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Sample records for 10-specific small interference

  1. Small Aircraft RF Interference Path Loss Measurements

    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. Small Aircraft RF Interference Path Loss

    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.

  3. ULS (ULtra-small angle Scattering instrument) and interference imaging

    The cold neutron beam port C1-3, ULS (ULtra Small angle scattering instrument) has been designed and built for the ultra-small angle scattering using a pair of Si-perfect crystals, neutron interferometry with Si-perfect crystal, double-crystal method to estimate the perfection of crystals. For these years, this beam port is used for the development of neutron interference imaging. The neutron interference imaging technique has been developed for these years with several methods. These years we are developing neutron interference imaging technique using gratings at ULS. The neutron interference imaging experiment with two absorption gratings has been done. We develop new way to fabricate absorption gratings for neutron with the pitch of 150 μm, 180 μm, and 200 μm. Small break in an acrylic plate was observed. (author)

  4. Interference-robust Air Interface for 5G Small Cells

    Tavares, Fernando Menezes Leitão

    new 5th Generation (5G) RAT standard is expected to support data rates greater than 10 Gbps with very low latency, very low energy consumption and provide the required scalability that will allow the network to transport a 1000 to 10000 times more mobile data traffic in 2020 than a similar network...... would do in 2010. To meet these challenging network capacity expansion requirements, the design of the new 5G RAT standard will make use of three main strategies: more antennas, more spectrum and more cells. All these strategies will have important roles in the new system, but the deployment of a...... expected gains. Due to the fundamental role of inter-cell interference in this type of networks, the inter-cell interference problem must be addressed since the beginning of the design of the new standard. This Ph.D. thesis deals with the design of an interference-robust air interface for 5G small cell...

  5. Experimental Evaluation of Interference Suppression Receivers and Rank Adaptation in 5G Small Cells

    Assefa, Dereje; Berardinelli, Gilberto; Catania, Davide;

    2015-01-01

    Advanced receivers are a key component of the 5th Generation (5G) ultra-dense small cells concept given their capability of efficiently dealing with the ever-increasing problem of inter-cell interference. In this paper, we evaluate the potential of interference suppression receivers in real network...

  6. Experimental Verification of Interference Mitigation Techniques for 5G Small Cells

    Assefa, Dereje; Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão;

    2015-01-01

    Inter-cell interference is the main performance limiting factor in the dense deployment of small cells targeted by the upcoming 5th Generation (5G) radio access technology. In this paper, we present an experimental evaluation of inter-cell interference mitigation techniques in a real indoor office...

  7. Evaluation of small hypothalamic hamartomas with 3D constructive interference in steady state (CISS) sequence

    Yamura, Masayuki; Hirai, Toshinori; Kitajima, Mika; Hayashida, Yoshiko; Ikushima, Ichiro; Yamashita, Yasuyuki [Graduate School of Medical Sciences, Kumamoto University, Department of Diagnostic Radiology, Kumamoto (Japan); Korogi, Yukunori [University of Occupational and Environmental Health, School of Medicine, Department of Radiology, Kitakyushu (Japan); Endo, Fumio [Kumamoto University, Department of Pediatrics,Graduate School of Medical Sciences, Kumamoto (Japan)

    2005-03-01

    Hypothalamic hamartomas are relatively rare, non-neoplastic congenital malformations. With conventional MR images alone, small hypothalamic hamartomas may be difficult to diagnose because of artifacts from cerebrospinal fluid. We present the usefulness of three-dimensional constructive interference in steady state sequence for evaluating small hypothalamic hamartomas in three pediatric patients. (orig.)

  8. Interference-Robust Air Interface for 5G Ultra-dense Small Cells

    Tavares, Fernando Menezes Leitão; Berardinelli, Gilberto; Mahmood, Nurul Huda;

    2016-01-01

    An ultra-dense deployment of small cells is foreseen as the solution to cope with the exponential increase of the data rate demand targeted by the 5th Generation (5G) radio access technology. In this article, we propose an interference-robust air interface built upon the usage of advanced receivers...

  9. Managing inter-cell interference with advanced receivers and rank adaptation in 5G small cells

    Tavares, Fernando Menezes Leitão; Berardinelli, Gilberto; Catania, Davide;

    2015-01-01

    The use of receivers with interference suppression capabilities is expected to be a significant performance booster in 5th Generation (5G) ultra-dense small cell networks. In this respect, they could represent an alternative to traditional frequency reuse techniques, facilitating the inter...

  10. An Interference-Aware Distributed Transmission Technique for Dense Small Cell Networks

    Mahmood, Nurul Huda; Berardinelli, Gilberto; Pedersen, Klaus I.;

    2015-01-01

    An ultra-dense deployment of small cells with multi-antenna nodes is expected to be the solution for coping with the huge traffic growth expected in near future. Mutual interference among coexisting users is one of the main performance bottlenecks in such dense deployment scenarios. A distributed...

  11. Small RNAs tackle large viruses: RNA interference-based antiviral defense against DNA viruses in insects

    Bronkhorst, Alfred W.; Miesen, Pascal; Ronald P. van Rij

    2013-01-01

    The antiviral RNA interference (RNAi) pathway processes viral double-stranded RNA (dsRNA) into viral small interfering RNAs (vsiRNA) that guide the recognition and cleavage of complementary viral target RNAs. In RNA virus infections, viral replication intermediates, dsRNA genomes or viral structured RNAs have been implicated as Dicer-2 substrates. In a recent publication, we demonstrated that a double-stranded DNA virus, Invertebrate iridescent virus 6, is a target of the Drosophila RNAi mach...

  12. Low-Complexity Interference-Free Downlink Channel Assignment with Improved Performance in Coordinated Small Cells

    Radaydeh, Redha M.

    2015-05-01

    This paper proposes a low-complexity interference-free channel assignment scheme with improved desired downlink performance in coordinated multi-antenna small-coverage access points (APs) that employ the open-access control strategy. The adopted system treats the case when each user can be granted an access to one of the available channels at a time. Moreover, each receive terminal can suppress a limited number of resolvable interfering sources via its highly-correlated receive array. On the other hand, the operation of the deployed APs can be coordinated to serve active users, and the availability of multiple physical channels and the use of uncorrelated transmit antennas at each AP are exploited to improve the performance of supported users. The analysis provides new approaches to use the transmit antenna array at each AP, the multiple physical channels, the receive antenna array at each user in order to identify interference-free channels per each user, and then to select a downlink channel that provides the best possible improved performance. The event of concurrent interference-free channel identification by different users is also treated to further improve the desired link associated with the scheduled user. The analysis considers the practical scenario of imperfect identification of interference-free channel by an active user and/or the imperfectness in scheduling concurrent users requests on the same channel. The developed formulations can be used to study any performance metric and they are applicable for any statistical and geometric channel models. © 2015 IEEE.

  13. Interference with phage lambda development by the small subunit of the phage 21 terminase, gp1.

    Johnson, G.,; Widner, W; Xin, W N; Feiss, M

    1991-01-01

    Bacteriophage lambda development is blocked in cells carrying a plasmid that expresses the terminase genes of phage 21. The interference is caused by the small subunit of phage 21 terminase, gp1. Mutants of lambda able to form plaques in the presence of gp1 include sti mutants. One such mutation, sti30, is an A. T-to-G.C transition mutation at base pair 184 on the lambda chromosome. The sti30 mutation extends the length of the ribosome-binding sequence of the Nul gene that is complementary to...

  14. Improved Interference-Free Channel Allocation in Coordinated Multiuser Multi-Antenna Open-Access Small Cells

    Radaydeh, Redha

    2016-02-16

    This paper investigates low-complexity joint interference avoidance and desired link improvement for single channel allocation in multiuser multi-antenna access points (APs) for open-access small cells. It is considered that an active user is equipped with an atenna array that can be used to suppress interference sources but not to provide spatial diversity. On the other hand, the operation of APs can be coordinated to meet design requirements, and each of which can unconditionally utilize assigned physical channels. Moreover, each AP is equipped with uncorrelated antennas that can be reused simultaneously to serve many active users. The analysis provides new approaches to exploit physical channels, transmit antennas, and APs to mitigate interference, while providing the best possible link gain to an active user through the most suitable interference-free channel. The event of concurrent service requests placed by active users on a specific interference-free channel is discussed for either interference avoidance through identifying unshared channels or desired link improvement via multiuser scheduling. The applicability of the approaches to balance downlink loads is explained, and practical scenarios due to imperfect identification of interference-free channels and/or scheduled user are thoroughly investigated. The developed results are applicable for any statistical and geometric models of the allocated channel to an active user as well as channel conditions of interference users. They can be used to study various performance measures. Numerical and simulation results are presented to explain some outcomes of this work.

  15. Interference statistics and capacity analysis for uplink transmission in two-tier small cell networks: A geometric probability approach

    Tabassum, Hina

    2014-07-01

    This paper presents a novel framework to derive the statistics of the interference considering dedicated and shared spectrum access for uplink transmission in two-tier small cell networks such as the macrocell-femtocell networks. The framework exploits the distance distributions from geometric probability theory to characterize the uplink interference while considering a traditional grid-model set-up for macrocells along with the randomly deployed femtocells. The derived expressions capture the impact of path-loss, composite shadowing and fading, uniform and non-uniform traffic loads, spatial distribution of femtocells, and partial and full spectral reuse among femtocells. Considering dedicated spectrum access, first, we derive the statistics of co-tier interference incurred at both femtocell and macrocell base stations (BSs) from a single interferer by approximating generalized- K composite fading distribution with the tractable Gamma distribution. We then derive the distribution of the number of interferers considering partial spectral reuse and moment generating function (MGF) of the cumulative interference for both partial and full spectral reuse scenarios. Next, we derive the statistics of the cross-tier interference at both femtocell and macrocell BSs considering shared spectrum access. Finally, we utilize the derived expressions to analyze the capacity in both dedicated and shared spectrum access scenarios. The derived expressions are validated by the Monte Carlo simulations. Numerical results are generated to assess the feasibility of shared and dedicated spectrum access in femtocells under varying traffic load and spectral reuse scenarios. © 2014 IEEE.

  16. Performance improvement of switched-based interference mitigation for channel assignment in over-loaded small-cell networks

    Gaaloul, Fakhreddine

    2013-05-01

    This paper proposes adequate methods to improve the interference mitigation capability of a recently investigated switched-based interference reduction scheme for single downlink channel assignment in over-loaded small-cell networks. The model assumes that the available orthogonal channels for small cells are distributed among access points in close vicinity, where each access point knows its allocated channels a priori. Each cell has a single antenna, employs the open access strategy, and can reuse its allocated channels simultaneously, while scheduling concurrent service requests. Moreover, the access points can not coordinate their transmissions, and can receive limited feedback from active users. The paper presents low-complexity schemes to identify a suitable channel to serve the scheduled user by maintaining the interference power level within a tolerable range. They attempt to either complement the switched-based scheme by minimum interference channel selection or adopt different interference thresholds on available channels, while reducing the channel examination load. The optimal thresholds for interference mitigation at the desired receive station are quantified for various performance criteria. The performance and processing load of the proposed schemes are obtained analytically, and then compared to those of the single-threshold scheme via numerical and simulation results. © 2002-2012 IEEE.

  17. Vertical nano superconducting quantum interference device based on Josepshon tunnel nanojunctions for small spin cluster detection

    The ultra high sensitivity exhibited by Superconducting Quantum Interference Device (SQUIDs) could be the key to explore new field of nanoscience such as the investigation of small cluster of elementary magnetic moments. In this paper, an ultra high sensitive niobium nanoSQUID based on submicron Josephson tunnel junction is presented. It has been fabricated in a vertical configuration by using a three-dimensional focused ion beam sculpting technique. In such a configuration, the nanosensor loop (area of 0.25 μm2) is perpendicular to the substrate plane allowing to drastically reduce the spurious effects of the external magnetic field employed to excite the nano-objects under investigation. Main device characteristics have been measured at T=4.2 K by using a low noise readout electronics. Due to high voltage responsivity, the nanosensor has exhibited a spectral density of the magnetic flux noise as low as 1.6 μΦ0/Hz1/2. - Highlights: • Magnetic nano-sensor including sub-micrometric Josephson tunnel junctions. • Vertical design that reduces the parasitic effect of exciting magnetic field. • Non-hysteretic behavior allowing the use as magnetic flux-to-voltage transducer. • High intrinsic responsivity due to high current modulation depth. • Low intrinsic magnetic flux noise leading high spin sensitivity

  18. Vertical nano superconducting quantum interference device based on Josepshon tunnel nanojunctions for small spin cluster detection

    Granata, Carmine, E-mail: c.granata@cib.na.cnr.it [Istituto di Cibernetica “E. Caianiello” del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Napoli) (Italy); Vettoliere, Antonio [Istituto di Cibernetica “E. Caianiello” del Consiglio Nazionale delle Ricerche, I-80078 Pozzuoli (Napoli) (Italy); Fretto, Matteo; Leo, Natascia De; Vincenzo, Lacquaniti [Istituto Nazionale di Ricerca Metrologica, Torino (Italy)

    2015-06-15

    The ultra high sensitivity exhibited by Superconducting Quantum Interference Device (SQUIDs) could be the key to explore new field of nanoscience such as the investigation of small cluster of elementary magnetic moments. In this paper, an ultra high sensitive niobium nanoSQUID based on submicron Josephson tunnel junction is presented. It has been fabricated in a vertical configuration by using a three-dimensional focused ion beam sculpting technique. In such a configuration, the nanosensor loop (area of 0.25 μm{sup 2}) is perpendicular to the substrate plane allowing to drastically reduce the spurious effects of the external magnetic field employed to excite the nano-objects under investigation. Main device characteristics have been measured at T=4.2 K by using a low noise readout electronics. Due to high voltage responsivity, the nanosensor has exhibited a spectral density of the magnetic flux noise as low as 1.6 μΦ{sub 0}/Hz{sup 1/2}. - Highlights: • Magnetic nano-sensor including sub-micrometric Josephson tunnel junctions. • Vertical design that reduces the parasitic effect of exciting magnetic field. • Non-hysteretic behavior allowing the use as magnetic flux-to-voltage transducer. • High intrinsic responsivity due to high current modulation depth. • Low intrinsic magnetic flux noise leading high spin sensitivity.

  19. Small interference RNA targeting tissue factor inhibits human lung adenocarcinoma growth in vitro and in vivo

    Wang Jianing

    2011-05-01

    Full Text Available Abstract Background The human coagulation trigger tissue factor (TF is overexpressed in several types of cancer and involved in tumor growth, vascularization, and metastasis. To explore the role of TF in biological processes of lung adenocarcinoma, we used RNA interference (RNAi technology to silence TF in a lung adenocarcinoma cell line A549 with high-level expression of TF and evaluate its antitumor effects in vitro and in vivo. Methods The specific small interfering RNA (siRNA designed for targeting human TF was transfected into A549 cells. The expression of TF was detected by reverse transcription-PCR and Western blot. Cell proliferation was measured by MTT and clonogenic assays. Cell apoptosis was assessed by flow cytometry. The metastatic potential of A549 cells was determined by wound healing, the mobility and Matrigel invasion assays. Expressions of PI3K/Akt, Erk1/2, VEGF and MMP-2/-9 in transfected cells were detected by Western blot. In vivo, the effect of TF-siRNA on the growth of A549 lung adenocarcinoma xenografts in nude mice was investigated. Results TF -siRNA significantly reduced the expression of TF in the mRNA and protein levels. The down-regulation of TF in A549 cells resulted in the suppression of cell proliferation, invasion and metastasis and induced cell apoptosis in dose-dependent manner. Erk MAPK, PI3K/Akt pathways as well as VEGF and MMP-2/-9 expressions were inhibited in TF-siRNA transfected cells. Moreover, intratumoral injection of siRNA targeting TF suppressed the tumor growth of A549 cells in vivo model of lung adenocarcinoma. Conclusions Down-regulation of TF using siRNA could provide a potential approach for gene therapy against lung adenocarcinoma, and the antitumor effects may be associated with inhibition of Erk MAPK, PI3K/Akt pathways.

  20. Small Interference RNA Targeting TLR4 Gene Effectively Attenuates Pulmonary Inflammation in a Rat Model

    Feixiang Wu

    2012-01-01

    Full Text Available Objective. The present study was to investigate the feasibility of adenovirus-mediated small interference RNA (siRNA targeting Toll-like receptor 4 (TLR4 gene in ameliorating lipopolysaccharide- (LPS- induced acute lung injury (ALI. Methods. In vitro, alveolar macrophages (AMs were treated with Ad-siTLR4 and Ad-EFGP, respectively, for 12 h, 24 h, and 48 h, and then with LPS (100 ng/mL for 2 h, and the function and expression of TLR4 were evaluated. In vivo, rats received intratracheal injection of 300 μL of normal saline (control group, 300 μL of Ad-EGFP (Ad-EGFP group, or 300 μL of Ad-siTLR4 (Ad-siTLR4 group and then were intravenously treated with LPS (50 mg/kg to induce ALI. Results. Ad-siTLR4 treatment significantly reduced TLR4 expression and production of proinflammatory cytokines following LPS treatment both in vitro and in vivo. Significant alleviation of tissue edema, microvascular protein leakage, and neutrophil infiltration was observed in the AdsiTLR4-treated animals. Conclusion. TLR4 plays a critical role in LPS-induced ALI, and transfection of Ad-siTLR4 can effectively downregulate TLR4 expression in vitro and in vivo, accompanied by alleviation of LPS-induced lung injury. These findings suggest that TLR4 may serve as a potential target in the treatment of ALI and RNA interfering targeting TLR4 expression represents a therapeutic strategy.

  1. Effects of down-regulation of clusterin by small interference RNA on human acute myeloid leukemia cells

    Wang, Xiaoli; Liu, Ruidong; Wang, Yanxia; Cai, Hengjuan; Zhang, Lei

    2015-01-01

    Aims and background: Up-regulation of clusterin is associated with the survival and progression of various malignancies, and down-regulation of clusterin promotes apoptosis and inhibits invasion. The aim of this study was to explore the effect of clusterin small interference RNA (siRNA) on the proliferation, apoptosis and invasion of HL-60 acute myeloid leukemia (AML) cells. Methods: siRNA transfection was performed using Lipofectamine™2000 reagent. Relative protein expressions were quantifie...

  2. Comparison of dengue virus type 2-specific small RNAs from RNA interference-competent and -incompetent mosquito cells.

    Jaclyn C Scott

    Full Text Available The exogenous RNA interference (RNAi pathway is an important antiviral defense against arboviruses in mosquitoes, and virus-specific small interfering (siRNAs are key components of this pathway. Understanding the biogenesis of siRNAs in mosquitoes could have important ramifications in using RNAi to control arbovirus transmission. Using deep sequencing technology, we characterized dengue virus type 2 (DENV2-specific small RNAs produced during infection of Aedes aegypti mosquitoes and A. aegypti Aag2 cell cultures and compared them to those produced in the C6/36 Aedes albopictus cell line. We show that the size and mixed polarity of virus-specific small RNAs from DENV-infected A. aegypti cells indicate that they are products of Dicer-2 (Dcr2 cleavage of long dsRNA, whereas C6/36 cells generate DENV2-specific small RNAs that are longer and predominantly positive polarity, suggesting that they originate from a different small RNA pathway. Examination of virus-specific small RNAs after infection of the two mosquito cell lines with the insect-only flavivirus cell fusing agent virus (CFAV corroborated these findings. An in vitro assay also showed that Aag2 A. aegypti cells are capable of siRNA production, while C6/36 A. albopictus cells exhibit inefficient Dcr2 cleavage of long dsRNA. Defective expression or function of Dcr2, the key initiator of the RNAi pathway, might explain the comparatively robust growth of arthropod-borne viruses in the C6/36 cell line, which has been used frequently as a surrogate for studying molecular interactions between arboviruses and cells of their mosquito hosts.

  3. Adaptive interference-aware multichannel assignment for shared overloaded small-cell access points under limited feedback

    Radaydeh, Redha Mahmoud

    2014-02-01

    This paper proposes a reduced-complexity multichannel assignment scheme for short-range cellular systems. It treats the scenario when a number of small-cell (e.g., femtocell) access points (APs) can be shared to serve active scheduled users. The APs employ isotropic antenna arrays and operate using an open-access control strategy. To improve the reuse ratio of physical resources, the APs are assumed to occupy a single physical channel, wherein coordination among them is infeasible. On the other hand, to improve the spatial coverage, a scheduled user can be served by a single transmit channel from an AP at a time. For the case of overloaded APs and when the feedback links are capacity limited, the scheme attempts to identify the suitable transmit channels from the deployed APs in an adaptive manner such that certain performance and/or processing load limits are satisfied. The effects of some system and design parameters on the outcomes of the scheme are thoroughly discussed. Novel results for the statistics of the resulting interference power are presented, from which results for some performance measures and processing loads are obtained. Numerical and simulations results are provided to clarify the achieved gains, as compared with related models under different operating conditions. © 2013 IEEE.

