode of the electrolyzer is sulfuric acid solutions containing dissolved sulfur dioxide. The partial pressure of sulfur dioxide may be varied in the range of 1 to 6 atm (15 to 90 psia). Temperatures may be controlled in the range from ambient to 80 C. Hydrogen generated at the cathode of the cell is collected for the purpose of flow measurement and composition analysis. The test facility proved to be easy to

  20. Rotational relaxation of 70S ribosomes by a depolarization method using triplet probes.

    Science.gov (United States)

    Lavalette, D; Amand, B; Pochon, F

    1977-01-01

    Rotational relaxation on the microsecond time scale has been followed by a depolarization technique using the properties of the long-lived triplet state of covalently bound labels. Two triplet probes, which efficiently bind to ribosomal proteins, are described. The rotational correlation time of 70S ribosomes of Escherichia coli has been measured. The average hydrodynamic radius of the functionally active 70S particle in solution has been estimated to 147 A. A concentration dependence of the correlation time has been observed, which may result from an association of the 70S ribosomes to form 100S dimers. PMID:323851

  1. Local mobility of polymer chain grafted onto polyethylene monitored by fluorescence depolarization

    Science.gov (United States)

    Tsuneda, Satoshi; Endo, Toshihiro; Saito, Kyoichi; Sugita, Kazuyuki; Horie, Kazuyuki; Yamashita, Takashi; Sugo, Takanobu

    1997-08-01

    The fluorescence depolarization method was used for investigating the local mobility of polymer chains grafted onto a porous polyethylene membrane. The real value of the rotational diffusion coefficient of a dansyl probe attached to the grafted polymer chain was obtained by using a correction method which eliminated the effect of multiple scattering on fluorescence anisotropy. The rotational mobility of the dansyl probe attached to the grafted polymer chain was sensitive to both degree of grafting and solvent polarity, which indicated that the conformation of the grafted polymer chain and the pore size of the base membrane strongly governed the dynamic parameters of the grafted polymer chain.

  2. Depolarization Induced Suppression of Excitation and the Emergence of Ultraslow Rhythms in Neural Networks

    Science.gov (United States)

    Hlinka, J.; Coombes, S.

    2010-02-01

    Ultraslow fluctuations (0.01-0.1 Hz) are a feature of intrinsic brain activity of as yet unclear origin. We propose a candidate mechanism based on retrograde endocannabinoid signaling in a synaptically coupled network of excitatory neurons. This is known to cause depolarization-induced suppression of excitation (DISE), which we model phenomenologically. We construct emergent network oscillations in a globally coupled network and show that for strong synaptic coupling DISE can lead to a synchronized population burst at the frequencies of resting brain rhythms.

  3. Inhibitory nature of tiagabine-augmented GABAA receptor-mediated depolarizing responses in hippocampal pyramidal cells.

    Science.gov (United States)

    Jackson, M F; Esplin, B; Capek, R

    1999-03-01

    Tiagabine is a potent GABA uptake inhibitor with demonstrated anticonvulsant activity. GABA uptake inhibitors are believed to produce their anticonvulsant effects by prolonging the postsynaptic actions of GABA, released during episodes of neuronal hyperexcitability. However, tiagabine has recently been reported to facilitate the depolarizing actions of GABA in the CNS of adult rats following the stimulation of inhibitory pathways at a frequency (100 Hz) intended to mimic interneuronal activation during epileptiform activity. In the present study, we performed extracellular and whole cell recordings from CA1 pyramidal neurons in rat hippocampal slices to examine the functional consequences of tiagabine-augmented GABA-mediated depolarizing responses. Orthodromic population spikes (PSs), elicited from the stratum radiatum, were inhibited following the activation of recurrent inhibitory pathways by antidromic conditioning stimulation of the alveus, which consisted of either a single stimulus or a train of stimuli delivered at high-frequency (100 Hz, 200 ms). The inhibition of orthodromic PSs produced by high-frequency conditioning stimulation (HFS), which was always of much greater strength and duration than that produced by a single conditioning stimulus, was greatly enhanced following the bath application of tiagabine (2-100 microM). Thus, in the presence of tiagabine (20 microM), orthodromic PSs, evoked 200 and 800 ms following HFS, were inhibited to 7.8 +/- 2.6% (mean +/- SE) and 34.4 +/- 18.5% of their unconditioned amplitudes compared with only 35.4 +/- 12.7% and 98.8 +/- 12.4% in control. Whole cell recordings revealed that the bath application of tiagabine (20 microM) either caused the appearance or greatly enhanced the amplitude of GABA-mediated depolarizing responses (DR). Excitatory postsynaptic potentials (EPSPs) evoked from stratum radiatum at time points that coincided with the DR were inhibited to below the threshold for action-potential firing

  4. Accuracy of depolarization and delay spread predictions using advanced ray-based modeling in indoor scenarios

    Directory of Open Access Journals (Sweden)

    Mani Francesco

    2011-01-01

    Full Text Available Abstract This article investigates the prediction accuracy of an advanced deterministic propagation model in terms of channel depolarization and frequency selectivity for indoor wireless propagation. In addition to specular reflection and diffraction, the developed ray tracing tool considers penetration through dielectric blocks and/or diffuse scattering mechanisms. The sensitivity and prediction accuracy analysis is based on two measurement campaigns carried out in a warehouse and an office building. It is shown that the implementation of diffuse scattering into RT significantly increases the accuracy of the cross-polar discrimination prediction, whereas the delay-spread prediction is only marginally improved.

  5. Spatial evolution of depolarization in homogeneous turbid media within the differential Mueller matrix formalism.

    Science.gov (United States)

    Agarwal, Naman; Yoon, Jiho; Garcia-Caurel, Enric; Novikova, Tatiana; Vanel, Jean-Charles; Pierangelo, Angelo; Bykov, Alexander; Popov, Alexey; Meglinski, Igor; Ossikovski, Razvigor

    2015-12-01

    We show, through visible-range Mueller polarimetry, as well as numerical simulations, that the depolarization in a homogeneous turbid medium consisting of submicron spherical particles follows a parabolic law with the path-length traveled by light through the medium. This result is in full agreement with the phenomenological theory of the fluctuating medium within the framework of the differential Mueller matrix formalism. We further found that the standard deviations of the fluctuating elementary polarization properties of the medium depend linearly on the concentration of particles. These findings are believed to be useful for the phenomenological interpretation of polarimetric experiments, with special emphasis on biomedical applications.

  6. CHARACTERIZATION TESTING AND ANALYSIS OF SINGLE CELL SO2 DEPOLARIZED ELECTROLYZER

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J; Timothy Steeper, T

    2006-09-15

    This document reports work performed at the Savannah River National Laboratory (SRNL) that further develops the use of a proton exchange membrane or PEM-type electrochemical cell to produce hydrogen via SO{sub 2}-depolarized water electrolysis. This work was begun at SRNL in 2005. This research is valuable in achieving the ultimate goal of an economical hydrogen production process based on the Hybrid Sulfur (HyS) Cycle. The HyS Process is a hybrid thermochemical cycle that may be used in conjunction with advanced nuclear reactors or centralized solar receivers to produce hydrogen by water-splitting. Like all other sulfur-based cycles, HyS utilizes the high temperature thermal decomposition of sulfuric acid to produce oxygen. The unique aspect of HyS is the generation of hydrogen in a water electrolyzer that is operated under conditions where dissolved sulfur dioxide depolarizes the anodic reaction, resulting in substantial voltage reduction. Sulfur dioxide is oxidized at the anode, producing sulfuric acid that is sent to the acid decomposition portion of the cycle. The focus of this work was to conduct single cell electrolyzer tests in order to prove the concept of SO{sub 2}-depolarization and to determine how the results can be used to evaluate the performance of key components of the HyS Process. A test facility for conducting SO{sub 2}-depolarized electrolyzer (SDE) testing was designed, constructed and commissioned. The maximum cell current is 50 amperes, which is equivalent to a hydrogen production rate of approximately 20 liters per hour. Feed to the anode of the electrolyzer is sulfuric acid solutions containing dissolved sulfur dioxide. The partial pressure of sulfur dioxide may be varied in the range of 1 to 6 atm (15 to 90 psia). Temperatures may be controlled in the range from ambient to 80 C. Hydrogen generated at the cathode of the cell is collected for the purpose of flow measurement and composition analysis. The test facility proved to be easy to

  7. If Information Wants To Be Free...Then Who's Going To Pay for It? [and] A Question of Access: SPARC, BioOne, and Society-Driven Electronic Publishing [and] Who Is Going To Mine Digital Library Resources? And How?

    Science.gov (United States)

    Kaser, Richard T.; Johnson, Richard K.; Rudner, Lawrence

    2000-01-01

    Discusses Fair Use and the public perception; models for funding information services; publishers illusion that information is/should be free; Internet's role in making information freely available; scholarly communication systems: Scholarly Publishing and Academic Resources Coalition (SPARC) and BioOne (an electronic aggregation of bioscience…

  8. If Information Wants To Be Free...Then Who's Going To Pay for It? [and] A Question of Access: SPARC, BioOne, and Society-Driven Electronic Publishing [and] Who Is Going To Mine Digital Library Resources? And How?

    Science.gov (United States)

    Kaser, Richard T.; Johnson, Richard K.; Rudner, Lawrence

    2000-01-01

    Discusses Fair Use and the public perception; models for funding information services; publishers illusion that information is/should be free; Internet's role in making information freely available; scholarly communication systems: Scholarly Publishing and Academic Resources Coalition (SPARC) and BioOne (an electronic aggregation of bioscience…

  9. Impact of two interventions on timeliness and data quality of an electronic disease surveillance system in a resource limited setting (Peru: a prospective evaluation

    Directory of Open Access Journals (Sweden)

    Quispe Jose A

    2009-03-01

    Full Text Available Abstract Background A timely detection of outbreaks through surveillance is needed in order to prevent future pandemics. However, current surveillance systems may not be prepared to accomplish this goal, especially in resource limited settings. As data quality and timeliness are attributes that improve outbreak detection capacity, we assessed the effect of two interventions on such attributes in Alerta, an electronic disease surveillance system in the Peruvian Navy. Methods 40 Alerta reporting units (18 clinics and 22 ships were included in a 12-week prospective evaluation project. After a short refresher course on the notification process, units were randomly assigned to either a phone, visit or control group. Phone group sites were called three hours before the biweekly reporting deadline if they had not sent their report. Visit group sites received supervision visits on weeks 4 & 8, but no phone calls. The control group sites were not contacted by phone or visited. Timeliness and data quality were assessed by calculating the percentage of reports sent on time and percentage of errors per total number of reports, respectively. Results Timeliness improved in the phone group from 64.6% to 84% in clinics (+19.4 [95% CI, +10.3 to +28.6]; p Conclusion Regular phone reminders significantly improved timeliness of reports in clinics and ships, whereas supervision visits led to improved data quality only among clinics. Further investigations are needed to establish the cost-effectiveness and optimal use of each of these strategies.

  10. Metadata for Electronic Information Resources

    Science.gov (United States)

    2004-12-01

    among digital libraries . METS provides an XML DTD that can point to metadata in other schemes by declaring the scheme that is being used. For example...site: www.niso.org/news/Metadata_simpler.pdf International Federation of Library Associations and Institutions (IFLA). (2002). Digital Libraries : Metadata

  11. 基于ASP.NET的电子资源整合系统设计与实现%Design and Realization of an Integrated Electronic Resource System Based on ASP.NET

    Institute of Scientific and Technical Information of China (English)

    冀宪武; 陈晓冬; 何燕; 杨方; 曹宇宾; 潘大丰

    2011-01-01

    电子信息资源的整合是数字图书馆建设中的一个非常重要的环节,论述了数字资源整合的必要性,结合农业图书馆的实际,开展了电子资源整合服务平台的设计与实现。%The integration of electronic information resources is a very important part in digital library construction.In this paper,the necessity for integration of digital resources was discussed,combined with the actuality of the agricultural library,the design and implementation about services platform of electronic resource integration were carried out.

  12. Membrane depolarization induces calcium-dependent secretion of tissue plasminogen activator.

    Science.gov (United States)

    Gualandris, A; Jones, T E; Strickland, S; Tsirka, S E

    1996-04-01

    Tissue plasminogen activator (tPA), a serine protease that converts inactive plasminogen to active plasmin, is produced in the rat and mouse hippocampus and participates in neuronal plasticity. To help define the role of tPA in the nervous system, we have analyzed the regulation of its expression in the neuronal cell line PC12. In control cultures, tPA activity is exclusively cell-associated, and no activity is measurable in the culture medium. When the cells are treated with depolarizing agents, such as KCI, tPA activity becomes detectable in the medium. The increased secreted tPA activity is not accompanied by an increase in tPA mRNA levels, and it is not blocked by protein synthesis inhibitors. In contrast, tPA release is abolished by Ca2+ channel blockers, suggesting that chemically induced membrane depolarization stimulates the secretion of preformed enzyme. Moreover, KCI has a similar effect in vivo when administered to the murine brain via an osmotic pump: tPA activity increases along the CA2-CA3 regions and dentate gyrus of the hippocampal formation. These results demonstrate a neuronal activity-dependent secretory mechanism that can rapidly increase the amount of tPA in neuronal tissue.

  13. Low temperature thermal windowing (TW) thermally stimulated depolarization current (TSDC) setup

    Science.gov (United States)

    Jain, Deepti; Sharath Chandra, L. S.; Nath, R.; Ganesan, V.

    2012-02-01

    We report here the design and implementation of a precise and easy to operate thermally stimulated depolarization current (TSDC) measurement setup for temperature range 77-400 K. The sample loading is made simple by sandwiching the sample between two copper disk electrodes using a spring-shaft arrangement. The salient features of the setup are precise thermal windowing (TW) capability and linear heating rate over the entire temperature range. The resolution in the measurement of depolarization current is of the order of 7×10-14 A. This is achieved by means of good electrical insulation of the electrodes from the rest of the setup and utilization of low noise circuitry. Precision of the system is demonstrated by its capability to resolve constituent relaxations present in complex relaxation processes using the TW experiments. Study and detection of glass transition processes in polyethylene terephthalate, four relaxation processes in polymethyl methacrylate, glass and crystallization transitions along with the onset of ferroelectric Curie transitions in polyvinylidene fluoride and characterization of electret state in amino acids l-arginine, phenylalanine, tyrosine, tryptophan, glutamic acid, glutamine and methionine show the versatility of our setup.

  14. Depolarization of the tegument precedes morphological alterations in Echinococcus granulosus protoscoleces incubated with ivermectin.

    Science.gov (United States)

    Pérez-Serrano, J; Grosman, C; Urrea-París, M A; Denegri, G; Casado, N; Rodríguez-Caabeiro, F

    2001-10-01

    The nematocidal activity of ivermectin (IVM) largely arises from its activity as a potent agonist of muscular and neuronal glutamate-gated chloride channels. A cestocidal effect has also been suggested following in vitro treatments, but the molecular basis of this activity is not clear. We studied the effect of IVM on the metacestode stage of the tapeworm Echinococcus granulosus by assessing the viability, ultrastructure, and tegumental membrane potential as a function of drug concentration and incubation time. Concentrations of 0.1 and 1.0 microg/ml of IVM had no effect on any of these three parameters for up to 6 days of treatment. A concentration of 10 microg/ml, however, elicited a sequence of alterations that started with a approximately 20-mV depolarization of the tegumental membrane, and was followed by rostellar disorganization, rigid paralysis and, eventually, loss of viability. It is likely that the IVM-induced depolarization of the tegument acts as the signal that initiates the cascade of degenerative processes that leads to the parasite's death. This would place the tegument as the primary target of action of IVM on cestodes. As an appropriate chemotherapy for the hydatid disease is still lacking, the cestocidal effect of IVM reported here is worth considering.

  15. Constraining regular and turbulent magnetic field strengths in M51 via Faraday depolarization

    CERN Document Server

    Shneider, Carl; Fletcher, Andrew; Shukurov, Anvar

    2014-01-01

    We employ an analytical model that incorporates both wavelength-dependent and wavelength-independent depolarization to describe radio polarimetric observations of polarization at $\\lambda \\lambda \\lambda \\, 3.5, 6.2, 20.5$ cm in M51 (NGC 5194). The aim is to constrain both the regular and turbulent magnetic field strengths in the disk and halo, modeled as a two- or three-layer magneto-ionic medium, via differential Faraday rotation and internal Faraday dispersion, along with wavelength-independent depolarization arising from turbulent magnetic fields. A reduced chi-squared analysis is used for the statistical comparison of predicted to observed polarization maps to determine the best-fit magnetic field configuration at each of four radial rings spanning $2.4 - 7.2$ kpc in $1.2$ kpc increments. We find that a two-layer modeling approach provides a better fit to the observations than a three-layer model, where the near and far sides of the halo are taken to be identical, although the resulting best-fit magnetic...

  16. Depolarization Ratio of Clouds Measured by Multiple-Field of view Multiple Scattering Polarization Lidar

    Science.gov (United States)

    Okamoto, Hajime; Sato, Kaori; Makino, Toshiyuki; Nishizawa, Tomoaki; Sugimoto, Nobuo; Jin, Yoshitaka; Shimizu, Atsushi

    2016-06-01

    We have developed the Multiple Field of view Multiple Scattering Polarization Lidar (MFMSPL) system for the study of optically thick low-level clouds. It has 8 telescopes; 4 telescopes for parallel channels and another 4 for perpendicular channels. The MFMSPL is the first lidar system that can measure depolarization ratio for optically thick clouds where multiple scattering is dominant. Field of view of each channel was 10mrad and was mounted with different angles ranging from 0 mrad (vertical) to 30mrad. And footprint size from the total FOV was achieved to be close to that of Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar at the altitude of 1km in order to reproduce similar degree of multiple scattering effects as observed from space. The MFMSPL has started observations since June 2014 and has been continuously operated at National Institute for Environmental Studies (NIES) in Tsukuba, Japan. Observations proved expected performance such that measured depolarization ratio was comparable to the one observed by CALIPSO lidar.

  17. Anions Govern Cell Volume: A Case Study of Relative Astrocytic and Neuronal Swelling in Spreading Depolarization.

    Directory of Open Access Journals (Sweden)

    Niklas Hübel

    Full Text Available Cell volume changes are ubiquitous in normal and pathological activity of the brain. Nevertheless, we know little about the dynamics of cell and tissue swelling, and the differential changes in the volumes of neurons and glia during pathological states such as spreading depolarizations (SD under ischemic and non-ischemic conditions, and epileptic seizures. By combining the Hodgkin-Huxley type spiking dynamics, dynamic ion concentrations, and simultaneous neuronal and astroglial volume changes into a comprehensive model, we elucidate why glial cells swell more than neurons in SD and the special case of anoxic depolarization (AD, and explore the relative contributions of the two cell types to tissue swelling. Our results demonstrate that anion channels, particularly Cl-, are intrinsically connected to cell swelling and blocking these currents prevents changes in cell volume. The model is based on a simple and physiologically realistic description. We introduce model extensions that are either derived purely from first physical principles of electroneutrality, osmosis, and conservation of particles, or by a phenomenological combination of these principles and known physiological facts. This work provides insights into numerous studies related to neuronal and glial volume changes in SD that otherwise seem contradictory, and is broadly applicable to swelling in other cell types and conditions.

  18. Anoxic depolarization of hippocampal astrocytes: possible modulation by P2X7 receptors.

    Science.gov (United States)

    Leichsenring, Anna; Riedel, Thomas; Qin, Ying; Rubini, Patrizia; Illes, Peter

    2013-01-01

    Current responses from CA1 neurons and stratum oriens astrocytes were recorded from hippocampal brain slices by means of the whole-cell patch-clamp technique. Anoxic depolarization (AD) was induced by an oxygen/glucose-deprived (OGD) medium also containing sodium iodoacetate and antimycin, in order to block glycolysis and oxidative phosphorylation, respectively. Anoxic depolarization has been reported to be due to the sudden increase of the extracellular K(+) concentration and the accompanying explosive rise in glutamate concentration. We asked ourselves whether the release of ATP activating P2X7 receptors is also involved in the AD. Although, the AD was evoked in absolute synchrony in neurons and astrocytes, and the NMDA receptor antagonistic AP-5 depressed these responses, neither the non-selective P2 receptor antagonist PPADS, nor the highly selective P2X7 receptor antagonist A438079 interfered with the AD or its delay time in neurons/astrocytes after inducing chemical hypoxia. However, A438079, but not PPADS increased in astrocytes the slow inward current observed in a hypoxic medium. It is concluded that ATP co-released with glutamate by hypoxic stimulation has only a minor function in the present brain slice system.

  19. Understanding order in compositionally graded ferroelectrics: Flexoelectricity, gradient, and depolarization field effects

    Science.gov (United States)

    Zhang, J.; Xu, R.; Damodaran, A. R.; Chen, Z.-H.; Martin, L. W.

    2014-06-01

    A nonlinear thermodynamic formalism based on Ginzburg-Landau-Devonshire theory is developed to describe the total free energy density in (001)-oriented, compositionally graded, and monodomain ferroelectric films including the relative contributions and importance of flexoelectric, gradient, and depolarization energy terms. The effects of these energies on the evolution of the spontaneous polarization, dielectric permittivity, and the pyroelectric coefficient as a function of position throughout the film thickness, temperature, and epitaxial strain state are explored. In general, the presence of a compositional gradient and the three energy terms tend to stabilize a polar, ferroelectric state even in compositions that should be paraelectric in the bulk. Flexoelectric effects produce large built-in fields which diminish the temperature dependence of the polarization and susceptibilities. Gradient energy terms, here used to describe short-scale correlation between dipoles, have minimal impact on the polarization and susceptibilities. Finally, depolarization energy significantly impacts the temperature and strain dependence, as well as the magnitude, of the susceptibilities. This approach provides guidance on how to more accurately model compositionally graded films and presents experimental approaches that could enable differentiation and determination of the constitutive coefficients of interest.

  20. Library resources on the Internet

    Science.gov (United States)

    Buchanan, Nancy L.

    1995-07-01

    Library resources are prevalent on the Internet. Library catalogs, electronic books, electronic periodicals, periodical indexes, reference sources, and U.S. Government documents are available by telnet, Gopher, World Wide Web, and FTP. Comparatively few copyrighted library resources are available freely on the Internet. Internet implementations of library resources can add useful features, such as full-text searching. There are discussion lists, Gophers, and World Wide Web pages to help users keep up with new resources and changes to existing ones. The future will bring more library resources, more types of library resources, and more integrated implementations of such resources to the Internet.

  1. Analysis of the depolarizing properties of normal and adenomatous polyps in colon mucosa for the early diagnosis of precancerous lesions

    Science.gov (United States)

    Ortega-Quijano, Noé; Fanjul-Vélez, Félix; de Cos-Pérez, Jesús; Arce-Diego, José Luis

    2011-09-01

    Optical characterization of biological tissues by means of polarimetric techniques is an area of growing interest. Polarized light can be used for malignant neoplasms detection. To our knowledge, few studies have so far focused on lesions that are prone to result in cancer. In this work we present a polarimetric study of depolarization in prepathological tissues. Specifically, we will focus on premalignant lesions in human colon due to their clinical relevance. Colonic adenoma, the potential precursor of malignant adenocarcinoma, provokes significant structural modifications in colon mucosa that affect light depolarization. The depolarizing properties of normal and adenomatous polyps mucosa are compared. The average linear degree of polarization is shown to present a strong dependence with the precancerous state of the colonic tissue. This method has the potential to enable an early diagnosis of colon cancer.

