WorldWideScience

Sample records for beacons

  1. Special Stamps:Historical Relic Beacons

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In May 2002, the State Postal Bureau issued a set of five stamps picturing historical relic beacons. They are the Mao Beacon, the Jiangxinyu Twin Beacon, the Huaniaoshan Beacon, the Laotieshan Beacon, and

  2. Auditory evacuation beacons

    NARCIS (Netherlands)

    Wijngaarden, S.J. van; Bronkhorst, A.W.; Boer, L.C.

    2005-01-01

    Auditory evacuation beacons can be used to guide people to safe exits, even when vision is totally obscured by smoke. Conventional beacons make use of modulated noise signals. Controlled evacuation experiments show that such signals require explicit instructions and are often misunderstood. A new si

  3. Molecular beacon sequence design algorithm.

    Science.gov (United States)

    Monroe, W Todd; Haselton, Frederick R

    2003-01-01

    A method based on Web-based tools is presented to design optimally functioning molecular beacons. Molecular beacons, fluorogenic hybridization probes, are a powerful tool for the rapid and specific detection of a particular nucleic acid sequence. However, their synthesis costs can be considerable. Since molecular beacon performance is based on its sequence, it is imperative to rationally design an optimal sequence before synthesis. The algorithm presented here uses simple Microsoft Excel formulas and macros to rank candidate sequences. This analysis is carried out using mfold structural predictions along with other free Web-based tools. For smaller laboratories where molecular beacons are not the focus of research, the public domain algorithm described here may be usefully employed to aid in molecular beacon design.

  4. 47 CFR 97.203 - Beacon station.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Beacon station. 97.203 Section 97.203... SERVICE Special Operations § 97.203 Beacon station. (a) Any amateur station licensed to a holder of a Technician, Technician Plus, General, Advanced or Amateur Extra Class operator license may be a beacon....

  5. Designing reduced beacon trajectory for sensor localization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Localization is one of the substantial issues in wireless sensor networks. The key problem for the mobile beacon localization is how to choose the appropriate beacon trajectory. However, little research has been done on it. In this paper, firstly,we deduce the number of positions for a beacon to send a packet according to the acreage of ROI (region of interest); and next we present a novel method based on virtual force to arrange the positions in arbitrary ROI; then we apply TSP (travelling salesman problem) algorithm to the positions sequence to obtain the optimal touring path, i.e. the reduced beacon trajectory. When a mobile beacon moves along the touring path, sending RF signals at every position, the sensors in ROI can work out their position with trilateration. Experimental results demonstrate that the localization method, based on the beacon reduced path, is efficient and has flexible accuracy.

  6. BBIS: Beacon Bus Information System

    Science.gov (United States)

    Kasim, Shahreen; Hafit, Hanayanti; Pei Juin, Kong; Afizah Afif, Zehan; Hashim, Rathiah; Ruslai, Husni; Jahidin, Kamaruzzaman; Syafwan Arshad, Mohammad

    2016-11-01

    Lack of bus information for example bus timetable, status of the bus and messy advertisement on bulletin board at the bus stop will give negative impact to tourist. Therefore, a real-time update bus information bulletin board provides all information needed so that passengers can save their bus information searching time. Supported with Android or iOS, Beacon Bus Information System (BBIS) provides bus information between Batu Pahat and Kluang area. BBIS is a system that implements physical web technology and interaction on demand. It built on Backend-as-a-Service, a cloud solution and Firebase non relational database as data persistence backend and syncs between user client in the real-time. People walk through bus stop with smart device and do not require any application. Bluetooth Beacon is used to achieve smart device's best performance of data sharing. Intellij IDEA 15 is one of the tools that that used to develop the BBIS system. Multi-language included front end and backend supported Integration development environment (IDE) helped to speed up integration process.

  7. The ANTARES optical beacon system

    Energy Technology Data Exchange (ETDEWEB)

    Ageron, M. [CPPM - Centre de Physique des Particules de Marseille, CNRS/IN2P3 et Universite de la Mediterranee, 163 Avenue de Luminy, Case 902, 13288 Marseille Cedex 9 (France); Aguilar, J.A. [IFIC - Instituto de Fisica Corpuscular, Edificios de Investigacion de Paterna, CSIC - Universitat de Valencia, Apdo. de Correos 22085, 46071 Valencia (Spain)]. E-mail: J.A.Aguilar@ific.uv.es; Albert, A. [GRPHE - Groupe de Recherche en Physique des Hautes Energies, Universite de Haute Alsace, 61 Rue Albert Camus, 68093 Mulhouse Cedex (France)) (and others)

    2007-08-11

    ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three-dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular, when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.

  8. The ANTARES Optical Beacon System

    CERN Document Server

    Ageron, M; Albert, A; Ameli, F; Anghinolfi, M; Anton, G; Anvar, S; Ardellier-Desages, F; Aslanides, E; Aubert, J J; Auer, R; Barbarito, E; Basa, S; Battaglieri, M; Becherini, Y; Beltramelli, J; Bertin, V; Bigi, A; Billault, M; Blaes, R; De Botton, N R; Bouwhuis, M C; Bradbury, S M; Bruijn, R; Brunner, J; Burgio, G F; Busto, J; Cafagna, F; Caillat, L; Calzas, A; Capone, A; Caponetto, L; Carmona, E; Carr, J; Cartwright, S L; Castel, D; Castorina, E; Cavasinni, V; Cecchini, S; Ceres, A; Charvis, P; Chauchot, P; Chiarusi, T; Circella, M; Colnard, C; Compere, C; Coniglione, R; Cottini, N; Coyle, P; Cuneo, S; Cussatlegras, A S; Damy, G; Van Dantzig, R; De Bonis, G; De Marzo, C; De Vita, R; Dekeyser, I; Delagnes, E; Denans, D; Deschamps, A; Destelle, J J; Dinkespieler, B; Distefano, C; Donzaud, C; Drogou, J F; Druillole, F; Durand, D; Ernenwein, J P; Escoffier, S; Falchini, E; Favard, S; Fehr, F; Feinstein, F; Ferry, S; Fiorello, C; Flaminio, V; Fratini, K; Fuda, J L; Galeotti, S; Gallone, J M; Giacomelli, G; Girard, N; Gojak, C; Goret, P; Graf, K; Hallewell, G; Harakeh, M N; Hartmann, B; Heijboer, A; Heine, E; Hello, Y; Hernández-Rey, J J; Hossl, J; Hoffman, C; Hogenbirk, J; Hubbard, John R; Jaquet, M; Jaspers, M; De Jong, M; Jouvenot, F; Kalantar-Nayestanaki, N; Kappes, A; Karg, T; Katz, U; Keller, P; Kok, E; Kok, H; Kooijman, P; Kopper, C; Korolkova, E V; Kouchner, A; Kretschmer, W; Kruijer, A; Kuch, S; Kudryavtsev, V A; Lagier, P; Lahmann, R; Lamanna, G; Lamare, P; Lambard, G; Languillat, J C; Laschinsky, H; Lavalle, J; Le Guen, Y; Le Provost, H; Le Van-Suu, A; Lefèvre, D; Legou, T; Lelaizant, G; Lim, G; Lo Presti, D; Löhner, H; Loucatos, Sotirios S; Louis, F; Lucarelli, F; Lyashuk, V; Marcelin, M; Margiotta, A; Masullo, R; Mazéas, F; Mazure, A; McMillan, J E; Megna, R; Melissas, M; Migneco, E; Milovanovic, A; Mongelli, M; Montaruli, T; Morganti, M; Moscoso, L; Musumeci, M; Naumann-Godo, M; Naumann, C; Niess, V; Noble, T; Olivetto, C; Ostasch, R; Palanque-Delabrouille, Nathalie; Payre, P; Peek, H; Pérez, A; Petta, C; Piattelli, P; Pillet, R; Pineau, J P; Poinsignon, J; Popa, V; Pradier, T; Racca, C; Randazzo, N; Van Randwijk, J; Real, D; Van Rens, B; Rethore, F; Rewiersma, P A M; Riccobene, G; Rigaud, V; Ripani, M; Roca, V; Roda, C; Rolin, J F; Rose, H J; Rostovtsev, A; Roux, J; Ruppi, M; Russo, G V; Rusydi, G; Salesa, F; Salomon, K; Sapienza, P; Schmitt, F; Schuller, J P; Shanidze, R; Sokalski, I A; Spona, T; Spurio, M; van der Steenhoven, G; Stolarczyk, T; Streeb, K; Sulak, L; Taiuti, M; Tamburini, C; Tao, C; Terreni, G; Thompson, L F; Urbano, F; Valdy, P; Valente, V; Vallage, B; Vaudaine, G; Venekamp, G; Verlaat, B; Vernin, P; De Vries-Uiterweerd, G; Van Wijk, R; Wijnker, G; De Witt-Huberts, P K A; Wobbe, G; De Wolf, E; Yao, A F; Zaborov, D; Zaccone, Henri; De Dios-Zornoza-Gomez, Juan; Zúñiga, J; al, et

    2007-01-01

    ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of ...

  9. Beacon data acquisition and display system

    Science.gov (United States)

    Skogmo, David G.; Black, Billy D.

    1991-01-01

    A system for transmitting aircraft beacon information received by a secondary surveillance radar through telephone lines to a remote display includes a digitizer connected to the radar for preparing a serial file of data records containing position and identification information of the beacons detected by each sweep of the radar. This information is transmitted through the telephone lines to a remote computer where it is displayed.

  10. Messaging with Cost-Optimized Interstellar Beacons

    Science.gov (United States)

    Benford, James; Benford, Gregory; Benford, Dominic

    2010-06-01

    On Earth, how would we build galactic-scale beacons to attract the attention of extraterrestrials, as some have suggested we should do? From the point of view of expense to a builder on Earth, experience shows an optimum trade-off. This emerges by minimizing the cost of producing a desired power density at long range, which determines the maximum range of detectability of a transmitted signal. We derive general relations for cost-optimal aperture and power. For linear dependence of capital cost on transmitter power and antenna area, minimum capital cost occurs when the cost is equally divided between antenna gain and radiated power. For nonlinear power-law dependence, a similar simple division occurs. This is validated in cost data for many systems; industry uses this cost optimum as a rule of thumb. Costs of pulsed cost-efficient transmitters are estimated from these relations by using current cost parameters (/W, /m2) as a basis. We show the scaling and give examples of such beacons. Galactic-scale beacons can be built for a few billion dollars with our present technology. Such beacons have narrow "searchlight" beams and short "dwell times" when the beacon would be seen by an alien observer in their sky. More-powerful beacons are more efficient and have economies of scale: cost scales only linearly with range R, not as R2, so number of stars radiated to iincreases as the square of cost. On a cost basis, they will likely transmit at higher microwave frequencies, ˜10 GHz. The natural corridor to broadcast is along the galactic radius or along the local spiral galactic arm we are in. A companion paper asks "If someone like us were to produce a beacon, how should we look for it?"

  11. Beach Advisory and Closing Online Notification (BEACON) system

    Data.gov (United States)

    U.S. Environmental Protection Agency — Beach Advisory and Closing Online Notification system (BEACON) is a colletion of state and local data reported to EPA about beach closings and advisories. BEACON is...

  12. iBeacon technology in the development of mobile applications

    OpenAIRE

    2015-01-01

    iBeacon technology, made possible by BLE, enables mobile application developers to base their applications on proximity. We would like to know how proximity can be integrated in the development of mobile applications. In the thesis we take a deeper look at iBeacon technology where monitoring and ranging are examined and the differences between location and proximity explained. Available options used for the configuration of iBeacons are also presented. Then two existing iBeacon applications a...

  13. 14 CFR 171.269 - Marker beacon performance requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Marker beacon performance requirements. 171.269 Section 171.269 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Landing System (ISMLS) § 171.269 Marker beacon performance requirements. ISMLS marker beacon...

  14. Analytically modelling the performance of piggybacking on beacons in VANETs

    NARCIS (Netherlands)

    Klein Wolterink, W.; Heijenk, G.; Berg, J.L. van den

    2012-01-01

    Piggybacking on beacons is a forwarding technique in vehicular ad-hoc networks (VANET) as a means to disseminate data. With this technique data is attached to and transmitted along with scheduled beacons. Nodes are assumed to beacon asynchronously. In this paper we present a first version of an anal

  15. An aptamer beacon responsive to botulinum toxins.

    Science.gov (United States)

    Bruno, John G; Richarte, Alicia M; Carrillo, Maria P; Edge, Allison

    2012-01-15

    Sixty candidate DNA aptamers were developed against botulinum neurotoxin (BoNT) type A light chain (LC) from ten rounds of selection, resulting in several identical sequences. Secondary structures of the identical aptamers were compared to structures of previously reported BoNT A DNA aptamers. A series of ten candidate loop structures were selected from this comparison as potential binding pockets and aptamer beacons. These candidate beacons were synthesized with 5'-TYE 665 and 3'-Iowa Black quencher labels for comparison of fluorescence levels as a function of BoNT A LC concentration. Only three of the ten candidates exhibited any fluorescence response to increasing levels of BoNT A LC. However, of the two most responsive candidates, one represented a subset loop of the larger more intensely fluorescent double-looped structure, designated Beacon 10. This beacon yielded a lower limit of detection of 1 ng/mL in buffer using a spectrofluorometer and a portable handheld fluorometer, but also responded substantially to BoNT A, B, E holotoxins and heavy or light chain components even in a dilute soil suspension, but not in 50% human serum. Beacon 10 did not respond strongly to a variety of other divergent peptides, suggesting that it is relatively specific to the level of botulinum toxins and is only useful for environmental testing. Beacon 10 also shared short sequence segments with other published BoNT aptamer DNA sequences, suggesting that these may be points of physical contact between the aptamers and BoNTs.

  16. Localization with a mobile beacon in underwater acoustic sensor networks.

    Science.gov (United States)

    Lee, Sangho; Kim, Kiseon

    2012-01-01

    Localization is one of the most important issues associated with underwater acoustic sensor networks, especially when sensor nodes are randomly deployed. Given that it is difficult to deploy beacon nodes at predetermined locations, localization schemes with a mobile beacon on the sea surface or along the planned path are inherently convenient, accurate, and energy-efficient. In this paper, we propose a new range-free Localization with a Mobile Beacon (LoMoB). The mobile beacon periodically broadcasts a beacon message containing its location. Sensor nodes are individually localized by passively receiving the beacon messages without inter-node communications. For location estimation, a set of potential locations are obtained as candidates for a node's location and then the node's location is determined through the weighted mean of all the potential locations with the weights computed based on residuals.

  17. Localization with a Mobile Beacon in Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sangho Lee

    2012-04-01

    Full Text Available Localization is one of the most important issues associated with underwater acoustic sensor networks, especially when sensor nodes are randomly deployed. Given that it is difficult to deploy beacon nodes at predetermined locations, localization schemes with a mobile beacon on the sea surface or along the planned path are inherently convenient, accurate, and energy-efficient. In this paper, we propose a new range-free Localization with a Mobile Beacon (LoMoB. The mobile beacon periodically broadcasts a beacon message containing its location. Sensor nodes are individually localized by passively receiving the beacon messages without inter-node communications. For location estimation, a set of potential locations are obtained as candidates for a node’s location and then the node’s location is determined through the weighted mean of all the potential locations with the weights computed based on residuals.

  18. Validation of the Calypso Surface Beacon Transponder.

    Science.gov (United States)

    Belanger, Maxwell; Saleh, Ziad; Volpe, Tom; Margiasso, Rich; Li, Xiang; Chan, Maria; Zhu, Xiaofeng; Tang, Xiaoli

    2016-07-08

    Calypso L-shaped Surface Beacon transponder has recently become available for clinical applications. We herein conduct studies to validate the Surface Beacon transponder in terms of stability, reproducibility, orientation sensitivity, cycle rate dependence, and respiratory waveform tracking accuracy. The Surface Beacon was placed on a Quasar respiratory phantom and positioned at the isocenter with its two arms aligned with the lasers. Breathing waveforms were simulated, and the motion of the transponder was tracked. Stability and drift analysis: sinusoidal waveforms (200 cycles) were produced, and the amplitudes of phases 0% (inhale) and 50% (exhale) were recorded at each breathing cycle. The mean and standard deviation (SD) of the amplitudes were calculated. Linear least-squares fitting was performed to access the possible amplitude drift over the breathing cycles. Reproducibility: similar setting to stability and drift analysis, and the phantom generated 100 cycles of the sinusoidal waveform per run. The Calypso system's was re-setup for each run. Recorded amplitude and SD of 0% and 50% phase were compared between runs to assess contribution of Calypso electromagnetic array setup variation. Beacon orientation sensitivity: the Calypso tracks sinusoidal phantom motion with a defined angular offset of the beacon to assess its effect on SD and peak-to-peak amplitude. Rate dependence: sinusoidal motion was generated at cycle rates of 1 Hz, .33 Hz, and .2 Hz. Peak-to-peak displacement and SDs were assessed. Respiratory waveform tracking accuracy: the phantom reproduced recorded breathing cycles (by volunteers and patients) were tracked by the Calypso system. Deviation in tracking position from produced waveform was used to calculate SD throughout entire breathing cycle. Stability and drift analysis: Mean amplitude ± SD of phase 0% or 50% were 20.01 ± 0.04 mm and -19.65 ± 0.08 mm, respectively. No clinically significant drift was detected with drift measured as 5.1

  19. Decimal Integer Multiplication based on Molecular Beacons

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2013-12-01

    Full Text Available Due to the enhancement of circuit integration level, and the accelerating of working frequency of traditional computer, it requires components dimension must be constantly decreased. So encapsulation, etching and other problems of chip are becoming more and more difficult to solve, which causes its performance also become unstable. In order to overcome this problem, DNA computing as a new kind of molecular computing mode, with its high parallelism, huge amounts of storage capacity, low energy consumption advantages has received extensive attention. Being the same with traditional electronic computer, DNA computer is composed by arithmetic operations such as addition, subtraction, multiplication and dividing and basic logic units such as AND, OR, NON gate. This paper puts forward a new method to realize decimal integer multiplication based on molecular beacons. The algorithm firstly converts decimal integer to binary number, and then resolves the multiplication process into multiplication of current bit and addition of intermediate result after shifting two steps. Molecular beacon is used as multiplying unit, coding sequence is used as multiplier in this method. Based on the working principle of molecular beacon, multiplication operation of two one-bit binary is simulated. And by recording fluorescence status of molecular beacon to observe intermediate result and carry-bit situation, the final result can be obtained through addition after shifting. Examples prove that this method can realize decimal integer multiplication rapidly and accurately. This method is similar to multiplication system in traditional electronic computer, and it provides a simple, easier operation method for DNA computer to realize arithmetic operation.

  20. Indoor location estimation using radio beacons

    Science.gov (United States)

    Ahmad, Uzair; Lee, Young-Koo; Lee, Sungyoug; Park, Chongkug

    2007-12-01

    We present a simple location estimation method for developing radio beacon based location system in the indoor environments. It employs an online learning approach for making large scale location systems in a short time collaboratively. The salient features of our method are low memory requirements and simple computations which make it suitable for both distributed location-aware applications based on client-server model as well as privacy sensitive applications residing on stand alone devices.

  1. Development of a universal RNA beacon for exogenous gene detection.

    Science.gov (United States)

    Guo, Yuanjian; Lu, Zhongju; Cohen, Ira Stephen; Scarlata, Suzanne

    2015-05-01

    Stem cell therapy requires a nontoxic and high-throughput method to achieve a pure cell population to prevent teratomas that can occur if even one cell in the implant has not been transformed. A promising method to detect and separate cells expressing a particular gene is RNA beacon technology. However, developing a successful, specific beacon to a particular transfected gene can take months to develop and in some cases is impossible. Here, we report on an off-the-shelf universal beacon that decreases the time and cost of applying beacon technology to select any living cell population transfected with an exogenous gene.

  2. Beacons In Brief. P/PV In Brief. Issue 2

    Science.gov (United States)

    Blank, Susan; Farley, Chelsea

    2004-01-01

    This second issue in P/PV's "In Brief" series focuses on the San Francisco Beacon Initiative and P/PV's recently released evaluation results. The Beacon Initiative established after-school programs in eight public schools in low-income San Francisco neighborhoods. P/PV's 36-month evaluation examined key developmental and academic outcomes.…

  3. Diagnosis of Neisseria gonorrhoeae Using Molecular Beacon

    Directory of Open Access Journals (Sweden)

    Divya Sachdev

    2015-01-01

    Full Text Available Neisseria gonorrhoeae is an important sexually transmitted diseases (STD causing pathogen worldwide. Due to absence of an affordable diagnostic assay, routine screening of gonococcal infection becomes impossible in developing countries where infection rates are maximum. Treatment is given on the basis of symptoms alone which leads to spread of infection. Thus, development of a rapid, sensitive, specific, and PCR based visual diagnostic assay suitable for developing countries, required for better disease management, is aimed at in present study. Endocervical swabs were collected from patients visiting gynecology department of various hospitals in Delhi. In-house PCR based assay was developed and modified to visual assay using molecular beacon for end-point detection. It was evaluated against Roche AMPLICOR NG kit and rmp gene. Specificity of beacon was confirmed by competition experiments. Diagnostic test was 98.21% specific and 99.59% sensitive whereas negative and positive predicted value were 99.40% and 98.78%, respectively. We also observed that twice the concentration (2X of premix was stable at 4°C for 4 months and dry swab samples gave concordant results with that of wet swabs. These features make the test best suitable for routine diagnosis of genital infections in developing countries.

  4. Molecular Beacon-Based MicroRNA Imaging During Neurogenesis.

    Science.gov (United States)

    Lee, Jonghwan; Kim, Soonhag

    2016-01-01

    The fluorescence monitoring system for examining endogenous microRNA (miRNA) activity in cellular level provides crucial information on not only understanding a critical role of miRNA involving a variety of biological processes, but also evaluating miRNA expression patterns in a noninvasive manner. In this protocol, we report the details of a new procedure for a molecular beacon-based miRNA monitoring system, which includes the illustration scheme for miRNA detection strategy, exogenous miRNA detection, and measurement of endogenous miRNA expression level during neurogenesis. The fluorescence signal of miR-124a beacon quenched by BHQ2 was gradually recovered as increasing concentration of the miR-124a in tube. The functional work of miR-124a beacon was examined in intracellular environment, allowing for the internalization of the miR-124a beacon by lipofectamine, which resulted in activated fluorescent signals of the miR-124a beacon in the HeLa cells after the addition of synthetic miR-124a. The endogenous miR-124a expression level was detected by miR-124a beacon system during neurogenesis, showing brighter fluorescence intensity in cytoplasmic area of P19 cells after induction of neuronal differentiation by retinoic acid. The molecular beacon based-miRNA detection technique could be applicable to the simultaneous visualization of a variety of miRNA expression patterns using different fluorescence dyes. For the study of examining endogenous miRNA expression level using miRNA-beacon system, if cellular differentiation step is already prepared, transfection step of miR-124a beacon into P19 cells, and acquisition of activated fluorescence signal measured by confocal microscope can be conducted approximately within 6 h.

  5. Modeling DNA beacons at the mesoscopic scale

    CERN Document Server

    Errami, Jalal; Theodorakopoulos, Nikos

    2007-01-01

    We report model calculations on DNA single strands which describe the equilibrium dynamics and kinetics of hairpin formation and melting. Modeling is at the level of single bases. Strand rigidity is described in terms of simple polymer models; alternative calculations performed using the freely rotating chain and the discrete Kratky-Porod models are reported. Stem formation is modeled according to the Peyrard-Bishop-Dauxois Hamiltonian. The kinetics of opening and closing is described in terms of a diffusion-controlled motion in an effective free energy landscape. Melting profiles, dependence of melting temperature on loop length, and kinetic time scales are in semiquantitative agreement with experimental data obtained from fluorescent DNA beacons forming poly(T) loops. Variation in strand rigidity is not sufficient to account for the large activation enthalpy of closing and the strong loop length dependence observed in hairpins forming poly(A) loops. Implications for modeling single strands of DNA or RNA are...

  6. Complementary terrain/single beacon-based AUV navigation

    Digital Repository Service at National Institute of Oceanography (India)

    Maurya, P.; Curado, T.F.; António, P.

    This paper describes work done towards the development of advanced geophysical-based navigation systems for autonomous underwater vehicles (AUVs). The specific problem that we tackle is that of combining terrain-aided navigation (TAN) with single-beacon...

  7. Beacon-Less Geographic Routing in Real Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    Juan A. Sánchez; Rafael Marín-Pérez; Pedro M. Ruiz

    2008-01-01

    Geographic Routing (GR) algorithms require nodes to periodically transmit HELLO messages to allow neigh-bors to know their positions (beaconing mechanism). Beacon-less routing algorithms have recently been proposed to reduce the control overheads due to these messages. However, existing beacon-less algorithms have not considered realistic physical layers. Therefore, those algorithms cannot work properly in realistic scenarios. In this paper we present a new beacon-less routing protocol called BOSS. Its design is based on the conclusions of our open-field experiments using Tmote-sky sensors. BOSS is adapted to error-prone networks and incorporates a new mechanism to reduce collisions and duplicate messages produced during the selection of the next forwarder node. We compare BOSS with Beacon-Less Routing (BLR)and Contention-Based Forwarding (CBF) algorithms through extensive simulations. The results show that our scheme is able to achieve almost perfect packet delivery ratio (like BLR) while having a low bandwidth consumption (even lower than CBF). Additionally, we carried out an empirical evaluation in a real testbed that shows the correctness of our simulation results.

  8. 14 CFR 171.321 - DME and marker beacon performance requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false DME and marker beacon performance... (MLS) § 171.321 DME and marker beacon performance requirements. (a) The DME equipment must meet the..._regulations/ibr_locations.html. (b) MLS marker beacon equipment must meet the performance...

  9. 76 FR 65216 - Beacon Medical Services, LLC, Aurora, CO; Notice of Negative Determination Regarding Application...

    Science.gov (United States)

    2011-10-20

    ... (76 FR 40401). The workers of Beacon Medical Services are engaged in activities related ] to the... Employment and Training Administration Beacon Medical Services, LLC, Aurora, CO; Notice of Negative... apply for Trade Adjustment Assistance (TAA) applicable to workers and former workers of Beacon...

  10. 76 FR 17625 - Proposed Information Collection; Comment Request; Emergency Beacon Registrations

    Science.gov (United States)

    2011-03-30

    ... Beacon Registrations AGENCY: National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION... ships, aircraft, or individuals in distress if they are equipped with an emergency radio beacon. Persons purchasing a digital distress beacon, operating in the frequency range of 406.000 to 406.100 MHz,...

  11. 33 CFR 149.535 - What are the requirements for rotating beacons on platforms?

    Science.gov (United States)

    2010-07-01

    ... rotating beacons on platforms? 149.535 Section 149.535 Navigation and Navigable Waters COAST GUARD... EQUIPMENT Aids to Navigation Lights on Platforms § 149.535 What are the requirements for rotating beacons on... rotating beacon that distinguishes the deepwater port from other surrounding offshore structures....

  12. 33 CFR 149.580 - What are the requirements for a radar beacon?

    Science.gov (United States)

    2010-07-01

    ... radar beacon? 149.580 Section 149.580 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Navigation Miscellaneous § 149.580 What are the requirements for a radar beacon? (a) A radar beacon (RACON... Morse code character, the length of which does not exceed 25 percent of the radar range expected to...

  13. Information Dissemination in VANETS by Piggybacking on Beacons - An Analysis of the Impact of Network Parameters

    NARCIS (Netherlands)

    Klein Wolterink, W.; Heijenk, G.J.; Karagiannis, G.

    2011-01-01

    Piggybacking on beacons is a forwarding technique that is regularly used in vehicular ad-hoc network (VANET) research as a means to disseminate data. With this technique data is attached to and transmitted along with scheduled beacons, without changing the timing of the beacons. In this paper we eva

  14. A Place To Grow: Evaluation of the New York City Beacons. Summary Report.

    Science.gov (United States)

    Warren, Constancia; Feist, Michelle; Nevarez, Nancy

    This study examined six Beacon centers, which are community centers located in public school buildings that offer a range of activities and services to participants of all ages, before and after school, in the evenings, and on weekends. Individual Beacons are managed by community-based organizations. The study examined how the Beacons provided…

  15. 78 FR 75392 - American Beacon Funds, et al.; Notice of Application

    Science.gov (United States)

    2013-12-11

    ...-Advised Fund as follows: (a) American Beacon Acadian Emerging Markets Managed Volatility Fund-- Acadian...--Bridgeway Capital Management, Inc.; (d) American Beacon Earnest Partners Emerging Markets Equity Fund--EARNEST Partners, LLC; (e) American Beacon Emerging Markets Fund--Brandes Investment Partners, LP,...

  16. New frontiers of molecular beacons: signal amplification and nanomachines

    DEFF Research Database (Denmark)

    Della Vedova, Paolo

    2013-01-01

    Gene expression is the process in which information stored into a gene is used to create a functional gene product, for example a protein or a functional RNA. Gene expression is used by all living organism to control cell life, differentiation, regeneration and cancer genesis. Molecular beacons...... provide a useful way to detect gene expression inside living cells without influencing the cell behavior. Molecular beacons are a particular kind of nucleic acid based probes composed by an oligonucleotide chain which assumes a hairpin configuration, encoding the target sequence of interest (loop) flanked...... section gives initially an overview of the molecular beacon technology usability and working principle. Later on the mechanism of molecular beacon’s internalization by SLO treatment was theoretically and experimentally investigated to determine optimal transfection condition and actual cell loading...

  17. Protein analysis based on molecular beacon probes and biofunctionalized nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With the completion of the human genome-sequencing project, there has been a resulting change in the focus of studies from genomics to proteomics. By utilizing the inherent advantages of molecular beacon probes and biofunctionalized nanoparticles, a series of novel principles, methods and techniques have been exploited for bioanalytical and biomedical studies. This review mainly discusses the applications of molecular beacon probes and biofunctionalized nanoparticles-based technologies for realtime, in-situ, highly sensitive and highly selective protein analysis, including the nonspecific or specific protein detection and separation, protein/DNA interaction studies, cell surface protein recognition, and antigen-antibody binding process-based bacteria assays. The introduction of molecular beacon probes and biofunctionalized nanoparticles into the protein analysis area would necessarily advance the proteomics research.

  18. Distributed localization using mobile beacons in wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    KUANG Xing-hong; SHAO Hui-he

    2007-01-01

    A new distributed node localization algorithm named mobile beacons-improved particle filter (MB-IPF) was proposed. In the algorithm, the mobile nodes equipped with globe position system (GPS) move around in the wireless sensor network (WSN) field based on the Gauss-Markov mobility model, and periodically broadcast the beacon messages. Each unknown node estimates its location in a fully distributed mode based on the received mobile beacons. The localization algorithm is based on the IPF and several refinements, including the proposed weighted centroid algorithm, the residual resampling algorithm, and the markov chain monte carlo (MCMC) method etc., which were also introduced for performance improvement. The simulation results show that our proposed algorithm is efficient for most applications.

  19. Exploring the transformative potential of Bluetooth beacons in higher education

    Directory of Open Access Journals (Sweden)

    Kieran McDonald

    2016-11-01

    Full Text Available The growing ubiquity of smartphones and tablet devices integrated into personal, social and professional life, facilitated by expansive communication networks globally, has the potential to disrupt higher education. Academics and students are considering the future possibilities of exploiting these tools and utilising networks to consolidate and expand knowledge, enhancing learning gain. Bluetooth beacon technology has been developed by both Apple and Google as a way to situate digital information within physical spaces, and this paper reflects on a beacon intervention in a contemporary art school in higher education conducted by the authors intended to develop a situated community of practice in Art & Design. The paper describes the project, including relevant theoretical foundations and background to the beacon technology, with regards to the potential of using these devices to create a connected learning community by enhancing learning and facilitating knowledge creation in a borderless learning space.

