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Sample records for adaptive medium access

  1. Traffic-Adaptive, Flow-Specific Medium Access for Wireless Networks

    DTIC Science & Technology

    2009-09-01

    free medium access and proposes a flow-specific medium access scheme for networked satellite systems that is based on traffic-adaptive CWS-MAC and...layer; Medium access control; Wireless; Energy-efficiency; Preamble sampling; Networked satellite systems 16. PRICE CODE 17. SECURITY... systems that is based on traffic-adaptive CWS- MAC and is shown to outperform both CSMA- and TDMA-based solutions. vi THIS PAGE INTENTIONALLY LEFT

  2. Energy Efficient Medium Access Control Protocol for Clustered Wireless Sensor Networks with Adaptive Cross-Layer Scheduling

    PubMed Central

    Sefuba, Maria; Walingo, Tom; Takawira, Fambirai

    2015-01-01

    This paper presents an Energy Efficient Medium Access Control (MAC) protocol for clustered wireless sensor networks that aims to improve energy efficiency and delay performance. The proposed protocol employs an adaptive cross-layer intra-cluster scheduling and an inter-cluster relay selection diversity. The scheduling is based on available data packets and remaining energy level of the source node (SN). This helps to minimize idle listening on nodes without data to transmit as well as reducing control packet overhead. The relay selection diversity is carried out between clusters, by the cluster head (CH), and the base station (BS). The diversity helps to improve network reliability and prolong the network lifetime. Relay selection is determined based on the communication distance, the remaining energy and the channel quality indicator (CQI) for the relay cluster head (RCH). An analytical framework for energy consumption and transmission delay for the proposed MAC protocol is presented in this work. The performance of the proposed MAC protocol is evaluated based on transmission delay, energy consumption, and network lifetime. The results obtained indicate that the proposed MAC protocol provides improved performance than traditional cluster based MAC protocols. PMID:26393608

  3. Energy Efficient Medium Access Control Protocol for Clustered Wireless Sensor Networks with Adaptive Cross-Layer Scheduling.

    PubMed

    Sefuba, Maria; Walingo, Tom; Takawira, Fambirai

    2015-09-18

    This paper presents an Energy Efficient Medium Access Control (MAC) protocol for clustered wireless sensor networks that aims to improve energy efficiency and delay performance. The proposed protocol employs an adaptive cross-layer intra-cluster scheduling and an inter-cluster relay selection diversity. The scheduling is based on available data packets and remaining energy level of the source node (SN). This helps to minimize idle listening on nodes without data to transmit as well as reducing control packet overhead. The relay selection diversity is carried out between clusters, by the cluster head (CH), and the base station (BS). The diversity helps to improve network reliability and prolong the network lifetime. Relay selection is determined based on the communication distance, the remaining energy and the channel quality indicator (CQI) for the relay cluster head (RCH). An analytical framework for energy consumption and transmission delay for the proposed MAC protocol is presented in this work. The performance of the proposed MAC protocol is evaluated based on transmission delay, energy consumption, and network lifetime. The results obtained indicate that the proposed MAC protocol provides improved performance than traditional cluster based MAC protocols.

  4. An ultra low-power and traffic-adaptive medium access control protocol for wireless body area network.

    PubMed

    Ullah, Sana; Kwak, Kyung Sup

    2012-06-01

    Wireless Body Area Network (WBAN) consists of low-power, miniaturized, and autonomous wireless sensor nodes that enable physicians to remotely monitor vital signs of patients and provide real-time feedback with medical diagnosis and consultations. It is the most reliable and cheaper way to take care of patients suffering from chronic diseases such as asthma, diabetes and cardiovascular diseases. Some of the most important attributes of WBAN is low-power consumption and delay. This can be achieved by introducing flexible duty cycling techniques on the energy constraint sensor nodes. Stated otherwise, low duty cycle nodes should not receive frequent synchronization and control packets if they have no data to send/receive. In this paper, we introduce a Traffic-adaptive MAC protocol (TaMAC) by taking into account the traffic information of the sensor nodes. The protocol dynamically adjusts the duty cycle of the sensor nodes according to their traffic-patterns, thus solving the idle listening and overhearing problems. The traffic-patterns of all sensor nodes are organized and maintained by the coordinator. The TaMAC protocol is supported by a wakeup radio that is used to accommodate emergency and on-demand events in a reliable manner. The wakeup radio uses a separate control channel along with the data channel and therefore it has considerably low power consumption requirements. Analytical expressions are derived to analyze and compare the performance of the TaMAC protocol with the well-known beacon-enabled IEEE 802.15.4 MAC, WiseMAC, and SMAC protocols. The analytical derivations are further validated by simulation results. It is shown that the TaMAC protocol outperforms all other protocols in terms of power consumption and delay.

  5. Equity of access: adaptive technology.

    PubMed

    Grodzinsky, F S

    2000-04-01

    In this age of information technology, it is morally imperative that equal access to information via computer systems be afforded to people with disabilities. This paper addresses the problems that computer technology poses for students with disabilities and discusses what is needed to ensure equity of access, particularly in a university environment.

  6. Scalable Lunar Surface Networks and Adaptive Orbit Access

    NASA Technical Reports Server (NTRS)

    Wang, Xudong

    2015-01-01

    Teranovi Technologies, Inc., has developed innovative network architecture, protocols, and algorithms for both lunar surface and orbit access networks. A key component of the overall architecture is a medium access control (MAC) protocol that includes a novel mechanism of overlaying time division multiple access (TDMA) and carrier sense multiple access with collision avoidance (CSMA/CA), ensuring scalable throughput and quality of service. The new MAC protocol is compatible with legacy Institute of Electrical and Electronics Engineers (IEEE) 802.11 networks. Advanced features include efficiency power management, adaptive channel width adjustment, and error control capability. A hybrid routing protocol combines the advantages of ad hoc on-demand distance vector (AODV) routing and disruption/delay-tolerant network (DTN) routing. Performance is significantly better than AODV or DTN and will be particularly effective for wireless networks with intermittent links, such as lunar and planetary surface networks and orbit access networks.

  7. A low-complexity medium access control framework for body sensor networks.

    PubMed

    Wang, Bo; Wang, Lei; Huang, Bang-Yu; Wu, Dan; Lin, Shao-Jie; Gu, Jia; Zhang, Yuan-Ting; Chen, Wei

    2009-01-01

    This paper proposed a low-complexity medium access control (MAC) protocol tailored for body sensor networks (BSN) applications. The MAC protocol was designated to handle collision avoidance by reducing the numbers of the overhead packets for handshake control within the BSN. We also suggested a novel message recovery mechanism for getting back the lost physiological information. The adaptive synchronization scheme we have implemented exploited the features of multiple data-rate and adjustable precision design to support differentiated healthcare applications. The MAC protocol was fully implemented using our BSN development platform. The experimental results suggested the improved MAC design was compact and energy-efficient.

  8. Adapting Historic Campus Structures for Accessibility.

    ERIC Educational Resources Information Center

    Milner, Margaret

    The issues involved in making accessibility modifications to buildings of historic value, architectural significance, or traditional interest are reviewed in this publication. A related document, ED 175 080, "Creating an Accessible Campus," contains information and design recommendations applicable to all buildings. The first part of the…

  9. User-Centered Indexing for Adaptive Information Access

    NASA Technical Reports Server (NTRS)

    Chen, James R.; Mathe, Nathalie

    1996-01-01

    We are focusing on information access tasks characterized by large volume of hypermedia connected technical documents, a need for rapid and effective access to familiar information, and long-term interaction with evolving information. The problem for technical users is to build and maintain a personalized task-oriented model of the information to quickly access relevant information. We propose a solution which provides user-centered adaptive information retrieval and navigation. This solution supports users in customizing information access over time. It is complementary to information discovery methods which provide access to new information, since it lets users customize future access to previously found information. It relies on a technique, called Adaptive Relevance Network, which creates and maintains a complex indexing structure to represent personal user's information access maps organized by concepts. This technique is integrated within the Adaptive HyperMan system, which helps NASA Space Shuttle flight controllers organize and access large amount of information. It allows users to select and mark any part of a document as interesting, and to index that part with user-defined concepts. Users can then do subsequent retrieval of marked portions of documents. This functionality allows users to define and access personal collections of information, which are dynamically computed. The system also supports collaborative review by letting users share group access maps. The adaptive relevance network provides long-term adaptation based both on usage and on explicit user input. The indexing structure is dynamic and evolves over time. Leading and generalization support flexible retrieval of information under similar concepts. The network is geared towards more recent information access, and automatically manages its size in order to maintain rapid access when scaling up to large hypermedia space. We present results of simulated learning experiments.

  10. Modelling of Medium Access Control (MAC) Protocols for Mobile Ad-Hoc Networks

    DTIC Science & Technology

    2005-06-01

    Slot IP Internet Protocol LAN Local Area Network MAC Medium Access Control MACAW Medium Access Protocol for Wireless LANs MANET Mobile Ad-hoc...Unforced state – It waits after entering the state until it is invoked by another process or an interrupt. It is in dark grey on this report, and red ... green in OPNET. A MAC process model is built for general initialisations of the MAC module, and to invoke the selected MAC protocol process model

  11. Energy-Efficient Boarder Node Medium Access Control Protocol for Wireless Sensor Networks

    PubMed Central

    Razaque, Abdul; Elleithy, Khaled M.

    2014-01-01

    This paper introduces the design, implementation, and performance analysis of the scalable and mobility-aware hybrid protocol named boarder node medium access control (BN-MAC) for wireless sensor networks (WSNs), which leverages the characteristics of scheduled and contention-based MAC protocols. Like contention-based MAC protocols, BN-MAC achieves high channel utilization, network adaptability under heavy traffic and mobility, and low latency and overhead. Like schedule-based MAC protocols, BN-MAC reduces idle listening time, emissions, and collision handling at low cost at one-hop neighbor nodes and achieves high channel utilization under heavy network loads. BN-MAC is particularly designed for region-wise WSNs. Each region is controlled by a boarder node (BN), which is of paramount importance. The BN coordinates with the remaining nodes within and beyond the region. Unlike other hybrid MAC protocols, BN-MAC incorporates three promising models that further reduce the energy consumption, idle listening time, overhearing, and congestion to improve the throughput and reduce the latency. One of the models used with BN-MAC is automatic active and sleep (AAS), which reduces the ideal listening time. When nodes finish their monitoring process, AAS lets them automatically go into the sleep state to avoid the idle listening state. Another model used in BN-MAC is the intelligent decision-making (IDM) model, which helps the nodes sense the nature of the environment. Based on the nature of the environment, the nodes decide whether to use the active or passive mode. This decision power of the nodes further reduces energy consumption because the nodes turn off the radio of the transceiver in the passive mode. The third model is the least-distance smart neighboring search (LDSNS), which determines the shortest efficient path to the one-hop neighbor and also provides cross-layering support to handle the mobility of the nodes. The BN-MAC also incorporates a semi

  12. Energy-efficient boarder node medium access control protocol for wireless sensor networks.

    PubMed

    Razaque, Abdul; Elleithy, Khaled M

    2014-03-12

    This paper introduces the design, implementation, and performance analysis of the scalable and mobility-aware hybrid protocol named boarder node medium access control (BN-MAC) for wireless sensor networks (WSNs), which leverages the characteristics of scheduled and contention-based MAC protocols. Like contention-based MAC protocols, BN-MAC achieves high channel utilization, network adaptability under heavy traffic and mobility, and low latency and overhead. Like schedule-based MAC protocols, BN-MAC reduces idle listening time, emissions, and collision handling at low cost at one-hop neighbor nodes and achieves high channel utilization under heavy network loads. BN-MAC is particularly designed for region-wise WSNs. Each region is controlled by a boarder node (BN), which is of paramount importance. The BN coordinates with the remaining nodes within and beyond the region. Unlike other hybrid MAC protocols, BN-MAC incorporates three promising models that further reduce the energy consumption, idle listening time, overhearing, and congestion to improve the throughput and reduce the latency. One of the models used with BN-MAC is automatic active and sleep (AAS), which reduces the ideal listening time. When nodes finish their monitoring process, AAS lets them automatically go into the sleep state to avoid the idle listening state. Another model used in BN-MAC is the intelligent decision-making (IDM) model, which helps the nodes sense the nature of the environment. Based on the nature of the environment, the nodes decide whether to use the active or passive mode. This decision power of the nodes further reduces energy consumption because the nodes turn off the radio of the transceiver in the passive mode. The third model is the least-distance smart neighboring search (LDSNS), which determines the shortest efficient path to the one-hop neighbor and also provides cross-layering support to handle the mobility of the nodes. The BN-MAC also incorporates a semi

  13. Energy latency tradeoffs for medium access and sleep scheduling in wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Gang, Lu

    Wireless sensor networks are expected to be used in a wide range of applications from environment monitoring to event detection. The key challenge is to provide energy efficient communication; however, latency remains an important concern for many applications that require fast response. The central thesis of this work is that energy efficient medium access and sleep scheduling mechanisms can be designed without necessarily sacrificing application-specific latency performance. We validate this thesis through results from four case studies that cover various aspects of medium access and sleep scheduling design in wireless sensor networks. Our first effort, DMAC, is to design an adaptive low latency and energy efficient MAC for data gathering to reduce the sleep latency. We propose staggered schedule, duty cycle adaptation, data prediction and the use of more-to-send packets to enable seamless packet forwarding under varying traffic load and channel contentions. Simulation and experimental results show significant energy savings and latency reduction while ensuring high data reliability. The second research effort, DESS, investigates the problem of designing sleep schedules in arbitrary network communication topologies to minimize the worst case end-to-end latency (referred to as delay diameter). We develop a novel graph-theoretical formulation, derive and analyze optimal solutions for the tree and ring topologies and heuristics for arbitrary topologies. The third study addresses the problem of minimum latency joint scheduling and routing (MLSR). By constructing a novel delay graph, the optimal joint scheduling and routing can be solved by M node-disjoint paths algorithm under multiple channel model. We further extended the algorithm to handle dynamic traffic changes and topology changes. A heuristic solution is proposed for MLSR under single channel interference. In the fourth study, EEJSPC, we first formulate a fundamental optimization problem that provides tunable

  14. Virus spreading in wireless sensor networks with a medium access control mechanism

    NASA Astrophysics Data System (ADS)

    Wang, Ya-Qi; Yang, Xiao-Yuan

    2013-04-01

    In this paper, an extended version of standard susceptible-infected (SI) model is proposed to consider the influence of a medium access control mechanism on virus spreading in wireless sensor networks. Theoretical analysis shows that the medium access control mechanism obviously reduces the density of infected nodes in the networks, which has been ignored in previous studies. It is also found that by increasing the network node density or node communication radius greatly increases the number of infected nodes. The theoretical results are confirmed by numerical simulations.

  15. Public access management as an adaptive wildlife management tool

    USGS Publications Warehouse

    Ouren, Douglas S.; Watts, Raymond D.

    2005-01-01

    One key issue in the Black Mesa – Black Canyon area is the interaction between motorized vehicles and. The working hypothesis for this study is that early season elk movement onto private lands and the National Park is precipitated by increased use of Off Highway Vehicles (OHV’s). Data on intensity of motorized use is extremely limited. In this study, we monitor intensity of motorized vehicle and trail use on elk movements and habitat usage and analyze interactions. If management agencies decide to alter accessibility, we will monitor wildlife responses to changes in the human-use regime. This provides a unique opportunity for adaptive management experimentation based on coordinated research and monitoring. The products from this project will provide natural resource managers across the nation with tools and information to better meet these resource challenges.

  16. Advertisement-Based Energy Efficient Medium Access Protocols for Wireless Sensor Networks

    NASA Astrophysics Data System (ADS)

    Ray, Surjya Sarathi

    One of the main challenges that prevents the large-scale deployment of Wireless Sensor Networks (WSNs) is providing the applications with the required quality of service (QoS) given the sensor nodes' limited energy supplies. WSNs are an important tool in supporting applications ranging from environmental and industrial monitoring, to battlefield surveillance and traffic control, among others. Most of these applications require sensors to function for long periods of time without human intervention and without battery replacement. Therefore, energy conservation is one of the main goals for protocols for WSNs. Energy conservation can be performed in different layers of the protocol stack. In particular, as the medium access control (MAC) layer can access and control the radio directly, large energy savings is possible through intelligent MAC protocol design. To maximize the network lifetime, MAC protocols for WSNs aim to minimize idle listening of the sensor nodes, packet collisions, and overhearing. Several approaches such as duty cycling and low power listening have been proposed at the MAC layer to achieve energy efficiency. In this thesis, I explore the possibility of further energy savings through the advertisement of data packets in the MAC layer. In the first part of my research, I propose Advertisement-MAC or ADV-MAC, a new MAC protocol for WSNs that utilizes the concept of advertising for data contention. This technique lets nodes listen dynamically to any desired transmission and sleep during transmissions not of interest. This minimizes the energy lost in idle listening and overhearing while maintaining an adaptive duty cycle to handle variable loads. Additionally, ADV-MAC enables energy efficient MAC-level multicasting. An analytical model for the packet delivery ratio and the energy consumption of the protocol is also proposed. The analytical model is verified with simulations and is used to choose an optimal value of the advertisement period

  17. Adaptation of Drosophila melanogaster to Unfavorable Growth Medium Affects Lifespan and Age-Related Fecundity.

    PubMed

    Yakovleva, E U; Naimark, E B; Markov, A V

    2016-12-01

    Experimental adaptation of Drosophila melanogaster to nutrient-deficient starch-based (S) medium resulted in lifespan shortening, increased early-life fecundity, accelerated reproductive aging, and sexually dimorphic survival curves. The direction of all these evolutionary changes coincide with the direction of phenotypic plasticity observed in non-adapted flies cultured on S medium. High adult mortality rate caused by unfavorable growth medium apparently was the main factor of selection during the evolutionary experiment. The results are partially compatible with Williams' hypothesis, which states that increased mortality rate should result in relaxed selection against mutations that decrease fitness late in life, and thus promote the evolution of shorter lifespan and earlier reproduction. However, our results do not confirm Williams' prediction that the sex with higher mortality rate should undergo more rapid aging: lifespan shortening by S medium is more pronounced in naïve males than females, but it was female lifespan that decreased more in the course of adaptation. These data, as well as the results of testing of F1 hybrids between adapted and control lineages, are compatible with the idea that the genetic basis of longevity is different in the two sexes, and that evolutionary response to increased mortality rate depends on the degree to which the mortality is selective. Selective mortality can result in the development of longer (rather than shorter) lifespan in the course of evolution. The results also imply that antagonistic pleiotropy of alleles, which increase early-life fecundity at the cost of accelerated aging, played an important role in the evolutionary changes of females in the experimental lineage, while accumulation of deleterious mutations with late-life effects due to drift was more important in the evolution of male traits.

  18. A time tree medium access control for energy efficiency and collision avoidance in wireless sensor networks.

    PubMed

    Lee, Kilhung

    2010-01-01

    This paper presents a medium access control and scheduling scheme for wireless sensor networks. It uses time trees for sending data from the sensor node to the base station. For an energy efficient operation of the sensor networks in a distributed manner, time trees are built in order to reduce the collision probability and to minimize the total energy required to send data to the base station. A time tree is a data gathering tree where the base station is the root and each sensor node is either a relaying or a leaf node of the tree. Each tree operates in a different time schedule with possibly different activation rates. Through the simulation, the proposed scheme that uses time trees shows better characteristics toward burst traffic than the previous energy and data arrival rate scheme.

  19. Adaptations and Access to Assessment of Common Core Content

    ERIC Educational Resources Information Center

    Kettler, Ryan J.

    2015-01-01

    This chapter introduces theory that undergirds the role of testing adaptations in assessment, provides examples of item modifications and testing accommodations, reviews research relevant to each, and introduces a new paradigm that incorporates opportunity to learn (OTL), academic enablers, testing adaptations, and inferences that can be made from…

  20. Heartbeat-driven medium-access control for body sensor networks.

    PubMed

    Li, Huaming; Tan, Jindong

    2010-01-01

    In this paper, a novel time division multiple access based MAC protocol designed for body sensor networks (BSNs) is presented. H-medium-access control (MAC) aims to improve BSNs energy efficiency by exploiting heartbeat rhythm information, instead of using periodic synchronization beacons, to perform time synchronization. Heartbeat rhythm is inherent in every human body and observable in various biosignals. Biosensors in a BSN can extract the heartbeat rhythm from their own sensory data by detecting waveform peaks. All rhythms represented by peak sequences are naturally synchronized since they are driven by the same source, i.e., the heartbeat. Following the rhythm, biosensors can achieve time synchronization without having to turn on their radio to receive periodic timing information from a central controller, so that energy cost for time synchronization can be completely eliminated and the lifetime of the network can be prolonged. An active synchronization recovery scheme is also developed, including two resynchronization approaches. The algorithms are simulated using the discrete event simulator OMNet + + with real-world data from the Massachusetts Institute of Technology-Boston's Beth Israel Hospital multiparameter database Multiparameter Intelligent Monitoring for Intensive Care. The results show that H-MAC can prolong the network life dramatically.

  1. Adaptation of Delftia acidovorans for degradation of 2,4-dichlorophenoxyacetate in a microfluidic porous medium.

    PubMed

    Yoon, Hongkyu; Leibeling, Sabine; Zhang, Changyong; Müller, Roland H; Werth, Charles J; Zilles, Julie L

    2014-07-01

    Delftia acidovorans MC1071 can productively degrade R-2-(2,4-dichlorophenoxy)propionate (R-2,4-DP) but not 2,4-dichlorophenoxyacetate (2,4-D) herbicides. This work demonstrates adaptation of MC1071 to degrade 2,4-D in a model two-dimensional porous medium (referred to here as a micromodel). Adaptation for 2,4-D degradation in the 2 cm-long micromodel occurred within 35 days of exposure to 2,4-D, as documented by substrate removal. The amount of 2,4-D degradation in the adapted cultures in two replicate micromodels (~10 and 20 % over 142 days) was higher than a theoretical maximum (4 %) predicted using published numerical simulation methods, assuming instantaneous biodegradation and a transverse dispersion coefficient obtained for the same pore structure without biomass present. This suggests that the presence of biomass enhances substrate mixing. Additional evidence for adaptation was provided by operation without R-2,4-DP, where degradation of 2,4-D slowly decreased over 20 days, but was restored almost immediately when R-2,4-DP was again provided. Compared to suspended growth systems, the micromodel system retained the ability to degrade 2,4-D longer in the absence of R-2,4-DP, suggesting slower responses and greater resilience to fluctuations in substrates might be expected in the soil environment than in a chemostat.

  2. Scale of Adaptive Information Technology Accessibility for Postsecondary Students with Disabilities (SAITAPSD): A Preliminary Investigation

    ERIC Educational Resources Information Center

    Fichten, Catherine S.; Nguyen, Mai N.; Barile, Maria; Asuncion, Jennison V.

    2007-01-01

    The responses of 81 Canadian junior and community college students with disabilities were used to develop and evaluate the Scale of Adaptive Information Technology Accessibility for Postsecondary Students with Disabilities (SAITAPSD). This is an 18-item self-administered tool that evaluates computing accessibility for and by students with various…

  3. Adaptive Technology for the Internet: Making Electronic Resources Accessible to All.

    ERIC Educational Resources Information Center

    Mates, Barbara T.

    This book seeks to guide information providers in establishing accessible World Wide Web sites and acquiring the hardware and software needed by people with disabilities, focusing on access to the Internet using large print, voice, and Braille. The book also covers how to acquire the funds for adaptive technology, what type of equipment to choose,…

  4. A low power medium access control protocol for wireless medical sensor networks.

    PubMed

    Lamprinos, I; Prentza, A; Sakka, E; Koutsouris, D

    2004-01-01

    The concept of a wireless integrated network of sensors, already applied in several sectors of our everyday life, such as security, transportation and environment monitoring, can as well provide an advanced monitor and control resource for healthcare services. By networking medical sensors wirelessly, attaching them in patient's body, we create the appropriate infrastructure for continuous and real-time monitoring of patient without discomforting him. This infrastructure can improve healthcare by providing the means for flexible acquisition of vital signs, while at the same time it provides more convenience to the patient. Given the type of wireless network, traditional medium access control (MAC) protocols cannot take advantage of the application specific requirements and information characteristics occurring in medical sensor networks, such as the demand for low power consumption and the rather limited and asymmetric data traffic. In this paper, we present the architecture of a low power MAC protocol, designated to support wireless networks of medical sensors. This protocol aims to improve energy efficiency by exploiting the inherent application features and requirements. It is oriented towards the avoidance of main energy wastage sources, such as idle listening, collision and power outspending.

  5. Using the Critical Incident Technique to Research Decision Making regarding Access to Training and Development in Medium-Sized Enterprises

    ERIC Educational Resources Information Center

    Coetzer, Alan; Redmond, Janice; Sharafizad, Jalleh

    2012-01-01

    Employees in small and medium-sized enterprises (SMEs) form part of a "disadvantaged" group within the workforce that receives less access to training and development (T&D) than employees in large firms. Prior research into reasons for the relatively low levels of employee participation in training and development has typically…

  6. Guaranteeing synchronous message deadlines with the timed token medium access control protocol

    NASA Technical Reports Server (NTRS)

    Agrawal, Gopal; Chen, Baio; Zhao, Wei; Davari, Sadegh

    1992-01-01

    We study the problem of guaranteeing synchronous message deadlines in token ring networks where the timed token medium access control protocol is employed. Synchronous capacity, defined as the maximum time for which a node can transmit its synchronous messages every time it receives the token, is a key parameter in the control of synchronous message transmission. To ensure the transmission of synchronous messages before their deadlines, synchronous capacities must be properly allocated to individual nodes. We address the issue of appropriate allocation of the synchronous capacities. Several synchronous capacity allocation schemes are analyzed in terms of their ability to satisfy deadline constraints of synchronous messages. We show that an inappropriate allocation of the synchronous capacities could cause message deadlines to be missed even if the synchronous traffic is extremely low. We propose a scheme called the normalized proportional allocation scheme which can guarantee the synchronous message deadlines for synchronous traffic of up to 33 percent of available utilization. To date, no other synchronous capacity allocation scheme has been reported to achieve such substantial performance. Another major contribution of this paper is an extension to the previous work on the bounded token rotation time. We prove that the time elapsed between any consecutive visits to a particular node is bounded by upsilon TTRT, where TTRT is the target token rotation time set up at system initialization time. The previous result by Johnson and Sevcik is a special case where upsilon = 2. We use this result in the analysis of various synchronous allocation schemes. It can also be applied in other similar studies.

  7. Use of medium-range weather forecasts for drought mitigation and adaptation under a Mediterranean area

    NASA Astrophysics Data System (ADS)

    Lahlou, Ouiam; Imani, Yasmina; Bennasser Alaoui, Si; Dutra, Emanuel; DiGiuseppe, Francesca; Pappenberger, Florian; Wetterhall, Fredrik

    2014-05-01

    Use of medium-range weather forecasts for drought mitigation and adaptation under a Mediterranean area Authors: Ouiam Lahlou1, Yasmina Imani1, Si Bennasser Alaoui1, Emmanuel Dutra 2, Francesca Di Guiseppe2, Florian Pappenberger2, Fredrik Wetterhall2 1: Institut Agronomique et Vétérinaire Hassan II (IAV Hassan II) 2: European Center for Medium-Range Weather Forecasts (ECMWF) The main pillar of economic development in Morocco is the agricultural sector employing 40% of the active workforce. Agriculture is still mainly dominated by rainfed agriculture which is vulnerable to an increasing frequency and severity of drought events. In rainfed agriculture, there are few interventions possible once crops are planted. Medium to long range weather forecasts could therefore provide valid information for crop selection and sowing time at the onset of the yield season and later to plan mitigation measures during dry-spell episodes. More than 600 daily forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble forecasting system were analyzed in terms of probabilistic skills scores. Results show that, while daily and weekly accumulated precipitation are poorly predicted there is good skill in the forecast of occurrence and extent of dry periods. The availability of this information to decision makers in the agricultural sector would mean moving from a reactive drought management plan to a proactive one. This is very important, especially for the remote areas where often the needed help comes late. A simulation case-study involving farmers who were made aware of the availability of forecasts for the next seasons, show that medium-range forecasts will allow i) governments and relief agencies to position themselves for more effective and cost-efficient drought interventions, ii) producers to be more aware of their production options and insure their payment rate, iii) Herders, to cope with higher food costs for their cattle iv) farmers to better plan

  8. A multiple access communication network based on adaptive arrays

    NASA Technical Reports Server (NTRS)

    Zohar, S.

    1981-01-01

    A single frequency communication system is considered consisting of K possibly moving users distributed in space simultaneously communicating with a central station equipped with a computationally adapted array of n = or K antennas. Such a configuration could result if K spacecraft were to be simultaneously tracked by a single DSN complex consisting of an n antennas array. The array employs K sets of n weights to segregate the signals received from the K users. The weights are determined by direct computation based on known position information of the K users. Currently known techniques require (for n = K) about (4/3)K to the 4th power computer operations (multiply and add) to perform such computations. A technique that accomplishes this same goal in 8 K to the 3rd power operations, yielding a reduction by a factor K/6, was developed.

  9. Metabolic and proteomic study of NS0 myeloma cell line following the adaptation to protein-free medium.

    PubMed

    de la Luz-Hernández, K R; Rojas-del Calvo, L; Rabasa-Legón, Y; Lage-Castellanos, A; Castillo-Vitlloch, A; Díaz, J; Gaskell, S

    2008-07-21

    Proteomics and metabolomics technologies are potentially useful tool for the study of the very complex process of cell adaptation to protein-free medium. In this work, we used the iTRAQ technology to analyze different protein levels in adapted and non-adapted NS0 myeloma cell line. Several proteins with differential expression profile were characterized and quantified. Carbohydrate metabolism, protein synthesis and membrane transport were the principal pathways that change after the adaptation. Changes in lactate production rate with respect to glucose consumption rate were observed according to the changes observed by proteomic.

  10. The Potential for Adaptable Accessible Learning Objects: A Case Study in Accessible Vodcasting

    ERIC Educational Resources Information Center

    Gkatzidou, Stavroula; Pearson, Elaine

    2009-01-01

    With the rapid development of wireless networks and mobile technologies and the increasing adoption of mobile learning, the need for "anywhere, anytime and any device" access to information becomes more evident. This has influenced the design of learning objects. The small but developing literature on vodcasting indicates its potential…

  11. Random access with adaptive packet aggregation in LTE/LTE-A.

    PubMed

    Zhou, Kaijie; Nikaein, Navid

    While random access presents a promising solution for efficient uplink channel access, the preamble collision rate can significantly increase when massive number of devices simultaneously access the channel. To address this issue and improve the reliability of the random access, an adaptive packet aggregation method is proposed. With the proposed method, a device does not trigger a random access for every single packet. Instead, it starts a random access when the number of aggregated packets reaches a given threshold. This method reduces the packet collision rate at the expense of an extra latency, which is used to accumulate multiple packets into a single transmission unit. Therefore, the tradeoff between packet loss rate and channel access latency has to be carefully selected. We use semi-Markov model to derive the packet loss rate and channel access latency as functions of packet aggregation number. Hence, the optimal amount of aggregated packets can be found, which keeps the loss rate below the desired value while minimizing the access latency. We also apply for the idea of packet aggregation for power saving, where a device aggregates as many packets as possible until the latency constraint is reached. Simulations are carried out to evaluate our methods. We find that the packet loss rate and/or power consumption are significantly reduced with the proposed method.

  12. Adapting Online Learning Resources for All: Planning for Professionalism in Accessibility

    ERIC Educational Resources Information Center

    McAndrew, Patrick; Farrow, Robert; Cooper, Martyn

    2012-01-01

    Online resources for education offer opportunities for those with disabilities but also raise challenges on how to best adjust resources to accommodate accessibility. Automated reconfiguration could in principle remove the need for expensive and time-consuming discussions about adaptation. On the other hand, human-based systems provide much needed…

  13. Accessing English and Networks at an English-Medium Multicultural Church in East Canada: An Ethnography

    ERIC Educational Resources Information Center

    Han, Huamei

    2014-01-01

    Drawing from a larger ethnography of skilled Chinese immigrants' language learning during settlement in Toronto, this article explores the role of informal interactions in facilitating immigrants learning English as a second language and settlement. Examining various activities and networks available at an English-medium multicultural church, this…

  14. Design of Unstructured Adaptive (UA) NAS Parallel Benchmark Featuring Irregular, Dynamic Memory Accesses

    NASA Technical Reports Server (NTRS)

    Feng, Hui-Yu; VanderWijngaart, Rob; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    We describe the design of a new method for the measurement of the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. The method involves the solution of a stylized heat transfer problem on an unstructured, adaptive grid. A Spectral Element Method (SEM) with an adaptive, nonconforming mesh is selected to discretize the transport equation. The relatively high order of the SEM lowers the fraction of wall clock time spent on inter-processor communication, which eases the load balancing task and allows us to concentrate on the memory accesses. The benchmark is designed to be three-dimensional. Parallelization and load balance issues of a reference implementation will be described in detail in future reports.

  15. Adaptive coded spreading OFDM signal for dynamic-λ optical access network

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Zhang, Lijia; Xin, Xiangjun

    2015-12-01

    This paper proposes and experimentally demonstrates a novel adaptive coded spreading (ACS) orthogonal frequency division multiplexing (OFDM) signal for dynamic distributed optical ring-based access network. The wavelength can be assigned to different remote nodes (RNs) according to the traffic demand of optical network unit (ONU). The ACS can provide dynamic spreading gain to different signals according to the split ratio or transmission length, which offers flexible power budget for the network. A 10×13.12 Gb/s OFDM access with ACS is successfully demonstrated over two RNs and 120 km transmission in the experiment. The demonstrated method may be viewed as one promising for future optical metro access network.

  16. Preliminary assessment of Tongue Drive System in medium term usage for computer access and wheelchair control.

    PubMed

    Yousefi, Behnaz; Huo, Xueliang; Ghovanloo, Maysam

    2011-01-01

    Tongue Drive System (TDS) is a wireless, wearable assistive technology that enables individuals with severe motor impairments access computers, drive wheelchairs, and control their environments using tongue motion. In this paper, we have evaluated the TDS performance as a computer input device using ISO9241-9 standard tasks for pointing and selecting, based on the well known Fitts' Law, and as a powered wheelchair controller through an obstacle course navigation task. Nine able-bodied subjects who already had tongue piercing participated in this trial over 5 sessions during 5 weeks, allowing us to study the TDS learning process and its current limiting factors. Subjects worn tongue rings made of titanium in the form of a barbell with a small rare earth magnetic tracer hermetically sealed inside the upper ball. Comparing the results between 1(st) and 5(th) sessions showed that subjects' performance improved in all the measures through 5 sessions, demonstrating the effects of learning.

  17. An Adaptive Channel Access Method for Dynamic Super Dense Wireless Sensor Networks.

    PubMed

    Lei, Chunyang; Bie, Hongxia; Fang, Gengfa; Zhang, Xuekun

    2015-12-03

    Super dense and distributed wireless sensor networks have become very popular with the development of small cell technology, Internet of Things (IoT), Machine-to-Machine (M2M) communications, Vehicular-to-Vehicular (V2V) communications and public safety networks. While densely deployed wireless networks provide one of the most important and sustainable solutions to improve the accuracy of sensing and spectral efficiency, a new channel access scheme needs to be designed to solve the channel congestion problem introduced by the high dynamics of competing nodes accessing the channel simultaneously. In this paper, we firstly analyzed the channel contention problem using a novel normalized channel contention analysis model which provides information on how to tune the contention window according to the state of channel contention. We then proposed an adaptive channel contention window tuning algorithm in which the contention window tuning rate is set dynamically based on the estimated channel contention level. Simulation results show that our proposed adaptive channel access algorithm based on fast contention window tuning can achieve more than 95 % of the theoretical optimal throughput and 0 . 97 of fairness index especially in dynamic and dense networks.

  18. Adaptation of a phenol-degrading denitrifying bacteria to high concentration of phenol in the medium.

    PubMed

    Son, T T; Błaszczyk, M; Mycielski, R

    1998-01-01

    The growth and uptake of phenol by 8 strains isolated from wastewater sediments in stationary cultures in medium with increasing concentrations of phenol (from 100 to 600 mg/L) under denitrifying conditions were studied. All the strains grew in media containing 250 mg phenol/L and only strains 101/1, 83/2 and 21/1/ in consecutive passages visibly increased both specific growth rate (mu day-1) as well as phenol-degrading activity (mg/L x day). Consecutive passages of the culture in medium containing 400 mg phenol/L resulted in the elimination of 3 out of the 5 strains growing in the medium in the first passage. Only strain 101/1 demonstrated high specific growth rate and phenol-degrading activity in medium containing 600 mg phenol/L. In consecutive passages in medium containing 250, 400 and 600 mg phenol/L the specific growth (mu day-1) and phenol-degrading activity (mg/L x day) of P. aeruginosa 101/1 were 0.38 and 36; 0.12 and 19; 0.09 and 20, respectively.

  19. Estimated performance of an adaptive trailing-edge device aimed at reducing fuel consumption on a medium-size aircraft

    NASA Astrophysics Data System (ADS)

    Diodati, Gianluca; Concilio, Antonio; Ricci, Sergio; De Gaspari, Alessandro; Huvelin, Fabien; Dumont, Antoine; Godard, Jean-Luc

    2013-03-01

    This paper deals with the estimation of the performance of a medium-size aircraft (3-hour flight range) equipped with an adaptive trailing edge device (ATED) that runs span-wise from the wing root in the flap zone and extends chord-wise for a limited percentage of the MAC. Computations are calculated referring to the full wing and do not refer to the complete aircraft configuration. Aerodynamic computations, taking into account ideal shapes, have been performed by using both Euler and Navier- Stokes method in order to extract the wing polars for the reference and the optimal wing, implementing an ATED, deflected upwards and downwards. A comparison of the achieved results is discussed. Considering the shape domain, a suitable interpolation procedure has been set up to obtain the wing polar envelop of the adaptive wing, intended as the set of "best" values, picked by each different polar. At the end, the performances of the complete reference and adaptive wing are computed and compared for a symmetric, centered, leveled and steady cruise flight for a medium size aircraft. A significant fuel burn reduction estimate or, alternatively, an increased range capability is demonstrated, with margins of further improvements. The research leading to these results has gratefully received funding from the European Union Seventh Framework Programme (FP7/2007- 2013) under Grant Agreement n° 284562.

  20. Multiobjective adaptive feedback control of two-photon absorption coupled with propagation through a dispersive medium

    SciTech Connect

    Laforge, Francois O.; Roslund, Jonathan; Shir, Ofer M.; Rabitz, Herschel

    2011-07-15

    This work uses shaped femtosecond laser pulses to control the two-photon absorption (TPA) of coumarin 153 in a dispersive toluene medium. The dispersive medium reshapes the pulse along the optical path, and management of this effect is used to achieve spatial localization of TPA. Other control objectives were successfully implemented, including dual localization and high resolution local optimization of TPA. The solutions to these objectives were explored by means of evolutionary single- and multi-objective algorithms within a laboratory feedback loop.

  1. Teacher Adaptations to a Core Reading Program: Increasing Access to Curriculum for Elementary Students in Urban Classrooms

    ERIC Educational Resources Information Center

    Maniates, Helen

    2017-01-01

    This article examines how three urban elementary school teachers adapted pedagogical strategies from a school district--adopted core reading program to increase their students' access to the curriculum. Using teacher interviews and classroom observations to construct a descriptive case study of teacher adaptation, analysis reveals that the…

  2. Adaptation of Mycobacterium smegmatis to an Industrial Scale Medium and Isolation of the Mycobacterial PorinMspA

    PubMed Central

    Wendel, Sebastian O; Perera, Ayomi S; Pfromm, Peter H; Czermak, Peter; Bossmann, Stefan H

    2013-01-01

    The adaptation of the organism to a simple and cost-effective growth medium is mandatory in developing a process for large scale production of the octamericporinMspA, which is isolated from Mycobacterium smegmatis. A fermentation optimization with the minimal nutrients required for growth has been performed. During the fermentation, the iron- and ammonium chloride concentrations in the medium were varied to determine their impact on the observed growth rates and cell mass yields. Common antibiotics to control contamination were eliminated in favor of copper sulfate to reduce costs. MspA has been successfully isolated from the harvested M. smegmatisusing aqueous nOPOE (n-octyloligooxyethylene) at 65°C. Because of the extraordinary stability of MspA, it is possible to denature and precipitate virtually all other proteins and contaminants by following this approach. To further purify the product, acetone is used for precipitation. Gel electrophoresis confirmed the presence and purity of MspA. A maximum of 840µg (via Bradford assay) of pure MspA per liter of the optimized simple growth medium has been obtained. This is a 40% increase with respect to the previously reported culture medium for MspA. PMID:23802026

  3. Virtual Reality as a Medium for Sensorimotor Adaptation Training and Spaceflight Countermeasures

    NASA Technical Reports Server (NTRS)

    Madansingh, S.; Bloomberg, J. J.

    2015-01-01

    With the upcoming shift to extra-long duration missions (1 year) aboard the ISS, sensorimotor adaptations during transitory periods in-and-out of microgravity are more important to understand and prepare for. Advances in virtual reality technology enables everyday adoption of these tools for entertainment and use in training. Experiencing virtual environments (VE) allows for the manipulation of visual flow to elicit automatic motor behavior and produce sensorimotor adaptation (SA). Recently, the ability to train individuals using repeatable and varied exposures to SA challenges has shown success by improving performance during exposure to a novel environment (Batson 2011). This capacity to 'learn to learn' is referred to as sensorimotor adaptive generalizability and, through the use of treadmill training, represents an untapped potential for individualized countermeasures. The goal of this study is to determine the feasibility of present head mounted displays (HMDs) to produce compelling visual flow information and the expected adaptations for use in future SA treadmill-based countermeasures. Participants experience infinite hallways providing congruent (baseline) or incongruent visual information (half or double speed) via HMD while walking on an instrumented treadmill at 1.1m/s. As gait performance approaches baseline levels, an adaptation time constant is derived to establish individual time-to-adapt (TTA). It is hypothesized that decreasing the TTA through SA treadmill training will facilitate sensorimotor adaptation during gravitational transitions. In this way, HMD technology represents a novel platform for SA training using off-the-shelf consumer products for greater training flexibility in astronaut and terrestrial applications alike.

  4. Adaptation of Escherichia coli to Long-Term Serial Passage in Complex Medium: Evidence of Parallel Evolution

    PubMed Central

    Kram, Karin E.; Geiger, Christopher; Ismail, Wazim Mohammed; Lee, Heewook; Tang, Haixu

    2017-01-01

    ABSTRACT Experimental evolution of bacterial populations in the laboratory has led to identification of several themes, including parallel evolution of populations adapting to carbon starvation, heat stress, and pH stress. However, most of these experiments study growth in defined and/or constant environments. We hypothesized that while there would likely continue to be parallelism in more complex and changing environments, there would also be more variation in what types of mutations would benefit the cells. In order to test our hypothesis, we serially passaged Escherichia coli in a complex medium (Luria-Bertani broth) throughout the five phases of bacterial growth. This passaging scheme allowed cells to experience a wide variety of stresses, including nutrient limitation, oxidative stress, and pH variation, and therefore allowed them to adapt to several conditions. After every ~30 generations of growth, for a total of ~300 generations, we compared both the growth phenotypes and genotypes of aged populations to the parent population. After as few as 30 generations, populations exhibit changes in growth phenotype and accumulate potentially adaptive mutations. There were many genes with mutant alleles in different populations, indicating potential parallel evolution. We examined 8 of these alleles by constructing the point mutations in the parental genetic background and competed those cells with the parent population; five of these alleles were found to be adaptive. The variety and swiftness of adaptive mutations arising in the populations indicate that the cells are adapting to a complex set of stresses, while the parallel nature of several of the mutations indicates that this behavior may be generalized to bacterial evolution. IMPORTANCE With a growing body of work directed toward understanding the mechanisms of evolution using experimental systems, it is crucial to decipher what effects the experimental setup has on the outcome. If the goal of experimental

  5. Virtual Reality as a Medium for Sensorimotor Adaptation Training and Spaceflight Countermeasures

    NASA Technical Reports Server (NTRS)

    Madansingh, S.; Bloomberg, J. J.

    2014-01-01

    Astronauts experience a profound sensorimotor adaptation during transition to and from the microgravity environment of space. With the upcoming shift to extra-long duration missions (upwards of 1 year) aboard the International Space Station, the immediate risks to astronauts during these transitory periods become more important than ever to understand and prepare for. Recent advances in virtual reality technology enable everyday adoption of these tools for entertainment and use in training. Embedding an individual in a virtual environment (VE) allows the ability to change the perception of visual flow, elicit automatic motor behavior and produce sensorimotor adaptation, not unlike those required during long duration microgravity exposure. The overall goal of this study is to determine the feasibility of present head mounted display technology (HMD) to produce reliable visual flow information and the expected adaptation associated with virtual environment manipulation to be used in future sensorimotor adaptability countermeasures. To further understand the influence of visual flow on gait adaptation during treadmill walking, a series of discordant visual flow manipulations in a virtual environment are proposed. Six healthy participants (3 male and 3 female) will observe visual flow information via HMD (Oculus Rift DK2) while walking on an instrumented treadmill at their preferred walking speed. Participants will be immersed in a series of VE's resembling infinite hallways with different visual characteristics: an office hallway, a hallway with pillars and the hallway of a fictional spacecraft. Participants will perform three trials of 10 min. each, which include walking on the treadmill while receiving congruent or incongruent visual information via the HMD. In the first trial, participants will experience congruent visual information (baseline) where the hallway is perceived to move at the same rate as their walking speed. The final two trials will be randomized

  6. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  7. Integration of variable-rate OWC with OFDM-PON for hybrid optical access based on adaptive envelope modulation

    NASA Astrophysics Data System (ADS)

    Chen, Chen; Zhong, Wen-De; Wu, Dehao

    2016-12-01

    In this paper, we investigate an integrated optical wireless communication (OWC) and orthogonal frequency division multiplexing based passive optical network (OFDM-PON) system for hybrid wired and wireless optical access, based on an adaptive envelope modulation technique. Both the outdoor and indoor wireless communications are considered in the integrated system. The data for wired access is carried by a conventional OFDM signal, while the data for wireless access is carried by an M-ary pulse amplitude modulation (M-PAM) signal which is modulated onto the envelope of a phase-modulated OFDM signal. By adaptively modulating the wireless M-PAM signal onto the envelope of the wired phase-modulated constant envelope OFDM (CE-OFDM) signal, hybrid wired and wireless optical access can be seamlessly integrated and variable-rate optical wireless transmission can also be achieved. Analytical bit-error-rate (BER) expressions are derived for both the CE-OFDM signal with M-PAM overlay and the overlaid unipolar M-PAM signal, which are verified by Monte Carlo simulations. The BER performances of wired access, indoor OWC wireless access and outdoor OWC wireless access are evaluated. Moreover, variable-rate indoor and outdoor optical wireless access based on the adaptive envelope modulation technique is also discussed.