  2. Characteristics of Gintonin-Mediated Membrane Depolarization of Pacemaker Activity in Cultured Interstitial Cells of Cajal

    Directory of Open Access Journals (Sweden)

    Byung Joo Kim

    2014-08-01

    Full Text Available Background/Aims: Ginseng regulates gastrointestinal (GI motor activity but the underlying components and molecular mechanisms are unknown. We investigated the effect of gintonin, a novel ginseng-derived G protein-coupled lysophosphatidic acid (LPA receptor ligand, on the pacemaker activity of the interstitial cells of Cajal (ICC in murine small intestine and GI motility. Materials and Methods: Enzymatic digestion was used to dissociate ICC from mouse small intestines. The whole-cell patch-clamp configuration was used to record pacemaker potentials and currents from cultured ICC in the absence or presence of gintonin. In vivo effects of gintonin on gastrointestinal (GI motility were investigated by measuring the intestinal transit rate (ITR of Evans blue in normal and streptozotocin (STZ-induced diabetic mice. Results: We investigated the effects of gintonin on pacemaker potentials and currents in cultured ICC from mouse small intestine. Gintonin caused membrane depolarization in current clamp mode but this action was blocked by Ki16425, an LPA1/3 receptor antagonist, and by the addition of GDPβS, a GTP-binding protein inhibitor, into the ICC. To study the gintonin signaling pathway, we examined the effects of U-73122, an active PLC inhibitor, and chelerythrine and calphostin, which inhibit PKC. All inhibitors blocked gintonin actions on pacemaker potentials, but not completely. Gintonin-mediated depolarization was lower in Ca2+-free than in Ca2+-containing external solutions and was blocked by thapsigargin. We found that, in ICC, gintonin also activated Ca2+-activated Cl- channels (TMEM16A, ANO1, but not TRPM7 channels. In vivo, gintonin (10-100 mg/kg, p.o. not only significantly increased the ITR in normal mice but also ameliorated STZ-induced diabetic GI motility retardation in a dose-dependent manner. Conclusions: Gintonin-mediated membrane depolarization of pacemaker activity and ANO1 activation are coupled to the stimulation of GI

  3. Multiply scattered waves through a spatially random medium : entropy production and depolarization

    Science.gov (United States)

    Bicout, Dominique; Brosseau, Christian

    1992-11-01

    This paper deals with the depolarization and decoherence effects of an incident pure state of polarization and of arbitrary state of coherence by a linear scattering medium which changes randomly with position. Using symmetry arguments and a maximum entropy principle we deduce the general form of the Mueller matrix describing the scattering medium which is consistent with the explicit computation done in the context of the Bethe-Salpeter equation handled in the diffusion approximation. The main result expresses the output degree of polarization and degree of spatial coherence as a function of the number of scattering events. From these results, two main conclusions can be drawn. The first is that the entropy production per scattering due to the irreversible process of depolarization is an exponentially decreasing function of the number of scattering events. The second result obtained is that full depolarization of linearly polarized light by Rayleigh scatterers requires more scattering events (typically a factor-of-2) than are required for a circularly polarized lightwave. Dans cette étude, on considère les phénomènes de dépolarisation et de décohérence d'un faisceau d'ondes planes incident, d'état pur de polarisation et d'état arbitraire de cohérence, par intéraction avec un milieu diffusant désordonné. Par des arguments de symétrie et un principe d'entropie maximum, nous déduisons la forme de la matrice de Mueller caractérisant le milieu diffusant qui est en accord avec le calcul explicite basé sur l'équation de Bethe-Salpeter traitée dans l'approximation de la diffusion. Le résultat principal exprime les degrés de polarisation et de cohérence spatiale en fonction du nombre de diffusions. Deux faits saillants sont à noter. Le premier exprime la décroissance exponentielle de la production d'entropie due à l'irréversibilité du processus de dépolarisation, en fonction du nombre de diffusions. Le second indique que la dépolarisation compl

  4. Evidence that heterosynaptic depolarization underlies associativity of long-term potentiation in rat hippocampus.

    Science.gov (United States)

    Clark, K A; Collingridge, G L

    1996-01-15

    1. Whole-cell patch-clamp recording has been used to study the effect of heterosynaptic depolarization on pure N-methyl-D-aspartate (NMDA) receptor-mediated synaptic transmission in the CA1 region of rat hippocampal slices. 2. In neurones voltage clamped at -60 mV, paired-pulse stimulation of one set of Schaffer collateral-commissural fibres resulted in homosynaptic paired-pulse facilitation of the NMDA receptor-mediated excitatory postsynaptic current (EPSCN). In contrast, stimulation of one set of fibres prior to stimulation of a second set of fibres (i.e. heterosynaptic paired-pulse stimulation) did not result in any heterosynaptic interactions. 3. However, under current-clamp conditions, heterosynaptic paired-pulse stimulation resulted in heterosynaptic 'paired-pulse facilitation' of the NMDA receptor-mediated excitatory postsynaptic potential (EPSPN). 4. In neurones held at -50 or -40 mV, perfusion of nominally Mg(2+)-free medium converted the response to heterosynaptic paired-pulse stimulation from 'heterosynaptic facilitation' to 'heterosynaptic depression' of EPSPN. 5. When neurones were held at potentials of between -30 and +40 mV then heterosynaptic paired-pulse stimulation, in normal Mg(2+)-containing medium, resulted in 'paired-pulse depression' of EPSPN. Under voltage-clamp conditions (tested at +40 mV) no heterosynaptic interactions were seen. 6. The time course of 'heterosynaptic facilitation' at -60 mV and of 'heterosynaptic depression' at +40 mV of EPSPN was similar to the time course of EPSCN. 7. We conclude, firstly, that the voltage clamp is able to prevent any voltage breakthrough associated with the synaptic activation of NMDA receptors from influencing neighbouring synapses. Secondly, when the neurone is not voltage clamped these same synapses are strongly influenced by the spreading depolarization generated by the synaptic activation of their neighbours. The time course and direction of this influence are compatible with the hypothesis that

  5. Research progress in rebound depolarization of neurons%神经元去极化反跳现象的研究进展

    Institute of Scientific and Technical Information of China (English)

    李凌超; 朱梦叶; 张达颖; 柳涛

    2016-01-01

    [ ABSTRACT] Rebound depolarization is a special phenomenon of the neurons which generates action potential fol-lowed by a hyperpolarization stimulation.It can be recorded in many kinds of neurons and is the intrinsic membrane charac-teristic of them.Rebound depolarization plays an important role in regulating the firing pattern, rhythmic activity and sy-naptic plasticity of neurons.This review focuses on the basic characteristics, the function and mechanism of the rebound depolarization in physiological and pathological conditions, which provides reference for the clinical treatment of rebound depolarization-related diseases.

  6. 基于 EZproxy 日志的电子资源异常访问行为研究%Research on Abnormal Access to Electronic Resources Based on EZproxy Logs

    Institute of Scientific and Technical Information of China (English)

    雷东升; 郭振英

    2016-01-01

    The off - campus access to electronic resources in the library benefits readers a lot .Meanwhile ,some abnormal access behavior arises .The paper analyzed the electronic resources access log with EZproxyog proxy server ,designed and devel-oped the EZproxy log analysis system so as to pretreat ,upload ,count and analyze the access log to electronic resources .To dis-cover the abnormal access behavior of readers on the basis of the characteristics of their access and to classify the abnormal behav -ior , the paper could avoid that IP is temporarily blocked by the supporters of database of electronic resources in the library so that can maintain the readers' rights and improve the efficiency of resource access .%校外访问图书馆电子资源在方便读者的同时也出现一些异常访问行为,利用 EZproxy 代理服务器日志信息分析异常访问行为特征,设计并开发 EZproxy 日志分析系统,完成对电子资源访问日志的预处理、上传、统计和分析,从访问特征发掘读者的异常访问行为,对异常行为情况分类处理,基本避免了异常访问行为导致图书馆电子资源被数据库商临时封掉 IP 的现象出现,维护图书馆读者的合法权利,提高资源访问效率。

  7. Thyrotropin-releasing hormone (TRH) depolarizes a subset of inspiratory neurons in the newborn mouse brain stem in vitro

    DEFF Research Database (Denmark)

    Rekling, J C; Champagnat, J; Denavit-Saubié, M

    1996-01-01

    was accompanied by an increase in spontaneous excitatory synaptic activity that disappeared late during the TRH application. The duration of the inspiratory potentials was increased, indicating that the hypoglossal motoneurons received a longer duration synaptic input from the respiratory rhythm generator. 4...... markedly during TRH. Four cells showed a transient depolarization with an increase in input resistance during TRH with TTX present in the superfusing solution. Thus type-3 neurons are depolarized postsynaptically by TRH. 7. We conclude that TRH increases the frequency of the respiratory rhythm in newborn...

  8. Relationship between depolarization-induced force responses and Ca2+ content in skeletal muscle fibres of rat and toad.

    Science.gov (United States)

    Owen, V J; Lamb, G D; Stephenson, D G; Fryer, M W

    1997-02-01

    1. The relationship between the total Ca2+ content of a muscle fibre and the magnitude of the force response to depolarization was examined in mechanically skinned fibres from the iliofibularis muscle of the toad and the extensor digitorum longus muscle of the rat. The response to depolarization in each skinned fibre was assessed either at the endogenous level of Ca2+ content or after depleting the fibre of Ca2+ to some degree. Ca2+ content was determined by a fibre lysing technique. 2. In both muscle types, the total Ca2+ content could be reduced from the endogenous level of approximately 1.3 mmol l-1 (expressed relative to intact fibre volume) to approximately 0.25 mmol l-1 by either depolarization or caffeine application in the presence of Ca2+ chelators, showing that the great majority of the Ca2+ was stored in the sarcoplasmic reticulum (SR). Chelation of Ca2+ in the transverse tubular (T-) system, either by exposure of fibres to EGTA before skinning or by permeabilizing the T-system with saponin after skinning, reduced the lower limit of Ca2+ content to < or = 0.12 mmol l-1, indicating that 10-20% of the total fibre Ca2+ resided in the T-system. 3. In toad fibres, both the peak and the area (i.e. time integral) of the force response to depolarization were reduced by any reduction in SR Ca2+ content, with both decreasing to zero in an approximately linear manner as the SR Ca2+ content was reduced to < 15% of the endogenous level. In rat fibres, the peak size of the force response was less affected by small decreases in SR content, but both the peak and area of the response decreased to zero with greater depletion. In partially depleted toad fibres, inhibition of SR Ca2+ uptake potentiated the force response to depolarization almost 2-fold. 4. The results show that in this skinned fibre preparation: (a) T-system depolarization and caffeine application can each virtually fully deplete the SR of Ca2+, irrespective of any putative inhibitory effect of SR depletion

  9. Hydrogen depolarized carbon dioxide concentrator performance improvements and cell pair structural tests. [for manned space station

    Science.gov (United States)

    Huddleston, J. D.; Aylward, J. R.

    1973-01-01

    The investigations and testing associated with the CO2 removal efficiency and voltage degradation of a hydrogen depolarized carbon oxide concentrator are reported. Also discussed is the vibration testing of a water vapor electrolysis cell pair. Performance testing of various HDC cell pairs with Cs2CO3 electrolyte provided sufficient parametric and endurance data to size a six man space station prototype CO2 removal system as having 36 HDC cell pairs, and to verify a life capability exceeding six moths. Testing also demonstrated that tetramethylammonium carbonate is an acceptable HDC electrolyte for operating over the relative humidity range of 30 to 90 percent and over a temperature range of 50 to 80 F.

  10. Decomposition of a depolarizing Mueller matrix into its nondepolarizing components by using symmetry conditions.

    Science.gov (United States)

    Kuntman, Ertan; Arteaga, Oriol

    2016-04-01

    A procedure for the parallel decomposition of a depolarizing Mueller matrix with an associated rank 2 covariance matrix into its two nondepolarizing components is presented. We show that, if one of the components agrees with certain symmetry conditions, the arbitrary decomposition becomes unique, and its calculation is straightforward. Solutions for six different symmetries, which are relevant for the physical interpretation of polarimetric measurements, are provided. With this procedure, a single polarimetric measurement is sufficient to fully disclose the complete polarimetric response of two different systems and evaluate their weights in the overall response. The decomposition method we propose is illustrated by obtaining the ellipsometric responses of a silicon wafer and a holographic grating from a single measurement in which the light spot illuminates sectors of both materials. In a second example, we use the decomposition to analyze an optical system in which a polarizing film is partially covered by another misaligned film.

  11. Structural relaxation and mode coupling in a non-glassforming liquid: depolarized light scattering in benzene

    Energy Technology Data Exchange (ETDEWEB)

    Wiebel, Sabine [Physik-Department E13, Technische Universitaet Muenchen, Garching (Germany); Wuttke, Joachim [Physik-Department E13, Technische Universitaet Muenchen, Garching (Germany) and Siemens AG, ICN ON RD AT 1, Munich (Germany)]. E-mail: jwuttke@ph.tum.de

    2002-07-01

    We have measured depolarized light scattering in liquid benzene over the whole accessible temperature range and over four decades in frequency. Between 40 and 180 GHz we find a susceptibility peak due to structural relaxation. This peak shows stretching and time-temperature scaling as known from alpha relaxation in glass-forming materials. A simple mode-coupling model provides consistent fits of the entire data set. These qualitative and quantitative results show that structural relaxation in ordinary liquids and alpha relaxation in glass-forming materials are one and the same physical process. Thus, a deeper understanding of equilibrium liquids is reached by applying concepts that were originally developed in the context of glass-transition research. (author)

  12. Depolarized SnO2-based gas anodes for electrowinning of silver in molten chlorides

    Directory of Open Access Journals (Sweden)

    Xiao S.

    2013-01-01

    Full Text Available SnO2-based porous anodes were prepared and the behavior of gas bubbles on the porous anodes with different original coarse grain size, immersed in ethanol to simulate molten chlorides, was primarily investigated. SnO2-based porous anodes were used as gas anodes for the electrowinning of silver in CaCl2-NaCl-CaO-AgCl melts at 680°C. Hydrogen was introduced to the anode/electrolyte interface through the gas anode. Carbon was used as the cathode. Obvious depolarization of the anode potential was observed after the introduction of hydrogen comparing with no reducing gas introduced, indicating the involvement of hydrogen in the anode reaction. Metallic silver was deposited on the cathode.

  13. Discovery of a complex linearly polarized spectrum of Betelgeuse dominated by depolarization of the continuum

    CERN Document Server

    Aurière, M; Ariste, López; Mathias, P; Lèbre, A; Josselin, E; Montargès, M; Petit, P; Chiavassa, A; Paletou, F; Fabas, N; Konstantinova-Antova, R; Donati, J -F; Grunhut, J H; Wade, G A; Herpin, F; Kervella, P; Perrin, G; Tessore, B

    2016-01-01

    Betelgeuse is an M supergiant that harbors spots and giant granules at its surface and presents linear polarization of its continuum. We have previously discovered linear polarization signatures associated with individual lines in the spectra of cool and evolved stars. Here, we investigate whether a similar linearly polarized spectrum exists for Betelgeuse. We used the spectropolarimeter Narval, combining multiple polarimetric sequences to obtain high signal-to-noise ratio spectra of individual lines, as well as the least-squares deconvolution (LSD) approach. We have discovered the existence of a linearly polarized spectrum for Betelgeuse, detecting a rather strong signal (at a few times 10$^{-4}$ of the continuum intensity level), both in individual lines and in the LSD profiles. Studying its properties and the signal observed for the resonant \\ion{Na}{i}\\,D lines, we conclude that we are mainly observing depolarization of the continuum by the absorption lines. The linear polarization of the Betelgeuse conti...

  14. Tensorial depolarization of alkali atoms by isotropic collisions with neutral hydrogen

    CERN Document Server

    Derouich, Moncef

    2012-01-01

    Results. We consider the problem of isotropic collisions between an alkali atom and neutral hydrogen. We calculate the collisional tensorial components of general p and s-states, characterized by their effective principal quantum number $n^{*}$. It is found that the behaviour of the tensorial components obey simple power laws allowing quick calculations of the depolarizing collisional rates. As application, our results should allow a rigorous treatment of the atomic polarization profiles of the D1 -D2 lines of alkali atoms. Conclusions. Close coupling treatments of atomic collisions are needed to decipher the information encoded in the polarized radiation from the Sun. Important problems remain unresolved like the role of collisions in the Paschen-Back conditions.

  15. Whole-exome sequencing and homozygosity analysis implicate depolarization-regulated neuronal genes in autism.

    Directory of Open Access Journals (Sweden)

    Maria H Chahrour

    Full Text Available Although autism has a clear genetic component, the high genetic heterogeneity of the disorder has been a challenge for the identification of causative genes. We used homozygosity analysis to identify probands from nonconsanguineous families that showed evidence of distant shared ancestry, suggesting potentially recessive mutations. Whole-exome sequencing of 16 probands revealed validated homozygous, potentially pathogenic recessive mutations that segregated perfectly with disease in 4/16 families. The candidate genes (UBE3B, CLTCL1, NCKAP5L, ZNF18 encode proteins involved in proteolysis, GTPase-mediated signaling, cytoskeletal organization, and other pathways. Furthermore, neuronal depolarization regulated the transcription of these genes, suggesting potential activity-dependent roles in neurons. We present a multidimensional strategy for filtering whole-exome sequence data to find candidate recessive mutations in autism, which may have broader applicability to other complex, heterogeneous disorders.

  16. Viscosity by Fluorescence Depolarization of Probe Molecules. A Physical Chemistry Laboratory Experiment.

    Energy Technology Data Exchange (ETDEWEB)

    Windisch, Charles F.; Exarhos, Gregory J.; Sharma, Shiv K.

    2005-06-01

    This two-session undergraduate laboratory experiment in physical chemistry involves the measurement of the viscosity of solutions using both a conventional method and a new method based on the fluorescence depolarization of a probe molecule. By comparing the results of the two approaches, students will come to a fundamental understanding of how a macroscopic property (viscosity) and molecular-level properties (molecular dynamics parameters) relate. They will also further their understandnig of the physical chemistry of fluorescence and learn how to perform spectroscopic measurements where polarization conditions are important. The experiment also has ramifications in the practical world, because the optical approach has shown promise as the basis for a sensor for in-situ viscostiy measurement.

  17. Hydrogen sulfide depolarizes neurons in the nucleus of the solitary tract of the rat.

    Science.gov (United States)

    Malik, Rishi; Ferguson, Alastair V

    2016-02-15

    Hydrogen sulfide (H2S) is a gasotransmitter that has been described to affect the membrane potential of neurons in a number of brain areas. Using whole cell patch-clamp electrophysiological techniques, we investigated the effects of H2S on the membrane potential of neurons in the nucleus of the solitary tract (NTS). Whole cell patch clamp recordings were obtained from 300 µm coronal NTS brain slices and bath application of the H2S donor, sodium hydrosulfide (NaHS)(1mM, 5mM and 10mM) was shown to have clear concentration-dependent, reversible, depolarizing effects on the membrane potential of 95% of neurons tested (72/76), an effect which in 64% (46/72) of these responding neurons was followed by a hyperpolarization. In the presence of the voltage-gated sodium channel blocker tetrodotoxin (TTX) and the glutamate receptor antagonist kynurenic acid (KA), these depolarizing effects of 5 mM NaHS (5.0 ± 2.2 mV (n=7)) were still observed, although they were significantly reduced compared to regular aCSF (7.7 ± 2.0 mV (n=7), p*<0.05, paired t-test). We also demonstrated that hyperpolarizations in response to 5mM NaHS resulted from modulation of the KATP channel with recordings showing that following KATP channel block with glibenclamide these hyperpolarizing effects were abolished (Control -7.9 ± 1.2 mV, Glibenclamide -1.9 ± 0.9 mV (n=8) p<0.05, paired t-test). This study has for the first time described post-synaptic effects of this gasotransmitter on the membrane potential of NTS neurons and thus implicates this transmitter in regulating the diverse autonomic systems controlled by the NTS.

  18. Neuromagnetic field strength outside the human head due to impedance changes from neuronal depolarization.

    Science.gov (United States)

    Ahadzi, G M; Liston, A D; Bayford, R H; Holder, D S

    2004-02-01

    The holy grail of neuroimaging would be to have an imaging system, which could image neuronal electrical activity over milliseconds. One way to do this would be by imaging the impedance changes associated with ion channels opening in neuronal membranes in the brain during activity. In principle, we could measure this change by using electrical impedance tomography (EIT) but it is close to its threshold of detectability. With the inherent limitation in the use of electrodes, we propose a new scheme based on recording the magnetic field resulting from an injected current with superconducting quantum interference devices (SQUIDs), used in magnetoencephalography (MEG). We have performed a feasibility study using computer simulation. The head was modelled as concentric spheres to mimic the scalp, skull, cerebrospinal fluid and brain using the finite element method. The magnetic field 1 cm away from the scalp was estimated. An impedance change of 1% in a 2 cm radius volume in the brain was modelled as the region of depolarization. A constant current of 100 microA was injected into the head from diametrically opposite electrodes. The model predicts that the standing magnetic field is about 10 pT and changed by about 3 fT (0.03%) on depolarization. The spectral noise density in a typical MEG system in the frequency band 1-100 Hz is about 7 fT, so this places the change at the limit of detectability. This is similar to electrical recording, as in conventional EIT systems, but there may be advantages to MEG in that the magnetic field directly traverses the skull and instrumentation errors from the electrode-skin interface will be obviated.

  19. Determining the Number of Parallel RC Branches in Polarization / Depolarization Current Modeling for XLPE Cable Insulation

    Directory of Open Access Journals (Sweden)

    S. Sulaiman

    2017-06-01

    Full Text Available An important element in the electric power distribution system is the underground cable. However continuous applications of high voltages unto the cable, may lead to insulation degradations and subsequent cable failure. Since any disruption to the electricity supply may lead to economic losses as well as lowering customer satisfaction, the maintenance of cables is very important to an electrical utility company. Thus, a reliable diagnostic technique that is able to accurately assess the condition of cable insulation operating is critical, in order for cable replacement exercise to be done. One such diagnostic technique to assess the level of degradation within the cable insulation is the Polarization / Depolarization Current (PDC analysis. This research work attempts to investigate PDC behaviour for medium voltage (MV cross-linked polyethylene (XLPE insulated cables, via baseline PDC measurements and utilizing the measured data to simulate for PDC analysis. Once PDC simulations have been achieved, the values of conductivity of XLPE cable insulations can be approximated. Cable conductivity serves as an indicator to the level of degradation within XLPE cable insulation. It was found that for new and unused XLPE cables, the polarization and depolarization currents have almost overlapping trendlines, as the cable insulation’s conduction current is negligible. Using a linear dielectric circuit equivalence model as the XLPE cable insulation and its corresponding governing equations, it is possible to optimize the number of parallel RC branches to simulate PDC analysis, with a very high degree of accuracy. The PDC simulation model has been validated against the baseline PDC measurements.

  20. FCCP depolarizes plasma membrane potential by activating proton and Na+ currents in bovine aortic endothelial cells.

    Science.gov (United States)

    Park, Kyu-Sang; Jo, Inho; Pak, Kim; Bae, Sung-Won; Rhim, Hyewhon; Suh, Suk-Hyo; Park, Jin; Zhu, Hong; So, Insuk; Kim, Ki Whan

    2002-01-01

    We investigated the effects of carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP), a protonophore and uncoupler of mitochondrial oxidative phosphorylation in mitochondria, on plasma membrane potential and ionic currents in bovine aortic endothelial cells (BAECs). The membrane potential and ionic currents of BAECs were recorded using the patch-clamp technique in current-clamp and voltage-clamp modes, respectively. FCCP activated ionic currents and depolarized the plasma membrane potential in a dose-dependent manner. Neither the removal of extracellular Ca2+ nor pretreatment with BAPTA/AM affected the FCCP-induced currents, implying that the currents are not associated with the FCCP-induced intracellular [Ca2+]i increase. FCCP-induced currents were significantly influenced by the changes in extracellular or intracellular pH; the increased proton gradient produced by lowering the extracellular pH or intracellular alkalinization augmented the changes in membrane potential and ionic currents caused by FCCP. FCCP-induced currents were significantly reduced under extracellular Na+-free conditions. The reversal potentials of FCCP-induced currents under Na+-free conditions were well fitted to the calculated equilibrium potential for protons. Interestingly, FCCP-induced Na+ transport (subtracted currents, I(control)- I(Na+-free) was closely dependent on extracellular pH, whereas FCCP-induced H+transport was not significantly affected by the absence of Na+. These results suggest that the FCCP-induced ionic currents and depolarization, which are strongly dependent on the plasmalemmal proton gradient, are likely to be mediated by both H+ and Na+ currents across the plasma membrane. The relationship between H+ and Na+ transport still needs to be determined.

  1. Analysis on the Thinking Modes of Medical Users Utilizing Library Electronic Resources%医药学用户使用图书馆电子资源的思维模式分析

    Institute of Scientific and Technical Information of China (English)

    陈东滨; 应峻; 辛继宾; 徐一新

    2012-01-01

    The paper studies the thinking modes of medical users utilizing electronic resources in college and university libraries. Combining with the questionnaires,in - depth analysis of utilization desire,utilization decision,impact factors of utilization behaviors are compiled,in order to provide references for college and university libraries formulating electronic resources marketing strategies.%研究高校图书馆医药学用户在使用电子资源过程中的思维模式,结合问卷调查结果深入分析思维模式中使用意愿、使用决策、使用行为的影响因素,为高校图书馆制定电子资源营销策略提供依据。

  2. Review of Researches on the Usage Standard Management of Electronic Resources in China from 2000 to 2010%2000—20l0年我国电子资源使用的规范管理研微

    Institute of Scientific and Technical Information of China (English)

    宛玲; 杜坤

    2012-01-01

    In recent years, electronic resources play an increasingly important role in research, teaching and other works. Through the statistical analysis of the domestic research on the usage standard management of electronic resources from 2000 to 2010, we find that the issue of the usage standard management of electronic resources is increasingly concerned by the public and researchers. But there are still some problems, such as lack of systematic discussion and empirical research, scattered research topics, most research results on guidance proposals, and so on. Our researches about usage standard management of electronic resources should strengthen researches on the user, related technologies, licensing alliance, strengthen the communication between libraries and database providers, and strengthen the analysis and absorption of foreign experience.%目前,电子资源在科研、教学等工作中扮演着越来越重要的角色。通过对2000-2010年我国电子资源使用规范管理研究文献的统计分析发现,虽然公众及科研人员对电子资源使用的规范的关注程度越来越高,但是仍存在缺乏系统性的论述和实证性的研究、研究主题过于分散、研究成果多为指导性建议等问题。我国电子资源使用规范管理研究应加强对用户、相关技术、许可联盟的研究,加强对图书馆与数据库商交流的研究,加强对国外经验的分析与吸收。

  3. 高校图书馆电子资源购买过程中的委托-代理关系探究%Principal-agent Relationship During the Electronic Resources Purchase Process of University Libraries

    Institute of Scientific and Technical Information of China (English)

    桂君; 吴冬曼

    2012-01-01

    The prineipal-agent relationship is throughout the whole process of the electronic resources purchase for university libraries. Based on the asymmetric informatiun theory the issues of information asymmetries in the purchase process of electronic resources for university libraries are analyzed. The major prineipal-agent relationships between the university libraries, the group organizers and the database providers ate studied. The operational characteristics and existing problems in the purchase process of electronic resources for university libraries are also discussed. Taking this opportunity to attention the principal-agent relationships existed in the electronic resources purchase of university libraries, the authors hope to solve some problems caused by the market information asymmetry.%委托-代理关系贯穿了高校图书馆电子资源的购买全过程,,基于信息不对称理论,分析高校图书馆电子资源购买中的信息不对称现象,并以高校图书馆、集团组织者、数据库提供者为主体,研究高校图书馆电子资源采购过程中存在的几种主要委托-代理关系、业务特点和存在的问题、通过对委托-代理关系的研究和分析,合理把握电子资源采购的规律,可以部分解决高校电子资源购买中由市场信息不平衡所带来的问题。

  4. Rapid State-Dependent Alteration in Kv3 Channel Availability Drives Flexible Synaptic Signaling Dependent on Somatic Subthreshold Depolarization

    Directory of Open Access Journals (Sweden)

    Matthew J.M. Rowan

    2017-02-01

    Full Text Available In many neurons, subthreshold depolarization in the soma can transiently increase action-potential (AP-evoked neurotransmission via analog-to-digital facilitation. The mechanisms underlying this form of short-term synaptic plasticity are unclear, in part, due to the relative inaccessibility of the axon to direct physiological interrogation. Using voltage imaging and patch-clamp recording from presynaptic boutons of cerebellar stellate interneurons, we observed that depolarizing somatic potentials readily spread into the axon, resulting in AP broadening, increased spike-evoked Ca2+ entry, and enhanced neurotransmission strength. Kv3 channels, which drive AP repolarization, rapidly inactivated upon incorporation of Kv3.4 subunits. This leads to fast susceptibility to depolarization-induced spike broadening and analog facilitation independent of Ca2+-dependent protein kinase C signaling. The spread of depolarization into the axon was attenuated by hyperpolarization-activated currents (Ih currents in the maturing cerebellum, precluding analog facilitation. These results suggest that analog-to-digital facilitation is tempered by development or experience in stellate cells.

