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Sample records for access interference mai

  1. Chip-interleaved optical code division multiple access relying on a photon-counting iterative successive interference canceller for free-space optical channels.

    PubMed

    Zhou, Xiaolin; Zheng, Xiaowei; Zhang, Rong; Hanzo, Lajos

    2013-07-01

    In this paper, we design a novel Poisson photon-counting based iterative successive interference cancellation (SIC) scheme for transmission over free-space optical (FSO) channels in the presence of both multiple access interference (MAI) as well as Gamma-Gamma atmospheric turbulence fading, shot-noise and background light. Our simulation results demonstrate that the proposed scheme exhibits a strong MAI suppression capability. Importantly, an order of magnitude of BER improvements may be achieved compared to the conventional chip-level optical code-division multiple-access (OCDMA) photon-counting detector.

  2. S-band multiple-access interference study for advanced tracking and data relay satellite systems

    NASA Technical Reports Server (NTRS)

    Peng, Wei-Chung; Yang, Chau-Chin

    1990-01-01

    The results of a study on the effect of mutual interference among S-band multiple access (SMA) system users of advanced tracking and data relay satellite system (ATDRSS) are presented. In the ATDRSS era, the SMA system is required to support data rates ranging from 10 kb/s to 3 Mb/s. The system will consist of four advanced tracking and data relay satellites (ATDRS) each supporting up to five telemetry links. All users have 10 MHz bandwidth with their carrier frequency equal to 2.2875 GHz. A hybrid SDMA/CDMA scheme is used to mitigate the effect of the interference among system users. SMA system interference probability is evaluated with CLASS software. User link margin degradation due to mutual interference between two users is evaluated. System interference probability is evaluated for the projected 1996 mission model, a reference mission model, and a modified reference mission model.

  3. Dispersion-flattened-fiber based optical thresholder for multiple-access-interference suppression in OCDMA system.

    PubMed

    Wang, Xu; Hamanaka, Taro; Wada, Naoya; Kitayama, Ken-Ichi

    2005-07-11

    An optical thresholding technique based on super-continuum generation in dispersion flattened fiber is proposed and experimentally demonstrated to enable data-rate detection in optical code division multiple access networks. The proposed scheme exhibits an excellent discrimination between a desired signal and interference signals with features of pulse reshaping, low insertion loss, polarization independency as well as reasonable operation power.

  4. Interference suppression for code-division multiple-access communications in an underwater acoustic channel.

    PubMed

    Yang, T C; Yang, Wen-Bin

    2009-07-01

    In a code-division multiple-access communications network, the signal from a nearby user often creates a strong interference for the signal from a distant user. This is known as the near-far problem. Power control of source levels is ineffective in an underwater acoustic channel due to the slow sound speed. Interference rejection based on code orthogonality is ineffective using matched-filter processing due to the fact that multipath arrivals effectively destroy the code orthogonality and that the signal arrival times between different users are not synchronized. An algorithm, called hyperspace cancellation by coordinate zeroing, is used in this paper to remove/suppress interference. Using a fast Walsh-Hadamard transform (FWHT) based on the interferer's code sequence, the interference signal is enhanced and removed by coordinate zeroing. The residual signal is transformed back using an inverse FWHT. The filtered data, with the interference signal largely removed, are processed using the desired signal code sequence. Two methods previously developed for direct-sequence spread-spectrum communications in an underwater channel are used to extract the transmitted symbols. Low bit error rate (<10(-2)) is found with the at-sea data for signal-to-interference ratio as low as -8 to -11 dB.

  5. Semantic Facilitation and Semantic Interference in Language Production: Further Evidence for the Conceptual Selection Model of Lexical Access

    ERIC Educational Resources Information Center

    Bloem, Ineke; van den Boogaard, Sylvia; Heij, Wido La

    2004-01-01

    Bloem and La Heij (2003) reported that in a word-translation task context words induce semantic interference whereas context pictures induce semantic facilitation. This finding was accounted for by a model of lexical access in which: (a) semantic facilitation is localized at the conceptual level, (b) semantic interference is localized at the…

  6. Optical beat interference noise reduction in OFDMA optical access link using self-homodyne balanced detection

    NASA Astrophysics Data System (ADS)

    Jung, Sang-Min; Won, Yong-Yuk; Han, Sang-Kook

    2013-12-01

    A Novel technique for reducing the OBI noise in optical OFDMA-PON uplink is presented. OFDMA is a multipleaccess/ multiplexing scheme that can provide multiplexing operation of user data streams onto the downlink sub-channels and uplink multiple access by means of dividing OFDM subcarriers as sub-channels. The main issue of high-speed, single-wavelength upstream OFDMA-PON arises from optical beating interference noise. Because the sub-channels are allocated dynamically to multiple access users over same nominal wavelength, it generates the optical beating interference among upstream signals. In this paper, we proposed a novel scheme using self-homodyne balanced detection in the optical line terminal (OLT) to reduce OBI noise which is generated in the uplink transmission of OFDMA-PON system. When multiple OFDMA sub-channels over the same nominal wavelength are received at the same time in the proposed architecture, OBI noises can be removed using balanced detection. Using discrete multitone modulation (DMT) to generate real valued OFDM signals, the proposed technique is verified through experimental demonstration.

  7. Electromagnetic interference-aware transmission scheduling and power control for dynamic wireless access in hospital environments.

    PubMed

    Phunchongharn, Phond; Hossain, Ekram; Camorlinga, Sergio

    2011-11-01

    We study the multiple access problem for e-Health applications (referred to as secondary users) coexisting with medical devices (referred to as primary or protected users) in a hospital environment. In particular, we focus on transmission scheduling and power control of secondary users in multiple spatial reuse time-division multiple access (STDMA) networks. The objective is to maximize the spectrum utilization of secondary users and minimize their power consumption subject to the electromagnetic interference (EMI) constraints for active and passive medical devices and minimum throughput guarantee for secondary users. The multiple access problem is formulated as a dual objective optimization problem which is shown to be NP-complete. We propose a joint scheduling and power control algorithm based on a greedy approach to solve the problem with much lower computational complexity. To this end, an enhanced greedy algorithm is proposed to improve the performance of the greedy algorithm by finding the optimal sequence of secondary users for scheduling. Using extensive simulations, the tradeoff in performance in terms of spectrum utilization, energy consumption, and computational complexity is evaluated for both the algorithms. PMID:21843997

  8. Electromagnetic interference-aware transmission scheduling and power control for dynamic wireless access in hospital environments.

    PubMed

    Phunchongharn, Phond; Hossain, Ekram; Camorlinga, Sergio

    2011-11-01

    We study the multiple access problem for e-Health applications (referred to as secondary users) coexisting with medical devices (referred to as primary or protected users) in a hospital environment. In particular, we focus on transmission scheduling and power control of secondary users in multiple spatial reuse time-division multiple access (STDMA) networks. The objective is to maximize the spectrum utilization of secondary users and minimize their power consumption subject to the electromagnetic interference (EMI) constraints for active and passive medical devices and minimum throughput guarantee for secondary users. The multiple access problem is formulated as a dual objective optimization problem which is shown to be NP-complete. We propose a joint scheduling and power control algorithm based on a greedy approach to solve the problem with much lower computational complexity. To this end, an enhanced greedy algorithm is proposed to improve the performance of the greedy algorithm by finding the optimal sequence of secondary users for scheduling. Using extensive simulations, the tradeoff in performance in terms of spectrum utilization, energy consumption, and computational complexity is evaluated for both the algorithms.

  9. Expanding health access in the more vulnerable region in the state of São Paulo, Brazil: is this a reflection of the Mais Médicos (More Doctors) Program?

    PubMed

    Silva, Bruna Pontes da; Stockmann, Denise; Lúcio, Donavan de Souza; Henna, Elaine; Rocha, Maria Carolina Pereira da; Junqueira, Fábio Miranda

    2016-09-01

    The Mais Médicos (More Doctors) Program seeks to broaden access to health by providing medical professionals, investments in health units and multi-professional integration geared to the Family Health Strategy. Vale do Ribeira includes 25 cities and is among the most vulnerable regions in São Paulo. It has been allocated 41 physicians from the Program. This study is to evaluate access to health, comparing health indicators before and after the Program. We collected data from DATASUS, SIAB, and the Ministry of Health. There was a marked increase in the number of appointments for infants under one year of age, adults, the elderly, STD/HIV patients and group patient care. There was a decrease in appointments outside the catchment area, as well as hospital admissions for other causes, mothers exclusively breastfeeding their infants up to four months. We concluded that after deployment of the Program, there was an increase in health access and health promotion focused on an area that presents an enormous challenge for Primary Health Care (PHC). It would seem that, since this is a high vulnerability area with a large area for care, hospital admissions for PHC care-sensitive conditions, as well as referrals for secondary services, did not decrease. PMID:27653074

  10. Expanding health access in the more vulnerable region in the state of São Paulo, Brazil: is this a reflection of the Mais Médicos (More Doctors) Program?

    PubMed

    Silva, Bruna Pontes da; Stockmann, Denise; Lúcio, Donavan de Souza; Henna, Elaine; Rocha, Maria Carolina Pereira da; Junqueira, Fábio Miranda

    2016-09-01

    The Mais Médicos (More Doctors) Program seeks to broaden access to health by providing medical professionals, investments in health units and multi-professional integration geared to the Family Health Strategy. Vale do Ribeira includes 25 cities and is among the most vulnerable regions in São Paulo. It has been allocated 41 physicians from the Program. This study is to evaluate access to health, comparing health indicators before and after the Program. We collected data from DATASUS, SIAB, and the Ministry of Health. There was a marked increase in the number of appointments for infants under one year of age, adults, the elderly, STD/HIV patients and group patient care. There was a decrease in appointments outside the catchment area, as well as hospital admissions for other causes, mothers exclusively breastfeeding their infants up to four months. We concluded that after deployment of the Program, there was an increase in health access and health promotion focused on an area that presents an enormous challenge for Primary Health Care (PHC). It would seem that, since this is a high vulnerability area with a large area for care, hospital admissions for PHC care-sensitive conditions, as well as referrals for secondary services, did not decrease.

  11. Lexical access in children with and without specific language impairment: a cross-modal picture-word interference study.

    PubMed

    Seiger-Gardner, Liat; Schwartz, Richard G

    2008-01-01

    Two experiments examined the time course of lexical information availability in 20 adults, 20 children (8;0-10;0) with typical language development, and in 20 children (8;0-10;0) with specific language impairment. A cross-modal picture-word interference paradigm was used in which participants named the pictures as quickly as possible while ignoring the phonologically and semantically related interfering words. A novel early phonological interference effect appeared in all groups. Similar temporal patterns were revealed for the adults and the typical language development group, supporting the notion of similar underlying lexicalization mechanisms. Parametric differences were found in overall response times and errors, with children responding slower and producing more errors than adults. The presence of a phonological facilitation effect suggests that children with specific language impairment utilize phonological primes to ease lexical access. Children with specific language impairment exhibited lingering semantic inhibition and a late semantic inhibition effect suggesting difficulty in processing semantic information. Data from all participants support the cascaded processing model of lexical access.

  12. Lexical access in children with and without specific language impairment: a cross-modal picture-word interference study.

    PubMed

    Seiger-Gardner, Liat; Schwartz, Richard G

    2008-01-01

    Two experiments examined the time course of lexical information availability in 20 adults, 20 children (8;0-10;0) with typical language development, and in 20 children (8;0-10;0) with specific language impairment. A cross-modal picture-word interference paradigm was used in which participants named the pictures as quickly as possible while ignoring the phonologically and semantically related interfering words. A novel early phonological interference effect appeared in all groups. Similar temporal patterns were revealed for the adults and the typical language development group, supporting the notion of similar underlying lexicalization mechanisms. Parametric differences were found in overall response times and errors, with children responding slower and producing more errors than adults. The presence of a phonological facilitation effect suggests that children with specific language impairment utilize phonological primes to ease lexical access. Children with specific language impairment exhibited lingering semantic inhibition and a late semantic inhibition effect suggesting difficulty in processing semantic information. Data from all participants support the cascaded processing model of lexical access. PMID:22612630

  13. Control of Access to Memory: The Use of Task Interference as a Behavioral Probe

    ERIC Educational Resources Information Center

    Loft, Shayne; Humphreys, Michael S.; Whitney, Susannah J.

    2008-01-01

    Directed forgetting and prospective memory methods were combined to examine differences in the control of memory access. Between studying two lists of target words, participants were either instructed to forget the first list, or to continue remembering the first list. After study participants performed a lexical decision task with an additional…

  14. Distractor Modality Can Turn Semantic Interference into Semantic Facilitation in the Picture-Word Interference Task: Implications for Theories of Lexical Access in Speech Production

    ERIC Educational Resources Information Center

    Hantsch, Ansgar; Jescheniak, Jorg D.; Schriefers, Herbert

    2009-01-01

    A number of recent studies have questioned the idea that lexical selection during speech production is a competitive process. One type of evidence against selection by competition is the observation that in the picture-word interference task semantically related distractors may facilitate the naming of a picture, whereas the selection by…

  15. The dark side of incremental learning: A model of cumulative semantic interference during lexical access in speech production

    PubMed Central

    Oppenheim, Gary M.; Dell, Gary S.; Schwartz, Myrna F.

    2010-01-01

    Naming a picture of a dog primes the subsequent naming of a picture of a dog (repetition priming) and interferes with the subsequent naming of a picture of a cat (semantic interference). Behavioral studies suggest that these effects derive from persistent changes in the way that words are activated and selected for production, and some have claimed that the findings are only understandable by positing a competitive mechanism for lexical selection. We present a simple model of lexical retrieval in speech production that applies error-driven learning to its lexical activation network. This model naturally produces repetition priming and semantic interference effects. It predicts the major findings from several published experiments, demonstrating that these effects may arise from incremental learning. Furthermore, analysis of the model suggests that competition during lexical selection is not necessary for semantic interference if the learning process is itself competitive. PMID:19854436

  16. Lexical access in children with hearing loss or specific language impairment, using the cross-modal picture-word interference paradigm.

    PubMed

    de Hoog, Brigitte E; Langereis, Margreet C; van Weerdenburg, Marjolijn; Knoors, Harry; Verhoeven, Ludo

    2015-02-01

    In this study we compared lexical access to spoken words in 25 deaf children with cochlear implants (CIs), 13 hard-of-hearing (HoH) children and 20 children with specific language impairment (SLI). Twenty-one age-matched typically developing children served as controls. The children with CIs and the HoH children in the present study had good speech perception abilities. We used a cross-modal picture-word interference paradigm to examine lexical access. Results showed that children with SLI revealed overall slower reaction times and produced more errors than the children with CIs, the HoH children, and the control children. Reaction times of children with CIs and the HoH children did not differ from those of the control children. Thus, problems with spoken language processing, as is the case in children with SLI, seem to affect lexical access more than limitations in auditory perception, as is the fundamental problem in children with hearing loss. We recommend that improvement of lexical access in children with SLI deserves specific attention in therapy and education.

  17. RNA Interference

    MedlinePlus

    ... NIGMS Home > Science Education > RNA Interference Fact Sheet RNA Interference Fact Sheet Tagline (Optional) Middle/Main Content Area What is RNA interference? RNA interference (RNAi) is a natural process ...

  18. Suppression of optical beat interference-noise in orthogonal frequency division multiple access-passive optical network link using self-homodyne balanced detection

    NASA Astrophysics Data System (ADS)

    Won, Yong-Yuk; Jung, Sang-Min; Han, Sang-Kook

    2014-08-01

    A new technique, which reduces optical beat interference (OBI) noise in orthogonal frequency division multiple access-passive optical network (OFDMA-PON) links, is proposed. A self-homodyne balanced detection, which uses a single laser for the optical line terminal (OLT) as well as for the optical network unit (ONU), reduces OBI noise and also improves the signal to noise ratio (SNR) of the discrete multi-tone (DMT) signal. The proposed scheme is verified by transmitting quadrature phase shift keying (QPSK)-modulated DMT signal over a 20-km single mode fiber. The optical signal to noise ratio (OSNR), that is required for BER of 10-5, is reduced by 2 dB in the balanced detection compared with a single channel due to the cancellation of OBI noise in conjunction with the local laser.

  19. Performance Study of Hybrid DS/FFH Spread-Spectrum Systems in the Presence of Frequency-Selective Fading and Multiple-Access Interference

    SciTech Connect

    Olama, Mohammed M; Smith, Stephen Fulton; Kuruganti, Phani Teja; Ma, Xiao

    2012-01-01

    Hybrid spread-spectrum (HSS) systems have recently received considerable interest in commercial, Smart Grid, and military communication systems because they accommodate high data rates with high link integrity, even in the presence of significant multipath effects and interfering signals. A highly useful form of this modulation scheme is the specific code-related combination of standard direct-sequence spread spectrum (DSSS) with fast frequency-hopping (FFH) spread spectrum, denoted hybrid DS/FFH, wherein multiple frequency hops occur within a single data-bit time. In this paper we perform a simulation-based study of the DS/FFH performance as compared to the existing standard DSSS and FHSS wireless networks. The performance metrics are bit-error probability and multiple-access capability. The parameter space of DS/FFH, including the DS spreading rate, frequency hopping rate, carrier frequencies, and numbers of users, is explored to show its performance under frequency-selective Rayleigh fading environments and multiuser interference. Direct digital synthesizers to achieve fast hopping speeds are also considered in our study.

  20. A Review on Successive Interference Cancellation Scheme Based on Optical CDMA Network

    NASA Astrophysics Data System (ADS)

    Alsowaidi, N.; Eltaif, T.; Mokhtar, M. R.

    2014-12-01

    Due to various desirable features of optical code division multiple access (OCDMA), it is believed this technique once developed and commercially available will be an integral part of optical access networks. Optical CDMA system suffers from a problem called multiple access interference (MAI) which limits the number of active users, it occurs when number of active users share the same carriers. The aim of this paper is to review successive interference cancellation (SIC) scheme based on optical CDMA system. The paper also reviews the system performance in presence of shot noise, thermal noise, and phase-induced intensity noise (PIIN). A comprehensive review on the mathematical model of SIC scheme using direct detection (DS) and spectral amplitude coding (SAC) were presented in this article.

  1. Light work at Chiang Mai University, Thailand

    NASA Astrophysics Data System (ADS)

    Wongtawatnugool, C.; Ngamjarurojana, A.; Lacharojana, Samran

    2002-05-01

    The teaching and learning optics in Thailand is some how rather slowly developed. This is could possibly due to its importance, as seen by the educators and scientists in Thailand, was not so pronounced in the past. This made Thai scientists and researchers in many other disciplines lag of basic optics knowledge to getting involve with today advanced optics and photonics technologies. The need for high precision and high speed of the measurement and control in today experiment urges them to get involve in optics and photonics techniques more than ever before. At Chiang Mai university we offer 4-credit course: Optics and Spectroscopy. It covers a conventional optics course detail as referred in most conventional optics text books. Advanced optics course is also offered at higher level. The development of research activities utilizing optics and photonics techniques has been very slow due to the higher cost for most of the equipment involved. Very often that we have to assemble our own designed micro-computer-based equipment. The multi-scaler and a computer to serve as a photon correlator in dynamic light scattering (DLS) system to study correlation length in a liquid mixture at its critical point is one of the examples. The Ph.D. projects work in our section involve medical laser and electro-optics properties of a liquid mixture are some examples of our interest.

  2. Mai-Mai militia and sexual violence in Democratic Republic of the Congo.

    PubMed

    Guy, Kitwe Mulunda

    2014-01-01

    This article sets the reasons for the brutal violence against women. It focuses on three field sites providing insight into Mai-Mai motivations and their attitudes toward sexual violence. According to most sources, 5.5 million people have died since the beginning of the war in the Democratic Republic of the Congo (DRC) in 1994, and rape is used as a weapon of destruction. More than 15,000 rapes were reported in the DRC in the last year--accounts of these rapes include descriptions of horrific acts, such as mutilation and the killing of unborn children. The sexual violence is so severe in the DRC that some have described rape in the country as the worst in the world. Sexual violence has long lasting consequences and far-reaching impacts on individual survivors, their families, and their communities in the Democratic Republic of the Congo.

  3. Blind Adaptive Interference Suppression Based on Set-Membership Constrained Constant-Modulus Algorithms With Dynamic Bounds

    NASA Astrophysics Data System (ADS)

    de Lamare, Rodrigo C.; Diniz, Paulo S. R.

    2013-03-01

    This work presents blind constrained constant modulus (CCM) adaptive algorithms based on the set-membership filtering (SMF) concept and incorporates dynamic bounds {for interference suppression} applications. We develop stochastic gradient and recursive least squares type algorithms based on the CCM design criterion in accordance with the specifications of the SMF concept. We also propose a blind framework that includes channel and amplitude estimators that take into account parameter estimation dependency, multiple access interference (MAI) and inter-symbol interference (ISI) to address the important issue of bound specification in multiuser communications. A convergence and tracking analysis of the proposed algorithms is carried out along with the development of analytical expressions to predict their performance. Simulations for a number of scenarios of interest with a DS-CDMA system show that the proposed algorithms outperform previously reported techniques with a smaller number of parameter updates and a reduced risk of overbounding or underbounding.

  4. Modal interference fiber optic sensor

    NASA Astrophysics Data System (ADS)

    Kondrat, Marcin; Szustakowski, Mieczyslaw; Gorka, Andrzej; Palka, Norbert; Zyczkowski, Marek; Niznik, Sylwester

    2004-11-01

    Modal Interference Fiber Optic Sensor (MIFOS) for permanent monitoring of the network is presented. A mechanical disturbance of a fiber cable influences on intensity distribution at the end-face of a multimode fiber. Variations in interfering images are analysed by means of a digital processing unit that determines the alarm in case of unauthorized access along the whole length of the fiber. A contrast of an interference pattern and a procedure of fiber optic selection for the sensor are shown. A simple criterion that bases on changes of local maximums positions of the interference patterns is applied. A laboratory arrangement of the sensor and its experimental research are shown.

  5. Underbarrier interference

    SciTech Connect

    Ivlev, B.

    2011-04-15

    Research Highlights: > In tunneling a momentum, tangent to a border of the prebarrier region, is important. > A tangent momentum, transferred under the barrier, is real in contrast to normal one. > Real momenta lead to caustics points under the barrier where new branches are formed. > Resulting eigenstate can be not small after the barrier. > This results in a possibility of penetration through an almost classical barrier. - Abstract: Quantum tunneling through a two-dimensional static barrier becomes unusual when a momentum of an electron has a tangent component with respect to a border of the prebarrier region. If the barrier is not homogeneous in the direction perpendicular to tunneling a fraction of the electron state is waves propagating away from the barrier. When the tangent momentum is zero a mutual interference of the waves results in an exponentially small outgoing flux. The finite tangent momentum destroys the interference due to formation of caustics by the waves. As a result, a significant fraction of the prebarrier density is carried away from the barrier providing a not exponentially small penetration even through an almost classical barrier. The total electron energy is well below the barrier.

  6. Performance Analysis of SAC Optical PPM-CDMA System-Based Interference Rejection Technique

    NASA Astrophysics Data System (ADS)

    Alsowaidi, N.; Eltaif, Tawfig; Mokhtar, M. R.

    2016-03-01

    In this paper, we aim to theoretically analyse optical code division multiple access (OCDMA) system that based on successive interference cancellation (SIC) using pulse position modulation (PPM), considering the interference between the users, imperfection cancellation occurred during the cancellation process and receiver noises. Spectral amplitude coding (SAC) scheme is used to suppress the overlapping between the users and reduce the receiver noises effect. The theoretical analysis of the multiple access interference (MAI)-limited performance of this approach indicates the influence of the size of M-ary PPM on OCDMA system. The OCDMA system performance improves with increasing M-ary PPM. Therefore, it was found that the SIC/SAC-OCDMA system using PPM technique along with modified prime (MPR) codes used as signature sequence code offers significant improvement over the one without cancellation and it can support up to 103 users at the benchmarking value of bit error rate (BER) = 10-9 with prime number p = 11 while the system without cancellation scheme can support only up to 52 users.

  7. Heterodyne detection using spectral line pairing for spectral phase encoding optical code division multiple access and dynamic dispersion compensation.

    PubMed

    Yang, Yi; Foster, Mark; Khurgin, Jacob B; Cooper, A Brinton

    2012-07-30

    A novel coherent optical code-division multiple access (OCDMA) scheme is proposed that uses spectral line pairing to generate signals suitable for heterodyne decoding. Both signal and local reference are transmitted via a single optical fiber and a simple balanced receiver performs sourceless heterodyne detection, canceling speckle noise and multiple-access interference (MAI). To validate the idea, a 16 user fully loaded phase encoded system is simulated. Effects of fiber dispersion on system performance are studied as well. Both second and third order dispersion management is achieved by using a spectral phase encoder to adjust phase shifts of spectral components at the optical network unit (ONU).

  8. [Original meaning of mai and its academic evolution].

    PubMed

    Sun, Jingwen; Tian, Yanpeng; Guo, Yan; Wang, Chaoyang; Liu, Qingguo

    2015-06-01

    Mai is the important concept in TCM and this term has been found in the early classic work of TCM. With the development and perfection of TCM theory, the original meaning of mai is "blood vessels entirely distrusted in the body". In five dynasties, the meaning of it was supplemented as "distribution of qi and blood in five zang and six fu organs to the four extremities", in which, not only blood but also qi has been included. With the constant understanding on mai, qi and blood, the unique concept of meridian and collateral is gradually generated. In terms of the modern study on the original meaning of mai and the academic evolution of meridian and collateral, it is discovered that qi is predominated and distributed in meridian and collateral as compared with blood. It is very significant to study the original meaning and academic evolution of mai, as well as the origin of the concept of meridian and collateral and to provide the reference support for the terminology standardization and basic study. PMID:26480573

  9. Herschel's Interference Demonstration.

    ERIC Educational Resources Information Center

    Perkalskis, Benjamin S.; Freeman, J. Reuben

    2000-01-01

    Describes Herschel's demonstration of interference arising from many coherent rays. Presents a method for students to reproduce this demonstration and obtain beautiful multiple-beam interference patterns. (CCM)

  10. Multiple Access in Ultra-Wideband Communications Using Multiple Pulses

    SciTech Connect

    Nekoogar, F; Dowla, F

    2003-04-11

    Multiple access (MA) in UWB communication is an area of active research. To date several time-division or code-division pulse amplitude modulation (PAM) or pulse position modulation (PPM) schemes have been proposed to separate multiple users in UWB communications. Conventionally, all users employ the same pulse shape and modulate the transmit pulse based on changing amplitude or position. One concern with using the same pulse for all channels is that the multiple access interference (MAI) increases as the number of users increase. This is due to increased cross-correlation between similar pulses of the different channels, raising thus the noise floor in such systems. In this paper we introduce and study the performance of a new MA scheme in the context of multiple orthogonal transmitted-reference (T-R) short duration (nsec) chirp pulses in the presence of multipath and additive white Gaussian noise (AWGN).

  11. Primary Health Care in Brazil and the Mais Médicos (More Doctors) Program: an analysis of production indicators.

    PubMed

    Lima, Rodrigo Tobias de Sousa; Fernandes, Tiotrefis Gomes; Balieiro, Antônio Alcirley da Silva; Costa, Felipe Dos Santos; Schramm, Joyce Mendes de Andrade; Schweickardt, Julio Cesar; Ferla, Alcindo Antonio

    2016-09-01

    This study analyzes the number of medical appointments and referrals performed in primary health care in Brazil focusing on the Mais Médicos Program (More Doctors Program). It is a cross-sectional study on the work of physicians included, or not, to the Mais Médicos Program in 2014. Based on validation protocols, a unified database was created from two health information system databases - SIAB and ESUS. Absolute indicators were defined: the total of medical appointments per month; medical referrals and community health education activities. In addition, other indicators were considered, such as weekly rates and productivity of appointments, in line with the profile of Brazilian municipalities. The mean of all appointments was 285 per month corresponding to an average of 14.4 appointments/day. In the poorest municipalities, the figures for the Mais Médicos Program physicians were higher than national rates. The educational activities provided by primary care teams that included a Mais Médicos Program professional were higher in Brazilian capital cities. The Mais Médicos Program achieved one of its main goals, which was to increase health access for vulnerable populations and to contribute towards the consolidation of primary health care in Brazil. PMID:27653054

  12. Primary Health Care in Brazil and the Mais Médicos (More Doctors) Program: an analysis of production indicators.

    PubMed

    Lima, Rodrigo Tobias de Sousa; Fernandes, Tiotrefis Gomes; Balieiro, Antônio Alcirley da Silva; Costa, Felipe Dos Santos; Schramm, Joyce Mendes de Andrade; Schweickardt, Julio Cesar; Ferla, Alcindo Antonio

    2016-09-01

    This study analyzes the number of medical appointments and referrals performed in primary health care in Brazil focusing on the Mais Médicos Program (More Doctors Program). It is a cross-sectional study on the work of physicians included, or not, to the Mais Médicos Program in 2014. Based on validation protocols, a unified database was created from two health information system databases - SIAB and ESUS. Absolute indicators were defined: the total of medical appointments per month; medical referrals and community health education activities. In addition, other indicators were considered, such as weekly rates and productivity of appointments, in line with the profile of Brazilian municipalities. The mean of all appointments was 285 per month corresponding to an average of 14.4 appointments/day. In the poorest municipalities, the figures for the Mais Médicos Program physicians were higher than national rates. The educational activities provided by primary care teams that included a Mais Médicos Program professional were higher in Brazilian capital cities. The Mais Médicos Program achieved one of its main goals, which was to increase health access for vulnerable populations and to contribute towards the consolidation of primary health care in Brazil.

  13. Improved CDMA Performance Using Parallel Interference Cancellation

    NASA Technical Reports Server (NTRS)

    Simon, Marvin; Divsalar, Dariush

    1995-01-01

    This report considers a general parallel interference cancellation scheme that significantly reduces the degradation effect of user interference but with a lesser implementation complexity than the maximum-likelihood technique. The scheme operates on the fact that parallel processing simultaneously removes from each user the interference produced by the remaining users accessing the channel in an amount proportional to their reliability. The parallel processing can be done in multiple stages. The proposed scheme uses tentative decision devices with different optimum thresholds at the multiple stages to produce the most reliably received data for generation and cancellation of user interference. The 1-stage interference cancellation is analyzed for three types of tentative decision devices, namely, hard, null zone, and soft decision, and two types of user power distribution, namely, equal and unequal powers. Simulation results are given for a multitude of different situations, in particular, those cases for which the analysis is too complex.

  14. Design of pulse waveform for waveform division multiple access UWB wireless communication system.

    PubMed

    Yin, Zhendong; Wang, Zhirui; Liu, Xiaohui; Wu, Zhilu

    2014-01-01

    A new multiple access scheme, Waveform Division Multiple Access (WDMA) based on the orthogonal wavelet function, is presented. After studying the correlation properties of different categories of single wavelet functions, the one with the best correlation property will be chosen as the foundation for combined waveform. In the communication system, each user is assigned to different combined orthogonal waveform. Demonstrated by simulation, combined waveform is more suitable than single wavelet function to be a communication medium in WDMA system. Due to the excellent orthogonality, the bit error rate (BER) of multiuser with combined waveforms is so close to that of single user in a synchronous system. That is to say, the multiple access interference (MAI) is almost eliminated. Furthermore, even in an asynchronous system without multiuser detection after matched filters, the result is still pretty ideal and satisfactory by using the third combination mode that will be mentioned in the study.

  15. The Mais Médicos (More Doctors) Program in Mato Grosso State, Brazil: implementation analysis.

    PubMed

    Mota, Reinaldo Gaspar da; Barros, Nelson Filice

    2016-09-01

    Although the 224 health professionals engaged by the More Doctors for Brazil Project (Projeto Mais Médicos para o Brazil, PMMB) to strengthen the National Primary Health Care Policy (Política Nacional de Atenção Básica, PNab) in 104 municipalities of Mato Grosso (MT) State have encountered significant problems in the work process, important advances have resulted in the health of populations served by the More Doctors Programme (Programa Mais Médicos, PMM). This article analyses the implementation and development of the PMM in MT, from 2013 to 2015, on the basis of primary data from focus groups and interviews of social stakeholders at the institutions involved and secondary data from reports by supervisors, tutors, managers and institutions on the MT State Coordinating Committee (CCE) of the PMM. Despite political difficulties in managing implementation, the results show that the endeavour was beneficial in that it surmounted previous obstacles, afforded users greater access, prompted discussion of the problem and proposed and experimented with ways to strengthen primary health care. We conclude that there is a need for broader academic discussion of the provision and training of doctors, of the model of care and of human resource capacity-building by continuing professional development with integration among teaching, service and community. PMID:27653072

  16. The Mais Médicos (More Doctors) Program: panorama of the scientific output.

    PubMed

    Kemper, Elisandréa Sguario; Mendonça, Ana Valeria Machado; Sousa, Maria Fátima de

    2016-09-01

    Despite the progress achieved by the Primary Health Care and Family Health Strategy in the Unified Health System (SUS) challenges still remain with regard to the universality of access and the quality of services, one of the factors being the unequal distribution of physicians. The Brazilian Government established the Mais Médicos Program (More Doctors Program), in order to move forward in the provision, placement and training of physicians in the SUS. This study consists of a review of the literature of the Mais Médicos Program, in order to map and assess the scientific production on the Program, as well as summarize the findings and present the results of the analysis. Fifty-four publications were selected, which evaluate the Program in terms of effectiveness, analysis of the implementation process, the media and the statements of the actors and assessment of the legal and constitutional precepts. The criticisms and limitations found were also systematically analyzed. With respect to the analysis, evaluations of the Program are overwhelmingly positive, showing important changes in the work processes in services and training. The studies that show the Program as being an important instrument for the effective implementation of the right to health are highlighted. PMID:27653063

  17. A Dynamic Simulation Model of the Management Accounting Information Systems (MAIS)

    NASA Astrophysics Data System (ADS)

    Konstantopoulos, Nikolaos; Bekiaris, Michail G.; Zounta, Stella

    2007-12-01

    The aim of this paper is to examine the factors which determine the problems and the advantages on the design of management accounting information systems (MAIS). A simulation is carried out with a dynamic model of the MAIS design.

  18. Analysis of airborne MAIS imaging spectrometric data for mineral exploration

    SciTech Connect

    Wang Jinnian; Zheng Lanfen; Tong Qingxi

    1996-11-01

    The high spectral resolution imaging spectrometric system made quantitative analysis and mapping of surface composition possible. The key issue will be the quantitative approach for analysis of surface parameters for imaging spectrometer data. This paper describes the methods and the stages of quantitative analysis. (1) Extracting surface reflectance from imaging spectrometer image. Lab. and inflight field measurements are conducted for calibration of imaging spectrometer data, and the atmospheric correction has also been used to obtain ground reflectance by using empirical line method and radiation transfer modeling. (2) Determining quantitative relationship between absorption band parameters from the imaging spectrometer data and chemical composition of minerals. (3) Spectral comparison between the spectra of spectral library and the spectra derived from the imagery. The wavelet analysis-based spectrum-matching techniques for quantitative analysis of imaging spectrometer data has beer, developed. Airborne MAIS imaging spectrometer data were used for analysis and the analysis results have been applied to the mineral and petroleum exploration in Tarim Basin area china. 8 refs., 8 figs.

  19. Thick Film Interference.

    ERIC Educational Resources Information Center

    Trefil, James

    1983-01-01

    Discusses why interference effects cannot be seen with a thick film, starting with a review of the origin of interference patterns in thin films. Considers properties of materials in films, properties of the light source, and the nature of light. (JN)

  20. Interference laser processing

    NASA Astrophysics Data System (ADS)

    Nakata, Yoshiki

    2016-02-01

    The most important component of quantum optics is laser interference. Interference patterns are formed by splitting a coherent beam into multiple beams and correlating them. This study introduces a variety of beam correlators and discusses their characteristics. Beam correlator basics such as interference region in terms of pulse width, group delay dispersion effects on pulse width, optical delay adjustment, and interference pattern simulation are explained. A discussion of the history of interference processing begins with the method in 1967 and continues through the advancement of shorter wavelengths and pulse widths. The recent techniques of solid-liquid-solid for 3D nanofabrication, duplicated structures with laser-induced periodic surface structure, processing inside transparent materials, and 2D and 3D periodic structures fabricated by photo-sensitization are also presented.

  1. The implementation of the Mais Médicos (More Doctors) Program and comprehensiveness of care in the Family Health Strategy.

    PubMed

    Comes, Yamila; Trindade, Josélia de Souza; Pessoa, Vanira Matos; Barreto, Ivana Cristina de Holanda Cunha; Shimizu, Helena Eri; Dewes, Diego; Arruda, Carlos André Moura; Santos, Leonor Maria Pacheco

    2016-09-01

    The Mais Médicos (More Doctors) Program is a Brazilian government program that aims to expand access to medical care and thus improve the quality of primary healthcare delivery. This study aims to analyze the perceptions of nondoctor members of the Family Health Strategy teams regarding comprehensiveness of care after the inclusion of doctors from the program. The study encompassed 32 poor municipalities in Brazil's five geographical regions. A total of 78 health workers were interviewed. The interviews were transcribed and analyzed using content analysis and the software Atlas.ti Version 1.0.36. The study found that the program led to: an increase in access to and accessibility of services provided under the Family Health Strategy; humanized care and the establishment of bonds - understanding, partnership, friendship and respect; going back to clinical approaches - dedicated time, listening attentively, and detailed physical examination; the desire and willingness to resolve problems; continuity of care; guarenteeing home visits; and coordination of multidisciplinary teams in networks. It was concluded that the Mais Médicos Program contributed to the enhancement of comprehensiveness, thus leading to improvements in primary health care delivery.

  2. The implementation of the Mais Médicos (More Doctors) Program and comprehensiveness of care in the Family Health Strategy.

    PubMed

    Comes, Yamila; Trindade, Josélia de Souza; Pessoa, Vanira Matos; Barreto, Ivana Cristina de Holanda Cunha; Shimizu, Helena Eri; Dewes, Diego; Arruda, Carlos André Moura; Santos, Leonor Maria Pacheco

    2016-09-01

    The Mais Médicos (More Doctors) Program is a Brazilian government program that aims to expand access to medical care and thus improve the quality of primary healthcare delivery. This study aims to analyze the perceptions of nondoctor members of the Family Health Strategy teams regarding comprehensiveness of care after the inclusion of doctors from the program. The study encompassed 32 poor municipalities in Brazil's five geographical regions. A total of 78 health workers were interviewed. The interviews were transcribed and analyzed using content analysis and the software Atlas.ti Version 1.0.36. The study found that the program led to: an increase in access to and accessibility of services provided under the Family Health Strategy; humanized care and the establishment of bonds - understanding, partnership, friendship and respect; going back to clinical approaches - dedicated time, listening attentively, and detailed physical examination; the desire and willingness to resolve problems; continuity of care; guarenteeing home visits; and coordination of multidisciplinary teams in networks. It was concluded that the Mais Médicos Program contributed to the enhancement of comprehensiveness, thus leading to improvements in primary health care delivery. PMID:27653058

  3. Electromagnetic interference analysis for CSRH

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Chen, Zhi-Jun; Liu, Yu-Ying; Yan, Yi-Hua; Ji, Guo-Shu

    2006-06-01

    The electromagnetic interference tolerance is discussed in this paper, the radio spectrum assignment and the sensitivity of interference measurement equipment are described. Interference to CSRH and forecast from synchronous orbit satellite, and interference due to low and middle orbit satellite are analysed. Transmission formula of interference from mobile base and conservative estimation from pulse radar are presented.

  4. Imaging of double slit interference by scanning gate microscopy

    NASA Astrophysics Data System (ADS)

    Kolasiński, K.; Szafran, B.; Nowak, M. P.

    2014-10-01

    We consider scanning gate microscopy imaging of the double slit interference for a pair of quantum point contacts (QPCs) defined within the two-dimensional electron gas. The interference is clearly present in the scattered electron wave functions for each of the incident subbands. Nevertheless, we find that the interference is generally missing in the experimentally accessible conductance maps for many incident subbands. We explain this finding on the basis of the Landauer approach. A setup geometry allowing for observation of the double slit interference by scanning gate microscopy is proposed.

  5. Dealing with LOFAR interference

    NASA Astrophysics Data System (ADS)

    Offringa, André

    2011-07-01

    LOFAR is a new radio telescope built in and around the Netherlands that will probe the universe between 10 and 200 MHz. Most of LOFAR's hardware has been installed and the next step is writing the required algorithms to process LOFAR's data. One such algorithm is the detection of interference. Since LOFAR is built in a populated environment, care has to be taken to deal with interference from terrestrial origin. A detection pipeline was written that removes interference in an automated way. This pipeline is now in use and the radio environment around LOFAR is being analyzed. Results show a relatively benign radio environment with a loss of data of a few per cent due to interference.

  6. 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.

  7. Mais Médicos (More Doctors) Program - a view from England.

    PubMed

    Harris, Matthew

    2016-09-01

    The Programa Mais Medicos (PMM) is a national strategy to increase the numbers of Brazilian trained doctors entering primary care and is possibly the most significant human resource intervention in Latin America in recent years. From an English perspective, there are clearly opportunities to learn the PMM. First, PAHO's role in the PMM provides an exemplar for an overarching human resource migration and recruitment role throughout the EU. The role of the WHO in influencing and overseeing the recruitment of doctors throughout the EU could be an opportunity for improved distribution, avoiding a reliance on market forces. Secondly, a centrally-coordinated and governed process following well-established criteria and guidance laid out in law has helped to ensure that doctors are allocated to regions of the greatest need. Finally, the deployment of primary care doctors to ensure that the needs of the whole population are met, including in hard-to-reach areas. However, Brazil should not fall into the trap of doing much, and evaluating little. Brazil is in an exciting position to conduct robust before-after studies regarding the improvement in access, outcomes and equity that the ESF has already been credited with. Evaluation must include the impact of the PMM on Cuba. PMID:27653077

  8. All-optical multiplexing schemes for multiple access networks based on wavelet packet filter banks

    NASA Astrophysics Data System (ADS)

    Cincotti, Gabriella; Svaluto Moreolo, Michela; Neri, Alessandro

    2004-08-01

    All optical architectures for Wavelet Packet Division Multiplexing (WPDM) are presented, that can be used in multiple access networks to increase the number of simultaneous users. Wavelet waveform coding spreads data signals both in time and frequency domains, with a large capacity improvement with respect to standard Optical-Code Division Multiple Access (O-CDMA) systems. In addition, the orthogonal property of the wavelet atoms ensures low InterSymbol Interference (ISI) and Multiple Access Interference (MAI) noises. To exploit the large bandwidth capacity of optical fibres, the Optical-Electrical-Optical (O-E-O) conversion is completely avoided, and we designed an all optical system that realizes the WPDM fully in the optical domain. A single Planar Lightwave Circuit (PLC) device multiplies/demultiplies N different users and a diffractive or an integrated optical device performs the waveform coding/decoding. The Wavelet Packet (WP) encoder/decoder is realized as a tree of lattice-form delay-line filters, and can be integrated on a single device along with the optical waveform modulator, resulting in a compact planar optical system. In addition, we show that different choices of WP encoders/decoders are possible to further enhance the system performances.

  9. Generalized Multiphoton Quantum Interference

    NASA Astrophysics Data System (ADS)

    Tillmann, Max; Tan, Si-Hui; Stoeckl, Sarah E.; Sanders, Barry C.; de Guise, Hubert; Heilmann, René; Nolte, Stefan; Szameit, Alexander; Walther, Philip

    2015-10-01

    Nonclassical interference of photons lies at the heart of optical quantum information processing. Here, we exploit tunable distinguishability to reveal the full spectrum of multiphoton nonclassical interference. We investigate this in theory and experiment by controlling the delay times of three photons injected into an integrated interferometric network. We derive the entire coincidence landscape and identify transition matrix immanants as ideally suited functions to describe the generalized case of input photons with arbitrary distinguishability. We introduce a compact description by utilizing a natural basis that decouples the input state from the interferometric network, thereby providing a useful tool for even larger photon numbers.

  10. Understanding ghost interference

    NASA Astrophysics Data System (ADS)

    Qureshi, Tabish; Chingangbam, Pravabati; Shafaq, Sheeba

    2016-08-01

    The ghost interference observed for entangled photons is theoretically analyzed using wave-packet dynamics. It is shown that ghost interference is a combined effect of virtual double-slit creation due to entanglement, and quantum erasure of which-path information for the interfering photon. For the case where the two photons are of different color, it is shown that fringe width of the interfering photon depends not only on its own wavelength, but also on the wavelength of the other photon which it is entangled with.

  11. Interference and radioastronomy

    NASA Astrophysics Data System (ADS)

    Thompson, A. R.; Vanden Bout, Paul A.; Gergely, Tomas E.

    1991-11-01

    The vulnerabilty of radio astronomy to the growing flood of interfering sources ranging from garage door openers to digital audio broadcast satellites is reviewed. Technical solutions to these problems are briefly examined, and work that needs to be done in the international regulatory system to ameliorate the interference is addressed. An overview is given of existing regulations.

  12. Quantum interference in polyenes

    SciTech Connect

    Tsuji, Yuta; Hoffmann, Roald; Movassagh, Ramis; Datta, Supriyo

    2014-12-14

    The explicit form of the zeroth Green's function in the Hückel model, approximated by the negative of the inverse of the Hückel matrix, has direct quantum interference consequences for molecular conductance. We derive a set of rules for transmission between two electrodes attached to a polyene, when the molecule is extended by an even number of carbons at either end (transmission unchanged) or by an odd number of carbons at both ends (transmission turned on or annihilated). These prescriptions for the occurrence of quantum interference lead to an unexpected consequence for switches which realize such extension through electrocyclic reactions: for some specific attachment modes the chemically closed ring will be the ON position of the switch. Normally the signs of the entries of the Green's function matrix are assumed to have no physical significance; however, we show that the signs may have observable consequences. In particular, in the case of multiple probe attachments – if coherence in probe connections can be arranged – in some cases new destructive interference results, while in others one may have constructive interference. One such case may already exist in the literature.

  13. Interference tables: a useful model for interference analysis in asynchronous multicarrier transmission

    NASA Astrophysics Data System (ADS)

    Medjahdi, Yahia; Terré, Michel; Ruyet, Didier Le; Roviras, Daniel

    2014-12-01

    In this paper, we investigate the impact of timing asynchronism on the performance of multicarrier techniques in a spectrum coexistence context. Two multicarrier schemes are considered: cyclic prefix-based orthogonal frequency division multiplexing (CP-OFDM) with a rectangular pulse shape and filter bank-based multicarrier (FBMC) with physical layer for dynamic spectrum access and cognitive radio (PHYDYAS) and isotropic orthogonal transform algorithm (IOTA) waveforms. First, we present the general concept of the so-called power spectral density (PSD)-based interference tables which are commonly used for multicarrier interference characterization in spectrum sharing context. After highlighting the limits of this approach, we propose a new family of interference tables called `instantaneous interference tables'. The proposed tables give the interference power caused by a given interfering subcarrier on a victim one, not only as a function of the spectral distance separating both subcarriers but also with respect to the timing misalignment between the subcarrier holders. In contrast to the PSD-based interference tables, the accuracy of the proposed tables has been validated through different simulation results. Furthermore, due to the better frequency localization of both PHYDYAS and IOTA waveforms, FBMC technique is demonstrated to be more robust to timing asynchronism compared to OFDM one. Such a result makes FBMC a potential candidate for the physical layer of future cognitive radio systems.

  14. Impact of the Mais Médicos (More Doctors) Program in reducing physician shortage in Brazilian Primary Healthcare.

    PubMed

    Girardi, Sábado Nicolau; Stralen, Ana Cristina de Sousa van; Cella, Joana Natalia; Wan Der Maas, Lucas; Carvalho, Cristiana Leite; Faria, Erick de Oliveira

    2016-09-01

    The Mais Médicos (More Doctors) Program (PMM) was put in place in Brazil aiming to reduce inequalities in access to Primary Healthcare. Based on diverse evidence that pointed to a scenario of profound shortage of doctors in the country, one of its central thrusts was emergency provision of these professionals in vulnerable areas, referred to as the Mais Médicos para o Brasil (More Doctors for Brazil) Project. The article analyses the impact of the PMM in reducing shortage of physicians in Brazilian municipalities. To do this, it uses the Primary Healthcare Physicians Shortage Index, which identifies and measures the shortage in the periods of March 2003 and September 2015, before and after implementation of the program. The results show that there was a substantial increase in the supply of physicians in primary healthcare in the period, which helped reduce the number of municipalities with shortage from 1,200 to 777. This impact also helped reduce inequalities between municipalities, but the inequities in distribution persisted. It was also found that there was a reduction in the regular supply of doctors made by municipalities, suggesting that these were being simply substituted by the supply coming from the program. Thus, an overall situation of insecurity in care persists, reflecting the dependence of municipalities on the physician supply from the federal government.

  15. Interference reflection microscopy.

    PubMed

    Barr, Valarie A; Bunnell, Stephen C

    2009-12-01

    Interference reflection microscopy (IRM) is an optical technique used to study cell adhesion or cell mobility on a glass coverslip. The interference of reflected light waves generates images with high contrast and definition. IRM can be used to examine almost any cell that will rest upon a glass surface, although it is most useful in examining sites of close contact between a cell and substratum. This unit presents methods for obtaining IRM images of cells with particular emphasis on IRM imaging with a laser scanning confocal microscope (LSCM), as most LSCM are already capable of recording these images without any modification of the instrument. Techniques are presented for imaging fixed and live cells, as well as simultaneous multi-channel capture of fluorescence and reflection images.

  16. Service users' perceptions of the Mais Médicos (More Doctors) Program in the Municipality of Mossoró, Brazil.

    PubMed

    Silva, Tiago Rodrigues Bento da; Silva, Jennifer do Vale E; Pontes, Andrezza Graziella Veríssimo; Cunha, Andrea Taborda Ribas da

    2016-09-01

    The Mais Médicos (More Doctors) Program (MMP), which was launched in 2013, sought to provide doctors to work in primary health care in priority areas within the Brazilian Unified Health System (SUS). This article analyzes the perception of MMP service users through the results of a qualitative study that consisted of interviews with service users of the Family Health Strategy (ESF) in which doctors from the MMP worked. The service users who were interviewed had a positive view of the MMP because it had expanded access to health care, although there still remained organizational and technical problems that limited the use of services. The performance of foreign doctors was well viewed, with an emphasis on a humanized relationship between doctor and service user, which was characterized by listening, attention and dialogue. In terms of communication with these professionals, some service users referred to language as being a barrier, which was ameliorated by the use of communication strategies within the ESF. The MMP offered a quick and satisfactory resolution to the historical problem of difficulty of access to doctors in Brazil. However, the effectiveness of the Brazilian health system requires that weaknesses are overcome, such as access to specialized services, organizational problems and the implementation of service production models that are centered on illness. PMID:27653070

  17. A Modular Artificial Intelligence Inference Engine System (MAIS) for support of on orbit experiments

    NASA Technical Reports Server (NTRS)

    Hancock, Thomas M., III

    1994-01-01

    This paper describes a Modular Artificial Intelligence Inference Engine System (MAIS) support tool that would provide health and status monitoring, cognitive replanning, analysis and support of on-orbit Space Station, Spacelab experiments and systems.