  8. Improving Inpatient Surveys: Web-Based Computer Adaptive Testing Accessed via Mobile Phone QR Codes

    PubMed Central

    2016-01-01

    Background The National Health Service (NHS) 70-item inpatient questionnaire surveys inpatients on their perceptions of their hospitalization experience. However, it imposes more burden on the patient than other similar surveys. The literature shows that computerized adaptive testing (CAT) based on item response theory can help shorten the item length of a questionnaire without compromising its precision. Objective Our aim was to investigate whether CAT can be (1) efficient with item reduction and (2) used with quick response (QR) codes scanned by mobile phones. Methods After downloading the 2008 inpatient survey data from the Picker Institute Europe website and analyzing the difficulties of this 70-item questionnaire, we used an author-made Excel program using the Rasch partial credit model to simulate 1000 patients’ true scores followed by a standard normal distribution. The CAT was compared to two other scenarios of answering all items (AAI) and the randomized selection method (RSM), as we investigated item length (efficiency) and measurement accuracy. The author-made Web-based CAT program for gathering patient feedback was effectively accessed from mobile phones by scanning the QR code. Results We found that the CAT can be more efficient for patients answering questions (ie, fewer items to respond to) than either AAI or RSM without compromising its measurement accuracy. A Web-based CAT inpatient survey accessed by scanning a QR code on a mobile phone was viable for gathering inpatient satisfaction responses. Conclusions With advances in technology, patients can now be offered alternatives for providing feedback about hospitalization satisfaction. This Web-based CAT is a possible option in health care settings for reducing the number of survey items, as well as offering an innovative QR code access. PMID:26935793

  9. Energy-efficiency analysis of a distributed queuing medium access control protocol for biomedical wireless sensor networks in saturation conditions.

    PubMed

    Otal, Begonya; Alonso, Luis; Verikoukis, Christos

    2011-01-01

    The aging population and the high quality of life expectations in our society lead to the need of more efficient and affordable healthcare solutions. For this reason, this paper aims for the optimization of Medium Access Control (MAC) protocols for biomedical wireless sensor networks or wireless Body Sensor Networks (BSNs). The hereby presented schemes always have in mind the efficient management of channel resources and the overall minimization of sensors' energy consumption in order to prolong sensors' battery life. The fact that the IEEE 802.15.4 MAC does not fully satisfy BSN requirements highlights the need for the design of new scalable MAC solutions, which guarantee low-power consumption to the maximum number of body sensors in high density areas (i.e., in saturation conditions). In order to emphasize IEEE 802.15.4 MAC limitations, this article presents a detailed overview of this de facto standard for Wireless Sensor Networks (WSNs), which serves as a link for the introduction and initial description of our here proposed Distributed Queuing (DQ) MAC protocol for BSN scenarios. Within this framework, an extensive DQ MAC energy-consumption analysis in saturation conditions is presented to be able to evaluate its performance in relation to IEEE 802.5.4 MAC in highly dense BSNs. The obtained results show that the proposed scheme outperforms IEEE 802.15.4 MAC in average energy consumption per information bit, thus providing a better overall performance that scales appropriately to BSNs under high traffic conditions. These benefits are obtained by eliminating back-off periods and collisions in data packet transmissions, while minimizing the control overhead.

  10. Energy-Efficiency Analysis of a Distributed Queuing Medium Access Control Protocol for Biomedical Wireless Sensor Networks in Saturation Conditions

    PubMed Central

    Otal, Begonya; Alonso, Luis; Verikoukis, Christos

    2011-01-01

    The aging population and the high quality of life expectations in our society lead to the need of more efficient and affordable healthcare solutions. For this reason, this paper aims for the optimization of Medium Access Control (MAC) protocols for biomedical wireless sensor networks or wireless Body Sensor Networks (BSNs). The hereby presented schemes always have in mind the efficient management of channel resources and the overall minimization of sensors’ energy consumption in order to prolong sensors’ battery life. The fact that the IEEE 802.15.4 MAC does not fully satisfy BSN requirements highlights the need for the design of new scalable MAC solutions, which guarantee low-power consumption to the maximum number of body sensors in high density areas (i.e., in saturation conditions). In order to emphasize IEEE 802.15.4 MAC limitations, this article presents a detailed overview of this de facto standard for Wireless Sensor Networks (WSNs), which serves as a link for the introduction and initial description of our here proposed Distributed Queuing (DQ) MAC protocol for BSN scenarios. Within this framework, an extensive DQ MAC energy-consumption analysis in saturation conditions is presented to be able to evaluate its performance in relation to IEEE 802.5.4 MAC in highly dense BSNs. The obtained results show that the proposed scheme outperforms IEEE 802.15.4 MAC in average energy consumption per information bit, thus providing a better overall performance that scales appropriately to BSNs under high traffic conditions. These benefits are obtained by eliminating back-off periods and collisions in data packet transmissions, while minimizing the control overhead. PMID:22319351

  11. Adaptive Code Division Multiple Access Protocol for Wireless Network-on-Chip Architectures

    NASA Astrophysics Data System (ADS)

    Vijayakumaran, Vineeth

    Massive levels of integration following Moore's Law ushered in a paradigm shift in the way on-chip interconnections were designed. With higher and higher number of cores on the same die traditional bus based interconnections are no longer a scalable communication infrastructure. On-chip networks were proposed enabled a scalable plug-and-play mechanism for interconnecting hundreds of cores on the same chip. Wired interconnects between the cores in a traditional Network-on-Chip (NoC) system, becomes a bottleneck with increase in the number of cores thereby increasing the latency and energy to transmit signals over them. Hence, there has been many alternative emerging interconnect technologies proposed, namely, 3D, photonic and multi-band RF interconnects. Although they provide better connectivity, higher speed and higher bandwidth compared to wired interconnects; they also face challenges with heat dissipation and manufacturing difficulties. On-chip wireless interconnects is one other alternative proposed which doesn't need physical interconnection layout as data travels over the wireless medium. They are integrated into a hybrid NOC architecture consisting of both wired and wireless links, which provides higher bandwidth, lower latency, lesser area overhead and reduced energy dissipation in communication. However, as the bandwidth of the wireless channels is limited, an efficient media access control (MAC) scheme is required to enhance the utilization of the available bandwidth. This thesis proposes using a multiple access mechanism such as Code Division Multiple Access (CDMA) to enable multiple transmitter-receiver pairs to send data over the wireless channel simultaneously. It will be shown that such a hybrid wireless NoC with an efficient CDMA based MAC protocol can significantly increase the performance of the system while lowering the energy dissipation in data transfer. In this work it is shown that the wireless NoC with the proposed CDMA based MAC protocol

  12. Accessibility

    EPA Pesticide Factsheets

    Federal laws, including Section 508 of the Rehabilitation Act, mandate that people with disabilities have access to the same information that someone without a disability would have. 508 standards cover electronic and information technology (EIT) products.

  13. Adaptive mobile access protocol (AMAP) for the message service of a land mobile satellite experiment (MSAT-X)

    NASA Technical Reports Server (NTRS)

    Li, V. O. K.; Yan, T.-Y.

    1984-01-01

    This paper describes a feasibility study of the adaptive mobile access protocol (AMAP) for MSATA-X, a proposed experimental mobile satellite communication network. The mobiles are dispersed over a wide geographical area and the channel data rate is limited due to the size and cost limitations of mobile antennas. AMAP is a reservation based multiple-access scheme. The available bandwidth is divided into subchannels, which are divided into reservation and message channels. The ALOHA multiple-access scheme is employed in the reservation channels, while the message channels are demand assigned. AMAP adaptively reallocates the reservation and message channels to optimize system performance. It has been shown that if messages are generated at a rate of one message per hour, AMAP can support approximately 2000 active users per 2400 bit/s channel with an average delay of 1.4 s.

  14. Efficient Consistency Achievement of Federated Identity and Access Management Based on a Novel Self-Adaptable Approach

    NASA Astrophysics Data System (ADS)

    Cha, Shi-Cho; Chang, Hsiang-Meng

    Federated identity and access management (FIAM) systems enable a user to access services provided by various organizations seamlessly. In FIAM systems, service providers normally stipulate that their users show assertions issued by allied parties to use their services as well as determine user privileges based on attributes in the assertions. However, the integrity of the attributes is important under certain circumstances. In such a circumstance, all released assertions should reflect modifications made to user attributes. Despite the ability to adopt conventional certification revocation technologies, including CRL or OCSP, to revoke an assertion and request the corresponding user to obtain a new assertion, re-issuing an entirely new assertion if only one attribute, such as user location or other environmental information, is changed would be inefficient. Therefore, this work presents a self-adaptive framework to achieve consistency in federated identity and access management systems (SAFIAM). In SAFIAM, an identity provider (IdP), which authenticates users and provides user attributes, should monitor access probabilities according to user attributes. The IdP can then adopt the most efficient means of ensuring data integrity of attributes based on related access probabilities. While Internet-based services emerge daily that have various access probabilities with respect to their user attributes, the proposed self-adaptive framework significantly contributes to efforts to streamline the use of FIAM systems.

  15. Medium-Range Predictability of Contrail-Cirrus Demonstrated during Experiments Ml-Cirrus and Access-Ii

    NASA Astrophysics Data System (ADS)

    Schumann, U.

    2015-12-01

    The Contrail Cirrus Prediction model CoCiP (doi:10.5194/gmd-5-543-2012) has been applied quasi operationally to predict contrails for flight planning of ML-CIRRUS (C. Voigt, DLR, et al.) in Europe and for ACCESS II in California (B. Anderson, NASA, et al.) in March-May 2014. The model uses NWP data from ECMWF and past airtraffic data (actual traffic data are used for analysis). The forecasts provided a sequence of hourly forecast maps of contrail cirrus optical depth for 3.5 days, every 12 h. CoCiP has been compared to observations before, e.g. within a global climate-aerosol-contrail model (Schumann, Penner et al., ACPD, 2015, doi:10.5194/acpd-15-19553-2015). Good predictions would allow for climate optimal routing (see, e.g., US patent by Mannstein and Schumann, US 2012/0173147 A1). The predictions are tested by: 1) Local eyewitness reports and photos, 2) satellite observed cloudiness, 3) autocorrelation analysis of predictions for various forecast periods, 4) comparisons of computed with observed optical depth from COCS (doi:10.5194/amt-7-3233-2014, 2014) by IR METEOSAT-SEVIRI observations over Europe. The results demonstrate medium-range predictability of contrail cirrus to a useful degree for given traffic, soot emissions, and high-quality NWP data. A growing set of satellite, Lidar, and in-situ data from ML-CIRRUS and ACCENT are becoming available and will be used to further test the forecast quality. The autocorrelation of optical depth predictions is near 70% for 3-d forecasts for Europe (outside times with high Sahara dust loads), and only slightly smaller for continental USA. Contrail cirrus is abundant over Europe and USA. More than 1/3 of all cirrus measured with the research aircraft HALO during ML-CIRRUS was impacted by contrails. The radiative forcing (RF) is strongly daytime and ambience dependent. The net annual mean RF, based on our global studies, may reach up to 0.08 W/m2 globally, and may well exceed 1 W/m2 regionally, with maximum over Europe

  16. EPA GHG certification of medium- and heavy-duty vehicles: Development of road grade profiles representative of US controlled access highways

    DOE PAGES

    Wood, Eric; Duran, Adam; Kelly, Kenneth

    2016-09-27

    In collaboration with the U.S. Environmental Protection Agency and the U.S. Department of Energy, the National Renewable Energy Laboratory has conducted a national analysis of road grade characteristics experienced by U.S. medium- and heavy-duty trucks on controlled access highways. These characteristics have been developed using TomTom's commercially available street map and road grade database. Using the TomTom national road grade database, national statistics on road grade and hill distances were generated for the U.S. network of controlled access highways. These statistical distributions were then weighted using data provided by the U.S. Environmental Protection Agency for activity of medium- and heavy-dutymore » trucks on controlled access highways. Here, the national activity-weighted road grade and hill distance distributions were then used as targets for development of a handful of sample grade profiles potentially to be used in the U.S. Environmental Protection Agency's Greenhouse Gas Emissions Model certification tool as well as in dynamometer testing of medium- and heavy-duty vehicles and their powertrains.« less

  17. EPA GHG certification of medium- and heavy-duty vehicles: Development of road grade profiles representative of US controlled access highways

    SciTech Connect

    Wood, Eric; Duran, Adam; Kelly, Kenneth

    2016-09-27

    In collaboration with the U.S. Environmental Protection Agency and the U.S. Department of Energy, the National Renewable Energy Laboratory has conducted a national analysis of road grade characteristics experienced by U.S. medium- and heavy-duty trucks on controlled access highways. These characteristics have been developed using TomTom's commercially available street map and road grade database. Using the TomTom national road grade database, national statistics on road grade and hill distances were generated for the U.S. network of controlled access highways. These statistical distributions were then weighted using data provided by the U.S. Environmental Protection Agency for activity of medium- and heavy-duty trucks on controlled access highways. Here, the national activity-weighted road grade and hill distance distributions were then used as targets for development of a handful of sample grade profiles potentially to be used in the U.S. Environmental Protection Agency's Greenhouse Gas Emissions Model certification tool as well as in dynamometer testing of medium- and heavy-duty vehicles and their powertrains.

  18. Temperature structure of the intracluster medium from smoothed-particle hydrodynamics and adaptive-mesh refinement simulations

    SciTech Connect

    Rasia, Elena; Lau, Erwin T.; Nagai, Daisuke; Avestruz, Camille; Borgani, Stefano; Dolag, Klaus; Granato, Gian Luigi; Murante, Giuseppe; Ragone-Figueroa, Cinthia; Mazzotta, Pasquale; Nelson, Kaylea

    2014-08-20

    Analyses of cosmological hydrodynamic simulations of galaxy clusters suggest that X-ray masses can be underestimated by 10%-30%. The largest bias originates from both violation of hydrostatic equilibrium (HE) and an additional temperature bias caused by inhomogeneities in the X-ray-emitting intracluster medium (ICM). To elucidate this large dispersion among theoretical predictions, we evaluate the degree of temperature structures in cluster sets simulated either with smoothed-particle hydrodynamics (SPH) or adaptive-mesh refinement (AMR) codes. We find that the SPH simulations produce larger temperature variations connected to the persistence of both substructures and their stripped cold gas. This difference is more evident in nonradiative simulations, whereas it is reduced in the presence of radiative cooling. We also find that the temperature variation in radiative cluster simulations is generally in agreement with that observed in the central regions of clusters. Around R {sub 500} the temperature inhomogeneities of the SPH simulations can generate twice the typical HE mass bias of the AMR sample. We emphasize that a detailed understanding of the physical processes responsible for the complex thermal structure in ICM requires improved resolution and high-sensitivity observations in order to extend the analysis to higher temperature systems and larger cluster-centric radii.

  19. Adaptation of AMO-FBMC-OQAM in optical access network for accommodating asynchronous multiple access in OFDM-based uplink transmission

    NASA Astrophysics Data System (ADS)

    Jung, Sun-Young; Jung, Sang-Min; Han, Sang-Kook

    2015-01-01

    Exponentially expanding various applications in company with proliferation of mobile devices make mobile traffic exploded annually. For future access network, bandwidth efficient and asynchronous signals converged transmission technique is required in optical network to meet a huge bandwidth demand, while integrating various services and satisfying multiple access in perceived network resource. Orthogonal frequency division multiplexing (OFDM) is highly bandwidth efficient parallel transmission technique based on orthogonal subcarriers. OFDM has been widely studied in wired-/wireless communication and became a Long term evolution (LTE) standard. Consequently, OFDM also has been actively researched in optical network. However, OFDM is vulnerable frequency and phase offset essentially because of its sinc-shaped side lobes, therefore tight synchronism is necessary to maintain orthogonality. Moreover, redundant cyclic prefix (CP) is required in dispersive channel. Additionally, side lobes act as interference among users in multiple access. Thus, it practically hinders from supporting integration of various services and multiple access based on OFDM optical transmission In this paper, adaptively modulated optical filter bank multicarrier system with offset QAM (AMO-FBMC-OQAM) is introduced and experimentally investigated in uplink optical transmission to relax multiple access interference (MAI), while improving bandwidth efficiency. Side lobes are effectively suppressed by using FBMC, therefore the system becomes robust to path difference and imbalance among optical network units (ONUs), which increase bandwidth efficiency by reducing redundancy. In comparison with OFDM, a signal performance and an efficiency of frequency utilization are improved in the same experimental condition. It enables optical network to effectively support heterogeneous services and multiple access.

  20. Adaptation of cholesterol-requiring NS0 mouse myeloma cells to high density growth in a fully defined protein-free and cholesterol-free culture medium.

    PubMed

    Keen, M J; Steward, T W

    1995-10-01

    NS0 has been used as a fusion partner for the production of hybridomas and has more recently been engineered to produce recombinant protein. A protein-free culture medium, designated W38 medium, has previously been developed which supported high density growth of rat myeloma and hybridoma cell lines. NS0 cells failed to grow in W38 medium and in a number of protein-free culture media which support the growth of other myeloma cell lines. NS0 cells are derived from the NS-1 cell line, which is known to require exogencus cholesterol. It was found that NS0 cells grew in W38 medium supplemented with phosphatidylcholine, cholesterol, and albumin and that NS0 were auxotrophic for cholesterol. Protein-free growth of NS0 cells was achieved by using β-cyclodextrin to replace albumin as a lipid carrier. The maximal cell density reached in this protein-free medium was in excess of 1.5×10(6) cell ml(-1). The lipid supplements in the medium precipitated after a few days storage at +4°C. In order to overcome this problem a protocol was developed which allowed NS0 cells to be adapted to cholesterol-independent growth in W38 medium. NS0.CF (cholesterol-independent NS0 cells) were cultured continuously in W38 medium for several months. In shake flask culture a cell density of 2.4×10(6) cells ml(-1) was achieved in W38 medium compared with 1.41×10(6) cells ml(-1) in RPMI 1640 medium containing 10% foetal bovine serum. NS0.CF cells readily grew in a 1 litre stirred bioreactor using W38 medium supplemented with Pluronic F68 reaching a density of 3.24×10(6) cells ml(-1). NS0.CF were cloned protein-free by limiting dilution in W38 medium, giving colonies in wells that were seeded at an average density of 0.32 cells per 200 μl. This study has demonstrated for the first time the growth of a cholesterol-requiring mouse myeloma cell line in a completely defined protein-free medium and its subsequent adaptation to cholesterol-independence.

  1. Developing Guidelines for Evaluating the Adaptation of Accessible Web-Based Learning Materials

    ERIC Educational Resources Information Center

    Radovan, Marko; Perdih, Mojca

    2016-01-01

    E-learning is a rapidly developing form of education. One of the key characteristics of e-learning is flexibility, which enables easier access to knowledge for everyone. Information and communications technology (ICT), which is e-learning's main component, enables alternative means of accessing the web-based learning materials that comprise the…

  2. Physiological and morphological adaptations in relation to water use efficiency in Mediterranean accessions of Solanum lycopersicum.

    PubMed

    Galmés, Jeroni; Conesa, Miquel Àngel; Ochogavía, Joan Manuel; Perdomo, Juan Alejandro; Francis, David M; Ribas-Carbó, Miquel; Savé, Robert; Flexas, Jaume; Medrano, Hipólito; Cifre, Josep

    2011-02-01

    The physiological traits underlying the apparent drought resistance of 'Tomàtiga de Ramellet' (TR) cultivars, a population of Mediterranean tomato cultivars with delayed fruit deterioration (DFD) phenotype and typically grown under non-irrigation conditions, are evaluated. Eight different tomato accessions were selected and included six TR accessions, one Mediterranean non-TR accession (NTR(M)) and a processing cultivar (NTR(O)). Among the TR accessions two leaf morphology types, normal divided leaves and potato-leaf, were selected. Plants were field grown under well-watered (WW) and water-stressed (WS) treatments, with 30 and 10% of soil water capacity, respectively. Accessions were clustered according to the leaf type and TR phenotype under WW and WS, respectively. Correlation among parameters under the different water treatments suggested that potential improvements in the intrinsic water-use efficiency (A(N)/g(s)) are possible without negative impacts on yield. Under WS TR accessions displayed higher A(N)/g(s), which was not due to differences in Rubisco-related parameters, but correlated with the ratio between the leaf mesophyll and stomatal conductances (g(m)/g(s)). The results confirm the existence of differential traits in the response to drought stress in Mediterranean accessions of tomato, and demonstrate that increases in the g(m)/g(s) ratio would allow improvements in A(N)/g(s) in horticultural crops.

  3. Morpho-anatomical adaptations to waterlogging by germplasm accessions in a tropical forage grass

    PubMed Central

    Cardoso, Juan Andrés; Rincón, Joisse; Jiménez, Juan de la Cruz; Noguera, Diana; Rao, Idupulapati M.

    2013-01-01

    Soil waterlogging reduces gas exchange between the soil and the atmosphere, leading to oxygen deprivation in the rhizosphere. Brachiaria spp. are the most widely sown forage grasses in tropical America. Among commercial Brachiaria grasses, B. humidicola shows superior tolerance to waterlogged soils based on maintenance of growth and reduced leaf chlorophyll loss and senescence. However, little is known about the underlying traits of waterlogging tolerance in B. humidicola or their intraspecific variation. For this purpose, an outdoor study was conducted using 12 germplasm accessions of B. humidicola that were grown in soil cylinders under drained or waterlogged soil conditions for 21 days. Dry mass production and morpho-anatomical responses (aerenchyma in shoots and roots, root diameter, proportional area of stele in roots, number of nodal and lateral roots, and length of the longest root) were determined. All accessions showed shorter roots and reduced root dry mass under waterlogged soil conditions. All accessions showed aerenchyma in shoots and roots under drained conditions but were further increased under waterlogging. All accessions showed a reduction in the proportional area of stele of roots in response to waterlogging. The accession (CIAT 26570) that showed a higher proportion of aerenchyma in shoots and roots and an increased number of nodal roots (with higher diameter and a reduction in the number of lateral roots) showed longer roots, less reduction in root dry mass and increased shoot growth under waterlogged conditions. We conclude that superior growth of one accession (CIAT 26570) under waterlogged soil conditions is probably a result of morpho-anatomical traits acting together to enhance root aeration and shoot ventilation. Further research is needed to test the ability to recover from waterlogging in B. humidicola accessions.

  4. Adaptation of Human Pluripotent Stem Cells to Feeder-Free Conditions in Chemically Defined Medium with Enzymatic Single-Cell Passaging

    PubMed Central

    Stover, Alexander E.; Schwartz, Philip H.

    2013-01-01

    This protocol describes the culture of human pluripotent stem cells (PSCs) under feeder-free conditions in a commercially available, chemically defined, growth medium, using Matrigel as a substrate and the enzyme solution Accutase for single-cell passaging. This system is strikingly different from traditional PSC culture, where the cells are co-cultured with feeder cells and in medium containing serum replacement. PSCs cultured in this new system have a different morphology than those cultured on feeder cells but retain their characteristic pluripotency. This feeder-free PSC culture system is conceptually similar to feeder-free systems that use mouse embryonic fibroblast (MEF)-conditioned medium (MEF-CM) and Matrigel substratum. Instead of MEF-CM, a very complex and undefined medium, this new system uses StemPro SFM, a chemically defined medium that permits enzymatic passaging with Accutase to disaggregate the colonies into single cells. Accutase passaging has been used in conjunction with Stempro in our hands for 20+ passages without detectable karyotypic abnormalities. We will also review techniques for adapting cultures previously grown on MEFs, routine passaging of the cells, and cryopreservation. PMID:21822872

  5. DI2ADEM: an adaptive hypermedia designed to improve access to relevant medical information.

    PubMed

    Pagesy, R; Soula, G; Fieschi, M

    2000-01-01

    The World Wide Web (web) provides the same type of information to widely different users and these users must then find the information suitable for their use in the package offered. The authors present the DI2ADEM project designed to take the user into account and intended to provide this user with appropriate medical information. To do that, DI2ADEM is suggesting an adaptive hypermedia based on the management of a meta-knowledge of the user and a knowledge of the information that can be circulated. An adaptive hypermedia prototype devoted to paediatric oncology was implemented on the intranet network of a university hospital.

  6. Cultural Intersection of Asian Indian Ethnicity and Presenting Problem: Adapting Multicultural Competence for Clinical Accessibility

    ERIC Educational Resources Information Center

    Bean, Roy A.; Titus, Gayatri

    2009-01-01

    A more accessible approach to using multicultural counseling competence is presented to bridge the researcher-practitioner gap and increase the likelihood of quality clinical services. The focus of the approach is on counselor awareness, knowledge, and skills as they relate to the most important contextualizing factors: ethnic culture and the…

  7. Access to Learning for Handicapped Children: A Handbook on the Instructional Adaptation Process. Field Test Version.

    ERIC Educational Resources Information Center

    Changar, Jerilynn; And Others

    The manual describes the results of a 36 month project to determine ways to modify existing curricula to meet the needs of special needs students in the mainstream. The handbook is designed in the main for administrators and facilitators as well as for teacher-adaptors. Each of eight steps in the adaptation process is broken down according to…

  8. Adaptive Technology that Provides Access to Computers. DO-IT Program.

    ERIC Educational Resources Information Center

    Washington Univ., Seattle.

    This brochure describes the different types of barriers individuals with mobility impairments, blindness, low vision, hearing impairments, and specific learning disabilities face in providing computer input, interpreting output, and reading documentation. The adaptive hardware and software that has been developed to provide functional alternatives…

  9. Performance analysis of an adaptive multiple access scheme for the message service of a land mobile satellite experiment (MSAT-X)

    NASA Technical Reports Server (NTRS)

    Yan, T.-Y.; Li, V. O. K.

    1984-01-01

    This paper describes an Adaptive Mobile Access Protocol (AMAP) for the message service of MSAT-X., a proposed experimental mobile satellite communication network. Message lengths generated by the mobiles are assumed to be uniformly distributed. The mobiles are dispersed over a wide geographical area and the channel data rate is limited. AMAP is a reservation based multiple access scheme. The available bandwidth is divided into subchannels, which are divided into reservation and message channels. The ALOHA multiple access scheme is employed in the reservation channels, while the message channels are demand assigned. AMAP adaptively reallocates the reservation and message channels to optimize the total average message delay.

  10. Accessing the fertilizing potential of cryopreserved sperm by its ability to maintain quality in a glycerol-free medium.

    PubMed

    Kolb, B A; Acosta, V C; Jeyendran, R S

    1999-01-01

    Cryopreserved sperm is less fertile than fresh sperm; probably due to dependence of sperm to glycerol, a common cryoprotective agent. Few data suggest any correlations between standard semen analysis and fertility. To develop a reliable assay, the authors hypothesized that sperm that withstand the physiochemical stress induced by glycerol during cryopreservation may have higher fertility potential. They analyzed 55 cryopreserved semen samples for sperm concentration, percent motility and progressive motility after allowing thawed sperm to migrate into medium containing either 0 or 12% glycerol for 3 h. The smaller the difference in sperm quality between the two media, the higher the fertility potential of the spermatozoa. There was significant negative correlation between the difference in both percent sperm motility and percent progressive sperm motility in the two media and in vitro fertilization outcome. There was a significantly higher number of ejaculates fertilized oocytes at a rate of > or = 80% when the difference was 20% or less. This easy to use, inexpensive test may be an effective means to evaluate the potential performance of cryopreserved sperm to be utilized in assisted reproductive technologies.

  11. SEEK-TIME IMPROVEMENT IN A RANDOM-ACCESS FILE BY APPLICATION OF AN ADAPTIVE ELEMENT

    DTIC Science & Technology

    An Adaline (adaptive linear neuron) can be trained to distinguish between sets of inputs. In general, the quantized output is used. This report...investigates the usefulness of the analog output of Adaline for measuring the frequency of occurrence of a number of different events. Each event is more...or less arbitrarily associated with a pattern and it is shown that the degree to which Adaline has been trained to recognize any one of these patterns

  12. Comparative assessment of the access of albendazole, fenbendazole and triclabendazole to Fasciola hepatica: effect of bile in the incubation medium.

    PubMed

    Alvarez, L I; Mottier, M L; Lanusse, C E

    2004-01-01

    The work reported here describes the comparative ability of albendazole (ABZ), fenbendazole (FBZ) and triclabendazole (TCBZ) to penetrate through the tegument of mature Fasciola hepatica, and the influence of the physicochemical composition of the incubation medium on the drug diffusion process. The data obtained from the trans-tegumental diffusion kinetic studies were complemented with the determination of lipid-to-water partition coefficients (octanol-water) for the benzimidazole (BZD) anthelmintic drugs assayed. Sixteen-week-old F. hepatica were obtained from untreated artificially infected sheep. The flukes were incubated (37 degrees C) over 60 and 90 min in incubation media (pH 7.4) prepared with different proportions of ovine bile and Krebs' Ringer Tris (KRT) buffer (100, 75, 50, 25 and 0% of bile) containing either ABZ, FBZ or TCBZ at a final concentration of 5 nmol/ml. After the incubation time expired, the liver fluke material was chemically processed and analysed by high performance liquid chromatography (HPLC) to measure drug concentrations within the parasite. Additionally, the octanol-water partition coefficients (PC) for each molecule were calculated (as an indicator of drug lipophilicity) using reversed phase HPLC. The 3 BZD molecules were recovered from F. hepatica at both incubation times in all incubation media assayed. The trans-tegumental diffusion of the most lipophilic molecules ABZ and FBZ (higher PC values) tended to be greater than that observed for TCBZ. Interestingly, the uptake of ABZ by the liver flukes was significantly greater than that measured for TCBZ, the most widely used flukicidal BZD compound. This differential uptake pattern may be a relevant issue to be considered to deal with TCBZ-resistant flukes. Drug concentrations measured within the parasite were lower in the incubations containing the highest bile proportions. The highest total availabilities of the 3 compounds were obtained in liver flukes incubated in the absence of

  13. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  14. Outline of a multiple-access communication network based on adaptive arrays

    NASA Technical Reports Server (NTRS)

    Zohar, S.

    1982-01-01

    Attention is given to a narrow-band communication system consisting of a central station trying to receive signals simultaneously from K spatially distinct mobile users sharing the same frequencies. One example of such a system is a group of aircraft and ships transmitting messages to a communication satellite. A reasonable approach to such a multiple access system may be based on equipping the central station with an n-element antenna array where n is equal to or greater than K. The array employs K sets of n weights to segregate the signals received from the K users. The weights are determined by direct computation based on position information transmitted by the users. A description is presented of an improved technique which makes it possible to reduce significantly the number of required computer operations in comparison to currently known techniques.

  15. Niche expansion leads to small-scale adaptive divergence along an elevation gradient in a medium-sized passerine bird

    PubMed Central

    McCormack, John E; Smith, Thomas B

    2008-01-01

    Niche expansion can lead to adaptive differentiation and speciation, but there are few examples from contemporary niche expansions about how this process is initiated. We assess the consequences of a niche expansion by Mexican jays (Aphelocoma ultramarina) along an elevation gradient. We predicted that jays at high elevation would have straighter bills adapted to feeding on pine cones, whereas jays at low elevation would have hooked bills adapted to feeding on acorns. We measured morphological and genetic variation of 95 adult jays and found significant differences in hook length between elevations in accordance with predictions, a pattern corroborated by analysis at the regional scale. Genetic results from microsatellite and mtDNA variation support phenotypic differentiation in the presence of gene flow coupled with weak, but detectable genetic differentiation between high- and low-elevation populations. These results demonstrate that niche expansion can lead to adaptive divergence despite gene flow between parapatric populations along an elevation gradient, providing information on a key precursor to ecological speciation. PMID:18544512

  16. An Energy-efficient Rate Adaptive Media Access Protocol (RA-MAC) for Long-lived Sensor Networks

    PubMed Central

    Hu, Wen; Chen, Quanjun; Corke, Peter; O’Rourke, Damien

    2010-01-01

    We introduce an energy-efficient Rate Adaptive Media Access Control (RA-MAC) algorithm for long-lived Wireless Sensor Networks (WSNs). Previous research shows that the dynamic and lossy nature of wireless communications is one of the major challenges to reliable data delivery in WSNs. RA-MAC achieves high link reliability in such situations by dynamically trading off data rate for channel gain. The extra gain that can be achieved reduces the packet loss rate which contributes to reduced energy expenditure through a reduced numbers of retransmissions. We achieve this at the expense of raw bit rate which generally far exceeds the application’s link requirement. To minimize communication energy consumption, RA-MAC selects the optimal data rate based on the estimated link quality at each data rate and an analytical model of the energy consumption. Our model shows how the selected data rate depends on different channel conditions in order to minimize energy consumption. We have implemented RA-MAC in TinyOS for an off-the-shelf sensor platform (the TinyNode) on top of a state-of-the-art WSN Media Access Control Protocol, SCP-MAC, and evaluated its performance by comparing our implementation with the original SCP-MAC using both simulation and experiment. PMID:22219675

  17. An energy-efficient rate adaptive media access protocol (RA-MAC) for long-lived sensor networks.

    PubMed

    Hu, Wen; Chen, Quanjun; Corke, Peter; O'Rourke, Damien

    2010-01-01

    We introduce an energy-efficient Rate Adaptive Media Access Control (RA-MAC) algorithm for long-lived Wireless Sensor Networks (WSNs). Previous research shows that the dynamic and lossy nature of wireless communications is one of the major challenges to reliable data delivery in WSNs. RA-MAC achieves high link reliability in such situations by dynamically trading off data rate for channel gain. The extra gain that can be achieved reduces the packet loss rate which contributes to reduced energy expenditure through a reduced numbers of retransmissions. We achieve this at the expense of raw bit rate which generally far exceeds the application's link requirement. To minimize communication energy consumption, RA-MAC selects the optimal data rate based on the estimated link quality at each data rate and an analytical model of the energy consumption. Our model shows how the selected data rate depends on different channel conditions in order to minimize energy consumption. We have implemented RA-MAC in TinyOS for an off-the-shelf sensor platform (the TinyNode) on top of a state-of-the-art WSN Media Access Control Protocol, SCP-MAC, and evaluated its performance by comparing our implementation with the original SCP-MAC using both simulation and experiment.

  18. Modifications to Langley 0.3-m TCT adaptive wall software for heavy gas test medium, phase 1 studies

    NASA Technical Reports Server (NTRS)

    Murthy, A. V.

    1992-01-01

    The scheme for two-dimensional wall adaptation with sulfur hexafluoride (SF6) as test gas in the NASA Langley Research Center 0.3-m Transonic Cryogenic Tunnel (0.3-m TCT) is presented. A unified version of the wall adaptation software has been developed to function in a dual gas operation mode (nitrogen or SF6). The feature of ideal gas calculations for nitrogen operation is retained. For SF6 operation, real gas properties have been computed using the departure function technique. Installation of the software on the 0.3-m TCT ModComp-A computer and preliminary validation with nitrogen operation were found to be satisfactory. Further validation and improvements to the software will be undertaken when the 0.3-m TCT is ready for operation with SF6 gas.

  19. Enhanced chlorine resistance of tap water-adapted Legionella pneumophila as compared with agar medium-passaged strains.

    PubMed

    Kuchta, J M; States, S J; McGlaughlin, J E; Overmeyer, J H; Wadowsky, R M; McNamara, A M; Wolford, R S; Yee, R B

    1985-07-01

    Previous studies have shown that bacteria maintained in a low-nutrient "natural" environment such as swimming pool water are much more resistant to disinfection by various chemical agents than strains maintained on rich media. In the present study a comparison was made of the chlorine (Cl2) susceptibility of hot-water tank isolates of Legionella pneumophila maintained in tap water and strains passaged on either nonselective buffered charcoal-yeast extract or selective differential glycine-vancomycin-polymyxin agar medium. Our earlier work has shown that environmental and clinical isolates of L. pneumophila maintained on agar medium are much more resistant to Cl2 than coliforms are. Under the present experimental conditions (21 degrees C, pH 7.6 to 8.0, and 0.25 mg of free residual Cl2 per liter, we found the tap water-maintained L. pneumophila strains to be even more resistant than the agar-passaged isolates. Under these conditions, 99% kill of tap water-maintained strains of L. pneumophila was usually achieved within 60 to 90 min compared with 10 min for agar-passaged strains. Samples from plumbing fixtures in a hospital yielded legionellae which were "super"-chlorine resistant when assayed under natural conditions. After one agar passage their resistance dropped to levels of comparable strains which had not been previously exposed to additional chlorination. These studies more closely approximate natural conditions than our previous work and show that tap water-maintained L. pneumophila is even more resistant to Cl2 than its already resistant agar medium-passaged counterpart.

  20. Behaviour of Saccharomyces cerevisiae wine strains during adaptation to unfavourable conditions of fermentation on synthetic medium: cell lipid composition, membrane integrity, viability and fermentative activity.

    PubMed

    Mannazzu, Ilaria; Angelozzi, Daniele; Belviso, Simona; Budroni, Marilena; Farris, Giovanni Antonio; Goffrini, Paola; Lodi, Tiziana; Marzona, Mario; Bardi, Laura

    2008-01-15

    During must fermentation wine strains are exposed to a variety of biotic and abiotic stresses which, when prevailing over the cellular defence systems, can affect cell viability with negative consequences on the progression of the fermentative process. To investigate the ability of wine strains to survive and adapt to unfavourable conditions of fermentation, the lipid composition, membrane integrity, cell viability and fermentative activity of three strains of Saccharomyces cerevisiae were analysed during hypoxic growth in a sugar-rich medium lacking lipid nutrients. These are stressful conditions, not unusual during must fermentation, which, by affecting lipid biosynthesis may exert a negative effect on yeast viability. The results obtained showed that the three strains were able to modulate cell lipid composition during fermentation. However, only two of them, which showed highest viability and membrane integrity at the end of the fermentation process, reached a fatty acid composition which seemed to be optimal for a successful adaptation. In particular, C16/TFA and UFA/TFA ratios, more than total lipid and ergosterol contents, seem to be involved in yeast adaptation.

  1. Computer Access in Higher Education for Students with Disabilities: A Practical Guide to the Selection and Use of Adapted Computer Technology. Second Edition.

    ERIC Educational Resources Information Center

    Brown, Carl; And Others

    The manual provides a review of trends in adapted computer technology as well as guidelines to the selection and use of computer technology in college programs serving disabled students. Changes in the second edition include a new section dealing with the computer access needs of the severely disabled, an enlarged product guide, a curriculum guide…

  2. Optimal Policy of Cross-Layer Design for Channel Access and Transmission Rate Adaptation in Cognitive Radio Networks

    NASA Astrophysics Data System (ADS)

    He, Hao; Wang, Jun; Zhu, Jiang; Li, Shaoqian

    2010-12-01

    In this paper, we investigate the cross-layer design of joint channel access and transmission rate adaptation in CR networks with multiple channels for both centralized and decentralized cases. Our target is to maximize the throughput of CR network under transmission power constraint by taking spectrum sensing errors into account. In centralized case, this problem is formulated as a special constrained Markov decision process (CMDP), which can be solved by standard linear programming (LP) method. As the complexity of finding the optimal policy by LP increases exponentially with the size of action space and state space, we further apply action set reduction and state aggregation to reduce the complexity without loss of optimality. Meanwhile, for the convenience of implementation, we also consider the pure policy design and analyze the corresponding characteristics. In decentralized case, where only local information is available and there is no coordination among the CR users, we prove the existence of the constrained Nash equilibrium and obtain the optimal decentralized policy. Finally, in the case that the traffic load parameters of the licensed users are unknown for the CR users, we propose two methods to estimate the parameters for two different cases. Numerical results validate the theoretic analysis.

  3. Adaptation of an automated assay for determination of beta-hydroxybutyrate in dogs using a random access analyzer.

    PubMed

    Christopher, Mary M.; Pereira, Jacqueline L.; Brigmon, Robin L.

    1992-01-01

    An automated method for measuring beta-hydroxybutyrate was adapted to the Ciba-Corning 550 Express trade mark random access analyzer. The assay was based on a kinetic reaction utilizing hydroxybutyrate-dehydrogenase. Beta-hydroxybutyrate concentration (mmol/L) was calculated ratiometrically using a 1.0 mmol/l standard. Canine serum, plasma, and urine were used without prior deproteinization and only a 30-microliter sample was required. The method demonstrated good linearity between 0 to 2 mmol/l of beta-hydroxybutyrate. Analytical recovery (accuracy) within these concentrations ranged from 85.8 to 113.3%. Both within-run and day-to-day precision were determined, as was specificity of the assay in the presence of a variety of interfering substances. The automated assay was rapid and economical, with reagent stability maintained for at least 2 weeks at 4 degrees C. This assay can readily be applied toward the assessment of ketoacidosis in dogs, and with further validation, other species.

  4. A methodology for the valuation and selection of adaptable technology portfolios and its application to small and medium airports

    NASA Astrophysics Data System (ADS)

    Pinon, Olivia J.

    The increase in the types of airspace users (large aircraft, small and regional jets, very light jets, unmanned aerial vehicles, etc.), as well as the very limited number of future new airport development projects are some of the factors that will characterize the next decades in air transportation. These factors, associated with a persistent growth in air traffic will worsen the current gridlock situation experienced at some major airports. As airports are becoming the major capacity bottleneck to continued growth in air traffic, it is therefore primordial to make the most efficient use of the current, and very often, underutilized airport infrastructure. This research thus proposes to address the increase in air traffic demand and resulting capacity issues by considering the implementation of operational concepts and technologies at underutilized airports. However, there are many challenges associated with sustaining the development of this type of airports. First, the need to synchronize evolving technologies with airports’ needs and investment capabilities is paramount. Additionally, it was observed that the evolution of secondary airports, and their needs, is tightly linked to the environment in which they operate. In particular, sensitivity of airports to changes in the dynamics of their environment is important, therefore requiring that the factors that drive the need for technology acquisition be identified and characterized. Finally, the difficulty to evaluate risk and make financially viable decisions, particularly when investing in new technologies, cannot be ignored. This research provides a methodology that addresses these challenges and ensures the sustainability of airport capacity-enhancement investments in a continuously changing environment. In particular, it is articulated around the need to provide decision makers with the capability to valuate and select adaptable technology portfolios to ensure airport financial viability. Hence, the four

  5. Physiological and morphological adaptations of herbaceous perennial legumes allow differential access to sources of varyingly soluble phosphate.

    PubMed

    Pang, Jiayin; Yang, Jiyun; Lambers, Hans; Tibbett, Mark; Siddique, Kadambot H M; Ryan, Megan H

    2015-08-01

    The aim of this study was to investigate the capacity of three perennial legume species to access sources of varyingly soluble phosphorus (P) and their associated morphological and physiological adaptations. Two Australian native legumes with pasture potential (Cullen australasicum and Kennedia prostrata) and Medicago sativa cv. SARDI 10 were grown in sand under two P levels (6 and 40 µg P g(-1) ) supplied as Ca(H2 PO4 )2 ·H2 O (Ca-P, highly soluble, used in many fertilizers) or as one of three sparingly soluble forms: Ca10 (OH)2 (PO4 )6 (apatite-P, found in relatively young soils; major constituent of rock phosphate), C6 H6 O24 P6 Na12 (inositol-P, the most common form of organic P in soil) and FePO4 (Fe-P, a poorly-available inorganic source of P). All species grew well with soluble P. When 6 µg P g(-1) was supplied as sparingly soluble P, plant dry weight (DW) and P uptake were very low for C. australasicum and M. sativa (0.1-0.4 g DW) with the exception of M. sativa supplied with apatite-P (1.5 g). In contrast, K. prostrata grew well with inositol-P (1.0 g) and Fe-P (0.7 g), and even better with apatite-P (1.7 g), similar to that with Ca-P (1.9 g). Phosphorus uptake at 6 µg P g(-1) was highly correlated with total root length, total rhizosphere carboxylate content and total rhizosphere acid phosphatase (EC 3.1.3.2) activity. These findings provide strong indications that there are opportunities to utilize local Australian legumes in low P pasture systems to access sparingly soluble soil P and increase perennial legume productivity, diversity and sustainability.

  6. Accessible bioprinting: adaptation of a low-cost 3D-printer for precise cell placement and stem cell differentiation.

    PubMed

    Reid, John A; Mollica, Peter A; Johnson, Garett D; Ogle, Roy C; Bruno, Robert D; Sachs, Patrick C

    2016-06-07

    The precision and repeatability offered by computer-aided design and computer-numerically controlled techniques in biofabrication processes is quickly becoming an industry standard. However, many hurdles still exist before these techniques can be used in research laboratories for cellular and molecular biology applications. Extrusion-based bioprinting systems have been characterized by high development costs, injector clogging, difficulty achieving small cell number deposits, decreased cell viability, and altered cell function post-printing. To circumvent the high-price barrier to entry of conventional bioprinters, we designed and 3D printed components for the adaptation of an inexpensive 'off-the-shelf' commercially available 3D printer. We also demonstrate via goal based computer simulations that the needle geometries of conventional commercially standardized, 'luer-lock' syringe-needle systems cause many of the issues plaguing conventional bioprinters. To address these performance limitations we optimized flow within several microneedle geometries, which revealed a short tapered injector design with minimal cylindrical needle length was ideal to minimize cell strain and accretion. We then experimentally quantified these geometries using pulled glass microcapillary pipettes and our modified, low-cost 3D printer. This systems performance validated our models exhibiting: reduced clogging, single cell print resolution, and maintenance of cell viability without the use of a sacrificial vehicle. Using this system we show the successful printing of human induced pluripotent stem cells (hiPSCs) into Geltrex and note their retention of a pluripotent state 7 d post printing. We also show embryoid body differentiation of hiPSC by injection into differentiation conducive environments, wherein we observed continuous growth, emergence of various evaginations, and post-printing gene expression indicative of the presence of all three germ layers. These data demonstrate an

  7. Study on a compact and adaptable Thomson Spectrometer for laser-initiated 11B(p,α)8Be reactions and low-medium energy particle detection

    NASA Astrophysics Data System (ADS)

    Consoli, F.; De Angelis, R.; Bonasera, A.; Sura, J.; Andreoli, P.; Cristofari, G.; Cipriani, M.; Di Giorgio, G.; Ingenito, F.; Barbarino, M.; Labaune, C.; Baccou, C.; Depierreux, S.; Goyon, C.; Yahia, V.