  5. Implementation of depolarization due to beam-beam effects in the beam-beam interaction simulation tool GUINEA-PIG++

    Science.gov (United States)

    Rimbault, C.; Le Meur, G.; Blampuy, F.; Bambade, P.; Schulte, D.

    2009-12-01

    Depolarization is a new feature in the beam-beam simulation tool GUINEA-PIG++ (GP++). The results of this simulation are studied and compared with another beam-beam simulation tool, CAIN, considering different beam parameters for the International Linear Collider (ILC) with a centre-of-mass energy of 500 GeV.

  6. Rapid State-Dependent Alteration in Kv3 Channel Availability Drives Flexible Synaptic Signaling Dependent on Somatic Subthreshold Depolarization.

    Science.gov (United States)

    Rowan, Matthew J M; Christie, Jason M

    2017-02-21

    In many neurons, subthreshold depolarization in the soma can transiently increase action-potential (AP)-evoked neurotransmission via analog-to-digital facilitation. The mechanisms underlying this form of short-term synaptic plasticity are unclear, in part, due to the relative inaccessibility of the axon to direct physiological interrogation. Using voltage imaging and patch-clamp recording from presynaptic boutons of cerebellar stellate interneurons, we observed that depolarizing somatic potentials readily spread into the axon, resulting in AP broadening, increased spike-evoked Ca(2+) entry, and enhanced neurotransmission strength. Kv3 channels, which drive AP repolarization, rapidly inactivated upon incorporation of Kv3.4 subunits. This leads to fast susceptibility to depolarization-induced spike broadening and analog facilitation independent of Ca(2+)-dependent protein kinase C signaling. The spread of depolarization into the axon was attenuated by hyperpolarization-activated currents (Ih currents) in the maturing cerebellum, precluding analog facilitation. These results suggest that analog-to-digital facilitation is tempered by development or experience in stellate cells.

  7. Estradiol inhibits depolarization-evoked exocytosis in PC12 cells via N-type voltage-gated calcium channels.

    NARCIS (Netherlands)

    Adams, K.L.; Maxson, M.M.; Mellander, L.; Westerink, R.H.S.; Ewing, A.G.

    2010-01-01

    Fast neuromodulatory effects of 17-β-estradiol (E2) on cytosolic calcium concentration ([Ca(2+)](i)) have been reported in many cell types, but little is known about its direct effects on vesicular neurotransmitter secretion (exocytosis). We examined the effects of E2 on depolarization-evoked [Ca(2+

  8. Hyposmotic membrane stretch potentiated muscarinic receptor agonist-induced depolarization of membrane potential in guinea-pig gastric myocytes

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Nan-Ge Jin; Lin Piao; Ming-Yu Hong; Zheng-Yuan Jin; Ying Li; Wen-Xie Xu

    2002-01-01

    AIM: To investigate the relationship betweenhyposmotic membrane stretch and muscarinic receptoragonist-induced depolarization of membrane potentialin antral gastric circular myocytes of guinea-pig.METHODS: Using whole cell patch-clamp techniquerecorded membrane potential and current in singlegastric myocytes isolated by collagena se.RESULTS: Hyposmotic membrane stretch hyperpolarizedmembrane potential from -60.0mV±1.0mV to -67.9mV±1.0mV. TEA (10mmol/L), a nonselective potassiumchannel blocker significantly inhibited hyposmoticmembrane stretch-induced hyperpolarization. After KCIin the pipette and NaCI in the external solution werereplaced by CsCI to block the potassium current,hyposmotic membrane stretch depolarized the membranepotential from -60.0 mV±-1.0mV to -44.8 mV±2.3mV(P<0.05), and atropine (1 pmol/L) inhibited thedepolarization of the membrane potential. Muscarinicreceptor agonist Carbachol depolarized membranepotential from -60.0mV±1.0mV to -50.3 mV±0.3mV(P<0.05) and hyposmotic membrane stretchpotentiated the depolarization. Carbachol inducedmuscarinic current (Icch) was greatly increased byhyposmotic membrane stretch.CONCLUSION: Hyposmotic membrane stretchpotentiated muscarinic receptor agonist-induceddepolarization of membrane potential, which is relatedto hyposmotic membrane stretch-induced increase ofmuscarinic current.

  9. High K+-induced contraction requires depolarization-induced Ca2+ release from internal stores in rat gut smooth muscle

    Institute of Scientific and Technical Information of China (English)

    Timo KIRSCHSTEIN; Mirko REHBERG; Rika BAJORAT; Tursonjan TOKAY; Katrin PORATH; Rudiger KOHLING

    2009-01-01

    Aim: Depolarization-induced contraction of smooth muscle is thought to be mediated by Ca2+influx through voltage-gated L-type Ca2+channels. We describe a novel contraction mechanism that is independent of Ca2+ entry.Methods: Pharmacological experiments were carried out on isolated rat gut longitudinal smooth muscle preparations, measuring iso-metric contraction strength upon high K+-induced depolarization.Results: Treatment with verapamil, which presumably leads to a conformational change in the channel, completely abolished K+-induced contraction, while residual contraction still occurred when Ca2+ entry was blocked with Cd2+. These results were further con-firmed by measuring intracellular Ca2+ transients using Fura-2. Co-application of Cd2+ and the ryanodine receptor blocker DHBP further reduced contraction, albeit incompletely. Additional blockage of either phospholipase C (U 73122) or inositol 1,4,5-trisphophate (IP3)receptors (2-APB) abolished most contractions, while sole application of these blockers and Cd2+ (without parallel ryanodine receptor manipulation) also resulted in incomplete contraction block.Conclusion: We conclude that there are parallel mechanisms of depolarization-induced smooth muscle contraction via (a) Ca2+ entry and (b) Ca2+ entry-independent, depolarization-induced Ca2+-release through ryanodine receptors and IP3, with the latter being depen-dent on phospholipase C activation.

  10. Printed Resources and Electronic Resources Integrated Services in Small and Medium-sized Libraries%中小型图书馆印本资源与电子资源一体化服务实践

    Institute of Scientific and Technical Information of China (English)

    刘胜

    2014-01-01

    Through analyzing the integrated service system of library resources, this paper sums up three methods for the integration of printed resources and digital resources including the digital resources catalog, digital resources navigate and open link system, and suggests that the libraries should give priority to books and periodicals integrated retrieval in the integrated service, and carry out the system construction within their capabilities by adopting the methods of making second development, introducing new system, and conducting independent development, etc.%通过对图书馆馆藏一体化服务系统的分析,归纳总结出印本资源与电子资源整合的3种主要模式———电子资源编目、电子资源导航与开放链接,并建议图书馆在进行一体化服务时,优先考虑图书和期刊的整合检索,在系统建设上量力而行,采取二次开发、引进新系统、自主开发等方式。

  11. 基于使用数据的馆藏电子资源评价方法与系统分析%Methods and Systems of Library Electronic Resources Evaluation Analysis Based on Usage Data

    Institute of Scientific and Technical Information of China (English)

    王丹丹

    2014-01-01

    The origin and methods of library electronic resources evaluation were summarized;the statistical standards of library users' us-age data were reviewed. Then four library electronic resources evaluation systems based on library users' usage data which are ScholarlyS-tats,Journal Use Reports,360 Counter and Ustat were compared and contrasted. The related work which librarians need to do and the con-sidering factors about the selection of electronic resources evaluation system was also analyzed.%总结了图书馆馆藏电子资源评价的缘起与方法,梳理了图书馆用户使用数据的统计规范。以此为基础对比了四个基于使用数据的馆藏电子资源评价系统---ScholarlyStats,Journal Use Reports,360 Counter,UStat,分析了图书馆选择电子资源评价系统的考虑因素和需要预先做好的相关工作。

  12. Triple-wavelength depolarization-ratio profiling of Saharan dust over Barbados during SALTRACE in 2013 and 2014

    Directory of Open Access Journals (Sweden)

    M. Haarig

    2017-09-01

    Full Text Available Triple-wavelength polarization lidar measurements in Saharan dust layers were performed at Barbados (13.1° N, 59.6° W, 5000–8000 km west of the Saharan dust sources, in the framework of the Saharan Aerosol Long-range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE-1, June–July 2013, SALTRACE-3, June–July 2014. Three case studies are discussed. High quality was achieved by comparing the dust linear depolarization ratio profiles measured at 355, 532, and 1064 nm with respective dual-wavelength (355, 532 nm depolarization ratio profiles measured with a reference lidar. A unique case of long-range transported dust over more than 12 000 km is presented. Saharan dust plumes crossing Barbados were measured with an airborne triple-wavelength polarization lidar over Missouri in the midwestern United States 7 days later. Similar dust optical properties and depolarization features were observed over both sites indicating almost unchanged dust properties within this 1 week of travel from the Caribbean to the United States. The main results of the triple-wavelength polarization lidar observations in the Caribbean in the summer seasons of 2013 and 2014 are summarized. On average, the particle linear depolarization ratios for aged Saharan dust were found to be 0.252 ± 0.030 at 355 nm, 0.280 ± 0.020 at 532 nm, and 0.225 ± 0.022 at 1064 nm after approximately 1 week of transport over the tropical Atlantic. Based on published simulation studies we present an attempt to explain the spectral features of the depolarization ratio of irregularly shaped mineral dust particles, and conclude that most of the irregularly shaped coarse-mode dust particles (particles with diameters > 1 µm have sizes around 1.5–2 µm. The SALTRACE results are also set into the context of the SAMUM-1 (Morocco, 2006 and SAMUM-2 (Cabo Verde, 2008 depolarization ratio studies. Again, only minor changes in the dust depolarization

  13. Orexins depolarize rostral ventrolateral medulla neurons and increase arterial pressure and heart rate in rats mainly via orexin 2 receptors.

    Science.gov (United States)

    Huang, Shang-Cheng; Dai, Yu-Wen E; Lee, Yen-Hsien; Chiou, Lih-Chu; Hwang, Ling-Ling

    2010-08-01

    An injection of orexin A or B into the cisterna magna or the rostral ventrolateral medulla (RVLM), where bulbospinal vasomotor neurons are located, elevated arterial pressure (AP) and heart rate (HR). We examined how orexins affected RVLM neurons to regulate cardiovascular functions by using in vitro recordings of neuronal activity of the RVLM and in vivo measurement of cardiovascular functions in rats. Orexin A and B concentration-dependently depolarized RVLM neurons. At 100 nM, both peptides excited 42% of RVLM neurons. Tetrodotoxin failed to block orexin-induced depolarization. In the presence of N-(2-methyl-6-benzoxazolyl)-N'-1, 5-naphthyridin-4-yl urea (SB-334867), an orexin 1 receptor (OX(1)R) antagonist, orexin A depolarized 42% of RVLM neurons with a smaller, but not significantly different, amplitude (4.9 +/- 0.8 versus 7.2 +/- 1.1 mV). In the presence of (2S)-1- (3,4-dihydro-6,7-dimethoxy-2(1H)-isoquinolinyl)-3,3-dimethyl-2-[(4-pyridinylmethyl)amino]-1-butanone hydrochloride (TCS OX2 29), an orexin 2 receptor (OX(2)R) antagonist, orexin A depolarized 25% of RVLM neurons with a significantly smaller amplitude (1.7 +/- 0.5 mV). Coapplication of both antagonists completely eliminated orexin A-induced depolarization. An OX(2)R agonist, [Ala(11),D-Leu(15)]-orexin B, concentration-dependently depolarized RVLM neurons. Regarding neuronal phenotypes, orexins depolarized 88% of adrenergic, 43% of nonadrenergic, and 36 to 41% of rhythmically firing RVLM neurons. Intracisternal TCS OX2 29 (3 and 10 nmol) suppressed intracisternal orexin A-induced increases of AP and HR, whereas intracisternal SB-334867 (3 and 10 nmol) had no effect on the orexin A-induced increase of HR but suppressed the orexin A-induced pressor response at 10 nmol. We concluded that orexins directly excite RVLM neurons, which include bulbospinal vasomotor neurons, and regulate cardiovascular function mainly via the OX(2)R, with a smaller contribution from the OX(1)R.

  14. Recovery of slow potentials in AC-coupled electrocorticography: application to spreading depolarizations in rat and human cerebral cortex.

    Science.gov (United States)

    Hartings, Jed A; Watanabe, Tomas; Dreier, Jens P; Major, Sebastian; Vendelbo, Leif; Fabricius, Martin

    2009-10-01

    Cortical spreading depolarizations (spreading depressions and peri-infarct depolarizations) are a pathology intrinsic to acute brain injury, generating large negative extracellular slow potential changes (SPCs) that, lasting on the order of minutes, are studied with DC-coupled recordings in animals. The spreading SPCs of depolarization waves are observed in human cortex with AC-coupled electrocorticography (ECoG), although SPC morphology is distorted by the high-pass filter stage of the amplifiers. Here, we present a signal processing method to reverse these distortions and recover approximate full-band waveforms from AC-coupled recordings. We constructed digital filters that reproduced the phase and amplitude distortions introduced by specific AC-coupled amplifiers and, based on this characterization, derived digital inverse filters to remove these distortions from ECoG recordings. Performance of the inverse filter was validated by its ability to recover both simulated and real low-frequency input test signals. The inverse filter was then applied to AC-coupled ECoG recordings from five patients who underwent invasive monitoring after aneurysmal subarachnoid hemorrhage. For 117 SPCs, the inverse filter recovered full-band waveforms with morphologic characteristics typical of the negative DC shifts recorded in animals. Compared with those recorded in the rat cortex with the same analog and digital methods, the negative DC shifts of human depolarizations had significantly greater durations (1:47 vs. 0:45 min:sec) and peak-to-peak amplitudes (10.1 vs. 4.2 mV). The inverse filter thus permits the study of spreading depolarizations in humans, using the same assessment of full-band DC potentials as that in animals, and suggests a particular solution for recovery of biosignals recorded with frequency-limited amplifiers.

  15. Slow Bursting Neurons of Mouse Cortical Layer 6b Are Depolarized by Hypocretin/Orexin and Major Transmitters of Arousal

    Science.gov (United States)

    Wenger Combremont, Anne-Laure; Bayer, Laurence; Dupré, Anouk; Mühlethaler, Michel; Serafin, Mauro

    2016-01-01

    Neurons firing spontaneously in bursts in the absence of synaptic transmission have been previously recorded in different layers of cortical brain slices. It has been suggested that such neurons could contribute to the generation of alternating UP and DOWN states, a pattern of activity seen during slow-wave sleep. Here, we show that in layer 6b (L6b), known from our previous studies to contain neurons highly responsive to the wake-promoting transmitter hypocretin/orexin (hcrt/orx), there is a set of neurons, endowed with distinct intrinsic properties, which displayed a strong propensity to fire spontaneously in rhythmic bursts. In response to small depolarizing steps, they responded with a delayed firing of action potentials which, upon higher depolarizing steps, invariably inactivated and were followed by a depolarized plateau potential and a depolarizing afterpotential. These cells also displayed a strong hyperpolarization-activated rectification compatible with the presence of an Ih current. Most L6b neurons with such properties were able to fire spontaneously in bursts. Their bursting activity was of intrinsic origin as it persisted not only in presence of blockers of ionotropic glutamatergic and GABAergic receptors but also in a condition of complete synaptic blockade. However, a small number of these neurons displayed a mix of intrinsic bursting and synaptically driven recurrent UP and DOWN states. Most of the bursting L6b neurons were depolarized and excited by hcrt/orx through a direct postsynaptic mechanism that led to tonic firing and eventually inactivation. Similarly, they were directly excited by noradrenaline, histamine, dopamine, and neurotensin. Finally, the intracellular injection of these cells with dye and their subsequent Neurolucida reconstruction indicated that they were spiny non-pyramidal neurons. These results lead us to suggest that the propensity for slow rhythmic bursting of this set of L6b neurons could be directly impeded by hcrt

  16. Analysis on Current Situation and Countermeasure of Domestic Electronic Commerce Logistics in the Internet Age——Based on Resource Dependence Theory

    Directory of Open Access Journals (Sweden)

    Zhang Jiapeng

    2017-01-01

    Full Text Available This paper analyzes the status of electric business logistics in the current Internet era in China, and combines the SWOT analysis with AHP to do the empirical analysis, then puts forward the countermeasure that the electric business logistics resource should be shared based on the resource dependence theory. Through the empirical analysis, it is found that the disadvantages and opportunities of the logistics status are important in the Internet era.The resource sharing strategy based on the resource dependence theory is more scientific. The rational use of Internet technology in electric business logistics industry can achieve “sharing”. It is of great significance for its balanced development, intelligent development and optimization and development.

  17. Geometry and quadratic nonlinearity of charge transfer complexes in solution using depolarized hyper-Rayleigh scattering.

    Science.gov (United States)

    Pandey, Ravindra; Ghosh, Sampa; Mukhopadhyay, S; Ramasesha, S; Das, Puspendu K

    2011-01-28

    We report large quadratic nonlinearity in a series of 1:1 molecular complexes between methyl substituted benzene donors and quinone acceptors in solution. The first hyperpolarizability, β(HRS), which is very small for the individual components, becomes large by intermolecular charge transfer (CT) interaction between the donor and the acceptor in the complex. In addition, we have investigated the geometry of these CT complexes in solution using polarization resolved hyper-Rayleigh scattering (HRS). Using linearly (electric field vector along X direction) and circularly polarized incident light, respectively, we have measured two macroscopic depolarization ratios D=I(2ω,X,X)/I(2ω,Z,X) and D(')=I(2ω,X,C)/I(2ω,Z,C) in the laboratory fixed XYZ frame by detecting the second harmonic scattered light in a polarization resolved fashion. The experimentally obtained first hyperpolarizability, β(HRS), and the value of macroscopic depolarization ratios, D and D('), are then matched with the theoretically deduced values from single and double configuration interaction calculations performed using the Zerner's intermediate neglect of differential overlap self-consistent reaction field technique. In solution, since several geometries are possible, we have carried out calculations by rotating the acceptor moiety around three different axes keeping the donor molecule fixed at an optimized geometry. These rotations give us the theoretical β(HRS), D and D(') values as a function of the geometry of the complex. The calculated β(HRS), D, and D(') values that closely match with the experimental values, give the dominant equilibrium geometry in solution. All the CT complexes between methyl benzenes and chloranil or 1,2-dichloro-4,5-dicyano-p-benzoquinone investigated here are found to have a slipped parallel stacking of the donors and the acceptors. Furthermore, the geometries are staggered and in some pairs, a twist angle as high as 30° is observed. Thus, we have demonstrated in

  18. Mechanisms of depolarizing inhibition at the crayfish giant motor synapse. II. Quantitative reconstruction.

    Science.gov (United States)

    Edwards, D H

    1990-08-01

    1. The relative strengths of four mechanisms of depolarizing synaptic inhibition described in the previous paper were evaluated with an electrical model of the giant motor synapse (GMS) and postsynaptic region of the motor giant motoneuron (MoG). 2. The model consists of one compartment that represents the presynaptic region of the medial giant (MG) interneuron and three compartments that represent the postsynaptic region and proximal axon of the MoG. The presynaptic MG compartment is linked to a postsynaptic MoG compartment by a rectifying conductance that represents the GMS. Each compartment consists of parallel paths to ground for active and/or passive membrane currents. 3. Parameter values of the model were set so the MG compartment would replicate an MG impulse and the MoG compartments would replicate the current-clamp, voltage-clamp, and synaptic responses of a single MoG neuron described in the previous paper. The Hodgkin-Huxley equations described voltage-sensitive sodium and potassium currents. 4. Comparison of the MoG compartment currents that mediate an inhibited excitatory postsynaptic potential (EPSP) [triggered during a depolarizing inhibitory postsynaptic potential (d-IPSP)] with those of an uninhibited EPSP indicate that all four mechanisms have significant inhibitory effects. Reverse bias of the GMS by the d-IPSP reduced the GMS current by 65 nA (12%). The remaining inward current was further reduced by a 243-nA outward current through the inhibitory postsynaptic conductance. The d-IPSP inactivated sodium conductance so the inward sodium current evoked by the EPSP was reduced by 319 nA (-68%). The d-IPSP reduced the latency for potassium activation by the EPSP so that the outward potassium current coincided with the inward sodium current and reduced the net inward current by 100 nA. Together, these mechanisms reduced the EPSP amplitude by 69%. 5. The resting potential of MoG is normally 15 mV more positive than MG rest potential, but in some

  19. Soft-contact conductive carbon enabling depolarization of LiFePO4 cathodes to enhance both capacity and rate performances of lithium ion batteries

    Science.gov (United States)

    Ren, Wenju; Wang, Kai; Yang, Jinlong; Tan, Rui; Hu, Jiangtao; Guo, Hua; Duan, Yandong; Zheng, Jiaxin; Lin, Yuan; Pan, Feng

    2016-11-01

    Conductive nanocarbons generally are used as the electronic conductive additives to contact with active materials to generate conductive network for electrodes of commercial Li-ion batteries (LIBs). A typical of LiFePO4 (LFP), which has been widely used as cathode material for LIBs with low electronic conductivity, needs higher quantity of conductive nanocarbons to enhance the performance for cathode electrodes. In this work, we systematically studied three types of conductive nanocarbons and related performances in the LFP electrodes, and classify them as hard/soft-contact conductive carbon (named as H/SCC), respectively, according to their crystallite size, surface graphite-defect, specific surface area and porous structure, in which SCC can generate much larger contact area with active nano-particles of cathode materials than that of HCC. It is found that LFP nanocrystals wrapped in SCC networks perform significantly enhanced both capacity and rate performance than that in HCC. Combined experiments with multiphysics simulation, the mechanism is that LFP nanoparticles embedded in SCC with large contact area enable to generate higher depolarized effects with a relatively uniform current density vector (is) and lithium flux vector (NLi) than that in HCC. This discovery will guide us to how to design LIBs by selective using conductive carbon for high-performance LIBs.

  20. Fiber resources

    Science.gov (United States)

    P. J. Ince

    2004-01-01

    In economics, primary inputs or factors of production define the term ‘resources.’ Resources include land resources (plants, animals, and minerals), labor, capital, and entrepreneurship. Almost all pulp and paper fiber resources are plant materials obtained from trees or agricultural crops. These resources encompass plant materials harvested directly from the land (...

  1. Primary afferent depolarization and flexion reflexes produced by radiant heat stimulation of the skin.

    Science.gov (United States)

    Burke, R E; Rudomin, P; Vyklický, L; Zajac, F E

    1971-02-01

    1. The reflex effects of pulses of intense radiant heat applied to the skin of the central plantar pad have been studied in unanaesthetized (decerebrate) spinal cats.2. Pad heat pulses produced flexion of the ipsilateral hind limb and increased ipsilateral flexor monosynaptic reflexes, due to post-synaptic excitation of flexor alpha motoneurones. These effects were accompanied by reduction of extensor monosynaptic reflexes and post-synaptic inhibition of extensor motoneurones.3. Ipsilateral (and contralateral) pad heat pulses consistently evoked negative dorsal root potentials (DRPs) as well as increased excitability of both cutaneous and group Ib muscle afferent terminals. The excitability of group Ia afferents was sometimes also increased during pad heat pulses, but to a lesser extent.4. Pad heat pulses produced negative DRPs in preparations in which positive DRP components could be demonstrated following electrical stimulation of both skin and muscle nerves.5. The motor and primary afferent effects of heat pulses always accompanied one another, beginning after the pad surface temperature had reached rather high levels (usually 48-55 degrees C).6. Negative DRPs increased excitability of cutaneous and group Ib afferents, and motoneurone activation produced by pad heat pulses was essentially unmodified when conduction in large myelinated afferents from the central plantar pad was blocked by cooling the posterior tibial nerve trunk.7. It is concluded that adequate noxious activation of cutaneous afferents of small diameter produces primary afferent depolarization in a variety of large diameter afferent fibres, as well as post-synaptic effects in alpha motoneurones.

  2. Photo-elastic effect, thermal lensing and depolarization in a-cut tetragonal laser crystals

    Science.gov (United States)

    Yumashev, K. V.; Zakharova, A. N.; Loiko, P. A.

    2016-06-01

    We report on analytical description of thermal lensing effect in tetragonal crystals cut along the [1 0 0] crystallographic axis, for the two principal light polarizations, E ┴ c and E || c, under diode-pumping (plane stress approximation). Within this approach, we take into account anisotropy of elastic, photo-elastic, thermal and optical properties of the material. Expressions for the ‘generalized’ thermo-optic coefficient χ are presented. It is shown that astigmatism of thermal lens is determined both by the photo-elastic and end-bulging effects. The sign of the photo-elastic term χ″ can be either positive or negative affecting significantly the sign of the thermal lens. Depolarization loss in a-cut tetragonal crystals is few orders of magnitude lower than that in cubic crystals. Calculations are performed for a-cut tetragonal molybdates, Nd:CaMoO4, Nd:PbMoO4 and Nd:NaBi(MoO4)2.

  3. Most robust and fragile two-qubit entangled states under depolarizing channels

    CERN Document Server

    Pang, Chao-Qian; Jiang, Yue; Liang, Mai-Lin

    2012-01-01

    In the two-qubit system under the local depolarizing channels, the most robust and the most fragile states for a given concurrence or negativity are derived. For the one-sided channel, with the aid of the evolution equation for entanglement given by Konrad \\emph{et al.} [Nat. Phys. 4, 99 (2008)], the pure states are proved to be the most robust. Based on a generalization of the evolution equation, we classify the ansatz states in our investigation by the amount of robustness, and consequently derive the most fragile states. For the two-sided channel, the pure states are proved to be the most robust for a fixed concurrence, but is the most fragile with a given negativity when the channel is uniform. Under the uniform channel, for a given negativity, the most robust states are the ones with the maximal concurrence, which are also the most fragile states when the concurrence is given in the region of [1/2,1]. When the entanglement approaches zero, the most fragile states for a given negativity become the pure st...