  18. Theoretical Accuracy of Along-Track Displacement Measurements from Multiple-Aperture Interferometry (MAI)

    PubMed Central

    Jung, Hyung-Sup; Lee, Won-Jin; Zhang, Lei

    2014-01-01

    The measurement of precise along-track displacements has been made with the multiple-aperture interferometry (MAI). The empirical accuracies of the MAI measurements are about 6.3 and 3.57 cm for ERS and ALOS data, respectively. However, the estimated empirical accuracies cannot be generalized to any interferometric pair because they largely depend on the processing parameters and coherence of the used SAR data. A theoretical formula is given to calculate an expected MAI measurement accuracy according to the system and processing parameters and interferometric coherence. In this paper, we have investigated the expected MAI measurement accuracy on the basis of the theoretical formula for the existing X-, C- and L-band satellite SAR systems. The similarity between the expected and empirical MAI measurement accuracies has been tested as well. The expected accuracies of about 2–3 cm and 3–4 cm (γ = 0.8) are calculated for the X- and L-band SAR systems, respectively. For the C-band systems, the expected accuracy of Radarsat-2 ultra-fine is about 3–4 cm and that of Sentinel-1 IW is about 27 cm (γ = 0.8). The results indicate that the expected MAI measurement accuracy of a given interferometric pair can be easily calculated by using the theoretical formula. PMID:25251408

  19. Reproducibility and quantification of illicit drugs using matrix-assisted ionization (MAI) mass spectrometry.

    PubMed

    Chakrabarty, Shubhashis; DeLeeuw, Jessica L; Woodall, Daniel W; Jooss, Kevin; Narayan, Srinivas B; Trimpin, Sarah

    2015-08-18

    Matrix-assisted ionization (MAI) mass spectrometry (MS) is a simple and sensitive method for analysis of low- and high-mass compounds, requiring only that the analyte in a suitable matrix be exposed to the inlet aperture of an atmospheric pressure ionization mass spectrometer. Here, we evaluate the reproducibility of MAI and its potential for quantification using six drug standards. Factors influencing reproducibility include the matrix compound used, temperature, and the method of sample introduction. The relative standard deviation (RSD) using MAI for a mixture of morphine, codeine, oxymorphone, oxycodone, clozapine, and buspirone and their deuterated internal standards using the matrix 3-nitrobenzonitrile is less than 10% with either a Waters SYNAPT G2 or a Thermo LTQ Velos mass spectrometer. The RSD values obtained using MAI are comparable to those using ESI or MALDI on these instruments. The day-to-day reproducibility of MAI determined for five consecutive days with internal standards was better than 20% using manual sample introduction. The reproducibility improved to better than 5% using a mechanically assisted sample introduction method. Hydrocodone, present in a sample of undiluted infant urine, was quantified with MAI using the standard addition method. PMID:26186653

  20. Interference competition and species coexistence.

    PubMed Central

    Amarasekare, Priyanga

    2002-01-01

    Interference competition is ubiquitous in nature. Yet its effects on resource exploitation remain largely unexplored for species that compete for dynamic resources. Here, I present a model of exploitative and interference competition with explicit resource dynamics. The model incorporates both biotic and abiotic resources. It considers interference competition both in the classical sense (i.e. each species suffers a net reduction in per capita growth rate via interference from, and interference on, the other species) and in the broad sense (i.e. each species suffers a net reduction in per capita growth rate via interference from, but can experience an increase in growth rate via interference on, the other species). Coexistence cannot occur under classical interference competition even when the species inferior at resource exploitation is superior at interference. Such a trade-off can, however, change the mechanism of competitive exclusion from dominance by the superior resource exploiter to a priority effect. Now the inferior resource exploiter can exclude the superior resource exploiter provided it has a higher initial abundance. By contrast, when interference is beneficial to the interacting species, coexistence is possible via a trade-off between exploitation and interference. These results hold regardless of whether the resource is biotic or abiotic, indicating that the outcome of exploitative and interference competition does not depend on the exact nature of resource dynamics. The model makes two key predictions. First, species that engage in costly interference mechanisms (e.g. territoriality, overgrowth or undercutting, allelopathy and other forms of chemical competition) should not be able to coexist unless they also engage in beneficial interference mechanisms (e.g. predation or parasitism). Second, exotic invasive species that displace native biota should be superior resource exploiters that have strong interference effects on native species with little

  1. Holographic interference filters

    NASA Astrophysics Data System (ADS)

    Diehl, Damon W.

    Holographic mirrors have wavelength-selection properties and thus qualify as a class of interference filters. Two theoretical methods for analyzing such structures are developed. The first method uses Hill's matrix method to yield closed-forms solutions in terms of the Floquet-Bloch waves within a periodic structure. A process is developed for implementing this solution method on a computer, using sparse-matrix memory allocation, numerical root-finding algorithms, and inverse-iteration techniques. It is demonstrated that Hill's matrix method is valid for the analysis of finite and multi-periodic problems. The second method of theoretical analysis is a transfer-matrix technique, which is herein termed thin-film decomposition. It is shown that the two methods of solution yield results that differ by, at worst, a fraction of a percent. Using both calculation techniques, a number of example problems are explored. Of key importance is the construction of a set of curves that are useful for the design and characterization of holographic interference filters. In addition to the theoretical development, methods are presented for the fabrication of holographic interference filters using DuPont HRF-800X001 photopolymer. Central to the exposure system is a frequency-stabilized, tunable dye laser. The types of filters fabricated include single-tone reflection filters, two types of multitone reflection filters, and reflection filters for infrared wavelengths. These filters feature index profiles that are not easily attainable through other fabrication methods. As a supplement to the body of the dissertation, the computer algorithms developed to implement Hill's matrix method and thin-film decomposition are also included as an appendix. Further appendices provide more information on Floquet's theorem and Hill's matrix method. A final appendix presents a design for an infrared laser spectrophotometer.

  2. Sensors Locate Radio Interference

    NASA Technical Reports Server (NTRS)

    2009-01-01

    After receiving a NASA Small Business Innovation Research (SBIR) contract from Kennedy Space Center, Soneticom Inc., based in West Melbourne, Florida, created algorithms for time difference of arrival and radio interferometry, which it used in its Lynx Location System (LLS) to locate electromagnetic interference that can disrupt radio communications. Soneticom is collaborating with the Federal Aviation Administration (FAA) to install and test the LLS at its field test center in New Jersey in preparation for deploying the LLS at commercial airports. The software collects data from each sensor in order to compute the location of the interfering emitter.

  3. Multiple Access Trade Study

    NASA Technical Reports Server (NTRS)

    Motamedi, Masoud

    1990-01-01

    The Personal Access Satellite System (PASS) strawman design uses a hybrid Time Division Multiple Access (TDMA)/Frequency Division Multiple Access (FDMA) implementation. TDMA is used for the forward direction (from Suppliers to Users), and FDMA for the return direction (from Users to Suppliers). An alternative architecture is proposed that will require minimal real time coordination and yet provide a fast access method by using random access Code Division Multiple Access (CDMA). The CDMA system issues are addressed such as connecting suppliers and users, both of whom may be located anywhere in the CONUS, when the user terminals are constrained in size and weight; and providing efficient traffic routing under highly variable traffic requirements. It is assumed that bandwidth efficiency is not of paramount importance. CDMA or Spread Spectrum Multiple Access (SSMA) communication is a method in which a group of carriers operate at the same nominal center frequency but are separable from each other by the low cross correlation of the spreading codes used. Interference and multipath rejection capability, ease of selective addressing and message screening, low density power spectra for signal hiding and security, and high resolution ranging are among the benefits of spread spectrum communications.

  4. How do Data Processing Choices Affect Multiple Aperture InSAR (MAI) Precision?

    NASA Astrophysics Data System (ADS)

    Bechor-Ben Dov, N.

    2015-12-01

    MAI data processing methods report different precisions, sometimes for the same data; we investigate these discrepancies here. MAI, a method to obtain phase-based along-track displacements from InSAR data, has been used for measuring volcanic, glacier, and earthquake displacements. However, different applications show vastly different precisions, ranging from a few millimeters to tens of centimeters per interferogram. While some spatial variability in precision is expected due to the InSAR phase noise dependence on terrain, some reports show different precisions for the same data. Here, I address the following questions: What is the true precision of MAI measurements? What are the MAI noise sources, and how do we mitigate them? We use data from 11 Envisat, 2 ERS, and 1 ALOS interferograms to analyze and quantify the MAI noise sources and their dependence on the method's implementation. To do that, we implement various processing steps with the JPL/Caltech InSAR data processor ROI_PAC. We find that there are several (sometimes surprising) nuances in data processing that together can reduce scatter noise by half, and other corrections that can reduce topography-related noise by up to 25 centimeters. We find that even with all the optimized data processing steps, the actual MAI errors (relative accuracy) are higher then the theoretical ones by a factor that depends on filter window size. We present an updated MAI data processor, which is capable of achieving relative accuracy and precision levels of 6 to 2 centimeters, respectively, in low to medium coherence terrains (correlation coefficient of 0.4 to 0.8), and provides error estimates that better reflect the actual relative accuracy of the measurement.

  5. Computer Supported Indexing: A History and Evaluation of NASA's MAI System

    NASA Technical Reports Server (NTRS)

    Silvester, June P.

    1997-01-01

    Computer supported or machine aided indexing (MAI) can be categorized in multiple ways. The system used by the National Aeronautics and Space Administration's (NASA's) Center for AeroSpace Information (CASI) is described as semantic and computational. It's based on the co-occurrence of domain-specific terminology in parts of a sentence, and the probability that an indexer will assign a particular index term when a given word or phrase is encountered in text. The NASA CASI system is run on demand by the indexer and responds in 3 to 9 seconds with a list of suggested, authorized terms. The system was originally based on a syntactic system used in the late 1970's by the Defense Technical Information Center (DTIC). The NASA mainframe-supported system consists of three components: two programs and a knowledge base (KB). The evolution of the system is described and flow charts illustrate the MAI procedures. Tests used to evaluate NASA's MAI system were limited to those that would not slow production. A very early test indicated that MAI saved about 3 minutes and provided several additional terms for each document indexed. It also was determined that time and other resources spent in careful construction of the KB pay off with high-quality output and indexer acceptance of MAI results.

  6. Long-term interference at the semantic level: Evidence from blocked-cyclic picture matching.

    PubMed

    Wei, Tao; Schnur, Tatiana T

    2016-01-01

    Processing semantically related stimuli creates interference across various domains of cognition, including language and memory. In this study, we identify the locus and mechanism of interference when retrieving meanings associated with words and pictures. Subjects matched a probe stimulus (e.g., cat) to its associated target picture (e.g., yarn) from an array of unrelated pictures. Across trials, probes were either semantically related or unrelated. To test the locus of interference, we presented probes as either words or pictures. If semantic interference occurs at the stage common to both tasks, that is, access to semantic representations, then interference should occur in both probe presentation modalities. Results showed clear semantic interference effects independent of presentation modality and lexical frequency, confirming a semantic locus of interference in comprehension. To test the mechanism of interference, we repeated trials across 4 presentation cycles and manipulated the number of unrelated intervening trials (zero vs. two). We found that semantic interference was additive across cycles and survived 2 intervening trials, demonstrating interference to be long-lasting as opposed to short-lived. However, interference was smaller with zero versus 2 intervening trials, which we interpret to suggest that short-lived facilitation counteracted the long-lived interference. We propose that retrieving meanings associated with words/pictures from the same semantic category yields both interference due to long-lasting changes in connection strength between semantic representations (i.e., incremental learning) and facilitation caused by short-lived residual activation. (PsycINFO Database Record

  7. Accessibility Videos.

    PubMed

    Kurppa, Ari; Nordlund, Marika

    2016-01-01

    It can be difficult to understand accessibility, if you do not have the personal experience. The Accessibility Centre ESKE produced short videos which demonstrate the meaning of accessibility in different situations. Videos will raise accessibility awareness of architects, other planners and professionals in the construction field and maintenance. PMID:27534282

  8. Evaluation of user satisfaction and service responsiveness in municipalities enrolled in the Mais Médicos (More Doctors) Program.

    PubMed

    Comes, Yamila; Trindade, Josélia de Souza; Shimizu, Helena Eri; Hamann, Edgar Merchan; Bargioni, Florencia; Ramirez, Loana; Sanchez, Mauro Niskier; Santos, Leonor Maria Pacheco

    2016-09-01

    The Mais Médicos (More Doctors) Program (PMM) addresses shortages of doctors, one of whose objectives is to reduce regional inequalities in access to health care. This descriptive cross-sectional study evaluated service responsiveness and user satisfaction with PMM doctors among 263 users of the public health system in 32 municipalities with 20% or more of extreme poverty. Questionnaires of open and closed questions were used. Users were satisfied with patient-doctor relationships, information about diseases and treatment and the clarity and comprehensibility of medical indications. The doctors' technical and humanised conduct helped ensure satisfaction among users, who stressed the importance of the programme's continuance. As regards responsiveness, most users were pleased with the non-medical aspects of care: prompt scheduling of appointments, waiting times of less than one hour and privacy. Users suggested improving infrastructure and making more medicines and more doctors available, which should be considered by SUS managers to help ensure access to the right to health guaranteed in Brazil's constitution. PMID:27653060

  9. Single-plasmon interferences.

    PubMed

    Dheur, Marie-Christine; Devaux, Eloïse; Ebbesen, Thomas W; Baron, Alexandre; Rodier, Jean-Claude; Hugonin, Jean-Paul; Lalanne, Philippe; Greffet, Jean-Jacques; Messin, Gaétan; Marquier, François

    2016-03-01

    Surface plasmon polaritons are electromagnetic waves coupled to collective electron oscillations propagating along metal-dielectric interfaces, exhibiting a bosonic character. Recent experiments involving surface plasmons guided by wires or stripes allowed the reproduction of quantum optics effects, such as antibunching with a single surface plasmon state, coalescence with a two-plasmon state, conservation of squeezing, or entanglement through plasmonic channels. We report the first direct demonstration of the wave-particle duality for a single surface plasmon freely propagating along a planar metal-air interface. We develop a platform that enables two complementary experiments, one revealing the particle behavior of the single-plasmon state through antibunching, and the other one where the interferences prove its wave nature. This result opens up new ways to exploit quantum conversion effects between different bosonic species as shown here with photons and polaritons. PMID:26998521

  10. Single-plasmon interferences.

    PubMed

    Dheur, Marie-Christine; Devaux, Eloïse; Ebbesen, Thomas W; Baron, Alexandre; Rodier, Jean-Claude; Hugonin, Jean-Paul; Lalanne, Philippe; Greffet, Jean-Jacques; Messin, Gaétan; Marquier, François

    2016-03-01

    Surface plasmon polaritons are electromagnetic waves coupled to collective electron oscillations propagating along metal-dielectric interfaces, exhibiting a bosonic character. Recent experiments involving surface plasmons guided by wires or stripes allowed the reproduction of quantum optics effects, such as antibunching with a single surface plasmon state, coalescence with a two-plasmon state, conservation of squeezing, or entanglement through plasmonic channels. We report the first direct demonstration of the wave-particle duality for a single surface plasmon freely propagating along a planar metal-air interface. We develop a platform that enables two complementary experiments, one revealing the particle behavior of the single-plasmon state through antibunching, and the other one where the interferences prove its wave nature. This result opens up new ways to exploit quantum conversion effects between different bosonic species as shown here with photons and polaritons.

  11. Single-plasmon interferences

    PubMed Central

    Dheur, Marie-Christine; Devaux, Eloïse; Ebbesen, Thomas W.; Baron, Alexandre; Rodier, Jean-Claude; Hugonin, Jean-Paul; Lalanne, Philippe; Greffet, Jean-Jacques; Messin, Gaétan; Marquier, François

    2016-01-01

    Surface plasmon polaritons are electromagnetic waves coupled to collective electron oscillations propagating along metal-dielectric interfaces, exhibiting a bosonic character. Recent experiments involving surface plasmons guided by wires or stripes allowed the reproduction of quantum optics effects, such as antibunching with a single surface plasmon state, coalescence with a two-plasmon state, conservation of squeezing, or entanglement through plasmonic channels. We report the first direct demonstration of the wave-particle duality for a single surface plasmon freely propagating along a planar metal-air interface. We develop a platform that enables two complementary experiments, one revealing the particle behavior of the single-plasmon state through antibunching, and the other one where the interferences prove its wave nature. This result opens up new ways to exploit quantum conversion effects between different bosonic species as shown here with photons and polaritons. PMID:26998521

  12. Graphene quantum interference photodetector

    PubMed Central

    Voss, Paul L

    2015-01-01

    Summary In this work, a graphene quantum interference (QI) photodetector was simulated in two regimes of operation. The structure consists of a graphene nanoribbon, Mach–Zehnder interferometer (MZI), which exhibits a strongly resonant transmission of electrons of specific energies. In the first regime of operation (that of a linear photodetector), low intensity light couples two resonant energy levels, resulting in scattering and differential transmission of current with an external quantum efficiency of up to 5.2%. In the second regime of operation, full current switching is caused by the phase decoherence of the current due to a strong photon flux in one or both of the interferometer arms in the same MZI structure. Graphene QI photodetectors have several distinct advantages: they are of very small size, they do not require p- and n-doped regions, and they exhibit a high external quantum efficiency. PMID:25821713

  13. Graphene quantum interference photodetector.

    PubMed

    Alam, Mahbub; Voss, Paul L

    2015-01-01

    In this work, a graphene quantum interference (QI) photodetector was simulated in two regimes of operation. The structure consists of a graphene nanoribbon, Mach-Zehnder interferometer (MZI), which exhibits a strongly resonant transmission of electrons of specific energies. In the first regime of operation (that of a linear photodetector), low intensity light couples two resonant energy levels, resulting in scattering and differential transmission of current with an external quantum efficiency of up to 5.2%. In the second regime of operation, full current switching is caused by the phase decoherence of the current due to a strong photon flux in one or both of the interferometer arms in the same MZI structure. Graphene QI photodetectors have several distinct advantages: they are of very small size, they do not require p- and n-doped regions, and they exhibit a high external quantum efficiency.

  14. Optically bistable interference filter

    NASA Astrophysics Data System (ADS)

    Feng, Weiting

    1990-07-01

    In general the temperature dependence of refractive index of coating materials is usually small. The most notable exception being the lead telluride. Thinfilm filters made of PbTe possess anomalously high nortlinearily in refractive index. We have investigated the phenomenon theoretically and experimexitally. 2 . BISTABLE CHARACTERISTICS OF INTERFERENCE FILTERS It can be proved that the transmittance and reflectance of a twin-cavity NLIF which consists of two F-B filters coupled by a single low-index are given by 2 a(1r1 )(1-r0) T --i. -. (1) -d (1r01) (1r12) (1-i-Fsin 4)(1+sin p) where a r01 F . Te phase change of the cavity 0 IS 2r0dnAI0D (2) 2k5dT 1k where the absorbtance A 00 the initial detunning of fresonance and the first term on the right side of the equation(1)-(2) the output characteristics of the NLIF can be calculated. 3 . EXPERIMENTAL CASE The interference filters suggested to be used in my research will be made by vacuum deposition with a thermal source. The filters will be made according to the prescripti The dominant mechanism responsible for d(nhl) must be the change in the refractive index. A low limit on the OB switch-on time is found to be O. 35us and switch-off time is 5. 5us. 4. REFERENCES 1. W. T. Feng " Temperature effects on properties of zinc selenide and lead telluride" to be published in Infrared Physics. 2. H. S. Carslaw Conduction

  15. Satellite-based interference analyzer

    NASA Technical Reports Server (NTRS)

    Varice, H.; Johannsen, K.; Sabaroff, S.

    1977-01-01

    System identifies terrestrial sources of radiofrequency interference and measures their frequency spectra and amplitudes. Designed to protect satellite communication networks, system measures entire noise spectrum over selected frequency band and can raster-scan geographical region to locate noise sources. Once interference is analyzed, realistic interference protection ratios are determined and mathematical models for predicting ratio-frequency noise spectra are established. This enhances signal-detection and locates optimum geographical positions and frequency bands for communication equipment.

  16. Inter-BAN Interference Mitigation: A Correlated Equilibrium Perspective.

    PubMed

    Marbukh, Vladimir; Sayrafian, Kamran; Barbi, Martina; Alasti, Mehdi

    2014-01-01

    A Body Area Network (BAN) is a wireless network of wearable or implantable computing devices. A BAN typically consists of several miniaturized radio-enabled body sensor/actuator that communicate with a single coordinator. Medical applications usually impose stringent constraints on the BAN operational reliability, quality of service, and power consumption. However, as there is no coordination among multiple co-located BANs, cross-interference could make achieving these objectives a challenging problem. Assuming Time Division Multiple Access (TDMA) at each BAN, this paper investigates the ability of regret matching based transmission scheduling algorithm to ease the impact of inter-BAN interference. This scheduling algorithm uses pattern of past interference for implicit coordination between different BAN transmissions. Simulation results demonstrate potential benefits of the proposed scheme for inter-BAN interference mitigation. PMID:24851973

  17. Another look at retroactive and proactive interference: a quantitative analysis of conversion processes.

    PubMed

    Blank, Hartmut

    2005-02-01

    Traditionally, the causes of interference phenomena were sought in "real" or "hard" memory processes such as unlearning, response competition, or inhibition, which serve to reduce the accessibility of target items. I propose an alternative approach which does not deny the influence of such processes but highlights a second, equally important, source of interference-the conversion (Tulving, 1983) of accessible memory information into memory performance. Conversion is conceived as a problem-solving-like activity in which the rememberer tries to find solutions to a memory task. Conversion-based interference effects are traced to different conversion processes in the experimental and control conditions of interference designs. I present a simple theoretical model that quantitatively predicts the resulting amount of interference. In two paired-associate learning experiments using two different types of memory tests, these predictions were corroborated. Relations of the present approach to traditional accounts of interference phenomena and implications for eyewitness testimony are discussed. PMID:15847231

  18. Quantum Interference in Graphene Nanoconstrictions.

    PubMed

    Gehring, Pascal; Sadeghi, Hatef; Sangtarash, Sara; Lau, Chit Siong; Liu, Junjie; Ardavan, Arzhang; Warner, Jamie H; Lambert, Colin J; Briggs, G Andrew D; Mol, Jan A

    2016-07-13

    We report quantum interference effects in the electrical conductance of chemical vapor deposited graphene nanoconstrictions fabricated using feedback controlled electroburning. The observed multimode Fabry-Pérot interferences can be attributed to reflections at potential steps inside the channel. Sharp antiresonance features with a Fano line shape are observed. Theoretical modeling reveals that these Fano resonances are due to localized states inside the constriction, which couple to the delocalized states that also give rise to the Fabry-Pérot interference patterns. This study provides new insight into the interplay between two fundamental forms of quantum interference in graphene nanoconstrictions.

  19. Exploring the time course of semantic interference and associative priming in the picture-word interference task.

    PubMed

    Sailor, Kevin; Brooks, Patricia J; Bruening, Paul R; Seiger-Gardner, Liat; Guterman, Mark

    2009-04-01

    The picture-word interference (PWI) task is a widely used technique for exploring effects of semantic context on lexical access. In this task, printed words are superimposed over pictures to be named, with the timing of the interfering word relative to the picture systematically manipulated. Two experiments (N = 24 adults in each) explored the time course of effects of associates (e.g., CARROT superimposed on a picture of a rabbit) versus coordinates (e.g., CHIPMUNK superimposed on a picture of a rabbit) on naming latencies. Associates led to faster picture naming than did unrelated words, with facilitative effects occurring at stimulus onset asynchronies (SOAs, in ms) ranging from -450 to 0. Coordinates led to slower naming latencies, with the interference effect restricted to SOAs of -150 and 0. The overlapping time course of associative priming and coordinate interference provides important constraints on models of lexical access in speech production. PMID:18726823

  20. Developmental Change in Proactive Interference.

    ERIC Educational Resources Information Center

    Kail, Robert

    2002-01-01

    Two studies examined age-related change in proactive interference from previously learned material. The meta-analysis of 26 studies indicated that proactive interference decreased with age. The cross-sectional study found that third through sixth graders' and college students' recall was accurate on Trial 1, but became less so over Trials 2…

  1. Interference Phenomenon with Mobile Displays

    ERIC Educational Resources Information Center

    Trantham, Kenneth

    2015-01-01

    A simple experiment is presented in which the spacing and geometric pattern of pixels in mobile displays is measured. The technique is based on optical constructive interference. While the experiment is another opportunity to demonstrate wave interference from a grating-like structure, this can also be used to demonstrate concepts of solid state…

  2. Output Interference in Recognition Memory

    ERIC Educational Resources Information Center

    Criss, Amy H.; Malmberg, Kenneth J.; Shiffrin, Richard M.

    2011-01-01

    Dennis and Humphreys (2001) proposed that interference in recognition memory arises solely from the prior contexts of the test word: Interference does not arise from memory traces of other words (from events prior to the study list or on the study list, and regardless of similarity to the test item). We evaluate this model using output…

  3. Serum indices: managing assay interference.

    PubMed

    Farrell, Christopher-John L; Carter, Andrew C

    2016-09-01

    Clinical laboratories frequently encounter samples showing significant haemolysis, icterus or lipaemia. Technical advances, utilizing spectrophotometric measurements on automated chemistry analysers, allow rapid and accurate identification of such samples. However, accurate quantification of haemolysis, icterus and lipaemia interference is of limited value if laboratories do not set rational alert limits, based on sound interference testing experiments. Furthermore, in the context of increasing consolidation of laboratories and the formation of laboratory networks, there is an increasing requirement for harmonization of the handling of haemolysis, icterus and lipaemia-affected samples across different analytical platforms. Harmonization may be best achieved by considering both the analytical aspects of index measurement and the possible variations in the effects of haemolysis, icterus and lipaemia interferences on assays from different manufacturers. Initial verification studies, followed up with ongoing quality control testing, can help a laboratory ensure the accuracy of haemolysis, icterus and lipaemia index results, as well as assist in managing any biases in index results from analysers from different manufacturers. Similarities, and variations, in the effect of haemolysis, icterus and lipaemia interference in assays from different manufacturers can often be predicted from the mechanism of interference. Nevertheless, interference testing is required to confirm expected similarities or to quantify differences. It is important that laboratories are familiar with a number of interference testing protocols and the particular strengths and weaknesses of each. A rigorous approach to all aspects of haemolysis, icterus and lipaemia interference testing allows the analytical progress in index measurement to be translated into improved patient care. PMID:27147624

  4. Supersonic Wave Interference Affecting Stability

    NASA Technical Reports Server (NTRS)

    Love, Eugene S.

    1958-01-01

    Some of the significant interference fields that may affect stability of aircraft at supersonic speeds are briefly summarized. Illustrations and calculations are presented to indicate the importance of interference fields created by wings, bodies, wing-body combinations, jets, and nacelles.

  5. Interference phenomenon with mobile displays

    NASA Astrophysics Data System (ADS)

    Trantham, Kenneth

    2015-07-01

    A simple experiment is presented in which the spacing and geometric pattern of pixels in mobile displays is measured. The technique is based on optical constructive interference. While the experiment is another opportunity to demonstrate wave interference from a grating-like structure, this can also be used to demonstrate concepts of solid state physics such as direct and reciprocal lattice vectors.

  6. Extreme ultraviolet Talbot interference lithography.

    PubMed

    Li, Wei; Marconi, Mario C

    2015-10-01

    Periodic nanopatterns can be generated using lithography based on the Talbot effect or optical interference. However, these techniques have restrictions that limit their performance. High resolution Talbot lithography is limited by the very small depth of focus and the demanding requirements in the fabrication of the master mask. Interference lithography, with large DOF and high resolution, is limited to simple periodic patterns. This paper describes a hybrid extreme ultraviolet lithography approach that combines Talbot lithography and interference lithography to render an interference pattern with a lattice determined by a Talbot image. As a result, the method enables filling the arbitrary shaped cells produced by the Talbot image with interference patterns. Detailed modeling, system design and experimental results using a tabletop EUV laser are presented. PMID:26480070

  7. Sagnac interference in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Bishara, Waheb; Refael, Gil; Bockrath, Marc

    2008-10-01

    The Sagnac interference mode arises when two interfering counterpropogating beams traverse a loop, but with their velocities detuned by a small amount 2u , with vR/L=vF±u . In this paper we perform a perturbative nonequilibrium calculation of Sagnac interference in single-channel wires as well as armchair nanotube loops. We study the dependence of the Sagnac conductance oscillations on temperature and interactions. We find that the Sagnac interference is not destroyed by strong interactions, but becomes weakly dependent on the velocity detuning u . In armchairs nanotubes with typical interaction strength, 0.25≤g≤0.5 , we find that the necessary temperature for observing the interference effect, TSAG is also only weakly dependent on the interaction, and is enhanced by a factor of 8 relative to the temperature necessary for observing Fabry-Pérot interference in the same system, TFP .

  8. Developmental change in proactive interference.

    PubMed

    Kail, Robert

    2002-01-01

    The aim of the present research was to examine age-related change in proactive interference, which refers to impaired recall due to interference from material presented previously. Study 1 was a meta-analysis based on 26 studies that included 82 data sets. The results indicated that proactive interference decreased between 4 and 13 years of age. In Study 2, children from grades 3 through 6 and college students (N = 125) were administered a short-term memory task in which they briefly remembered sets of three words. For all ages, recall was accurate on Trial 1. However, recall became less accurate over Trials 2 through 4, particularly for the younger children in the sample. In addition, structural equation modeling revealed that age-related change in interference was linked to age-related change in speed of information processing. Results are discussed in terms of the nature of age-related change in interference.

  9. The Mais Médicos (More Doctors) Program: the placement of physicians in priority municipalities in Brazil from 2013 to 2014.

    PubMed

    Oliveira, João Paulo Alves; Sanchez, Mauro Niskier; Santos, Leonor Maria Pacheco

    2016-09-01

    The inadequate placement and distribution of health professionals are problems that occur in various countries. The scope of the "Programa Mais Médicos" (More Doctors Program) was to reduce the shortfall of physicians and diminish regional inequalities in health. A descriptive study on the placement of physicians between 2013 and 2014 using the Ministry of Health database is presented. There was an allocation of 14,168 physicians to the 3,785 municipalities that signed up to the program: 2,377 met the priority and/or vulnerability criteria and received 77.7% of the physicians; 1,408 received 22.3% of the physicians, but did not meet the established priorities. This study reveals the reduction in the lack of physicians, mainly in the North and Northeast. These regions account for 36% of the Brazilian population and 46.3% of the physicians were allocated there. However, the introduction of an eligibility profile, which allocated 3,166 physicians in 1,408 non-priority municipalities is questionable. The conclusion drawn is that this may have hindered the ability of the Mais Médicos Program to fully achieve its objectives as a public policy aimed at reducing regional inequalities of access to primary healthcare. Further studies are necessary to evaluate the impact of the Mais Médicos Program. PMID:27653057

  10. Multifunctional coating MAI D5 intended for the protection of refractory materials

    NASA Astrophysics Data System (ADS)

    Zhestkov, B. E.; Terent'eva, V. S.

    2010-01-01

    A thin-layer heterophase MAI D5 coating intended for the protection of carbon-containing composite materials (C-C-, C-SiC-, SiC-SiC-composite material) and refractory metal-based alloys against high-temperature gas corrosion and erosion is tested. The coating is formed from a specially developed Si-Ti-Mo-B-Y microcomposition powder material. A new approach to creating self-healing heterophase coatings is used. At operating temperatures, the structure and phase composition of the MAI D5 coating provides rapid self-healing of random defects on the coating surface and in the base material owing to the presence of a silicon-containing eutectic, which favors rapid recovery of a protective amorphous silica layer consumed during operation. Under operating conditions, the coating undergoes self-organization to form a multilayer system with a number of functional oxide micro-, submicro-, and nanolayers. Samples with the MAI D5 coating are subjected to combined tests on bench plants located at MAI and TsAGI under conditions emulating the re-entry of a hypersonic aircraft, when its surface temperature reaches 2400 K. Certification tests are performed in wind tunnels located at TsAGI during a simultaneous action of a hypersonic dissociated-air flow and mechanical loads. The protection of heat-loaded structural elements in space vehicles made of ultrahigh-temperature materials against high-temperature gas corrosion and erosion by the MAI D5 coating in hypersonic dissociated-air flows is shown to be efficient.

  11. Human Health Impact of Fluoride in Groundwater in the Chiang Mai Basin

    NASA Astrophysics Data System (ADS)

    Matsui, Y.; Takizawa, S.; Wattanachira, S.; Wongrueng, A.; Ibaraki, M.

    2005-12-01

    Chiang Mai Basin, in Northern Thailand, is known as a fluorotic area. Groundwater of the Chiang Mai Basin has been gradually replaced by contaminated surface water since the 1980's. People have been exposed to fluoride contaminated groundwater since that time. As a result, harmful health effects on dental and skeletal growth were observed in the 90's. These include dental and skeletal fluorosis. Dental fluorosis is characterized by yellow or white spots on teeth and pitting or mottled enamel, consequently causing the teeth to look unsightly. Skeletal fluorosis leads to changes in bone structure, making them extremely weak and brittle. The most severe form of this is known as ``crippling skeletal fluorosis,'' a condition that can cause immobility, muscle wasting, and neurological problems related to spinal cord compression. This study focuses on the problematic issue of the Chiang Mai Basin's groundwater from the viewpoint of fluoride occurrence and current health impacts. Chiang Mai and Lamphun Provinces comprise the Chiang Mai Basin. Fluoride rich granites or fluorite deposits are scattered across the mountainside of the Lamphun Province. Tropical savanna climate conditions with seasonal monsoons bring more than 1,000 mm of annual precipitation, which can prompt weathering of minerals containing fluoride. The Ping River dominates the Basin, and the main eastern tributary of the Ping River runs through the Lamphun Province. The Basin has geological units composed of lower semi-consolidated Tertiary fluvial and upper unconsolidated Quaternary alluvium deposits. The main aquifers are in the upper unconsolidated unit. High fluoride concentrations tend to be observed in the aquifer located in lower part of this unconsolidated unit. We have been investigating two areas in the Basin. These two locations are similar with respect to geological and hydrological settings. However, one area in which groundwater is Ca-bicarbonate dominant has a low fluoride occurrence

  12. Optical interference with digital holograms

    NASA Astrophysics Data System (ADS)

    Gossman, David; Perez-Garcia, Benjamin; Hernandez-Aranda, Raul I.; Forbes, Andrew

    2016-07-01

    In 1804, Thomas Young reported the observation of fringes in the intensity of light, and attributed it to the concept of interference between coherent sources. In this paper, we revisit this famous experiment and show how it can easily be demonstrated with digital holography. We look closely at the concept of interference with light and ask, "fringes in what?" We then show that depending on how light interferes, fringe patterns in observables other than intensity can be seen. We explain this conceptually and demonstrate it experimentally. We provide a holistic approach to the topic, aided by modern laboratory practices for a straightforward demonstration of the underlying physics.

  13. Profiler/satellite interference analysis

    NASA Astrophysics Data System (ADS)

    Chadwick, R. B.

    1987-02-01

    An engineering analysis of potential radio interference between the Wind Profiler Demonstration Network and three NOAA satellite-based systems is presented. These three systems are: Geostationary Operational Environmental Satellite (GOES) system, the Search and Rescue Satellite (SARSAT) system, and the TIROS series Data Collection System (TDCS). The Profiler considered in this analysis is the UHF Wind Profiler to be supplied by Sperry Corporation under a contract awarded June 1986. The analysis is based on the interference-to-noise ratio at the satellite receiver. Several engineering changes have been made to the original contract to reduce potential interference. The effects of these changes are presented.

  14. 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…

  15. Knemidocoptes sp. on wild passerines at the Mai Po Nature Reserve, Hong Kong.

    PubMed

    Mainka, S A; Melville, D S; Galsworthy, A; Black, S R

    1994-04-01

    Free-ranging passerine birds banded at the Mai Po Nature Reserve, Hong Kong, were affected with a skin disease characterized by crusty, proliferative lesions on legs, feet and beaks. Based on retrospective examination of 1990 to 1992 banding records, 83 of 16,353 birds and 5 of 161 species banded at Mai Po were identified as having these lesions. Eurasian tree sparrows (Passer montanus) were most commonly affected (58 of 411 birds) although 19 of 428 black-faced buntings (Emberiza pusilla), 3 of 92 spotted doves (Streptopelia chinensis), and 2 of 616 eastern great reed warblers (Acrocephalus orientalis) also had clinical signs of infestation. Adult Eurasian tree sparrows were affected more often than juveniles and males were affected more often than females. Lesions on juveniles usually were on the feet while on adults lesions also were found on legs and beak. The effects of this parasitic infestation on body weight of wild Eurasian tree sparrows was not significant.

  16. 47 CFR 87.425 - Interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Airport Control Tower Stations § 87.425 Interference. Control towers and RCOs must not cause harmful interference to control towers or RCOs at adjacent airports. If interference between adjacent control towers...

  17. 47 CFR 87.425 - Interference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Airport Control Tower Stations § 87.425 Interference. Control towers and RCOs must not cause harmful interference to control towers or RCOs at adjacent airports. If interference between adjacent control towers...

  18. 47 CFR 87.425 - Interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Airport Control Tower Stations § 87.425 Interference. Control towers and RCOs must not cause harmful interference to control towers or RCOs at adjacent airports. If interference between adjacent control towers...

  19. Stimulus Structure, Discrimination, and Interference

    ERIC Educational Resources Information Center

    Runquist, Willard N.

    1975-01-01

    The general purpose of this experiment was to determine whether differences in stimulus discrimination, as determined by the MIR (missing-item recognition) test, are correlated with interference in recall, as demanded by the discriminative coding hypothesis. (Author/RK)

  20. Interference of quantum market strategies

    NASA Astrophysics Data System (ADS)

    Piotrowski, Edward W.; Sładkowski, Jan; Syska, Jacek

    2003-02-01

    Recent development in quantum computation and quantum information theory allows to extend the scope of game theory for the quantum world. The paper is devoted to the analysis of interference of quantum strategies in quantum market games.

  1. Optical interference with noncoherent states

    NASA Astrophysics Data System (ADS)

    Sagi, Yoav; Firstenberg, Ofer; Fisher, Amnon; Ron, Amiram

    2003-03-01

    We examine a typical two-source optical interference apparatus consisting of two cavities, a beam splitter, and two detectors. We show that field-field interference occurs even when the cavities are not initially in coherent states but rather in other nonclassical states. However, we find that the visibility of the second-order interference, that is, the expectation values of the detectors’ readings, changes from 100%, when the cavities are prepared in coherent states, to zero visibility when they are initially in single Fock states. We calculate the fourth-order interference, and for the latter case find that it corresponds to a case where the currents oscillate with 100% visibility, but with a random phase for every experiment. Finally, we suggest an experimental realization of the apparatus with nonclassical sources.

  2. Interference problems for nongeostationary satellites

    NASA Technical Reports Server (NTRS)

    Sollfrey, W.

    1984-01-01

    The interference problems faced by nongeostationary satellites may be of major significance. A general discussion indicates the scope of the problems and describes several configurations of importance. Computer programs are described, which are employed by NASA/JPL and the U.S. Air Force Satellite Control Facility to provide interference-free scheduling of commands and data transmission. Satellite system mission planners are not concerned with the precise prediction of interference episodes, but rather with the expected total amount of interference, the mean and maximum duration of events, and the mean spacing between episodes. The procedures in the theory of probability developed by the author which permit calculation of such quantities are described and applied to several real cases. It may be anticipated that the problems will become steadily worse in the future as more and more data transmissions attempt to occupy the same frequency band.

  3. Interference Colors in Thin Films.

    ERIC Educational Resources Information Center

    Armstrong, H. L.

    1979-01-01

    Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)

  4. 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…

  5. 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…

  6. Different Loci of Semantic Interference in Picture Naming vs. Word-Picture Matching Tasks.

    PubMed

    Harvey, Denise Y; Schnur, Tatiana T

    2016-01-01

    Naming pictures and matching words to pictures belonging to the same semantic category impairs performance relative to when stimuli come from different semantic categories (i.e., semantic interference). Despite similar semantic interference phenomena in both picture naming and word-picture matching tasks, the locus of interference has been attributed to different levels of the language system - lexical in naming and semantic in word-picture matching. Although both tasks involve access to shared semantic representations, the extent to which interference originates and/or has its locus at a shared level remains unclear, as these effects are often investigated in isolation. We manipulated semantic context in cyclical picture naming and word-picture matching tasks, and tested whether factors tapping semantic-level (generalization of interference to novel category items) and lexical-level processes (interactions with lexical frequency) affected the magnitude of interference, while also assessing whether interference occurs at a shared processing level(s) (transfer of interference across tasks). We found that semantic interference in naming was sensitive to both semantic- and lexical-level processes (i.e., larger interference for novel vs. old and low- vs. high-frequency stimuli), consistent with a semantically mediated lexical locus. Interference in word-picture matching exhibited stable interference for old and novel stimuli and did not interact with lexical frequency. Further, interference transferred from word-picture matching to naming. Together, these experiments provide evidence to suggest that semantic interference in both tasks originates at a shared processing stage (presumably at the semantic level), but that it exerts its effect at different loci when naming pictures vs. matching words to pictures.

  7. Different Loci of Semantic Interference in Picture Naming vs. Word-Picture Matching Tasks

    PubMed Central

    Harvey, Denise Y.; Schnur, Tatiana T.

    2016-01-01

    Naming pictures and matching words to pictures belonging to the same semantic category impairs performance relative to when stimuli come from different semantic categories (i.e., semantic interference). Despite similar semantic interference phenomena in both picture naming and word-picture matching tasks, the locus of interference has been attributed to different levels of the language system – lexical in naming and semantic in word-picture matching. Although both tasks involve access to shared semantic representations, the extent to which interference originates and/or has its locus at a shared level remains unclear, as these effects are often investigated in isolation. We manipulated semantic context in cyclical picture naming and word-picture matching tasks, and tested whether factors tapping semantic-level (generalization of interference to novel category items) and lexical-level processes (interactions with lexical frequency) affected the magnitude of interference, while also assessing whether interference occurs at a shared processing level(s) (transfer of interference across tasks). We found that semantic interference in naming was sensitive to both semantic- and lexical-level processes (i.e., larger interference for novel vs. old and low- vs. high-frequency stimuli), consistent with a semantically mediated lexical locus. Interference in word-picture matching exhibited stable interference for old and novel stimuli and did not interact with lexical frequency. Further, interference transferred from word-picture matching to naming. Together, these experiments provide evidence to suggest that semantic interference in both tasks originates at a shared processing stage (presumably at the semantic level), but that it exerts its effect at different loci when naming pictures vs. matching words to pictures. PMID:27242621

  8. Single Photon diffraction and interference

    NASA Astrophysics Data System (ADS)

    Hodge, John

    2015-04-01

    A previous paper based on the Scalar Theory of Everything studied photon diffraction and interference (IntellectualArchive, Vol.1, No. 3, P. 20, Toronto, Canada July 2012. http://intellectualarchive.com/?link=item&id=597). Several photons were required in the experiment at the same time. Interference experiments with one photon in the experiment at a time also showed interference patterns. The previous paper with the Bohm Interpretation, models of the screen and mask, and the Transaction Interpretation of Quantum Mechanics were combined. The reverse wave required by the Transaction Interpretation was provided by a reflected plenum wave rather than a reverse time wave. The speed of the plenum wave was assumed to be much faster than the speed of photons/light. Using the assumptions of Fraunhofer diffraction resulted in the same equation for the photon distribution on a screen as the intensity pattern of the Fraunhofer diffraction. (http://myplace.frontier.com/ ~ jchodge/)

  9. Whirling waves in Interference experiments

    NASA Astrophysics Data System (ADS)

    Sinha, Urbasi; Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna

    2014-03-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well- known text books in quantum mechanics implicitly and/or explicitly use this assumption, the wave function hypothesis, which is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from non-classical paths in interference experiments which provide a measurable deviation from the wave function hypothesis. A direct experimental demonstration for the existence of these non-classical paths is hard. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence. I will also describe some ongoing experimental efforts towards testing our theoretical findings.

  10. Design and Evaluation of a Virtual Quadrant Receiver for 4-ary Pulse Position Modulation/Optical Code Division Multiple Access (4-ary PPM/O-CDMA)

    SciTech Connect

    Mendez, A J; Hernandez, V J; Gagliardi, R M; Bennett, C V

    2006-12-29

    M-ary pulse position modulation (M-ary PPM) is an alternative to on-off-keying (OOK) that transmits multiple bits as a single symbol occupying a frame of M slots. PPM does not require thresholding as in OOK signaling, instead performing a comparison test among all slots in a frame to make the slot decision. Combining PPM with optical code division multiple access (PPM/O-CDMA) adds the benefit of supporting multiple concurrent, asynchronous bursty PPM users. While the advantages of PPM/O-CDMA are well known, implementing a receiver that performs comparison test can be difficult. This paper describes the design of a novel array receiver for M-ary PPM/O-CDMA (M = 4) where the received signal is mapped onto an xy-plane whose quadrants define the PPM slot decision by means of an associated control law. The receiver does not require buffering or nonlinear operations. In this paper we describe a planar lightwave circuit (PLCs) implementation of the receiver. We give detailed numerical simulations that test the concept and investigate the effects of multi-access interference (MAI) and optical beat interference (OBI) on the slot decisions. These simulations provide guidelines for subsequent experimental measurements that will be described.

  11. Interference of probabilities in dynamics

    SciTech Connect

    Zak, Michail

    2014-08-15

    A new class of dynamical systems with a preset type of interference of probabilities is introduced. It is obtained from the extension of the Madelung equation by replacing the quantum potential with a specially selected feedback from the Liouville equation. It has been proved that these systems are different from both Newtonian and quantum systems, but they can be useful for modeling spontaneous collective novelty phenomena when emerging outputs are qualitatively different from the weighted sum of individual inputs. Formation of language and fast decision-making process as potential applications of the probability interference is discussed.

  12. Interference-based molecular transistors

    PubMed Central

    Li, Ying; Mol, Jan A.; Benjamin, Simon C.; Briggs, G. Andrew D.

    2016-01-01

    Molecular transistors have the potential for switching with lower gate voltages than conventional field-effect transistors. We have calculated the performance of a single-molecule device in which there is interference between electron transport through the highest occupied molecular orbital and the lowest unoccupied molecular orbital of a single molecule. Quantum interference results in a subthreshold slope that is independent of temperature. For realistic parameters the change in gate potential required for a change in source-drain current of two decades is 20 mV, which is a factor of six smaller than the theoretical limit for a metal-oxide-semiconductor field-effect transistor. PMID:27646692

  13. Interference of diffusive light waves.

    PubMed

    Schmitt, J M; Knüttel, A; Knutson, J R

    1992-10-01

    We examine interference effects resulting from the superposition of photon-density waves produced by coherently modulated light incident upon a turbid medium. Photon-diffusion theory is used to derive expressions for the ac magnitude and phase of the aggregate diffusive wave produced in full- and half-space volumes by two sources. Using a frequency-domain spectrometer operating at 410 MHz, we verify interference patterns predicted by the model in scattering samples having optical properties similar to those of skin tissue. Potential imaging applications of interfering diffusive waves are discussed in the context of the theoretical and experimental results.

  14. [Progress of RNA interference mechanism].

    PubMed

    Yan, Fei; Cheng, Zhuo-Min

    2005-01-01

    RNA interference (RNAi) is a phenomenon that the double-stranded RNA (dsRNA) intermediates the degradation of complementary mRNA found in many organisms. This is a specifically mechanism involved in kinds of proteins to complete the interference function. Structure of siRNA affects which strand will be assembled into RISC. Another role of siRNA is directing RITS complex to bind with homologue chromosome, and then induces heterochromatinization. Although systemic silence induced by dsRNA is observed in Caenorhabditis elegans and plants, this progress is probably transmembrane protein-dependent, and mostly, the systemic silencing is controlled by multi-factors.

  15. Interference-based molecular transistors.

    PubMed

    Li, Ying; Mol, Jan A; Benjamin, Simon C; Briggs, G Andrew D

    2016-01-01

    Molecular transistors have the potential for switching with lower gate voltages than conventional field-effect transistors. We have calculated the performance of a single-molecule device in which there is interference between electron transport through the highest occupied molecular orbital and the lowest unoccupied molecular orbital of a single molecule. Quantum interference results in a subthreshold slope that is independent of temperature. For realistic parameters the change in gate potential required for a change in source-drain current of two decades is 20 mV, which is a factor of six smaller than the theoretical limit for a metal-oxide-semiconductor field-effect transistor. PMID:27646692

  16. Gaining Access.

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2000-01-01

    Discusses issues schools and universities have encountered in complying with the Americans with Disabilities Act (ADA) and making their facilities more accessible to the disabled. The ADA's vagueness and the architect's need for understanding the regulations is highlighted. (GR)

  17. 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)

  18. Capital access.

    PubMed

    Towne, Jennifer

    2004-06-01

    To maintain their viability, hospitals are being compelled to invest in big capital projects such as information technology and renovation and construction. This gatefold examines the trends in credit and capital, and how they affect hospitals' access to money.

  19. A survey on polycyclic aromatic hydrocarbon concentrations in soil in Chiang-Mai, Thailand

    SciTech Connect

    Amagai, Takashi; Takahashi, Yukari; Matsushita, Hidetsuru; Morknoy, D.; Sukasem, P.; Taucanon, M.

    1999-07-01

    Soil samples were collected at 30 sampling sites along roadsides in the city of Chiang-Mai, Thailand, in February 1996, and concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined. The distribution of PAH concentration in the soil samples was almost log-normal for all PAHs. Concentrations of pyrene (Py) and fluoranthene (Fluor) were the highest, followed by those of benzo[ghi]perylene and coronene (Cor). Since PAH concentrations were highest on the roadside where the traffic density was high, vehicles were the main determinants of PAH concentration in soil in Chiang-Mai. Significant correlations among PAH concentrations were found for almost all PAHs. PAH profiles in the air were different from those in the soil. For example, relative benzo[a]pyrene (BaP) concentration in the soil was significantly lower than that in the air. Relative concentrations of Fluor, Py, chrysene, and Cor in the soil were considerably higher than those in the air, due presumably to their difference in photochemical reactivities and in sources. The sampling of soil has advantages relative to that of air: (1) collection of soil is easy; (2) it needs no special equipment and electricity; (3) it takes little time; and (4) it can be collected anywhere. Therefore PAH analysis in soil was useful as a proxy-screening tool for air pollution levels with consideration of compositional differences between soil and air samples.

  20. STIGMA, SOCIAL SUPPORT, AND TREATMENT ADHERENCE AMONG HIV-POSITIVE PATIENTS IN CHIANG MAI, THAILAND

    PubMed Central

    Li, Michael Jonathan; Murray, Jordan Keith; Suwanteerangkul, Jiraporn; Wiwatanadate, Phongtape

    2016-01-01

    Our study assessed the influence of HIV-related stigma on treatment adherence among people living with HIV in Chiang Mai, Thailand, and whether social support had a moderating effect on this relationship. We recruited 128 patients living with HIV from Sansai Hospital, a community hospital in Chiang Mai, Thailand, and collected data through structured interviews. All forms of HIV-related stigma considered in this study (personalized experience, disclosure, negative self-image, and public attitudes) were negatively correlated with adherence to anti-retroviral regimens. Multiple linear regression indicated that total HIV-related stigma was more predictive of treatment adherence than any individual stigma type, after adjusting for socio-demographic and health characteristics. Tests of interaction showed that social support did not appear to moderate the association between HIV stigma and treatment adherence. Our findings suggest that community and government efforts to improve public perceptions about people living with HIV might promote treatment adherence behaviors among HIV-positive patients. PMID:25299810

  1. Epidemiology of cercarial stage of trematodes in freshwater snails from Chiang Mai province, Thailand

    PubMed Central

    Chontananarth, Thapana; Wongsawad, Chalobol

    2013-01-01

    Objective To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand. Methods The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012. The prevalence of cercarial infection in snails was investigated using the crushing method. The drawing was done with the help of a camera lucida for the morphological study. Results A total of 2 479 snail individuals were collected and classified into 7 families, 11 genera, and 14 species, Among them, 8 snails species were found to be infected with an overall prevalence of 17.27% (428/2 479), which infected with nine groups of cercariae; gymnocephalous cercaria, strigea cercaria, megalurous cercaria, monostome cercaria, parapleurolophocercous cercaria (Haplorchis cercaria), pleurolophocercous cercaria, furcocercous cercaria (Transversotrema cercaria), xiphidiocercaria, and virgulate cercaria. The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails (64.25%). Conclusions The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals. This work will provide new information on both the distribution and first intermediate host of trematodes. PMID:23620846

  2. DISCRIMINATION 28S RIBOSOMAL GENE OF TREMATODE CERCARIAE IN SNAILS FROM CHIANG MAI PROVINCE, THAILAND.

    PubMed

    Wongsawad, Chalobol; Wongsawad, Pheravut; Sukontason, Kom; Phalee, Anawat; Noikong-Phalee, Waraporn; Chai, Jong Yil

    2016-03-01

    Trematode cercariae are commonly found in many freshwater gastropods. These cercariae can serve to identify the occurrence of such trematodes as Centrocestus formosanus, Haplorchis taichui, Haplorchoides sp, and Stellantchasmus falcatus, which are important parasites in Chiang Mai Province, Thailand. As the species of these cercariae cannot be identified accurately based on morphology, this study employed sequencing of a fragment of 28S ribosomal DNA and phylogenetic analysis to identify the trematode cercariae found in freshwater gastropods in Chiang Mai Province. Eight types of trematode cercariae were identified, namely, distome cercaria (grouped with Philophthalmus spp clade), echinostome cercaria (grouped with Echinostoma spp clade), furcocercous cercaria (grouped with Posthodiplostomum sp/Alaria taxideae/Hysteromorpha triloba clade), monostome cercaria (grouped with Catatropis indicus clade), parapleurolophocercous cercaria (grouped with Haplorchoides sp clade), pleurolophocercous cercaria (grouped with Centrocestusformosanus clade), transversotrema cercaria (grouped with Transversotrema spp clade), and xiphidiocercaria (grouped with Prosthodendrium spp clade). These results provide important information that can be used for identifying these parasites in epidemiological surveys. PMID:27244956

  3. Subsequent Oophorectomy and Ovarian Cancer after Hysterectomy for Benign Gynecologic Conditions at Chiang Mai University Hospital.