    2016-05-01

    Thomson Spectrometers are of primary importance in the discrimination of particles produced by laser-plasma interaction, according to their energy and charge-mass ratio. We describe here a detailed study on a set of Thomson Spectrometers, adaptable to different experimental situations, with the aim of being placed directly within the experimental chamber, rather than in additional extensions, in order to increase the solid angle of observation. These instruments are suitable for detection of low-medium energy particles and can be effectively employed in laser-plasma experiments of 11B(p,α)8Be fusion. They are provided with permanent magnets, have small dimensions and compact design. In these small configurations electric and magnetic fringing fields play a primary role for particle deflection, and their accurate characterization is required. It was accomplished by means of COMSOL electromagnetic solver coupled to an effective analytical model, very suitable for practical use of the spectrometers. Data from experimental measurements of the magnetic fields have been also used. We describe the application of the spectrometers to an experiment of laser-plasma interaction, coupled to Imaging Plate detectors. Data analysis for spectrum and yield of the detected radiation is discussed in detail.

  8. Catalase activity is stimulated by H(2)O(2) in rich culture medium and is required for H(2)O(2) resistance and adaptation in yeast.

    PubMed

    Martins, Dorival; English, Ann M

    2014-01-01

    Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1) protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A) does not increase the H2O2 sensitivity of yeast challenged in phosphate buffer (pH 7.4). This we attributed to our observation that catalase activity is depressed when yeast are challenged with H2O2 in nutrient-poor media. Hence, we performed a systematic comparison of catalase activity and cell viability of wild-type yeast and of the single catalase knockouts, ctt1∆ and cta1∆, following H2O2 challenge in nutrient-rich medium (YPD) and in phosphate buffer (pH 7.4). Ctt1 but not Cta1 activity is strongly induced by H2O2 when cells are challenged in YPD but suppressed when cells are challenged in buffer. Consistent with the activity results, exponentially growing ctt1∆ cells in YPD are more sensitive to H2O2 than wild-type or cta1∆ cells, whereas in buffer all three strains exhibit comparable H2O2 hypersensitivity. Furthermore, catalase activity is increased during adaptation to sublethal H2O2 concentrations in YPD but not in buffer. We conclude that induction of cytosolic Ctt1 activity is vital in protecting yeast against exogenous H2O2 but this activity is inhibited by H2O2 when cells are challenged in nutrient-free media.

  9. The Resilience Activation Framework: A conceptual model of how access to social resources promotes adaptation and rapid recovery in post-disaster settings

    PubMed Central

    Abramson, David M.; Grattan, Lynn M.; Mayer, Brian; Colten, Craig E.; Arosemena, Farah A.; Rung, Ariane; Lichtveld, Maureen

    2014-01-01

    A number of governmental agencies have called for enhancing citizen’s resilience as a means of preparing populations in advance of disasters, and as a counter-balance to social and individual vulnerabilities. This increasing scholarly, policy and programmatic interest in promoting individual and communal resilience presents a challenge to the research and practice communities: to develop a translational framework that can accommodate multi-disciplinary scientific perspectives into a single, applied model. The Resilience Activation Framework provides a basis for testing how access to social resources, such as formal and informal social support and help, promotes positive adaptation or reduced psychopathology among individuals and communities exposed to the acute collective stressors associated with disasters, whether manmade, natural, or technological in origin. Articulating the mechanisms by which access to social resources activate and sustain resilience capacities for optimal mental health outcomes post-disaster can lead to the development of effective preventive and early intervention programs. PMID:24870399

  10. The resilience activation framework: a conceptual model of how access to social resources promotes adaptation and rapid recovery in post-disaster settings.

    PubMed

    Abramson, David M; Grattan, Lynn M; Mayer, Brian; Colten, Craig E; Arosemena, Farah A; Bedimo-Rung, Ariane; Lichtveld, Maureen

    2015-01-01

    A number of governmental agencies have called for enhancing citizens' resilience as a means of preparing populations in advance of disasters, and as a counterbalance to social and individual vulnerabilities. This increasing scholarly, policy, and programmatic interest in promoting individual and communal resilience presents a challenge to the research and practice communities: to develop a translational framework that can accommodate multidisciplinary scientific perspectives into a single, applied model. The Resilience Activation Framework provides a basis for testing how access to social resources, such as formal and informal social support and help, promotes positive adaptation or reduced psychopathology among individuals and communities exposed to the acute collective stressors associated with disasters, whether human-made, natural, or technological in origin. Articulating the mechanisms by which access to social resources activate and sustain resilience capacities for optimal mental health outcomes post-disaster can lead to the development of effective preventive and early intervention programs.

  11. Adaption of an in vitro digestion method to screen carotenoid liberation and in vitro accessibility from differently processed spinach preparations.

    PubMed

    Eriksen, Jane N; Luu, Amy Y; Dragsted, Lars O; Arrigoni, Eva

    2017-06-01

    Dark green leafy vegetables are primary food sources for lutein and β-carotene, however these bioactives have low bioavailability. The effects of mechanical and thermal processing as well as fat addition and fat type on lutein and β-carotene liberation and in vitro accessibility from spinach were investigated. Lutein liberation and in vitro accessibility were three-fold higher from spinach puree compared to whole leaves. Results for β-carotene liberation were similar, whereas that of β-carotene accessibility was only about two-fold. Steaming had no or a negative effect on carotenoid liberation. Fat addition increased β-carotene liberation from raw and steamed puree, but reduced lutein liberation from steamed leaves and raw puree. Fat types affected β-carotene differently. Butter addition led to a 2.5 fold increased liberation from raw spinach puree, while the effect of olive and peanut oil was significantly lower, but only minor effects were observed for lutein.

  12. Decision Making Regarding Access to Training and Development in Medium-Sized Enterprises: An Exploratory Study Using the Critical Incident Technique

    ERIC Educational Resources Information Center

    Coetzer, Alan; Redmond, Janice; Sharafizad, Jalleh

    2012-01-01

    Purpose: The purpose of this paper is to develop an understanding of factors that impinge on managerial decision-making processes regarding employee access to structured training and development (T&D) opportunities that are at least partially funded by the firm. Design/methodology/approach: Semi-structured interviews incorporating the Critical…

  13. Effects of an Adaptive Game Intervention on Accessing Number Sense in Low-Socioeconomic-Status Kindergarten Children

    ERIC Educational Resources Information Center

    Wilson, Anna J.; Dehaene, Stanislas; Dubois, Ophelie; Fayol, Michel

    2009-01-01

    "The Number Race" is an adaptive game designed to improve number sense. We tested its effectiveness using a cross-over design in 53 low socioeconomic status kindergarteners in France. Children showed improvements in tasks traditionally used to assess number sense (numerical comparison of digits and words). However, there was no…

  14. Community Adaptation of Youth Accessing Residential Programs or a Home-Based Alternative: Contact with the Law and Delinquent Activities

    ERIC Educational Resources Information Center

    Cameron, Gary; Frensch, Karen; Preyde, Michele; Quosai, Trudy Smit

    2011-01-01

    This article presents the findings from a longitudinal investigation of the prevalence of negative contact with the law for a sample of youth 12-18 months after graduating from residential and intensive children's mental health programming. Results of this study suggest serious community adaptation difficulties face many youth graduating from…

  15. Effects of feed access after hatch and inclusion of fish oil and medium chain fatty acids in a pre-starter diet on broiler chicken growth performance and humoral immunity.

    PubMed

    Lamot, D M; van der Klein, S A S; van de Linde, I B; Wijtten, P J A; Kemp, B; van den Brand, H; Lammers, A

    2016-09-01

    Delayed feed and water access is known to impair growth performance of day old broiler chickens. Although effects of feed access on growth performance and immune function of broilers have been examined before, effects of dietary composition and its potential interaction with feed access are hardly investigated. This experiment aimed to determine whether moment of first feed and water access after hatch and pre-starter composition (0 to 7 days) affect growth rate and humoral immune function in broiler chickens. Direct fed chickens received feed and water directly after placement in the grow-out facility, whilst delayed fed chickens only after 48 h. Direct and delayed fed chickens received a control pre-starter diet, or a diet containing medium chain fatty acids (MCFA) or fish oil. At 21 days, chickens were immunized by injection of sheep red blood cells. The mortality rate depended on an interaction between feed access and pre-starter composition (P=0.014). Chickens with direct feed access fed the control pre-starter diet had a higher risk for mortality than chickens with delayed feed access fed the control pre-starter diet (16.4% v. 4.2%) whereas the other treatment groups were in-between. BW gain and feed intake till 25 days in direct fed chickens were higher compared with delayed fed chickens, whilst gain to feed ratio was lower. Within the direct fed chickens, the control pre-starter diet resulted in the highest BW at 28 days and the MCFA pre-starter diet the lowest (Δ=2.4%), whereas this was opposite for delayed fed chickens (Δ=3.0%; P=0.033). Provision of MCFA resulted in a 4.6% higher BW gain and a higher gain to feed ratio compared with other pre-starter diets, but only during the period it was provided (2 to 7 days). Minor treatment effects were found for humoral immune response by measuring immunoglobulins, agglutination titers, interferon gamma (IFN- γ ), and complement activity. Concluding, current inclusion levels of fish oil (5 g/kg) and MCFA (30 g

  16. Medium-range objective predictions of thunderstorms on the McIDAS/CSIS interactive computer system. [Computer Interactive Data Access System/Centralized Storm Information System

    NASA Technical Reports Server (NTRS)

    Wilson, G. S.

    1982-01-01

    Until recently, all operational meteorological data has been made available to forecasters in a variety of different forms. Predictions based upon these different data formats have been complicated by the inability of forecasters to easily assimilate, in real-time, all data to provide an optimum decision regarding future weather occurrences. By March 1980, a joint NASA/NOAA effort had been initiated to develop the Centralized Storm Information System (CSIS). The primary objectives of this joint project are related to an improvement of the overall severe storm forecast and warning procedure and to a demonstration of the operational utility of techniques developed within the applied research community. CSIS is to utilize the Man Computer Interactive Data Access System (McIDAS). The present investigation is concerned with one of the first attempts to employ the CSIS system for the evaluation of a new research technique involving the prediction of thunderstorms over a forecast period of 12-48 hours.

  17. Peak-to-average power ratio mitigation and adaptive bit assignment in single-carrier frequency division multiplexing access via hierarchical modulation

    NASA Astrophysics Data System (ADS)

    Zhang, Lijia; Liu, Bo; Xin, Xiangjun; Wang, Yongjun

    2014-11-01

    A hierarchical modulation with multilevels is proposed for an optical single-carrier frequency division multiplexing access (SC-FDMA) system. It can mitigate the nonlinearity by reducing the peak-to-average power ratio (PAPR) of the SC-FDM signal. According to different optical signal-to-noise ratio requirements, the adaptive bit allocation can be implemented on different levels during hierarchical modulation. In the experiment, the PAPR of the hierarchical-modulated SC-FDM signal outperforms the conventional SC-FDM signal by 0.7 dB. Signals with 4- and 6-bit hierarchical modulation are successfully demodulated by the optical network unit with power penalties less than 0.2 and 0.45 dB, respectively.

  18. High Speed, Low Cost Telemetry Access from Space Development Update on Programmable Ultra Lightweight System Adaptable Radio (PULSAR)

    NASA Technical Reports Server (NTRS)

    Simms, William Herbert, III; Varnavas, Kosta; Eberly, Eric

    2014-01-01

    Software Defined Radio (SDR) technology has been proven in the commercial sector since the early 1990's. Today's rapid advancement in mobile telephone reliability and power management capabilities exemplifies the effectiveness of the SDR technology for the modern communications market. In contrast, the foundations of transponder technology presently qualified for satellite applications were developed during the early space program of the 1960's. Conventional transponders are built to a specific platform and must be redesigned for every new bus while the SDR is adaptive in nature and can fit numerous applications with no hardware modifications. A SDR uses a minimum amount of analog / Radio Frequency (RF) components to up/down-convert the RF signal to/from a digital format. Once the signal is digitized, all processing is performed using hardware or software logic. Typical SDR digital processes include; filtering, modulation, up/down converting and demodulation. NASA Marshall Space Flight Center (MSFC) Programmable Ultra Lightweight System Adaptable Radio (PULSAR) leverages existing MSFC SDR designs and commercial sector enhanced capabilities to provide a path to a radiation tolerant SDR transponder. These innovations (1) reduce the cost of NASA Low Earth Orbit (LEO) and Deep Space standard transponders, (2) decrease power requirements, and (3) commensurately reduce volume. A second pay-off is the increased SDR flexibility by allowing the same hardware to implement multiple transponder types simply by altering hardware logic - no change of hardware is required - all of which will ultimately be accomplished in orbit. Development of SDR technology for space applications will provide a highly capable, low cost transponder to programs of all sizes. The MSFC PULSAR Project results in a Technology Readiness Level (TRL) 7 low-cost telemetry system available to Smallsat and CubeSat missions, as well as other platforms. This paper documents the continued development and

  19. Programmable Ultra Lightweight System Adaptable Radio (PULSAR) Low Cost Telemetry - Access from Space Advanced Technologies or Down the Middle

    NASA Technical Reports Server (NTRS)

    Sims. Herb; Varnavas, Kosta; Eberly, Eric

    2013-01-01

    Software Defined Radio (SDR) technology has been proven in the commercial sector since the early 1990's. Today's rapid advancement in mobile telephone reliability and power management capabilities exemplifies the effectiveness of the SDR technology for the modern communications market. In contrast, presently qualified satellite transponder applications were developed during the early 1960's space program. Programmable Ultra Lightweight System Adaptable Radio (PULSAR, NASA-MSFC SDR) technology revolutionizes satellite transponder technology by increasing data through-put capability by, at least, an order of magnitude. PULSAR leverages existing Marshall Space Flight Center SDR designs and commercially enhanced capabilities to provide a path to a radiation tolerant SDR transponder. These innovations will (1) reduce the cost of NASA Low Earth Orbit (LEO) and Deep Space transponders, (2) decrease power requirements, and (3) a commensurate volume reduction. Also, PULSAR increases flexibility to implement multiple transponder types by utilizing the same hardware with altered logic - no analog hardware change is required - all of which can be accomplished in orbit. This provides high capability, low cost, transponders to programs of all sizes. The final project outcome would be the introduction of a Technology Readiness Level (TRL) 7 low-cost CubeSat to SmallSat telemetry system into the NASA Portfolio.

  20. ACCESS Pointing Control System

    NASA Technical Reports Server (NTRS)

    Brugarolas, Paul; Alexander, James; Trauger, John; Moody, Dwight; Egerman, Robert; Vallone, Phillip; Elias, Jason; Hejal, Reem; Camelo, Vanessa; Bronowicki, Allen; O'Connor, David; Partrick, Richard; Orzechowski, Pawel; Spitter, Connie; Lillie, Chuck

    2010-01-01

    ACCESS (Actively-Corrected Coronograph for Exoplanet System Studies) was one of four medium-class exoplanet concepts selected for the NASA Astrophysics Strategic Mission Concept Study (ASMCS) program in 2008/2009. The ACCESS study evaluated four major coronograph concepts under a common space observatory. This paper describes the high precision pointing control system (PCS) baselined for this observatory.

  1. Metabolic and proteomic adaptation of Lactobacillus rhamnosus strains during growth under cheese-like environmental conditions compared to de Man, Rogosa, and Sharpe medium.

    PubMed

    Bove, Claudio Giorgio; De Angelis, Maria; Gatti, Monica; Calasso, Maria; Neviani, Erasmo; Gobbetti, Marco

    2012-11-01

    The aim of this study was to demonstrate the metabolic and proteomic adaptation of Lactobacillus rhamnosus strains, which were isolated at different stages of Parmigiano Reggiano cheese ripening. Compared to de Man, Rogosa, and Sharpe (MRS) broth, cultivation under cheese-like conditions (cheese broth, CB) increased the number of free amino acids used as carbon sources. Compared with growth on MRS or pasteurized and microfiltrated milk, all strains cultivated in CB showed a low synthesis of d,l-lactic acid and elevated levels of acetic acid. The proteomic maps of the five representative strains, showing different metabolic traits, were comparatively determined after growth on MRS and CB media. The amount of intracellular and cell-associated proteins was affected by culture conditions and diversity between strains, depending on their time of isolation. Protein spots showing decreased (62 spots) or increased (59 spot) amounts during growth on CB were identified using MALDI-TOF-MS/MS or LC-nano-ESI-MS/MS. Compared with cultivation on MRS broth, the L. rhamnosus strains cultivated under cheese-like conditions had modified amounts of some proteins responsible for protein biosynthesis, nucleotide, and carbohydrate metabolisms, the glycolysis pathway, proteolytic activity, cell wall, and exopolysaccharide biosynthesis, cell regulation, amino acid, and citrate metabolism, oxidation/reduction processes, and stress responses.

  2. Adapting an evidence-based intervention for HIV to avail access to testing and risk-reduction counseling for female victims of sexual violence in post-earthquake Haiti.

    PubMed

    Rahill, Guitele J; Joshi, Manisha; Hernandez, Anthony

    2016-01-01

    Haiti has the highest prevalence of HIV/AIDS in the Caribbean. Before the 2010 earthquake, Haitian women bore a disproportionate burden of HIV/AIDS, had lower HIV knowledge, less capacity to negotiate for safer sex, and limited access to HIV testing and risk-reduction (RR) counseling. Since 2010, there has been an increase in sexual violence against women, characterized by deliberate vaginal injuries by non-intimate partners, increasing victims' risk of sexually transmitted infections including HIV/AIDS. Needed is an adaptation of evidence-based interventions for HIV that include HIV testing and counseling for this stigmatized population. We reviewed several features of Centers for Disease Control and Prevention's 103 evidence-based interventions for HIV (e.g., measures used, participant risk characteristics, theoretical framework, outcome variables, and evidence tier) in an attempt to seek a feasibly adaptable evidence-based intervention for HIV that could be used for victims of sexual violence (VOSV). RESPECT, one of the reviewed evidence-based HIV interventions, comprises of one-on-one, client-focused HIV prevention/RR counseling, and RAPID HIV testing. Adapting RESPECT can enhance access to testing for Haitian VOSV and can influence their perceptions of HIV risk, and establishment of RR goals for future consensual intimate relations. Adapting and implementing RESPECT can increase uptake of evidence-based HIV interventions among Haitians and positively affect a region with high HIV prevalence and increased rates of sexual violence.

  3. Expressing Adaptation Strategies Using Adaptation Patterns

    ERIC Educational Resources Information Center

    Zemirline, N.; Bourda, Y.; Reynaud, C.

    2012-01-01

    Today, there is a real challenge to enable personalized access to information. Several systems have been proposed to address this challenge including Adaptive Hypermedia Systems (AHSs). However, the specification of adaptation strategies remains a difficult task for creators of such systems. In this paper, we consider the problem of the definition…

  4. Throughput and packet delay analysis for the H-network - CSMA/CD with adaptive and nonadaptive backoff protocols. [Carrier Sense Multiple-Access

    NASA Technical Reports Server (NTRS)

    Dimopoulos, Nikitas J.

    1987-01-01

    The structure of a high-data-rate (about 7 Mbytes/sec) local area network named the H-Network is described which is used to provide point to point analysis and broadcast communication in a multiprocessor environment, the Homogeneous Multiprocessor (Dimopoulos, 1983). The throughput and packet delay characteristics for the H-Network operating under CSMA/CD are presented, using adaptive and nonadaptive backoff protocols. The network is found to perform quite well, with an average utilization factor of over 60 percent and a maximum packet delay of less than 500 microsec for the case of 10 competing stations.

  5. Arteriovenous Access

    PubMed Central

    MacRae, Jennifer M.; Dipchand, Christine; Oliver, Matthew; Moist, Louise; Yilmaz, Serdar; Lok, Charmaine; Leung, Kelvin; Clark, Edward; Hiremath, Swapnil; Kappel, Joanne; Kiaii, Mercedeh; Luscombe, Rick; Miller, Lisa M.

    2016-01-01

    Complications of vascular access lead to morbidity and may reduce quality of life. In this module, we review both infectious and noninfectious arteriovenous access complications including neuropathy, aneurysm, and high-output access. For the challenging patients who have developed many complications and are now nearing their last vascular access, we highlight some potentially novel approaches. PMID:28270919

  6. Adaptive equalization

    NASA Astrophysics Data System (ADS)

    Qureshi, S. U. H.

    1985-09-01

    Theoretical work which has been effective in improving data transmission by telephone and radio links using adaptive equalization (AE) techniques is reviewed. AE has been applied to reducing the temporal dispersion effects, such as intersymbol interference, caused by the channel accessed. Attention is given to the Nyquist telegraph transmission theory, least mean square error adaptive filtering and the theory and structure of linear receive and transmit filters for reducing error. Optimum nonlinear receiver structures are discussed in terms of optimality criteria as a function of error probability. A suboptimum receiver structure is explored in the form of a decision-feedback equalizer. Consideration is also given to quadrature amplitude modulation and transversal equalization for receivers.

  7. A spin transfer torque magnetoresistance random access memory-based high-density and ultralow-power associative memory for fully data-adaptive nearest neighbor search with current-mode similarity evaluation and time-domain minimum searching

    NASA Astrophysics Data System (ADS)

    Ma, Yitao; Miura, Sadahiko; Honjo, Hiroaki; Ikeda, Shoji; Hanyu, Takahiro; Ohno, Hideo; Endoh, Tetsuo

    2017-04-01

    A high-density nonvolatile associative memory (NV-AM) based on spin transfer torque magnetoresistive random access memory (STT-MRAM), which achieves highly concurrent and ultralow-power nearest neighbor search with full adaptivity of the template data format, has been proposed and fabricated using the 90 nm CMOS/70 nm perpendicular-magnetic-tunnel-junction hybrid process. A truly compact current-mode circuitry is developed to realize flexibly controllable and high-parallel similarity evaluation, which makes the NV-AM adaptable to any dimensionality and component-bit of template data. A compact dual-stage time-domain minimum searching circuit is also developed, which can freely extend the system for more template data by connecting multiple NM-AM cores without additional circuits for integrated processing. Both the embedded STT-MRAM module and the computing circuit modules in this NV-AM chip are synchronously power-gated to completely eliminate standby power and maximally reduce operation power by only activating the currently accessed circuit blocks. The operations of a prototype chip at 40 MHz are demonstrated by measurement. The average operation power is only 130 µW, and the circuit density is less than 11 µm2/bit. Compared with the latest conventional works in both volatile and nonvolatile approaches, more than 31.3% circuit area reductions and 99.2% power improvements are achieved, respectively. Further power performance analyses are discussed, which verify the special superiority of the proposed NV-AM in low-power and large-memory-based VLSIs.

  8. Automated Image Intelligence Adaptive Sensor Management System for High Altitude Long Endurance UAVs in a Dynamic and Anti-Access Area Denial Environment

    NASA Astrophysics Data System (ADS)

    Kim, Gi Young

    The problem we investigate deals with an Image Intelligence (IMINT) sensor allocation schedule for High Altitude Long Endurance UAVs in a dynamic and Anti-Access Area Denial (A2AD) environment. The objective is to maximize the Situational Awareness (SA) of decision makers. The value of SA can be improved in two different ways. First, if a sensor allocated to an Areas of Interest (AOI) detects target activity, then the SA value will be increased. Second, the SA value increases if an AOI is monitored for a certain period of time, regardless of target detections. These values are functions of the sensor allocation time, sensor type and mode. Relatively few studies in the archival literature have been devoted to an analytic, detailed explanation of the target detection process, and AOI monitoring value dynamics. These two values are the fundamental criteria used to choose the most judicious sensor allocation schedule. This research presents mathematical expressions for target detection processes, and shows the monitoring value dynamics. Furthermore, the dynamics of target detection is the result of combined processes between belligerent behavior (target activity) and friendly behavior (sensor allocation). We investigate these combined processes and derive mathematical expressions for simplified cases. These closed form mathematical models can be used for Measures of Effectiveness (MOEs), i.e., target activity detection to evaluate sensor allocation schedules. We also verify these models with discrete event simulations which can also be used to describe more complex systems. We introduce several methodologies to achieve a judicious sensor allocation schedule focusing on the AOI monitoring value. The first methodology is a discrete time integer programming model which provides an optimal solution but is impractical for real world scenarios due to its computation time. Thus, it is necessary to trade off the quality of solution with computation time. The Myopic Greedy

  9. Chemically defined medium and Caenorhabditis elegans

    NASA Technical Reports Server (NTRS)

    Szewczyk, Nathaniel J.; Kozak, Elena; Conley, Catharine A.

    2003-01-01

    BACKGROUND: C. elegans has been established as a powerful genetic system. Use of a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of use in large-scale growth and screening of animals. RESULTS: We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats to using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change the composition of the defined medium. CONCLUSIONS: As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  10. Web Accessibility and Accessibility Instruction

    ERIC Educational Resources Information Center

    Green, Ravonne A.; Huprich, Julia

    2009-01-01

    Section 508 of the Americans with Disabilities Act (ADA) mandates that programs and services be accessible to people with disabilities. While schools of library and information science (SLIS*) and university libraries should model accessible Web sites, this may not be the case. This article examines previous studies about the Web accessibility of…

  11. Cooperative Energy Harvesting-Adaptive MAC Protocol for WBANs

    PubMed Central

    Esteves, Volker; Antonopoulos, Angelos; Kartsakli, Elli; Puig-Vidal, Manel; Miribel-Català, Pere; Verikoukis, Christos

    2015-01-01

    In this paper, we introduce a cooperative medium access control (MAC) protocol, named cooperative energy harvesting (CEH)-MAC, that adapts its operation to the energy harvesting (EH) conditions in wireless body area networks (WBANs). In particular, the proposed protocol exploits the EH information in order to set an idle time that allows the relay nodes to charge their batteries and complete the cooperation phase successfully. Extensive simulations have shown that CEH-MAC significantly improves the network performance in terms of throughput, delay and energy efficiency compared to the cooperative operation of the baseline IEEE 802.15.6 standard. PMID:26029950

  12. Cooperative energy harvesting-adaptive MAC protocol for WBANs.

    PubMed

    Esteves, Volker; Antonopoulos, Angelos; Kartsakli, Elli; Puig-Vidal, Manel; Miribel-Català, Pere; Verikoukis, Christos

    2015-05-28

    In this paper, we introduce a cooperative medium access control (MAC) protocol, named cooperative energy harvesting (CEH)-MAC, that adapts its operation to the energy harvesting (EH) conditions in wireless body area networks (WBANs). In particular, the proposed protocol exploits the EH information in order to set an idle time that allows the relay nodes to charge their batteries and complete the cooperation phase successfully. Extensive simulations have shown that CEH-MAC significantly improves the network performance in terms of throughput, delay and energy efficiency compared to the cooperative operation of the baseline IEEE 802.15.6 standard.

  13. Technology transfer for adaptation

    NASA Astrophysics Data System (ADS)

    Biagini, Bonizella; Kuhl, Laura; Gallagher, Kelly Sims; Ortiz, Claudia

    2014-09-01

    Technology alone will not be able to solve adaptation challenges, but it is likely to play an important role. As a result of the role of technology in adaptation and the importance of international collaboration for climate change, technology transfer for adaptation is a critical but understudied issue. Through an analysis of Global Environment Facility-managed adaptation projects, we find there is significantly more technology transfer occurring in adaptation projects than might be expected given the pessimistic rhetoric surrounding technology transfer for adaptation. Most projects focused on demonstration and early deployment/niche formation for existing technologies rather than earlier stages of innovation, which is understandable considering the pilot nature of the projects. Key challenges for the transfer process, including technology selection and appropriateness under climate change, markets and access to technology, and diffusion strategies are discussed in more detail.

  14. Data Bus Adapts to Changing Traffic Level

    NASA Technical Reports Server (NTRS)

    Lew, Eugene; Deruiter, John; Varga, Mike

    1987-01-01

    Access becomes timed when collisions threaten. Two-mode scheme used to grant terminals access to data bus. Causes bus to alternate between random accessibility and controlled accessibility to optimize performance and adapt to changing data-traffic conditions. Bus is part of 100-Mb/s optical-fiber packet data system.

  15. Access Denied

    ERIC Educational Resources Information Center

    Villano, Matt

    2008-01-01

    Building access control (BAC)--a catchall phrase to describe the systems that control access to facilities across campus--has traditionally been handled with remarkably low-tech solutions: (1) manual locks; (2) electronic locks; and (3) ID cards with magnetic strips. Recent improvements have included smart cards and keyless solutions that make use…

  16. Open Access

    ERIC Educational Resources Information Center

    Suber, Peter

    2012-01-01

    The Internet lets us share perfect copies of our work with a worldwide audience at virtually no cost. We take advantage of this revolutionary opportunity when we make our work "open access": digital, online, free of charge, and free of most copyright and licensing restrictions. Open access is made possible by the Internet and copyright-holder…

  17. Synthetic laser medium

    DOEpatents

    Stokowski, S.E.

    1987-10-20

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chromium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  18. Synthetic laser medium

    DOEpatents

    Stokowski, Stanley E.

    1989-01-01

    A laser medium is particularly useful in high average power solid state lasers. The laser medium includes a chormium dopant and preferably neodymium ions as codopant, and is primarily a gadolinium scandium gallium garnet, or an analog thereof. Divalent cations inhibit spiral morphology as large boules from which the laser medium is derived are grown, and a source of ions convertible between a trivalent state and a tetravalent state at a low ionization energy are in the laser medium to reduce an absorption coefficient at about one micron wavelength otherwise caused by the divalent cations. These divalent cations and convertible ions are dispersed in the laser medium. Preferred convertible ions are provided from titanium or cerium sources.

  19. Equal Access.

    ERIC Educational Resources Information Center

    De Patta, Joe

    2003-01-01

    Presents an interview with Stephen McCarthy, co-partner and president of Equal Access ADA Consulting Architects of San Diego, California, about designing schools to naturally integrate compliance with the Americans with Disabilities Act (ADA). (EV)

  20. Using Internet Audio to Enhance Online Accessibility

    ERIC Educational Resources Information Center

    Schwartz, Linda Matula

    2004-01-01

    Accessibility to online education programs is an important factor that requires continued research, improvement, and regulation. Particularly valuable in the enhancement of online accessibility is the Voice-over Internet Protocol (VOIP) medium. VOIP compresses analog voice data and converts it into digital packets for transmission over the…

  1. Subject Access in the Small Library.

    ERIC Educational Resources Information Center

    Turock, Betty J.; Shelton, Hildred C.

    This pilot study on the subject access problems of patrons of small to medium size libraries was designed to measure the extent to which users' vocabularies matched the search vocabulary of bibliographic records in the card catalog, and to enhance subject access by develooping a microcomputer system which integrated Library of Congress Subject…

  2. Consumer access to utility billing envelopes

    SciTech Connect

    Anglin, M.K.

    1984-09-13

    Billing envelope inserts are a medium of advertising used by utilities for a variety of purposes, from encouraging conservation to expressing political opinions. Recently, consumer groups have begun to assert a right of access to the same medium. A constitutional right of reply has been advocated. Commissions have found regulatory authority to direct companies to provide access on the basis of several different theories. At least two states have passed legislation permitting consumer groups to use bill inserts to solicit members and contributions. When examined, these developments reveal a trend of granting organizations access to utility billing envelopes.

  3. Development of comprehensive medium for micropropagation of cultivated Cassava accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cassava is one of the most important foods in the human diet in the tropics, where it ranks fifth as a source of energy, after rice, sugar cane, and maize. Since it is a vegetative propagated crop, the use of in vitro propagation is very important to preserve germplasm free of pest and diseases. M...

  4. Analytical Modeling of Medium Access Control Protocols in Wireless Networks

    DTIC Science & Technology

    2006-03-01

    provide the basic functionalities that are common to any com - puter network. The proposed modeling framework focuses on the interactions between the...colleagues I had the pleasure to meet at the Computer Com - munication Research Group (CCRG). In particular, I would like to thank Marco Spohn, Re- nato...Brazil), the Baskin Chair of Com - puter Engineering at UCSC, the National Science Foundation under Grant CNS-0435522, the UCOP CLC under Grant SC-05

  5. Expanding Access

    ERIC Educational Resources Information Center

    Roach, Ronald

    2007-01-01

    There is no question that the United States lags behind most industrialized nations in consumer access to broadband Internet service. For many policy makers and activists, this shortfall marks the latest phase in the struggle to overcome the digital divide. To remedy this lack of broadband affordability and availability, one start-up firm--with…

  6. Easy Access

    ERIC Educational Resources Information Center

    Gettelman, Alan

    2009-01-01

    School and university restrooms, locker and shower rooms have specific ADA accessibility requirements that serve the needs of staff, students and campus visitors who are disabled as a result of injury, illness or age. Taking good care of them is good for the reputation of a sensitive community institution, and fosters positive public relations.…

  7. Access Denied

    ERIC Educational Resources Information Center

    Raths, David

    2012-01-01

    As faculty members add online and multimedia elements to their courses, colleges and universities across the country are realizing that there is a lot of work to be done to ensure that disabled students (and employees) have equal access to course material and university websites. Unfortunately, far too few schools consider the task a top priority.…

  8. Screening of faba bean (Vicia faba L.) accessions to acidity and aluminium stresses

    PubMed Central

    Stoddard, Frederick L.

    2017-01-01

    Background Faba bean is an important starch-based protein crop produced worldwide. Soil acidity and aluminium toxicity are major abiotic stresses affecting its production, so in regions where soil acidity is a problem, there is a gap between the potential and actual productivity of the crop. Hence, we set out to evaluate acidity and aluminium tolerance in a range of faba bean germplasm using solution culture and pot experiments. Methods A set of 30 accessions was collected from regions where acidity and aluminium are or are not problems. The accessions were grown in solution culture and a subset of 10 was grown first in peat and later in perlite potting media. In solution culture, morphological parameters including taproot length, root regrowth and root tolerance index were measured, and in the pot experiments the key measurements were taproot length, plant biomass, chlorophyll concentration and stomatal conductance. Result Responses to acidity and aluminium were apparently independent. Accessions Dosha and NC 58 were tolerant to both stress. Kassa and GLA 1103 were tolerant to acidity showing less than 3% reduction in taproot length. Aurora and Messay were tolerant to aluminium. Babylon was sensitive to both, with up to 40% reduction in taproot length from acidity and no detectable recovery from Al3+ challenge. Discussion The apparent independence of the responses to acidity and aluminium is in agreement with the previous research findings, suggesting that crop accessions separately adapt to H+ and Al3+ toxicity as a result of the difference in the nature of soil parent materials where the accession originated. Differences in rankings between experiments were minor and attributable to heterogeneity of seed materials and the specific responses of accessions to the rooting media. Use of perlite as a potting medium offers an ideal combination of throughput, inertness of support medium, access to leaves for detection of their stress responses, and harvest of clean

  9. Hypermedia as medium

    NASA Technical Reports Server (NTRS)

    Dede, Christopher J.

    1990-01-01

    Claims and rebuttals that hypermedia (the associative, nonlinear interconnection of multimedia materials) is a fundamentally innovative means of thinking and communicating are described. This representational architecture has many advantages that make it a major advance over other media; however, it also has several intrinsic problems that severly limits its effectiveness as a medium. These advantages and limits in applications are discussed.

  10. Holographic recording medium

    NASA Technical Reports Server (NTRS)

    Gange, Robert Allen (Inventor)

    1977-01-01

    A holographic recording medium comprising a conductive substrate, a photoconductive layer and an electrically alterable layer of a linear, low molecular weight hydrocarbon polymer has improved fatigue resistance. An acrylic barrier layer can be interposed between the photoconductive and electrically alterable layers.

  11. Hemodialysis access - self care

    MedlinePlus

    Kidney failure - chronic-hemodialysis access; Renal failure - chronic-hemodialysis access; Chronic renal insufficiency - hemodialysis access; Chronic kidney failure - hemodialysis access; Chronic renal failure - hemodialysis access; dialysis - hemodialysis ...

  12. Visual Adaptation

    PubMed Central

    Webster, Michael A.

    2015-01-01

    Sensory systems continuously mold themselves to the widely varying contexts in which they must operate. Studies of these adaptations have played a long and central role in vision science. In part this is because the specific adaptations remain a powerful tool for dissecting vision, by exposing the mechanisms that are adapting. That is, “if it adapts, it's there.” Many insights about vision have come from using adaptation in this way, as a method. A second important trend has been the realization that the processes of adaptation are themselves essential to how vision works, and thus are likely to operate at all levels. That is, “if it's there, it adapts.” This has focused interest on the mechanisms of adaptation as the target rather than the probe. Together both approaches have led to an emerging insight of adaptation as a fundamental and ubiquitous coding strategy impacting all aspects of how we see. PMID:26858985

  13. Liquid chromatographic extraction medium

    DOEpatents

    Horwitz, E.P.; Dietz, M.L.

    1994-09-13

    A method and apparatus are disclosed for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water. 1 fig.

  14. Liquid chromatographic extraction medium

    DOEpatents

    Horwitz, E. Philip; Dietz, Mark L.

    1994-01-01

    A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

  15. Adaptive Management

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive managem...

  16. Adaptive Biomedical Innovation.

    PubMed

    Honig, P K; Hirsch, G

    2016-12-01

    Adaptive Biomedical Innovation (ABI) is a multistakeholder approach to product and process innovation aimed at accelerating the delivery of clinical value to patients and society. ABI offers the opportunity to transcend the fragmentation and linearity of decision-making in our current model and create a common collaborative framework that optimizes the benefit and access of new medicines for patients as well as creating a more sustainable innovation ecosystem.

  17. Water access, water scarcity, and climate change.

    PubMed

    Mukheibir, Pierre

    2010-05-01

    This article investigates the approaches of the various discourses operating in the water sector and how they address the issues of scarcity and equitable access under projected climate change impacts. Little synergy exists between the different approaches dealing with these issues. Whilst being a sustainable development and water resources management issue, a holistic view of access, scarcity and the projected impacts of climate change is not prevalent in these discourses. The climate change discourse too does not adequately bridge the gap between these issues. The projected impacts of climate change are likely to exacerbate the problems of scarcity and equitable access unless appropriate adaptation strategies are adopted and resilience is built. The successful delivery of accessible water services under projected climate change impacts therefore lies with an extension of the adaptive water management approach to include equitable access as a key driver.

  18. Ultradispersive adaptive prism based on a coherently prepared atomic medium

    SciTech Connect

    Sautenkov, Vladimir A.; Li Hebin; Rostovtsev, Yuri V.; Scully, Marlan O.

    2010-06-15

    We have experimentally demonstrated an ultra-dispersive optical prism made from a coherently driven Rb atomic vapor. The prism possesses spectral angular dispersion that is 6 orders of magnitude higher than that of a prism made of optical glass; such angular dispersion allows one to spatially resolve light beams with different frequencies separated by a few kilohertz. The prism operates near the resonant frequency of atomic vapor and its dispersion is optically controlled by a coherent driving field.

  19. [An improved differential medium, CA medium, for differentiating Shigella].

    PubMed

    Tokoro, M; Nagano, I; Goto, K; Nakamura, A

    1990-07-01

    We devised a Citrate-Acetate (CA) medium for rapidly differentiating Shigella. The medium consisted of 3.0 g of sodium citrate, 2.0 g of sodium acetate, 0.2 g of glucose, 1.0 g of dipotassium phosphate, 1.0 g of mono ammonium phosphate, 0.2 g of magnesium sulfate, 5.0 g of sodium chloride, 0.08 g of brom thymol blue, 15.0 g of agar, and 1000 ml of distilled water. An evaluation was made of the CA medium, for the rapid differentiation of 23 Shigella strains, 129 Escherichia coli strains and 130 isolates, that formed colourless colonies suspected to be Shigella on SS agar plate, from feces of healthy people. The results obtained were as follows 1) On the CA medium, all Shigella strains did not grow and there was no change in colour. 2) Positive growth rates of E. coli strains after incubation for 24 hr at 37 degrees C on CA medium, sodium acetate medium (Acet) and Christensen citrate medium (C-Cit) were 96.0%, 95.2% and 28.0%, respectively. Therefore, the positive growth rate of E. coli strains after incubation for 24 hr on CA medium was significantly higher (p less than 0.01) than that on C-Cit medium. 3) Positive growth rates of isolates after incubation for 24 hr at 37 degrees C on CA medium, Acet medium and C-Cit medium were 95.4%, 83.1% and 71.5%, respectively. Therefore, the positive growth rates of isolates after incubation for 24 hr on CA medium was significantly higher (p less than 0.01) than that on Acet medium and C-Cit medium.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. DENSE MEDIUM CYCLONE OPTIMIZATON

    SciTech Connect

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  1. Chemically Defined Medium and Caenorhabditis elegans: A Powerful Approach

    NASA Technical Reports Server (NTRS)

    Szewczyk, N. J.; Kozak, E.; Conley, C. A.

    2003-01-01

    C. elegans has been established as a powerful genetic system. Growth in a chemically defined medium (C. elegans Maintenance Medium (CeMM)) now allows standardization and systematic manipulation of the nutrients that animals receive. Liquid cultivation allows automated culturing and experimentation and should be of me in large-scale growth and screening of animals. Here we present our initial results from developing culture systems with CeMM. We find that CeMM is versatile and culturing is simple. CeMM can be used in a solid or liquid state, it can be stored unused for at least a year, unattended actively growing cultures may be maintained longer than with standard techniques, and standard C. elegans protocols work well with animals grown in defined medium. We also find that there are caveats of using defined medium. Animals in defined medium grow more slowly than on standard medium, appear to display adaptation to the defined medium, and display altered growth rates as they change defined medium composition. As was suggested with the introduction of C. elegans as a potential genetic system, use of defined medium with C. elegans should prove a powerful tool.

  2. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  3. [Drug access in poor countries].

    PubMed

    Sebbag, Robert

    2007-11-01

    As a responsible player in the global pharmaceutical industry, Sanofi-Aventis recognizes its special responsibility to provide poor countries with access to drugs and vaccines. This is a key component of the Group's approach to sustainable development. As such, the Access to Medicines department draws on Sanofi-Aventis' expertise in order to address major public health issues, starting with the treatment of malaria, tuberculosis, sleeping sickness, leishmaniasis and epilepsy, as well as access to vaccines. The department has four main activities: research and development of new drugs; improvement of existing treatments; information, communication and education of patients and healthcare professionals; and development of a differential pricing and distribution policy adapted to patients' income, with a "no profit-no loss" equilibrium.

  4. Improving knowledge navigation with adaptive hypermedia.

    PubMed

    Pagesy, R; Soula, G; Fieschi, M

    2000-01-01

    Web applications provide access to a tremendous amount of information: hypertext, hypermedia and on-line databases. However, since users' knowledge, motivation and goals are different, they cannot find the relevant information in the data being diffused. Giving the users applications or environments that will take their differences into account is one way of improving their access to knowledge. The authors' objective is to improve knowledge navigation by adapting users' navigation. Adaptive hypermedia is one way of returning information adapted to the user. This paper presents an adaptive hypermedia system based on user representation with the stereotype model. Both adaptive presentation and navigation techniques are also implemented. This paper focuses on the architecture of the general adaptive hypermedia system as well as adaptivity management. A-TOP, a medical adaptive hypermedia prototype implemented in a hospital intranet system, is described. Adaptive hypermedia is a preliminary approach to the vast problem of user access to knowledge. In conclusion, we hope to extend our reflections to the problems involved in access to knowledge on the World Wide Web (Web).

  5. Climate adaptation

    NASA Astrophysics Data System (ADS)

    Kinzig, Ann P.

    2015-03-01

    This paper is intended as a brief introduction to climate adaptation in a conference devoted otherwise to the physics of sustainable energy. Whereas mitigation involves measures to reduce the probability of a potential event, such as climate change, adaptation refers to actions that lessen the impact of climate change. Mitigation and adaptation differ in other ways as well. Adaptation does not necessarily have to be implemented immediately to be effective; it only needs to be in place before the threat arrives. Also, adaptation does not necessarily require global, coordinated action; many effective adaptation actions can be local. Some urban communities, because of land-use change and the urban heat-island effect, currently face changes similar to some expected under climate change, such as changes in water availability, heat-related morbidity, or changes in disease patterns. Concern over those impacts might motivate the implementation of measures that would also help in climate adaptation, despite skepticism among some policy makers about anthropogenic global warming. Studies of ancient civilizations in the southwestern US lends some insight into factors that may or may not be important to successful adaptation.

  6. Accelerated Adaptive Integration Method

    PubMed Central

    2015-01-01

    Conformational changes that occur upon ligand binding may be too slow to observe on the time scales routinely accessible using molecular dynamics simulations. The adaptive integration method (AIM) leverages the notion that when a ligand is either fully coupled or decoupled, according to λ, barrier heights may change, making some conformational transitions more accessible at certain λ values. AIM adaptively changes the value of λ in a single simulation so that conformations sampled at one value of λ seed the conformational space sampled at another λ value. Adapting the value of λ throughout a simulation, however, does not resolve issues in sampling when barriers remain high regardless of the λ value. In this work, we introduce a new method, called Accelerated AIM (AcclAIM), in which the potential energy function is flattened at intermediate values of λ, promoting the exploration of conformational space as the ligand is decoupled from its receptor. We show, with both a simple model system (Bromocyclohexane) and the more complex biomolecule Thrombin, that AcclAIM is a promising approach to overcome high barriers in the calculation of free energies, without the need for any statistical reweighting or additional processors. PMID:24780083

  7. REVISITING NUCLEOPHILIC SUBSTITUTION REACTIONS: MICROWAVE-ASSISTED SYNTHESIS OF AZIDES, THIOCYANATES AND SULFONES IN AQUEOUS MEDIUM

    EPA Science Inventory

    A practical, rapid and efficient microwave (MW) promoted synthesis of various azides, thiocyanates and sulfones, is described in aqueous medium. This general and expeditious MW-enhanced nucleophilic substitution approach uses easily accessible starting materials such as halides o...

  8. Adaptive Devices and the Computer.

    ERIC Educational Resources Information Center

    Taber, Florence M.

    1986-01-01

    Guidelines for selecting appropriate assistive devices which afford disabled individuals access to computers are presented. In general, the individual who is to use the computer must be evaluated first to ensure that the adaptive device makes the most efficient use of his/her muscle control, mobility, reflexes, etc. (CB)

  9. Synchronization of cells with activator-inhibitor pathways through adaptive environment-mediated coupling

    NASA Astrophysics Data System (ADS)

    Ghomsi, P. Guemkam; Moukam Kakmeni, F. M.; Tchawoua, C.; Kofane, T. C.

    2015-11-01

    In this paper, we report the synchronized dynamics of cells with activator-inhibitor pathways via an adaptive environment-mediated coupling scheme with feedbacks and control mechanisms. The adaptive character of the extracellular medium is modeled via its damping parameter as a physiological response aiming at annihilating the cellular differentiation existing between the chaotic biochemical pathways of the cells, in order to preserve homeostasis. We perform an investigation on the existence and stability of the synchronization manifold of the coupled system under the proposed coupling pattern. Both mathematical and computational tools suggest the accessibility of conducive prerequisites (conditions) for the emergence of a robust synchronous regime. The relevance of a phase-synchronized dynamics is appraised and several numerical indicators advocate for the prevalence of this fascinating phenomenon among the interacting cells in the phase space.