  4. Backscatter and depolarization measurements of aerosolized biological simulants using a chamber lidar system

    Science.gov (United States)

    Brown, David M.; Thrush, Evan P.; Thomas, Michael E.; Santarpia, Josh; Quizon, Jason; Carter, Christopher C.

    2010-04-01

    To ensure agent optical cross sections are well understood from the UV to the LWIR, volume integrated measurements of aerosolized agent material at a few key wavelengths is required to validate existing simulations. Ultimately these simulations will be used to assess the detection performance of various classes of lidar technology spanning the entire range of the optical spectrum. The present work demonstrates an optical measurement architecture based on lidar allowing the measurement of backscatter and depolarization ratio from biological aerosols released in a refereed, 1-m cubic chamber. During 2009, various upgrades have been made to the chamber LIDAR system, which operates at 1.064 μm with sub nanosecond pulses at a 120 Hz repetition rate. The first build of the system demonstrated a sensitivity of aerosolized Bacillus atrophaeus (BG) on the order of 5×105 ppl with 1 GHz InGaAs detectors. To increase the sensitivity and reduce noise, the InGaAs detectors were replaced with larger-area silicon avalanche photodiodes for the second build of the system. In addition, computer controlled step variable neutral density filters are now incorporated to facilitate calibrating the system for absolute back-scatter measurements. Calibrated hard target measurements will be combined with data from the ground truth instruments for cross-section determination of the material aerosolized in the chamber. Measured results are compared to theoretical simulations of cross-sections.

  5. Ketamine modulation of the haemodynamic response to spreading depolarization in the gyrencephalic swine brain.

    Science.gov (United States)

    Sánchez-Porras, Renán; Santos, Edgar; Schöll, Michael; Kunzmann, Kevin; Stock, Christian; Silos, Humberto; Unterberg, Andreas W; Sakowitz, Oliver W

    2017-05-01

    Spreading depolarization (SD) generates significant alterations in cerebral haemodynamics, which can have detrimental consequences on brain function and integrity. Ketamine has shown an important capacity to modulate SD; however, its impact on SD haemodynamic response is incompletely understood. We investigated the effect of two therapeutic ketamine dosages, a low-dose of 2 mg/kg/h and a high-dose of 4 mg/kg/h, on the haemodynamic response to SD in the gyrencephalic swine brain. Cerebral blood volume, pial arterial diameter and cerebral blood flow were assessed through intrinsic optical signal imaging and laser-Doppler flowmetry. Our findings indicate that frequent SDs caused a persistent increase in the baseline pial arterial diameter, which can lead to a diminished capacity to further dilate. Ketamine infused at a low-dose reduced the hyperemic/vasodilative response to SD; however, it did not alter the subsequent oligemic/vasoconstrictive response. This low-dose did not prevent the baseline diameter increase and the diminished dilative capacity. Only infusion of ketamine at a high-dose suppressed SD and the coupled haemodynamic response. Therefore, the haemodynamic response to SD can be modulated by continuous infusion of ketamine. However, its use in pathological models needs to be explored to corroborate its possible clinical benefit.

  6. Pacemaker rate and depolarization block in nigral dopamine neurons: a somatic sodium channel balancing act

    Science.gov (United States)

    Tucker, Kristal R.; Huertas, Marco A.; Horn, John P.; Canavier, Carmen C.; Levitan, Edwin S.

    2012-01-01

    Midbrain dopamine (DA) neurons are slow intrinsic pacemakers that undergo depolarization (DP) block upon moderate stimulation. Understanding DP block is important because it has been correlated with the clinical efficacy of chronic antipsychotic drug treatment. Here we describe how voltage-gated sodium (NaV) channels regulate DP block and pacemaker activity in DA neurons of the substantia nigra using rat brain slices. The distribution, density and gating of NaV currents were manipulated by blocking native channels with tetrodotoxin and by creating virtual channels and anti-channels with dynamic clamp. Although action potentials initiate in the axon initial segment (AIS) and NaV channels are distributed in multiple dendrites, selective reduction of NaV channel activity in the soma was sufficient to decrease pacemaker frequency and increase susceptibility to DP block. Conversely, increasing somatic NaV current density raised pacemaker frequency and lowered susceptibility to DP block. Finally, when NaV currents were restricted to the soma, pacemaker activity occurred at abnormally high rates due to excessive local subthreshold NaV current. Together with computational simulations, these data show that both the slow pacemaker rate and the sensitivity to DP block that characterizes DA neurons result from the low density of somatic NaV channels. More generally, we conclude that the somatodendritic distribution of NaV channels is a major determinant of repetitive spiking frequency. PMID:23077037

  7. Quantifying the polarization properties of non-depolarizing optical elements with virtual distorting elements.

    Science.gov (United States)

    Wang, Xiao; Yang, Feng; Yin, Jianhua

    2017-04-01

    It is well known that polarization can be potentially distorted by optical elements in optical paths, which intensively influences researches and techniques related to polarization analysis. For this, we proposed to exactly quantify the polarization properties of non-depolarizing optical elements with virtual distorting elements characterized by three parameters: orientation Θ, diattenuation Γ, and retardation Δ. Utilizing the least-squares fitting method, these three parameters can be determined by fitting the measured output polarization states from the optical element with the polarization responses of VDEs. The principle of this method is detailed, and a corresponding experimental setup is further presented. The feasibility of this method has been verified in reflective mirrors and a dichroic mirror. Based on the quantification results with our setup, we have successfully compensated the polarization distortion induced by a dichroic mirror. The precision of this method has been investigated in detail with Monte Carlo simulations. The investigation results show that this method has high precision at certain measurement conditions, and the precision can be further improved.

  8. Mechanisms of spreading depolarization in vertebrate and insect central nervous systems.

    Science.gov (United States)

    Spong, Kristin E; Andrew, R David; Robertson, R Meldrum

    2016-09-01

    Spreading depolarization (SD) is generated in the central nervous systems of both vertebrates and invertebrates. SD manifests as a propagating wave of electrical depression caused by a massive redistribution of ions. Mammalian SD underlies a continuum of human pathologies from migraine to stroke damage, whereas insect SD is associated with environmental stress-induced neural shutdown. The general cellular mechanisms underlying SD seem to be evolutionarily conserved throughout the animal kingdom. In particular, SD in the central nervous system of Locusta migratoria and Drosophila melanogaster has all the hallmarks of mammalian SD. Locust SD is easily induced and monitored within the metathoracic ganglion (MTG) and can be modulated both pharmacologically and by preconditioning treatments. The finding that the fly brain supports repetitive waves of SD is relatively recent but noteworthy, since it provides a genetically tractable model system. Due to the human suffering caused by SD manifestations, elucidating control mechanisms that could ultimately attenuate brain susceptibility is essential. Here we review mechanisms of SD focusing on the similarities between mammalian and insect systems. Additionally we discuss advantages of using invertebrate model systems and propose insect SD as a valuable model for providing new insights to mammalian SD.

  9. Depolarizing GABA/glycine synaptic events switch from excitation to inhibition during frequency increases

    Science.gov (United States)

    Branchereau, Pascal; Cattaert, Daniel; Delpy, Alain; Allain, Anne-Emilie; Martin, Elodie; Meyrand, Pierre

    2016-02-01

    By acting on their ionotropic chloride channel receptors, GABA and glycine represent the major inhibitory transmitters of the central nervous system. Nevertheless, in various brain structures, depolarizing GABAergic/glycinergic postsynaptic potentials (dGPSPs) lead to dual inhibitory (shunting) and excitatory components, the functional consequences of which remain poorly acknowledged. Indeed, the extent to which each component prevails during dGPSP is unclear. Understanding the mechanisms predicting the dGPSP outcome on neural network activity is therefore a major issue in neurobiology. By combining electrophysiological recordings of spinal embryonic mouse motoneurons and modelling study, we demonstrate that increasing the chloride conductance (gCl) favors inhibition either during a single dGPSP or during trains in which gCl summates. Finally, based on this summation mechanism, the excitatory effect of EPSPs is overcome by dGPSPs in a frequency-dependent manner. These results reveal an important mechanism by which dGPSPs protect against the overexcitation of neural excitatory circuits.

  10. On the development and the utilization of library holding in electronic resources Taking the Library of Shandong University of Science and Technology%试论电子资源的馆藏发展与利用——以山东科技大学图书馆为例

    Institute of Scientific and Technical Information of China (English)

    陈明华; 马圣芹

    2012-01-01

    通过分析电子资源馆藏发展的意义及模式,对电子资源发展的目标及有效管理进行了探讨,并提出一些提高电子资源利用率的措施。%This paper analyses the mode and the importance of library holding development in electronic resources. It also ex- plores the aim and the affective management in electronic resource development and put forwards some measures to improve the utilization ratio of electronic resources.

  11. Electronic Library: A TERI Experiment.

    Science.gov (United States)

    Kar, Debal C.; Deb, Subrata; Kumar, Satish

    2003-01-01

    Discusses the development of Electronic Library at TERI (The Energy and Resources Institute, New Delhi). Highlights include: hardware and software used; the digital library/Virtual Electronic Library; directory of Internet journals; virtual reference resources; electronic collection/Physical Electronic Library; downloaded online full-length…

  12. Measurement of the Linear Depolarization Ratio of Aged Dust at Three Wavelengths (355, 532 and 1064 nm Simultaneously over Barbados

    Directory of Open Access Journals (Sweden)

    Haarig Moritz

    2016-01-01

    Full Text Available A ground-based polarization Raman lidar is presented, that is able to measure the depolarization ratio at three wavelengths (355, 532 and 1064 nm simultaneously. This new feature is implemented for the first time in a Raman lidar. It provides a full dataset of 3 backscatter coefficients, two extinction coefficients and 3 depolarization ratios (3+2+3 lidar system. To ensure the data quality, it has been compared to the well characterized two-wavelength polarization lidar POLIS. Measurements of long-range transported dust have been performed in the framework of the Saharan Aerosol Long-Range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE in the Caribbean.

  13. Rf Depolarizing Resonances In The Presence Of A Full Siberian Snake And Full Snake Spin-flipping

    CERN Document Server

    Blinov, B B

    2000-01-01

    Frequent polarization reversals, or spin-flips, of a stored polarized beam in high energy scattering asymmetry experiments may greatly reduce systematic errors of spin asymmetry measurements. A spin-flipping technique is being developed by using rf magnets running at a frequency close to the spin precession frequency, thereby creating spin-depolarizing resonances; the spin can then be flipped by ramping the rf magnet's frequency through the resonance. We studied, at the Indiana University Cyclotron Facility Cooler Ring, properties of such rf depolarizing resonances in the presence of a nearly-full Siberian snake and their possible application for spin- flipping. By using an rf-solenoid magnet, we reached a 98.7 ± 1% efficiency of spin-flipping. However, an rf-dipole magnet is more practical at high energies; hence, studies of spin-flipping by an rf-dipole are underway at IUCF.

  14. Quantitative analysis of the cell voltage of SO{sub 2}-depolarized electrolysis in hybrid sulfur process

    Energy Technology Data Exchange (ETDEWEB)

    Lulu, Xue; Ping, Zhang, E-mail: zhangping77@mail.tsinghua.edu.cn; Songzhe, Chen; Laijun, Wang

    2016-09-15

    SO{sub 2}-depolarized electrolysis (SDE) is the pivotal reaction in hybrid sulfur process. To date, the total cell potential for an SO{sub 2}-depolarized electrolyzer has been identified to be controlled dominantly by the sulfuric acid concentration of the anolyte and electrolysis temperature. Potential loss in SDE can be separated into four components, i.e., equilibrium potential, anodic polarization overpotential, cathodic polarization overpotential, and ohmic loss. In this work, the potential individual components of SDE were measured and calculated. Results showed that the anodic polarization overpotential exhibited the highest ratio in the cell voltage of SDE reaction, and the kinetics of the anodic reaction was controlled by a distinct reaction process under different cell potentials. This study increases understanding on SDE and provides assistance to improve its performance.

  15. Intrinsic reduction the depolarization loss in electro-optical Q-switched laser using a rectangular KD*P crystal

    Science.gov (United States)

    Yin, Xingliang; Jiang, Menghua; Sun, Zhe; Hui, Yongling; Lei, Hong; Li, Qiang

    2017-09-01

    We presented the first demonstration of a new structure KD*P crystal as electro-optic switch, in which the thermal depolarization loss was intrinsically reduced. The thermally induced birefringence and depolarization of both cylindrical and rectangular crystalline structure were simulated. The higher pulse energy or average power output was achieved in the diode pumped E-O Q-switched laser using a rectangular KD*P crystal. At the repetition rate of 100 Hz, the maximum average output power was 27.2 W at 145 A pump current, corresponding to the pulse energy was 272 mJ with pulse width of 65 ns and the beam quality of M2=20.4. Comparing the highest average power or corresponding single pulse energy, the laser with the rectangular KD*P crystal was two times of the laser with the traditional cylindrical KD*P crystal.

  16. Innovative Resources for Education and Public Information: Electronic Services, Data and Information from NASA's Hubble Space Telescope and Other NASA Missions.

    Science.gov (United States)

    Christian, Carol A.

    The Space Telescope Science Institute (STScI), which supports the operation of the Hubble Space Telescope, is actively investigating and supporting innovative and experimental methods for improving science and math education content. The educational resources on the World Wide Web are derived from the latest data, scientific results, and advances…

  17. An implementation case study. Implementation of the Indian Health Service's Resource and Patient Management System Electronic Health Record in the ambulatory care setting at the Phoenix Indian Medical Center.

    Science.gov (United States)

    Dunnigan, Anthony; John, Karen; Scott, Andrea; Von Bibra, Lynda; Walling, Jeffrey

    2010-01-01

    The Phoenix Indian Medical Center (PIMC) has successfully implemented the Resource and Patient Management System Electronic Health Record (RPMS-EHR) in its Ambulatory Care departments. One-hundred and twenty-six providers use the system for essentially all elements of documentation, ordering, and coding. Implementation of one function at a time, in one clinical area at a time, allowed for focused training and support. Strong departmental leadership and the development of 'super-users' were key elements. Detailed assessments of each clinic prior to implementation were vital, resulting in optimal workstation utilization and a greater understanding of each clinic's unique flow. Each phase saw an increasing reluctance to revert to old paper processes. The success of this implementation has placed pressure on the remainder of the hospital to implement the RPMS-EHR, and has given the informatics team an increased awareness of what resources are required to achieve this result.

  18. Hexabromocyclododecane inhibits depolarization-induced increase in intracellular calcium levels and neurotransmitter release in PC12 cells.

    Science.gov (United States)

    Dingemans, Milou M L; Heusinkveld, Harm J; de Groot, Aart; Bergman, Ake; van den Berg, Martin; Westerink, Remco H S

    2009-02-01

    Environmental levels of the brominated flame retardant (BFR) hexabromocyclododecane (HBCD) have been increasing. HBCD has been shown to cause adverse effects on learning and behavior in mice, as well as on dopamine uptake in rat synaptosomes and synaptic vesicles. For other BFRs, alterations in the intracellular Ca(2+) homeostasis have been observed. Therefore, the aim of this study was to investigate whether the technical HBCD mixture and individual stereoisomers affect the intracellular Ca(2+) concentration ([Ca(2+)](i)) in a neuroendocrine in vitro model (PC12 cells). [Ca(2+)](i) and vesicular catecholamine release were measured using respectively single-cell Fura-2 imaging and amperometry. Exposure of PC12 cells to the technical HBCD mixture or individual stereoisomers did neither affect basal [Ca(2+)](i), nor the frequency of basal neurotransmitter release. However, exposure to HBCD (0-20 microM) did cause a dose-dependent reduction of a subsequent depolarization-evoked increase in [Ca(2+)](i). This effect was apparent only when HBCD was applied at least 5 min before depolarization (maximum effect after 20 min exposure). The effects of alpha- and beta-HBCD were comparable to that of the technical mixture, whereas the inhibitory effect of gamma-HBCD was larger. Using specific blockers of L-, N- or P/Q-type voltage-gated Ca(2+) channels (VGCCs) it was shown that the inhibitory effect of HBCD is not VGCC-specific. Additionally, the number of cells showing depolarization-evoked neurotransmitter release was markedly reduced following HBCD exposure. Summarizing, HBCD inhibits depolarization-evoked [Ca(2+)](i) and neurotransmitter release. As increasing HBCD levels should be anticipated, these findings justify additional efforts to establish an adequate exposure, hazard and risk assessment.

  19. Study Case of Air-Mass Modification over Poland and Romania Observed by the Means of Multiwavelength Raman Depolarization Lidars

    OpenAIRE

    Costa-Surós Montserrat; Janicka Lucja; Stachlewska Iwona S.; Nemuc Anca; Talianu Camelia; Heese Birgit; Engelmann Ronny

    2016-01-01

    An air-mass modification, on its way from Poland to Romania, observed between 19-21 July 2014 is discussed. The air-mass was investigated using data of two multi-wavelength lidars capable of performing regular elastic, depolarization and Raman measurements in Warsaw, Poland, and in Magurele, Romania. The analysis was focused on evaluating optical properties of aerosol in order to search for similarities and differences in the vertical profiles describing the atmospheric layers above the two s...

  20. 大學圖書館電子資源之需求分析與行銷策略之研究 A Study of Demands Analysis and Marketing Strategy of Electronic Resources in University Library

    Directory of Open Access Journals (Sweden)

    Huang-Yu Liu

    2008-03-01

    Full Text Available 電子資源的出現,使得知識載體有了新的突破,提高了使用者的便利性與即時性。對於圖書館而言,如何使電子資源的使用效益達到最高,必須思考一套有效的行銷策略。電子資源行銷概念應以讀者為導向,尊重讀者的資訊需求,並利用各種宣傳技巧,行銷電子資源,使圖書館能提供更完善的服務。本研究之目的旨在探討讀者的使用需求及電子資源的推廣策略,以獲致最有效益的行銷方式。研究對象以開南大學日間部四學院(商學院、運輸觀光學院、資訊學院、人文社會學院)學生為樣本,佐以缺口分析模型為分析架構,藉以找出個案中讀者/學生對於電子資源使用的真實需求,並進而歸納出提供服務的大學圖書館在其推廣或行銷服務上可有的因應策略。The emergence of electronic resources has made new breakthrough in knowledge carriers because of their ease of use, instant availability, and the characteristic of no time and space constraints. For public libraries to achieve maximum efficiency in its electronic resources, it is necessary to seek the most effective marketing strategies. Therefore, the marketing concept of the electronic resources should be reader oriented, such as respecting and understanding library user’s information needs. Libraries also need to utilize various media and techniques to market the electronic resources, so that more comprehensive services and experiences can be provided to readers. The purpose of this study is to investigate library user’s needs and promotion strategies of electronic resources in order to identify the most effective ways of marketing. This study focuses on the students of the four colleges (College of Business, College of Tourism, College of Information, and College of Humanities and Social Science in Kainan University as subjects in the survey questionnaire. It uses the Gap Analysis

  1. Amrinone effects on electromechanical coupling and depolarization-induced automaticity in ventricular muscle of guinea pigs and ferrets.

    Science.gov (United States)

    Malécot, C O; Arlock, P; Katzung, B G

    1985-01-01

    The effects of the cardiotonic agent, amrinone (0.05-4 mM), on electrical and mechanical activities of ferret and guinea-pig papillary muscles were studied using current and voltage clamp (single sucrose gap) techniques. In current clamp studies, amrinone increased, in a dose-dependent manner, contractile force elicited by action potential in both species. Depolarization-induced automaticity was facilitated in ferret muscles at all maximum diastolic potentials between -70 and -15 mV. Facilitation of automaticity in guinea-pig muscles occurred only at potentials more negative than -35 mV and was suppressed at more positive potentials. Cimetidine (10 microM) partially reversed the effects of amrinone on automaticity in both species. In voltage clamp studies, amrinone increased the slow inward current. Steady-state outward current was increased in guinea-pig but not in ferret muscles. A dual effect of amrinone on tension was observed. Amrinone was found to increase phasic tension of ferret papillary muscles only for depolarizations lasting less than 250 to 300 msec. For longer depolarizations, amrinone decreased the phasic tension (in a dose-dependent manner), whereas the tonic tension was not modified. The decrease as well as the increase in tension was associated with an increase of the slow inward current. The results suggest that amrinone may be arrhythmogenic and may have an intracellular action at the sarcoplasmic reticulum level (partial inhibition) in addition to its action on the calcium current.

  2. Insulinotropic actions of Moringa oleifera involves the induction of membrane depolarization and enhancement of intracellular calcium concentration

    Directory of Open Access Journals (Sweden)

    Opeolu O. Ojo

    2015-03-01

    Methods: Phytochemical composition of M.oleifera extract was determined using standard procedures. Total flavonoid and total phenolic compounds in the extract were also quantified. Effects of the extracts on glucose stimulated insulin secretion, membrane depolarization and intracellular calcium concentration were investigated using BRIN-BD11 clonal pancreatic beta cells. Results: Results obtained showed the preponderance of alkaloids, flavonoids, glycosides, phenols, saponins and tannins in the extract. The glucose dependent insulinotropic effects of the extract were significantly inhibited in the presence of diazoxide (48% or verapamil (35% and in the absence of extracellular calcium (47%. Co-incubation of cells with the extract and IBMX (3-isobutyl-1-methylxanthine or tolbutamide increased insulin secretion by 2-fold while a 1.2-fold increase was observed in cells depolarized with 30 mM KCl in the presence of the plant extract. The extract significantly induced membrane depolarization (7.1-fold and enhanced intracellular calcium concentration (2.6-fold in BRIN-BD11 cells. Conclusion: These observations suggest that the insulinotropic actions of acetone extract of M.oleifera may be mediated via the KATP-dependent pathway of insulin release. [J Exp Integr Med 2015; 5(1.000: 36-41

  3. Correspondence between neutron depolarization and higher order magnetic susceptibility to investigate ferromagnetic clusters in phase separated systems.

    Science.gov (United States)

    Manna, Kaustuv; Samal, D; Bera, A K; Elizabeth, Suja; Yusuf, S M; Kumar, P S Anil

    2014-01-08

    It is a tough task to distinguish a short-range ferromagnetically correlated cluster-glass phase from a canonical spin-glass-like phase in many magnetic oxide systems using conventional magnetometry measurements. As a case study, we investigate the magnetic ground state of La0.85Sr0.15CoO3, which is often debated based on phase separation issues. We report the results of two samples of La0.85Sr0.15CoO3 (S-1 and S-2) prepared under different conditions. Neutron depolarization, higher harmonic ac susceptibility and magnetic relaxation studies were carried out along with conventional magnetometry measurements to differentiate subtle changes at the microscopic level. There is no evidence of ferromagnetic correlation in the sample S-2 attributed to a spin-glass phase, and this is compounded by the lack of existence of a second order component of higher harmonic ac susceptibility and neutron depolarization. A magnetic relaxation experiment at different temperatures complements the spin glass characteristic in S-2. All these signal a sharp variance when we consider the cluster-glass-like phase (phase separated) in S-1, especially when prepared from an improper chemical synthesis process. This shows that the nonlinear ac susceptibility is a viable tool to detect ferromagnetic clusters such as those the neutron depolarization study can reveal.

  4. Autonomic nervous system regulation of the sinoatrial cell depolarization rate: Unifying computational models.

    Science.gov (United States)

    Castellanos, P; Godinez, R

    2015-01-01

    In the last years different computational models have been proposed to simulate the sinoatrial node cell (SANC) action potential. Also, there has been a great effort to model the heart regulation mechanism by the autonomic nervous system (ANS) through the sympathetic and parasympathetic pathways. Both computational models have tried to fit the rabbit and/or the guinea-pig experimental heart rate data with an increasing success. Thus, the aim of this work was to unify the available models that have been reported to study the heart rate behavior when the SANC is stimulated by using different frequency patterns. Our results contribute to the unification of part of the Scepanovic's model [1] (involved with second messengers dynamics and its influence over specific SANC ionic channels), and the SANC ionic channels computational model proposed by Severi et al. [2] in 2012. In this model unification we did refit some parameters, particularly, those related to the Hill functions in the dynamic modeling of phosphokinase and its effect on the ionic channels currents If and ICaL, and over the Pup, parameter that is related to the Ca(++) uptake by the sarcoplasmic reticulum. Also, we eliminated the neurotransmitter effect over the ionic current IKr that is not presented in the Severi's model. These modifications were enough to successfully reproduce the heart rate experimental recordings under acetylcholine (Ach) or norepinephrine (NE) for independent stimulation: Ach 10 nM stimulation showed a 21.54% action potential shift compared with the 20% reported for experimental recordings; Isoprenaline 1 μM, also displayed a depolarization increased rate of 29.3%, compared with the experimental data of 28.2%. Furthermore, we were able to reproduce the guinea-pig experimental heart rate recordings, when the SANC model was vagal stimulated by using a 2 Hz, 10 Hz and 20 Hz frequency for 10 seconds and the experimental heart rate data for a sympathetic stimulation of 10 Hz frequency for

  5. Raised activity of L-type calcium channels renders neurons prone to form paroxysmal depolarization shifts.

    Science.gov (United States)

    Rubi, Lena; Schandl, Ulla; Lagler, Michael; Geier, Petra; Spies, Daniel; Gupta, Kuheli Das; Boehm, Stefan; Kubista, Helmut

    2013-09-01

    Neuronal L-type voltage-gated calcium channels (LTCCs) are involved in several physiological functions, but increased activity of LTCCs has been linked to pathology. Due to the coupling of LTCC-mediated Ca(2+) influx to Ca(2+)-dependent conductances, such as KCa or non-specific cation channels, LTCCs act as important regulators of neuronal excitability. Augmentation of after-hyperpolarizations may be one mechanism that shows how elevated LTCC activity can lead to neurological malfunctions. However, little is known about other impacts on electrical discharge activity. We used pharmacological up-regulation of LTCCs to address this issue on primary rat hippocampal neurons. Potentiation of LTCCs with Bay K8644 enhanced excitatory postsynaptic potentials to various degrees and eventually resulted in paroxysmal depolarization shifts (PDS). Under conditions of disturbed Ca(2+) homeostasis, PDS were evoked frequently upon LTCC potentiation. Exposing the neurons to oxidative stress using hydrogen peroxide also induced LTCC-dependent PDS. Hence, raising LTCC activity had unidirectional effects on brief electrical signals and increased the likeliness of epileptiform events. However, long-lasting seizure-like activity induced by various pharmacological means was affected by Bay K8644 in a bimodal manner, with increases in one group of neurons and decreases in another group. In each group, isradipine exerted the opposite effect. This suggests that therapeutic reduction in LTCC activity may have little beneficial or even adverse effects on long-lasting abnormal discharge activities. However, our data identify enhanced activity of LTCCs as one precipitating cause of PDS. Because evidence is continuously accumulating that PDS represent important elements in neuropathogenesis, LTCCs may provide valuable targets for neuroprophylactic therapy.