  20. Frequency Estimator Performance for a Software-Based Beacon Receiver

    Science.gov (United States)

    Zemba, Michael J.; Morse, Jacquelynne Rose; Nessel, James A.; Miranda, Felix

    2014-01-01

    As propagation terminals have evolved, their design has trended more toward a software-based approach that facilitates convenient adjustment and customization of the receiver algorithms. One potential improvement is the implementation of a frequency estimation algorithm, through which the primary frequency component of the received signal can be estimated with a much greater resolution than with a simple peak search of the FFT spectrum. To select an estimator for usage in a QV-band beacon receiver, analysis of six frequency estimators was conducted to characterize their effectiveness as they relate to beacon receiver design.

  1. Omnidirectional beacon-localization using a catadioptric system.

    Science.gov (United States)

    Shen, Thomas C; Drost, Robert J; Sadler, Brian M; Rzasa, John R; Davis, Christopher C

    2016-04-01

    We present a catadioptric beacon localization system that can provide mobile network nodes with omnidirectional situational awareness of neighboring nodes. In this system, a receiver composed of a hyperboloidal mirror and camera is used to estimate the azimuth, elevation, and range of an LED beacon. We provide a general framework for understanding the propagation of error in the angle-of-arrival estimation and then present an experimental realization of such a system. The situational awareness provided by the proposed system can enable the alignment of communication nodes in an optical wireless network, which may be particularly useful in addressing RF-denied environments.

  2. BEACON SYNCHRONIZATION TECHNOLOGY FOR “BEIDOU” TERRESTRIAL IMPROVEMENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WEIJin-chen; TANGJi-qiang; SHENFeng

    2005-01-01

    Synchronization is an essential technology in the radio navigation system. The technique for improving the “Beidou” positioning ability is presented through constituting the terrestrial improvement system, and the beacon synchronization of the improvement system with the “Beidou” one-way time transfer model is realized.The direct digital synthesis (DDS) is adopted to generate the pseudo-random code clock having high precision and stability. Meanwhile, the CPLD device is used to design the synchronization pulse picking-up module, the spread spectrum PN code generator and the spread spectrum modulator. Measurement results indicate that the beacon synchronization has the high precision and the stability.

  3. Optimalization of Beacon Selection for Localization in Wireless AD-HOC Networks

    Directory of Open Access Journals (Sweden)

    Martin Matula

    2008-01-01

    Full Text Available In this paper we engage in optimalization of convenient beacons for localization position of a node in the ad-hoc network. An algorithm designed by us localizes position of moving or static node by RSS (Received Signal Strength method and trilateration. At first, localization of unknown node runs by combination of all beacons. Than optimalizating algorithmreduces the number of beacons (and repeats localization, while only three left. Its reduction is based on highest levels of received signal strength. It is only when signals are from the nearest beacons. Position localizating exactness is statistically interpreted from all localization by beacons combination and its repeating.

  4. mRNA detection in living cell using phosphorothioate-modified molecular beacon

    Institute of Scientific and Technical Information of China (English)

    TANG HongXing; YANG XiaoHai; WANG KeMin; TAN WeiHong; LI Wei

    2009-01-01

    In this study, GFP mRNA in COS-7 cell and GFP-transfected COS-7 cell was detected in real time using phosphorothioate-modified molecular beacon based on living cell imaging method. Results showed that phosphorothioate-modified molecular beacon still kept the advantages of molecular beacon, such as, excellent selectivity, high sensitivity, and no separation detection. In addition, this modification could significantly increase the nuclease resistance of molecular beacon. Phosphorothioate-modified molecular beacon can efficiently reduce the false positive signal and improve the accuracy of living cell mRNA detection.

  5. Evolution of stratospheric chemistry in the Saturn storm beacon region

    Science.gov (United States)

    Moses, Julianne I.; Armstrong, Eleanor S.; Fletcher, Leigh N.; Friedson, A. James; Irwin, Patrick G. J.; Sinclair, James A.; Hesman, Brigette E.

    2015-11-01

    The giant northern-hemisphere storm that erupted on Saturn in December 2010 triggered significant changes in stratospheric temperatures and species abundances that persisted for more than a year after the original outburst. The stratospheric regions affected by the storm have been nicknamed "beacons" due to their prominent infrared-emission signatures (Fletcher, L.N. et al. [2011]. Science 332, 1413). The two beacon regions that were present initially merged in April 2011 to form a single, large, anticyclonic vortex (Fletcher, L.N. et al. [2012]. Icarus 221, 560). We model the expected photochemical evolution of the stratospheric constituents in the beacons from the initial storm onset through the merger and on out to March 2012. The results are compared with longitudinally resolved Cassini/CIRS spectra from May 2011. If we ignore potential changes due to vertical winds within the beacon, we find that C2H2, C2H6, and C3H8 remain unaffected by the increased stratospheric temperatures in the beacon, the abundance of the shorter-lived CH3C2H decreases, and the abundance of C2H4 increases significantly due to the elevated temperatures, the latter most notably in a secondary mixing-ratio peak located near mbar pressures. The C4H2 abundance in the model decreases by a factor of a few in the 0.01-10 mbar region but has a significant increase in the 10-30 mbar region due to evaporation of the previously condensed phase. The column abundances of C6H6 and H2O above ∼30 mbar also increase due to aerosol evaporation. Model-data comparisons show that models that consider temperature changes alone underpredict the abundance of C2Hx species by a factor of 2-7 in the beacon core in May 2011, suggesting that other processes not considered by the models, such as downwelling winds in the vortex, are affecting the species profiles. Additional calculations indicate that downwelling winds of order - 10 cm s-1 near ∼0.1 mbar need to be included in the photochemical models in order to

  6. Overshadowing of geometric cues by a beacon in a spatial navigation task.

    Science.gov (United States)

    Redhead, Edward S; Hamilton, Derek A; Parker, Matthew O; Chan, Wai; Allison, Craig

    2013-06-01

    In three experiments, we examined whether overshadowing of geometric cues by a discrete landmark (beacon) is due to the relative saliences of the cues. Using a virtual water maze task, human participants were required to locate a platform marked by a beacon in a distinctively shaped pool. In Experiment 1, the beacon overshadowed geometric cues in a trapezium, but not in an isosceles triangle. The longer escape latencies during acquisition in the trapezium control group with no beacon suggest that the geometric cues in the trapezium were less salient than those in the triangle. In Experiment 2, we evaluated whether generalization decrement, caused by the removal of the beacon at test, could account for overshadowing. An additional beacon was placed in an alternative corner. For the control groups, the beacons were identical; for the overshadow groups, they were visually unique. Overshadowing was again found in the trapezium. In Experiment 3, we tested whether the absence of overshadowing in the triangle was due to the geometric cues being more salient than the beacon. Following training, the beacon was relocated to a different corner. Participants approached the beacon rather than the trained platform corner, suggesting that the beacon was more salient. These results suggest that associative processes do not fully explain cue competition in the spatial domain.

  7. Exploration of Adaptive Beaconing for Efficient Intervehicle Safety Communication

    NARCIS (Netherlands)

    Schmidt, Robert K.; Leinmüller, Tim; Schoch, Elmar; Kargl, Frank; Schäfer, Günther

    2010-01-01

    In the future intervehicle communication will make driving safer, easier, and more comfortable. As a cornerstone of the system, vehicles need to be aware of other vehicles in the vicinity. This cooperative awareness is achieved by beaconing, the exchange of periodic single-hop broadcast messages tha

  8. Remarks on the observability of single beacon underwater navigation

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Ross, Andrew

    This paper contributes a simple and intuitive result in the analysis of underwater navigation using a single ranging beacon. This analysis should help with the design of small and lightweight underwater vehicles by reducing the amount of instrumentation required for accurate navigation. The concept...

  9. The morpholino molecular beacon for specific RNA visualization in vivo.

    Science.gov (United States)

    Chen, Jianbin; Wu, Jikui; Hong, Yunhan

    2016-02-21

    A non-invasive fluorescent probe, morpholino molecular beacon (MO-MB), was designed for RNA visualization in vivo. Featuring negligible toxicity, stability, and high target specificity in living embryos, MO-MB is superior to conventional probes and has the potential for specific RNA visualization in basic biological and clinical research.

  10. Smartphone-Based Indoor Localization with Bluetooth Low Energy Beacons

    Directory of Open Access Journals (Sweden)

    Yuan Zhuang

    2016-04-01

    Full Text Available Indoor wireless localization using Bluetooth Low Energy (BLE beacons has attracted considerable attention after the release of the BLE protocol. In this paper, we propose an algorithm that uses the combination of channel-separate polynomial regression model (PRM, channel-separate fingerprinting (FP, outlier detection and extended Kalman filtering (EKF for smartphone-based indoor localization with BLE beacons. The proposed algorithm uses FP and PRM to estimate the target’s location and the distances between the target and BLE beacons respectively. We compare the performance of distance estimation that uses separate PRM for three advertisement channels (i.e., the separate strategy with that use an aggregate PRM generated through the combination of information from all channels (i.e., the aggregate strategy. The performance of FP-based location estimation results of the separate strategy and the aggregate strategy are also compared. It was found that the separate strategy can provide higher accuracy; thus, it is preferred to adopt PRM and FP for each BLE advertisement channel separately. Furthermore, to enhance the robustness of the algorithm, a two-level outlier detection mechanism is designed. Distance and location estimates obtained from PRM and FP are passed to the first outlier detection to generate improved distance estimates for the EKF. After the EKF process, the second outlier detection algorithm based on statistical testing is further performed to remove the outliers. The proposed algorithm was evaluated by various field experiments. Results show that the proposed algorithm achieved the accuracy of <2.56 m at 90% of the time with dense deployment of BLE beacons (1 beacon per 9 m, which performs 35.82% better than <3.99 m from the Propagation Model (PM + EKF algorithm and 15.77% more accurate than <3.04 m from the FP + EKF algorithm. With sparse deployment (1 beacon per 18 m, the proposed algorithm achieves the accuracies of <3.88 m at

  11. BEACON: automated tool for Bacterial GEnome Annotation ComparisON

    KAUST Repository

    Kalkatawi, Manal Matoq Saeed

    2015-08-18

    Background Genome annotation is one way of summarizing the existing knowledge about genomic characteristics of an organism. There has been an increased interest during the last several decades in computer-based structural and functional genome annotation. Many methods for this purpose have been developed for eukaryotes and prokaryotes. Our study focuses on comparison of functional annotations of prokaryotic genomes. To the best of our knowledge there is no fully automated system for detailed comparison of functional genome annotations generated by different annotation methods (AMs). Results The presence of many AMs and development of new ones introduce needs to: a/ compare different annotations for a single genome, and b/ generate annotation by combining individual ones. To address these issues we developed an Automated Tool for Bacterial GEnome Annotation ComparisON (BEACON) that benefits both AM developers and annotation analysers. BEACON provides detailed comparison of gene function annotations of prokaryotic genomes obtained by different AMs and generates extended annotations through combination of individual ones. For the illustration of BEACON’s utility, we provide a comparison analysis of multiple different annotations generated for four genomes and show on these examples that the extended annotation can increase the number of genes annotated by putative functions up to 27 %, while the number of genes without any function assignment is reduced. Conclusions We developed BEACON, a fast tool for an automated and a systematic comparison of different annotations of single genomes. The extended annotation assigns putative functions to many genes with unknown functions. BEACON is available under GNU General Public License version 3.0 and is accessible at: http://www.cbrc.kaust.edu.sa/BEACON/

  12. Single and multiple molecular beacon probes for DNA hybridization studies on a silica glass surface

    Science.gov (United States)

    Fang, Xiaohong; Liu, Xiaojing; Tan, Weihong

    1999-05-01

    Surface immobilizable molecular beacons have been developed for DNA hybridization studies on a silica glass plate. Molecular beacons are a new class of oligonucleotide probes that have a loop-and-stem structure with a fluorophore and a quencher attached to the two ends of the stem. They only emit intense fluorescence when hybridize to their target molecules. This provides an excellent selectivity for the detection of DNA molecules. We have designed biotinylated molecular beacons which can be immobilized onto a solid surface. The molecular beacon is synthesized using DABCYL as the quencher and an optical stable dye, tetramethylrhodamine, as the fluorophore. Mass spectrometry is used to confirm the synthesized molecular beacon. The molecular beacons have been immobilized onto a silica surface through biotin-avidin binding. The surface immobilized molecular beacons have been used for the detection of target DNA with subnanomolar analytical sensitivity. have also immobilized two different molecular beacons on a silica surface in spatially resolved microscopic regions. The hybridization study of these two different molecular beacon probes has shown excellent selectivity for their target sequences. The newly designed molecular beacons are intended for DNA molecular interaction studies at an interface and for the development of ultrasensitive DNA sensors for a variety of applications including disease diagnosis, disease mechanism studies, new drug development, and in the investigation of molecular interactions between DNA molecules and other interesting biomolecules.

  13. iBeacon-perustaiset maamerkit sisätilapaikannuksessa

    OpenAIRE

    2015-01-01

    Tämän opinnäytetyön aihe saatiin HAMKin Älykkäät palvelut MATEC-tutkimusryhmästä. MATECssa on käynnissä koko vuoden kestävä projekti, Itsenäistä liikkumista sujuvoittavat iBeacon-tienlöytämisratkaisut (ILSI), minkä osana tämä työ toteutettiin. Projektissa haettiin mahdollisia ratkaisu-ja, käyttäen iBeacon-teknologiaa, jonka avulla voidaan helpottaa sokeiden ihmisten itsenäistä selviytymistä erilaisissa sisätilaympäristöissä. Työn tarkoituksena oli luoda älypuhelinsovellus Applen iOS-alust...

  14. Q-Band (37 to 41 GHz) Satellite Beacon Architecture for RF Propagation Experiments

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    In this paper, the design of a beacon transmitter that will be flown as a hosted payload on a geostationary satellite to enable propagation experiments at Q-band (37 to 41 GHz) frequencies is presented. The beacon uses a phased locked loop stabilized dielectric resonator oscillator and a solid-state power amplifier to achieve the desired output power. The satellite beacon antenna is configured as an offset-fed cutparaboloidal reflector.

  15. Q-Band (37-41 GHz) Satellite Beacon Architecture for RF Propagation Experiments

    Science.gov (United States)

    Simmons, Rainee N.; Wintucky, Edwin G.

    2012-01-01

    In this paper, the design of a beacon transmitter that will be flown as a hosted payload on a geostationary satellite to enable propagation experiments at Q-band (37-41 GHz) frequencies is presented. The beacon uses a phased locked loop stabilized dielectric resonator oscillator and a solid-state power amplifier to achieve the desired output power. The satellite beacon antenna is configured as an offset-fed cut-paraboloidal reflector.

  16. SU-E-J-257: Image Artifacts Caused by Implanted Calypso Beacons in MRI Studies

    Energy Technology Data Exchange (ETDEWEB)

    Amro, H; Chetty, I; Gordon, J; Wen, N [Henry Ford Health System, Detroit, MI (United States)

    2014-06-01

    Purpose: The presence of Calypso Beacon-transponders in patients can cause artifacts during MRI imaging studies. This could be a problem for post-treatment follow up of cancer patients using MRI studies to evaluate metastasis and for functional imaging studies.This work assesses (1) the volume immediately surrounding the transponders that will not be visualized by the MRI due to the beacons, and (2) the dependence of the non-visualized volume on beacon orientation, and scanning techniques. Methods: Two phantoms were used in this study (1) water filled box, (2) and a 2300 cc block of pork meat. Calypso beacons were implanted in the phantoms both in parallel and perpendicular orientations with respect to the MR scanner magnetic field. MR image series of the phantom were obtained with on a 1.0T high field open MR-SIM with multiple pulse sequences, for example, T1-weighted fast field echo and T2-weighted turbo spin echo. Results: On average, a no-signal region with 2 cm radius and 3 cm length was measured. Image artifacts are more significant when beacons are placed parallel to scanner magnetic field; the no-signal area around the beacon was about 0.5 cm larger in orthogonal orientation. The no-signal region surrounding the beacons slightly varies in dimension for the different pulse sequences. Conclusion: The use of Calypso beacons can prohibit the use of MRI studies in post-treatment assessments, especially in the immediate region surrounding the implanted beacon. A characterization of the MR scanner by identifying the no-signal regions due to implanted beacons is essential. This may render the use of Calypso beacons useful for some cases and give the treating physician a chance to identify those patients prior to beacon implantation.

  17. Smartphone-Based Indoor Localization with Bluetooth Low Energy Beacons.

    Science.gov (United States)

    Zhuang, Yuan; Yang, Jun; Li, You; Qi, Longning; El-Sheimy, Naser

    2016-04-26

    Indoor wireless localization using Bluetooth Low Energy (BLE) beacons has attracted considerable attention after the release of the BLE protocol. In this paper, we propose an algorithm that uses the combination of channel-separate polynomial regression model (PRM), channel-separate fingerprinting (FP), outlier detection and extended Kalman filtering (EKF) for smartphone-based indoor localization with BLE beacons. The proposed algorithm uses FP and PRM to estimate the target's location and the distances between the target and BLE beacons respectively. We compare the performance of distance estimation that uses separate PRM for three advertisement channels (i.e., the separate strategy) with that use an aggregate PRM generated through the combination of information from all channels (i.e., the aggregate strategy). The performance of FP-based location estimation results of the separate strategy and the aggregate strategy are also compared. It was found that the separate strategy can provide higher accuracy; thus, it is preferred to adopt PRM and FP for each BLE advertisement channel separately. Furthermore, to enhance the robustness of the algorithm, a two-level outlier detection mechanism is designed. Distance and location estimates obtained from PRM and FP are passed to the first outlier detection to generate improved distance estimates for the EKF. After the EKF process, the second outlier detection algorithm based on statistical testing is further performed to remove the outliers. The proposed algorithm was evaluated by various field experiments. Results show that the proposed algorithm achieved the accuracy of localization accuracy in environments with sparse beacon deployment.

  18. Rayleigh beacon for measuring the surface profile of a radio telescope.

    Science.gov (United States)

    Padin, S

    2014-12-01

    Millimeter-wavelength Rayleigh scattering from water droplets in a cloud is proposed as a means of generating a bright beacon for measuring the surface profile of a radio telescope. A λ=3  mm transmitter, with an output power of a few watts, illuminating a stratiform cloud, can generate a beacon with the same flux as Mars in 10 GHz bandwidth, but the beacon has a narrow line width, so it is extremely bright. The key advantage of the beacon is that it can be used at any time, and positioned anywhere in the sky, as long as there are clouds.

  19. Cyclostationary Beacon for Assisting Spectrum Sensing in Opportunistic Spectrum Access

    Directory of Open Access Journals (Sweden)

    Thomas Kaiser

    2011-03-01

    Full Text Available Cognitive radio is a promising solution to the problem of spectrum scarcity by means of allowing secondary radio networks access the spectrum opportunistically. One of the most important issues in cognitive radio is how to detect existing over-the-air signals reliably. Not a few literatures have reported that signals could be detected via their inherent or embedded properties. However, this approach may not be reliable and flexible enough for all kinds of signals with different modulation types. In this paper, we propose a type of multitone beacon signal carrying cyclostationary signatures, which is able to enhance the reliability and efficiency of signal detection at low cost of spectrum overhead. This beacon not only can indicate the presence or absence of user signal but also can reveal some other information helpful to opportunistic spectrum access through the information bits carried on its cyclostationary signatures. It could be applied to device/network identification, indication of spectrum allocation and spectrum rendezvous, both for primary and secondary users. Based on our previous work reported in [1], the generation and detection algorithm of the beacon signal are extended with improved spectral efficiency. Performance is discussed with both computer simulation and testbed validation.

  20. Beacon- and Schema-Based Method for Recognizing Algorithms from Students' Source Code

    Science.gov (United States)

    Taherkhani, Ahmad; Malmi, Lauri

    2013-01-01

    In this paper, we present a method for recognizing algorithms from students programming submissions coded in Java. The method is based on the concept of "programming schemas" and "beacons". Schemas are high-level programming knowledge with detailed knowledge abstracted out, and beacons are statements that imply specific…

  1. 77 FR 41271 - Safety Zone; Newburgh to Beacon Swim, Newburgh, Hudson River, NY

    Science.gov (United States)

    2012-07-13

    ... Acronyms DHS Department of Homeland Security FR Federal Register CFR Code of Federal Regulations NPRM... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Newburgh to Beacon Swim, Newburgh, Hudson... Newburgh, NY for the annual Newburgh Beacon Swim event. This temporary safety zone is necessary to...

  2. Weak beacon detection for air-to-ground optical wireless link establishment.

    Science.gov (United States)

    Han, Yaoqiang; Dang, Anhong; Tang, Junxiong; Guo, Hong

    2010-02-01

    In an air-to-ground free-space optical communication system, strong background interference seriously affects the beacon detection, which makes it difficult to establish the optical link. In this paper, we propose a correlation beacon detection scheme under strong background interference conditions. As opposed to traditional beacon detection schemes, the beacon is modulated by an m-sequence at the transmitting terminal with a digital differential matched filter (DDMF) array introduced at the receiving end to detect the modulated beacon. This scheme is capable of suppressing both strong interference and noise by correlation reception of the received image sequence. In addition, the DDMF array enables each pixel of the image sensor to have its own DDMF of the same structure to process its received image sequence in parallel, thus it makes fast beacon detection possible. Theoretical analysis and an outdoor experiment have been demonstrated and show that the proposed scheme can realize fast and effective beacon detection under strong background interference conditions. Consequently, the required beacon transmission power can also be reduced dramatically.

  3. 46 CFR 169.744 - Emergency position indicating radio beacon (EPIRB).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Emergency position indicating radio beacon (EPIRB). 169.744 Section 169.744 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS... position indicating radio beacon (EPIRB). Each EPIRB must be marked with the vessel's name....

  4. What Happened to the Beacon Schools? Policy Reform and Educational Equity

    Science.gov (United States)

    Smith, Emma

    2015-01-01

    This paper considers the impact of the Beacon schools initiative on the social and academic characteristics of secondary schools in England. The Beacon schools programme ran from 1998 to 2004 and epitomised the (then) Labour government's focus on school improvement through diversity, collaboration and partnership. This paper looks at variation in…

  5. The Development of Landmark and Beacon Use in Young Children: Evidence from a Touchscreen Search Task

    Science.gov (United States)

    Sutton, Jennifer E.

    2006-01-01

    Children ages 2, 3 and 4 years participated in a novel hide-and-seek search task presented on a touchscreen monitor. On beacon trials, the target hiding place could be located using a beacon cue, but on landmark trials, searching required the use of a nearby landmark cue. In Experiment 1, 2-year-olds performed less accurately than older children…

  6. 46 CFR 169.555 - Emergency position indicating radio beacon (EPIRB).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Emergency position indicating radio beacon (EPIRB). 169.555 Section 169.555 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS... Emergency position indicating radio beacon (EPIRB). (a) Each vessel certificated for exposed waters...

  7. 46 CFR 169.831 - Emergency position indicating radio beacon (EPIRB).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Emergency position indicating radio beacon (EPIRB). 169.831 Section 169.831 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS... radio beacon (EPIRB). The master shall ensure that— (a) The EPIRB required in § 169.555 of...

  8. Down-regulation of the beacon gene expression in the regenerating rat adrenal cortex.

    Science.gov (United States)

    Ziolkowska, Agnieszka; Rucinski, Marcin; Tyczewska, Marianna; Belloni, Anna Sandra; Nowak, Magdalena; Nussdorfer, Gastone G; Malendowicz, Ludwik K

    2006-12-01

    Beacon, a hypothalamic peptide involved in the regulation of food intake, has been recently shown to be expressed in the adrenal cortex, and to inhibit its secretion and growth. To further characterize the role of beacon in the control of adrenal growth, we investigated the level of beacon gene expression in the regenerating rat adrenal cortex. Conventional reverse transcription-polymerase chain reaction (PCR) and immunocytochemistry demonstrated the expression of beacon mRNA and protein in the adrenals at both days 5 and 8 of regeneration after enucleation and contralateral adrenalectomy. Semiquantitative real time-PCR revealed a net down-regulation of beacon mRNA in the regenerating glands, as compared to the intact adrenal cortex of sham-operated animals. Beacon gene expression was higher at day 8 than at day 5 of regeneration. Mitotic index, as assayed by the stachmokinetic method with vincristin, was negligible in the intact adrenal, but greatly elevated in regenerating gland, with a higher index found at day 5 than at day 8 after surgery. Taken together our findings indicate that the level of beacon gene expression is inversely correlated with the proliferative activity of adrenocortical cells, and suggest that beacon might act as an endogenous inhibitor of adrenocortical growth in the rat.

  9. 46 CFR 28.150 - Emergency Position Indicating Radio Beacons (EPIRBs).

    Science.gov (United States)

    2010-10-01

    ... beacon (EPIRB) as required by 46 CFR part 25, subpart 25.26. Note: Each vessel which uses radio..., as set forth in 47 CFR part 80. ... 46 Shipping 1 2010-10-01 2010-10-01 false Emergency Position Indicating Radio Beacons (EPIRBs)....

  10. Immobilization of aptamer-based molecular beacons onto optically-encoded micro-sized beads.

    Science.gov (United States)

    Jun, Bong-Hyun; Kim, Ji-Eun; Rho, Chul; Byun, Jang-Woong; Kim, Yo Han; Kang, Homan; Kim, Jong-Ho; Kang, Taegyu; Cho, Myung-Haing; Lee, Yoon-Sik

    2011-07-01

    This paper presents a method for the novel immobilization of aptamer-based molecular beacons (apta-beacons) onto optically-encoded micro-sized beads (apta-beacon beads). To immobilize apta-beacons onto flourescently-encoded micro-sized beads, core-shell type beads containing a fluorescent dye-encoded core and apta beacon-coupled shell were prepared. The fluorescent dye-encoded beads were prepared from TentaGel resins by coupling RITC to the amino groups of the core region, after partial protection of amino groups with Fmoc-OSu in a diffusion-controlled manner. After deprotection of the Fmoc-amino groups, FITC-coupled molecular beacons (MBs) were immobilized to the beads together with a quencher by covelent bonding. Briefly, aspartic acid (Asp) was coupled to the shell part of the beads. Then, the quencher was coupled to the N-terminal amino group of Asp and the MBs were coupled to the side chain carboxyl group. In a model study, thrombin was directly detected using this apta-beacon bead method. The thrombin-bound apta-beacon beads were easily recognized by the appearance of fluorescence without any further labeling step.

  11. Molecular beacon probes combined with amplification by NASBA enable homogeneous, real-time detection of RNA

    NARCIS (Netherlands)

    Leone, G.; Schijndel, van H.; Gemen, van B.; Kramer, F.R.; Schoen, C.D.

    1998-01-01

    Molecular beacon probes can be employed in a NASBA amplicon detection system to generate a specific fluorescent signal concomitantly with amplification. A molecular beacon, designed to hybridize within the target sequence, was introduced into NASBA reactions that amplify the genomic RNA of potato le

  12. Crowdsourcing for Context: Regarding Privacy in Beacon Encounters via Contextual Integrity

    Directory of Open Access Journals (Sweden)

    Bello-Ogunu Emmanuel

    2016-07-01

    Full Text Available Research shows that context is important to the privacy perceptions associated with technology. With Bluetooth Low Energy beacons, one of the latest technologies for providing proximity and indoor tracking, the current identifiers that characterize a beacon are not sufficient for ordinary users to make informed privacy decisions about the location information that could be shared. One solution would be to have standardized category and privacy labels, produced by beacon providers or an independent third-party. An alternative solution is to find an approach driven by users, for users. In this paper, we propose a novel crowdsourcing based approach to introduce elements of context in beacon encounters.We demonstrate the effectiveness of this approach through a user study, where participants use a crowd-based mobile app designed to collect beacon category and privacy information as a scavenger hunt game. Results show that our approach was effective in helping users label beacons according to the specific context of a given beacon encounter, as well as the privacy perceptions associated with it. This labeling was done with an accuracy of 92%, and with an acceptance rate of 82% of all recommended crowd labels. Lastly, we conclusively show how crowdsourcing for context can be used towards a user-centric framework for privacy management during beacon encounters.

  13. Molecular beacon – tool for real time studying gene activity in stem cells

    DEFF Research Database (Denmark)

    Ilieva, Mirolyuba; Dufva, Martin

    and cancerogenesis. Molecular beacon technology is based on fluorescence resonance energy transfer (FRET) and the complementary pairing principles. These fluorescent molecular probes are highly specific and sensitive and are one important tool in in vitro diagnostics. Here molecular beacons are used to follow...

  14. Detection of DNA damage by using hairpin molecular beacon probes and graphene oxide.

    Science.gov (United States)

    Zhou, Jie; Lu, Qian; Tong, Ying; Wei, Wei; Liu, Songqin

    2012-09-15

    A hairpin molecular beacon tagged with carboxyfluorescein in combination with graphene oxide as a quencher reagent was used to detect the DNA damage by chemical reagents. The fluorescence of molecular beacon was quenched sharply by graphene oxide; while in the presence of its complementary DNA the quenching efficiency decreased because their hybridization prevented the strong adsorbability of molecular beacon on graphene oxide. If the complementary DNA was damaged by a chemical reagent and could not form intact duplex structure with molecular beacon, more molecular beacon would adsorb on graphene oxide increasing the quenching efficiency. Thus, damaged DNA could be detected based on different quenching efficiencies afforded by damaged and intact complementary DNA. The damage effects of chlorpyrifos-methyl and three metabolites of styrene such as mandelieaeids, phenylglyoxylieaeids and epoxystyrene on DNA were studied as models. The method for detection of DNA damage was reliable, rapid and simple compared to the biological methods.

  15. Measuring Transport Time of Mine Equipment in an Underground Mine Using a Bluetooth Beacon System

    Directory of Open Access Journals (Sweden)

    Jihoo Jung

    2016-12-01

    Full Text Available In this study, the time taken for mine haulage equipment to travel between destinations in an underground mine was measured and analyzed using a Bluetooth beacon system. In this system, Bluetooth beacons are attached to multiple points in an underground mine environment, and smartphones are mounted on mine equipment, such as haulage trucks, to collect transport time data. An underground limestone mine in Korea was selected to test the Bluetooth beacon system. The field experiments indicated that smartphones mounted on haulage trucks can recognize all Bluetooth beacons installed in the vicinity. The results also revealed that the Bluetooth beacon system can be used successfully in underground mines to quantitatively analyze transport times of haulage trucks going back and forth between loading and dumping points.

  16. Directionality based Location Discovery Scheme Using Beacon Nodes with Transmission Capabilities throughout Sensor Network

    Directory of Open Access Journals (Sweden)

    Qinli An

    2013-06-01

    Full Text Available In this paper, we propose a range-free localization scheme for wireless sensor networks (WSNs using four beacon nodes(BNs equipped with a directional antenna with special transmission capabilities for sending wireless beacon signals throughout the sensor network. Each beacon node rotates with a constant angular speed and broadcasts its angular bearings. A sensor node can determine its location by listening to wireless transmissions from the four fixed beacon nodes. The proposed method is based on an angle-of-arrival estimation technique that does not increase the complexity or cost of construction of the sensor nodes. We present error analysis and the best positions of beacon nodes in the proposed method. Numerical results, obtained by simulating several scenarios, show that the algorithm can reach a good level of convergence.

  17. Deep sea AUV navigation using multiple acoustic beacons

    Science.gov (United States)

    Ji, Da-xiong; Song, Wei; Zhao, Hong-yu; Liu, Jian

    2016-04-01

    Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles (AUVs). To estimate the vehicle position, we present an algorithm using an extended Kalman filter (EKF) to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment. Owing to high latency, variable sound speed multipath transmissions and unreliability in acoustic measurements, outlier recognition techniques are proposed as well. The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments. Our results show the improved performance over prior techniques based on position computation.

  18. Molecular Beacon CNT-based Detection of SNPs

    Science.gov (United States)

    Egorova, V. P.; Krylova, H. V.; Lipnevich, I. V.; Veligura, A. A.; Shulitsky, B. G.; Y Fedotenkova, L.

    2015-11-01

    An fluorescence quenching effect due to few-walled carbon nanotubes chemically modified by carboxyl groups has been utilized to discriminate Single Nucleotide Polymorphism (SNP). It was shown that the complex obtained from these nanotube and singlestranded primer DNA is formed due to stacking interactions between the hexagons of the nanotubes and aromatic rings of nucleotide bases as well as due to establishing of hydrogen bonds between acceptor amine groups of nucleotide bases and donor carboxyl groups of the nanotubes. It has been demonstrated that these complexes may be used to make highly effective DNA biosensors detecting SNPs which operate as molecular beacons.