  10. Hemodialysis access procedures

    MedlinePlus

    ... returned to your body. Usually the access is put in your arm but it can also go ... A surgeon will put the access in. There are 3 types of access. Fistula: The surgeon joins an artery and vein under the ...

  11. Toothbrush Adaptations.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1987

    1987-01-01

    Suggestions are presented for helping disabled individuals learn to use or adapt toothbrushes for proper dental care. A directory lists dental health instructional materials available from various organizations. (CB)

  12. Transcriptome profiling of Xanthomonas campestris pv. campestris grown in minimal medium MMX and rich medium NYG.

    PubMed

    Liu, Wei; Yu, Yan-Hua; Cao, Shi-Yuan; Niu, Xiang-Na; Jiang, Wei; Liu, Guo-Fang; Jiang, Bo-Le; Tang, Dong-Jie; Lu, Guang-Tao; He, Yong-Qiang; Tang, Ji-Liang

    2013-06-01

    Xanthomonas campestris pathovar campestris (Xcc) is the causal agent of black rot disease in cruciferous plants worldwide. Although the complete genomes of several Xcc strains have been determined, the gene expression and regulation mechanisms in this pathogen are far from clear. In this work, transcriptome profiling of Xcc 8004 grown in MMX medium (minimal medium for Xanthomonas campestris) and NYG medium (peptone yeast glycerol medium) were investigated by RNA-Seq. Using the Illumina HiSeq 2000 platform, a total of 26,514,630 reads (90 nt in average) were generated, of which 15,708,478 reads mapped uniquely to coding regions of Xcc 8004 genome. Of the 4273 annotated protein-coding genes of Xcc 8004, 629 were found differentially expressed in Xcc grown in MMX and NYG. Of the differentially expressed genes, 495 were up-regulated and 134 were down-regulated in MMX. The MMX-induced genes are mainly involved in amino acid metabolism, transport systems, atypical condition adaptation and pathogenicity, especially the type III secretion system, while the MMX-repressed genes are mainly involved in chemotaxis and degradation of small molecules. The global transcriptome analyzes of Xcc 8004 grown in MMX and NYG might facilitate the gene functional characterization of this phytopathogenic bacterium.

  13. United States Access Board

    MedlinePlus

    ... disabilities through leadership in accessible design and the development of accessibility guidelines and standards for the built environment, transportation, communication, medical diagnostic equipment, and information technology. ...

  14. Critical Access Hospitals (CAH)

    MedlinePlus

    ... use requirements for Critical Access Hospitals related to Electronic Health Records (EHRs)? Critical Access Hospital (CAH) are eligible for Electronic Health Record (EHR) incentive payments and can receive ...

  15. New medium licensed for campylobacter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A medium, “Campy-Cefex”, has been licensed by the ARS Office of Technology Transfer with Becton Dickinson (No. 1412-002) and Neogen (No. 1412-001) based on patent No. 5,891,709, “Campy-Cefex Selective and Differential Medium for Campylobacter” by Dr. Norman Stern of the Poultry Microbiological Safet...

  16. Planning an Authority Control Project at a Medium-Sized University Library.

    ERIC Educational Resources Information Center

    Zhang, Sha Li

    2001-01-01

    Authority control is a vital part of providing students and faculty with adequate access to collections in university libraries. Small and medium-sized libraries find it challenging to meet rising user expectations and provide adequate access in an online environment through appropriate authority work. A planning process is offered on an authority…

  17. A Theory of Access

    ERIC Educational Resources Information Center

    Ribot, Jesse C.; Peluso, Nancy Lee

    2003-01-01

    The term "access" is frequently used by property and natural resource analysts without adequate definition. In this paper we develop a concept of access and examine a broad set of factors that differentiate access from property. We define access as "the "ability" to derive benefits from things," broadening from property's classical definition as…

  18. Adaptive management

    USGS Publications Warehouse

    Allen, Craig R.; Garmestani, Ahjond S.

    2015-01-01

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive management has explicit structure, including a careful elucidation of goals, identification of alternative management objectives and hypotheses of causation, and procedures for the collection of data followed by evaluation and reiteration. The process is iterative, and serves to reduce uncertainty, build knowledge and improve management over time in a goal-oriented and structured process.

  19. Mobile access control vestibule

    NASA Astrophysics Data System (ADS)

    DePoy, Jennifer M.

    1998-12-01

    The mobile access control vestibule (MACV) is an adaptation of techniques developed for mobile military command centers. The overall configuration of modules acts as an entry control/screening facility or transportable command center. The system would provide the following capabilities: (1) A key element for force protection, rapid deployment units sent to areas having no prepositioned equipment or where there has been a degradation of that equipment as a result of natural disasters or civil unrest. (2) A rapidly deployable security control center to upgrade the security at nonmilitary sites (e.g., diplomatic or humanitarian organizations). (3) Personnel screening, package screening, badge/identification card production for authorized personnel, centralized monitoring of deployed perimeter sensors, and centralized communications for law enforcement personnel. (4) Self-contained screening and threat detection systems, including explosives detection using the system developed by Sandia National Laboratories for the FAA. When coupled with transportable electric generators, the system is self-sufficient. The communication system for the MACV would be a combination of physically wired and wireless communication units that supports by ad hoc networking.

  20. Medium-dependent control of the bacterial growth rate.

    PubMed

    Ehrenberg, Måns; Bremer, Hans; Dennis, Patrick P

    2013-04-01

    By combining results from previous studies of nutritional up-shifts we here re-investigate how bacteria adapt to different nutritional environments by adjusting their macromolecular composition for optimal growth. We demonstrate that, in contrast to a commonly held view the macromolecular composition of bacteria does not depend on the growth rate as an independent variable, but on three factors: (i) the genetic background (i.e. the strain used), (ii) the physiological history of the bacteria used for inoculation of a given growth medium, and (iii) the kind of nutrients in the growth medium. These factors determine the ribosome concentration and the average rate of protein synthesis per ribosome, and thus the growth rate. Immediately after a nutritional up-shift, the average number of ribosomes in the bacterial population increases exponentially with time at a rate which eventually is attained as the final post-shift growth rate of all cell components. After a nutritional up-shift from one minimal medium to another minimal medium of higher nutritional quality, ribosome and RNA polymerase syntheses are co-regulated and immediately increase by the same factor equal to the increase in the final growth rate. However, after an up-shift from a minimal medium to a medium containing all 20 amino acids, RNA polymerase and ribosome syntheses are no longer coregulated; a smaller rate of synthesis of RNA polymerase is compensated by a gradual increase in the fraction of free RNA polymerase, possibly due to a gradual saturation of mRNA promoters. We have also analyzed data from a recent publication, in which it was concluded that the macromolecular composition in terms of RNA/protein and RNA/DNA ratios is solely determined by the effector molecule ppGpp. Our analysis indicates that this is true only in special cases and that, in general, medium adaptation also depends on factors other than ppGpp.

  1. Adaptive Thresholds

    SciTech Connect

    Bremer, P. -T.

    2014-08-26

    ADAPT is a topological analysis code that allow to compute local threshold, in particular relevance based thresholds for features defined in scalar fields. The initial target application is vortex detection but the software is more generally applicable to all threshold based feature definitions.

  2. World Wide Access: Accessible Web Design.

    ERIC Educational Resources Information Center

    Washington Univ., Seattle.

    This brief paper considers the application of "universal design" principles to Web page design in order to increase accessibility for people with disabilities. Suggestions are based on the World Wide Web Consortium's accessibility initiative, which has proposed guidelines for all Web authors and federal government standards. Seven guidelines for…

  3. Adaptation of adaptive optics systems.

    NASA Astrophysics Data System (ADS)

    Xin, Yu; Zhao, Dazun; Li, Chen

    1997-10-01

    In the paper, a concept of an adaptation of adaptive optical system (AAOS) is proposed. The AAOS has certain real time optimization ability against the variation of the brightness of detected objects m, atmospheric coherence length rO and atmospheric time constant τ by means of changing subaperture number and diameter, dynamic range, and system's temporal response. The necessity of AAOS using a Hartmann-Shack wavefront sensor and some technical approaches are discussed. Scheme and simulation of an AAOS with variable subaperture ability by use of both hardware and software are presented as an example of the system.

  4. Access Nets: Modeling Access to Physical Spaces

    NASA Astrophysics Data System (ADS)

    Frohardt, Robert; Chang, Bor-Yuh Evan; Sankaranarayanan, Sriram

    Electronic, software-managed mechanisms using, for example, radio-frequency identification (RFID) cards, enable great flexibility in specifying access control policies to physical spaces. For example, access rights may vary based on time of day or could differ in normal versus emergency situations. With such fine-grained control, understanding and reasoning about what a policy permits becomes surprisingly difficult requiring knowledge of permission levels, spatial layout, and time. In this paper, we present a formal modeling framework, called AccessNets, suitable for describing a combination of access permissions, physical spaces, and temporal constraints. Furthermore, we provide evidence that model checking techniques are effective in reasoning about physical access control policies. We describe our results from a tool that uses reachability analysis to validate security policies.

  5. Quantum internet using code division multiple access.

    PubMed

    Zhang, Jing; Liu, Yu-xi; Ozdemir, Sahin Kaya; Wu, Re-Bing; Gao, Feifei; Wang, Xiang-Bin; Yang, Lan; Nori, Franco

    2013-01-01

    A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels.

  6. Quantum internet using code division multiple access

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Liu, Yu-Xi; Özdemir, Şahin Kaya; Wu, Re-Bing; Gao, Feifei; Wang, Xiang-Bin; Yang, Lan; Nori, Franco

    2013-07-01

    A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels.

  7. Quantum internet using code division multiple access

    PubMed Central

    Zhang, Jing; Liu, Yu-xi; Özdemir, Şahin Kaya; Wu, Re-Bing; Gao, Feifei; Wang, Xiang-Bin; Yang, Lan; Nori, Franco

    2013-01-01

    A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels. PMID:23860488

  8. Medium for presumptive identification of Yersinia enterocolitica.

    PubMed

    Weagant, S D

    1983-02-01

    A medium, lysine-arginine-iron agar, was developed for the presumptive identification of Yersinia enterocolitica isolates. This medium was a modification of lysine-iron agar and allowed for the testing of five biochemical characteristics in a single tube medium. The reactions of Y. enterocolitica on this medium were reliable and distinctive. The medium significantly simplified the identification of Y. enterocolitica isolates.

  9. Access National Parks: A Guide for Handicapped Visitors.

    ERIC Educational Resources Information Center

    National Park Service (Dept. of Interior), Washington, DC.

    The manual provides information on accessibility of facilities, services, and interpretive programs in approximately 300 areas of the U.S. National Park System. Details are arranged alphabetically within each state and usually include a brief historical description, parking, entrance and restroom accessibility, and special adaptations for the…

  10. Adaptive RTS threshold for maximum network throughput in IEEE 802.11 DCF

    NASA Astrophysics Data System (ADS)

    Yan, Shaohu; Zhuo, Yongning; Wu, Shiqi; Guo, Wei

    2004-04-01

    The IEEE 802.11 medium access control (MAC) protocol provides shared access to wireless channel. Its primary MAC technique is called distributed coordination function (DCF) that includes two packet transmission schemes, namely, basic access and RTS/CTS access mechanisms. In a "hybrid" network combining the two schemes, packets with payload longer than a given threshold (RTS Threshold) are transmitted according to the RTS/CTS mechanism. Based on delicate mathematical model, the average time in a successful and unsuccessful transmission is analyzed in the assumption of idea channel. Then the relation of network saturation throughput and RTS threshold was found and expressed in theoretical formula. We present the numerical techniques to find out the optimum RTS threshold that can maximize the network capacity. An adaptive RTS threshold adjust algorithm (ARTA), with which a station can automatically adjust its RTS threshold to the current optimum value, is also presented in detail. A special procedure is also developed to help ARTA in determination of station numbers. All theoretical analysis and algorithm are validated through computer simulation.

  11. Connector adapter

    NASA Technical Reports Server (NTRS)

    Hacker, Scott C. (Inventor); Dean, Richard J. (Inventor); Burge, Scott W. (Inventor); Dartez, Toby W. (Inventor)

    2007-01-01

    An adapter for installing a connector to a terminal post, wherein the connector is attached to a cable, is presented. In an embodiment, the adapter is comprised of an elongated collet member having a longitudinal axis comprised of a first collet member end, a second collet member end, an outer collet member surface, and an inner collet member surface. The inner collet member surface at the first collet member end is used to engage the connector. The outer collet member surface at the first collet member end is tapered for a predetermined first length at a predetermined taper angle. The collet includes a longitudinal slot that extends along the longitudinal axis initiating at the first collet member end for a predetermined second length. The first collet member end is formed of a predetermined number of sections segregated by a predetermined number of channels and the longitudinal slot.

  12. Adaptive sampler

    DOEpatents

    Watson, B.L.; Aeby, I.

    1980-08-26

    An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  13. Adaptive antennas

    NASA Astrophysics Data System (ADS)

    Barton, P.

    1987-04-01

    The basic principles of adaptive antennas are outlined in terms of the Wiener-Hopf expression for maximizing signal to noise ratio in an arbitrary noise environment; the analogy with generalized matched filter theory provides a useful aid to understanding. For many applications, there is insufficient information to achieve the above solution and thus non-optimum constrained null steering algorithms are also described, together with a summary of methods for preventing wanted signals being nulled by the adaptive system. The three generic approaches to adaptive weight control are discussed; correlation steepest descent, weight perturbation and direct solutions based on sample matrix conversion. The tradeoffs between hardware complexity and performance in terms of null depth and convergence rate are outlined. The sidelobe cancellor technique is described. Performance variation with jammer power and angular distribution is summarized and the key performance limitations identified. The configuration and performance characteristics of both multiple beam and phase scan array antennas are covered, with a brief discussion of performance factors.

  14. Primary vascular access.

    PubMed

    Gibbons, C P

    2006-05-01

    Primary vascular access is usually achievable by a distal autogenous arterio-venous fistula (AVF). This article describes the approach to vascular access planning, the usual surgical options and the factors affecting patency.

  15. [Accessible Rural Housing.

    ERIC Educational Resources Information Center

    Baker, Nick, Ed.

    1995-01-01

    This issue of the quarterly newsletter "Rural Exchange" provides information and resources on accessible rural housing for the disabled. "Accessible Manufactured Housing Could Increase Rural Home Supply" (Nick Baker) suggests that incorporation of access features such as lever door handles and no-step entries into manufactured housing could help…

  16. Reflective Database Access Control

    ERIC Educational Resources Information Center

    Olson, Lars E.

    2009-01-01

    "Reflective Database Access Control" (RDBAC) is a model in which a database privilege is expressed as a database query itself, rather than as a static privilege contained in an access control list. RDBAC aids the management of database access controls by improving the expressiveness of policies. However, such policies introduce new interactions…

  17. Open Access Alternatives

    ERIC Educational Resources Information Center

    Tenopir, Carol

    2004-01-01

    Open access publishing is a hot topic today. But open access publishing can have many different definitions, and pros and cons vary with the definitions. Open access publishing is especially attractive to companies and small colleges or universities that are likely to have many more readers than authors. A downside is that a membership fee sounds…

  18. Demystifying Remote Access

    ERIC Educational Resources Information Center

    Howe, Grant

    2009-01-01

    With money tight, more and more districts are considering remote access as a way to reduce expenses and budget information technology costs more effectively. Remote access allows staff members to work with a hosted software application from any school campus without being tied to a specific physical location. Each school can access critical…

  19. Properties of the nuclear medium.

    PubMed

    Baldo, M; Burgio, G F

    2012-02-01

    We review our knowledge on the properties of the nuclear medium that have been studied, over many years, on the basis of many-body theory, laboratory experiments and astrophysical observations. Throughout the presentation particular emphasis is placed on the possible relationship and links between the nuclear medium and the structure of nuclei, including the limitations of such an approach. First we consider the realm of phenomenological laboratory data and astrophysical observations and the hints they can give on the characteristics that the nuclear medium should possess. The analysis is based on phenomenological models, that however have a strong basis on physical intuition and an impressive success. More microscopic models are also considered, and it is shown that they are able to give invaluable information on the nuclear medium, in particular on its equation of state. The interplay between laboratory experiments and astrophysical observations is particularly stressed, and it is shown how their complementarity enormously enriches our insights into the structure of the nuclear medium. We then introduce the nucleon-nucleon interaction and the microscopic many-body theory of nuclear matter, with a critical discussion about the different approaches and their results. The Landau-Fermi liquid theory is introduced and briefly discussed, and it is shown how fruitful it can be in discussing the macroscopic and low-energy properties of the nuclear medium. As an illustrative example, we discuss neutron matter at very low density, and it is shown how it can be treated within the many-body theory. The general bulk properties of the nuclear medium are reviewed to indicate at which stage of our knowledge we stand, taking into account the most recent developments both in theory and experiments. A section is dedicated to the pairing problem. The connection with nuclear structure is then discussed, on the basis of the energy density functional method. The possibility of linking

  20. Knowledge-based media adaptation

    NASA Astrophysics Data System (ADS)

    Leopold, Klaus; Jannach, Dietmar; Hellwagner, Hermann

    2004-10-01

    This paper introduces the principal approach and describes the basic architecture and current implementation of the knowledge-based multimedia adaptation framework we are currently developing. The framework can be used in Universal Multimedia Access scenarios, where multimedia content has to be adapted to specific usage environment parameters (network and client device capabilities, user preferences). Using knowledge-based techniques (state-space planning), the framework automatically computes an adaptation plan, i.e., a sequence of media conversion operations, to transform the multimedia resources to meet the client's requirements or constraints. The system takes as input standards-compliant descriptions of the content (using MPEG-7 metadata) and of the target usage environment (using MPEG-21 Digital Item Adaptation metadata) to derive start and goal states for the planning process, respectively. Furthermore, declarative descriptions of the conversion operations (such as available via software library functions) enable existing adaptation algorithms to be invoked without requiring programming effort. A running example in the paper illustrates the descriptors and techniques employed by the knowledge-based media adaptation system.

  1. Adaptation of fictional and online conversations to communication media

    NASA Astrophysics Data System (ADS)

    Alis, C. M.; Lim, M. T.

    2012-12-01

    Conversations allow the quick transfer of short bits of information and it is reasonable to expect that changes in communication medium affect how we converse. Using conversations in works of fiction and in an online social networking platform, we show that the utterance length of conversations is slowly shortening with time but adapts more strongly to the constraints of the communication medium. This indicates that the introduction of any new medium of communication can affect the way natural language evolves.

  2. Computer adaptive testing.

    PubMed

    Gershon, Richard C

    2005-01-01

    The creation of item response theory (IRT) and Rasch models, inexpensive accessibility to high speed desktop computers, and the growth of the Internet, has led to the creation and growth of computerized adaptive testing or CAT. This form of assessment is applicable for both high stakes tests such as certification or licensure exams, as well as health related quality of life surveys. This article discusses the historical background of CAT including its many advantages over conventional (typically paper and pencil) alternatives. The process of CAT is then described including descriptions of the specific differences of using CAT based upon 1-, 2- and 3-parameter IRT and various Rasch models. Numerous specific topics describing CAT in practice are described including: initial item selection, content balancing, test difficulty, test length and stopping rules. The article concludes with the author's reflections regarding the future of CAT.

  3. Access to Photography: Making Photography Accessible to Persons with Exceptional Educational Needs.

    ERIC Educational Resources Information Center

    Peterson, Charles R., Ed.

    This guide to making photography accessible to persons with exceptional educational needs contains several papers, a list of 27 organizational and bibliographic resources, a list of sources of adaptive equipment, and drawings of sample equipment modifications. Nine papers make up the text of the guide. In "An Adventure into Photography," Charles…

  4. Review of hadrons in medium

    SciTech Connect

    Krein, Gastão

    2016-01-22

    I review the present status in the theoretical and phenomenological understanding of hadron properties in strongly interacting matter. The topics covered are the EMC effect, nucleon structure functions in cold nuclear matter, spectral properties of light vector mesons in hot and cold nuclear matter, and in-medium properties of heavy flavored hadrons.

  5. Integrating Adaptive Games in Student-Centered Virtual Learning Environments

    ERIC Educational Resources Information Center

    del Blanco, Angel; Torrente, Javier; Moreno-Ger, Pablo; Fernandez-Manjon, Baltasar

    2010-01-01

    The increasing adoption of e-Learning technology is facing new challenges, such as how to produce student-centered systems that can be adapted to each student's needs. In this context, educational video games are proposed as an ideal medium to facilitate adaptation and tracking of students' performance for assessment purposes, but integrating the…

  6. Commercial cinema: a medium for development communication.

    PubMed

    Riber, J; Smith, S

    1985-01-01

    concerns about family planning. Understanding audience expectations in a commercial cinema context is the key to successfully adapting this medium for social development messages. Although some foreign technical assistance was provided, the success of the 2 films described depended on how their themes were adapted to the traditional feature film format. To date, commercial cinema has been an underutilized medium for development messages. WIF's experiences demonstrate how effective, well-conceived social messages can be presented in a commercial cinema context. It is hoped this will encourage other to use this widely available channel of mass communication.

  7. Medium modifications with recoil polarization

    SciTech Connect

    Brand, J.F.J. van den; Ent, R.

    1994-04-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He({rvec e},e{prime},{rvec p}){sup 3}H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium.

  8. Medium Modification of Vector Mesons

    SciTech Connect

    Chaden Djalali, Michael Paolone, Dennis Weygand, Michael H. Wood, Rakhsha Nasseripour

    2011-03-01

    The theory of the strong interaction, Quantum Chromodynamics (QCD), has been remarkably successful in describing high-energy and short-distance-scale experiments involving quarks and gluons. However, applying QCD to low energy and large-distance scale experiments has been a major challenge. Various QCD-inspired models predict a partial restoration of chiral symmetry in nuclear matter with modifications of the properties of hadrons from their free-space values. Measurable changes such as a shift in mass and/or a change of width are predicted at normal nuclear density. Photoproduction of vector mesons off nuclei have been performed at different laboratories. The properties of the ρ, ω and φ mesons are investigated either directly by measuring their mass spectra or indirectly through transparency ratios. The latest results regarding medium modifications of the vector mesons in the nuclear medium will be discussed.

  9. Adaptable and Adaptive Automation for Supervisory Control of Multiple Autonomous Vehicles

    DTIC Science & Technology

    2012-10-01

    Adaptable and Adaptive Automation for Supervisory Control of Multiple Autonomous Vehicles Brian Kidwell , 1 Gloria L. Calhoun, 2 Heath A. Ruff...correlated with selection of the high LOA ( r = .789, p < .01), as well as the disuse of the medium LOA ( r = -.823, p < .01). There was not a...AFRL. Brian Kidwell and Raja Parasuraman were supported by Air Force Office of Scientific Research grant FA9550-10-1-0385 and the Center of

  10. Ultrasound-fluoroscopy guided access to the intrarenal excretory system.

    PubMed

    Montanari, E; Serrago, M; Esposito, N; Rocco, B; Kartalas-Goumas, I; Del Nero, A; Zanetti, G; Trinchieri, A; Pisani, E

    1999-01-01

    The access to the collecting system can be performed under fluoroscopy computerized tomography, ultrasonographic, mixed ultrasonographic and fluoroscopic guidance. In this paper the creation of a percutaneous transparenchymal ultrasound-fluoroscopy guided access to the intrarenal collecting system completely performed by urologist for different purposes is presented. In five years 297 patients underwent 330 percutaneous kidney accesses to perform derivative nephrostomies (217 pts), percutaneous nephrolithotomies (37 pts), antegrade ureteral manoeuvres (34 pts), antegrade endopyelotomies (7 pts), transitional cell carcinoma of the upper tract resection (2 pts). 11 patients out of these had a percutaneous kidney access in a transplanted kidney. The percutaneous access was successful in 98% of the attemps. A posterior calyx of the lower group (74%), of the medium group (25%) or of the upper group (1%) was accessed. In 73 accesses the mean target calyx diameter was 12.8 mm (range 5-45 mm), the mean operative time 5.4 minutes and the mean fluoroscopy time 5.1 seconds. In 84.5% of the patients the access was performed under local anesthesia when a dilation of the tract was not required. Gross haematuria was observed in 3.9% of the accesses and an arterial lesion treated by embolization in 0.9% of the accesses. Blood transfusion was required in 0.3% of the patients. The ultrasound-fluoroscopy guided access is at least as precise as the fluoroscopy guided one moreover it makes the procedure less invasive and it makes more precise the surgical planning.

  11. Channel Access in Erlang

    SciTech Connect

    Nicklaus, Dennis J.

    2013-10-13

    We have developed an Erlang language implementation of the Channel Access protocol. Included are low-level functions for encoding and decoding Channel Access protocol network packets as well as higher level functions for monitoring or setting EPICS process variables. This provides access to EPICS process variables for the Fermilab Acnet control system via our Erlang-based front-end architecture without having to interface to C/C++ programs and libraries. Erlang is a functional programming language originally developed for real-time telecommunications applications. Its network programming features and list management functions make it particularly well-suited for the task of managing multiple Channel Access circuits and PV monitors.

  12. Web Accessibility and Guidelines

    NASA Astrophysics Data System (ADS)

    Harper, Simon; Yesilada, Yeliz

    Access to, and movement around, complex online environments, of which the World Wide Web (Web) is the most popular example, has long been considered an important and major issue in the Web design and usability field. The commonly used slang phrase ‘surfing the Web’ implies rapid and free access, pointing to its importance among designers and users alike. It has also been long established that this potentially complex and difficult access is further complicated, and becomes neither rapid nor free, if the user is disabled. There are millions of people who have disabilities that affect their use of the Web. Web accessibility aims to help these people to perceive, understand, navigate, and interact with, as well as contribute to, the Web, and thereby the society in general. This accessibility is, in part, facilitated by the Web Content Accessibility Guidelines (WCAG) currently moving from version one to two. These guidelines are intended to encourage designers to make sure their sites conform to specifications, and in that conformance enable the assistive technologies of disabled users to better interact with the page content. In this way, it was hoped that accessibility could be supported. While this is in part true, guidelines do not solve all problems and the new WCAG version two guidelines are surrounded by controversy and intrigue. This chapter aims to establish the published literature related to Web accessibility and Web accessibility guidelines, and discuss limitations of the current guidelines and future directions.

  13. Intestinal resident yeast Candida glabrata requires Cyb2p-mediated lactate assimilation to adapt in mouse intestine.

    PubMed

    Ueno, Keigo; Matsumoto, Yasuhiko; Uno, Jun; Sasamoto, Kaname; Sekimizu, Kazuhisa; Kinjo, Yuki; Chibana, Hiroji

    2011-01-01

    The intestinal resident Candida glabrata opportunistically infects humans. However few genetic factors for adaptation in the intestine are identified in this fungus. Here we describe the C. glabrata CYB2 gene encoding lactate dehydrogenase as an adaptation factor for survival in the intestine. CYB2 was identified as a virulence factor by a silkworm infection study. To determine the function of CYB2, we analysed in vitro phenotypes of the mutant Δcyb2. The Δcyb2 mutant grew well in glucose medium under aerobic and anaerobic conditions, was not supersensitive to nitric oxide which has fungicidal-effect in phagocytes, and had normal levels of general virulence factors protease, lipase and adherence activities. A previous report suggested that Cyb2p is responsible for lactate assimilation. Additionally, it was speculated that lactate assimilation was required for Candida virulence because Candida must synthesize glucose via gluconeogenesis under glucose-limited conditions such as in the host. Indeed, the Δcyb2 mutant could not grow on lactate medium in which lactate is the sole carbon source in the absence of glucose, indicating that Cyb2p plays a role in lactate assimilation. We hypothesized that Cyb2p-mediated lactate assimilation is necessary for proliferation in the intestinal tract, as the intestine is rich in lactate produced by bacteria flora, but not glucose. The Δcyb2 mutant showed 100-fold decreased adaptation and few cells of Saccharomyces cerevisiae can adapt in mouse ceca. Interestingly, C. glabrata could assimilate lactate under hypoxic conditions, dependent on CYB2, but not yeast S. cerevisiae. Because accessible oxygen is limited in the intestine, the ability for lactate assimilation in hypoxic conditions may provide an advantage for a pathogenic yeast. From those results, we conclude that Cyb2p-mediated lactate assimilation is an intestinal adaptation factor of C. glabrata.

  14. Energy adaptive MAC protocol for IEEE 802.15.7 with energy harvesting

    NASA Astrophysics Data System (ADS)

    Wang, Hong-qiao; Chi, Xue-fen; Zhao, Lin-lin

    2016-09-01

    The medium access control (MAC) protocol for indoor visible light communication (VLC) with energy harvesting is explored in this paper. The unfairness of throughput exists among devices due to the significant difference of their energy harvesting rates which changes with distance, acceptance angle and the obstruction probability. We propose an energy harvesting model, a new obstruction probability model and an energy adaptive contention algorithm to overcome the unfairness problem. This device can adjust its contention window according to the energy harvesting rate. As a result, the device with lower energy harvesting rate can get shorter contention window to improve its transmission opportunity. Simulation results show that our MAC protocol can achieve a higher degree of fairness.

  15. AccessAbility @ Cleveland Public Library.

    ERIC Educational Resources Information Center

    Mates, Barbara T.

    2003-01-01

    Describes several programs that were developed by staff at the Cleveland (Ohio) Public Library to be accessible to users with disabilities. Highlights include a Braille reading program; sensory garden; poetry club; book club based on talking books; wheelchair athletics; touching museum artifacts; and a mobile library for users who could not visit…

  16. Test Target for Adaptive Optics.

    DTIC Science & Technology

    adaptive optics comprising, in the preferred embodiment, a plurality of nine adjacent, stacked, and aligned rows of a multiplicity of alternate opaque sections and transparent sections in a repeating bar pattern, with all sections being positioned on a flat transparent medium (such as film or glass), and with each opaque section being an opaque bar and with each transparent section being a transparent bar. Each row has a different spatial frequency than any other of the nine rows, with the spatial frequency of any one row being of a different multiple of the row having the

  17. Optical Access Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Ansari, Nirwan

    2005-05-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

  18. Optical Access Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Ansari, Nirwan; Jersey Inst Ansari, New; Jersey Inst, New

    2005-04-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

  19. Optical Access Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Ansari, Nirwan

    2005-06-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

  20. Re-Evaluation of Reportedly Metal Tolerant Arabidopsis thaliana Accessions

    PubMed Central

    Silva-Guzman, Macarena; Addo-Quaye, Charles; Dilkes, Brian P.

    2016-01-01

    Santa Clara, Limeport, and Berkeley are Arabidopsis thaliana accessions previously identified as diversely metal resistant. Yet these same accessions were determined to be genetically indistinguishable from the metal sensitive Col-0. We robustly tested tolerance for Zn, Ni and Cu, and genetic relatedness by growing these accessions under a range of Ni, Zn and Cu concentrations for three durations in multiple replicates. Neither metal resistance nor variance in growth were detected between them and Col-0. We re-sequenced the genomes of these accessions and all stocks available for each accession. In all cases they were nearly indistinguishable from the standard laboratory accession Col-0. As Santa Clara was allegedly collected from the Jasper Ridge serpentine outcrop in California, USA we investigated the possibility of extant A. thaliana populations adapted to serpentine soils. Botanically vouchered Arabidopsis accessions in the Jepson database were overlaid with soil maps of California. This provided no evidence of A. thaliana collections from serpentine sites in California. Thus, our work demonstrates that the Santa Clara, Berkeley and Limeport accessions are not metal tolerant, not genetically distinct from Col-0, and that there are no known serpentine adapted populations or accessions of A. thaliana. PMID:27467746

  1. Standards and Access.

    ERIC Educational Resources Information Center

    Fox, Tom

    1993-01-01

    Argues that easy claims about the relationship between language mastery and academic or economic access (made by both conservative commentators on education and mainstream writing teachers) are false and obscure real social and political boundaries, such as racism, sexism, elitism, and homophobia, that really do prevent access. (SR)

  2. The Equal Access Act.

    ERIC Educational Resources Information Center

    Catron, J. Gregory

    1987-01-01

    Reviews past history of access of religious activities in public schools in relation to the establishment clause of the First Amendment and sets forth the prerequisites in the Equal Access Act of 1984 for creating a well-defined forum for student-initiated free speech including religious groups in public high schools. (MD)

  3. Access to Higher Education

    ERIC Educational Resources Information Center

    Briscoe, Felecia; De Oliver, Miguel

    2006-01-01

    This case study researches the degree to which the location and services offered by a multicampus university, geographically situated consistent with the commercial principles of a large mass-market enterprise, facilitate access for educationally underserved groups. First, the necessity of democratizing educational access to an underprivileged…

  4. Granting Each Equal Access.

    ERIC Educational Resources Information Center

    Walling, Linda Lucas

    1992-01-01

    Summarizes federal legislation regarding equal access for students with disabilities and discusses environmental barriers to accessibility in the library media center. Solutions to these design problems are suggested in the following areas: material formats and space requirements; the physical setting, including furniture, floor coverings,…

  5. MedlinePlus: Accessibility

    MedlinePlus

    ... Tools Español You Are Here: Home → MedlinePlus Accessibility URL of this page: https://medlineplus.gov/accessibility.html ... or (301) 594-5983 and provide the address (URL) of the page on which you need assistance, ...

  6. Design for Accessibility.

    ERIC Educational Resources Information Center

    Conn, David R.; McCallum, Barry

    1982-01-01

    Discusses the facets of building design which affect the accessibility of libraries for the physically disabled and presents some basic guidelines for designing accessible libraries. Types of disabilities, questions relating to site design, and specific architectural and physical features of libraries (entranceways, lighting, stairways, and…

  7. Precise adaptation in chemotaxis through ``assistance neighborhoods"

    NASA Astrophysics Data System (ADS)

    Endres, Robert; Wingreen, Ned

    2006-03-01

    The chemotaxis network in Escherichia coli is remarkable for its sensitivity to small relative changes in the concentrations of multiple chemical signals over a broad range of ambient concentrations. Key to this sensitivity is an adaptation system that relies on methylation and demethylation/deamidation of specific modification sites of the chemoreceptors by the enzymes CheR and CheB, respectively. These enzymes can access 5-7 receptors once tethered to a particular receptor. Based on these ``assistance neighborhoods'', we present a model for precise adaptation of mixed clusters of two-state chemoreceptors. In agreement with experiment the response of adapted cells to addition/removal of attractant scales with the free-energy change at fixed ligand affinity. Our model further predicts two possible limits of precise adaptation: either the response to further addition of attractant stops through saturation of the receptors, or receptors fully methylate before they saturate and therefore stop adapting.

  8. Web accessibility and open source software.

    PubMed

    Obrenović, Zeljko

    2009-07-01

    A Web browser provides a uniform user interface to different types of information. Making this interface universally accessible and more interactive is a long-term goal still far from being achieved. Universally accessible browsers require novel interaction modalities and additional functionalities, for which existing browsers tend to provide only partial solutions. Although functionality for Web accessibility can be found as open source and free software components, their reuse and integration is complex because they were developed in diverse implementation environments, following standards and conventions incompatible with the Web. To address these problems, we have started several activities that aim at exploiting the potential of open-source software for Web accessibility. The first of these activities is the development of Adaptable Multi-Interface COmmunicator (AMICO):WEB, an infrastructure that facilitates efficient reuse and integration of open source software components into the Web environment. The main contribution of AMICO:WEB is in enabling the syntactic and semantic interoperability between Web extension mechanisms and a variety of integration mechanisms used by open source and free software components. Its design is based on our experiences in solving practical problems where we have used open source components to improve accessibility of rich media Web applications. The second of our activities involves improving education, where we have used our platform to teach students how to build advanced accessibility solutions from diverse open-source software. We are also partially involved in the recently started Eclipse projects called Accessibility Tools Framework (ACTF), the aim of which is development of extensible infrastructure, upon which developers can build a variety of utilities that help to evaluate and enhance the accessibility of applications and content for people with disabilities. In this article we briefly report on these activities.

  9. A study on moving mesh finite element solution of the porous medium equation

    NASA Astrophysics Data System (ADS)

    Ngo, Cuong; Huang, Weizhang

    2017-02-01

    An adaptive moving mesh finite element method is studied for the numerical solution of the porous medium equation with and without variable exponents and absorption. The method is based on the moving mesh partial differential equation approach and employs its newly developed implementation. The implementation has several improvements over the traditional one, including its explicit, compact form of the mesh velocities, ease to program, and less likelihood of producing singular meshes. Three types of metric tensor that correspond to uniform and arclength-based and Hessian-based adaptive meshes are considered. The method shows first-order convergence for uniform and arclength-based adaptive meshes, and second-order convergence for Hessian-based adaptive meshes. It is also shown that the method can be used for situations with complex free boundaries, emerging and splitting of free boundaries, and the porous medium equation with variable exponents and absorption. Two-dimensional numerical results are presented.

  10. A Heterogeneous Medium Analytical Benchmark

    SciTech Connect

    Ganapol, B.D.

    1999-09-27

    A benchmark, called benchmark BLUE, has been developed for one-group neutral particle (neutron or photon) transport in a one-dimensional sub-critical heterogeneous plane parallel medium with surface illumination. General anisotropic scattering is accommodated through the Green's Function Method (GFM). Numerical Fourier transform inversion is used to generate the required Green's functions which are kernels to coupled integral equations that give the exiting angular fluxes. The interior scalar flux is then obtained through quadrature. A compound iterative procedure for quadrature order and slab surface source convergence provides highly accurate benchmark qualities (4- to 5- places of accuracy) results.

  11. Medium Effects in Parton Distributions

    SciTech Connect

    William Detmold, Huey-Wen Lin

    2011-12-01

    A defining experiment of high-energy physics in the 1980s was that of the EMC collaboration where it was first observed that parton distributions in nuclei are non-trivially related to those in the proton. This result implies that the presence of the nuclear medium plays an important role and an understanding of this from QCD has been an important goal ever since Here we investigate analogous, but technically simpler, effects in QCD and examine how the lowest moment of the pion parton distribution is modified by the presence of a Bose-condensed gas of pions or kaons.

  12. Optical Access Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Ansari, Nirwan

    2005-03-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

  13. An Automatic Online Calibration Design in Adaptive Testing

    ERIC Educational Resources Information Center

    Makransky, Guido; Glas, Cees A. W.

    2010-01-01

    An accurately calibrated item bank is essential for a valid computerized adaptive test. However, in some settings, such as occupational testing, there is limited access to test takers for calibration. As a result of the limited access to possible test takers, collecting data to accurately calibrate an item bank in an occupational setting is…

  14. How Does the Medium Affect the Message?

    ERIC Educational Resources Information Center

    Dommermuth, William P.

    1974-01-01

    This experimental comparison of the advertising effectiveness of television, movies, radio, and print finds no support for McLuhan's idea that television is a "cool" medium and movies are a "hot" medium. (RB)

  15. Medium-Frequency Pseudonoise Georadar

    NASA Technical Reports Server (NTRS)

    Arendt, G. Dickey; Carl, J. R.; Byerly, Kent A.; Amini, B. Jon

    2005-01-01

    Ground-probing radar systems featuring medium-frequency carrier signals phase-modulated by binary pseudonoise codes have been proposed. These systems would be used to locate and detect movements of subterranean surfaces; the primary intended application is in warning of the movement of underground water toward oil-well intake ports in time to shut down those ports to avoid pumping of water. Other potential applications include oil-well logging and monitoring of underground reservoirs. A typical prior georadar system operates at a carrier frequency of at least 50 MHz in order to provide useable range resolution. This frequency is too high for adequate penetration of many underground layers of interest. On the other hand, if the carrier frequency were to be reduced greatly to increase penetration, then bandwidth and thus range resolution would also have to be reduced, thereby rendering the system less useful. The proposed medium-frequency pseudonoise georadar systems would offer the advantage of greater penetration at lower carrier frequencies, but without the loss of resolution that would be incurred by operating typical prior georadar systems at lower frequencies.

  16. Gravitational lensing in plasmic medium

    SciTech Connect

    Bisnovatyi-Kogan, G. S. Tsupko, O. Yu.

    2015-07-15

    The influence of plasma on different effects of gravitational lensing is reviewed. Using the Hamiltonian approach for geometrical optics in a medium in the presence of gravity, an exact formula for the photon deflection angle by a black hole (or another body with a Schwarzschild metric) embedded in plasma with a spherically symmetric density distribution is derived. The deflection angle in this case is determined by the mutual combination of different factors: gravity, dispersion, and refraction. While the effects of deflection by the gravity in vacuum and the refractive deflection in a nonhomogeneous medium are well known, the new effect is that, in the case of a homogeneous plasma, in the absence of refractive deflection, the gravitational deflection differs from the vacuum deflection and depends on the photon frequency. In the presence of a plasma nonhomogeneity, the chromatic refractive deflection also occurs, so the presence of plasma always makes gravitational lensing chromatic. In particular, the presence of plasma leads to different angular positions of the same image if it is observed at different wavelengths. It is discussed in detail how to apply the presented formulas for the calculation of the deflection angle in different situations. Gravitational lensing in plasma beyond the weak deflection approximation is also considered.

  17. Gravitational lensing in plasmic medium

    NASA Astrophysics Data System (ADS)

    Bisnovatyi-Kogan, G. S.; Tsupko, O. Yu.

    2015-07-01

    The influence of plasma on different effects of gravitational lensing is reviewed. Using the Hamiltonian approach for geometrical optics in a medium in the presence of gravity, an exact formula for the photon deflection angle by a black hole (or another body with a Schwarzschild metric) embedded in plasma with a spherically symmetric density distribution is derived. The deflection angle in this case is determined by the mutual combination of different factors: gravity, dispersion, and refraction. While the effects of deflection by the gravity in vacuum and the refractive deflection in a nonhomogeneous medium are well known, the new effect is that, in the case of a homogeneous plasma, in the absence of refractive deflection, the gravitational deflection differs from the vacuum deflection and depends on the photon frequency. In the presence of a plasma nonhomogeneity, the chromatic refractive deflection also occurs, so the presence of plasma always makes gravitational lensing chromatic. In particular, the presence of plasma leads to different angular positions of the same image if it is observed at different wavelengths. It is discussed in detail how to apply the presented formulas for the calculation of the deflection angle in different situations. Gravitational lensing in plasma beyond the weak deflection approximation is also considered.

  18. Providing Service-Based Personalization in an Adaptive Hypermedia System

    ERIC Educational Resources Information Center

    Yudelson, Michael V.

    2010-01-01

    Adaptive hypermedia is one of the most popular approaches of personalized information access. When the field started to emerge, the expectation was that soon nearly all published hypermedia content could be adapted to the needs, preferences, and abilities of its users. However, after a decade and a half, the gap between the amount of total…

  19. Content adaptation for visual impairment in MPEG-21

    NASA Astrophysics Data System (ADS)

    Yang, Seungji; Thang, Truong C.; Ro, Yong M.

    2004-06-01

    In this paper, we propose content adaptation for visual impairments in MPEG-21. The proposed content adaptation aims to give enhanced visual accessibility to users with visual impairment in MPEG-21. In this paper, we consider two major visual impairments: low vision impairment and color vision deficiency. The proposed method includes description for the visual impairments and content adaptation technique based on it. We have developed a symptom-based description of visual impairment characteristics for users with visual impairment in the context of MPEG-21 digital item adaptation (DIA). To verify usefulness of the proposed method, we performed some experiments with the content adaptation based on the description in MPEG-21. The experiment results showed that the proposed method is effective content adaptation for user with visual impairment and gives enhanced visual accessibility to them.

  20. NASA Access Mechanism (NAM)

    NASA Technical Reports Server (NTRS)

    Hunter, Judy

    1993-01-01

    A 1991 user survey indicated that NASA users want (1) access to diverse sources of information; (2) an intuitive approach to system use; (3) avoidance of system query languages; (4) access to peers and other informal sources of information; and (5) simplified and enhanced presentation of search results. Based on these requirements and the use of an intelligent gateway processor, the NASA Access Mechanism (NAM) is being developed to provide the users with the semblance of a one stop shopping environment for information management.

  1. Optical Access Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Ansari, Nirwan

    2005-01-01

    Call for Papers: Optical Access Networks

    Guest Editors Jun Zheng, University of Ottawa Nirwan Ansari, New Jersey Institute of Technology

    Submission Deadline: 1 June 2005

    Background

    With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the

  2. Adaptive Composite Map Projections.

    PubMed

    Jenny, B

    2012-12-01

    All major web mapping services use the web Mercator projection. This is a poor choice for maps of the entire globe or areas of the size of continents or larger countries because the Mercator projection shows medium and higher latitudes with extreme areal distortion and provides an erroneous impression of distances and relative areas. The web Mercator projection is also not able to show the entire globe, as polar latitudes cannot be mapped. When selecting an alternative projection for information visualization, rivaling factors have to be taken into account, such as map scale, the geographic area shown, the map's height-to-width ratio, and the type of cartographic visualization. It is impossible for a single map projection to meet the requirements for all these factors. The proposed composite map projection combines several projections that are recommended in cartographic literature and seamlessly morphs map space as the user changes map scale or the geographic region displayed. The composite projection adapts the map's geometry to scale, to the map's height-to-width ratio, and to the central latitude of the displayed area by replacing projections and adjusting their parameters. The composite projection shows the entire globe including poles; it portrays continents or larger countries with less distortion (optionally without areal distortion); and it can morph to the web Mercator projection for maps showing small regions.

  3. Parallel Optical Random Access Memory (PORAM)

    NASA Technical Reports Server (NTRS)

    Alphonse, G. A.

    1989-01-01

    It is shown that the need to minimize component count, power and size, and to maximize packing density require a parallel optical random access memory to be designed in a two-level hierarchy: a modular level and an interconnect level. Three module designs are proposed, in the order of research and development requirements. The first uses state-of-the-art components, including individually addressed laser diode arrays, acousto-optic (AO) deflectors and magneto-optic (MO) storage medium, aimed at moderate size, moderate power, and high packing density. The next design level uses an electron-trapping (ET) medium to reduce optical power requirements. The third design uses a beam-steering grating surface emitter (GSE) array to reduce size further and minimize the number of components.

  4. Parallel Optical Random Access Memory (PORAM)

    NASA Astrophysics Data System (ADS)

    Alphonse, G. A.