  6. Differential action of (-)-baclofen on the primary afferent depolarization produced by segmental and descending inputs.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Jiménez, I; Rudomin, P

    1992-01-01

    The purpose of the present series of experiments was to analyze, in anesthetized and paralyzed cats, the effects of (-)-baclofen and picrotoxin on the primary afferent depolarization (PAD) generated in single Ib afferent fibers by either intraspinal microstimulation or stimulation of the segmental and descending pathways. PAD was estimated by recording dorsal root potentials and by measuring the changes in the intraspinal activation threshold of single Ib muscle afferent fibers. The PAD elicited by stimulation of group I muscle or cutaneous afferents was readily depressed and often abolished 20-40 min after the intravenous injection of 1-2 mg/kg (-)-baclofen. In contrast, the same amounts of (-)-baclofen produced a relatively small depression of the PAD elicited by stimulation of the brainstem reticular formation (RF). The monosynaptic PAD produced in single Ib fibers by intraspinal microstimulation within the intermediate nucleus was depressed and sometimes abolished following the i.v. injections of 1-2 mg/kg (-)-baclofen. Twenty to forty minutes after the i.v. injection of picrotoxin (0.5-1 mg/kg), there was a strong depression of the PAD elicited by stimulation of muscle and cutaneous afferents as well as of the PAD produced by stimulation of the RF and the PAD produced by intraspinal microstimulation. The results obtained suggest that, in addition to its action on primary afferents, (-)-baclofen may depress impulse activity and/or transmitter release in a population of last-order GABAergic interneurons that mediate the PAD of Ib fibers. The existence of GABAb autoreceptors in last-order interneurons mediating the PAD may function as a self-limiting mechanism controlling the synaptic efficacy of these interneurons.

  7. Reduction in Cortical Gamma Synchrony during Depolarized State of Slow Wave Activity in Mice

    Directory of Open Access Journals (Sweden)

    EUNJIN eHWANG

    2013-12-01

    Full Text Available EEG gamma band oscillations have been proposed to account for the neural synchronization crucial for perceptual integration. While increased gamma power and synchronization is generally observed during cognitive tasks performed during wake, several studies have additionally reported increased gamma power during sleep or anesthesia, raising questions about the characteristics of gamma oscillation during impaired consciousness and its role in conscious processing. Phase-amplitude modulation has been observed between slow wave activity (SWA, 0.5–4 Hz and gamma oscillations during ketamine/xylazine anesthesia or sleep, showing increased gamma activity corresponding to the depolarized (ON state of SWA. Here we divided gamma activity into its ON and OFF (hyperpolarized state components based on the phase of SWA induced by ketamine/xylazine anesthesia and compared their power and synchrony with wake state levels in mice. We further investigated the state-dependent changes in both gamma power and synchrony across primary motor and primary somatosensory cortical regions and their interconnected thalamic regions throughout anesthesia and recovery. As observed previously, gamma power was as high as during wake specifically during the ON state of SWA. However, the synchrony of this gamma activity between somatosensory-motor cortical regions was significantly reduced compared to the baseline wake state. In addition, the somatosensory-motor cortical synchrony of gamma oscillations was reduced and restored in an anesthetic state-dependent manner, reflecting the changing depth of anesthesia. Our results provide evidence that during anesthesia changes in long-range information integration between cortical regions might be more critical for changes in consciousness than changes in local gamma oscillatory power.

  8. Depolarized Photon Correlation Spectroscopic Study of the Glass-Forming Liquid Cumene at Very High Pressures

    Science.gov (United States)

    Lyon, Kevin; Ransom, Tim; Oliver, William

    2014-03-01

    In recent years full-spectrum analysis of light-scattering data has been utilized to explore the liquid-glass transition at variable temperatures and ambient pressure. We have developed methods for doing depolarized photon correlation spectroscopy (PCS) in the diamond anvil cell in order to probe directly the structural relaxation time of glass-forming liquids at very high pressures. Here we present results for liquid cumene at 25 C between 1 bar and pressures approaching the room-temperature glass transition at 2.1 GPa. Data along higher-temperature isotherms will also be presented. Methods for minimizing any undesired heterodyne component in the collected light as well as the use of the longitudinal modes of the Brillouin spectrum to aid in the acquisition and spatial filtering of the scattered light will be discussed. Intensity-intensity correlation data were found to be well represented by the KWW equation with a nearly constant stretching parameter of g = 0.66 for 25 C. Furthermore, the relaxation time as a function of pressure is described will using a modified VTF expression: (P)=0exp{DP/(P0-P)}, with values of 0 = 11.9 ps, D = 18.6, and P0 = 3.4 GPa at T = 25 °C. Thus, (P) has been obtained at 25 °C for Cumene over seven decades from about a microsecond to several seconds and is found to be in excellent agreement with previously determined values for the alpha relaxation at lower pressures obtained from Brillouin data [G. Li, et al., Phys. Rev. Lett. 74, 2280 (1995)]. Partially supported by NSF Grant Number: DMR 0552944.

  9. Thermally stimulated depolarization currents in the natural fluorite; Correntes de despolarizacao termicamente estimuladas na fluorita natural

    Energy Technology Data Exchange (ETDEWEB)

    Valerio, Mario Ernesto Giroldo

    1986-12-31

    The present work deals with natural calcium fluoride from Criciuma, Santa Catarina. Thermally Stimulated Depolarization Currents (TSDC) can be used to determine the properties of dipole defects present in this crystal. The TSDC spectrum of this material shows three bands in the temperature range of 80 to 450 K. The first one, at 130 K, is due the dipoles formed by a trivalent impurity and an interstitial fluorine ion in the next nearest position of an impurity ion (nn R{sub s}{sup 3+} -F{sub i}{sup -}). The second one, at 102 k, is due to the presence of small aggregates of dipoles (like a dimer). The last band, at 360 k is due to the formation of Large Clusters. The continuous distribution model gave the best fit for these bands with mean activation energies of 0.41 eV, 0.595 eV and 1.02 eV for the first, second and third band respectively. Thermal treatments can modify the number of dipoles, dimers and clusters present in the crystal. The variation in the areas under each band can be used to measure this effect. In this work we used thermal treatments between 15 minutes and 10 hours and temperatures between 200 deg C and 500 deg C. For thermal treatments at 300 deg C, the dipoles and dimers are created and the clusters are destroyed as the time of thermal treatment increases. At 400 deg C the clusters are created and the dipoles and dimers and 350 deg C for the clusters. (author) 60 refs., 41 figs., 1 tab.

  10. Site-Specific Fluorescence Depolarization Kinetics Distinguishes the Amyloid Folds Responsible for Distinct Yeast Prion Strains.

    Science.gov (United States)

    Narang, Dominic; Swasthi, Hema M; Mahapatra, Sayanta; Mukhopadhyay, Samrat

    2017-08-25

    The prion determinant of a yeast prion protein, Sup35NM, assembles into β-rich amyloid fibrils that switch the non-prion [psi-] state to the prion [PSI+] state of yeast. Previous studies have shown that two distinct forms of amyloids (Sc4 and Sc37), generated in vitro at two different temperatures (4°C and 37°C), recapitulate the strain phenomenon in Saccharomyces cerevisiae. Sc4 demonstrates a strong [PSI+] phenotype, whereas, Sc37 shows a weak phenotype. In order to discern the residue-specific structural and dynamical attributes associated with the amyloids that display stain-diversity, we took advantage of non-occurrence of tryptophan (Trp) in the NM-domain and created 18 single-Trp variants spanning the entire polypeptide length. The fluorescence readouts from these locations reported the site-specific structural details in Sc4 and Sc37 fibrils. Highly sensitive picosecond fluorescence depolarization measurements at these positions allowed us construct a conformational mobility map. Nearly all the residue positions demonstrated higher local flexibility in Sc4 amyloid that exhibits strong phenotype. The differences in the amplitude of local mobility were more pronounced at the two end segments of the N-domain compared to the central region. The M-domain is partially exposed and exhibits higher amplitude of local mobility indicating a lower degree of chain packing in the amyloid state and exhibited higher mobility in Sc4 state compared to Sc37 state. The altered local conformational dynamics in two distinct amyloid states provide molecular insights into the varied fragility and severing efficiency that govern the inheritance pattern of strong and weak prion strains.

  11. Comparative effectiveness of Calabadion and sugammadex to reverse non-depolarizing neuromuscular blocking agents

    Science.gov (United States)

    Haerter, Friederike; Simons, Jeroen Cedric Peter; Foerster, Urs; Duarte, Ingrid Moreno; Diaz-Gil, Daniel; Ganapati, Shweta; Eikermann-Haerter, Katharina; Ayata, Cenk; Zhang, Ben; Blobner, Manfred; Isaacs, Lyle; Eikermann, Matthias

    2015-01-01

    Background We evaluated the comparative effectiveness of calabadion 2 to reverse non-depolarizing neuromuscular blocking agents (NMBAs) by binding and inactivation. Methods The dose-response relationship of drugs to reverse vecuronium, rocuronium, and cisatracurium-induced neuromuscular block (NMB) was evaluated in vitro (competition binding assays and urine analysis), ex vivo (n=34; phrenic nerve hemidiaphragm preparation) and in vivo (n=108; quadriceps femoris muscle of the rat). Cumulative dose-response curves of calabadions, neostigmine, or sugammadex were created ex vivo at steady-state deep NMB. In living rats, we studied the dose-response relationship of the test drugs to reverse deep block under physiological conditions and we measured the amount of calabadion 2 excreted in the urine. Results In vitro experiments showed that calabadion 2 binds rocuronium with 89 times the affinity of sugammadex (Ka = 3.4 × 109 M−1 and Ka = 3.8 × 107 M−1). Urine analysis (proton nuclear magnetic resonance), competition binding assays and ex vivo study results obtained in the absence of metabolic deactivation are in accordance with an 1:1 binding ratio of sugammadex and calabadion 2 toward rocuronium. In living rats, calabadion 2 dose-dependently and rapidly reversed all NMBAs tested. The molar potency of calabadion 2 to reverse vecuronium and rocuronium was higher compared to sugammadex. Calabadion 2 was eliminated renally, and did not affect blood pressure or heart rate. Conclusion Calabadion 2 reverses NMB-induced by benzylisoquinolines and steroidal NMBAs in rats more effectively, i.e. faster, than sugammadex. Calabadion 2 is eliminated in the urine and well tolerated in rats. PMID:26418697

  12. Atrial depolarization in Wolf-Parkinson-White and Lown-Ganong-Levine syndrome: vectorcardiographic features.

    Science.gov (United States)

    Zoneraich, O; Zoneraich, S

    1979-07-01

    The atrial depolarization pattern was studied in 22 patients with Wolff-Parkinson-White and Lown-Ganong-Levine syndrome. The influence of the accessory pathways on the shape, magnitude and conduction pattern of the PSE loop was analyzed. An accurate evaluation of the beginning of the delta wave and of the P loop distortions was obtained by using high magnification (1 mV = 30 cm) recordings. The Frank lead system was used. The influence of atrial size (documented by echocardiography) on the PSE loop is emphasized. Special attention has been focused on the terminal vectors as compared to a control group. In Wolff-Parkinson-White syndrome the size of the PSE loop was smaller than in Lown-Ganong-Levine syndrome or in the normal group. When atrial conduction disturbances and/or atrial enlargement was present the PSE loop was larger and distorted. The terminal vectors were abnormally oriented in 75 percent of the patients with Wolff-Parkinson-White syndrome, but only in one with Lown-Ganong-Levine syndrome. The beginning of the delta wave in patients with Wolff-Parkinson-White syndrome was located to the left of the E point in all but two. When the "concertina" effect was present, the direction of the terminal vectors remained unchanged. In four patients with the Lown-Ganong-Levine syndrome, the PSE loop closed, and in three patients, a small opening was present. We suggest that the changes in contour, duration and amplitude of the PSE loop are due to an abnormal pattern of atrial depolorization in Wolff-Parkinson-White syndrome.

  13. EVALUATION OF PROTON-CONDUCTING MEMBRANES FOR USE IN A SULFUR-DIOXIDE DEPOLARIZED ELECTROLYZER

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.; Elvington, M.; Colon-Mercado, H.

    2009-11-11

    The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDE's function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 C in 60 wt. % H{sub 2}SO{sub 4} for 24 hours. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO{sub 2} transport was evaluated using a two-chamber permeation cell. SO{sub 2} was introduced into one chamber whereupon SO{sub 2} transported across the membrane into the other chamber and oxidized to H{sub 2}SO{sub 4} at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO{sub 2} flux and SO{sub 2} transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO{sub 2} transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density versus a constant cell voltage (1V, 80 C in SO{sub 2} saturated 30 wt% H2SO{sub 4}). Finally, candidate membranes were evaluated considering all measured parameters including SO{sub 2} flux, SO{sub 2} transport, ionic conductivity, HyS electrolyzer performance, and membrane stability. Candidate membranes included both PFSA and non-PFSA polymers and polymer blends of which the non-PFSA polymers, BPVE-6F and PBI, showed the best selectivity.

  14. 电子商务系统内的人力资源管理模式解析%The analytic model of human resource management in electronic commerce system

    Institute of Scientific and Technical Information of China (English)

    王斌

    2013-01-01

      企业人力资源管理工作在现代电子商务环境下呈现出多方面的电子化新特征,且较之于传统的人力资源管理工作有非常多显著的优势可言,基本上已经成为了企业获取更大成功的基本导向。电子商务系统内的人力资源管理新模式E-HR就是在这样一种背景下应运而生的,E-HR管理模式不仅已经成为了众多企业发展的趋势,而且在实际应用的过程当中也已经给企业带来了非常多的利益。本文正是在此背景之下对电子商务系统内的人力资源管理模式E-HR进行解析,希望能够对其有更深入的理解并更好的应用到实践当中去。%The enterprise human resources management in modern electronic commerce environment presents many new characteristics of the electron,and compared with the traditional human resource management has many significant advantages,basically has become a basic guide for more successful enterprises.E-HR is a new mode of human resource management system emerge as the times require electronic commerce is in such a background,the E-HR management model not only has become the trend of development of many enterprises, but also in the process of practical application also has to the enterprise has brought a lot of benefits. This paper is analyzed under this background to the electronic commerce system within the human resources management mode of E-HR,the application wishes to have a deeper understanding and better on it into practice.

  15. Positive Perceptions of Access to Online Library Resources Correlates with Quality and Quantity of Scholarly Publications among Finnish Academics. A Review of: Vakkari, Pertti. “Perceived Influence of the Use of Electronic Information Resources on Scholarly Work and Publication Productivity.” Journal of the American Society for Information Science and Technology 59.4 (Feb. 15, 2008: 602-12.

    Directory of Open Access Journals (Sweden)

    Scott Marsalis

    2008-12-01

    Full Text Available Objective – To investigate the relationship between academics’ use of library electronic resources and their opinions regarding how these resources have impacted their work, and to investigate the association between this perceived influence and publication productivity during the previous two years.Design – Two specific questions added to an annual online user-survey questionnaire; additional data mined from surveySetting – Twenty-two Finnish Universities served by FinELib, the Finnish Electronic Library.Subjects – Seven hundred and sixty seven academic staff and full-time doctoral students.Methods – A questionnaire was posted in April 2007 on FinELib’s homepage and advertised on each university library’s mainpage, and focused on respondents’ experience in the previous two years. Participants selected answers either from a list of category choices, or, when measuring perceptions, by rating agreement with statements along a four-point scale. Controlled variables measured were the respondents’ academic position, their discipline, membership in a research group, whether their literature use was discipline-specific or interdisciplinary, and their perception of the availability online of the relevant core literature. The independent variable measured was the scholars’ perception of the impact of the use of electronic library resources on their work. The dependent variable measured was the scholars’ self-reported publications in the two years preceding the survey.Main Results – Participants reported a positive impact on the efficiency of their work, most strongly in areas of ease of access, with lesser impacts in the range of materials available to them and the ease with which they can keep up-to-date in their field. To a lesser extent, the scholars perceived a positive impact on the quality of their work. Upon analysis, the study found that access to online library resources improved scholars’ work by the interconnected

  16. Structural stability and depolarization of manganese-doped (Bi₀.₅Na₀.₅){sub 1−x}Ba{sub x}TiO₃ relaxor ferroelectrics

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sheng-Fen [Department of Physics, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China); Tu, Chi-Shun, E-mail: 039611@mail.fju.edu.tw [Department of Physics, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China); Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China); Chang, Ting-Lun; Chen, Pin-Yi [Department of Mechanical Engineering, Ming-Chi University of Technology, New Taipei City 24301, Taiwan (China); Chen, Cheng-Sao [Department of Mechanical Engineering, Hwa-Hsia University of Technology, New Taipei City 23567, Taiwan (China); Hugo Schmidt, V. [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States); Anthoniappen, J. [Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China)

    2014-10-21

    This work reveals that 0.5 mol. % manganese (Mn) doping in (Bi₀.₅Na₀.₅){sub 1−x}Ba{sub x}TiO₃ (x = 0 and 0.075) solid solutions can increase structural thermal stability, depolarization temperature (T{sub d}), piezoelectric coefficient (d₃₃), and electromechanical coupling factor (kₜ). High-resolution X-ray diffraction and transmission electron microscopy reveal coexistence of rhombohedral (R) R3c and tetragonal (T) P4bm phases in (Bi₀.₅Na₀.₅)₀.₉₂₅Ba₀.₀₇₅TiO₃ (BN7.5BT) and 0.5 mol. % Mn-doped BN7.5BT (BN7.5BT-0.5Mn). (Bi₀.₅Na₀.₅)TiO₃ (BNT) and BN7.5BT show an R − R + T phase transition, which does not occur in 0.5 mol. % Mn-doped BNT (BNT-0.5Mn) and BN7.5BT-0.5Mn. Dielectric permittivity (ε′) follows the Curie-Weiss equation, ε′ = C/(T − T{sub o}), above the Burns temperature (TB), below which polar nanoregions begin to develop. The direct piezoelectric coefficient (d₃₃) and electromechanical coupling factor (kₜ) of BN7.5BT-0.5Mn reach 190 pC/N and 47%.

  17. Lactation resources for clinicians.

    Science.gov (United States)

    Turner-Maffei, Cynthia

    2007-01-01

    Breastfeeding is widely acknowledged as the optimal infant feeding choice. However, many clinicians working in maternal and child health do not receive adequate university preparation to support breastfeeding. Knowledge and skill are most often gained through on-the-job and personal experience. Myriad resources exist to support clinicians in delivering the best quality care to breastfeeding clients. Among the available resources are policies and protocols of professional organizations, governmental, and health advocacy groups. Breastfeeding-focused academic and continuing education programs are identified. Electronic and other resources for breastfeeding information are available for both professional and consumer audiences.

  18. Effect of Sodium-Potassium Pump Inhibitors and Membrane-Depolarizing Agents on Sodium Nitroprusside-Induced Relaxation and Cyclic Guanosine Monophosphate Accumulation in Rat Aorta

    National Research Council Canada - National Science Library

    Rapoport, Robert M; Schwartz, Karen; Murad, Ferid

    1985-01-01

    ... or tetraethylammonium, membrane-depolarizing agents, inhibited relaxation to nitroprusside. These conditions had little or no effect on the elevated cyclic guanosine monophosphate levels at a concentration of nitroprusside (0.1 μM...

  19. Renewable energy resources

    DEFF Research Database (Denmark)

    Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

    2014-01-01

    Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

  20. Merge of terminological resources

    DEFF Research Database (Denmark)

    Henriksen, Lina; Braasch, Anna

    2012-01-01

    In our globalized world, the amount of cross-national communication increases rapidly, which also calls for easy access to multi-lingual high quality terminological resources. Sharing of terminology resources is currently becoming common practice, and efficient strategies for integration...... – or merging – of terminology resources are strongly needed. This paper discusses prerequisites for successful merging with the focus on identification of candidate duplicates of a subject domain found in the resources to be merged, and it describes automatic merging strategies to be applied to such duplicates...... in electronic terminology resources. Further, some perspectives of manual, supplementary assessment methods supporting the automatic procedures are sketched. Our considerations are primarily based on experience gained in the IATE and EuroTermBank projects, as merging was a much discussed issue in both projects....

  1. Metabolic and perfusion responses to recurrent peri-infarct depolarization during focal ischemia in the Spontaneously Hypertensive Rat: dominant contribution of sporadic CBF decrements to infarct expansion

    OpenAIRE

    Takeda,Yoshimasa; Zhao, Liang; Jacewicz, Michael; PULSINELLI, WILLIAM A.; Nowak, Thaddeus S.

    2011-01-01

    Peri-infarct depolarizations (PIDs) contribute to the evolution of focal ischemic lesions. Proposed mechanisms include both increased metabolic demand under conditions of attenuated perfusion and overt vasoconstrictive responses to depolarization. The present studies investigated the relative contributions of metabolic and perfusion effects to PID-associated infarct expansion during middle cerebral artery (MCA) occlusion in the Spontaneously Hypertensive Rat. The initial distribution of ische...

  2. The organization of primary afferent depolarization in the isolated spinal cord of the frog

    Science.gov (United States)

    Carpenter, D. O.; Rudomin, P.

    1973-01-01

    1. The organization of primary afferent depolarization (PAD) produced by excitation of peripheral sensory and motor nerves was studied in the frog cord isolated with hind limb nerves. 2. Dorsal root potentials from sensory fibres (DR-DRPs) were evoked on stimulation of most sensory nerves, but were largest from cutaneous, joint and flexor muscle afferents. With single shock stimulation the largest cutaneous and joint afferent fibres gave DR-DRPs, but potentials from muscle nerves resulted from activation of sensory fibres with thresholds to electrical stimulation higher than 1·2-1·5 times the threshold of the most excitable fibres in the nerve. This suggests that PAD from muscle afferents is probably due to excitation of extrafusal receptors. 3. Dorsal root potentials produced by antidromic activation of motor fibres (VR-DRPs) were larger from extensor muscles and smaller or absent from flexor muscles. The VR-DRPs were produced by activation of the lowest threshold motor fibres. 4. Three types of interactions were found between test and conditioning DRPs from the same or different nerves. With maximal responses occlusion was usually pronounced. At submaximal levels linear summation occurred. Near threshold the conditioning stimulus frequently resulted in a large facilitation of the test DRP. All three types of interactions were found with two DR-DRPs, two VR-DRPs or one DR-DRP and one VR-DRP. 5. The excitability of sensory nerve terminals from most peripheral nerves was increased during the DR-DRP. The magnitude of the excitability increase varied roughly with the magnitude of the DR-DRP evoked by the conditioning stimulus. 6. There was a marked excitability increase of cutaneous and extensor muscle afferent terminals during the VR-DRP. Flexor muscle afferent terminals often showed no excitability changes to ventral root stimulation. In those experiments where afferent terminals from flexor muscles did show an excitability increase, the effects were smaller than

  3. Reticulospinal actions on primary afferent depolarization of cutaneous and muscle afferents in the isolated frog neuraxis.

    Science.gov (United States)

    González, H; Jiménez, I; Rudomin, P

    1993-01-01

    The effects of the brainstem reticular formation on the intraspinal excitability of low threshold cutaneous and muscle afferents were studied in the frog neuraxis isolated together with the right hindlimb nerves. Stimulation of low threshold fibers (less than two times threshold) in cutaneous nerves produced short latency, negative field potentials in the ipsilateral dorsal neuropil (200-400 microns depth) that reversed to positivity at deeper regions (500-700 microns). Stimulation of low threshold fibers (less than two times threshold) in muscle nerves produced, instead, negative response that acquired their maximum amplitude in the ventral neuropil (700-900 microns depth). These electrophysiological findings suggest, in agreement with observations in the cat, that low threshold cutaneous and muscle afferents end at different sites in the spinal cord. Intraspinal microstimulation applied within the dorsal neuropil produced antidromic responses in low threshold cutaneous afferents that were increased in size following stimulation of the dorsal or ventral roots, as well as of the brainstem reticular formation. This increase in excitability is interpreted as being due to primary afferent depolarization (PAD) of the intraspinal terminals of cutaneous fibers. Antidromic responses recorded in muscle nerves following intraspinal stimulation within the ventral neuropil were also increased following conditioning stimulation of adjacent dorsal or ventral roots. However, stimulation of the bulbar reticular formation produced practically no changes in the antidromic responses, but was able to inhibit the PAD of low threshold muscle afferents elicited by stimulation of the dorsal or ventral roots. It is suggested that the PAD of low threshold cutaneous and muscle afferents is mediated by independent sets of interneurons. Reticulospinal fibers would have excitatory connections with the interneurons mediating the PAD of cutaneous fibers and inhibitory connections with the

  4. Discovery of a complex linearly polarized spectrum of Betelgeuse dominated by depolarization of the continuum

    Science.gov (United States)

    Aurière, M.; López Ariste, A.; Mathias, P.; Lèbre, A.; Josselin, E.; Montargès, M.; Petit, P.; Chiavassa, A.; Paletou, F.; Fabas, N.; Konstantinova-Antova, R.; Donati, J.-F.; Grunhut, J. H.; Wade, G. A.; Herpin, F.; Kervella, P.; Perrin, G.; Tessore, B.