  19. Deep Sea AUV Navigation Using Multiple Acoustic Beacons

    Institute of Scientific and Technical Information of China (English)

    冀大雄; 宋伟; 赵宏宇; 刘健

    2016-01-01

    Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles (AUVs). To estimate the vehicle position, we present an algorithm using an extended Kalman filter (EKF) to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment. Owing to high latency, variable sound speed multipath transmissions and unreliability in acoustic measurements, outlier recognition techniques are proposed as well. The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments. Our results show the improved performance over prior techniques based on position computation.

  20. Beacon Hill公司的水彩系列

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Beacon Hill's公司最新的水彩系列有多种不同的颜色变化,跨度从微妙的柔和的中性色彩一直到充满异国情调的色彩。为了让客户更好地体验到这种水彩的感觉,他们采用了半透明色调的颜料绘制图案。

  1. Inversion of Ionospheric Electron Density from GPS Beacon Observations

    Institute of Scientific and Technical Information of China (English)

    ZouYu-hua; XuJi-sheng

    2003-01-01

    This paper studies the mathematical foundation of time-dependent three-dimensional (3-D) computerized ionospheric tomography (CIT) for reconstructing ionospheric electron density, N~, from ground-based GPS beacon observations. After simplifying the relation between N. and time,the time-dependent 3-D inversion in consideration is reduced to a 3-D tomography with incomplete projections. To see clearly the effects of the incompleteness on the quality of reconstruction under 3-D condition, the formula of 3-D parallelbeam tomogtTaphy is deduced theoretically. After establishing the mathematical foundation, simulations based on actual GPS ray paths with the help of the IRI-90 model are performed,and reasonable time-dependent 3-D distribution images of Ne are obtained when taking proper layout of the network and allowing variable resolutions. The quality of the reconstruction is rather good when compared with the images from the IRI-90 model directly. Therefore, results in this paper demonstrate that imaging of the ionospheric electron density distribution from GPS beacon observations is reasonable in theor yand feasible in practice.

  2. Inversion of Ionospheric Electron Density from GPS Beacon Observations

    Institute of Scientific and Technical Information of China (English)

    Zou Yu-hua; Xu Ji-sheng

    2003-01-01

    This paper studies the mathematical foundation of time-dependent three-dimensional (3-D) computerized ionospheric tomography (CIT) for reconstructing ionospheric electron density, Ne, from ground-based GPS beacon observations. After simplifying the relation between Ne and time,the time-dependent 3-D inversion in consideration is reduced to a 3-D tomography with incomplete projections.To see clearly the effects of the incompleteness on the quality of reconstruction under 3-D condition, the formula of 3-D parallel-beam tomography is deduced theoretically. After establishing the mathematical foundation, simulations based on actual GPS ray paths with the help of the IRI-90 model are performed,and reasonable time-dependent 3-D distribution images of Neare obtained when taking proper layout of the network and allowing variable resolutions. The quality of the reconstruction is rather good when compared with the images from the IRI-90 model directly. Therefore, results in this paper demon-strate that imaging of the ionospheric electron density distri-bution from GPS beacon observations is reasonable in theory and feasible in practice.

  3. Molecular Beacons: Powerful Tools for Imaging RNA in Living Cells

    Science.gov (United States)

    Monroy-Contreras, Ricardo; Vaca, Luis

    2011-01-01

    Recent advances in RNA functional studies highlights the pivotal role of these molecules in cell physiology. Diverse methods have been implemented to measure the expression levels of various RNA species, using either purified RNA or fixed cells. Despite the fact that fixed cells offer the possibility to observe the spatial distribution of RNA, assays with capability to real-time monitoring RNA transport into living cells are needed to further understand the role of RNA dynamics in cellular functions. Molecular beacons (MBs) are stem-loop hairpin-structured oligonucleotides equipped with a fluorescence quencher at one end and a fluorescent dye (also called reporter or fluorophore) at the opposite end. This structure permits that MB in the absence of their target complementary sequence do not fluoresce. Upon binding to targets, MBs emit fluorescence, due to the spatial separation of the quencher and the reporter. Molecular beacons are promising probes for the development of RNA imaging techniques; nevertheless much work remains to be done in order to obtain a robust technology for imaging various RNA molecules together in real time and in living cells. The present work concentrates on the different requirements needed to use successfully MB for cellular studies, summarizing recent advances in this area. PMID:21876785

  4. Molecular Beacons: Powerful Tools for Imaging RNA in Living Cells

    Directory of Open Access Journals (Sweden)

    Ricardo Monroy-Contreras

    2011-01-01

    Full Text Available Recent advances in RNA functional studies highlights the pivotal role of these molecules in cell physiology. Diverse methods have been implemented to measure the expression levels of various RNA species, using either purified RNA or fixed cells. Despite the fact that fixed cells offer the possibility to observe the spatial distribution of RNA, assays with capability to real-time monitoring RNA transport into living cells are needed to further understand the role of RNA dynamics in cellular functions. Molecular beacons (MBs are stem-loop hairpin-structured oligonucleotides equipped with a fluorescence quencher at one end and a fluorescent dye (also called reporter or fluorophore at the opposite end. This structure permits that MB in the absence of their target complementary sequence do not fluoresce. Upon binding to targets, MBs emit fluorescence, due to the spatial separation of the quencher and the reporter. Molecular beacons are promising probes for the development of RNA imaging techniques; nevertheless much work remains to be done in order to obtain a robust technology for imaging various RNA molecules together in real time and in living cells. The present work concentrates on the different requirements needed to use successfully MB for cellular studies, summarizing recent advances in this area.

  5. DNA aptamer beacon assay for C-telopeptide and handheld fluorometer to monitor bone resorption.

    Science.gov (United States)

    Bruno, John Gordon; Carrillo, Maria P; Phillips, Taylor; Hanson, Douglas; Bohmann, Jonathan A

    2011-09-01

    A novel DNA aptamer beacon is described for quantification of a 26-amino acid C-telopeptide (CTx) of human type I bone collagen. One aptamer sequence and its reverse complement dominated the aptamer pool (31.6% of sequenced clones). Secondary structures of these aptamers were examined for potential binding pockets. Three-dimensional computer models which analyzed docking topologies and binding energies were in agreement with empirical fluorescence experiments used to select one candidate loop for beacon assay development. All loop structures from the aptamer finalists were end-labeled with TYE 665 and Iowa Black quencher for comparison of beacon fluorescence levels as a function of CTx concentration. The optimal beacon, designated CTx 2R-2h yielded a low ng/ml limit of detection using a commercially available handheld fluorometer. The CTx aptamer beacon bound full-length 26-amino acid CTx peptide, but not a shorter 8-amino acid segment of CTx peptide which is a common target for commercial CTx ELISA kits. The prototype assay was shown to detect CTx peptide from human urine after creatinine and urea were removed by size-exclusion chromatography to prevent nonspecific denaturing of the aptamer beacon. This work demonstrates the potential of aptamer beacons to be utilized for rapid and sensitive bone health monitoring in a handheld or point-of-care format.

  6. Detection of MDR1 mRNA expression with optimized gold nanoparticle beacon

    Science.gov (United States)

    Zhou, Qiumei; Qian, Zhiyu; Gu, Yueqing

    2016-03-01

    MDR1 (multidrug resistance gene) mRNA expression is a promising biomarker for the prediction of doxorubicin resistance in clinic. However, the traditional technical process in clinic is complicated and cannot perform the real-time detection mRNA in living single cells. In this study, the expression of MDR1 mRNA was analyzed based on optimized gold nanoparticle beacon in tumor cells. Firstly, gold nanoparticle (AuNP) was modified by thiol-PEG, and the MDR1 beacon sequence was screened and optimized using a BLAST bioinformatics strategy. Then, optimized MDR1 molecular beacons were characterized by transmission electron microscope, UV-vis and fluorescence spectroscopies. The cytotoxicity of MDR1 molecular beacon on L-02, K562 and K562/Adr cells were investigated by MTT assay, suggesting that MDR1 molecular beacon was low inherent cytotoxicity. Dark field microscope was used to investigate the cellular uptake of hDAuNP beacon assisted with ultrasound. Finally, laser scanning confocal microscope images showed that there was a significant difference in MDR1 mRNA expression in K562 and K562/Adr cells, which was consistent with the results of q-PCR measurement. In summary, optimized MDR1 molecular beacon designed in this study is a reliable strategy for detection MDR1 mRNA expression in living tumor cells, and will be a promising strategy for in guiding patient treatment and management in individualized medication.

  7. Pedestrian and motorists' actions at pedestrian hybrid beacon sites: findings from a pilot study.

    Science.gov (United States)

    Pulugurtha, Srinivas S; Self, Debbie R

    2015-01-01

    This paper focuses on an analysis of pedestrian and motorists' actions at sites with pedestrian hybrid beacons and assesses their effectiveness in improving the safety of pedestrians. Descriptive and statistical analyses (one-tail two-sample T-test and two-proportion Z-test) were conducted using field data collected during morning and evening peak hours at three study sites in the city of Charlotte, NC, before and after the installation of pedestrian hybrid beacons. Further, an analysis was conducted to assess the change in pedestrian and motorists' actions over time (before the installation; 1 month, 3 months, 6 months, and 12 months after the installation). Results showed an increase in average traffic speed at one of the pedestrian hybrid beacon sites while no specific trends were observed at the other two pedestrian hybrid beacon sites. A decrease in the number of motorists not yielding to pedestrians, pedestrians trapped in the middle of the street, and pedestrian-vehicle conflicts were observed at all the three pedestrian hybrid beacon sites. The installation of pedestrian hybrid beacons did not have a negative effect on pedestrian actions at two out of the three sites. Improvements seem to be relatively more consistent 3 months after the installation of the pedestrian hybrid beacon.

  8. Fast molecular beacon hybridization in organic solvents with improved target specificity.

    Science.gov (United States)

    Dave, Neeshma; Liu, Juewen

    2010-12-01

    DNA hybridization is of tremendous importance in biology, bionanotechnology, and biophysics. Molecular beacons are engineered DNA hairpins with a fluorophore and a quencher labeled on each of the two ends. A target DNA can open the hairpin to give an increased fluorescence signal. To date, the majority of molecular beacon detections have been performed only in aqueous buffers. We describe herein DNA detection in nine different organic solvents, methanol, ethanol, isopropanol, acetonitrile, formamide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethylene glycol, and glycerol, varying each up to 75% (v/v). In comparison with detection in water, the detection in organic solvents showed several important features. First, the molecular beacon hybridizes to its target DNA in the presence of all nine solvents up to a certain percentage. Second, the rate of this hybridization was significantly faster in most organic solvents compared with water. For example, in 56% ethanol, the beacon showed a 70-fold rate enhancement. Third, the ability of the molecular beacon to discriminate single-base mismatch is still maintained. Lastly, the DNA melting temperature in the organic solvents showed a solvent concentration-dependent decrease. This study suggests that molecular beacons can be used for applications where organic solvents must be involved or organic solvents can be intentionally added to improve the molecular beacon performance.

  9. Highly selective single nucleotide polymorphism recognition by a chiral (5S) PNA beacon.

    Science.gov (United States)

    Totsingan, Filbert; Tedeschi, Tullia; Sforza, Stefano; Corradini, Roberto; Marchelli, Rosangela

    2009-01-01

    A chiral peptide nucleic acid (PNA) beacon containing a C-5 modified monomer based on L-lysine was synthesized. The terminal amino group of the lysine side chain was linked to a spacer for future applications on surfaces. The PNA beacon bears a carboxyfluorescein fluorophore and a dabcyl quencher at opposite ends. The DNA binding properties were compared with those of a homologous PNA beacon containing only achiral monomers. Both beacons underwent a fluorescence increase in the presence of complementary DNA, with higher efficiency and higher selectivity (evaluated using single mismatched DNA sequences) observed for the chiral monomer containing PNA. Ion exchange (IE) HPLC with fluorimetric detection was used in combination with the beacon for the selective detection of complementary DNA. A fluorescent peak corresponding to the PNA beacon:DNA duplex was observed at a very low detection limit (1 nM). The discriminating capacity of the chiral PNA beacon for a single mismatch was found to be superior to those observed with the unmodified one, thus confirming the potency of chirality for increasing the affinity and specificity of DNA recognition.

  10. Gold nanoparticle fluorescent molecular beacon for low-resolution DQ2 gene HLA typing.

    Science.gov (United States)

    Beni, Valerio; Zewdu, Taye; Joda, Hamdi; Katakis, Ioanis; O'Sullivan, Ciara K

    2012-01-01

    Coeliac disease is an inflammation of the small intestine triggered by gluten ingestion. We present a fluorescent genosensor, exploiting molecular-beacon-functionalized gold nanoparticles, for the identification of human leukocyte antigen (HLA) DQ2 gene, a key genetic factor in coeliac disease. Optimization of sensor performance was achieved by tuning the composition of the oligonucleotide monolayer immobilized on the gold nanoparticle and the molecular beacon design. Co-immobilization of the molecular beacon with a spacing oligonucleotide (thiolated ten-thymine oligonucleotide) in the presence of ten-adenine oligonucleotides resulted in a significant increase of the sensor response owing to improved spacing of the molecular beacons and extension of the distance from the nanoparticle surface, which renders them more available for recognition. Further increase in the response (approximately 40%) was shown to be achievable when the recognition sequence of the molecular beacon was incorporated in the stem. Improvement of the specificity of the molecular beacons was also achieved by the incorporation within their recognition sequence of a one-base mismatch. Finally, gold nanoparticles functionalized with two molecular beacons targeting the DQA1*05* and DQB1*02* alleles allowed the low-resolution typing of the DQ2 gene at the nanomolar level.

  11. An analysis of iBeacons and critical minimum distances in device placement

    OpenAIRE

    2014-01-01

    This project has been carried out in, and under the supervision of the Mobile Services Laboratory at the department of Communication Systems, KTH. The task was to explore the technical specifics of the iBeacon technology and its practical limitations in terms of reliability and device placement. In plain text; how close the beacons can be placed to allow for reliable isolation of the pertinent beacon. The main method of reaching the set goal was data capture at certain key positions around th...

  12. Detecting and Preventing Beacon Replay Attacks in Receiver-Initiated MAC Protocols for Energy Efficient WSNs

    DEFF Research Database (Denmark)

    Di Mauro, Alessio; Fafoutis, Xenofon; Mödersheim, Sebastian Alexander

    2013-01-01

    In receiver-initiated MAC protocols for Wireless Sensor Networks (WSNs), communication is initiated by the receiver of the data through beacons containing the receiver's identity. In this paper, we consider the case of a network intruder that captures and replays such beacons towards legitimate...... nodes, pretending to have a fake identity within the network. To prevent this attack we propose RAP, a challenge-response authentication protocol that is able to detect and prevent the beacon replay attack. The effectiveness of the protocol is formally verified using OFMC and ProVerif. Furthermore, we...

  13. Easy-to-Build Satellite Beacon Receiver for Propagation Experimentation at Millimeter Bands

    Directory of Open Access Journals (Sweden)

    F. Machado

    2014-04-01

    Full Text Available This paper describes the design and development of a digital satellite beacon receiver for propagation experimentation. Satellite beacons are frequently available for pointing large antennas, but such signals can be used for measuring rain attenuation and other phenomena as, for example, tropospheric scintillation. A fairly inexpensive beacon receiver has been built using off-the-shelf parts. This instrument is not at all bulky making it suitable for easy transportation. This article analyzes the receiver specifications, describes in detail its structure and presents some operational test results.

  14. Tight Bounds for Beacon-Based Coverage in Simple Rectilinear Polygons

    KAUST Repository

    Bae, Sang Won

    2016-03-21

    We establish tight bounds for beacon-based coverage problems. In particular, we show that $$\\\\lfloor \\\\frac{n}{6} \\ floor $$⌊n6⌋ beacons are always sufficient and sometimes necessary to cover a simple rectilinear polygon P with n vertices. When P is monotone and rectilinear, we prove that this bound becomes $$\\\\lfloor \\\\frac{n+4}{8} \\ floor $$⌊n+48⌋. We also present an optimal linear-time algorithm for computing the beacon kernel of P.

  15. Beacons of discovery the worldwide science of particle physics

    CERN Document Server

    International Committee for Future Accelerators (ICFA)

    2011-01-01

    To discover what our world is made of and how it works at the most fundamental level is the challenge of particle physics. The tools of particle physics—experiments at particle accelerators and underground laboratories, together with observations of space—bring opportunities for discovery never before within reach. Thousands of scientists from universities and laboratories around the world collaborate to design, build and use unique detectors and accelerators to explore the fundamental physics of matter, energy, space and time. Together, in a common world-wide program of discovery, they provide a deep understanding of the world around us and countless benefits to society. Beacons of Discovery presents a vision of the global science of particle physics at the dawn of a new light on the mystery and beauty of the universe.

  16. Seamless Guidance System Combining GPS, BLE Beacon, and NFC Technologies

    Directory of Open Access Journals (Sweden)

    Rung-Shiang Cheng

    2016-01-01

    Full Text Available Users rely increasingly on Location-Based Services (LBS and automated navigation/guidance systems nowadays. However, while such services are easily implemented in outdoor environments using Global Positioning System (GPS technology, a requirement still exists for accurate localization and guidance schemes in indoor settings. Accordingly, the present study proposes a system based on GPS, Bluetooth Low Energy (BLE beacons, and Near Field Communication (NFC technology. Through establishing graphic information and the design of algorithm, this study develops a guidance system for indoors and outdoors on smart phones, wishing to give user perfect smart life through this system. The proposed system is implemented on a smart phone and evaluated on a student campus environment. The experimental results confirm the ability of the proposed app to switch automatically from an outdoor mode to an indoor mode and to guide the user to requested target destination via the shortest possible route.

  17. Directional pattern measurement of the BRAMS beacon antenna system

    Science.gov (United States)

    Martínez Picar, A.; Marqué, C.; Anciaux, M.; Lamy, H.

    2015-01-01

    The typical methods for measuring antenna characteristics are mostly based on the use of remote transmitters or receivers. For antennas used in radio communications, calibrations are usually done on an antenna test stand using transmitters with known power output. In order to minimize the ground effects while performing measurements, it is necessary to place the transmitter or receiver high above ground with the aid of aircrafts. It is, however, necessary to determine precisely the coordinates of the airborne devices as well as to maintain high stability. This used to be excessively difficult to carry out, but recent advances in Unmanned Aerial Vehicle (UAV) technologies have brought a feasible option. In this paper, the results of using a low-cost system for measuring the directional pattern of BRAMS beacon antenna system based on an UAV are presented.

  18. Multi-kW Uplink Fiber-Laser Beacon with Agile Signal Format Project

    Data.gov (United States)

    National Aeronautics and Space Administration —  Laser beacons with scalable powers are needed for ground to deep-space optical communication uplinks. They serve as absolute reference for tracking of...

  19. Highly sensitive and rapid bacteria detection using molecular beacon-Au nanoparticles hybrid nanoprobes.

    Science.gov (United States)

    Cao, Jing; Feng, Chao; Liu, Yan; Wang, Shouyu; Liu, Fei

    2014-07-15

    Since many diseases are caused by pathogenic bacterial infections, accurate and rapid detection of pathogenic bacteria is in urgent need to timely apply appropriate treatments and to reduce economic costs. To end this, we designed molecular beacon-Au nanoparticle hybrid nanoprobes to improve the bacterial detection efficiency and sensitivity. Here, we show that the designed molecular beacon modified Au nanoparticles could specifically recognize synthetic DNAs targets and can readily detect targets in clinical samples. Moreover, the hybrid nanoprobes can recognize Escherichia coli within an hour at a concentration of 10(2) cfu/ml, which is 1000-folds sensitive than using molecular beacon directly. Our results show that the molecular beacon-Au nanoparticle hybrid nanoprobes have great potential in medical and biological applications.

  20. LDB: Localization with Directional Beacons for Sparse 3D Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Hanjiang Luo

    2010-01-01

    Full Text Available In this paper, we propose a novel distributed localization scheme LDB, a 3D localization scheme with directional beacons for Underwater Acoustic Sensor Networks (UWA-SNs. LDB localizes sensor nodes using an Autonomous Underwater Vehicle (AUV as a mobile beacon sender. Mounted with a directional transceiver which creates conical shaped directional acoustic beam, the AUV patrols over the 3D deployment volume with predefined trajectory sending beacons with constant interval towards the sensor nodes. By listening two or more beacons sent from the AUV, the nodes can localize themselves silently. Through theoretical analysis, we provide the upper bound of the estimation error of the scheme. We also evaluate the scheme by simulations and the results show that our scheme can achieve a high localization accuracy, even in sparse networks.

  1. Tracking neuronal marker expression inside living differentiating cells using molecular beacons

    DEFF Research Database (Denmark)

    Ilieva, Mirolyuba; Della Vedova, Paolo; Hansen, Ole

    2013-01-01

    Monitoring gene expression is an important tool for elucidating mechanisms of cellular function. In order to monitor gene expression during nerve cell development, molecular beacon (MB) probes targeting markers representing different stages of neuronal differentiation were designed and synthesized...

  2. Multi-kW Uplink Fiber-Laser Beacon with Agile Signal Format Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Uplink Laser Beacons for deep-space communication, can benefit greatly from migration to the 1010-1030nm wavelengths, via use of Silicon-APDs on the spacecraft...

  3. Digital beacon receiver for ionospheric TEC measurement developed with GNU Radio

    Science.gov (United States)

    Yamamoto, M.

    2008-11-01

    A simple digital receiver named GNU Radio Beacon Receiver (GRBR) was developed for the satellite-ground beacon experiment to measure the ionospheric total electron content (TEC). The open-source software toolkit for the software defined radio, GNU Radio, is utilized to realize the basic function of the receiver and perform fast signal processing. The software is written in Python for a LINUX PC. The open-source hardware called Universal Software Radio Peripheral (USRP), which best matches the GNU Radio, is used as a front-end to acquire the satellite beacon signals of 150 and 400 MHz. The first experiment was successful as results from GRBR showed very good agreement to those from the co-located analog beacon receiver. Detailed design information and software codes are open at the URL http://www.rish.kyoto-u.ac.jp/digitalbeacon/.

  4. Creation of a library tour application for mobile equipment using iBeacon technology

    OpenAIRE

    2016-01-01

    We describe the design, development, and deployment of a library tour application utilizing Bluetooth Low Energy devices know as iBeacons. The tour application will serve as library orientation for incoming students. The students visit stations in the library with mobile equipment running a special tour app. When the app detects a beacon nearby, it automatically plays a video that describes the current location. After the tour, students are assessed according to the defined learning objective...

  5. Perancangan Prototipe Receiver Beacon Black Box Locator Acoustic 37,5 kHz Pingers

    OpenAIRE

    RUSTAMAJI RUSTAMAJI; PAULINE RAHMIATI; SARAH PERMATASARI

    2016-01-01

    Abstrak Ketika suatu pesawat terbang mengalami kecelakaan terjatuh ke dalam air, maka lokasi keberadaannya dapat dideteksi oleh alat yang disebut receiver beacon black box locator acoustic (pingers receiver). Pingers receiver berfungsi untuk menerima sinyal dengan frekuensi 37,5 kHz ± 1 kHz dari pingers transmitter atau Underwater Locator Beacon (ULB) yang berada pada black box pesawat. Dalam penelitian ini dibuat perancangan pingers receiver yang tersusun dari rangkaian Band Pass Filter (BPF...

  6. Detection of jamming transmission of beacon in vehicular networks%VANETs 中 beacon 的传输攻击实时检测算法

    Institute of Scientific and Technical Information of China (English)

    陈丹; 彭利民

    2015-01-01

    车载自组织网(vehicular Ad hoc networks,VANETs)中的车辆通过周期交互 beacon 实现信息共享,从而提高交通安全,然而 VANETs 无线网络特性系统易遭受多类攻击,特别是对 beacon 的传输攻击,即干扰 beacon的传输,其严重影响 VANETs 的安全性能。为此,建立车队 platooning 模型,提出实时检测干扰 beacon 传输的攻击方案。该方案首先将节点 beacon 传输时间分为相互独立的时隙,并依据此时隙将车辆分为不同的群,使得群间的 beacon 彼此不碰撞,从而降低 beacon 被干扰的概率。最后,针对两类攻击类型进行仿真。仿真结果表明,提出的检测攻击方案具有良好的性能,初始检测时间小于150 ms,平均检测率不低于0.9。在两个干扰者的情况下,漏警率小于0.15,平均的虚警率小于0.2。%The cooperation between the vehicles in the VANET is achieved by the frequent exchange of periodic broadcast messages carrying information on vehicle position and velocity,which is referred to as beacons,which is in favor of improving the security of VANET.However,the nature of medium in wireless networks makes it easy for adversary to launch a attack, especially jamming the beacon transmission,which seriously affects the performance of VANET.Therefore,this paper con-structed the model of platooning,and proposed a real-time detection jamming-beacon-transmission scheme.In this scheme,it divided time for transmission beacon into independent time slot.In the way that beacons from different groups never collided, it reduced the probability of interference with beacon.Finally,in view of the two types of attack types were simulated.The simulation results show that the proposed detection attack scheme has good performance,the initial detecting time is less than 150 ms,the average detection rate is not less than 0.9.In the case of two jammers,FNR is less than 0.15,the average FPR is less than 0.2.

  7. An adaptive scheme for robot localization and mapping with dynamically configurable inter-beacon range measurements.

    Science.gov (United States)

    Torres-González, Arturo; Martinez-de Dios, Jose Ramiro; Ollero, Anibal

    2014-04-25

    This work is motivated by robot-sensor network cooperation techniques where sensor nodes (beacons) are used as landmarks for range-only (RO) simultaneous localization and mapping (SLAM). This paper presents a RO-SLAM scheme that actuates over the measurement gathering process using mechanisms that dynamically modify the rate and variety of measurements that are integrated in the SLAM filter. It includes a measurement gathering module that can be configured to collect direct robot-beacon and inter-beacon measurements with different inter-beacon depth levels and at different rates. It also includes a supervision module that monitors the SLAM performance and dynamically selects the measurement gathering configuration balancing SLAM accuracy and resource consumption. The proposed scheme has been applied to an extended Kalman filter SLAM with auxiliary particle filters for beacon initialization (PF-EKF SLAM) and validated with experiments performed in the CONET Integrated Testbed. It achieved lower map and robot errors (34% and 14%, respectively) than traditional methods with a lower computational burden (16%) and similar beacon energy consumption.

  8. Serum inverts and improves the fluorescence response of an aptamer beacon to various vitamin D analytes.

    Science.gov (United States)

    Bruno, John G; Carrillo, Maria P; Phillips, Taylor; Edge, Allison

    2012-01-01

    A dominant aptamer loop structure from a library of nearly 100 candidate aptamer sequences developed against immobilized 25-hydroxyvitamin D(3) (calcidiol) was converted into a 5'-TYE 665 and 3'-Iowa black-labelled aptamer beacon. The aptamer beacon exhibited a mild 'lights on' reaction in buffer as a function of increasing concentrations of several vitamin D analogues and metabolites, with a limit of detection of approximately 200 ng/mL, and was not specific for any particular congener. In 10% or 50% human serum, the same aptamer beacon inverted its fluorescence behaviour to become a more intense 'lights off' reaction with an improved limit of detection in the range 4-16 ng/mL. We hypothesized that this drastic change in fluorescence behaviour was due to the presence of creatinine and urea in serum, which might destabilize the quenched beacon, causing an increase in fluorescence followed by decreasing fluorescence as a function of vitamin D concentrations that may bind and quench increasingly greater fractions of the denatured beacons. However, the results of several control experiments in the presence of physiological or greater concentrations of creatinine and urea, alone or combined in buffer, failed to produce the beacon fluorescence inversion. Other possible mechanistic hypotheses are also discussed.

  9. An Adaptive Scheme for Robot Localization and Mapping with Dynamically Configurable Inter-Beacon Range Measurements

    Directory of Open Access Journals (Sweden)

    Arturo Torres-González

    2014-04-01

    Full Text Available This work is motivated by robot-sensor network cooperation techniques where sensor nodes (beacons are used as landmarks for range-only (RO simultaneous localization and mapping (SLAM. This paper presents a RO-SLAM scheme that actuates over the measurement gathering process using mechanisms that dynamically modify the rate and variety of measurements that are integrated in the SLAM filter. It includes a measurement gathering module that can be configured to collect direct robot-beacon and inter-beacon measurements with different inter-beacon depth levels and at different rates. It also includes a supervision module that monitors the SLAM performance and dynamically selects the measurement gathering configuration balancing SLAM accuracy and resource consumption. The proposed scheme has been applied to an extended Kalman filter SLAM with auxiliary particle filters for beacon initialization (PF-EKF SLAM and validated with experiments performed in the CONET Integrated Testbed. It achieved lower map and robot errors (34% and 14%, respectively than traditional methods with a lower computational burden (16% and similar beacon energy consumption.

  10. A Measurement Study of BLE iBeacon and Geometric Adjustment Scheme for Indoor Location-Based Mobile Applications

    OpenAIRE

    2016-01-01

    Bluetooth Low Energy (BLE) and the iBeacons have recently gained large interest for enabling various proximity-based application services. Given the ubiquitously deployed nature of Bluetooth devices including mobile smartphones, using BLE and iBeacon technologies seemed to be a promising future to come. This work started off with the belief that this was true: iBeacons could provide us with the accuracy in proximity and distance estimation to enable and simplify the development of many previo...

  11. Quantum dot-based molecular beacon to monitor intracellular microRNAs.

    Science.gov (United States)

    Lee, Jonghwan; Moon, Sung Ung; Lee, Yong Seung; Ali, Bahy A; Al-Khedhairy, Abdulaziz A; Ali, Daoud; Ahmed, Javed; Al Salem, Abdullah M; Kim, Soonhag

    2015-06-02

    Fluorescence monitoring of endogenous microRNA (miRNA or miR) activity related to neuronal development using nano-sized materials provides crucial information on miRNA expression patterns in a noninvasive manner. In this study, we report a new method to monitor intracellular miRNA124a using quantum dot-based molecular beacon (R9-QD-miR124a beacon). The R9-QD-miR124a beacon was constructed using QDs and two probes, miR124a-targeting oligomer and arginine rich cell-penetrating peptide (R9 peptide). The miR124a-targeting oligomer contains a miR124a binging sequence and a black hole quencher 1 (BHQ1). In the absence of target miR124a, the R9-QD-miR124a beacon forms a partial duplex beacon and remained in quenched state because the BHQ1 quenches the fluorescence signal of the R9-QD-miR124a beacon. The binding of miR124a to the miR124a binding sequence of the miR124a-targeting oligomer triggered the separation of the BHQ1 quencher and subsequent signal-on of a red fluorescence signal. Moreover, enhanced cellular uptake was achieved by conjugation with the R9 peptide, which resulted in increased fluorescent signal of the R9-QD-miR124a beacons in P19 cells during neurogenesis due to the endogenous expression of miR124a.

  12. Analytical performance of molecular beacons on surface immobilized gold nanoparticles of varying size and density.

    Science.gov (United States)

    Uddayasankar, Uvaraj; Krull, Ulrich J

    2013-11-25

    The high quenching efficiency of metal nanoparticles has facilitated its use as quenchers in molecular beacons. To optimize this system, a good understanding of the many factors that influence molecular beacon performance is required. In this study, molecular beacon performance was evaluated as a function of gold nanoparticle size and its immobilization characteristics. Gold nanoparticles of 4 nm, 15 nm and 87 nm diameter, were immobilized onto glass slides. Each size regime offered distinctive optical properties for fluorescence quenching of molecular dyes that were conjugated to oligonucleotides that were immobilized to the gold nanoparticles. Rigid double stranded DNA was used as a model to place fluorophores at different distances from the gold nanoparticles. The effect of particle size and also the immobilization density of nanoparticles was evaluated. The 4 nm and 87 nm gold nanoparticles offered the highest sensitivity in terms of the change in fluorescence intensity as a function of distance (3-fold improvement for Cy5). The optical properties of the molecular fluorophore was of significance, with Cy5 offering higher contrast ratios than Cy3 due to the red-shifted emission spectrum relative to the plasmon peak. A high density of gold nanoparticles reduced contrast ratios, indicating preference for a monolayer of immobilized nanoparticles when considering analytical performance. Molecular beacon probes were then used in place of the double stranded oligonucleotides. There was a strong dependence of molecular beacon performance on the length of a linker used for attachment to the nanoparticle surface. The optimal optical performance was obtained with 4 nm gold nanoparticles that were immobilized as monolayers of low density (5.7×10(11)particles cm(-2)) on glass surfaces. These nanoparticle surfaces offered a 2-fold improvement in analytical performance of the molecular beacons when compared to other nanoparticle sizes investigated. The principles developed

  13. STEREO Space Weather and the Space Weather Beacon

    Science.gov (United States)

    Biesecker, D. A.; Webb, D F.; SaintCyr, O. C.