  4. INHIBITION OF PROLIFERATION OF HUMAN BREAST CANCER MCF-7 CELLS BY SMALL INTERFERENCE RNA AGAINST LRP16 GENE

    韩为东; 赵亚力; 李琦; 母义明; 李雪; 宋海静; 陆祖谦

    2004-01-01

    Objective: Our previous studies have firstly demonstrated that 17(-E2 up-regulates LRP16 gene expression in human breast cancer MCF-7 cells, and ectopic expression of the LRP16 gene promotes MCF-7 cells proliferation. Here, the effects of the LRP16 gene expression on growth of MCF-7 human breast cancer cells and the mechanism were further studied by establishing two stably LRP16-inhibitory MCR-7 cell lines. Methods: Hairpin small interference RNA (siRNA) strategy, by which hairpin siRNA was released by U6 promoter and was mediated by pLPC-based retroviral vector, was adopted to knockdown endogenous LRP16 level in MCF-7 cells. And the hairpin siRNA against green fluorescence protein (GFP) was used as the negative control. The suppressant efficiency of the LRP16 gene expression was confirmed by Nothern blot. Cell proliferation assay and soft agar colony formation assay were used to determine the status of the cells proliferation. Cell cycle checkpoints including cyclin E and cyclin D1 were examined by Western blot. Results: The results from cell proliferation assays suggested that down-regulation of LRP16 gene expression is capable of inhibiting MCF-7 breast cancer cell growth and down-regulation of the LRP16 gene expression is able to inhibit anchorage-independent growth of breast cancer cells in soft agar. We also demonstrated that cyclin E and cyclin D1 proteins were much lower in the LRP16-inhibitory cells than in the control cells. Conclusion: These data suggest that LRP16 gene play an important role in MCF-7 cells proliferation by regulating the pathway of the G1/S transition and may function as an important modulator in regulating the process of tumorigenesis in human breast.

  5. Small switching power supply design of anti-electromagnetic interference%小型开关电源的抗电磁干扰设计

    刘翔

    2013-01-01

    Due to the small switching power supply will produce electromagnetic interference and pollutes grid, at the same time, they are also vulnerable to the influence of the external electromagnetic environment, so that they can not work accurately. We use filtering, shielding, grounding, and other technologies, so that the small switching power supply EMI is controlled in EMC standards prescribed and not pollutes grid. Particularly small switching power supply circuit in this article has been improved to effectively absorb and suppress interference. A lot of practice proved the program used in this article economically and reliably solutes small switching power supply interference, not only can improve the performance of small switching power supply, but also reduce the failure rate of small switching power supply, so that the small switching power supply is more extensively used.%基于小型开关电源会产生电磁干扰污染电网,同时它们又容易受到外部电磁环境的影响,不能精确地工作.我们采用了滤波、屏蔽、接地等技术,使小开关电源的EMI被控制在EMC标准规定的极限下,使它们能够良好地工作又不至于污染电网.特别在文中对小开关电源的电路进行了改进,使这类电源能够有效地吸收和抑制干扰.大量的实践证明本文中采用的方案经济可靠地解决了小开关电源的抗干扰问题,不但能够改善小开关电源的性能,还降低了小开关电源的故障率,使小型开关电源的使用范围更加广泛.

  6. Suppression of sphingomyelin synthase 1 by small interference RNA is associated with enhanced ceramide production and apoptosis after photodamage

    Separovic, Duska; Semaan, Louie; Tarca, Adi L.; Maitah, Ma’In Yehya Awad; Hanada, Kentaro; Bielawski, Jacek; Villani, Maristella; Luberto, Chiara

    2008-01-01

    We have shown that overexpression of SMS1, an enzyme that converts de novo ceramide into sphingomyelin, is accompanied by attenuated ceramide response and apoptotic resistance after photodamage with the photosensitizer Pc 4 (photodynamic therapy; PDT). To test whether SMS1 overexpression-related effects after PDT can be reversed, in this study SMS1 was downregulated in Jurkat T lymphoma/leukemia cells using small inhibitory RNA (siRNA) for SMS1. Compared to scrambled (control) siRNA-transfect...

  7. Silencing of MGMT with small interference RNA reversed resistance in human BCUN-resistant glioma cell lines

    XIE Si-ming; FANG Mao; GUO Hui; ZHONG Xue-yun

    2011-01-01

    Background Our previous study had cloned two glioma cell lines SWOZ1 and SWOZ2 isolated from parental glioma cell line SWO38.The 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) resistance of SWOZ1 was higher than that of SWOZ2.Since O6-methylguanine-DNA methyltransferase (MGMT) was thought to be closely related to BCNU resistance in glioma,this study aimed to explore the function of MGMT in glioma resistant to BCNU.Methods A BCNU resistant glioma cell line SWOZ2-BCNU was established.The expression of MGMT was detected in SWOZ1,SWOZ2 and SWOZ2-BCNU.Small interferencing RNA targeting MGMT was used to silence the expression of MGMT in resistant cell lines SWOZ1 and SWOZ2-BCNU.The cytotoxicity of BCNU to these cells was measured using the cell counting kit-8 assay.Statistical analysis was carried out by one-way analysis of variance in statistical package SPSS 13.0.Results The resistance of SWOZ1 and SWOZ2-BCNU against BCNU was 4.9-fold and 5.3-fold higher than that of SWOZ2.The results of quantitative RT-PCR and Western blotting confirmed that MGMT was both significantly increased in SWOZ1 and SWOZ2-BCNU compared to SOWZ2.After transfection with small interferencing RNA targeting MGMT,a decreased level of MGMT mRNA expression in SWOZ1 and SWOZ2-BCNU for more than 75% compared to negative control was found and confirmed by Western blotting.As a result,the resistance against BCNU was reversed for about 50% both in the BCNU-resistant cell lines SWOZ1 and SWOZ2-BCNU.Conclusions Silencing MGMT with specific small interferencing RNA can reverse the BCNU resistant phenotype in these glioma cell lines.MGMT may play an important role both in intrinsic and acquired BCNU-resistance in glioma.

  8. Interference Spins

    Popovski, Petar; Simeone, Osvaldo; Nielsen, Jimmy Jessen;

    2015-01-01

    traffic load and interference condition leads to performance gains. In this letter, a general network of multiple interfering two-way links is studied under the assumption of a balanced load in the two directions for each link. Using the notion of interference spin, we introduce an algebraic framework for...

  9. Identification of a Small Molecular Anti - HIV - 1 Compound that Interferes with Formation of the Fusion - active gp41 Core

    2001-01-01

    The human immunodeficiency virus type 1 (HIV - 1 ) envelope glycoprotein gp41 plays a critical role in the fusion of viral and target cell membranes. The gp41 extracellular domain, which contains fusion peptide (FP), N - and C - terminal hydrophobic heptad repeats (NHR and CHR, respectively). Peptides derived from NHR and CHR regions,designated N- and C- peptides, respectively, can interact with each other to form a six - stranded coiled - coil domain, representing the fusion-active gp41 core. Our previous studies demonstrated that the C- peptides have potent inhibitory activity against HIV- 1 infection.These peptides inhibit HIV- 1 -mediated membrane fusion by binding to NHR regions for preventing the formation of fusion- active gp41 core. One of the C - peptides, T - 20, which is in the phase Ⅲ clinical trails, is expected to become the first peptide HIV fusion inhibitory drug in the near future. However, this peptide HIV fusion inhibitor lacks oral availability and is sensitive to the proteolytic digestion.Therefore, it is essential to develop small molecular non -peptide HIV fusion inhibitors having similar mechanism of action as the C- peptides. We have established an ELISA- based screening assay using a unique monoclonal antibody, NC- 1, which can specifically bind to a conformational epitope on the gp41 core domain. Using this screening assay, we have identified a small molecular anti- HIV- 1 compound,named ADS-Jl, which inhibits HIV- 1- mediated membrane fusion by blocking the interaction between the NHR and CHR regions to form the fusion - active gp41 core. This compound will be used as a lead to design and develop novel HIV fusion inhibitors as new drugs for the treatment of HIV infection and/or AIDS.

  10. Small RNA interference-mediated gene silencing of heparanase abolishes the invasion, metastasis and angiogenesis of gastric cancer cells

    Heparanase facilitates the invasion and metastasis of cancer cells, and is over-expressed in many kinds of malignancies. Our studies indicated that heparanase was frequently expressed in advanced gastric cancers. The aim of this study is to determine whether silencing of heparanase expression can abolish the malignant characteristics of gastric cancer cells. Three heparanase-specific small interfering RNA (siRNAs) were designed, synthesized, and transfected into cultured gastric cancer cell line SGC-7901. Heparanase expression was measured by RT-PCR, real-time quantitative PCR and Western blot. Cell proliferation was detected by MTT colorimetry and colony formation assay. The in vitro invasion and metastasis of cancer cells were measured by cell adhesion assay, scratch assay and matrigel invasion assay. The angiogenesis capabilities of cancer cells were measured by tube formation of endothelial cells. Transfection of siRNA against 1496-1514 bp of encoding regions resulted in reduced expression of heparanase, which started at 24 hrs and lasted for 120 hrs post-transfection. The siRNA-mediated silencing of heparanase suppressed the cellular proliferation of SGC-7901 cells. In addition, the in vitro invasion and metastasis of cancer cells were attenuated after knock-down of heparanase. Moreover, transfection of heparanase-specific siRNA attenuated the in vitro angiogenesis of cancer cells in a dose-dependent manner. These results demonstrated that gene silencing of heparanase can efficiently abolish the proliferation, invasion, metastasis and angiogenesis of human gastric cancer cells in vitro, suggesting that heparanase-specific siRNA is of potential values as a novel therapeutic agent for human gastric cancer

  11. Silencing of hpv16 e6 and e7 oncogenic activities by small interference rna induces autophagy and apoptosis in human cervical cancer cells

    Jonathan Salazar-León

    2011-08-01

    Full Text Available Cervical cancer is the second most common form of death by cancer in women worldwide and has special attention for the development of new treatment strategies. Human Papilloma Virus (HPV persistent infection is the main etiological agent of this neoplasia, and the main cellular transformation mechanism is by disruption of p53 and pRb function by interaction with HPV E6 and E7 oncoproteins. This generates alterations in cellular differentiation and cellular death inhibition. Thus, HPV E6 and E7 oncogenes represent suitable targets for the development of gene therapy strategies against cervical cancer. An attractive technology platform is developing for post-transcriptional selective silencing of gene expression, using small interference RNA. Therefore, in the present study, we used SiHa cells (HPV16+ transiently transfected with specific siRNA expression plasmids for HPV16 E6 and E7 oncogenes. In this model we detected repression of E6 and E7 oncogene and oncoprotein expression, an increase in p53 and hypophosphorylated pRb isoform protein expression, and autophagy and apoptosis morphology features. These findings suggest that selective silencing of HPV16 E6 and E7 oncogenes by siRNAs, has significant biological effects on the survival of human cancer cells and is a potential gene therapy strategy against cervical cancer.

  12. Targeting the epidermal growth factor receptor in non-small cell lung cancer cells: the effect of combining RNA interference with tyrosine kinase inhibitors or cetuximab

    Chen Gang

    2012-03-01

    Full Text Available Abstract Background The epidermal growth factor receptor (EGFR is a validated therapeutic target in non-small cell lung cancer (NSCLC. However, current single agent receptor targeting does not achieve a maximal therapeutic effect, and some mutations confer resistance to current available agents. In the current study we have examined, in different NSCLC cell lines, the combined effect of RNA interference targeting the EGFR mRNA, and inactivation of EGFR signaling using different receptor tyrosine kinase inhibitors (TKIs or a monoclonal antibody cetuximab. Methods NSCLC cells (cell lines HCC827, H292, H358, H1650, and H1975 were transfected with EGFR siRNA and/or treated with the TKIs gefitinib, erlotinib, and afatinib, and/or with the monoclonal antibody cetuximab. The reduction of EGFR mRNA expression was measured by real-time quantitative RT-PCR. The down-regulation of EGFR protein expression was measured by western blot, and the proliferation, viability, caspase3/7 activity, and apoptotic morphology were monitored by spectrophotometry, fluorimetry, and fluorescence microscopy. The combined effect of EGFR siRNA and different drugs was evaluated using a combination index. Results EGFR-specific siRNA strongly inhibited EGFR protein expression almost equally in all cell lines and inhibited cell growth and induced cell apoptosis in all NSCLC cell lines studied, albeit with a different magnitude. The effects on growth obtained with siRNA was strikingly different from the effects obtained with TKIs. The effects of siRNA probably correlate with the overall oncogenic significance of the receptor, which is only partly inhibited by the TKIs. The cells which showed weak response to TKIs, such as the H1975 cell line containing the T790M resistance mutation, were found to be responsive to siRNA knockdown of EGFR, as were cell lines with downstream TKI resistance mutations. The cell line HCC827, harboring an exon 19 deletion mutation, was more than 10-fold

  13. Synergistic effects of nuclear factor-kappa B inhibition by small interference RNA on 131I therapy in differentiated thyroid cancer cells

    Objective: To study the effect of nuclear factor-kappa B (NF-κB) inhibition by small interference RNA (siRNA) on the apoptosis of DTC cells treated by 131I. Methods: DNA binding assay was performed at 24 h after 131I treatment (2 × 104 MBq/L) on KTC-1 cells. The cell survival assay was conducted at 48 h after 131I treatment. Western blot was used to detect the changes of NF-κB p65 at 6 h after 131I treatment, and the changes of anti-apoptotic factors and apoptotic key factors at 24 h after 131I treatment. The anti-apoptotic factors included in this study were X chromosome-linked inhibitor of apoptosis (XIAP), cellular inhibitor of apoptosis 1 (cIAP1) and B-cell lymphoma extra large (Bcl-xL), and the apoptotic key factors were caspase 3 and poly-ADP-ribose polymerase (PARP). A total of 4 groups were studied for the detection of p65 and anti-apoptotic factors by Western blot:no oligonucleotide transfection control group (A), no oligonucleotide transfection + 131I group (B), scrambled oligonucleotides transfection + 131I group (C) and p65 siRNA transfection + 131I group (D). Another 6 groups of studies were: oligonucleotide transfection control group (1), scrambled oligonucleotides transfection group (2), p65 siRNA transfection group (3), no oligonucleotide transfection + 131I group (4), scrambled oligonucleotides transfection +131I group (5) and p65 siRNA transfection + 131I group (6). One-way analysis of variance and q test were performed for statistical analysis. Results: The results of DNA binding assays for the 6 groups (1, 2, 3, 4, 5, 6) were (100.00 ± 11.65)%,(96.00 ± 17.98)%, (9.28 ±5.01)%, (322.72 ±50.81)%, (311.36 ±44.81)% and (36.96 ± 15.66)%, respectively (F=137.74, P<0.01). NF-κB functions were strengthened with 131I treatment (qgroup 4:1=10.90, qgroup 5:2=11.38, both P<0.01). However, NF-κB p65 siRNA transfection could inhibit NF-κB functions (qgroup 1:3=18.25, qgroup 4:6=13.71, both P<0.01). Cell survival rates of the 6 groups were (100.00

  14. Blind Known Interference Cancellation

    Zhang, Shengli; Wang, Hui

    2011-01-01

    This paper investigates interference-cancellation schemes at the receiver, in which the original data of the interference is known a priori. Such a priori knowledge is common in wireless relay networks. For example, a transmitting relay could be relaying data that was previously transmitted by a node, in which case the interference received by the node now is actually self information. Besides the case of self information, the node could also have overheard or received the interference data in a prior transmission by another node. Directly removing the known interference requires accurate estimate of the interference channel, which may be difficult in many situations. In this paper, we propose a novel scheme, Blind Known Interference Cancellation (BKIC), to cancel known interference without interference channel information. BKIC consists of two steps. The first step combines adjacent symbols to cancel the interference, exploiting the fact that the channel coefficients are almost the same between successive sy...

  15. IETS and quantum interference

    Jørgensen, Jacob Lykkebo; Gagliardi, Alessio; Pecchia, Alessandro;

    2014-01-01

    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...... 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....

  16. Opportunistic Interference Alignment in MIMO Interference Channels

    Perlaza, Samir Medina; Lasaulce, Samson; Chaufray, Jean Marie

    2008-01-01

    We present two interference alignment techniques such that an opportunistic point-to-point multiple input multiple output (MIMO) link can reuse, without generating any additional interference, the same frequency band of a similar pre-existing primary link. In this scenario, we exploit the fact that under power constraints, although each radio maximizes independently its rate by water-filling on their channel transfer matrix singular values, frequently, not all of them are used. Therefore, by aligning the interference of the opportunistic radio it is possible to transmit at a significant rate while insuring zero-interference on the pre-existing link. We propose a linear pre-coder for a perfect interference alignment and a power allocation scheme which maximizes the individual data rate of the secondary link. Our numerical results show that significant data rates are achieved even for a reduced number of antennas.

  17. Graphene quantum interference photodetector

    Mahbub Alam

    2015-03-01

    Full Text Available 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.

  18. Communication and interference coordination

    Blasco-Serrano, Ricardo; Thobaben, Ragnar; Skoglund, Mikael

    2014-01-01

    We study the problem of controlling the interference created to an external observer by a communication processes. We model the interference in terms of its type (empirical distribution), and we analyze the consequences of placing constraints on the admissible type. Considering a single interfering link, we characterize the communication-interference capacity region. Then, we look at a scenario where the interference is jointly created by two users allowed to coordinate their actions prior to...

  19. Interference of composite bosons

    Brougham, Thomas; Barnett, Stephen M.; Jex, Igor

    2010-01-01

    We investigate multi-boson interference. A Hamiltonian is presented that treats pairs of bosons as a single composite boson. This Hamiltonian allows two pairs of bosons to interact as if they were two single composite bosons. We show that this leads to the composite bosons exhibiting novel interference effects such as Hong-Ou-Mandel interference. We then investigate generalizations of the formalism to the case of interference between two general composite bosons. Finally, we show how one can ...

  20. Small interference RNA profiling reveals the essential role of human membrane trafficking genes in mediating the infectious entry of dengue virus

    Chu Justin

    2010-02-01

    Full Text Available Abstract Background Dengue virus (DENV is the causative agent of Dengue fever and the life-threatening Dengue Haemorrhagic fever or Dengue shock syndrome. In the absence of anti-viral agents or vaccine, there is an urgent need to develop an effective anti-viral strategy against this medically important viral pathogen. The initial interplay between DENV and the host cells may represent one of the potential anti-viral targeting sites. Currently the involvements of human membrane trafficking host genes or factors that mediate the infectious cellular entry of dengue virus are not well defined. Results In this study, we have used a targeted small interfering RNA (siRNA library to identify and profile key cellular genes involved in processes of endocytosis, cytoskeletal dynamics and endosome trafficking that are important and essential for DENV infection. The infectious entry of DENV into Huh7 cells was shown to be potently inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis. The important role of clathrin-mediated endocytosis was confirmed by the expression of well-characterized dominant-negative mutants of genes in this pathway and by using the clathrin endocytosis inhibitor chlorpromazine. Furthermore, DENV infection was shown to be sensitive to the disruption of human genes in regulating the early to late endosomal trafficking as well as the endosomal acidic pH. The importance and involvement of both actin and microtubule dynamics in mediating the infectious entry of DENV was also revealed in this study. Conclusions Together, the findings from this study have provided a detail profiling of the human membrane trafficking cellular genes and the mechanistic insight into the interplay of these host genes with DENV to initiate an infection, hence broadening our understanding on the entry pathway of this medically important viral pathogen. These data may also provide a new potential avenue for development of anti

  1. Inter-WBAN Coexistence and Interference Mitigation

    Bin Liu; Xiaosong Zhao; Lei Zou; Chang Wen Chen

    2015-01-01

    With promising applications in e⁃health and entertainment, wireless body area networks (WBANs) have attracted the in⁃terest of both academia and industry. If WBANs are densely deployed within a small area, serious problems may arise be⁃tween the WBANs. In this paper, we discuss issues related to the coexistence of WBANs and investigate the main fac⁃tors that cause inter⁃WBAN interference. We survey inter⁃WBAN interference mitigation strategies and track recent re⁃search developments. We also discuss unresolved issues re⁃lated to inter⁃WBAN interference mitigation and propose fu⁃ture research directions.

  2. Interference of Fano-Rashba conductance dips

    We study the interference of two tunable Rashba regions in a quantum wire with one propagating mode. The transmission dips (Fano-Rashba dips) of the two regions either cross or anti-cross, depending on the distance between the two regions. For large separations we find Fabry-Perot oscillations due to the interference of forwards and backwards propagating modes. At small separations overlapping evanescent modes play a prominent role, leading to an enhanced transmission and destroying the conductance dip. Analytical expressions in scattering matrix theory are given and the relevance of the interference effect in a device is discussed.