    1989-06-01

    It is shown that the need to minimize component count, power and size, and to maximize packing density require a parallel optical random access memory to be designed in a two-level hierarchy: a modular level and an interconnect level. Three module designs are proposed, in the order of research and development requirements. The first uses state-of-the-art components, including individually addressed laser diode arrays, acousto-optic (AO) deflectors and magneto-optic (MO) storage medium, aimed at moderate size, moderate power, and high packing density. The next design level uses an electron-trapping (ET) medium to reduce optical power requirements. The third design uses a beam-steering grating surface emitter (GSE) array to reduce size further and minimize the number of components.

  5. Lamb shift of an atom in a dielectric medium

    SciTech Connect

    Milonni, P.W.; Schaden, M.; Spruch, L.

    1999-06-01

    Adapting an approach used by Feynman for the Lamb shift of an isolated atom, we obtain a nonperturbative expression for the Lamb shift of an atom in a dielectric medium, previously calculated perturbatively [P. W. Milonni, J. Mod. Opt. {bold 42}, 1191 (1995)]. The separation of the Lamb and Casimir components of the field energy is greatly simplified, and previous nonperturbative results for the Lamb shift [M. Schaden, L. Spruch, and F. Zhou, Phys. Rev. A {bold 57}, 1108 (1998)], based on the generalized argument theorem, are obtained much more easily and directly. {copyright} {ital 1999} {ital The American Physical Society}

  6. Adaptive Behavior for Mobile Robots

    NASA Technical Reports Server (NTRS)

    Huntsberger, Terrance

    2009-01-01

    The term "System for Mobility and Access to Rough Terrain" (SMART) denotes a theoretical framework, a control architecture, and an algorithm that implements the framework and architecture, for enabling a land-mobile robot to adapt to changing conditions. SMART is intended to enable the robot to recognize adverse terrain conditions beyond its optimal operational envelope, and, in response, to intelligently reconfigure itself (e.g., adjust suspension heights or baseline distances between suspension points) or adapt its driving techniques (e.g., engage in a crabbing motion as a switchback technique for ascending steep terrain). Conceived for original application aboard Mars rovers and similar autonomous or semi-autonomous mobile robots used in exploration of remote planets, SMART could also be applied to autonomous terrestrial vehicles to be used for search, rescue, and/or exploration on rough terrain.

  7. Coherent Digital Holographic Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Liu, Changgeng

    A new type of adaptive optics (AO) based on the principles of digital holography (DH) is proposed and developed for the use in wide-field and confocal retinal imaging. Digital holographic adaptive optics (DHAO) dispenses with the wavefront sensor and wavefront corrector of the conventional AO system. DH is an emergent imaging technology that gives direct numerical access to the phase of the optical field, thus allowing precise control and manipulation of the optical field. Incorporation of DH in an ophthalmic imaging system can lead to versatile imaging capabilities at substantially reduced complexity and cost of the instrument. A typical conventional AO system includes several critical hardware pieces: spatial light modulator, lenslet array, and a second CCD camera in addition to the camera for imaging. The proposed DHAO system replaces these hardware components with numerical processing for wavefront measurement and compensation of aberration through the principles of DH. (Abstract shortened by UMI.).

  8. 49 CFR 195.306 - Test medium.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Test medium. 195.306 Section 195.306... PIPELINE Pressure Testing § 195.306 Test medium. (a) Except as provided in paragraphs (b), (c), and (d) of this section, water must be used as the test medium. (b) Except for offshore pipelines,...

  9. 27 CFR 19.914 - Medium plants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Medium plants. 19.914... OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Distilled Spirits For Fuel Use Permits § 19.914 Medium plants. Any person wishing to establish a medium plant shall make application for and obtain...

  10. Particle dynamics in an active medium

    SciTech Connect

    Schaechter, L.

    1997-03-01

    When a point-charge moves in an active medium it can gain energy at the expense of that stored in the medium. The maximum gradient is evaluated and its relation to the energy stored in the medium is established. The dynamics of a distribution of electrons was also examined and it is reported here. {copyright} {ital 1997 American Institute of Physics.}

  11. 49 CFR 195.306 - Test medium.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Test medium. 195.306 Section 195.306... PIPELINE Pressure Testing § 195.306 Test medium. (a) Except as provided in paragraphs (b), (c), and (d) of this section, water must be used as the test medium. (b) Except for offshore pipelines,...

  12. 49 CFR 195.306 - Test medium.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Test medium. 195.306 Section 195.306... PIPELINE Pressure Testing § 195.306 Test medium. (a) Except as provided in paragraphs (b), (c), and (d) of this section, water must be used as the test medium. (b) Except for offshore pipelines,...

  13. Adaptive holography for optical sensing applications

    NASA Astrophysics Data System (ADS)

    Residori, S.; Bortolozzo, U.; Peigné, A.; Molin, S.; Nouchi, P.; Dolfi, D.; Huignard, J. P.

    2016-03-01

    Adaptive holography is a promising method for high sensitivity phase modulation measurements in the presence of slow perturbations from the environment. The technique is based on the use of a nonlinear recombining medium, here an optically addressed spatial light modulator specifically realized to operate at 1.55 μm. Owing to the physical mechanisms involved, the interferometer adapts to slow phase variations within a range of 5-10 Hz, thus filtering out low frequency noise while transmitting higher frequency phase modulations. We present the basic principles of the adaptive interferometer and show that it can be used in association with a sensing fiber in order to detect phase modulations. Finally, a phase-OTDR architecture using the adaptive holographic interferometer is presented and shown to allows the detection of localized perturbations along the sensing fiber.

  14. The Impact of Language on Educational Access in South Africa. CREATE Pathways to Access. Research Monograph No. 24

    ERIC Educational Resources Information Center

    Lafon, Michel

    2009-01-01

    The role of Medium of Instruction or Language of Learning and Teaching has not received sufficient attention as a factor denying meaningful access to education in South Africa. Yet the majority of under-performing learners are also children who learn in a language that is not their mother-tongue. This research aims to assess how recent language…

  15. HRP Data Accessibility 2009

    NASA Video Gallery

    Dr. Clarence Sams spoke at the 2009 Human Research Program's Investigators Workshop on the current status of Data Accessibility. In this presentation he discusses the content of the Human Life Scie...

  16. Accessibility and assistive products

    PubMed Central

    Rodríguez-Porrero, Cristina

    2009-01-01

    Introduction Accessibility and assistive products and technologies are needed to ensure the rights of persons with disabilities and older persons. Many developments have been implemented in laws, standards, markets and from the consumers perspective, at international, European and national levels. The real issue is that not all the potential users benefit from the use of assistive products or accessible measures. Discussion Innovative methods are needed to allow all potential users to have real advantage of assistive technologies and accessible and design for all facilities. Best practices will be presented and existing gaps and recommendations will be discussed. Cost-benefits aspects will also be presented. Conclusion In order to get advantages from opportunities of globalization, hard work and responsibilities of all stakeholders are needed, so that assistive products and accessibility reach a whole range of situations and environments and contribute to ensure quality of life in a society for all.

  17. Access denied; invalid password.

    PubMed

    Chambers, David W

    2006-11-01

    Progress addressing access to oral health is difficult to evaluate because it is unclear what access means. Ozar's proposal that access should be defined by dentists as true dental need is criticized. It is proposed that four different types of treatment are currently identifiable in dentistry: 1) traditional oral health care, 2) oral care that has minimal or no health component, 3) episodic care, and 4) oral health outcomes not resulting from dentist interventions such as fluoridation. Each of these models has a different definition of care and of access. The profession is becoming segmented--including growing disparities among dentists in earning potential--to the point where a single model may no longer be able to cover all needs for oral health.

  18. EPA Accessibility Statement

    EPA Pesticide Factsheets

    EPA is committed to making its websites and other electronic and information technology (EIT) accessible to the widest possible audience, including people with disabilities, in accordance with Section 508 of the Rehabilitation Act.

  19. Equal Access to All.

    ERIC Educational Resources Information Center

    Schettler, Joel

    2002-01-01

    Discusses the Section 508 amendment to the Rehabilitation Act of 1973 that directs the use of technology. Describes guidelines for online training accessibility with which vendors hoping for government business must fully comply. (JOW)

  20. Access to Investigational Drugs

    MedlinePlus

    ... access to investigational drugs being developed by pharmaceutical companies? Are there specific criteria used to determine whether ... laboratory. If the results are promising, the drug company or sponsor must apply for FDA approval to ...

  1. Problems of Accessibility.

    ERIC Educational Resources Information Center

    Servedio, William; McLeod, William

    1980-01-01

    Increased participation in recreational programing by persons with handicapping conditions is a right that calls for significant changes in accessibility of facilities. Both interior and exterior building modifications must be made. (CJ)

  2. First Accessible Boat Launch

    EPA Pesticide Factsheets

    This is a story about how the Northwest Indiana urban waters partnership location supported the process to create and open the first handicap accessible canoe and kayak launch in the state of Indiana.

  3. Optical Access Networks

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Ansari, Nirwan

    2005-02-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

  4. Design study of the accessible focal plane telescope for shuttle

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The design and cost analysis of an accessible focal plane telescope for Spacelab is presented in blueprints, tables, and graphs. Topics covered include the telescope tube, the telescope mounting, the airlock plus Spacelab module aft plate, the instrument adapter, and the instrument package. The system allows access to the image plane with instrumentation that can be operated by a scientist in a shirt sleeve environment inside a Spacelab module.

  5. PYRITHIAMINE ADAPTATION OF STAPHYLOCOCCUS AUREUS I.

    PubMed Central

    Das, S. K.; Chatterjee, G. C.

    1962-01-01

    Das, S. K. (University of Calcutta, Calcutta, India) and G. C. Chatterjee. Pyrithiamine adaptation of Staphylococcus aureus. I. Adaptation and carbohydrate utilization. J. Bacteriol. 83:1251–1259. 1962.—Staphylococcus aureus has been adapted to pyrithiamine, a thiamine analogue; as a result of this adaptation, the color of the pigment of the organism changes from orange-yellow to lemon-yellow. The adaptation is reversible; the adapted strain will revert after repeated subculture in a medium containing thiamine and no pyrithiamine. Of the major biochemical alterations resulting from adaptation, severe depression in glucose utilization and simultaneous stimulation of acetate utilization have been noticed. The effect of metabolic inhibitors on the utilization of glucose and acetate has also been studied. By measuring the rate of formation of C14O2 from glucose-1-C14 and glucose-6-C14, it has been observed that the reduction in C14O2 formation from glucose-1-C14 by the adapted organism is much more than that obtained from glucose-6-C14, causing thereby a decreased metabolic ratio of these two substrates after such adaptation. Relative to the normal strain, the adapted strain utilizes acetate-C14 at a much faster rate, both in the formation of C14O2 and also in the incorporation of C14 into the protein and lipid fractions; the rate of formation of C14O2 from pyruvate-1-C14 is not greatly altered. It has been postulated that there is a partial blocking of the pentose phosphate cycle, because of the lowered glucose-1-C14 utilization, and simultaneous stimulation of the tricarboxylic acid cycle; or perhaps the initiation of some other route after pyrithiamine adaptation would account for the great increase in acetate utilization. PMID:13883630

  6. Mobile multiple access study

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Multiple access techniques (FDMA, CDMA, TDMA) for the mobile user and attempts to identify the current best technique are discussed. Traffic loading is considered as well as voice and data modulation and spacecraft and system design. Emphasis is placed on developing mobile terminal cost estimates for the selected design. In addition, design examples are presented for the alternative techniques of multiple access in order to compare with the selected technique.

  7. Vascular Access in Children

    SciTech Connect

    Krishnamurthy, Ganesh Keller, Marc S.

    2011-02-15

    Establishment of stable vascular access is one of the essential and most challenging procedures in a pediatric hospital. Many clinical specialties provide vascular service in a pediatric hospital. At the top of the 'expert procedural pyramid' is the pediatric interventional radiologist, who is best suited and trained to deliver this service. Growing awareness regarding the safety and high success rate of vascular access using image guidance has led to increased demand from clinicians to provide around-the-clock vascular access service by pediatric interventional radiologists. Hence, the success of a vascular access program, with the pediatric interventional radiologist as the key provider, is challenging, and a coordinated multidisciplinary team effort is essential for success. However, there are few dedicated pediatric interventional radiologists across the globe, and also only a couple of training programs exist for pediatric interventions. This article gives an overview of the technical aspects of pediatric vascular access and provides useful tips for obtaining vascular access in children safely and successfully using image guidance.

  8. Adaptive Image Denoising by Mixture Adaptation

    NASA Astrophysics Data System (ADS)

    Luo, Enming; Chan, Stanley H.; Nguyen, Truong Q.

    2016-10-01

    We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the Expectation-Maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad-hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper: First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. Experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms.

  9. Adaptive Image Denoising by Mixture Adaptation.

    PubMed

    Luo, Enming; Chan, Stanley H; Nguyen, Truong Q

    2016-10-01

    We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the expectation-maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper. First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. The experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms.

  10. Sintered composite medium and filter

    DOEpatents

    Bergman, Werner

    1987-01-01

    A particulate filter medium is formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers. A preferred composition is about 40 vol. % quartz and about 60 vol. % stainless steel fibers. The media is sintered at about 1100.degree. C. to bond the stainless steel fibers into a cage network which holds the quartz fibers. High filter efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550.degree. C. The invention also includes methods to form the composite media and a HEPA filter utilizing the composite media. The filter media can be used to filter particles in both liquids and gases.

  11. Uplink Access Schemes for LTE-Advanced

    NASA Astrophysics Data System (ADS)

    Liu, Le; Inoue, Takamichi; Koyanagi, Kenji; Kakura, Yoshikazu

    The 3GPP LTE-Advanced has been attracting much attention recently, where the channel bandwidth would be beyond the maximum bandwidth of LTE, 20MHz. In LTE, single carrier-frequency division multiple access (SC-FDMA) was accepted as the uplink access scheme due to its advantage of very low cubic metric (CM). For LTE-A wideband transmission, multicarrier access would be more effective than single carrier access to make use of multi-user diversity and can maintain the physical channel structure of LTE, where the control information is transmitted on the edges of each 20MHz. In this paper, we discuss the access schemes in bandwidth under 20MHz as well as over 20MHz. In the case of bandwidth under 20MHz, we propose the access schemes allowing discontinuous resource allocation to enhance average throughput while maintaining cell-edge user throughput, that is, DFT-spread-OFDM with spectrum division control (SDC) and adaptive selection of SC-FDMA and OFDM (SC+OFDM). The number of discontinuous spectrums is denoted as spectrum division (SD). For DFT-S-OFDM, we define a parameter max SD as the upper limit of SD. We evaluate our proposed schemes in bandwidth under 20MHz and find that SC+OFDM as well as SDC with common max SD or UE-specific max SD can improve average throughput while their cell-edge user throughput can approach that of SC-FDMA. In the case of bandwidth over 20MHz, we consider key factors to decide a feasible access scheme for aggregating several 20MHz-wide bands.

  12. Investigating the Small and Medium Enterprise Landscape of Accra, Ghana: Prospects and Barriers to Economic Development

    DTIC Science & Technology

    2012-02-01

    Entrepreneurship and Public Sector Branding to its clients. AHR is fits the definition of a Small and Medium Enterprise as defined by USAID; they have 6...these challenges to accessing capital. Social entrepreneurship and corporate social responsibility consciousness ( CSR ) is embedded within the

  13. Xylose utilizing zymomonas mobilis with improved ethanol production in biomass hydrolysate medium

    SciTech Connect

    Caimi, Perry G; Hitz, William D; Stieglitz, Barry; Viitanen, Paul V

    2013-07-02

    Xylose-utilizing, ethanol producing strains of Zymomonas mobilis with improved performance in medium comprising biomass hydrolysate were isolated using an adaptation process. Independently isolated strains were found to have independent mutations in the same coding region. Mutation in this coding may be engineered to confer the improved phenotype.

  14. Xylose utilizing Zymomonas mobilis with improved ethanol production in biomass hydrolysate medium

    SciTech Connect

    Caimi, Perry G; Hitz, William D; Viitanen, Paul V; Stieglitz, Barry

    2013-10-29

    Xylose-utilizing, ethanol producing strains of Zymomonas mobilis with improved performance in medium comprising biomass hydrolysate were isolated using an adaptation process. Independently isolated strains were found to have independent mutations in the same coding region. Mutation in this coding may be engineered to confer the improved phenotype.

  15. Context-aware access control for pervasive access to process-based healthcare systems.

    PubMed

    Koufi, Vassiliki; Vassilacopoulos, George

    2008-01-01

    Healthcare is an increasingly collaborative enterprise involving a broad range of healthcare services provided by many individuals and organizations. Grid technology has been widely recognized as a means for integrating disparate computing resources in the healthcare field. Moreover, Grid portal applications can be developed on a wireless and mobile infrastructure to execute healthcare processes which, in turn, can provide remote access to Grid database services. Such an environment provides ubiquitous and pervasive access to integrated healthcare services at the point of care, thus improving healthcare quality. In such environments, the ability to provide an effective access control mechanism that meets the requirement of the least privilege principle is essential. Adherence to the least privilege principle requires continuous adjustments of user permissions in order to adapt to the current situation. This paper presents a context-aware access control mechanism for HDGPortal, a Grid portal application which provides access to workflow-based healthcare processes using wireless Personal Digital Assistants. The proposed mechanism builds upon and enhances security mechanisms provided by the Grid Security Infrastructure. It provides tight, just-in-time permissions so that authorized users get access to specific objects according to the current context. These permissions are subject to continuous adjustments triggered by the changing context. Thus, the risk of compromising information integrity during task executions is reduced.

  16. Dynamic Adaption of Vascular Morphology

    PubMed Central

    Okkels, Fridolin; Jacobsen, Jens Christian Brings

    2012-01-01

    The structure of vascular networks adapts continuously to meet changes in demand of the surrounding tissue. Most of the known vascular adaptation mechanisms are based on local reactions to local stimuli such as pressure and flow, which in turn reflects influence from the surrounding tissue. Here we present a simple two-dimensional model in which, as an alternative approach, the tissue is modeled as a porous medium with intervening sharply defined flow channels. Based on simple, physiologically realistic assumptions, flow-channel structure adapts so as to reach a configuration in which all parts of the tissue are supplied. A set of model parameters uniquely determine the model dynamics, and we have identified the region of the best-performing model parameters (a global optimum). This region is surrounded in parameter space by less optimal model parameter values, and this separation is characterized by steep gradients in the related fitness landscape. Hence it appears that the optimal set of parameters tends to localize close to critical transition zones. Consequently, while the optimal solution is stable for modest parameter perturbations, larger perturbations may cause a profound and permanent shift in systems characteristics. We suggest that the system is driven toward a critical state as a consequence of the ongoing parameter optimization, mimicking an evolutionary pressure on the system. PMID:23060814

  17. Enriching the hot circumgalactic medium

    NASA Astrophysics Data System (ADS)

    Crain, Robert A.; McCarthy, Ian G.; Schaye, Joop; Theuns, Tom; Frenk, Carlos S.

    2013-07-01

    Simple models of galaxy formation in a cold dark matter universe predict that massive galaxies are surrounded by a hot, quasi-hydrostatic circumgalactic corona of slowly cooling gas, predominantly accreted from the intergalactic medium (IGM). This prediction is borne out by the recent cosmological hydrodynamical simulations of Crain et al., which reproduce observed scaling relations between the X-ray and optical properties of nearby disc galaxies. Such coronae are metal poor, but observations of the X-ray emitting circumgalactic medium (CGM) of local galaxies typically indicate enrichment to near-solar iron abundance, potentially signalling a shortcoming in current models of galaxy formation. We show here that, while the hot CGM of galaxies formed in the simulations is typically metal poor in a mass-weighted sense, its X-ray luminosity-weighted metallicity is often close to solar. This bias arises because the soft X-ray emissivity of a typical ˜0.1 keV corona is dominated by collisionally excited metal ions that are synthesized in stars and recycled into the hot CGM. We find that these metals are ejected primarily by stars that form in situ to the main progenitor of the galaxy, rather than in satellites or external galaxies. The enrichment of the hot CGM therefore proceeds in an `inside-out' fashion throughout the assembly of the galaxy: metals are transported from the central galaxy by supernova-driven winds and convection over several Gyr, establishing a strong negative radial metallicity gradient. Whilst metal ions synthesized by stars are necessary to produce the X-ray emissivity that enables the hot CGM of isolated galaxies to be detected with current instrumentation, the electrons that collisionally excite them are equally important. Since our simulations indicate that the electron density of hot coronae is dominated by the metal-poor gas accreted from the IGM, we infer that the hot CGM observed via X-ray emission is the outcome of both hierarchical

  18. Developing Adaptive Training in the Classroom

    DTIC Science & Technology

    2009-09-01

    Developing Adaptive Proficiency in Special Forces Officers (2005), p. A-4. 2-3 Such a critical incident speaks to a performance requirement to...Order of speaking Body language Prepare both cases: your and their arguments Build rapport Main Discussion Agreement is the simultaneous...think you can make a judgment, check “N/A” for not applicable. Adjectives* High Medium Low N/A • Extroverted (outgoing, talkative

  19. ISDC Data Access Layer

    NASA Astrophysics Data System (ADS)

    Jennings, D.; Borkowski, J.; Contessi, T.; Lock, T.; Rohlfs, R.; Walter, R.

    The ISDC Data Access Layer (DAL) is an ANSI C and \\fortran 90 compatible library under development in support of the ESA INTEGRAL mission data analysis software. DALs primary purpose is to isolate the analysis software from the specifics of the data formats while at the same time providing new data abstraction and access capabilities. DAL supports the creation and manipulation of hierarchical data sets which may span multiple files and, in theory, multiple computer systems. A number of Application Programming Interfaces (APIs) are supported by DAL that allow software to view and access data at different levels of complexity. DAL also allows data sets to reside on disk, in conventional memory or in shared memory in a way that is transparent to the user/application.

  20. Vascular access for hemodialysis.

    PubMed

    Vanholder, R; Ringoir, S

    1994-04-01

    Indwelling central venous catheters were consecutively used as access for acute and chronic hemodialysis, emergency treatment of pulmonary fluid overload, intoxication and electrolyte disturbances, plasmapheresis, and semiacute continuous dialysis strategies, such as continuous arteriovenous hemofiltration (CAVH). Modification in catheter structure also made it possible to use this access for long-term treatment (e.g., surgically insertable catheters [Hickman], soft large-bore catheters for blind insertion). We discuss the remaining open questions in this field: Which is the insertion site of preference (i.e., subclavian, femoral, or deep jugular)? Should we prefer stiff or soft catheters? Should soft catheters be positioned surgically or is blind insertion by nonsurgeons as adequate? Is it necessary to couple catheter insertion to adjuvant techniques, such as echographic guidance, to reduce complications? Is the currently used polymer structure of the catheters acceptable? Should catheter dialysis be used with single or double vascular access?

  1. Restaurant wheelchair accessibility.

    PubMed

    McClain, L; Beringer, D; Kuhnert, H; Priest, J; Wilkes, E; Wilkinson, S; Wyrick, L

    1993-07-01

    This study was designed to determine the compliance of restaurants to the wheelchair accessibility standards set forth in the Uniform Federal Accessibility Standards. The standards that were operationalized in this study are also found in Title III of the Americans With Disabilities Act of 1990. The data were collected at 120 sites in three midwestern states. For one who uses a wheelchair, parking the car is often an obstacle to eating out. Only 53% of the restaurants surveyed provide handicapped parking. Entering the building may also be a problem. Of the restaurants that required a ramp, only 66% provided them. Inside the restaurant, the key problems were accessible rest-rooms and the height of tables. The study provided comparisons between restaurants in rural and urban settings, as well as comparisons between conventional restaurants and fast food restaurants. No notable differences emerged for these comparisons.

  2. The Circumgalactic Medium of Andromeda

    NASA Astrophysics Data System (ADS)

    Lehner, Nicolas; Project AMIGA team

    2017-03-01

    Our view of galaxies has been transformed in recent years with diffuse halo gas surrounding galaxies that contains at least as many metals and baryons as their disks. While single sight lines through galaxy halos seen in absorption have provided key new constraints, they provide only average properties. Our massive neighbor, the Andromeda (M31) galaxy, provides an unique way to study its circumgalactic medium whereby we can study it using not one or two, but ~36 sightlines thanks to its proximity. With our Large HST program - Project AMIGA (Absorption Maps In the Gas of Andromeda), our goals are to determine the spatial distribution of the halo properties of a L* galaxy using 36 background targets at different radii and azimuths. In this brief paper, I discuss briefly the scientific rationale of Project AMIGA and some early science results. In particular, for the first time we have demonstrated that M31 has a gaseous halo that extends to R vir with as much as metal and baryonic masses than in its disk and has substantial change in its ionization properties with more highly ionized gas found at R ~ R vir than cooler gas found near the disk.

  3. Studies in medium energy physics

    SciTech Connect

    Green, A.; Hoffmann, G.W.; McDonough, J.; Purcell, M.J.; Ray, R.L.; Read, D.E.; Worn, S.D.

    1991-12-01

    This document constitutes the (1991--1992) technical progress report and continuation proposal for the ongoing medium energy nuclear physics research program supported by the US Department of Energy through special Research Grant DE-FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF) and the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics; (2) provide unique, first-of-a-kind exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics.

  4. Habituation of visual adaptation

    PubMed Central

    Dong, Xue; Gao, Yi; Lv, Lili; Bao, Min

    2016-01-01

    Our sensory system adjusts its function driven by both shorter-term (e.g. adaptation) and longer-term (e.g. learning) experiences. Most past adaptation literature focuses on short-term adaptation. Only recently researchers have begun to investigate how adaptation changes over a span of days. This question is important, since in real life many environmental changes stretch over multiple days or longer. However, the answer to the question remains largely unclear. Here we addressed this issue by tracking perceptual bias (also known as aftereffect) induced by motion or contrast adaptation across multiple daily adaptation sessions. Aftereffects were measured every day after adaptation, which corresponded to the degree of adaptation on each day. For passively viewed adapters, repeated adaptation attenuated aftereffects. Once adapters were presented with an attentional task, aftereffects could either reduce for easy tasks, or initially show an increase followed by a later decrease for demanding tasks. Quantitative analysis of the decay rates in contrast adaptation showed that repeated exposure of the adapter appeared to be equivalent to adaptation to a weaker stimulus. These results suggest that both attention and a non-attentional habituation-like mechanism jointly determine how adaptation develops across multiple daily sessions. PMID:26739917

  5. Medium factors on anaerobic production of rhamnolipids by Pseudomonas aeruginosa SG and a simplifying medium for in situ microbial enhanced oil recovery applications.

    PubMed

    Zhao, Feng; Zhou, Jidong; Han, Siqin; Ma, Fang; Zhang, Ying; Zhang, Jie

    2016-04-01

    Aerobic production of rhamnolipid by Pseudomonas aeruginosa was extensively studied. But effect of medium composition on anaerobic production of rhamnolipid by P. aeruginosa was unknown. A simplifying medium facilitating anaerobic production of rhamnolipid is urgently needed for in situ microbial enhanced oil recovery (MEOR). Medium factors affecting anaerobic production of rhamnolipid were investigated using P. aeruginosa SG (Genbank accession number KJ995745). Medium composition for anaerobic production of rhamnolipid by P. aeruginosa is different from that for aerobic production of rhamnolipid. Both hydrophobic substrate and organic nitrogen inhibited rhamnolipid production under anaerobic conditions. Glycerol and nitrate were the best carbon and nitrogen source. The commonly used N limitation under aerobic conditions was not conducive to rhamnolipid production under anaerobic conditions because the initial cell growth demanded enough nitrate for anaerobic respiration. But rhamnolipid was also fast accumulated under nitrogen starvation conditions. Sufficient phosphate was needed for anaerobic production of rhamnolipid. SO4(2-) and Mg(2+) are required for anaerobic production of rhamnolipid. Results will contribute to isolation bacteria strains which can anaerobically produce rhamnolipid and medium optimization for anaerobic production of rhamnolipid. Based on medium optimization by response surface methodology and ions composition of reservoir formation water, a simplifying medium containing 70.3 g/l glycerol, 5.25 g/l NaNO3, 5.49 g/l KH2PO4, 6.9 g/l K2HPO4·3H2O and 0.40 g/l MgSO4 was designed. Using the simplifying medium, 630 mg/l of rhamnolipid was produced by SG, and the anaerobic culture emulsified crude oil to EI24 = 82.5 %. The simplifying medium was promising for in situ MEOR applications.

  6. Central venous access.

    PubMed

    Ganeshan, Arul; Warakaulle, Dinuke R; Uberoi, Raman

    2007-01-01

    Central venous access plays an important role in the management of an ever-increasing population of patients ranging from those that are critically ill to patients with difficult clinical access. Interventional radiologists are key in delivering this service and should be familiar with the wide range of techniques and catheters now available to them. A comprehensive description of these catheters with regard to indications, technical aspects of catheterization, success rates, and associated early and late complications, as well as a review of various published guidelines on central venous catheter insertion are given in this article.

  7. Accessibility | Smokefree 60+

    Cancer.gov

    60plus.smokefree.gov is committed to making its websites accessible to all individuals—disabled or not—who are seeking information. To provide this information, the Smokefree 60+ website has been designed to comply with Section 508 of the Rehabilitation Act (as amended). Section 508 requires that all individuals with disabilities (whether they are federal government employees or members of the general public) have access to and use of information and data comparable to that provided to individuals without disabilities, unless an undue burden would be imposed.

  8. Disability access. Open season.

    PubMed

    Morgan, Brian

    2003-04-24

    A disability access audit carried out at a trust operating over 50 sites revealed that a 2.3m Pounds programme of work was needed. The audit took four months, with the team spending a day at each of the premises. The audit has been followed by a staff training programme in disability awareness. The trust's information systems now show if a patient did not attend an appointment because of difficulties with physical access. All letters to patients are produced in a minimum 12-point type.

  9. Medium Range Flood Forecasting for Agriculture Damage Reduction

    NASA Astrophysics Data System (ADS)

    Fakhruddin, S. H. M.

    2014-12-01

    Early warning is a key element for disaster risk reduction. In recent decades, major advancements have been made in medium range and seasonal flood forecasting. This progress provides a great opportunity to reduce agriculture damage and improve advisories for early action and planning for flood hazards. This approach can facilitate proactive rather than reactive management of the adverse consequences of floods. In the agricultural sector, for instance, farmers can take a diversity of options such as changing cropping patterns, applying fertilizer, irrigating and changing planting timing. An experimental medium range (1-10 day) flood forecasting model has been developed for Bangladesh and Thailand. It provides 51 sets of discharge ensemble forecasts of 1-10 days with significant persistence and high certainty. This type of forecast could assist farmers and other stakeholders for differential preparedness activities. These ensembles probabilistic flood forecasts have been customized based on user-needs for community-level application focused on agriculture system. The vulnerabilities of agriculture system were calculated based on exposure, sensitivity and adaptive capacity. Indicators for risk and vulnerability assessment were conducted through community consultations. The forecast lead time requirement, user-needs, impacts and management options for crops were identified through focus group discussions, informal interviews and community surveys. This paper illustrates potential applications of such ensembles for probabilistic medium range flood forecasts in a way that is not commonly practiced globally today.

  10. Medium of Instruction in Thai Science Learning

    NASA Astrophysics Data System (ADS)

    Chanjavanakul, Natpat

    The goal of this study is to compare classroom discourse in Thai 9th grade science lessons with English or Thai as a medium of instruction. This is a cross-sectional study of video recordings from five lessons in an English-medium instruction class and five lessons in a Thai- medium instruction class from a Thai secondary school. The study involved two teachers and two groups of students. The findings show the use of both English and Thai in English-medium lessons. Students tend to be more responsive to teacher questions in Thai than in English. The findings suggest the use of students' native language during English-medium lessons to help facilitate learning in certain situations. Additionally, the study provides implications for research, practice and policy for using English as a medium of instruction.

  11. Opinion: Adaptive Computing and the Internet: One Step forward, Two Steps Back?

    ERIC Educational Resources Information Center

    Lazzaro, Joseph J.

    1994-01-01

    This overview of adaptive technology for computers and networking identifies issues that must be addressed for people with disabilities to participate fully in online activities. Discussion includes adaptive equipment; Internet access; and graphical user interface (GUI) concerns. Contact information for vendors for adaptive technology and…

  12. Empower: access to medicine - working towards early access.

    PubMed

    Pearson, Jennifer Bryant; Turgoose, James; Hargrave, James

    2015-01-01

    Empower: Access to Medicine's contribution will document the founding of Empower: Access to Medicine and tactics used to create a lobbying campaign designed to facilitate the debate around barriers to medical innovation and patient access to medicines. The article will detail the evolution of the campaign's goals and the potential solutions to an expensive and slow system. Specifically the submission will look at the influence that Empower: Access to Medicine had on the Government's thinking and development of an early access scheme.

  13. Medium chain triglycerides and hepatic encephalopathy

    PubMed Central

    Morgan, M. Hilary; Bolton, C. H.; Morris, J. S.; Read, A. E.

    1974-01-01

    The oral administration of short (C6) and medium (C8 and (C10) chain triglycerides produced no clinical or electroencephalographic changes in patients with cirrhosis of the liver. Arterial ammonia levels were also monitored in these patients and showed no significant change after medium chain triglycerides. It was concluded that medium chain triglycerides, known to be of potential value in the treatment of malabsorption in patients with cirrhosis, are not clinically contraindicated, even in patients with evidence of hepatic encephalopathy. PMID:4841275

  14. The performance of dense medium processes

    SciTech Connect

    Horsfall, D.W.

    1993-12-31

    Dense medium washing in baths and cyclones is widely carried out in South Africa. The paper shows the reason for the preferred use of dense medium processes rather than gravity concentrators such as jigs. The factors leading to efficient separation in baths are listed and an indication given of the extent to which these factors may be controlled and embodied in the deployment of baths and dense medium cyclones in the planning stages of a plant.

  15. Accessing genetic diversity for crop improvement.

    PubMed

    Glaszmann, J C; Kilian, B; Upadhyaya, H D; Varshney, R K

    2010-04-01

    Vast germplasm collections are accessible but their use for crop improvement is limited-efficiently accessing genetic diversity is still a challenge. Molecular markers have clarified the structure of genetic diversity in a broad range of crops. Recent developments have made whole-genome surveys and gene-targeted surveys possible, shedding light on population dynamics and on the impact of selection during domestication. Thanks to this new precision, germplasm description has gained analytical power for resolving the genetic basis of trait variation and adaptation in crops such as major cereals, chickpea, grapevine, cacao, or banana. The challenge now is to finely characterize all the facets of plant behavior in carefully chosen materials. We suggest broadening the use of 'core reference sets' so as to facilitate material sharing within the scientific community.

  16. Managing Information Resources for Accessibility.

    ERIC Educational Resources Information Center

    General Services Administration, Washington, DC. Clearinghouse on Computer Accommodation.

    This handbook presents guidance for federal managers and other personnel who are unfamiliar with the policy and practice of information accessibility to accommodate users with disabilities and to provide for their effective access to information resources. It addresses federal requirements for accessibility, adopting accessibility as a sound…

  17. Digital Scholarship and Open Access

    ERIC Educational Resources Information Center

    Losoff, Barbara; Pence, Harry E.

    2010-01-01

    Open access publications provide scholars with unrestricted access to the "conversation" that is the basis for the advancement of knowledge. The large number of open access journals, archives, and depositories already in existence demonstrates the technical and economic viability of providing unrestricted access to the literature that is the…

  18. Unstructured Adaptive Meshes: Bad for Your Memory?

    NASA Technical Reports Server (NTRS)

    Biswas, Rupak; Feng, Hui-Yu; VanderWijngaart, Rob

    2003-01-01

    This viewgraph presentation explores the need for a NASA Advanced Supercomputing (NAS) parallel benchmark for problems with irregular dynamical memory access. This benchmark is important and necessary because: 1) Problems with localized error source benefit from adaptive nonuniform meshes; 2) Certain machines perform poorly on such problems; 3) Parallel implementation may provide further performance improvement but is difficult. Some examples of problems which use irregular dynamical memory access include: 1) Heat transfer problem; 2) Heat source term; 3) Spectral element method; 4) Base functions; 5) Elemental discrete equations; 6) Global discrete equations. Nonconforming Mesh and Mortar Element Method are covered in greater detail in this presentation.

  19. In-Medium Pion Valence Distribution Amplitude

    NASA Astrophysics Data System (ADS)

    Tsushima, K.; de Melo, J. P. B. C.

    2017-03-01

    After a brief review of the quark-based model for nuclear matter, and some pion properties in medium presented in our previous works, we report new results for the pion valence wave function as well as the valence distribution amplitude in medium, which are presented in our recent article. We find that both the in-medium pion valence distribution and the in-medium pion valence wave function, are substantially modified at normal nuclear matter density, due to the reduction in the pion decay constant.

  20. Computer Access. Tech Use Guide: Using Computer Technology.

    ERIC Educational Resources Information Center

    Council for Exceptional Children, Reston, VA. Center for Special Education Technology.

    One of nine brief guides for special educators on using computer technology, this guide focuses on access including adaptations in input devices, output devices, and computer interfaces. Low technology devices include "no-technology" devices (usually modifications to existing devices), simple switches, and multiple switches. High technology input…

  1. Metals in the intracluster medium

    NASA Astrophysics Data System (ADS)

    Matsushita, Kyoko; Sato, Kosuke; Sakuma, Eri; Tamura, Takayuki

    2012-03-01

    We derived radial abundance profiles of O, Mg, Si, S and Fe in the intracluster medium (ICM) of several clusters and groups of galaxies up to about 0.3 r180 with Suzaku and those of Fe in 28 nearby brightest clusters of galaxies up to 0.3-0.5 r180 with XMM. Within 0.05 r180, Fe abundance scatters from 0.5 to 1 solar. The scatter may be caused by a difference in recent metal supplies with supernovae Ia and stellar mass loss from cD galaxies. In these regions and also in ISM in giant elliptical galaxies, the abundance patterns of O, Mg, Si, S and Fe are close to the solar ratio adopting the new solar abundance defined by Lodders [1]. At 0.1-0.5 r180, relaxed clusters with a cD galaxy at their X-ray peak have flat Fe abundance profiles at 0.4-0.5 solar, with a small scatter. In these clusters, the ratio of Fe mass in the ICM to the light from galaxies have similar profiles, and increases toward outer regions. In addition, several systems show a hint of enhancement of O/Fe and Mg/Fe ratios. These results indicate that the metal-enrichment process in these clusters has been universal, and a significant amount of Fe is synthesized at a very early stage in cluster formation. Scatter in the metal-mass-to-light ratios and similarity in the abundances in the ICM of groups and clusters of galaxies also indicate early metal synthesis.

  2. Serving up Access

    ERIC Educational Resources Information Center

    Rich, Sarah

    2011-01-01

    When low-income students returned to Chicago public schools this fall, many had better access to technology, thanks to a public-private partnership. Chicago families with children enrolled in the National School Lunch Program are eligible for subsidized computers and Internet connections through an agreement between the city and telecom giant…

  3. ACCESS Project: Final Report

    SciTech Connect

    Weller, Heiko

    2015-04-01

    The ACCESS project addressed the development, testing, and demonstration of the proposed advanced technologies and the associated emission and fuel economy improvement at an engine dynamometer and on a full-scale vehicle. Improve fuel economy by 25% with minimum performance penalties Achieve SULEV level emissions with gasoline Demonstrate multi-mode combustion engine management system

  4. ACCENT ON ACCESS.

    ERIC Educational Resources Information Center

    CHATELAIN, LEON, JR.; AND OTHERS

    EMPHASIS IS GIVEN ON ACCESSIBILITY TO PUBLIC BUILDINGS BY THE HANDICAPPED. ATTENTION IS DIRECTED TO THIS SUBJECT INASMUCH AS ARCHITECTS GENERALLY HAVE OVERLOOKED THE PROBLEM. HENCE, PUBLIC BUILDINGS ARE NOT TRULY AVAILABLE TO THE TOTAL PUBLIC. IN RECENT YEARS, HOWEVER, LEGISLATION HAS BECOME INCREASINGLY MORE COMMON TO CORRECT THE SITUATION. THE…

  5. Partners: Promoting Accessible Recreation.

    ERIC Educational Resources Information Center

    Sable, Janet; Gravink, Jill

    1995-01-01

    The Promoting Accessible Recreation through Networking, Education, Resources and Services (PARTNERS) Project, a partnership between Northeast Passage, the University of New Hampshire, and Granite State Independent Living Foundation, helps create barrier-free recreation for individuals with physical disabilities. The paper describes PARTNERS and…

  6. College Access Marketing

    ERIC Educational Resources Information Center

    Tremblay, Christopher W.

    2011-01-01

    College Access Marketing (CAM) is a relatively new phenomenon that seeks to positively influence the college-going rate. This report defines CAM, describes CAM examples, and discusses how CAM seeks to counter barriers to college. It explores four main elements of CAM: information, marketing, advocacy, and social mobilization. Further, it…

  7. Unique Access to Learning

    ERIC Educational Resources Information Center

    Goble, Don

    2009-01-01

    This article describes the many learning opportunities that broadcast technology students at Ladue Horton Watkins High School in St. Louis, Missouri, experience because of their unique access to technology and methods of learning. Through scaffolding, stepladder techniques, and trial by fire, students learn to produce multiple television programs,…

  8. Improved Access to Learning.

    ERIC Educational Resources Information Center

    Miller, Sandra; Simkins, Michael

    2002-01-01

    Describes efforts by principal of the Willow Elementary School in the Charter Oak Unified School District (California) to provide students with technology-enhanced access to information and learning resources to improve reading and mathematics skills. Includes list of the Web addresses for the skills software used at the school. (PKP)

  9. Internet 2 Access Grid.

    ERIC Educational Resources Information Center

    Simco, Greg

    2002-01-01

    Discussion of the Internet 2 Initiative, which is based on collaboration among universities, businesses, and government, focuses on the Access Grid, a Computational Grid that includes interactive multimedia within high-speed networks to provide resources to enable remote collaboration among the research community. (Author/LRW)

  10. Accessible Theatre Arts Programs

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin. Div. of Curriculum Development.

    Intended to help administrators and theatre teachers provide a theatre arts program accessible to disabled actors, technicians, and audiences, the guide focuses on ways to alleviate limitations in the theatre. The following topics are addressed (sample subtopics in parentheses): awareness (use of improvisations and simulations); acclimatization…

  11. Access to Knowledge.

    ERIC Educational Resources Information Center

    Leslie, Donald S.

    1996-01-01

    Discusses how modern library systems can protect collections while not impeding disabled persons' access to facilities. Describes the problem with swinging gates and offers some security alternatives, such as high-tech gateless security, video detection, and voice alarms, that do not impede disabled persons' movements. (RJM)

  12. CAS. Controlled Access Security

    SciTech Connect

    Martinez, B.; Pomeroy, G.

    1989-12-01

    The Security Alarm System is a data acquisition and control system which collects data from intrusion sensors and displays the information in a real-time environment for operators. The Access Control System monitors and controls the movement of personnel with the use of card readers and biometrics hand readers.

  13. Accessing Electronic Theses: Progress?

    ERIC Educational Resources Information Center

    Tennant, Roy

    2000-01-01

    Describes various ways by which universities provide access to their electronic theses and dissertations (ETDs), discussing UMI (University Microfilms International), XML (eXtensible Markup Language), and other formats. Discusses key leaders--national and international--in the ETD effort. Outlines the two main methods for locating ETDs. Presents a…

  14. APS and Open Access

    NASA Astrophysics Data System (ADS)

    2011-03-01

    The movement toward Open Access continues to gain momentum. A brief review of APS efforts in this area will be presented by APS Editor in Chief, Gene Sprouse. Editors from Physical Review A, B, E, Focus, Letters, and X, Reviews of Modern Physics, and Physics will address your questions about publishing in this evolving environment.

  15. Accessibility Standards, Illustrated.

    ERIC Educational Resources Information Center

    Jones, Michael A.

    The book sets forth Illinois environmental accessibility standards for disabled persons based on observation and interview data. Photographs, drawings, and detailed floor plans are included in sections dealing with human data (including space requirements for maneuvering wheelchairs, color blindness, incontinence, and severe auditory or visual…

  16. Computer Accessibility Technology Packet.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    This technology information packet includes information about the technical aspects of access to technology, legal obligations concerning technology and individuals with disabilities, and a list of resources for further information and assistance. A question and answer section addresses: barriers to educational technology for students with…

  17. Fixed Access Network Sharing

    NASA Astrophysics Data System (ADS)

    Cornaglia, Bruno; Young, Gavin; Marchetta, Antonio

    2015-12-01

    Fixed broadband network deployments are moving inexorably to the use of Next Generation Access (NGA) technologies and architectures. These NGA deployments involve building fiber infrastructure increasingly closer to the customer in order to increase the proportion of fiber on the customer's access connection (Fibre-To-The-Home/Building/Door/Cabinet… i.e. FTTx). This increases the speed of services that can be sold and will be increasingly required to meet the demands of new generations of video services as we evolve from HDTV to "Ultra-HD TV" with 4k and 8k lines of video resolution. However, building fiber access networks is a costly endeavor. It requires significant capital in order to cover any significant geographic coverage. Hence many companies are forming partnerships and joint-ventures in order to share the NGA network construction costs. One form of such a partnership involves two companies agreeing to each build to cover a certain geographic area and then "cross-selling" NGA products to each other in order to access customers within their partner's footprint (NGA coverage area). This is tantamount to a bi-lateral wholesale partnership. The concept of Fixed Access Network Sharing (FANS) is to address the possibility of sharing infrastructure with a high degree of flexibility for all network operators involved. By providing greater configuration control over the NGA network infrastructure, the service provider has a greater ability to define the network and hence to define their product capabilities at the active layer. This gives the service provider partners greater product development autonomy plus the ability to differentiate from each other at the active network layer.

  18. An incremental database access method for autonomous interoperable databases

    NASA Technical Reports Server (NTRS)

    Roussopoulos, Nicholas; Sellis, Timos

    1994-01-01

    We investigated a number of design and performance issues of interoperable database management systems (DBMS's). The major results of our investigation were obtained in the areas of client-server database architectures for heterogeneous DBMS's, incremental computation models, buffer management techniques, and query optimization. We finished a prototype of an advanced client-server workstation-based DBMS which allows access to multiple heterogeneous commercial DBMS's. Experiments and simulations were then run to compare its performance with the standard client-server architectures. The focus of this research was on adaptive optimization methods of heterogeneous database systems. Adaptive buffer management accounts for the random and object-oriented access methods for which no known characterization of the access patterns exists. Adaptive query optimization means that value distributions and selectives, which play the most significant role in query plan evaluation, are continuously refined to reflect the actual values as opposed to static ones that are computed off-line. Query feedback is a concept that was first introduced to the literature by our group. We employed query feedback for both adaptive buffer management and for computing value distributions and selectivities. For adaptive buffer management, we use the page faults of prior executions to achieve more 'informed' management decisions. For the estimation of the distributions of the selectivities, we use curve-fitting techniques, such as least squares and splines, for regressing on these values.