    2007-01-01

    The Solar Terrestrial Relations Observatory (STEREO) is first and foremost a solar and interplanetary research mission, with one of the natural applications being in the area of space weather. The obvious potential for space weather applications is so great that NOAA has worked to incorporate the real-time data into their forecast center as much as possible. A subset of the STEREO data will be continuously downlinked in a real-time broadcast mode, called the Space Weather Beacon. Within the research community there has been considerable interest in conducting space weather related research with STEREO. Some of this research is geared towards making an immediate impact while other work is still very much in the research domain. There are many areas where STEREO might contribute and we cannot predict where all the successes will come. Here we discuss how STEREO will contribute to space weather and many of the specific research projects proposed to address STEREO space weather issues. We also discuss some specific uses of the STEREO data in the NOAA Space Environment Center.

  14. Energy-Efficient BOP-Based Beacon Transmission Scheduling in Wireless Sensor Networks

    Science.gov (United States)

    Kim, Eui-Jik; Youm, Sungkwan; Choi, Hyo-Hyun

    Many applications in wireless sensor networks (WSNs) require the energy efficiency and scalability. Although IEEE 802.15.4/Zigbee which is being considered as general technology for WSNs enables the low duty-cycling with time synchronization of all the nodes in network, it still suffer from its low scalability due to the beacon frame collision. Recently, various algorithms to resolve this problem are proposed. However, their manners to implement are somewhat ambiguous and the degradation of energy/communication efficiency is serious by the additional overhead. This paper describes an Energy-efficient BOP-based Beacon transmission Scheduling (EBBS) algorithm. EBBS is the centralized approach, in which a resource-sufficient node called as Topology Management Center (TMC) allocates the time slots to transmit a beacon frame to the nodes and manages the active/sleep schedules of them. We also propose EBBS with Adaptive BOPL (EBBS-AB), to adjust the duration to transmit beacon frames in every beacon interval, adaptively. Simulation results show that by using the proposed algorithm, the energy efficiency and the throughput of whole network can be significantly improved. EBBS-AB is also more effective for the network performance when the nodes are uniformly deployed on the sensor field rather than the case of random topologies.

  15. Quencher-free molecular beacon tethering 7-hydroxycoumarin detects targets through protonation/deprotonation.

    Science.gov (United States)

    Kashida, Hiromu; Yamaguchi, Kyohei; Hara, Yuichi; Asanuma, Hiroyuki

    2012-07-15

    In this study, we synthesized a simple but efficient quencher-free molecular beacon tethering 7-hydroxycoumarin on D-threoninol based on its pK(a) change. The pK(a) of 7-hydroxycoumarin in a single strand was determined as 8.8, whereas that intercalated in the duplex was over 10. This large pK(a) shift (more than 1.2) upon hybridization could be attributed to the anionic and hydrophobic microenvironment inside the DNA duplex. Because 7-hydroxycoumarin quenches its fluorescence upon protonation, the emission intensity of the duplex at pH 8.5 was 1/15 that of the single strand. We applied this quenching mechanism to the preparation of a quencher-free molecular beacon by introducing the dye into the middle of the stem part. In the absence of the target, the stem region formed a duplex and fluorescence was quenched. However, when the target was added, the molecular beacon opened and the dye was deprotonated. As a result, the emission intensity of the molecular beacon with the target was 10 times higher than that without the target. Accordingly, a quencher-free molecular beacon utilizing the pK(a) change was successfully developed.

  16. A dual molecular beacon approach for fast detection of Mycobacterium tuberculosis.

    Science.gov (United States)

    Yu, Chuan-Xing; Zhao, Zi-Yun; Lv, Jian-Xin; Zhu, Ling

    2013-02-01

    The main objectives of this study were to assess a dual molecular beacon approach for fast detection of Mycobacterium tuberculosis (MT). MT beacon (Tb-B) was designed to target the unique IS6110 (114 bp) and rpoB (215 bp) fragment of the MT (H37Ra) genome, and the two fragments were inserted into the PMD-19T vector after purification, by PCR and sequencing, to construct plasmids. Different dilutions of positive plasmid standards were used for dual molecular beacon RT-PCR of rpoB and IS6110, and standard curves were established.The results show that the dual molecular beacon of rpoB and IS6110 detecting MT was stable (CV is 1.91-2.68 %) with a high amplification efficiency (95.6 %). In addition, the strains of non MT did not generate fluorescence signals, while strains of MT did, indicating that the primers and molecular beacons were specific, and only MT complex was amplified. The linear range was wide (10(3)-10(11) copies/mL), and clinical specimens presenting different bacterial counts can be detected.

  17. "Molecular beacon"-based fluorescent assay for selective detection of glutathione and cysteine.

    Science.gov (United States)

    Xu, Hui; Hepel, Maria

    2011-02-01

    We report on the development of a fluorescence turn-on "molecular beacon" probe for the detection of glutathione (GSH) and cysteine (Cys). The method is based on a competitive ligation of Hg(2+) ions by GSH/Cys and thymine-thymine (T-T) mismatches in a DNA strand of the self-hybridizing beacon strand. The assay relies on the distance-dependent optical properties of the fluorophore/quencher pair attached to the ends of the molecular beacon DNA strand. In a very selective coordination of Hg(2+) to GSH/Cys, the fluorophore/quencher distance increases concomitantly with the dehybridization and dissociation of the beacon stem T-Hg(2+)-T due to the extraction of Hg(2+) ions. This process results in switching the molecular beacon to the "on" state. The concentration range of the probe is 4-200 nM with the limit of detection (LOD) of 4.1 nM for GSH and 4.2 nM Cys. The probe tested satisfactorily against interference for a range of amino acids including sulfur-containing methionine.

  18. A spiral wave front beacon for underwater navigation: transducer prototypes and testing.

    Science.gov (United States)

    Dzikowicz, Benjamin R; Hefner, Brian T

    2012-05-01

    Transducers for acoustic beacons which can produce outgoing signals with wave fronts whose horizontal cross sections are circular or spiral are studied experimentally. A remote hydrophone is used to determine its aspect relative to the transducers by comparing the phase of the circular signal to the phase of the spiral signal. The transducers for a "physical-spiral" beacon are made by forming a strip of 1-3 piezocomposite transducer material around either a circular or spiral backing. A "phased-spiral" beacon is made from an array of transducer elements which can be driven either in phase or staggered out of phase so as to produce signals with either a circular or spiral wave front. Measurements are made to study outgoing signals and their usefulness in determining aspect angle. Vertical beam width is also examined and phase corrections applied when the hydrophone is out of the horizontal plane of the beacon. While numerical simulations indicate that the discontinuity in the physical-spiral beacon introduces errors into the measured phase, damping observed at the ends of the piezocomposite material is a more significant source of error. This damping is also reflected in laser Doppler vibrometer measurements of the transducer's surface velocity.

  19. Real-time quantitative nicking endonuclease-mediated isothermal amplification with small molecular beacons.

    Science.gov (United States)

    Xu, Wentao; Wang, Chenguang; Zhu, Pengyu; Guo, Tianxiao; Xu, Yuancong; Huang, Kunlun; Luo, Yunbo

    2016-04-21

    Techniques of isothermal amplification have recently made great strides, and have generated significant interest in the field of point-of-care detection. Nicking endonuclease-mediated isothermal amplification (NEMA) is an example of simple isothermal technology. In this paper, a real-time quantitative nicking endonuclease-mediated isothermal amplification with small molecular beacons (SMB-NEMA) of improved specificity and sensitivity is described. First, we optimized the prohibition of de novo synthesis by choosing Nt·BstNBI endonuclease. Second, the whole genome was successfully amplified with Nt·BstNBI (6 U), betaine (1 M) and trehalose (60 mM) for the first time. Third, we achieved 10 pg sensitivity for the first time after adding a small molecular beacon that spontaneously undergoes a conformational change when hybridizing to target, and the practical test validated the assay's application. The small molecular beacon has a similar melting temperature to the reaction temperature, but is approximately 10 bp shorter than the length of a traditional molecular beacon. A new threshold regulation was also established for isothermal conditions. Finally, we established a thermodynamic model for designing small molecular beacons. This multistate model is more correct than the traditional algorithm. This theoretical and practical basis will help us to monitor SMB-NEMA in a quantitative way. In summary, our SMB-NEMA method allows the simple, specific and sensitive assessment of isothermal DNA quantification.

  20. First tests of wavefront sensing with a constellation of laser guide beacons

    CERN Document Server

    Lloyd-Hart, M; Milton, N M; Stalcup, T; Snyder, M; Putnam, N; Angel, J R P

    2005-01-01

    Adaptive optics to correct current telescopes over wide fields, or future very large telescopes over even narrow fields, will require real-time wavefront measurements made with a constellation of laser beacons. Here we report the first such measurements, made at the 6.5 m MMT with five Rayleigh beacons in a 2 arcmin pentagon. Each beacon is made with a pulsed beam at 532 nm, of 4 W at the exit pupil of the projector. The return is range-gated from 20-29 km and recorded at 53 Hz by a 36-element Shack-Hartmann sensor. Wavefronts derived from the beacons are compared with simultaneous wavefronts obtained for individual natural stars within or near the constellation. Observations were made in seeing averaging 1.0 arcsec with 2/3 of the aberration measured to be from a ground layer of mean height 380 m. Under these conditions, subtraction of the simple instantaneous average of the five beacon wavefronts from the stellar wavefronts yielded a 40% rms reduction in the measured modes of the distortion over a 2 arcmin ...

  1. Study of an Innovative Indoor Robotic Navigation Approach Based on Beacons and PSD

    Directory of Open Access Journals (Sweden)

    Wang Zhenxing

    2016-01-01

    Full Text Available In this paper, innovative indoor navigation methods have been proposed to meet the challenges in robotic navigation systems. The general positioning methods for robotic navigation include vision-based approaches, WIFI beacons, infrared beacons, ultrasonic beacons, etc. However, the common problem with these methods is their inaccuracy. Especially, improving the precision of robotic positioning mechanisms is the key to indoor navigation systems. This paper proposes an approach that combines the external rotating beacon with an internal rotation of position sensitive devices (PSD which are installed on the robot. While two infrared beams from an external beacon source are equally projected to both sides of the PSD, the robot‟s position can be calculated precisely. The high performance and accurate results can be achieved by optimizing the rotation aligning time, dividing the working area, and compensating errors with information fusion. In comparison with other generic approaches, this proposed innovative approach requires less computing resources and is easier to implement due to its much lower complexity for the computing algorithms.

  2. Polarization Methods of Measuring the Roll Angle of an Object in Motion in Radio Beacon Navigation Systems

    Science.gov (United States)

    Gulko, V. L.; Mescheryakov, A. A.

    2016-06-01

    Polarization methods of measuring the roll angle of an object in motion with the help of radio beacon systems are considered. The polarization properties of the beacon signals received on board the object and amplitude-phase processing of their orthogonal polarized components are used to accomplish this goal.

  3. 75 FR 20364 - Public Buildings Service; Key Largo Beacon Annex Site; Key Largo, FL; Transfer of Property

    Science.gov (United States)

    2010-04-19

    ... From the Federal Register Online via the Government Publishing Office GENERAL SERVICES ADMINISTRATION Public Buildings Service; Key Largo Beacon Annex Site; Key Largo, FL; Transfer of Property..., identified as Key Largo Beacon Annex Site, Key Largo, FL to the U.S. Fish and Wildlife Service, Department...

  4. A molecular beacon-based DNA switch for reversible pH sensing in vesicles and live cells.

    Science.gov (United States)

    Narayanaswamy, Nagarjun; Nair, Raji R; Suseela, Y V; Saini, Deepak Kumar; Govindaraju, T

    2016-07-01

    In this Communication, a molecular beacon-based DNA switch (LMB) is developed as an efficient and reversible pH sensing probe. Remarkably, LMB exhibited reversible structural transition between the closed (molecular beacon) and open (A-motif) states very efficiently in synthetic vesicles and live cells without the need for any transfection agents.

  5. A Measurement Study of BLE iBeacon and Geometric Adjustment Scheme for Indoor Location-Based Mobile Applications

    Directory of Open Access Journals (Sweden)

    Jeongyeup Paek

    2016-01-01

    Full Text Available Bluetooth Low Energy (BLE and the iBeacons have recently gained large interest for enabling various proximity-based application services. Given the ubiquitously deployed nature of Bluetooth devices including mobile smartphones, using BLE and iBeacon technologies seemed to be a promising future to come. This work started off with the belief that this was true: iBeacons could provide us with the accuracy in proximity and distance estimation to enable and simplify the development of many previously difficult applications. However, our empirical studies with three different iBeacon devices from various vendors and two types of smartphone platforms prove that this is not the case. Signal strength readings vary significantly over different iBeacon vendors, mobile platforms, environmental or deployment factors, and usage scenarios. This variability in signal strength naturally complicates the process of extracting an accurate location/proximity estimation in real environments. Our lessons on the limitations of iBeacon technique lead us to design a simple class attendance checking application by performing a simple form of geometric adjustments to compensate for the natural variations in beacon signal strength readings. We believe that the negative observations made in this work can provide future researchers with a reference on how well of a performance to expect from iBeacon devices as they enter their system design phases.

  6. A beacon interval shifting scheme for interference mitigation in body area networks.

    Science.gov (United States)

    Kim, Seungku; Kim, Seokhwan; Kim, Jin-Woo; Eom, Doo-Seop

    2012-01-01

    This paper investigates the issue of interference avoidance in body area networks (BANs). IEEE 802.15 Task Group 6 presented several schemes to reduce such interference, but these schemes are still not proper solutions for BANs. We present a novel distributed TDMA-based beacon interval shifting scheme that reduces interference in the BANs. A design goal of the scheme is to avoid the wakeup period of each BAN coinciding with other networks by employing carrier sensing before a beacon transmission. We analyze the beacon interval shifting scheme and investigate the proper back-off length when the channel is busy. We compare the performance of the proposed scheme with the schemes presented in IEEE 802.15 Task Group 6 using an OMNeT++ simulation. The simulation results show that the proposed scheme has a lower packet loss, energy consumption, and delivery-latency than the schemes of IEEE 802.15 Task Group 6.

  7. A spiral wave front beacon for underwater navigation: basic concept and modeling.

    Science.gov (United States)

    Hefner, Brian T; Dzikowicz, Benjamin R

    2011-06-01

    A spiral wave front source produces an acoustic field that has a phase that is proportional to the azimuthal angle about the source. The concept of a spiral wave front beacon is developed by combining this source with a reference source that has a phase that is constant with the angle. The phase difference between these sources contains information about the receiver's azimuthal angle relative to the beacon and can be used for underwater navigation. To produce the spiral wave front, two sources are considered: a "physical-spiral" source, which produces the appropriate phase by physically deforming the active element of the source into a spiral, and a "phased-spiral" source, which uses an array of active elements, each driven with the appropriate phase, to produce the spiral wave front. Using finite element techniques, the fields produced by these sources are examined in the context of the spiral wave front beacon, and the advantages of each source are discussed.

  8. Visual detection of Akt mRNA in living cell using gold nanoparticle beacon

    Science.gov (United States)

    Ma, Yi; Tian, Caiping; Li, Siwen; Wang, Zhaohui; Gu, Yueqing

    2014-09-01

    PI3K-Akt signaling pathway plays the key role in cell apoptosis and survival, and the components of PI3K /Akt signaling pathway are often abnormally expressed in human tumors. Therefore, determination of the Akt (protein kinase B, PKB) messenger ribonucleic acid (mRNA) expression is significantly important in understanding the mechanism of tumor progression. In this study, we designed a special hairpin deoxyribonucleic acid (DNA) functionalized with gold nanoparticles and fluorescein isothiocyanate(FITC) as a beacon for detecting human Akt mRNA. Spectrofluorometer was used to detect the fluorescence quenching and recovery of the beacons, and laser confocal scanning microscopy was adopted to image Akt mRNA in cells. The results showed that this beacon could sensitively and quantitatively measure the Akt mRNA in living cells . This strategy is potentially useful for the cellular imaging of RNA or protein expression in living cells.

  9. A new class of SETI beacons that contain information (22-aug-2010)

    CERN Document Server

    Harp, G R; Blair, Samantha K; Arbunich, J; Backus, P R; Tarter, J C

    2012-01-01

    In the cm-wavelength range, an extraterrestrial electromagnetic narrow band (sine wave) beacon is an excellent choice to get alien attention across interstellar distances because 1) it is not strongly affected by interstellar / interplanetary dispersion or scattering, and 2) searching for narrowband signals is computationally efficient (scales as Ns log(Ns) where Ns = number of voltage samples). Here we consider a special case wideband signal where two or more delayed copies of the same signal are transmitted over the same frequency and bandwidth, with the result that ISM dispersion and scattering cancel out during the detection stage. Such a signal is both a good beacon (easy to find) and carries arbitrarily large information rate (limited only by the atmospheric transparency to about 10 GHz). The discovery process uses an autocorrelation algorithm, and we outline a compute scheme where the beacon discovery search can be accomplished with only 2x the processing of a conventional sine wave search, and discuss...

  10. Kontextbaserad information genom iBeacon : En implementation i iOS och Android

    OpenAIRE

    2014-01-01

    I dagsläget växer behovet av rätt information vid rätt plats, kontextbaserad information. Med hjälp av iBeacon kan man till en stor utsträckning förse det här behovet med en lösning. I uppsatsen undersöks användningsområden för iBeacon och idéer för hur man kan utveckla lösningar med hjälp av iBeacon. Ett koncept kommer att implementeras för att distribuera kontextbaserad information på mässor. Konceptet utvecklades till iOS och Android. Applikationerna tar hjälp av en webbtjänst för att unde...

  11. Development of an aptamer beacon for detection of interferon-gamma.

    Science.gov (United States)

    Tuleuova, Nazgul; Jones, Caroline N; Yan, Jun; Ramanculov, Erlan; Yokobayashi, Yohei; Revzin, Alexander

    2010-03-01

    Traditional antibody-based affinity sensing strategies employ multiple reagents and washing steps and are unsuitable for real-time detection of analyte binding. Aptamers, on the other hand, may be designed to monitor binding events directly, in real-time, without the need for secondary labels. The goal of the present study was to design an aptamer beacon for fluorescence resonance energy transfer (FRET)-based detection of interferon-gamma (IFN-gamma)--an important inflammatory cytokine. Variants of DNA aptamer modified with biotin moieties and spacers were immobilized on avidin-coated surfaces and characterized by surface plasmon resonance (SPR). The SPR studies showed that immobilization of aptamer via the 3' end resulted in the best binding IFN-gamma (K(d) = 3.44 nM). This optimal aptamer variant was then used to construct a beacon by hybridizing fluorophore-labeled aptamer with an antisense oligonucleotide strand carrying a quencher. SPR studies revealed that IFN-gamma binding with an aptamer beacon occurred within 15 min of analyte introduction--suggesting dynamic replacement of the quencher-complementary strand by IFN-gamma molecules. To further highlight biosensing applications, aptamer beacon molecules were immobilized inside microfluidic channels and challenged with varying concentration of analyte. Fluorescence microscopy revealed low fluorescence in the absence of analyte and high fluorescence after introduction of IFN-gamma. Importantly, unlike traditional antibody-based immunoassays, the signal was observed directly upon binding of analyte without the need for multiple washing steps. The surface immobilized aptamer beacon had a linear range from 5 to 100 nM and a lower limit of detection of 5 nM IFN-gamma. In conclusion, we designed a FRET-based aptamer beacon for monitoring of an inflammatory cytokine-IFN-gamma. In the future, this biosensing strategy will be employed to monitor dynamics of cytokine production by the immune cells.

  12. Time-Resolved Nucleic Acid Hybridization Beacons Utilizing Unimolecular and Toehold-Mediated Strand Displacement Designs.

    Science.gov (United States)

    Massey, Melissa; Ancona, Mario G; Medintz, Igor L; Algar, W Russ

    2015-12-01

    Nucleic acid hybridization probes are sought after for numerous assay and imaging applications. These probes are often limited by the properties of fluorescent dyes, prompting the development of new probes where dyes are paired with novel or nontraditional luminescent materials. Luminescent terbium complexes are an example of such a material, and these complexes offer several unique spectroscopic advantages. Here, we demonstrate two nonstem-loop designs for light-up nucleic acid hybridization beacons that utilize time-resolved Förster resonance energy transfer (TR-FRET) between a luminescent Lumi4-Tb cryptate (Tb) donor and a fluorescent reporter dye, where time-resolved emission from the dye provides an analytical signal. Both designs are based on probe oligonucleotides that are labeled at their opposite termini with Tb and a fluorescent reporter dye. In one design, a probe is partially blocked with a quencher dye-labeled oligonucleotide, and target hybridization is signaled through toehold-mediated strand displacement and loss of a competitive FRET pathway. In the other design, the intrinsic folding properties of an unblocked probe are utilized in combination with a temporal mechanism for signaling target hybridization. This temporal mechanism is based on a recently elucidated "sweet spot" for TR-FRET measurements and exploits distance control over FRET efficiencies to shift the Tb lifetime within or outside the time-gated detection window for measurements. Both the blocked and unblocked beacons offer nanomolar (femtomole) detection limits, response times on the order of minutes, multiplexing through the use of different reporter dyes, and detection in complex matrices such as serum and blood. The blocked beacons offer better mismatch selectivity, whereas the unblocked beacons are simpler in design. The temporal mechanism of signaling utilized with the unblocked beacons also plays a significant role with the blocked beacons and represents a new and effective

  13. A complementary palette of NanoCluster Beacons.

    Science.gov (United States)

    Obliosca, Judy M; Babin, Mark C; Liu, Cong; Liu, Yen-Liang; Chen, Yu-An; Batson, Robert A; Ganguly, Mainak; Petty, Jeffrey T; Yeh, Hsin-Chih

    2014-10-28

    NanoCluster Beacons (NCBs), which use few-atom DNA-templated silver clusters as reporters, are a type of activatable molecular probes that are low-cost and easy to prepare. While NCBs provide a high fluorescence enhancement ratio upon activation, their activation colors are currently limited. Here we report a simple method to design NCBs with complementary emission colors, creating a set of multicolor probes for homogeneous, separation-free detection. By systematically altering the position and the number of cytosines in the cluster-nucleation sequence, we have tuned the activation colors of NCBs to green (C8-8, 460 nm/555 nm); yellow (C5-5, 525 nm/585 nm); red (C3-4, 580 nm/635 nm); and near-infrared (C3-3, 645 nm/695 nm). At the same NCB concentration, the activated yellow NCB (C5-5) was found to be 1.3 times brighter than the traditional red NCB (C3-4). Three of the four colors (green, yellow, and red) were relatively spectrally pure. We also found that subtle changes in the linker sequence (down to the single-nucleotide level) could significantly alter the emission spectrum pattern of an NCB. When the length of linker sequences was increased, the emission peaks were found to migrate in a periodic fashion, suggesting short-range interactions between silver clusters and nucleobases. Size exclusion chromatography results indicated that the activated NCBs are more compact than their native duplex forms. Our findings demonstrate the unique photophysical properties and environmental sensitivities of few-atom DNA-templated silver clusters, which are not seen before in common organic dyes or luminescent crystals.

  14. A transfection reporter for the prevention of false-negative results in molecular beacon experiments.

    Science.gov (United States)

    Toga, Tatsuya; Kuraoka, Isao; Yasui, Akira; Iwai, Shigenori

    2013-09-01

    We previously developed a molecular beacon-type probe to detect the strand scission in cellular base excision repair and found that the phosphodiester linkages in the fluorophore/quencher linkers were cleaved. This reaction was applied to a transfection reporter, which contained the unmodified phosphodiester in the linker to another type of fluorophore. After cotransfection of cells with the probe and the reporter, the signals were used to detect the incision and to confirm the proper transfection, respectively. This method will contribute to the prevention of false-negative results in experiments using molecular beacon-type probes.

  15. Code Development and Analysis Program: developmental checkout of the BEACON/MOD2A code. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Ramsthaler, J. A.; Lime, J. F.; Sahota, M. S.

    1978-12-01

    A best-estimate transient containment code, BEACON, is being developed by EG and G Idaho, Inc. for the Nuclear Regulatory Commission's reactor safety research program. This is an advanced, two-dimensional fluid flow code designed to predict temperatures and pressures in a dry PWR containment during a hypothetical loss-of-coolant accident. The most recent version of the code, MOD2A, is presently in the final stages of production prior to being released to the National Energy Software Center. As part of the final code checkout, seven sample problems were selected to be run with BEACON/MOD2A.

  16. Establishment of an accurate and fast detection method using molecular beacons in loop-mediated isothermal amplification assay

    Science.gov (United States)

    Liu, Wei; Huang, Simo; Liu, Ningwei; Dong, Derong; Yang, Zhan; Tang, Yue; Ma, Wen; He, Xiaoming; Ao, Da; Xu, Yaqing; Zou, Dayang; Huang, Liuyu

    2017-01-01

    This study established a constant-temperature fluorescence quantitative detection method, combining loop-mediated isothermal amplification (LAMP) with molecular beacons. The advantages of LAMP are its convenience and efficiency, as it does not require a thermocycler and results are easily visualized by the naked eye. However, a major disadvantage of current LAMP techniques is the use of indirect evaluation methods (e.g., electrophoresis, SYBR Green I dye, precipitation, hydroxynaphthol blue dye, the turbidimetric method, calcein/Mn2+ dye, and the composite probe method), which cannot distinguish between the desired products and products of nonspecific amplification, thereby leading to false positives. Use of molecular beacons avoids this problem because molecular beacons produce fluorescence signals only when binding to target DNA, thus acting as a direct indicator of amplification products. Our analyses determined the optimal conditions for molecular beacons as an evaluation tool in LAMP: beacon length of 25–45 bp, beacon concentration of 0.6–1 pmol/μL, and reaction temperature of 60–65 °C. In conclusion, we validated a novel molecular beacon loop-mediated isothermal amplification method (MB-LAMP), realizing the direct detection of LAMP product. PMID:28059137

  17. Sequential strand displacement beacon for detection of DNA coverage on functionalized gold nanoparticles.

    Science.gov (United States)

    Paliwoda, Rebecca E; Li, Feng; Reid, Michael S; Lin, Yanwen; Le, X Chris

    2014-06-17

    Functionalizing nanomaterials for diverse analytical, biomedical, and therapeutic applications requires determination of surface coverage (or density) of DNA on nanomaterials. We describe a sequential strand displacement beacon assay that is able to quantify specific DNA sequences conjugated or coconjugated onto gold nanoparticles (AuNPs). Unlike the conventional fluorescence assay that requires the target DNA to be fluorescently labeled, the sequential strand displacement beacon method is able to quantify multiple unlabeled DNA oligonucleotides using a single (universal) strand displacement beacon. This unique feature is achieved by introducing two short unlabeled DNA probes for each specific DNA sequence and by performing sequential DNA strand displacement reactions. Varying the relative amounts of the specific DNA sequences and spacing DNA sequences during their coconjugation onto AuNPs results in different densities of the specific DNA on AuNP, ranging from 90 to 230 DNA molecules per AuNP. Results obtained from our sequential strand displacement beacon assay are consistent with those obtained from the conventional fluorescence assays. However, labeling of DNA with some fluorescent dyes, e.g., tetramethylrhodamine, alters DNA density on AuNP. The strand displacement strategy overcomes this problem by obviating direct labeling of the target DNA. This method has broad potential to facilitate more efficient design and characterization of novel multifunctional materials for diverse applications.

  18. The Effects of a Rectangular Rapid-Flashing Beacon on Vehicle Speed

    Science.gov (United States)

    VanWagner, Michelle; Van Houten, Ron; Betts, Brian

    2011-01-01

    In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal…

  19. Genotyping Single Nucleotide Polymorphisms Using Different Molecular Beacon Multiplexed within a Suspended Core Optical Fiber

    Directory of Open Access Journals (Sweden)

    Linh Viet Nguyen

    2014-08-01

    Full Text Available We report a novel approach to genotyping single nucleotide polymorphisms (SNPs using molecular beacons in conjunction with a suspended core optical fiber (SCF. Target DNA sequences corresponding to the wild- or mutant-type have been accurately recognized by immobilizing two different molecular beacons on the core of a SCF. The two molecular beacons differ by one base in the loop-probe and utilize different fluorescent indicators. Single-color fluorescence enhancement was obtained when the immobilized SCFs were filled with a solution containing either wild-type or mutant-type sequence (homozygous sample, while filling the immobilized SCF with solution containing both wild- and mutant-type sequences resulted in dual-color fluorescence enhancement, indicating a heterozygous sample. The genotyping was realized amplification-free and with ultra low-volume for the required DNA solution (nano-liter. This is, to our knowledge, the first genotyping device based on the combination of optical fiber and molecular beacons.

  20. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

    Directory of Open Access Journals (Sweden)

    Yuanfu Mo

    Full Text Available In a vehicular ad hoc network (VANET, the periodic exchange of single-hop status information broadcasts (beacon frames produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

  1. Beacon-Based Service Publishing Framework in Multiservice Wi-Fi Hotspots

    Directory of Open Access Journals (Sweden)

    Di Sorte Dario

    2007-01-01

    Full Text Available In an expected future multiaccess and multiservice IEEE 802.11 environment, the problem of providing users with useful service-related information to support a correct rapid network selection is expected to become a very important issue. A feasible short-term 802.11-tailored working solution, compliant with existing equipment, is to publish service information encoded within the SSID information element within beacon frames. This makes it possible for an operator to implement service publishing in 802.11 networks while waiting for a standardized mechanism. Also, this straightforward approach has allowed us to evaluate experimentally the performance of a beacon-based service publishing solution. In fact, the main focus of the paper is indeed to present a quantitative comparison of service discovery times between the legacy scenario, where the user is forced to associate and authenticate with a network point of access to check its service offer, and the enhanced scenario where the set of service-related information is broadcasted within beacons. These discovery times are obtained by processing the results of a measurement campaign performed in a multiaccess/service 802.11 environment. This analysis confirms the effectiveness of the beacon-based approach. We also show that the cost in terms of wireless bandwidth consumption of such solution is low.

  2. Molecular beacon nanosensors for live cell detection and tracking differentiation and reprogramming

    DEFF Research Database (Denmark)

    Ilieva, Mirolyuba

    2013-01-01

    cell level is molecular beacons (MBs). They are stem-loop structured antisense oligonucleotide probes labelled with a reporter fluorophore at one end and with quencher at the other end. Upon hybridization with complementary target, hydrogen bonds between stem nucleotide bases brake, resulting...

  3. Reliable beacon transmission based MAC protocol for LR-WPANs over WLAN interferences

    Institute of Scientific and Technical Information of China (English)

    Ji-Hoon PARK; Byung-Seo KIM

    2014-01-01

    The use of IEEE 802.15.4 standard based application systems has been rapidly increasing, for example, in medical services, sensor networks, public safety systems, and home automation systems. However, issues arise from the fact that IEEE 802.15.4 standard based low rate wireless personal area networks (LR-WPANs) use the same frequency bands as wireless local area networks (WLANs), and they interfere with each other. Based on past research on this issue, the interference has a more serious impact on LR-WPANs’ performance than on WLANs’ performance. In this paper we propose a method to improve LR-WPANs’ performance while coexisting with WLANs, which is called the reliable beacon transmission based medium access control (MAC) protocol. Since the reliability of a beacon frame is important, in this method, only the beacon frame is transmitted in interference-free channels, and the data packets are transmitted in interfered channels instead of abandoning the channels altogether. This method increases the reliability of beacon frames as well as overall channel utilizations. The effectiveness of the proposed method was evaluated through extensive simulations, and this paper proves that this method improves the performance of IEEE 802.15.4 based wireless sensor networks (WSNs) over WLANs’ interferences.