    PubMed

    Jitkunnatumkul, Aurapin; Tantipalakorn, Charuwan; Charoenkwan, Kittipat; Srisomboon, Jatupol

    2016-01-01

    This study was undertaken to determine the incidence of subsequent oophorectomy due to ovarian pathology or ovarian cancer in women with prior hysterectomy for benign gynecologic conditions at Chiang Mai University Hospital. Medical records of women who underwent hysterectomy for benign gynecologic diseases and pre-cancerous lesions between January 1, 2004 and December 31, 2013 at Chiang Mai University Hospital were retrospectively reviewed. The incidence and indications of oophorectomy following hysterectomy were analyzed. During the study period, 1,035 women had hysterectomy for benign gynecologic conditions. Of these, 590 women underwent hysterectomy with bilateral salpingo-oophorectomy and 445 hysterectomy with bilateral ovarian preservation or unilateral salpingo-oophorectomy. The median age was 47 years (range, 11-75 years). Ten women (2.45 %) had subsequent oophorectomy for benign ovarian cysts. No case of ovarian cancer was found. The mean time interval between hysterectomy and subsequent oophorectomy was 43.1 months (range, 2-97 months) and the mean follow-up time for this patient cohort was 51 months (range, 1.3-124.9 months). According to our hospital-based data, the incidence of subsequent oophorectomy in women with prior hysterectomy for benign gynecologic conditions is low and all present with benign conditions. PMID:27644627

  4. Stigma, social support, and treatment adherence among HIV-positive patients in Chiang Mai, Thailand.

    PubMed

    Li, Michael Jonathan; Murray, Jordan Keith; Suwanteerangkul, Jiraporn; Wiwatanadate, Phongtape

    2014-10-01

    Our study assessed the influence of HIV-related stigma on treatment adherence among people living with HIV in Chiang Mai, Thailand, and whether social support had a moderating effect on this relationship. We recruited 128 patients living with HIV from Sansai Hospital, a community hospital in Chiang Mai, Thailand, and collected data through structured interviews. All forms of HIV-related stigma considered in this study (personalized experience, disclosure, negative self-image, and public attitudes) were negatively correlated with adherence to anti-retroviral regimens. Multiple linear regression indicated that total HIV-related stigma was more predictive of treatment adherence than any individual stigma type, after adjusting for socio-demographic and health characteristics. Tests of interaction showed that social support did not appear to moderate the association between HIV stigma and treatment adherence. Our findings suggest that community and government efforts to improve public perceptions about people living with HIV might promote treatment adherence behaviors among HIV-positive patients. PMID:25299810

  5. Suprasegmental Aspects of Reading Interference.

    ERIC Educational Resources Information Center

    Westbrook, Colston R.

    Information is presented in this paper regarding suprasegmental features of Black English thay may cause reading interference for some Black children. Much of the research concerning reading problems of many Afro-American students stresses the segmental differences of the phonology, the morphology, the syntax, and lexical selection between two…

  6. Political Interference in Climate Science

    NASA Astrophysics Data System (ADS)

    Kumar, Mohi

    2007-02-01

    ``All of us have a right to our own views about the seriousness of global warming,'' U.S. Rep. Henry Waxman (D-Calif.), chair of the House Oversight and Government Reform Committee, said at a 30 January committee hearing held to examine political interference in climate science. ``But we don't have a right to our own science.''

  7. "Quantum Interference with Slits" Revisited

    ERIC Educational Resources Information Center

    Rothman, Tony; Boughn, Stephen

    2011-01-01

    Marcella has presented a straightforward technique employing the Dirac formalism to calculate single- and double-slit interference patterns. He claims that no reference is made to classical optics or scattering theory and that his method therefore provides a purely quantum mechanical description of these experiments. He also presents his…

  8. Fano Interference in Classical Oscillators

    ERIC Educational Resources Information Center

    Satpathy, S.; Roy, A.; Mohapatra, A.

    2012-01-01

    We seek to illustrate Fano interference in a classical coupled oscillator by using classical analogues of the atom-laser interaction. We present an analogy between the dressed state picture of coherent atom-laser interaction and a classical coupled oscillator. The Autler-Townes splitting due to the atom-laser interaction is analogous to the…

  9. In planta gene expression analysis of Xanthomonas oryzae pathovar oryzae, African strain MAI1

    PubMed Central

    2010-01-01

    Background Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo), induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian X. oryzae pv. oryzicola (Xoc). Results Changes in gene expression of the African Xoo strain MAI1 in the susceptible rice cultivar Nipponbare were profiled, using an SSH Xoo DNA microarray. Microarray hybridization was performed comparing bacteria recovered from plant tissues at 1, 3, and 6 days after inoculation (dai) with bacteria grown in vitro. A total of 710 bacterial genes were found to be differentially expressed, with 407 up-regulated and 303 down-regulated. Expression profiling indicated that less than 20% of the 710 bacterial transcripts were induced in the first 24 h after inoculation, whereas 63% were differentially expressed at 6 dai. The 710 differentially expressed genes were one-end sequenced. 535 sequences were obtained from which 147 non-redundant sequences were identified. Differentially expressed genes were related to metabolism, secretion and transport, pathogen adherence to plant tissues, plant cell-wall degradation, IS elements, and virulence. In addition, various other genes encoding proteins with unknown function or showing no similarity to other proteins were also induced. The Xoo MAI1 non-redundant set of sequences was compared against several X. oryzae genomes, revealing a specific group of genes that was present only in MAI1. Numerous IS elements were also found to be differentially expressed. Quantitative real-time PCR confirmed 86% of the identified profile on a set of 14 genes selected according to the microarray analysis. Conclusions This is the first report to compare the expression of Xoo genes in planta across different time points during infection. This work shows that as-yet-unidentified and

  10. Saying the right word at the right time: Syntagmatic and paradigmatic interference in sentence production.

    PubMed

    Dell, Gary S; Oppenheim, Gary M; Kittredge, Audrey K

    2008-06-01

    Retrieving a word in a sentence requires speakers to overcome syntagmatic, as well as paradigmatic interference. When accessing cat in "The cat chased the string," not only are similar competitors such as dog and cap activated, but also other words in the planned sentence, such as chase and string. We hypothesize that both types of interference impact the same stage of lexical access, and review connectionist models of production that use an error-driven learning algorithm to overcome that interference. This learning algorithm creates a mechanism that limits syntagmatic interference, the syntactic "traffic cop," a configuration of excitatory and inhibitory connections from syntactic-sequential states to lexical units. We relate the models to word and sentence production data, from both normal and aphasic speakers. PMID:20622975

  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 access

  12. Implementation of integrated heterogeneous electronic electrocardiography data into Maharaj Nakorn Chiang Mai Hospital Information System.

    PubMed

    Khumrin, Piyapong; Chumpoo, Pitupoom

    2016-03-01

    Electrocardiography is one of the most important non-invasive diagnostic tools for diagnosing coronary heart disease. The electrocardiography information system in Maharaj Nakorn Chiang Mai Hospital required a massive manual labor effort. In this article, we propose an approach toward the integration of heterogeneous electrocardiography data and the implementation of an integrated electrocardiography information system into the existing Hospital Information System. The system integrates different electrocardiography formats into a consistent electrocardiography rendering by using Java software. The interface acts as middleware to seamlessly integrate different electrocardiography formats. Instead of using a common electrocardiography protocol, we applied a central format based on Java classes for mapping different electrocardiography formats which contains a specific parser for each electrocardiography format to acquire the same information. Our observations showed that the new system improved the effectiveness of data management, work flow, and data quality; increased the availability of information; and finally improved quality of care.

  13. Highland-lowland conflict over natural resources: a case of Mae Soi, Chiang Mai, Thailand.

    PubMed

    Tungittiplakorn, W

    1995-01-01

    Interviews were conducted among 150 Hmong highland and ethnic Thai lowland villagers during May-August 1992 in Chiang Mai in northern Thailand. Officials from national and international drug abuse control and development agencies were also interviewed. The aim was to determine the nature of the conflict between the highlanders and the lowlanders. The lowlanders perceived that the conflict was due to environmental causes brought on by the Hmongs' destruction of forest and pollution of the river. The Mai Soi stream that was relied on by lowlanders was viewed as threatened by drought and water reduction from forest destruction. Shinawatra researched water runoff from major rivers during seasonal changes and found reduced volume during 1970-80. Alford found no significant change in stream flow. 71% of lowlanders reported that stream flow was reduced over a 3-6 year period. 40% reported that the forests were fenced off in order to protect the forests, but 22% were forced by village headmen to do so. 32% were promised land in the allocation areas. The highlanders perceived the conflict in diverse ways. Many attributed the conflict to the murder of a lowlander cattle thief in a Hmong village in 1984. A 1983 report confirmed ethnic conflict and the killing and stealing of Hmong animals. Some highlanders and lowlanders believe the conflict arose due to one person, Ajahn Pongsak Techadhammo, who tried to create environmental awareness among all tribes and ethnic groups. He was against lowlanders' misuse of forests and wanted relocation of the hill tribes that cultivated opium. Social status differences fuel the conflict. Lowlanders consider themselves superior to hill tribes that do not speak Thai and are not Buddhists. The hill tribes create discord because of their economic success with cash crops. The authors recommend forest, soil, and water conservation among highlanders and lowlanders and broadening development to include other communities.

  14. EASI - EQUILIBRIUM AIR SHOCK INTERFERENCE

    NASA Technical Reports Server (NTRS)

    Glass, C. E.

    1994-01-01

    New research on hypersonic vehicles, such as the National Aero-Space Plane (NASP), has raised concerns about the effects of shock-wave interference on various structural components of the craft. State-of-the-art aerothermal analysis software is inadequate to predict local flow and heat flux in areas of extremely high heat transfer, such as the surface impingement of an Edney-type supersonic jet. EASI revives and updates older computational methods for calculating inviscid flow field and maximum heating from shock wave interference. The program expands these methods to solve problems involving the six shock-wave interference patterns on a two-dimensional cylindrical leading edge with an equilibrium chemically reacting gas mixture (representing, for example, the scramjet cowl of the NASP). The inclusion of gas chemistry allows for a more accurate prediction of the maximum pressure and heating loads by accounting for the effects of high temperature on the air mixture. Caloric imperfections and specie dissociation of high-temperature air cause shock-wave angles, flow deflection angles, and thermodynamic properties to differ from those calculated by a calorically perfect gas model. EASI contains pressure- and temperature-dependent thermodynamic and transport properties to determine heating rates, and uses either a calorically perfect air model or an 11-specie, 7-reaction reacting air model at equilibrium with temperatures up to 15,000 K for the inviscid flowfield calculations. EASI solves the flow field and the associated maximum surface pressure and heat flux for the six common types of shock wave interference. Depending on the type of interference, the program solves for shock-wave/boundary-layer interaction, expansion-fan/boundary-layer interaction, attaching shear layer or supersonic jet impingement. Heat flux predictions require a knowledge (from experimental data or relevant calculations) of a pertinent length scale of the interaction. Output files contain flow

  15. Measurement-induced decoherence and information in double-slit interference

    NASA Astrophysics Data System (ADS)

    Kincaid, Joshua; McLelland, Kyle; Zwolak, Michael

    2016-07-01

    The double slit experiment provides a classic example of both interference and the effect of observation in quantum physics. When particles are sent individually through a pair of slits, a wave-like interference pattern develops, but no such interference is found when one observes which "path" the particles take. We present a model of interference, dephasing, and measurement-induced decoherence in a one-dimensional version of the double-slit experiment. Using this model, we demonstrate how the loss of interference in the system is correlated with the information gain by the measuring apparatus/observer. In doing so, we give a modern account of measurement in this paradigmatic example of quantum physics that is accessible to students taking quantum mechanics at the graduate or senior undergraduate levels.

  16. Measurement-induced decoherence and information in double-slit interference

    PubMed Central

    Kincaid, Joshua; McLelland, Kyle; Zwolak, Michael

    2016-01-01

    The double slit experiment provides a classic example of both interference and the effect of observation in quantum physics. When particles are sent individually through a pair of slits, a wave-like interference pattern develops, but no such interference is found when one observes which “path” the particles take. We present a model of interference, dephasing, and measurement-induced decoherence in a one-dimensional version of the double-slit experiment. Using this model, we demonstrate how the loss of interference in the system is correlated with the information gain by the measuring apparatus/observer. In doing so, we give a modern account of measurement in this paradigmatic example of quantum physics that is accessible to students taking quantum mechanics at the graduate or senior undergraduate levels. PMID:27807373

  17. REM sleep rescues learning from interference.

    PubMed

    McDevitt, Elizabeth A; Duggan, Katherine A; Mednick, Sara C

    2015-07-01

    Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost. PMID:25498222

  18. REM sleep rescues learning from interference.

    PubMed

    McDevitt, Elizabeth A; Duggan, Katherine A; Mednick, Sara C

    2015-07-01

    Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost.

  19. 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.…

  20. 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.…

  1. 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…

  2. Silicon superconducting quantum interference device

    SciTech Connect

    Duvauchelle, J. E.; Francheteau, A.; Marcenat, C.; Lefloch, F.; Chiodi, F.; Débarre, D.; Hasselbach, K.; Kirtley, J. R.

    2015-08-17

    We have studied a Superconducting Quantum Interference Device (SQUID) made from a single layer thin film of superconducting silicon. The superconducting layer is obtained by heavily doping a silicon wafer with boron atoms using the gas immersion laser doping technique. The SQUID is composed of two nano-bridges (Dayem bridges) in a loop and shows magnetic flux modulation at low temperature and low magnetic field. The overall behavior shows very good agreement with numerical simulations based on the Ginzburg-Landau equations.

  3. Interference techniques in fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Dogan, Mehmet

    We developed a set of interference-based optical microscopy techniques to study biological structures through nanometer-scale axial localization of fluorescent biomarkers. Spectral self-interference fluorescence microscopy (SSFM) utilizes interference of direct and reflected waves emitted from fluorescent molecules in the vicinity of planar reflectors to reveal the axial position of the molecules. A comprehensive calculation algorithm based on Green's function formalism is presented to verify the validity of approximations used in a far-field approach that describes the emission of fluorescent markers near interfaces. Using the validated model, theoretical limits of axial localization were determined with emphasis given to numerical aperture (NA) dependence of localization uncertainty. SSFM was experimentally demonstrated in conformational analysis of nucleoproteins. In particular, interaction between surface-tethered 75-mer double strand DNA and integration host factor (IHF) protein was probed on Si-SiO2 substrates by determining the axial position of fluorescent labels attached to the free ends of DNA molecules. Despite its sub-nanometer precision axial localization capability, SSFM lacks high lateral resolution due to the low-NA requirement for planar reflectors. We developed a second technique, 4Pi-SSFM, which improves the lateral resolution of a conventional SSFM system by an order of magnitude while achieving nanometer-scale axial localization precision. Using two opposing high-NA objectives, fluorescence signal is interferometrically collected and spectral interference pattern is recorded. Axial position of emitters is found from analysis of the spectra. The 4Pi-SSFM technique was experimentally demonstrated by determining the surface profiles of fabricated glass surfaces and outer membranes of Shigella, a type of Gram-negative bacteria. A further discussion is presented to localize surface O antigen, which is an important oligosaccharide structure in the

  4. Oculomotor interference of bimodal distractors.

    PubMed

    Heeman, Jessica; Nijboer, Tanja C W; Van der Stoep, Nathan; Theeuwes, Jan; Van der Stigchel, Stefan

    2016-06-01

    When executing an eye movement to a target location, the presence of an irrelevant distracting stimulus can influence the saccade metrics and latency. The present study investigated the influence of distractors of different sensory modalities (i.e. auditory, visual and audiovisual) which were presented at various distances (i.e. close or remote) from a visual target. The interfering effects of a bimodal distractor were more pronounced in the spatial domain than in the temporal domain. The results indicate that the direction of interference depended on the spatial layout of the visual scene. The close bimodal distractor caused the saccade endpoint and saccade trajectory to deviate towards the distractor whereas the remote bimodal distractor caused a deviation away from the distractor. Furthermore, saccade averaging and trajectory deviation evoked by a bimodal distractor was larger compared to the effects evoked by a unimodal distractor. This indicates that a bimodal distractor evoked stronger spatial oculomotor competition compared to a unimodal distractor and that the direction of the interference depended on the distance between the target and the distractor. Together, these findings suggest that the oculomotor vector to irrelevant bimodal input is enhanced and that the interference by multisensory input is stronger compared to unisensory input. PMID:27164053

  5. Quantum interference in plasmonic circuits

    NASA Astrophysics Data System (ADS)

    Heeres, Reinier W.; Kouwenhoven, Leo P.; Zwiller, Valery

    2013-10-01

    Surface plasmon polaritons (plasmons) are a combination of light and a collective oscillation of the free electron plasma at metal/dielectric interfaces. This interaction allows subwavelength confinement of light beyond the diffraction limit inherent to dielectric structures. As a result, the intensity of the electromagnetic field is enhanced, with the possibility to increase the strength of the optical interactions between waveguides, light sources and detectors. Plasmons maintain non-classical photon statistics and preserve entanglement upon transmission through thin, patterned metallic films or weakly confining waveguides. For quantum applications, it is essential that plasmons behave as indistinguishable quantum particles. Here we report on a quantum interference experiment in a nanoscale plasmonic circuit consisting of an on-chip plasmon beamsplitter with integrated superconducting single-photon detectors to allow efficient single plasmon detection. We demonstrate a quantum-mechanical interaction between pairs of indistinguishable surface plasmons by observing Hong-Ou-Mandel (HOM) interference, a hallmark non-classical interference effect that is the basis of linear optics-based quantum computation. Our work shows that it is feasible to shrink quantum optical experiments to the nanoscale and offers a promising route towards subwavelength quantum optical networks.

  6. A POI-Based RFID Reader Deployment and Associated Interference Effect

    NASA Astrophysics Data System (ADS)

    An, Donghun; Yang, Hoongee; Yang, Sunghyun; Kim, Youngsoo; Yook, Jonggwan; Kang, Bongsoon

    This paper presents a simulation based method to predict the amount of frequency interference in a passive type RFID system. To judge occurrence of frequency interference, we use a parameter POI (probability of interference) that depends on several factors such as multiple access method, emission mask, the number of channel, etc. Due to its dependence on several factors, a Monte-carlo based simulation is suitably used. Through the simulation, we draw minimum separation distance between two readers and examine performance degradation due to aggregate interfering readers. Moreover, we present a reader deployment strategy based on the average POI of active readers operating in some area.

  7. 47 CFR 74.1203 - Interference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... cause limited interference to its primary station's signal, provided it does not disrupt the existing..., provided it does not disrupt the existing service of its primary station or cause such interference...

  8. Primary Salvage Survey of the Interference of Radiowaves Emitted by Smartphones on Medical Equipment.

    PubMed

    Takao, Hiroyuki; Yeh, Yu Chih; Arita, Hiroyuki; Obatake, Takumi; Sakano, Teppei; Kurihara, Minoru; Matsuki, Akira; Ishibashi, Toshihiro; Murayama, Yuichi

    2016-10-01

    Use of mobile phones has become a standard reality of everyday living for many people worldwide, including medical professionals, as data sharing has drastically helped to improve quality of care. This increase in the use of mobile phones within hospitals and medical facilities has raised concern regarding the influence of radio waves on medical equipment. Although comprehensive studies have examined the effects of electromagnetic interference from 2G wireless communication and personal digital cellular systems on medical equipment, similar studies on more recent wireless technologies such as Long Term Evolution, wideband code division multiple access, and high-speed uplink access have yet to be published. Numerous tests targeting current wireless technologies were conducted between December 2012 and March 2013 in an anechoic chamber, shielded from external radio signals, with a dipole antenna to assess the effects of smartphone interference on several types of medical equipment. The interference produced by electromagnetic waves across five frequency bands from four telecommunication standards was assessed on 49 components from 22 pieces of medical equipment. Of the 22 pieces of medical equipment tested, 13 experienced interference at maximum transmission power. In contrast, at minimum transmission power, the maximum interference distance varied from 2 to 5 cm for different wireless devices. Four machines were affected at the minimum transmission power, and the maximum interference distance at the maximum transmission power was 38 cm. Results show that the interference from smartphones on medical equipment is very controllable. PMID:27575351

  9. Primary Salvage Survey of the Interference of Radiowaves Emitted by Smartphones on Medical Equipment.

    PubMed

    Takao, Hiroyuki; Yeh, Yu Chih; Arita, Hiroyuki; Obatake, Takumi; Sakano, Teppei; Kurihara, Minoru; Matsuki, Akira; Ishibashi, Toshihiro; Murayama, Yuichi

    2016-10-01

    Use of mobile phones has become a standard reality of everyday living for many people worldwide, including medical professionals, as data sharing has drastically helped to improve quality of care. This increase in the use of mobile phones within hospitals and medical facilities has raised concern regarding the influence of radio waves on medical equipment. Although comprehensive studies have examined the effects of electromagnetic interference from 2G wireless communication and personal digital cellular systems on medical equipment, similar studies on more recent wireless technologies such as Long Term Evolution, wideband code division multiple access, and high-speed uplink access have yet to be published. Numerous tests targeting current wireless technologies were conducted between December 2012 and March 2013 in an anechoic chamber, shielded from external radio signals, with a dipole antenna to assess the effects of smartphone interference on several types of medical equipment. The interference produced by electromagnetic waves across five frequency bands from four telecommunication standards was assessed on 49 components from 22 pieces of medical equipment. Of the 22 pieces of medical equipment tested, 13 experienced interference at maximum transmission power. In contrast, at minimum transmission power, the maximum interference distance varied from 2 to 5 cm for different wireless devices. Four machines were affected at the minimum transmission power, and the maximum interference distance at the maximum transmission power was 38 cm. Results show that the interference from smartphones on medical equipment is very controllable.

  10. 47 CFR 27.1221 - Interference protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Interference protection. 27.1221 Section 27... Technical Standards § 27.1221 Interference protection. (a) Interference protection will be afforded to BRS... height benchmark (hbm). (c) Protection for receiving antennas not exceeding the height benchmark....

  11. 47 CFR 74.703 - Interference.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... station to correct any condition of interference which results from the radiation of radio frequency... a low-power TV or TV translator station causes interference to a CATV system by radiations within.... When a low-power TV or TV translator station causes interference to a BRS or EBS system by...

  12. 49 CFR 193.2633 - Interference currents.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2633 Interference currents. (a) Each component that is subject to electrical current interference must be protected by a continuing program to minimize the... 49 Transportation 3 2011-10-01 2011-10-01 false Interference currents. 193.2633 Section...

  13. 49 CFR 193.2633 - Interference currents.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2633 Interference currents. (a) Each component that is subject to electrical current interference must be protected by a continuing program to minimize the... 49 Transportation 3 2012-10-01 2012-10-01 false Interference currents. 193.2633 Section...

  14. 49 CFR 193.2633 - Interference currents.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2633 Interference currents. (a) Each component that is subject to electrical current interference must be protected by a continuing program to minimize the... 49 Transportation 3 2014-10-01 2014-10-01 false Interference currents. 193.2633 Section...

  15. 49 CFR 193.2633 - Interference currents.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2633 Interference currents. (a) Each component that is subject to electrical current interference must be protected by a continuing program to minimize the... 49 Transportation 3 2010-10-01 2010-10-01 false Interference currents. 193.2633 Section...

  16. 49 CFR 193.2633 - Interference currents.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: FEDERAL SAFETY STANDARDS Maintenance § 193.2633 Interference currents. (a) Each component that is subject to electrical current interference must be protected by a continuing program to minimize the... 49 Transportation 3 2013-10-01 2013-10-01 false Interference currents. 193.2633 Section...

  17. Questões mais freqüentes na área de astronomia

    NASA Astrophysics Data System (ADS)

    Segundo, H. A. S.; Garcia, G. C.; Caretta, C. A.; Lima, F. P.

    2003-08-01

    É amplamente reconhecido que as pessoas em geral têm grande fascínio e interesse pela Astronomia. Por outro lado, o conteúdo dessa área incluído no ensino formal está longe de ser abrangente e suficiente para suprir a demanda. Esse interesse permite otimizar a divulgação e o ensino não formal de Astronomia aliando a adequação do conteúdo à expectativa das pessoas. Nesse intuito, nosso trabalho busca mapear que assuntos da Astronomia despertam mais a atenção e o interesse das pessoas e o quanto disso é estimulado pela mídia, que freqüentemente aproveita-se desse interesse de forma sensacionalista, trazendo contribuições positivas e negativas. Para esta avaliação, utilizamos as pesquisas específicas e de caracterização do público que freqüentou o MAst nos anos de 2001 a 2003, pesquisa das matérias de Astronomia veiculadas na mídia escrita da cidade do Rio de Janeiro no mesmo período, além da base de dados do programa Pergunte a um astrônomo, realizado no Observatório Nacional nos anos de 1997 a 1999. Para a análise dos dados, dividimos as perguntas em dez categorias, cada uma com suas subcategorias, tomando como referência as divisões, comissões e grupos de trabalho da IAU. Apresentamos neste trabalho os resultados dessa pesquisa, que incluem, entre outros, a predominância de questões nas categorias Observação do Céu e Sistemas Planetários enquanto nos jornais dominam as notícias de Sistemas Planetários e Espaço & Astronáutica. Outro resultado interessante indicou que as dúvidas de crianças do ensino fundamental se concentram em algumas categorias enquanto as questões de adultos são mais distribuídas por todas as categorias. Os resultados dessa pesquisa serão aplicados diretamente no aperfeiçoamento das atividades do Programa de Observação de Céu, bem como na elaboração de novos projetos e eventos realizados no MAst.

  18. Spread-spectrum multiple access using wideband noncoherent MFSK

    NASA Astrophysics Data System (ADS)

    Ha, Tri T.; Pratt, Timothy; Maggenti, Mark A.

    1987-11-01

    Two spread-spectrum multiple access systems which use wideband M-ary frequency shift keying (FSK) (MFSK) as the primary modulation are presented. A bit error rate performance analysis is presented and system throughput is calculated for sample C band and Ku band satellite systems. Sample link analyses are included to illustrate power and adjacent satellite interference considerations in practical multiple access systems.

  19. Coital Experience Among Adolescents in Three Social-Educational Groups in Urban Chiang Mai, Thailand

    PubMed Central

    Tangmunkongvorakul, Arunrat; Carmichael, Gordon; Banwell, Cathy; Seubsman, Sam-ang; Sleigh, Adrian

    2012-01-01

    This article compares coital experience of Chiang Mai 17–20-year-olds who were: (1) out-of-school; (2) studying at vocational schools; and (3) studying at general schools or university. Four-fifths, two-thirds and one-third, respectively, of males in these groups had had intercourse, compared to 53, 62 and 15 per cent of females. The gender difference for general school/university students, but not vocational school students, probably reflects HIV/AIDS refocusing male sexual initiation away from commercial sex workers. Vocational school females may have been disproportionately affected. Loss of virginity was associated, for both sexes, with social-educational background and lifestyle, and was less likely in certain minority ethnic groups. Among males, it was also associated with age and parental marital dissolution, and among females, with independent living and parental disharmony. Within social-educational groups, lifestyle variables dominated, but among general school/university students, parental marital dissolution (for males) and disharmony (for females) were also important, and Chinese ethnicity deterred male sexual experimentation. PMID:22754584

  20. Molecular identification of larval trematode in intermediate hosts from Chiang Mai, Thailand.

    PubMed

    Chuboon, Suksan; Wongsawad, Chalobol

    2009-11-01

    Snail and fish intermediate hosts were collected from rice fields in 3 districts; Mueang, Mae Taeng and Mae Rim of Chiang Mai Province during April-July 2008. For identification of larval trematode infection, standard (cracked for snail and enzymatically digested for fish) and molecular methods were performed. The results showed that three types of cercariae were found, pleurolophocercus, cotylocercous, and echinostome among 4 species of snail with a prevalence of 29, 23 and 3% respectively. Melanoides tuberculata snail was the most susceptible host for cercariae infection. Four species of metacercariae, Haplorchis taichui, Stellantchasmus falcatus, Haplorchoides sp and Centrocestus caninus, were found with a prevalence of 67, 25, 60 and 20%, respectively. The Siamese mud carp (Henicorhynchus siamensis) was the most susceptible fish host for H. taichui, and half- beaked fish (Dermogenys pusillus) for S. falcatus metacercariae infection, whereas Haplorchoides sp and C. caninus were concomitantly found in Puntius brevis. HAT-RAPD profile confirmed that pleurolophocercus cercariae found in Melanoides tuberculata from Mae Taeng District belonged to H. taichui and in Tarebia granifera from Mueang District were S. falcatus.

  1. Forensic and phylogeographic characterization of mtDNA lineages from northern Thailand (Chiang Mai).

    PubMed

    Zimmermann, Bettina; Bodner, Martin; Amory, Sylvain; Fendt, Liane; Röck, Alexander; Horst, David; Horst, Basil; Sanguansermsri, Torpong; Parson, Walther; Brandstätter, Anita

    2009-11-01

    The immigration of diverse ethnic groups over the past centuries from surrounding countries into Thailand left footprints in the genetic composition of Thai mitochondrial DNA (mtDNA) lineages. The entire mtDNA control region (1,122 bp) was typed in 190 unrelated male volunteers from the northern Thailand province of Chiang Mai following highest quality standards. For a more precise haplogroup classification, selected single nucleotide polymorphisms from the mtDNA coding region were genotyped. We found several new, so far undescribed mtDNA lineages. Quasi-median networks were constructed for visualisation of character conflicts. The data were put into population-genetic relationships with other Southeast Asian populations. Although the frequencies of the Thai haplogroups were characteristic for Southeast Asia in terms of haplotype composition and genetic structure, the Thai population was significantly different from other Southeast Asian populations. This necessitates establishing regional databases, especially for forensic applications. The population data have been submitted to the EMPOP database (www.empop.org) and will be available on publication. PMID:19727793

  2. Soil-Gas Radon Anomaly Map of an Unknown Fault Zone Area, Chiang Mai, Northern Thailand

    NASA Astrophysics Data System (ADS)

    Udphuay, S.; Kaweewong, C.; Imurai, W.; Pondthai, P.

    2015-12-01

    Soil-gas radon concentration anomaly map was constructed to help detect an unknown subsurface fault location in San Sai District, Chiang Mai Province, Northern Thailand where a 5.1-magnitude earthquake took place in December 2006. It was suspected that this earthquake may have been associated with an unrecognized active fault in the area. In this study, soil-gas samples were collected from eighty-four measuring stations covering an area of approximately 50 km2. Radon in soil-gas samples was quantified using Scintrex Radon Detector, RDA-200. The samplings were conducted twice: during December 2014-January 2015 and March 2015-April 2015. The soil-gas radon map obtained from this study reveals linear NNW-SSE trend of high concentration. This anomaly corresponds to the direction of the prospective fault system interpreted from satellite images. The findings from this study support the existence of this unknown fault system. However a more detailed investigation should be conducted in order to confirm its geometry, orientation and lateral extent.

  3. Sexual identities and lifestyles among non-heterosexual urban Chiang Mai adolescents: implications for health

    PubMed Central

    Tangmunkongvorakul, Arunrat; Banwell, Cathy; Carmichael, Gordon; Utomo, Iwu Dwisetyani; Sleigh, Adrian

    2011-01-01

    Drawing upon quantitative and qualitative data we explore perspectives on and experiences of sexual lifestyles and relationships among more than 1,750 adolescents aged 17-20 years who reside in urban Chiang Mai, Thailand. We focus on respondents’ representations and understandings of their sexual/gender identities derived mainly from in-depth interviews and focus group discussions, supplemented with observations and field notes. Our results show that while many young Thais described themselves as heterosexual males or females others described themselves as gay, kathoey, tom, dii, bisexual or something else. Some were still questioning their own identities. The terms gay, kathoey, tom and dii are commonly used by these Thais to describe a range of sexual/gender identities relating to persons who are sexually or romantically attracted to the same biological sex. We use case studies to illustrate the distinctive characterizations, sexual lifestyles and relationships of each of these identities. We conclude that the sexual lifestyles encountered among Northern Thai non-heterosexual adolescents could lead to negative health consequences and indicated a need for improved relationship education, counselling and sensitive sexual health services. PMID:20665299

  4. Impulsive interference in communication channels and its mitigation by SPART and other nonlinear filters

    NASA Astrophysics Data System (ADS)

    Nikitin, Alexei V.; Epard, Marc; Lancaster, John B.; Lutes, Robert L.; Shumaker, Eric A.

    2012-12-01

    A strong digital communication transmitter in close physical proximity to a receiver of a weak signal can noticeably interfere with the latter even when the respective channels are tens or hundreds of megahertz apart. When time domain observations are made in the signal chain of the receiver between the first mixer and the baseband, this interference is likely to appear impulsive. The impulsive nature of this interference provides an opportunity to reduce its power by nonlinear filtering, improving the quality of the receiver channel. This article describes the mitigation, by a particular nonlinear filter, of the impulsive out-of-band (OOB) interference induced in High Speed Downlink Packet Access (HSDPA) by WiFi transmissions, protocols which coexist in many 3G smartphones and mobile hotspots. Our measurements show a decrease in the maximum error-free bit rate of a 1.95 GHz HSDPA receiver caused by the impulsive interference from an OOB 2.4 GHz WiFi transmission, sometimes down to a small fraction of the rate observed in the absence of the interference. We apply a nonlinear SPART filter to recover a noticeable portion of the lost rate and maintain an error-free connection under much higher levels of the WiFi interference than a receiver that does not contain such a filter. These measurements support our wider investigation of OOB interference resulting from digital modulation, which appears impulsive in a receiver, and its mitigation by nonlinear filters.

  5. IETS and quantum interference: Propensity rules in the presence of an interference feature

    SciTech Connect

    Lykkebo, Jacob; Solomon, Gemma C.; Gagliardi, Alessio; Pecchia, Alessandro

    2014-09-28

    Destructive quantum interference in single molecule electronics is an intriguing phenomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference effects in the transmission lead to either low current or a particular line shape in current-voltage curves, depending on the position of the interference feature. Second, we consider how inelastic electron tunneling spectroscopy can be used to probe the presence of an interference feature by identifying vibrational modes that are selectively suppressed when quantum interference effects dominate. That is, we expand the understanding of propensity rules in inelastic electron tunneling spectroscopy to molecules with destructive quantum interference.

  6. Hemodialysis access procedures

    MedlinePlus

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

  7. Measurement of slow-moving along-track displacement from an efficient multiple-aperture SAR interferometry (MAI) stacking

    USGS Publications Warehouse

    Jo, Min-Jeong; Jung, Hyung-Sup; Won, Joong-Sun; Poland, Michael; Miklius, Asta; Lu, Zhong

    2015-01-01

    Multiple-aperture SAR interferometry (MAI) has demonstrated outstanding measurement accuracy of along-track displacement when compared to pixel-offset-tracking methods; however, measuring slow-moving (cm/year) surface displacement remains a challenge. Stacking of multi-temporal observations is a potential approach to reducing noise and increasing measurement accuracy, but it is difficult to achieve a significant improvement by applying traditional stacking methods to multi-temporal MAI interferograms. This paper proposes an efficient MAI stacking method, where multi-temporal forward- and backward-looking residual interferograms are individually stacked before the MAI interferogram is generated. We tested the performance of this method using ENVISAT data from Kīlauea Volcano, Hawai‘i, where displacement on the order of several centimeters per year is common. By comparing results from the proposed stacking methods with displacements from GPS data, we documented measurement accuracies of about 1.03 and 1.07 cm/year for the descending and ascending tracks, respectively—an improvement of about a factor of two when compared with that from the conventional stacking approach. Three-dimensional surface-displacement maps can be constructed by combining stacked InSAR and MAI observations, which will contribute to a better understanding of a variety of geological phenomena.

  8. Long working distance interference microscope

    DOEpatents

    Sinclair, Michael B.; DeBoer, Maarten P.; Smith, Norman F.

    2004-04-13

    Disclosed is a long working distance interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. The long working distance of 10-30 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-D height profiles of MEMS test structures to be acquired across an entire wafer. A well-matched pair of reference/sample objectives is not required, significantly reducing the cost of this microscope, as compared to a Linnik microinterferometer.

  9. Perceptual interference decays over short unfilled intervals.

    PubMed

    Schulkind, M D

    2000-09-01

    The perceptual interference effect refers to the fact that object identification is directly related to the amount of information available at initial exposure. The present article investigated whether perceptual interference would dissipate when a short, unfilled interval was introduced between exposures to a degraded object. Across three experiments using both musical and pictorial stimuli, identification performance increased directly with the length of the unfilled interval. Consequently, significant perceptual interference was obtained only when the interval between exposures was relatively short (< 500 msec for melodies; < 300 msec for pictures). These results are consistent with explanations that attribute perceptual interference to increased perceptual noise created by exposures to highly degraded objects. The data also suggest that perceptual interference is mediated by systems that are not consciously controlled by the subject and that perceptual interference in the visual domain decays more rapidly than perceptual interference in the auditory domain. PMID:11105520

  10. Microwave Photonic Filters for Interference Cancellation and Adaptive Beamforming

    NASA Astrophysics Data System (ADS)

    Chang, John

    Wireless communication has experienced an explosion of growth, especially in the past half- decade, due to the ubiquity of wireless devices, such as tablets, WiFi-enabled devices, and especially smartphones. Proliferation of smartphones with powerful processors and graphic chips have given an increasing amount of people the ability to access anything from anywhere. Unfortunately, this ease of access has greatly increased mobile wireless bandwidth and have begun to stress carrier networks and spectra. Wireless interference cancellation will play a big role alongside the popularity of wire- less communication. In this thesis, we will investigate optical signal processing methods for wireless interference cancellation methods. Optics provide the perfect backdrop for interference cancellation. Mobile wireless data is already aggregated and transported through fiber backhaul networks in practice. By sandwiching the signal processing stage between the receiver and the fiber backhaul, processing can easily be done locally in one location. Further, optics offers the advantages of being instantaneously broadband and size, weight, and power (SWAP). We are primarily concerned with two methods for interference cancellation, based on microwave photonic filters, in this thesis. The first application is for a co-channel situation, in which a transmitter and receiver are co-located and transmitting at the same frequency. A novel analog optical technique extended for multipath interference cancellation of broadband signals is proposed and experimentally demonstrated in this thesis. The proposed architecture was able to achieve a maximum of 40 dB of cancellation over 200 MHz and 50 dB of cancellation over 10 MHz. The broadband nature of the cancellation, along with its depth, demonstrates both the precision of the optical components and the validity of the architecture. Next, we are interested in a scenario with dynamically changing interference, which requires an adaptive photonic

  11. Familiarity interferes with filial imprinting.

    PubMed

    van Kampen, H S; de Vos, G J

    1996-10-01

    The present study was performed to investigate whether and how pre-exposure to an object affects subsequent filial imprinting to that object. In Experiment 1 junglefowl chicks (Gallus gallus spadiceus) were first exposed to either a red object alone (control group), or a red and a yellow object simultaneously (experimental group; phase 1). Subsequently, all chicks were exposed to the yellow object in the presence of a black and blue one (phase 2). At the end of phase 1, most experimental chicks had developed a preference for the red object over the yellow one. At the end of phase 2, preferences of experimental chicks were shifted away from the yellow object towards the novel black and blue object, relative to preferences of control chicks. This shows that pre-exposure may interfere with imprinting. Experiment 2 revealed that when control chicks were tested with the yellow object at the end of phase 1, filial responses were as strong as in experimental chicks. This shows that the yellow object had not acquired control over filial behaviour during phase 1, and also that the relatively impaired imprinting on that object in phase 2 was not due to reduced generalization from the red object. One possible explanation why pre-exposure may interfere with imprinting is that familiarity alters the level of attention attracted by an object, a mechanism suggested to underlie 'latent inhibition' in conditioning. PMID:24897630

  12. Motor interference in interactive contexts

    PubMed Central

    Chinellato, Eris; Castiello, Umberto; Sartori, Luisa

    2015-01-01

    Action observation and execution share overlapping neural substrates, so that simultaneous activation by observation and execution modulates motor performance. Previous literature on simple prehension tasks has revealed that motor influence can be two-sided: facilitation for observed and performed congruent actions and interference for incongruent actions. But little is known of the specific modulations of motor performance in complex forms of interaction. Is it possible that the very same observed movement can lead either to interference or facilitation effects on a temporally overlapping congruent executed action, depending on the context? To answer this question participants were asked to perform a reach-to-grasp movement adopting a precision grip (PG) while: (i) observing a fixation cross, (ii) observing an actor performing a PG with interactive purposes, (iii) observing an actor performing a PG without interactive purposes. In particular, in the interactive condition the actor was shown trying to pour some sugar on a large cup located out of her reach but close to the participant watching the video, thus eliciting in reaction a complementary whole-hand grasp. Notably, fine-grained kinematic analysis for this condition revealed a specific delay in the grasping and reaching components and an increased trajectory deviation despite the observed and executed movement’s congruency. Moreover, early peaks of trajectory deviation seem to indicate that socially relevant stimuli are acknowledged by the motor system very early. These data suggest that interactive contexts can determine a prompt modulation of stimulus–response compatibility effects. PMID:26113835

  13. High Sensitivity Analysis of Nanoliter Volumes of Volatile and Nonvolatile Compounds using Matrix Assisted Ionization (MAI) Mass Spectrometry.

    PubMed

    Hoang, Khoa; Pophristic, Milan; Horan, Andrew J; Johnston, Murray V; McEwen, Charles N

    2016-10-01

    First results are reported using a simple, fast, and reproducible matrix-assisted ionization (MAI) sample introduction method that provides substantial improvements relative to previously published MAI methods. The sensitivity of the new MAI methods, which requires no laser, high voltage, or nebulizing gas, is comparable to those reported for MALDI-TOF and n-ESI. High resolution full acquisition mass spectra having low chemical background are acquired from low nanoliters of solution using only a few femtomoles of analyte. The limit-of-detection for angiotensin II is less than 50 amol on an Orbitrap Exactive mass spectrometer. Analysis of peptides, including a bovine serum albumin digest, and drugs, including drugs in urine without a purification step, are reported using a 1 μL zero dead volume syringe in which only the analyte solution wetting the walls of the syringe needle is used in the analysis. PMID:27349254

  14. High Sensitivity Analysis of Nanoliter Volumes of Volatile and Nonvolatile Compounds using Matrix Assisted Ionization (MAI) Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Hoang, Khoa; Pophristic, Milan; Horan, Andrew J.; Johnston, Murray V.; McEwen, Charles N.

    2016-10-01

    First results are reported using a simple, fast, and reproducible matrix-assisted ionization (MAI) sample introduction method that provides substantial improvements relative to previously published MAI methods. The sensitivity of the new MAI methods, which requires no laser, high voltage, or nebulizing gas, is comparable to those reported for MALDI-TOF and n-ESI. High resolution full acquisition mass spectra having low chemical background are acquired from low nanoliters of solution using only a few femtomoles of analyte. The limit-of-detection for angiotensin II is less than 50 amol on an Orbitrap Exactive mass spectrometer. Analysis of peptides, including a bovine serum albumin digest, and drugs, including drugs in urine without a purification step, are reported using a 1 μL zero dead volume syringe in which only the analyte solution wetting the walls of the syringe needle is used in the analysis.

  15. Sheng-mai-san reduces adriamycin-induced cardiomyopathy in rats.

    PubMed

    You, Jyh-Sheng; Huang, Hui-Feng; Chang, Ying-Ling; Lee, Ying-Shiung

    2006-01-01

    The traditional Chinese medicine prescription "sheng-mai-san (SMS)" has been used for treating patients with coronary heart disease for a long time and was found to have antioxidative effects. Here, we applied adriamycin (doxorubicin, ADR), a highly effective anticancer agent, as an inducer to establish the animal model of dose-related cardiomyopathy due to inhibition of nucleic acid as well as protein synthesis, formation of free radicals, and lipid peroxidation. The objective of this study was to investigate the protective effects of SMS on adriamycin-induced cardiomyopathy. Wistar rats were divided into four groups: CONT (control), ADR, SMS, and ADR + SMS. ADR (cumulative dose, 15 mg/kg) was administered to rats in six equal intraperitoneal injections over a period of 2 weeks and SMS was administered via a feeding tube throughout the mouth once a day for 30 days (cumulative dose, 150 g/kg). At the end of the 5-week post-treatment period, the hearts of the rats were surgically removed for the study of synthesis rates of DNA, RNA and proteins. Besides myocardial antioxidants, lipid peroxidation and morphological ultrastructure were also evaluated. Three weeks after the treatment, cardiomyopathy and congestive heart failure were characterized according to assessment in ascites, congested liver, depressed cardiac function and myocardial cell damage. The results demonstrated that nucleic acid as well as protein synthesis was inhibited, while lipid peroxidation was increased. Myocardial glutathione peroxidase (GSHPx) activity was decreased and electron microscopic examination revealed myocardial lesion indicative of ADR-induced cardiomyopathy. In contrast, administration of SMS before and concurrent with ADR significantly attenuated the myocardial effects. It also lowered mortality as well as the amount of ascites. In addition, indexes in myocardial GSHPx, macromolecular biosynthesis and superoxide dismutase activities were increasing, with a concomitant decrease in

  16. Assessment of a self-deferral form for screening blood donors, Chiang Mai University Hospital, Thailand.

    PubMed

    Thaikruea, Lakkana; Nantachit, Niwes; Leetrakool, Nipapan; Fongsatitkul, Ladda; Sompan, Prakai; Heaton, Andrew; Nelson, Kenrad E

    2008-09-01

    A self-deferral form has been used to screen Chiang Mai University Hospital blood donors and was improved in 2005. It has never been evaluated. The study aimed to assess the self-deferral form procedures in detecting infected donors. Sera from 5,083 donors, who passed the self-deferral screening form, were tested with the routine immuno-assays (serology) for HIV 1 and 2 antibodies, P24 antigen, HCV antibodies, HBV surface antigen, and syphilis. Antibody negative sera were also tested individually with the the Procleix Ultrio Assay for HIV-1 DNA, HCV RNA, and HBV DNA. The donors who had discrepant results between serology and NAT were evaluated with additional tests, including a more sensitive Alternative Nucleic Acid Test, AntiBcore IgM, AntiBcore IgG, HBsAg and Anti HBs. Among 5,083 donors, 331 (6.5%) had at least one positive marker. In multiple logistic regression analysis, the statistically significant factors (adjusted odds ratio and 95% CI) for infection were age 30 years or below [1.45 (1.03, 2.03)], male gender [2.73 (1.64, 4.56)], primary school or lower education [1.56 (1.09, 2.23)], first-time donation [1.82 (1.25, 2.67)], and frequent donation [0.80 (0.70, 0.92)]. The safest donors were females, older than 30 years, with an education more than primary school, and frequent donation. Because of missing responses to some sensitive questions, there remains a need for further improvement of the self-deferral form.

  17. Sheng-mai-san reduces adriamycin-induced cardiomyopathy in rats.

    PubMed

    You, Jyh-Sheng; Huang, Hui-Feng; Chang, Ying-Ling; Lee, Ying-Shiung

    2006-01-01

    The traditional Chinese medicine prescription "sheng-mai-san (SMS)" has been used for treating patients with coronary heart disease for a long time and was found to have antioxidative effects. Here, we applied adriamycin (doxorubicin, ADR), a highly effective anticancer agent, as an inducer to establish the animal model of dose-related cardiomyopathy due to inhibition of nucleic acid as well as protein synthesis, formation of free radicals, and lipid peroxidation. The objective of this study was to investigate the protective effects of SMS on adriamycin-induced cardiomyopathy. Wistar rats were divided into four groups: CONT (control), ADR, SMS, and ADR + SMS. ADR (cumulative dose, 15 mg/kg) was administered to rats in six equal intraperitoneal injections over a period of 2 weeks and SMS was administered via a feeding tube throughout the mouth once a day for 30 days (cumulative dose, 150 g/kg). At the end of the 5-week post-treatment period, the hearts of the rats were surgically removed for the study of synthesis rates of DNA, RNA and proteins. Besides myocardial antioxidants, lipid peroxidation and morphological ultrastructure were also evaluated. Three weeks after the treatment, cardiomyopathy and congestive heart failure were characterized according to assessment in ascites, congested liver, depressed cardiac function and myocardial cell damage. The results demonstrated that nucleic acid as well as protein synthesis was inhibited, while lipid peroxidation was increased. Myocardial glutathione peroxidase (GSHPx) activity was decreased and electron microscopic examination revealed myocardial lesion indicative of ADR-induced cardiomyopathy. In contrast, administration of SMS before and concurrent with ADR significantly attenuated the myocardial effects. It also lowered mortality as well as the amount of ascites. In addition, indexes in myocardial GSHPx, macromolecular biosynthesis and superoxide dismutase activities were increasing, with a concomitant decrease in

  18. RNA Interference for Antimetastatic Therapy.

    PubMed

    Dahlmann, Mathias; Stein, Ulrike

    2015-01-01

    The suppression of genes involved in tumor progression, metastasis formation, or therapy resistance by RNA interference is a promising tool to treat cancer disease. Efficient delivery of interfering molecules and their sustained presence in tumor cells are required for therapeutic success. This chapter describes a method of systemic application of shRNA expression plasmid via tail vein injection in xenograft mice, causing the sustained reduction of target gene expression in the primary tumor. By choosing S100A4 as a metastasis driving target gene, this therapeutic approach restricted the formation of distant colorectal cancer metastases after intrasplenic transplantation. In vivo imaging of bioluminescent cancer cells allows the monitoring of tumor growth and metastasis formation over time. End point analysis of the trial included scoring of the metastatic burden and the quantification of target gene expression in the tumor. Average S100A4 expression in tumor tissues was reduced by 30 %, causing a 70 % decrease of liver metastases. PMID:26072407

  19. Can bacterial interference prevent infection?

    PubMed

    Reid, G; Howard, J; Gan, B S

    2001-09-01

    The concept that one bacterial species can interfere with the ability of another to colonize and infect the host has at its foundation the prerequisite that bacteria must attach to biological surfaces to cause infection. Although this is an over-simplification of pathogenesis, it has led to studies aimed at creating vaccines that block adhesion events. Arguably, the use of commensal bacteria (also referred to as "normal flora", "indigenous" or "autochthonous" microorganisms) to inhibit pathogens has even greater potential than vaccine use, because these bacteria are natural competitors of pathogens and their action does not require host immune stimulation. Exogenous application of commensal organisms (probiotics) has been shown to reduce the risk of infections in the gut, urogenital tract and wound sites. To manipulate and optimize these effects, further studies are required to understand cell signaling amongst commensals and pathogens within biofilms adherent to host tissues. The potential for new therapeutic regimens using probiotics is significant and worthy of further study.