  19. A Priority-Based Adaptive MAC Protocol for Wireless Body Area Networks

    PubMed Central

    Bhandari, Sabin; Moh, Sangman

    2016-01-01

    In wireless body area networks (WBANs), various sensors and actuators are placed on/inside the human body and connected wirelessly. WBANs have specific requirements for healthcare and medical applications, hence, standard protocols like the IEEE 802.15.4 cannot fulfill all the requirements. Consequently, many medium access control (MAC) protocols, mostly derived from the IEEE 802.15.4 superframe structure, have been studied. Nevertheless, they do not support a differentiated quality of service (QoS) for the various forms of traffic coexisting in a WBAN. In particular, a QoS-aware MAC protocol is essential for WBANs operating in the unlicensed Industrial, Scientific, and Medical (ISM) bands, because different wireless services like Bluetooth, WiFi, and Zigbee may coexist there and cause severe interference. In this paper, we propose a priority-based adaptive MAC (PA-MAC) protocol for WBANs in unlicensed bands, which allocates time slots dynamically, based on the traffic priority. Further, multiple channels are effectively utilized to reduce access delays in a WBAN, in the presence of coexisting systems. Our performance evaluation results show that the proposed PA-MAC outperforms the IEEE 802.15.4 MAC and the conventional priority-based MAC in terms of the average transmission time, throughput, energy consumption, and data collision ratio. PMID:26999162

  20. A Priority-Based Adaptive MAC Protocol for Wireless Body Area Networks.

    PubMed

    Bhandari, Sabin; Moh, Sangman

    2016-03-18

    In wireless body area networks (WBANs), various sensors and actuators are placed on/inside the human body and connected wirelessly. WBANs have specific requirements for healthcare and medical applications, hence, standard protocols like the IEEE 802.15.4 cannot fulfill all the requirements. Consequently, many medium access control (MAC) protocols, mostly derived from the IEEE 802.15.4 superframe structure, have been studied. Nevertheless, they do not support a differentiated quality of service (QoS) for the various forms of traffic coexisting in a WBAN. In particular, a QoS-aware MAC protocol is essential for WBANs operating in the unlicensed Industrial, Scientific, and Medical (ISM) bands, because different wireless services like Bluetooth, WiFi, and Zigbee may coexist there and cause severe interference. In this paper, we propose a priority-based adaptive MAC (PA-MAC) protocol for WBANs in unlicensed bands, which allocates time slots dynamically, based on the traffic priority. Further, multiple channels are effectively utilized to reduce access delays in a WBAN, in the presence of coexisting systems. Our performance evaluation results show that the proposed PA-MAC outperforms the IEEE 802.15.4 MAC and the conventional priority-based MAC in terms of the average transmission time, throughput, energy consumption, and data collision ratio.

  1. 78 FR 51746 - Trade Barriers That U.S. Small and Medium-sized Enterprises Perceive as Affecting Exports to the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... COMMISSION Trade Barriers That U.S. Small and Medium-sized Enterprises Perceive as Affecting Exports to the... Barriers that U.S. Small and Medium-sized Enterprises Perceive as Affecting Exports to the European Union... ). Persons with mobility impairments who will need special assistance in gaining access to the...

  2. 78 FR 45969 - Trade Barriers That U.S. Small and Medium-Sized Enterprises Perceive as Affecting Exports to the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-30

    ... COMMISSION Trade Barriers That U.S. Small and Medium-Sized Enterprises Perceive as Affecting Exports to the... and Medium- sized Enterprises Perceive as Affecting Exports to the European Union. DATES: September 13... ). Persons with mobility impairments who will need special assistance in gaining access to the...

  3. 78 FR 66950 - Trade Barriers That U.S. Small and Medium-Sized Enterprises Perceive as Affecting Exports to the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... COMMISSION Trade Barriers That U.S. Small and Medium-Sized Enterprises Perceive as Affecting Exports to the... ). Persons with mobility impairments who will need special assistance in gaining access to the Commission... prepare a report that catalogs trade barriers that U.S. small and medium-sized enterprises (SMEs)...

  4. Workshop AccessibleTV "Accessible User Interfaces for Future TV Applications"

    NASA Astrophysics Data System (ADS)

    Hahn, Volker; Hamisu, Pascal; Jung, Christopher; Heinrich, Gregor; Duarte, Carlos; Langdon, Pat

    Approximately half of the elderly people over 55 suffer from some type of typically mild visual, auditory, motor or cognitive impairment. For them interaction, especially with PCs and other complex devices is sometimes challenging, although accessible ICT applications could make much of a difference for their living quality. Basically they have the potential to enable or simplify participation and inclusion in their surrounding private and professional communities. However, the availability of accessible user interfaces being capable to adapt to the specific needs and requirements of users with individual impairments is very limited. Although there are a number of APIs [1, 2, 3, 4] available for various platforms that allow developers to provide accessibility features within their applications, today none of them provides features for the automatic adaptation of multimodal interfaces being capable to automatically fit the individual requirements of users with different kinds of impairments. Moreover, the provision of accessible user interfaces is still expensive and risky for application developers, as they need special experience and effort for user tests. Today many implementations simply neglect the needs of elderly people, thus locking out a large portion of their potential users. The workshop is organized as part of the dissemination activity for the European-funded project GUIDE "Gentle user interfaces for elderly people", which aims to address this situation with a comprehensive approach for the realization of multimodal user interfaces being capable to adapt to the needs of users with different kinds of mild impairments. As application platform, GUIDE will mainly target TVs and Set-Top Boxes, such as the emerging Connected-TV or WebTV platforms, as they have the potential to address the needs of the elderly users with applications such as for home automation, communication or continuing education.

  5. Electro-molecular Assembly: Electrical Writing of Information into an Erasable Polysaccharide Medium.

    PubMed

    Yan, Kun; Xiong, Yuan; Wu, Si; Bentley, William E; Deng, Hongbing; Du, Yumin; Payne, Gregory F; Shi, Xiao-Wen

    2016-08-03

    We report that information can be written into an erasable hydrogel medium by precisely imposing controlled electrical signals that trigger supramolecular self-assembly. We prepare the medium from a blend of two stimuli-responsive self-assembling polysaccharides agarose (thermally responsive) and chitosan (pH-responsive). Upon cooling the blend, agarose forms the hydrogel medium while the embedded chitosan chains can be induced to self-assemble in response to imposed pH cues. Importantly, these triggering pH-cues can be imposed electrically (by inserted electrodes) enabling complex messages (e.g., self-assembled multilayers) to be written within the hydrogel medium. The reversibility of these self-assembly mechanisms allow the written information, and the medium itself, to be erased. These physicochemical properties enable this dual responsive medium to encrypt information, while the responsiveness of this structural information and the biocompatibility of the medium suggest uses for accessing/reporting information in diverse life science applications, such as foods, cosmetics, medicine, and the environment.

  6. 49 CFR 236.811 - Speed, medium.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour....

  7. 49 CFR 236.811 - Speed, medium.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour....

  8. Rethinking English in Maori-Medium Education

    ERIC Educational Resources Information Center

    Hill, Richard

    2011-01-01

    English language instruction in New Zealand's Maori-medium schools is controversial, with many schools either excluding it from their curriculum or adopting a tokenistic approach. Yet, how Maori-medium educators can best support their students' academic English language growth is still an under-researched and unresolved question. This paper…

  9. 49 CFR 236.811 - Speed, medium.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour....

  10. 49 CFR 236.811 - Speed, medium.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour....

  11. 49 CFR 236.811 - Speed, medium.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour....

  12. Adaptive Phase Delay Generator

    NASA Technical Reports Server (NTRS)

    Greer, Lawrence

    2013-01-01

    There are several experimental setups involving rotating machinery that require some form of synchronization. The adaptive phase delay generator (APDG) the Bencic-1000 is a flexible instrument that allows the user to generate pulses synchronized to the rising edge of a tachometer signal from any piece of rotating machinery. These synchronized pulses can vary by the delay angle, pulse width, number of pulses per period, number of skipped pulses, and total number of pulses. Due to the design of the pulse generator, any and all of these parameters can be changed independently, yielding an unparalleled level of versatility. There are two user interfaces to the APDG. The first is a LabVIEW program that has the advantage of displaying all of the pulse parameters and input signal data within one neatly organized window on the PC monitor. Furthermore, the LabVIEW interface plots the rpm of the two input signal channels in real time. The second user interface is a handheld portable device that goes anywhere a computer is not accessible. It consists of a liquid-crystal display and keypad, which enable the user to control the unit by scrolling through a host of command menus and parameter listings. The APDG combines all of the desired synchronization control into one unit. The experimenter can adjust the delay, pulse width, pulse count, number of skipped pulses, and produce a specified number of pulses per revolution. Each of these parameters can be changed independently, providing an unparalleled level of versatility when synchronizing hardware to a host of rotating machinery. The APDG allows experimenters to set up quickly and generate a host of synchronizing configurations using a simple user interface, which hopefully leads to faster results.

  13. The energy-speed-accuracy tradeoff in sensory adaptation

    PubMed Central

    Lan, Ganhui; Sartori, Pablo; Neumann, Silke; Sourjik, Victor; Tu, Yuhai

    2012-01-01

    Adaptation is the essential process by which an organism becomes better suited to its environment. The benefits of adaptation are well documented, but the cost it incurs remains poorly understood. Here, by analysing a stochastic model of a minimum feedback network underlying many sensory adaptation systems, we show that adaptive processes are necessarily dissipative, and continuous energy consumption is required to stabilize the adapted state. Our study reveals a general relation among energy dissipation rate, adaptation speed and the maximum adaptation accuracy. This energy-speed-accuracy relation is tested in the Escherichia coli chemosensory system, which exhibits near-perfect chemoreceptor adaptation. We identify key requirements for the underlying biochemical network to achieve accurate adaptation with a given energy budget. Moreover, direct measurements confirm the prediction that adaptation slows down as cells gradually de-energize in a nutrient-poor medium without compromising adaptation accuracy. Our work provides a general framework to study cost-performance tradeoffs for cellular regulatory functions and information processing. PMID:22737175

  14. An Adaptive Security Construct: Insurgency in Sudan

    DTIC Science & Technology

    2007-12-01

    feb01. pdf (accessed August 10, 2007). 11 Theodore S. Dagne, Library of Congress, and Congressional Research Service, "Sudan: The Crisis in Darfur and...concept was later adapted for urban guerrilla conflict. See also Carlos Marighella, “Minimanual do guerrilheiro urbano ,” translated by Robert Moss...as a lack of infrastructure and transportation means worked in favor of the “bush-fighting” insurgents.106 Conventional operations grew increasingly

  15. Internet access to ionosondes

    NASA Astrophysics Data System (ADS)

    Galkin, I. A.; Kitrosser, D. F.; Kecic, Z.; Reinisch, B. W.

    1999-01-01

    Connecting ionosondes to the Internet gives easy access to real-time information on ionospheric conditions. Some of the ionosonde sites provide just the ionogram displays, others give in addition the scaled ionospheric characteristics directly usable for frequency management and HF channel assessment. Some sounders also store days or months of station data, which makes it possible remotely to evaluate the time history of geophysical events. The Internet link is also a convenient means for remote system maintenance and control. The paper addresses various aspects of the Internet ionosonde scenario, including data base support, WWW publishing, user interface, security, and data format. A list of Internet accessible ionosonde stations is provided with a brief description.

  16. Access and control of information and intellectual property

    NASA Astrophysics Data System (ADS)

    Lang, Gerald S.

    1996-03-01

    This paper introduces the technology of two pioneering patents for the secure distribution of information and intellectual property. The seminal technology has been used in the control of sensitive material such as medical records and imagery in distributed networks. It lends itself to the implementation of an open architecture access control system that provides local or remote user selective access to digital information stored on any computer system or storage medium, down to the data element, pixel, and sub-pixel levels. Use of this technology is especially suited for electronic publishing, health care records, MIS, and auditing.

  17. [Complex vascular access].

    PubMed

    Mangiarotti, G; Cesano, G; Thea, A; Hamido, D; Pacitti, A; Segoloni, G P

    1998-03-01

    Availability of a proper vascular access is a basic condition for a proper extracorporeal replacement in end-stage chronic renal failure. However, biological factors, management and other problems, may variously condition their middle-long term survival. Therefore, personal experience of over 25 years has been critically reviewed in order to obtain useful information. In particular "hard" situations necessitating complex procedures have been examined but, if possible, preserving the peripherical vascular features.

  18. History of vascular access.

    PubMed

    Dudrick, Stanley J

    2006-01-01

    Milestones in the history of the development of vascular access and the subsequent advances in practical clinical applications of the knowledge, techniques, technology, and experience to the beneficial management of a variety of patients are described. The original achievements are presented and briefly discussed primarily, but not exclusively, in relationship to the successful development of parenteral nutrition (PN). Beginning with the discovery of the circulation of blood, landmark events, resulting from astute observations, experimentation, and ingenious technological advances, are summarized or outlined chronologically over the past 4 centuries, with emphasis on the many recent accomplishments of basic and clinical scientists during the past 6 decades. Brief descriptions of several seminal contributions to safe and effective IV access, management, and therapy acknowledge and recognize the historical highlights that have allowed a complex and potentially hazardous therapeutic modality to evolve into a commonly applied useful adjunct to our current inpatient and outpatient armamentarium. A comprehensive list of references documents the highlights of the development of vascular access for the student of history.

  19. Access and Influence: SOF’s Trajectory Through the Diplomatic Medium

    DTIC Science & Technology

    2012-04-24

    the aim of addressing social issues affecting the agro -pastoral community and furthering partnership capacity building.40 Crucial to making this...must know something about strategy and tactics and… logistics , but also economics and politics and diplomacy and history. You must know everything you

  20. Interference Analysis for Highly Directional 60 GHz Mesh Networks: The Case for Rethinking Medium Access Control

    DTIC Science & Technology

    2010-11-24

    transmission equation for mm-waves gives the received power as a function of range r as PRx (r) = PTxGRxGTx ( λ 4πr )2 e−αr (1) where PTx is the...R0 (e.g., R0 =100m and 200m in our numerical results) is denoted by P0 = PRx (R0), with GTx = GRx = Gmax, where Gmax denotes the maximum antenna gain...maximum distance an interferer can be from the receiver and still cause a collision. Using (1), the signal and interference powers are evaluated as PRx

  1. Energy efficient medium access protocol for wireless medical body area sensor networks.

    PubMed

    Omeni, O; Wong, A; Burdett, A J; Toumazou, C

    2008-12-01

    This paper presents a novel energy-efficient MAC Protocol designed specifically for wireless body area sensor networks (WBASN) focused towards pervasive healthcare applications. Wireless body area networks consist of wireless sensor nodes attached to the human body to monitor vital signs such as body temperature, activity or heart-rate. The network adopts a master-slave architecture, where the body-worn slave node periodically sends sensor readings to a central master node. Unlike traditional peer-to-peer wireless sensor networks, the nodes in this biomedical WBASN are not deployed in an ad hoc fashion. Joining a network is centrally managed and all communications are single-hop. To reduce energy consumption, all the sensor nodes are in standby or sleep mode until the centrally assigned time slot. Once a node has joined a network, there is no possibility of collision within a cluster as all communication is initiated by the central node and is addressed uniquely to a slave node. To avoid collisions with nearby transmitters, a clear channel assessment algorithm based on standard listen-before-transmit (LBT) is used. To handle time slot overlaps, the novel concept of a wakeup fallback time is introduced. Using single-hop communication and centrally controlled sleep/wakeup times leads to significant energy reductions for this application compared to more ldquoflexiblerdquo network MAC protocols such as 802.11 or Zigbee. As duty cycle is reduced, the overall power consumption approaches the standby power. The protocol is implemented in hardware as part of the Sensiumtrade system-on-chip WBASN ASIC, in a 0.13- mum CMOS process.

  2. Medium Access Control in Ad Hoc Networks With Omni-Directional and Directional Antennas

    DTIC Science & Technology

    2004-06-01

    49 3.3.2 The DTOR Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 3.3.3 The MTOR Scheme...53 3.3 Calculation of various areas . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 3.4 The MTOR scheme...directional or directional reception can be applied to this approach. When the former is used, we call it MTOR scheme (short for “mixed-directional

  3. After Access: Underrepresented Students' Postmatriculation Perceptions of College Access Capital

    ERIC Educational Resources Information Center

    Means, Darris R.; Pyne, Kimberly B.

    2016-01-01

    This qualitative study explores the perceived impact of college-going capital gained during participation in a college access program. In three, semistructured interviews spanning the first-year college experience, 10 first-year college students who participated in a college access program articulate the value of access programming and also raise…

  4. The environmental genomics of metazoan thermal adaptation

    PubMed Central

    Porcelli, D; Butlin, R K; Gaston, K J; Joly, D; Snook, R R

    2015-01-01

    Continued and accelerating change in the thermal environment places an ever-greater priority on understanding how organisms are going to respond. The paradigm of ‘move, adapt or die', regarding ways in which organisms can respond to environmental stressors, stimulates intense efforts to predict the future of biodiversity. Assuming that extinction is an unpalatable outcome, researchers have focussed attention on how organisms can shift in their distribution to stay in the same thermal conditions or can stay in the same place by adapting to a changing thermal environment. How likely these respective outcomes might be depends on the answer to a fundamental evolutionary question, namely what genetic changes underpin adaptation to the thermal environment. The increasing access to and decreasing costs of next-generation sequencing (NGS) technologies, which can be applied to both model and non-model systems, provide a much-needed tool for understanding thermal adaptation. Here we consider broadly what is already known from non-NGS studies about thermal adaptation, then discuss the benefits and challenges of different NGS methodologies to add to this knowledge base. We then review published NGS genomics and transcriptomics studies of thermal adaptation to heat stress in metazoans and compare these results with previous non-NGS patterns. We conclude by summarising emerging patterns of genetic response and discussing future directions using these increasingly common techniques. PMID:25735594

  5. Solute transport through a deforming porous medium

    NASA Astrophysics Data System (ADS)

    Peters, Glen P.; Smith, David W.

    2002-06-01

    Solute transport through a porous medium is typically modelled assuming the porous medium is rigid. However, many applications exist where the porous medium is deforming, including, municipal landfill liners, mine tailings dams, and land subsidence. In this paper, mass balance laws are used to derive the flow and transport equations for a deforming porous medium. The equations are derived in both spatial and material co-ordinate systems. Solute transport through an engineered landfill liner is used as an illustrative example to show the differences between the theory for a rigid porous medium, and small and large deformation analysis of a deforming porous medium. It is found that the large deformation model produces shorter solute breakthrough times, followed by the small deformation model, and then the rigid porous medium model. It is also found that it is important to include spatial and temporal void ratio variations in the large deformation analysis. It is shown that a non-linear large deformation model may greatly reduce the solute breakthrough time, compared to a standard transport analysis typically employed by environmental engineers.

  6. Collaborative Manufacturing for Small-Medium Enterprises

    NASA Astrophysics Data System (ADS)

    Irianto, D.

    2016-02-01

    Manufacturing systems involve decisions concerning production processes, capacity, planning, and control. In a MTO manufacturing systems, strategic decisions concerning fulfilment of customer requirement, manufacturing cost, and due date of delivery are the most important. In order to accelerate the decision making process, research on decision making structure when receiving order and sequencing activities under limited capacity is required. An effective decision making process is typically required by small-medium components and tools maker as supporting industries to large industries. On one side, metal small-medium enterprises are expected to produce parts, components or tools (i.e. jigs, fixture, mold, and dies) with high precision, low cost, and exact delivery time. On the other side, a metal small- medium enterprise may have weak bargaining position due to aspects such as low production capacity, limited budget for material procurement, and limited high precision machine and equipment. Instead of receiving order exclusively, a small-medium enterprise can collaborate with other small-medium enterprise in order to fulfill requirements high quality, low manufacturing cost, and just in time delivery. Small-medium enterprises can share their best capabilities to form effective supporting industries. Independent body such as community service at university can take a role as a collaboration manager. The Laboratory of Production Systems at Bandung Institute of Technology has implemented shared manufacturing systems for small-medium enterprise collaboration.

  7. Resilience through adaptation

    PubMed Central

    van Voorn, George A. K.; Ligtenberg, Arend; Molenaar, Jaap

    2017-01-01

    Adaptation of agents through learning or evolution is an important component of the resilience of Complex Adaptive Systems (CAS). Without adaptation, the flexibility of such systems to cope with outside pressures would be much lower. To study the capabilities of CAS to adapt, social simulations with agent-based models (ABMs) provide a helpful tool. However, the value of ABMs for studying adaptation depends on the availability of methodologies for sensitivity analysis that can quantify resilience and adaptation in ABMs. In this paper we propose a sensitivity analysis methodology that is based on comparing time-dependent probability density functions of output of ABMs with and without agent adaptation. The differences between the probability density functions are quantified by the so-called earth-mover’s distance. We use this sensitivity analysis methodology to quantify the probability of occurrence of critical transitions and other long-term effects of agent adaptation. To test the potential of this new approach, it is used to analyse the resilience of an ABM of adaptive agents competing for a common-pool resource. Adaptation is shown to contribute positively to the resilience of this ABM. If adaptation proceeds sufficiently fast, it may delay or avert the collapse of this system. PMID:28196372

  8. Thinking in words: language as an embodied medium of thought.

    PubMed

    Dove, Guy

    2014-07-01

    Recently, there has been a great deal of interest in the idea that natural language enhances and extends our cognitive capabilities. Supporters of embodied cognition have been particularly interested in the way in which language may provide a solution to the problem of abstract concepts. Toward this end, some have emphasized the way in which language may act as form of cognitive scaffolding and others have emphasized the potential importance of language-based distributional information. This essay defends a version of the cognitive enhancement thesis that integrates and builds on both of these proposals. I argue that the embodied representations associated with language processing serve as a supplementary medium for conceptual processing. The acquisition of a natural language provides a means of extending our cognitive reach by giving us access to an internalized combinatorial symbol system that augments and supports the context-sensitive embodied representational systems that exist independently of language.

  9. Propagation of transients in a random medium

    NASA Technical Reports Server (NTRS)

    Wenzel, A. R.

    1975-01-01

    The propagation of transient scalar waves in a three-dimensional random medium is considered. The analysis is based on the smoothing method. An integro-differential equation for the coherent (or average) wave is derived and solved for the case of a statistically homogeneous and isotropic medium and a delta-function source. This yields the coherent Green's function of the medium. It is found that the waveform of the coherent wave depends generally on the distance from the source measured in terms of a certain dimensionless parameter. Based on the magnitude of this parameter, three propagation zones, called the near zone, the far zone, and the intermediate zone, are defined.

  10. Method to prepare nanoparticles on porous mediums

    DOEpatents

    Vieth, Gabriel M [Knoxville, TN; Dudney, Nancy J [Oak Ridge, TN; Dai, Sheng [Knoxville, TN

    2010-08-10

    A method to prepare porous medium decorated with nanoparticles involves contacting a suspension of nanoparticles in an ionic liquid with a porous medium such that the particles diffuse into the pores of the medium followed by heating the resulting composition to a temperature equal to or greater than the thermal decomposition temperature of the ionic liquid resulting in the removal of the liquid portion of the suspension. The nanoparticles can be a metal, an alloy, or a metal compound. The resulting compositions can be used as catalysts, sensors, or separators.

  11. Bridging the Gap: Adaptive Games and Student-Centered VLEs

    NASA Astrophysics Data System (ADS)

    Del Blanco, Ángel; Torrente, Javier; Moreno-Ger, Pablo; Fernández-Manjón, Baltasar

    The widely used e-learning technology is facing new challenges such as how to produce student-centered systems that can be adapted to the needs of each student. Those objectives should be met in a standard compliant way to simplify general adoption. In this context, educational videogames are proposed as an ideal medium to facilitate adaptation and tracking of the students’ performance for assessment purposes. However, there are still barriers between the gaming and e-learning worlds preventing their mutual interaction. In this paper we propose a middleware to bridge this gap, integrating adaptive educational videogames in e-learning environments with a special focus on the ongoing standardization efforts.

  12. Soot blower using fuel gas as blowing medium

    DOEpatents

    Tanca, Michael C.

    1982-01-01

    A soot blower assembly (10) for use in combination with a coal gasifier (14). The soot blower assembly is adapted for use in the hot combustible product gas generated in the gasifier as the blowing medium. The soot blower lance (20) and the drive means (30) by which it is moved into and out of the gasifier is housed in a gas tight enclosure (40) which completely surrounds the combination. The interior of the enclosure (40) is pressurized by an inert gas to a pressure level higher than that present in the gasifier so that any combustible product gas leaking from the soot blower lance (20) is forced into the gasifier rather than accumulating within the enclosure.

  13. EPICS: Channel Access security design

    SciTech Connect

    Kraimer, M.; Hill, J.

    1994-05-01

    This document presents the design for implementing the requirements specified in: EPICS -- Channel Access Security -- functional requirements, Ned. D. Arnold, 03/09/92. Use of the access security system is described along with a summary of the functional requirements. The programmer`s interface is given. Security protocol is described and finally aids for reading the access security code are provided.

  14. Organizational Adaptation and Higher Education.

    ERIC Educational Resources Information Center

    Cameron, Kim S.

    1984-01-01

    Organizational adaptation and types of adaptation needed in academe in the future are reviewed and major conceptual approaches to organizational adaptation are presented. The probable environment that institutions will face in the future that will require adaptation is discussed. (MLW)

  15. Selective medium for isolation of Actinobacillus actinomycetemcomitans.

    PubMed Central

    Slots, J

    1982-01-01

    A selective medium, TSBV (tryptic soy-serum-bacitracin-vancomycin) agar, was developed for the isolation of Actinobacillus actinomycetemcomitans, TSBV agar contained (per liter) 40 g of tryptic soy agar, 1 g of yeast extract, 100 ml of horse serum. 75 mg of bacitracin, and 5 mg of vancomycin. The TSBV medium suppressed most oral species and permitted significantly higher recovery of A. actinomycetemcomitans than nonselective blood agar medium. The distinct colonial morphology and positive catalase reaction of A. actinomycetemcomitans easily distinguished this bacterium from Haemophilus aphrophilus, Capnocytophaga species, and a few other contaminating organisms. With the TSBV medium, even modestly equipped laboratories will be able to isolate and identify A. actinomycetemcomitans from clinical specimens. Images PMID:7068837

  16. Acoustics of a Nonhomogeneous Moving Medium.

    NASA Technical Reports Server (NTRS)

    Blokhintsev, D I

    1956-01-01

    Theoretical basis of the acoustics of a moving nonhomogeneous medium is considered in this report. Experiments that illustrate or confirm some of the theoretical explanation or derivation of these acoustics are also included.

  17. Incompatibility of Contrast Medium and Trisodium Citrate

    SciTech Connect

    Delcour, Christian Bruninx, Guy

    2013-02-15

    To test the compatibility of trisodium citrate, a catheter lock solution, with iodinated contrast medium. Iohexol, iobitridol, iodixanol, ioxaglate, ioxithalamate, iomeprol, and iopromide were tested. In all tests, 2 ml of contrast medium were mixed with 2 ml of trisodium citrate solution. Iodixanol and ioxaglate provoked a highly viscous gluelike precipitation when mixed with trisodium citrate. A brief transient precipitate was observed with iohexol, iomeprol, and ioxithalamate. Permanent precipitation occurred with iobitridol and iopromide. One must be aware of the potential for precipitation when contrast medium is mixed with trisodium citrate solution. Before trisodium citrate solution is injected, the catheter should be thoroughly flushed with saline if a contrast medium has previously been injected through it.

  18. Human heat adaptation.

    PubMed

    Taylor, Nigel A S

    2014-01-01

    In this overview, human morphological and functional adaptations during naturally and artificially induced heat adaptation are explored. Through discussions of adaptation theory and practice, a theoretical basis is constructed for evaluating heat adaptation. It will be argued that some adaptations are specific to the treatment used, while others are generalized. Regarding ethnic differences in heat tolerance, the case is put that reported differences in heat tolerance are not due to natural selection, but can be explained on the basis of variations in adaptation opportunity. These concepts are expanded to illustrate how traditional heat adaptation and acclimatization represent forms of habituation, and thermal clamping (controlled hyperthermia) is proposed as a superior model for mechanistic research. Indeed, this technique has led to questioning the perceived wisdom of body-fluid changes, such as the expansion and subsequent decay of plasma volume, and sudomotor function, including sweat habituation and redistribution. Throughout, this contribution was aimed at taking another step toward understanding the phenomenon of heat adaptation and stimulating future research. In this regard, research questions are posed concerning the influence that variations in morphological configuration may exert upon adaptation, the determinants of postexercise plasma volume recovery, and the physiological mechanisms that modify the cholinergic sensitivity of sweat glands, and changes in basal metabolic rate and body core temperature following adaptation.

  19. Dynamic equations of a prestressed magnetoelectroelastic medium

    NASA Astrophysics Data System (ADS)

    Belyankova, T. I.; Kalinchuk, V. V.

    2016-09-01

    The constitutive relations of nonlinear mechanics of a magnetoelectroelastic medium subjected to initial mechanical stresses are linearized in the framework of material (Lagrangian) coordinates. The final expressions are constructed independently of the choice of curvilinear coordinates and are represented in a form convenient for theoretical and applied studies. The constitutive relations for the motion of a prestressed magnetoelectroelastic medium are given in rectangular Cartesian coordinates. The influence of the initial mechanical stresses on piezomagnetoelectric materials of the class 6mm is studied.

  20. Motility-indole-lysine-sulfide medium.

    PubMed

    Ederer, G M; Lund, M E; Blazevic, D J; Reller, L B; Mirrett, S

    1975-09-01

    A medium designed for the detection of motility, indole, lysine decarboxylase and deaminase reactions, and H2S production was devised and evaluated. Results, using 157 strains of enteric pathogens, were in agreement with reference methods. When 300 isolates from fecal cultures were screened using this medium, Shigella was easily differentiated from Escherichia and more of the Proteus species, especially P. morganii, could be eliminated from further study.

  1. [Evaluation of a new medium, eggplant (Solanum melongena) agar as a screening medium for Cryptococcus neoformans in environmental samples].

    PubMed

    Sengul, Mustafa; Ergin, Cağrı; Kartal, Tuğba

    2014-04-01

    Cryptococcus neofomans is an encapsulated yeast-like fungus that causes life-threatening infections, especially in immunosuppresive patients. C.neoformans infection is believed to be acquired via inhalation of aerosolized particles from the environment. Avian guano, decaying tree hollows and soil are the related known environmental niches. Brown pigmented yeast growth from the precursors in growth media is an important step for the identification and isolation of C.neoformans. Seeds of plants in nature are preferred owing to easy accessibility and low costs for the preparation of such media. Guizotia abysinicca (Niger seed) as Staib agar, Helianthus annus (Sunflower) as Pal's medium, Brassica nigra (Mustard) agar, tobacco agar, Mucuna pruriens (Velvet bean) seed agar, Perilla frutescens (Beefsteak plant) seed agar, Rubus fruticosus (Blackberry) agar and ground red hot pepper agar are pigment-based selective media for the differentiation of C.neoformans. The aim of this study was to observe the pigment production of C.neoformans in a new medium based on eggplant (Solanum melongena) and also to compare its performance with the simplified Staib, Pal's and tobacco agar for isolation from the environment. Three different eggplant-based medium (S.melongena Melanzaza viserba, S.melongena Pinstripe F1 and S.ovigerum Ivory F1) were included in the study. Pigment-forming eggplant medium, simplified Staib agar, Pal's agar and tobacco agar were used for the cultivation of the environmental swabbed samples from 19 Eucalyptus camaldulensis trunk hollows in continuous colonization region. While pigment formation were observed with S.melongena Melanzaza viserba and S.melongena Pinstripe F1 containing media, S.ovigerum Ivory F1 medium was found to be non-reactive. In colonization area (Gökova-Akyaka, Turkey), 11 (57.9%) out of 19 E.camaldulensis samples were positive with simplified Staib agar, Pal's agar and eggplant agar while 10 (52.6%) of them are positive with tobacco agar. C

  2. New Medium for Pharmaceutical Grade Arthrospira

    PubMed Central

    Amara, Amro A.; Steinbüchel, Alexander

    2013-01-01

    The aim of this study is to produce a pharmaceutical grade single cell product of Arthrospira from a mixed culture. We have designed a medium derived from a combination between George's and Zarrouk's media. Our new medium has the ability to inhibit different forms of cyanobacterium and microalgae except the Chlorella. The medium and the cultivation conditions have been investigated to map the points where only Arthrospira could survive. For that, a mixed culture of pure Chlorella and Arthrospira (~90 : 10) has been used to develop the best medium composition that can lead to the enrichment of the Arthrospira growth and the inhibition of the Chlorella growth. To enable better control and to study its growth, an 80 l photobioreactor has been used. We have used high saline (2xA-St) medium which has been followed by in fermentor reducing its concentration to 1.5x. The investigation proves that Chlorella has completely disappeared. A method and a new saline medium have been established using a photobioreactor for in fermentor production of single cell Arthrospira. Such method enables the production of pure pharmaceutical grade Arthrospira for medicinal and pharmaceutical applications or as a single cell protein. PMID:26904724

  3. Selective medium for culture of Mycoplasma hyopneumoniae.

    PubMed

    Cook, Beth S; Beddow, Jessica G; Manso-Silván, Lucía; Maglennon, Gareth A; Rycroft, Andrew N

    2016-11-15

    The fastidious porcine respiratory pathogen Mycoplasma hyopneumoniae has proven difficult to culture since it was first isolated in 1965. A reliable solid medium has been particularly challenging. Moreover, clinical and pathological samples often contain the fast-growing M. hyorhinis which contaminates and overgrows M. hyopneumoniae in primary culture. The aim of this study was to optimise the culture medium for recovery of M. hyopneumoniae and to devise a medium for selection of M. hyopneumoniae from clinical samples also containing M. hyorhinis. The solid medium devised by Niels Friis was improved by use of Purified agar and incorporation of DEAE-dextran. Addition of glucose or neutralization of acidity in liquid medium with NaOH did not improve the final yield of viable organisms or alter the timing of peak viability. Analysis of the relative susceptibility of M. hyopneumoniae and M. hyorhinis strains to four antimicrobials showed that M. hyopneumoniae is less susceptible than M. hyorhinis to kanamycin. This was consistent in all UK and Danish strains tested. A concentration of 2μg/ml of kanamycin selectively inhibited the growth of all M. hyorhinis tested, while M. hyopneumoniae was able to grow. This forms the basis of an effective selective culture medium for M. hyopneumoniae.

  4. Sustained Reaction Waves Against Flow in Porous Medium: Frozen Fronts

    NASA Astrophysics Data System (ADS)

    Salin, Dominique; Atis, Severine; Auradou, Harold; Saha, Sandeep; Talon, Laurent

    2012-11-01

    Autocatalytic reactions lead to fronts propagating as solitary, self-sustained, waves with a constant velocity and an invariant, flat, concentration profile resulting from a balance between reaction and diffusion. In the presence of a hydrodynamic flow, such fronts, while propagating at a new constant velocity, adapt their shape in order to achieve a balance between reaction diffusion and flow advection all over the front. The issue addressed here is the behaviour of autocatalytic reaction fronts when the forced advection is a heterogeneous flow field. It has been recently observed that in inside a porous medium there exist static, frozen, fronts over a wide range of mean flow rates in the opposite direction of the chemical wave propagation. To account for this dynamical equilibrium where the front is pinned at different points, we use both designed experiments around different configurations of solid obstacles and lattice Boltzmann numerical simulations which allows a control of the flow field heterogeneities. These approach allows us to account for the dependence of the range of observation of frozen states with th control parameters. In the case of the porous medium flow field, the transition to this frozen state is understood in term of percolation like path.

  5. Biophotonic applications of eigenchannels in a scattering medium (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kim, Moonseok; Choi, Wonjun; Choi, Youngwoon; Yoon, Changhyeong; Choi, Wonshik

    2016-03-01

    When waves travel through disordered media such as ground glass and skin tissues, they are scattered multiple times. Most of the incoming energy bounces back at the superficial layers and only a small fraction can penetrate deep inside. This has been a limiting factor for the working depth of various optical techniques. We present a systematic method to enhance wave penetration to the scattering media. Specifically, we measured the reflection matrix of a disordered medium with wide angular coverage for each orthogonal polarization states. From the reflection matrix, we identified reflection eigenchannels of the medium, and shaped the incident wave into the reflection eigenchannel with smallest eigenvalue, which we call anti-reflection mode. This makes reflectance reduced and wave penetration increased as a result of the energy conservation. We demonstrated transmission enhancement by more than a factor of 3 by the coupling of the incident waves to the anti-reflection modes. Based on the uneven distribution of eigenvalues of reflection eigenchannels, we further developed an iterative feedback control method for finding and coupling light to anti-reflection modes. Since this adaptive control method can keep up with sample perturbation, it promotes the applicability of exploiting reflection eigenchannels. Our approach of delivering light deep into the scattering media will contribute to enhancing the sensitivity of detecting objects hidden under scattering layers, which is universal problem ranging from geology to life science.

  6. Chemistry of nitrile anions in the interstellar medium

    SciTech Connect

    Carles, S.; Le Garrec, J.-L.; Biennier, L.; Guillemin, J.-C.

    2015-12-31

    Despite the extreme conditions of temperature (down to 10K) and density (down to 100 molecules/cm{sup 3}), the giant molecular clouds and the circumstellar envelopes present a rich and complex chemistry. To date, more than 180 molecules have been detected in the InterStellar Medium (ISM) with a large abundance of nitriles (RC≡N). In addition, several anions have been recently observed in this medium: C{sub 4}H{sup ¯}, C{sub 6}H{sup ¯}, C{sub 8}H{sup ¯}, CN{sup ¯}, C{sub 3}N{sup ¯} and C{sub 5}N{sup ¯}. These last species should play a key role in the molecular growth towards complexity. To explore this hypothesis, their reactivity must be studied in the laboratory. The FALP-MS and the CRESU experimental apparatuses of the Rennes University are able to measure absolute rate coefficient of various chemical reactions, including the ion – molecule reactions, in gas phase at low temperature (from 300K for the FALP-MS down to 15K for the CRESU). Therefore, these experimental tools are particularly adapted to the kinetic studies of reactions potentially involved in the Interstellar Medium. One of the difficulties encountered in experiments with anions is their generation. We describe here the formation of the CN{sup ¯} and C{sub 3}N{sup ¯} anions by dissociative electron attachment on the molecular precursors BrCN and BrC{sub 3}N.

  7. Macroscopic characterisations of Web accessibility

    NASA Astrophysics Data System (ADS)

    Lopes, Rui; Carriço, Luis

    2010-12-01

    The Web Science framework poses fundamental questions on the analysis of the Web, by focusing on how microscopic properties (e.g. at the level of a Web page or Web site) emerge into macroscopic properties and phenomena. One research topic on the analysis of the Web is Web accessibility evaluation, which centres on understanding how accessible a Web page is for people with disabilities. However, when framing Web accessibility evaluation on Web Science, we have found that existing research stays at the microscopic level. This article presents an experimental study on framing Web accessibility evaluation into Web Science's goals. This study resulted in novel accessibility properties of the Web not found at microscopic levels, as well as of Web accessibility evaluation processes themselves. We observed at large scale some of the empirical knowledge on how accessibility is perceived by designers and developers, such as the disparity of interpretations of accessibility evaluation tools warnings. We also found a direct relation between accessibility quality and Web page complexity. We provide a set of guidelines for designing Web pages, education on Web accessibility, as well as on the computational limits of large-scale Web accessibility evaluations.

  8. Gravitational adaptation of animals

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Burton, R. R.

    1982-01-01

    The effect of gravitational adaptation is studied in a group of five Leghorn cocks which had become physiologically adapted to 2 G after 162 days of centrifugation. After this period of adaptation, they are periodically exposed to a 2 G field, accompanied by five previously unexposed hatch-mates, and the degree of retained acceleration adaptation is estimated from the decrease in lymphocyte frequency after 24 hr at 2 G. Results show that the previously adapted birds exhibit an 84% greater lymphopenia than the unexposed birds, and that the lymphocyte frequency does not decrease to a level below that found at the end of 162 days at 2 G. In addition, the capacity for adaptation to chronic acceleration is found to be highly heritable. An acceleration tolerant strain of birds shows lesser mortality during chronic acceleration, particularly in intermediate fields, although the result of acceleration selection is largely quantitative (a greater number of survivors) rather than qualitative (behavioral or physiological changes).

  9. Parallel Anisotropic Tetrahedral Adaptation

    NASA Technical Reports Server (NTRS)

    Park, Michael A.; Darmofal, David L.

    2008-01-01

    An adaptive method that robustly produces high aspect ratio tetrahedra to a general 3D metric specification without introducing hybrid semi-structured regions is presented. The elemental operators and higher-level logic is described with their respective domain-decomposed parallelizations. An anisotropic tetrahedral grid adaptation scheme is demonstrated for 1000-1 stretching for a simple cube geometry. This form of adaptation is applicable to more complex domain boundaries via a cut-cell approach as demonstrated by a parallel 3D supersonic simulation of a complex fighter aircraft. To avoid the assumptions and approximations required to form a metric to specify adaptation, an approach is introduced that directly evaluates interpolation error. The grid is adapted to reduce and equidistribute this interpolation error calculation without the use of an intervening anisotropic metric. Direct interpolation error adaptation is illustrated for 1D and 3D domains.

  10. Origins of adaptive immunity.

    PubMed

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity.

  11. Jejunal access loop cholangiogram and intervention using image guided access.

    PubMed

    Amitha Vikrama, K S; Keshava, S N; Surendrababu, N R S; Moses, V; Joseph, P; Vyas, F; Sitaram, V

    2010-02-01

    Jejunal access loop is fashioned in patients who undergo Roux en Y hepaticojejunostomy and biliary intervention is anticipated on follow up. Post-operative study of the biliary tree through the access loop is usually done under fluoroscopic guidance. We present a series of 20 access loop cholangiograms performed in our institution between August 2004 and November 2008. We aimed to evaluate the safety and efficacy of the procedure and to highlight the role of CT guidance in procuring access. Access loop was accessed using CT (n = 13), ultrasound (n = 3) or fluoroscopic guidance (n = 4). Fluoroscopy was used for performing cholangiograms and interventions. Twelve studies had balloon plasty of the stricture at anastomotic site or high up in the hepatic ducts. Seven studies showed normal cholangiogram. Plasty was unsuccessful in one study. Technical success in accessing the jejunal access loop was 100%; in cannulation of anastomotic site and balloon plasty it was 95%. One case required two attempts. Procedure-related complications were not seen. All patients who underwent balloon plasty of the stricture were doing well for variable lengths of time. Access loop cholangiogram and interventions are safe and effective. CT guidance in locating/procuring the access loop is a good technique.

  12. Quantifying the adaptive cycle

    USGS Publications Warehouse

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  13. Human adaptation to smog

    SciTech Connect

    Evans, G.W. Jacobs, S.V.; Frager, N.B.

    1982-10-01

    This study examined the health effects of human adaptation to photochemical smog. A group of recent arrivals to the Los Angeles air basin were compared to long-term residents of the basin. Evidence for adaptation included greater irritation and respiratory problems among the recent arrivals and desensitization among the long-term residents in their judgments of the severity of the smog problem to their health. There was no evidence for biochemical adaptation as measured by hemoglobin response to oxidant challenge. The results were discussed in terms of psychological adaption to chronic environmental stressors.

  14. Quantifying the Adaptive Cycle.

    PubMed

    Angeler, David G; Allen, Craig R; Garmestani, Ahjond S; Gunderson, Lance H; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994-2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  15. Adaptive parallel logic networks

    NASA Technical Reports Server (NTRS)

    Martinez, Tony R.; Vidal, Jacques J.

    1988-01-01

    Adaptive, self-organizing concurrent systems (ASOCS) that combine self-organization with massive parallelism for such applications as adaptive logic devices, robotics, process control, and system malfunction management, are presently discussed. In ASOCS, an adaptive network composed of many simple computing elements operating in combinational and asynchronous fashion is used and problems are specified by presenting if-then rules to the system in the form of Boolean conjunctions. During data processing, which is a different operational phase from adaptation, the network acts as a parallel hardware circuit.

  16. Golf in the United States: an evolution of accessibility.

    PubMed

    Parziale, John R

    2014-09-01

    Golf affords physical and psychological benefits to persons who are physically challenged. Advances in adaptive technology, changes in golf course design, and rules modifications have enabled persons with neurological, musculoskeletal, and other impairments to play golf at a recreational, elite amateur, or professional level. The Americans with Disabilities Act has been cited in both federal and US Supreme Court rulings that have improved access for physically challenged golfers. Medical specialties, including physiatry, have played an important role in this process. This article reviews the history of golf's improvements in accessibility, and provides clinicians and physically challenged golfers with information that will facilitate participation in the sport.

  17. An investigation of mediums who claim to give information about deceased persons.

    PubMed

    Kelly, Emily Williams; Arcangel, Dianne

    2011-01-01

    Growing public interest in the phenomenon of mediumship, particularly among bereaved persons, suggests the need for renewed controlled studies of mediums, both to provide potential clients with criteria for judging mediums and to help researchers learn whether they can produce specific and accurate information to which they have had no normal access and, if so, under what conditions. Two research studies were conducted in which mediums provided readings about particular deceased persons to a proxy sitter. The real sitters then blindly rated the reading that was intended for them along with several control readings. In the first study, the results were not significant. In the second, much larger study the results were highly significant (z = -3.89, p < 0.0001, 2-tailed). The authors discuss 2 possible weaknesses of the successful study and indicate some directions for further research.

  18. Access in crisis.

    PubMed

    1996-09-01

    Recent advances in HIV drug access and affordability have collided with a health care delivery system unequipped to handle the flow equitably and inexpensively. The AIDS Drug Assistance Program (ADAP) concludes that $169 million more in Federal spending is needed in 1997 to maintain an essential core of HIV/AIDS treatments, and presidential and congressional funding proposals are falling far short. ADAP funding also differs from state to state, but it is often inadequate and many programs cannot supply drugs. Several program aspects to be considered to ensure a strong ADAP are discussed and include the need to assure there is enough state funding, the need for programs to achieve better pricing for drugs, a formalized decision process on who decides what drugs ADAP covers, standardized eligibility criteria, and community members and advocates ensuring that ADAP information is adequately distributed to those who can use it.

  19. Ethanol production using a soy hydrolysate-based medium or a yeast autolysate-based medium

    DOEpatents

    Ingram, Lonnie O.