  4. Analysis and Enhancement of IEEE 802.15.4e DSME Beacon Scheduling Model

    Directory of Open Access Journals (Sweden)

    Kwang-il Hwang

    2014-01-01

    Full Text Available In order to construct a successful Internet of things (IoT, reliable network construction and maintenance in a sensor domain should be supported. However, IEEE 802.15.4, which is the most representative wireless standard for IoT, still has problems in constructing a large-scale sensor network, such as beacon collision. To overcome some problems in IEEE 802.15.4, the 15.4e task group proposed various different modes of operation. Particularly, the IEEE 802.15.4e deterministic and synchronous multichannel extension (DSME mode presents a novel scheduling model to solve beacon collision problems. However, the DSME model specified in the 15.4e draft does not present a concrete design model but a conceptual abstract model. Therefore, in this paper we introduce a DSME beacon scheduling model and present a concrete design model. Furthermore, validity and performance of DSME are evaluated through experiments. Based on experiment results, we analyze the problems and limitations of DSME, present solutions step by step, and finally propose an enhanced DSME beacon scheduling model. Through additional experiments, we prove the performance superiority of enhanced DSME.

  5. Beacon signal in transcranial color coded ultrasound: A sign for brain death

    Directory of Open Access Journals (Sweden)

    Mehmet Akif Topçuoğlu

    2014-04-01

    Full Text Available A widely under-recognized brain-death confirming transcranial ultrasonography pattern resembling the red-blue beacon signal was demonstrated. Familiarity to this distinct and characteristic ultrasonic pattern seems to be important in the perspective of point-of-care neurological ultrasound use and knobology.

  6. Aplicació de seguiment i visualització de dispositus iBeacon

    OpenAIRE

    2015-01-01

    Els beacons són dispositius que emeten senyal bluetooth low energy (BLE) de manera contínua durant un llarg període de temps. Aquesta jove i emergent tecnologia esta cridada a ser una revolució en molts camps de la nostra vida diària.

  7. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs

    Science.gov (United States)

    Mo, Yuanfu; Yu, Dexin; Song, Jun; Zheng, Kun; Guo, Yajuan

    2015-01-01

    In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network. PMID:26571042

  8. A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

    Science.gov (United States)

    Mo, Yuanfu; Yu, Dexin; Song, Jun; Zheng, Kun; Guo, Yajuan

    2015-01-01

    In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

  9. Working Together To Build Beacon Centers in San Francisco: Evaluation Findings from 1998-2000.

    Science.gov (United States)

    Walker, Karen E.; Arbreton, Amy J. A.

    The Beacons Initiative aimed to transform eight public schools (five middle schools and three high schools) into youth and family centers in low-income neighborhoods in San Francisco, California. Using a coalition of local partners and funding from public agencies and foundations, the centers served 7,500 youth and adults between July 1, 1999, and…

  10. Leveraging Health IT to Reduce Disparities in Three Underserved Beacon Communities.

    Science.gov (United States)

    Des Jardins, Terrisca; Drone, Shenetta A; Hashisaka, Susan; Hazzard, Jobyna; Hunt, Susan B; Massey, Kimberly; Rein, Alison; Schachter, Abigail; Turske, Scott

    2016-01-01

    Using health information technology (IT) can potentially address health disparities by increasing access to care, delivering higher-quality care, improving patient-provider communication, and enhancing patient safety. It describes challenges encountered by three underserved Beacon Communities that implemented health IT interventions, including inadequate connectivity infrastructure, technical support, expertise, and financial resources; provider shortages and staff turnover; and equipment theft.

  11. Impacts of Fog Characteristics, Forward Illumination, and Warning Beacon Intensity Distribution on Roadway Hazard Visibility.

    Science.gov (United States)

    Bullough, John D; Rea, Mark S

    2016-01-01

    Warning beacons are critical for the safety of transportation, construction, and utility workers. These devices need to produce sufficient luminous intensity to be visible without creating glare to drivers. Published standards for the photometric performance of warning beacons do not address their performance in conditions of reduced visibility such as fog. Under such conditions light emitted in directions other than toward approaching drivers can create scattered light that makes workers and other hazards less visible. Simulations of visibility of hazards under varying conditions of fog density, forward vehicle lighting, warning beacon luminous intensity, and intensity distribution were performed to assess their impacts on visual performance by drivers. Each of these factors can influence the ability of drivers to detect and identify workers and hazards along the roadway in work zones. Based on the results, it would be reasonable to specify maximum limits on the luminous intensity of warning beacons in directions that are unlikely to be seen by drivers along the roadway, limits which are not included in published performance specifications.

  12. A nanocluster beacon based on the template transformation of DNA-templated silver nanoclusters.

    Science.gov (United States)

    Teng, Ye; Jia, Xiaofang; Zhang, Shan; Zhu, Jinbo; Wang, Erkang

    2016-01-28

    In this work, we developed a novel light-up nanocluster beacon (NCB) based on shuttling dark silver nanoclusters (NCs) to a bright scaffold through hybridization. The fluorescence enhancement was as high as 70-fold when the two templates were on the opposite sides of the duplexes, enabling sensitive and selective detection of DNA.

  13. Single-cell detection of mRNA expression using nanofountain-probe electroporated molecular beacons.

    Science.gov (United States)

    Giraldo-Vela, Juan P; Kang, Wonmo; McNaughton, Rebecca L; Zhang, Xuemei; Wile, Brian M; Tsourkas, Andrew; Bao, Gang; Espinosa, Horacio D

    2015-05-01

    New techniques for single-cell analysis enable new discoveries in gene expression and systems biology. Time-dependent measurements on individual cells are necessary, yet the common single-cell analysis techniques used today require lysing the cell, suspending the cell, or long incubation times for transfection, thereby interfering with the ability to track an individual cell over time. Here a method for detecting mRNA expression in live single cells using molecular beacons that are transfected into single cells by means of nanofountain probe electroporation (NFP-E) is presented. Molecular beacons are oligonucleotides that emit fluorescence upon binding to an mRNA target, rendering them useful for spatial and temporal studies of live cells. The NFP-E is used to transfect a DNA-based beacon that detects glyceraldehyde 3-phosphate dehydrogenase and an RNA-based beacon that detects a sequence cloned in the green fluorescence protein mRNA. It is shown that imaging analysis of transfection and mRNA detection can be performed within seconds after electroporation and without disturbing adhered cells. In addition, it is shown that time-dependent detection of mRNA expression is feasible by transfecting the same single cell at different time points. This technique will be particularly useful for studies of cell differentiation, where several measurements of mRNA expression are required over time.

  14. Visual detection of STAT5B gene expression in living cell using the hairpin DNA modified gold nanoparticle beacon.

    Science.gov (United States)

    Xue, Jianpeng; Shan, Lingling; Chen, Haiyan; Li, Yang; Zhu, Hongyan; Deng, Dawei; Qian, Zhiyu; Achilefu, Samuel; Gu, Yueqing

    2013-03-15

    Signal transducer and activator of transcription 5B (STAT5B) is an important protein in JAK-STAT signaling pathway that is responsible for the metastasis and proliferation of tumor cells. Determination of the STAT5B messenger Ribonucleic Acid (mRNA) relating to the STAT5B expression provides insight into the mechanism of tumor progression. In this study, we designed and used a special hairpin deoxyribonucleic acid (DNA) for human STAT5B mRNA to functionalize gold nanoparticles, which served as a beacon for detecting human STAT5B expression. Up to 90% quenching efficiency was achieved. Upon hybridizing with the target mRNA, the hairpin DNA modified gold nanoparticle beacons (hDAuNP beacons) release the fluorophores attached at 5' end of the oligonucleotide sequence. The fluorescence properties of the beacon before and after the hybridization with the complementary DNA were confirmed in vitro. The stability of hDAuNP beacons against degradation by DNase I and GSH indicated that the prepared beacon is stable inside cells. The detected fluorescence in MCF-7 cancer cells correlates with the specific STAT5B mRNA expression, which is consistent with the result from PCR measurement. Fluorescence microscopy showed that the hDAuNP beacons internalized in cells without using transfection agents, with intracellular distribution in the cytoplasm rather than the nucleus. The results demonstrated that this beacon could directly provide quantitative measurement of the intracellular STAT5B mRNA in living cells. Compared to the previous approaches, this beacon has advantages of higher target to background ratio of detection and an increased resistance to nuclease degradation. The strategy reported in this study is a promising approach for the intracellular measurement of RNA or protein expression in living cells, and has great potential in the study of drug screening and discovery.

  15. Določanje konteksta okolja s pomočjo tehnologij iBeacon in Eddystone

    OpenAIRE

    2016-01-01

    V diplomskem delu se poglobimo v delovanje iBeacon in Eddystone tehnologije, ki temelji na Nizkoenergetskem Bluetoothu. Primerjamo njune prednosti in slabosti ter analiziramo varnostne ranljivosti tehnologije. Raziščemo tudi koncept Fizični splet, v sklopu katerega z Beacon oddajniki oddajamo URL naslove s predmetov v bližnje okolje. Prepoznamo in naštejemo priložnosti za integracijo Beacon oddajnikov v praktične in tržne rešitve. V praktičnem delu se posvetimo načrtovanju uporabniškga vm...

  16. Double-hairpin molecular-beacon-based amplification detection for gene diagnosis linked to cancer.

    Science.gov (United States)

    Xu, Huo; Zhang, Rongbo; Li, Feng; Zhou, Yingying; Peng, Ting; Wang, Xuedong; Shen, Zhifa

    2016-09-01

    A powerful double-hairpin molecular beacon (DHMB) was developed for cancer-related KRAS gene detection based on the one-to-two stoichiometry. During target DNA detection, DHMB can execute signal transduction even if no any exogenous element is involved. Unlike the conventional molecular beacon based on the one-to-one interaction, one target DNA not only hybridizes with one DHMB and opens its hairpin but also promotes the interaction between two DHMBs, causing the separation of two fluorophores from quenchers. This leads to an enhanced fluorescence signal. As a result, the target KRAS gene is able to be detected within a wide dynamic range from 0.05 to 200 nM with the detection limit of 50 pM, indicating a dramatic improvement compared with traditional molecular beacons. Moreover, the point mutations existing in target DNAs can be easily screened. The potential application for target species in real samples was indicated by the analysis of PCR amplicons of DNAs from the DNA extracted from SW620 cell. Besides becoming a promising candidate probe for molecular biology research and clinical diagnosis of genetic diseases, the DHMB is expected to provide a significant insight into the design of DNA probe-based homogenous sensing systems. Graphical Abstract A powerful double-hairpin molecular beacon (DHMB) was developed for cancer-related gene KRAS detection based on the one-to-two stoichiometry. Without the help of any exogenous probe, the point mutation is easily screened, and the target DNA can be quantified down to 50 pM, indicating a dramatic improvement compared with traditional molecular beacons.

  17. Improving the detectability of oxygen saturation level targets for preterm neonates: A laboratory test of tremolo and beacon sonifications.

    Science.gov (United States)

    Deschamps, Marie-Lys; Sanderson, Penelope; Hinckfuss, Kelly; Browning, Caitlin; Loeb, Robert G; Liley, Helen; Liu, David

    2016-09-01

    Recent guidelines recommend oxygen saturation (SpO2) levels of 90%-95% for preterm neonates on supplemental oxygen but it is difficult to discern such levels with current pulse oximetry sonifications. We tested (1) whether adding levels of tremolo to a conventional log-linear pulse oximetry sonification would improve identification of SpO2 ranges, and (2) whether adding a beacon reference tone to conventional pulse oximetry confuses listeners about the direction of change. Participants using the Tremolo (94%) or Beacon (81%) sonifications identified SpO2 range significantly more accurately than participants using the LogLinear sonification (52%). The Beacon sonification did not confuse participants about direction of change. The Tremolo sonification may have advantages over the Beacon sonification for monitoring SpO2 of preterm neonates, but both must be further tested with clinicians in clinically representative scenarios, and with different levels of ambient noise and distractions.

  18. Observability analysis of 2D single-beacon navigation in the presence of constant currents for two classes of maneuvers

    Digital Repository Service at National Institute of Oceanography (India)

    Crasta, N.; Bayat, M.; Aguiar, A.P.; Pascoal, A.M.

    We analyze the observability properties of an underwater vehicle (moving in 2D) performing single beacon navigation for two specic classes of maneuvers, whereby the vehicle measures its distance to a xed transponder located at a known position using...

  19. Traveling-Wave Tube Amplifier Second Harmonic as Millimeter-Wave Beacon Source for Atmospheric Propagation Studies

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.

    2014-01-01

    This paper presents the design and test results of a CW millimeter-wave satellite beacon source, based on the second harmonic from a traveling-wave tube amplifier and utilizes a novel waveguide multimode directional coupler. A potential application of the beacon source is for investigating the atmospheric effects on Q-band (37-42 GHz) and V/W-band (71- 76 GHz) satellite-to-ground signals.

  20. Cleavable DNA-protein hybrid molecular beacon: A novel efficient signal translator for sensitive fluorescence anisotropy bioassay.

    Science.gov (United States)

    Hu, Pan; Yang, Bin

    2016-01-15

    Due to its unique features such as high sensitivity, homogeneous format, and independence on fluorescent intensity, fluorescence anisotropy (FA) assay has become a hotspot of study in oligonucleotide-based bioassays. However, until now most FA probes require carefully customized structure designs, and thus are neither generalizable for different sensing systems nor effective to obtain sufficient signal response. To address this issue, a cleavable DNA-protein hybrid molecular beacon was successfully engineered for signal amplified FA bioassay, via combining the unique stable structure of molecular beacon and the large molecular mass of streptavidin. Compared with single DNA strand probe or conventional molecular beacon, the DNA-protein hybrid molecular beacon exhibited a much higher FA value, which was potential to obtain high signal-background ratio in sensing process. As proof-of-principle, this novel DNA-protein hybrid molecular beacon was further applied for FA bioassay using DNAzyme-Pb(2+) as a model sensing system. This FA assay approach could selectively detect as low as 0.5nM Pb(2+) in buffer solution, and also be successful for real samples analysis with good recovery values. Compatible with most of oligonucleotide probes' designs and enzyme-based signal amplification strategies, the molecular beacon can serve as a novel signal translator to expand the application prospect of FA technology in various bioassays.

  1. Proceedings of the Symposium of the COSPAR Satellite Beacon Group on the Geophysical Use of Satellite Beacon Observations Held at Boston University on 1- 4 June 1976

    Science.gov (United States)

    1976-06-04

    the value of To. and t at the previous step. mLiz0 m EUNO+ONN ISPEON.TR F IATMSPHRE -I, IEUATONS TOTOiO ZTO PLSMi,,o. ~~O Wi.. AND, ,~ MODELO N , N...sophisti- cated calculations. The main features AiplieFiore Componentar th() Modelo in Figure 8 are the following: (a) the XSlow FioreC o n initial rapid...satellite 695 I.- ’I1 I VG.K. Hartmann 1969 Explorer 22 (con’d)J. Atinos . Terr. Phys. 31, (cont’d)663-669 Y.V. Somayajula 1976 Satellite radio beacon Tuhi

  2. Design of a K/Q-Band Beacon Receiver for the Alphasat TDP#5 Experiment

    Science.gov (United States)

    Morse, Jacquelynne R.

    2014-01-01

    This paper describes the design and performance of a coherent KQ-band (2040 GHz) beacon receiver developed at NASA Glenn Research Center (GRC) that will be installed at the Politecnico di Milano (POLIMI) for use in the Alphasat Technology Demonstration Payload 5 (TDP5) beacon experiment. The goal of this experiment is to characterize rain fade attenuation at 40 GHz to improve the performance of existing statistical rain attenuation models in the Q-band. The ground terminal developed by NASA GRC utilizes an FFT-based frequency estimation receiver capable of characterizing total path attenuation effects due to gaseous absorption, clouds, rain, and scintillation. The receiver system has been characterized in the lab and demonstrates a system dynamic range performance of better than 58 dB at 1 Hz and better than 48 dB at 10 Hz rates.

  3. Method and apparatus for a multibeam beacon laser assembly for optical communications

    Science.gov (United States)

    Biswas, Abhijit (Inventor); Sanji, Babak (Inventor); Wright, Malcolm W. (Inventor); Page, Norman Alan (Inventor)

    2005-01-01

    An optical beacon is comprised of a telescope having a primary focal plane or Coud? focal plane, a plurality of fiber coupled laser sources for generating a plurality of beams, a collimator for collimating the plurality of beams, and optics for combining and focusing the plurality of collimated beams onto the primary or Coud? focal plane of the telescope. The telescope propagates the optical beacon, which is arranged into a ring of incoherent plurality of collimated beams. The apparatus further comprises fiber splitters coupled to each laser source to provide at least eight beams from at least four laser sources. The optics comprises a prism assembly, a combiner lens, a focusing lens and a field lens for focusing the plurality of collimated beams onto the primary focal plane or Coud? focal plane of the telescope.

  4. Multi-Band Multi-Tone Tunable Millimeter-Wave Frequency Synthesizer For Satellite Beacon Transmitter

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.

    2016-01-01

    This paper presents the design and test results of a multi-band multi-tone tunable millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a satellite beacon transmitter for radio wave propagation studies at K-band (18 to 26.5 GHz), Q-band (37 to 42 GHz), and E-band (71 to 76 GHz). In addition, the architecture for a compact beacon transmitter, which includes the multi-tone synthesizer, polarizer, horn antenna, and power/control electronics, has been investigated for a notional space-to-ground radio wave propagation experiment payload on a small satellite. The above studies would enable the design of robust high throughput multi-Gbps data rate future space-to-ground satellite communication links.

  5. Performance Evaluation Of BEACON-ENABLED IEEE 802.15.4 Under NS2

    Directory of Open Access Journals (Sweden)

    Faiza Charfi

    2012-04-01

    Full Text Available The increasing demand for real-time applications has made the Quality of Service (Qos support for wireless sensor networks (WSN a fairly new research framework. In this paper, we propose an extended model of the Beacon enabled IEEE 802.15.4 including the Guaranteed Time Slot GTS allocation mechanism in the aim to analyze and evaluate network performances. Series of extensive simulations were performed to analyze the impact of the Beacon Order BO and the Superframe Order SO on the network performance based on commonly known metrics. In particular, we examine data packet delivery performance and the throughput for different duty cycle rates. Also, we analyze the impact of the number of nodes on collision probability. Thus, for high number of nodes, collision becomes higher and the reachability begins to decline slightly. We discuss and compare simulation results conducted under various parameter settings to the IEEE 802.11network.

  6. A Telomerase-Specific Doxorubicin-Releasing Molecular Beacon for Cancer Theranostics.

    Science.gov (United States)

    Ma, Yi; Wang, Zhaohui; Zhang, Min; Han, Zhihao; Chen, Dan; Zhu, Qiuyun; Gao, Weidong; Qian, Zhiyu; Gu, Yueqing

    2016-03-01

    A molecular beacon-based drug delivery system was designed for both detection of telomerase activity in living cells and telomerase-triggered drug release for precise cancer treatment. This system is composed of a gold nanoparticle core densely packed with FITC-labeled hairpin DNA sequences hybridized with telomerase primers. Molecules of the anticancer drug doxorubicin were intercalated into the stem region of the DNA sequence. The presence of telomerase will elongate the primers, leading to inner chain substitution followed by the release of the FITC fluorescence and the trapped doxorubicin. This molecular beacon could specifically distinguish tumor cells and normal cells based on telomerase activity, precisely release doxorubicin in response to telomerase activity in the tumor cells, and prevent toxicity to normal organs.

  7. Performance evaluation of beacon enabled IEEE 802.15.4 under NS2

    CERN Document Server

    Charfi, Faiza

    2012-01-01

    The increasing demand for real-time applications has made the Quality of Service (Qos) support for wireless sensor networks (WSN) a fairly new research framework. In this paper, we propose an extended model of the Beacon enabled IEEE 802.15.4 including the Guaranteed Time Slot GTS allocation mechanism in the aim to analyze and evaluate network performances. Series of extensive simulations were performed to analyze the impact of the Beacon Order BO and the Superframe Order SO on the network performance based on commonly known metrics. In particular, we examine data packet delivery performance and the throughput for different duty cycle rates. Also, we analyze the impact of the number of nodes on collision probability. Thus, for high number of nodes, collision becomes higher and the reachability begins to decline slightly. We discuss and compare simulation results conducted under various parameter settings to the IEEE 802.11 network.

  8. Creation of a Library Tour Application for Mobile Equipment using iBeacon Technology

    Directory of Open Access Journals (Sweden)

    Jonathan Bradley

    2016-04-01

    Full Text Available We describe the design, development, and deployment of a library tour application utilizing Bluetooth Low Energy devices know as iBeacons. The tour application will serve as library orientation for incoming students. The students visit stations in the library with mobile equipment running a special tour app. When the app detects a beacon nearby, it automatically plays a video that describes the current location. After the tour, students are assessed according to the defined learning objectives. Special attention is given to issues encountered during development, deployment, content creation, and testing of this application that depend on functioning hardware, and the necessity of appointing a project manager to limit scope, define priorities, and create an actionable plan for the experiment.

  9. BEACON FRAME MANIPULATION TO MITIGATE ROGUE ACCESS POINTS: CASE OF ANDROID SMARTPHONE ROGUE ACCESS POINTS

    Directory of Open Access Journals (Sweden)

    Thambo Nyathi

    2015-11-01

    Full Text Available The use of wireless devices to access corporate network resources is now part of the norm within corporate environments. When wireless users need to connect to a network they hardly question the source of their connectivity. Mobile phones, particularly smartphones allow users to access network resources. These harmless looking wireless devices can be a source of major threats if configured to be so. The Internet is awash with mobile apps capable of performing packet sniffing. These applications, coupled with the capability of the smartphone to be configured as an access point, can present a Smartphone Rogue Access Point. Access Points advertise their availability using what is called a beacon frame. This research paper proposes a solution which restructures this beacon frame to include an Authentic Access Point Value which can be used to defend against Rogue Access Points.

  10. Ultrasensitive monitoring of ribozyme cleavage product using molecular-beacon-ligation system

    Institute of Scientific and Technical Information of China (English)

    MENG XiangXian; TANG ZhiWen; WANG KeMin; TAN WeiHong; YANG XiaoHai; LI Jun; GUO QiuPing

    2007-01-01

    This paper reports a new approach to detect ribozyme cleavage product based on the molecular- beacon-ligation system. The molecular beacon, designed in such a way that one-half of its loop is complementary to ribozyme cleavage product, is used to monitor ligation process of RNA/DNA complex in a homogeneous solution and to convert directly cleavage product information into fluorescence signal. The method need not label ribozyme and ribozyme substrate, which is fast, simple and ultrasensitive for detection of cleavage product. Detection limit of the assay is 0.05 nmol/L. The cleavage product of hammerhead ribozyme against hepatitis C virus RNA (HCV-RNA) was detected perfectly based on this assay. Owing to its ultrasensitivity, excellent specificity, convenience and fidelity, this method might hold out great promise in ribozyme reaction and ribozyme gene therapy.

  11. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Directory of Open Access Journals (Sweden)

    Huege Tim

    2017-01-01

    Full Text Available Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this “beacon correction” using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  12. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    CERN Document Server

    Huege, Tim

    2016-01-01

    Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for event-by-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  13. Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

    Science.gov (United States)

    Huege, Tim

    2017-03-01

    Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for eventby-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.

  14. Topical MMP beacon enabled fluorescence-guided resection of oral carcinoma.

    Science.gov (United States)

    Burgess, Laura; Chen, Juan; Wolter, Nikolaus E; Wilson, Brian; Zheng, Gang

    2016-03-01

    Each year almost 300,000 individuals worldwide are diagnosed with oral cancer, more than 90% of these being oral carcinoma [N. Engl. J. Med.328, 1841993]. Surgical resection is the standard of care, but accurate delineation of the tumor boundaries is challenging, resulting in either under-resection with risk of local recurrence or over-resection with increased functional loss and negative impact on quality of life. This study evaluates, in two pre-clinical in vivo tumor models, the potential of fluorescence-guided resection using molecular beacons activated by metalloproteinases, which are frequently upregulated in human oral cancer. In both models there was rapid (beacon activation upon local application, allowing clear fluoresecence imaging in vivo and confirmed by ex vivo fluorescence microscopy and HPLC, with minimal activation in normal oral tissues. Although the tissue penetration was limited using topical application, these findings support further development of this approach towards translation to first-in-human trials.

  15. Increased dose near the skin due to electromagnetic surface beacon transponder.

    Science.gov (United States)

    Ahn, Kang-Hyun; Manger, Ryan; Halpern, Howard J; Aydogan, Bulent

    2015-05-08

    The purpose of this study was to evaluate the increased dose near the skin from an electromagnetic surface beacon transponder, which is used for localization and tracking organ motion. The bolus effect due to the copper coil surface beacon was evaluated with radiographic film measurements and Monte Carlo simulations. Various beam incidence angles were evaluated for both 6 MV and 18 MV experimentally. We performed simulations using a general-purpose Monte Carlo code MCNPX (Monte Carlo N-Particle) to supplement the experimental data. We modeled the surface beacon geometry using the actual mass of the glass vial and copper coil placed in its L-shaped polyethylene terephthalate tubing casing. Film dosimetry measured factors of 2.2 and 3.0 enhancement in the surface dose for normally incident 6 MV and 18 MV beams, respectively. Although surface dose further increased with incidence angle, the relative contribution from the bolus effect was reduced at the oblique incidence. The enhancement factors were 1.5 and 1.8 for 6 MV and 18 MV, respectively, at an incidence angle of 60°. Monte Carlo simulation confirmed the experimental results and indicated that the epidermal skin dose can reach approximately 50% of the dose at dmax at normal incidence. The overall effect could be acceptable considering the skin dose enhancement is confined to a small area (~ 1 cm2), and can be further reduced by using an opposite beam technique. Further clinical studies are justified in order to study the dosimetric benefit versus possible cosmetic effects of the surface beacon. One such clinical situation would be intact breast radiation therapy, especially large-breasted women.

  16. ENHANCED COMPOSITE APPROACH WITH MOBILE BEACON SHORTEST PATH TO SOLVE LOCALIZATION PROBLEM IN WIRELESS SENSOR NETWORK

    Directory of Open Access Journals (Sweden)

    Sunil Kumar,

    2010-12-01

    Full Text Available Wireless sensor network is tremendously being used in different environments to perform various monitoring task such as search, rescue, disaster relief, target tracking and a number of tasks in smart environment. In this paper a unique localization algorithm is proposed that gives the high accuracy in wireless sensor network. We propose amobile beacon algorithm and then merge it with DV- hop algorithm to introduce a unique approach which solves the localization problem in wireless sensor network.

  17. Developing children's palliative care in Africa through beacon centres: lessons learnt.

    Science.gov (United States)

    Downing, Julia D; Marston, Joan; Selwyn, Casey; Ross-Gakava, Laura

    2013-02-18

    Much progress has been made in the provision of palliative care across sub-Saharan Africa, however much still remains to be done, particularly in the area of children's palliative care (CPC). The Beacon Centres programme was set up in 2009, aimed at improving access to CPC in South Africa, Uganda and Tanzania through more and better-trained health professionals and CPC clinical services of a high standard. Having identified sites in each country to develop into CPC Beacon Centres, Navigators were identified who would be the 'champions' for CPC in those sites and lead a programme of training, mentorship and support. Five navigators (2 in Uganda and Tanzania and 1 in South Africa) were trained between September and December 2009. Following this they undertook CPC needs assessments at the 3 centres and set up and delivered a six-month CPC training programme, providing mentorship and support to students to enable them to integrate CPC into their workplaces. To date, 188 participants have commenced the six-month course, with 80 having completed it. CPC has been integrated into the activities of the centres and a CPC virtual resource centre set up in South Africa. The achievements from the Beacon project have been great and the work of the navigators immense, but as in all projects it has not been without its challenges. Lessons learnt include issues around: the focus of the project; the length and nature of the training; assessment; accreditation; the choice of navigators; mentoring; administrative support; co-ordination; the choice of project sites; and the integration of CPC into services. The need for CPC is not going to go away and it is therefore important that models of scaling-up are found that are not only practical, feasible, affordable and sustainable, but that focus on the outcome of improved CPC for all those who need it. It is hoped that the lessons shared from the Beacon Project will help in developing and implementing such models.

  18. Cuba’s Education System: A Beacon of Light in Latin America Facing an Uncertain Future

    OpenAIRE

    Johnstone, Brian

    2008-01-01

    While the international community, through the United Nations Educational, Scientific and Cultural Organization (UNESCO), is promoting a global policy of Education for All (EFA), Cuba stands out as a beacon to other developing countries that have so far been unable to achieve their EFA goals. This paper presents a regional quantitative comparison of eleven Latin American and Caribbean countries—Argentina, Bolivia, Brazil, Chile, Colombia, Cuba, Honduras, Mexico, Paraguay, Dominican Republic, ...

  19. Photodynamic Molecular Beacons: An Image-Guided Therapeutic Approach to Breast Cancer Vertebral Metastases

    Science.gov (United States)

    2011-03-01

    which will restrict the drug and light doses that can be used safely. MMP PDT beacons potentially address this limitation. We have demonstrated the...Shao, R., Ji, X., Gelovani, J. G., and Li, C. (2007) A novel method for imaging in vivo degradation of poly(L-glutamic acid), a biodegradable drug ...Piwnica-Worms, D. (2003) Quantitative analysis of permeation peptide complexes labeled with Technetium-99m: chiral and sequence-specific effects on net cell

  20. A multistatic HF beacon network for ionospheric specification in the Peruvian sector

    Science.gov (United States)

    Hysell, D. L.; Milla, M. A.; Vierinen, J.

    2016-05-01

    A small network of HF beacon transmitters and receivers has been deployed in Peru for specifying the F region ionosphere in the sector. The effort is motivated by ionospheric disturbances associated with equatorial spread F (ESF) and specifically disturbances arising under inauspicious conditions for ESF as determined by numerical simulations. The beacons operate at dual frequencies (2.72 and 3.64 MHz). They are CW but incorporate pseudorandom noise (PRN) coding so that the group delays of the links can be measured. Other observables are power, Doppler shift, bearing, and polarization. A transmitter is currently deployed at Ancon (11°46'37''S, 77°09'1''W, 51 m above sea level (asl)), while receivers are at Jicamarca (11°57'5.8''S, 76°52'27''W, 510 m asl) and Huancayo (12°02'30''S, 75°19'15''W, 3315 m asl). An algorithm for inverting the beacon data combined with electron density profiles from Jicamarca is described. Data and representative solutions from an experimental campaign held in August 2015 are presented and evaluated.

  1. Magnetic resonance beacon to detect intracellular microRNA during neurogenesis.

    Science.gov (United States)

    Lee, Jonghwan; Jin, Yeon A; Ko, Hae Young; Lee, Yong Seung; Heo, Hyejung; Cho, Sujeong; Kim, Soonhag

    2015-02-01

    Magnetic resonance imaging (MRI) offers great spatial resolution for viewing deep tissues and anatomy. We developed a self-assembling signal-on magnetic fluorescence nanoparticle to visualize intracellular microRNAs (miRNAs or miRs) during neurogenesis using MRI. The self-assembling nanoparticle (miR124a MR beacon) was aggregated by the incubation of three different oligonucleotides: a 3' adaptor, a 5' adaptor, and a linker containing miR124a-binding sequences. The T2-weighted magnetic resonance (MR) signal of the self-assembled nanoparticle was quenched when miR124a was absent from test tubes or was minimally expressed in cells and tissues. When miR124a was present in test tubes or highly expressed in vitro and in vivo during P19 cell neurogenesis, it hybridized with the miR124a MR beacon, causing the linker to detach, resulting in increased signal-on MRI intensity. This MR beacon can be used as a new imaging probe to monitor the miRNA-mediated regulation of cellular processes.