  20. RNA interference and antiviral therapy

    PubMed Central

    Ma, Yan; Chan, Chu-Yan; He, Ming-Liang

    2007-01-01

    RNA interference (RNAi) is an evolutionally conserved gene silencing mechanism present in a variety of eukaryotic species. RNAi uses short double-stranded RNA (dsRNA) to trigger degradation or translation repression of homologous RNA targets in a sequence-specific manner. This system can be induced effectively in vitro and in vivo by direct application of small interfering RNAs (siRNAs), or by expression of short hairpin RNA (shRNA) with non-viral and viral vectors. To date, RNAi has been extensively used as a novel and effective tool for functional genomic studies, and has displayed great potential in treating human diseases, including human genetic and acquired disorders such as cancer and viral infections. In the present review, we focus on the recent development in the use of RNAi in the prevention and treatment of viral infections. The mechanisms, strategies, hurdles and prospects of employing RNAi in the pharmaceutical industry are also discussed. PMID:17876887

  1. Application of an extension of the MAI method to the Acapulco City, Mexico

    NASA Astrophysics Data System (ADS)

    Contreras, M.; Aguirre, J.

    2001-12-01

    The site effects and the source parameters, are inverted from a Fourier displacement spectra of seismograms that are corrected by geometrical spreading and regional attenuation valid for south center of Mexico(Ordaz and Singh, 1992). We used Genetic Algorithms (GA) to perform the non-linear inversion, like in the MAI method (Moya et al., 2000) . The GA have proved to produce better results than other traditional methods which are frequently trapped in a local minimum. GA is a method that mimics the evolution laws in living creatures. The best individuals reproduce and develop themselves with every generation. In our case each individual correspond to one source and the genes correspond to the source parameters. As in nature, the best source remain and are improved with each iteration. We assume that the site effect at each station are the same independently of the earthquake, because of that we can search for the combination of sources that can produce the smaller standard deviation of the estimated site effects from the different Fourier displacement earthquake spectra. Then we use the obtained site effects to generate a Fourier displacement spectra of an earthquake scenario. With this, we are able to compute the response spectra by means of random vibration theory (Reinoso et al., 1990). We apply this method to four stations located in the Acapulco City, Mexico, that recorded four earthquakes with epicenter located in the Guerrero Subduction Zone. The site effect estimated for one of the stations, called ACAZ, shows a good agreement with the estimated by Chávez-García et al. (1994) using spectral ratios between the ACAZ station and a rock reference site. Also we compare the response spectra from other earthquake, obtained by the former method and the response spectra computed using the acceleration record. We find an acceptable correlation between them. Chávez-García, J. Cuenca y M. Cárdenas (1994), "Estudio complementario de efectos de sitio en Acapulco

  2. Improved Iterative Parallel Interference Cancellation Receiver for Future Wireless DS-CDMA Systems

    NASA Astrophysics Data System (ADS)

    Morosi, Simone; Fantacci, Romano; Bernacchioni, Andrea

    2005-12-01

    We present a new turbo multiuser detector for turbo-coded direct sequence code division multiple access (DS-CDMA) systems. The proposed detector is based on the utilization of a parallel interference cancellation (PIC) and a bank of turbo decoders. The PIC is broken up in order to perform interference cancellation after each constituent decoder of the turbo decoding scheme. Moreover, in the paper we propose a new enhanced algorithm that provides a more accurate estimation of the signal-to-noise-plus-interference-ratio used in the tentative decision device and in the MAP decoding algorithm. The performance of the proposed receiver is evaluated by means of computer simulations for medium to very high system loads, in AWGN and multipath fading channel, and compared to recently proposed interference cancellation-based iterative MUD, by taking into account the number of iterations and the complexity involved. We will see that the proposed receiver outperforms the others especially for highly loaded systems.

  3. MAI (Multi-Dimensional Activity Based Integrated Approach): A Strategy for Cognitive Development of the Learners at the Elementary Stage

    ERIC Educational Resources Information Center

    Basantia, Tapan Kumar; Panda, B. N.; Sahoo, Dukhabandhu

    2012-01-01

    Cognitive development of the learners is the prime task of each and every stage of our school education and its importance especially in elementary state is quite worth mentioning. Present study investigated the effectiveness of a new and innovative strategy (i.e., MAI (multi-dimensional activity based integrated approach)) for the development of…

  4. Saying the Right Word at the Right Time: Syntagmatic and Paradigmatic Interference in Sentence Production

    ERIC Educational Resources Information Center

    Dell, Gary S.; Oppenheim, Gary M.; Kittredge, Audrey K.

    2008-01-01

    Retrieving a word in a sentence requires speakers to overcome syntagmatic, as well as paradigmatic interference. When accessing "cat" in "The cat chased the string", not only are similar competitors such as "dog" and "cap" activated, but also other words in the planned sentence, such as "chase" and "string". We hypothesise that both types of…

  5. The perirhinal cortex and recognition memory interference

    PubMed Central

    Watson, H.C.; Lee, A. C. H.

    2013-01-01

    There has recently been an increase in interest in the effects of visual interference on memory processing, with the aim of eluciating the role of the perirhinal cortex (PRC) in recognition memory. One view argues that the PRC processes highly complex conjunctions of object features, and recent evidence from rodents suggests that these representations may be vital for buffering against the effects of pre-retrieval interference on object recognition memory. To investigate whether PRC-dependent object representations play a similar role in humans, we used functional magnetic resonance imaging to scan neurologically healthy participants while they carried out a novel interference-match-to-sample task. This paradigm was specifically designed to concurrently assess the impact of object vs. spatial interference, on recognition memory for objects or scenes, while keeping constant the amount of object and scene information presented across all trials. Activity at retrieval was examined, within an anatomically defined PRC region of interest, according to the demand for object or scene memory, following a period of object compared to spatial interference. Critically, we found greater PRC activity for object memory following object interference, compared to object memory following scene interference, and no difference between object and scene interference for scene recognition. These data demonstrate a role for the human PRC following a period of object, but not scene, interference, during object recognition memory, and emphasize the importance of representational content to mnemonic processing. PMID:23447626

  6. Hyperspectral imaging camera using wavefront division interference.

    PubMed

    Bahalul, Eran; Bronfeld, Asaf; Epshtein, Shlomi; Saban, Yoram; Karsenty, Avi; Arieli, Yoel

    2016-03-01

    An approach for performing hyperspectral imaging is introduced. The hyperspectral imaging is based on Fourier transform spectroscopy, where the interference is performed by wavefront division interference rather than amplitude division interference. A variable phase delay between two parts of the wavefront emanating from each point of an object is created by a spatial light modulator (SLM) to obtain variable interference patterns. The SLM is placed in the exit pupil of an imaging system, thus enabling conversion of a general imaging optical system into an imaging hyperspectral optical system. The physical basis of the new approach is introduced, and an optical apparatus is built. PMID:26974085

  7. Fiber-Optic Surface Temperature Sensor Based on Modal Interference.

    PubMed

    Musin, Frédéric; Mégret, Patrice; Wuilpart, Marc

    2016-01-01

    Spatially-integrated surface temperature sensing is highly useful when it comes to controlling processes, detecting hazardous conditions or monitoring the health and safety of equipment and people. Fiber-optic sensing based on modal interference has shown great sensitivity to temperature variation, by means of cost-effective image-processing of few-mode interference patterns. New developments in the field of sensor configuration, as described in this paper, include an innovative cooling and heating phase discrimination functionality and more precise measurements, based entirely on the image processing of interference patterns. The proposed technique was applied to the measurement of the integrated surface temperature of a hollow cylinder and compared with a conventional measurement system, consisting of an infrared camera and precision temperature probe. As a result, the optical technique is in line with the reference system. Compared with conventional surface temperature probes, the optical technique has the following advantages: low heat capacity temperature measurement errors, easier spatial deployment, and replacement of multiple angle infrared camera shooting and the continuous monitoring of surfaces that are not visually accessible. PMID:27483271

  8. Fiber-Optic Surface Temperature Sensor Based on Modal Interference

    PubMed Central

    Musin, Frédéric; Mégret, Patrice; Wuilpart, Marc

    2016-01-01

    Spatially-integrated surface temperature sensing is highly useful when it comes to controlling processes, detecting hazardous conditions or monitoring the health and safety of equipment and people. Fiber-optic sensing based on modal interference has shown great sensitivity to temperature variation, by means of cost-effective image-processing of few-mode interference patterns. New developments in the field of sensor configuration, as described in this paper, include an innovative cooling and heating phase discrimination functionality and more precise measurements, based entirely on the image processing of interference patterns. The proposed technique was applied to the measurement of the integrated surface temperature of a hollow cylinder and compared with a conventional measurement system, consisting of an infrared camera and precision temperature probe. As a result, the optical technique is in line with the reference system. Compared with conventional surface temperature probes, the optical technique has the following advantages: low heat capacity temperature measurement errors, easier spatial deployment, and replacement of multiple angle infrared camera shooting and the continuous monitoring of surfaces that are not visually accessible. PMID:27483271

  9. Proactive AP Selection Method Considering the Radio Interference Environment

    NASA Astrophysics Data System (ADS)

    Taenaka, Yuzo; Kashihara, Shigeru; Tsukamoto, Kazuya; Yamaguchi, Suguru; Oie, Yuji

    In the near future, wireless local area networks (WLANs) will overlap to provide continuous coverage over a wide area. In such ubiquitous WLANs, a mobile node (MN) moving freely between multiple access points (APs) requires not only permanent access to the Internet but also continuous communication quality during handover. In order to satisfy these requirements, an MN needs to (1) select an AP with better performance and (2) execute a handover seamlessly. To satisfy requirement (2), we proposed a seamless handover method in a previous study. Moreover, in order to achieve (1), the Received Signal Strength Indicator (RSSI) is usually employed to measure wireless link quality in a WLAN system. However, in a real environment, especially if APs are densely situated, it is difficult to always select an AP with better performance based on only the RSSI. This is because the RSSI alone cannot detect the degradation of communication quality due to radio interference. Moreover, it is important that AP selection is completed only on an MN, because we can assume that, in ubiquitous WLANs, various organizations or operators will manage APs. Hence, we cannot modify the APs for AP selection. To overcome these difficulties, in the present paper, we propose and implement a proactive AP selection method considering wireless link condition based on the number of frame retransmissions in addition to the RSSI. In the evaluation, we show that the proposed AP selection method can appropriately select an AP with good wireless link quality, i.e., high RSSI and low radio interference.

  10. Interference and the Law of Energy Conservation

    ERIC Educational Resources Information Center

    Drosd, Robert; Minkin, Leonid; Shapovalov, Alexander S.

    2014-01-01

    Introductory physics textbooks consider interference to be a process of redistribution of energy from the wave sources in the surrounding space resulting in constructive and destructive interferences. As one can expect, the total energy flux is conserved. However, one case of apparent non-conservation energy attracts great attention. Imagine that…

  11. 47 CFR 74.604 - Interference avoidance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Interference avoidance. 74.604 Section 74.604 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO... Stations § 74.604 Interference avoidance. (a) (b) Where two or more licensees are assigned a common...

  12. Is There Semantic Interference in Delayed Naming?

    ERIC Educational Resources Information Center

    Madebach, Andreas; Oppermann, Frank; Hantsch, Ansgar; Curda, Christian; Jescheniak, Jorg D.

    2011-01-01

    The semantic interference effect in the picture-word interference task is interpreted as an index of lexical competition in prominent speech production models. Janssen, Schirm, Mahon, and Caramazza (2008) challenged this interpretation on the basis of experiments with a novel version of this task, which introduced a task-switching component.…

  13. 47 CFR 74.1203 - Interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM DISTRIBUTIONAL SERVICES FM Broadcast Translator Stations and FM Broadcast Booster Stations § 74.1203 Interference. (a) An authorized FM translator or booster station will not be permitted to continue to operate if it causes any actual interference to: (1)...

  14. 47 CFR 74.1203 - Interference.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM DISTRIBUTIONAL SERVICES FM Broadcast Translator Stations and FM Broadcast Booster Stations § 74.1203 Interference. (a) An authorized FM translator or booster station will not be permitted to continue to operate if it causes any actual interference to: (1)...

  15. 47 CFR 74.1203 - Interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM DISTRIBUTIONAL SERVICES FM Broadcast Translator Stations and FM Broadcast Booster Stations § 74.1203 Interference. (a) An authorized FM translator or booster station will not be permitted to continue to operate if it causes any actual interference to: (1)...

  16. INDIVIDUAL DIFFERENCES IN LEARNING--INTERFERENCE FACTOR.

    ERIC Educational Resources Information Center

    JENSEN, ARTHUR R.

    AN INVESTIGATION WAS CONDUCTED (1) TO DEVISE A NUMBER OF LABORATORY MEASURES OF INDIVIDUAL DIFFERENCES IN SUSCEPTIBILITY TO INTERFERENCE EFFECTS IN LEARNING AND (2) TO DETERMINE THEIR DIMENSIONALITY IN A VARIETY OF INTERFERENCE EFFECTS. SUBJECTS WERE 530 STUDENTS IN INTRODUCTORY COURSES IN EDUCATIONAL PSYCHOLOGY AT THE UNIVERSITY OF CALIFORNIA,…

  17. The Nature and Diagnosis of Interference Phenomena.

    ERIC Educational Resources Information Center

    Denison, Norman

    1966-01-01

    The recognition of the systematic nature of the interference of the mother tongue when learning a second language is among the most significant advances in linguistics for the teaching and learning of foreign languages. The work of Weinreich showed that interference between language systems--the absorption of loan words, calques, and phonological,…

  18. Aerosol propellant interference with clinical mass spectrometers.

    PubMed

    Kharasch, E D; Sivarajan, M

    1991-04-01

    Metered dose inhalers containing halogenated propellants may interfere with mass spectrometer quantitation of halogenated inhalation anesthetics. We identify the propellant(s) in a commercially available metered dose inhaler that caused erroneous mass spectrometer readings. In addition, we identify the causes of different types of interference in different mass spectrometers. PMID:2072131

  19. The Contextual Interference Effect in Applied Settings

    ERIC Educational Resources Information Center

    Barreiros, Joao; Figueiredo, Teresa; Godinho, Mario

    2007-01-01

    This paper analyses the research literature that approaches the contextual interference effect in applied settings. In contrast to the laboratory settings, in which high interference conditions depress acquisition and promote learning evaluated in retention and transfer tests, in applied settings most of the studies (60%) fail to observe positive…

  20. Multimodality Imaging of RNA Interference

    PubMed Central

    Nayak, Tapas R.; Krasteva, Lazura K.; Cai, Weibo

    2013-01-01

    The discovery of small interfering RNAs (siRNAs) and their potential to knock down virtually any gene of interest has ushered in a new era of RNA interference (RNAi). Clinical use of RNAi faces severe limitations due to inefficiency delivery of siRNA or short hairpin RNA (shRNA). Many molecular imaging techniques have been adopted in RNAi-related research for evaluation of siRNA/shRNA delivery, biodistribution, pharmacokinetics, and the therapeutic effect. In this review article, we summarize the current status of in vivo imaging of RNAi. The molecular imaging techniques that have been employed include bioluminescence/fluorescence imaging, magnetic resonance imaging/spectroscopy, positron emission tomography, single-photon emission computed tomography, and various combinations of these techniques. Further development of non-invasive imaging strategies for RNAi, not only focusing on the delivery of siRNA/shRNA but also the therapeutic efficacy, is critical for future clinical translation. Rigorous validation will be needed to confirm that biodistribution of the carrier is correlated with that of siRNA/shRNA, since imaging only detects the label (e.g. radioisotopes) but not the gene or carrier themselves. It is also essential to develop multimodality imaging approaches for realizing the full potential of therapeutic RNAi, as no single imaging modality may be sufficient to simultaneously monitor both the gene delivery and silencing effect of RNAi. PMID:23745567

  1. ``Quantum'' interference with bouncing drops

    NASA Astrophysics Data System (ADS)

    Bohr, Tomas; Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens

    2013-11-01

    In a series of recent papers (most recently) Yves Couder and collaborators have explored the dynamics of walking drops on the surface of a vibrated bath of silicon oil and have demonstrated a close analogy to quantum phenomena. The bouncing drop together with the surface wave that it excites seems to be very similar to the pilot wave envisaged by de Broglie for quantum particles. In particular, have studied a double slit experiment with walking drops, where an interference pattern identical to the quantum version is found even though it is possible to follow the orbits of the drops and unambigously determine which slit it goes through, something which in quantum mechanics would be ruled out by the Heisenberg uncertainly relations. We have repeated the experiment and present a somewhat more complicated picture. Theoretically, we study a Schrödinger equation with a source term originating from a localised ``particle'' being simultaneously guided by the wave. We present simple solutions to such a field theory and discuss the fundamental difficulties met by such a theory in order to comply with quantum mechanics.

  2. Interference competition and parasite virulence.

    PubMed Central

    Massey, Ruth C.; Buckling, Angus; ffrench-Constant, Richard

    2004-01-01

    Within-host competition between parasites, a consequence of infection by multiple strains, is predicted to favour rapid host exploitation and greater damage to hosts (virulence). However, the inclusion of biological variables can drastically change this relationship. For example, if competing parasite strains produce toxins that kill each other (interference competition), their growth rates and virulence may be reduced relative to single-strain infections. Bacteriocins are antimicrobial toxins produced by bacteria that target closely related strains and species, and to which the producing strain is immune. We investigated competition between bacteriocin-producing, insect-killing bacteria (Photorhabdus and Xenorhabdus) and how this competition affected virulence in caterpillars. Where one strain could kill the other, and not vice versa, the non-killing strain was competitively excluded, and insect mortality was the same as that of the killing strain alone. However, when caterpillars were multiply infected by strains that could kill each other, we did not observe competitive exclusion and their virulence was less than single-strain infections. The ubiquity and diversity of bacteriocins among pathogenic bacteria suggest mixed infections will be, on average, less virulent than single infections. PMID:15255095

  3. Phonon-Mediated Nonclassical Interference in Diamond

    NASA Astrophysics Data System (ADS)

    England, Duncan G.; Fisher, Kent A. G.; MacLean, Jean-Philippe W.; Bustard, Philip J.; Heshami, Khabat; Resch, Kevin J.; Sussman, Benjamin J.

    2016-08-01

    Quantum interference of single photons is a fundamental aspect of many photonic quantum processing and communication protocols. Interference requires that the multiple pathways through an interferometer be temporally indistinguishable to within the coherence time of the photon. In this Letter, we use a diamond quantum memory to demonstrate interference between quantum pathways, initially temporally separated by many multiples of the optical coherence time. The quantum memory can be viewed as a light-matter beam splitter, mapping a THz-bandwidth single photon to a variable superposition of the output optical mode and stored phononic mode. Because the memory acts both as a beam splitter and as a buffer, the relevant coherence time for interference is not that of the photon, but rather that of the memory. We use this mechanism to demonstrate nonclassical single-photon and two-photon interference between quantum pathways initially separated by several picoseconds, even though the duration of the photons themselves is just ˜250 fs .

  4. RNA Interference in Chicken Embryos

    NASA Astrophysics Data System (ADS)

    van Hateren, Nick J.; Jones, Rachel S.; Wilson, Stuart A.

    The chicken has played an important role in biological discoveries since the 17th century (Stern, 2005). Many investigations into vertebrate development have utilized the chicken due to the accessibility of the chick embryo and its ease of manipulation (Brown et al., 2003). However, the lack of genetic resources has often handicapped these studies and so the chick is frequently overlooked as a model organism for the analysis of vertebrate gene function in favor of mice or zebrafish. In the past six years this situation has altered dramatically with the generation of over half a million expressed sequence tags and >20,000 fully sequenced chicken cDNAs (Boardman et al. 2002; Caldwell et al., 2005; Hubbard et al., 2005) together with a 6X coverage genome sequence (Hillier et al., 2004). These resources have created a comprehensive catalogue of chicken genes with readily accessible cDNA and EST resources available via ARK-GENOMICS (www.ark-genomics.org) for the functional analysis of vertebrate gene function.

  5. Characteristics of the distribution of doctors in the Mais Médicos (More Doctors) Program in the states of Brazil's Northeast.

    PubMed

    Nogueira, Priscila Tamar Alves; Bezerra, Adriana Falangola Benjamin; Leite, Antonio Flaudiano Bem; Carvalho, Islândia Maria de Sousa; Gonçalves, Rogério Fabiano; Brito-Silva, Keila Silene de

    2016-09-01

    Inequalities in access to health, reflecting shortages and inadequate geographical distribution of health professionals, have been indicated as a challenge for Brazil. This paper analyzes the geographical distribution of professionals of the Mais Médicos Program allocated in the Northeastern Region of Brazil, through a descriptive cross-sectional study. Secondary data provided by the Health Ministry were used, and thematic maps of distribution of doctors in the Region were prepared. Data on 4,716 doctors who became members of health teams in 1,294 municipalities in six Indigenous Health Districts in the years 2013 and 2014 were analyzed. The greater part of the municipalities of the Region received between one and five doctors. The municipalities most benefited had, at least, 20% of their population in extreme poverty. 99.9% of the doctors were allocated in a Health Center or Primary Healthcare Unit. The majority were women (57%), predominantly of the 45-49 age group (24%). In spite of the advances achieved by the Program - such as distribution of the doctors in locations with greater vulnerability - some States continue to have significant shortages of healthcare.

  6. Characteristics of the distribution of doctors in the Mais Médicos (More Doctors) Program in the states of Brazil's Northeast.

    PubMed

    Nogueira, Priscila Tamar Alves; Bezerra, Adriana Falangola Benjamin; Leite, Antonio Flaudiano Bem; Carvalho, Islândia Maria de Sousa; Gonçalves, Rogério Fabiano; Brito-Silva, Keila Silene de

    2016-09-01

    Inequalities in access to health, reflecting shortages and inadequate geographical distribution of health professionals, have been indicated as a challenge for Brazil. This paper analyzes the geographical distribution of professionals of the Mais Médicos Program allocated in the Northeastern Region of Brazil, through a descriptive cross-sectional study. Secondary data provided by the Health Ministry were used, and thematic maps of distribution of doctors in the Region were prepared. Data on 4,716 doctors who became members of health teams in 1,294 municipalities in six Indigenous Health Districts in the years 2013 and 2014 were analyzed. The greater part of the municipalities of the Region received between one and five doctors. The municipalities most benefited had, at least, 20% of their population in extreme poverty. 99.9% of the doctors were allocated in a Health Center or Primary Healthcare Unit. The majority were women (57%), predominantly of the 45-49 age group (24%). In spite of the advances achieved by the Program - such as distribution of the doctors in locations with greater vulnerability - some States continue to have significant shortages of healthcare. PMID:27653073

  7. The Mais Médicos (More Doctors) Program, the infrastructure of Primary Health Units and the Municipal Human Development Index.

    PubMed

    Soares, Joaquim José; Machado, Maria Helena; Alves, Cecília Brito

    2016-09-01

    The main objective of this article was to examine the context in which professionals working within the Mais Médicos (More Doctors) Program operate. This study used the infrastructure scale of primary health units (PHUs), which was recently developed by Soares Neto and colleagues to provide more information regarding the relationship between the infrastructure of PHUs and the Municipal Human Development Index (MHDI) of municipalities that received Mais Médicos Program doctors. Using exploratory and inferential statistics, the article shows that 65.2% of the PHUs that received Mais Médicos Program doctors had medium-quality infrastructure and only 5.8% of them had low-quality infrastructure. The correlation of 0.50 between the infrastructure indicator and the MHDI points to a moderate tendency for municipalities with low MHDIs to have more precarious PHUs. Using multiple linear regression analysis it can be inferred that the main factor that contributed to the increase in the infrastructure indicator of the PHUs was the average municipal income. On the other hand, the factor that negatively affected the infrastructure of the PHUs was being located in the north or northeast regions. PMID:27653056

  8. The Mais Médicos (More Doctors) Program, the infrastructure of Primary Health Units and the Municipal Human Development Index.

    PubMed

    Soares, Joaquim José; Machado, Maria Helena; Alves, Cecília Brito

    2016-09-01

    The main objective of this article was to examine the context in which professionals working within the Mais Médicos (More Doctors) Program operate. This study used the infrastructure scale of primary health units (PHUs), which was recently developed by Soares Neto and colleagues to provide more information regarding the relationship between the infrastructure of PHUs and the Municipal Human Development Index (MHDI) of municipalities that received Mais Médicos Program doctors. Using exploratory and inferential statistics, the article shows that 65.2% of the PHUs that received Mais Médicos Program doctors had medium-quality infrastructure and only 5.8% of them had low-quality infrastructure. The correlation of 0.50 between the infrastructure indicator and the MHDI points to a moderate tendency for municipalities with low MHDIs to have more precarious PHUs. Using multiple linear regression analysis it can be inferred that the main factor that contributed to the increase in the infrastructure indicator of the PHUs was the average municipal income. On the other hand, the factor that negatively affected the infrastructure of the PHUs was being located in the north or northeast regions.

  9. Applying contextual interference to the Pawlata roll.

    PubMed

    Smith, P J; Davies, M

    1995-12-01

    Contextual interference is manipulated by changing the practice order of a number of similar motor tasks, so that the learning context of each interferes with that of the other. The effect has been found to generalize to baseball batting, badminton serving and volleyball skills. The present study examined whether this practice technique could be applied to a Pawlata roll in a kayak. The study was further motivated by the fact that many instructors in Britain currently advocate learning the Pawlata roll in one direction only to a criterion of accuracy, thereafter transferring to the opposite direction. Contextual interference literature predicts that skill retention would be better served by practising on alternate sides. Accordingly, 16 undergraduate students with no kayaking experience were randomly allocated to either a low contextual interference group, which followed U'ren's (1993) recommendations, or a high contextual interference group, which practised the skill on alternate sides. The high contextual interference group took less time to acquire the skill, and were also quicker to achieve successful performance in retention (full roll) and transfer (half roll) tests, regardless of the direction of the roll, 1 week later. The time savings in practice were not expected, as acquisition under high contextual interference was improved rather than impaired. This finding suggests that bilateral transfer was increased by randomizing practice. These results are worthy of further investigation, in that they suggest that the recommended training methods may not be optimal. PMID:8850571

  10. Applying contextual interference to the Pawlata roll.

    PubMed

    Smith, P J; Davies, M

    1995-12-01

    Contextual interference is manipulated by changing the practice order of a number of similar motor tasks, so that the learning context of each interferes with that of the other. The effect has been found to generalize to baseball batting, badminton serving and volleyball skills. The present study examined whether this practice technique could be applied to a Pawlata roll in a kayak. The study was further motivated by the fact that many instructors in Britain currently advocate learning the Pawlata roll in one direction only to a criterion of accuracy, thereafter transferring to the opposite direction. Contextual interference literature predicts that skill retention would be better served by practising on alternate sides. Accordingly, 16 undergraduate students with no kayaking experience were randomly allocated to either a low contextual interference group, which followed U'ren's (1993) recommendations, or a high contextual interference group, which practised the skill on alternate sides. The high contextual interference group took less time to acquire the skill, and were also quicker to achieve successful performance in retention (full roll) and transfer (half roll) tests, regardless of the direction of the roll, 1 week later. The time savings in practice were not expected, as acquisition under high contextual interference was improved rather than impaired. This finding suggests that bilateral transfer was increased by randomizing practice. These results are worthy of further investigation, in that they suggest that the recommended training methods may not be optimal.

  11. Signal enhancement in AM-FM interference

    NASA Astrophysics Data System (ADS)

    Quantieri, Thomas F.; Dunn, Robert B.; McAulay, Robert J.

    1994-05-01

    A new approach to interference suppression is developed to enhance the audibility of signals corrupted by amplitude-modulated (AM) and frequency-modulated (FM) tonal interference. The suppression algorithm uses a short-time, least-squares estimation of the parameters of an AM-FM model of the time-varying tonal interference. The method, developed in a sine-wave analysis/synthesis framework, can be integrated with time and frequency modifications for further signal enhancement. Suppression is applied to single and multitone synthetic and actual AM-FM interference, the latter including man-made signals (e.g., siren interference) and those that occur naturally (e.g., biologic interference). The relative advantages and disadvantages of the sine-wave framework in contrast to a short-time Fourier transform overlap-add framework are described. The enhancement techniques are robust in a large range of environments and can be designed to preserve a random noise background. Finally, it is shown that interference suppression on multichannels prior to beamforming enhances beamformer performance.

  12. Revisiting speech interference in classrooms.

    PubMed

    Picard, M; Bradley, J S

    2001-01-01

    A review of the effects of ambient noise and reverberation on speech intelligibility in classrooms has been completed because of the long-standing lack of agreement on preferred acoustical criteria for unconstrained speech accessibility and communication in educational facilities. An overwhelming body of evidence has been collected to suggest that noise levels in particular are usually far in excess of any reasonable prescription for optimal conditions for understanding speech in classrooms. Quite surprisingly, poor classroom acoustics seem to be the prevailing condition for both normally-hearing and hearing-impaired students with reported A-weighted ambient noise levels 4-37 dB above values currently agreed upon to provide optimal understanding. Revision of currently proposed room acoustic performance criteria to ensure speech accessibility for all students indicates the need for a guideline weighted for age and one for more vulnerable groups. For teens (12-year-olds and older) and young adults having normal speech processing in noise, ambient noise levels not exceeding 40 dBA are suggested as acceptable, and reverberation times of about 0.5 s are concluded to be optimum. Younger students, having normal speech processing in noise for their age, would require noise levels ranging from 39 dBA for 10-11-year-olds to only 28.5 dBA for 6-7-year-olds. By contrast, groups suspected of delayed speech processing in noise may require levels as low as only 21.5 dBA at age 6-7. As one would expect, these more vulnerable students would include the hearing-impaired in the course of language development and non-native listeners. PMID:11688542

  13. Gas Interference in Sucker Rod Pump

    NASA Astrophysics Data System (ADS)

    Samad, Abdus

    2010-10-01

    Commonly used artificial lift or dewatering system is sucker rod pump and gas interference of the pump is the biggest issue in the oil and gas industry. Gas lock or fluid pound problems occur due to the gas interference when the pump has partially or completely unfilled plunger barrel. There are several techniques available in the form of patents to solve these problems but those techniques have positive as well as negative aspects. Some of the designs rely on the leakage and some of the designs rely on the mechanical arrangements etc to break the gas lock. The present article compares the existing gas interference handling techniques.

  14. Neurogenesis-mediated forgetting minimizes proactive interference

    PubMed Central

    Epp, Jonathan R.; Silva Mera, Rudy; Köhler, Stefan; Josselyn, Sheena A.; Frankland, Paul W.

    2016-01-01

    Established memories may interfere with the encoding of new memories, particularly when existing and new memories overlap in content. By manipulating levels of hippocampal neurogenesis, here we show that neurogenesis regulates this form of proactive interference. Increasing hippocampal neurogenesis weakens existing memories and, in doing so, facilitates the encoding of new, conflicting (but not non-conflicting) information in mice. Conversely, decreasing neurogenesis stabilizes existing memories, and impedes the encoding of new, conflicting information. These results suggest that reduced proactive interference is an adaptive benefit of neurogenesis-induced forgetting. PMID:26917323

  15. Wave and Particle in Molecular Interference Lithography

    SciTech Connect

    Juffmann, Thomas; Truppe, Stefan; Geyer, Philipp; Major, Andras G.; Arndt, Markus; Deachapunya, Sarayut; Ulbricht, Hendrik

    2009-12-31

    The wave-particle duality of massive objects is a cornerstone of quantum physics and a key property of many modern tools such as electron microscopy, neutron diffraction or atom interferometry. Here we report on the first experimental demonstration of quantum interference lithography with complex molecules. Molecular matter-wave interference patterns are deposited onto a reconstructed Si(111) 7x7 surface and imaged using scanning tunneling microscopy. Thereby both the particle and the quantum wave character of the molecules can be visualized in one and the same image. This new approach to nanolithography therefore also represents a sensitive new detection scheme for quantum interference experiments.

  16. A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS

    SciTech Connect

    Schmidt, K. F.; Little, J. R.; Ellingson, W. A.; Green, W.

    2009-03-03

    A portable, microwave interference scanning system, that can be used in situ, with one-sided, non-contact access, has been developed. It has demonstrated capability of damage detection on composite ceramic armor. Specimens used for validation included specially fabricated surrogates, and non-ballistic impact-damaged specimens. Microwave data results were corroborated with high resolution direct-digital x-ray imaging. Microwave interference scanning detects cracks, laminar features and material properties variations. This paper will present details of the system and discuss results obtained.

  17. Long-Term and Transitory Interference Effects

    ERIC Educational Resources Information Center

    Glazer, Howard I.; Weiss, Jay M.

    1976-01-01

    If animals receive inescapable electric shocks, their subsequent avoidance-escape learning is poor. This phenomenon, which can be called "the interference effect", was studied in four experiments. (Editor)

  18. Shockwave-boundary layer interference heating analysis.

    NASA Technical Reports Server (NTRS)

    Hung, F. T.; Barnett, D. O.

    1973-01-01

    Interference heating correlations have been developed based on existing wind tunnel test data taken with simple configurations such as wedge/flat plate and compression corner models. For turbulent flow, peak interference heating was first correlated with shock strength (pressure ratio across shock wave) and then as a function of Reynolds number. The peak interference Stanton number was found to exhibit the same Reynolds number and Prandtl number characteristics as the Stanton number variation for undisturbed flow over a flat plate. Similar correlations were developed for laminar flow. Results indicated that for laminar flow at higher Reynolds number, the impinging shockwave may act as a boundary layer trip and cause boundary layer transition resulting in high interference heating. The correlations derived in this study can be used to scale wind tunnel model test data to a full-scale space vehicle at supersonic or hypersonic flight conditions.

  19. 47 CFR 24.237 - Interference protection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 446 (e) For microwave paths of 25 kilometers or less, interference determinations shall be based on... Microwave Systems,” May 1994 (TSB10-F). (f) For microwave paths longer than 25 kilometers, the...

  20. Small Aircraft RF Interference Path Loss

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to better interference risk assessment.

  1. Small Aircraft RF Interference Path Loss Measurements

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to more meaningful interference risk assessment.

  2. Interference rejection techniques in spread spectrum communications

    NASA Astrophysics Data System (ADS)

    Milstein, Laurence B.

    1988-06-01

    It is argued that the ability of a spread-spectrum system to withstand interference, both intentional and unintentional, is probably its greatest asset. Any spread spectrum receiver can only suppress a given amount of interference; if the level of interference becomes too great, the system will not function properly. Even under these latter circumstances, however, other techniques, which enhance the performance of the system over and above the performance improvement that comes automatically to systems simply from using spread spectrum, are available for use. These techniques typically involve some type of additional signal processing and are examined here. Two general types of narrowband interference suppression schemes are discussed and an overview is presented for several other techniques. The two classes of rejection schemes emphasized are (1) those based on least-mean-square estimation techniques, and (2) those based on transform-domain processing structures.

  3. [FT4 immunoassay interference : A case report].

    PubMed

    Chaabouni, Khansa; Hargafi, Khaoula; Elleuch, Aida; Messedi, Mariem; Turki, Mouna; Lahyani, Amina; Ayedi, Fatma

    2015-04-01

    Measurement of thyrotropin and free thyroxin made using immunoassays are usually needed in clinical endocrinology. Here, we report a case of a patient with type 2 diabetes who presented a weight loss. To eliminate hyperthyroidism, thyroid function tests were performed. Free thyroxin (FT4) was decreased using two automated immunoassays TOSOH AIA 1800 and Roche ELECSYS 2010, with a normal thyrotropin value. Thyroid function tests repeated a month later were normal. The patient's history revealed contact with sheep, which may partly explain the interference. Investigations into the patient's serum were carried out using both the PEG test and dilution test. Interference factors were probably antibodies. Despite progress in immunoassays, we should be aware of interference occurrence since it can lead to false results, unnecessary investigations and incorrect treatment. Thus, simple tests must be carried out as if interference in immunoassays were suspected. Dilutions and PEG tests are generally performed as first line investigations. PMID:26375746

  4. Devices That May Interfere with Pacemakers

    MedlinePlus

    ... and the devices that may interfere with pulse generators. Carry your pacemaker ID card to prove that ... 3 watts) don't appear to damage pulse generators or affect how the pacemaker works. Technology is ...

  5. Exploiting Genetic Interference for Antiviral Therapy.

    PubMed

    Tanner, Elizabeth J; Kirkegaard, Karla A; Weinberger, Leor S

    2016-05-01

    Rapidly evolving viruses are a major threat to human health. Such viruses are often highly pathogenic (e.g., influenza virus, HIV, Ebola virus) and routinely circumvent therapeutic intervention through mutational escape. Error-prone genome replication generates heterogeneous viral populations that rapidly adapt to new selection pressures, leading to resistance that emerges with treatment. However, population heterogeneity bears a cost: when multiple viral variants replicate within a cell, they can potentially interfere with each other, lowering viral fitness. This genetic interference can be exploited for antiviral strategies, either by taking advantage of a virus's inherent genetic diversity or through generating de novo interference by engineering a competing genome. Here, we discuss two such antiviral strategies, dominant drug targeting and therapeutic interfering particles. Both strategies harness the power of genetic interference to surmount two particularly vexing obstacles-the evolution of drug resistance and targeting therapy to high-risk populations-both of which impede treatment in resource-poor settings.

  6. Understanding conoscopic interference patterns in anisotropic crystals

    NASA Astrophysics Data System (ADS)

    Olorunsola, Oluwatobi Gabriel

    The interference patterns observed in conoscopy are important in studying the optical and geometrical properties of anisotropic materials. They have also been used to identify minerals and to explore the structure of biological tissues. In a conoscopic interferometer, an optically anisotropic specimen is placed between two crossed linear polarizers and illuminated by a convergent light beam. The interference patterns are produced because in an anisotropic material an incident light is split into two eigenwaves, namely the ordinary and the extraordinary waves. We report our work on the theoretical simulation and experimental observation of the conoscopic interference patterns in anisotropic crystals. In our simulation, the interference patterns are decomposed into fringes of isogyres and isochromates. For each light propagation direction inside the crystal there exist two eigenwaves that have their own characteristic velocities and vibration directions. The isogyres are obtained by computing the angle between the polarization of the incident light and the vibration directions of the two eigenwaves. The isochromates are obtained by computing the phase retardance between the two eigenwaves inside the crystal. The interference patterns are experimentally observed in several crystals, with their optic axes either parallel or perpendicular to their surfaces. An external electric field is applied to deform the crystals from uniaxial to biaxial. The results of our experimental observation agree well with our computer simulation. In conventional interferometers the isochromatic interference fringes are observed by using a circular polarizer and a circular analyzer, both constructed by a linear polarizer and a quarter wave plate. However, due to the dispersion of the quarter wave plates, the phase-retardance between the two light waves inside the quarter wave plates is wavelength-dependent, which results in different conoscopic interference patterns for different colors of

  7. United States Access Board

    MedlinePlus

    ... Communications & IT Access to information and communication technology (ICT) is addressed by Board standards and guidelines issued ... Engineer (November 3) Access Board Approves Rules on ICT Refresh and Medical Diagnostic Equipment (September 14) Access ...

  8. Conditions for quantum interference in cognitive sciences.

    PubMed

    Yukalov, Vyacheslav I; Sornette, Didier

    2014-01-01

    We present a general classification of the conditions under which cognitive science, concerned, e.g. with decision making, requires the use of quantum theoretical notions. The analysis is done in the frame of the mathematical approach based on the theory of quantum measurements. We stress that quantum effects in cognition can arise only when decisions are made under uncertainty. Conditions for the appearance of quantum interference in cognitive sciences and the conditions when interference cannot arise are formulated. PMID:24259280

  9. Gene expression: RNA interference in adult mice

    NASA Astrophysics Data System (ADS)

    McCaffrey, Anton P.; Meuse, Leonard; Pham, Thu-Thao T.; Conklin, Douglas S.; Hannon, Gregory J.; Kay, Mark A.

    2002-07-01

    RNA interference is an evolutionarily conserved surveillance mechanism that responds to double-stranded RNA by sequence-specific silencing of homologous genes. Here we show that transgene expression can be suppressed in adult mice by synthetic small interfering RNAs and by small-hairpin RNAs transcribed in vivo from DNA templates. We also show the therapeutic potential of this technique by demonstrating effective targeting of a sequence from hepatitis C virus by RNA interference in vivo.

  10. Interference Fit Life Factors for Roller Bearings

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2008-01-01

    The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner ring interference fit. Calculations were performed for up to seven interference fit classes for each of ten bearing sizes. Each fit was taken at tightest, average and loosest values within the fit class for RBEC-5 tolerance, thus requiring 486 separate analyses. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. The method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings based on interference fit. All calculated lives are for zero initial bearing internal clearance. Any reduction in bearing clearance due to interference fit was compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate and heavy loads and interference fits ranging from extremely light to extremely heavy and for bearing accuracy class RBEC 5 (ISO class 5). Interference fits on the inner bearing ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference fit life factors for a particular fit. The tightest fit at the high end of the RBEC-5 tolerance band defined in ANSI/ABMA shaft fit tables produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

  11. Collision-induced constructive quantum interference

    SciTech Connect

    Yang, Xihua; Xie, Hankun

    2003-06-01

    We theoretically study the collision-induced constructive quantum interference in an open four-level system with the density-matrix approach based on the experimental observation of constructive quantum interference between two transition pathways 3P{sub 1/2}-5S (or 4D) and 3P{sub 3/2}-5S (or 4D) via equal-frequency hybrid excitation in the Na{sub 2}-Na system. The effects of the collision-induced coherent and incoherent decay rates and the ratio of the two transition dipole moments on the interference are analyzed. It is shown that through the incoherent process (collision), the coherence between a widely separated doublet and subsequent constructive quantum interference can be realized. The physical origin of the constructive interference can be seen clearly in the dressed-atom picture. The theoretical results can also be used to qualitatively explain the dependence of quantum interference on the experimental buffer gas pressure and sample temperature.

  12. Ethical Perspectives on RNA Interference Therapeutics

    PubMed Central

    Ebbesen, Mette; Jensen, Thomas G.; Andersen, Svend; Pedersen, Finn Skou

    2008-01-01

    RNA interference is a mechanism for controlling normal gene expression which has recently begun to be employed as a potential therapeutic agent for a wide range of disorders, including cancer, infectious diseases and metabolic disorders. Clinical trials with RNA interference have begun. However, challenges such as off-target effects, toxicity and safe delivery methods have to be overcome before RNA interference can be considered as a conventional drug. So, if RNA interference is to be used therapeutically, we should perform a risk-benefit analysis. It is ethically relevant to perform a risk-benefit analysis since ethical obligations about not inflicting harm and promoting good are generally accepted. But the ethical issues in RNA interference therapeutics not only include a risk-benefit analysis, but also considerations about respecting the autonomy of the patient and considerations about justice with regard to the inclusion criteria for participation in clinical trials and health care allocation. RNA interference is considered a new and promising therapeutic approach, but the ethical issues of this method have not been greatly discussed, so this article analyses these issues using the bioethical theory of principles of the American bioethicists, Tom L. Beauchamp and James F. Childress. PMID:18612370

  13. Spatial Correlation Analysis between Particulate Matter 10 (PM10) Hazard and Respiratory Diseases in Chiang Mai Province, Thailand

    NASA Astrophysics Data System (ADS)

    Trang, N. Ha; Tripathi, N. K.

    2014-11-01

    Every year, during dry season, Chiang Mai and other northern provinces of Thailand face the problem of haze which is mainly generated by the burning of agricultural waste and forest fire, contained high percentage of particulate matter. Particulate matter 10 (PM10), being very small in size, can be inhaled easily to the deepest parts of the human lung and throat respiratory functions. Due to this, it increases the risk of respiratory diseases mainly in the case of continuous exposure to this seasonal smog. MODIS aerosol images (MOD04) have been used for four weeks in March 2007 for generating the hazard map by linking to in-situ values of PM10. Simple linear regression model between PM10 and AOD got fair correlation with R2 = 0.7 and was applied to transform PM10 pattern. The hazard maps showed the dominance of PM10 in northern part of Chiang Mai, especially in second week of March when PM10 level was three to four times higher than standard. The respiratory disease records and public health station of each village were collected from Provincial Public Health Department in Chiang Mai province. There are about 300 public health stations out of 2070 villages; hence thiessen polygon was created to determine the representative area of each public health station. Within each thiessen polygon, respiratory disease incident rate (RDIR) was calculated based on the number of patients and population. Global Moran's I was computed for RDIR to explore spatial pattern of diseases through four weeks of March. Moran's I index depicted a cluster pattern of respiratory diseases in 2nd week than other weeks. That made sense for a relationship between PM10 and respiratory diseases infections. In order to examine how PM10 affect the human respiratory system, geographically weighted regression model was used to observe local correlation coefficient between RDIR and PM10 across study area. The result captured a high correlation between respiratory diseases and high level of PM10 in

  14. Particle Identification in the ACCESS Mission

    NASA Technical Reports Server (NTRS)

    Wang, J. Z.; Adams, J. H., Jr.; Kim, K. C.; Seo, E. S.

    2000-01-01

    ACCESS (Assembly Concept for Construction of Erectable Space Structures) is a planned Space Station mission to measure the elemental energy spectra of Galactic cosmic rays at energies above 100 GeV/nuc. ACCESS consists of a transition radiation detector (TRD) mounted on top of an ionization calorimeter (IC). A silicon matrix detector placed on top of the IC determines the elemental identity of each cosmic ray measured by the IC. The silicon matrix must be designed to identify each cosmic ray in the presence of backscatter from the calorimeter. Because the TRD is mounted above the IC, the matrix must also recognize cosmic rays that have interacted within the TRD before reaching the IC. We will report the results of detailed GEANT simulations of the silicon matrix in ACCESS. Results will be presented on backscatter interference with charge identification and the ability of the matrix to recognize cosmic rays that interacted in the TRD.

  15. Interference effects and Fano resonance in transport across a two dot system in the Kondo regime

    NASA Astrophysics Data System (ADS)

    Sztenkiel, D.; Swirkowicz, R.

    2007-09-01

    Transport across a double dot system of a special geometry with two channels accessible for tunneling electrons is theoretically studied in a region of low temperatures corresponding to the Kondo regime, and interference effects are analyzed. The spectral function and the linear conductance are calculated using the Green function formalism based on the equation of motion method. It is shown that interference processes strongly influence the spectral function. Moreover, due to interference effects the conductance, which is close to zero in a low energy region, shows at higher gate voltages a well defined Fano resonance. A development of the Fano peak as the system undergoes a gradual transition from the serial configuration to the geometry with two dots partially connected to both electrodes is demonstrated. The position and intensity of the Fano resonance strongly depend on the inter-dot tunneling rate. The influence of temperature on the resonance is also discussed.

  16. Below-baseline suppression of competitors during interference resolution by younger but not older adults.

    PubMed

    Healey, M Karl; Ngo, K W Joan; Hasher, Lynn

    2014-01-01

    Resolving interference from competing memories is a critical factor in efficient memory retrieval, and several accounts of cognitive aging suggest that difficulty resolving interference may underlie memory deficits such as those seen in the elderly. Although many researchers have suggested that the ability to suppress competitors is a key factor in resolving interference, the evidence supporting this claim has been the subject of debate. Here, we present a new paradigm and results demonstrating that for younger adults, a single retrieval attempt is sufficient to suppress competitors to below-baseline levels of accessibility even though the competitors are never explicitly presented. The extent to which individual younger adults suppressed competitors predicted their performance on a memory span task. In a second experiment, older adults showed no evidence of suppression, which supports the theory that older adults' memory deficits are related to impaired suppression.

  17. Call admission control for CDMA systems with Interference Guard Margin (IGM)

    NASA Astrophysics Data System (ADS)

    Chen, Huan; Kumar, Sunil; Kuo, C.-C. Jay

    2002-01-01

    A call admission control (CAC) scheme and a resource-reservation estimation (RRE) method suitable for the interference-based wireless system, such as wide-band code division multiple access (W-CDMA), are proposed in this work. The proposed CAC scheme gives preferential treatment to high priority handoff calls by pre-reserving a certain amount of interference margin called the interference guard margin (IGM). The amount of guard margin is determined by the measurement performed by the RRE module in base stations. Each RRE module dynamically adjusts the level of guard margin by considering traffic conditions in neighboring cells based upon handoff requests. A service model is adopted to support multiple services, which includes mobile terminal's data rate, different levels of priorities, mobility and rate adaptivity characteristics. Simulations are conducted with OPNET to study the performance of the proposed scheme in terms of the objective function, blocking probabilities and system utilization under different traffic conditions.

  18. Josephson phase diffusion in the superconducting quantum interference device ratchet

    SciTech Connect

    Spiechowicz, Jakub; Łuczka, Jerzy

    2015-05-15

    We study diffusion of the Josephson phase in the asymmetric superconducting quantum interference device (SQUID) subjected to a time-periodic current and pierced by an external magnetic flux. We analyze a relation between phase diffusion and quality of transport characterized by the dc voltage across the SQUID and efficiency of the device. In doing so, we concentrate on the previously reported regime [J. Spiechowicz and J. Łuczka, New J. Phys. 17, 023054 (2015)] for which efficiency of the SQUID attains a global maximum. For long times, the mean-square displacement of the phase is a linear function of time, meaning that diffusion is normal. Its coefficient is small indicating rather regular phase evolution. However, it can be magnified several times by tailoring experimentally accessible parameters like amplitudes of the ac current or external magnetic flux. Finally, we prove that in the deterministic limit this regime is essentially non-chaotic and possesses an unexpected simplicity of attractors.

  19. Perspectives for quantum interference with biomolecules and biomolecular clusters

    NASA Astrophysics Data System (ADS)

    Geyer, P.; Sezer, U.; Rodewald, J.; Mairhofer, L.; Dörre, N.; Haslinger, P.; Eibenberger, S.; Brand, C.; Arndt, M.

    2016-06-01

    Modern quantum optics encompasses a wide field of phenomena that are either related to the discrete quantum nature of light, the quantum wave nature of matter or light–matter interactions. We here discuss new perspectives for quantum optics with biological nanoparticles. We focus in particular on the prospects of matter-wave interferometry with amino acids, nucleotides, polypeptides or DNA strands. We motivate the challenge of preparing these objects in a ‘biomimetic’ environment and argue that hydrated molecular beam sources are promising tools for quantum-assisted metrology. The method exploits the high sensitivity of matter-wave interference fringes to dephasing and shifts in the presence of external perturbations to access and determine molecular properties.

  20. Quantum interference in a driven two-level atom

    NASA Astrophysics Data System (ADS)

    Ficek, Z.; Rudolph, T.

    1999-12-01

    We show that a dynamical suppression of spontaneous emission, predicted for a three-level atom [S.-Y. Zhu and M. O. Scully, Phys. Rev. Lett. 76, 388 (1996)] can occur in a two-level atom driven by a polychromatic field. We find that the quantum interference, responsible for the cancellation of spontaneous emission, appears between different channels of transitions among the dressed states of the driven atom. We discuss the effect for bichromatic and trichromatic (amplitude-modulated) fields and find that these two cases lead to the cancellation of spontaneous emission in different parts of the fluorescence spectrum. Our system has the advantage of being easily accessible by current experiments.