    2000-01-01

    This invention presents a method for the production of ethanol that utilizes a soy hydrolysate-based nutrient medium or a yeast autolysate-based medium nutrient medium in conjunction with ethanologenic bacteria and a fermentable sugar for the cost-effective production of ethanol from lignocellulosic biomass. The invention offers several advantages over presently available media for use in ethanol production, including consistent quality, lack of toxins and wide availability.

  20. Vascular access today

    PubMed Central

    Pantelias, Konstantinos; Grapsa, Eirini

    2012-01-01

    The number of patients with chronic kidney disease requiring renal replacement therapy has increased worldwide. The most common replacement therapy is hemodialysis (HD). Vascular access (VA) has a key role for successful treatment. Despite the advances that have taken place in the field of the HD procedure, few things have changed with regards to VA in recent years. Arteriovenous fistula (AVF), polytetrafluoroethylene graft and the cuffed double lumen silicone catheter are the most common used for VA. In the long term, a number of complications may present and more than one VA is needed during the HD life. The most common complications for all of VA types are thrombosis, bleeding and infection, the most common cause of morbidity in these patients. It has been estimated that VA dysfunction is responsible for 20% of all hospitalizations. The annual cost of placing and looking after dialysis VA in the United States exceeds 1 billion dollars per year. A good functional access is also vital in order to deliver adequate HD therapy. It seems that the native AVF that Brescia and Cimino described in 1966 still remains the first choice for VA. The native forearm AVFs have the longest survival and require the fewest interventions. For this reason, the forearm AVF is the first choice, followed by the upper-arm AVF, the arteriovenous graft and the cuffed central venous catheter is the final choice. In conclusion, VA remains the most important issue for patients on HD and despite the technical improvements, a number of problems and complications have to be resolved. PMID:24175244

  1. Chemists, Access, Statistics

    NASA Astrophysics Data System (ADS)

    Holmes, Jon L.

    2000-06-01

    New JCE Internet Feature at JCE Online Biographical Snapshots of Famous Chemists is a new JCE Internet feature on JCE Online. Edited by Barbara Burke, this feature provides biographical information on leading chemists, especially women and minority chemists, fostering the attitude that the practitioners of chemistry are as human as those who endeavor to learn about it. Currently, the column features biographical "snapshots" of 30 chemists. Each snapshot includes keywords and bibliography and several contain links to additional online information about the chemist. More biographical snapshots will appear in future installments. In addition, a database listing over 140 women and minority chemists is being compiled and will be made available online with the snapshots in the near future. The database includes the years of birth and death, gender and ethnicity, major and minor discipline, keywords to facilitate searching, and references to additional biographical information. We welcome your input into what we think is a very worthwhile resource. If you would like to provide additional biographical snapshots, see additional chemists added to the database, or know of additional references for those that are already in the database, please contact JCE Online or the feature editor. Your feedback is welcome and appreciated. You can find Biographical Snapshots of Famous Chemists starting from the JCE Online home page-- click the Features item under JCE Internet and then the Chemist Bios item. Access JCE Online without Name and Password We have recently been swamped by libraries requesting IP-number access to JCE Online. With the great benefit IP-number authentication gives to librarians (no user names and passwords to administer) and to their patrons (no need to remember and enter valid names and passwords) this is not surprising. If you would like access to JCE Online without the need to remember and enter a user name and password, you should tell your librarian about our

  2. Public Access and Open Access: Is There a Difference? | Poster

    Cancer.gov

    By Robin Meckley, Contributing Writer, and Tracie Frederick, Guest Writer Open access and public access—are they different concepts or are they the same? What do they mean for the researchers at NCI at Frederick? “Open-access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions. What makes it possible is the Internet and the consent of the author or copyright-holder,” according to an open access website maintained by Peter Suber, director, Harvard Open Access Project.

  3. Physiologic adaptation to space - Space adaptation syndrome

    NASA Technical Reports Server (NTRS)

    Vanderploeg, J. M.

    1985-01-01

    The adaptive changes of the neurovestibular system to microgravity, which result in space motion sickness (SMS), are studied. A list of symptoms, which range from vomiting to drowsiness, is provided. The two patterns of symptom development, rapid and gradual, and the duration of the symptoms are described. The concept of sensory conflict and rearrangements to explain SMS is being investigated.

  4. CHROMagar Orientation Medium Reduces Urine Culture Workload

    PubMed Central

    Manickam, Kanchana; Karlowsky, James A.; Adam, Heather; Lagacé-Wiens, Philippe R. S.; Rendina, Assunta; Pang, Paulette; Murray, Brenda-Lee

    2013-01-01

    Microbiology laboratories continually strive to streamline and improve their urine culture algorithms because of the high volumes of urine specimens they receive and the modest numbers of those specimens that are ultimately considered clinically significant. In the current study, we quantitatively measured the impact of the introduction of CHROMagar Orientation (CO) medium into routine use in two hospital laboratories and compared it to conventional culture on blood and MacConkey agars. Based on data extracted from our Laboratory Information System from 2006 to 2011, the use of CO medium resulted in a 28% reduction in workload for additional procedures such as Gram stains, subcultures, identification panels, agglutination tests, and biochemical tests. The average number of workload units (one workload unit equals 1 min of hands-on labor) per urine specimen was significantly reduced (P < 0.0001; 95% confidence interval [CI], 0.5326 to 1.047) from 2.67 in 2006 (preimplementation of CO medium) to 1.88 in 2011 (postimplementation of CO medium). We conclude that the use of CO medium streamlined the urine culture process and increased bench throughput by reducing both workload and turnaround time in our laboratories. PMID:23363839

  5. Access to College for All: ITAC Project--Computer and Adaptive Computer Technologies in the Cegeps for Students with Disabilities = L'accessibilite au cegep pour tous: Projet ITAC--informatique et technologies adaptees dans les cegeps pour les etudiants handicapes.

    ERIC Educational Resources Information Center

    Fichten, Catherine S.; Barile, Maria

    This report discusses outcomes of three empirical studies which investigated the computer and adaptive computer technology needs and concerns of Quebec college students with various disabilities, professors, and individuals responsible for providing services to students with disabilities. Key findings are highlighted and recommendations are made…

  6. Water Resource Adaptation Program

    EPA Science Inventory

    The Water Resource Adaptation Program (WRAP) contributes to the U.S. Environmental Protection Agency’s (U.S. EPA) efforts to provide water resource managers and decision makers with the tools needed to adapt water resources to demographic and economic development, and future clim...

  7. On Teaching Adaptively

    ERIC Educational Resources Information Center

    Corno, Lyn

    2008-01-01

    New theory on adaptive teaching reflects the social dynamics of classrooms to explain what practicing teachers do to address student differences related to learning. In teaching adaptively, teachers respond to learners as they work. Teachers read student signals to diagnose needs on the fly and tap previous experience with similar learners to…

  8. Computerized Adaptive Ability Measurement.

    ERIC Educational Resources Information Center

    Weiss, David J.

    The general objective of a research program on adaptive testing was to identify several sources of potential error in test scores, and to study adaptive testing as a means for reducing these errors. Errors can result from the mismatch of item difficulty to the individual's ability; the psychological effects of testing and the test environment; the…

  9. Uncertainty in adaptive capacity

    NASA Astrophysics Data System (ADS)

    Adger, W. Neil; Vincent, Katharine

    2005-03-01

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. To cite this article: W.N. Adger, K. Vincent, C. R. Geoscience 337 (2005).

  10. Retinal Imaging: Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Goncharov, A. S.; Iroshnikov, N. G.; Larichev, Andrey V.

    This chapter describes several factors influencing the performance of ophthalmic diagnostic systems with adaptive optics compensation of human eye aberration. Particular attention is paid to speckle modulation, temporal behavior of aberrations, and anisoplanatic effects. The implementation of a fundus camera with adaptive optics is considered.

  11. Research, Adaptation, & Change.

    ERIC Educational Resources Information Center

    Morris, Lee A., Ed.; And Others

    Research adaptation is an endeavor that implies solid collaboration among school practitioners and university and college researchers. This volume addresses the broad issues of research as an educational endeavor, adaptation as a necessary function associated with applying research findings to school situations, and change as an inevitable…

  12. Adaptive Wavelet Transforms

    SciTech Connect

    Szu, H.; Hsu, C.

    1996-12-31

    Human sensors systems (HSS) may be approximately described as an adaptive or self-learning version of the Wavelet Transforms (WT) that are capable to learn from several input-output associative pairs of suitable transform mother wavelets. Such an Adaptive WT (AWT) is a redundant combination of mother wavelets to either represent or classify inputs.

  13. Performance of Improved Channel Allocation for Multicarrier CDMA with Adaptive Frequency Hopping and Multiuser Detection

    DTIC Science & Technology

    2008-08-29

    SECURITY CLASSIFICATION OF: Subchannel allocation for the reverse link of multicarrier code-division multiplex-access (MC-CDMA) system with adaptive...Triangle Park, NC 27709-2211 15. SUBJECT TERMS subchannel allocation, fading channels, CDMA Tao Jia, Alexandra Duel-Hallen North Carolina State University... Subchannel allocation for the reverse link of multicarrier code-division multiplex-access (MC-CDMA) system with adaptive frequency hopping (AFH) is

  14. 75 FR 57859 - Specially Adapted Housing and Special Home Adaptation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... AFFAIRS 38 CFR Part 3 RIN 2900-AN21 Specially Adapted Housing and Special Home Adaptation AGENCY... housing and special home adaptation grants. This final rule incorporates certain provisions from the... adapted housing (SAH) grants and special home adaptation (SHA) grants. The public comment period ended...

  15. Financing climate change adaptation.

    PubMed

    Bouwer, Laurens M; Aerts, Jeroen C J H

    2006-03-01

    This paper examines the topic of financing adaptation in future climate change policies. A major question is whether adaptation in developing countries should be financed under the 1992 United Nations Framework Convention on Climate Change (UNFCCC), or whether funding should come from other sources. We present an overview of financial resources and propose the employment of a two-track approach: one track that attempts to secure climate change adaptation funding under the UNFCCC; and a second track that improves mainstreaming of climate risk management in development efforts. Developed countries would need to demonstrate much greater commitment to the funding of adaptation measures if the UNFCCC were to cover a substantial part of the costs. The mainstreaming of climate change adaptation could follow a risk management path, particularly in relation to disaster risk reduction. 'Climate-proofing' of development projects that currently do not consider climate and weather risks could improve their sustainability.

  16. 36 CFR 9.32 - Access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MANAGEMENT Non-Federal Oil and Gas Rights § 9.32 Access. (a) No access on, across or through lands or waters... access is by foot, pack animal, or designated road. Persons using designated roads for access to such...

  17. Positron annihilation in the interstellar medium

    NASA Technical Reports Server (NTRS)

    Guessoum, Nidhal; Ramaty, Reuven; Lingenfelter, Richard E.

    1991-01-01

    Positronium formation and annihilation are studied in a model for the interstellar medium consisting of cold cloud cores, warm partially ionized cloud envelopes, and hot intercloud gas. The gamma-ray spectra resulting from positron annihilation in these components of the interstellar medium are calculated. The spectra from the individual components are then combined, using two limiting assumptions for the propagation of the positrons, namely, that the positrons propagate freely throughout the interstellar medium, and that the positrons are excluded from the cold cloud cores. In the first case, the bulk of the positrons annihilate in the cloud cores and the annihilation line exhibits broad wings resulting from the annihilation of positronium formed by charge exchange in flight. In the second case, the positrons annihilate mainly in the warm envelopes, and the line wings are suppressed.

  18. Remote Data Access with IDL

    NASA Technical Reports Server (NTRS)

    Galloy, Michael

    2013-01-01

    A tool based on IDL (Interactive Data Language) and DAP (Data Access Protocol) has been developed for user-friendly remote data access. A difficulty for many NASA researchers using IDL is that often the data to analyze are located remotely and are too large to transfer for local analysis. Researchers have developed a protocol for accessing remote data, DAP, which is used for both SOHO and STEREO data sets. Server-side side analysis via IDL routine is available through DAP.

  19. Adaptation to climate across the Arabidopsis thaliana genome.

    PubMed

    Hancock, Angela M; Brachi, Benjamin; Faure, Nathalie; Horton, Matthew W; Jarymowycz, Lucien B; Sperone, F Gianluca; Toomajian, Chris; Roux, Fabrice; Bergelson, Joy

    2011-10-07

    Understanding the genetic bases and modes of adaptation to current climatic conditions is essential to accurately predict responses to future environmental change. We conducted a genome-wide scan to identify climate-adaptive genetic loci and pathways in the plant Arabidopsis thaliana. Amino acid-changing variants were significantly enriched among the loci strongly correlated with climate, suggesting that our scan effectively detects adaptive alleles. Moreover, from our results, we successfully predicted relative fitness among a set of geographically diverse A. thaliana accessions when grown together in a common environment. Our results provide a set of candidates for dissecting the molecular bases of climate adaptations, as well as insights about the prevalence of selective sweeps, which has implications for predicting the rate of adaptation.

  20. Atomic memory access hardware implementations

    DOEpatents

    Ahn, Jung Ho; Erez, Mattan; Dally, William J

    2015-02-17

    Atomic memory access requests are handled using a variety of systems and methods. According to one example method, a data-processing circuit having an address-request generator that issues requests to a common memory implements a method of processing the requests using a memory-access intervention circuit coupled between the generator and the common memory. The method identifies a current atomic-memory access request from a plurality of memory access requests. A data set is stored that corresponds to the current atomic-memory access request in a data storage circuit within the intervention circuit. It is determined whether the current atomic-memory access request corresponds to at least one previously-stored atomic-memory access request. In response to determining correspondence, the current request is implemented by retrieving data from the common memory. The data is modified in response to the current request and at least one other access request in the memory-access intervention circuit.

  1. Vehicle barrier with access delay

    DOEpatents

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  2. Performance metrics for advanced access.

    PubMed

    Gupta, Diwakar; Potthoff, Sandra; Blowers, Donald; Corlett, John

    2006-01-01

    Advanced access is an outpatient scheduling technique that aims to provide sameday appointment access. It is designed to reduce the time patients must wait for a scheduled appointment and to improve continuity of care by matching daily appointment supply and demand. Factors that make it difficult to sustain initial success in achieving supply-demand balance include different practice styles of doctors, differences in panel compositions and patient preferences, and time-varying demand patterns. This article proposes several performance measures that can help clinic directors monitor and evaluate their advanced access implementation. We also discuss strategies for sustaining advanced access in the long run.

  3. Solar collector having a solid transmission medium

    DOEpatents

    Schertz, William W.; Zwerdling, Solomon

    1977-06-14

    There is provided a radiant energy transmission device capable of operation in a concentrative mode in which energy incident on an entrance area is directed toward and concentrated on an exit area of smaller area than the entrance area. The device includes a solid radiant energy transmission medium having surfaces coincident with the entrance and exit areas and particularly contoured reflective side walls. The surface coinciding with the entrance area is coupled to a cover plate formed of a radiant energy transmissive material. An energy transducer is coupled to the surface of the medium coinciding with the exit area.

  4. Abundance fluctuations in the interstellar medium

    NASA Technical Reports Server (NTRS)

    Jura, M.

    1982-01-01

    The determination of abundances within the interstellar medium is reviewed. It appears that interstellar abundances within 1 kpc of the Sun are uniform to within a factor of two or three, but it is not yet possible to determine whether there are real fluctuations at this level except for deuterium for which the factor of two variations appear to be real. Establishing the level of local fluctuations in the abundances is of considerable importance for understanding the history of nucleosynthesis in the solar neighborhood, the evolution of the interstellar medium and the formation of stars.

  5. Mode Medium Interaction. A Theoretical Study.

    DTIC Science & Technology

    1980-09-01

    CPILNI’S CATALOG NUMBER 4 t (&Ad Subtitle)- 815. TYPE Q RF-PORT & PESLOD COVERLD Final echnical ,re.t af, Medium , nJulep"t Mode Medium Interactionj’%A...nonuniformity of the eigenmode and changes of the cavity flux. q U . :AVCO L VLH!L VT U SECTION II A THREE-WAVE LASER INSTABILITY A. INTRODUCTION It has been...instability in the output flux is already evident. It is as if the laser were being acoustically-3 Q -switched. Further evidence of an acoustic connection

  6. Medium Effects of Low Energy Pions

    NASA Astrophysics Data System (ADS)

    Friedman, E.

    2004-03-01

    Fits of pion--nucleus potentials to large sets of pionic atom data reveal departures of parameter values from the corresponding free π N parameters. These medium effects can be quantitatively reproduced by a chiral-motivated model where the pion decay constant is modified in the medium or by including the empirical on-shell energy dependence of the amplitudes. No consistency is obtained between pionic atoms and the free π N interaction when an extreme off-shell chiral model is used. The role of the size of data sets is briefly discussed.

  7. High Q at Low and Medium Field

    SciTech Connect

    Gianluigi Ciovati

    2004-09-22

    The surface resistance of a bulk niobium superconducting rf cavity as function of the surface magnetic field is often characterized by three peculiar dependencies at low, medium and high field. Understanding the causes and the physics behind these anomalous behaviors is important to improve the performance of superconducting cavities used in particle accelerators. In this paper attention will be focused on low and medium field regions by presenting experimental results of several cavity test series and reviewing the models that try to explain these non-linearities of the surface resistance.

  8. Structure and Dynamics of the Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Tenorio-Tagle, Guillermo; Moles, Mariano; Melnick, Jorge

    Here for the first time is a book that treats practically all aspects of modern research in interstellar matter astrophysics. 20 review articles and 40 carefully selected and refereed papers give a thorough overview of the field and convey the flavor of enthusiastic colloquium discussions to the reader. The book includes sections on: - Molecular clouds, star formation and HII regions - Mechanical energy sources - Discs, outflows, jets and HH objects - The Orion Nebula - The extragalactic interstellar medium - Interstellar matter at high galactic latitudes - The structure of the interstellar medium

  9. Medium Source Diversity and Medium Reliance: In Search of Issue Diversity.

    ERIC Educational Resources Information Center

    Ferguson, Mary Ann; Weigold, Michael

    A study examined the relationships among source diversity, medium reliance, and nominal issue diversity. Source diversity is defined as the number of categories or classes of sources, and in the study nominal diversity within media (newspapers, television and magazines) was examined. Medium reliance is defined as the perceived usefulness of a…

  10. Supplementation of CHROMagar Candida medium with Pal's medium for rapid identification of Candida dubliniensis.

    PubMed

    Sahand, Ismail H; Moragues, María D; Eraso, Elena; Villar-Vidal, María; Quindós, Guillermo; Pontón, José

    2005-11-01

    CHROMagar Candida medium is used for the isolation and identification of Candida species, but it does not differentiate Candida albicans from Candida dubliniensis. This differentiation can be achieved by using Pal's agar, which cannot be used in primary isolation. We have combined both media to obtain a new medium that can be used for the isolation and identification of C. dubliniensis in primary cultures.

  11. Access to Public Educational Facilities under the Equal Access Act.

    ERIC Educational Resources Information Center

    Wood, R. Craig; Goldblatt, Steven M.

    1988-01-01

    Discussion centers on the legal bases by which school administrators permit access to public educational facilities by religiously and politically oriented student organizations. It concludes that access should be granted to students whose purposes do not disrupt teaching and learning. (JAM)

  12. Adaptation of Selenastrum capricornutum (Chlorophyceae) to copper

    USGS Publications Warehouse

    Kuwabara, J.S.; Leland, H.V.

    1986-01-01

    Selenastrum capricornutum Printz, growing in a chemically defined medium, was used as a model for studying adaptation of algae to a toxic metal (copper) ion. Cells exhibited lag-phase adaptation to 0.8 ??M total Cu (10-12 M free ion concentration) after 20 generations of Cu exposure. Selenastrum adapted to the same concentration when Cu was gradually introduced over an 8-h period using a specially designed apparatus that provided a transient increase in exposure concentration. Cu adaptation was not attributable to media conditioning by algal exudates. Duration of lag phase was a more sensitive index of copper toxicity to Selenastrum that was growth rate or stationary-phase cell density under the experimental conditions used. Chemical speciation of the Cu dosing solution influenced the duration of lag phase even when media formulations were identical after dosing. Selenastrum initially exposed to Cu in a CuCl2 injection solution exhibited a lag phase of 3.9 d, but this was reduced to 1.5 d when a CuEDTA solution was used to achieve the same total Cu and EDTA concentrations. Physical and chemical processes that accelerated the rate of increase in cupric ion concentration generally increased the duration of lag phase. ?? 1986.

  13. Unstructured Adaptive (UA) NAS Parallel Benchmark. Version 1.0

    NASA Technical Reports Server (NTRS)

    Feng, Huiyu; VanderWijngaart, Rob; Biswas, Rupak; Mavriplis, Catherine

    2004-01-01

    We present a complete specification of a new benchmark for measuring the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. It complements the existing NAS Parallel Benchmark suite. The benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh.

  14. Microcomputer Network for Computerized Adaptive Testing (CAT): Program Listing.

    ERIC Educational Resources Information Center

    Quan, Baldwin; And Others

    This program listing is a supplement to the Microcomputer Network for Computerized Adaptive Testing (CAT). The driver textfile program allows access to major subprograms of the CAT project. The test administration textfile program gives examinees a prescribed set of subtests. The parameter management textfile program establishes a file containing…

  15. An animal component free medium that promotes the growth of various animal cell lines for the production of viral vaccines.

    PubMed

    Rourou, Samia; Ben Ayed, Yousr; Trabelsi, Khaled; Majoul, Samy; Kallel, Héla

    2014-05-19

    IPT-AFM is a proprietary animal component free medium that was developed for rabies virus (strain LP 2061) production in Vero cells. In the present work, we demonstrated the versatility of this medium and its ability to sustain the growth of other cell lines and different virus strains. Here, three models were presented: Vero cells/rabies virus (strain LP 2061), MRC-5 cells/measles virus (strain AIK-C) and BHK-21 cells/rabies virus (strain PV-BHK21). The cell lines were first adapted to grow in IPT-AFM, by progressive reduction of the amount of serum in the culture medium. After their adaptation, BHK-21 cells grew in suspension by forming clumps, whereas MRC-5 cells remained adherent. Then, kinetics of cell growth were studied in agitated cultures for both cell lines. In addition, kinetics of virus replication were investigated.

  16. Access to space study

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This report summarizes the results of a comprehensive NASA in-house study to identify and assess alternate approaches to access to space through the year 2030, and to select and recommend a preferred cause of action. The goals of the study were to identify the best vehicles and transportation architectures to make major reductions in the cost of space transportation (at least 50%), while at the same time increasing safety for flight crews by at least an order of magnitude. In addition, vehicle reliability was to exceed 0.98 percent, and, as important, the robustness, pad time, turnaround time, and other aspects of operability were to be vastly improved. This study examined three major optional architectures: (1) retain and upgrade the Space Shuttle and expendable launch vehicles; (2) develop new expendable vehicles using conventional technologies and transition from current vehicles beginning in 2005; and (3) develop new reusable vehicles using advanced technology, and transition from current vehicles beginning in 2008. The launch-needs, mission model utilized for for the study was based upon today's projection of civil, defense, and commercial mission payload requirements.

  17. Nonvolatile random access memory

    NASA Technical Reports Server (NTRS)

    Wu, Jiin-Chuan (Inventor); Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor)

    1994-01-01

    A nonvolatile magnetic random access memory can be achieved by an array of magnet-Hall effect (M-H) elements. The storage function is realized with a rectangular thin-film ferromagnetic material having an in-plane, uniaxial anisotropy and inplane bipolar remanent magnetization states. The thin-film magnetic element is magnetized by a local applied field, whose direction is used to form either a 0 or 1 state. The element remains in the 0 or 1 state until a switching field is applied to change its state. The stored information is detcted by a Hall-effect sensor which senses the fringing field from the magnetic storage element. The circuit design for addressing each cell includes transistor switches for providing a current of selected polarity to store a binary digit through a separate conductor overlying the magnetic element of the cell. To read out a stored binary digit, transistor switches are employed to provide a current through a row of Hall-effect sensors connected in series and enabling a differential voltage amplifier connected to all Hall-effect sensors of a column in series. To avoid read-out voltage errors due to shunt currents through resistive loads of the Hall-effect sensors of other cells in the same column, at least one transistor switch is provided between every pair of adjacent cells in every row which are not turned on except in the row of the selected cell.

  18. Remote direct memory access

    DOEpatents

    Archer, Charles J.; Blocksome, Michael A.

    2012-12-11

    Methods, parallel computers, and computer program products are disclosed for remote direct memory access. Embodiments include transmitting, from an origin DMA engine on an origin compute node to a plurality target DMA engines on target compute nodes, a request to send message, the request to send message specifying a data to be transferred from the origin DMA engine to data storage on each target compute node; receiving, by each target DMA engine on each target compute node, the request to send message; preparing, by each target DMA engine, to store data according to the data storage reference and the data length, including assigning a base storage address for the data storage reference; sending, by one or more of the target DMA engines, an acknowledgment message acknowledging that all the target DMA engines are prepared to receive a data transmission from the origin DMA engine; receiving, by the origin DMA engine, the acknowledgement message from the one or more of the target DMA engines; and transferring, by the origin DMA engine, data to data storage on each of the target compute nodes according to the data storage reference using a single direct put operation.

  19. Making Astronomy Accessible

    NASA Astrophysics Data System (ADS)

    Grice, Noreen A.

    2011-05-01

    A new semester begins, and your students enter the classroom for the first time. You notice a student sitting in a wheelchair or walking with assistance from a cane. Maybe you see a student with a guide dog or carrying a Braille computer. Another student gestures "hello” but then continues hand motions, and you realize the person is actually signing. You wonder why another student is using an electronic device to speak. Think this can't happen in your class? According to the U.S. Census, one out of every five Americans has a disability. And some disabilities, such as autism, dyslexia and arthritis, are considered "invisible” disabilities. This means you have a high probability that one of your students will have a disability. As an astronomy instructor, you have the opportunity to reach a wide variety of learners by using creative teaching strategies. I will share some suggestions on how to make astronomy and your part of the universe more accessible for everyone.

  20. Effective medium approximation for effective propagation constant calculation in a dense random medium. [electromagnetic wave scattering

    NASA Technical Reports Server (NTRS)

    Zhu, P. Y.; Fung, A. K.

    1986-01-01

    The effective medium approximation (EMA) formalism developed for scalar wave calculations in solid state physics is generalized to electromagnetic wave scattering in a dense random medium. Results are applied to compute the effective propagation constant in a dense medium involving discrete spherical scatterers. When compared with a common quasicrystalline approximation (QCA), it is found that EMA accounts for backward scattering and the effect of correlation among three scatterers which are not available in QCA. It is also found that there is not much difference in the calculated normalized phase velocity between the use of these two approximations. However, there is a significant difference in the computed effective loss tangent in a nonabsorptive random medium. The computed effective loss tangent using EMA and measurements from a snow medium are compared, showing good agreement.

  1. The role of endovascular stents in dialysis access maintenance

    PubMed Central

    Kassem, Mohamad El; Alghamdi, Issam; Vazquez-Padron, Roberto I; Asif, Arif; Lenz, Oliver; Sanjar, Tina; Fayad, Fadi; Salman, Loay

    2015-01-01

    Vascular stenosis is most often the culprit behind hemodialysis vascular access dysfunction, and while percutaneous transluminal angioplasty (PTA) remains the gold standard treatment for vascular stenosis, over the past decade the use of stents as a treatment option has been on the rise. Aside from the two FDA approved stent-grafts for the treatment of venous graft anastomosis (VGA) stenosis, use of all other stents in vascular access dysfunction is off-label. KDOQI recommends limiting stent use to specific conditions, such as elastic lesions and recurrent stenosis; otherwise, additional adapted indications are in procedure-related complications, such as grade 2 and 3 hematomas. Published reports have shown the potential use of stents in a variety of conditions leading to vascular access dysfunction; such as VGA stenosis, cephalic arch stenosis, central venous stenosis, dialysis access aneurysmal elimination, Cardiac Implantable Electronic Device induced stenosis, and thrombosed arteriovenous grafts (AVG). While further research is needed for many of these conditions, evidence for recommendations has been clear in some; for instance, we know now that stents should be avoided along cannulations sites and should not be used in eliminating dialysis access aneurysms. In this review article, we evaluate the available evidence for the use of stents in each of the aforementioned conditions leading to hemodialysis vascular access dysfunctions. PMID:26524950

  2. Adaptation to blur

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Webster, Shernaaz M.; MacDonald, Jennifer; Bahradwadj, Shrikant R.

    2001-06-01

    Blur is an intrinsic property of the retinal image that can vary substantially in natural viewing. We examined how processes of contrast adaptation might adjust the visual system to regulate the perception of blur. Observers viewed a blurred or sharpened image for 2-5 minutes, and then judged the apparent focus of a series of 0.5-sec test images interleaved with 6-sec of readaptation. A 2AFC staircase procedure was used to vary the amplitude spectrum of successive test to find the image that appeared in focus. Adapting to a blurred image causes a physically focused image to appear too sharp. Opposite after-effects occur for sharpened adapting images. Pronounced biases were observed over a wide range of magnitudes of adapting blur, and were similar for different types of blur. After-effects were also similar for different classes of images but were generally weaker when the adapting and test stimuli were different images, showing that the adaptation is not adjusting simply to blur per se. These adaptive adjustments may strongly influence the perception of blur in normal vision and how it changes with refractive errors.

  3. Mathematical Model of Porous Medium Dynamics

    NASA Astrophysics Data System (ADS)

    Gerschuk, Peotr; Sapozhnikov, Anatoly

    1999-06-01

    Semiempirical model describing porous material strains under pulse mechanical and thermal loadings is proposed. Porous medium is considered as continuous one but with special form of pressure dependence upon strain. This model takes into account principal features of porous materials behavior which can be observed when the material is strained in dynamic and static experiments ( non-reversibility of large strains, nonconvexity of loading curve). Elastoplastic properties of porous medium, its damages when it is strained and dynamic fracture are also taken into account. Dispersion of unidirectional motion caused by medium heterogeneity (porousness) is taken into acount by introducing the physical viscosity depending upon pores size. It is supposed that at every moment of time pores are in equilibrium with pressure i.e. kinetic of pores collapse is not taken into account. The model is presented by the system of differential equations connecting pressure and energy of porous medium with its strain. These equations close system of equations of motion and continuity which then is integrated numerically. The proposed model has been tested on carbon materials and porous copper . Results of calculation of these materials shock compressing are in satisfactory agreement with experimental data. Results of calculation of thin plate with porous copper layer collision are given as an illustration.

  4. Microprint as a medium for primary publication

    USGS Publications Warehouse

    Herman, C.M.; Luhn, H.P.

    1964-01-01

    Microprint has been demonstrated an acceptable medium for publication in an experiment conducted by the Wildlife Disease Association. With author composition costs slightly over seven cents per 3x5 inch card, up to 47 pages. Need is recognized for development of standards and improvement of accessory retrieval apparatus.

  5. Effects of medium concentration on antibody production

    NASA Technical Reports Server (NTRS)

    Williams, J.

    1984-01-01

    Antibody production by two different cell lines was measured as the media were supplemented with varied amounts of glucose and fetal bovine serum. Both cell lines elaborated antidinitrophenyl hapten antibodies. Two basic media were used: RPMI 1640 and Dulbecco's modified Eagle's medium. The production of antibodies was followed from 0 to 180 h and was assayed by radioimmunoassay.

  6. A Dark Horse Medium in Basic Business

    ERIC Educational Resources Information Center

    Eckert, Sidney W.

    1974-01-01

    The Dark Horse (DH) board is described and discussed as one medium which may be utilized in the classroom. The DH Board holds fairly heavy three-dimensional display objects and consists of two components: a special material which serves as the display surface and an adhesive material which is fixed to objects displayed. (SC)

  7. Hytrast: A New Contrast Medium for Bronchography

    PubMed Central

    Misener, F. J.; Quinlan, J. J.; Hiltz, J. E.

    1965-01-01

    In 1962 Hytrast, an aqueous suspension containing 50% w/v of combined iodine as a mixture of N-(2,3-dihydroxypropyl)-3,5-diiodopyridone-4 and 3,5-diiodopyridone-4, was introduced as a contrast medium for bronchography. Extensive clinical trials had suggested that this agent was superior to products usually employed for this purpose. At the Nova Scotia Sanatorium, Hytrast was used as a bronchographic contrast medium in 31 consecutive cases. For comparison purposes, the records of the first 50 patients in whom another contrast medium, Dionosil Oily, was used were reviewed. In all cases the contrast medium was introduced through a catheter passed into the bronchus with the aid of a laryngeal mirror, after local anesthesia was induced by pontocaine 2%. Experience in this limited number of cases was at variance with most published results. Hytrast was more irritating than Dionosil Oily, had a greater tendency to produce alveolarization, caused more frequent undesirable sequelae, and was retained in the lung for prolonged periods. PMID:14264971

  8. Particle Diffusion in an Inhomogeneous Medium

    ERIC Educational Resources Information Center

    Bringuier, E.

    2011-01-01

    This paper is an elementary introduction to particle diffusion in a medium where the coefficient of diffusion varies with position. The introduction is aimed at third-year university courses. We start from a simple model of particles hopping on a discrete lattice, in one or more dimensions, and then take the continuous-space limit so as to obtain…

  9. Separation medium containing thermally exfoliated graphite oxide

    NASA Technical Reports Server (NTRS)

    Prud'homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor); Herrera-Alonso, Margarita (Inventor)

    2012-01-01

    A separation medium, such as a chromatography filling or packing, containing a modified graphite oxide material, which is a thermally exfoliated graphite oxide with a surface area of from about 300 m.sup.2/g to 2600 m.sup.2/g, wherein the thermally exfoliated graphite oxide has a surface that has been at least partially functionalized.

  10. Towards the exact calculation of medium nuclei

    SciTech Connect

    Gandolfi, Stefano; Carlson, Joseph Allen; Lonardoni, Diego; Wang, Xiaobao

    2016-12-19

    The prediction of the structure of light and medium nuclei is crucial to test our knowledge of nuclear interactions. The calculation of the nuclei from two- and three-nucleon interactions obtained from rst principle is, however, one of the most challenging problems for many-body nuclear physics.

  11. The Digital Medium Meets the Advertising Message.

    ERIC Educational Resources Information Center

    Nisenholtz, Martin

    1994-01-01

    Discusses the likelihood that companies will use online services as an advertising medium. Topics addressed include the art of interactive marketing; advertising in the digital age; early experiments with interactive marketing, including the use of videotex and videodisc; and recent trends that set the stage for interactive marketing to personal…

  12. Innovation in Small and Medium Firms.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France). Committee for Scientific and Technical Personnel.

    A study analyzed the policies of 20 Organisation for Economic Cooperation and Development (OECD) member countries pertaining to small and medium enterprises (SMEs). Aims of the study were to assess the current role of SMEs as generators and users of innovations, to analyze the components of a favorable climate for innovation in SMEs, and to…

  13. Environmental Acceptable Medium Caliber Ammunition Percussion Primers

    DTIC Science & Technology

    2008-05-01

    percussion primers typically consist of lead styphnate and antimony sulfide. Although highly effective, these heavy material compounds were identified under...Percussion primers, including those used in medium caliber ammunition, typically contain lead styphnate and antimony sulfide along with other constituents...Furthermore, current percussion primer compositions also contain barium nitrate. Although not negatively categorized by the Environmental Protection

  14. Radiofrequency recombination lines from the interstellar medium

    NASA Technical Reports Server (NTRS)

    Dupree, A. K.

    1971-01-01

    Observations of recombination lines form normal H II regions, extended H II regions, nonthermal sources, and the H I medium are discussed. Detection of recombination lines from elements other than hydrogen may provide a means of identifying fossil Stromgren spheres at high temperature.

  15. [Adaptive optics for ophthalmology].

    PubMed

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy.

  16. Adaptive network countermeasures.

    SciTech Connect

    McClelland-Bane, Randy; Van Randwyk, Jamie A.; Carathimas, Anthony G.; Thomas, Eric D.

    2003-10-01

    This report describes the results of a two-year LDRD funded by the Differentiating Technologies investment area. The project investigated the use of countermeasures in protecting computer networks as well as how current countermeasures could be changed in order to adapt with both evolving networks and evolving attackers. The work involved collaboration between Sandia employees and students in the Sandia - California Center for Cyber Defenders (CCD) program. We include an explanation of the need for adaptive countermeasures, a description of the architecture we designed to provide adaptive countermeasures, and evaluations of the system.

  17. Adaptive optics ophthalmoscopy.

    PubMed

    Roorda, A

    2000-01-01

    Retinal images in the human eye are normally degraded because we are forced to use the optical system of the human eye--which is fraught with aberrations--as the objective lens. The recent application of adaptive optics technology to measure and compensate for these aberrations has produced retinal images in human eyes with unprecedented resolution. The adaptive optics ophthalmoscope is used to take pictures of photoreceptors and capillaries and to study spectral and angular tuning properties of individual photoreceptors. Application of adaptive optics technology for ophthalmoscopy promises continued progress toward understanding the basic properties of the living human retina and also for clinical applications.

  18. Adaptive Telemetry Multiplexer

    NASA Technical Reports Server (NTRS)

    Sinderson, R. L.; Salazar, G. A.; Haddick, C. M., Jr.; Spahn, C. J.; Venkatesh, C. N.

    1989-01-01

    Telemetry-data-acquisition unit adjusted remotely to produce changes in sampling rate, sampling channels, measurement scale, and output-bias level. Functional configuration adapted to changing conditions or new requirements by distant operator over telemetry link. Reconfiguration done in real time, without removing equipment from service. Bus-interface unit accepts reprogramming commands and translates them for low-rate adaptive multiplexer. Reprogrammable equipment reduces need for spare parts, since not necessary to stock variety of hardware with fixed characteristics. Adaptive multiplexer performs well in tests, amplitude errors less than 0.5 percent, distortion less than 0.25 percent, and crosstalk and common-mode rejection indiscernible.

  19. Distributed reservation control protocols for random access broadcasting channels

    NASA Astrophysics Data System (ADS)

    Greene, E. P.; Ephremides, A.

    1981-05-01

    Attention is given to a communication network consisting of an arbitrary number of nodes which can communicate with each other via a time-division multiple access (TDMA) broadcast channel. The reported investigation is concerned with the development of efficient distributed multiple access protocols for traffic consisting primarily of single packet messages in a datagram mode of operation. The motivation for the design of the protocols came from the consideration of efficient multiple access utilization of moderate to high bandwidth (4-40 Mbit/s capacity) communication satellite channels used for the transmission of short (1000-10,000 bits) fixed length packets. Under these circumstances, the ratio of roundtrip propagation time to packet transmission time is between 100 to 10,000. It is shown how a TDMA channel can be adaptively shared by datagram traffic and constant bandwidth users such as in digital voice applications. The distributed reservation control protocols described are a hybrid between contention and reservation protocols.

  20. Distributed reservation control protocols for random access broadcasting channels

    NASA Technical Reports Server (NTRS)

    Greene, E. P.; Ephremides, A.

    1981-01-01

    Attention is given to a communication network consisting of an arbitrary number of nodes which can communicate with each other via a time-division multiple access (TDMA) broadcast channel. The reported investigation is concerned with the development of efficient distributed multiple access protocols for traffic consisting primarily of single packet messages in a datagram mode of operation. The motivation for the design of the protocols came from the consideration of efficient multiple access utilization of moderate to high bandwidth (4-40 Mbit/s capacity) communication satellite channels used for the transmission of short (1000-10,000 bits) fixed length packets. Under these circumstances, the ratio of roundtrip propagation time to packet transmission time is between 100 to 10,000. It is shown how a TDMA channel can be adaptively shared by datagram traffic and constant bandwidth users such as in digital voice applications. The distributed reservation control protocols described are a hybrid between contention and reservation protocols.

  1. NASA Access Mechanism - Graphical user interface information retrieval system

    NASA Technical Reports Server (NTRS)

    Hunter, Judy F.; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited by factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  2. NASA access mechanism: Graphical user interface information retrieval system

    NASA Technical Reports Server (NTRS)

    Hunter, Judy; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited to factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  3. Improving access to psychological treatments: lessons from developing countries.

    PubMed

    Patel, Vikram; Chowdhary, Neerja; Rahman, Atif; Verdeli, Helen

    2011-09-01

    Even though psychological treatments have been advocated as treatments for a range of mental disorders by the WHO for scaling up through primary care globally, the vast majority of potential beneficiaries are unable to access these treatments. Two major barriers impede the path between evidence based treatments and improved access: the lack of skilled human resources and the acceptability of treatments across cultures. This essay synthesizes the experiences of programs which developed and evaluated psychological treatments for depression in three resource poor developing countries. These programs addressed the human resource barrier by training lay or community health workers to deliver the treatments and addressed the acceptability barrier by systematically adapting the treatment to contextual factors. All programs demonstrated significant benefits in recovery rates when compared with usual care demonstrating the effectiveness of the approach. The implications for these experiences to improving access to psychological treatments in the global context are discussed.

  4. Arteriovenous access ischemic steal (AVAIS) in haemodialysis: a consensus from the Charing Cross Vascular Access Masterclass 2016.

    PubMed

    Inston, Nicholas; Schanzer, Harry; Widmer, Matthias; Deane, Colin; Wilkins, Jason; Davidson, Ingemar; Gibbs, Paul; Zanow, Jeurgen; Bourquelot, Pierre; Valenti, Domenico

    2017-01-18

    Arteriovenous access ischaemic steal (AVAIS) is a serious and not infrequent complication of vascular access. Pathophysiology is key to diagnosis, investigation and management. Ischaemia distal to an AV access is due to multiple factors. Clinical steal is not simply blood diversion but pressure changes within the adapted vasculature with distal hypoperfusion and resultant poor perfusion pressures in the distal extremity. Reversal of flow within the artery distal to the AV access may be seen but this is not associated with ischaemia in most cases.Terminology is varied and it is suggested that arteriovenous access ischemic steal (AVAIS) is the preferred term. In all cases AVAIS should be carefully classified on clinical symptoms as these determine management options and allow standardisation for studies.Diabetes and peripheral arterial occlusive disease are risk factors but a 'high risk patient' profile is not clear and definitive vascular access should not be automatically avoided in these patient groups.Multiple treatment modalities have been described and their use should be directed by appropriate assessment, investigation and treatment of the underlying pathophysiology. Comparison of treatment options is difficult as published studies are heavily biased. Whilst no single technique is suitable for all cases of AVAIS there are some that suit particular scenarios and mild AVAIS may benefit from observation whilst more severe steal mandates surgical intervention.

  5. Internet Access to Spacecraft

    NASA Technical Reports Server (NTRS)

    Rash, James; Parise, Ron; Hogie, Keith; Criscuolo, Ed; Langston, Jim; Jackson, Chris; Price, Harold; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The Operating Missions as Nodes on the Internet (OMNI) project at NASA's Goddard Space flight Center (GSFC), is demonstrating the use of standard Internet protocols for spacecraft communication systems. This year, demonstrations of Internet access to a flying spacecraft have been performed with the UoSAT-12 spacecraft owned and operated by Surrey Satellite Technology Ltd. (SSTL). Previously, demonstrations were performed using a ground satellite simulator and NASA's Tracking and Data Relay Satellite System (TDRSS). These activities are part of NASA's Space Operations Management Office (SOMO) Technology Program, The work is focused on defining the communication architecture for future NASA missions to support both NASA's "faster, better, cheaper" concept and to enable new types of collaborative science. The use of standard Internet communication technology for spacecraft simplifies design, supports initial integration and test across an IP based network, and enables direct communication between scientists and instruments as well as between different spacecraft, The most recent demonstrations consisted of uploading an Internet Protocol (IP) software stack to the UoSAT- 12 spacecraft, simple modifications to the SSTL ground station, and a series of tests to measure performance of various Internet applications. The spacecraft was reconfigured on orbit at very low cost. The total period between concept and the first tests was only 3 months. The tests included basic network connectivity (PING), automated clock synchronization (NTP), and reliable file transfers (FTP). Future tests are planned to include additional protocols such as Mobile IP, e-mail, and virtual private networks (VPN) to enable automated, operational spacecraft communication networks. The work performed and results of the initial phase of tests are summarized in this paper. This work is funded and directed by NASA/GSFC with technical leadership by CSC in arrangement with SSTL, and Vytek Wireless.

  6. ERIC Data Access System (EDAS).

    ERIC Educational Resources Information Center

    Rao, Pal V.

    The ERIC Data Access System (EDAS) is an information retrieval system developed at Eastern Illinois University to access the Educational Resources Information Center (ERIC) database and make it available to Eastern faculty and students in a convenient and timely fashion. This paper describes briefly why and how Eastern developed and implemented…

  7. Minority Access to Higher Education

    ERIC Educational Resources Information Center

    Jackson, Nathaniel

    2012-01-01

    Blacks, Hispanics, Native Americans, and Asian Americans are entitled to equal access to all institutions of higher education. Ensuring greater access and participation by minorities in higher education is one of the most practical ways of moving America closer to the ideal of equal opportunity, which is the actualization of the American dream.…

  8. Accessible Multimedia for the Web.

    ERIC Educational Resources Information Center

    Zaparyniuk, Nicholas; Code, Jillianne

    With the Internet taking a dominant role in corporate training, education, retail, and customer based product exploration, authors of Web-based information need to ensure that the media they deliver is accessible to the widest possible audience. Whether users have a visual, auditory, physical, or developmental disability, accessible multimedia can…

  9. Automatically Producing Accessible Learning Objects

    ERIC Educational Resources Information Center

    Di Iorio, Angelo; Feliziani, Antonio Angelo; Mirri, Silvia; Salomoni, Paola; Vitali, Fabio

    2006-01-01

    The "Anywhere, Anytime, Anyway" slogan is frequently associated to e-learning with the aim to emphasize the wide access offered by on-line education. Otherwise, learning materials are currently created to be used with a specific technology or configuration, leaving out from the virtual classroom students who have limited access capabilities and,…

  10. Editorial: Next Generation Access Networks

    NASA Astrophysics Data System (ADS)

    Ruffini, Marco; Cincotti, Gabriella; Pizzinat, Anna; Vetter, Peter

    2015-12-01

    Over the past decade we have seen an increasing number of operators deploying Fibre-to-the-home (FTTH) solutions in access networks, in order to provide home users with a much needed network access upgrade, to support higher peak rates, higher sustained rates and a better and more uniform broadband coverage of the territory.