  2. Enhancement-Mode TACAN Beaconing Antenna%增强型塔康信标天线

    Institute of Scientific and Technical Information of China (English)

    史小鸣; 苟锋

    2015-01-01

    The operating range and measuring accuracy are directly influenced by TACAN beaconing antenna, currently TACAN beaconing antenna has the characters of modulation circuit loss and modulation pattern reduction and it may enlarge the transmitting power of ground equipment demand. A zero subsidence area exists within the covering range which is unable to measure. The two enhancement-mode TACAN beaconing antennas which use the receiving and sending beam separation theory are presented in this paper. They may effective improve and solve those problems.%塔康信标天线直接影响塔康系统的作用距离和测位精度.现有塔康信标天线存在调制电路损耗与调制方向图衰减等固有特性,造成地面设备需求的发射功率大,并且覆盖距离内往往存在无法测距的"零陷区".本文提出应用收、发波束分离原理的两种增强型塔康天线概念,可望有效改善或解决这些问题.

  3. A Microfluidic Love-Wave Biosensing Device for PSA Detection Based on an Aptamer Beacon Probe.

    Science.gov (United States)

    Zhang, Feng; Li, Shuangming; Cao, Kang; Wang, Pengjuan; Su, Yan; Zhu, Xinhua; Wan, Ying

    2015-06-11

    A label-free and selective aptamer beacon-based Love-wave biosensing device was developed for prostate specific antigen (PSA) detection. The device consists of the following parts: LiTaO3 substrate with SiO2 film as wave guide layer, two set of inter-digital transducers (IDT), gold film for immobilization of the biorecongniton layer and a polydimethylsiloxane (PDMS) microfluidic channels. DNA aptamer, or "artificial antibody", was used as the specific biorecognition probe for PSA capture. Some nucleotides were added to the 3'-end of the aptamer to form a duplex with the 3'-end, turning the aptamer into an aptamer-beacon. Taking advantage of the selective target-induced assembly changes arising from the "aptamer beacon", highly selective and specific detection of PSA was achieved. Furthermore, PDMS microfluidic channels were designed and fabricated to realize automated quantitative sample injection. After optimization of the experimental conditions, the established device showed good performance for PSA detection between 10 ng/mL to 1 μg/mL, with a detection limit of 10 ng/mL. The proposed sensor might be a promising alternative for point of care diagnostics.

  4. Mega-nano detection of foodborne pathogens and transgenes using molecular beacon and semiconductor quantum dot technologies.

    Science.gov (United States)

    Burris, Kellie P; Wu, Tsai-Chin; Vasudev, Milana; Stroscio, Michael A; Millwood, Reginald J; Stewart, C Neal

    2013-09-01

    Signature molecules derived from Listeria monocytogenes, Bacillus thuringiensis, and Salmonella Typhimurium were detected directly on food substrates (mega) by coupling molecular beacon technology utilizing fluorescent resonance energy transfer (FRET), luminescent nanoscale semiconductor quantum dots, and nanoscale quenchers. We designed target DNA sequences for detecting hlyA, Bt cry1Ac, and invA genes from L. monocytogenes, B. thuringiensis and Salmonella Typhimurium, respectively, and prepared molecular beacons for specific targets for use in real-time monitoring. We successfully detected increased fluorescence in the presence of signature molecules at molecular beacon (MB) concentrations from 1.17 nM to 40 nM, depending upon system tested in (water, milk or plant leaves), respective target (hlyA, Bt cry1Ac, or invA) and genomic DNA target concentration (50-800 ng). We were able to detect bacterial genomic DNA derived from L. monocytogenes and Salmonella sp. in a food system, 2% milk ( > 20% of total volume). Furthermore, we infiltrated the Bt cry1Ac beacon in the presence of genomic DNA extracted from B. thuringiensis into Arabidopsis thaliana leaves and observed increased fluorescence in the presence of the target, indicating the ability to use these beacons in a plant system.

  5. Monte Carlo simulation of a gas measurement beacon: computation and validation, ASGA/VGM beacon; Simulation monte carlo d'une balise de mesures de gaz calcul et validation, balise ASGA/VGM

    Energy Technology Data Exchange (ETDEWEB)

    Ferragut, A. [Ste Saphymo, 5 rue du Theatre, 91884 Massy Cedex (France)

    2010-07-01

    The author reports a Monte Carlo simulation of a gas measurement sensor (ASGA or Ventilation Gas Monitor) used to monitor and detect radioactivity in the ventilation of the CERN's LHC (Large Hadron Collider). He recalls the performance required for these beacons, and the different factors governing their detection threshold. He discusses the possibilities offered by the GEANT4 code to model and simulation the beacon physics, and to generate events. Results are obtained in terms of spectrum of deposited energy. The author reports the sensitivity determination

  6. Research on Beacon Hill School Education Practice%比肯山学校教育实践研究

    Institute of Scientific and Technical Information of China (English)

    张蔚

    2015-01-01

    比肯山学校是1927年由罗素夫妇创办的新式学校,罗素夫妇将他们的教育思想运用于实践。教育生态学、教育人类学、教育文化学和教育管理学等多学科的视角下对比肯山学校进行研究,从而考察比肯山学校所具有的历史价值。%Beacon Hill school is an new schools started by Russell couple on 1927. Russell couples are turning their ideas on education in practice. This article make an contrast study on Beacon Hill School from a multidisciplinary perspective of educational ecology, educational anthropology, science of culture and education management and so on, Thus investigate the historical value of the Beacon Hill school.

  7. Preliminary Results of the NASA Beacon Receiver for Alphasat Aldo Paraboni TDP5 Propagation Experiment

    Science.gov (United States)

    Nessel, James; Morse, Jacquelynne; Zemba, Michael; Riva, Carlo; Luini, Lorenzo

    2014-01-01

    NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have initiated a joint propagation campaign within the framework of the Alphasat propagation experiment to characterize rain attenuation, scintillation, and gaseous absorption effects of the atmosphere in the 40 GHz band. NASA GRC has developed and installed a K/Q-band (20/40 GHz) beacon receiver at the POLIMI campus in Milan, Italy, which receives the 20/40 GHz signals broadcast from the Alphasat Aldo Paraboni TDP#5 beacon payload. The primary goal of these measurements is to develop a physical model to improve predictions of communications systems performance within the Q-band. Herein, we describe the design and preliminary performance of the NASA propagation terminal, which has been installed and operating in Milan since May 2014. The receiver is based upon a validated Fast Fourier Transform (FFT) I/Q digital design approach utilized in other operational NASA propagation terminals, but has been modified to employ power measurement via a frequency estimation technique and to coherently track and measure the amplitude of the 20/40 GHz beacon signals. The system consists of a 1.2-m K-band and a 0.6-m Qband Cassegrain reflector employing synchronous open-loop tracking to track the inclined orbit of the Alphasat satellite. An 8 Hz sampling rate is implemented to characterize scintillation effects, with a 1-Hz measurement bandwidth dynamic range of 45 dB. A weather station with an optical disdrometer is also installed to characterize rain drop size distribution for correlation with physical based models.

  8. Performance of the NASA Beacon Receiver for the Alphasat Aldo Paraboni TDP5 Propagation Experiment

    Science.gov (United States)

    Nessel, James; Morse, Jacquelynne; Zemba, Michael; Riva, Carlo; Luini, Lorenzo

    2015-01-01

    NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have initiated a joint propagation campaign within the framework of the Alphasat propagation experiment to characterize rain attenuation, scintillation, and gaseous absorption effects of the atmosphere in the 40 gigahertz band. NASA GRC has developed and installed a K/Q-band (20/40 gigahertz) beacon receiver at the POLIMI campus in Milan, Italy, which receives the 20/40 gigahertz signals broadcast from the Alphasat Aldo Paraboni Technology Demonstration Payload (TDP) no. 5 beacon payload. The primary goal of these measurements is to develop a physical model to improve predictions of communications systems performance within the Q-band. Herein, we describe the design and preliminary performance of the NASA propagation terminal, which has been installed and operating in Milan since June 2014. The receiver is based upon a validated Fast Fourier Transform (FFT) I/Q digital design approach utilized in other operational NASA propagation terminals, but has been modified to employ power measurement via a frequency estimation technique and to coherently track and measure the amplitude of the 20/40 gigahertz beacon signals. The system consists of a 1.2-meter K-band and a 0.6-meter Q-band Cassegrain reflector employing synchronous open-loop tracking to track the inclined orbit of the Alphasat satellite. An 8 hertz sampling rate is implemented to characterize scintillation effects, with a 1-hertz measurement bandwidth dynamic range of 45 decibels. A weather station with an optical disdrometer is also installed to characterize rain drop size distribution for correlation with physical based models.

  9. A distance-dependent metal-enhanced fluorescence sensing platform based on molecular beacon design.

    Science.gov (United States)

    Zhou, Zhenpeng; Huang, Hongduan; Chen, Yang; Liu, Feng; Huang, Cheng Zhi; Li, Na

    2014-02-15

    A new metal-enhanced fluorescence (MEF) based platform was developed on the basis of distance-dependent fluorescence quenching-enhancement effect, which combined the easiness of Ag-thiol chemistry with the MEF property of noble-metal structures as well as the molecular beacon design. For the given sized AgNPs, the fluorescence enhancement factor was found to increase with a d(6) dependency in agreement with fluorescence resonance energy transfer mechanism at shorter distance and decrease with a d(-3) dependency in agreement with plasmonic enhancement mechanism at longer distance between the fluorophore and the AgNP surface. As a proof of concept, the platform was demonstrated by a sensitive detection of mercuric ions, using thymine-containing molecular beacon to tune silver nanoparticle (AgNP)-enhanced fluorescence. Mercuric ions were detected via formation of a thymine-mercuric-thymine structure to open the hairpin, facilitating fluorescence recovery and AgNP enhancement to yield a limit of detection of 1 nM, which is well below the U.S. Environmental Protection Agency regulation of the Maximum Contaminant Level Goal (10nM) in drinking water. Since the AgNP functioned as not only a quencher to reduce the reagent blank signal but also an enhancement substrate to increase fluorescence of the open hairpin when target mercuric ions were present, the quenching-enhancement strategy can greatly improve the detection sensitivity and can in principle be a universal approach for various targets when combined with molecular beacon design.

  10. Making it local: Beacon Communities use health information technology to optimize care management.

    Science.gov (United States)

    Allen, Amy; Des Jardins, Terrisca R; Heider, Arvela; Kanger, Chatrian R; Lobach, David F; McWilliams, Lee; Polello, Jennifer M; Rein, Alison L; Schachter, Abigail A; Singh, Ranjit; Sorondo, Barbara; Tulikangas, Megan C; Turske, Scott A

    2014-06-01

    Care management aims to provide cost-effective, coordinated, non-duplicative care to improve care quality, population health, and reduce costs. The 17 communities receiving funding from the Office of the National Coordinator for Health Information Technology through the Beacon Community Cooperative Agreement Program are leaders in building and strengthening their health information technology (health IT) infrastructure to provide more effective and efficient care management. This article profiles 6 Beacon Communities' health IT-enabled care management programs, highlighting the influence of local context on program strategy and design, and describing challenges, lessons learned, and policy implications for care delivery and payment reform. The unique needs (eg, disease burden, demographics), community partnerships, and existing resources and infrastructure all exerted significant influence on the overall priorities and design of each community's care management program. Though each Beacon Community needed to engage in a similar set of care management tasks--including patient identification, stratification, and prioritization; intervention; patient engagement; and evaluation--the contextual factors helped shape the specific strategies and tools used to carry out these tasks and achieve their objectives. Although providers across the country are striving to deliver standardized, high-quality care, the diverse contexts in which this care is delivered significantly influence the priorities, strategies, and design of community-based care management interventions. Gaps and challenges in implementing effective community-based care management programs include: optimizing allocation of care management services; lack of available technology tailored to care management needs; lack of standards and interoperability; integrating care management into care settings; evaluating impact; and funding and sustainability.

  11. Specific survivin dual fluorescence resonance energy transfer molecular beacons for detection of human bladder cancer cells

    Institute of Scientific and Technical Information of China (English)

    Zhi-qiang WANG; Jun ZHAO; Jin ZENG; Kai-jie WU; Yu-le CHEN; Xin-ya ng WANG; Luke S CHANG; Da-lin HE

    2011-01-01

    Survivin molecular beacons can be used to detectbladder cancer cells in urine samples non-invasively.The aim of this study is to improve the specificity of detection of bladder cancer cells using survivin dual fluorescence resonance energy transfer molecular beacons (FRET MBs) that have fluorophores forming one donor-acceptor pair.Methods:Survivin-targeting dual fluorescence resonance energy transfer molecular beacons with unique target sequences were designed,which had no overlap with the other genes in the apoptosis inhibitor protein family.Human bladder cancer cell lines 5637,253J and T24,as well as the exfoliated cells in the urine of healthy adults and patients with bladder cancer were examined.Images of cells were taken using a laser scanning confocal fluorescence microscope.For assays using dual FRET MBs,the excitation wavelength was 488 nm,and the emission detection wavelengths were 520+20 nm and 560+20 nm,respectively.Results:The human bladder cancer cell lines and exfoliated cells in the urine of patients with bladder cancer incubated with the survivin dual FRET MBs exhibited strong fluorescence signals.In contrast,no fluorescence was detected in the survivin-negative human dermal fibroblasts-adult (HDF-a) cells or exfoliated cells in the urine of healthy adults incubated with the survivin dual FRET MBs.Conclusion:The results suggest that the survivin dual FRET MBs may be used as a specific and non-invasive method for early detection and follow-up of patients with bladder cancer.

  12. Simultaneous and multiplexed detection of exosome microRNAs using molecular beacons.

    Science.gov (United States)

    Lee, Ji Hye; Kim, Jeong Ah; Jeong, Seunga; Rhee, Won Jong

    2016-12-15

    Simultaneous and multiplexed detection of microRNAs (miRNAs) in a whole exosome is developed, which can be utilized as a PCR-free efficient diagnosis method for various diseases. Exosomes are small extracellular vesicles that contain biomarker miRNAs from parental cells. Because they circulate throughout bodily fluids, exosomal biomarkers offer great advantages for diagnosis in many aspects. In general, PCR-based methods can be used for exosomal miRNA detection but they are laborious, expensive, and time-consuming, which make them unsuitable for high-throughput diagnosis of diseases. Previously, we reported that single miRNA in the exosomes can be detected specifically using an oligonucleotide probe or molecular beacon. Herein, we demonstrate for the first time that multiple miRNAs can be detected simultaneously in exosomes using miRNA-targeting molecular beacons. Exosomes from a breast cancer cell line, MCF-7, were used for the production of exosomes because MCF-7 has a high level of miR-21, miR-375, and miR-27a as target miRNAs. Molecular beacons successfully hybridized with multiple miRNAs in the cancer cell-derived exosomes even in the presence of high human serum concentration. In addition, it is noteworthy that the choice of fluorophores for multiplexing biomarkers in an exosome is crucial because of its small size. The proposed method described in this article is beneficial to high-throughput analysis for disease diagnosis, prognosis, and response to treatment because it is a time-, labor-, and cost-saving technique.

  13. Performance of beacon safety message dissemination in Vehicular Ad hoc NETworks (VANETs)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Currently, there is a growing belief that putting an IEEE 802.11-like radio into road vehicles can help the drivers to travel more safely. Message dissemination protocols are primordial for safety vehicular applications. There are two types of safety messages which may be exchanged between vehicles: alarm and beacon. In this paper we investigate the feasibility of deploying safety applications based on beacon message dissemination through extensive simulation study and pay special attention to the safety requirements. Vehicles are supposed to issue these messages periodically to announce to other vehicles their current situation and use received messages for preventing possible unsafe situations. We evaluate the performance of a single-hop dissemination protocol while taking into account the quality of service (QoS) metrics like delivery rate and delay. We realize that reliability is the main concern in beacon message dissemination. Thus, a new metric named effective range is defined which gives us more accurate facility for evaluating QoS in safety applications specifically. Then, in order to improve the performance, the effects of three parameters including vehicle's transmission range, message transmission's interval time and message payload size are studied. Due to special characteristics of the safety applications, we model the relationship between communication-level QoS and application-level QoS and evaluate them for different classes of safety applications. As a conclusion, the current technology of IEEE 802.11 MAC layer has still some challenges for automatic safety applications but it can provide acceptable QoS to driver assistance safety applications.

  14. Perancangan Prototipe Receiver Beacon Black Box Locator Acoustic 37,5 kHz Pingers

    Directory of Open Access Journals (Sweden)

    RUSTAMAJI RUSTAMAJI

    2016-02-01

    Full Text Available Abstrak Ketika suatu pesawat terbang mengalami kecelakaan terjatuh ke dalam air, maka lokasi keberadaannya dapat dideteksi oleh alat yang disebut receiver beacon black box locator acoustic (pingers receiver. Pingers receiver berfungsi untuk menerima sinyal dengan frekuensi 37,5 kHz ± 1 kHz dari pingers transmitter atau Underwater Locator Beacon (ULB yang berada pada black box pesawat. Dalam penelitian ini dibuat perancangan pingers receiver yang tersusun dari rangkaian Band Pass Filter (BPF, detektor selubung, penguat audio, dan loud speaker. Frekuensi sinyal 37,5 kHz ± 1 kHz yang dikirim oleh pingers transmitter akan diterima oleh pingers receiver, dimana tahap pertama melewati rangkaian Band Pass Filter (BPF selanjutnya sinyal akan dideteksi oleh detektor selubung untuk mengambil kembali sinyal informasi yang berupa sinyal pulsa dengan lebar pulsa 10 milidetik dan interval 1 detik sebagai sinyal pingers yang nantinya mampu didengar oleh telinga manusia. Berdasarkan perancangan yang telah dibuat, output sinyal yang dihasilkan oleh prototipe pingers receiver tersebut memiliki lebar pulsa 14 milidetik dengan interval 1 detik. Kata kunci: pingers receiver, band pass filter (BPF, detektor selubung, loud speaker. Abstract When an aircraft caught in an accident and crashes into the water, its location can be detected using a device called a receiver beacon black box locator acoustic (pingers receiver. The pingers receiver functioned as a reciever signal with 37,5 kHz ± 1 kHz frequency from trnasmitter pingers or Underwater Locator Beacon (ULB which is on air plane black blox. In this research made design pingers receiver composed of a series of  Band Pass Filter (BPF, envelope detector, audio amplifier, and loud speaker. The signal of 37,5 kHz ± 1 kHz  frequency sent by pingers transmitter will bereceived by pingers receiver, after which the signal will be processed by the Band Pass Filter (BPF circuit before being detected by envelope detector

  15. Real time monitoring of nucleic acids ligation based on molecular beacon

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel method has been developed to monitor the nucleic acids ligation process. Molecular beacon was employed here to convert the ligation information into fluorescence signal quickly and quantitatively. This method provides effective and original approach to researching the dynamic ligation process and the interactions between nucleic acids and ligase. An analytical method for T4 DNA ligase based on this way has been built up with a linear detection range from 2.3×10?4 U/mL to 0.23 U/mL. It is rapid and sensitive to detect 2.8×10?5 U T4 DNA ligase in 10 min.

  16. Steranes and triterpanes in the Beacon Supergroup samples from southern Victoria Land in Antarctica

    Science.gov (United States)

    Matsumoto, Genki I.; Machihara, Tsutomu; Suzuki, Noriyuki; Funaki, Minoru; Watanuki, Kunihiko

    1987-10-01

    Steranes and triterpanes in Beacon Supergroup samples (sedimentary rock and silicified wood) from Allan Hills and Carapace Nunatak of southern Victoria Land in Antarctica were studied to elucidate sources of organic materials, sedimentary paleoenvironment and thermal history after deposition. Relative abundances of C 27, C 28 and C 29 steranes and visual kerogen results of Beacon Supergroup samples from Allan Hills imply that organic materials in the sedimentary paleoenvironments are contributed mainly by vascular plants with some influence of microorganisms, while those of the Carapace Nunatak sample may be largely due to fern spores. The pristane/phytane and pristane/heptadecane ratios of the samples were generally close to unity and between 0.50 and 0.99, respectively, suggesting that the sedimentary paleoenvironment was shallow lacustrine with alternating oxic and anoxic conditions. The ( 22S/22R)-17α(H),21β(H)-C 31-C 33 triterpane ratios are approximately at thermal equilibrium values ( ca. 1.5) in most samples, while the ( 20S/20R)-5α(H), 14α(H), 17α(H)-C 29 sterane ratios and the (20R + 20S)-5α(H), 14β(H), 17β(H)/5α(H), 14α(H), 17α(H)-C 29 sterane ratios vary from 0.0 to 1.1 and from 0.0 to 1.4, respectively. Most of the ( 20S/20R)-5α(H), 14α(H), 17α(H)-C 29 sterane ratios did not reach thermal equilibrium values. The correlation coefficient between the ( 20S/20R)-5α(H), 14α(H), 17α(H)-C 29 sterane ratios and (20R + 20S)-5α(H), 14β(H), 17β(H)/5α(H), 14α(H), 17α(H)-C 29, sterane ratios is very high (0.96). These variable maturities probably reflect thermal effects of basaltic dikes on the Beacon Supergroup at Allan Hills and Carapace Nunatak during Jurassic time. Thermal stresses on the Beacon Supergroup prior to basaltic intrusion have been estimated to be quite low, so the paleotemperatures of this formation have been quite low.

  17. Telemetry beacon for Polish payload on BRITE-PL-2 satellite

    Science.gov (United States)

    Woźniak, Grzegorz; Stolarski, Marcin

    2013-10-01

    Small satellite missions are becoming more popular. To reduce costs of such projects COTS are used to build the spacecraft and amateur bands are utilized to communicate with it. Although using the hamradio frequencies is free of charge and requires only coordination procedures [1], it is good habit to include on satellite some service for radioamateur society in return. The BRITE-PL-2 Heweliusz [2] satellite - the second Polish satellite from BRITE constellation - will have an S-Band beacon transmitting Morse code signals.

  18. A mobile indoor positioning system based on iBeacon technology.

    Science.gov (United States)

    Lin, Xin-Yu; Ho, Te-Wei; Fang, Cheng-Chung; Yen, Zui-Shen; Yang, Bey-Jing; Lai, Feipei

    2015-01-01

    To increase the efficiency in the emergency room, the goal of this research is to implement a mobile-based indoor positioning system using mobile applications (APP) with the iBeacon solution based on the Bluetooth Low Energy (BLE) technology. We use the Received Signal Strength (RSS) based localization method to estimate the patients' locations. Our positioning algorithm achieves 97.22% (95% Confidence Interval = 95.90% - 98.55%) accuracy of classification. As the result, our mechanism is reliable enough to satisfy the need for medical staff to track the locations of their patients.

  19. Tecnología iBeacon aplicada a la monitorización de clientes

    OpenAIRE

    2015-01-01

    En el presente trabajo se desarrolla una aplicación para la monitorización de usuarios a través de la tecnología iBeacon de Apple. Este documento refleja las decisiones de diseño, funcionalidades y validaciones realizadas, tanto en el apartado de la aplicación móvil, como en el de la aplicación web, aportando finalmente una serie de valoraciones acerca de los resultados obtenidos y sobre el desarrollo del trabajo en general.

  20. Dual-band beacon experiment over Southeast Asia for ionospheric irregularity analysis

    Science.gov (United States)

    Watthanasangmechai, K.; Yamamoto, M.; Saito, A.; Saito, S.; Maruyama, T.; Tsugawa, T.; Nishioka, M.

    2013-12-01

    An experiment of dual-band beacon over Southeast Asia was started in March 2012 in order to capture and analyze ionospheric irregularities in equatorial region. Five GNU Radio Beacon Receivers (GRBRs) were aligned along 100 degree geographic longitude. The distances between the stations reach more than 500 km. The field of view of this observational network covers +/- 20 degree geomagnetic latitude including the geomagnetic equator. To capture ionospheric irregularities, the absolute TEC estimation technique was developed. The two-station method (Leitinger et al., 1975) is generally accepted as a suitable method to estimate TEC offsets of dual-band beacon experiment. However, the distances between the stations directly affect on the robustness of the technique. In Southeast Asia, the observational network is too sparse to attain a benefit of the classic two-station method. Moreover, the least-squares approch used in the two-station method tries too much to adjust the small scales of the TEC distribution which are the local minima. We thus propose a new technique to estimate the TEC offsets with the supporting data from absolute GPS-TEC from local GPS receivers and the ionospheric height from local ionosondes. The key of the proposed technique is to utilize the brute-force technique with weighting function to find the TEC offset set that yields a global minimum of RMSE in whole parameter space. The weight is not necessary when the TEC distribution is smooth, while it significantly improves the TEC estimation during the ESF events. As a result, the latitudinal TEC shows double-hump distribution because of the Equatorial Ionization Anomaly (EIA). In additions, the 100km-scale fluctuations from an Equatorial Spread F (ESF) are captured at night time in equinox seasons. The plausible linkage of the meridional wind with triggering of ESF is under invatigating and will be presented. The proposed method is successful to estimate the latitudinal TEC distribution from dual

  1. Fluorescence monitoring of riboswitch transcription regulation using a dual molecular beacon assay.

    Science.gov (United States)

    Chinnappan, Raja; Dubé, Audrey; Lemay, Jean-François; Lafontaine, Daniel A

    2013-05-01

    Riboswitches are mRNA elements that specifically bind cellular metabolites and control gene expression by modifying their structure. As riboswitches often control essential genes in pathogenic bacteria, riboswitches have been proposed as new targets for antibiotics. High-throughput screening provides a powerful approach to identify riboswitch ligand analogs that could act as powerful antibacterial drugs. Biochemical assays have already been used to find riboswitch-binding analogs, but those methods do take into account the transcriptional context for riboswitch regulation. As the importance of co-transcriptional ligand binding has been shown for several riboswitches, it is vital to develop an assay that screens riboswitch-binding analogs during the transcriptional process. Here, we describe the development of a dual molecular beacon system monitoring the transcriptional regulation activity of the Bacillus subtilis pbuE adenine riboswitch. This system relies on two molecular beacons that enable the monitoring of transcription efficiency, as well as the regulatory activity of the riboswitch. Different analogs were tested using our system, and a good correlation was observed between riboswitch activity and reported metabolite affinities. This method is specific, reliable and could be applied at the high-throughput level for the identification of new potential antibiotics targeting any riboswitch-regulating gene expression at the mRNA level.

  2. Performance Evaluation of Beacon-Enabled Mode for IEEE 802.15.4 Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    M. Udin Harun Al Rasyid

    2013-12-01

    Full Text Available IEEE 802.15.5 standard support structure of star and peer-to-peer network formation. Strating from these, the cluster tree network can be built as a special case of peer-to-peer network to increse coverage area. In this paper, we provide an performance evaluation of beacon- enabled mode for IEEE 802.15.4 wireless sensor network on star and cluster topology in order to get the maximum result to apply the appropriate topology model as needed. We conduct analysis on each topology model by using the numbers of nodes from 10 nodes to 100 nodes to analyze throughput, delay, energy consumption, and probability success packet by using NS2 simulator. The simulation results show that the throughput and the probability of success packet of cluster topology are higher than that of star topology, and the energy consumption of cluster topology is lesser than that of star topology. However, cluster topology increases the delay more than star topology. Keywords: IEEE 802.15.4, wireless sensor network, beacon-enabled mode, topology, csma/ca

  3. Preliminary Statistics from the NASA Alphasat Beacon Receiver in Milan, Italy

    Science.gov (United States)

    Nessel, James; Zemba, Michael; Morse, Jacquelynne; Luini, Lorenzo; Riva, Carlo

    2015-01-01

    NASA Glenn Research Center (GRC) and the Politecnico di Milano (POLIMI) have initiated a joint propagation campaign within the framework of the Alphasat propagation experiment to characterize rain attenuation, scintillation, and gaseous absorption effects of the atmosphere in the 40 gigahertz band. NASA GRC has developed and installed a K/Q-band (20/40 gigahertz) beacon receiver at the POLIMI campus in Milan, Italy, which receives the 20/40 gigahertz signals broadcast from the Alphasat Aldo Paraboni TDP no. 5 beacon payload. The primary goal of these measurements is to develop a physical model to improve predictions of communications systems performance within the Q-band. Herein, we provide an overview of the design and data calibration procedure, and present 6 months of preliminary statistics of the NASA propagation terminal, which has been installed and operating in Milan since May 2014. The Q-band receiver has demonstrated a dynamic range of 40 decibels at an 8-hertz sampling rate. A weather station with an optical disdrometer is also installed to characterize rain drop size distribution for correlation with physical based models.

  4. Temporal change of EIA asymmetry revealed by a beacon receiver network in Southeast Asia

    Science.gov (United States)

    Watthanasangmechai, Kornyanat; Yamamoto, Mamoru; Saito, Akinori; Maruyama, Takashi; Yokoyama, Tatsuhiro; Nishioka, Michi; Ishii, Mamoru

    2015-05-01

    To reveal the temporal change of the equatorial ionization anomaly (EIA) asymmetry, a multipoint satellite-ground beacon experiment was conducted along the meridional plane of the Thailand-Indonesia sector. The observation includes one station near the magnetic equator and four stations at off-equator latitudes. This is the first EIA asymmetry study with high spatial resolution using GNU Radio Beacon Receiver (GRBR) observations in Southeast Asia. GRBR-total electron contents (TECs) from 97 polar-orbit satellite passes in March 2012 were analyzed in this study. Successive passes captured rapid evolution of EIA asymmetry, especially during geomagnetic disturbances. The penetrating electric fields that occur during geomagnetic disturbed days are not the cause of the asymmetry. Instead, high background TEC associated with an intense electric field empowers the neutral wind to produce severe asymmetry of the EIA. Such rapid evolution of EIA asymmetry was not seen during nighttime, when meridional wind mainly controlled the asymmetric structures. Additional data are necessary to identify the source of the variations, i.e., atmospheric waves. Precisely capturing the locations of the crests and the evolution of the asymmetry enhances understanding of the temporal change of EIA asymmetry at the local scale and leads to a future local modeling for TEC prediction in Southeast Asia.

  5. Analysis of rocket beacon transmissions for computerized reconstruction of ionospheric densities

    Science.gov (United States)

    Bernhardt, P. A.; Huba, J. D.; Chaturvedi, P. K.; Fulford, J. A.; Forsyth, P. A.; Anderson, D. N.; Zalesak, S. T.

    1993-08-01

    Three methods are described to obtain ionospheric electron densities from transionospheric, rocket-beacon TEC data. First, when the line-of-sight from a ground receiver to the rocket beacon is tangent to the flight trajectory, the electron concentration can be obtained by differentiating the TEC with respect to the distance to the rocket. A similar method may be used to obtain the electron-density profile if the layer is horizontally stratified. Second, TEC data obtained during chemical release experiments may be interpreted with the aid of physical models of the disturbed ionosphere to yield spatial maps of the modified regions. Third, computerized tomography (CT) can be used to analyze TEC data obtained along a chain of ground-based receivers aligned along the plane of the rocket trajectory. CT analysis of TEC data is used to reconstruct a 2D image of a simulated equatorial plume. TEC data is computed for a linear chain of nine receivers with adjacent spacings of either 100 or 200 km. The simulation data are analyzed to provide an F region reconstruction on a grid with 15 x 15 km pixels. Ionospheric rocket tomography may also be applied to rocket-assisted measurements of amplitude and phase scintillations and airglow intensities.