  3. Dark Matter Interference

    Del Nobile, Eugenio; Kouvaris, Christoforos; Sannino, Francesco;

    2012-01-01

    We study different patterns of interference in WIMP-nuclei elastic scattering that can accommodate the DAMA and CoGeNT experiments via an isospin violating ratio $f_n/f_p=-0.71$. We study interference between the following pairs of mediators: Z and Z', Z' and Higgs, and two Higgs fields. We show ...

  4. Real Interference Alignment

    Motahari, Abolfazl Seyed; Maddah-Ali, Mohammad-Ali; Khandani, Amir Keyvan

    2010-01-01

    In this paper, we show that the total Degrees-Of-Freedoms (DOF) of the $K$-user Gaussian Interference Channel (GIC) can be achieved by incorporating a new alignment technique known as \\emph{real interference alignment}. This technique compared to its ancestor \\emph{vector interference alignment} performs on a single real line and exploits the properties of real numbers to provide optimal signaling. The real interference alignment relies on a new coding scheme in which several data streams having fractional multiplexing gains are sent by transmitters and interfering streams are aligned at receivers. The coding scheme is backed up by a recent result in the field of Diophantine approximation, which states that the convergence part of the Khintchine-Groshev theorem holds for points on non-degenerate manifolds.

  5. Intercollisional interference effects

    First, some qualitative aspects of intercollisional interference effects are discussed. These effects are closely related to what is sometimes called 'shielding by Newton's second law', as outlined in Section 3. Finally, some phenomenological models are introduced. (KBE)

  6. DNA-guided DNA interference by a prokaryotic Argonaute

    Swarts, Daan C.; Jore, Matthijs M.; Westra, Edze R.; Zhu, Yifan; Janssen, Jorijn H.; Snijders, Ambrosius P.; Wang, Yanli; Patel, Dinshaw J.; Berenguer, José; Brouns, Stan J. J.; van der Oost, John

    2014-01-01

    RNA interference is widely distributed in eukaryotes and has a variety of functions, including antiviral defence and gene regulation1,2. All RNA interference pathways use small single-stranded RNA (ssRNA) molecules that guide proteins of the Argonaute (Ago) family to complementary ssRNA targets: RNA-guided RNA interference1,2. The role of prokaryotic Ago variants has remained elusive, although bioinformatics analysis has suggested their involvement in host defence3. Here we demonstrate that A...

  7. Interference in wireless ad hoc networks with smart antennas

    Alabdulmohsin, Ibrahim

    2014-08-01

    In this paper, we show that the use of directional antennas in wireless ad hoc networks can actually increase interference due to limitations of virtual carrier sensing. We derive a simple mathematical expression for interference in both physical and virtual carrier sense networks, which reveals counter-intuitively that receivers in large dense networks with directional antennas can experience larger interference than in omnidirectional networks unless the beamwidth is sufficiently small. Validity of mathematical analysis is confirmed using simulations.

  8. Interference in immunoassay

    Interfering factors are evident in both limited reagent (radioimmunoassay) and excess reagent (immunometric assay) technologies and should be suspected whenever there is a discrepancy between analytical results and clinical findings in the investigation of particular diseases. The overall effect of interference in immunoassay is analytical bias in result, either positive or negative of variable magnitude. The interference maybe caused by a wide spectrum of factors from poor sample collection and handling to physiological factors e.g. lipaemia, heparin treatment, binding protein abnormalities, autoimmunity and drug treatments. The range of interfering factors is extensive and difficult to discuss effectively in a short review

  9. Remote sensing of nearshore wave interference

    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.

  10. Quantum interference in polyenes

    Tsuji, Yuta; Hoffmann, Roald, E-mail: rh34@cornell.edu [Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, New York 14853 (United States); Movassagh, Ramis [Department of Mathematics, Northeastern University, Boston, Massachusetts 02115, USA and Department of Mathematics, Massachusetts Institute of Technology, Building E18, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307 (United States); Datta, Supriyo [School of Electrical and Computer Engineering, Purdue University, Electrical Engineering Building, 465 Northwestern Ave., West Lafayette, Indiana 47907-2035 (United States)

    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.

  11. Kvantová interference

    Peřina, Jan

    2003-01-01

    Roč. 48, č. 4 (2003), s. 99-103. ISSN 0447-6441 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : interference * quantum cryptography * quantum computing * quantum teleportation Subject RIV: BH - Optics, Masers, Lasers

  12. RNA interference and antiviral therapy

    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.

  13. Abstract Certification of Global Non-Interference in Rewriting Logic

    Alba-Castro, Mauricio; Escobar, Santiago

    2010-01-01

    Non-interference is a semantic program property that assigns confidentiality levels to data objects and prevents illicit information flows from occurring from high to low security levels. In this paper, we present a novel security model for global non-interference which approximates non-interference as a safety property. We also propose a certification technique for global non-interference of complete Java classes based on rewriting logic, a very general logical and semantic framework that is efficiently implemented in the high-level programming language Maude. Starting from an existing Java semantics specification written in Maude, we develop an extended, information-flow Java semantics that allows us to correctly observe global non-interference policies. In order to achieve a finite state transition system, we develop an abstract Java semantics that we use for secure and effective non-interference Java analysis. The analysis produces certificates that are independently checkable and are small enough to be u...

  14. Laser Interference Lithography

    Wolferen, van, Henk A.G.M.; Abelmann, Leon; Hennessy, Theodore C.

    2011-01-01

    In this chapter we explain how submicron gratings can be prepared by Laser Interference Lithography (LIL). In this maskless lithography technique, the standing wave pattern that exists at the intersection of two coherent laser beams is used to expose a photosensitive layer. We show how to build the basic setup, with special attention for the optical aspects. The pros and cons of different types of resist as well as the limitations and errors of the setup are discussed. The bottleneck in Laser...

  15. RNA Interference in livestock

    Merkl, Claudia

    2010-01-01

    RNA Interference (RNAi) allows experimental reduction of gene expression, providing a tool for the investigation of gene function, disease therapy and the generation of animal models for human diseases. RNAi offers an opportunity to carry out precise genetic manipulations in a wide variety of species. This thesis describes the use of RNAi to downregulate two porcine genes, the whey protein Beta-Lactoglobulin (BLG) and the tumor suppressor protein p53. BLG is a major component in porcine and r...

  16. Quantum Confined Fano Interference

    We study the transition from a dense continuum to a sparse quasicontinuum in the Fano problem. Transmission measurements on epitaxial layers of GaAs in a high magnetic field and calculations of the optical absorption show how the Fano interference disappears as quantum confinement discretizes the continuum states. The transition between quasi-one-dimensional and quasi-zero-dimensional systems occurs at length scales which are unusually large for optical experiments. copyright 1997 The American Physical Society

  17. Ghost Interference and Quantum Erasure

    Chingangbam, Pravabati; Qureshi, Tabish

    2005-01-01

    The two-photon ghost interference experiment, generalized to the case of massive particles, is theoretically analyzed. It is argued that the experiment is intimately connected to a double-slit interference experiment where, the which-path information exists. The reason for not observing first order interference behind the double-slit, is clarified.It is shown that the underlying mechanism for the appearance of ghost interference is, the more familiar, quantum erasure.

  18. Interference competition and species coexistence.

    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 interferen...

  19. RNA interference in Lepidoptera

    Terenius, Ole; Papanicolaou, Alexie; Garbutt, Jennie S.;

    2011-01-01

    Gene silencing through RNA interference (RNAi) has revolutionized the study of gene function, particularly in non-model insects. However, in Lepidoptera (moths and butterflies) RNAi has many times proven to be difficult to achieve. Most of the negative results have been anecdotal and the positive...... in RNAi experiments in Lepidoptera are discussed. The review also points to a need to further investigate the mechanism of RNAi in lepidopteran insects and its possible connection to the innate immune response. Our general understanding of RNAi in Lepidoptera will be further aided in the future as...

  20. Entanglement and quantum interference

    O'Hara, Paul

    2006-01-01

    In the history of quantum mechanics, much has been written about the double-slit experiment, and much debate as to its interpretation has ensued. Indeed, to explain the interference patterns for sub-atomic particles, explanations have been given not only in terms of the principle of complementarity and wave-particle duality but also in terms of quantum consciousness and parallel universes. In this paper, the topic will be discussed from the perspective of spin-coupling in the hope of further ...

  1. Coping with Radio Frequency Interference

    Lewis, B. M.

    2009-01-01

    The radio spectrum is a finite resource, on which humanity makes many demands. And pressure on it is ever increasing with the development of new technology and ideas for radio services. After all, we all benefit from wifi and cell phones. Radio astronomers have a small percentage of the spectrum allocated to them at octave intervals in the metre-centimetre bands, and at important frequencies, such as that of the 21cm line of HI. Signals from other services, as well as from our own poorly-engineered equipment, sometimes contaminate our bands: these signals constitute RFI. These may totally obliterate the astronomical signal, or, in the case of CLOUDSAT, may be capable of completely destroying a receiver, which introduces us to the new possibility of 'destructive interference'. A geo-stationary satellite can block access to a piece of sky from one site. Good equipment design eliminates self-inflicted interference, while physical separation often provides adequate practical mitigation at many frequencies. However, new observatories end up being located in the West Australian desert or Antarctica. In future they may be on the back side of the Moon. But there is no Earth-bound protection via physical separation against satellite signals. Some mitigation can be achieved by frequent data dumps and the excision of RFI, or by real-time detection and blanking of the receiver, or by more sophisticated algoriths. Astronomers of necessity aim to achieve mitigation via coordination, at the local level, and by participating in spectrum management at the national and international levels. This involves them spending a lot of time in Geneva at the International Telegraphic Union protecting their access to spectrum, and access to clean spectrum from the L3 point and the far side of the Moon.

  2. CRISPR Interference Directs Strand Specific Spacer Acquisition

    Daan C Swarts; Cas Mosterd; van Passel, Mark W. J.; Brouns, Stan J. J.

    2012-01-01

    BACKGROUND: CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. RESULTS: We describe how a CRISPR-activated E. coli ...

  3. Interference layer metallography

    Refractory metallic materials for application in Gas Cooled High Temperature Reactors are age-hardened nickel or iron base alloys. To control their behaviour and to adapt it to realistic load conditions, these materials have to be subjected to suitable informing tests and characterized. In the past few years, interference layer metallography has proved to be a highly flexible characterization procedure, suitable as an independent investigation method as well as an outstanding way of sample preparation for application of automatic quantitative image analysis to refractory alloys. This paper reports the problems of characterization of the Ni and Fe base alloys to be solved by interference layer metallography and the physical background of this method. The procedure of chromatic contrasting is discussed. From these considerations arises the result that for technical applications the optimum layer material for each special sample should be selected a priori. For that purpose it is necessary to measure the optical constants of the respective structural elements of the alloys as well as those of the candidate layer materials. The measuring procedures are discussed in detail. A routine procedure is deduced which allows to determine a priori the layer material and thickness fitting best to a given problem. (orig.)

  4. Beamforming design with proactive interference cancelation in MISO interference channels

    Li, Yang; Tian, Yafei; Yang, Chenyang

    2015-12-01

    In this paper, we design coordinated beamforming at base stations (BSs) to facilitate interference cancelation at users in interference networks, where each BS is equipped with multiple antennas and each user is with a single antenna. By assuming that each user can select the best decoding strategy to mitigate the interference, either canceling the interference after decoding when it is strong or treating it as noise when it is weak, we optimize the beamforming vectors that maximize the sum rate for the networks under different interference scenarios and find the solutions of beamforming with closed-form expressions. The inherent design principles are then analyzed, and the performance gain over passive interference cancelation is demonstrated through simulations in heterogeneous cellular networks.

  5. Sensing via optical interference

    Ryan C. Bailey

    2005-04-01

    Full Text Available Chemical and biological sensing are problems of tremendous contemporary technological importance in multiple regulatory and human health contexts, including environmental monitoring, water quality assurance, workplace air quality assessment, food quality control, many aspects of biodiagnostics, and, of course, homeland security. Frequently, what is needed, or at least wanted, are sensors that are simultaneously cheap, fast, reliable, selective, sensitive, robust, and easy to use. Unfortunately, these are often conflicting requirements. Over the past few years, however, a number of promising ideas based on optical interference effects have emerged. Each is based to some extent on advances in the design and fabrication of functional materials. Generally, the advances are of two kinds: chemo- and bio-selective recognition and binding, and efficient methods for micropatterning or microstructuring.

  6. Single-plasmon interferences.

    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

  7. Quantum Interference in Graphene Nanoconstrictions.

    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. PMID:27295198

  8. Interference in ballistic motor learning - is motor interference really sensory?

    Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C;

    Skill gained after a short period of practice in one motor task can be abolished if a second task is learned shortly afterwards. We hypothesised that interference requires the same circuits to be engaged in the two tasks and provoke competing processes of synaptic plasticity. To test this, subjects...... not require learning. Repeated transcranial magnetic stimulation (rTMS) of corticospinal motor output at intensities below ankle movement threshold did not cause interference, whereas suprathreshold rTMS did. Furthermore, electrical stimulation of the peripheral nerve to the plantarflexors (but not...... extensors) caused interference. We conclude that interference is remarkably specific for circuits involved in a specific movement direction / activation of individual muscles and depends crucially on sensory error signals. One possible mechanism of interference may be disruption of early motor memory...

  9. RF Self-Interference cancellation for Full-Duplex

    Liempd, van B.; Debaillie, B.; Craninckx, J.; Lavin, C.; Palacios, C.; Malotaux, S.; Long, J.R.; Broek, van den J.D.; Klumperink, E.A.M.

    2014-01-01

    This paper proposes two RF self-interference cancellation techniques. Their small form-factor enables full-duplex communication links for small-to-medium size portable devices and hence promotes the adoption of full-duplex in mass-market applications and next-generation standards, e.g. IEEE802.11 an

  10. Canceling Interference in Acupuncture Points Signal

    Yanexy San Martín Reyes

    2012-07-01

    Full Text Available The present paper propose the cancellation of interference or artifacts by the method of Allen in signals captured in different acupuncture points (Small Intestine Meridian, points ID1-ID2 and ID1-ID19. It is considered that the biosignal under study should be able to be characterized after its acquisition by subtracting the different interference variables that may coexist in the measurement zone, as it is in the case of ECG or any other artifact. The biosignal obtained as a result of the cancellation will be the acupuncture signal or from its imperfection another wave can be obtained as from a bioelectrical point of view such imperfection can be characterized and at the same time can bb useful to establish a long-term correspondence between the behavior of the signals on various acupuncture points and different diseases.

  11. Adaptive transmit selection with interference suppression

    Radaydeh, Redha Mahmoud Mesleh

    2010-01-01

    This paper studies the performance of adaptive transmit channel selection in multipath fading channels. The adaptive selection algorithms are configured for single-antenna bandwidth-efficient or power-efficient transmission with as low transmit channel estimations as possible. Due to the fact that the number of active co-channel interfering signals and their corresponding powers experience random behavior, the adaptation to channels conditions, assuming uniform buffer and traffic loading, is proposed to be jointly based on the transmit channels instantaneous signal-to-noise ratios (SNRs) and signal-to- interference-plus- noise ratios (SINRs). Two interference cancelation algorithms, which are the dominant cancelation and the less complex arbitrary cancelation, are considered, for which the receive antenna array is assumed to have small angular spread. Analytical formulation for some performance measures in addition to several processing complexity and numerical comparisons between various adaptation schemes are presented. ©2010 IEEE.

  12. Multiscale Investigation of Chemical Interference in Proteins

    Samiotakis, Antonios; Cheung, Margaret S

    2010-01-01

    We developed a multiscale approach (MultiSCAAL) that integrates the potential of mean force (PMF) obtained from all-atomistic molecular dynamics simulations with a knowledge-based energy function for coarse-grained molecular simulations in better exploring the energy landscape of a small protein under chemical interference such as chemical denaturation. An excessive amount of water molecules in all-atomistic molecular dynamics simulations often negatively impacts the sampling efficiency of some advanced sampling techniques such as the replica exchange method and it makes the investigation of chemical interferences on protein dynamics difficult. Thus, there is a need to develop an effective strategy that focuses on sampling structural changes in protein conformations rather than solvent molecule fluctuations. In this work, we address this issue by devising a multiscale simulation scheme (MultiSCAAL) that bridges the gap between all-atomistic molecular dynamics simulation and coarse-grained molecular simulation...

  13. The RNA interference revolution

    G. Lenz

    2005-12-01

    Full Text Available The discovery of double-stranded RNA-mediated gene silencing has rapidly led to its use as a method of choice for blocking a gene, and has turned it into one of the most discussed topics in cell biology. Although still in its infancy, the field of RNA interference has already produced a vast array of results, mainly in Caenorhabditis elegans, but recently also in mammalian systems. Micro-RNAs are short hairpins of RNA capable of blocking translation, which are transcribed from genomic DNA and are implicated in several aspects from development to cell signaling. The present review discusses the main methods used for gene silencing in cell culture and animal models, including the selection of target sequences, delivery methods and strategies for a successful silencing. Expected developments are briefly discussed, ranging from reverse genetics to therapeutics. Thus, the development of the new paradigm of RNA-mediated gene silencing has produced two important advances: knowledge of a basic cellular mechanism present in the majority of eukaryotic cells and access to a potent and specific new method for gene silencing.

  14. Serum indices: managing assay interference.

    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

  15. Communications in interference limited networks

    2016-01-01

    This book offers means to handle interference as a central problem of operating wireless networks. It investigates centralized and decentralized methods to avoid and handle interference as well as approaches that resolve interference constructively. The latter type of approach tries to solve the joint detection and estimation problem of several data streams that share a common medium. In fact, an exciting insight into the operation of networks is that it may be beneficial, in terms of an overall throughput, to actively create and manage interference. Thus, when handled properly, "mixing" of data in networks becomes a useful tool of operation rather than the nuisance as which it has been treated traditionally. With the development of mobile, robust, ubiquitous, reliable and instantaneous communication being a driving and enabling factor of an information centric economy, the understanding, mitigation and exploitation of interference in networks must be seen as a centrally important task.

  16. Reproductive interference between animal species.

    Gröning, Julia; Hochkirch, Axel

    2008-09-01

    Although sexual interactions between species (reproductive interference) have been reported from a wide range of animal taxa, their potential for determining species coexistence is often disregarded. Here, we review evidence from laboratory and field studies illustrating that heterospecific sexual interactions are frequently associated with fitness loss and can have severe ecological and evolutionary consequences. We define reproductive interference as any kind of interspecific interaction during the process of mate acquisition that adversely affects the fitness of at least one of the species involved and that is caused by incomplete species recognition. We distinguish seven types of reproductive interference: signal jamming, heterospecific rivalry, misdirected courtship, heterospecific mating attempts, erroneous female choice, heterospecific mating, and hybridization. We then discuss the sex-specific costs of these types and highlight two typical features of reproductive interference: density-dependence and asymmetry. Similar to competition, reproductive interference can lead to displacement of one species (sexual exclusion), spatial, temporal, or habitat segregation, changes in life history parameters, and reproductive character displacement. In many cases, patterns of coexistence might be shaped by reproductive interference rather than by resource competition, as the presence of a few heterospecifics might substantially decrease reproductive success. Therefore, interspecific sexual interactions should receive more attention in ecological research. Reproductive interference has mainly been discussed in the context of invasive species or hybrid zones, whereas its influence on naturally-occurring sympatric species pairs has rarely been addressed. To improve our knowledge of the ecological significance of reproductive interference, findings from laboratory experiments should be validated in the field. Future studies should also focus on ecological mechanisms, such

  17. Improved Interference Suppression Algorithm Against Broadband BPSK Interference

    AN Jian-ping; XIA Cai-jie; WANG Ai-hua

    2008-01-01

    An improved polar exciser (IMPE) interference suppression method against broadband constant envelope binary phase shift keying (BPSK) interference is proposed. The disadvantage of traditional polar exciser (PE) is the performance degradation when the power of interference is low, i.e., the threshold effect. The proposed improved PE (IMPE) algorithm can overcome the threshold effect of PE by introducing compression gain (CG) metric, which forces PE suppressor active only at larger jammer-to-signal ratio (JSR) and switch to matched filter (MF) at lower JSR. Theoretical analysis and numerical simulations show the exactness of CG as a switching metric and the validity of the IMPE algorithm.