    2016-06-01

    Context. Betelgeuse is an M supergiant that harbors spots and giant granules at its surface and presents linear polarization of its continuum. Aims: We have previously discovered linear polarization signatures associated with individual lines in the spectra of cool and evolved stars. Here, we investigate whether a similar linearly polarized spectrum exists for Betelgeuse. Methods: We used the spectropolarimeter Narval, combining multiple polarimetric sequences to obtain high signal-to-noise ratio spectra of individual lines, as well as the least-squares deconvolution (LSD) approach, to investigate the presence of an averaged linearly polarized profile for the photospheric lines. Results: We have discovered the existence of a linearly polarized spectrum for Betelgeuse, detecting a rather strong signal (at a few times 10-4 of the continuum intensity level), both in individual lines and in the LSD profiles. Studying its properties and the signal observed for the resonant Na i D lines, we conclude that we are mainly observing depolarization of the continuum by the absorption lines. The linear polarization of the Betelgeuse continuum is due to the anisotropy of the radiation field induced by brightness spots at the surface and Rayleigh scattering in the atmosphere. We have developed a geometrical model to interpret the observed polarization, from which we infer the presence of two brightness spots and their positions on the surface of Betelgeuse. We show that applying the model to each velocity bin along the Stokes Q and U profiles allows the derivation of a map of the bright spots. We use the Narval linear polarization observations of Betelgeuse obtained over a period of 1.4 yr to study the evolution of the spots and of the atmosphere. Conclusions: Our study of the linearly polarized spectrum of Betelgeuse provides a novel method for studying the evolution of brightness spots at its surface and complements quasi-simultaneous observations obtained with PIONIER at the

  5. Metabolic and perfusion responses to recurrent peri-infarct depolarization during focal ischemia in the Spontaneously Hypertensive Rat: dominant contribution of sporadic CBF decrements to infarct expansion.

    Science.gov (United States)

    Takeda, Yoshimasa; Zhao, Liang; Jacewicz, Michael; Pulsinelli, William A; Nowak, Thaddeus S

    2011-09-01

    Peri-infarct depolarizations (PIDs) contribute to the evolution of focal ischemic lesions. Proposed mechanisms include both increased metabolic demand under conditions of attenuated perfusion and overt vasoconstrictive responses to depolarization. The present studies investigated the relative contributions of metabolic and perfusion effects to PID-associated infarct expansion during middle cerebral artery (MCA) occlusion in the Spontaneously Hypertensive Rat. The initial distribution of ischemic depolarization (ID) was established within minutes after MCA occlusion at a cerebral blood flow threshold of ∼40 mL/100 g per minute, with expansion of the depolarized territory during 3 hours detected in half of the animals. Peri-infarct depolarizations were associated with transient metabolic responses, comparable to those observed after spreading depression, with no evidence of cumulative energy failure after multiple transient depolarizations during 1 hour. Speckle contrast imaging of PID-associated flow transients documented prominent distal hyperemic flow responses that became progressively attenuated in regions of already impaired perfusion, with modest propagated flow decreases more proximal to the ischemic core. However, sporadic PIDs were associated with persistent decrements in perfusion, increasing tissue volume below the threshold for energy failure, ID and infarction. These latter, comparatively rare, events can account for the pattern of stepwise infarct expansion in this model.

  6. Evaluating the use of a simulated electronic health record and online drug reference in a case study to enhance nursing students' understanding of pharmacologic concepts and resources.

    Science.gov (United States)

    Vana, Kimberly D; Silva, Graciela E

    2014-01-01

    Nursing students should learn to navigate the complexities of the healthcare arena, such as integrating use of electronic health records (EHRs) and online drug references into patient care. Using a simulated EHR in a nursing pharmacology course allowed students to interact with these technologies while learning and applying pharmacologic concepts to a case study. The authors discuss how they created and facilitated such a case study, as well as students' outcomes.

  7. 浅谈高职院校图书馆电子资源的管理和服务%On the Management and Service of the Electronic Resources of Higher Vocational College Library

    Institute of Scientific and Technical Information of China (English)

    邓正芳

    2014-01-01

    Under the background of rapid development of social economy, the computer technology, computer network technology, communication technology, database technology and other information technology, China has entered the information age ahead of time. In higher vocational colleges, the library electronic resources have become an important way for teachers and students to get teaching knowledge and scientific research information, providing reliable, timely and accurate books resources information service for teachers and students. In order to ensure the effective utilization of library electronic resources in higher vocational colleges, scientific and reasonable management is necessary, so as to promote the construction of digital libraries in higher vocational colleges, to achieve better and faster development.%在社会经济的快速发展背景下,我国计算机技术、计算机网络技术、通讯技术以及数据库技术等信息技术的产生,使我国提前进入信息化时代。在高职院校中,图书馆电子资源已经成为老师和学生获取教学知识、科研信息等方面的重要途径,为学校老师和学生提供了可靠、及时、准确的图书资源信息化服务。为了确保高职院校图书馆电子资源的有效利用,需要对其进行科学合理的管理,促进高职院校图书馆数字化建设,使其更好更快地发展。

  8. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

  9. Electronic collection management

    CERN Document Server

    Mcginnis, Suzan D

    2013-01-01

    Build and manage your collection of digital resources with these successful strategies! This comprehensive volume is a practical guide to the art and science of acquiring and organizing electronic resources. The collections discussed here range in size from small college libraries to large research libraries, but all are facing similar problems: shrinking budgets, increasing demands, and rapidly shifting formats. Electronic Collection Management offers new ideas for coping with these issues. Bringing together diverse aspects of collection development, Electronic Collection

  10. 基于高校图书馆电子资源的采访调查与分析——以海南大学图书馆为例%Survey and Analysis Based on the Electronic Resource of University Libraries Taking Hainan University library as an Example

    Institute of Scientific and Technical Information of China (English)

    杨莹

    2011-01-01

    随着信息化时代的到来,高校图书馆的馆藏资源建设模式已经发生了变化,形成了纸质资源与电子资源并存的局面,电子资源以其方便快捷深受读者喜爱,电子资源的采购比例越来越重,如何协调电子资源的采购比例,是图书馆界丞待解决的问题.文章通过对海南大学2006-2010年间的电子资源经费使用情况进行统计、对比和分析,对此问题进行了初步的探讨.%With the arrival of information age, college library collection resources construction mode has changed, and the paper-based resources and electroic resources coexist.With the convenience of electronic resources, the acquisition proportion of electronic resources grows.How to coordinate the acquisition of electronic resource proportion is a problem faced by the libraries.Through the funds statistics, contrast and analysis of electronic resources in hainan university 2006-2010 this article provides a preliminary discussion.

  11. Depolarization-stimulated /sup 42/K+ efflux in rat aorta is calcium- and cellular volume-dependent

    Energy Technology Data Exchange (ETDEWEB)

    Magliola, L.; Jones, A.W.

    1987-07-01

    The purpose of this study was to investigate the factors controlling membrane permeability to potassium of smooth muscle cells from rat aorta stimulated by depolarization. The increase /sup 42/K+ efflux (change in the rate constant) induced by depolarization (application of high concentrations of potassium chloride) was inhibited significantly by the calcium antagonists diltiazem and nisoldipine. Parallel inhibitory effects on contraction were observed. Diltiazem also inhibited potassium-stimulated /sup 36/Cl- efflux. The addition of 25-150 mM KCl to normal physiologic solution stimulated /sup 42/K+ efflux in a concentration-dependent manner. Diltiazem suppressed potassium-stimulated /sup 42/K+ efflux approximately 90% at 25 mM KCl and approximately 40% at 150 mM KCl. The ability of nisoldipine to inhibit /sup 42/K+ efflux also diminished as the potassium chloride concentration was elevated. The component of efflux that was resistant to calcium antagonists probably resulted from a decrease in the electrochemical gradient for potassium. Cellular water did not change during potassium addition. Substitution of 80 and 150 mM KCl for sodium chloride produced cellular swelling and enhanced potassium-stimulated /sup 42/K+ efflux compared with potassium chloride addition. The addition of sucrose to prevent cellular swelling reduced efflux response to potassium substitution toward that of potassium addition. A hypoosmolar physiologic solution produced an increase in the /sup 42/K+ efflux and a contracture that were both prevented by the addition of sucrose. We concluded that the depolarization-mediated /sup 42/K+ efflux has three components: one is calcium dependent; a second is dependent on cellular volume; and a third is resistant to inhibition by calcium antagonists.

  12. Temporo-spectral imaging of intrinsic optical signals during hypoxia-induced spreading depression-like depolarization.

    Directory of Open Access Journals (Sweden)

    Maria Mané

    Full Text Available Spreading depression (SD is characterized by a sustained near-complete depolarization of neurons, a massive depolarization of glia, and a negative deflection of the extracellular DC potential. These electrophysiological signs are accompanied by an intrinsic optical signal (IOS which arises from changes in light scattering and absorption. Even though the underlying mechanisms are unclear, the IOS serves as non-invasive tool to define the spatiotemporal dynamics of SD in brain slices. Usually the tissue is illuminated by white light, and light reflectance or transmittance is monitored. Using a polychromatic, fast-switchable light source we now performed temporo-spectral recordings of the IOS associated with hypoxia-induced SD-like depolarization (HSD in rat hippocampal slices kept in an interface recording chamber. Recording full illumination spectra (320-680 nm yielded distinct reflectance profiles for the different phases of HSD. Early during hypoxia tissue reflectance decreased within almost the entire spectrum due to cell swelling. HSD was accompanied by a reversible reflectance increase being most pronounced at 400 nm and 460 nm. At 440 nm massive porphyrin absorption (Soret band was detected. Hypotonic solutions, Ca(2+-withdrawal and glial poisoning intensified the reflectance increase during HSD, whereas hypertonic solutions dampened it. Replacement of Cl(- inverted the reflectance increase. Inducing HSD by cyanide distorted the IOS and reflectance at 340-400 nm increased irreversibly. The pronounced changes at short wavelengths (380 nm, 460 nm and their cyanide sensitivity suggest that block of mitochondrial metabolism contributes to the IOS during HSD. For stable and reliable IOS recordings during HSD wavelengths of 460-560 nm are recommended.

  13. EFFECTIVE ELECTRONIC TUTORIAL

    Directory of Open Access Journals (Sweden)

    Andrei A. Fedoseev

    2014-01-01

    Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

  14. Study Case of Air-Mass Modification over Poland and Romania Observed by the Means of Multiwavelength Raman Depolarization Lidars

    Directory of Open Access Journals (Sweden)

    Costa-Surós Montserrat

    2016-01-01

    Full Text Available An air-mass modification, on its way from Poland to Romania, observed between 19-21 July 2014 is discussed. The air-mass was investigated using data of two multi-wavelength lidars capable of performing regular elastic, depolarization and Raman measurements in Warsaw, Poland, and in Magurele, Romania. The analysis was focused on evaluating optical properties of aerosol in order to search for similarities and differences in the vertical profiles describing the atmospheric layers above the two stations within given period.

  15. Specific and potassium components in the depolarization of the la afferents in the spinal cord of the cat.

    Science.gov (United States)

    Jiménez, I; Rudomin, P; Solodkin, M; Vyklicky, L

    1983-08-01

    In the cat spinal cord, primary afferent depolarization (PAD) of group Ia fibers of extensor muscles is produced by high-frequency stimulation (100 Hz) of group I muscle flexor afferents without significant increases in extracellular potassium. On the other hand, the PAD produced by stimulation of mixed and pure cutaneous nerves correlates well with increases in potassium ions. We conclude that the PAD produced by group I muscle afferents results from the activation of specific pathways making axo-axonic synapses with the Ia fiber terminals. The PAD of Ia fibers resulting from activation of cutaneous nerves involves instead unspecific accumulation of potassium ions.

  16. Characteristics of the Cholecystokinin-Induced Depolarization of Pacemaking Activity in Cultured Interstitial Cells of Cajal from Murine Small Intestine

    Directory of Open Access Journals (Sweden)

    Jae Hwa Lee

    2013-04-01

    Full Text Available Background/Aims: In this study, we studied the effects of cholecystokinin (CCK on pacemaker potentials in cultured interstitial cells of Cajal (ICCs from mouse small intestine using the whole cell patch clamp technique. Methods: ICCs are pacemaker cells that exhibit periodic spontaneous depolarization, which is responsible for the production of slow waves in gastrointestinal smooth muscle, and generate periodic pacemaker potentials in current-clamp mode. Results: Exposure to CCK (100 nM-5 µM decreased the amplitudes of pacemaker potentials and depolarized resting membrane potentials. To identify the type of CCK receptors involved in ICCs, we examined the effects of CCK agonists and found that the addition of CCK1 agonist (A-71323, 1 µM depolarized resting membrane potentials, whereas exposure to CCK2 agonist (gastrin , 1 µM had no effect on pacemaker potentials. To confirm these results, we examined the effects of CCK antagonists and found that pretreatment with CCK1 antagonist (SR 27897, 1 µM blocked CCK-induced effects. However, pretreatment with CCK2 antagonist (LY 225910, 1 µM did not. Furthermore, intracellular GDPβS suppressed CCK-induced effects. To investigate the involvements of phospholipase C (PLC, protein kinase C (PKC, and protein kinase A (PKA in the effects of CCK in cultured ICCs, we used U-73122 (an active PLC inhibitor, chelerythrine (a PKC inhibitor, SQ-22536 (an inhibitor of adenylate cyclase, or mPKAI (an inhibitor of myristoylated PKA. All inhibitors blocked the CCK-mediated effects on pacemaker potentials. In addition, we found that transient receptor potential classical 5 (TRPC5 channel was involved in CCK-activated currents in cultured ICCs. Conclusion: These results suggest that the CCK induced depolarization of pacemaking activity occurs in a G-protein-, PLC-, PKC-, and PKA-dependent manner via CCK1 receptor and TRPC5 channel is a candidate for CCK-activated currents in cultured ICCs in murine small intestine

  17. Study Case of Air-Mass Modification over Poland and Romania Observed by the Means of Multiwavelength Raman Depolarization Lidars

    Science.gov (United States)

    Costa-Surós, Montserrat; Janicka, Lucja; Stachlewska, Iwona S.; Nemuc, Anca; Talianu, Camelia; Heese, Birgit; Engelmann, Ronny

    2016-06-01

    An air-mass modification, on its way from Poland to Romania, observed between 19-21 July 2014 is discussed. The air-mass was investigated using data of two multi-wavelength lidars capable of performing regular elastic, depolarization and Raman measurements in Warsaw, Poland, and in Magurele, Romania. The analysis was focused on evaluating optical properties of aerosol in order to search for similarities and differences in the vertical profiles describing the atmospheric layers above the two stations within given period.

  18. Depolarization technique for wavelength conversion using four-wave mixing in a dispersion-flattened photonic crystal fiber.

    Science.gov (United States)

    Yang, Taotao; Shu, Chester; Lin, Chinlon

    2005-07-11

    We have developed a depolarization technique to achieve polarization-insensitive wavelength conversion using four-wave mixing in an optical fiber. A maximum conversion efficiency of -11.79 dB was achieved over a 3 dB bandwidth of 26 nm in a 100-m-long dispersion-flattened photonic crystal fiber. The polarization-dependent conversion efficiency was less than 0.38 dB and the measured power penalty for a 10 Gbit/s NRZ signal was 1.9 dB. The relation between the conversion efficiency and the degree of polarization of the pump was also formulated.

  19. Effect of nifedipine on depolarization-induced force responses in skinned skeletal muscle fibres of rat and toad.

    Science.gov (United States)

    Posterino, G S; Lamb, G D

    1998-01-01

    The effect of the dihydropyridine, nifedipine, on excitation-contraction coupling was compared in toad and rat skeletal muscle, using the mechanically skinned fibre technique, in order to understand better the apparently disparate results of previous studies and to examine recent proposals on the importance of certain intracellular factors in determining the efficacy of dihydropyridines. In twitch fibres from the iliofibularis muscle of the toad, 10 microM nifedipine completely inhibited depolarization-induced force responses within 30 s, without interfering with direct activation of the Ca(2+)-release channels by caffeine application or reduction of myoplasmic [Mg2+]. At low concentrations of nifedipine, inhibition was considerably augmented by repeated depolarizations, with half-maximal inhibition occurring at < 0.1 microM nifedipine. In contrast, in rat extensor digitorum longus (EDL) fibres 1 microM nifedipine had virtually no effect on depolarization-induced force responses, and 10 microM nifedipine caused only approximately 25% reduction in the responses, even upon repeated depolarizations. In rat fibres, 10 microM nifedipine shifted the steady-state force inactivation curve to more negative potentials by < 11 mV, whereas in toad fibres the potent inhibitory effect of nifedipine indicated a much larger shift. The inhibitory effect of nifedipine in rat fibres was little, if at all, increased by the absence of Ca2+ in the transverse tubular (t-) system, provided that the Ca2+ was replaced with sufficient Mg2+. The presence of the reducing agents dithiothreitol (10 mM) or glutathione (10 mM) in the solution bathing a toad skinned fibre did not reduce the inhibitory effect of nifedipine, suggesting that the potency of nifedipine in toad skinned fibres was not due to the washout of intracellular reducing agents. The results are considered in terms of a model that can account for the markedly different effects of nifedipine on the two putative functions of the

  20. The polarized electron beam at ELSA

    Science.gov (United States)

    Hoffmann, M.; Drachenfels, W. V.; Frommberger, F.; Gowin, M.; Helbing, K.; Hillert, W.; Husmann, D.; Keil, J.; Michel, T.; Naumann, J.; Speckner, T.; Zeitler, G.

    2001-06-01

    The future medium energy physics program at the electron stretcher accelerator ELSA of Bonn University mainly relies on experiments using polarized electrons in the energy range from 1 to 3.2 GeV. To provide a polarized beam with high polarization and sufficient intensity a dedicated source has been developed and set into operation. To prevent depolarization during acceleration in the circular accelerators several depolarizing resonances have to be corrected for. Intrinsic resonances are compensated using two pulsed betatron tune jump quadrupoles. The influence of imperfection resonances is successfully reduced applying a dynamic closed orbit correction in combination with an empirical harmonic correction on the energy ramp. In order to minimize beam depolarization, both types of resonances and the correction techniques have been studied in detail. It turned out that the polarization in ELSA can be conserved up to 2.5 GeV and partially up to 3.2 GeV which is demonstrated by measurements using a Møller polarimeter installed in the external GDH1-beamline. .

  1. Polarization of a stored electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Chao, A.W.

    1981-07-01

    Synchrotron radiation by a point charge is a familiar subject in classical electrodynamics. Perhaps less familiar are some quantum mechanical corrections to the classical results. Some of those quantum aspects of synchrotron radiation are described. One of the quantum effects leads to the expectation that electrons in a storage ring will polarize themselves to 92% - a surprisingly high value. A semi-classical derivation of the quantum effects is given. An effort has been made to minimize the need of using quantum mechanics. Results are put together to derive a final expression of beam polarization. Conditions under which the expected 92% polarization is destroyed are found and attributed to depolarization resonances. The various depolarization mechanisms are first illustrated by an idealized example and then systematically treated by a matrix formalism. It is shown that the strength of depolarization is specified by a key quantity called the spin chromaticity. Finally as an application of the obtained results, an estimate of the achievable level of beam polarization for two existing electron storage rings, SPEAR and PEP, is given.

  2. GABA actions in hippocampal area CA3 during postnatal development: differential shift from depolarizing to hyperpolarizing in somatic and dendritic compartments.

    Science.gov (United States)

    Romo-Parra, Héctor; Treviño, Mario; Heinemann, Uwe; Gutiérrez, Rafael

    2008-03-01

    Gamma-aminobutyric acid type A receptor (GABA(A)-R) activation leads to depolarization of pyramidal cells during the first postnatal week and produces hyperpolarization from the second week. However, immunohistochemical evidence has suggested that during the second and third postnatal weeks the NKCC1 cotransporter relocates from the soma to the dendrites of CA3 pyramidal cells. We hypothesized that this leads to depolarizing responses in apical dendrites. Here we show that the activation of GABA(A)-R in the distal dendrites of CA3 pyramidal cells at P15 by restricted application of muscimol or synaptic activation by stimulation of interneurons in stratum radiatum (SR) causes depolarizing postsynaptic potentials (PSPs), which are blocked by NKCC1 cotransporter antagonists. By contrast, activation of proximal GABA(A)-R by muscimol application or by stimulation of interneurons in s. oriens (SO) leads to hyperpolarizing PSPs. Activation of the dentate gyrus (DG) in the presence of glutamatergic blockers evokes hyperpolarizing responses during the second postnatal week; however, the reversal potential of the DG-evoked inhibitory (I)PSPs is more depolarized than that of IPSPs evoked by activation of SO interneurons. Despite the shift of GABA action from depolarizing to hyperpolarizing, DG-evoked field potentials (f-PSPs) recorded in s. lucidum/radiatum (SL/R) do not change in polarity until the third week. Current source density analysis yielded results consistent with depolarizing actions of GABA in the dendritic compartment. Our data suggest that GABAergic input to apical dendrites of pyramidal cells of CA3 evokes depolarizing PSPs long after synaptic inhibition has become hyperpolarizing in the somata, in the axon initial segments and in basal dendrites.

  3. Polarized and depolarized light-scattering studies on Brownian diffusional and critical fluid systems: theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, C.M.

    1976-01-01

    An effort to expand light-scattering autocorrelation techniques to Brownian diffusional and critical fluid systems in which multiple scattering effects are important, and to understand the observed similarity of the Rayleigh linewidth of light scattered from these two seemingly different systems is discussed. A formalism was developed to find the light field multiply scattered from a suspension of Brownian diffusing particles. For the field doubly scattered from a system of noninteracting Brownian particles, the intensity and correlation time were much less dependent on the scattering angle than for the singly scattered component. The polarized and depolarized correlation times of light scattered from Brownian particle systems were measured. The double-scattering formalism was extended to light scattered from critical fluid systems. In the region k xi greater than 5 the doubly and singly scattered correlation times were nearly equal. The dynamic droplet model of critical phenomena was developed which gives the proper, experimentally verified, forms for the intensity and linewidth of light scattered from a critical fluid. To test the dynamic droplet model and the mode theories Rayleigh linewidth predictions, light-scattering measurements were performed on the critical fluid system methanol and cyclohexane. The data agreed with both the dynamic droplet and decoupled mode theory predictions. The depolarized scattered spectra from a critical fluid were measured, and qualitative agreement with the double-scattering theory was found. 57 figures, 5 tables.

  4. Involvement of tissue plasminogen activator-plasmin system in depolarization-evoked dopamine release in the nucleus accumbens of mice.

    Science.gov (United States)

    Ito, Mina; Nagai, Taku; Kamei, Hiroyuki; Nakamichi, Noritaka; Nabeshima, Toshitaka; Takuma, Kazuhiro; Yamada, Kiyofumi

    2006-11-01

    Tissue plasminogen activator (tPA), a serine protease, catalyzes the conversion of plasminogen to plasmin. In the present study, we investigated the role of the tPA-plasmin system in depolarization-evoked dopamine (DA) and acetylcholine (ACh) release in the nucleus accumbens (NAc) and hippocampus, respectively, of mice, by using in vivo microdialysis. Microinjection of either tPA or plasmin significantly potentiated 40 mM KCl-induced DA release without affecting basal DA levels. In contrast, plasminogen activator inhibitor-1 dose-dependently reduced 60 mM KCl-induced DA release. The 60 mM KCl-evoked DA release in the NAc was markedly diminished in tPA-deficient (tPA-/-) mice compared with wild-type mice, although basal DA levels did not differ between the two groups. Microinjections of either exogenous tPA (100 ng) or plasmin (100 ng) into the NAc of tPA-/-mice restored 60 mM KCl-induced DA release, as observed in wild-type mice. In contrast, there was no difference in either basal or 60 mM KCl-induced ACh release in the hippocampus between wild-type and tPA-/-mice. Our findings suggest that the tPA-plasmin system is involved in the regulation of depolarization-evoked DA release in the NAc.

  5. Magnesium sulfate enhances non-depolarizing muscle relaxant vecuronium action at adult muscle-type nicotinic acetylcholine receptor in vitro

    Institute of Scientific and Technical Information of China (English)

    Hong WANG; Qi-sheng LIANG; Lan-ren CHENG; Xiao-hong LI; Wei FU; Wen-tao DAI; Shi-tong LI

    2011-01-01

    To investigate the effect of magnesium sulfate and its interaction with the non-depolarizing muscle relaxant vecuronium at adult muscle-type acetylcholine receptors in vitro.Methods:Adult muscle-type acetylcholine receptors were expressed in HEK293 cells.Drug-containing solution was applied via a gravity-driven perfusion system.The inward currents were activated by brief application of acetylcholine (ACh),and recorded using whole-cell voltage-clamp technique.Results:Magnesium sulfate (1-100 mmol/L) inhibited the inward currents induced ACh (10 μmol/L) in a concentration-dependent manner (IC5o=29.2 mmol/L).The inhibition of magnesium sulfate was non-competitive.In contrast,vecuronium produced a potent inhibition on the adult muscle-type acetylcholine receptor (IC50=8.7 nmol/L) by competitive antagonism.Magnesium sulfate at the concentrations of 1,3,and 6 mmol/L markedly enhanced the inhibition of vecuronium (10 nmol/L) on adult muscle-type acetylcholine receptors.Conclusion:Clinical enhancement of vecuronium-induced muscle relaxation by magnesium sulfate can be attributed partly to synergism between magnesium sulfate and non-depolarizing muscle relaxants at adult muscle-type acetylcholine receptors.