  1. Spatially resolving valley quantum interference of a donor in silicon.

    PubMed

    Salfi, J; Mol, J A; Rahman, R; Klimeck, G; Simmons, M Y; Hollenberg, L C L; Rogge, S

    2014-06-01

    Electron and nuclear spins of donor ensembles in isotopically pure silicon experience a vacuum-like environment, giving them extraordinary coherence. However, in contrast to a real vacuum, electrons in silicon occupy quantum superpositions of valleys in momentum space. Addressable single-qubit and two-qubit operations in silicon require that qubits are placed near interfaces, modifying the valley degrees of freedom associated with these quantum superpositions and strongly influencing qubit relaxation and exchange processes. Yet to date, spectroscopic measurements have only probed wavefunctions indirectly, preventing direct experimental access to valley population, donor position and environment. Here we directly probe the probability density of single quantum states of individual subsurface donors, in real space and reciprocal space, using scanning tunnelling spectroscopy. We directly observe quantum mechanical valley interference patterns associated with linear superpositions of valleys in the donor ground state. The valley population is found to be within 5% of a bulk donor when 2.85 ± 0.45 nm from the interface, indicating that valley-perturbation-induced enhancement of spin relaxation will be negligible for depths greater than 3 nm. The observed valley interference will render two-qubit exchange gates sensitive to atomic-scale variations in positions of subsurface donors. Moreover, these results will also be of interest for emerging schemes proposing to encode information directly in valley polarization. PMID:24705384

  2. Spatially resolving valley quantum interference of a donor in silicon.

    PubMed

    Salfi, J; Mol, J A; Rahman, R; Klimeck, G; Simmons, M Y; Hollenberg, L C L; Rogge, S

    2014-06-01

    Electron and nuclear spins of donor ensembles in isotopically pure silicon experience a vacuum-like environment, giving them extraordinary coherence. However, in contrast to a real vacuum, electrons in silicon occupy quantum superpositions of valleys in momentum space. Addressable single-qubit and two-qubit operations in silicon require that qubits are placed near interfaces, modifying the valley degrees of freedom associated with these quantum superpositions and strongly influencing qubit relaxation and exchange processes. Yet to date, spectroscopic measurements have only probed wavefunctions indirectly, preventing direct experimental access to valley population, donor position and environment. Here we directly probe the probability density of single quantum states of individual subsurface donors, in real space and reciprocal space, using scanning tunnelling spectroscopy. We directly observe quantum mechanical valley interference patterns associated with linear superpositions of valleys in the donor ground state. The valley population is found to be within 5% of a bulk donor when 2.85 ± 0.45 nm from the interface, indicating that valley-perturbation-induced enhancement of spin relaxation will be negligible for depths greater than 3 nm. The observed valley interference will render two-qubit exchange gates sensitive to atomic-scale variations in positions of subsurface donors. Moreover, these results will also be of interest for emerging schemes proposing to encode information directly in valley polarization.

  3. A fast, robust algorithm for power line interference cancellation in neural recording

    NASA Astrophysics Data System (ADS)

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2014-04-01

    Objective. Power line interference may severely corrupt neural recordings at 50/60 Hz and harmonic frequencies. The interference is usually non-stationary and can vary in frequency, amplitude and phase. To retrieve the gamma-band oscillations at the contaminated frequencies, it is desired to remove the interference without compromising the actual neural signals at the interference frequency bands. In this paper, we present a robust and computationally efficient algorithm for removing power line interference from neural recordings. Approach. The algorithm includes four steps. First, an adaptive notch filter is used to estimate the fundamental frequency of the interference. Subsequently, based on the estimated frequency, harmonics are generated by using discrete-time oscillators, and then the amplitude and phase of each harmonic are estimated by using a modified recursive least squares algorithm. Finally, the estimated interference is subtracted from the recorded data. Main results. The algorithm does not require any reference signal, and can track the frequency, phase and amplitude of each harmonic. When benchmarked with other popular approaches, our algorithm performs better in terms of noise immunity, convergence speed and output signal-to-noise ratio (SNR). While minimally affecting the signal bands of interest, the algorithm consistently yields fast convergence (<100 ms) and substantial interference rejection (output SNR >30 dB) in different conditions of interference strengths (input SNR from -30 to 30 dB), power line frequencies (45-65 Hz) and phase and amplitude drifts. In addition, the algorithm features a straightforward parameter adjustment since the parameters are independent of the input SNR, input signal power and the sampling rate. A hardware prototype was fabricated in a 65 nm CMOS process and tested. Software implementation of the algorithm has been made available for open access at https://github.com/mrezak/removePLI. Significance. The proposed

  4. 49 CFR 38.159 - Mobility aid accessibility.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... barriers shall not interfere with maneuvering into or out of the aisle. The loading-edge barrier (outer... aid from riding over or defeating it. The outer barrier of the lift shall automatically raise or close... inches (1220 mm). Such space shall adjoin, and may overlap, an access path. Not more than 6 inches...

  5. 46 CFR 503.86 - Public access to records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS PUBLIC INFORMATION Public Observation of Federal Maritime Commission Meetings and Public Access to Information Pertaining to Commission Meetings... (i) Interfere with enforcement proceedings, (ii) Deprive a person of a right to a fair trial or...

  6. Dynamic resource allocation in hybrid access femtocell network.

    PubMed

    Ahmed, Afaz Uddin; Islam, Mohammad Tariqul; Ismail, Mahamod; Ghanbarisabagh, Mohammad

    2014-01-01

    Intercell interference is one of the most challenging issues in femtocell deployment under the coverage of existing macrocell. Allocation of resources between femtocell and macrocell is essential to counter the effects of interference in dense femtocell networks. Advances in resource management strategies have improved the control mechanism for interference reduction at lower node density, but most of them are ineffective at higher node density. In this paper, a dynamic resource allocation management algorithm (DRAMA) for spectrum shared hybrid access OFDMA femtocell network is proposed. To reduce the macro-femto-tier interference and to improve the quality of service, the proposed algorithm features a dynamic resource allocation scheme by controlling them both centrally and locally. The proposed scheme focuses on Femtocell Access Point (FAP) owners' satisfaction and allows maximum utilization of available resources based on congestion in the network. A simulation environment is developed to study the quantitative performance of DRAMA in hybrid access-control femtocell network and compare it to closed and open access mechanisms. The performance analysis shows that higher number of random users gets connected to the FAP without compromising FAP owners' satisfaction allowing the macrocell to offload a large number of users in a dense heterogeneous network. PMID:24782662

  7. GIDL: Generalized Interference Detection and Localization System

    NASA Astrophysics Data System (ADS)

    Gromov, Konstantin Gennadievich

    The Local Area Augmentation System (LAAS) and the Wide Area Augmentation System (WAAS) are being developed by the U.S. Federal Aviation Administration (FAA) to provide satellite navigation performance compliant with the stringent requirements for aircraft precision approach and landing. A primary design goal of both systems is to insure that signal-in-space failures are detected by ground facilities and to exclude the affected measurements before differential corrections are broadcast to users. One such failure is unintentional interference or intentional jamming in the GPS frequency band. To protect integrity, LAAS and WAAS ground facilities must quickly detect the presence of any hazardous interference falling within the restricted band used by GPS. To protect availability, ground personnel must be able to quickly locate and deactivate the interference source. In order to serve this purpose, the prototype Generalized Interference Detection and Localization System (GIDL) has been developed. This prototype includes four antennae and RF sections slaved to a common clock to allow detection and determination of a three-dimensional interference location. Measurements of differential signal propagation delays across the multiple baselines between the GIDL antennae are combined to estimate the location of the undesired interference transmitter. The GIDL system can be implemented in parallel with a three- or four-receiver LAAS ground facility (sharing components with the LAAS reference receivers and processors) or as a separate installation to support nearby LAAS and WAAS sites. This dissertation describes the GIDL theory and GIDL receiver design and derives theoretical predictions of the ability of the GIDL to accurately locate interference sources. The GIDL System has been successfully demonstrated to the Federal Aviation Administration (FAA).

  8. 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…

  9. YiQiFuMai Powder Injection Ameliorates Cerebral Ischemia by Inhibiting Endoplasmic Reticulum Stress-Mediated Neuronal Apoptosis

    PubMed Central

    Hu, Yang

    2016-01-01

    YiQiFuMai (YQFM) powder injection as a modern preparation derived from Sheng Mai San, a traditional Chinese medicine, has been widely used in the treatment of cardiovascular and cerebrovascular diseases. However, its neuroprotective effect and underlying mechanism in cerebral ischemia remain to be explored. The present study was designed to investigate the neuroprotective effect of YQFM on endoplasmic reticulum (ER) stress-mediated neuronal apoptosis in the permanent middle cerebral artery occlusion- (MCAO-) injured mice and the oxygen-glucose deprivation- (OGD-) induced pheochromocytoma (PC12) cells. The results showed that single administration of YQFM (1.342 g/kg, i.p.) could reduce the brain infarction and improve the neurological deficits and the cerebral blood flow (CBF) after MCAO for 24 h in mice. Moreover, incubation with YQFM (100, 200, and 400 μg/mL) could increase the cell viability, decrease the caspase-3 activity, and inhibit the cell apoptosis in OGD-induced PC12 cells for 12 h. In addition, YQFM treatment could significantly modulate cleaved caspase-3 and Bcl-2 expressions and inhibit the expressions of ER stress-related marker proteins and signaling pathways in vivo and in vitro. In conclusion, our findings provide the first evidence that YQFM ameliorates cerebral ischemic injury linked with modulating ER stress-related signaling pathways, which provided some new insights for its prevention and treatment of cerebral ischemia diseases. PMID:27087890

  10. The nature and impact of chronic stressors on refugee children in Ban Mai Nai Soi camp, Thailand.

    PubMed

    Meyer, Sarah; Murray, Laura K; Puffer, Eve S; Larsen, Jillian; Bolton, Paul

    2013-01-01

    Refugee camps are replete with risk factors for mental health problems among children, including poverty, disruption of family structure, family violence and food insecurity. This study, focused on refugee children from Burma, in Ban Mai Nai Soi camp in Thailand, sought to identify the particular risks children are exposed to in this context, and the impacts on their mental health and psychosocial well-being. This study employed two qualitative methods--free list interviews and key informant interviews--to identify the main problems impacting children in Ban Mai Nai Soi camp and to explore the causes of these problems and their impact on children's well-being. Respondents in free list interviews identified a number of problems that impact children in this context, including fighting between adults, alcohol use by adults and children, and child abuse and neglect. Across the issues, the causes included economic and social conditions associated with living in the camp and changes in family structures. Children are chronically exposed to stressors during their growth and development in the camp environment. Policies and interventions in areas of protracted displacement in camp-based settings should work to address these stressors and their impacts at community, household and individual levels.

  11. Diurnal variation, vertical distribution and source apportionment of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Chiang-Mai, Thailand.

    PubMed

    Pongpiachan, Siwatt

    2013-01-01

    Diurnal variation of particulate polycyclic aromatic hydrocarbons (PAHs) was investigated by collecting PM10 at three different sampling altitudes using high buildings in the city center of Chiang-Mai, Thailand, during the relatively cold period in late February 2008. At site-1 (12 m above ground level), B[a]P concentrations ranged from 30.3 -1,673 pg m-3 with an average of 506±477 pg m-3, contributing on average, 8.09±8.69% to ?PAHs. Ind and B[b]F concentrations varied from 54.6 to 4,579 pg m-3 and from 80.7 to 2,292 pg m-3 with the highest average of 1,187±1,058 pg m-3 and 963±656 pg m-3, contributing on average, 19.0±19.3% and 15.4±12.0% to ?PAHs, respectively. Morning maxima were predominantly detected in all observatory sites, which can be described by typical diurnal variations of traffic flow in Chiang-Mai City, showing a morning peak between 6 AM. and 9 AM. Despite the fact that most monitoring sites might be subjected to specific-site impacts, it could be seen that PAH profiles in Site-1 and Site-2 were astonishingly homogeneous. The lack of differences suggests that the source signatures of several PAHs become less distinct possibly due to the impacts of traffic and cooking emissions from ground level. PMID:23679286

  12. Occurrence of two heterophyid metacercariae Haplorchis and Haplorchoides in cyprinoid fish of some districts in Chiang Mai and Lumphun Province.

    PubMed

    Namue, C; Rojanapaibul, A; Wongsawad, C

    1998-06-01

    According to currently available information, the metacercaria of one heterophyid trematode, Haplorchis, is commonly found in freshwater fishes, especially the cyprinoid group. Thus, in an investigation into the level of Haplorchis metacercaria infection in cyprinoid fishes, comprising ten species, 811 cyprinoid fishes were captured from canals, reservoirs and rivers in six districts of Chiang Mai Province and 4 districts of Lumphun Province, Thailand, 43.03% of the fishes comprising seven species viz Puntius leiacanthus, P. gonionotus, P. orphoides, P. stolickkae, Cirrhina spp, Rasbora spp and R. lateristriata, were found infected, with the prevalence of infection at 77.29, 70.31, 56.52, 47.14, 18.48, 7.94 and 5.18% respectively. Infected fishes were collected from Mae Rim and Sansai districts of Chiang Mai, and Pasang, Ban Hong and Li districts of Lumphun. It should be noted that the Haplorchis metacercariae are commonly found along with Haplorchoides metacercariae. Both minute heterophyids metacercariae were mainly localized in scales, a few were found in fins and gills of fishes.

  13. Lead and cadmium in leaves of deciduous trees in Beijing, China: development of a metal accumulation index (MAI).

    PubMed

    Liu, Yan-Ju; Zhu, Yong-Guan; Ding, Hui

    2007-01-01

    Lead and cadmium uptake was investigated for common deciduous street trees in Beijing in this study. Species having Cd accumulation included Populus tomentosa, Sophora japonica and Catalpa speciosa. P. tomentosa had the highest ratios between leaf and soil Cd (0.848), followed by S. japonica (0.536), C. speciosa (0.493), Paulownia tomentosa (0.453) and Juglans regia (0.415). Pb levels were high in leaves of C. speciosa, J. regia and Pa. tomentosa. S. japonica had the highest ratio between leaf Pb and soil Pb (0.146), followed by Pa. tomentosa (0.143), Ginko biloba (0.103) and C. speciosa (0.095). A predictive foliar metal accumulation index (MAI) was developed and C. speciosa was calculated to have the highest MAI value (53.8). This suggests that C. speciosa would be a good choice for planting in areas of Beijing where soil contamination with Cd and Pb may be a problem. PMID:16797111

  14. Phonon-Mediated Nonclassical Interference in Diamond.

    PubMed

    England, Duncan G; Fisher, Kent A G; MacLean, Jean-Philippe W; Bustard, Philip J; Heshami, Khabat; Resch, Kevin J; Sussman, Benjamin J

    2016-08-12

    Quantum interference of single photons is a fundamental aspect of many photonic quantum processing and communication protocols. Interference requires that the multiple pathways through an interferometer be temporally indistinguishable to within the coherence time of the photon. In this Letter, we use a diamond quantum memory to demonstrate interference between quantum pathways, initially temporally separated by many multiples of the optical coherence time. The quantum memory can be viewed as a light-matter beam splitter, mapping a THz-bandwidth single photon to a variable superposition of the output optical mode and stored phononic mode. Because the memory acts both as a beam splitter and as a buffer, the relevant coherence time for interference is not that of the photon, but rather that of the memory. We use this mechanism to demonstrate nonclassical single-photon and two-photon interference between quantum pathways initially separated by several picoseconds, even though the duration of the photons themselves is just ∼250  fs. PMID:27563963

  15. Disentangling posterror and postconflict reduction of interference.

    PubMed

    Van der Borght, Liesbet; Braem, Senne; Notebaert, Wim

    2014-12-01

    Conflict monitoring theory (CMT; Botvinick, Braver, Barch, Carter, & Cohen Psychological Review, 108, 624-652, 2001) states that response conflict, the simultaneous activation of two competing responses, increases task focus and reduces interference from irrelevant information. CMT also defines errors as conflict, and reduced interference effects have consistently been reported following errors (Ridderinkhof Psychological Research, 66, 312-323, 2002). However, previous computations of this posterror reduction of interference (PERI) have overlooked the congruency of the previous trial. This is problematic, because most errors are made on incongruent trials, creating a confound between (previous) accuracy and (previous) congruency. Therefore, it is likely that reduced interference following errors is in fact the congruency sequence effect (i.e., reduced interference following incongruent, relative to congruent, trials). Our results corroborate this idea by demonstrating that participants indeed showed significant PERI following a congruent trial, but inverse PERI following an incongruent trial. These findings are discussed in light of the adaptation-by-binding account (Verguts & Notebaert Psychological Review, 115, 518-525, 2008, Trends in Cognitive Sciences, 13, 252-257, 2009).

  16. Lipemia: causes, interference mechanisms, detection and management

    PubMed Central

    Nikolac, Nora

    2014-01-01

    In the clinical laboratory setting, interferences can be a significant source of laboratory errors with potential to cause serious harm for the patient. After hemolysis, lipemia is the most frequent endogenous interference that can influence results of various laboratory methods by several mechanisms. The most common preanalytical cause of lipemic samples is inadequate time of blood sampling after the meal or parenteral administration of synthetic lipid emulsions. Although the best way of detecting the degree of lipemia is measuring lipemic index on analytical platforms, laboratory experts should be aware of its problems, like false positive results and lack of standardization between manufacturers. Unlike for other interferences, lipemia can be removed and measurement can be done in a clear sample. However, a protocol for removing lipids from the sample has to be chosen carefully, since it is dependent on the analytes that have to be determined. Investigation of lipemia interference is an obligation of manufacturers of laboratory reagents; however, several literature findings report lack of verification of the declared data. Moreover, the acceptance criteria currently used by the most manufacturers are not based on biological variation and need to be revised. Written procedures for detection of lipemia, removing lipemia interference and reporting results from lipemic samples should be available to laboratory staff in order to standardize the procedure, reduce errors and increase patient safety. PMID:24627715

  17. Remote sensing of nearshore wave interference

    NASA Astrophysics Data System (ADS)

    Smit, P. B.; Bland, R.; Janssen, T. T.; Laughlin, B.

    2016-05-01

    Wave focusing of energetic swell fields can result in small-scale variations associated with coherent interference that can be important for nearshore circulation and beach dynamics. However, coherent interference is difficult to measure with conventional in situ instruments and is not accounted for in operational wave models. As a result, such effects are generally ignored. In this work, we analyze X-band radar observations collected at Ocean Beach, San Francisco using a Wigner-Ville or coupled-mode spectrum, to show how long-dwell remote sensing technology allows us to identify coherent wave interference. Our analysis demonstrates that during energetic swell events, the nearshore wave field consists of two noncollinear, but coherent, swell patterns that originate from the same offshore source but are directionally separated due to refraction over the San Francisco Bar. The length scale of the associated alongshore wave height variability (200 m) is consistent with the wavenumber separation obtained from the coupled mode analysis. This confirms that the small-scale variability is primarily due to coherent interference. In addition, our analysis shows that the shoreline exhibits a strong localized response near the radar site on the 200 m scale, which suggests that coherent interference effects can affect wave-driven nearshore transport processes and localized erosion.

  18. Interference of light from independent sources

    SciTech Connect

    Pegg, David T.

    2006-12-15

    We extend and generalize previous work on the interference of light from independent cavities that began with the suggestion of Pfleegor and Mandel [Phys. Rev. 159, 1084 (1967)] that their observed interference of laser beams should not be associated too closely with particular states of the beams but more with the detection process itself. In particular we examine how the detection of interference induces a nonrandom-phase difference between internal cavity states with initial random phases for a much broader range of such states than has previously been considered. We find that a subsequent interference measurement should give results consistent with the induced phase difference. The inclusion of more cavities in the interference measurements enables the construction in principle of a laboratory in the sense used by Aharonov and Susskind, made up of cavity fields that can serve as frames of phase reference. We also show reasonably simply how intrinsic phase coherence of a beam of light leaking from a single cavity arises for any internal cavity state, even a photon number state. Although the work presented here may have some implications for the current controversy over whether or not a typical laboratory laser produces a coherent state, it is not the purpose of this paper to enter this controversy; rather it is to examine the interesting quantum physics that arises for cavities with more general internal states.

  19. Phonon-Mediated Nonclassical Interference in Diamond.

    PubMed

    England, Duncan G; Fisher, Kent A G; MacLean, Jean-Philippe W; Bustard, Philip J; Heshami, Khabat; Resch, Kevin J; Sussman, Benjamin J

    2016-08-12

    Quantum interference of single photons is a fundamental aspect of many photonic quantum processing and communication protocols. Interference requires that the multiple pathways through an interferometer be temporally indistinguishable to within the coherence time of the photon. In this Letter, we use a diamond quantum memory to demonstrate interference between quantum pathways, initially temporally separated by many multiples of the optical coherence time. The quantum memory can be viewed as a light-matter beam splitter, mapping a THz-bandwidth single photon to a variable superposition of the output optical mode and stored phononic mode. Because the memory acts both as a beam splitter and as a buffer, the relevant coherence time for interference is not that of the photon, but rather that of the memory. We use this mechanism to demonstrate nonclassical single-photon and two-photon interference between quantum pathways initially separated by several picoseconds, even though the duration of the photons themselves is just ∼250  fs.

  20. General Quantum Interference Principle and Duality Computer

    NASA Astrophysics Data System (ADS)

    Long, Gui-Lu

    2006-05-01

    In this article, we propose a general principle of quantum interference for quantum system, and based on this we propose a new type of computing machine, the duality computer, that may outperform in principle both classical computer and the quantum computer. According to the general principle of quantum interference, the very essence of quantum interference is the interference of the sub-waves of the quantum system itself. A quantum system considered here can be any quantum system: a single microscopic particle, a composite quantum system such as an atom or a molecule, or a loose collection of a few quantum objects such as two independent photons. In the duality computer, the wave of the duality computer is split into several sub-waves and they pass through different routes, where different computing gate operations are performed. These sub-waves are then re-combined to interfere to give the computational results. The quantum computer, however, has only used the particle nature of quantum object. In a duality computer, it may be possible to find a marked item from an unsorted database using only a single query, and all NP-complete problems may have polynomial algorithms. Two proof-of-the-principle designs of the duality computer are presented: the giant molecule scheme and the nonlinear quantum optics scheme. We also propose thought experiment to check the related fundamental issues, the measurement efficiency of a partial wave function.

  1. Delaying Interference Training Has Equivalent Effects in Various Pavlovian Interference Paradigms

    ERIC Educational Resources Information Center

    Powell, Elizabeth J.; Escobar, Martha; Kimble, Whitney

    2013-01-01

    Spontaneous recovery in extinction appears to be inversely related to the acquisition-to-extinction interval, but it remains unclear why this is the case. Rat subjects trained with one of three interference paradigms exhibited less spontaneous recovery of the original response after delayed than immediate interference, regardless of whether…

  2. 37 CFR 2.98 - Adding party to interference.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Adding party to interference....98 Adding party to interference. A party may be added to an interference only upon petition to the... interference is not added, the examiner may suspend action on the application pending termination of...

  3. 37 CFR 2.98 - Adding party to interference.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Adding party to interference....98 Adding party to interference. A party may be added to an interference only upon petition to the... interference is not added, the examiner may suspend action on the application pending termination of...

  4. Reading Ability Is Negatively Related to Stroop Interference

    ERIC Educational Resources Information Center

    Protopapas, Athanassios; Archonti, Anastasia; Skaloumbakas, Christos

    2007-01-01

    Stroop interference is often taken as evidence for reading automaticity even though young and poor readers, who presumably lack reading automaticity, present strong interference. Here the relationship between reading skills and Stroop interference was studied in a 7th-grade sample. Greater interference was observed in children diagnosed with…

  5. 40 CFR 89.318 - Analyzer interference checks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... one being analyzed can interfere with the reading in several ways. Positive interference occurs in... to a lesser degree. Negative interference occurs in NDIR instruments by the interfering gas... the radiation. The interference checks described in this section are to be made initially and...

  6. 40 CFR 90.325 - Analyzer interference checks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... one being analyzed can interfere with the reading in several ways. Positive interference occurs in... to a lesser degree. Negative interference occurs in NDIR instruments by the interfering gas... the radiation. The interference checks described in this section are to be made initially and...

  7. A controlled-force laser interference profilometer

    NASA Astrophysics Data System (ADS)

    Yang, Bo; Chang, Suping; Xie, Tiebang; Pan, Wen

    2011-12-01

    This paper presents a controlled-force laser interference surface measuring system, which can achieve high-precision surface profile measurements in a large range. The key technology of the system is the controlled-force laser interference displacement sensor based on Michelson interference principle. The system operates in micro-force by the voice coil motor (VCM) which alters the measuring contact force in real time and reduces the scratches caused by the stylus tip on the surfaces of the tested samples. The position of the stylus can also be changed, which avoids the damage of the system when the stylus scans across high steps or deep grooves. The optical and mechanical principles of the displacement sensor, the realization method of controllable measuring force and photoelectric signal processing are discussed in this paper. Additionally, this paper introduces the two-dimensional stage used for high precision scanner, and presents primitive experimental results.

  8. Bargaining and the MISO Interference Channel

    NASA Astrophysics Data System (ADS)

    Nokleby, Matthew; Swindlehurst, A. Lee

    2009-12-01

    We examine the MISO interference channel under cooperative bargaining theory. Bargaining approaches such as the Nash and Kalai-Smorodinsky solutions have previously been used in wireless networks to strike a balance between max-sum efficiency and max-min equity in users' rates. However, cooperative bargaining for the MISO interference channel has only been studied extensively for the two-user case. We present an algorithm that finds the optimal Kalai-Smorodinsky beamformers for an arbitrary number of users. We also consider joint scheduling and beamformer selection, using gradient ascent to find a stationary point of the Kalai-Smorodinsky objective function. When interference is strong, the flexibility allowed by scheduling compensates for the performance loss due to local optimization. Finally, we explore the benefits of power control, showing that power control provides nontrivial throughput gains when the number of transmitter/receiver pairs is greater than the number of transmit antennas.

  9. Phonon wave interference and thermal bandgap materials

    NASA Astrophysics Data System (ADS)

    Maldovan, Martin

    2015-07-01

    Wave interference modifies phonon velocities and density of states, and in doing so creates forbidden energy bandgaps for thermal phonons. Materials that exhibit wave interference effects allow the flow of thermal energy to be manipulated by controlling the material's thermal conductivity or using heat mirrors to reflect thermal vibrations. The technological potential of these materials, such as enhanced thermoelectric energy conversion and improved thermal insulation, has fuelled the search for highly efficient phonon wave interference and thermal bandgap materials. In this Progress Article, we discuss recent developments in the understanding and manipulation of heat transport. We show that the rational design and fabrication of nanostructures provides unprecedented opportunities for creating wave-like behaviour of heat, leading to a fundamentally new approach for manipulating the transfer of thermal energy.

  10. Adaptive interference techniques for mobile antennas

    NASA Astrophysics Data System (ADS)

    Griffiths, Lloyd J.; Satorius, E.

    1988-05-01

    The results of a study performed to investigate effective, low cost adaptive signal processing techniques for suppressing mutual satellite interference that can arise in a mobile satellite (MSAT) communication system are discussed. The study focused on the use of adaptive sidelobe cancelling as a method to overcome undesired interference caused by a multiplicity of satellite transmissions within the field of view of the ground station. Results are presented which show that the conventional sidelobe canceller produces undesired reduction of the useful signal. This effect is due to the presence of the useful component in the reference antenna element. An alternative structure, the generalized sidelobe canceller (GSC), has been proposed to overcome this difficulty. A preliminary investigation of possible implementations of the GSC was conducted. It was found that at most 8 bits would be required to implement the GSC processor under conditions in which the desired signal-to-interference ratio is 25 dB.

  11. Topoisomerase II Mediates Meiotic Crossover Interference

    PubMed Central

    Zhang, Liangran; Wang, Shunxin; Yin, Shen; Hong, Soogil; Kim, Keun P.; Kleckner, Nancy

    2014-01-01

    Summary Spatial patterning is a ubiquitous feature of biological systems. Meiotic crossovers provide an interesting example, defined by the classical phenomenon of crossover interference. Here, analysis of crossover patterns in budding yeast identifies a molecular pathway for interference. Topoisomerase II (Topo II) plays a central role, thus identifying a new function for this critical molecule. SUMOylation [of TopoII and axis component Red1] and ubiquitin-mediated removal of SUMOylated proteins are also required. These and other findings support the hypothesis that crossover interference involves accumulation, relief and redistribution of mechanical stress along the protein/DNA meshwork of meiotic chromosome axes, with TopoII required to adjust spatial relationships among DNA segments. PMID:25043020

  12. Adult hippocampal neurogenesis and memory interference.

    PubMed

    Winocur, Gordon; Becker, Suzanna; Luu, Paul; Rosenzweig, Shira; Wojtowicz, J Martin

    2012-02-14

    Rats, subjected to low-dose irradiation that suppressed hippocampal neurogenesis, or a sham treatment, were administered a visual discrimination task under conditions of high, or low interference. Half of the rats engaged in running activity and the other half did not. In the non-runners, there was no effect of irradiation on learning, or remembering the discrimination response under low interference, but irradiation treatment increased their susceptibility to interference, resulting in loss of memory for the previously learned discrimination. Irradiated rats that engaged in running activity exhibited increased neuronal growth and protection from memory impairment. The results, which show that hippocampal cells generated in adulthood play a role in differentiating between conflicting, context-dependent memories, provide further evidence of the importance of neurogenesis in hippocampus-sensitive memory tasks. The results are consistent with computational models of hippocampal function that specify a central role for neurogenesis in the modulation of interfering influences during learning and memory.

  13. Nonclassical paths in quantum interference experiments.

    PubMed

    Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna; Sinha, Urbasi

    2014-09-19

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well-known text books in quantum mechanics implicitly and/or explicitly use this assumption that is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from nonclassical paths in quantum interference experiments that provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these nonclassical paths is difficult to present. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence. PMID:25279612

  14. Nonclassical paths in quantum interference experiments.

    PubMed

    Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna; Sinha, Urbasi

    2014-09-19

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well-known text books in quantum mechanics implicitly and/or explicitly use this assumption that is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from nonclassical paths in quantum interference experiments that provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these nonclassical paths is difficult to present. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.

  15. Nonclassical Paths in Quantum Interference Experiments

    NASA Astrophysics Data System (ADS)

    Sawant, Rahul; Samuel, Joseph; Sinha, Aninda; Sinha, Supurna; Sinha, Urbasi

    2014-09-01

    In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well-known text books in quantum mechanics implicitly and/or explicitly use this assumption that is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from nonclassical paths in quantum interference experiments that provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these nonclassical paths is difficult to present. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.

  16. Time and interference: Effects on working memory.

    PubMed

    Botto, Marta; Palladino, Paola

    2016-05-01

    This study tested predictions from the time-based resource-sharing (TBRS) model with a classical verbal working memory (WM) task, where target and non-target information interfere strongly with each other. Different predictions can be formulated according to the dominant perspectives (TBRS and interference hypothesis) on the role of inhibitory control in WM task performance. Here, we aimed to trace the activation of irrelevant information, examining priming effects in a lexical decision task immediately following WM recall. Results indicate the roles of both time and interference constraints in determining task performance. In particular, the role of time available seemed crucial at the highest WM loads (i.e., 3 and 4 memoranda). These were also associated with a higher activation of no-longer-relevant information but, in this case, independently from time available for processing. PMID:26085338

  17. Phonon wave interference and thermal bandgap materials.

    PubMed

    Maldovan, Martin

    2015-07-01

    Wave interference modifies phonon velocities and density of states, and in doing so creates forbidden energy bandgaps for thermal phonons. Materials that exhibit wave interference effects allow the flow of thermal energy to be manipulated by controlling the material's thermal conductivity or using heat mirrors to reflect thermal vibrations. The technological potential of these materials, such as enhanced thermoelectric energy conversion and improved thermal insulation, has fuelled the search for highly efficient phonon wave interference and thermal bandgap materials. In this Progress Article, we discuss recent developments in the understanding and manipulation of heat transport. We show that the rational design and fabrication of nanostructures provides unprecedented opportunities for creating wave-like behaviour of heat, leading to a fundamentally new approach for manipulating the transfer of thermal energy.

  18. Adaptive interference techniques for mobile antennas

    NASA Technical Reports Server (NTRS)

    Griffiths, Lloyd J.; Satorius, E.

    1988-01-01

    The results of a study performed to investigate effective, low cost adaptive signal processing techniques for suppressing mutual satellite interference that can arise in a mobile satellite (MSAT) communication system are discussed. The study focused on the use of adaptive sidelobe cancelling as a method to overcome undesired interference caused by a multiplicity of satellite transmissions within the field of view of the ground station. Results are presented which show that the conventional sidelobe canceller produces undesired reduction of the useful signal. This effect is due to the presence of the useful component in the reference antenna element. An alternative structure, the generalized sidelobe canceller (GSC), has been proposed to overcome this difficulty. A preliminary investigation of possible implementations of the GSC was conducted. It was found that at most 8 bits would be required to implement the GSC processor under conditions in which the desired signal-to-interference ratio is 25 dB.

  19. Getting more from visual working memory: Retro-cues enhance retrieval and protect from visual interference.

    PubMed

    Souza, Alessandra S; Rerko, Laura; Oberauer, Klaus

    2016-06-01

    Visual working memory (VWM) has a limited capacity. This limitation can be mitigated by the use of focused attention: if attention is drawn to the relevant working memory content before test, performance improves (the so-called retro-cue benefit). This study tests 2 explanations of the retro-cue benefit: (a) Focused attention protects memory representations from interference by visual input at test, and (b) focusing attention enhances retrieval. Across 6 experiments using color recognition and color reproduction tasks, we varied the amount of color interference at test, and the delay between a retrieval cue (i.e., the retro-cue) and the memory test. Retro-cue benefits were larger when the memory test introduced interfering visual stimuli, showing that the retro-cue effect is in part because of protection from visual interference. However, when visual interference was held constant, retro-cue benefits were still obtained whenever the retro-cue enabled retrieval of an object from VWM but delayed response selection. Our results show that accessible information in VWM might be lost in the processes of testing memory because of visual interference and incomplete retrieval. This is not an inevitable state of affairs, though: Focused attention can be used to get the most out of VWM. (PsycINFO Database Record PMID:26752731

  20. Frequent video game players resist perceptual interference.

    PubMed

    Berard, Aaron V; Cain, Matthew S; Watanabe, Takeo; Sasaki, Yuka

    2015-01-01

    Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT), a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning.

  1. 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…

  2. Sensorimotor Interference When Reasoning About Described Environments

    NASA Astrophysics Data System (ADS)

    Avraamides, Marios N.; Kyranidou, Melina-Nicole

    The influence of sensorimotor interference was examined in two experiments that compared pointing with iconic arrows and verbal responding in a task that entailed locating target-objects from imagined perspectives. Participants studied text narratives describing objects at locations around them in a remote environment and then responded to targets from memory. Results revealed only minor differences between the two response modes suggesting that bodily cues do not exert severe detrimental interference on spatial reasoning from imagined perspective when non-immediate described environments are used. The implications of the findings are discussed.

  3. Phonon interference effects in molecular junctions

    SciTech Connect

    Markussen, Troels

    2013-12-28

    We study coherent phonon transport through organic, π-conjugated molecules. Using first principles calculations and Green's function methods, we find that the phonon transmission function in cross-conjugated molecules, like meta-connected benzene, exhibits destructive quantum interference features very analogous to those observed theoretically and experimentally for electron transport in similar molecules. The destructive interference features observed in four different cross-conjugated molecules significantly reduce the thermal conductance with respect to linear conjugated analogues. Such control of the thermal conductance by chemical modifications could be important for thermoelectric applications of molecular junctions.

  4. Control of exciton transport using quantum interference

    NASA Astrophysics Data System (ADS)

    Lusk, Mark T.; Stafford, Charles A.; Zimmerman, Jeramy D.; Carr, Lincoln D.

    2015-12-01

    It is shown that quantum interference can be employed to create an exciton transistor. An applied potential gates the quasiparticle motion and also discriminates between quasiparticles of differing binding energy. When implemented within nanoscale assemblies, such control elements could mediate the flow of energy and information. Quantum interference can also be used to dissociate excitons as an alternative to using heterojunctions. A finite molecular setting is employed to exhibit the underlying discrete, two-particle, mesoscopic analog to Fano antiresonance. Selected entanglement measures are shown to distinguish regimes of behavior which cannot be resolved from population dynamics alone.

  5. Interference effects on scattering by parallel fibers

    NASA Technical Reports Server (NTRS)

    White, Susan M.; Kumar, Sunil

    1989-01-01

    The present examination of radiative heat transfer through fibrous materials gives attention to the interactions between radiation scattered from individual parallel fibers for the case of a normally-incident plane EM wave and different representative geometries. Experimental results are obtained for the specific case corresponding to fibers in one plane. Analytical models are developed for the radiative scattering behavior of fibrous media when the interference mechanism is accounted for; the results obtained indicate that interference decreases the scattering efficiency of fibrous media containing a large number of randomly positioned fibers.

  6. Four-wave interference and perfect blaze.

    PubMed

    Güther, R

    2012-10-01

    The recently calculated high diffraction efficiencies for TE- and TM-polarized light (perfect blaze) for echelette gratings are explained by four-wave interference, which is formed as a double periodical pattern in the cross section of the grating plane. The blazed grating profile should match this interference pattern for a single reference light wavelength. The recently published data are the special case of a general design. The prognoses of the model are connected with large grating constants in comparison with the light wavelength, where short grating constants need comparison with numerical methods.

  7. Advanced multiple access concepts in mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Ananasso, Fulvio

    1990-01-01

    Some multiple access strategies for Mobile Satellite Systems (MSS) are discussed. These strategies were investigated in the context of three separate studies conducted for the International Maritime Satellite Organization (INMARSAT) and the European Space Agency (ESA). Satellite-Switched Frequency Division Multiple Access (SS-FDMA), Code Division Multiple Access (CDMA), and Frequency-Addressable Beam architectures are addressed, discussing both system and technology aspects and outlining advantages and drawbacks of either solution with associated relevant hardware issues. An attempt is made to compare the considered option from the standpoint of user terminal/space segment complexity, synchronization requirements, spectral efficiency, and interference rejection.

  8. Ka-band geostationary satellite spacing requirements and access schemes

    NASA Technical Reports Server (NTRS)

    Caron, Mario; Hindson, Daniel J.

    1995-01-01

    Geostationary satellite systems for wideband personal communications applications have been proposed. This paper looks at the geostationary satellite spacing requirement to meet the ITU-R sharing criterion for FDMA and CDMA access schemes. CDMA capacity equation is first developed. Then the basis for the interference analysis between two systems with an overlapping coverage area is developed for the cases of identical and different access schemes and for bandwidth and power limited systems. An example of an interference analysis between two systems is fully carried out. The paper also points out the inherent problems when comparing systems with different access schemes. It is found that under certain scenarios, CDMA can allow a closer spacing between satellites.

  9. Visceral pentastomiasis caused by Armillifer armillatus in a captive striped hyena (Hyaena hyaena) in Chiang Mai Night Safari, Thailand.

    PubMed

    Dechkajorn, Sakorn; Nomsiri, Raksiri; Boonsri, Kittikorn; Sripakdee, Duanghatai; Sukontason, Kabkaew L; Wannasan, Anchalee; Chailangkarn, Sasisophin; Tiwananthagorn, Saruda

    2016-02-01

    Visceral pentastomiasis (porocephalosis) caused by Armillifer armillatus larvae was incidentally diagnosed in a female striped hyena (Hyaena hyaena) of unknown age which died unexpectedly in 2013. The hyena had been imported from Tanzania 8years earlier and have been since then in a zoo in Chiang Mai, northern Thailand. Pathological examination revealed visceral nymph migrans of pentastomes throughout the intestine, liver, diaphragm, omentum and mesentery, spleen, kidneys, and urinary bladder. Polymerase chain reaction and sequencing that targeted the pentastomid-specific 18S rRNA gene determined 100% identity with reference sequence for A. armillatus, suggesting that its ova can infect the hyena to serve as an intermediate host for the parasite. Further studies to identify the source of infection, its risk factors, and host range for A. armillatus are important to determine its zoonotic potential and to better prevent and manage the disease to protect animal and human health. PMID:26460150

  10. Visceral pentastomiasis caused by Armillifer armillatus in a captive striped hyena (Hyaena hyaena) in Chiang Mai Night Safari, Thailand.

    PubMed

    Dechkajorn, Sakorn; Nomsiri, Raksiri; Boonsri, Kittikorn; Sripakdee, Duanghatai; Sukontason, Kabkaew L; Wannasan, Anchalee; Chailangkarn, Sasisophin; Tiwananthagorn, Saruda

    2016-02-01

    Visceral pentastomiasis (porocephalosis) caused by Armillifer armillatus larvae was incidentally diagnosed in a female striped hyena (Hyaena hyaena) of unknown age which died unexpectedly in 2013. The hyena had been imported from Tanzania 8years earlier and have been since then in a zoo in Chiang Mai, northern Thailand. Pathological examination revealed visceral nymph migrans of pentastomes throughout the intestine, liver, diaphragm, omentum and mesentery, spleen, kidneys, and urinary bladder. Polymerase chain reaction and sequencing that targeted the pentastomid-specific 18S rRNA gene determined 100% identity with reference sequence for A. armillatus, suggesting that its ova can infect the hyena to serve as an intermediate host for the parasite. Further studies to identify the source of infection, its risk factors, and host range for A. armillatus are important to determine its zoonotic potential and to better prevent and manage the disease to protect animal and human health.

  11. Generalized quantum interference of correlated photon pairs

    PubMed Central

    Kim, Heonoh; Lee, Sang Min; Moon, Han Seb

    2015-01-01

    Superposition and indistinguishablility between probability amplitudes have played an essential role in observing quantum interference effects of correlated photons. The Hong-Ou-Mandel interference and interferences of the path-entangled photon number state are of special interest in the field of quantum information technologies. However, a fully generalized two-photon quantum interferometric scheme accounting for the Hong-Ou-Mandel scheme and path-entangled photon number states has not yet been proposed. Here we report the experimental demonstrations of the generalized two-photon interferometry with both the interferometric properties of the Hong-Ou-Mandel effect and the fully unfolded version of the path-entangled photon number state using photon-pair sources, which are independently generated by spontaneous parametric down-conversion. Our experimental scheme explains two-photon interference fringes revealing single- and two-photon coherence properties in a single interferometer setup. Using the proposed interferometric measurement, it is possible to directly estimate the joint spectral intensity of a photon pair source. PMID:25951143

  12. 47 CFR 78.19 - Interference.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....” Editorial Note: For Federal Register citations affecting § 78.19, see the List of CFR Sections Affected...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at...

  13. 47 CFR 78.19 - Interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....” Editorial Note: For Federal Register citations affecting § 78.19, see the List of CFR Sections Affected...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at...

  14. 47 CFR 78.19 - Interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....” Editorial Note: For Federal Register citations affecting § 78.19, see the List of CFR Sections Affected...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at...

  15. Exploiting Genetic Interference for Antiviral Therapy.

    PubMed

    Tanner, Elizabeth J; Kirkegaard, Karla A; Weinberger, Leor S

    2016-05-01

    Rapidly evolving viruses are a major threat to human health. Such viruses are often highly pathogenic (e.g., influenza virus, HIV, Ebola virus) and routinely circumvent therapeutic intervention through mutational escape. Error-prone genome replication generates heterogeneous viral populations that rapidly adapt to new selection pressures, leading to resistance that emerges with treatment. However, population heterogeneity bears a cost: when multiple viral variants replicate within a cell, they can potentially interfere with each other, lowering viral fitness. This genetic interference can be exploited for antiviral strategies, either by taking advantage of a virus's inherent genetic diversity or through generating de novo interference by engineering a competing genome. Here, we discuss two such antiviral strategies, dominant drug targeting and therapeutic interfering particles. Both strategies harness the power of genetic interference to surmount two particularly vexing obstacles-the evolution of drug resistance and targeting therapy to high-risk populations-both of which impede treatment in resource-poor settings. PMID:27149616

  16. 47 CFR 78.19 - Interference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....” Editorial Note: For Federal Register citations affecting § 78.19, see the List of CFR Sections Affected...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at...

  17. 47 CFR 78.19 - Interference.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....” Editorial Note: For Federal Register citations affecting § 78.19, see the List of CFR Sections Affected...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at...

  18. Wakeful rest alleviates interference-based forgetting.

    PubMed

    Mercer, Tom

    2015-01-01

    Retroactive interference (RI)--the disruptive influence of events occurring after the formation of a new memory--is one of the primary causes of forgetting. Placing individuals within an environment that postpones interference should, therefore, greatly reduce the likelihood of information being lost from memory. For example, a short period of wakeful rest should diminish interference-based forgetting. To test this hypothesis, participants took part in a foreign language learning activity and were shown English translations of 20 Icelandic words for immediate recall. Half of the participants were then given an 8-min rest before completing a similar or dissimilar interfering distractor task. The other half did not receive a rest until after the distractor task, at which point interference had already taken place. All participants were then asked to translate the Icelandic words for a second time. Results revealed that retention was significantly worse at the second recall test, but being allowed a brief rest before completing the distractor task helped reduce the amount of forgetting. Taking a short, passive break can shield new memories from RI and alleviate forgetting. PMID:24410154

  19. 47 CFR 74.703 - Interference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... business hours at the: Federal Communications Commission, 445 12th Street, S.W., Reference Information... a low-power TV or TV translator station causes interference to a CATV system by radiations within its assigned channel at the cable headend or on the output channel of any system converter located...

  20. Memory Retrieval and Interference: Working Memory Issues

    ERIC Educational Resources Information Center

    Radvansky, Gabriel A.; Copeland, David E.

    2006-01-01

    Working memory capacity has been suggested as a factor that is involved in long-term memory retrieval, particularly when that retrieval involves a need to overcome some sort of interference (Bunting, Conway, & Heitz, 2004; Cantor & Engle, 1993). Previous work has suggested that working memory is related to the acquisition of information during…

  1. Cue-Dependent Interference in Comprehension

    ERIC Educational Resources Information Center

    Van Dyke, Julie A.; McElree, Brian

    2011-01-01

    The role of interference as a primary determinant of forgetting in memory has long been accepted, however its role as a contributor to poor comprehension is just beginning to be understood. The current paper reports two studies, in which speed-accuracy tradeoff and eye-tracking methodologies were used with the same materials to provide converging…

  2. Verbal interference suppresses exact numerical representation.

    PubMed

    Frank, Michael C; Fedorenko, Evelina; Lai, Peter; Saxe, Rebecca; Gibson, Edward

    2012-02-01

    Language for number is an important case study of the relationship between language and cognition because the mechanisms of non-verbal numerical cognition are well-understood. When the Pirahã (an Amazonian hunter-gatherer tribe who have no exact number words) are tested in non-verbal numerical tasks, they are able to perform one-to-one matching tasks but make errors in more difficult tasks. Their pattern of errors suggests that they are using analog magnitude estimation, an evolutionarily- and developmentally-conserved mechanism for estimating quantities. Here we show that English-speaking participants rely on the same mechanisms when verbal number representations are unavailable due to verbal interference. Followup experiments demonstrate that the effects of verbal interference are primarily manifest during encoding of quantity information, and-using a new procedure for matching difficulty of interference tasks for individual participants-that the effects are restricted to verbal interference. These results are consistent with the hypothesis that number words are used online to encode, store, and manipulate numerical information. This linguistic strategy complements, rather than altering or replacing, non-verbal representations.

  3. Interference of Bose-Einstein condensates.

    PubMed

    Band, Y B

    2008-12-18

    A formalism for describing the coherence and interference properties of two atomic clouds of Bose-Einstein condensates (BEC) is presented, which is applicable even in the opposite limits when the BEC clouds are initially coherent and when they are initially independent. First, we develop a mean-field theory wherein one mean-field mode is used, and then, for fragmented (i.e., independent) condensates, we use a mean-field theory with two modes. We then develop a full two-mode field theory, with a field operator composed of a sum of two terms containing matter wave mode functions phi1 and phi2, that multiply the destruction operators of the modes, a1 and a2. When atom-atom interactions are present and when the mode functions overlap, the matter wave mode functions phi1 and phi2 develop components moving to the right and left, and this results in interference fringes in the density. At the many-body level, another source of interference arises from expectation values of the form (a(i)+a(j)) with i double dagger j, which become nonzero due to tunneling and interactions. We detail how these two sources of interference affect the density profile and the density-density correlation functions of Bose-Einstein condensates in the coherent and in the fragmented regimes.

  4. Sources of Interference in Recognition Testing

    ERIC Educational Resources Information Center

    Annis, Jeffrey; Malmberg, Kenneth J.; Criss, Amy H.; Shiffrin, Richard M.

    2013-01-01

    Recognition memory accuracy is harmed by prior testing (a.k.a., output interference [OI]; Tulving & Arbuckle, 1966). In several experiments, we interpolated various tasks between recognition test trials. The stimuli and the tasks were more similar (lexical decision [LD] of words and nonwords) or less similar (gender identification of male and…

  5. Exploiting Genetic Interference for Antiviral Therapy

    PubMed Central

    Kirkegaard, Karla A.; Weinberger, Leor S.

    2016-01-01

    Rapidly evolving viruses are a major threat to human health. Such viruses are often highly pathogenic (e.g., influenza virus, HIV, Ebola virus) and routinely circumvent therapeutic intervention through mutational escape. Error-prone genome replication generates heterogeneous viral populations that rapidly adapt to new selection pressures, leading to resistance that emerges with treatment. However, population heterogeneity bears a cost: when multiple viral variants replicate within a cell, they can potentially interfere with each other, lowering viral fitness. This genetic interference can be exploited for antiviral strategies, either by taking advantage of a virus’s inherent genetic diversity or through generating de novo interference by engineering a competing genome. Here, we discuss two such antiviral strategies, dominant drug targeting and therapeutic interfering particles. Both strategies harness the power of genetic interference to surmount two particularly vexing obstacles—the evolution of drug resistance and targeting therapy to high-risk populations—both of which impede treatment in resource-poor settings. PMID:27149616

  6. Ghost interference with pseudo-thermal light

    NASA Astrophysics Data System (ADS)

    Yao, Yin-Ping; Wan, Ren-Gang; Zhang, Shi-Wei; Song, Jia-Zheng; Zhang, Tong-Yi

    2012-11-01

    Ghost imaging (correlated imaging) has been extensively investigated in recent years, both theoretically and experimentally. By using the second-order or high-order coherence properties of light field and the correlation measurement, ghost imaging was realized with quantum entangled light, pseudo-thermal light and even true thermal light. In this work, basing on the theory of statistical optics, we model the dynamic process of thermal variation, and obtain the ghost interference and ghost imaging by means of simulated calculation. In the later experiment, a pseudo-thermal source is firstly prepared by using a laser beam to pass through a rotating ground glass plate, and the parameters of the pseudo-thermal source are obtained via Hanbury-Brown-Twiss (HBT) experiment. With the pseudo-thermal light, we perform ghost interference. The experimental results demonstrate the accordance of numerical prediction. And our conclusion shows that the quality of ghost interference is influenced by the size of the pinhole in the reference path, the little pinhole due to a higher quality of ghost interference.

  7. Preserved Proactive Interference in Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Carmo, Joana C.; Duarte, Elsa; Pinho, Sandra; Filipe, Carlos N.; Marques, J. Frederico

    2016-01-01

    In this study, we aimed to evaluate further the functioning and structuring of the semantic system in autism spectrum disorders (ASD). We analyzed the performance of 19 high-functioning young adults with ASD and a group of 20 age-, verbal IQ- and education-matched individuals with the Proactive Interference (PI) Paradigm to evaluate semantic…

  8. Reading aloud: the cumulative lexical interference effect.

    PubMed

    Mulatti, Claudio; Peressotti, Francesca; Job, Remo; Saunders, Steven; Coltheart, Max

    2012-08-01

    Picture naming shows a cumulative semantic interference effect: Latency for naming a target picture increases as a function of the number of pictures semantically similar to the target that have previously been named (Howard, Nickels, Coltheart, & Cole-Virtue, Cognition 100:464-482, 2006). Howard and colleagues, and also Oppenheim, Dell, and Schwartz (Cognition 114:227-252, 2010), argued that this occurs because of the joint presence in the picture-naming system of three critical properties: shared activation, priming, and competition. They also discussed the possibility that whenever any cognitive system possesses these three properties, a cumulative similarity-based interference effect from repeated use of that cognitive system will occur. We investigated this possibility by looking for a cumulative lexical interference effect when the task is reading aloud: Will the latency of reading a target word aloud increase as a function of the number of words orthographically/phonologically similar to the target that have previously been read aloud? We found that this was so. This supports the general idea that cumulative similarity-based interference effects will arise whenever any cognitive system that possesses the three key properties of shared activation, priming, and competition is repeatedly used. PMID:22623265

  9. Resistance to Interference of Olfactory Perceptual Learning

    ERIC Educational Resources Information Center

    Stevenson, Richard J.; Case, Trevor I.; Tomiczek, Caroline

    2007-01-01

    Olfactory memory is especially persistent. The current study explored whether this applies to a form of perceptual learning, in which experience of an odor mixture results in greater judged similarity between its elements. Experiment 1A contrasted 2 forms of interference procedure, "compound" (mixture AW, followed by presentation of new mixtures…

  10. Movement Interference in Autism-Spectrum Disorder

    ERIC Educational Resources Information Center

    Gowen, E.; Stanley, J.; Miall, R. C.