  18. Non-opiate [beta]-endorphin fragments and dopamine--I the neuroleptic-like [gamma]-endorphin fragments interfere with the behavioural effects elicited by small doses of apomorphine

    Ree, J.M. van; Innemee, H.; Louwerens, J.W.; Kahn, R.S.; Wied, D. de

    1982-01-01

    In rats, the β- endorphin fragment, 6–17 (des-enkephalin-γ-endorphin, DEγE), dose-dependently antagonized the reduction of the rate of locomotion and rearing induced by small doses of apomorphine. Structure-activity studies revealed that the active moiety of γ-endorphin fragments with respect to cou

  19. Interference in motor learning - is motor interference sensory?

    Jensen, Jesper Lundbye; Petersen, Tue Hvass; Rothwell, John C;

    Skill gained after a short period of practice in one motor task can be abolished if a second task is learned shortly afterwards, but not all motor activities cause interference. After all it is not necessary to remain completely still after practicing a task for learning to occur. Here we ask which...... mechanisms determine whether or not interference occurs. We hypothesised that interference requires the same neural circuits to be engaged in the two tasks and provoke competing processes of synaptic plasticity. To test this, subjects learned a ballistic ankle plantarflexion task. Early motor memory was...... learning of the primary task, no interference was observed. Previous studies have suggested that primary motor cortex (M1) may be involved in early motor memory consolidation. 1Hz Repetitive Transcranial Magnetic Stimulation (rTMS) of corticospinal motor output at intensities below ankle movement threshold...

  20. Asymmetric interference in molecular photoprocesses

    For the first time, the Coulomb continuum effects in asymmetric molecular interference have been studied analytically in photoionization, photorecombination, bremsstrahlung and Compton ionization. Simple, closed-form factors describe the interference not only in monochromatic photoprocesses, but also in the continuous photoelectron spectra generated by attosecond x-ray pulses with a frequency-dependent phase and broad bandwidth. Using HeH2+ molecular ion as an example, we show how the plane wave interference pattern is strongly modified by the two-centre Coulomb continuum. Asymmetric Coulomb continuum introduces qualitative changes in a photoionization process

  1. Optical interference with digital holograms

    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.

  2. RF interference at ground stations located in populated areas

    Adams, N.; Bitman, J.; Copeland, D.; Srinivasan, D.; Garcia, A.

    Ground stations located in populated areas must contend with RF interference (RFI). While RF interference may disrupt occasional satellite contacts, disruption statistics in many cases are manageable. Thus the RF environment must be statistically characterized in order to predict availability and detect changes in the environment. An RF monitoring and recording system is essential to both characterize the RF environment and send alarms when interference appears. This paper presents a study of RF interference at the Satellite Communications Facility (SCF) located at The Johns Hopkins University Applied Physics Laboratory, and describes the impact of RF interference on the NASA Van Allen Probes mission. The area surrounding the SCF, located in Laurel, Maryland, was rural farmland when the SCF was commissioned in 1963. Since then the area has experienced tremendous commercial and residential development. Concurrent with this development RF activity has increased. In particular, increased RF interference is evident within the Van Allen Probes' S-band downlink allocation. The interference is due to other licensed parties, out-of-band commercial emissions, as well as natural phenomena. Some RFI sources have been identified, whereas others remain unknown. In this paper we describe the RF environment, and present a statistical characterization that shows that RFI has only a small impact on ground station availability. We also discuss operational considerations, including hand-shaking protocols and coordination with spectrum management.

  3. Interference of Quantum Market Strategies

    Piotrowski, Edward W.; Jan Sladkowski; Jacek Syska

    2002-01-01

    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.

  4. Electromagnetic Interference In New Aircraft

    Larsen, William E.

    1991-01-01

    Report reviews plans to develop tests and standards to ensure that digital avionics systems in new civil aircraft immune to electromagnetic interference (EMI). Updated standards reflect more severe environment and vulnerabilities of modern avionics.

  5. Multipolar interference effects in nanophotonics

    Liu, Wei

    2016-01-01

    Scattering of electromagnetic waves by an arbitrary nanoscale object can be characterized by a multipole decomposition of the electromagnetic field that allows to describe the scattering intensity and radiation pattern through interferences of dominating excited multipole modes. In modern nanophotonics, both generation and interference of multipole modes start to play an indispensable role, and they enable nanoscale manipulation of light with many related applications. Here we review the multipolar interference effects in metallic, metal-dielectric, and dielectric nanostructures, and suggest a comprehensive view on many phenomena involving the interferences of electric, magnetic and toroidal multipoles, which drive a number of recently discussed effects in nanophotonics such as unidirectional scattering, effective optical antiferromagnetism, generalized Kerker scattering with controlled angular patterns, generalized Brewster angle, and nonradiating optical anapoles. We further discuss other types of possible ...

  6. Quantum Erasure: Quantum Interference Revisited

    Walborn, Stephen P.; Cunha, Marcelo O Terra; Pádua, Sebastião; Monken, Carlos H.

    2005-01-01

    Recent experiments in quantum optics have shed light on the foundations of quantum physics. Quantum erasers - modified quantum interference experiments - show that quantum entanglement is responsible for the complementarity principle.

  7. Non-opiate [beta]-endorphin fragments and dopamine--I the neuroleptic-like [gamma]-endorphin fragments interfere with the behavioural effects elicited by small doses of apomorphine

    de Ree, J M; Innemee, H.; Louwerens, J. W.; Kahn, R.S.; Wied, D. de

    1982-01-01

    In rats, the β- endorphin fragment, 6–17 (des-enkephalin-γ-endorphin, DEγE), dose-dependently antagonized the reduction of the rate of locomotion and rearing induced by small doses of apomorphine. Structure-activity studies revealed that the active moiety of γ-endorphin fragments with respect to counteracting apomorphine-induced behavioural changes resides in the fragment 6–17. The influence of DEγE appeared to be specific for dopamine systems mediating apomorphine-induced hypomotility, since...

  8. Interference between gestures and words

    Langton, Stephen R. H.

    1996-01-01

    This thesis explores the idea that a speaker's gestural and verbal behaviours are mutually influential in the comprehension process. A Stroop-type interference paradigm was adopted as a tool for investigating whether or not listeners process to-be-ignored gestural information and how this information influences the processing of spoken words. In Experiments 1-4, static pointing (deictic) gestures and corresponding spoken and written words showed symmetrical interference. Incongruent words ...

  9. Exploiting Interference through Algebraic Structure

    Nazer, Bobak Anthony

    2009-01-01

    In a network, interference between transmitters is usually viewed as highly undesirable and clever algorithms and protocols have been devised to avoid it. Collectively, these strategies transform the physical layer into a set of reliable bit pipes which can then be used seamlessly by higher layers in the protocol stack. Unfortunately, interference avoidance results in sharply decreasing rates as the number of users increases. In this thesis, we develop a new tool, computation coding, that all...

  10. CRISPR interference directs strand specific spacer acquisition.

    Daan C Swarts

    Full Text Available BACKGROUND: CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. RESULTS: We describe how a CRISPR-activated E. coli K12 is cured from a high copy number plasmid under non-selective conditions in a CRISPR-mediated way. Cured clones integrated at least one up to five anti-plasmid spacers in genomic CRISPR loci. New spacers are integrated directly downstream of the leader sequence. The spacers are non-randomly selected to target protospacers with an AAG protospacer adjacent motif, which is located directly upstream of the protospacer. A co-occurrence of PAM deviations and CRISPR repeat mutations was observed, indicating that one nucleotide from the PAM is incorporated as the last nucleotide of the repeat during integration of a new spacer. When multiple spacers were integrated in a single clone, all spacer targeted the same strand of the plasmid, implying that CRISPR interference caused by the first integrated spacer directs subsequent spacer acquisition events in a strand specific manner. CONCLUSIONS: The E. coli Type I-E CRISPR/Cas system provides resistance against bacteriophage infection, but also enables removal of residing plasmids. We established that there is a positive feedback loop between active spacers in a cluster--in our case the first acquired spacer--and spacers acquired thereafter, possibly through the use of specific DNA degradation products of the CRISPR interference machinery by the CRISPR adaptation machinery. This loop enables a rapid expansion of the spacer repertoire against an actively present DNA element that is already targeted, amplifying the

  11. Advanced Interference Management Technique: Potentials and Limitations

    Lee, Namyoon; Heath Jr, Robert W.

    2014-01-01

    Interference management has the potential to improve spectrum efficiency in current and next generation wireless systems (e.g. 3GPP LTE and IEEE 802.11). Recently, new paradigms for interference management have emerged to tackle interference in a general class of wireless networks: interference shaping and interference exploitation. Both approaches offer better performance in interference-limited communication regimes than traditionally thought possible. This article provides a high-level ove...

  12. Interference-Assisted Secret Communication

    Tang, Xiaojun; Spasojevic, Predrag; Poor, H Vincent

    2008-01-01

    Wireless communication is susceptible to adversarial eavesdropping due to the broadcast nature of the wireless medium. In this paper it is shown how eavesdropping can be alleviated by exploiting the superposition property of the wireless medium. A wiretap channel with a helping interferer (WT-HI), in which a transmitter sends a confidential message to its intended receiver in the presence of a passive eavesdropper, and with the help of an independent interferer, is considered. The interferer, which does not know the confidential message, helps in ensuring the secrecy of the message by sending independent signals. An achievable secrecy rate for the WT-HI is given. The results show that interference can be exploited to assist secrecy in wireless communications. An important example of the Gaussian case, in which the interferer has a better channel to the intended receiver than to the eavesdropper, is considered. In this situation, the interferer can send a (random) codeword at a rate that ensures that it can be...

  13. Inhibition of RANKL-dependent cellular fusion in pre-osteoclasts by amiloride and a NHE10-specific monoclonal antibody.

    Mine, Yuichi; Shuto, Takahiro; Nikawa, Hiroki; Kawai, Toshihisa; Ohara, Masaru; Kawahara, Kazuko; Ohta, Kouji; Kukita, Toshio; Terada, Yoshihiro; Makihira, Seicho

    2015-06-01

    The functions of Na(+) /H(+) exchangers (NHEs) during osteoclastic differentiation were investigated using the NHE inhibitor amiloride and a monoclonal antibody (MAb). Compared with sRANKL-stimulated control cells, amiloride decreased the number of large TRAP-positive osteoclast cells (OCs) with ≥10 nuclei and increased the number of small TRAP-positive OCs with ≤10 nuclei during sRANKL-dependent osteoclastic differentiation of RAW264.7 cells. NHE10 mRNA expression and OC differentiation markers were increased by sRANKL stimulation in dose- and time-dependent manners. NHEs 1-9 mRNA expression was not increased by sRANKL stimulation. Similar to amiloride, a rat anti-mouse NHE10 MAb (clone 6B11) decreased the number of large TRAP-positive OCs, but increased the number of small TRAP-positive OCs. These findings suggested that inhibition of NHEs by amiloride or an anti-NHE10 MAb prevented sRANKL-promoted cellular fusion. The anti-NHE10 MAb has the potential for use as an effective inhibitor of bone resorption for targeted bone disease therapy. PMID:25612314

  14. On Feasibility of Interference Alignment in MIMO Interference Networks

    Yetis, Cenk M; Jafar, Syed A; Kayran, Ahmet H

    2009-01-01

    We explore the feasibility of interference alignment in signal vector space -- based only on beamforming -- for K-user MIMO interference channels. Our main contribution is to relate the feasibility issue to the problem of determining the solvability of a multivariate polynomial system, considered extensively in algebraic geometry. It is well known, e.g. from Bezout's theorem, that generic polynomial systems are solvable if and only if the number of equations does not exceed the number of variables. Following this intuition, we classify signal space interference alignment problems as either proper or improper based on the number of equations and variables. Rigorous connections between feasible and proper systems are made through Bernshtein's theorem for the case where each transmitter uses only one beamforming vector. The multi-beam case introduces dependencies among the coefficients of a polynomial system so that the system is no longer generic in the sense required by both theorems. In this case, we show tha...

  15. Whirling waves in Interference experiments

    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.

  16. "Quantum Interference with Slits" Revisited

    Rothman, Tony

    2010-01-01

    Marcella [arXiv:quant-ph/0703126] 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 calculation as if no approximations are employed. We show that he implicitly makes the same approximations found in classical treatments of interference and that no new physics has been introduced. At the same time, some of the quantum mechanical arguments Marcella gives are, at best, misleading.

  17. Interference of probabilities in dynamics

    Zak, Michail, E-mail: michail.zak@gmail.com [Jet Propulsion Laboratory California Institute of Technology, Pasadena, CA 91109 (United States)

    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.

  18. Interference of spontaneously emitted photons

    Beige, A; Pachos, J; Beige, Almut; Schoen, Christian; Pachos, Jiannis

    2002-01-01

    We discuss an experimental setup where two laser-driven atoms spontaneously emit photons and every photon causes a ``click'' at a point on a screen. By deriving the probability density for an emission into a certain direction from basic quantum mechanical principles we predict a spatial interference pattern. Similarities and differences with the classical double-slit experiment are discussed.

  19. "Quantum Interference with Slits" Revisited

    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…

  20. Interference of spontaneously emitted photons

    Beige, Almut; Schoen, Christian; Pachos, Jiannis

    2001-01-01

    We discuss an experimental setup where two laser-driven atoms spontaneously emit photons and every photon causes a ``click'' at a point on a screen. By deriving the probability density for an emission into a certain direction from basic quantum mechanical principles we predict a spatial interference pattern. Similarities and differences with the classical double-slit experiment are discussed.

  1. Fano Interference in Classical Oscillators

    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…

  2. Suppression of heavy-current grid interference with spectrometer operation

    Mains hum interference with the spectrometric signal is manifest in peak deformation and deteriorated energy resolution. A pulse generator can be used in testing whether spectral peaks are expanded due to the mains hum. If this is the case, the penetration of spurious voltage in the amplification chain can be suppressed by improved instrument earthing using the floating or the resting earth system or by decreasing instrument sensitivity to interference using a balanced coaxial connection of the preamplifier to the amplifier, adjusting a lower derivative constant, or selecting an amplifier with a small input circuit non-linearity. (Ha)

  3. A generalized and parameterized interference model for cognitive radio networks

    Mahmood, Nurul Huda

    2011-06-01

    For meaningful co-existence of cognitive radios with primary system, it is imperative that the cognitive radio system is aware of how much interference it generates at the primary receivers. This can be done through statistical modeling of the interference as perceived at the primary receivers. In this work, we propose a generalized model for the interference generated by a cognitive radio network, in the presence of small and large scale fading, at a primary receiver located at the origin. We then demonstrate how this model can be used to estimate the impact of cognitive radio transmission on the primary receiver in terms of different outage probabilities. Finally, our analytical findings are validated through some selected computer-based simulations. © 2011 IEEE.

  4. Parasitic interference in nulling interferometry

    Matter, Alexis; Danchi, William C; Lopez, Bruno; Absil, Olivier

    2013-01-01

    Nulling interferometry aims to detect faint objects close to bright stars. Its principle is to produce a destructive interference along the line-of-sight so that the stellar flux is rejected, while the flux of the off-axis source can be transmitted. In practice, various instrumental perturbations can degrade the nulling performance. Any imperfection in phase, amplitude, or polarization produces a spurious flux that leaks to the interferometer output and corrupts the transmitted off-axis flux. One of these instrumental pertubations is the crosstalk phenomenon, which occurs because of multiple parasitic reflections inside transmitting optics, and/or diffraction effects related to beam propagation along finite size optics. It can include a crosstalk of a beam with itself, and a mutual crosstalk between different beams. This can create a parasitic interference pattern, which degrades the intrinsic transmission map - or intensity response - of the interferometer. In this context, we describe how this instrumental ...

  5. Task duration in contextual interference.

    Smith, Peter J K

    2002-12-01

    Duration of practice trial on a pursuit rotor task in contextual interference was investigated. Participants practiced at each of 4 angular velocities, with 24 participants completing 28 trials lasting 20 sec., and 24 participants completing 112 trials of 5 sec. Half of the participants in each trial-duration condition practiced in a blocked format and half practiced in a random format. After random practice posttest performance was better than blocked practice when practice-trial duration was 20 sec., but worse when practice-trial duration was 5 sec. This result is not consistent with theoretical explanations of the contextual interference effect and is discussed with reference to the task characteristics and demands of the pursuit rotor. PMID:12578255

  6. Fano interference in classical oscillators

    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 splitting of normal-mode frequencies of a coupled oscillator. Using this analogy, we simulate and experimentally demonstrate Fano interference and the associated phenomena in three-level atoms in a coupled electrical resonator circuit. This work aims to highlight analogies between classical and quantum systems for students at the postgraduate and graduate levels. Also, the reported technique can be easily realized in undergraduate laboratories. (paper)

  7. Correction of multigroup cross sections for resolved resonance interference in mixed absorbers

    The effect that interference between resolved resonances has on averaging multigroup cross sections is examined for thermal reactor-type problems. A simple and efficient numerical scheme is presented to correct a preprocessed multigroup library for interference effects. The procedure is implemented in a design oriented lattice physics computer code and compared with rigorous numerical calculations. The approximate method for computing resonance interference correction factors is applied to obtaining fine-group cross sections for a homogeneous uranium-plutonium mixture and a uranium oxide lattice. It was found that some fine group cross sections are changed by more than 40% due to resonance interference. The change in resonance interference correction factors due to burnup of a PWR fuel pin is examined and found to be small. The effect of resolved resonance interference on collapsed broad-group cross sections for thermal reactor calculations is discussed

  8. Interference in multilayer relativistic mirrors

    Mirzanejhad, Saeed; Sohbatzadeh, Farshad; Babaei, Javad; Taghipour, Meisam; Mohammadzadeh, Zahra

    2015-10-01

    In this paper, reflection coefficient of a relativistic ultra-thin electron multilayer is calculated using electromagnetic interference procedures. The relativistic electron layers are assumed to be formed by nonlinear plasma wake waves that constitute the electron density cusps. It is shown that the interference between successive relativistic mirrors is restricted by the condition, τ p ≫ ( 2 γ 0 ) 5 / 2 / ω p 0 , where τp is the laser pulse duration. The results showed that tailoring the pulse amplitude, incident wave frequency value, incidence angle, and plasma density leads to increasing reflection coefficient a few orders of magnitudes. This constructive interference condition can be used for increasing conversion efficiency in the reflected energy from relativistic mirrors for the purpose of generating ultra-short coherence pulses in the extreme ultraviolet and x-ray regions. We also performed reflection from relativistic thin electron layers using relativistic 1D3V electromagnetic particle-in-cell (PIC) simulation. It was found that the results of PIC simulation are in agreement with analytical considerations.

  9. Continuous Time Channels with Interference

    Ivan, Ioana; Thaler, Justin; Yuen, Henry

    2012-01-01

    Khanna and Sudan studied a natural model of continuous time channels where signals are corrupted by the effects of both noise and delay, and showed that, surprisingly, in some cases both are not enough to prevent such channels from achieving unbounded capacity. Inspired by their work, we consider channels that model continuous time communication with adversarial delay errors. The sender is allowed to subdivide time into arbitrarily large number $M$ of micro-units in which binary symbols may be sent, but the symbols are subject to unpredictable delays and may interfere with each other. We model interference by having symbols that land in the same micro-unit of time be summed, and a $k$-interference channels allows receivers to distinguish sums up to the value $k$. We consider both a channel adversary that has a limit on the maximum number of steps it can delay each symbol, and a more powerful adversary that only has a bound on the average delay. We give precise characterizations of the threshold between finite...

  10. Cooperative Algorithms for MIMO Interference Channels

    Peters, Steven W

    2010-01-01

    Interference alignment is a transmission technique for exploiting all available degrees of freedom in the interference channel with an arbitrary number of users. Most prior work on interference alignment, however, neglects interference from other nodes in the network not participating in the alignment operation. This paper proposes three generalizations of interference alignment for the multiple-antenna interference channel with multiple users that account for colored noise, which models uncoordinated interference. First, a minimum interference-plus-noise leakage algorithm is presented, and shown to be equivalent to previous subspace methods when noise is spatially white or negligible. A joint minimum mean squared error design is then proposed that jointly optimizes the transmit precoders and receive spatial filters, whereas previous designs neglect the receive spatial filter. This algorithm is shown to be a generalization of previous joint MMSE designs for other system configurations such as the broadcast ch...

  11. Devices That May Interfere with Pacemakers

    ... group of cellphone companies is studying that possibility. Bluetooth® headsets do not appear to interfere with pacemakers. ... group of cellphone companies is studying that possibility. Bluetooth® headsets do not appear to interfere with pacemakers. ...

  12. Photon wave functions and quantum interference experiments

    Lapaire, G. G.; Sipe, J. E.

    2006-01-01

    We present a general theory to describe two-photon interference, including a formal description of few photon intereference in terms of single-photon amplitudes. With this formalism, it is possible to describe both frequency entangled and separable two-photon interference in terms of single-photon wave functions. Using this description, we address issues related to the physical interpretation of two-photon interference experiments. We include a discussion on how few-photon interference can be...

  13. Interference Alignment Using Variational Mean Field Annealing

    Badiu, Mihai Alin; Guillaud, Maxime; Fleury, Bernard Henri

    2014-01-01

    We study the problem of interference alignment in the multiple-input multiple- output interference channel. Aiming at minimizing the interference leakage power relative to the receiver noise level, we use the deterministic annealing approach to solve the optimization problem. In the corresponding...