  6. A role for CaV1 and calcineurin signaling in depolarization-induced changes in neuronal DNA methylation

    Directory of Open Access Journals (Sweden)

    Eilis Hannon

    2015-07-01

    Full Text Available Direct manipulations of neuronal activity have been shown to induce changes in DNA methylation (DNAm, although little is known about the cellular signaling pathways involved. Using reduced representation bisulfite sequencing, we identify DNAm changes associated with moderate chronic depolarization in dissociated rat hippocampal cultures. Consistent with previous findings, these changes occurred primarily in the vicinity of loci implicated in neuronal function, being enriched in intergenic regions and underrepresented in CpG-rich promoter regulatory regions. We subsequently used 2 pharmacological interventions (nifedipine and FK-506 to test whether the identified changes depended on 2 interrelated signaling pathways known to mediate multiple forms of neuronal plasticity. Both pharmacological manipulations had notable effects on the extent and magnitude of depolarization-induced DNAm changes indicating that a high proportion of activity-induced changes are likely to be mediated by calcium entry through L-type CaV1 channels and/or downstream signaling via the calcium-dependent phosphatase calcineurin.

  7. A late slow depolarization unmasked in the presence of tetraethylammonium in neonatal rat sympathetic neurons in vitro.

    Science.gov (United States)

    Suppes, T

    1984-02-20

    Neonatal rat superior cervical ganglia were mechanically dissociated, and the sympathetic neurons grown in dispersed cell cultures. Intracellular microelectrodes were used to study the effects of tetraethylammonium (TEA+), a blocker of outward K+ currents, on the excitable properties of these neurons. Addition of TEA+ to the perfusion media (TEA+-media) caused the resting potential to depolarize and the action potential to increase in duration. In TEA+-media (20-60 mM), a late delayed depolarization (LDD) followed the falling phase of the action potential with a delay of 1.5-2 s (n = 95). The LDD peak amplitude was in the range of 4-26 mV and the duration, to full return of the resting potential, was in the range of 18-90 s. For a given cell the amplitude and duration of the LDD were constant. The LDD was associated with a conductance increase. No LDD could be elicited in the presence of calcium channel blockers. Evidence was found for a Ca2+-dependence of the LDD: increasing the extracellular Ca2+ concentration caused increases in the amplitude and duration of the LDD. The significance of an endogenous LDD-like potential and possible explanations for the origin of the LDD are discussed.

  8. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...

  9. Muscarinic excitatory and inhibitory mechanisms involved in afferent fibre-evoked depolarization of motoneurones in the neonatal rat spinal cord.

    Science.gov (United States)

    Kurihara, T.; Suzuki, H.; Yanagisawa, M.; Yoshioka, K.

    1993-01-01

    1. The involvement of acetylcholine and muscarinic receptors in spinal synaptic responses evoked by electrical and noxious sensory stimuli was investigated in the neonatal rat spinal cord in vitro. 2. Potentials were recorded extracellularly from a ventral root (L3-L5) of the isolated spinal cord, spinal cord-cutaneous nerve, and spinal cord-skin preparations of 1- to 4-day-old rats. Spinal reflexes were elicited by electrical stimulation of the ipsilateral dorsal root or the cutaneous saphenous nerve, or by noxious skin stimulation. 3. Single shock stimulation of supramaximum intensity of a dorsal root induced a mono-synaptic reflex in the corresponding ventral root. Bath-application of the muscarinic agonists, muscarine (0.3-30 microM) and (+)-cis-dioxolane (0.1-100 microM), produced an inhibition of the mono-synaptic reflex and a depolarization of motoneurones. Other muscarinic agonists, arecoline (10 nM-10 microM) and oxotremorine (10 nM-1 microM), inhibited the mono-synaptic reflex with little or no depolarization of motoneurones. Repetitive stimulation of the saphenous nerve at C-fibre strength induced a slow depolarizing response lasting about 30 s of the L3 ventral root. This slow ventral root potential (VRP) was also inhibited by arecoline (10 nM-10 microM) and oxotremorine (10 nM-1 microM). 4. In the spinal cord-saphenous nerve-skin preparation, a slow VRP was evoked by application of capsaicin (0.5 microM), bradykinin (3 microM), or noxious heat (47 degrees C) to skin. This slow VRP was depressed by the muscarinic agonists, arecoline (3 microM) and oxotremorine (1 microM). 5. Of the (+)-cis-dioxolane-induced inhibition of mono-synaptic reflex and motoneurone depolarization, the M2 antagonists, AF-DX 116 (0.1-1 microM) and methoctramine (100-300 nM), preferentially blocked the former response, whereas the M3 antagonists, 4-DAMP (3-10 nM) and p-F-HHSiD (0.3-3 microM), preferentially blocked the latter response. AF-DX 116 (0.1-1 microM) and methoctramine

  10. PI3K and PKC contribute to membrane depolarization mediated by α2-adrenoceptors in the canine isolated mesenteric vein

    Directory of Open Access Journals (Sweden)

    Mutafova-Yambolieva Violeta N

    2005-06-01

    Full Text Available Abstract Background Norepinephrine (NE, a classic neurotransmitter in the sympathetic nervous system, induces vasoconstriction of canine isolated mesenteric vein that is accompanied by a sustained membrane depolarization. The mechanisms underlying the NE-elicited membrane depolarization remain undefined. In the present study we hypothesized that phosphatidylinositol 3-kinase (PI3K and protein kinase C (PKC are involved in the electrical field stimulation (EFS-induced slow membrane depolarization (SMD in canine isolated mesenteric vein. EFS (0.1–2 Hz, 0.1 ms, 15V, 10 s-induced changes in the membrane potential were recorded with a conventional intracellular microelectrode technique and evaluated in the absence and presence of inhibitors of neuronal activity, α-adrenoceptors, membrane ion channels, PI3K, inositol 1,4,5-triphosphate (InsP3 receptors, and PKC. Activation of PI3Kγ and PKCζ in response to exogenous NE and clonidine in the absence and presence of receptor and kinase inhibitors were also determined. Results Contractile responses to NE and clonidine (0.05 – 10 μM were significantly diminished in the presence of yohimbine (0.1 μM. Exogenous NE (0.1 μM and clonidine (1 μM elicited SMD. The resting membrane potential of canine mesenteric vein smooth muscle cells was -68.8 ± 0.8 mV. EFS elicited a biphasic depolarization comprised of excitatory junction potentials and SMD that are purinergic and adrenergic in nature, respectively. The magnitude of the SMD in response to EFS at 0.5 Hz was 9.4 ± 0.7 mV. This response was reduced by 65–98% by the fast Na+ channel inhibitor tetrodotoxin (1 μM, by the inhibitor of N-type Ca2+ channels ω-conotoxin GVIA (5 nM, the non-selective α-adrenoceptor blocker phentolamine (1 μM, the selective α2-adrenoceptor blocker yohimbine (0.1 μM, the ion channel inhibitors niflumic acid (NFA, 100 μM, 5-nitro-2-(3-phenylpropylamino benzoic acid (NPPB, 30 μM, 4,4'-diisothiocyanatostilbene-2

  11. Study of time-lapse processing for dynamic hydrologic conditions. [electronic satellite image analysis console for Earth Resources Technology Satellites imagery

    Science.gov (United States)

    Serebreny, S. M.; Evans, W. E.; Wiegman, E. J.

    1974-01-01

    The usefulness of dynamic display techniques in exploiting the repetitive nature of ERTS imagery was investigated. A specially designed Electronic Satellite Image Analysis Console (ESIAC) was developed and employed to process data for seven ERTS principal investigators studying dynamic hydrological conditions for diverse applications. These applications include measurement of snowfield extent and sediment plumes from estuary discharge, Playa Lake inventory, and monitoring of phreatophyte and other vegetation changes. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The most unique feature of the system is the capability to time lapse the imagery and analytic displays of the imagery. Data products included quantitative measurements of distances and areas, binary thematic maps based on monospectral or multispectral decisions, radiance profiles, and movie loops. Applications of animation for uses other than creating time-lapse sequences are identified. Input to the ESIAC can be either digital or via photographic transparencies.

  12. Resource Manual

    Science.gov (United States)

    Human Development Institute, 2008

    2008-01-01

    This manual was designed primarily for use by individuals with developmental disabilities and related conditions. The main focus of this manual is to provide easy-to-read information concerning available resources, and to provide immediate contact information for the purpose of applying for resources and/or locating additional information. The…

  13. Rethinking Resourcing.

    Science.gov (United States)

    Norris, Donald M.; Olson, Mark A.

    2003-01-01

    This adaptation of an excerpt from a book, "The Business Value Web: Resourcing Business Processes and Solutions in Higher Education," addresses ways to look at college business processes systematically, take fresh approaches to resourcing, and create real value for stakeholders. (EV)

  14. Assessment of use of library resources on research activities of ...

    African Journals Online (AJOL)

    Open Access DOWNLOAD FULL TEXT ... Library resources use contribute immensely to the research output of agricultural scientists and ... electronics Library resources such as electronic journals, e-books, scholarly databases, ... researchers to have access to a wide range of high quality electronic information resources.

  15. Genetic toxicology: web resources.

    Science.gov (United States)

    Young, Robert R

    2002-04-25

    Genetic toxicology is the scientific discipline dealing with the effects of chemical, physical and biological agents on the heredity of living organisms. The Internet offers a wide range of online digital resources for the field of Genetic Toxicology. The history of genetic toxicology and electronic data collections are reviewed. Web-based resources at US National Library of Medicine (NLM), including MEDLINE, PUBMED, Gateway, Entrez, and TOXNET, are discussed. Search strategies and Medical Subject Headings (MeSH) are reviewed in the context of genetic toxicology. The TOXNET group of databases are discussed with emphasis on those databases with genetic toxicology content including GENE-TOX, TOXLINE, Hazardous Substances Data Bank, Integrated Risk Information System, and Chemical Carcinogenesis Research Information System. Location of chemical information including chemical structure and linkage to health and regulatory information using CHEMIDPLUS at NLM and other databases is reviewed. Various government agencies have active genetic toxicology research programs or use genetic toxicology data to assist fulfilling the agency's mission. Online resources at the US Food and Drug Administration (FDA), the US Environmental Protection Agency (EPA), the National Institutes of Environmental Health Sciences, and the National Toxicology Program (NTP) are outlined. Much of the genetic toxicology for pharmaceuticals, industrial chemicals and pesticides that is performed in the world is regulatory-driven. Regulatory web resources are presented for the laws mandating testing, guidelines on study design, Good Laboratory Practice (GLP) regulations, and requirements for electronic data collection and reporting. The Internet provides a range of other supporting resources to the field of genetic toxicology. The web links for key professional societies and journals in genetic toxicology are listed. Distance education, educational media resources, and job placement services are also

  16. A rotating quantum vacuum and the depolarization problem in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Lorenci, V.A. de; Svaiter, N.F.

    1997-02-01

    We investigate the consequences of using a Lorentz-like transformation to connect measurements between a inertial a rotating frame of reference. We obtain a new rotating vacuum (of a massless scalar field) different from the Minkowski one. After this we consider a monopole detector interacting with the field. The radiative processes are discussed from a rotating and inertial frame point of view. Finally using this formalism the polarization effects of electrons in circular accelerators is discussed. (author). 16 refs.

  17. 地方高校的电子文献资源建设——以南京晓庄学院为例%Construction of Electronic Literature Resources of Local University Library —— A Case Study ofNanjing Xiaozhuang University

    Institute of Scientific and Technical Information of China (English)

    王雯

    2012-01-01

    以南京晓庄学院图书馆为蓝本,从电子资源的文献价值入手,阐明了编制电子资源的采访标准和评价指标的意义,指出在当前网络环境下,地方高校加强电子文献资源建设的重要性和发展方向。%This paper is on the original version ofNanjing Xiaozhuang University library, from the literature value of electron- ic resource, expounds the meaning of compiling electronic resources acquisition standard and evaluation index, points out under current network environment, the importance of local university library strengthen electronic litera-ture resources construction and development direction.

  18. The Strategies for the Construction of the Electronic Journal Resources in Higher Vocational College Library in the Network Environment%网络环境下高职院校图书馆电子期刊资源建设策略

    Institute of Scientific and Technical Information of China (English)

    黄妙琼

    2015-01-01

    This paper expounds some main principles of the construction of the network electronic journal resources in higher vocational college library in the network environment, introduces several types of the network electronic journal resources, and probes into some strategies for the construction of electronic journal resources in higher vocational college library.%阐述了高职院校图书馆网络电子期刊资源建设的主要原则,介绍了网络电子期刊资源的几种类型, 探讨了高职院校图书馆电子期刊资源建设的策略.

  19. 区域性高校数字图书馆联盟电子资源建设研究--以湖南省高校数字图书馆为例%Study on the Electronic Resources Construction of Regional University Digital Library Alliance---Taking Hunan Academic Digital Library (HNADL)as an Example

    Institute of Scientific and Technical Information of China (English)

    唐婷

    2015-01-01

    介绍了湖南省高校数字图书馆电子资源建设情况,阐述了各联盟成员馆电子资源建设现状,探讨了湖南省高校数字图书馆电子资源建设存在的问题,并提出了相应的对策及建议。%ABSTRACT:This paper introduces the situation of the electronic resources construction of HNADL, expounds the current status of the electronic resources construction of each number library, probes into the problems existing in the electronic resources construction of HNADL,and puts forward some corresponding countermeasures and suggestions.

  20. Correlation between temperature-dependent permittivity dispersion and depolarization behaviours in Zr4+-modified BiFeO3–BaTiO3 piezoelectric ceramics

    Indian Academy of Sciences (India)

    Weidong Zeng; Changrong Zhou; Jianrong Xiao; Jiafeng Ma

    2015-12-01

    The correlation between permittivity frequency dispersion and depoling process upon heating was investigated in Zr4+-modified 0.75BiFeO3–0.25BaTiO3 (BF–BZT) ceramics. The temperature-dependent permittivity r() and the piezoelectric coefficient 33 for poled samples were measured under heating conditions to clarify the depolarization mechanism. The results indicate that the poling temperature plays a crucial role in the domains' alignment process, as expected. The temperature-dependent permittivity frequency dispersion and depolarization behaviours may have same origin. The aligned domains' break up into random state/nanodomains at depoling temperature ( d), which causes strong frequency dependence of the permittivity, simultaneously, induces the loss of piezoelectricity. It suggests that the temperature-dependent permittivity measurements method is a simple way to determine the depolarization temperature.

  1. Depolarization effect in rare-earth doped Y{sub 2}O{sub 3} films in blue and UV spectral range

    Energy Technology Data Exchange (ETDEWEB)

    Gasimov, Naghi; Mammadov, Eldar; Babayev, Sardar; Mamedova, Irada; Mamedov, Nazim [Department of Ellipsometry, Institute of Physics, Azerbaijan National Academy of Sciences, H. Javid ave. 33, Baku-1143 (Azerbaijan); Joudrier, Anne L.; Andriamiadamanana, Christian; Naghavi, Negar; Guillemoles, Jean F. [Institute for Research and Development of Photovoltaic Energy, 6 Quai Watier, 78401 Chatou, Paris (France)

    2015-06-15

    The 200 to 300 nm thick, Er and Er,Yb doped Y{sub 2}O{sub 3} films deposited onto silicon substrate by spin coating have been studied by spectroscopic ellipsometry over the 192-1680 nm spectral range at room temperature. All samples have been found to be strongly depolarizing in the blue and UV part of the spectrum. Complimentary examination of the sample surfaces, using confocal photoluminescence microscopy has disclosed the non-uniform distribution of the rare-earth dopants. The depolarization effects have then been modeled and found to be best reproduced by taking the thickness non-uniformity as the main source of depolarization. The optical constants of the studied films have been determined after four-step modeling with sequential decrease of the mean square error. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Telecommunications--Electronic Mail.

    Science.gov (United States)

    Kelly, Luke E.; Zuckerman, B. Michael

    1989-01-01

    This article identifies resources needed in order for physical education, recreation, and dance professionals to use computer-based telecommunications; discusses electronic mail; and explains how telecommunications can enhance communication in the field, both within and across professions. (IAH)

  3. Rethinking resources

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, W.L. [Univ. of Texas, Austin, TX (United States)

    1994-09-01

    We class energy and mineral resources as finite because we are reasonably certain that they do not form at a rate remotely approaching man`s rate of use. We have certain environments of the earth that have limits in carrying capacity, and we presume that the global environment does as well. These facts and presumptions, coupled with anxieties over growth in population and consumption, have posed pictures of impending catastrophe from Malthus through the Club of Rome and currently, among certain advocates of what is called sustainable development. To avoid future calamity, command and control management of resource use is urged by many. But, quite simply, such management would presume a wisdom that historical experience suggests does not exist. As a recent example, consider natural gas resources. A decade and a half ago, the resource base of natural gas in the United States was judged to be near exhaustion. Estimates of remaining resources by governmental agencies, academicians, and several major energy companies indicated the ultimate resource would be at about 100 tcf today, with essential depletion by the end of the century. Such was the near universal wisdom that compelled Congress to enact legislation to outright prohibit certain use of natural gas. Today, after nearly eight years of gas supply in excess of demand and with entirely new appreciation of the impact of technology, estimates of the remaining gas resource by industry, government, and others are an order of magnitude greater than those made just 15 yr ago, and the same government that then sought to husband a resource presumed to be near depletion now aggressively promotes its use and consumption. Limits to resources and limits to environmental carrying capacity do indeed exist, but we have yet to define those limits and the paths thereto.

  4. Depolarization by K+ and glutamate activates different neurotransmitter release mechanisms in GABAergic neurons: vesicular versus non-vesicular release of GABA

    DEFF Research Database (Denmark)

    Belhage, B; Hansen, Gert Helge; Schousboe, A

    1993-01-01

    Neurotransmitter release and changes in the concentration of intracellular free calcium ([Ca++]i) were studied in cultured GABAergic cerebral cortical neurons, from mice, upon depolarization with either an unphysiologically high potassium concentration (55 mM) or the physiological excitatory...... neurotransmitter glutamate (100 microM). Both depolarizing stimuli exerted prompt increases in the release of preloaded [3H]GABA as well as in [Ca++]i. However, the basic properties of transmitter release and the increase in [Ca++]i under a variety of conditions were different during stimulation with K...... in nature whereas that induced by the neurotransmitter glutamate is not....

  5. The depolarizing action of 5-hydroxytryptamine on rabbit vagal afferent and sympathetic neurones in vitro and its selective blockade by ICS 205-930.

    OpenAIRE

    1986-01-01

    Depolarizing responses to 5-hydroxytryptamine (5-HT) were recorded from rabbit nodose (NG) and superior cervical (SCG) ganglia using the sucrose-gap technique. The antagonist potency and selectivity of ICS 205-930 ([3 alpha-tropanyl]-1H-indole-3-carboxylic acid ester) were investigated. In NG, 5-HT (5 to 80 nmol) evoked depolarizations of graded amplitude. The ED50 was 18.2 (10.9-30.5) nmol (geometric mean, 95% confidence limits). Responses were blocked surmountably by ICS 205-930, 10(-11) an...

  6. Arthritis - resources

    Science.gov (United States)

    Resources - arthritis ... The following organizations provide more information on arthritis : American Academy of Orthopaedic Surgeons -- orthoinfo.aaos.org/menus/arthritis.cfm Arthritis Foundation -- www.arthritis.org Centers for Disease Control and Prevention -- www. ...

  7. Diabetes - resources

    Science.gov (United States)

    Resources - diabetes ... The following sites provide further information on diabetes: American Diabetes Association -- www.diabetes.org Juvenile Diabetes Research Foundation International -- www.jdrf.org National Center for Chronic Disease Prevention and Health Promotion -- ...

  8. Seaweed resources

    Digital Repository Service at National Institute of Oceanography (India)

    Deshmukhe, G.V.; Dhargalkar, V.K.; Untawale, A.G.

    The chapter summarizes our present knowledge of the seaweed resources of the Indian Ocean region with regard to the phytogeographical distribution, composition, biomass, utilization, cultivation, conservation and management. The voluminous data...

  9. Mineral resources

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.

    (placers), biogenous (ooze, limestone) or chemogenous (phosphorites and polymetallic nodules) type. In recent years, hydrothermal deposits, cobalt crust and methane gas hydrates are considered as frontier resources. Their distribution depends upon proximity...

  10. Depression - resources

    Science.gov (United States)

    Resources - depression ... Depression is a medical condition. If you think you may be depressed, see a health care provider. ... following organizations are good sources of information on depression : American Psychological Association -- www.apa.org/topics/depress/ ...

  11. Land Resources

    Science.gov (United States)

    Young, Anthony

    1998-08-01

    Unless action is taken, the developing world will face recurrent problems of food security and conflict. This volume provides a summary and perspective of the field of land resources and suggests improvements needed to conserve resources for future generations. Coverage provides an authoritative review of the resources of soils, water, climate, forests and pastures on which agriculture depends. It assesses the interactions between land resources and wider aspects of development, including population and poverty. It provides a strong critique of current methods of assessing land degradation and placing an economic value on land. It should be read by all involved in rural development, including scientists, economists, geographers, sociologists, planners, and students of development studies.

  12. Hemophilia - resources

    Science.gov (United States)

    Resources - hemophilia ... The following organizations provide further information on hemophilia : Centers for Disease Control and Prevention -- www.cdc.gov/ncbddd/hemophilia/index.html National Heart, Lung, and Blood Institute -- www.nhlbi.nih.gov/ ...

  13. Neurogenic role of the depolarizing chloride gradient revealed by global overexpression of KCC2 from the onset of development.

    Science.gov (United States)

    Reynolds, Annie; Brustein, Edna; Liao, Meijiang; Mercado, Adriana; Babilonia, Elisa; Mount, David B; Drapeau, Pierre

    2008-02-13

    GABA- and glycine-induced depolarization is thought to provide important developmental signals, but the role of the underlying chloride gradient has not been examined from the onset of development. We therefore overexpressed globally the potassium-chloride cotransporter 2 (KCC2) in newly fertilized zebrafish embryos to reverse the chloride gradient. This rendered glycine hyperpolarizing in all neurons, tested at the time that motor behaviors (but not native KCC2) first appear. KCC2 overexpression resulted in fewer mature spontaneously active spinal neurons, more immature silent neurons, and disrupted motor activity. We observed fewer motoneurons and interneurons, a reduction in the elaboration of axonal tracts, and smaller brains and spinal cords. However, we observed no increased apoptosis and a normal complement of sensory neurons, glia, and progenitors. These results suggest that chloride-mediated excitation plays a crucial role in promoting neurogenesis from the earliest stages of embryonic development.

  14. Supply-demand mismatch transients in susceptible peri-infarct hot zones explain the origin of spreading injury depolarizations

    Science.gov (United States)

    von Bornstädt, Daniel; Houben, Thijs; Seidel, Jessica; Zheng, Yi; Dilekoz, Ergin; Qin, Tao; Sandow, Nora; Kura, Sreekanth; Eikermann-Haerter, Katharina; Endres, Matthias; Boas, David A.; Moskowitz, Michael A.; Lo, Eng H.; Dreier, Jens P.; Woitzik, Johannes; Sakadžić, Sava; Ayata, Cenk

    2015-01-01

    SUMMARY Peri-infarct depolarizations (PIDs) are seemingly spontaneous spreading depression-like waves that negatively impact tissue outcome in both experimental and human stroke. Factors triggering PIDs are unknown. Here, we show that somatosensory activation of peri-infarct cortex triggers PIDs when the activated cortex is within a critical range of ischemia. We show that the mechanism involves increased oxygen utilization within the activated cortex, worsening the supply-demand mismatch. We support the concept by clinical data showing that mismatch predisposes to PIDs in human stroke as well. Conversely, transient worsening of mismatch by episodic hypoxemia or hypotension also reproducibly triggers PIDs. Therefore, PIDs are triggered upon supply-demand mismatch transients in metastable peri-infarct hot zones due to increased demand or reduced supply. Based on the data, we propose that minimizing sensory stimulation and hypoxic or hypotensive transients in stroke and brain injury would reduce PID incidence and their adverse impact on outcome. PMID:25741731

  15. The MR detection of neuronal depolarization during 3-Hz spike-and-wave complexes in generalized epilepsy.

    Science.gov (United States)

    Liston, Adam D; Salek-Haddadi, Afraim; Kiebel, Stefan J; Hamandi, Khalid; Turner, Robert; Lemieux, Louis

    2004-12-01

    Previously, an analysis of activations observed in a patient with idiopathic generalized epilepsy using electroencephalogram-correlated functional magnetic resonance imaging (MRI) during runs of 3-Hz generalized spike-wave discharge (GSWD) was presented by Salek-Haddadi. Time-locked, bilateral, thalamic blood oxygenation level-dependent increases were reported to be accompanied by widespread, symmetric, cortical deactivation with a frontal maximum. In light of recent investigations into MRI detection of the magnetic field perturbations caused by neuronal current loops during depolarization, we revisited the analysis of the data of Salek-Haddadi as a preliminary search for a neuroelectric signal. We modeled the MRI response as the sum of a fast signal and a slower signal and demonstrated significant MRI activity at a time scale of the order of 30 ms associated with GSWDs. Further work is necessary before firm conclusions may be drawn about the nature of this signal.

  16. Recovery of slow potentials in AC-coupled electrocorticography: application to spreading depolarizations in rat and human cerebral cortex

    DEFF Research Database (Denmark)

    Hartings, Jed A; Watanabe, Tomas; Dreier, Jens P

    2009-01-01

    . The spreading SPCs of depolarization waves are observed in human cortex with AC-coupled electrocorticography (ECoG), although SPC morphology is distorted by the high-pass filter stage of the amplifiers. Here, we present a signal processing method to reverse these distortions and recover approximate full......-band waveforms from AC-coupled recordings. We constructed digital filters that reproduced the phase and amplitude distortions introduced by specific AC-coupled amplifiers and, based on this characterization, derived digital inverse filters to remove these distortions from ECoG recordings. Performance...... of the inverse filter was validated by its ability to recover both simulated and real low-frequency input test signals. The inverse filter was then applied to AC-coupled ECoG recordings from five patients who underwent invasive monitoring after aneurysmal subarachnoid hemorrhage. For 117 SPCs, the inverse filter...