  6. A Microfluidic Love-Wave Biosensing Device for PSA Detection Based on an Aptamer Beacon Probe

    Directory of Open Access Journals (Sweden)

    Feng Zhang

    2015-06-01

    Full Text Available A label-free and selective aptamer beacon-based Love-wave biosensing device was developed for prostate specific antigen (PSA detection. The device consists of the following parts: LiTaO3 substrate with SiO2 film as wave guide layer, two set of inter-digital transducers (IDT, gold film for immobilization of the biorecongniton layer and a polydimethylsiloxane (PDMS microfluidic channels. DNA aptamer, or “artificial antibody”, was used as the specific biorecognition probe for PSA capture. Some nucleotides were added to the 3'-end of the aptamer to form a duplex with the 3'-end, turning the aptamer into an aptamer-beacon. Taking advantage of the selective target-induced assembly changes arising from the “aptamer beacon”, highly selective and specific detection of PSA was achieved. Furthermore, PDMS microfluidic channels were designed and fabricated to realize automated quantitative sample injection. After optimization of the experimental conditions, the established device showed good performance for PSA detection between 10 ng/mL to 1 μg/mL, with a detection limit of 10 ng/mL. The proposed sensor might be a promising alternative for point of care diagnostics.

  7. A molecular-beacon-based asymmetric PCR assay for easy visualization of amplicons in the diagnosis of trichomoniasis.

    Science.gov (United States)

    Sonkar, Subash C; Sachdev, Divya; Mishra, Prashant K; Kumar, Anita; Mittal, Pratima; Saluja, Daman

    2016-12-15

    The currently available nucleic acid amplification tests (NAATs) for trichomoniasis are accurate, quick and confirmative with superior sensitivity than traditional culture-based microbiology assays. However, these assays are associated with problems of carry over contamination, false positive results, requirement of technical expertise for performance and detection of end product. Hence, a diagnostic assay with easy visualization of the amplified product will be profitable. An in-house, rapid, sensitive, specific molecular-beacon-based PCR assay, using primers against pfoB gene of Trichomonas vaginalis, was developed and evaluated using dry ectocervical swabs (n=392) from symptomatic females with vaginal discharge. Total DNA was isolated and used as template for the PCR assays. The performance and reproducibility of PCR assay was evaluated by composite reference standard (CRS). For easy visualization of the amplified product, molecular-beacon was designed and amplicons were visualized directly using fluorescent handheld dark reader or by Micro-Plate Reader. Molecular-beacons are single-stranded hairpin shaped nucleic acid probes composed of a stem, with fluorophore/quencher pair and a loop region complementary to the desired DNA. The beacon-based PCR assay designed in the present study is highly specific as confirmed by competition experiments and extremely sensitive with detection limit of 20fg of genomic DNA (3-4 pathogens). The minimum infrastructure requirement and ease to perform the assay makes this method highly useful for resource poor countries for better disease management.

  8. Guiding Math Students to Campus Services: An Impact Evaluation of the Beacon Program at South Texas College

    Science.gov (United States)

    Visher, Mary; Butcher, Kristin F.; Cerna, Oscar S.

    2011-01-01

    This research rigorously evaluates whether a low-cost intervention can improve students' performance in developmental math. The "Beacon Mentoring Program" was developed at South Texas College by professors, administrators, and staff at the college. Surveys of students revealed that many did not have someone on campus whom they felt they could turn…

  9. Measurements of Tilt and Focus for Sodium Beacon Adaptive Optics on the Starfire 3.5 Meter Telescope

    Science.gov (United States)

    2010-09-01

    beacon and natural guide star operation. This approach, and a more complicated approach, are described in detail by Link and Foucault [3]. They show these...Astronomical Telescopes and Instrumentation Conference, Glasgow, Scotland, 21–25 June 2004. 3. Link D. and Foucault B., "Investigation of focus control

  10. REAL-TIME DETECTION OF SURVIVIN mRNA EXPRESSION IN CERVICAL CANCER CELL LINES USING MOLECULAR BEACON IMAGING

    Institute of Scientific and Technical Information of China (English)

    An Ruifang; He Dalin; Xue Yan; Wang Shu; Xie Li; Zhao Jun; Wang Xinyang; Yang Lili

    2006-01-01

    Objective To detect the expression of survivin mRNA in cervical cancer cell lines using molecular beacon imaging technology. Methods Human cervical cancer cells (HeLa and SiHa) and human fetal lung fibroblast HFL-I were cultured in vitro. After adding 100 nmol/L survivin mRNA molecular beacon, the fluorescent signals were observed under fluorescent microscope. The expressions of survivin in cervical cancer cells and HFL-I cell were examined by immunocytochemical streptravidin-biothin peroxidase (SP) assay at the same time. Results Two kinds of survivin mRNA molecular beacon, with different color fluorescence, had strong fluorescent signal in cervical cancer cell lines, and the signal in SiHa cell line was stronger, but these signals were not found in HFL-I ; Immunocytochemical staining of positive survivin was located in the cytoplasm of cervical cancer cell lines HeLa and SiHa, whereas, no expression of survivin was detected in HFL-I cell line. Conclusion The technology of molecular beacon imaging can be used to detect the expression of survivin mRNA in viable cells successfully, and may provide a new approach to the diagnosis of early stage cervical cancer and the following-up in the clinic.

  11. A quencher-free molecular beacon design based on pyrene excimer fluorescence using pyrene-labeled UNA (unlocked nucleic acid)

    DEFF Research Database (Denmark)

    Karlsen, Kasper Kannegård; Okholm, Anders Hauge; Kjems, Jørgen

    2013-01-01

    A quencher-free molecular beacon capable of generating pyrene excimer fluorescence has been constructed using strategically positioned pyrene-UNA monomers. Hybridization of a fully complementary RNA target was accompanied by a pyrene excimer emission increase of more than 900%, and detection of RNA...

  12. Impact of IEEE 1609.4 channel switching on the IEEE 802.11p beaconing performance

    NARCIS (Netherlands)

    Eenennaam, van Martijn; Venis, van de Anne; Karagiannis, Georgios

    2012-01-01

    The IEEE 802.11p Wireless Access in Vehicular Environment (WAVE) protocol can only transmit packets on one channel. To support multi-channel operations, channel switching procedures have been proposed in IEEE 1609.4. This paper provides an analysis of the beaconing performance of IEEE 802.11p when t

  13. To Light a Beacon: What Administrators Can Do To Make Schools Successful for All Students. ERIC/OSEP Topical Brief.

    Science.gov (United States)

    ERIC Clearinghouse on Disabilities and Gifted Education, Arlington, VA. ERIC/OSEP Special Project.

    In some schools, students with disabilities achieve exemplary results. To find out what these schools do that set them apart, the U.S. Office of Special Education Programs sponsored a series of studies focused on "Beacons of Excellence Schools." This topical brief highlights results from three of these studies. The University of Maryland study…

  14. A DNA tetrahedron-based molecular beacon for tumor-related mRNA detection in living cells.

    Science.gov (United States)

    Xie, Nuli; Huang, Jin; Yang, Xiaohai; Yang, Yanjing; Quan, Ke; Wang, He; Ying, Le; Ou, Min; Wang, Kemin

    2016-02-01

    Due to its low cytotoxicity, high resistance to enzymatic degradation, and cellular permeability, a DNA tetrahedron-based molecular beacon (DTMB) is designed for tumor-related TK1 mRNA detection in living cells, where the target sequence can induce the tetrahedron from contraction to extension, resulting in fluorescence restoration.

  15. Beacon of Hope? Lessons Learned from Efforts to Reduce Civilian Deaths from Police Shootings in an Australian State.

    Science.gov (United States)

    Saligari, Jessica; Evans, Richard

    2016-04-01

    In the 1990s, the police service in Victoria, Australia, faced a crisis of community confidence due to a spate of civilian deaths from police shootings. In that decade, twice as many civilians died at the hands of the police in Victoria than in every other Australian state combined. Most of those killed were mentally ill and affected by drugs and alcohol, and were rarely a serious threat except to themselves. The problem was also almost entirely an urban phenomenon. Shootings in rural communities, where mentally ill people were more likely to be personally known to local police, were (and remain) almost unknown. The large number of fatalities was recognised as a serious threat to public confidence, and Victoria Police introduced a ground-breaking training programme, Operation Beacon. Operating procedures and weapons training were fundamentally changed, to focus on de-escalation of conflict and avoiding or minimising police use of force. In the short term, Operation Beacon was successful. Shooting incidents were dramatically reduced. However, during the first decade of the new century, the number of civilians being killed again increased. This article examines Operation Beacon, both as a successful model for reducing civilian deaths at the hand of police and as a cautionary tale for police reform. We argue that the lessons of Operation Beacon have been gradually forgotten and that old habits and attitudes resurfaced. Fatal shootings of mentally ill civilians can be prevented, but if success is to be other than temporary, the Beacon philosophy must be continually reemphasised by police management.

  16. Use of a molecular beacon to track the activity of base excision repair protein OGG1 in live cells.

    Science.gov (United States)

    Mirbahai, Leda; Kershaw, Rachael M; Green, Richard M; Hayden, Rachel E; Meldrum, Rosalind A; Hodges, Nikolas J

    2010-02-01

    An abundant form of DNA damage caused by reactive oxygen species is 8-oxo-7,8-dihydroguanine for which the base excision repair protein 8-oxoguanine-DNA glycosylase 1 (OGG1) is a major repair enzyme. To assess the location and intracellular activity of the OGG1 protein in response to oxidative stress, we have utilised a fluorescence-quench molecular beacon switch containing a 8-oxo-dG:C base pair and a fluorescent and quencher molecule at opposite ends of a hairpin oligonucleotide. Oxidative stress was induced by treatment with potassium bromate. Flow cytometry demonstrated a concentration-dependent increase in the activity of OGG1 that was detected by the fluorescence produced when the oligonucleotide was cleaved in the cells treated with potassium bromate. This signal is highly specific and not detectable in OGG1 knock out cells. Induction of OGG1 activity is not a result of induction of OGG1 gene expression as assessed by qPCR suggesting a role for protein stabilisation or increased OGG1 catalytic activity. High resolution confocal microscopy pinpointed the location of the fluorescent molecular beacon in live cells to perinuclear regions that were identified as mitochondria by co-staining with mitotracker dye. There is no evidence of cut beacon within the nuclear compartment of the cell. Control experiments with a positive control beacon (G:C base pair and lacking the DAB quencher) did not result in mitochondrial localisation of fluorescence signal indicating that the dye does not accumulate in mitochondria independent of OGG1 activity. Furthermore, faint nuclear staining was apparent confirming that the beacon structure is able to enter the nucleus. In conclusion, these data indicate that the mitochondria are the major site for OGG1 repair activity under conditions of oxidative stress.

  17. Molecular beacon-based enzyme-free strategy for amplified DNA detection.

    Science.gov (United States)

    Huang, Jiahao; Wu, Jueqi; Li, Zhigang

    2016-05-15

    We report an enzyme-free, sensitive strategy for DNA detections through fluorescence amplification. The sensing method employs molecular beacons (MBs) and two single-stranded helper DNA probes. In the presence of a DNA target, it binds and opens an MB. This triggers the hybridizations between the MB and helper probes, and consequently releases the DNA target, which becomes available to react with another MB and enhances the fluorescence emission of the MBs. The detection limit of the proposed strategy is 0.58 pM, which is about 3 orders of magnitude better than the conventional MB-based method. This method is also fast and exhibits good selectivity. It is superior to previous MB-based amplification approaches employing enzymes or nanomaterials.

  18. Numerical simulation research on sodium laser beacon imagings through the atmosphere turbulence

    Science.gov (United States)

    Liu, Xiangyuan; Qian, Xianmei; Zhang, Suimeng; Zhao, Minfu; Cui, Chaolong; Huang, Honghua

    2016-01-01

    Based on the relative intensity distributions of Sodium Laser Beacon (SLB) and analysis of the on-axis imaging of incoherent light, considering the effects of atmospheric turbulence and the changes of telescope receiving diameter on the short-exposure SLB imagings on the focal plane, imagings of an extended source SLB are simulated under the three atmospheric turbulence models. Results indicate that sharpness and peak strehl ratio of SLB imagings increase but sharpness radius decrease with the decrease of atmosphere turbulence strengths. Moreover, the changes of telescope diameter from 3.0m to 1.5m cause the decrease of sharpness and peak strehl ratio but the increase of sharpness radius.

  19. Ground-water appraisal of the Fishkill-Beacon area, Dutchess County, New York

    Science.gov (United States)

    Snavely, Deborah S.

    1980-01-01

    The most productive aquifers in the Fishkill-Beacon area, Dutchess County, N.Y., are the sand and gravel beds in the northeast corner of the area and along the valleys of Fishkill and Clove Creeks. The average yield of these aquifers to wells is 190 gal/min (gallons per minute). The most productive bedrock aquifer is limestone, which yields an average of about 150 gal/min. Shale and granite each yield an average of less than 35 gal/min. About 4 billion gallons of available ground water is estimated to be in storage in the sand and gravel aquifers in the area. The area withdraws an average of 3.3 Mgal/d (million gallons per day) of water in June, July, and August and 2 Mgal/d during the remainder of the year. (USGS)

  20. Performance Analysis of Beacon-Less IEEE 802.15.4 Multi-Hop Networks

    CERN Document Server

    Srivastava, Rachit

    2012-01-01

    We develop an approximate analytical technique for evaluating the performance of multi-hop networks based on beacon-less CSMA/CA as standardised in IEEE 802.15.4, a popular standard for wireless sensor networks. The network comprises sensor nodes, which generate measurement packets, and relay nodes which only forward packets. We consider a detailed stochastic process at each node, and analyse this process taking into account the interaction with neighbouring nodes via certain unknown variables (e.g., channel sensing rates, collision probabilities, etc.). By coupling these analyses of the various nodes, we obtain fixed point equations that can be solved numerically to obtain the unknown variables, thereby yielding approximations of time average performance measures, such as packet discard probabilities and average queueing delays. Different analyses arise for networks with no hidden nodes and networks with hidden nodes. We apply this approach to the performance analysis of tree networks rooted at a data sink. ...

  1. Angular anisoplanatism of a focused beam using beacons over horizontal path

    Science.gov (United States)

    Wu, Wu-ming; Ning, Yu

    2016-01-01

    The performance of the achieve laser beam propagation through atmospheric turbulence with adaptive optics is degraded by the fact that the wavefront aberrations difference. This error is only include the angular anisoplanatism when there is separation between the achieve laser beam and beacon. In the paper we derive an analytic expression for the effective angular anisoplanatism as a function of displacement angular when the turbulence profile is uniform. It shows that the effective angular anisoplanatism becomes weaker as the diameter of laser beams and the Fried transverse coherence length increase. We report results from field experiments that the effective angular anisoplanatism of a focused beam over horizontal path. It is found that measured and theoretical results are consistent. The effective wavefront variance increases with the strength of atmospheric turbulence and the angular displacement. And the constant phase of angular anisoplanatism has no effect on the Strehl ratio of the beam.

  2. Nanomechanical DNA origami 'single-molecule beacons' directly imaged by atomic force microscopy

    Science.gov (United States)

    Kuzuya, Akinori; Sakai, Yusuke; Yamazaki, Takahiro; Xu, Yan; Komiyama, Makoto

    2011-01-01

    DNA origami involves the folding of long single-stranded DNA into designed structures with the aid of short staple strands; such structures may enable the development of useful nanomechanical DNA devices. Here we develop versatile sensing systems for a variety of chemical and biological targets at molecular resolution. We have designed functional nanomechanical DNA origami devices that can be used as 'single-molecule beacons', and function as pinching devices. Using 'DNA origami pliers' and 'DNA origami forceps', which consist of two levers ~170 nm long connected at a fulcrum, various single-molecule inorganic and organic targets ranging from metal ions to proteins can be visually detected using atomic force microscopy by a shape transition of the origami devices. Any detection mechanism suitable for the target of interest, pinching, zipping or unzipping, can be chosen and used orthogonally with differently shaped origami devices in the same mixture using a single platform. PMID:21863016

  3. Isothermal amplification detection of nucleic acids by a double-nicked beacon.

    Science.gov (United States)

    Shi, Chao; Zhou, Meiling; Pan, Mei; Zhong, Guilin; Ma, Cuiping

    2016-03-01

    Isothermal and rapid amplification detection of nucleic acids is an important technology in environmental monitoring, foodborne pathogen detection, and point-of-care clinical diagnostics. Here we have developed a novel method of isothermal signal amplification for single-stranded DNA (ssDNA) detection. The ssDNA target could be used as an initiator, coupled with a double-nicked molecular beacon, to originate amplification cycles, achieving cascade signal amplification. In addition, the method showed good specificity and strong anti-jamming capability. Overall, it is a one-pot and isothermal strand displacement amplification method without the requirement of a stepwise procedure, which greatly simplifies the experimental procedure and decreases the probability of contamination of samples. With its advantages, the method would be very useful to detect nucleic acids in point-of-care or field use.

  4. ATS-6 radio beacon electron content measurements at Ootacamund, India, October 1975-July 1976

    Energy Technology Data Exchange (ETDEWEB)

    Bouwer, S.D.; Davies, K.; Donnelly, R.F.; Grubb, R.N.; Jones, J.E.

    1980-03-01

    An atlas of total slant-path columnar electron content data measured between the ATS-6 satellite and Ootacamund, India, a site near the magnetic Equator is presented. Although these measurements were taken during a solar minimum, the general level of flare and geomagnetic activity that occurred during the observation period is summarized. These total content (N(T)) data were derived from the modulation phase (group delay) of a carrier signal transmitted from the geostationary satellite's Radio Beacon Experiment. This atlas contains two data sets: (1) N(T) as 2-min subsamples digitally recorded between 2 October 1975 and 28 January 1976 corrected for ATS-6 pitch maneuvers and (2) N(T) as 15-min subsamples chart recorded between 21 October 1975 and 22 July 1976 but uncorrected for changes in satellite orientation.

  5. Considerations for community-based mHealth initiatives: insights from three Beacon Communities.

    Science.gov (United States)

    Abebe, Nebeyou A; Capozza, Korey L; Des Jardins, Terrisca R; Kulick, David A; Rein, Alison L; Schachter, Abigail A; Turske, Scott A

    2013-10-15

    Mobile health (mHealth) is gaining widespread attention for its potential to engage patients in their health and health care in their daily lives. Emerging evidence suggests that mHealth interventions can be used effectively to support behavior change, but numerous challenges remain when implementing these programs at the community level. This paper provides an overview of considerations when implementing community-based mHealth initiatives, based on the experiences of three Beacon Communities across the United States that have launched text messaging (short message service, SMS) pilot programs aimed at diabetes risk reduction and disease management. The paper addresses lessons learned and suggests strategies to overcome challenges related to developing text message content, conducting marketing and outreach, enrolling participants, engaging providers, evaluating program effectiveness, and sustaining and scaling the programs.

  6. PERFORMANCE ANALYSIS OF ANTI-COLLISION ENABLED ROBOT USING HYBRID BEACON SCHEDULING APPROACH

    Directory of Open Access Journals (Sweden)

    P. Prabakaran

    2014-01-01

    Full Text Available In multi-robot environment, when many robots are moving in the same workspace, there is a possibility of their physical collision with themselves as well as with physical objects. In this study, hybrid beacon scheduling protocol is proposed and for avoiding such collisions in robotic mobile environment with low latency and power consumption. The purpose of deploying this protocol is to collect relevant data for processing and reporting. In particular, based on data reporting, the robotic nodes can be classified as time-driven or event-driven. The motivation behind this research is that it dynamically switches between the event-driven data-reporting and time-driven data-reporting schemes. As such, the proposed protocol accurately analyzes the environment being monitored using only moderate resource consumption. We have implemented the proposed protocol on a network simulator and analyzed its behaviors under various conditions.

  7. Development of BEACON technology. Volume I. Final report, April 1980-April 1983

    Energy Technology Data Exchange (ETDEWEB)

    None

    1983-08-01

    The BEACON process is based on the catalytic deposition of a highly reactive carbon from low heating value gases, primarily by the carbon monoxide disproportionation reaction. This carbon is subsequently reacted with steam to produce predominantly methane or hydrogen, depending on the catalyst formulation and operating conditions. Commercial application envisions an air-blown coal gasification combined-cycle power plant with a coproduct of either methane or hydrogen. Significant cost reductions are anticipated relative to corresponding oxygen-blown coal gasification systems. Excellent fluid bed catalysts have been developed which have retained initial activity for over 400 hours of steady state operation. This stability was demonstrated in a tandem reactor system which provides for semi-continuous catalyst circulation between the carbon deposition and steam gasification fluid bed reactors.

  8. 16S rRNA beacons for bacterial monitoring during human space missions.

    Science.gov (United States)

    Larios-Sanz, Maia; Kourentzi, Katerina D; Warmflash, David; Jones, Jeffrey; Pierson, Duane L; Willson, Richard C; Fox, George E

    2007-04-01

    Microorganisms are unavoidable in space environments and their presence has, at times, been a source of problems. Concerns about disease during human space missions are particularly important considering the significant changes the immune system incurs during spaceflight and the history of microbial contamination aboard the Mir space station. Additionally, these contaminants may have adverse effects on instrumentation and life-support systems. A sensitive, highly specific system to detect, characterize, and monitor these microbial populations is essential. Herein we describe a monitoring approach that uses 16S rRNA targeted molecular beacons to successfully detect several specific bacterial groupings. This methodology will greatly simplify in-flight monitoring by minimizing sample handling and processing. We also address and provide solutions to target accessibility problems encountered in hybridizations that target 16S rRNA.

  9. A simple molecular beacon with duplex-specific nuclease amplification for detection of microRNA.

    Science.gov (United States)

    Li, Yingcun; Zhang, Jiangyan; Zhao, Jingjing; Zhao, Likun; Cheng, Yongqiang; Li, Zhengping

    2016-02-01

    MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene activity, promoting or inhibiting cell proliferation, migration and apoptosis. Abnormal expression of miRNAs is associated with many diseases. Therefore, it is essential to establish a simple, rapid and sensitive miRNA detection method. In this paper, based on a simple molecular beacon (MB) and duplex-specific nuclease (DSN), we developed a target recycling amplification method for miRNA detection. By controlling the number of stem bases to 5, the MB probe used in this method can be prevented from hydrolysis by DSN without special modification. This assay is direct and simple to quantitatively detect miRNA with high sensitivity and specificity. The MB probe design provides a new strategy for nuclease-based amplification reaction.

  10. Biomaterial constructs for delivery of multiple therapeutic genes: a spatiotemporal evaluation of efficacy using molecular beacons.

    Directory of Open Access Journals (Sweden)

    Jennifer C Alexander

    Full Text Available Gene therapy is emerging as a potential therapeutic approach for cardiovascular pathogenesis. An appropriate therapy may require multiple genes to enhance therapeutic outcome by modulating inflammatory response and angiogenesis in a controlled and time-dependent manner. Thus, the aim of this research was to assess the spatiotemporal efficacy of a dual-gene therapy model based on 3D collagen scaffolds loaded with the therapeutic genes interleukin 10 (IL-10, a potent anti-inflammatory cytokine, and endothelial nitric oxide synthase (eNOS, a promoter of angiogenesis. A collagen-based scaffold loaded with plasmid IL-10 polyplexes and plasmid eNOS polyplexes encapsulated into microspheres was used to transfect HUVECs and HMSCs cells.The therapeutic efficacy of the system was monitored at 2, 7 and 14 days for eNOS and IL-10 mRNA expression using RT-PCR and live cell imaging molecular beacon technology. The dual gene releasing collagen-based scaffold provided both sustained and delayed release of functional polyplexes in vitro over a 14 day period which was corroborated with variation in expression levels seen using RT-PCR and MB imaging. Maximum fold increases in IL-10 mRNA and eNOS mRNA expression levels occurred at day 7 in HMSCs and HUVECs. However, IL-10 mRNA expression levels seemed dependent on frequency of media changes and/or ease of transfection of the cell type. It was demonstrated that molecular beacons are able to monitor changes in mRNA levels at various time points, in the presence of a 3D scaffolding gene carrier system and the results complemented those of RT-PCR.

  11. Research on IEEE 802.22.1 Beacon Networks Application%IEEE 802.22.1信标网络应用研究

    Institute of Scientific and Technical Information of China (English)

    杨大全

    2012-01-01

    Several IEEE 802.22.1 beacon devices are used to build beacon network by self-organization. IEEE 802.22.1 beacon protocol is introduced, and the decision strategies of beacon networks in the process of establishing and maintenance are discussed. IEEE 802.22.1 beacon networks sensing and information detection in WRAN device are introduced. The maximum latency before scheduling a quiet period that will ensure to capture the full information of the beacon network is given.%多个IEEE 802.22.1信标设备将自组织成信标网络.介绍了IEEE 802.22.1标准中定义的自组织方案;讨论了信标网络建立与维持过程中的判决策略;介绍了无线区域网络(WRAN)设备对IEEE 802.22.1信标网络的识别与信息获取机制;给出了确保实现对信标网络信息解析所需要安排的最大时延.

  12. Design of a K/Q-Band Beacon Receiver for the Alphasat Technology Demonstration Payload (TDP) #5 Experiment

    Science.gov (United States)

    Morse, Jacquelynne R.

    2014-01-01

    This paper describes the design and performance of a coherent KQ-band (2040 GHz) beacon receiver developed at NASA Glenn Research Center (GRC) that will be installed at the Politecnico di Milano (POLIMI) for use in the Alphasat Technology Demonstration Payload 5 (TDP5) beacon experiment. The goal of this experiment is to characterize rain fade attenuation at 40 GHz to improve the performance of existing statistical rain attenuation models in the Q-band. The ground terminal developed by NASA GRC utilizes an FFT-based frequency estimation receiver capable of characterizing total path attenuation effects due to gaseous absorption, clouds, rain, and scintillation. The receiver system has been characterized in the lab and demonstrates a system dynamic range performance of better than 58 dB at 1 Hz and better than 48 dB at 10 Hz rates.

  13. Use of molecular beacons for the rapid analysis of DNA damage induced by exposure to an atmospheric pressure plasma jet

    Science.gov (United States)

    Kurita, Hirofumi; Miyachika, Saki; Yasuda, Hachiro; Takashima, Kazunori; Mizuno, Akira

    2015-12-01

    A rapid method for evaluating the damage caused to DNA molecules upon exposure to plasma is demonstrated. Here, we propose the use of a molecular beacon for rapid detection of DNA strand breaks induced by atmospheric pressure plasma jet (APPJ) irradiation. Scission of the molecular beacon by APPJ irradiation leads to separation of the fluorophore-quencher pair, resulting in an increase in fluorescence that directly correlates with the DNA strand breaks. The results show that the increase in fluorescence intensity is proportional to the exposure time and the rate of fluorescence increase is proportional to the discharge power. This simple and rapid method allows the estimation of DNA damage induced by exposure to a non-thermal plasma.

  14. Simple, rapid detection of influenza A (H1N1) viruses using a highly sensitive peptide-based molecular beacon.

    Science.gov (United States)

    Lim, Eun-Kyung; Guk, Kyeonghye; Kim, Hyeran; Chung, Bong-Hyun; Jung, Juyeon

    2016-01-01

    A peptide-based molecular beacon (PEP-MB) was prepared for the simple, rapid, and specific detection of H1N1 viruses using a fluorescence resonance energy transfer (FRET) system. The PEP-MB exhibited minimal fluorescence in its "closed" hairpin structure. However, in the presence of H1N1 viruses, the specific recognition of the hemagglutinin (HA) protein of H1 strains by the PEP-MB causes the beacon to assume an "open" structure that emits strong fluorescence. The PEP-MB could detect H1N1 viruses within 15 min or even 5 min and can exhibit strong fluorescence even at low viral concentrations, with a detection limit of 4 copies.

  15. Use of molecular beacons for the rapid analysis of DNA damage induced by exposure to an atmospheric pressure plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Kurita, Hirofumi, E-mail: kurita@ens.tut.ac.jp, E-mail: mizuno@ens.tut.ac.jp; Miyachika, Saki; Yasuda, Hachiro; Takashima, Kazunori; Mizuno, Akira, E-mail: kurita@ens.tut.ac.jp, E-mail: mizuno@ens.tut.ac.jp [Department of Environmental and Life Sciences, Toyohashi University of Technology, Aichi 441-8580 (Japan)

    2015-12-28

    A rapid method for evaluating the damage caused to DNA molecules upon exposure to plasma is demonstrated. Here, we propose the use of a molecular beacon for rapid detection of DNA strand breaks induced by atmospheric pressure plasma jet (APPJ) irradiation. Scission of the molecular beacon by APPJ irradiation leads to separation of the fluorophore-quencher pair, resulting in an increase in fluorescence that directly correlates with the DNA strand breaks. The results show that the increase in fluorescence intensity is proportional to the exposure time and the rate of fluorescence increase is proportional to the discharge power. This simple and rapid method allows the estimation of DNA damage induced by exposure to a non-thermal plasma.

  16. Research on the acquisition and tracking simulation system of light beacon in satellite-ground optical communications

    Institute of Scientific and Technical Information of China (English)

    ZUO Tao; AI Yong; HUANG Hai-bo; SU Gui-bo

    2010-01-01

    @@ The study on the acquisition and tracking simulation system in satellite-ground optical communications is presented here.By applying global positioning system(GPS)coordinate calculation,the time needed in initial acquisition of light beacon can be reduced largely.Smith predictor is applied to compensate the mechanical hysteresis of tracking system and to improve the dynamic performance of the system.Tracking experiments over a i 6 km distance on the ground are conducted to verify the tracking of light beacon in satellite-ground optical communications.The standard deviation of horizontal coordinates is 35.3568 μrad and the maximum offset is 209.3675 μrad in stable tracking.

  17. A FRET-enabled molecular peptide beacon with a significant red shift for the ratiometric detection of nucleic acids.

    Science.gov (United States)

    Maity, Debabrata; Jiang, Juanjuan; Ehlers, Martin; Wu, Junchen; Schmuck, Carsten

    2016-05-01

    A cationic molecular peptide beacon NAP1 functionalized with a fluorescence resonance energy transfer-pair at its ends allows the ratiometric detection of ds-DNA with a preference for AT rich sequences. NAP1 most likely binds in a folded form into the minor groove of ds-DNA, which results in a remarkable change in its fluorescence properties. As NAP1 exhibits quite low cytotoxicity, it can also be used for imaging of nuclear DNA in cells.

  18. Molecular beacon probes–base multiplex NASBA Real-time for detection of HIV-1 and HCV

    Directory of Open Access Journals (Sweden)

    Samira Mohammadi Yeganeh

    2012-06-01

    Full Text Available Background and Objectives: Developed in 1991, nucleic acid sequence-based amplification (NASBA has been introduced as a rapid molecular diagnostic technique, where it has been shown to give quicker results than PCR, and it can also be more sensitive. This paper describes the development of a molecular beacon-based multiplex NASBA assay for simultaneous detection of HIV-1 and HCV in plasma samples.Materials and Methods: A well-conserved region in the HIV-1 pol gene and 5’-NCR of HCV genome were used for primers and molecular beacon design. The performance features of HCV/HIV-1 multiplex NASBA assay including analytical sensitivity and specificity, clinical sensitivity and clinical specificity were evaluated.Results: The analysis of scalar concentrations of the samples indicated that the limit of quantification of the assay was < 1000 copies/ml for HIV-1 and < 500copies/ml for HCV with 95% confidence interval. Multiplex NASBA assay showed a 98% sensitivity and 100% specificity. The analytical specificity study with BLAST software demonstrated that the primers do not attach to any other sequences except for that of HIV-1 or HCV. The primers and molecular beacon probes detected all HCV genotypes and all major variants of HIV-1.Conclusion: This method may represent a relatively inexpensive isothermal method for detection of HIV-1/HCV co-infection in monitoring of patients.

  19. DNA-templated silver nanoclusters based label-free fluorescent molecular beacon for the detection of adenosine deaminase.

    Science.gov (United States)

    Zhang, Kai; Wang, Ke; Xie, Minhao; Zhu, Xue; Xu, Lan; Yang, Runlin; Huang, Biao; Zhu, Xiaoli

    2014-02-15

    A general and reliable fluorescent molecular beacon is proposed in this work utilizing DNA-templated silver nanoclusters (AgNCs). The fluorescent molecular beacon has been employed for sensitive determination of the concentration of adenosine deaminase (ADA) and its inhibition. A well-designed oligonucleotide containing three functional regions (an aptamer region for adenosine assembly, a sequence complementary to the region of the adenosine aptamer, and an inserted six bases cytosine-loop) is adopted as the core element in the strategy. The enzymatic reaction of adenosine catalyzed by ADA plays a key role as well in the regulation of the synthesis of the DNA-templated AgNCs, i.e. the signal indicator. The intensity of the fluorescence signal may thereby determine the concentration of the enzyme and its inhibitor. The detection limit of the ADA can be lowered to 0.05 UL(-1). Also, 100 fM of a known inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine hydrochloride (EHNA) is enough to present distinguishable fluorescence emission. Moreover, since the fluorescent signal indicator is not required to be bound with the oligonucleotide, this fluorescent molecular beacon may integrate the advantages of both the label-free and signal-on strategies.