  14. RNA干扰抑制ERCC1对非小细胞肺癌化疗敏感性的影响%The effect of RNA interference-mediated ERCC1 gene on the chemo-treatment sensitivity of non-small-cell lung cancer

    宋志雨; 周航

    2011-01-01

    目的 探讨利用RNA干扰技术沉默切除修复交叉互补基因组1(ERCC1)表达对非小细胞肺癌耐药细胞株顺铂化疗敏感性的影响.方法 设计并合成3段靶向人的ERCC1基因的小分子干扰RNA(siRNA),构建携带ERCC1-shRNA的重组质粒表达载体,采用脂质体Lipofectamine 2000转染入人肺癌细胞株A549/DDP,荧光镜下观察并测定转染效率;应用逆转录聚合酶链反应(RT-PCR)检测转染前后ERCC1 mRNA的表达情况;应用四甲基偶氮唑蓝比色法(MTT)检测干扰ERCC1后A549/DDP细胞对顺铂敏感性的变化.结果 转染针对ERCC1的siRNA后,转染组A549/DDP细胞内ERCC1 mRNA表达均下降,转染后肺癌A549/DDP细胞对顺铂敏感性增加.结论 利用RNA干扰技术能够筛选出高效的特异阻断ERCC1基因表达的siRNA;ERCC1基因表达下调能够增加肺癌A549/DDP细胞对顺铂的敏感性,部分逆转耐药.%Objective To investigate changes of platinum-based chemotherapy sensitivity of silencing excision repair cross complementation 1(ERCC1) gene expression by using RNA interference in non-small-cell lung cancer ( NSCLC) drug resistance cell lines. Methods Three siRNA sequences targeting ERCC1 gene were designed and synthesized. Recombinant plasmid expression vector which carrying ERCCl-shRNA was constructed and transfected into A54 9/DDP cells with Lipofectamine 2000. Transfection efficiency was measured in the fluorescent microscope. The expression of ERCC1 Mrna was detected by reverse transcription-poly-merase chain reaction(RT-PCR). The change of cisplatin sensitivity after interference was test by MTT assay. Results After transfection of ERCCl-siRNA,the ERCC1 Mrna expressions in A549/DDP cells were all reduced. The sensitivity to cisplatin of A549/ DDP cell line was increased after transfection. The sensitivity to cisplatin of A54 9/DDP cell line was increased after transfection. Conclusion Highly effective and specific siRNA targeting ERCC1 gene can be successfully

  15. Codebook-based interference alignment for uplink MIMO interference channels

    Lee, Hyun Ho

    2014-02-01

    In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute the transmit precoder and inform its quantized index to the associated user via limited rate feedback link.We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load tomaintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF. © 2014 KICS.

  16. INTERFERENCE OF UNIDIRECTIONAL SHOCK WAVES

    P. V. Bulat

    2015-05-01

    Full Text Available Subject of study.We consider interference of unidirectional shock waves or, as they are called, catching up shock waves. The scope of work is to give a classification of the shock-wave structures that arise in this type of interaction of shock waves, and the area of their existence. Intersection of unidirectional shock waves results in arising of a shock-wave structure at the intersection point, which contains the main shock wave, tangential discontinuity and one more reflected gas-dynamic discontinuity of unknown beforehand type. The problem of determining the type of reflected discontinuity is the main problem that one has to solve in the study of catching shock waves interference. Main results.The paper presents the pictures of shock-wave structures arising at the interaction of catching up shock waves. The areas with a regular and irregular unidirectional interaction of shocks are described. Characteristic shock-wave structures are of greatest interest, where reflected gas-dynamic discontinuity degenerates into discontinuous characteristics. Such structures have a number of extreme properties. We have found the areas of existence for such shock-wave structures. There are also areas in which the steady-state solution is not available. The latter has determined revival of interest for the theoretical study of the problem, because the facts of sudden shock-wave structure destruction inside the air intake of supersonic aircrafts at high Mach numbers have been discovered. Practical significance.The theory of interference for unidirectional shock waves and design procedure are usable in the design of supersonic air intakes. It is also relevant for application possibility investigation of catching up oblique shock waves to create overcompressed detonation in perspective detonation air-jet and rocket engines.

  17. IETS and quantum interference: propensity rules in the presence of an interference feature.

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

    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. PMID:25273424

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

    Lykkebo, Jacob; Solomon, Gemma C., E-mail: gsolomon@nano.ku.dk [Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø (Denmark); Gagliardi, Alessio [Technische Universität München, Electrical Engineering and Information Tech., Arcisstr. 21, 80333 München (Germany); Pecchia, Alessandro [Consiglio Nazionale delle Ricerche, ISMN, Via Salaria km 29.6, 00017 Monterotondo (Rome) (Italy)

    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.

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

    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

  20. Interference Mitigation in Cognitive Femtocells

    Da Costa, Gustavo Wagner Oliveira; Cattoni, Andrea Fabio; Alvarez Roig, Victor;

    2010-01-01

    , management and optimization can be prohibitive. Instead, self-optimization of an uncoordinated deployment should be considered. Cognitive Radio enabled femtocells are considered to be a promising solution to enable self-optimizing femtocells to effectively manage the inter-cell interference, especially in...... densely deployed femto scenarios. In this paper, two key elements of cognitive femtocells are combined: a power control algorithm and a fully distributed dynamic spectrum allocation method. The resulting solution was evaluated through system-level simulations and compared to the separate algorithms and...

  1. Long working distance interference microscope

    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.

  2. Embracing interference in wireless systems

    Gollakota, Shyamnath

    2014-01-01

    The wireless medium is a shared resource. If nearby devices transmit at thesame time, their signals interfere, resulting in a collision. In traditionalnetworks, collisions cause the loss of the transmitted information. For thisreason, wireless networks have been designed with the assumption thatinterference is intrinsically harmful and must be avoided.This book, a revised version of the author's award-winning Ph.D.dissertation, takes an alternate approach: Instead of viewing interferenceas an inherently counterproductive phenomenon that should to be avoided, wedesign practical systems that tra

  3. Interference Mitigation in Large Random Wireless Networks

    Aldridge, Matthew

    2011-01-01

    A central problem in the operation of large wireless networks is how to deal with interference -- the unwanted signals being sent by transmitters that a receiver is not interested in. This thesis looks at ways of combating such interference. In Chapters 1 and 2, we outline the necessary information and communication theory background, including the concept of capacity. We also include an overview of a new set of schemes for dealing with interference known as interference alignment, paying special attention to a channel-state-based strategy called ergodic interference alignment. In Chapter 3, we consider the operation of large regular and random networks by treating interference as background noise. We consider the local performance of a single node, and the global performance of a very large network. In Chapter 4, we use ergodic interference alignment to derive the asymptotic sum-capacity of large random dense networks. These networks are derived from a physical model of node placement where signal strength d...

  4. RNA interference and Register Machines (extended abstract

    Masahiro Hamano

    2012-11-01

    Full Text Available RNA interference (RNAi is a mechanism whereby small RNAs (siRNAs directly control gene expression without assistance from proteins. This mechanism consists of interactions between RNAs and small RNAs both of which may be single or double stranded. The target of the mechanism is mRNA to be degraded or aberrated, while the initiator is double stranded RNA (dsRNA to be cleaved into siRNAs. Observing the digital nature of RNAi, we represent RNAi as a Minsky register machine such that (i The two registers hold single and double stranded RNAs respectively, and (ii Machine's instructions are interpreted by interactions of enzyme (Dicer, siRNA (with RISC com- plex and polymerization (RdRp to the appropriate registers. Interpreting RNAi as a computational structure, we can investigate the computational meaning of RNAi, especially its complexity. Initially, the machine is configured as a Chemical Ground Form (CGF, which generates incorrect jumps. To remedy this problem, the system is remodeled as recursive RNAi, in which siRNA targets not only mRNA but also the machine instructional analogues of Dicer and RISC. Finally, probabilistic termination is investigated in the recursive RNAi system.

  5. Quasiparticle interference from magnetic impurities

    Derry, Philip G.; Mitchell, Andrew K.; Logan, David E.

    2015-07-01

    Fourier transform scanning tunneling spectroscopy (FT-STS) measures the scattering of conduction electrons from impurities and defects, giving information about the electronic structure of both the host material and adsorbed impurities. We interpret such FT-STS measurements in terms of the quasiparticle interference (QPI), here investigating in detail the QPI due to single magnetic impurities adsorbed on a range of representative nonmagnetic host surfaces, and contrasting with the case of a simple scalar impurity or point defect. We demonstrate how the electronic correlations present for magnetic impurities markedly affect the QPI, showing, e.g., a large intensity enhancement due to the Kondo effect, and universality at low temperatures/scanning energies. The commonly used joint density of states interpretation of FT-STS measurements is also considered, and shown to be insufficient in many cases, including that of magnetic impurities.

  6. Ramsey interference with single photons

    Clemmen, Stéphane; Ramelow, Sven; Gaeta, Alexander L

    2016-01-01

    Interferometry using discrete energy levels in nuclear, atomic or molecular systems is the foundation for a wide range of physical phenomena and enables powerful techniques such as nuclear magnetic resonance, electron spin resonance, Ramsey-based spectroscopy and laser/maser technology. It also plays a unique role in quantum information processing as qubits are realized as energy superposition states of single quantum systems. Here, we demonstrate quantum interference of different energy states of single quanta of light in full analogy to energy levels of atoms or nuclear spins and implement a Ramsey interferometer with single photons. We experimentally generate energy superposition states of a single photon and manipulate them with unitary transformations to realize arbitrary projective measurements, which allows for the realization a high-visibility single-photon Ramsey interferometer. Our approach opens the path for frequency-encoded photonic qubits in quantum information processing and quantum communicati...

  7. Graphene Superconducting Quantum Interference Device

    Girit, Çaǧlar; Bouchiat, Vincent; Naaman, Ofer; Zhang, Yuanbo; Crommie, Michael; Zettl, Alex; Siddiqi, Irfan

    2010-03-01

    Graphene can support Cooper pair transport when contacted with two superconducting electrodes, resulting in the well-known Josephson effect. By depositing aluminum/palladium electrodes in the geometry of a loop onto a single graphene sheet, we fabricate a two junction dc superconducting quantum interference device (SQUID). Not only an the supercurrent in this device be increased by moving the electrostatic gate away from the Dirac point, but it can also be modulated periodically by an applied magnetic field---a potentially powerful probe of electronic transport in graphene. We analyze the magnetic field modulation of the critical current with the asymmetric/inductive SQUID model of Fulton and Dynes and discuss the variation of the fitting parameters with gate voltage.

  8. Parasitic interference in nulling interferometry

    Matter, A.; Defrère, D.; Danchi, W. C.; Lopez, B.; Absil, O.

    2013-05-01

    Nulling interferometry aims to detect faint objects close to bright stars. Its principle is to produce a destructive interference along the line of sight so that the stellar flux is rejected, while the flux of the off-axis source can be transmitted. In practice, various instrumental perturbations can degrade the nulling performance. Any imperfection in phase, amplitude or polarization produces a spurious flux that leaks to the interferometer output and corrupts the transmitted off-axis flux. One of these instrumental perturbations is the crosstalk phenomenon, which occurs because of multiple parasitic reflections inside transmitting optics, and/or diffraction effects related to beam propagation along finite size optics. It can include a crosstalk of a beam with itself, and a mutual crosstalk between different beams. This can create a parasitic interference pattern, which degrades the intrinsic transmission map - or intensity response - of the interferometer. In this context, we describe how this instrumental effect impairs the performance of a Bracewell interferometer. A simple formalism is developed to derive the corresponding modified intensity response of the interferometer, as a function of the two parameters of interest: the crosstalk level (or contamination rate) and the phase shift between the primary and secondary - parasitic - beams. We then apply our mathematical approach to a few scientific cases, both analytically and using the GENIESIM simulation software, adapted to handle coherent crosstalk. Our results show that a coherent crosstalk level of about 1 per cent implies a 20 per cent drop of the signal-to-noise ratio at most. Careful attention should thus be paid to reduce the crosstalk level inside an interferometric instrument and ensure an instrumental stability that provides the necessary sensitivity through calibration procedures.

  9. Measurement-Based Interference in Quantum Computation

    Xu, You-Yang

    2013-09-01

    The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent with the visibility in qubit systems. By taking cluster states as examples, we show in the one-way quantum computation that the gate fidelity is proportional to the interference of the measured qubit and is inversely proportional to the interference of all register qubits. We also find that the interference increases with the number of the computing steps. So we conjecture that the interference may be the source of the speedup of the one-way quantum computation.

  10. Measurement-Based Interference in Quantum Computation

    The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent with the visibility in qubit systems. By taking cluster states as examples, we show in the one-way quantum computation that the gate fidelity is proportional to the interference of the measured qubit and is inversely proportional to the interference of all register qubits. We also find that the interference increases with the number of the computing steps. So we conjecture that the interference may be the source of the speedup of the one-way quantum computation. (general)

  11. CDMA with interference cancellation for multiprobe missions

    Divsalar, D.; Simon, M. K.

    1995-01-01

    Code division multiple-access spread spectrum has been proposed for use in future multiprobe/multispacecraft missions. This article considers a general parallel interference-cancellation scheme that significantly reduces the degradation effect of probe (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 probe (user) the total interference produced by the remaining most reliably received probes (users) accessing the channel. 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 probe/spacecraft interference. The one-stage interference cancellation was analyzed for two types of tentative decision devices, namely, hard and null zone decisions. Simulation results are given for one- and two-stage interference cancellation for equal as well as unequal received power probes.

  12. Collision-induced constructive quantum interference

    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 3P1/2-5S (or 4D) and 3P3/2-5S (or 4D) via equal-frequency hybrid excitation in the Na2-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

  13. GPS and GLONASS Radio Interference in Germany

    Butsch, Felix

    1997-01-01

    The goal of the work described here was to search for interference sources that could pose a threat to the application of GPS for automatic airport approach and landing of aircraft. For this purpose field measurements were conducted in the vicinity of airports, radar facilities andother radio frequency transmitters throughout Germany,and interference resistance measurements of commercial GPS receivers were taken. An additional aim was to examine the interference problems of GLONASS signals. T...

  14. Nonlinear multimode interference coupler for biological sensing

    Tajaddini, Mehdi; Mat Jafri, Mohd Zubir

    2013-06-01

    In this study, we propose an all optical sensor based on nonlinearity in a multimode interference coupler. The sensor can be tuned to highest sensitivity in the refractive index ranges sufficient to detect protein- based molecules or other water- soluble chemical or biological materials. The nonlinear regimes show the capability to operate on any choice of materials for slab waveguide even conventional glass. The Kerr nonlinear effect is considered as the nonlinear effect for third order nonlinearity materials; this effect is studied in the multimode waveguide with MPA method that promises to investigate the coupler in small lengths. The visible changes of field profile at output facet in various surrounding layer refractive index show the high sensitivity to the refractive index of surrounding layer that is foundation of introducing a sensor. Also, the result show the high distinguished changes on output intensity in various refractive index of surrounding layer even in conventional glass as a chosen material for coupler. To the best of our knowledge this is the first time that a nonlinear MMI in a few micrometers is proposed as a robustness sensor. In fact, this paper brings a useful and powerful way to progress the all optical sensors based on MMI couplers.

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

    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.

  16. INTERFERENCE OF COUNTERPROPAGATING SHOCK WAVES

    P. V. Bulat

    2015-03-01

    -dynamic discontinuities, the intensities corresponding to the transition from regular to irregular interference were described. Numerical calculations of the shock-wave structure transformation in the conditions of hysteresis were performed. The results were compared with the experiments carried out by hydraulic analogy method. Practical significance. Results of the work complement well the theory of stationary gas-dynamic discontinuities interference and can be used at designing of perspective images of supersonic and hypersonic aircraft.

  17. IETS and quantum interference: propensity rules in the presence of an interference feature

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

    2014-01-01

    Destructive quantum interference in single molecule electronics is an intriguing phe- nomenon; however, distinguishing quantum interference effects from generically low transmission is not trivial. In this paper, we discuss how quantum interference ef- fects 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. Sec- ondly, we consider how inelastic electron tunneling spectroscopy can be used ...

  18. Merging molecular imaging and RNA interference: early experience in live animals

    Bogdanov, Alexei A.

    2008-01-01

    The rapid development of non-invasive imaging techniques and imaging reporters coincided with the enthusiastic response that the introduction of RNAi (RNA interference) techniques created in the research community. Imaging in experimental animals provides quantitative or semi-quantitative information regarding the biodistribution of small interfering RNAs and the levels of gene interference (i.e. knockdown of the target mRNA) in living animals. In this review we give a brief summary of the fi...

  19. Onboard Interference Prediction for the Cognitive Medium Access in the LEO Satellite Uplink Transmission

    Zhuochen Xie; Huijie Liu; Xuwen Liang

    2014-01-01

    Cognitive radio (CR) is an efficient way to increase spectrum efficiency for the small low earth orbit (LEO) satellite communication system. Due to the implementation difficulties, we focus on the CR in the uplink transmission. In CR, the cognitive medium access (CMA) is designed to enable the coexistence with the interferences from other systems. However, the CMA schemes designed for the terrestrial system cannot deal well with the global history of interferences in our system. Here, we desi...

  20. Quantum interference in an asymmetric Mach-Zehnder interferometer

    Trenti, A.; Borghi, M.; Mancinelli, M.; Price, H. M.; Fontana, G.; Pavesi, L.

    2016-08-01

    A re-visitation of the well known free space Mach-Zehnder interferometer is reported here. The coexistence between one-photon and two-photons interference from collinear color entangled photon pairs is investigated. Thisarises from an arbitrarily small unbalance in the arm transmittance. The tuning of such asymmetry is reflected in dramatic changes in the coincidence detection, revealing beatings between one particle and two particle interference patterns. In particular, the role of the losses and of the intrinsic phase imperfectness of the lossy beamsplitter are explored in a single-port excited Mach-Zehnder interferometer. This configuration is especially useful for quantum optics on a chip, where the guiding geometry forces photons to travel in the same spatial mode.

  1. Exploiting CRISPR/Cas: Interference Mechanisms and Applications

    André Plagens

    2013-07-01

    Full Text Available The discovery of biological concepts can often provide a framework for the development of novel molecular tools, which can help us to further understand and manipulate life. One recent example is the elucidation of the prokaryotic adaptive immune system, clustered regularly interspaced short palindromic repeats (CRISPR/CRISPR-associated (Cas that protects bacteria and archaea against viruses or conjugative plasmids. The immunity is based on small RNA molecules that are incorporated into versatile multi-domain proteins or protein complexes and specifically target viral nucleic acids via base complementarity. CRISPR/Cas interference machines are utilized to develop novel genome editing tools for different organisms. Here, we will review the latest progress in the elucidation and application of prokaryotic CRISPR/Cas systems and discuss possible future approaches to exploit the potential of these interference machineries.

  2. Asymptomatic Bacteriuria and Bacterial Interference.

    Nicolle, Lindsay E

    2015-10-01

    Asymptomatic bacteriuria is very common. In healthy women, asymptomatic bacteriuria increases with age, from asymptomatic bacteriuria, irrespective of age or gender. The prevalence is very high in residents of long-term-care facilities, from 25% to 50% of women and 15% to 40% of men. Escherichia coli is the most frequent organism isolated, but a wide variety of other organisms may occur. Bacteriuria may be transient or persist for a prolonged period. Pregnant women with asymptomatic bacteriuria identified in early pregnancy and who are untreated have a risk of pyelonephritis later in pregnancy of 20% to 30%. Bacteremia is frequent in bacteriuric subjects following mucosal trauma with bleeding, with 5% to 10% of patients developing severe sepsis or septic shock. These two groups with clear evidence of negative outcomes should be screened for bacteriuria and appropriately treated. Asymptomatic bacteriuria in other populations is benign and screening and treatment are not indicated. Antimicrobial treatment has no benefits but is associated with negative outcomes including reinfection with antimicrobial resistant organisms and a short-term increased frequency of symptomatic infection post-treatment. The observation of increased symptomatic infection post-treatment, however, has led to active investigation of bacterial interference as a strategy to prevent symptomatic episodes in selected high risk patients. PMID:26542046

  3. Partial interference subspace rejection in CDMA systems

    Hansen, Henrik; Affes, Sofiene; Mewelstein, Paul

    2001-01-01

    Previously presented interference subspace rejection (ISR) proposed a family of new efficient multiuser detectors for CDMA. We reconsider in this paper the modes of ISR using decision feedback (DF). DF modes share similarities with parallel interference cancellation (PIC) but attempt to cancel...

  4. Interference and the Law of Energy Conservation

    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…

  5. Quantum theory of two-photon interference

    Wu, Xiang-Yao; Zhang, Bo-Jun; Liu, Xiao-Jing; LI Hong; Zhang, Si-Qi; Jing WANG; Wu, Yi-Heng; Li, Jing-Wu

    2012-01-01

    In this paper, we study two-photon interference with the approach of photon quantum theory, with specific attention to the two-photon interference experiment carried out by Milena D'Angelo et al. (Phys. Rev. Lett 87:013602, 2001). We find the theoretical result is accordance with experiment data.