  17. PKA Phosphorylation of NCLX Reverses Mitochondrial Calcium Overload and Depolarization, Promoting Survival of PINK1-Deficient Dopaminergic Neurons

    Directory of Open Access Journals (Sweden)

    Marko Kostic

    2015-10-01

    Full Text Available Mitochondrial Ca2+ overload is a critical, preceding event in neuronal damage encountered during neurodegenerative and ischemic insults. We found that loss of PTEN-induced putative kinase 1 (PINK1 function, implicated in Parkinson disease, inhibits the mitochondrial Na+/Ca2+ exchanger (NCLX, leading to impaired mitochondrial Ca2+ extrusion. NCLX activity was, however, fully rescued by activation of the protein kinase A (PKA pathway. We further show that PKA rescues NCLX activity by phosphorylating serine 258, a putative regulatory NCLX site. Remarkably, a constitutively active phosphomimetic mutant of NCLX (NCLXS258D prevents mitochondrial Ca2+ overload and mitochondrial depolarization in PINK1 knockout neurons, thereby enhancing neuronal survival. Our results identify an mitochondrial Ca2+ transport regulatory pathway that protects against mitochondrial Ca2+ overload. Because mitochondrial Ca2+ dyshomeostasis is a prominent feature of multiple disorders, the link between NCLX and PKA may offer a therapeutic target.

  18. A comparison of some metabolic effects of N-methylaspartate stereoisomers, glutamate and depolarization: a multinuclear MRS study.

    Science.gov (United States)

    Thatcher, N M; Badar-Goffer, R S; Ben-Yoseph, O; McLean, M A; Morris, P G; Prior, M J W; Taylor, A; Bachelard, H S

    2002-02-01

    Exposure of guinea pig brain slices to low concentrations (10 microM) of NMDA caused decreases in PCr and ATP within 30 min, with a slower decrease in NAA and increase in lactate, both detectable after 1 h. Exposure to NMDA for over 1 h or at higher concentrations caused further increases in lactate and decreases in NAA, with no further change in PCr or ATP. The L-isomer, NMLA, and the racemic mixture, NMDLA, caused similar changes in lactate and NAA, but both produced greater decreases in the energy state than NMDA, similar to those caused by prolonged exposure to glutamate. MK-801 prevented the changes in the energy state caused by NMDA, but not those caused by NMLA or by glutamate. The results are compared to previous studies on depolarization and discussed in terms of the role of the NMDA sub-type of glutamate receptor in the excitotoxic hypothesis of neuronal degeneration.

  19. Forest Resources

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Forest biomass is an abundant biomass feedstock that complements the conventional forest use of wood for paper and wood materials. It may be utilized for bioenergy production, such as heat and electricity, as well as for biofuels and a variety of bioproducts, such as industrial chemicals, textiles, and other renewable materials. The resources within the 2016 Billion-Ton Report include primary forest resources, which are taken directly from timberland-only forests, removed from the land, and taken to the roadside.

  20. Acute stress increases depolarization-evoked glutamate release in the rat prefrontal/frontal cortex: the dampening action of antidepressants.

    Directory of Open Access Journals (Sweden)

    Laura Musazzi

    Full Text Available BACKGROUND: Behavioral stress is recognized as a main risk factor for neuropsychiatric diseases. Converging evidence suggested that acute stress is associated with increase of excitatory transmission in certain forebrain areas. Aim of this work was to investigate the mechanism whereby acute stress increases glutamate release, and if therapeutic drugs prevent the effect of stress on glutamate release. METHODOLOGY/FINDINGS: Rats were chronically treated with vehicle or drugs employed for therapy of mood/anxiety disorders (fluoxetine, desipramine, venlafaxine, agomelatine and then subjected to unpredictable footshock stress. Acute stress induced marked increase in depolarization-evoked release of glutamate from synaptosomes of prefrontal/frontal cortex in superfusion, and the chronic drug treatments prevented the increase of glutamate release. Stress induced rapid increase in the circulating levels of corticosterone in all rats (both vehicle- and drug-treated, and glutamate release increase was blocked by previous administration of selective antagonist of glucocorticoid receptor (RU 486. On the molecular level, stress induced accumulation of presynaptic SNARE complexes in synaptic membranes (both in vehicle- and drug-treated rats. Patch-clamp recordings of pyramidal neurons in the prefrontal cortex revealed that stress increased glutamatergic transmission through both pre- and postsynaptic mechanisms, and that antidepressants may normalize it by reducing release probability. CONCLUSIONS/SIGNIFICANCE: Acute footshock stress up-regulated depolarization-evoked release of glutamate from synaptosomes of prefrontal/frontal cortex. Stress-induced increase of glutamate release was dependent on stimulation of glucocorticoid receptor by corticosterone. Because all drugs employed did not block either elevation of corticosterone or accumulation of SNARE complexes, the dampening action of the drugs on glutamate release must be downstream of these processes

  1. Postsynaptic GABA(B) Receptors Contribute to the Termination of Giant Depolarizing Potentials in CA3 Neonatal Rat Hippocampus

    Science.gov (United States)

    Khalilov, Ilgam; Minlebaev, Marat; Mukhtarov, Marat; Juzekaeva, Elvira; Khazipov, Roustem

    2017-01-01

    During development, hippocampal CA3 network generates recurrent population bursts, so-called Giant Depolarizing Potentials (GDPs). GDPs are characterized by synchronous depolarization and firing of CA3 pyramidal cells followed by afterhyperpolarization (GDP-AHP). Here, we explored the properties of GDP-AHP in CA3 pyramidal cells using gramicidin perforated patch clamp recordings from neonatal rat hippocampal slices. We found that GDP-AHP occurs independently of whether CA3 pyramidal cells fire action potentials (APs) or remain silent during GDPs. However, the amplitude of GDP-AHP increased with the number of APs the cells fired during GDPs. The reversal potential of the GDP-AHP was close to the potassium equilibrium potential. During voltage-clamp recordings, current-voltage relationships of the postsynaptic currents activated during GDP-AHP were characterized by reversal near the potassium equilibrium potential and inward rectification, similar to the responses evoked by the GABA(B) receptor agonists. Finally, the GABA(B) receptor antagonist CGP55845 strongly reduced GDP-AHP and prolonged GDPs, eventually transforming them to the interictal and ictal-like discharges. Together, our findings suggest that the GDP-AHP involves two mechanisms: (i) postsynaptic GABA(B) receptor activated potassium currents, which are activated independently on whether the cell fires or not during GDPs; and (ii) activity-dependent, likely calcium activated potassium currents, whose contribution to the GDP-AHP is dependent on the amount of firing during GDPs. We propose that these two complementary inhibitory postsynaptic mechanisms cooperate in the termination of GDP. PMID:28701925

  2. PINK1 is activated by mitochondrial membrane potential depolarization and stimulates Parkin E3 ligase activity by phosphorylating Serine 65

    Science.gov (United States)

    Kondapalli, Chandana; Kazlauskaite, Agne; Zhang, Ning; Woodroof, Helen I.; Campbell, David G.; Gourlay, Robert; Burchell, Lynn; Walden, Helen; Macartney, Thomas J.; Deak, Maria; Knebel, Axel; Alessi, Dario R.; Muqit, Miratul M. K.

    2012-01-01

    Summary Missense mutations in PTEN-induced kinase 1 (PINK1) cause autosomal-recessive inherited Parkinson's disease (PD). We have exploited our recent discovery that recombinant insect PINK1 is catalytically active to test whether PINK1 directly phosphorylates 15 proteins encoded by PD-associated genes as well as proteins reported to bind PINK1. We have discovered that insect PINK1 efficiently phosphorylates only one of these proteins, namely the E3 ligase Parkin. We have mapped the phosphorylation site to a highly conserved residue within the Ubl domain of Parkin at Ser65. We show that human PINK1 is specifically activated by mitochondrial membrane potential (Δψm) depolarization, enabling it to phosphorylate Parkin at Ser65. We further show that phosphorylation of Parkin at Ser65 leads to marked activation of its E3 ligase activity that is prevented by mutation of Ser65 or inactivation of PINK1. We provide evidence that once activated, PINK1 autophosphorylates at several residues, including Thr257, which is accompanied by an electrophoretic mobility band-shift. These results provide the first evidence that PINK1 is activated following Δψm depolarization and suggest that PINK1 directly phosphorylates and activates Parkin. Our findings indicate that monitoring phosphorylation of Parkin at Ser65 and/or PINK1 at Thr257 represent the first biomarkers for examining activity of the PINK1-Parkin signalling pathway in vivo. Our findings also suggest that small molecule activators of Parkin that mimic the effect of PINK1 phosphorylation may confer therapeutic benefit for PD. PMID:22724072

  3. Depolarization in Delivering Public Services? Impacts of Minimum Service Standards (MSS on the Quality of Health Services in Indonesia

    Directory of Open Access Journals (Sweden)

    Mohammad Roudo

    2016-03-01

    Full Text Available Abstract. Some scholars argue that decentralization policy tends to create polarization, i.e. an increase of inequality/disparity among districts. To deal with this problem, Minimum Service Standards (MSS were introduced as a key strategy in decentralizing Indonesia. In this research, we tried to find out through MSS performance measurements whether imposing standards can be effective in a decentralized system by seeking its impacts on polarization/depolarization in the delivery of public services, specifically in the health sector. This question is basically a response to the common criticism that decentralization is good to create equality between central government and local governments but often does not work to achieve equality among local governments. Using self-assessment data from a sample of 54 districts from 534 districts in Indonesia, from 2010 to 2013, we found that the existence of depolarization in the delivery of public services could potentially occur among regions by reducing the gap between their public service performance and the targets of MSS. We acknowledge that there are weaknesses in the validity of the self-assessment data, caused by a lack of knowledge and skills to execute the self-assessment according to the official guidelines, by the overrating of target achievements, as well as the lack of data from independent sources to confirm the self-assessment outcomes. We also acknowledge that differences in financial capacity are still the main determinant why one district is more successful in achieving the MSS targets compared to other districts. Keywords. Decentralization, Public Service, Minimum Standard Service

  4. Exogenously Applied 24-Epibrassinolide (EBL) Ameliorates Detrimental Effects of Salinity by Reducing K+ Efflux via Depolarization-Activated K+ Channels.

    Science.gov (United States)

    Azhar, Nazila; Su, Nana; Shabala, Lana; Shabala, Sergey

    2017-04-01

    This study has investigated mechanisms conferring beneficial effects of exogenous application of 24-epibrassinolides (EBL) on plant growth and performance under saline conditions. Barley seedlings treated with 0.25 mg l-1 EBL showed significant improvements in root hair length, shoot length, shoot fresh weight and relative water content when grown in the presence of 150 mM NaCl in the growth medium. In addition, EBL treatment significantly decreased the Na+ content in both shoots (by approximately 50%) and roots. Electrophysiological experiments revealed that pre-treatment with EBL for 1 and 24 h suppressed or completely prevented the NaCl-induced K+ leak in the elongation zone of barley roots, but did not affect root sensitivity to oxidative stress. Further experiments using Arabidopsis loss-of-function gork1-1 (lacking functional depolarization-activated outward-rectifying K+ channels in the root epidermal cells) and akt1 (lacking inward-rectifying K+ uptake channel) mutants showed that NaCl-induced K+ loss in the elongation zone of roots was reduced by EBL pre-treatment 50- to 100-fold in wild-type Col-0 and akt1, but only 10-fold in the gork1-1 mutant. At the same time, EBL treatment shifted vanadate-sensitive H+ flux towards net efflux. Taken together, these data indicate that exogenous application of EBL effectively improves plant salinity tolerance by prevention of K+ loss via regulating depolarization-activated K+ channels. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. Model for Presenting Resources in Scholar's Portal

    Science.gov (United States)

    Feeney, Mary; Newby, Jill

    2005-01-01

    Presenting electronic resources to users through a federated search engine introduces unique opportunities and challenges to libraries. This article reports on the decision-making tools and processes used for selecting collections of electronic resources by a project team at the University of Arizona (UA) Libraries for the Association of Research…

  6. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  7. Stellar occultation of polarized light from circumstellar electrons. I - Flat envelopes viewed edge on

    Science.gov (United States)

    Brown, John C.; Fox, Geoffrey K.

    1989-01-01

    The depolarizing and occultation effects of a finite spherical light source on the polarization of light Thomson-scattered from a flat circumstellar envelope seen edge-on are analyzed. The analysis shows that neglect of the finite size of the light source leads to a gross overestimate of the polarization for a given disk geometry. By including occultation and depolarization, it is found that B-star envelopes are necessarily highly flattened disk-type structures. For a disk viewed edge-on, the effect of occultation reduces the polarization more than the inclusion of the depolarization factor alone. Analysis of a one-dimensional plume leads to a powerful technique that permits the electron density distribution to be explicitly obtained from the polarimetric data.

  8. Multilingual digital resources with Bulgarian language

    Directory of Open Access Journals (Sweden)

    Ludmila Dimitrova

    2015-11-01

    Full Text Available Multilingual digital resources with Bulgarian language The paper presents in brief Bulgarian language resources as a part of multilingual digital resources developed in the frame of some international projects, among them parallel annotated and aligned corpora, comparable corpora, morpho-syntactic specifications for corpora annotation and dictionaries encoding, lexicons, lexical databases, and electronic dictionaries.

  9. STEP electronic system design

    Science.gov (United States)

    Couch, R. H.; Johnson, J. W.

    1984-01-01

    The STEP electronic system design is discussed. The purpose of the design is outlined. The electronic system design is summarized and it is found that: an effective conceptual system design is developed; the design represents a unique set of capabilities; makes efficient use of available orbiter resources; the system capabilities exceed identified potential experiment needs.

  10. Involvement of transient receptor potential melastatin type 7 channels on Poncirus fructus-induced depolarizations of pacemaking activity in interstitial cells of Cajal from murine small intestine

    Directory of Open Access Journals (Sweden)

    Byung Joo Kim

    2013-06-01

    Conclusion: These results suggest that the PTE-induced depolarization of pacemaking activity occurs in a G-protein-, phospholipase C-, and 1,4,5-inositol triphosphate-dependent manner via TRPM7 channels in cultured ICCs from murine small intestine, which indicates that ICCs are PTE targets and that their interactions affect intestinal motility.

  11. Muon spin depolarization in a thermalized molecular ion He{sub 2}{mu}{sup +} in crystalline phase of {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Belousov, Yu.M. [Theoretical Physics Department, Moscow Institute of Physics and Technology, Institutsky dstr., Dolgoprudny, Moscow reg., 141700 (Russian Federation)]. E-mail: bel@theor.op.mipt.ru

    2006-03-31

    Muon spin depolarization rate is calculated for thermalized molecular ions He{sub 2}{mu}{sup +}. Only 34 of the muon spin polarization will be depolarized if all spin states of the molecular ion He{sub 2}{mu}{sup +} have the equal probability. The effective spin-hamiltonian of the ortho-ion differs for rotational states [K=1,M=0> and [K=1,M=1>. Different relaxation rates of the muon spin polarization is observed for these states. Relaxation processes are connected with direct magnetic dipole-dipole and spin-phonon interactions. Direct magnetic dipole-dipole interactions play the main role at temperature T>1K. At lower temperature spin-phonon interaction plays the main role. Relaxation rates are calculated within the frame work of the Wangsness-Bloch equations in the limit of strong magnetic fields for the case of spin-phonon interaction. It is shown that depolarization rates could strongly differ for states [K=1,M=0> and [K=1,M=1>. A fit of experimental data by one exponent is not correct in the above mentioned case. Depolarization pattern depends on {sup 4}He impurity concentration because thermalized molecular ions containing at least one {sup 4}He atom have K=0 where no hyperfine interaction exists.

  12. 高校图书馆外文电子资源的建设与利用研究——以安徽建筑大学图书馆为例%Study on the Construction and Utilization of Foreign Electronic Resources in University Library ——A Case Study of the Library of AUA

    Institute of Scientific and Technical Information of China (English)

    黄静

    2015-01-01

    This paper makes an investigation and statistical analysis on the current construction ans utilization of foreign electronic resources of the library of AUA from the aspects of the quantities, funds as well as utilization rate of foreign database, discusses some factors influencing the construction and utilization of foreign electronic resources, and probes into the countermeasures for strengthening the construction of foreign electronic resources and improving the utilization rate of foreign electronic resources.%从外文数据库的数量、经费和利用率等方面,对安徽建筑大学图书馆外文电子资源建设与利用现状进行了调查研究与统计分析,论述了影响外文电子资源建设与利用的因素,探讨了加强外文电子资源建设、提高外文数据库利用率的对策.

  13. Interactive Technologies in Electronic Educational Resources

    Science.gov (United States)

    Anisimova, Tatyana Ivanovna; Krasnova, Lyubov Alekseevna

    2015-01-01

    Modern professional education in the transition to a tiered system of specialists training is focused not on the transfer of ready knowledge but on teaching to find this knowledge and to apply them in situations close to the professional conditions. The educational process, relying on use of interactive methods of teaching, which is organized with…

  14. Patterns of primary afferent depolarization of segmental and ascending intraspinal collaterals of single joint afferents in the cat.

    Science.gov (United States)

    Rudomin, P; Lomelí, J

    2007-01-01

    We have examined in the anesthetized cat the threshold changes produced by sensory and supraspinal stimuli on intraspinal collaterals of single afferents from the posterior articular nerve (PAN). Forty-eight fibers were tested in the L3 segment, in or close to Clarke's column, and 70 fibers in the L6-L7 segments within the intermediate zone. Of these, 15 pairs of L3 and L6-L7 collaterals were from the same afferent. Antidromically activated fibers had conduction velocities between 23 and 74 m/s and peripheral thresholds between 1.1 and 4.7 times the threshold of the most excitable fibers (xT), most of them below 3 xT. PAN afferents were strongly depolarized by stimulation of muscle afferents and by cutaneous afferents, as well as by stimulation of the bulbar reticular formation and the midline raphe nuclei. Stimulation of muscle nerves (posterior biceps and semitendinosus, quadriceps) produced a larger PAD (primary afferent depolarization) in the L6-L7 than in the L3 terminations. Group II were more effective than group I muscle afferents. As with group I muscle afferents, the PAD elicited in PAN afferents by stimulation of muscle nerves could be inhibited by conditioning stimulation of cutaneous afferents. Stimulation of the cutaneous sural and superficial peroneal nerves increased the threshold of few terminations (i.e., produced primary afferent hyperpolarization, PAH) and reduced the threshold of many others, particularly of those tested in the L6-L7 segments. Yet, there was a substantial number of terminals where these conditioning stimuli had minor or no effects. Autogenetic stimulation of the PAN with trains of pulses increased the intraspinal threshold in 46% and reduced the threshold in 26% of fibers tested in the L6-L7 segments (no tests were made with trains of pulses on fibers ending in L3). These observations indicate that PAN afferents have a rather small autogenetic PAD, particularly if this is compared with the effects of heterogenetic stimulation

  15. Stabilization of the Activated hERG Channel Voltage Sensor by Depolarization Involves the S4-S5 Linker.

    Science.gov (United States)

    Thouta, Samrat; Hull, Christina M; Shi, Yu Patrick; Sergeev, Valentine; Young, James; Cheng, Yen M; Claydon, Thomas W

    2017-01-24

    Slow deactivation of hERG channels is critical for preventing cardiac arrhythmia yet the mechanistic basis for the slow gating transition is unclear. Here, we characterized the temporal sequence of events leading to voltage sensor stabilization upon membrane depolarization. Progressive increase in step depolarization duration slowed voltage-sensor return in a biphasic manner (τfast = 34 ms, τslow = 2.5 s). The faster phase of voltage-sensor return slowing correlated with the kinetics of pore opening. The slower component occurred over durations that exceeded channel activation and was consistent with voltage sensor relaxation. The S4-S5 linker mutation, G546L, impeded the faster phase of voltage sensor stabilization without attenuating the slower phase, suggesting that the S4-S5 linker is important for communications between the pore gate and the voltage sensor during deactivation. These data also demonstrate that the mechanisms of pore gate-opening-induced and relaxation-induced voltage-sensor stabilization are separable. Deletion of the distal N-terminus (Δ2-135) accelerated off-gating current, but did not influence the relative contribution of either mechanism of stabilization of the voltage sensor. Lastly, we characterized mode-shift behavior in hERG channels, which results from stabilization of activated channel states. The apparent mode-shift depended greatly on recording conditions. By measuring slow activation and deactivation at steady state we found the "true" mode-shift to be ∼15 mV. Interestingly, the "true" mode-shift of gating currents was ∼40 mV, much greater than that of the pore gate. This demonstrates that voltage sensor return is less energetically favorable upon repolarization than pore gate closure. We interpret this to indicate that stabilization of the activated voltage sensor limits the return of hERG channels to rest. The data suggest that this stabilization occurs as a result of reconfiguration of the pore gate upon opening by

  16. COMPARATIVE STUDY OF RAISE OF SERUM CREATINE PHOSPHOKINASE CONCENTRATION WITH DEPOLARIZING MUSCLE RELAXANT SUCCINYL CHOLINE AND NON-DEPOLARIZING MUSCLE RELAXANT VECURONIUM IN ASA GRADE-I PATIENT IN PAEDIATRIC AGE GROUP

    Directory of Open Access Journals (Sweden)

    Venkateshwar Reddy

    2016-02-01

    Full Text Available BACKGROUND Neuromuscular blocking agents are classified as depolarising and non-depolarising agents. Each category of drug has its own advantages and along with them comes the side-effects. Selection of neuromuscular blocking agent therefore depends on their actions. AIM OF STUDY Present study is undertaken to compare the raise of serum creatine phosphokinase concentration with depolarising muscle relaxant (succinyl choline and non-depolarizing muscle relaxant (vecuronium in ASA grade 1 patients in paediatric age group undergoing minor surgeries (minimal or no muscle cutting MATERIALS AND METHODS In the present study, 80 paediatric patients (aged between 1-12 years were randomly selected into Group A and Group B with 40 patients in each. Group A received inj. succinylcholine 2mg/kg and Group B received inj. vecuronium 0.1mg/kg to facilitate intubation. Pre-operative and post-operative blood samples were collected and Serum creatine phosphokinase levels were recorded. RESULTS The rise in serum creatine phosphokinase was observed in both group A and group B. But, the rise in group A was statistically significant. CONCLUSION Group A recorded a significant rise in serum creatine phosphokinase and Group B although recorded a rise in the enzyme levels it was statistically insignificant. So, whenever possible an alternative drug for succinylcholine to facilitate endotracheal intubation has to be sought in paediatric age group.

  17. Resource Abundance and Resource Dependence in China

    NARCIS (Netherlands)

    Ji, K.; Magnus, J.R.; Wang, W.

    2010-01-01

    This paper reconsiders the ‘curse of resources’ hypothesis for the case of China, and distinguishes between resource abundance, resource rents, and resource dependence. Resource abundance and resource rents are shown to be approximately equivalent, and their association with resource dependence vari

  18. Algae Resources

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    Algae are highly efficient at producing biomass, and they can be found all over the planet. Many use sunlight and nutrients to create biomass, which contain key components—including lipids, proteins, and carbohydrates— that can be converted and upgraded to a variety of biofuels and products. A functional algal biofuels production system requires resources such as suitable land and climate, sustainable management of water resources, a supplemental carbon dioxide (CO2) supply, and other nutrients (e.g., nitrogen and phosphorus). Algae can be an attractive feedstock for many locations in the United States because their diversity allows for highpotential biomass yields in a variety of climates and environments. Depending on the strain, algae can grow by using fresh, saline, or brackish water from surface water sources, groundwater, or seawater. Additionally, they can grow in water from second-use sources such as treated industrial wastewater; municipal, agricultural, or aquaculture wastewater; or produced water generated from oil and gas drilling operations.

  19. Supply-demand mismatch transients in susceptible peri-infarct hot zones explain the origins of spreading injury depolarizations.

    Science.gov (United States)

    von Bornstädt, Daniel; Houben, Thijs; Seidel, Jessica L; Zheng, Yi; Dilekoz, Ergin; Qin, Tao; Sandow, Nora; Kura, Sreekanth; Eikermann-Haerter, Katharina; Endres, Matthias; Boas, David A; Moskowitz, Michael A; Lo, Eng H; Dreier, Jens P; Woitzik, Johannes; Sakadžić, Sava; Ayata, Cenk

    2015-03-04

    Peri-infarct depolarizations (PIDs) are seemingly spontaneous spreading depression-like waves that negatively impact tissue outcome in both experimental and human stroke. Factors triggering PIDs are unknown. Here, we show that somatosensory activation of peri-infarct cortex triggers PIDs when the activated cortex is within a critical range of ischemia. We show that the mechanism involves increased oxygen utilization within the activated cortex, worsening the supply-demand mismatch. We support the concept by clinical data showing that mismatch predisposes stroke patients to PIDs as well. Conversely, transient worsening of mismatch by episodic hypoxemia or hypotension also reproducibly triggers PIDs. Therefore, PIDs are triggered upon supply-demand mismatch transients in metastable peri-infarct hot zones due to increased demand or reduced supply. Based on the data, we propose that minimizing sensory stimulation and hypoxic or hypotensive transients in stroke and brain injury would reduce PID incidence and their adverse impact on outcome. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Raphe magnus and reticulospinal actions on primary afferent depolarization of group I muscle afferents in the cat.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Jiménez, I; Rudomin, P

    1995-02-01

    1. In the anaesthetized cat, electrical stimulation of the bulbar reticular formation produced a short latency (2.1 +/- 0.3 ms) positive potential in the cord dorsum. In contrast, stimulation of the nucleus raphe magnus with strengths below 50 microA evoked a slow negative potential with a mean latency of 5.5 +/- 0.6 ms that persisted after sectioning the contralateral pyramid and was abolished by sectioning the ipsilateral dorsolateral funiculus. 2. The field potentials evoked by stimulation of the bulbar reticular formation and of the nucleus raphe magnus had a different intraspinal distribution, suggesting activation of different sets of segmental interneurones. 3. Stimulation of these two supraspinal nuclei produced primary afferent depolarization (PAD) in single Ib fibres and inhibited the PAD elicited by group I volleys in single Ia fibres. The inhibition of the PAD of Ia fibres produced by reticulospinal and raphespinal inputs appears to be exerted on different interneurones along the PAD pathway. 4. It is concluded that, although reticulospinal and raphespinal pathways have similar inhibitory effects on PAD of Ia fibres, and similar excitatory effects on the PAD of Ib fibres, their actions are conveyed by partly independent pathways. This would allow their separate involvement in the control of posture and movement.