    2008-01-01

    Movement interference occurs when concurrently observing and executing incompatible actions and is believed to be due to co-activation of conflicting populations of mirror neurons. It has also been suggested that mirror neurons contribute towards the imitation of observed actions. However, the exact neural substrate of imitation may depend on task…

  11. Interference, Integration and the Synchronic Fallacy.

    ERIC Educational Resources Information Center

    Mackey, William F.

    The purposes of this paper are to examine the effects of synchronic description in distinguishing between interference and integration in cases of language contact, and to suggest alternative methods of description suitable for the analysis of systems in motion. The "synchronic fallacy" is defined here as the belief that one can describe a…

  12. Simulation Tools Prevent Signal Interference on Spacecraft

    NASA Technical Reports Server (NTRS)

    2014-01-01

    NASA engineers use simulation software to detect and prevent interference between different radio frequency (RF) systems on a rocket and satellite before launch. To speed up the process, Kennedy Space Center awarded SBIR funding to Champaign, Illinois-based Delcross Technologies LLC, which added a drag-and-drop feature to its commercial simulation software, resulting in less time spent preparing for the analysis.

  13. Noise and Speech Interference: Proceedings of Minisymposium

    NASA Technical Reports Server (NTRS)

    Shepherd, W. T. (Editor)

    1975-01-01

    Several papers are presented which deal with the psychophysical effects of interference with speech and listening activities by different forms of noise masking and filtering. Special attention was given to the annoyance such interruptions cause, particularly that due to aircraft flyover noises. Activities such as telephone listening and television watching were studied. A number of experimental investigations are described and the results are analyzed.

  14. Inkjet Color Printing by Interference Nanostructures.

    PubMed

    Yakovlev, Aleksandr V; Milichko, Valentin A; Vinogradov, Vladimir V; Vinogradov, Alexandr V

    2016-03-22

    Color printing technology is developing rapidly; in less than 40 years, it moved from dot matrix printers with an ink-soaked cloth ribbon to 3D printers used to make three-dimensional color objects. Nevertheless, what remained unchanged over this time is the fact that in each case, dye inks (CMYK or RGB color schemes) were exclusively used for coloring, which inevitably limits the technological possibilities and color reproduction. As a next step in printing color images and storing information, we propose the technology of producing optical nanostructures. In this paper, we report use of inkjet technology to create colored interference layers with high accuracy without the need for high-temperature fixing. This was made possible due to using titania-based colloidal ink yielding monolithic coatings with a high refractive index (2.00 ± 0.08 over the entire visible range) when naturally dried. By controlling the film thickness by using inkjet deposition, we produced images based on controlled interference and implementing color printing with one ink. The lack of dyes in the proposed method has good environmental prospects, because applied systems based on a crystalline anatase sol are nontoxic and biologically inert. The paper explains in detail the principle of producing interference images by the classical inkjet method and shows the advantages of this technique in depositing coatings with uniform thickness, which are required for large-scale interference color imaging even on unprepared polymer films. This article demonstrates the possibility of inkjet printing of nanostructures with a precision in thickness of up to 50 nm, we believe that the proposed approach will be the groundwork for developing interference color printing approach and allow to implement new methods of forming optical nano-objects by widely available techniques.

  15. A wall interference assessment/correction system

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.

    1993-01-01

    A Wall Signature method originally developed by Hackett was selected to be adapted for the Ames 12-ft Wind Tunnel Wall Interference Assessment/Correction (WIAC) System in the project. This method uses limited measurements of the static pressure at the wall, in conjunction with the solid wall boundary condition, to determine the strength and distribution of singularities representing the test article. The singularities are used in turn for estimating wall interference at the model location. The lifting interference will be treated separately by representing in a horseshoe vortex system for the model's lifting effects. The development and implementation of a working prototype will be completed, delivered, and documented with a software manual. The WIAC code will be validated by conducting numerically simulated experiments rather than actual wind tunnel experiments. The simulations will be used to generate both free-air and confined wind-tunnel flow fields for each of the test articles over a range of test configurations. Specifically, the pressure signature at the test section wall will be computed for the tunnel case to provide the simulated 'measured' data. These data will serve as the input for the WIAC method - Wall Signature method. The performance of the WIAC method then may be evaluated by comparing the corrected parameters with those for the free-air simulation. The following two additional tasks are included in the supplement No. 1 to the basic Grant. On-line wall interference calculation: The developed wall signature method (modified Hackett's method) for Ames 12-ft Tunnel will be the pre-computed coefficients which facilitate the on-line calculation of wall interference; and support system effects estimation: The effects on the wall pressure measurements due to the presence of the model support systems will be evaluated.

  16. 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…

  17. [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…

  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. Open Access and beyond.

    PubMed

    Mathur, Shawn; Schmidt, Christian; Das, Chhaya; Tucker, Philip W

    2006-01-01

    Uncensored exchange of scientific results hastens progress. Open Access does not stop at the removal of price and permission barriers; still, censorship and reading disabilities, to name a few, hamper access to information. Here, we invite the scientific community and the public to discuss new methods to distribute, store and manage literature in order to achieve unfettered access to literature. PMID:16956402

  20. 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…

  1. Movement Coordination or Movement Interference: Visual Tracking and Spontaneous Coordination Modulate Rhythmic Movement Interference

    PubMed Central

    Romero, Veronica; Coey, Charles; Schmidt, R. C.; Richardson, Michael J.

    2012-01-01

    When an actor performs a rhythmic limb movement while observing a spatially incongruent movement he or she exhibits increased movement orthogonal to the instructed motion. Known as rhythmic movement interference, this phenomenon has been interpreted as a motor contagion effect, whereby observing the incongruent movement interferes with the intended movement and results in a motor production error. Here we test the hypothesis that rhythmic movement interference is an emergent property of rhythmic coordination. Participants performed rhythmic limb movements at a self-selected tempo while observing a computer stimulus moving in a congruent or incongruent manner. The degree to which participants visually tracked the stimulus was manipulated to influence whether participants became spontaneously entrained to the stimulus or not. Consistent with the rhythmic coordination hypothesis, participants only exhibited the rhythmic movement interference effect when they became spontaneously entrained to the incongruent stimulus. PMID:23028607

  2. Analysis of optical frequency-modulated continuous-wave interference.

    PubMed

    Zheng, Jesse

    2004-07-20

    I systematically analyze the theory of optical frequency-modulated continuous-wave (FMCW) interference. There are three different versions of optical FMCW interference, discussed in detail: sawtooth-wave optical FMCW interference, triangular-wave optical FMCW interference, and sinusoidal-wave optical FMCW interference. The essential concepts and technical terms are clearly defined, the necessary simplifications are introduced according to the characteristics of optical waves, and the formulas used to calculate the signal intensities under two different situations (static and dynamic) are properly derived. Advantages and limitations of each version of optical FMCW interference are also discussed. PMID:15291063

  3. Dependency-dependent interference: NPI interference, agreement attraction, and global pragmatic inferences

    PubMed Central

    Xiang, Ming; Grove, Julian; Giannakidou, Anastasia

    2013-01-01

    Previous psycholinguistics studies have shown that when forming a long distance dependency in online processing, the parser sometimes accepts a sentence even though the required grammatical constraints are only partially met. A mechanistic account of how such errors arise sheds light on both the underlying linguistic representations involved and the processing mechanisms that put such representations together. In the current study, we contrast the negative polarity items (NPI) interference effect, as shown by the acceptance of an ungrammatical sentence like “The bills that democratic senators have voted for will ever become law,” with the well-known phenomenon of agreement attraction (“The key to the cabinets are … ”). On the surface, these two types of errors look alike and thereby can be explained as being driven by the same source: similarity based memory interference. However, we argue that the linguistic representations involved in NPI licensing are substantially different from those of subject-verb agreement, and therefore the interference effects in each domain potentially arise from distinct sources. In particular, we show that NPI interference at least partially arises from pragmatic inferences. In a self-paced reading study with an acceptability judgment task, we showed NPI interference was modulated by participants' general pragmatic communicative skills, as quantified by the Autism-Spectrum Quotient (AQ, Baron-Cohen et al., 2001), especially in offline tasks. Participants with more autistic traits were actually less prone to the NPI interference effect than those with fewer autistic traits. This result contrasted with agreement attraction conditions, which were not influenced by individual pragmatic skill differences. We also show that different NPI licensors seem to have distinct interference profiles. We discuss two kinds of interference effects for NPI licensing: memory-retrieval based and pragmatically triggered. PMID:24109468

  4. Interference effects on Space Station Freedom and space shuttle orbiter Ku-band downlinks

    NASA Technical Reports Server (NTRS)

    Kwon, Hyuck M.; Loh, Yin-Chung; Tu, Kwei

    1993-01-01

    The space shuttle orbiter (SSO) and Ku-band single access return (KSAR) link and the Space Station Freedom (SSF) KSAR link via the tracking and data relay satellite system (TDRSS) use the same carrier frequency. The interference between spacecraft is minimized by opposite antenna polarizations and by TDRSS antenna beam pointing, but if the SSF and SSO are in close proximity, it is expected that mutual interference will be significant. Recently, Tsang and Su (1988, 1989) simulated the mutual interference effects, using a practical nonlinear bandlimited channel. The purpose of this paper is to demonstrate that a simplified (i.e., linear band-limited channel) analytical approach will yield adequate accuracy for the expected range of operating conditions. Relative degradation in bit energy-to-thermal noise power spectral density ratio to achieve a 10 exp -5 coded bit-error-probability is determined to be 4 dB for the Ku-band SSO-to-TDRS I-channel return link with a 4.5 dB effective signal-to-interference total power ratio (S/I) when the Ku-band SSF-to-TDRS return link interferes, whereas Su's simulation yields approximately 5 dB degradation. For the Ku-band SSF-to-TDRS return link, both analysis and simulation results yield a relative signal degradation of 0.4 dB at the effective S/I = 21.6 dB. In conclusion, interference on the Ku-band SSO-to-TDRS I-channel return link is significant, but on the Ku-band SSF-to-TDRS return link it is negligible.

  5. Genetic algorithm used in interference filter's design

    NASA Astrophysics Data System (ADS)

    Li, Jinsong; Fang, Ying; Gao, Xiumin

    2009-11-01

    An approach for designing of interference filter is presented by using genetic algorithm (here after refer to as GA) here. We use GA to design band stop filter and narrow-band filter. Interference filter designed here can calculate the optimal reflectivity or transmission rate. Evaluation function used in our genetic algorithm is different from the others before. Using characteristic matrix to calculate the photonic band gap of one-dimensional photonic crystal is similar to electronic structure of doped. If the evaluation is sensitive to the deviation of photonic crystal structure, the approach by genetic algorithm is effective. A summary and explains towards some uncompleted issues are given at the end of this paper.

  6. Short-interference RNAs: becoming medicines

    PubMed Central

    Martínez, Tamara; Jiménez, Ana Isabel; Pañeda, Covadonga

    2015-01-01

    RNA interference is a cellular mechanism by which small molecules of double stranded RNA modulate gene expression acting on the concentration and/or availability of a given messenger RNA. Almost 10 years after Fire and Mello received the Nobel Prize for the discovery of this mechanism in flat worms, RNA interference is on the edge of becoming a new class of therapeutics. With various phase III studies underway, the following years will determine whether RNAi-therapeutics can rise up to the challenge and become mainstream medicines. The present review gives a thorough overview of the current status of this technology focusing on the path to the clinic of this new class of compounds. PMID:26648823

  7. Stereoscopic surround displays using interference filters

    NASA Astrophysics Data System (ADS)

    Peikert, Silvio; Gerhardt, Jérémie

    2012-03-01

    To achieve stereoscopy on surround displays interference filters have some advantages over other techniques. However these filters introduce strong color differences between the projectors, which may reveal that the display is compound by multiple projectors. This article presents methods for a computationally efficient correction of the colorimetric properties of multi-projector surround displays. This correction is based on automated measurements by multiple cameras and a spectrometer. The described methods were validated by applying them to a stereoscopic dome display made up of 16 high definition projectors equipped with Infitec filters. On that display we achieved a significant improvement of the colorimetric properties compared to regular soft-edge blending. Our reference setup shows that the multi-projector approach combined with interference filters allows to build highly immersive stereoscopic surround displays fulfilling today's requirements on spatial resolution, frame rates and interaction latencies.

  8. Quantum interference between resonant and nonresonant photorecombination

    NASA Astrophysics Data System (ADS)

    Tu, B.; Xiao, J.; Yao, K.; Shen, Y.; Yang, Y.; Lu, D.; Li, W. X.; Qiu, M. L.; Wang, X.; Chen, C. Y.; Fu, Y.; Wei, B.; Zheng, C.; Huang, L. Y.; Zhang, B. H.; Tang, Y. J.; Hutton, R.; Zou, Y.

    2016-03-01

    In this paper, we present experimental and theoretical studies on the interference between resonant and nonresonant photorecombinations for the main resonances of ground-state He-, Be-, B-, C-, N-, and O-like W ions. Experiments were done using a fast electron energy scanning technique at the upgraded Shanghai electron-beam ion trap. Asymmetric resonances were observed, and their Fano factors, which measure the interference degree, were determined. The calculations were done under the framework of Fano's theory by using the flexible atomic code, in which the relativistic configuration interaction method was employed. Among the nine resonances studied in this work, eight experimental results agree with the calculation within experimental uncertainties. But the experimental result for the resonance of Be-like W ions, through the intermediate state of [(1s2s22p 1 /2) 12 p3 /2] 5 /2, deviates from its corresponding theoretical result by 1.3 times experimental uncertainty.

  9. Flow Measurement by Means of Light Interference

    NASA Technical Reports Server (NTRS)

    Zobel, Th.

    1949-01-01

    There has been under development for the high-speed wind tunnel of the LFA an optical measuring arrangement for the qualitative and quantitative investigation of flow. By the use of interference measurements, the determination of density at the surface of the bodies being tested in the air stream and in the vicinity of these bodies can be undertaken. The results obtained so far in the simple preliminary investigations show that it is possible, even at a low Reynolds number, to obtain the density field in the neighborhood of a test body by optical means. Simple analytical expressions give the relation between density, pressure, velocity, and temperature. In addition to this, the interference measurement furnishes valuable data on the state of the boundary layer, that is, the sort of boundary layer (whether laminar or turbulent), as well as the temperature and velocity distribution.

  10. Interference examiner for certification of precision autocollimators

    SciTech Connect

    Martynov, V.T.; Brda, V.A.; Likhttsinder, B.A.; Shestopalov, Y.N.

    1985-05-01

    Regular polygonal prisms together with an autocollimator are usually employed as standard means in the study and certification of angle-measuring instruments and apparatus; the prisims, in turn, must be certified with high accuracy. The interference examiner employs an optical system similar to that of the examiner in the new State primary standard plane-angle unit. The examiner is based on a twin-wave Michelson interferometer. Instead of a separate scale, the interference examiner uses two vertical marks applied directly to the end reflectors. A comparison was made of the rotation angles of the mirror in the range of 0-1/sup 0/ as reproduced by the examiner alpha /sub T/ (trigonometric method) and as measured by a UDP-025 precision angle-measuring instrument alpha /sub g/ (goniometric method). Processing of the obtained measurement results showed that the difference between alpha /sub T/ and alpha /sub g/ does not exceed the measurement error of the UDP-025.

  11. Electron Interference in Ballistic Graphene Nanoconstrictions

    NASA Astrophysics Data System (ADS)

    Baringhaus, Jens; Settnes, Mikkel; Aprojanz, Johannes; Power, Stephen R.; Jauho, Antti-Pekka; Tegenkamp, Christoph

    2016-05-01

    We realize nanometer size constrictions in ballistic graphene nanoribbons grown on sidewalls of SiC mesa structures. The high quality of our devices allows the observation of a number of electronic quantum interference phenomena. The transmissions of Fabry-Perot-like resonances are probed by in situ transport measurements at various temperatures. The energies of the resonances are determined by the size of the constrictions, which can be controlled precisely using STM lithography. The temperature and size dependence of the measured conductances are in quantitative agreement with tight-binding calculations. The fact that these interference effects are visible even at room temperature makes the reported devices attractive as building blocks for future carbon based electronics.

  12. Capacity and interference in a PCS system

    NASA Technical Reports Server (NTRS)

    Lee, William C. Y.

    1991-01-01

    In order to increase the capacity of a Personal Communication Service (PCS) system, the PCS system environment needs to be understood. The PCS system environment is briefly described in this paper. Because the frequency reuse concept is used to increase the capacity of PCS, the cochannel cells created cause cochannel interference. There are two approaches to reduce cochannel interference. One is the microcell approach (within the existing system) and the other is the reduction of cochannel cell separation approach (developing a new system). In-building communications using PCS systems has been addressed. Also, the Intelligent Network (IN) is described to show its importance. The cellular system has great potential to be the future PCS system.

  13. Interference and Chaos in Metamaterials Cavities

    NASA Astrophysics Data System (ADS)

    Litchinitser, Natalia; Jose, Jorge

    2014-03-01

    Optical metamaterials are engineered artificial nanostructures that possess optical properties not available in nature. As metamaterials research continues to mature, their practical applications as well as fundamental questions on wave propagation in these materials attract significant interest. In this talk we focus on wave propagation and interference in chaotic wave cavities with negative or near-zero index of refraction and in double-slit configurations. In this context, we explicitly consider an incomplete two-dimensional D-cavity previously studied, which shows chaotic ray propagation together with scars. We have addressed the question as to how that type of wave propagation is modified by adding metamaterials in these chaotic cavities. We find that the wave interference patterns show significant qualitatively and quantitative changes depending on the effective parameters of the cavity, illumination conditions (planes waves versus beams), and geometry of the system. We will discuss possible experimental setups where these results may be validated.

  14. Short-interference RNAs: becoming medicines.

    PubMed

    Martínez, Tamara; Jiménez, Ana Isabel; Pañeda, Covadonga

    2015-01-01

    RNA interference is a cellular mechanism by which small molecules of double stranded RNA modulate gene expression acting on the concentration and/or availability of a given messenger RNA. Almost 10 years after Fire and Mello received the Nobel Prize for the discovery of this mechanism in flat worms, RNA interference is on the edge of becoming a new class of therapeutics. With various phase III studies underway, the following years will determine whether RNAi-therapeutics can rise up to the challenge and become mainstream medicines. The present review gives a thorough overview of the current status of this technology focusing on the path to the clinic of this new class of compounds. PMID:26648823

  15. Electromagnetic Interference in a Private Swimming Pool

    PubMed Central

    Iskandar, Sandia; Lavu, Madhav; Atoui, Moustapha; Lakkireddy, Dhanunjaya

    2016-01-01

    Although current lead design and filtering capabilities have greatly improved, Electromagnetic Interference (EMI) from environmental sources has been increasingly reported in patients with Cardiac Implantable Electronic Device (CIED) [1]. Few cases of inappropriate intracardiac Cardioverter Defibrillator (ICD) associated with swimming pool has been described [2]. Here we present a case of 64 year old male who presented with an interesting EMI signal that was subsequently identified to be related to AC current leak in his swimming pool. PMID:27479205

  16. Interference to satellite systems produced by rainscatter

    NASA Astrophysics Data System (ADS)

    Howell, R. G.; Thompson, P. T.

    1991-10-01

    Data, obtained from eight small dish receivers, placed around the United Kingdom, and designed to detect the scattering by rain of signals from the British Telecom (BT) 11 GHz microwave network, is presented. Fifteen site years of measurements were analyzed to produce cumulative distributions of effective receive antenna noise temperature and, where rainscattered signals were detected, cumulative distributions of transmission loss. The results obtained are compared with those predicted by a BT/University of Essex rainscatter interference prediction model (SCIMP).

  17. Helicopter hub fairing and pylon interference drag

    NASA Technical Reports Server (NTRS)

    Graham, D. R.; Sung, D. Y.; Young, L. A.; Louie, A. W.; Stroub, R. H.

    1989-01-01

    A wind tunnel test was conducted to study the aerodynamics of helicopter hub and pylon fairings. The test was conducted in the 7-by 10 Foot Subsonic Wind Tunnel (Number 2) at Ames Research Center using a 1/5-scale XH-59A fuselage model. The primary focus of the test was on the rotor hub fairing and pylon mutual interference drag. Parametric studies of pylon and hub fairing geometry were also conducted. This report presents the major findings of the test as well as tabulated force and moment data, flow visualization photographs, and graphical presentations of the drag data. The test results indicate that substantial drag reduction can be attained through the use of a cambered hub fairing with circular arc upper surface and flat lower surface. Furthermore, a considerable portion of the overall drag reduction is attributed to the reduction in the hub-on-pylon interference drag. It is also observed that the lower surface curvature of the fairing has a strong influence on the hub fairing and on pylon interference drag. However, the drag reduction benefit that was obtained by using the cambered hub fairing with a flat lower surface was adversely affected by the clearance between the hub fairing and the pylon.

  18. Segregation of unvoiced speech from nonspeech interference.

    PubMed

    Hu, Guoning; Wang, DeLiang

    2008-08-01

    Monaural speech segregation has proven to be extremely challenging. While efforts in computational auditory scene analysis have led to considerable progress in voiced speech segregation, little attention has been given to unvoiced speech, which lacks harmonic structure and has weaker energy, hence more susceptible to interference. This study proposes a new approach to the problem of segregating unvoiced speech from nonspeech interference. The study first addresses the question of how much speech is unvoiced. The segregation process occurs in two stages: Segmentation and grouping. In segmentation, the proposed model decomposes an input mixture into contiguous time-frequency segments by a multiscale analysis of event onsets and offsets. Grouping of unvoiced segments is based on Bayesian classification of acoustic-phonetic features. The proposed model for unvoiced speech segregation joins an existing model for voiced speech segregation to produce an overall system that can deal with both voiced and unvoiced speech. Systematic evaluation shows that the proposed system extracts a majority of unvoiced speech without including much interference, and it performs substantially better than spectral subtraction. PMID:18681616

  19. Immunizing digital systems against electromagnetic interference

    NASA Astrophysics Data System (ADS)

    Ewing, P. D.; Korsah, K.; Antonescu, C.

    This paper discusses the development of the technical basis for acceptance criteria applicable to the immunization of digital systems against electromagnetic interference (EMI). The work is sponsored by the US Nuclear Regulatory Commission and stems from the safety-related issues that need to be addressed as a result of the application of digital instrumentation and control systems in nuclear power plants. Designers of digital circuits are incorporating increasingly higher clock frequencies and lower logic level voltages, thereby leading to potentially greater susceptibility of spurious interference being misinterpreted as legitimate logic. Development of the technical basis for acceptance criteria to apply to these digital systems centers around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems. First, good EMC design and installation practices are needed to control the emissions from interference sources and thereby their impact on other nearby circuits and systems. Secondly, a test and evaluation program is needed to outline the EMI tests to be performed, the associated test methods to be followed, and adequate test limits to ensure that the circuit or system under test meets the recommended guidelines. Test and evaluation should be followed by periodic maintenance to assess whether the recommended EMI control practices continue to be adhered to as part of the routine operation of the nuclear power plant. By following these steps, the probability of encountering safety-related instrumentation problems associated with EMI will be greatly reduced.

  20. Mais Médicos (More Doctors) Program: its contribution in view of WHO recommendations for provision of doctors.

    PubMed

    Carvalho, Viviane Karoline da Silva; Marques, Carla Pintas; Silva, Everton Nunes da

    2016-09-01

    In order to examine whether Brazil's Mais Médicos (More Doctors) Programme (PMM) reflected World Health Organisation (WHO) recommendations for improved attraction, retention and recruitment of health workers in remote and rural areas, this descriptive, qualitative study drew on document analysis in order to compare the WHO recommendations published in 2010 with Brazil's Law No. 12,871/13, which instituted the PMM. Of the 16 WHO recommendations systematised here, the PMM met 37.5%. Recommendations not incorporated into the PMM include career development programmes and public recognition strategies. Although reflecting WHO recommendations and already in place elsewhere in the SUS prior to announcement of the PMM, the National Retention Grant Programme and multi-professional teams (as in the Family Health Strategy) were not implemented by the PMM. The programme contains innovative components such as a new curriculum for medical schools and compulsory medical service. On the other hand, the PMM could have invested more in personal and professional support. PMID:27653062

  1. Protective Effects of Sheng-Mai-San on Right Ventricular Dysfunction during Chronic Intermittent Hypoxia in Mice

    PubMed Central

    Chai, Cheng-Zhi; Mo, Wei-Lan; Zhuang, Xian-Fei; Yan, Yong-Qing

    2016-01-01

    Right ventricular (RV) dysfunction and failure contribute to the increasing morbidity and mortality of cardiovascular diseases; however, current treatment strategies are grossly inadequate. Sheng-Mai-San (SMS) has been used to treat heart diseases for hundreds of years in China, and its protective effects on RV have not been observed. The present study was to investigate the protective effects of SMS aqueous extract on RV dysfunction in chronic intermittent hypoxia (CIH) mice model. The results showed that CIH mice model presented RV dysfunction and maladaptive compensation after 28-day-CIH and SMS treatment significantly reversed these changes. Diastolic function of RV was restored and systolic dysfunction was attenuated, including elevation of RV stroke volume and fractional shortening, as well as pulmonary circulation. Structurally, SMS treatment inhibited RV dilation, cardiomyocytes vacuolization, ultrastructure abnormalities, and the expression of cleaved caspase-3. Of importance, SMS showed remarkable antioxidant activity by decreasing the levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), increasing the levels of superoxide dismutase (SOD) and heme oxygenase-1 (HO-1), as well as inhibiting the overexpression of 3-NT in RV. Our results indicate that SMS preserve RV structure and function in CIH-exposed mice by involving regulation in both ROS and Reactive Nitrogen Species (RNS) production. PMID:27073402

  2. Potentially pathogenic free-living amoebae in some flood-affected areas during 2011 Chiang Mai flood.

    PubMed

    Wannasan, Anchalee; Uparanukraw, Pichart; Songsangchun, Apichart; Morakote, Nimit

    2013-01-01

    The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA.

  3. Genetic population structure of polychaeta Neanthes glandicincta (Nereididae) of the Mai Po Inner Deep Bay Ramsar Site, Hong Kong.

    PubMed

    Shen, Ping-Ping; Gu, Ji-Dong

    2015-10-01

    Neanthes glandicincta (Nereididae, Polychaeta) is the first numerically dominant benthic infauna in the Mai Po international Ramsar site, Hong Kong and also an economically important species for food source of birds and fishes. In present study, highly conserved nuclear ribosomal DNA (SSU and LSU rDNA) and mitochondrial COI gene were employed to study the population structure of N. glandicincta in the subtropical mudflat. The specimens were collected from five localities in February 2006, February-August 2007 and preserved at -80 °C, methanol or formalin, respectively. DNA extraction efficiency was the highest in fresh materials and lowest in formalin-fixed samples. The 18S (1774 bp), 28S D1 (383 bp) and COI genes were sequenced and analyzed. Both 18S and 28S D1 rDNA were highly conserved and showed no difference among the populations, whereas COI gene exhibited relatively high-level intraspecific polymorphism (2.2 %). The population from onshore and near mangrove station was phylogenetic different from other sites, indicating restricted gene exchange between the region of river mouth and mangrove forest. The mangrove may form a barrier for the dispersal of pelagic/benthic larvae of the population, which indicates that the population genetic difference is related to different habitats. PMID:25967938

  4. Protective effect of the extract of Yi-Qi-Fu-Mai preparation on hypoxia-induced heart injury in mice.

    PubMed

    Feng, Ya-Qian; Ju, Ai-Chun; Liu, Chun-Hua; Wang, Ting; Yu, Bo-Yang; Qi, Jin

    2016-06-01

    Yi-Qi-Fu-Mai (YQFM) is extensively used clinically to treat cardiovascular diseases in China. To explore the anti-hypoxia effect of the extract of YQFM preparation (EYQFM), the EYQFM (1.4, 2.8, and 5.5 g·kg(-1)·d(-1)) was assessed for its heart-protective effect in a chronic intermittent hypoxia (CIH) animal model (oxygen pressure 7%-8%, 20 min per day) for 28 days of treatment. Betaloc (0.151 6 g·kg(-1)·d(-1)) was used as a positive control. The histopathological analyses of heart in CIH mice were conducted. Several cardiac state parameters, such as left ventricular ejection fractions (EF), stroke volume (SV), expression of creatine kinase (CK), lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA) were measured. The results showed that treatment with EYQFM markedly reversed swelling of the endothelial cells and vacuolization in the heart when compared with the model group. Further study demonstrated that EYQFM significantly improved ventricular myocardial contractility by increasing EF and SV. In addition, EYQFM inhibited the activity of CK, LDH, decreased the level of MDA and improved SOD activity. The results demonstrated that EYQFM significantly improved the tolerability of myocardium to hypoxia and ameliorated the cardiac damage in the CIH model. PMID:27473956

  5. POTENTIALLY PATHOGENIC FREE-LIVING AMOEBAE IN SOME FLOOD-AFFECTED AREAS DURING 2011 CHIANG MAI FLOOD

    PubMed Central

    Wannasan, Anchalee; Uparanukraw, Pichart; Songsangchun, Apichart; Morakote, Nimit

    2013-01-01

    SUMMARY The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA. PMID:24213194

  6. Pallisentis rexus from the Chiang Mai Basin, Thailand: ultrastructural studies on egg envelope development and the mechanism of egg expansion.

    PubMed

    Wongkham, W; Whitfield, P J

    2004-03-01

    Pallisentis rexus Wongkham & Whitfield, 1999 (Eoacanthocephala: Quadrigyridae) infects the freshwater snakehead fish, Channa striata, in the Chiang Mai Basin, Thailand. All stages of egg development within the body cavity of the female parasite were observed, using transmission electron microscopy. Changes in mature eggs after contact with water were also investigated. The mature egg has five egg envelopes separated from each other by four gaps. The fertilization membrane, which is formed first, is pushed centrifugally by other, subsequently formed, envelopes and gaps, which produces a final total shell thickness of 8-36 microm around the acanthor. The disappearance of the outermost layer and the unpleating of an adjacent inner layer causes the expansion of eggs on contact with water. The volume of an expanded egg is approximately 27 times that of an unexpanded one, but the density of eggs is reduced from a value greater than water to one almost equal to water. This is believed to aid the dispersion of eggs. PMID:14972041

  7. Genetic population structure of polychaeta Neanthes glandicincta (Nereididae) of the Mai Po Inner Deep Bay Ramsar Site, Hong Kong.

    PubMed

    Shen, Ping-Ping; Gu, Ji-Dong

    2015-10-01

    Neanthes glandicincta (Nereididae, Polychaeta) is the first numerically dominant benthic infauna in the Mai Po international Ramsar site, Hong Kong and also an economically important species for food source of birds and fishes. In present study, highly conserved nuclear ribosomal DNA (SSU and LSU rDNA) and mitochondrial COI gene were employed to study the population structure of N. glandicincta in the subtropical mudflat. The specimens were collected from five localities in February 2006, February-August 2007 and preserved at -80 °C, methanol or formalin, respectively. DNA extraction efficiency was the highest in fresh materials and lowest in formalin-fixed samples. The 18S (1774 bp), 28S D1 (383 bp) and COI genes were sequenced and analyzed. Both 18S and 28S D1 rDNA were highly conserved and showed no difference among the populations, whereas COI gene exhibited relatively high-level intraspecific polymorphism (2.2 %). The population from onshore and near mangrove station was phylogenetic different from other sites, indicating restricted gene exchange between the region of river mouth and mangrove forest. The mangrove may form a barrier for the dispersal of pelagic/benthic larvae of the population, which indicates that the population genetic difference is related to different habitats.

  8. 47 CFR 74.643 - Interference to geostationary-satellites.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Interference to geostationary-satellites. 74... Television Broadcast Auxiliary Stations § 74.643 Interference to geostationary-satellites. Applicants and... geostationary-satellites....

  9. 47 CFR 74.643 - Interference to geostationary-satellites.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Interference to geostationary-satellites. 74... Television Broadcast Auxiliary Stations § 74.643 Interference to geostationary-satellites. Applicants and... geostationary-satellites....

  10. 47 CFR 74.643 - Interference to geostationary-satellites.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Interference to geostationary-satellites. 74... Television Broadcast Auxiliary Stations § 74.643 Interference to geostationary-satellites. Applicants and... geostationary-satellites....

  11. 47 CFR 74.643 - Interference to geostationary-satellites.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Interference to geostationary-satellites. 74... Television Broadcast Auxiliary Stations § 74.643 Interference to geostationary-satellites. Applicants and... geostationary-satellites....

  12. 47 CFR 74.643 - Interference to geostationary-satellites.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Interference to geostationary-satellites. 74... Television Broadcast Auxiliary Stations § 74.643 Interference to geostationary-satellites. Applicants and... geostationary-satellites....

  13. Spectral anomalies in Young's double-slit interference experiment.

    PubMed

    Pu, Jixiong; Cai, Chao; Nemoto, Shojiro

    2004-10-18

    We report a phenomenon of spectral anomalies in the interference field of Young's double-slit interference experiment. The potential applications of the spectral anomalies in the information encoding and information transmission in free space are also considered.

  14. The Cost of Learning: Interference Effects in Memory Development

    PubMed Central

    Darby, Kevin P.; Sloutsky, Vladimir M.

    2015-01-01

    Learning often affects future learning and memory for previously learned information by exerting either facilitation or interference effects. Several theoretical accounts of interference effects have been proposed, each making different developmental predictions. This research examines interference effects across development, with the goal of better understanding mechanisms of interference and of memory development. Preschool-aged children and adults participated in a three-phased associative learning paradigm containing stimuli that were either unique or repeated across phases. Both age groups demonstrated interference effects, but only for repeated items. Whereas proactive interference effects were comparable across age groups, retroactive interference reached catastrophic-like levels in children. Additionally, retroactive interference increased in adults when contextual differences between phases were minimized (Experiment 2), and decreased in adults who were more successful at encoding repeated pairs of stimuli during a training phase (Experiment 3). These results are discussed with respect to theories of memory and memory development. PMID:25688907

  15. Interference Mitigation Effects on Synthetic Aperture Radar Coherent Data Products

    SciTech Connect

    Musgrove, Cameron

    2014-05-01

    For synthetic aperture radar image products interference can degrade the quality of the images while techniques to mitigate the interference also reduce the image quality. Usually the radar system designer will try to balance the amount of mitigation for the amount of interference to optimize the image quality. This may work well for many situations, but coherent data products derived from the image products are more sensitive than the human eye to distortions caused by interference and mitigation of interference. This dissertation examines the e ect that interference and mitigation of interference has upon coherent data products. An improvement to the standard notch mitigation is introduced, called the equalization notch. Other methods are suggested to mitigation interference while improving the quality of coherent data products over existing methods.

  16. Inter-cell interference mitigation in multi-cellular visible light communications.

    PubMed

    Jung, Sun-Young; Kwon, Do-Hoon; Yang, Se-Hoon; Han, Sang-Kook

    2016-04-18

    Inter-cell interference hinders multi-cellular optical wireless communication to support various applications. We proposed and experimentally demonstrated a multicarrier-based cell partitioning scheme, combined with frequency reuse, which could be effective in optical communications although it is inefficient in RF wireless communications. For multicarrier-based cell partitioning, Orthogonal frequency division multiplexing-based multiple access (OFDMA) was employed to accommodate multi-cellular optical wireless communications without a large guard band between adjacent cells and without additional RF components. Moreover, we employed filter bank-based multicarrier (FBMC) to mitigate inter-cell interference generated in OFDMA-based cell partitioning due to asynchronous signals originated from RF path difference. By using FBMC-based cell partitioning, inter-cell interference could be effectively mitigated as well as capacity and spectral efficiency were improved about 1.5 times compared to those of OFDMA. Because no cyclic prefix (CP) is required in FBMC, the improvement factor could be increased if there is a large RF path difference between lighting cells. Moreover, it could be a stronger solution when many neighboring cells exist causing large interference. The proposed multicarrier-based cell partitioning combined with FBMC will effectively support visible light communication (VLC)-based localization-based services (LBS) and indoor positioning system by transparently providing trilateration-based positioning method. PMID:27137289

  17. Inter-cell interference mitigation in multi-cellular visible light communications.

    PubMed

    Jung, Sun-Young; Kwon, Do-Hoon; Yang, Se-Hoon; Han, Sang-Kook

    2016-04-18

    Inter-cell interference hinders multi-cellular optical wireless communication to support various applications. We proposed and experimentally demonstrated a multicarrier-based cell partitioning scheme, combined with frequency reuse, which could be effective in optical communications although it is inefficient in RF wireless communications. For multicarrier-based cell partitioning, Orthogonal frequency division multiplexing-based multiple access (OFDMA) was employed to accommodate multi-cellular optical wireless communications without a large guard band between adjacent cells and without additional RF components. Moreover, we employed filter bank-based multicarrier (FBMC) to mitigate inter-cell interference generated in OFDMA-based cell partitioning due to asynchronous signals originated from RF path difference. By using FBMC-based cell partitioning, inter-cell interference could be effectively mitigated as well as capacity and spectral efficiency were improved about 1.5 times compared to those of OFDMA. Because no cyclic prefix (CP) is required in FBMC, the improvement factor could be increased if there is a large RF path difference between lighting cells. Moreover, it could be a stronger solution when many neighboring cells exist causing large interference. The proposed multicarrier-based cell partitioning combined with FBMC will effectively support visible light communication (VLC)-based localization-based services (LBS) and indoor positioning system by transparently providing trilateration-based positioning method.

  18. Nutrition and interference competition have interactive effects on the behavior and performance of Argentine ants.

    PubMed

    Kay, Adam D; Zumbusch, Taylor; Heinen, Justa L; Marsh, Tom C; Holway, David A

    2010-01-01

    Food availability often influences competitive outcomes through effects on consumer growth. Although it has received less attention, food availability may also affect competition through nutritional effects on behavior. One hypothesis linking nutrition and competition in ants posits that increased access to carbohydrates favors greater investment in worker traits that underlie behavioral dominance. We tested this hypothesis by varying dietary protein:carbohydrate (P:C) ratios and levels of interspecific interference for Argentine ants (Linepithema humile), a widespread invasive species. As predicted, colonies facing interference increased patrolling more when reared on low P:C diets; this result is the first demonstration of an interactive effect of nutrition and interference on ant colonies. Several results suggest that this dietary effect on patrolling was due primarily to changes in colony size rather than worker behavior. Colonies on lower P:C diets had lower worker mortality and larger final colony sizes. Diet had little effect on per capita patrolling, and worker behavior in performance assays depended more on previous exposure to interference than on diet. Our findings indicate that dietary P:C ratios can influence Argentine ant performance in a competitive environment and suggest a mechanism by which monopolization of carbohydrate-rich resources can help invasive ants displace native ant competitors.

  19. Language processing in children with cochlear implants: a preliminary report on lexical access for production and comprehension.

    PubMed

    Schwartz, Richard G; Steinman, Susan; Ying, Elizabeth; Mystal, Elana Ying; Houston, Derek M

    2013-04-01

    In this plenary paper, we present a review of language research in children with cochlear implants along with an outline of a 5-year project designed to examine the lexical access for production and recognition. The project will use auditory priming, picture naming with auditory or visual interfering stimuli (Picture-Word Interference and Picture-Picture Interference, respectively) and eye tracking paradigms to examine the roles of semantic and various phonological factors. Preliminary data are presented from auditory priming, picture-word interference and picture-picture interference tasks. The emergence of group difference is briefly discussed.

  20. Language processing in children with cochlear implants: a preliminary report on lexical access for production and comprehension.

    PubMed

    Schwartz, Richard G; Steinman, Susan; Ying, Elizabeth; Mystal, Elana Ying; Houston, Derek M

    2013-04-01

    In this plenary paper, we present a review of language research in children with cochlear implants along with an outline of a 5-year project designed to examine the lexical access for production and recognition. The project will use auditory priming, picture naming with auditory or visual interfering stimuli (Picture-Word Interference and Picture-Picture Interference, respectively) and eye tracking paradigms to examine the roles of semantic and various phonological factors. Preliminary data are presented from auditory priming, picture-word interference and picture-picture interference tasks. The emergence of group difference is briefly discussed. PMID:23489339

  1. Estimation Of Interference In Satellite/Ground Communications

    NASA Technical Reports Server (NTRS)

    Kantak, Anil V.

    1990-01-01

    Relative strengths of desired and interfering signals computed for known orbits. Satellite Interference Analysis and Simulation Using Personal Computers (AKSATINT) computer program calculates interference experienced by generic satellite communications receiving station from interfering satellite. Also computes interference-to-signal-power ratio, taking into account losses suffered by links. Of general use to designers of systems and managers of frequencies in selecting proper frequencies under interference scenarios. Written in BASIC.

  2. Development of a multilayer interference simulation program for MSS systems

    NASA Technical Reports Server (NTRS)

    Izadian, Jamal S.

    1993-01-01

    This paper discusses the development of a multilayer interference analysis and simulation program which is used to evaluate interference between non-geostationary and geostationary satellites. In addition to evaluating interference, this program can be used in the development of sharing criteria and coordination among various Mobile Satellite Services (MSS) systems. A C++/Windows implementation of this program, called Globalstar Interference Simulation Program (GISP), has been developed.

  3. Mutual Diffusional Interference Between Adjacent Stomata of a Leaf 1

    PubMed Central

    Cook, G. D.; Viskanta, R.

    1968-01-01

    The mutual diffusional interference between adjacent stomata in laminar flow over a leaf is shown to play a decisive role in determining overall transpiration. The magnitude of this interference varies with the interaction of the vapor diffusional shells forming above each stoma and the air flow over the leaf. The interference decreases with increasing incident radiation and wind velocity. The effect of interference on the stomatal resistance to diffusion plays a major role in the overall variations in transpiration. PMID:16656876

  4. Quantum interference in an electron-hole graphene ring system

    SciTech Connect

    Smirnov, D.; Schmidt, H.; Haug, R. J.

    2013-12-04

    Quantum interference is observed in a graphene ring system via the Aharonov Bohm effect. As graphene is a gapless semiconductor, this geometry allows to study the unique situation of quantum interference between electrons and holes in addition to the unipolar quantum interference. The period and amplitude of the observed Aharonov-Bohm oscillations are independent of the sign of the applied gate voltage showing the equivalence between unipolar and dipolar interference.

  5. Access to modern contraception.

    PubMed

    Welsh, Michael J; Stanback, John; Shelton, James

    2006-06-01

    Access to modern contraception has become a recognized human right, improving the health and well-being of women, families and societies worldwide. However, contraceptive access remains uneven. Irregular contraceptive supply, limited numbers of service delivery points and specific geographic, economic, informational, psychosocial and administrative barriers (including medical barriers) undermine access in many settings. Widening the range of providers enabled to offer contraception can improve contraceptive access, particularly where resources are most scarce. International efforts to remove medical barriers include the World Health Organization's Medical Eligibility Criteria. Based on the best available evidence, these criteria provide guidance for weighing the risks and benefits of contraceptive choice among women with specific clinical conditions. Clinical job aids can also improve access. More research is needed to further elucidate the pathways for expanding contraceptive access. Further progress in removing medical barriers will depend on systems for improving provider education and promoting evidence-based contraceptive service delivery. PMID:16443395

  6. Bimanual Interference Associated with Handling Different Tool Transformations

    ERIC Educational Resources Information Center

    Massen, Cristina; Sattler, Christine

    2013-01-01

    Research on bimanual coordination of hand movements has identified several loci of bimanual interference, including interference because of programming different movement parameters or selecting different targets for the two hands. This study investigates the extent and origin of interference when participants execute bimanual actions with tools.…

  7. Visualizing the Solute Vaporization Interference in Flame Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Dockery, Christopher R.; Blew, Michael J.; Goode, Scott R.

    2008-01-01

    Every day, tens of thousands of chemists use analytical atomic spectroscopy in their work, often without knowledge of possible interferences. We present a unique approach to study these interferences by using modern response surface methods to visualize an interference in which aluminum depresses the calcium atomic absorption signal. Calcium…

  8. Dissociating Interference-Control Processes between Memory and Response

    ERIC Educational Resources Information Center

    Bissett, Patrick G.; Nee, Derek Evan; Jonides, John

    2009-01-01

    The ability to mitigate interference is of central importance to cognition. Previous research has provided conflicting accounts about whether operations that resolve interference are singular in character or form a family of functions. Here, the authors examined the relationship between interference-resolution processes acting on working memory…

  9. 36 CFR 331.16 - Interference with government employees.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Interference with government... WILDLIFE CONSERVATION AREA, KENTUCKY AND INDIANA § 331.16 Interference with government employees. Interference with any Government employee in the conduct of his or her official duties pertaining to...

  10. 36 CFR 331.16 - Interference with government employees.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Interference with government... WILDLIFE CONSERVATION AREA, KENTUCKY AND INDIANA § 331.16 Interference with government employees. Interference with any Government employee in the conduct of his or her official duties pertaining to...

  11. Addressing Cultural and Native Language Interference in Second Language Acquisition

    ERIC Educational Resources Information Center

    Allard, Daniele; Bourdeau, Jacqueline; Mizoguchi, Riichiro

    2011-01-01

    This paper addresses the problem of cultural and native language interference in second/foreign language acquisition. More specifically, it examines issues of interference that can be traced to a student's native language and that also have a cultural component. To this effect, an understanding of what actually comprises both interference and…

  12. Mathematical models for cochannel interference in FH/MFSK multiple-access systems

    NASA Technical Reports Server (NTRS)

    Yan, T.-Y.; Wang, C. C.

    1984-01-01

    FH/MFSK has been proposed for a multiuser spread spectrum digital communication system to combat both self-jamming and intentional jamming. An independence assumption at the energy detector outputs is used to evaluate such a system for a digitized voice mobile radio system (Yue, 1981). This paper presents a correlated model and compares its performance to an independence model under the symbol error probability criterion. A Gaussian process model is also developed for comparison. It is found that the conventional Gaussian approximation is inadequate in predicting the number of users that can be accommodated by an FH/MFSK system using the conventional receiver. Furthermore, for the cases evaluated, the independence model provides an excellent approximation to the correlated model. Additionally, a conditional Chernoff bound is presented for the more general case of frequency-hopping systems with multiple hops per symbol.

  13. Towards Mitigating Heterogeneous Wireless Interference in Spectrum Bands with Unlicensed Access

    ERIC Educational Resources Information Center

    Nychis, George P.

    2013-01-01

    In the past two decades, we have seen an unprecedented rise in unlicensed wireless devices and applications of wireless technology. To meet various application constraints, we continually customize the radios and their protocols to the application domain which has led to significant diversity in spectrum use. Unfortunately, this diversity (coupled…

  14. Morphological Processing and Lexical Access in Speech Production in Hebrew: Evidence from Picture-Word Interference

    ERIC Educational Resources Information Center

    Kolan, Limor; Leikin, Mark; Zwitserlood, Pienie

    2011-01-01

    This study investigated the nature of the retrieval architecture of Semitic morphemic entities in word production in Hebrew, a language with a non-concatenated morphology. By taking advantage of the potential for dissociation of form and meaning in Hebrew, we explored the relative contribution of word-form and semantics to morphological…

  15. Recent HIV Testing Among Young Men Who Have Sex with Men in Bangkok and Chiang Mai: HIV Testing and Prevention Strategies Must Be Enhanced in Thailand.

    PubMed

    Johnston, Lisa G; Steinhaus, Mara C; Sass, Justine; Sirinirund, Petchsri; Lee, Catherine; Benjarattanaporn, Patchara; Gass, Robert

    2016-09-01

    HIV infection among men who have sex with men, particularly in Thai urban settings and among younger cohorts, is escalating. HIV testing and counseling (HTC) are important for prevention and obtaining treatment and care. We examine data from a 2013 survey of males, 15-24 years, reporting past-year sex with a male and living in Bangkok or Chiang Mai. Almost three quarters of young MSM (YMSM) in Bangkok and only 27 % in Chiang Mai had an HIV test in the previous year. Associations for HIV testing varied between cities, although having employment increased the odds of HIV testing for both cities. In Bangkok, family knowledge of same sex attraction and talking to parents/guardians about HIV/AIDS had higher odds of HIV testing. Expanded HTC coverage is needed for YMSM in Chiang Mai. All health centers providing HTC, including those targeting MSM, need to address the specific needs of younger cohorts.

  16. Recent HIV Testing Among Young Men Who Have Sex with Men in Bangkok and Chiang Mai: HIV Testing and Prevention Strategies Must Be Enhanced in Thailand.

    PubMed

    Johnston, Lisa G; Steinhaus, Mara C; Sass, Justine; Sirinirund, Petchsri; Lee, Catherine; Benjarattanaporn, Patchara; Gass, Robert

    2016-09-01

    HIV infection among men who have sex with men, particularly in Thai urban settings and among younger cohorts, is escalating. HIV testing and counseling (HTC) are important for prevention and obtaining treatment and care. We examine data from a 2013 survey of males, 15-24 years, reporting past-year sex with a male and living in Bangkok or Chiang Mai. Almost three quarters of young MSM (YMSM) in Bangkok and only 27 % in Chiang Mai had an HIV test in the previous year. Associations for HIV testing varied between cities, although having employment increased the odds of HIV testing for both cities. In Bangkok, family knowledge of same sex attraction and talking to parents/guardians about HIV/AIDS had higher odds of HIV testing. Expanded HTC coverage is needed for YMSM in Chiang Mai. All health centers providing HTC, including those targeting MSM, need to address the specific needs of younger cohorts. PMID:26884309

  17. 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.

  18. Reoperative venous access.

    PubMed

    Juno, Russell J; Knott, Andrew W; Racadio, John; Warner, Brad W

    2003-05-01

    The maintenance of long-term venous access is critical to the livelihood of children in a variety of clinical situations, especially those who are dependent on parenteral nutrition. Whereas the traditional routes of either peripheral or central venous access are initially adequate, most of these sites eventually succumb to the pitfalls associated with long-term venous access. This review provides a comprehensive and multidisciplinary approach to the management of reoperative venous access with regard to preoperative planning and imaging and specific techniques in interventional radiology and surgery.

  19. Access Interface Strategies

    PubMed Central

    Fager, Susan; Beukelman, David R.; Fried-Oken, Melanie; Jakobs, Tom; Baker, John

    2013-01-01

    Individuals who rely on augmentative and alternative communication (AAC) devices to support their communication often have physical movement challenges that require alternative methods of access. Technology that supports access, particularly for those with the most severe movement deficits, have expanded substantially over the years. The purposes of this article are to review the state of the science of access technologies that interface with augmentative and alternative communication devices and to propose a future research and development agenda that will enhance access options for people with limited movement capability due to developmental and acquired conditions. PMID:22590797

  20. 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.

  1. Updating realistic access.

    PubMed

    Rossner, Mike

    2010-05-01

    Nearly six years ago Ira Mellman, then Editor-in-Chief of the JCB, published an editorial entitled "Providing realistic access" (1). It described the Journal's efforts to reconcile its subscription-based business model with the goal of providing public access to scholarly journal content. Since then, developments in the public-access movement are bringing us closer to the ideal of universal public access. But will there still be a place for selective journals like the JCB when we achieve that objective? PMID:20375430

  2. 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…

  3. Alcohol intoxication in road traffic accidents leads to higher impact speed difference, higher ISS and MAIS, and higher preclinical mortality.