  6. Using Interference to Block RFID Tags

    Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund;

    We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag....

  7. Phonon-Mediated Nonclassical Interference in Diamond

    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 .

  8. Understanding quantum interference in General Nonlocality

    Wanng, Hai-Jhun

    2010-01-01

    In this paper we attempt to give an understanding of quantum double-slit interference of fermions in the framework of General Nonlocality (GN) [J. Math. Phys. 49, 033513 (2008)] by studying the self-interaction of matter wave. From the metric of the GN, we derive a special formalism to interpret the interference contrast when the self-interaction is perturbative. According to the formalism, the characteristic of interference pattern is in agreement with experiment qualitatively. As examples, we apply the formalism to the cases governed by Schr\\"odinger current and Dirac current respectively, both of which are relevant to topology. The gap between these two cases corresponds to a spin-current effect, which is possible to test in the near future. In addition, a general interference formalism for both perturbative and non-perturbative self-interactions is presented. By analyzing the general formalism we predict that in the nonperturbative limit there is no interference at all.

  9. Laser self-mixing interference fiber sensor

    Zhu Jun; Zhao Yan; Jin Guo-fan

    2008-01-01

    Fibre sensors exhibit a number of advantages over other sensors such as high sensitivity, electric insulation, corrosion resistance, interference rejection and so on. And laser elf-mixing interference can accurately detect the phase difference of feedback light. In this paper, a novel laser self-mixing interference fibre sensor that combines the advantages of fibre sensors with those of laser self-mixing interference is presented. Experimental configurations are set up to study the relationship between laser power output and phase of laser feedback light when the fibre trembles or when the fibre is stretched or pressed. The theoretical analysis of pressure sensors based on laser self-mixing interference is indicated to accord with the experimental results.

  10. Improved CDMA Performance Using Parallel Interference Cancellation

    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.

  11. Improvement of Resonance Interference Treatment in STREAM

    CHoi, Sooyoung; Khassenov, Azamat; Lee Deokjung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The conventional resonance interference model simply adds the absorption XSs of resonance isotopes to the background XS. The Bondarenko iteration method performs iteration on it till effective XSs converge. However, the conventional models are not enough to consider the interference effects, which results in nonnegligible errors in computing effective XSs. The conventional methods assume that the absorption XSs are flat within an energy group, but the resonance interference occurs complicatedly within a coarse MG, therefore a way to solve this problem is to increase the number of resonance energy groups sufficiently, such as with the ultra-fine group (UFG) method. Recently research has been performed on UFG methods which solve the slowing down equation and then calculate the MG XS or the correction factor, but the UFG transport calculations cannot be practically used due to limited computing capacity. In addition, there are still problems such as geometric limitations and long computation time. In this paper, a new practical resonance interference method is presented which uses the resonance interference factor (RIF) method. However, unlike the original RIF method, this new method interpolates the RIFs in a pre-generated RIF library and corrects the effective XS, rather than solving the time consuming slowing down calculation. The new RIF method and conventional resonance interference methods have been implemented and compared in STREAM. The verification results using the proposed method show significant improvements of accuracy in treating the interference effect. A new resonance interference model based on the RIF library has been developed and verified. The method interpolates the RIF in the RIF library and uses it to treat the resonance interference effect. The RIF library method has been compared to the conventional resonance interference method and the Bondarenko iteration method. From the verification results, the RIF library method shows less than 73 pcm of

  12. Improvement of Resonance Interference Treatment in STREAM

    The conventional resonance interference model simply adds the absorption XSs of resonance isotopes to the background XS. The Bondarenko iteration method performs iteration on it till effective XSs converge. However, the conventional models are not enough to consider the interference effects, which results in nonnegligible errors in computing effective XSs. The conventional methods assume that the absorption XSs are flat within an energy group, but the resonance interference occurs complicatedly within a coarse MG, therefore a way to solve this problem is to increase the number of resonance energy groups sufficiently, such as with the ultra-fine group (UFG) method. Recently research has been performed on UFG methods which solve the slowing down equation and then calculate the MG XS or the correction factor, but the UFG transport calculations cannot be practically used due to limited computing capacity. In addition, there are still problems such as geometric limitations and long computation time. In this paper, a new practical resonance interference method is presented which uses the resonance interference factor (RIF) method. However, unlike the original RIF method, this new method interpolates the RIFs in a pre-generated RIF library and corrects the effective XS, rather than solving the time consuming slowing down calculation. The new RIF method and conventional resonance interference methods have been implemented and compared in STREAM. The verification results using the proposed method show significant improvements of accuracy in treating the interference effect. A new resonance interference model based on the RIF library has been developed and verified. The method interpolates the RIF in the RIF library and uses it to treat the resonance interference effect. The RIF library method has been compared to the conventional resonance interference method and the Bondarenko iteration method. From the verification results, the RIF library method shows less than 73 pcm of

  13. Optical Layout Analysis of Polarization Interference Imaging Spectrometer by Jones Calculus in View of both Optical Throughput and Interference Fringe Visibility

    Zhang, Xuanni; Zhang, Chunmin

    2013-01-01

    A polarization interference imaging spectrometer based on Savart polariscope was presented. Its optical throughput was analyzed by Jones calculus. The throughput expression was given, and clearly showed that the optical throughput mainly depended on the intensity of incident light, transmissivity, refractive index and the layout of optical system. The simulation and analysis gave the optimum layout in view of both optical throughput and interference fringe visibility, and verified that the layout of our former design was optimum. The simulation showed that a small deviation from the optimum layout influenced interference fringe visibility little for the optimum one, but influenced severely for others, so a small deviation is admissible in the optimum, and this can mitigate the manufacture difficulty. These results pave the way for further research and engineering design.

  14. Applying contextual interference to the Pawlata roll.

    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

  15. Gas Interference in Sucker Rod Pump

    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.

  16. Coulomb continuum effects in molecular interference

    We study analytically the interference in photoionization of molecules by monochromatic and attosecond x-ray pulses. Using the hydrogen molecule ion as a test case, we obtain simple analytical factors describing the Coulomb continuum molecular interference. We show how chirped attosecond pulse with a frequency-dependent phase and broad bandwidth creates the continuous photoelectron spectra. Due to the long-range Coulomb forces, the plane wave interference patterns are strongly modified by two-centre Coulomb continuum even at large internuclear distances. (letter to the editor)

  17. Wave and Particle in Molecular Interference Lithography

    Juffmann, Thomas; Geyer, Philipp; Major, Andras G; Deachapunya, Sarayut; Ulbricht, Hendrik; Arndt, Markus; 10.1103/PhysRevLett.103.263601

    2010-01-01

    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.

  18. Multiple Beam Interference in a Relativistic Medium

    Rakshit, Supantho

    2016-01-01

    In this paper the effects of movement of optical medium on the conditions of interference, transmission pattern and performance of spectroscopes like Febry Perot are investigated. Firstly, the conditions of constructive and destructive interference of two beams in a moving thin film is derived. Then the idea is expanded to multiple beam interference and a new modified equation of the transmission pattern is formulated with the help of basic Lorentz transformation of space and time co-ordinates and electromagnetic field. Further the new effective resolving power of a Febry Perot spectroscope is determined using this idea, which has a moving dielectric medium in its etalon.

  19. Sub-wavelength interference in macroscopic observation

    We study the generalized Young's double-slit interference for the beam produced in the spontaneous parametric down-conversion (SPDC). It has been found that the sub-wavelength interference can occur macroscopically in both the two-photon intensity measurement and the single-photon spatial intensity-correlation measurement. The former refers to the quantum entanglement and the latter originates from the thermal spatial correlation. We show the visibility and the strength of the interference fringe related to the SPDC interaction, which may provide a strong sub-wavelength lithography with a moderate visibility in practical application

  20. CORRELATED INTERFERENCE CANCELLATION FOR IR-UWB

    Zhang Zaichen; Yu Xutao; Bi Guangguo

    2008-01-01

    In this letter,we propose a hybrid analog/digital detection algorithm,the Correlated Interference Cancellation (CIC) algorithm,for Impulse Radio Ultra-WideBand (IR-UWB) system. The CIC algorithm correlates received signal with its delayed versions in the analog domain and samples the correlation output at the symbol rate. The symbol rate samples are processed in the digital domain to perform interference cancellation. Therefore,CIC works for high data rate systems with heavy InterSymbol Interference (ISI). Simulation results show that CIC achieves good performance in typical UWB channels.

  1. Role of RNA interference in plant improvement

    Jagtap, Umesh Balkrishna; Gurav, Ranjit Gajanan; Bapat, Vishwas Anant

    2011-06-01

    Research to alter crops for their better performance involving modern technology is underway in numerous plants, and achievements in transgenic plants are impacting crop improvements in unparalleled ways. Striking progress has been made using genetic engineering technology over the past two decades in manipulating genes from diverse and exotic sources, and inserting them into crop plants for inducing desirable characteristics. RNA interference (RNAi) has recently been identified as a natural mechanism for regulation of gene expression in all higher organisms from plants to humans and promises greater accuracy and precision to plant improvement. The expression of any gene can be down-regulated in a highly explicit manner exclusive of affecting the expression of any other gene by using RNAi technologies. Additional research in this field has been focused on a number of other areas including microRNAs, hairpin RNA, and promoter methylation. Manipulating new RNAi pathways, which generate small RNA molecules to amend gene expression in crops, can produce new quality traits and having better potentiality of protection against abiotic and biotic stresses. Nutritional improvement, change in morphology, or enhanced secondary metabolite synthesis are some of the other advantages of RNAi technology. In addition to its roles in regulating gene expression, RNAi is also used as a natural defense mechanism against molecular parasites such as jumping genes and viral genetic elements that affect genome stability. Even though much advancement has been made on the field of RNAi over the preceding few years, the full prospective of RNAi for crop improvement remains to be fully realized. The intricacy of RNAi pathway, the molecular machineries, and how it relates to plant development are still to be explained.

  2. Study of the Interference Affecting the Performance of the Theremin

    Carmen Bachiller Martín

    2012-01-01

    Full Text Available The theremin is one of the earliest electronic musical instruments. It is named after the Russian physics Professor Lev S. Termen who invented it in 1919. This musical instrument belongs to a very short list of devices which are played without physical contact between the musician and the instrument. theremin players complain about the interference that any object in a radius of approximately 3 meters produces when playing the theremin, modifying the intonation of the instrument. This is a problem when playing in small scenarios, with other musicians which move around it. With the aim of reducing the degree of interference from nearby obstacles, some metallic isolating bars conforming an antenna array can be placed around the theremin pitch antenna. The paper shows different simulations calculated with the commercial software Ansoft HFSS, a tool which allows three-dimensional full wave electromagnetic field simulation, with radio frequencies, millimeter and micro waves, and experimental measures, both showing a reduction in the effect of the interference.

  3. Airborne system for detection and location of radio interference sources

    Audone, Bruno; Pastore, Alberto

    1992-11-01

    The rapid expansion of telecommunication has practically saturated every band of Radio Frequency Spectrum; a similar expansion of electrical and electronic devices has affected all radio communications which are, in some way, influenced by a large amount of interferences, either intentionally or unintentionally produced. Operational consequences of these interferences, particularly in the frequency channels used for aeronautical services, can be extremely dangerous, making mandatory a tight control of Electromagnetic Spectrum. The present paper analyzes the requirements and the problems related to the surveillance, for civil application, of the Electromagnetic Spectrum between 20 and 1000 MHz, with particular attention to the detection and location of radio interference sources; after a brief introduction and the indication of the advantages of an airborne versus ground installation, the airborne system designed by Alenia in cooperation with Italian Ministry of Post and Telecommunication, its practical implementation and the prototype installation on board of a small twin turboprop aircraft for experimentation purposes is presented. The results of the flight tests are also analyzed and discussed.

  4. Accumulative Interference Modeling for Distributed Cognitive Radio Networks

    Francky Catthoor

    2009-04-01

    Full Text Available

    A Cognitive Radio (CR network should be able to sense its environment to adapt its communication so that it can utilize unused licensed spectrum without interfering with incumbent users. Properly modeling the expected interference from the entire CR network is therefore very important to effectively protect these incumbent users. We model the accumulative interference generated from a large-scale CR network and investigate how the CR network density affects the sensing requirements of the CRs to meet an interference constraint. More specifically, our model considers the impact of discrete network topology, the impact of imperfect sensing and the impact of collisions when the CR uses a distributed channel access scheme. We then apply our model to a CR network based on the IEEE 802.11 standard. We show that the collisions occurring frequently in these networks only have a small on the sensing requirements to protect the incumbent network.

  5. Inhibition of proliferation of human non-Hodgkin's lymphoma Raji cells by small interference RNA silencing Pokemon gene%siRNA 沉默 Pokemon 基因抑制人非霍奇金淋巴瘤 Raji细胞的增殖

    董珂; 蒲业迪; 刘琼; 代广霞; 李丽珍; 李颢; 王玲玲; 王鲁群

    2014-01-01

    Objective Small interference RNA ( siRNA) was used to silence Pokemon gene in human non-Hodgkin's lymphoma Raji cells, then to observe the change of proliferation of Raji cells and explore its possible molecular mecha-nisms.Methods Pokemon-targeted siRNA was constructed with lentivirus vector and transfected to Raji cells. RT-PCR and Western blotting were adopted to confirm the silence effect of Pokemon gene in Raji cells, which were then used to determine the mRNA and protein expressions of bcl-6 and mutant p53.Flow cytometry was used to detect the cell apoptosis of each group.Results Pokemon-siRNA constructed with lentivirus vector could efficiently silence the expression of Pokemon gene in Raji cell (P<0.05).After that, the mRNA and protein expressions of bcl-6 and mutant p53 were significantly decreased (P<0.05) and the cell apoptosis rate was markedly elevated compared with the controls.Conclusion The siRNA Pokemon gene silencing promotes human non-Hodgkin's lymphoma Raji cells apoptosis by lowering the expressions of bcl-6 and mutant p53 gene and protein and inhibiting the proliferation.Poke-mon gene is expected to become a new target for non-Hodgkin's lymphoma treatment.%目的:采用siRNA干扰技术沉默人非霍奇金淋巴瘤Raji细胞中Pokemon基因,观察Raji细胞增殖活性的变化,并探讨其可能的分子机制。方法构建靶向Pokemon基因的siRNA重组慢病毒载体并转染Raji细胞。采用实时定量PCR法和Western blotting法检测Raji细胞Pokemon基因的沉默效果,在Raji细胞中沉默Pokemon基因的表达后采用实时定量PCR法和Western blotting法检测bcl-6和突变型p53表达水平的变化;采用流式细胞术检测Pokemon基因沉默后Raji细胞凋亡的情况。结果利用Pokemon靶向siRNA重组慢病毒载体感染Raji细胞有效沉默Raji细胞Pokemon基因表达(P<0.05)。沉默Pokemon基因后,bcl-6和突变型p53基因和蛋白表达均显著降低(P<0.05)

  6. Lipid-based transfection reagents can interfere with cholesterol biosynthesis.

    Danielli, Mauro; Marinelli, Raúl A

    2016-02-15

    Lipid-based transfection reagents are widely used for delivery of small interfering RNA into cells. We examined whether the commonly used commercial transfection reagents DharmaFECT-4 and Lipofectamine 2000 can interfere with lipid metabolism by studying cholesterogenesis. Cholesterol de novo synthesis from [(14)C]acetate was assessed in human hepatocyte-derived Huh-7 cells. The results revealed that DharmaFECT, but not Lipofectamine, markedly inhibited cholesterol biosynthesis by approximately 70%. Cell viability was not significantly altered. These findings suggest that caution is required in the choice of certain lipid-based transfection reagents for gene silencing experiments, particularly when assessing cholesterol metabolism. PMID:26656923

  7. Signal interference RF photonic bandstop filter.

    Aryanfar, Iman; Choudhary, Amol; Shahnia, Shayan; Pagani, Mattia; Liu, Yang; Marpaung, David; Eggleton, Benjamin J

    2016-06-27

    In the microwave domain, signal interference bandstop filters with high extinction and wide stopbands are achieved through destructive interference of two signals. Implementation of this filtering concept using RF photonics will lead to unique filters with high performance, enhanced tuning range and reconfigurability. Here we demonstrate an RF photonic signal interference filter, achieved through the combination of precise synthesis of stimulated Brillouin scattering (SBS) loss with advanced phase and amplitude tailoring of RF modulation sidebands. We achieve a square-shaped, 20-dB extinction RF photonic filter over a tunable bandwidth of up to 1 GHz with a central frequency tuning range of 16 GHz using a low SBS loss of ~3 dB. Wideband destructive interference in this novel filter leads to the decoupling of the filter suppression from its bandwidth and shape factor. This allows the creation of a filter with all-optimized qualities. PMID:27410650

  8. Interference Channels with One Cognitive Transmitter

    Cao, Yi

    2009-01-01

    This paper studies the problem of interference channels with one cognitive transmitter (ICOCT) where "cognitive" is defined from both the noncausal and causal perspectives. For the noncausal ICOCT, referred to as interference channels with degraded message sets (IC-DMS), we propose a new achievable rate region that generalizes existing achievable rate regions for IC-DMS. In the absence of the noncognitive transmitter, the proposed region coincides with Marton's region for the broadcast channel. Based on this result, the capacity region of a class of semi-deterministic IC-DMS is established. For the causal ICOCT, due to the complexity of the channel model, we focus primarily on the cognitive Z interference channel (ZIC), where the interference link from the cognitive transmitter to the primary receiver is assumed to be absent due to practical design considerations. Capacity bounds for such channels in different parameter regimes are obtained and the impact of such causal cognitive ability is carefully studied....

  9. Fight plant pests using RNA interference

    2008-01-01

    @@ CAS plant physiologists have recently invented a plant-mediated RNA interference (RNAi) technique to effectively and specifically control the gene expression of the cotton bollworm (Helicoverpa armigera) and stunt its growth.

  10. Parallel interference cancellation for CDMA applications

    Divsalar, Dariush (Inventor); Simon, Marvin K. (Inventor); Raphaeli, Dan (Inventor)

    1997-01-01

    The present invention provides a method of decoding a spread spectrum composite signal, the composite signal comprising plural user signals that have been spread with plural respective codes, wherein each coded signal is despread, averaged to produce a signal value, analyzed to produce a tentative decision, respread, summed with other respread signals to produce combined interference signals, the method comprising scaling the combined interference signals with a weighting factor to produce a scaled combined interference signal, scaling the composite signal with the weighting factor to produce a scaled composite signal, scaling the signal value by the complement of the weighting factor to produce a leakage signal, combining the scaled composite signal, the scaled combined interference signal and the leakage signal to produce an estimate of a respective user signal.

  11. Assessment of life interference in anxious children

    Rapee, Ronald; Thastum, Mikael; Chavira, Denise

    associated with mental disorders arguably the key issue of relevance to both sufferers and therapists. Yet among both childhood and adult disorders the primary focus in terms of assessment and treatment is on symptoms, with far less attention paid to the impact of these symptoms on the sufferer's life. This...... imbalance has particularly characterised research on child anxiety where few studies have examined either the impact of anxiety disorders on children's lives or the effects of treatments on life interference. To some extent this lack of attention has come from a lack of well developed measures to assess...... life interference derived from symptoms of anxiety. Broader and more general life interference measures tend to have minimal relevance for children with anxiety disorders. The current paper will describe two measures of life interference that have been developed at the Centre for Emotional Health...

  12. Radio VLBI and the quantum interference paradox

    Singal, Ashok K

    2016-01-01

    We address here the question of interference of radio signals from astronomical sources like distant quasars, in a very long baseline interferometer (VLBI), where two (or more) distantly located radio telescopes (apertures), receive simultaneous signal from the sky. In an equivalent optical two-slit experiment, it is generally argued that for the photons involved in the interference pattern on the screen, it is not possible, even in principle, to ascertain which of the two slits a particular photon went through. It is argued that any procedure to ascertain this destroys the interference pattern. But in the case of the modern radio VLBI, it is a routine matter to record the phase and amplitude of the voltage outputs from the two radio antennas on a recording media separately and then do the correlation between the two recorded signals later in an offline manner. Does this not violate the quantum interference principle? We provide a resolution of this problem here.

  13. Conducted Electromagnetic Interference (EMI) in Smart Grids

    Smolenski, Robert

    2012-01-01

    As power systems develop to incorporate renewable energy sources, the delivery systems may be disrupted by the changes involved. The grid’s technology and management must be developed to form Smart Grids between consumers, suppliers and producers. Conducted Electromagnetic Interference (EMI) in Smart Grids considers the specific side effects related to electromagnetic interference (EMI) generated by the application of these Smart Grids. Conducted Electromagnetic Interference (EMI) in Smart Grids presents specific EMI conducted phenomena as well as effective methods to filter and handle them once identified. After introduction to Smart Grids, the following sections cover dedicated methods for EMI reduction and potential avenues for future development including chapters dedicated to: •potential system services, •descriptions of the EMI spectra shaping methods, •methods of interference voltage compensation, and theoretical analysis of experimental results.  By focusing on these key aspects, Conducted El...