  11. "Accessions": Researching, Designing Higher Education

    ERIC Educational Resources Information Center

    Taylor, Yvette

    2011-01-01

    This brief viewpoint piece depicts educational (dis)engagements apparent in researching and (re)designing higher education in and through "Accessions". "Accessions", a collaborative research-design project, probed at how cultures, climates and conditions of higher education may be reproducing or reshaping social inequalities…

  12. Electronic Information: Options for Access.

    ERIC Educational Resources Information Center

    Pesch, Oliver

    1994-01-01

    Discusses three electronic information formats: CD-ROM, tape loads, and online hosts; reviews some of the hardware platforms used for accessing information in these formats; and discusses some of the issues involved in interconnecting computer systems to increase access to electronic collections. (Author)

  13. Accessibility on the Hudson River

    ERIC Educational Resources Information Center

    Exceptional Parent, 2010

    2010-01-01

    This article describes how Beverly and Martin Ryfa, working with an architect who specializes in accessible design, were able to build a house that is handicap accessible for their 9-year-old daughter, Danielle, who suffered an intraventricular hemorrhage when she was three days old. The article describes the features of their house that make…

  14. Accessibility in E-Assessment

    ERIC Educational Resources Information Center

    Ball, Simon

    2009-01-01

    E-assessment offers many opportunities to broaden the range of tools at the assessor's disposal and thereby improve the overall accessibility of the assessment experience. In 2006, TechDis commissioned a report, produced by Edexcel, on the state of guidance on accessibility at the various stages of the assessment process--question design,…

  15. Hybrid haemodialysis vascular access salvage.

    PubMed

    Potisek, Maja; Ključevšek, Tomaž; Leskovar, Boštjan

    2017-03-01

    A well-functioning vascular access is essential for successful haemodialysis in patients with end-stage kidney failure. Sometimes, when we have exploited all conventional ways of vascular access salvage, we have to find a unique solution to preserve it.

  16. Guidelines for Outsourcing Remote Access.

    ERIC Educational Resources Information Center

    Hassler, Ardoth; Neuman, Michael

    1996-01-01

    Discusses the advantages and disadvantages of outsourcing remote access to campus computer networks and the Internet, focusing on improved service, cost-sharing, partnerships with vendors, supported protocols, bandwidth, scope of access, implementation, support, network security, and pricing. Includes a checklist for a request for proposals on…

  17. Bibliographic Access and Control System.

    ERIC Educational Resources Information Center

    Kelly, Betsy; And Others

    1982-01-01

    Presents a brief summary of the functions of the Bibliographic Access & Control System (BACS) implemented at the Washington University School of Medicine Library, and outlines the design, development, and uses of the system. Bibliographic control of books and serials and user access to the system are also discussed. (Author/JL)

  18. Adapting Language Arts, Social Studies, and Science Materials for the Inclusive Classroom. ERIC/OSEP Digest.

    ERIC Educational Resources Information Center

    Lenz, Keith; Schumaker, Jean

    This digest, based on a larger publication of the same title, offers a nine-step process for planning and implementing adaptations to instructional materials for students with disabilities in the inclusive classroom. Introductory material notes that adaptations should be approached as a short-term solution to increase access to the curriculum and…

  19. Medium energy heavy ion operations at RHIC

    SciTech Connect

    Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

  20. In-medium properties of mesons

    NASA Astrophysics Data System (ADS)

    Metag, Volker; Nanova, Mariana; Brinkmann, Kai-Thomas

    2017-01-01

    In the project B.4, the modification of meson properties (mass, width) in a nuclear medium has been studied in photoproduction of mesons off nuclear targets. This work has been motivated by theoretical expectations of in-medium modifications of hadrons based on the conjecture of a partial restoration of chiral symmetry in a strongly interacting medium. It has been shown that these in-medium changes can be discussed in a compact form in terms of an optical potential describing the meson-nucleus interaction. Experimental approaches to determine the real and imaginary part of the meson-nucleus potential have been developed. The experiments have been performed with the Crystal Barrel/TAPS detector at the electron accelerator ELSA (Bonn) and the Crystal Ball/TAPS detector at MAMI (Mainz). Measuring the excitation function and momentum distribution for photo production of ω and η' mesons, the real parts of the ω and η'-nucleus potential, given by the in-medium mass shift, have been determined. For the η' meson a lowering of the mass at normal nuclear matter density by -(39±7(stat)±15(syst)) MeV is observed, while for the ω meson a slightly smaller mass shift is found, however, with much larger uncertainties, not excluding a zero mass shift. The imaginary part of the potentials has been extracted from the measurement of the transparency ratio which compares the meson production cross section per nucleon within a nucleus to the production cross section off the free proton. For the η' meson the imaginary part of the potential is found to be smaller than the real part. In case of the ω meson the opposite is observed. This makes the η' meson a good candidate for the search for meson-nucleus bound states while no resolved ω mesic states can be expected. The results are compared with theoretical predictions. An outlook on future experiments is given.

  1. Gendered knowledge and adaptive practices: Differentiation and change in Mwanga District, Tanzania.

    PubMed

    Smucker, Thomas A; Wangui, Elizabeth Edna

    2016-12-01

    We examine the wider social knowledge domain that complements technical and environmental knowledge in enabling adaptive practices through two case studies in Tanzania. We are concerned with knowledge production that is shaped by gendered exclusion from the main thrusts of planned adaptation, in the practice of irrigation in a dryland village and the adoption of fast-maturing seed varieties in a highland village. The findings draw on data from a household survey, community workshops, and key informant interviews. The largest challenge to effective adaptation is a lack of access to the social networks and institutions that allocate resources needed for adaptation. Results demonstrate the social differentiation of local knowledge, and how it is entwined with adaptive practices that emerge in relation to gendered mechanisms of access. We conclude that community-based adaptation can learn from engaging the broader social knowledge base in evaluating priorities for coping with greater climate variability.

  2. Power port contrast medium flushing and trapping: impact of temperature, an in vitro experimental study

    PubMed Central

    Guiffant, Gérard; Durussel, Jean Jacques; Flaud, Patrice; Royon, Laurent; Marcy, Pierre Yves; Merckx, Jacques

    2013-01-01

    Purpose The use of totally implantable venous access devices (TIVADs) certified as “high pressure resistant” or “power port” has begun to spread worldwide as a safe procedure for power contrast injection. Owing to the thermo-rheological properties of the contrast media, the primary aim of this work is to present an in vitro experimental impact study concerning the impact of the temperature level on flushing efficiency after contrast medium injection. Moreover, we report experimental data that confirms the role of needle bevel orientation. The secondary aim is to answer the following questions: Is there significant device contrast medium trapping after contrast medium injection? Is saline flushing efficient? And, finally, is it safe to inject contrast medium through an indwelled port catheter? Results The experimental results show that in addition to hydrodynamics, temperature is a key parameter for the efficiency of device flushing after contrast medium injection. It appears that this is the case when the cavity is incompletely rinsed after three calibrated flushing volumes of 10 mL saline solution, even by using the Huber needle bevel opposite to the port exit. This leads to a potentially important trapped volume of contrast medium in the port, and consequently to the possibility of subsequent salt precipitates and long term trisubstituted benzene nuclei delivery that might impair the solute properties, which may be further injected via the power port later on. Conclusion We thus suggest, in TIVADS patients, the use of a temporary supplementary intravenous line rather than the port to perform contrast medium injections in daily radiology routine practice. PMID:24043959

  3. Telescope Adaptive Optics Code

    SciTech Connect

    Phillion, D.

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The default parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST

  4. Adaptive Heat Engine.

    PubMed

    Allahverdyan, A E; Babajanyan, S G; Martirosyan, N H; Melkikh, A V

    2016-07-15

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where-due to feedback from the functional part-the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment.

  5. Rocketing into Adaptive Inquiry.

    ERIC Educational Resources Information Center

    Farenga, Stephen J.; Joyce, Beverly A.; Dowling, Thomas W.

    2002-01-01

    Defines adaptive inquiry and argues for employing this method which allows lessons to be shaped in response to student needs. Illustrates this idea by detailing an activity in which teams of students build rockets. (DDR)

  6. Adaptive Management of Ecosystems

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management. As such, management may be treated as experiment, with replication, or management may be conducted in an iterative manner. Although the concept has resonated with many...

  7. Fracture and Medium Modeling, by Analizing Hidraulic Fracturing Induced Microseismicity

    NASA Astrophysics Data System (ADS)

    Gomez Alba, S.; Vargas Jiménez, C. A.

    2014-12-01

    Hydraulic fracturing is an essential technology for most unconventional hydrocarbon resources and many conventional ones as well. The primary limitation on the improvement and optimization of the fracturing process is the minimal access to observe the behavior of the fracture in the subsurface. Without direct observational evidence, hypothetical mechanisms must be assumed and then tested for their validity with indirect information such as wellbore measurements, indirect production and pressure behavior. One of the most important sources of information today is the relation made between micro seismic source mechanisms and fracture behavior. Hydraulic fractures induce some level of micro seismicity when the stress conditions in the Earth are altered by changes in stress during the operations. The result is the sudden movement between rock elements and the radiation of both compressional and shear energy in a seismic range that can be detected and recorded with sensitive receivers. The objective of this work is to provide reasonable information when applying inversion methods in order to estimate the vertical and horizontal spatial heterogeneities in medium and energy radiation distribution of microseisms while fracking operations. The method consist in record microseisms at a previous lineal array of stations (triaxial accelerometers) which are located close to the source coordinates and cover the area of study. The analysis clarify some ideas about what information can be gained from the micro seismic source data and according to the obtained results, what kind of comparisons and associations might be done to evaluate the fracking performance operation. Non uniformities in medium such as faults would be revealed by interpreted scattering coefficients. Fracture properties like distance, velocity and orientation would be also determined by analyzing energy radiation.

  8. The Copernicus Climate Change Service (C3S): Open Access to a Climate Data Store

    NASA Astrophysics Data System (ADS)

    Thepaut, Jean-Noel; Dee, Dick

    2016-04-01

    In November 2014, The European Centre for Medium-range Weather Forecasts (ECMWF) signed an agreement with the European Commission to deliver two of the Copernicus Earth Observation Programme Services on the Commission's behalf. The ECMWF delivered services - the Copernicus Climate Change Service (C3S) and Atmosphere Monitoring Service (CAMS) - will bring a consistent standard to how we monitor and predict atmospheric conditions and climate change. They will maximise the potential of past, current and future earth observations - ground, ocean, airborne, satellite - and analyse these to monitor and predict atmospheric conditions and in the future, climate change. With the wealth of free and open data that the services provide, they will help business users to assess the impact of their business decisions and make informed choices, delivering a more energy efficient and climate aware economy. These sound investment decisions now will not only stimulate growth in the short term, but reduce the impact of climate change on the economy and society in the future. C3S is in its proof of concept phase and through its Climate Data Store will provide • global and regional climate data reanalyses; • multi-model seasonal forecasts; • customisable visual data to enable examination of wide range of scenarios and model the impact of changes; • access to all the underlying data, including climate data records from various satellite and in-situ observations. In addition, C3S will provide key indicators on climate change drivers (such as carbon dioxide) and impacts (such as reducing glaciers). The aim of these indicators will be to support European adaptation and mitigation policies in a number of economic sectors. At the heart of the Service is the provision of open access to a one stop shop (the Climate Data Store) of climate data and modelling, analysing more than 20 Essential Climate Variables to build a global picture of our past, present and future climate and developing

  9. [Adaptation of yeasts of the genus Debaryomyces to protocatechuic acid].

    PubMed

    Karasevich, Iu N

    1980-01-01

    Among five yeast strains belonging to the genus Debaryomyces that were unable of utilizing aromatic compounds (phenols and hydroxybenzoic acids), three strains, viz. D. kloeckeri BKM-Y-1044, D. marama BKM-Y-100 and D. marama BKM-Y-2045, were adapted to protocatechuic acid. The adapted yeasts utilized protocatechuic acid if its concentration in the medium was 0.1%, but did not utilize it, or did at a very low rate, if the concentration of protocatechuic acid was decreased to 0.05%. The mechanism of adaptation is rare mutations occurring in succession, and the process takes therefore several months. The adaptation seems to be based on reversion of inactivated genes for enzymes involved in the preparative metabolism of protocatechuic acid. Three typical yeast species of the Debaryomyces genus are proposed (D. hansenii, D. kloeckeri and D. konokotinae) which include all of the Debaryomyces species and strains available at the Institute of Microbiology of the USSR Academy of Sciences.

  10. Leak test adapter for containers

    DOEpatents

    Hallett, Brian H.; Hartley, Michael S.

    1996-01-01

    An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

  11. Robust Adaptive Control

    NASA Technical Reports Server (NTRS)

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  12. Adaptive Gaussian Pattern Classification

    DTIC Science & Technology

    1988-08-01

    redundant model of the data to be used in classification . There are two classes of learning, or adaptation schemes. The first, unsupervised learning...37, No. 3, pp. 242-247, 1983. [2] E. F. Codd, Cellular Automata , Academic Press, 1968. [31 H. Everett, G. Gilbreath, S. Alderson, D. J. Marchette...Na al Oca aytm aete !JTI FL E COPY AD-A 199 030 Technical Document 1335 August 1988 Adaptive Gaussian Pattern Classif ication C. E. Priebe D. J

  13. Driver Adaptive Warning Systems

    DTIC Science & Technology

    1998-03-01

    this threshold, an alarm is triggered. Since TLC based systems can have user defined thresholds, a warning can be given as early as desired. However, the...Driver Adaptive Warning Systems Thesis Proposal Parag H. Batavia CMU-RI-TR-98-07 The Robotics Institute Carnegie Mellon University Pittsburgh...control number. 1. REPORT DATE MAR 1998 2. REPORT TYPE 3. DATES COVERED 00-00-1998 to 00-00-1998 4. TITLE AND SUBTITLE Driver Adaptive Warning

  14. Adaptable DC offset correction

    NASA Technical Reports Server (NTRS)

    Golusky, John M. (Inventor); Muldoon, Kelly P. (Inventor)

    2009-01-01

    Methods and systems for adaptable DC offset correction are provided. An exemplary adaptable DC offset correction system evaluates an incoming baseband signal to determine an appropriate DC offset removal scheme; removes a DC offset from the incoming baseband signal based on the appropriate DC offset scheme in response to the evaluated incoming baseband signal; and outputs a reduced DC baseband signal in response to the DC offset removed from the incoming baseband signal.

  15. 30 CFR 75.703-2 - Approved grounding mediums.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved grounding mediums. 75.703-2 Section 75... mediums. For purposes of grounding offtrack direct-current machines, the following grounding mediums are... alternating current grounding medium where such machines are fed by an ungrounded direct-current power...

  16. 30 CFR 75.703-2 - Approved grounding mediums.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Approved grounding mediums. 75.703-2 Section 75... mediums. For purposes of grounding offtrack direct-current machines, the following grounding mediums are... alternating current grounding medium where such machines are fed by an ungrounded direct-current power...

  17. 30 CFR 75.703-2 - Approved grounding mediums.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Approved grounding mediums. 75.703-2 Section 75... mediums. For purposes of grounding offtrack direct-current machines, the following grounding mediums are... alternating current grounding medium where such machines are fed by an ungrounded direct-current power...

  18. 30 CFR 75.703-2 - Approved grounding mediums.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Approved grounding mediums. 75.703-2 Section 75... mediums. For purposes of grounding offtrack direct-current machines, the following grounding mediums are... alternating current grounding medium where such machines are fed by an ungrounded direct-current power...

  19. 30 CFR 75.703-2 - Approved grounding mediums.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Approved grounding mediums. 75.703-2 Section 75... mediums. For purposes of grounding offtrack direct-current machines, the following grounding mediums are... alternating current grounding medium where such machines are fed by an ungrounded direct-current power...

  20. Intestinal adaptation following resection.

    PubMed

    Tappenden, Kelly A

    2014-05-01

    Intestinal adaptation is a natural compensatory process that occurs following extensive intestinal resection, whereby structural and functional changes in the intestine improve nutrient and fluid absorption in the remnant bowel. In animal studies, postresection structural adaptations include bowel lengthening and thickening and increases in villus height and crypt depth. Functional changes include increased nutrient transporter expression, accelerated crypt cell differentiation, and slowed transit time. In adult humans, data regarding adaptive changes are sparse, and the mechanisms underlying intestinal adaptation remain to be fully elucidated. Several factors influence the degree of intestinal adaptation that occurs post resection, including site and extent of resection, luminal stimulation with enteral nutrients, and intestinotrophic factors. Two intestinotrophic growth factors, the glucagon-like peptide 2 analog teduglutide and recombinant growth hormone (somatropin), are now approved for clinical use in patients with short bowel syndrome (SBS). Both agents enhance fluid absorption and decrease requirements for parenteral nutrition (PN) and/or intravenous fluid. Intestinal adaptation has been thought to be limited to the first 1-2 years following resection in humans. However, recent data suggest that a significant proportion of adult patients with SBS can achieve enteral autonomy, even after many years of PN dependence, particularly with trophic stimulation.

  1. Adaptation and perceptual norms

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Yasuda, Maiko; Haber, Sara; Leonard, Deanne; Ballardini, Nicole

    2007-02-01

    We used adaptation to examine the relationship between perceptual norms--the stimuli observers describe as psychologically neutral, and response norms--the stimulus levels that leave visual sensitivity in a neutral or balanced state. Adapting to stimuli on opposite sides of a neutral point (e.g. redder or greener than white) biases appearance in opposite ways. Thus the adapting stimulus can be titrated to find the unique adapting level that does not bias appearance. We compared these response norms to subjectively defined neutral points both within the same observer (at different retinal eccentricities) and between observers. These comparisons were made for visual judgments of color, image focus, and human faces, stimuli that are very different and may depend on very different levels of processing, yet which share the property that for each there is a well defined and perceptually salient norm. In each case the adaptation aftereffects were consistent with an underlying sensitivity basis for the perceptual norm. Specifically, response norms were similar to and thus covaried with the perceptual norm, and under common adaptation differences between subjectively defined norms were reduced. These results are consistent with models of norm-based codes and suggest that these codes underlie an important link between visual coding and visual experience.

  2. Adaptation through proportion

    NASA Astrophysics Data System (ADS)

    Xiong, Liyang; Shi, Wenjia; Tang, Chao

    2016-08-01

    Adaptation is a ubiquitous feature in biological sensory and signaling networks. It has been suggested that adaptive systems may follow certain simple design principles across diverse organisms, cells and pathways. One class of networks that can achieve adaptation utilizes an incoherent feedforward control, in which two parallel signaling branches exert opposite but proportional effects on the output at steady state. In this paper, we generalize this adaptation mechanism by establishing a steady-state proportionality relationship among a subset of nodes in a network. Adaptation can be achieved by using any two nodes in the sub-network to respectively regulate the output node positively and negatively. We focus on enzyme networks and first identify basic regulation motifs consisting of two and three nodes that can be used to build small networks with proportional relationships. Larger proportional networks can then be constructed modularly similar to LEGOs. Our method provides a general framework to construct and analyze a class of proportional and/or adaptation networks with arbitrary size, flexibility and versatile functional features.

  3. The Climate Adaptation Frontier

    SciTech Connect

    Preston, Benjamin L

    2013-01-01

    Climate adaptation has emerged as a mainstream risk management strategy for assisting in maintaining socio-ecological systems within the boundaries of a safe operating space. Yet, there are limits to the ability of systems to adapt. Here, we introduce the concept of an adaptation frontier , which is defined as a socio-ecological system s transitional adaptive operating space between safe and unsafe domains. A number of driving forces are responsible for determining the sustainability of systems on the frontier. These include path dependence, adaptation/development deficits, values conflicts and discounting of future loss and damage. The cumulative implications of these driving forces are highly uncertain. Nevertheless, the fact that a broad range of systems already persist at the edge of their frontiers suggests a high likelihood that some limits will eventually be exceeded. The resulting system transformation is likely to manifest as anticipatory modification of management objectives or loss and damage. These outcomes vary significantly with respect to their ethical implications. Successful navigation of the adaptation frontier will necessitate new paradigms of risk governance to elicit knowledge that encourages reflexive reevaluation of societal values that enable or constrain sustainability.

  4. Highly selective medium for isolation of Listeria monocytogenes from food.

    PubMed

    al-Zoreky, N; Sandine, W E

    1990-10-01

    A new selective medium (Al-Zoreky-Sandine listeria medium [ASLM]) was formulated to recover Listeria monocytogenes from food specimens; the medium completely inhibited common food microflora. Recognition of Listeria colonies is evident by black discoloration of the medium due to esculin hydrolysis without need for special illuminating equipment. The medium contains acriflavin, ceftazidime, and moxalactam as selective agents. Compared with Listeria Selective Agar, ASLM was equally effective in recovering L. monocytogenes. However, ASLM inhibited micrococci, enterococci, and gram-negative bacteria, especially a strain that mimicked L. monocytogenes on Listeria Selective Agar. The new medium was able to recover heat injured cells with only 15% less count than the nonselective medium.

  5. Success factors for open access.

    PubMed

    Till, James E

    2003-01-01

    Open access to the peer-reviewed primary research literature would greatly facilitate knowledge transfer between the creators and the users of the results of research and scholarship. Criteria are needed to assess the impact of recent initiatives, such as the Budapest Open Access Initiative. For example, how many open-access research journals exist within a given field, and what is the reputation of each one? And, how many openly-accessible institutional e-print archives have been created and how many are actually are being used by researchers and scholars? A simple approach to an assessment of the open-access portion of the medical literature is described, and some preliminary results are summarized. These preliminary results point to the need for incentives to foster the implementation of initiatives such as the Budapest Open Access Initiative. An example of an incentive model is proposed, where an agency or foundation that provides peer-reviewed grants-in-aid to researchers establishes an e-print archive. Only current grantees of the agency would be eligible to post reports about the results of research projects or programs that have been supported by the agency. Some advantages and implications of this particular model are outlined. It is suggested that incentive models of this kind are needed to increase the likelihood that open access to the primary medical research literature will soon reach a "tipping point" and move quickly toward wide acceptance.

  6. Creating Electronic Access to Newspaper Information in Nigeria: The Information Aid Network (IFAnet) Experience

    ERIC Educational Resources Information Center

    Ola, Christopher O.; Ojo, Reuben A.

    2006-01-01

    This paper highlights the value of newspaper information and the methods adopted in organizing, preserving and disseminating it. The paper dwells on the traditional ways of managing newspaper resources and the need to device a new medium of accessing the information contents of the resource. It enumerates the steps taken in conserving newspaper…

  7. Internet Access and Usage in Improving Students' Self-Directed Learning in Indonesia Open University

    ERIC Educational Resources Information Center

    Rahardjo, Djoko; Sumardjo; Lubis, Djuara P.; Harijati, Sri Ir.

    2016-01-01

    Internet is well known nowadays, however higher distance education students who live in remote rural areas still have not been able to take advantages of this medium optimally for their learning process. For accessing the internet the students have to be available with the minimum prerequisites: the existence of adequate devices and the sufficient…

  8. Language Access and Theory of Mind Reasoning: Evidence from Deaf Children in Bilingual and Oralist Environments

    ERIC Educational Resources Information Center

    Meristo, Marek; Falkman, Kerstin W.; Hjelmquist, Erland; Tedoldi, Mariantonia; Surian, Luca; Siegal, Michael

    2007-01-01

    This investigation examined whether access to sign language as a medium for instruction influences theory of mind (ToM) reasoning in deaf children with similar home language environments. Experiment 1 involved 97 deaf Italian children ages 4-12 years: 56 were from deaf families and had LIS (Italian Sign Language) as their native language, and 41…

  9. [Phenotypic and epigenetic adaptation of the moss clone to mercury].

    PubMed

    Khorkavtsiv, Ia D; Ripets'kyĭ, R T; Baïk, O L

    2009-01-01

    On agar-Knop medium containing 0.5 microM HgCl2 about one third of microregenerants of the clone from the individual gametophyte cell of the moss Pottia intermedia survived and gave rise to protonemal mats. The high survival percentage testifies to epigenetic nature of adaptation. The latter proved to be correlated to the increase of leaf cell number and of peroxidase activity as well as to intensification of activity zone of peroxidase isoform with MM in limits of 66 kD and to appearance of two isoforms of the enzyme on electrophoregrams. The increase of peroxidase activity, though considerably weaker expressed, has been stated at 0.2 microM HgCl2 when practically all regenerants survived and on the mercury-free medium epigenetically adapted regenerants differed from physiologically adapted ones only in intensification of activity zone of peroxidase isoform with 66 kD. This gives reason to regard the adaptation of the regenerants to 0.5 microM HgCl2 as intensified epigenocopy of modification and indicates the generality of mechanisms of both types of adaptation.

  10. Modeling Excitable Systems Coupled Through External Medium

    NASA Astrophysics Data System (ADS)

    Noorbakhsh, Javad; Mehta, Pankaj

    2013-03-01

    Excitable systems are stable dynamical systems in which any input beyond a threshold results in a significant output. This behavior is ubiquitous in nature and is seen in biological systems such as Dictyostelium discoideum amoeba and neurons to oscillatory chemical reactions. In this work we will focus on transition to oscillation in populations of excitable systems coupled through an external medium and will study their synchronization. We will describe a mechanism to tune the frequency of oscillations using an external input and will study the effects of stochasticity and inhomogeneity on the collective behavior of the system. Furthermore we will include diffusion into the dynamics of the external medium and will study formation of spatial patterns, their characteristics and their robustness to different factors.

  11. Writing in the granular gel medium

    PubMed Central

    Bhattacharjee, Tapomoy; Zehnder, Steven M.; Rowe, Kyle G.; Jain, Suhani; Nixon, Ryan M.; Sawyer, W. Gregory; Angelini, Thomas E.

    2015-01-01

    Gels made from soft microscale particles smoothly transition between the fluid and solid states, making them an ideal medium in which to create macroscopic structures with microscopic precision. While tracing out spatial paths with an injection tip, the granular gel fluidizes at the point of injection and then rapidly solidifies, trapping injected material in place. This physical approach to creating three-dimensional (3D) structures negates the effects of surface tension, gravity, and particle diffusion, allowing a limitless breadth of materials to be written. With this method, we used silicones, hydrogels, colloids, and living cells to create complex large aspect ratio 3D objects, thin closed shells, and hierarchically branched tubular networks. We crosslinked polymeric materials and removed them from the granular gel, whereas uncrosslinked particulate systems were left supported within the medium for long times. This approach can be immediately used in diverse areas, contributing to tissue engineering, flexible electronics, particle engineering, smart materials, and encapsulation technologies. PMID:26601274

  12. Sliding through a superlight granular medium.

    PubMed

    Pacheco-Vázquez, F; Ruiz-Suárez, J C

    2009-12-01

    We explore the penetration dynamics of an intruder in a granular medium composed of expanded polystyrene spherical particles. Three features distinguish our experiment from others studied so far in granular physics: (a) the impact is horizontal, decoupling the effects of gravity and the drag force; (b) the density of the intruder rho(i) is up to 350 times larger than the density of the granular medium rho(m); and (c) the way the intruder moves through the material, sliding at the bottom of the column with small friction. Under these conditions we find that the final penetration D scales with (rho(i)/rho(m)) and the drag force Fd and D saturate with the height of the granular bed.

  13. Writing in the granular gel medium.

    PubMed

    Bhattacharjee, Tapomoy; Zehnder, Steven M; Rowe, Kyle G; Jain, Suhani; Nixon, Ryan M; Sawyer, W Gregory; Angelini, Thomas E

    2015-09-01

    Gels made from soft microscale particles smoothly transition between the fluid and solid states, making them an ideal medium in which to create macroscopic structures with microscopic precision. While tracing out spatial paths with an injection tip, the granular gel fluidizes at the point of injection and then rapidly solidifies, trapping injected material in place. This physical approach to creating three-dimensional (3D) structures negates the effects of surface tension, gravity, and particle diffusion, allowing a limitless breadth of materials to be written. With this method, we used silicones, hydrogels, colloids, and living cells to create complex large aspect ratio 3D objects, thin closed shells, and hierarchically branched tubular networks. We crosslinked polymeric materials and removed them from the granular gel, whereas uncrosslinked particulate systems were left supported within the medium for long times. This approach can be immediately used in diverse areas, contributing to tissue engineering, flexible electronics, particle engineering, smart materials, and encapsulation technologies.

  14. Gas Kinematics in the Multiphase Circumgalactic Medium

    NASA Astrophysics Data System (ADS)

    Nielsen, Nikole M.; Kacprzak, Glenn G.; Churchill, Christopher W.; Murphy, Michael T.; Muzahid, Sowgat; Charlton, Jane C.; Evans, Jessica L.

    2017-03-01

    We use high-resolution Keck, VLT, or Hubble Space Telescope spectra of background quasars to examine the kinematic properties of the multiphase, metal-enriched circumgalactic medium in the outskirts of galaxies at 0.08 < z gal < 1.0, focusing on the low-ionization Mgii and high-ionization Ovi doublets. The absorption kinematics of low-ionization gas in the circumgalactic medium depend strongly on the star formation activity and the location about the host galaxy, where the largest velocity dispersions are associated with blue, face-on galaxies probed along the minor axis. Conversely, high-ionization gas kinematics are independent of galaxy star formation activity and orientation.

  15. Supplementation of CHROMagar Candida Medium with Pal's Medium for Rapid Identification of Candida dubliniensis

    PubMed Central

    Sahand, Ismail H.; Moragues, María D.; Eraso, Elena; Villar-Vidal, María; Quindós, Guillermo; Pontón, José

    2005-01-01

    CHROMagar Candida medium is used for the isolation and identification of Candida species, but it does not differentiate Candida albicans from Candida dubliniensis. This differentiation can be achieved by using Pal's agar, which cannot be used in primary isolation. We have combined both media to obtain a new medium that can be used for the isolation and identification of C. dubliniensis in primary cultures. PMID:16272515

  16. HIDEC F-15 adaptive engine control system flight test results

    NASA Technical Reports Server (NTRS)

    Smolka, James W.

    1987-01-01

    NASA-Ames' Highly Integrated Digital Electronic Control (HIDEC) flight test program aims to develop fully integrated airframe, propulsion, and flight control systems. The HIDEC F-15 adaptive engine control system flight test program has demonstrated that significant performance improvements are obtainable through the retention of stall-free engine operation throughout the aircraft flight and maneuver envelopes. The greatest thrust increase was projected for the medium-to-high altitude flight regime at subsonic speed which is of such importance to air combat. Adaptive engine control systems such as the HIDEC F-15's can be used to upgrade the performance of existing aircraft without resort to expensive reengining programs.

  17. GALE: a generic open source extensible adaptation engine

    NASA Astrophysics Data System (ADS)

    De Bra, Paul; Knutov, Evgeny; Smits, David; Stash, Natalia; Ramos, Vinicius F. C.

    2013-06-01

    This paper motivates and describes GALE, the Generic Adaptation Language and Engine that came out of the GRAPPLE EU FP7 project. The main focus of the paper is the extensible nature of GALE. The purpose of this description is to illustrate how a single core adaptation engine can be used for different types of adaptation, applied to different types of information items and documents. We illustrate the adaptive functionality on some examples of hypermedia documents. In April 2012, David Smits defended the world's first adaptive PhD thesis on this topic. The thesis, available for download and direct adaptive access at http://gale.win.tue.nl/thesis, shows that a single source of information can serve different audiences and at the same time also allows more freedom of navigation than is possible in any paper or static hypermedia document. The same can be done for course texts, hyperfiction, encyclopedia, museum, or other cultural heritage websites, etc. We explain how to add functionality to GALE if desired, to adapt the system's behavior to whatever the application requires. This stresses our main objective: to provide a technological base for adaptive (hypermedia) system researchers on which they can build extensions for the specific research they have in mind.

  18. A generalized differential effective medium theory

    NASA Astrophysics Data System (ADS)

    Norris, A. N.; Callegari, A. J.; Sheng, P.

    A GENERALIZATION of the Differential Effective Medium approximation (DEM) is discussed. The new scheme is applied to the estimation of the effective permittivity of a two phase dielectric composite. Ordinary DEM corresponds to a realizable microgeometry in which the composite is built up incrementally through a process of homogenization, with one phase always in dilute suspension and the other phase associated with the percolating backbone. The generalization of DEM assumes a third phase which acts as a backbone. The other two phases are progressively added to the backbone such that each addition is in an effectively homogeneous medium. A canonical ordinary differential equation is derived which describes the change in material properties as a function of the volume concentration φ of the added phases in the composite. As φ→ 1, the Effective Medium Approximation (EMA) is obtained. For φ < 1, the result depends upon the backbone and the mixture path that is followed. The approach to EMA for φ ≊ 1 is analysed and a generalization of Archie's law for conductor-insulator composites is described. The conductivity mimics EMA above the percolation threshold and DEM as the conducting phase vanishes.

  19. Random lasing in a nanocomposite medium

    SciTech Connect

    Smetanin, Sergei N; Basiev, Tasoltan T

    2013-01-31

    The characteristics of a random laser based on a nanocomposite medium consisting of a transparent dielectric and scattering doped nanocrystals are calculated. It is proposed to use ytterbium laser media with a high concentration of active ions as nanocrystals and to use gases, liquids, or solid dielectrics with a refractive index lower than that of nanocrystals as dielectric matrices for nanocrystals. Based on the concept of nonresonant distributed feedback due to the Rayleigh scattering, an expression is obtained for the minimum length of a nanocomposite laser medium at which the random lasing threshold is overcome. Expressions are found for the critical (maximum) and the optimal size of nanocrystals, as well as for the optimal relative refractive index of nanocomposites that corresponds not only to the maximum gain but also to the minimum of the medium threshold length at the optimal size of nanocrystals. It is shown that the optimal relative refractive index of a nanocomposite increases with increasing pump level, but is independent of the other nanocomposite parameters. (nanocomposites)

  20. 5 CFR 2606.203 - Granting access.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Granting access. 2606.203 Section 2606... Access to Records and Accounting of Disclosures § 2606.203 Granting access. (a) The methods for allowing access to records, when such access has been granted by OGE or the other agency concerned are:...

  1. 10 CFR 1017.21 - Limited access.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Limited access. 1017.21 Section 1017.21 Energy DEPARTMENT... INFORMATION Access to Unclassified Controlled Nuclear Information § 1017.21 Limited access. (a) A person who is not eligible for routine access to specific UCNI under § 1017.20 may request limited access...

  2. 10 CFR 1017.19 - Access limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Access limitations. 1017.19 Section 1017.19 Energy... INFORMATION Access to Unclassified Controlled Nuclear Information § 1017.19 Access limitations. A person may only have access to UCNI if he or she has been granted routine access by an Authorized Individual...

  3. 5 CFR 2606.203 - Granting access.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Granting access. 2606.203 Section 2606... Access to Records and Accounting of Disclosures § 2606.203 Granting access. (a) The methods for allowing access to records, when such access has been granted by OGE or the other agency concerned are:...

  4. 5 CFR 2606.203 - Granting access.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Granting access. 2606.203 Section 2606... Access to Records and Accounting of Disclosures § 2606.203 Granting access. (a) The methods for allowing access to records, when such access has been granted by OGE or the other agency concerned are:...

  5. 32 CFR 154.49 - Granting access.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 1 2014-07-01 2014-07-01 false Granting access. 154.49 Section 154.49 National... SECURITY PROGRAM REGULATION Issuing Clearance and Granting Access § 154.49 Granting access. (a) Access to classified information shall be granted to persons whose official duties require such access and who have...

  6. 32 CFR 154.49 - Granting access.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 1 2012-07-01 2012-07-01 false Granting access. 154.49 Section 154.49 National... SECURITY PROGRAM REGULATION Issuing Clearance and Granting Access § 154.49 Granting access. (a) Access to classified information shall be granted to persons whose official duties require such access and who have...

  7. 5 CFR 2606.203 - Granting access.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Granting access. 2606.203 Section 2606... Access to Records and Accounting of Disclosures § 2606.203 Granting access. (a) The methods for allowing access to records, when such access has been granted by OGE or the other agency concerned are:...

  8. 32 CFR 154.49 - Granting access.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 1 2013-07-01 2013-07-01 false Granting access. 154.49 Section 154.49 National... SECURITY PROGRAM REGULATION Issuing Clearance and Granting Access § 154.49 Granting access. (a) Access to classified information shall be granted to persons whose official duties require such access and who have...

  9. 5 CFR 2606.203 - Granting access.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Granting access. 2606.203 Section 2606... Access to Records and Accounting of Disclosures § 2606.203 Granting access. (a) The methods for allowing access to records, when such access has been granted by OGE or the other agency concerned are:...

  10. 32 CFR 154.49 - Granting access.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Granting access. 154.49 Section 154.49 National... SECURITY PROGRAM REGULATION Issuing Clearance and Granting Access § 154.49 Granting access. (a) Access to classified information shall be granted to persons whose official duties require such access and who have...

  11. SAGE - MULTIDIMENSIONAL SELF-ADAPTIVE GRID CODE

    NASA Technical Reports Server (NTRS)

    Davies, C. B.

    1994-01-01

    acceptable since it makes possible an overall and local error reduction through grid redistribution. SAGE includes the ability to modify the adaption techniques in boundary regions, which substantially improves the flexibility of the adaptive scheme. The vectorial approach used in the analysis also provides flexibility. The user has complete choice of adaption direction and order of sequential adaptions without concern for the computational data structure. Multiple passes are available with no restraint on stepping directions; for each adaptive pass the user can choose a completely new set of adaptive parameters. This facility, combined with the capability of edge boundary control, enables the code to individually adapt multi-dimensional multiple grids. Zonal grids can be adapted while maintaining continuity along the common boundaries. For patched grids, the multiple-pass capability enables complete adaption. SAGE is written in FORTRAN 77 and is intended to be machine independent; however, it requires a FORTRAN compiler which supports NAMELIST input. It has been successfully implemented on Sun series computers, SGI IRIS's, DEC MicroVAX computers, HP series computers, the Cray YMP, and IBM PC compatibles. Source code is provided, but no sample input and output files are provided. The code reads three datafiles: one that contains the initial grid coordinates (x,y,z), one that contains corresponding flow-field variables, and one that contains the user control parameters. It is assumed that the first two datasets are formatted as defined in the plotting software package PLOT3D. Several machine versions of PLOT3D are available from COSMIC. The amount of main memory is dependent on the size of the matrix. The standard distribution medium for SAGE is a 5.25 inch 360K MS-DOS format diskette. It is also available on a .25 inch streaming magnetic tape cartridge in UNIX tar format or on a 9-track 1600 BPI ASCII CARD IMAGE format magnetic tape. SAGE was developed in 1989, first

  12. Adaptive spectral doppler estimation.

    PubMed

    Gran, Fredrik; Jakobsson, Andreas; Jensen, Jørgen Arendt

    2009-04-01

    In this paper, 2 adaptive spectral estimation techniques are analyzed for spectral Doppler ultrasound. The purpose is to minimize the observation window needed to estimate the spectrogram to provide a better temporal resolution and gain more flexibility when designing the data acquisition sequence. The methods can also provide better quality of the estimated power spectral density (PSD) of the blood signal. Adaptive spectral estimation techniques are known to provide good spectral resolution and contrast even when the observation window is very short. The 2 adaptive techniques are tested and compared with the averaged periodogram (Welch's method). The blood power spectral capon (BPC) method is based on a standard minimum variance technique adapted to account for both averaging over slow-time and depth. The blood amplitude and phase estimation technique (BAPES) is based on finding a set of matched filters (one for each velocity component of interest) and filtering the blood process over slow-time and averaging over depth to find the PSD. The methods are tested using various experiments and simulations. First, controlled flow-rig experiments with steady laminar flow are carried out. Simulations in Field II for pulsating flow resembling the femoral artery are also analyzed. The simulations are followed by in vivo measurement on the common carotid artery. In all simulations and experiments it was concluded that the adaptive methods display superior performance for short observation windows compared with the averaged periodogram. Computational costs and implementation details are also discussed.

  13. Solar tomography adaptive optics.

    PubMed

    Ren, Deqing; Zhu, Yongtian; Zhang, Xi; Dou, Jiangpei; Zhao, Gang

    2014-03-10

    Conventional solar adaptive optics uses one deformable mirror (DM) and one guide star for wave-front sensing, which seriously limits high-resolution imaging over a large field of view (FOV). Recent progress toward multiconjugate adaptive optics indicates that atmosphere turbulence induced wave-front distortion at different altitudes can be reconstructed by using multiple guide stars. To maximize the performance over a large FOV, we propose a solar tomography adaptive optics (TAO) system that uses tomographic wave-front information and uses one DM. We show that by fully taking advantage of the knowledge of three-dimensional wave-front distribution, a classical solar adaptive optics with one DM can provide an extra performance gain for high-resolution imaging over a large FOV in the near infrared. The TAO will allow existing one-deformable-mirror solar adaptive optics to deliver better performance over a large FOV for high-resolution magnetic field investigation, where solar activities occur in a two-dimensional field up to 60'', and where the near infrared is superior to the visible in terms of magnetic field sensitivity.

  14. Adaptation with transcriptional regulation

    NASA Astrophysics Data System (ADS)

    Shi, Wenjia; Ma, Wenzhe; Xiong, Liyang; Zhang, Mingyue; Tang, Chao

    2017-02-01

    Biochemical adaptation is one of the basic functions that are widely implemented in biological systems for a variety of purposes such as signal sensing, stress response and homeostasis. The adaptation time scales span from milliseconds to days, involving different regulatory machineries in different processes. The adaptive networks with enzymatic regulation (ERNs) have been investigated in detail. But it remains unclear if and how other forms of regulation will impact the network topology and other features of the function. Here, we systematically studied three-node transcriptional regulatory networks (TRNs), with three different types of gene regulation logics. We found that the topologies of adaptive gene regulatory networks can still be grouped into two general classes: negative feedback loop (NFBL) and incoherent feed-forward loop (IFFL), but with some distinct topological features comparing to the enzymatic networks. Specifically, an auto-activation loop on the buffer node is necessary for the NFBL class. For IFFL class, the control node can be either a proportional node or an inversely-proportional node. Furthermore, the tunability of adaptive behavior differs between TRNs and ERNs. Our findings highlight the role of regulation forms in network topology, implementation and dynamics.

  15. Adaptation with transcriptional regulation.

    PubMed

    Shi, Wenjia; Ma, Wenzhe; Xiong, Liyang; Zhang, Mingyue; Tang, Chao

    2017-02-24

    Biochemical adaptation is one of the basic functions that are widely implemented in biological systems for a variety of purposes such as signal sensing, stress response and homeostasis. The adaptation time scales span from milliseconds to days, involving different regulatory machineries in different processes. The adaptive networks with enzymatic regulation (ERNs) have been investigated in detail. But it remains unclear if and how other forms of regulation will impact the network topology and other features of the function. Here, we systematically studied three-node transcriptional regulatory networks (TRNs), with three different types of gene regulation logics. We found that the topologies of adaptive gene regulatory networks can still be grouped into two general classes: negative feedback loop (NFBL) and incoherent feed-forward loop (IFFL), but with some distinct topological features comparing to the enzymatic networks. Specifically, an auto-activation loop on the buffer node is necessary for the NFBL class. For IFFL class, the control node can be either a proportional node or an inversely-proportional node. Furthermore, the tunability of adaptive behavior differs between TRNs and ERNs. Our findings highlight the role of regulation forms in network topology, implementation and dynamics.

  16. Adaptation and risk management

    SciTech Connect

    Preston, Benjamin L

    2011-01-01

    Adaptation assessment methods are compatible with the international risk management standard ISO:31000. Risk management approaches are increasingly being recommended for adaptation assessments at both national and local levels. Two orientations to assessments can commonly be identified: top-down and bottom-up, and prescriptive and diagnostic. Combinations of these orientations favor different types of assessments. The choice of orientation can be related to uncertainties in prediction and taking action, in the type of adaptation and in the degree of system stress. Adopting multiple viewpoints is to be encouraged, especially in complex situations. The bulk of current guidance material is consistent with top-down and predictive approaches, thus is most suitable for risk scoping and identification. Abroad range ofmaterial fromwithin and beyond the climate change literature can be used to select methods to be used in assessing and implementing adaptation. The framing of risk, correct formulation of the questions being investigated and assessment methodology are critical aspects of the scoping phase. Only when these issues have been addressed should be issue of specific methods and tools be addressed. The reorientation of adaptation from an assessment focused solely on anthropogenic climate change to broader issues of vulnerability/resilience, sustainable development and disaster risk, especially through a risk management framework, can draw from existing policy and management understanding in communities, professions and agencies, incorporating existing agendas, knowledge, risks, and issues they already face.

  17. Adaptation with transcriptional regulation

    PubMed Central

    Shi, Wenjia; Ma, Wenzhe; Xiong, Liyang; Zhang, Mingyue; Tang, Chao

    2017-01-01

    Biochemical adaptation is one of the basic functions that are widely implemented in biological systems for a variety of purposes such as signal sensing, stress response and homeostasis. The adaptation time scales span from milliseconds to days, involving different regulatory machineries in different processes. The adaptive networks with enzymatic regulation (ERNs) have been investigated in detail. But it remains unclear if and how other forms of regulation will impact the network topology and other features of the function. Here, we systematically studied three-node transcriptional regulatory networks (TRNs), with three different types of gene regulation logics. We found that the topologies of adaptive gene regulatory networks can still be grouped into two general classes: negative feedback loop (NFBL) and incoherent feed-forward loop (IFFL), but with some distinct topological features comparing to the enzymatic networks. Specifically, an auto-activation loop on the buffer node is necessary for the NFBL class. For IFFL class, the control node can be either a proportional node or an inversely-proportional node. Furthermore, the tunability of adaptive behavior differs between TRNs and ERNs. Our findings highlight the role of regulation forms in network topology, implementation and dynamics. PMID:28233824

  18. Solar Adaptive Optics.

    PubMed

    Rimmele, Thomas R; Marino, Jose

    Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given.

  19. Mobile App to Assess Universal Access Compliance.

    PubMed

    Fransolet, Colette

    2016-01-01

    terms of compliance with National Building Regulations, within a tight budget as well as within minimal timeframes, an innovative mobile application was developed by Universal Design Africa. This App heralds the dawn of a new method to measure universal access compliance. The operation and format of this technology and its application could be adapted to meet all forms of compliance and information gathering, including international regulations and best practice.

  20. Ultrasound guidance for vascular access.

    PubMed

    Abboud, Paul-André C; Kendall, John L

    2004-08-01

    The evidence that supports the general application of US guidance for venous access in the ED has reached a critical mass. The increasing familiarity of emergency physicians with US and the recent focus on patient safety and clinical outcomes has intensified attention on the capacity for US to improve patient care in the ED. US guidance can increase the safety and efficiency of venous access procedures and offers improved outcomes. The potential for these improvements is compelling, especially among certain types of ED patients such as those with difficult or complicated access. Varying levels of evidence support the use of US guidance over the traditional landmark approach for venous access in adult and pediatric populations and for central and peripheral veins. Many different techniques may be applied, depending on the clinical situation and equipment available.