    PubMed

    Stübig, Timo; Petri, Maximilian; Zeckey, Christian; Brand, Stephan; Müller, Christian; Otte, Dietmar; Krettek, Christian; Haasper, Carl

    2012-11-01

    Alcohol is one of the most important personal risk factors for serious and fatal injuries, contributing to approximately one third of all deaths from accidents. It is also described that alcohol intoxication leads to a higher mortality in the clinical course. In this study, we hypothesized that alcohol intoxication leads to different accident kinematics, a higher ISS (Injury Severity Score), and higher preclinical mortality compared to sober patients. A technical and medical investigation of alcohol intoxicated road users was performed on the scene of the crash and at the primary admitting hospital. Alcohol testing was performed with either breath alcohol tests or measurement of blood alcohol concentration (BAC) in a standard laboratory test. Between 1999 and 2010, 37,635 road traffic accidents were evaluated by the Accident Research Unit. Overall 20,741 patients were injured, 2.3% of the patients were killed. Among the injured patients, 2.2% with negative BAC were killed, compared to 4.6% fatal injuries in patients with a positive BAC (p < 0.0001). Of the patients with a positive BAC, 8.0% were severely injured, compared to 3.6% in the BAC negative group (p < 0.0001). Regarding the relative speed at impact (Δv for motorized drivers, vehicle collision speed for pedestrians and bikers), there was a significant higher difference for BAC positive patients (30 ± 20) compared to the BAC negative patients (25 ± 19, p < 0.0001). Alcohol intoxication in trauma patients leads to higher preclinical mortality, higher impact speed difference, and higher injury severity. The subgroup analysis for different alcohol concentrations shows no difference in ISS, MAIS, and relative speed, but a correlation of increasing age of patients with higher alcohol concentrations.

  4. Alcohol intoxication in road traffic accidents leads to higher impact speed difference, higher ISS and MAIS, and higher preclinical mortality.

    PubMed

    Stübig, Timo; Petri, Maximilian; Zeckey, Christian; Brand, Stephan; Müller, Christian; Otte, Dietmar; Krettek, Christian; Haasper, Carl

    2012-11-01

    Alcohol is one of the most important personal risk factors for serious and fatal injuries, contributing to approximately one third of all deaths from accidents. It is also described that alcohol intoxication leads to a higher mortality in the clinical course. In this study, we hypothesized that alcohol intoxication leads to different accident kinematics, a higher ISS (Injury Severity Score), and higher preclinical mortality compared to sober patients. A technical and medical investigation of alcohol intoxicated road users was performed on the scene of the crash and at the primary admitting hospital. Alcohol testing was performed with either breath alcohol tests or measurement of blood alcohol concentration (BAC) in a standard laboratory test. Between 1999 and 2010, 37,635 road traffic accidents were evaluated by the Accident Research Unit. Overall 20,741 patients were injured, 2.3% of the patients were killed. Among the injured patients, 2.2% with negative BAC were killed, compared to 4.6% fatal injuries in patients with a positive BAC (p < 0.0001). Of the patients with a positive BAC, 8.0% were severely injured, compared to 3.6% in the BAC negative group (p < 0.0001). Regarding the relative speed at impact (Δv for motorized drivers, vehicle collision speed for pedestrians and bikers), there was a significant higher difference for BAC positive patients (30 ± 20) compared to the BAC negative patients (25 ± 19, p < 0.0001). Alcohol intoxication in trauma patients leads to higher preclinical mortality, higher impact speed difference, and higher injury severity. The subgroup analysis for different alcohol concentrations shows no difference in ISS, MAIS, and relative speed, but a correlation of increasing age of patients with higher alcohol concentrations. PMID:22819121

  5. High incidence of plasmids in marine Vibrio species isolated from Mai Po Nature Reserve of Hong Kong.

    PubMed

    Zhang, Ruifu; Pan, Li; Zhao, Zhenye; Gu, Ji-Dong

    2012-08-01

    Mai Po Nature Reserve is the largest mangrove ecosystem and the most polluted coastal water body in Hong Kong. Plasmids screening of 100 Vibrio isolates randomly showed 45 % of them contained 1-3 plasmids. These plasmid(s)-bearing isolates could be divided into 12 groups based on their plasmid profiles. Phylogenetic analysis of the partial 16S rRNA gene sequences confirmed that all plasmid(s)-bearing isolates belonged to Vibrio cholerae. Full DNA sequences of the plasmids in Groups I (pVCG1.1 and pVCG1.2), II (pVCG2.1), III (pVCG3.2) and IV (pVCG4.1) have been determined and the results showed that pVCG1.1, pVCG2.1 and pVCG3.2 were almost identical. Plasmids pVCG1.1, pVCG1.2 and pVCG4.1 are comprised of 4,439, 2,357 and 2,163 bp with the overall G+C content of 45.57, 53.54 and 43.09 %, respectively. pVCG1.1 is a novel plasmid, and plasmids pVCG1.2 and pVCG4.1 showed homology of replication initiation proteins to that of the theta type replicons. Attempts to cure the plasmids from their hosts were unsuccessful. These data suggest that plasmids of Vibrio spp. are a significant gene reservoir in the marine ecosystem. PMID:22684730

  6. Aerosol transport from Chiang Mai, Thailand to Mt. Lulin, Taiwan - Implication of aerosol aging during long-range transport

    NASA Astrophysics Data System (ADS)

    Chuang, Ming-Tung; Lee, Chung-Te; Chou, Charles C.-K.; Engling, Guenter; Chang, Shih-Yu; Chang, Shuenn-Chin; Sheu, Guey-Rong; Lin, Neng-Huei; Sopajaree, Khajornsak; Chang, You-Jia; Hong, Guo-Jun

    2016-07-01

    The transport of biomass burning (BB) aerosol from Indochina may cause a potential effect on climate change in Southeast Asia, East Asia, and the Western Pacific. Up to now, the understanding of BB aerosol composition modification during long-range transport (LRT) is still very limited due to the lack of observational data. In this study, atmospheric aerosols were collected at the Suthep/Doi Ang Khang (DAK) mountain sites in Chiang Mai, Thailand and the Lulin Atmospheric Background Station (Mt. Lulin) in central Taiwan from March to April 2010 and from February to April 2013, respectively. During the study period, an upwind and downwind relationship between the Suthep/DAK and Lulin sites (2400 km apart) was validated by backward trajectories. Comprehensive aerosol properties were resolved for PM2.5 water-soluble inorganic ions, carbonaceous content, water-soluble/insoluble organic carbon (WSOC/WIOC), dicarboxylic acids and their salts (DCAS), and anhydrosugars. A Modification Factor (MF) is proposed by employing non-sea-salt potassium ion (nss-K+) or fractionalized elemental carbon evolved at 580 °C after pyrolized OC correction (EC1-OP) as a BB aerosol tracer to evaluate the mass fraction changes of aerosol components from source to receptor regions during LRT. The MF values of nss-SO42-, NH4+, NO3-, OC1 (fractionalized organic carbon evolved from room temperature to 140 °C), OP (pyrolized OC fraction), DCAS, and WSOC were above unity, which indicated that these aerosol components were enhanced during LRT as compared with those in the near-source region. In contrast, the MF values of anhydrosugars ranged from 0.1 to 0.3, indicating anhydrosugars have degraded during LRT.

  7. Changes in urinary Cu, Zn, and Se levels in cancer patients after treatment with Sha Shen Mai Men Dong Tang

    PubMed Central

    Lai, Tung-Yuan; Kuo, Hsien-Wen

    2015-01-01

    Sha Shen Mai Men Dong Tang (SMD-2; 沙參麥冬湯 shā shēn mài dōng tāng) is a Chinese medicinal herb (CMH; 中草藥 zhōng cǎo yào) used to treat symptoms associated with cancer therapy. The objective of this study was to assess the effect of SMD-2 on the levels of urinary copper (Cu), zinc (Zn), and selenium (Se) in lung cancer patients and head and neck cancer patients receiving chemoradiotherapy. Forty-two head and neck cancer patients and 10 lung cancer patients participated in our clinical trial. Each patient received chemoradiotherapy for 4 weeks. In addition, each patient was treated with SMD-2 for 8 weeks, including 2 weeks prior to and after the chemoradiotherapy treatment. Comparison of urinary Cu, Zn, and Se levels and the ratios of Zn to Cu and Se to Cu at three time points in the two types of cancer were assessed using the generalized estimating equations (GEEs). After the patients received chemoradiotherapy for 4 weeks, SMD-2 treatment was found to be associated with a significant decrease in urinary Cu levels, whereas urinary Zn and Se levels increased significantly. In addition, the ratios of Zn to Cu and Se to Cu in the urine samples of these patients also increased significantly. Both the urinary Zn levels and the ratio of Zn to Cu in head and neck cancer patients were significantly higher than in lung cancer patients. Urinary Zn and Se levels and the ratios of Zn to Cu and Se to Cu, but not urinary Cu levels, increased significantly during and after treatment when assessed using the GEE model. The SMD-2 treatments significantly increased Zn and Se levels in the urine of head and neck cancer patients. Increased Zn and Se levels in urine strengthened immune system. PMID:27114935

  8. Comparison of wet-only and bulk deposition at Chiang Mai (Thailand) based on rainwater chemical composition

    NASA Astrophysics Data System (ADS)

    Chantara, Somporn; Chunsuk, Nawarut

    The chemical composition of 122 rainwater samples collected daily from bulk and wet-only collectors in a sub-urban area of Chiang Mai (Thailand) during August 2005-July 2006 has been analyzed and compared to assess usability of a cheaper and less complex bulk collector over a sophisticated wet-only collector. Statistical analysis was performed on log-transformed daily rain amount and depositions of major ions for each collector type. The analysis of variance (ANOVA) test revealed that the amount of rainfall collected from a rain gauge, bulk collector and wet-only collector showed no significant difference ( ∝=0.05). The volume weight mean electro-conductivity (EC) values of bulk and wet-only samples were 0.69 and 0.65 mS/m, respectively. The average pH of the samples from both types of collectors was 5.5. Scatter plots between log-transformed depositions of specific ions obtained from bulk and wet-only samples showed high correlation ( r>0.91). Means of log-transformed bulk deposition were 14% (Na + and K +), 13% (Mg 2+), 7% (Ca 2+), 4% (NO 3-), 3% (SO 42- and Cl -) and 2% (NH 4+) higher than that of wet-only deposition. However, multivariate analysis of variance (MANOVA) revealed that ion depositions obtained from bulk and wet-only collectors were not significantly different ( ∝=0.05). Therefore, it was concluded that a bulk collector can be used instead of a wet-only collector in a sub-urban area.

  9. Juxtaposition of heterozygous and homozygous regions causes reciprocal crossover remodelling via interference during Arabidopsis meiosis.

    PubMed

    Ziolkowski, Piotr A; Berchowitz, Luke E; Lambing, Christophe; Yelina, Nataliya E; Zhao, Xiaohui; Kelly, Krystyna A; Choi, Kyuha; Ziolkowska, Liliana; June, Viviana; Sanchez-Moran, Eugenio; Franklin, Chris; Copenhaver, Gregory P; Henderson, Ian R

    2015-03-27

    During meiosis homologous chromosomes undergo crossover recombination. Sequence differences between homologs can locally inhibit crossovers. Despite this, nucleotide diversity and population-scaled recombination are positively correlated in eukaryote genomes. To investigate interactions between heterozygosity and recombination we crossed Arabidopsis lines carrying fluorescent crossover reporters to 32 diverse accessions and observed hybrids with significantly higher and lower crossovers than homozygotes. Using recombinant populations derived from these crosses we observed that heterozygous regions increase crossovers when juxtaposed with homozygous regions, which reciprocally decrease. Total crossovers measured by chiasmata were unchanged when heterozygosity was varied, consistent with homeostatic control. We tested the effects of heterozygosity in mutants where the balance of interfering and non-interfering crossover repair is altered. Crossover remodeling at homozygosity-heterozygosity junctions requires interference, and non-interfering repair is inefficient in heterozygous regions. As a consequence, heterozygous regions show stronger crossover interference. Our findings reveal how varying homolog polymorphism patterns can shape meiotic recombination.

  10. Interference cancellation technique of optical AND gate receiver using optical thyristor.

    PubMed

    Kang, Tae-Gu

    2008-09-01

    We demonstrate an interference cancellation technique of optical AND gate receiver using optical thyristor for fiber-optic code division multiple access (FO-CDMA) systems. In particular, we fabricate the optical thyristor operating as optical hard-limiter and evaluate that the optical AND gate receiver using fabricated optical thyristor excludes the peaks of side-lobe and cross-correlation result in the system performance degradation. It found that the optical AND gate receiver using optical thyristor excludes the intensity of interference signal resulting in that the peaks of side-lobe and cross-correlation can be fully eliminated for any two users. Therefore, the optical AND gate receiver using optical thyristor is shown to be effective to accommodate more simultaneous users.

  11. OPTIMIZING A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS

    SciTech Connect

    Schmidt, K. F. Jr.; Little, J. R. Jr.; Ellingson, W. A.; Green, W.

    2010-02-22

    The projected microwave energy pattern, wave guide geometry, positioning methods and process variables have been optimized for use of a portable, non-contact, lap-top computer-controlled microwave interference scanning system on multi-layered dielectric materials. The system can be used in situ with one-sided access and has demonstrated capability of damage detection on composite ceramic armor. Specimens used for validation included specially fabricated surrogates, and ballistic impact-damaged specimens. Microwave data results were corroborated with high resolution direct-digital x-ray imaging. Microwave interference scanning detects cracks, laminar features and material properties variations. This paper presents the details of the system, the optimization steps and discusses results obtained.

  12. Analysis of interference to remote passive microwave sensors

    NASA Technical Reports Server (NTRS)

    Boyd, Douglas; Tillotson, Tom

    1986-01-01

    The final acts of the 1979 World Administrative Radio Conference (WARC) were analyzed to determine potential interference to remote passive microwave sensors. Using interferer populations determined from the U.S. Government and FCC Master File Lists and assuming uniform geographical distribution of interferers, the level of interference from shared services and active services in adjacent and subharmonic bands was calculated for each of the 22 passive sensing bands. In addition, due to the theoretically large antennas required for passive sensing, an analysis was performed to determine if smaller antennas, i.e., relaxed resolution requirements, would have an effect on interference and to what extent.

  13. A table of polyatomic interferences in ICP-MS

    USGS Publications Warehouse

    May, Thomas W.; Wiedmeyer, Ray H.

    1998-01-01

    Spectroscopic interferences are probably the largest class of interferences in ICP-MS and are caused by atomic or molecular ions that have the same mass-to-charge as analytes of interest. Current ICP-MS instrumental software corrects for all known atomic “isobaric” interferences, or those caused by overlapping isotopes of different elements, but does not correct for most polyatomic interferences. Such interferences are caused by polyatomic ions that are formed from precursors having numerous sources, such as the sample matrix, reagents used for preparation, plasma gases, and entrained atmospheric gases.

  14. Larval RNA Interference in the Red Flour Beetle, Tribolium castaneum

    PubMed Central

    Tomoyasu, Yoshinori

    2014-01-01

    The red flour beetle, Tribolium castaneum, offers a repertoire of experimental tools for genetic and developmental studies, including a fully annotated genome sequence, transposon-based transgenesis, and effective RNA interference (RNAi). Among these advantages, RNAi-based gene knockdown techniques are at the core of Tribolium research. T. castaneum show a robust systemic RNAi response, making it possible to perform RNAi at any life stage by simply injecting double-stranded RNA (dsRNA) into the beetle’s body cavity. In this report, we provide an overview of our larval RNAi technique in T. castaneum. The protocol includes (i) isolation of the proper stage of T. castaneum larvae for injection, (ii) preparation for the injection setting, and (iii) dsRNA injection. Larval RNAi is a simple, but powerful technique that provides us with quick access to loss-of-function phenotypes, including multiple gene knockdown phenotypes as well as a series of hypomorphic phenotypes. Since virtually all T. castaneum tissues are susceptible to extracellular dsRNA, the larval RNAi technique allows researchers to study a wide variety of tissues in diverse contexts, including the genetic basis of organismal responses to the outside environment. In addition, the simplicity of this technique stimulates more student involvement in research, making T. castaneum an ideal genetic system for use in a classroom setting. PMID:25350485

  15. Larval RNA interference in the red flour beetle, Tribolium castaneum.

    PubMed

    Linz, David M; Clark-Hachtel, Courtney M; Borràs-Castells, Ferran; Tomoyasu, Yoshinori

    2014-10-13

    The red flour beetle, Tribolium castaneum, offers a repertoire of experimental tools for genetic and developmental studies, including a fully annotated genome sequence, transposon-based transgenesis, and effective RNA interference (RNAi). Among these advantages, RNAi-based gene knockdown techniques are at the core of Tribolium research. T. castaneum show a robust systemic RNAi response, making it possible to perform RNAi at any life stage by simply injecting double-stranded RNA (dsRNA) into the beetle's body cavity. In this report, we provide an overview of our larval RNAi technique in T. castaneum. The protocol includes (i) isolation of the proper stage of T. castaneum larvae for injection, (ii) preparation for the injection setting, and (iii) dsRNA injection. Larval RNAi is a simple, but powerful technique that provides us with quick access to loss-of-function phenotypes, including multiple gene knockdown phenotypes as well as a series of hypomorphic phenotypes. Since virtually all T. castaneum tissues are susceptible to extracellular dsRNA, the larval RNAi technique allows researchers to study a wide variety of tissues in diverse contexts, including the genetic basis of organismal responses to the outside environment. In addition, the simplicity of this technique stimulates more student involvement in research, making T. castaneum an ideal genetic system for use in a classroom setting.

  16. Precoding Method Interference Management for Quasi-EVD Channel

    PubMed Central

    Song, Wei; Song, Sang Seob

    2014-01-01

    The Cholesky decomposition-block diagonalization (CD-BD) interference alignment (IA) for a multiuser multiple input multiple output (MU-MIMO) relay system is proposed, which designs precoders for the multiple access channel (MAC) by employing the singular value decomposition (SVD) as well as the mean square error (MSE) detector for the broadcast Hermitian channel (BHC) taken advantage of in our design. Also, in our proposed CD-BD IA algorithm, the relaying function is made use to restructure the quasieigenvalue decomposition (quasi-EVD) equivalent channel. This approach used for the design of BD precoding matrix can significantly reduce the computational complexity and proposed algorithm can address several optimization criteria, which is achieved by designing the precoding matrices in two steps. In the first step, we use Cholesky decomposition to maximize the sum-of-rate (SR) with the minimum mean square error (MMSE) detection. In the next step, we optimize the system BER performance with the overlap of the row spaces spanned by the effective channel matrices of different users. By iterating the closed form of the solution, we are able not only to maximize the achievable sum-of-rate (ASR), but also to minimize the BER performance at a high signal-to-noise ratio (SNR) region. PMID:25258731

  17. Stroop interference in adults with dyslexia.

    PubMed

    Proulx, Michael J; Elmasry, Hannah-May

    2015-01-01

    Prior research on developmental dyslexia using Stroop tasks with young participants has found increased interference in participants with dyslexia relative to controls. Here we extend these findings to adult participants, and introduce a novel test of Stroop incongruity, whereby the color names appeared on an object colored in the incongruent color. The results imply that impaired inhibitory and executive attentional mechanisms are still deficient in adults with dyslexia and that other forms of attentional mechanisms, such as object-based attention, might also be impaired in dyslexia. Dyslexia arises not only from deficits in phonological processing, but from attentional mechanisms as well.

  18. RNA interference: genetic wand and genetic watchdog.

    PubMed

    Bosher, J M; Labouesse, M

    2000-02-01

    In many species, introduction of double-stranded RNA (dsRNA) induces potent and specific gene silencing, a phenomenon called RNA interference or RNAi. The apparently widespread nature of RNAi in eukaryotes, ranging from trypanosome to mouse, has sparked great interest from both applied and fundamental standpoints. Here we review the technical improvements being made to increase the experimental potential of this technique. We also discuss recent advances in uncovering the proteins that act during the RNAi process, discoveries that have revealed enticing links between transposition, transgene silencing and RNAi. PMID:10655601

  19. Increased Localization Precision by Interference Fringe Analysis

    PubMed Central

    Ebeling, Carl G.; Meiri, Amihai; Martineau, Jason; Zalevsky, Zeev; Gerton, Jordan M.; Menon, Rajesh

    2016-01-01

    We report a novel optical single-emitter-localization methodology that uses the phase induced by path length differences in a Mach-Zehnder interferometer to improve localization precision. Using information theory, we demonstrate that the localization capability of a modified Fourier domain signal generated by photon interference enables a more precise localization compared to a standard Gaussian intensity distribution of the corresponding point spread function. The calculations were verified by numerical simulations and an exemplary experiment, where the centers of metal nanoparticles were localized to a precision of 3 nm. PMID:25999093

  20. Quantum Radiation Reaction: From Interference to Incoherence.

    PubMed

    Dinu, Victor; Harvey, Chris; Ilderton, Anton; Marklund, Mattias; Torgrimsson, Greger

    2016-01-29

    We investigate quantum radiation reaction in laser-electron interactions across different energy and intensity regimes. Using a fully quantum approach which also accounts exactly for the effect of the strong laser pulse on the electron motion, we identify in particular a regime in which radiation reaction is dominated by quantum interference. We find signatures of quantum radiation reaction in the electron spectra which have no classical analogue and which cannot be captured by the incoherent approximations typically used in the high-intensity regime. These signatures are measurable with presently available laser and accelerator technology.

  1. Stroboscopic white-light interference microscopy

    SciTech Connect

    Groot, Peter de

    2006-08-10

    The principle of stroboscopic motion freezing of oscillating objects extends directly to interference microscopes that use coherence as part of the measurement principle. Analysis shows, however, that the fringe contrast loss for out-of-plan emotion in stroboscopic interferometry is a wavelength-dependent phenomenon,which can alter the apparent nominal center wavelength of the white-light source.As in monochromatic systems, the key adjustable parameter is the duty cycle,equal to the product of the vibrational frequency and the pulse width. This theoretical study provides detailed graphs of expected errors as a function of the duty cycle, including fringe contrast loss, apparent wavelength shift, and measurement error.

  2. Interference Effects of Strongly Localized Electrons

    NASA Astrophysics Data System (ADS)

    Medina, Ernesto Antonio

    We explore the possible role of quantum interference phenomena in conduction in the Variable Range Hopping, or deep insulating regime. The critical resistors in the Miller-Abrahams network are regarded as the phase coherent units. We consider a simple model of forward scattering paths (disregard backscattering) on a diagonal lattice. The hopping probability for non-resonant tunneling between two impurity sites, is computed numerically by evolving all directed Feynman paths in a disordered matrix of elastically scattering sites (intermediate impurities). The whole probability distribution for two dimensional samples is very broad, well fitted to a log-normal form. The average of the distribution increases linearly with the hopping length t, determining a global contribution to the localization length, coming from the interference part. The fluctuations grow with the hopping length as a non-trivial power law of t^{1over 3} . The system has a bound state which gives rise to the properties of the model. The exponents found are the same as those for directed polymers (DP) in a random media. Next we consider the effects of a magnetic field applied perpendicularly to the plane of the sample. The probability distribution for hopping is preserved in the field. We also find a positive magnetoconductance (MC) for small fields due to an increased localization length, in agreement with recent experiments. The features observed numerically are explained on the basis of the moment analysis, which suggests a single governing parameter for the interference effects. The effects of spin-orbit (SO) scattering are also studied (strong scattering limit). The interference contribution to the localization length is field independent in presence of SO. A small positive MC is found due to changes in the amplitude. Finally we investigate the problem of the universality of high moments in the strongly localized regime, by studying directed paths on a hierarchical lattice. We find non

  3. Multipolar interference for directed light emission.

    PubMed

    Hancu, Ion M; Curto, Alberto G; Castro-López, Marta; Kuttge, Martin; van Hulst, Niek F

    2014-01-01

    By directing light, optical antennas can enhance light-matter interaction and improve the efficiency of nanophotonic devices. Here we exploit the interference among the electric dipole, quadrupole, and magnetic dipole moments of a split-ring resonator to experimentally realize a compact directional optical antenna. This single-element antenna design robustly directs emission even when covered with nanometric emitters at random positions, outperforming previously demonstrated nanoantennas with a bandwidth of 200 nm and a directivity of 10.1 dB from a subwavelength structure. The advantages of this approach bring directional optical antennas closer to practical applications.

  4. Does Probability Interference Exist In Social Science?

    NASA Astrophysics Data System (ADS)

    Khrennikov, Andrei Yu.; Haven, Emmanuel

    2007-02-01

    In this paper we discuss the rationale why sub(super)-additive probabilities in a psychological setting could be explained via the use of quantum probability interference. We propose to measure the complementarity of two variables: i) time of processing (by experiment participants) of (non-moving) images and ii) the ability (by experiment participants) of recognizing deformations of (non-moving) pictures. We argue in the paper why we can not find this complementarity using the Heisenberg Uncertainty Principle. The paper provides for the details on the experimental set up to test the complementarity.

  5. Angular momentum sensitive two-center interference.

    PubMed

    Ilchen, M; Glaser, L; Scholz, F; Walter, P; Deinert, S; Rothkirch, A; Seltmann, J; Viefhaus, J; Decleva, P; Langer, B; Knie, A; Ehresmann, A; Al-Dossary, O M; Braune, M; Hartmann, G; Meissner, A; Tribedi, L C; AlKhaldi, M; Becker, U

    2014-01-17

    In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

  6. Angular Momentum Sensitive Two-Center Interference

    NASA Astrophysics Data System (ADS)

    Ilchen, M.; Glaser, L.; Scholz, F.; Walter, P.; Deinert, S.; Rothkirch, A.; Seltmann, J.; Viefhaus, J.; Decleva, P.; Langer, B.; Knie, A.; Ehresmann, A.; Al-Dossary, O. M.; Braune, M.; Hartmann, G.; Meissner, A.; Tribedi, L. C.; AlKhaldi, M.; Becker, U.

    2014-01-01

    In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

  7. Ribonucleic acid interference induced gene knockdown

    PubMed Central

    Gottumukkala, Sruthima N. V. S.; Dwarakanath, C. D.; Sudarsan, Sabitha

    2013-01-01

    Despite major advances in periodontal regeneration over the past three decades, complete regeneration of the lost periodontium on a regular and predictable basis in humans has still remained elusive. The identification of stem cells in the periodontal ligament together with the growing concept of tissue engineering has opened new vistas in periodontal regenerative medicine. In this regard, ribonucleic acid interference (RNAi) opens a new gate way for a novel RNA based approach in periodontal management. This paper aims to summarize the current opinion on the mechanisms underlying RNAi, in vitro and in vivo existing applications in the dental research, which could lead to their future use in periodontal regeneration. PMID:24174717

  8. 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…

  9. Accessing the Microform Publication.

    ERIC Educational Resources Information Center

    Schindler, Stan

    1985-01-01

    Characterizes types of indexing programs used by Research Publications, Inc. and describes provision of access to four major projects: "The Official Washington Post Index" (provides access to newspaper and microfilm edition); "The Eighteenth Century"; "The Declassified Documents Reference System" (ongoing fiche project abstracted and indexed…

  10. Planning for Accessibility.

    ERIC Educational Resources Information Center

    Cassell, Marianne Kotch

    This practical manual provides useful, concrete ideas and suggestions to help public libraries make libraries more accessible to persons with disabilities. Most suggestions are for persons who have difficulty with mobility. Reviews of pertinent laws and regulations are followed by concrete, step-by step suggestions for planning for accessibility,…

  11. Intellectual Access to Images.

    ERIC Educational Resources Information Center

    Chen, Hsin-Liang; Rasmussen, Edie M.

    1999-01-01

    The increased availability of digital images is accompanied by a need for solutions to the problems inherent in indexing them for retrieval. Problems in image description and access are discussed, with a perspective on traditional and new solutions. Recent developments in intellectual access to images are surveyed and contrasted with…

  12. 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,…

  13. Improving School Access Control

    ERIC Educational Resources Information Center

    National Clearinghouse for Educational Facilities, 2008

    2008-01-01

    Few things are more important for school safety and security than controlling access to buildings and grounds. It is relatively easy to incorporate effective access control measures in new school designs but more difficult in existing schools, where most building and site features cannot be readily altered or reconfigured. The National…

  14. Auditory list memory and interference processes in monkeys.

    PubMed

    Wright, A A

    1999-07-01

    Memory of 2 rhesus monkeys (Macaca mulatta) was tested in a serial probe recognition task with lists of 4 natural or environmental sounds, different retention intervals, and different manipulations of interference. At short retention intervals, increasing the separation of list items reduced the primacy effect and produced a recency effect. Similar results were shown by increasing interference across lists through item repetitions or making the first 2 list items high-interference items. These results indicated that decreasing first-item performance reduced proactive interference on memory of the last list items. At long (20 s) retention intervals, making the last list items of high interference reduced the recency effect, reduced retroactive interference, and produced a primacy effect. Taken together, interference plays a role in determining the primacy and recency effects of the serial-position function.

  15. Interference coloration as an anti-predator defence

    PubMed Central

    Pike, Thomas W.

    2015-01-01

    Interference coloration, in which the perceived colour varies predictably with the angle of illumination or observation, is extremely widespread across animal groups. However, despite considerable advances in our understanding of the mechanistic basis of interference coloration in animals, we still have a poor understanding of its function. Here, I show, using avian predators hunting dynamic virtual prey, that the presence of interference coloration can significantly reduce a predator's attack success. Predators required more pecks to successfully catch interference-coloured prey compared with otherwise identical prey items that lacked interference coloration, and attacks against prey with interference colours were less accurate, suggesting that changes in colour or brightness caused by prey movement hindered a predator's ability to pinpoint their exact location. The pronounced anti-predator benefits of interference coloration may explain why it has evolved independently so many times. PMID:25878050

  16. Detection of Gaussian signals in Poisson-modulated interference.

    PubMed

    Streit, R L

    2000-10-01

    Passive broadband detection of target signals by an array of hydrophones in the presence of multiple discrete interferers is analyzed under Gaussian statistics and low signal-to-noise ratio conditions. A nonhomogeneous Poisson-modulated interference process is used to model the ensemble of possible arrival directions of the discrete interferers. Closed-form expressions are derived for the recognition differential of the passive-sonar equation in the presence of Poisson-modulated interference. The interference-compensated recognition differential differs from the classical recognition differential by an additive positive term that depend on the interference-to-noise ratio, the directionality of the Poisson-modulated interference, and the array beam pattern.

  17. Grouping Influences Output Interference in Short-term Memory: A Mixture Modeling Study

    PubMed Central

    Kang, Min-Suk; Oh, Byung-Il

    2016-01-01

    Output interference is a source of forgetting induced by recalling. We investigated how grouping influences output interference in short-term memory. In Experiment 1, the participants were asked to remember four colored items. Those items were grouped by temporal coincidence as well as spatial alignment: two items were presented in the first memory array and two were presented in the second, and the items in both arrays were either vertically or horizontally aligned as well. The participants then performed two recall tasks in sequence by selecting a color presented at a cued location from a color wheel. In the same-group condition, the participants reported both items from the same memory array; however, in the different-group condition, the participants reported one item from each memory array. We analyzed participant responses with a mixture model, which yielded two measures: guess rate and precision of recalled memories. The guess rate in the second recall was higher for the different-group condition than for the same-group condition; however, the memory precisions obtained for both conditions were similarly degraded in the second recall. In Experiment 2, we varied the probability of the same- and different-group conditions with a ratio of 3 to 7. We expected output interference to be higher in the same-group condition than in the different-group condition. This is because items of the other group are more likely to be probed in the second recall phase and, thus, protecting those items during the first recall phase leads to a better performance. Nevertheless, the same pattern of results was robustly reproduced, suggesting grouping shields the grouped items from output interference because of the secured accessibility. We discussed how grouping influences output interference. PMID:27199820

  18. Grouping Influences Output Interference in Short-term Memory: A Mixture Modeling Study.

    PubMed

    Kang, Min-Suk; Oh, Byung-Il

    2016-01-01

    Output interference is a source of forgetting induced by recalling. We investigated how grouping influences output interference in short-term memory. In Experiment 1, the participants were asked to remember four colored items. Those items were grouped by temporal coincidence as well as spatial alignment: two items were presented in the first memory array and two were presented in the second, and the items in both arrays were either vertically or horizontally aligned as well. The participants then performed two recall tasks in sequence by selecting a color presented at a cued location from a color wheel. In the same-group condition, the participants reported both items from the same memory array; however, in the different-group condition, the participants reported one item from each memory array. We analyzed participant responses with a mixture model, which yielded two measures: guess rate and precision of recalled memories. The guess rate in the second recall was higher for the different-group condition than for the same-group condition; however, the memory precisions obtained for both conditions were similarly degraded in the second recall. In Experiment 2, we varied the probability of the same- and different-group conditions with a ratio of 3 to 7. We expected output interference to be higher in the same-group condition than in the different-group condition. This is because items of the other group are more likely to be probed in the second recall phase and, thus, protecting those items during the first recall phase leads to a better performance. Nevertheless, the same pattern of results was robustly reproduced, suggesting grouping shields the grouped items from output interference because of the secured accessibility. We discussed how grouping influences output interference. PMID:27199820

  19. New Interference Mechanism Controls Ultracold Chemistry

    NASA Astrophysics Data System (ADS)

    Kendrick, Brian K.; Hazra, Jisha; Balakrishnan, N.

    2016-05-01

    A newly discovered interference mechanism has been shown to control the outcome of ultracold chemical reactions. The mechanism originates from the unique properties associated with ultracold collisions, namely: (1) isotropic (s-wave) scattering and (2) an effective quantization of the scattering phase shift (which originates from the bound state structure of the molecule). These two properties can lead to maximum constructive or destructive interference between two interfering reaction pathways (such as exchange and non-exchange in systems with two or more identical nuclei). If the molecular system exhibits a conical intersection, then the associated geometric phase is shown to act as a ``quantum switch'' which can turn the reactivity on or off. Reaction rate coefficients for the O + OH --> H + O2 and H + H2, reactions are presented which explicitly demonstrate the effect. Experimentalists might exploit this new mechanism to control ultracold reactions by the application of external electric or magnetic fields or by the selection of a particular nuclear spin state. This work was supported in part by the LDRD program (Grant No. 20140309ER) at LANL (B.K.) and by NSF Grant PHY-1505557 (N.B.) and ARO MURI Grant No. W911NF-12-1-0476 (N.B.).

  20. Interference processes in monkey auditory list memory.

    PubMed

    Wright, Anthony A; Roediger, Henry L

    2003-09-01

    A rhesus monkey's memory was tested for single items and four-item lists of natural and environmental sounds. Memory items were presented from a center speaker, followed by a retention delay and then a choice response to a test sound presented simultaneously from two side speakers. Recognition of the last item of four-item lists was much poorer than that of single items at 0-, 1-, and 2-sec delays, despite there being the same temporal relations between study and test. This result showed that the first three items proactively interfered with memory of the last list item. Proactive interference dissipated after 2 sec, revealing a recency effect that eventually equaled single-item performance. Recognition of the first item of four-item lists was much poorer than single items at 20- and 30-sec delays, showing that the last three items retroactively interfered with memory of the first list item. The results point to the critical nature of interference processes in the understanding of serial position functions.

  1. Reducing Interference in ATC Voice Communication

    NASA Technical Reports Server (NTRS)

    Battle, John O.

    2009-01-01

    Three methods have been proposed to be developed to enable reduction of the types of interference that often occur among voice-communication radio signals involved in air-traffic control (ATC). For historical reasons and for compatibility with some navigation systems, control towers and aircraft use amplitude modulation (AM) for voice communication. In the presence of two simultaneous AM transmissions in the same frequency channel, what is heard through a receiver includes not only the audio portions of both transmissions but also an audio heterodyne signal at the difference between the carrier frequencies of the transmissions (as a practical matter, the carrier frequencies almost always differ somewhat). The situation is further complicated by multiple heterodyne signals in the presence of more than two simultaneous transmissions. Even if one of the transmissions does not include AM because of a transmitter malfunction or because a transmitter was inadvertently turned on or left on, the heterodyne signal makes it difficult to understand the audio of the other transmission. The proposed methods would utilize digital signal processing to counteract this type of interference.

  2. Digital communications in spatially distributed interference channels

    NASA Astrophysics Data System (ADS)

    Modestino, J. W.; Daut, D. C.; Eyuboglu, V. M.; Jung, K. Y.; Mathis, K. R.; Ningo, A. Y.

    1982-12-01

    This report is concerned with the characterization of the structure and performance of digital communication systems operating in spatially distributed interference channels when a multi-element array processing capability is available. It represents one phase of a continuing investigation and covers the period 1 July, 1980 through 31 March, 1981. This report is organized into five parts. Part 1 describes an optimum receiver when a multi-element array capability is available and under specific and somewhat simplified modeling assumptions. The results are useful in demonstrating the subtle interactions between spatial and temporal processing characteristics of an optimum receiver, particularly the modulation/coding tradeoffs. Part 2 discusses some new reduced complexity soft-decision decoding algorithms for linear block codes while Part 3 describes some new rational-rate convolutional code constructions. Both of these should be useful in impulsive or burst interference environments. In Part 4 we describe some results on the modeling and analysis of selected linear and nonlinear receiver structures in impulsive or burst noise channels. Finally, an outline of how multi-element adaptive array processing structures are to be incorporated into the RPI developed Interactive Communications Simulator (ICS) is provided in Part 5.

  3. Ultrawideband Electromagnetic Interference to Aircraft Radios

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Fuller, Gerald L.; Shaver, Timothy W.

    2002-01-01

    A very recent FCC Final Rule now permits marketing and operation of new products that incorporate Ultrawideband (UWB) technology into handheld devices. Wireless product developers are working to rapidly bring this versatile, powerful and expectedly inexpensive technology into numerous consumer wireless devices. Past studies addressing the potential for passenger-carried portable electronic devices (PEDs) to interfere with aircraft electronic systems suggest that UWB transmitters may pose a significant threat to aircraft communication and navigation radio receivers. NASA, United Airlines and Eagles Wings Incorporated have performed preliminary testing that clearly shows the potential for handheld UWB transmitters to cause cockpit failure indications for the air traffic control radio beacon system (ATCRBS), blanking of aircraft on the traffic alert and collision avoidance system (TCAS) displays, and cause erratic motion and failure of instrument landing system (ILS) localizer and glideslope pointers on the pilot horizontal situation and attitude director displays. This paper provides details of the preliminary testing and recommends further assessment of aircraft systems for susceptibility to UWB electromagnetic interference.

  4. Normalized GNSS Interference Pattern Technique for Altimetry

    PubMed Central

    Ribot, Miguel Angel; Kucwaj, Jean-Christophe; Botteron, Cyril; Reboul, Serge; Stienne, Georges; Leclère, Jérôme; Choquel, Jean-Bernard; Farine, Pierre-André; Benjelloun, Mohammed

    2014-01-01

    It is well known that reflected signals from Global Navigation Satellite Systems (GNSS) can be used for altimetry applications, such as monitoring of water levels and determining snow height. Due to the interference of these reflected signals and the motion of satellites in space, the signal-to-noise ratio (SNR) measured at the receiver slowly oscillates. The oscillation rate is proportional to the change in the propagation path difference between the direct and reflected signals, which depends on the satellite elevation angle. Assuming a known receiver position, it is possible to compute the distance between the antenna and the surface of reflection from the measured oscillation rate. This technique is usually known as the interference pattern technique (IPT). In this paper, we propose to normalize the measurements in order to derive an alternative model of the SNR variations. From this model, we define a maximum likelihood estimate of the antenna height that reduces the estimation time to a fraction of one period of the SNR variation. We also derive the Cramér–Rao lower bound for the IPT and use it to assess the sensitivity of different parameters to the estimation of the antenna height. Finally, we propose an experimental framework, and we use it to assess our approach with real GPS L1 C/A signals. PMID:24922453

  5. Normalized GNSS interference pattern technique for altimetry.

    PubMed

    Ribot, Miguel Angel; Kucwaj, Jean-Christophe; Botteron, Cyril; Reboul, Serge; Stienne, Georges; Leclère, Jérôme; Choquel, Jean-Bernard; Farine, Pierre-André; Benjelloun, Mohammed

    2014-06-11

    It is well known that reflected signals from Global Navigation Satellite Systems (GNSS) can be used for altimetry applications, such as monitoring of water levels and determining snow height. Due to the interference of these reflected signals and the motion of satellites in space, the signal-to-noise ratio (SNR) measured at the receiver slowly oscillates. The oscillation rate is proportional to the change in the propagation path difference between the direct and reflected signals, which depends on the satellite elevation angle. Assuming a known receiver position, it is possible to compute the distance between the antenna and the surface of reflection from the measured oscillation rate. This technique is usually known as the interference pattern technique (IPT). In this paper, we propose to normalize the measurements in order to derive an alternative model of the SNR variations. From this model, we define a maximum likelihood estimate of the antenna height that reduces the estimation time to a fraction of one period of the SNR variation. We also derive the Cramér-Rao lower bound for the IPT and use it to assess the sensitivity of different parameters to the estimation of the antenna height. Finally, we propose an experimental framework, and we use it to assess our approach with real GPS L1 C/A signals.

  6. Quantum interference in an interfacial superconductor

    NASA Astrophysics Data System (ADS)

    Goswami, Srijit; Mulazimoglu, Emre; Monteiro, Ana M. R. V. L.; Wölbing, Roman; Koelle, Dieter; Kleiner, Reinhold; Blanter, Ya. M.; Vandersypen, Lieven M. K.; Caviglia, Andrea D.

    2016-10-01

    The two-dimensional superconductor that forms at the interface between the complex oxides lanthanum aluminate (LAO) and strontium titanate (STO) has several intriguing properties that set it apart from conventional superconductors. Most notably, an electric field can be used to tune its critical temperature (Tc; ref. 7), revealing a dome-shaped phase diagram reminiscent of high-Tc superconductors. So far, experiments with oxide interfaces have measured quantities that probe only the magnitude of the superconducting order parameter and are not sensitive to its phase. Here, we perform phase-sensitive measurements by realizing the first superconducting quantum interference devices (SQUIDs) at the LAO/STO interface. Furthermore, we develop a new paradigm for the creation of superconducting circuit elements, where local gates enable the in situ creation and control of Josephson junctions. These gate-defined SQUIDs are unique in that the entire device is made from a single superconductor with purely electrostatic interfaces between the superconducting reservoir and the weak link. We complement our experiments with numerical simulations and show that the low superfluid density of this interfacial superconductor results in a large, gate-controllable kinetic inductance of the SQUID. Our observation of robust quantum interference opens up a new pathway to understanding the nature of superconductivity at oxide interfaces.

  7. Bidirectional semantic interference between action and speech.

    PubMed

    Liepelt, Roman; Dolk, Thomas; Prinz, Wolfgang

    2012-07-01

    Research on embodied cognition assumes that language processing involves modal simulations that recruit the same neural systems that are usually used for action execution. If this is true, one should find evidence for bidirectional crosstalk between action and language. Using a direct matching paradigm, this study tested if action-languages interactions are bidirectional (Experiments 1 and 2), and whether the effect of crosstalk between action perception and language production is due to facilitation or interference (Experiment 3). Replicating previous findings, we found evidence for crosstalk when manual actions had to be performed simultaneously to action-word perception (Experiment 1) and also when language had to be produced during simultaneous perception of hand actions (Experiment 2). These findings suggest a clear bidirectional relationship between action and language. The latter crosstalk effect was due to interference between action and language (Experiment 3). By extending previous research of embodied cognition, the present findings provide novel evidence suggesting that bidirectional functional relations between action and language are based on similar conceptual-semantic representations.

  8. Harnessing Quantum Interference in Molecular Dielectric Materials.

    PubMed

    Bergfield, Justin P; Heitzer, Henry M; Van Dyck, Colin; Marks, Tobin J; Ratner, Mark A

    2015-06-23

    We investigate the relationship between dielectric response and charge transport in molecule-based materials operating in the quantum coherent regime. We find that quantum interference affects these observables differently, for instance, allowing current passing through certain materials to be reduced by orders of magnitude without affecting dielectric behavior (or band gap). As an example, we utilize ab initio electronic structure theory to calculate conductance and dielectric constants of cross-conjugated anthraquinone (AQ)-based and linearly conjugated anthracene (AC)-based materials. In spite of having nearly equal fundamental gaps, electrode bonding configurations, and molecular dimensions, we find a ∼1.7 order of magnitude (∼50-fold) reduction in the conductance of the AQ-based material relative to the AC-based material, a value in close agreement with recent measurements, while the calculated dielectric constants of both materials are nearly identical. From these findings, we propose two molecular materials in which quantum interference is used to reduce leakage currents across a ∼25 Å monolayer gap with dielectric constants larger than 4.5.

  9. Carbon Nanotube Superconducting Quantum Interference Device.

    NASA Astrophysics Data System (ADS)

    Bouchiat, Vincent; Cleuziou, Jean-Pierre; Ondarcuhu, Thierry; Monthioux, Marc; Wernsdorfer, Wolfgang

    2007-03-01

    We report on the study of a superconducting quantum interference device (SQUID) with Josephson junctions made of portions of metallic single-walled carbon nanotube [1]. Quantum confinement in each nanotube junction induces a discrete quantum dot (QD) energy level structure, which can be controlled with a lateral electrostatic gate. In addition, a backgate electrode can vary the transparency of the QD barriers, thus permitting to change the hybridization of the QD states with the superconducting contacts [2]. The gates are also used to directly tune the quantum phase interference of the Cooper pairs circulating in the SQUID ring. Optimal modulation of a 6nA supercurrent current with magnetic flux is achieved when both QD junctions are in the ``on'' or ``off'' state. Futhermore, the SQUID design establishes that these CNT Josephson junctions can be used as gate-controlled π-junctions. This allow to verify that the sign of the current-phase relation across a proximity coupled Qdot can be reversed with a gate voltage. Noise studies shows that the noise figure of the nanotube SQUID together with the size of the junction should allow the detection of a single molecule magnet. [1] J-P. Cleuziou et al. Nature Nanotec., 1, 53, (2006). [2] J-P. Cleuziou et al. cond-mat/0610622.

  10. Dephasing of mesoscopic interferences from Electron Fractionalization

    NASA Astrophysics Data System (ADS)

    Lehur, Karyn

    2006-03-01

    The understanding of dephasing processes (the physical causes of supressed interference effects) constitutes a topics of perpetual interest in mesoscopic systems. Phase-breaking mechanisms in ballistic systems of dimensionality less than two are presently not completely understood and therefore deserve intensive theoretical and experimental endeavors. In this talk, we investigate the dephasing of mesoscopic interferences by electron-electron interactions in a well-defined geometry composed of two tunnel-coupled wires embodied by a Luttinger liquid. We thoroughly demonstrate that interactions can produce a visible attenuation of Aharonov-Bohm oscillations [1]. Moreover, in our geometry, we firmly emphasize that the emerging dephasing time results from the electron factionalization phenomenon that is known to produce an electron life-time in 1/T with T being the temperature [2]. A dephasing time in 1/T has been reported in one-dimensional GaAs rings. [1] Karyn Le Hur, Phys. Rev. Lett. 95, 076801 (2005). [2] Karyn Le Hur, Phys. Rev. B 65, 233314 (2002).

  11. Discrete interference modeling via boolean algebra.

    PubMed

    Beckhoff, Gerhard

    2011-01-01

    Two types of boolean functions are considered, the locus function of n variables, and the interval function of ν = n - 1 variables. A 1-1 mapping is given that takes elements (cells) of the interval function to antidual pairs of elements in the locus function, and vice versa. A set of ν binary codewords representing the intervals are defined and used to generate the codewords of all genomic regions. Next a diallelic three-point system is reviewed in the light of boolean functions, which leads to redefining complete interference by a logic function. Together with the upper bound of noninterference already defined by a boolean function, it confines the region of interference. Extensions of these two functions to any finite number of ν are straightforward, but have been also made in terms of variables taken from the inclusion-exclusion principle (expressing "at least" and "exactly equal to" a decimal integer). Two coefficients of coincidence for systems with more than three loci are defined and discussed, one using the average of several individual coefficients and the other taking as coefficient a real number between zero and one. Finally, by way of a malfunction of the mod-2 addition, it is shown that a four-point system may produce two different functions, one of which exhibiting loss of a class of odd recombinants.

  12. Monitoring Radio Frequency Interference in Southwest Virginia

    NASA Astrophysics Data System (ADS)

    Rapp, Steve

    2010-01-01

    The radio signals received from astronomical objects are extremely weak. Because of this, radio sources are easily shrouded by interference from devices such as satellites and cell phone towers. Radio astronomy is very susceptible to this radio frequency interference (RFI). Possibly even worse than complete veiling, weaker interfering signals can contaminate the data collected by radio telescopes, possibly leading astronomers to mistaken interpretations. To help promote student awareness of the connection between radio astronomy and RFI, an inquiry-based science curriculum was developed to allow high school students to determine RFI levels in their communities. The Quiet Skies Project_the result of a collaboration between the National Aeronautics and Space Administration (NASA), the National Science Foundation (NSF), and the National Radio Astronomy Observatory (NRAO)_encourages students to collect and analyze RFI data and develop conclusions as a team. Because the project focuses on electromagnetic radiation, it is appropriate for physics, physical science, chemistry, or general science classes. My class-about 50 students from 15 southwest Virginia high schools-participated in the Quiet Skies Project and were pioneers in the use of the beta version of the Quiet Skies Detector (QSD), which is used to detect RFI. Students have been involved with the project since 2005 and have collected and shared data with NRAO. In analyzing the data they have noted some trends in RFI in Southwest Virginia.

  13. Normalized GNSS interference pattern technique for altimetry.

    PubMed

    Ribot, Miguel Angel; Kucwaj, Jean-Christophe; Botteron, Cyril; Reboul, Serge; Stienne, Georges; Leclère, Jérôme; Choquel, Jean-Bernard; Farine, Pierre-André; Benjelloun, Mohammed

    2014-01-01

    It is well known that reflected signals from Global Navigation Satellite Systems (GNSS) can be used for altimetry applications, such as monitoring of water levels and determining snow height. Due to the interference of these reflected signals and the motion of satellites in space, the signal-to-noise ratio (SNR) measured at the receiver slowly oscillates. The oscillation rate is proportional to the change in the propagation path difference between the direct and reflected signals, which depends on the satellite elevation angle. Assuming a known receiver position, it is possible to compute the distance between the antenna and the surface of reflection from the measured oscillation rate. This technique is usually known as the interference pattern technique (IPT). In this paper, we propose to normalize the measurements in order to derive an alternative model of the SNR variations. From this model, we define a maximum likelihood estimate of the antenna height that reduces the estimation time to a fraction of one period of the SNR variation. We also derive the Cramér-Rao lower bound for the IPT and use it to assess the sensitivity of different parameters to the estimation of the antenna height. Finally, we propose an experimental framework, and we use it to assess our approach with real GPS L1 C/A signals. PMID:24922453

  14. Application of Distributed Hydrology-Soil-Vegetation Model in Pang Khum Experimental Watershed, Chiang Mai Province, Thailand

    NASA Astrophysics Data System (ADS)

    Cuo, L.; Giambelluca, T. W.; Ziegler, A. D.; Sutherland, R. A.; Nullet, M. A.; Larkin, E. D.; Vana, T. T.