  14. Automotive radar - investigation of mutual interference mechanisms

    Goppelt, M.; Blöcher, H.-L.; Menzel, W.

    2010-09-01

    In the past mutual interference between automotive radar sensors has not been regarded as a major problem. With an increasing number of such systems, however, this topic is receiving more and more attention. The investigation of mutual interference and countermeasures is therefore one topic of the joint project "Radar on Chip for Cars" (RoCC) funded by the German Federal Ministry of Education and Research (BMBF). RoCC's goal is to pave the way for the development of high-performance, low-cost 79 GHz radar sensors based on Silicon-Germanium (SiGe) Monolithic Microwave Integrated Circuits (MMICs). This paper will present some generic interference scenarios and report on the current status of the analysis of interference mechanisms.

  15. Quantified Interference for a While Language

    Clark, D. (David); Hunt, S.; Malacaria, P.

    2005-01-01

    We show how information theory can be used to give a quantitative definition of interference between variables in imperative programming languages. In this paper we focus on a particular case of this definition of interference: leakage of information from private variables to public ones in While language programs. The major result of the paper is a quantitative analysis for this language that employs a use-definition graph to calculate bounds on the leakage into each variable.

  16. Interference Alignment with Analog Channel State Feedback

    Ayach, Omar El; Heath Jr, Robert W.

    2010-01-01

    Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel. While the achieved sum rate with IA is much higher than previously thought possible, the improvement often comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet potentially costly approach that incurs large overhead. In this paper we propose analog feedback as an alternative to limited feedback ...

  17. Interference Fit Life Factors for Roller Bearings

    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.

  18. Visual Working Memory Capacity and Proactive Interference

    Hartshorne, Joshua K.

    2008-01-01

    BACKGROUND: Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory tasks, like verbal working memory tasks, are subject to proactive interference, coupled with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggests that visual working memory capacity may be systematically under-estimated. METHODOLOGY/P...

  19. Fading and interference mitigation in wireless communications

    Panic, Stefan; Anastasov, Jelena; Spalevic, Petar

    2013-01-01

    The rapid advancement of various wireless communication system services has created the need to analyze the possibility of their performance improvement. Introducing the basic principles of digital communications performance analysis and its mathematical formalization, Fading and Interference Mitigation in Wireless Communications will help you stay up to date with recent developments in the performance analysis of space diversity reception over fading channels in the presence of cochannel interference.The book presents a unified method for computing the performance of digital communication sys

  20. Analysis and improvements of module incidental interference faults of water level control system pressurize NPP

    In Daya Bay nuclear power plant, there have been many times that the module used to value the water level outputs a small pulse interference when the pressurizer water level control system is in operation, and the interference exists only in analog storage operation module, which can directly impact the control of the water level of the pressurizer, causing the water level fluctuations and adversely affecting the safe operation of the reactor. This paper analyzes the module incidental interference faults of the water level control system of the NPP pressurizer from the point view of the system control and design of module hardware, and finds out the reasons by the system simulation experiment and power supply circuit test. It is suggested to further improve on the design of hardware loops, add more inductance and capacity to eliminate the interference. (authors)

  1. Dynamic control of coherent pulses via Fano-type interference in asymmetric double quantum wells

    We study the temporal and spatial dynamics of two light pulses, a probe and a switch, propagating through an asymmetric double quantum well where tunneling-induced quantum interference may be observed. When such an interference takes place, in the absence of the switch, the quantum well is transparent to the probe which propagates over sufficiently long distances at very small group velocities. In the presence of a relatively strong switch, however, the probe pulse is absorbed due to the quenching of tunneling-induced quantum interference. The probe may be made to vanish even when switch and probe are somewhat delayed with respect to one another. Conversely, our asymmetric double quantum well may be rendered either opaque or transparent to the switch pulse. Such a probe-switch 'reciprocity' can be used to devise a versatile all-optical quantum interference-based solid-state switch for optical communication devices

  2. Ethical Perspectives on RNA Interference Therapeutics

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

    2008-01-01

    Full Text Available 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.

  3. Indonesian Young Adults’ Interference in Translating

    Indra Nugraha

    2013-09-01

    Full Text Available Interference has become a crucial matter to recognize in bilingual and multilingual communities. The phenomenon of interference has affected how we as at least members of bilingual or even multilingual communities speak to the others. As the members of multilingual communities, the Indonesian young adults receive many influences in the way they speak and understand languages. However, these influences often lead to the wrong way. In this case, many Indonesian young adults understand English cursing inappropriately. This misunderstanding may lead to the abuse of English cursing in daily conversations. This article provides the insight of how interference affects the way the Indonesian young adults understand English cursing. Using the questionnaire-based research method, this articles tends to find out the attitudes of Indonesian young adults towards translating English cursing to Indonesian, which interference that affects the translation process of English cursing resulting to the inappropriate understanding of English cursing among Indonesian young adults, and which suitable translation method for translating English cursing to Indonesian. Apparently, the present writer has found out that there are two attitudes towards translating English cursing to Indonesian, that is, first, the English cursing is translated to the Indonesian cursing and second, the English cursing is translated literaly to Indonesian. Further, the present writer has found out that the interlingual interference has affected the translation process of English cursing to Indonesian and the suitable method for translating English cursing to Indonesian is adaptation based on Newmark (1988.Keywords: Interference, Multilingual communities, Translating English cursing, Indonesian young adults

  4. Investigation of Interference Models for RFID Systems.

    Zhang, Linchao; Ferrero, Renato; Gandino, Filippo; Rebaudengo, Maurizio

    2016-01-01

    The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols. PMID:26861326

  5. Investigation of Interference Models for RFID Systems

    Linchao Zhang

    2016-02-01

    Full Text Available The reader-to-reader collision in an RFID system is a challenging problem for communications technology. In order to model the interference between RFID readers, different interference models have been proposed, mainly based on two approaches: single and additive interference. The former only considers the interference from one reader within a certain range, whereas the latter takes into account the sum of all of the simultaneous interferences in order to emulate a more realistic behavior. Although the difference between the two approaches has been theoretically analyzed in previous research, their effects on the estimated performance of the reader-to-reader anti-collision protocols have not yet been investigated. In this paper, the influence of the interference model on the anti-collision protocols is studied by simulating a representative state-of-the-art protocol. The results presented in this paper highlight that the use of additive models, although more computationally intensive, is mandatory to improve the performance of anti-collision protocols.

  6. Cross-limb interference during motor learning.

    Benedikt Lauber

    Full Text Available It is well known that following skill learning, improvements in motor performance may transfer to the untrained contralateral limb. It is also well known that retention of a newly learned task A can be degraded when learning a competing task B that takes place directly after learning A. Here we investigate if this interference effect can also be observed in the limb contralateral to the trained one. Therefore, five different groups practiced a ballistic finger flexion task followed by an interfering visuomotor accuracy task with the same limb. Performance in the ballistic task was tested before the training, after the training and in an immediate retention test after the practice of the interference task for both the trained and the untrained hand. After training, subjects showed not only significant learning and interference effects for the trained limb but also for the contralateral untrained limb. Importantly, the interference effect in the untrained limb was dependent on the level of skill acquisition in the interfering motor task. These behavioural results of the untrained limb were accompanied by training specific changes in corticospinal excitability, which increased for the hemisphere ipsilateral to the trained hand following ballistic training and decreased during accuracy training of the ipsilateral hand. The results demonstrate that contralateral interference effects may occur, and that interference depends on the level of skill acquisition in the interfering motor task. This finding might be particularly relevant for rehabilitation.

  7. On the Feasibility of Linear Interference Alignment for MIMO Interference Broadcast Channels with Constant Coefficients

    Liu, Tingting; Yang, Chenyang

    2012-01-01

    In this paper, we analyze the feasibility of linear interference alignment (IA) for multi-input-multi-output (MIMO) interference broadcast channel (MIMO-IBC) with constant coefficients. We pose and prove the necessary conditions of linear IA feasibility for general MIMO-IBC. Except for the proper condition, we find another necessary condition to ensure a kind of irreducible interference to be eliminated. We then prove the necessary and sufficient conditions for a special class of MIMO-IBC, wh...

  8. Outage analysis of interference-limited systems using STBC with co-channel MIMO interferers

    Yongzhao LI; Leonard J.CIMINI,JR.; Nageen HIMAYAT

    2009-01-01

    The performance of Space-Time Block Coding (STBC) with co-channel MIMO interference is investigated.For an interference-limited environment, the closed-form ex-pressions for the probability density functions of the signal-to-interference ratio are derived and applied to analyze the outage probability with three typical types of co-channel MIMO interferers: STBC, open-loop spatial multiplexing and closed-loop spatial multiplexing. Both theoretical anal-yses and simulation results show that the performance of STBC is independent of the MIMO modes used in the in-terfering links.

  9. REFIM: A Practical Interference Management in Heterogeneous Wireless Access Networks

    Son, Kyuho; Yi, Yung; Chong, Song

    2011-01-01

    Due to the increasing demand of capacity in wireless cellular networks, the small cells such as pico and femto cells are becoming more popular to enjoy a spatial reuse gain, and thus cells with different sizes are expected to coexist in a complex manner. In such a heterogeneous environment, the role of interference management (IM) becomes of more importance, but technical challenges also increase, since the number of cell-edge users, suffering from severe interference from the neighboring cells, will naturally grow. In order to overcome low performance and/or high complexity of existing static and other dynamic IM algorithms, we propose a novel low-complex and fully distributed IM scheme, called REFIM, in the downlink of heterogeneous multi-cell networks. We first formulate a general optimization problem that turns out to require intractable computation complexity for global optimality. To have a practical solution with low computational and signaling overhead, which is crucial for low-cost small-cell solutio...

  10. General Quantum Interference Principle and Duality Computer

    LONG Gui-Lu

    2006-01-01

    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 thesub-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.

  11. Epulis and pyogenic granuloma with occlusal interference

    Widowati Witjaksono

    2005-06-01

    Full Text Available In dental clinic of Hospital University Science Malaysia (HUSM, there were cases with Localized Gingival Enlargement (LGE in the oral cavity with occlusal interference. In this study, three cases were observed. They were a 13 - year- old female with fibrous lge around 31 and 32 with occlusal interference in protrusive movement due to X bite, a 15 - year – old female with pyogenic granuloma near 11 & 21 with occlusal interference due to deep bite; and a 24 – year – old female who was eight months in pregnancy with pyogenic granuloma on the 34-35 and severe generalized pregnancy gingivitis with occlusal interference in centric occlusion and lateral movement. Clinical and histopathological diagnosis of the first case showed fibrous epulis, whereas the second and third cases disclosed pyogenic granuloma. Chronic trauma of the gingiva due to occlusal interference was assumed to be the cause of those LGE in case 1 and 2, while in case 3 poor oral hygiene and chronic trauma were assumed to be the etiologic factors.

  12. Disentangling posterror and postconflict reduction of interference.

    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). PMID:24740696

  13. Analysing Self Interference Cancellation in Full Duplex Radios

    Mahmood, Nurul Huda; Shafique Ansari, Imran; Berardinelli, Gilberto;

    2016-01-01

    interference power is modelled as a noise-like constant level interference floor. However, experimental validations have shown that the self interference power is in practice a random variable depending on a number of factors such as the surrounding wireless environment and the degree of interference...

  14. Collisional quantum interference on rotational energy transfer: physical interpretation of the differential interference angle

    Li Yong-Qing; Li Jian; Ma Feng-Cai

    2006-01-01

    Collisional quantum interference (CQI) on the intramolecular rotational energy transfer is observed in an experiment with a static cell, and the integral interference angles are measured. To obtain more accurate information, an experiment with a molecular beam is carried out, and thereby the relationship between the differential interference angle and the scattering angle is obtained. Based on the first-Born approximation of time-dependent perturbation theory,the theoretical model of CQI is developed in an atom-diatom system in the condition of the molecular beam, with the long-range interaction potential taken into account. The method of measuring correctly the differential interference angle is presented. The tendencies of the differential interference angle changing with the impact parameter and relative velocity are discussed. The theoretical model presented here is important for understanding or performing the experiment in the molecular beam.

  15. Multichannel interference mitigation methods in radio astronomy

    Leshem, A; Boonstra, A J; Leshem, Amir; Veen, Alle-Jan van der; Boonstra, Albert-Jan

    2000-01-01

    Radio-astronomical observations are increasingly corrupted by RF interference, and online detection and filtering algorithms are becoming essential. To facilitate the introduction of such techniques into radio astronomy, we formulate the astronomical problem in an array signal processing language, and give an introduction to some elementary algorithms from that field. We consider two topics in detail: interference detection by rank estimation of short-term covariance matrices, and spatial filtering by subspace estimation and projection. We discuss experimental data collected at the Westerbork radio telescope, and illustrate the effectiveness of the space-time detection and blanking process on the recovery of a 3C48 absorption line in the presence of GSM mobile telephony interference.

  16. Bargaining and the MISO Interference Channel

    Matthew Nokleby

    2009-01-01

    Full Text Available 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.

  17. Time and interference: Effects on working memory.

    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

  18. Nonclassical Paths in Quantum Interference Experiments

    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.

  19. Non-classical paths in interference experiments

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

    2014-01-01

    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 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 quantum interference experiments which provide a measurable deviation from a naive application of the superposition principle. 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.

  20. Cross-limb Interference during motor learning

    Lauber, Benedikt; Jensen, Jesper Lundbye; Keller, Martin;

    2013-01-01

    It is well known that following skill learning, improvements in motor performance may transfer to the untrained contralateral limb. It is also well known that retention of a newly learned task A can be degraded when learning a competing task B that takes place directly after learning A. Here we...... investigate if this interference effect can also be observed in the limb contralateral to the trained one. Therefore, five different groups practiced a ballistic finger flexion task followed by an interfering visuomotor accuracy task with the same limb. Performance in the ballistic task was tested before the...... training, after the training and in an immediate retention test after the practice of the interference task for both the trained and the untrained hand. After training, subjects showed not only significant learning and interference effects for the trained limb but also for the contralateral untrained limb...

  1. Interference Channels with Correlated Receiver Side Information

    Liu, Nan; Goldsmith, Andrea J; Poor, H Vincent

    2008-01-01

    The problem of joint source-channel coding in transmitting independent sources over interference channels with correlated receiver side information is studied. When each receiver has side information correlated with its own desired source, it is shown that source-channel code separation is optimal. When each receiver has side information correlated with the interfering source, sufficient conditions for reliable transmission are provided based on a joint source-channel coding scheme using the superposition encoding and partial decoding idea of Han and Kobayashi. When the receiver side information is a deterministic function of the interfering source, source-channel code separation is again shown to be optimal. As a special case, for a class of Z-interference channels, when the side information of the receiver facing interference is a deterministic function of the interfering source, necessary and sufficient conditions for reliable transmission are provided in the form of single letter expressions. As a byprodu...

  2. Electromagnetic Interference on Large Wind Turbines

    Florian Krug

    2009-11-01

    Full Text Available Electromagnetic interference (EMI can both affect and be transmitted by mega-watt wind turbines. This paper provides a general overview on EMI with respect to mega-watt wind turbines. Possibilities of measuring all types of electromagnetic interference are shown. Electromagnetic fields resulting from a GSM transmitter mounted on a mega-watt wind turbine will be analyzed in detail. This cellular system operates as a real-time communication link. The method-of-moments is used to analytically describe the electro-magnetic fields. The electromagnetic interference will be analyzed under the given boundary condition with a commercial simulation tool. Different transmitter positions are judged on the basis of their radiation patterns. The principal EMI mechanisms are described and taken into consideration.

  3. On Interference of Chinese with ELL

    九曼

    2011-01-01

    It is popularly admitted that the foreign language learning is strongly influenced by learners' first language.Generally speaking,the interference of Chinese with ELL is divided into negative transfer and positive transfer,which are manifested at various levels during ELL.The thesis aims to show the interference of Chinese with ELL,with the approach of qualitative analysis,the paper is arranged into Part Ⅰ:Introduction; Part Ⅱ:The Contrast between ELL and Chinese Language Acquisition; Part Ⅲ:The Influence of Chinese on ELL:Part Ⅵ:Conclusion.Being aware of the interference of Chinese with ELL will help students overcome the obstacles and promote ELL.

  4. Frequent video game players resist perceptual interference.

    Aaron V Berard

    Full Text Available 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.

  5. Medial Amygdala Lesions in Male Rats Reduce Aggressive Behavior : Interference With Experience

    Vochteloo, J.D.; Koolhaas, J.M.

    1987-01-01

    The medial nucleus of the amygdala (am) has been implicated in a variety of social behaviors. The present experiment will test the hypothesis that the effect of am lesions on intermale aggressive behavior is due to interference with social learning processes. Small electrolytic lesions of the am had

  6. A Simple Laboratory Practical to Illustrate RNA Mediated Gene Interference Using Drosophila Cell Culture

    Buluwela, Laki; Kamalati, Tahereh; Photiou, Andy; Heathcote, Dean A.; Jones, Michael D.; Ali, Simak

    2010-01-01

    RNA mediated gene interference (RNAi) is now a key tool in eukaryotic cell and molecular biology research. This article describes a five session laboratory practical, spread over a seven day period, to introduce and illustrate the technique. During the exercise, students working in small groups purify PCR products that encode "in vitro"…

  7. Deploying 5G-technologies in smart city and smart home wireless sensor networks with interferences

    Lynggaard, Per; Skouby, Knud Erik

    2015-01-01

    , it is able to overcome the WiFi interferences and the wall penetration losses for a limited power cost. By simulation it has been found that power saving in the range of 10–23 % can be achieved for a small bandwidth cost. Additionally, it has been found that the choice of the smart home gateway location can...

  8. Observation of two-center interference effects for electron impact ionization of N2

    Chaluvadi, Hari; Nur Ozer, Zehra; Dogan, Mevlut; Ning, Chuangang; Colgan, James; Madison, Don

    2015-08-01

    In 1966, Cohen and Fano (1966 Phys. Rev. 150 30) suggested that one should be able to observe the equivalent of Young’s double slit interference if the double slits were replaced by a diatomic molecule. This suggestion inspired many experimental and theoretical studies searching for double slit interference effects both for photon and particle ionization of diatomic molecules. These effects turned out to be so small for particle ionization that this work proceeded slowly and evidence for interference effects were only found by looking at cross section ratios. Most of the early particle work concentrated on double differential cross sections for heavy particle scattering and the first evidence for two-center interference for electron-impact triple differential cross section (TDCS) did not appear until 2006 for ionization of H2. Subsequent work has now firmly established that two-center interference effects can be seen in the TDCS for electron-impact ionization of H2. However, in spite of several experimental and theoretical studies, similar effects have not been found for electron-impact ionization of N2. Here we report the first evidence for two-center interference for electron-impact ionization of N2.

  9. Phonon interference effects in molecular junctions

    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

  10. Phonon interference effects in molecular junctions

    Markussen, Troels, E-mail: troels.markussen@gmail.com [Center for Atomic-scale Materials Design (CAMD), Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)

    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.

  11. Interference-free ultrasonic level measuring sensor

    To avoid interference phenomena depending on the level, an ultrasonic level measuring sensor is proposed, which has an envelope tube around the path of the ultrasonic signal to prevent reflection. An ultrasonic transducer suspended by means of a linkage on a flange is additionally provided with a corrugated hose or a sintered metal tube around the path of the ultrasonic signal. A reference element necessary to raise the accuracy can be fitted in a cutout of the envelope tube. This device makes very precise measurement of the level possible without variations in the accuracy of measurement depending on the level, as interference due to shunt reflection is prevented. (orig./HP)

  12. Inertial and interference effects in optical spectroscopy

    Karstens, W.; Y Smith, D.

    2015-04-01

    Interference between free-space and material components of the displacement current plays a key role in determining optical properties. This is illustrated by an analogy between the Lorentz optical model and a-c circuits. Phase shifts in material-polarization currents, which are inertial, relative to the non-inertial vacuum-polarization current cause interference in the total displacement current and, hence, variation in E-M wave propagation. If the displacement-current is reversed, forward propagation is inhibited yielding the semimetallic reflectivity exhibited by intrinsic silicon. Complete cancellation involves material currents offsetting free-space currents to form current-loops that correspond to plasmons.

  13. Gathering algorithms on paths under interference constraints

    Bermond, Jean-Claude; Correa, Ricardo; Yu, Min-Li

    2006-01-01

    International audience We study the problem of gathering information from the nodes of a multi-hop radio network into a pre-determined destination node under interference constraints which are modeled by an integer d 1, so that any node within distance d of a sender cannot receive calls from any other sender. A set of calls which do not interfere with each other is referred to as a round. We give algorithms and lower bounds on the minimum number of rounds for this problem, when the network...

  14. Carbon nanostructure composite for electromagnetic interference shielding

    Anupama Joshi; Suwarna Datar

    2015-06-01

    This communication reviews current developments in carbon nanostructure-based composite materials for electromagnetic interference (EMI) shielding. With more and more electronic gadgets being used at different frequencies, there is a need for shielding them from one another to avoid interference. Conventionally, metal-based shielding materials have been used. But due to the requirement of light weight, corrosion resistive materials, lot of work is being done on composite materials. In this research the forerunner is the nanocarbon-based composite material whose different forms add different characteristics to the composite. The article focusses on composites based on graphene, graphene oxide, carbon nanotubes, and several other novel forms of carbon.

  15. Gyroscopic effects in interference of matter waves

    A new gyroscopic interference effect stemming from the Galilean translational factor in the matter wave function is pointed out. In contrast to the well-known Sagnac effect that stems from the geometric phase and leads to a shift of interference fringes, this effect causes slanting of the fringes. We illustrate it by calculations for two split cigar-shaped Bose-Einstein condensates under the conditions of a recent experiment, see Y. Shin et al., Phys. Rev. Lett. 92, 050405 (2004). Importantly, the measurement of slanting obviates the need of a third reference cloud

  16. Gyroscopic effects in interference of matter waves

    Tolstikhin, Oleg I.; Morishita, Toru; Watanabe, Shinichi

    2005-01-01

    A new gyroscopic interference effect stemming from the Galilean translational factor in the matter wave function is pointed out. In contrast to the well-known Sagnac effect that stems from the geometric phase and leads to a shift of interference fringes, this effect causes slanting of the fringes. We illustrate it by calculations for two split cigar-shaped Bose-Einstein condensates under the conditions of a recent experiment, see Y.Shin et al., Phys. Rev. Lett. 92, 050405 (2004). Importantly,...

  17. Interference Alignment with Incomplete CSIT Sharing

    De Kerret, Paul; Gesbert, David

    2012-01-01

    In this work, we study the impact of having only incomplete channel state information at the transmitters (CSIT) over the feasibility of interference alignment (IA) in a K-user MIMO interference channel (IC). Incompleteness of CSIT refers to the perfect knowledge at each transmitter (TX) of only a sub-matrix of the global channel matrix, where the sub-matrix is specific to each TX. This paper investigates the notion of IA feasibility for CSIT configurations being as incomplete as possible, as...

  18. Sensorimotor Interference When Reasoning About Described Environments

    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.

  19. Control of exciton transport using quantum interference

    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.

  20. New insights into control of arbovirus replication and spread by insect RNA interference pathways

    Donald, Claire L.; Alain Kohl; Esther Schnettler

    2012-01-01

    Arthropod-borne (arbo) viruses are transmitted by vectors, such as mosquitoes, to susceptible vertebrates. Recent research has shown that arbovirus replication and spread in mosquitoes is not passively tolerated but induces host responses to control these pathogens. Small RNA-mediated host responses are key players among these antiviral immune strategies. Studies into one such small RNA-mediated antiviral response, the exogenous RNA interference (RNAi) pathway, have generated a wealth of info...

  1. Magneto-Conductance Anisotropy and Interference Effects in Variable Range Hopping

    Medina, Ernesto; Kardar, Mehran; Rangel, Rafael

    1995-01-01

    We investigate the magneto-conductance (MC) anisotropy in the variable range hopping regime, caused by quantum interference effects in three dimensions. When no spin-orbit scattering is included, there is an increase in the localization length (as in two dimensions), producing a large positive MC. By contrast, with spin-orbit scattering present, there is no change in the localization length, and only a small increase in the overall tunneling amplitude. The numerical data for small magnetic fi...

  2. Multiple-Antenna Interference Cancellation for WLAN with MAC Interference Avoidance in Open Access Networks

    Kuzminskiy Alexandr M

    2007-01-01

    Full Text Available The potential of multiantenna interference cancellation receiver algorithms for increasing the uplink throughput in WLAN systems such as 802.11 is investigated. The medium access control (MAC in such systems is based on carrier sensing multiple-access with collision avoidance (CSMA/CA, which itself is a powerful tool for the mitigation of intrasystem interference. However, due to the spatial dependence of received signal strengths, it is possible for the collision avoidance mechanism to fail, resulting in packet collisions at the receiver and a reduction in system throughput. The CSMA/CA MAC protocol can be complemented in such scenarios by interference cancellation (IC algorithms at the physical (PHY layer. The corresponding gains in throughput are a result of the complex interplay between the PHY and MAC layers. It is shown that semiblind interference cancellation techniques are essential for mitigating the impact of interference bursts, in particular since these are typically asynchronous with respect to the desired signal burst. Semiblind IC algorithms based on second- and higher-order statistics are compared to the conventional no-IC and training-based IC techniques in an open access network (OAN scenario involving home and visiting users. It is found that the semiblind IC algorithms significantly outperform the other techniques due to the bursty and asynchronous nature of the interference caused by the MAC interference avoidance scheme.

  3. Multiple-Antenna Interference Cancellation for WLAN with MAC Interference Avoidance in Open Access Networks

    Alexandr M. Kuzminskiy

    2007-10-01

    Full Text Available The potential of multiantenna interference cancellation receiver algorithms for increasing the uplink throughput in WLAN systems such as 802.11 is investigated. The medium access control (MAC in such systems is based on carrier sensing multiple-access with collision avoidance (CSMA/CA, which itself is a powerful tool for the mitigation of intrasystem interference. However, due to the spatial dependence of received signal strengths, it is possible for the collision avoidance mechanism to fail, resulting in packet collisions at the receiver and a reduction in system throughput. The CSMA/CA MAC protocol can be complemented in such scenarios by interference cancellation (IC algorithms at the physical (PHY layer. The corresponding gains in throughput are a result of the complex interplay between the PHY and MAC layers. It is shown that semiblind interference cancellation techniques are essential for mitigating the impact of interference bursts, in particular since these are typically asynchronous with respect to the desired signal burst. Semiblind IC algorithms based on second- and higher-order statistics are compared to the conventional no-IC and training-based IC techniques in an open access network (OAN scenario involving home and visiting users. It is found that the semiblind IC algorithms significantly outperform the other techniques due to the bursty and asynchronous nature of the interference caused by the MAC interference avoidance scheme.

  4. Phase-Modulation Laser Interference Microscopy

    Brazhe, Alexey; Brazhe, Nadezda; Maximov, G. V.;

    2008-01-01

    We describe how phase-modulation laser interference microscopy and wavelet analysis can be applied to noninvasive nonstained visualization and study of the structural and dynamical properties of living cells. We show how phase images of erythrocytes can reveal the difference between various...

  5. Exploiting Genetic Interference for Antiviral Therapy

    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. Two-order Interference of Single Photon

    JIANG Yunkun; LI Jian; SHI Baosen; FAN Xiaofeng; GUO Guangcan

    2000-01-01

    A pair of photons called signal and idler photons, respectively, are produced through the nonlinear process of type-I spontaneous parametric downconversion in BBO crystal pumped by the second-harmonic wave of a Ti:sapphire femtosecond laser pulse. The two-order interference phenomenon of the signal photon in Michelson interferometer is observed and give an analysis in detail.

  7. Electron Interference in Ballistic Graphene Nanoconstrictions

    Baringhaus, Jens; Settnes, Mikkel; Aprojanz, Johannes;

    2016-01-01

    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...

  8. Interference Fragmentation Functions and the Nucleon's Transversity

    Jaffe, R. L.; Jin, Xuemin; Tang, Jian

    1997-01-01

    We introduce twist-two quark interference fragmentation functions in helicity density matrix formalism and study their physical implications. We show how the nucleon's transversity distribution can be probed through the final state interaction between two mesons ($\\pi^+\\pi^-$, $K\\bar K$, or $\\pi K$) produced in the current fragmentation region in deep inelastic scattering on a transversely polarized nucleon.

  9. Impact of MIMO Co-Channel Interference

    Rahman, Muhammad Imadur; De Carvalho, Elisabeth; Prasad, Ramjee

    2007-01-01

    In a real cellular system, existence of a number of multi-antenna schemes in neighboring cells means that different multi-antenna schemes will experience Co-Channel Interference (CCI) from the same or other multi-antenna schemes. In this work, we have summarized our analysis and simulations relat...

  10. Identical particle interference in $D^{+}$ meson lifetime

    Altarelli, Guido

    1982-01-01

    A calculation is presented of the contribution to the D^{+} non- leptonic decay rate of the interference between the active and spectator d antiquarks, relating this effect to the shape of the electron energy spectrum in D semi-leptonic decay. Predictions for the D^{+} life-time and semi-leptonic branching ratio are also derived and discussed.

  11. Neutron Interference Experiments and Quantum Measurement Theory

    Namiko, M.; Otake, Y.; Soshi, H.

    1987-03-01

    Physical and epistemological implications of recent experiments on the neutron interference are discussed from the viewpoint of the Machida-Namiki theory of measurement in quantum mechanics, without resort to discussion on the number-phase uncertainty relation. The same idea is also applied to the neutrino oscillation problem.

  12. Jam-X: Wireless Agreement under Interference

    Boano, Carlo Alberto; Zúñiga, Marco Antonio; Voigt, Thiemo

    2012-01-01

    Wireless low-power transceivers used in sensor networks such as IEEE 802.15.4 typically operate in unlicensed frequency bands that are subject to external interference from devices transmitting at much higher power. Communication protocols should therefore be designed to be robust against such interference. A critical building block of many protocols at all layers is agreement on a piece of information among a set of nodes. At the MAC layer, nodes may need to agree on a new time slot or frequency channel; at the application layer nodes may need to agree on handing over a leader role from one node to another. Message loss caused by interference may break agreement in two different ways: none of the nodes use the new information (time slot, channel, leader) and stick with the previous assignment, or - even worse - some nodes use the new information and some do not. This may lead to reduced performance or failures. In this paper we investigate the problem of agreement under interference and point out the limitat...

  13. Bacteria interfere with A-actinomycetemcomitans colonization

    Teughels, Wim; Haake, S. Kinder; Sliepen, Isabelle; Pauwels, Martine; Van Eldere, Johan; Cassiman, Jean-Jacques; Quirynen, Marc

    2007-01-01

    It is known that beneficial bacteria can suppress the emergence of pathogenic bacteria, particularly in the gastrointestinal tract. This study examined the potential for a similar suppression of Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans colonization of epithelial cells, due to its potential relevance in periodontal diseases. Seven presumed beneficial bacteria were examined for their ability to interfere, exclude, or displace A. actinomycetemcomitans from epithelial cells...

  14. Photon number conservation and photon interference

    Koniorczyk, Matyas; Janszky, Jozsef

    2001-01-01

    The group theoretical aspect of the description of passive lossless optical four-ports (beam splitters) is revisited. It is shown through an example, that this approach can be useful in understanding interferometric schemes where a low number of photons interfere. The formalism is extended to passive lossless optical six-ports, their SU(3)-theory is outlined.

  15. On optimization of interference fit assembly

    Pedersen, Niels Leergaard

    2016-01-01

    Assembly of shaft and hub by an interference fitis a classical connection with known advantages and disadvantages.The advantage being the level of possible torque transfer while the disadvantage is a possible fretting fatigue failure at the points of stress concentration. To improve the assembly ...

  16. Engine Power Effects on Support Interference

    Horsten, B.J.C.; Veldhuis, L.L.M.

    2009-01-01

    Renewed interest in propeller propulsion on aircraft configurations combined with higher propeller loads lead to the question how the effects of the propulsion on model support disturbances should be accounted for. In this paper, the determination of engine power effects on support interference of s

  17. Interference Coordination for Dense Wireless Networks

    Soret, Beatriz; Pedersen, Klaus I.; Jørgensen, Niels T.K.;

    2015-01-01

    The promise of ubiquitous and super-fast connectivity for the upcoming years will be in large part fulfilled by the addition of base stations and spectral aggregation. The resulting very dense networks (DenseNets) will face a number of technical challenges. Among others, the interference emerges as...

  18. Feshbach Resonance Induced Fano Interference in Photoassociation

    Deb, Bimalendu

    2009-01-01

    We consider photoassociation from a state of two free atoms when the continuum state is close to a magnetic field induced Feshbach resonance and demonstrate the possibility of Fano interference in photoassociation. We introduce an analog of Fano asymmetry parameter which characterizes the minimum in photoassociation profiles. We further show a nonlinear analog of Fano effect, which was recently observed in quantum dots.

  19. Phonon interference effects in molecular junctions

    Markussen, Troels

    2013-01-01

    We study coherent phonon transport through organic, p-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...

  20. Exploiting Genetic Interference for Antiviral Therapy.

    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

  1. Exploiting Genetic Interference for Antiviral Therapy.

    Elizabeth J Tanner

    2016-05-01

    Full Text Available 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.

  2. Variability of Practice and Contextual Interference in Motor Skill Learning.

    Hall, K. G.; Magill, R. A.

    1995-12-01

    The purpose of this study was to investigate whether learning benefits in multiple-task learning situations are a result of contextual interference or of schema enhancement related to the amount of variability in the practice session. Two experiments were designed that replicated and extended the experiment reported by Wulf and Schmidt (1988). In a 2 (same vs. different relative time) x 2 (blocked vs. random practice schedule) design, 48 right-handed subjects were randomly assigned to one of four experimental conditions. A tapping task was employed that required a right-handed tap of three small brass plates arranged in a diamond pattern. Each segment had a specific time requirement. Target times and response times were provided on a computer screen directly in front of the subject. Each subject participated in two acquisition sessions (i.e., 198 practice trials) and was tested for learning on several different retention and transfer tests. In Experiment 2, a control group was added that received no acquisition phase. Results of both experiments showed a typical contextual interference effect, with depressed scores by the random groups during acquisition but significantly better scores than the blocked groups on several retention and transfer tests. Certain characteristics of the tests were found to influence the demonstration of the practice schedule effects. These results were consistent with predictions from Magill and Hall (1990) that the learning benefits of contextual interference are more likely to occur when skill variations are from different classes of movement and that the amount of variability in practice is more influential when the to-be-learned tasks are parameter modifications of the same generalized motor program. PMID:12529226

  3. Interference effects of categorization on decision making.

    Wang, Zheng; Busemeyer, Jerome R

    2016-05-01

    Many decision making tasks in life involve a categorization process, but the effects of categorization on subsequent decision making has rarely been studied. This issue was explored in three experiments (N=721), in which participants were shown a face stimulus on each trial and performed variations of categorization-decision tasks. On C-D trials, they categorized the stimulus and then made an action decision; on X-D trials, they were told the category and then made an action decision; on D-alone trials, they only made an action decision. An interference effect emerged in some of the conditions, such that the probability of an action on the D-alone trials (i.e., when there was no explicit categorization before the decision) differed from the total probability of the same action on the C-D or X-D trials (i.e., when there was explicit categorization before the decision). Interference effects are important because they indicate a violation of the classical law of total probability, which is assumed by many cognitive models. Across all three experiments, a complex pattern of interference effects systematically occurred for different types of stimuli and for different types of categorization-decision tasks. These interference effects present a challenge for traditional cognitive models, such as Markov and signal detection models, but a quantum cognition model, called the belief-action entanglement (BAE) model, predicted that these results could occur. The BAE model employs the quantum principles of superposition and entanglement to explain the psychological mechanisms underlying the puzzling interference effects. The model can be applied to many important and practical categorization-decision situations in life. PMID:26896726

  4. Inkjet Color Printing by Interference Nanostructures.

    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. PMID:26805775

  5. Miniaturized superconducting quantum interference magnetometers for high sensitivity applications

    Granata, C.; Vettoliere, A.; Russo, M.

    2007-09-01

    A miniaturized niobium based dc superconducting quantum interference device (SQUID) magnetometer for high magnetic field sensitivity applications has been developed. The sensing coil consists of an integrated square superconducting coil with a length of 3mm, involving a device area much smaller with respect to the standard SQUID magnetometers with a comparable magnetic field sensitivity; so it allows increasing the spatial resolution keeping the magnetic field sensitivity unaltered. Furthermore, a small pickup coil minimizes its antenna gain, reducing the radio frequency interference. At T =4.2K, the sensors have shown smooth and resonance free V-Φ characteristics and an intrinsic white magnetic field noise spectral density as low as 5.8fT /Hz1/2, measured in flux locked loop configuration. The good agreement with the theoretical predictions guarantees the reliability and the controllability of the sensors. Due to their compactness and good characteristic parameters, such sensors are suitable for large multichannel systems used in biomagnetic imaging.

  6. Elements of Cellular Blind Interference Alignment --- Aligned Frequency Reuse, Wireless Index Coding and Interference Diversity

    Jafar, Syed A

    2012-01-01

    We explore degrees of freedom (DoF) characterizations of partially connected wireless networks, especially cellular networks, with no channel state information at the transmitters. Specifically, we introduce three fundamental elements --- aligned frequency reuse, wireless index coding and interference diversity --- through a series of examples, focusing first on infinite regular arrays, then on finite clusters with arbitrary connectivity and message sets, and finally on heterogeneous settings with asymmetric multiple antenna configurations. Aligned frequency reuse refers to the optimality of orthogonal resource allocations in many cases, but according to unconventional reuse patterns that are guided by interference alignment principles. Wireless index coding highlights both the intimate connection between the index coding problem and cellular blind interference alignment, as well as the added complexity inherent to wireless settings. Interference diversity refers to the observation that in a wireless network ...

  7. The differential interference angle in collisional quantum interference on rotational energy transfer

    Wang Wei-Li; Miao Gang; Chen Yue-Hui; Tang Dan; Ma Feng-Cai

    2008-01-01

    Collisional quantum interference (CQI) in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers.[1] The interference angle, which measuring the degree of the coherence, were measured in the experiment of the static cell. Based on the first Born approximation of time dependent perturbation theory, taking into accounts the anisotropic Lennard-Jones interaction potentials, this paper describes the theoretical model of CQI in intramolecular rotational energy transfer in an atom-diatom collision system. In the model, the differential interference angle for the experiment of the molecular beam is calculated, the changing tendencies of the differential interference angle with the impact parameter and collision partners are obtained. This theoretical model is important for understanding or performing this kind of experiments.

  8. Receive Diversity and Ergodic Performance of Interference Alignment on the MIMO Gaussian Interference Channel

    Guillaud, Maxime

    2010-01-01

    We consider interference alignment (IA) over K-user Gaussian MIMO interference channel (MIMO-IC) when the SNR is not asymptotically high. We introduce a generalization of IA which enables receive diversity inside the interference-free subspace. We generalize the existence criterion of an IA solution proposed by Yetis et al. to this case, thereby establishing a multi-user diversity-multiplexing trade-off (DMT) for the interference channel. Furthermore, we derive a closed-form tight lower-bound for the ergodic mutual information achievable using IA over a Gaussian MIMO-IC with Gaussian i.i.d. channel coefficients at arbitrary SNR, when the transmitted signals are white inside the subspace defined by IA. Finally, as an application of the previous results, we compare the performance achievable by IA at various operating points allowed by the DMT, to a recently introduced distributed method based on game theory.

  9. Feedback-Topology Designs for Interference Alignment in MIMO Interference Channels

    Cho, Sungyoon; Huang, Kaibin; Kim, Dongku; Lau, Vincent K N; Seo, Hanbyul; Kim, Byounghoon

    2011-01-01

    Interference alignment (IA) is a joint-transmission technique that achieves the capacity of the interference channel for high signal-to-noise ratios (SNRs). Most prior work on IA is based on the impractical assumption that perfect and global channel-state information(CSI) is available at all transmitters. To implement IA, each receiver has to feed back CSI to all interferers, resulting in overwhelming feedback overhead. In particular, the sum feedback rate of each receiver scales quadratically with the number of users even if the quantized CSI is fed back. To substantially suppress feedback overhead, this paper focuses on designing efficient arrangements of feedback links, called feedback topologies, under the IA constraint. For the multiple-input-multiple-output (MIMO) K-user interference channel, we propose the feedback topology that supports sequential CSI exchange (feedback and feedforward) between transmitters and receivers so as to achieve IA progressively. This feedback topology is shown to reduce the ...

  10. Interference Mitigation by Statistical Interference Modeling in an Impulse Radio UWB Receiver

    Flury, Manuel; Le Boudec, Jean-Yves

    2006-01-01

    Some impulse radio UWB (IR-UWB) networks may allow concurrent transmissions without power control (for example MAC protocols that do not use power control, or co-exisiting, non-coordinated piconets). In such cases, it has been proposed to mitigate multi-user interference (MUI) at the physical layer, but existing proposals for interference mitigation do not account for the multipath nature of UWB channels. We address this problem and propose a receiver that employs a combination of statistical...