    2001-12-01

    Distributed hydrology-soil-vegetation model (DHSVM) uses a digital elevation model (DEM) and accounts for topographic effects on soil moisture, groundwater, and surface water redistribution in a complex terrain. In this study, DHSVM is used to simulate soil moisture, net radiation and stream flow in a 1-km2 tropical mountainous watershed in Pang Khum, Chang Mai, Thailand. Pang Khum Experimental Watershed (PKEW) has two meteorological stations, four soil moisture stations, and one stream flow station at basin outlet. Meteorological measurements are used as forcing data for DHSVM. The grid resolution for this simulation is 50 m. Initial soil and vegetation parameter settings based on field measurements and literature review are adjusted through model calibration. The model is run for a six month warm-up period, followed by a calibration period of approximately one year. Validation is done for two periods totaling 18 months. At the forested site, net radiation is reasonably well simulated, although underestimated in the dry season, and overestimated in the wet season. At the agricultural site, net radiation is consistently overestimated. Soil moisture is well simulated at the forest site. In the simulation, the water table rises into the soil zone during the wet season, saturating all three soil layers at the agricultural site; measured values remained at unsaturated levels. Baseflow is significantly underestimated in calibration and validation periods. Difficulty in simulating streamflow may be caused by road-related effects in the basin. Our prior field work has shown that the road significantly alters runoff in PKEW. The principal mechanism of road-induced effects is Horton Overland Flow (HOF) generated on the road surface. In its present form DHSVM can account for interception of subsurface flow by roads, but not HOF generated on the road. We do not think subsurface flow interception is important in PKEW, and have therefore not implemented the road in our

  15. GNSS space-time interference mitigation and attitude determination in the presence of interference signals.

    PubMed

    Daneshmand, Saeed; Jahromi, Ali Jafarnia; Broumandan, Ali; Lachapelle, Gérard

    2015-05-26

    The use of Space-Time Processing (STP) in Global Navigation Satellite System (GNSS) applications is gaining significant attention due to its effectiveness for both narrowband and wideband interference suppression. However, the resulting distortion and bias on the cross correlation functions due to space-time filtering is a major limitation of this technique. Employing the steering vector of the GNSS signals in the filter structure can significantly reduce the distortion on cross correlation functions and lead to more accurate pseudorange measurements. This paper proposes a two-stage interference mitigation approach in which the first stage estimates an interference-free subspace before the acquisition and tracking phases and projects all received signals into this subspace. The next stage estimates array attitude parameters based on detecting and employing GNSS signals that are less distorted due to the projection process. Attitude parameters enable the receiver to estimate the steering vector of each satellite signal and use it in the novel distortionless STP filter to significantly reduce distortion and maximize Signal-to-Noise Ratio (SNR). GPS signals were collected using a six-element antenna array under open sky conditions to first calibrate the antenna array. Simulated interfering signals were then added to the digitized samples in software to verify the applicability of the proposed receiver structure and assess its performance for several interference scenarios.

  16. GNSS space-time interference mitigation and attitude determination in the presence of interference signals.

    PubMed

    Daneshmand, Saeed; Jahromi, Ali Jafarnia; Broumandan, Ali; Lachapelle, Gérard

    2015-01-01

    The use of Space-Time Processing (STP) in Global Navigation Satellite System (GNSS) applications is gaining significant attention due to its effectiveness for both narrowband and wideband interference suppression. However, the resulting distortion and bias on the cross correlation functions due to space-time filtering is a major limitation of this technique. Employing the steering vector of the GNSS signals in the filter structure can significantly reduce the distortion on cross correlation functions and lead to more accurate pseudorange measurements. This paper proposes a two-stage interference mitigation approach in which the first stage estimates an interference-free subspace before the acquisition and tracking phases and projects all received signals into this subspace. The next stage estimates array attitude parameters based on detecting and employing GNSS signals that are less distorted due to the projection process. Attitude parameters enable the receiver to estimate the steering vector of each satellite signal and use it in the novel distortionless STP filter to significantly reduce distortion and maximize Signal-to-Noise Ratio (SNR). GPS signals were collected using a six-element antenna array under open sky conditions to first calibrate the antenna array. Simulated interfering signals were then added to the digitized samples in software to verify the applicability of the proposed receiver structure and assess its performance for several interference scenarios. PMID:26016909

  17. GNSS Space-Time Interference Mitigation and Attitude Determination in the Presence of Interference Signals

    PubMed Central

    Daneshmand, Saeed; Jahromi, Ali Jafarnia; Broumandan, Ali; Lachapelle, Gérard

    2015-01-01

    The use of Space-Time Processing (STP) in Global Navigation Satellite System (GNSS) applications is gaining significant attention due to its effectiveness for both narrowband and wideband interference suppression. However, the resulting distortion and bias on the cross correlation functions due to space-time filtering is a major limitation of this technique. Employing the steering vector of the GNSS signals in the filter structure can significantly reduce the distortion on cross correlation functions and lead to more accurate pseudorange measurements. This paper proposes a two-stage interference mitigation approach in which the first stage estimates an interference-free subspace before the acquisition and tracking phases and projects all received signals into this subspace. The next stage estimates array attitude parameters based on detecting and employing GNSS signals that are less distorted due to the projection process. Attitude parameters enable the receiver to estimate the steering vector of each satellite signal and use it in the novel distortionless STP filter to significantly reduce distortion and maximize Signal-to-Noise Ratio (SNR). GPS signals were collected using a six-element antenna array under open sky conditions to first calibrate the antenna array. Simulated interfering signals were then added to the digitized samples in software to verify the applicability of the proposed receiver structure and assess its performance for several interference scenarios. PMID:26016909

  18. 76 FR 8802 - On Behalf of the Accessibility Committee of the Federal CIO Council (29 U.S.C. 794d); Listening...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... concerns and propose ideas. Persons with disabilities, their advocates, and government employees are...) accessible to people with disabilities. Inaccessible technology interferes with the ability to obtain and use... technology, open new opportunities for people with disabilities, and encourage development of...

  19. Real-time observation of interference between atomic one-electron and two-electron excitations.

    PubMed

    Geiseler, Henning; Rottke, Horst; Zhavoronkov, Nickolai; Sandner, Wolfgang

    2012-03-23

    We present results of real-time tracking of atomic two-electron dynamics in an autoionizing transient wave packet in krypton. A coherent superposition of two Fano resonances is excited with a femtosecond extreme-ultraviolet pulse. The evolution of the corresponding wave packet is subsequently probed with a delayed infrared pulse. In our specific case, we get access to the interference between one- and two-electron excitation channels in the launched wave packet, which is superimposed on its decay through autoionization. A simple model is able to account for the observed dynamical evolution of this wave packet.

  20. New concept for combining three telescopes with integrated optics: multi-mode interferences (MMI)

    NASA Astrophysics Data System (ADS)

    Rooms, Frederic; Morand, Alain; Schanen-Duport, Isabelle; Broquin, Jean-Emmanuel; Haguenauer, Pierre; Berger, Jean-Philippe; Martin, M.; Benyattou, Taha

    2003-02-01

    Integrated optics technologies are an attractive alternative to classical bulk optics for the beam combination function of an interferometer. We propose a new integrated optics combiner for three apertures giving access to the closure phase on each output. It uses a multimode interference combination scheme realized by ion exchange on a glass substrate. This paper describes the theoretical behaviour of the beam combiner and its design constraints. Its interferometric behaviour is simulated and first experimental results using for the first time, as far as we know, a Near field Scanning Optical Measurement (NSOM) technique are discussed.

  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. Language nonselective lexical access in bilingual toddlers.

    PubMed

    Von Holzen, Katie; Mani, Nivedita

    2012-12-01

    We examined how words from bilingual toddlers' second language (L2) primed recognition of related target words in their first language (L1). On critical trials, prime-target word pairs were either (a) phonologically related, with L2 primes overlapped phonologically with L1 target words [e.g., slide (L2 prime)-Kleid (L1 target, "dress")], or (b) phonologically related through translation, with L1 translations of L2 primes rhymed with the L1 target words [e.g., leg (L2 prime, L1 translation, "Bein")-Stein (L1 target, "stone"). Evidence of facilitated target recognition in the phonological priming condition suggests language nonselective access but not necessarily lexical access. However, a late interference effect on target recognition in the phonological priming through translation condition provides evidence for language nonselective lexical access: The L2 prime (leg) could influence L1 target recognition (Stein) in this condition only if both the L2 prime (leg) and its L1 translation ("Bein") were concurrently activated. In addition, age- and gender-matched monolingual toddler controls showed no difference between conditions, providing further evidence that the results with bilingual toddlers were driven by cross-language activation. The current study, therefore, presents the first-ever evidence of cross-talk between the two languages of bilinguals even as they begin to acquire fluency in their second language.

  3. Language nonselective lexical access in bilingual toddlers.

    PubMed

    Von Holzen, Katie; Mani, Nivedita

    2012-12-01

    We examined how words from bilingual toddlers' second language (L2) primed recognition of related target words in their first language (L1). On critical trials, prime-target word pairs were either (a) phonologically related, with L2 primes overlapped phonologically with L1 target words [e.g., slide (L2 prime)-Kleid (L1 target, "dress")], or (b) phonologically related through translation, with L1 translations of L2 primes rhymed with the L1 target words [e.g., leg (L2 prime, L1 translation, "Bein")-Stein (L1 target, "stone"). Evidence of facilitated target recognition in the phonological priming condition suggests language nonselective access but not necessarily lexical access. However, a late interference effect on target recognition in the phonological priming through translation condition provides evidence for language nonselective lexical access: The L2 prime (leg) could influence L1 target recognition (Stein) in this condition only if both the L2 prime (leg) and its L1 translation ("Bein") were concurrently activated. In addition, age- and gender-matched monolingual toddler controls showed no difference between conditions, providing further evidence that the results with bilingual toddlers were driven by cross-language activation. The current study, therefore, presents the first-ever evidence of cross-talk between the two languages of bilinguals even as they begin to acquire fluency in their second language. PMID:22980955

  4. Critical Access Hospitals (CAH)

    MedlinePlus

    ... CAH Conditions of Participation . What are the location requirements for CAH status? Critical Access Hospitals must be ... clinic that does not meet the CAH distance requirements? As of January 1, 2008, all CAHs, including ...

  5. 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...

  6. 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.

  7. Extra- and intrathoracic access.

    PubMed

    Lazarides, Miltos K; Georgakarakos, Efstratios I; Schoretsanitis, Nikolaos

    2014-01-01

    The most complex patients requiring vascular access are those with bilateral central vein occlusions. Endovascular repair of the central lesions when feasible allow upper extremity use for access. When endovascular repair is not feasible, femoral vein transposition should be the next choice. When lower limb access sites have been exhausted or are contraindicated as in obese patients and in patients with peripheral arterial obstructive disease, a range of extrathoracic "exotic" extra-anatomic access procedures as the necklace cross-chest arteriovenous (AV) grafts, the ipsilateral axillo-axillary loops, the brachial-jugular AV grafts, the axillo-femoral AV grafts or even intra-thoracic ones as the right atrial AV bypasses represent the vascular surgeon's last resort. The selection among those extra-anatomical chest-wall procedures should be based upon each patient's anatomy or patient-specific factors. PMID:24817469

  8. Access cavity preparation.

    PubMed

    Adams, N; Tomson, P L

    2014-03-01

    Each stage of root canal treatment should be carried out to the highest possible standard. The access cavity is arguably the most important technical stage, as subsequent preparation of the root canal(s) can be severely comprised if this is not well executed. Inadequate access can lead to canals being left untreated, poorly disinfected, difficult to shape and obturate, and may ultimately lead to the failure of the treatment. This paper highlights common features in root canal anatomy and outlines basic principles for locating root canals and producing a good access cavity. It also explores each phase of the preparation in detail and offers suggestions of instruments that have been specifically designed to overcome potential difficulties in the process. Good access design and preparation will result in an operative environment which will facilitate cleaning, shaping and obturation of the root canal system in order to maximise success.

  9. Remote Access Astronomy.

    ERIC Educational Resources Information Center

    O'Connor, Erin

    1994-01-01

    Describes the Remote Access Astronomy Project, a computerized optical telescope and dial-in data distribution system that places high-quality images and image processing techniques into computer workstations in junior and high school classrooms. (PR)

  10. Minimizing End-to-End Interference in I/O Stacks Spanning Shared Multi-Level Buffer Caches

    ERIC Educational Resources Information Center

    Patrick, Christina M.

    2011-01-01

    This thesis presents an end-to-end interference minimizing uniquely designed high performance I/O stack that spans multi-level shared buffer cache hierarchies accessing shared I/O servers to deliver a seamless high performance I/O stack. In this thesis, I show that I can build a superior I/O stack which minimizes the inter-application interference…

  11. Adapting Web Browsers for Accessibility.

    ERIC Educational Resources Information Center

    Hendrix, Paul; Birkmire, Mike

    This paper examines ways to make World Wide Web browsers accessible for individuals with disabilities, and through them, gain access to the information on the Web. It discusses which browsers can be made more accessible and evaluates different types of input. Mouse access, keyboard access, and voice input are reviewed. Processing aids, such as…

  12. 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.

  13. Long working distance incoherent interference microscope

    DOEpatents

    Sinclair, Michael B.; De Boer, Maarten P.

    2006-04-25

    A full-field imaging, long working distance, incoherent interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. A long working distance greater than 10 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-dimensional height profiles of MEMS test structures to be acquired across an entire wafer while being actively probed, and, optionally, through a transparent window. An optically identical pair of sample and reference arm objectives is not required, which reduces the overall system cost, and also the cost and time required to change sample magnifications. Using a LED source, high magnification (e.g., 50.times.) can be obtained having excellent image quality, straight fringes, and high fringe contrast.

  14. Symbiont-mediated RNA interference in insects.

    PubMed

    Whitten, Miranda M A; Facey, Paul D; Del Sol, Ricardo; Fernández-Martínez, Lorena T; Evans, Meirwyn C; Mitchell, Jacob J; Bodger, Owen G; Dyson, Paul J

    2016-02-24

    RNA interference (RNAi) methods for insects are often limited by problems with double-stranded (ds) RNA delivery, which restricts reverse genetics studies and the development of RNAi-based biocides. We therefore delegated to insect symbiotic bacteria the task of: (i) constitutive dsRNA synthesis and (ii) trauma-free delivery. RNaseIII-deficient, dsRNA-expressing bacterial strains were created from the symbionts of two very diverse pest species: a long-lived blood-sucking bug, Rhodnius prolixus, and a short-lived globally invasive polyphagous agricultural pest, western flower thrips (Frankliniella occidentalis). When ingested, the manipulated bacteria colonized the insects, successfully competed with the wild-type microflora, and sustainably mediated systemic knockdown phenotypes that were horizontally transmissible. This represents a significant advance in the ability to deliver RNAi, potentially to a large range of non-model insects. PMID:26911963

  15. Aerodynamic interference between two Darrieus wind turbines

    SciTech Connect

    Schatzle, P.R.; Klimas, P.C.; Spahr, H.R.

    1981-04-01

    The effect of aerodynamic interference on the performance of two curved bladed Darrieus-type vertical axis wind turbines has been calculated using a vortex/lifting line aerodynamic model. The turbines have a tower-to-tower separation distance of 1.5 turbine diameters, with the line of turbine centers varying with respect to the ambient wind direction. The effects of freestream turbulence were neglected. For the cases examined, the calculations showed that the downwind turbine power decrement (1) was significant only when the line of turbine centers was coincident with the ambient wind direction, (2) increased with increasing tipspeed ratio, and (3) is due more to induced flow angularities downstream than to speed deficits near the downstream turbine.

  16. Young-Type Interferences with Electrons

    NASA Astrophysics Data System (ADS)

    Frémont, François

    The discovery of the characteristics and properties of light was not straightforward. It took a long time, a lot of mistakes, hesitations, and reversals of ideas, before finally reaching a satisfactory concept of light. Many assumptions were made, based either on philosophical approaches or, more recently, on observations. We can distinguish roughly two periods. Before the work of Isaac Newton, light was not considered in and of itself, as an object. Newton had the brilliant idea to try to define light, independently of its effects. Thanks to him, the question then arose as to whether light should be defined as particles, with a defined spatial extent, or as something more vague, such as non-localized waves for example. It is this history that we summarize here, with particular emphasis on the notion of interference introduced by Thomas Young in the early nineteenth century.

  17. Avionics electromagnetic interference immunity and environment

    NASA Technical Reports Server (NTRS)

    Clarke, C. A.

    1986-01-01

    Aircraft electromagnetic spectrum and radio frequency (RF) field strengths are charted, profiling the higher levels of electromagnetic voltages encountered by the commercial aircraft wiring. Selected military, urban, and rural electromagnetic field levels are plotted and provide a comparison of radiation amplitudes. Low frequency magnetic fields and electric fields from 400 H(Z) power systems are charted versus frequency and wire separation to indicate induced voltages on adjacent or neighboring circuits. Induced EMI levels and attenuation characteristics of electric, magnetic, RF fields, and transients are plotted and graphed for common types of wire circuits. The significance of wire circuit returns and shielding is emphasized to highlight the techniques that help block the paths of electromagnetic interference and maintain avionic interface signal quality.

  18. Symbiont-mediated RNA interference in insects

    PubMed Central

    Whitten, Miranda M. A.; Facey, Paul D.; Del Sol, Ricardo; Fernández-Martínez, Lorena T.; Evans, Meirwyn C.; Mitchell, Jacob J.; Bodger, Owen G.

    2016-01-01

    RNA interference (RNAi) methods for insects are often limited by problems with double-stranded (ds) RNA delivery, which restricts reverse genetics studies and the development of RNAi-based biocides. We therefore delegated to insect symbiotic bacteria the task of: (i) constitutive dsRNA synthesis and (ii) trauma-free delivery. RNaseIII-deficient, dsRNA-expressing bacterial strains were created from the symbionts of two very diverse pest species: a long-lived blood-sucking bug, Rhodnius prolixus, and a short-lived globally invasive polyphagous agricultural pest, western flower thrips (Frankliniella occidentalis). When ingested, the manipulated bacteria colonized the insects, successfully competed with the wild-type microflora, and sustainably mediated systemic knockdown phenotypes that were horizontally transmissible. This represents a significant advance in the ability to deliver RNAi, potentially to a large range of non-model insects. PMID:26911963

  19. Electromagnetic interference shielding effectiveness of monolayer graphene.

    PubMed

    Hong, Seul Ki; Kim, Ki Yeong; Kim, Taek Yong; Kim, Jong Hoon; Park, Seong Wook; Kim, Joung Ho; Cho, Byung Jin

    2012-11-16

    We report the first experimental results on the electromagnetic interference (EMI) shielding effectiveness (SE) of monolayer graphene. The monolayer CVD graphene has an average SE value of 2.27 dB, corresponding to ~40% shielding of incident waves. CVD graphene shows more than seven times (in terms of dB) greater SE than gold film. The dominant mechanism is absorption rather than reflection, and the portion of absorption decreases with an increase in the number of graphene layers. Our modeling work shows that plane-wave theory for metal shielding is also applicable to graphene. The model predicts that ideal monolayer graphene can shield as much as 97.8% of EMI. This suggests the feasibility of manufacturing an ultrathin, transparent, and flexible EMI shield by single or few-layer graphene. PMID:23085718

  20. Scattering and interference in epitaxial graphene.

    PubMed

    Rutter, G M; Crain, J N; Guisinger, N P; Li, T; First, P N; Stroscio, J A

    2007-07-13

    A single sheet of carbon, graphene, exhibits unexpected electronic properties that arise from quantum state symmetries, which restrict the scattering of its charge carriers. Understanding the role of defects in the transport properties of graphene is central to realizing future electronics based on carbon. Scanning tunneling spectroscopy was used to measure quasiparticle interference patterns in epitaxial graphene grown on SiC(0001). Energy-resolved maps of the local density of states reveal modulations on two different length scales, reflecting both intravalley and intervalley scattering. Although such scattering in graphene can be suppressed because of the symmetries of the Dirac quasiparticles, we show that, when its source is atomic-scale lattice defects, wave functions of different symmetries can mix.

  1. On the superposition principle in interference experiments.

    PubMed

    Sinha, Aninda; H Vijay, Aravind; Sinha, Urbasi

    2015-01-01

    The superposition principle is usually incorrectly applied in interference experiments. This has recently been investigated through numerics based on Finite Difference Time Domain (FDTD) methods as well as the Feynman path integral formalism. In the current work, we have derived an analytic formula for the Sorkin parameter which can be used to determine the deviation from the application of the principle. We have found excellent agreement between the analytic distribution and those that have been earlier estimated by numerical integration as well as resource intensive FDTD simulations. The analytic handle would be useful for comparing theory with future experiments. It is applicable both to physics based on classical wave equations as well as the non-relativistic Schrödinger equation. PMID:25973948

  2. On the superposition principle in interference experiments

    PubMed Central

    Sinha, Aninda; H. Vijay, Aravind; Sinha, Urbasi

    2015-01-01

    The superposition principle is usually incorrectly applied in interference experiments. This has recently been investigated through numerics based on Finite Difference Time Domain (FDTD) methods as well as the Feynman path integral formalism. In the current work, we have derived an analytic formula for the Sorkin parameter which can be used to determine the deviation from the application of the principle. We have found excellent agreement between the analytic distribution and those that have been earlier estimated by numerical integration as well as resource intensive FDTD simulations. The analytic handle would be useful for comparing theory with future experiments. It is applicable both to physics based on classical wave equations as well as the non-relativistic Schrödinger equation. PMID:25973948

  3. ATS-6 - Radio Frequency Interference Measurement Experiment

    NASA Technical Reports Server (NTRS)

    Henry, V. F.

    1975-01-01

    The frequency band from 5.925 to 6.425 GHz is served by fixed satellites and by terrestrial microwave links. There is a possibility of microwave links pointed at the horizon causing interference to the uplinks of domestic and international communications satellites sharing the same frequency band. A mathematical model has been derived for predicting the fields at geostationary orbit based on the known characteristics and known distribution of the terrestrial microwave relay system. The Applications Technology Satellite-6 (ATS-6) is sensitive to signals in the range of 10 dBW radiated in the direction of the satellite. Signals in the range of 10-30 dBW have been recorded over various parts of the United States.

  4. Transgenic inhibitors of RNA interference in Drosophila.

    PubMed

    Chou, Yu-ting; Tam, Bergin; Linay, Fabien; Lai, Eric C

    2007-01-01

    RNA silencing functions as an adaptive antiviral defense in both plants and animals. In turn, viruses commonly encode suppressors of RNA silencing, which enable them to mount productive infection. These inhibitor proteins may be exploited as reagents with which to probe mechanisms and functions of RNA silencing pathways. In this report, we describe transgenic Drosophila strains that allow inducible expression of the viral RNA silencing inhibitors Flock House virus-B2, Nodamura virus-B2, vaccinia virus-E3L, influenza A virus-NS1 and tombusvirus P19. Some of these, especially the B2 proteins, are effective transgenic inhibitors of double strand RNA-induced gene silencing in flies. On the other hand, none of them is effective against the Drosophila microRNA pathway. Their functional selectivity makes these viral silencing proteins useful reagents with which to study biological functions of the Drosophila RNA interference pathway.

  5. Event-related potentials and oscillatory brain responses associated with semantic and Stroop-like interference effects in overt naming.

    PubMed

    Piai, Vitória; Roelofs, Ardi; van der Meij, Roemer

    2012-04-23

    Picture-word interference is a widely employed paradigm to investigate lexical access in word production: Speakers name pictures while trying to ignore superimposed distractor words. The distractor can be congruent to the picture (pictured cat, word cat), categorically related (pictured cat, word dog), or unrelated (pictured cat, word pen). Categorically related distractors slow down picture naming relative to unrelated distractors, the so-called semantic interference. Categorically related distractors slow down picture naming relative to congruent distractors, analogous to findings in the colour-word Stroop task. The locus of semantic interference and Stroop-like effects in naming performance has recently become a topic of debate. Whereas some researchers argue for a pre-lexical locus of semantic interference and a lexical locus of Stroop-like effects, others localise both effects at the lexical selection stage. We investigated the time course of semantic and Stroop-like interference effects in overt picture naming by means of event-related potentials (ERP) and time-frequency analyses. Moreover, we employed cluster-based permutation for statistical analyses. Naming latencies showed semantic and Stroop-like interference effects. The ERP waveforms for congruent stimuli started diverging statistically from categorically related stimuli around 250 ms. Deflections for the categorically related condition were more negative-going than for the congruent condition (the Stroop-like effect). The time-frequency analysis revealed a power increase in the beta band (12-30 Hz) for categorically related relative to unrelated stimuli roughly between 250 and 370 ms (the semantic effect). The common time window of these effects suggests that both semantic interference and Stroop-like effects emerged during lexical selection.

  6. The Development of Stimulus and Response Interference Control in Midchildhood

    PubMed Central

    2015-01-01

    Interference control, the ability to overcome distraction from irrelevant information, undergoes considerable improvement during childhood, yet the mechanisms driving these changes remain unclear. The present study investigated the relative influence of interference at the level of the stimulus or the response. Seven-, 10-, and 20-year-olds completed a flanker paradigm in which stimulus and response interference was experimentally manipulated. The influence of stimulus interference decreased from 7 to 10 years, whereas there was no difference in response interference across age groups. The findings demonstrate that a range of processes contribute to the development of interference control and may influence performance to a greater or lesser extent depending on the task requirements and the age of the child. PMID:26595353

  7. Increased Stroop interference with better second-language reading skill.

    PubMed

    Braet, Wouter; Noppe, Nele; Wagemans, Johan; Op de Beeck, Hans

    2011-03-01

    Skilled readers demonstrate remarkable efficiency in processing written words, unlike beginning readers for whom reading occurs more serially and places higher demands on visual attention. In the present study, we used the Stroop paradigm to investigate the relationship between reading skill and automaticity, in individuals learning a second language with a different orthographic system. Prior studies using this paradigm have presented a mixed picture, finding a positive, a negative, or no relationship between the size of Stroop interference and reading skills. Our results show that Stroop interference in the second language was positively related to reading skill (when controlled for interference in the first language). Furthermore, interference was positively related to objective but not subjective indices of the amount of exposure to the second language. We suggest that the lack of consistency in the results of earlier studies may be due, at least in part, to these studies looking at Stroop interference in isolation, rather than comparing interference between languages.

  8. Word reading practice reduces Stroop interference in children.

    PubMed

    Protopapas, Athanassios; Vlahou, Eleni L; Moirou, Despoina; Ziaka, Laoura

    2014-05-01

    Stroop interference is thought to index reading automaticity and is expected to increase with reading practice and to decrease with improved color naming. We investigated the effects of practice in word reading and color naming on interference in 92 adults and 109 children in Grades 4-5. For children, interference was reduced after reading practice with color words. In neither group was interference affected by practice in color naming of neutral stimuli. These findings are consistent with a direct negative relationship between reading ability and interference and challenge the automaticity account in favor of a blocking mechanism whereby interference is determined by the delay to inhibit the reading response rather than by the efficiency of color naming.

  9. Interference Mitigation Effects on Synthetic Aperture Radar Coherent Data Products

    SciTech Connect

    Musgrove, Cameron

    2015-07-01

    For synthetic aperture radars radio frequency interference from sources external to the radar system and techniques to mitigate the interference can degrade the quality of the image products. Usually the radar system designer will try to balance the amount of mitigation for an acceptable amount of interference to optimize the image quality. This dissertation examines the effect of interference mitigation upon coherent data products of fine resolution, high frequency synthetic aperture radars using stretch processing. Novel interference mitigation techniques are introduced that operate on single or multiple apertures of data that increase average coherence compared to existing techniques. New metrics are applied to evaluate multiple mitigation techniques for image quality and average coherence. The underlying mechanism for interference mitigation techniques that affect coherence is revealed.

  10. Access to health care

    PubMed Central

    Fortin, Martin; Maltais, Danielle; Hudon, Catherine; Lapointe, Lise; Ntetu, Antoine Lutumba

    2005-01-01

    OBJECTIVE To explore access to health care for patients presenting with multiple chronic conditions and to identify barriers and factors conducive to access. DESIGN Qualitative study with focus groups. SETTING Family practice unit in Chicoutimi (Saguenay), Que. PARTICIPANTS Twenty-five male and female adult patients with at least four chronic conditions but no cognitive disorders or decompensating conditions. METHODS For this pilot study, only three focus group discussions were held. MAIN FINDINGS The main barriers to accessing follow-up appointments included long waits on the telephone, automated telephone-answering systems, and needing to attend at specific times to obtain appointments. The main barriers to specialized care were long waiting times and the need to get prescriptions and referrals from family physicians. Factors reported conducive to access included systematic callbacks and the personal involvement of family physicians. Good communication between family physicians and specialists was also perceived to be an important factor in access. CONCLUSION Systematic callbacks, family physicians’ personal efforts to obtain follow-up visits, and better physician-specialist communication were all suggested as ways to improve access to care for patients with multiple chronic conditions. PMID:16926944

  11. 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.

  12. Diffractive interference optical analyzer (DiOPTER)

    NASA Astrophysics Data System (ADS)

    Sasikumar, Harish; Prasad, Vishnu; Pal, Parama; Varma, Manoj M.

    2016-03-01

    This report demonstrates a method for high-resolution refractometric measurements using, what we have termed as, a Diffractive Interference Optical Analyzer (DiOpter). The setup consists of a laser, polarizer, a transparent diffraction grating and Si-photodetectors. The sensor is based on the differential response of diffracted orders to bulk refractive index changes. In these setups, the differential read-out of the diffracted orders suppresses signal drifts and enables time-resolved determination of refractive index changes in the sample cell. A remarkable feature of this device is that under appropriate conditions, the measurement sensitivity of the sensor can be enhanced by more than two orders of magnitude due to interference between multiply reflected diffracted orders. A noise-equivalent limit of detection (LoD) of 6x10-7 RIU was achieved in glass. This work focuses on devices with integrated sample well, made on low-cost PDMS. As the detection methodology is experimentally straightforward, it can be used across a wide array of applications, ranging from detecting changes in surface adsorbates via binding reactions to estimating refractive index (and hence concentration) variations in bulk samples. An exciting prospect of this technique is the potential integration of this device to smartphones using a simple interface based on transmission mode configuration. In a transmission configuration, we were able to achieve an LoD of 4x10-4 RIU which is sufficient to explore several applications in food quality testing and related fields. We are envisioning the future of this platform as a personal handheld optical analyzer for applications ranging from environmental sensing to healthcare and quality testing of food products.

  13. Design and Performance of Overlap FFT Filter-Bank for Dynamic Spectrum Access Applications

    NASA Astrophysics Data System (ADS)

    Tanabe, Motohiro; Umehira, Masahiro

    An OFDMA-based (Orthogonal Frequency Division Multiple Access-based) channel access scheme for dynamic spectrum access has the drawbacks of large PAPR (Peak to Average Power Ratio) and large ACI (Adjacent Channel Interference). To solve these problems, a flexible channel access scheme using an overlap FFT filter-bank was proposed based on single carrier modulation for dynamic spectrum access. In order to apply the overlap FFT filter-bank for dynamic spectrum access, it is necessary to clarify the performance of the overlap FFT filter-bank according to the design parameters since its frequency characteristics are critical for dynamic spectrum access applications. This paper analyzes the overlap FFT filter-bank and evaluates its performance such as frequency characteristics and ACI performance according to the design parameters.

  14. Dual-Task Interference When A Response is Not Required

    NASA Technical Reports Server (NTRS)

    VanSelst, Mark; Johnston, James C.; Shafto, Michael (Technical Monitor)

    2002-01-01

    When subjects are required to respond to two stimuli presented in rapid succession, responses to the second stimulus are delayed. Such dual-task interference has been attributed to a fundamental processing bottleneck preventing simultaneous processing on both tasks. Two experiments show dual-task interference even when the first task does not require a response. The observed interference is caused by a bottleneck in central cognitive processing, rather than in response initiation or execution.

  15. NEW APPROACHES: Demonstration of a dancing interference fringe

    NASA Astrophysics Data System (ADS)

    Kagawa, K.; Yamanaka, H.; Yokoi, S.; Hattori, H.

    1997-11-01

    A unique and amusing piece of laser art is proposed for use in physics education. It is shown that a dynamic and beautiful interference fringe can be produced when a He - Ne laser beam illuminates a droplet, which is called Brandy's tear, on a glass surface. This interference fringe can be explained in terms of the interference of multiple spherical waves scattered by the droplet. This kind of demonstration experiment is very helpful for exciting students' curiosity.

  16. Access to care save lives.

    PubMed

    Blaney, C L

    1994-02-01

    Emergency treatment of such major complications of pregnancy as obstructed labor, hemorrhage, infection, hypertension disorders, and the effects of unsafe abortion, helps ameliorate morbidity and prevent mortality. Access to life-saving treatment (e.g., antibiotics, Cesarean sections, and blood transfusions) in developing countries is limited. Maternal mortality in one area of The Gambia, for example, is 2200 per 100,000 births. Improving access to care depends upon the availability of these services in communities, trained health personnel, service improvements, transportation provision, and community education. Detection of complications and early referral to an appropriate facility with a supportive and professional environment is key to saving lives. Political will and public pressure are needed before improvement in services can be successfully accomplished; politicians may ignore women with low status. Barriers to care are physical, cultural, technical, and economic. Cost or distance from home may prevent women from seeking care. Infection, hemorrhage, and uterine injury are frequently related to unsafe abortions, particularly among teenage women. Hospitals must be equipped with a reliable management system, surgical facilities, and clinical services. The WHO recommends upgrading community health centers with trained personnel, adequate supervision, and equipment. In Uganda, midwives are specially trained in advanced skills for use in remote areas: administration of oxytocin to evacuate the uterus and reduce bleeding, use of antibiotics for infections, and surgical repair of vaginal tears. Nurses in Zaire are trained to do Cesarean sections. In Sierra Leone and Nigeria, doctors are encouraged to receive training in obstetrics and to be posted in rural areas. In Sierra Leone, young men are trained to bring pregnant women in to care on stretchers. Maternity waiting homes near hospitals are another means to save lives. Lack of permission from a male relative may

  17. The Active Mai'iu Low Angle Normal Fault, Woodlark Rift: Spatial and Temporal Slip Distributions, and Rider Block Abandonment Chronology.

    NASA Astrophysics Data System (ADS)

    Webber, S. M.; Little, T.; Norton, K. P.; Mizera, M.; Oesterle, J.; Ellis, S. M.

    2015-12-01

    Low-angle normal faults (LANFs) have induced debate due to their apparent non-Andersonian behavior and lack of significant seismicity associated with slip. Dipping ~21°, the Mai'iu Fault, Woodlark Rift is an active, rapidly slipping LANF located at the transition between continental extension and seafloor spreading. Based on campaign GPS data [Wallace et al., 2014] the Mai'iu Fault is thought to slip at 7-9 mm/yr, accommodating a large fraction of total basinal extension, although it is uncertain whether slip is seismic or aseismic. Surface geomorphology indicates that the fault scarp is not significantly eroded despite high rainfall and ~3000 m relief. We have obtained 15 rock samples (~5 m spacing) from the lowermost Mai'iu Fault scarp in order to determine Holocene slip rate and style over the last ~10 kyr using cosmogenic 10Be in quartz. This slip direction-parallel profile in exposed bedrock is supported by a suite of soil samples for 10Be analysis, which extend our temporal coverage. We model exposure age data in terms of slip rate and style by identification of discontinuities within the profile. Of particular interest is whether slip is seismic or aseismic. In addition we analyze the structure of conglomeratic strata and abandoned, back-rotated rider blocks in the Mai'iu Fault hanging wall, which record Quaternary splay faulting and tilting in response to sustained LANF slip. 20 quartz pebble samples were obtained from hanging wall conglomerates for the purpose of calculating cosmogenic burial (26Al/10Be) ages. These constrain the chronology of Quaternary hanging wall deformation. High-angle (~50°) faulting competes with LANF slip at <2 km depths, with high-angle faults cutting the main LANF and exposing footwall metabasalt up to 2 km north of the Mai'iu Fault. Past splay faulting is recorded in the progressive back-tilting and folding of the Gwoira rider block in a ~2 km deep depression in the corrugated Mai'iu fault plane. Our results provide new

  18. Assessing communication accessibility in the university classroom: towards a goal of universal hearing accessibility.

    PubMed

    Cheesman, Margaret F; Jennings, Mary Beth; Klinger, Lisa

    2013-01-01

    Measures of accessibility typically focus on the physical environment and aspects relating to getting into and out of spaces. The transient sound environment is less well characterized in typical accessibility measures. Hearing accessibility measures can be based upon physical indices or functional assessment. The physical measures are indices that use signal-to-noise ratios to evaluate audibility while the functional assessment tool adopts universal design for hearing (UDH) principles derived from principles of universal design. The UDH principles include (1) Optimization of the hearing environment for all; (2) Optimization of interactions between persons and objects to promote better hearing in an environment; (3) Optimization of opportunities for people to have multiple choices of interactions with one another; (4) Optimization of opportunities for people to perform different activities in and across environments; (5) Optimization of opportunities for people to have safe, private, and secure use of the environment while minimizing distraction, interference, or cognitive loading; and (6) Optimization of opportunities for people to use the environment without extra steps for hearing access during preparatory, use and/or after use phases. This paper compares the two approaches using case examples from post-secondary classrooms in order to describe the potential advantages and limitations of each. PMID:24004801

  19. Assessing communication accessibility in the university classroom: towards a goal of universal hearing accessibility.

    PubMed

    Cheesman, Margaret F; Jennings, Mary Beth; Klinger, Lisa

    2013-01-01

    Measures of accessibility typically focus on the physical environment and aspects relating to getting into and out of spaces. The transient sound environment is less well characterized in typical accessibility measures. Hearing accessibility measures can be based upon physical indices or functional assessment. The physical measures are indices that use signal-to-noise ratios to evaluate audibility while the functional assessment tool adopts universal design for hearing (UDH) principles derived from principles of universal design. The UDH principles include (1) Optimization of the hearing environment for all; (2) Optimization of interactions between persons and objects to promote better hearing in an environment; (3) Optimization of opportunities for people to have multiple choices of interactions with one another; (4) Optimization of opportunities for people to perform different activities in and across environments; (5) Optimization of opportunities for people to have safe, private, and secure use of the environment while minimizing distraction, interference, or cognitive loading; and (6) Optimization of opportunities for people to use the environment without extra steps for hearing access during preparatory, use and/or after use phases. This paper compares the two approaches using case examples from post-secondary classrooms in order to describe the potential advantages and limitations of each.

  20. Communication: Finding destructive interference features in molecular transport junctions

    SciTech Connect

    Reuter, Matthew G.; Hansen, Thorsten

    2014-11-14

    Associating molecular structure with quantum interference features in electrode-molecule-electrode transport junctions has been difficult because existing guidelines for understanding interferences only apply to conjugated hydrocarbons. Herein we use linear algebra and the Landauer-Büttiker theory for electron transport to derive a general rule for predicting the existence and locations of interference features. Our analysis illustrates that interferences can be directly determined from the molecular Hamiltonian and the molecule–electrode couplings, and we demonstrate its utility with several examples.

  1. 47 CFR 27.64 - Protection from interference.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.64 Protection from interference. Wireless Communications Service (WCS) stations operating in full accordance with applicable FCC rules...

  2. 47 CFR 27.64 - Protection from interference.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.64 Protection from interference. Wireless Communications Service (WCS) stations operating in full accordance with applicable FCC rules...

  3. 47 CFR 27.64 - Protection from interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.64 Protection from interference. Wireless Communications Service (WCS) stations operating in full accordance with applicable FCC rules...

  4. 47 CFR 27.64 - Protection from interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.64 Protection from interference. Wireless Communications Service (WCS) stations operating in full accordance with applicable FCC rules...

  5. 47 CFR 27.64 - Protection from interference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Technical Standards § 27.64 Protection from interference. Wireless Communications Service (WCS) stations operating in full accordance with applicable FCC rules...

  6. Communication: Finding destructive interference features in molecular transport junctions.

    PubMed

    Reuter, Matthew G; Hansen, Thorsten

    2014-11-14

    Associating molecular structure with quantum interference features in electrode-molecule-electrode transport junctions has been difficult because existing guidelines for understanding interferences only apply to conjugated hydrocarbons. Herein we use linear algebra and the Landauer-Büttiker theory for electron transport to derive a general rule for predicting the existence and locations of interference features. Our analysis illustrates that interferences can be directly determined from the molecular Hamiltonian and the molecule-electrode couplings, and we demonstrate its utility with several examples. PMID:25399124

  7. Multiple beam interference model for measuring parameters of a capillary.

    PubMed

    Xu, Qiwei; Tian, Wenjing; You, Zhihong; Xiao, Jinghua

    2015-08-01

    A multiple beam interference model based on the ray tracing method and interference theory is built to analyze the interference patterns of a capillary tube filled with a liquid. The relations between the angular widths of the interference fringes and the parameters of both the capillary and liquid are derived. Based on these relations, an approach is proposed to simultaneously determine four parameters of the capillary, i.e., the inner and outer radii of the capillary, the refractive indices of the liquid, and the wall material. PMID:26368114

  8. Neural basis of semantic and syntactic interference in sentence comprehension.

    PubMed

    Glaser, Yi G; Martin, Randi C; Van Dyke, Julie A; Hamilton, A Cris; Tan, Yingying

    2013-09-01

    According to the cue-based parsing approach (Lewis, Vasishth, & Van Dyke, 2006), sentence comprehension difficulty derives from interference from material that partially matches syntactic and semantic retrieval cues. In a 2 (low vs. high semantic interference)×2 (low vs. high syntactic interference) fMRI study, greater activation was observed in left BA44/45 for high versus low syntactic interference conditions following sentences and in left BA45/47 for high versus low semantic interference conditions following comprehension questions. A conjunction analysis showed BA45 associated with both types of interference, while BA47 was associated with only semantic interference. Greater activation was also observed in the left STG in the high interference conditions. Importantly, the results for the LIFG could not be attributed to greater working memory capacity demands for high interference conditions. The results favor a fractionation of the LIFG wherein BA45 is associated with post-retrieval selection and BA47 with controlled retrieval of semantic information.

  9. The right posterior paravermis and the control of language interference.

    PubMed

    Filippi, Roberto; Richardson, Fiona M; Dick, Frederic; Leech, Robert; Green, David W; Thomas, Michael S C; Price, Cathy J

    2011-07-20

    Auditory and written language in humans' comprehension necessitates attention to the message of interest and suppression of interference from distracting sources. Investigating the brain areas associated with the control of interference is challenging because it is inevitable that activation of the brain regions that control interference co-occurs with activation related to interference per se. To isolate the mechanisms that control verbal interference, we used a combination of structural and functional imaging techniques in Italian and German participants who spoke English as a second language. First, we searched structural MRI images of Italian participants for brain regions in which brain structure correlated with the ability to suppress interference from the unattended dominant language (Italian) while processing heard sentences in their weaker language (English). This revealed an area in the posterior paravermis of the right cerebellum in which gray matter density was higher in individuals who were better at controlling verbal interference. Second, we found functional activation in the same region when our German participants made semantic decisions on written English words in the presence of interference from unrelated words in their dominant language (German). This combination of structural and functional imaging therefore highlights the contribution of the right posterior paravermis to the control of verbal interference. We suggest that the importance of this region for language processing has previously been missed because most fMRI studies limit the field of view to increase sensitivity, with the lower part of the cerebellum being the region most likely to be excluded.

  10. Two-photon interference with non-identical photons

    NASA Astrophysics Data System (ADS)

    Liu, Jianbin; Zhou, Yu; Zheng, Huaibin; Chen, Hui; Li, Fu-li; Xu, Zhuo

    2015-11-01

    Two-photon interference with non-identical photons is studied based on the superposition principle in Feynman's path integral theory. The second-order temporal interference pattern is observed by superposing laser and pseudothermal light beams with different spectra. The reason why there is two-photon interference for photons of different spectra is that non-identical photons can be indistinguishable for the detection system when Heisenberg's uncertainty principle is taken into account. These studies are helpful to understand the second-order interference of light in the language of photons.

  11. Resolving Semantic Interference During Word Production Requires Central Attention

    PubMed Central

    Kleinman, Daniel

    2013-01-01

    The semantic picture-word interference task has been used to diagnose how speakers resolve competition while selecting words for production. The attentional demands of this resolution process were assessed in two dual-task experiments (tone classification followed by picture naming). In Experiment 1, when pictures and distractor words were presented simultaneously, semantic interference was not observed when tasks maximally overlapped. This replicates a key finding from the literature that suggested that semantic picture-word interference does not require capacity-limited central attentional resources and occurs prior to lexical selection, an interpretation that runs counter to the claims of all major theories of word production. In another Experiment 1 condition, when distractors were presented 250 ms after pictures, interference emerged when tasks maximally overlapped. Together, these findings support an account in which interference resolution and lexical selection both require central resources, but the activation of lexical representations from written words does not. Subsequent analysis revealed that discrepant results obtained in previous replication attempts may be attributable to differences in phonological (ir)regularity between languages. In Experiment 2, degree of semantic interference was manipulated using the cumulative semantic interference paradigm. Interference was observed regardless of task overlap, confirming that lexical selection requires central resources. Together, these findings indicate that a lexical selection locus of semantic picture-word interference – and models of word production that assume such a locus – may be retained. PMID:23773184

  12. Multiple beam interference model for measuring parameters of a capillary.

    PubMed

    Xu, Qiwei; Tian, Wenjing; You, Zhihong; Xiao, Jinghua

    2015-08-01

    A multiple beam interference model based on the ray tracing method and interference theory is built to analyze the interference patterns of a capillary tube filled with a liquid. The relations between the angular widths of the interference fringes and the parameters of both the capillary and liquid are derived. Based on these relations, an approach is proposed to simultaneously determine four parameters of the capillary, i.e., the inner and outer radii of the capillary, the refractive indices of the liquid, and the wall material.

  13. Interference susceptibility measurements for an MSK satellite communication link

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Fujikawa, Gene

    1992-01-01

    The results are presented of measurements of the degradation of an MSK satellite link due to modulated and CW (unmodulated) interference. These measurements were made using a hardware based satellite communication link simulator at NASA-Lewis. The results indicate the amount of bit error rate degradation caused by CW interference as a function of frequency and power level, and the degradation caused by adjacent channel and cochannel modulated interference as a function of interference power level. Results were obtained for both the uplink case (including satellite nonlinearity) and the downlink case (linear channel).

  14. 47 CFR 101.509 - Interference protection criteria.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., and radiation pattern of the transmitting and receiving antennas. Licensees are expected to cooperate fully in attempting to resolve problems of potential interference before bringing the matter to...

  15. Note: Interference effects elimination in wave plates manufacture.

    PubMed

    Chen, Wenxue; Zhang, Shulian; Long, Xingwu

    2013-01-01

    Wave plate manufacturing precision is critical to the functionality of the instruments that use these wave plates among their optical components. In current manufacturing processes, the optical interference effects of the wave plate affect the manufacturing precision of the plate itself. To manufacture high-precision wave plates, we have researched the physical mechanism of these interference effects theoretically. Based on our analysis, an interference effects elimination structure is proposed that will allow us to ignore the interference effects of the wave plate. On the basis of this work, the precision of manufacture can be improved greatly.

  16. Measuring terrestrial radio frequency interference at orbit altitudes

    NASA Technical Reports Server (NTRS)

    Bayol, M. E.; Locke, P. A.

    1973-01-01

    An experiment has been designed to measure and characterize the effect of man-made interference on satellite receivers at orbital altitudes. The experiment, as designed, requires dedicated hardware on a spacecraft of specified orbit and will measure (within the frequency range from 400 MHz to 12.4 GHz) peak levels of interference in cells dimensioned in space, time, and frequency. The experiment will provide data indicative of some of the statistical characteristics of interference levels at satellite orbital altitudes and will provide designers of satellite communications links with new facilities for the prediction and prevention of interference problems.

  17. A shift from exploitation to interference competition with increasing density affects population and community dynamics.

    PubMed

    Holdridge, Erica M; Cuellar-Gempeler, Catalina; terHorst, Casey P

    2016-08-01

    Intraspecific competition influences population and community dynamics and occurs via two mechanisms. Exploitative competition is an indirect effect that occurs through use of a shared resource and depends on resource availability. Interference competition occurs by obstructing access to a resource and may not depend on resource availability. Our study tested whether the strength of interference competition changes with protozoa population density. We grew experimental microcosms of protozoa and bacteria under different combinations of protozoan density and basal resource availability. We then solved a dynamic predator-prey model for parameters of the functional response using population growth rates measured in our experiment. As population density increased, competition shifted from exploitation to interference, and competition was less dependent on resource levels. Surprisingly, the effect of resources was weakest when competition was the most intense. We found that at low population densities, competition was largely exploitative and resource availability had a large effect on population growth rates, but the effect of resources was much weaker at high densities. This shift in competitive mechanism could have implications for interspecific competition, trophic interactions, community diversity, and natural selection. We also tested whether this shift in the mechanism of competition with protozoa density affected the structure of the bacterial prey community. We found that both resources and protozoa density affected the structure of the bacterial prey community, suggesting that competitive mechanism may also affect trophic interactions.

  18. A shift from exploitation to interference competition with increasing density affects population and community dynamics.

    PubMed

    Holdridge, Erica M; Cuellar-Gempeler, Catalina; terHorst, Casey P

    2016-08-01

    Intraspecific competition influences population and community dynamics and occurs via two mechanisms. Exploitative competition is an indirect effect that occurs through use of a shared resource and depends on resource availability. Interference competition occurs by obstructing access to a resource and may not depend on resource availability. Our study tested whether the strength of interference competition changes with protozoa population density. We grew experimental microcosms of protozoa and bacteria under different combinations of protozoan density and basal resource availability. We then solved a dynamic predator-prey model for parameters of the functional response using population growth rates measured in our experiment. As population density increased, competition shifted from exploitation to interference, and competition was less dependent on resource levels. Surprisingly, the effect of resources was weakest when competition was the most intense. We found that at low population densities, competition was largely exploitative and resource availability had a large effect on population growth rates, but the effect of resources was much weaker at high densities. This shift in competitive mechanism could have implications for interspecific competition, trophic interactions, community diversity, and natural selection. We also tested whether this shift in the mechanism of competition with protozoa density affected the structure of the bacterial prey community. We found that both resources and protozoa density affected the structure of the bacterial prey community, suggesting that competitive mechanism may also affect trophic interactions. PMID:27551386

  19. Primary care in Brazil, and the Mais Médicos (More Doctors) Program in the Unified Health System: achievements and limits.

    PubMed

    Campos, Gastão Wagner de Sousa; Pereira, Nilton

    2016-09-01

    An historical analysis of Brazil's policies in Primary Healthcare, with emphasis on the Family Health Strategy (FHS), and the Mais Médicos Program (PMM). Studies were made of documents and secondary official data, and the bibliography that has been produced on this theme. It was found that primary healthcare has been established and successfully consolidated as an option in healthcare for a great part of the population of Brazil. There have, however, been structural hurdles, which have tended to compromise the effectiveness and sustainability of this policy. It was identified that these obstacles arise principally from insufficient financing and from inefficient modes of planning and management. The Mais Médicos Program has widened care coverage and made the distribution of primary healthcare doctors more equitable, although it has not resolved the structural problems of the public system. PMID:27653048

  20. RNA interference targets arbovirus replication in Culicoides cells.

    PubMed

    Schnettler, Esther; Ratinier, Maxime; Watson, Mick; Shaw, Andrew E; McFarlane, Melanie; Varela, Mariana; Elliott, Richard M; Palmarini, Massimo; Kohl, Alain

    2013-03-01

    Arboviruses are transmitted to vertebrate hosts by biting arthropod vectors such as mosquitoes, ticks, and midges. These viruses replicate in both arthropods and vertebrates and are thus exposed to different antiviral responses in these organisms. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism that has been shown to play a major role in the antiviral response against arboviruses in mosquitoes. Culicoides midges are important vectors of arboviruses, known to transmit pathogens of humans and livestock such as bluetongue virus (BTV) (Reoviridae), Oropouche virus (Bunyaviridae), and likely the recently discovered Schmallenberg virus (Bunyaviridae). In this study, we investigated whether Culicoides cells possess an antiviral RNAi response and whether this is effective against arboviruses, including those with double-stranded RNA (dsRNA) genomes, such as BTV. Using reporter gene-based assays, we established the presence of a functional RNAi response in Culicoides sonorensis-derived KC cells which is effective in inhibiting BTV infection. Sequencing of small RNAs from KC and Aedes aegypti-derived Aag2 cells infected with BTV or the unrelated Schmallenberg virus resulted in the production of virus-derived small interfering RNAs (viRNAs) of 21 nucleotides, similar to the viRNAs produced during arbovirus infections of mosquitoes. In addition, viRNA profiles strongly suggest that the BTV dsRNA genome is accessible to a Dicer-type nuclease. Thus, we show for the first time that midge cells target arbovirus replication by mounting an antiviral RNAi response mainly resembling that of other insect vectors of arboviruses.