  20. A SHORT INTERFERING RNA MOLECULAR BEACON FOR THE ATTENUATION OF MYCOBACTERIAL INFECTION

    Directory of Open Access Journals (Sweden)

    Remo George

    2014-01-01

    Full Text Available The ability of the pathogen Mycobacterium Tuberculosis (MTB to invade and survive within macrophages of granulomas is attributed to the product of the Mammalian Cell Entry (MCE operon whose gene, mce4A, encodes a cholesterol transporter that transports host lipids into the bacterium that allows the bacterium to survive during chronic infection. Here, we proposed and tested the hypothesis that a mce4A siRNA molecular beacon can be used to attenuate mycobacterial infection in macrophages. Mce4A gene was cloned and expressed in E. coli (E. coli-4A and differentiated U937 cells were transduced with piLenti-siRNA-GFP phage expressing the mce4A siRNA for 24 h. This was followed by infection with either E. coli-4A or M. smegmatis for 3 h followed by incubation for 0, 3, 6, 24 and 48 h. The cells were lysed and the lysates were plated on LB agar plates containing ampicillin (100 µg mL-1 or on 7H11 media and incubated at 37°C overnight. Our results showed that the siRNA treatment attenuated E.coli-4A infection in macrophages at 3, 6, 24 and 48 h by 0, 77, 59.6 and 99.7%, respectively. Our results also showed that the siRNA treatment attenuated M. smegmatis infection in macrophages at 3, 6, 24 and 48 h. by 94.8, 70.3, 98.9 and 93.4%, respectively. In conclusion, a mce4A siRNA molecular beacon was successfully delivered and stably expressed in macrophages which attenuated E. coli expressing mce4A (E. coli-4A and M. smegmatis infection in macrophages.

  1. NanoCluster Beacons as reporter probes in rolling circle enhanced enzyme activity detection

    Science.gov (United States)

    Juul, Sissel; Obliosca, Judy M.; Liu, Cong; Liu, Yen-Liang; Chen, Yu-An; Imphean, Darren M.; Knudsen, Birgitta R.; Ho, Yi-Ping; Leong, Kam W.; Yeh, Hsin-Chih

    2015-04-01

    As a newly developed assay for the detection of endogenous enzyme activity at the single-catalytic-event level, Rolling Circle Enhanced Enzyme Activity Detection (REEAD) has been used to measure enzyme activity in both single human cells and malaria-causing parasites, Plasmodium sp. Current REEAD assays rely on organic dye-tagged linear DNA probes to report the rolling circle amplification products (RCPs), the cost of which may hinder the widespread use of REEAD. Here we show that a new class of activatable probes, NanoCluster Beacons (NCBs), can simplify the REEAD assays. Easily prepared without any need for purification and capable of large fluorescence enhancement upon hybridization, NCBs are cost-effective and sensitive. Compared to conventional fluorescent probes, NCBs are also more photostable. As demonstrated in reporting the human topoisomerases I (hTopI) cleavage-ligation reaction, the proposed NCBs suggest a read-out format attractive for future REEAD-based diagnostics.As a newly developed assay for the detection of endogenous enzyme activity at the single-catalytic-event level, Rolling Circle Enhanced Enzyme Activity Detection (REEAD) has been used to measure enzyme activity in both single human cells and malaria-causing parasites, Plasmodium sp. Current REEAD assays rely on organic dye-tagged linear DNA probes to report the rolling circle amplification products (RCPs), the cost of which may hinder the widespread use of REEAD. Here we show that a new class of activatable probes, NanoCluster Beacons (NCBs), can simplify the REEAD assays. Easily prepared without any need for purification and capable of large fluorescence enhancement upon hybridization, NCBs are cost-effective and sensitive. Compared to conventional fluorescent probes, NCBs are also more photostable. As demonstrated in reporting the human topoisomerases I (hTopI) cleavage-ligation reaction, the proposed NCBs suggest a read-out format attractive for future REEAD-based diagnostics. Electronic

  2. A quantum dot-aptamer beacon using a DNA intercalating dye as the FRET reporter: application to label-free thrombin detection.

    Science.gov (United States)

    Chi, Chun-Wei; Lao, Yeh-Hsing; Li, Yi-Shan; Chen, Lin-Chi

    2011-03-15

    A new quantum dot (QD)-aptamer (apt) beacon that acts by folding-induced dissociation of a DNA intercalating dye, BOBO-3(B), is demonstrated with label-free thrombin detection. The beacon, denoted as QD-apt:B, is constructed by (1) coupling of a single-stranded thrombin aptamer to Qdot 565 via EDC/Sulfo-NHS chemistry and (2) staining the duplex regions of the aptamer on QD with excess BOBO-3 before thrombin binding. When mixing a thrombin sample with QD-apt:B, BOBO-3 is competed away from the beacon due to target-induced aptamer folding, which then causes a decrease in QD fluorescence resonance energy transfer (FRET)-mediated BOBO-3 emission and achieves thrombin quantitation. In this work, the effects of Mg(2+), coupling time, and aptamer type on the beacon's performances are investigated and discussed thoroughly with various methods, including transmission electron microscopy (TEM), dynamic light scattering (DLS), and two-color differential gel electrophoresis. Using the best aptamer beacon (HTQ37), we attain highly specific and wide-range detection (from nM to μM) of thrombin in buffer, and the beacon can sense nM-range thrombin in 15% diluted serum. Compared to the reported QD aptamer assays, our method is advantageous from the aspect of using a simple sensory unit design without losing the detection sensitivity. Therefore, we consider the QD-apt:B beacon a potential alternative to immuno-reagents and an effective tool to study nucleic acid folding on QD as well.

  3. Beacon-like/ubiquitin-5-like immunoreactivity is highly expressed in human hypothalamus and increased in haloperidol-treated schizophrenics and a rat model of schizophrenia.

    Science.gov (United States)

    Bernstein, Hans-Gert; Lendeckel, Uwe; Dobrowolny, Henrik; Stauch, Renate; Steiner, Johann; Grecksch, Gisela; Becker, Axel; Jirikowski, Gustav F; Bogerts, Bernhard

    2008-04-01

    The beacon gene is involved in the regulation of energy metabolism, food intake, and obesity. We localized its gene product, beacon-/ubiquitin 5-like immunoreactivity in brains of normal-weight, non-psychotic individuals, adipose (BMI over 32), non-psychotic individuals, and haloperidol-treated schizophrenics. The protein was found to be highly expressed in many neurons of the paraventricular and supraoptic hypothalamic nuclei. Besides, it was detected in neurons of other hypothalamic areas (suprachiasmatic, arcuate, and ventromedial nuclei) as well as outside the hypothalamus (Nuc. basalis Meynert, thalamus, hippocampus, and some neocortical areas). A morphometric analysis of beacon-immunoreactive hypothalamic and neocortical neurons revealed that compared to normal-weight controls in haloperidol-treated schizophrenics, there was a significant increase of protein-expressing supraoptic, paraventricular, and orbitofrontal neurons. However, a significant increase in beacon-expressing supraoptic neurons was also seen in adipose, non-psychotic individuals in comparison with normal-weight controls. Haloperidol at different doses has no effect on beacon expression in SHSY5Y neuroblastoma cells, which makes the assumption unlikely that haloperidol per se is responsible for the increased neuronal expression of the peptide in schizophrenics. In rats with a neonatal lesion of the ventral hippocampus (a widely used animal model of schizophrenia), we found an increased neuronal expression of beacon in the paraventricular and supraoptic nuclei. We suppose that elevated hypothalamic expression of beacon-like protein in non-obese schizophrenics is not primarily related to metabolic alterations, but to a certain role in schizophrenia, which is possibly unrelated to aspects of weight gain and obesity. The latter assumption finds some support by data obtained in rats with ventral hippocampus lesion.

  4. Appoach to realizing weak hydroacoustic beaconing signal based on DSP%一种基于DSP的声信标弱信号提取方法

    Institute of Scientific and Technical Information of China (English)

    李笑媛; 程晶; 那健

    2014-01-01

    介绍一种基于DSP处理模块实现声信标弱信号提取的方法。针对声信标的性能参数及其具体应用环境,采用一种在加性白噪声环境下能够使信号的输出信噪比达到最大的匹配滤波方法,并将其在DSP处理模块上实现,最终将检测结果以音频和视频的形式输出。经过实际应用测试,该方法易于实现,实时性好,在复杂的海洋背景噪声下可以较好提高声信标的作用距离。%This paper introduces a method to realize weak hydroacoustic beaconing signal detecting base on DSP. According to the capability parameters of the hydroacoustic beaconing that the subject have adopted and the application of the hydroacoustic beaconing to the specific environment, also because the matching filter is the best filter means in the condition of additive white noise, it can make the SNR of the output signal to maximize, so this paper adopted the matching filter method, and at last the subject realized weak hydroacoustic beaconing signal detecting on DSP module. After real testing, the system which is good for weak hydroacoustic beaconing signal detecting can run real-time and realize easily. After sea trials, the system using the method can quickly find the target when hydroacoustic beaconing in a long distance. The sea trials shows the method can improve detection distance and easy to use in the areas of the weak hydroacoustic beaconing signal detecting.

  5. Cincinnati Beacon Community Program highlights challenges and opportunities on the path to care transformation.

    Science.gov (United States)

    Fairbrother, Gerry; Trudnak, Tara; Christopher, Ronda; Mansour, Mona; Mandel, Keith

    2014-05-01

    The Cincinnati, Ohio, metropolitan area was one of seventeen US communities to participate in the federal Beacon Community Cooperative Agreement Program to demonstrate how health information technology (IT) could be used to improve health care. Given $13.7 million to spend in thirty-one months, the Cincinnati project involved hundreds of physicians, eighty-seven primary care practices, eighteen major hospital partners, and seven federally qualified health centers and community health centers. The thrust of the program was to build a shared health IT infrastructure to support quality improvement through data exchange, registries, and alerts that notified primary care practices when a patient visited an emergency department or was admitted to a hospital. A special focus of this program was on applying these tools to adult patients with diabetes and pediatric patients with asthma. Despite some setbacks and delays, the basic technology infrastructure was built, the alert system was implemented, nineteen practices focusing on diabetes improvement were recognized as patient-centered medical homes, and many participants agreed that the program had helped transform care. However, the experience also demonstrated that the ability to transfer data was limited in electronic health record systems; that considerable effort was required to adapt technology to support quality improvement; and that the ambitious agenda required more time for planning, training, and implementation than originally thought.

  6. A molecular beacon biosensor based on the nanostructured aluminum oxide surface.

    Science.gov (United States)

    Che, Xiangchen; He, Yuan; Yin, Haocheng; Que, Long

    2015-10-15

    A new class of molecular beacon biosensors based on the nanostructured aluminum oxide or anodic aluminum oxide (AAO) surface is reported. In this type of sensor, the AAO surface is used to enhance the fluorescent signals of the fluorophore-labeled hairpin DNA. When a target DNA with a complementary sequence to that of the hairpin DNA is applied on the sensor, the fluorophores are forced to move away from the AAO surface due to the hybridization between the hairpin DNA and the target DNA, resulting in the significant decrease of the fluorescent signals. The observed signal reduction is sufficient to achieve a demonstrated detection limit of 10nM, which could be further improved by optimizing the AAO surface. The control experiments have also demonstrated that the bioassay used in the experiments has excellent specificity and selectivity, indicating the great promise of this type of sensor for diagnostic applications. Since the arrayed AAO micropatterns can be fabricated on a single chip in a cost-effective manner, the arrayed sensors could provide an ideal technical platform for studying fundamental biological process and monitoring disease biomarkers.

  7. Beacon Hill end moraine, Boston: new explanation of an important urban feature

    Science.gov (United States)

    Kaye, Clifford A.; Coates, Donald R.

    1976-01-01

    The usefulness of geology to engineers is in direct proportion to how well it helps us predict the subsurface; these predictions, in turn, depend on our knowledge of the geomorphic processes that molded the terrain. The uncertainties of interpretation are particularly great in glaciated terrain because our understanding of both glacial processes and history is so incomplete, a fact well illustrated in Beacon Hill. Recent construction activities in the eastern part of the hill, until now classified as a drumlin, have shown that it is better interpreted as an end moraine formed by a Wisconsonian glacial readvance. Instead of the firm till that was anticipated as foundation material, excavations exposed a complex of sand, gravel, and clay, with only minor zones of till. The structure of these deposits strongly suggests that originally they were plates of the glacial bed that froze to the glacier and were transported englacially. Thrust faulting and other deformations are glacial structures formed within the ice in the glacier's terminal zone. In spite of the complex englacial history, these deposits lost little of their original appearance and intergranular relationships. Upon deglaciation, the frozen moraine thawed, and slumping formed complex secondary structures on the ridge's lower flanks.

  8. Electrochemical molecular beacon biosensor for sequence-specific recognition of double-stranded DNA.

    Science.gov (United States)

    Miao, Xiangmin; Guo, Xiaoting; Xiao, Zhiyou; Ling, Liansheng

    2014-09-15

    Direct recognition of double-stranded DNA (dsDNA) was crucial to disease diagnosis and gene therapy, because DNA in its natural state is double stranded. Here, a novel sensor for the sequence-specific recognition of dsDNA was developed based on the structure change of ferrocene (Fc) redox probe modified molecular beacon (MB). For constructing such a sensor, gold nanoparticles (AuNPs) were initially electrochemical-deposited onto glass carbon electrode (GCE) surface to immobilize thiolated MB in their folded states with Au-S bond. Hybridization of MB with target dsDNA induced the formation of parallel triplex DNA and opened the stem-loop structure of it, which resulted in the redox probe (Fc) away from the electrode and triggered the decrease of current signals. Under optimal conditions, dsDNA detection could be realized in the range from 350 pM to 25 nM, with a detection limit of 275 pM. Moreover, the proposed method has good sequence-specificity for target dsDNA compared with single base pair mismatch and two base pairs mismatches.

  9. A molecular beacon microarray based on a quantum dot label for detecting single nucleotide polymorphisms.

    Science.gov (United States)

    Guo, Qingsheng; Bai, Zhixiong; Liu, Yuqian; Sun, Qingjiang

    2016-03-15

    In this work, we report the application of streptavidin-coated quantum dot (strAV-QD) in molecular beacon (MB) microarray assays by using the strAV-QD to label the immobilized MB, avoiding target labeling and meanwhile obviating the use of amplification. The MBs are stem-loop structured oligodeoxynucleotides, modified with a thiol and a biotin at two terminals of the stem. With the strAV-QD labeling an "opened" MB rather than a "closed" MB via streptavidin-biotin reaction, a sensitive and specific detection of label-free target DNA sequence is demonstrated by the MB microarray, with a signal-to-background ratio of 8. The immobilized MBs can be perfectly regenerated, allowing the reuse of the microarray. The MB microarray also is able to detect single nucleotide polymorphisms, exhibiting genotype-dependent fluorescence signals. It is demonstrated that the MB microarray can perform as a 4-to-2 encoder, compressing the genotype information into two outputs.

  10. Rapid detection of infectious rotavirus group A using a molecular beacon assay.

    Science.gov (United States)

    Bertol, Jéssica Wildgrube; Gatti, Maria Silvia Viccari

    2016-08-01

    Rapid, sensitive and specific methods are necessary to detect and quantify infectious viruses. Cultivating and detecting enteric viruses in cell culture are difficult, thus impairing the advancement of knowledge regarding virus-induced diarrhea. Rotavirus (RV) detection has been conducted by serological or molecular biology methods, which do not provide information regarding viral infectivity. Molecular beacons (MBs) have demonstrated efficacy for viral detection in cell culture. We propose a MB assay to detect human rotavirus group A (HuRVA) in cell culture. MA104 cells were mock-infected or infected with HuRVA strains (RotaTeq(®) vaccine and K8 strains), and a specific MB for the HuRVA VP6 gene was used for virus detection. Mock-infected cells showed basal fluorescence, while infected cells exhibited increased fluorescence emission. MB hybridization to the viral mRNA target of HuRVA was confirmed. Fluorescence increased according to the increase in the number of infectious viral particles per cell (MOI 0.5-MOI 1). This technique provides quick and efficient HuRVA detection in cell culture without a need for viral culture for several days or many times until cytopathic effects are visualized. This methodology could be applied in the selection of samples for developing RV vaccines.

  11. The keys to governance and stakeholder engagement: the southeast michigan beacon community case study.

    Science.gov (United States)

    Des Jardins, Terrisca R

    2014-01-01

    Community-based health information exchanges (HIEs) and efforts to consolidate and house data are growing, given the advent of Accountable Care Organizations (ACOs) under the Affordable Care Act and other similar population health focused initiatives. The Southeast Michigan Beacon Community (SEMBC) can be looked to as one case study that offers lessons learned, insights on challenges faced and accompanying workarounds related to governance and stakeholder engagement. The SEMBC case study employs an established Data Warehouse Governance Framework to identify and explain the necessary governance and stakeholder engagement components, particularly as they relate to community-wide data sharing and data warehouses or repositories. Perhaps the biggest lesson learned through the SEMBC experience is that community-based work is hard. It requires a great deal of community leadership, collaboration and resources. SEMBC found that organizational structure and guiding principles needed to be continually revisited and nurtured in order to build the relationships and trust needed among stakeholder organizations. SEMBC also found that risks and risk mitigation tactics presented challenges and opportunities at the outset and through the duration of the three year pilot period. Other communities across the country embarking on similar efforts need to consider realistic expectations about community data sharing infrastructures and the accompanying and necessary governance and stakeholder engagement fundamentals.

  12. Quantification of Salmonella Typhi in water and sediments by molecular-beacon based qPCR.

    Science.gov (United States)

    Rani, Neetika; Vajpayee, Poornima; Bhatti, Saurabh; Singh, Smriti; Shanker, Rishi; Gupta, Kailash Chand

    2014-10-01

    A molecular-beacon based qPCR assay targeting staG gene was designed for specific detection and quantification of S. Typhi and validated against water and sediment samples collected from the river Ganga, Yamuna and their confluence on two days during Mahakumbha mela 2012-2013 (a) 18 December, 2012: before six major religious holy dips (Makar Sankranti, Paush Poornima, Mauni Amavasya, Basant Panchami, Maghi Poornima and Mahashivratri) (b) 10 February, 2013: after the holy dip was taken by over 3,00,00,000 devotees led by ascetics of Hindu sects at Sangam on 'Mauni Amavasya' (the most auspicious day of ritualistic mass bathing). The assay could detect linearly lowest 1 genomic equivalent per qPCR and is highly sensitive and selective for S. Typhi detection in presence of non specific DNA from other bacterial strains including S. Paratyphi A and S. Typhimurium. It has been observed that water and sediment samples exhibit S. Typhi. The mass holy dip by devotees significantly affected the water and sediment quality by enhancing the number of S. Typhi in the study area. The qPCR developed in the study might be helpful in planning the intervention and prevention strategies for control of enteric fever outbreaks in endemic regions.

  13. The use of nanocrystal quantum dot as fluorophore reporters in molecular beacon-based assays

    Science.gov (United States)

    Adegoke, Oluwasesan; Park, Enoch Y.

    2016-12-01

    The utilization of molecular beacon (MB) biosensor probes to detect nucleic acid targets has received enormous interest within the scientific community. This interest has been stimulated by the operational qualities of MB-based probes with respect to their unique sensitivity and specificity. The design of MB biosensors entails not only optimizing the sequence of the loop to hybridize with the nucleic acid target or optimization of the length of the stem to tune the sensitivity but also the selection of the appropriate fluorophore reporter to generate the signal transduction read-out upon hybridization of the probe with the target sequence. Traditional organic fluorescent dyes are mostly used for signal reporting in MB assays but their optical properties in comparison to semiconductor fluorescent quantum dot (Qdot) nanocrystals are at a disadvantage. This review highlights the progress made in exploiting Qdot as fluorophore reporters in MB-based assays with the aim of instigating further development in the field of Qdot-MB technology. The development reported to date indicates that unparalleled fluorescence signal reporting in MB-based assays can be achieved using well-constructed Qdot fluorophores.

  14. Theranostic properties of a survivin-directed molecular beacon in human melanoma cells.

    Directory of Open Access Journals (Sweden)

    Sara Carpi

    Full Text Available Survivin is an inhibitor of apoptosis overexpressed in different types of tumors and undetectable in most terminally differentiated normal tissues. In the current study, we sought to evaluate the in vitro theranostic properties of a molecular beacon-oligodeoxynucleotide (MB that targets survivin mRNA. We used laser scanning confocal microscopy to study MB delivery in living cells and real-time PCR and western blot to assess selective survivin-targeting in human malignant melanoma cells. We further assess the pro-apoptotic effect of MB by measuring internucleosomal DNA fragmentation, dissipation of mitochondrial membrane potential (MMP and changes in nuclear morphology. Transfection of MB into A375 and 501 Mel cells generated high signal intensity from the cytoplasm, while no signal was detected in the extracellular environment and in survivin-negative cells (i.e., human melanocytes and monocytes. MB time dependently decreased survivin mRNA and protein expression in melanoma cells with the maximum effect reached at 72 h. Treatment of melanoma cells with MB induced apoptosis by significant changes in MMP, accumulation of histone-complexed DNA fragments in the cytoplasm and nuclear condensation. MB also enhanced the pro-apoptotic effect of standard chemotherapeutic drugs tested at clinically relevant concentrations. The MB tested in the current study conjugates the ability of imaging with the pharmacological silencing activity against survivin mRNA in human melanoma cells and may represent an innovative approach for cancer diagnosis and treatment.

  15. With the Bible toward the year 2000: scriptural engagement as barometer, beacon and bellwether

    Directory of Open Access Journals (Sweden)

    J. H. Elliott

    1990-06-01

    Full Text Available Through the centuries, engagement with the Bible has served as a barometer (recording and reflec­ting the history of shifting circumstances, as a beacon (constituting a source of light illuminating theological reflection and guiding human conduct and as a bellwether (leading the way in setting new agendas for the Church, her theology and her encounter with the world. Against this back­ ground, the history of biblical engagement through the centuries is briefly traced. The main focus of the article is, however, to reflect on the role of the Bible in the next millenium. The author foresees an even stronger ecumenical engagement, an enhanced focus on a critical faith and a self-critical rationality, a stronger rejection of absolutist claims, renewed respect for the diversity of voices in the biblical canon, the emergence of biblical study to an attentive dialogue partner within other fields of human knowledge and a renewed search for wisdom in the Bible in future in order to face the problems which will confront humankind. Against the background of these developments the study of the Bible will, in the third millenium, become even more an interconfessional, international, interdisciplinary and intersocial enterprise, sustained by the conviction that the Bible is a holy and privileged word, both about human existence and humanity’s relation to God, society, history, and the cosmos.

  16. The use of Molecular Beacons to Directly Measure Bacterial mRNA Abundances and Transcript Degradation

    Science.gov (United States)

    Kuechenmeister, Lisa J.; Anderson, Kelsi L.; Morrison, John M.; Dunman, Paul M.

    2009-01-01

    The regulation of mRNA turnover is a dynamic means by which bacteria regulate gene expression. Although current methodologies allow characterization of the stability of individual transcripts, procedures designed to measure alterations in transcript abundance/turnover on a high throughput scale are lacking. In the current report, we describe the development of a rapid and simplified molecular beacon-based procedure to directly measure the mRNA abundances and mRNA degradation properties of well-characterized Staphylococcus aureus pathogenicity factors. This method does not require any PCR-based amplification, can monitor the abundances of multiple transcripts within a single RNA sample, and was successfully implemented into a high throughput screen of transposon mutant library members to detect isolates with altered mRNA turnover properties. It is expected that the described methodology will provide great utility in characterizing components of bacterial RNA degradation processes and can be used to directly measure the mRNA levels of virtually any bacterial transcript. PMID:18992285

  17. Learning from health information exchange technical architecture and implementation in seven beacon communities.

    Science.gov (United States)

    McCarthy, Douglas B; Propp, Karen; Cohen, Alexander; Sabharwal, Raj; Schachter, Abigail A; Rein, Alison L

    2014-01-01

    As health care providers adopt and make "meaningful use" of health information technology (health IT), communities and delivery systems must set up the infrastructure to facilitate health information exchange (HIE) between providers and numerous other stakeholders who have a role in supporting health and care. By facilitating better communication and coordination between providers, HIE has the potential to improve clinical decision-making and continuity of care, while reducing unnecessary use of services. When implemented as part of a broader strategy for health care delivery system and payment reform, HIE capability also can enable the use of analytic tools needed for population health management, patient engagement in care, and continuous learning and improvement. The diverse experiences of seven communities that participated in the three-year federal Beacon Community Program offer practical insight into factors influencing the technical architecture of exchange infrastructure and its role in supporting improved care, reduced cost, and a healthier population. The case studies also document challenges faced by the communities, such as significant time and resources required to harmonize variations in the interpretation of data standards. Findings indicate that their progress developing community-based HIE strategies, while driven by local needs and objectives, is also influenced by broader legal, policy, and market conditions.

  18. Entropy Beacon: A Hairpin-Free DNA Amplification Strategy for Efficient Detection of Nucleic Acids.

    Science.gov (United States)

    Lv, Yifan; Cui, Liang; Peng, Ruizi; Zhao, Zilong; Qiu, Liping; Chen, Huapei; Jin, Cheng; Zhang, Xiao-Bing; Tan, Weihong

    2015-12-01

    Here, we propose an efficient strategy for enzyme- and hairpin-free nucleic acid detection called an entropy beacon (abbreviated as Ebeacon). Different from previously reported DNA hybridization/displacement-based strategies, Ebeacon is driven forward by increases in the entropy of the system, instead of free energy released from new base-pair formation. Ebeacon shows high sensitivity, with a detection limit of 5 pM target DNA in buffer and 50 pM in cellular homogenate. Ebeacon also benefits from the hairpin-free amplification strategy and zero-background, excellent thermostability from 20 °C to 50 °C, as well as good resistance to complex environments. In particular, based on the huge difference between the breathing rate of a single base pair and two adjacent base pairs, Ebeacon also shows high selectivity toward base mutations, such as substitution, insertion, and deletion and, therefore, is an efficient nucleic acid detection method, comparable to most reported enzyme-free strategies.

  19. Turbulence-induced low order aberrations of optical wavefronts in partial adaptive compensation with Rayleigh beacon or sodium beacon%激光导引星自适应光学系统对大气湍流低阶像差校正效果分析

    Institute of Scientific and Technical Information of China (English)

    万敏; 苏毅; 向汝建

    2001-01-01

    The residual phase error after correction for turbulence-induced phase aberrations by a partially compensating adaptive optics system (with temporal lag and limited space resolution) is computed by using the phase expansion on the Zernike polynomials in this paper. The computation can be used to derive the maximum order of aberration to be corrected to get the most from the compensation. The partially compensating adaptive optics system with Rayleigh beacon or sodium beacon as reference is computed also in this paper. The results show, the system with sodium beacon requires higher space frequency than the system with Rayleigh beacon. And the off-axis anisoplanatism effect due to the angular separation between the object and the beacon or the system temporal lag is more serious for the system with sodium beacon. The correction for high order aberration is more suitable for the system with sodium beacon than the system with Rayleigh beacon.%在对大气湍流相位扰动进行Zernike多项式展开的基础上,通过对信标和目标光的Zernike系数相关因子的推导,得到了实际自适应光学系统(系统存在时间滞后和有限的空间分辨率)对相位扰动各阶像差的校正残差公式。同时结合实际,对瑞利导星以及钠导星自适应光学系统补偿大气湍流各阶像差的能力进行了计算和分析,为实际自适应光学系统的设计提供了理论参考。

  20. Gold nanoparticle-based beacon to detect STAT5b mRNA expression in living cells: a case optimized by bioinformatics screen.

    Science.gov (United States)

    Deng, Dawei; Li, Yang; Xue, Jianpeng; Wang, Jie; Ai, Guanhua; Li, Xin; Gu, Yueqing

    2015-01-01

    Messenger RNA (mRNA), a single-strand ribonucleic acid with functional gene information is usually abnormally expressed in cancer cells and has become a promising biomarker for the study of tumor progress. Hairpin DNA-coated gold nanoparticle (hDAuNP) beacon containing a bare gold nanoparticle (AuNP) as fluorescence quencher and thiol-terminated fluorescently labeled stem-loop-stem oligonucleotide sequences attached by Au-S bond is currently a new nanoscale biodiagnostic platform capable of mRNA detection, in which the design of the loop region sequence is crucial for hybridizing with the target mRNA. Hence, in this study, to improve the sensitivity and selectivity of hDAuNP beacon simultaneously, the loop region of hairpin DNA was screened by bioinformatics strategy. Here, signal transducer and activator of transcription 5b (STAT5b) mRNA was selected and used as a practical example. The results from the combined characterizations using optical techniques, flow cytometry assay, and cell microscopic imaging showed that after optimization, the as-prepared hDAuNP beacon had higher selectivity and sensitivity for the detection of STAT5b mRNA in living cells, as compared with our previous beacon. Thus, the bioinformatics method may be a promising new strategy for assisting in the designing of the hDAuNP beacon, extending its application in the detection of mRNA expression and the resultant mRNA-based biological processes and disease pathogenesis.

  1. Application of a molecular beacon based real-time isothermal amplification (MBRTIA) technology for simultaneous detection of Bacillus cereus and Staphylococcus aureus.

    Science.gov (United States)

    Mandappa, I M; Joglekar, Prasanna; Manonmani, H K

    2015-07-01

    A multiplex real-time isothermal amplification assay was developed using molecular beacons for the detection of Bacillus cereus and Staphylococcus aureus by targeting four important virulence genes. A correlation between targeting highly accessible DNA sequences and isothermal amplification based molecular beacon efficiency and sensitivity was demonstrated using phi(Φ)29 DNA polymerase at a constant isothermal temperature of 30 °C. It was very selective and consistently detected down to 10(1) copies of DNA. The specificity and sensitivity of this assay, when tested with pure culture were high, surpassing those of currently used PCR assays for the detection of these organisms. The molecular beacon based real-time isothermal amplification (MBRTIA) assay could be carried out entirely in 96 well plates or well strips, enabling a rapid and high-throughput detection of food borne pathogens.

  2. Molecular Beacon Enables Combination of Highly Processive and Highly Sensitive Rolling Circle Amplification Readouts for Detection of DNA-Modifying Enzymes

    DEFF Research Database (Denmark)

    Kristoffersen, Emil Laust; Gonzales, Maria; Stougaard, Magnus

    2015-01-01

    -modifying enzymes like type IB Topoisomerases and subsequently amplified by a rolling circle amplification (RCA) mechanism. The RCA process can be followed in real-time by the addition of a molecular beacon with a fluorophore/quencher pair. Upon hybridization to the amplified product, the fluorophore/quencher pair...... is separated, giving rise to a fluorescent signal, measurable in pseudo real-time using a qPCR machine or in a fluorimeter. The RCA products in complex with the molecular beacon can subsequently be moved to microscopic slides and analyzed in a fluorescence microscope. We describe the proof of the principle...... of this molecular beacon-based method combining the qPCR readout format with the standard Rolling circle Enhanced Enzymatic Assay previously reported. Although the qPCR setup is less sensitive, it allows easy, fast, and high-throughput measurement of enzyme activities. Human Topoisomerase IB (TopIB) is a well...

  3. Ultra-Stable Beacon Source for Laboratory Testing of Optical Tracking

    Science.gov (United States)

    Aso, Yoichi; Marka, Szabolcs; Kovalik, Joseph

    2008-01-01

    The ultra-stable beacon source (USBS) provides a laser-beam output with a very low angular jitter and can be used as an absolute angular reference to simulate a beacon in the laboratory. The laser is mounted on the top of a very short (approximately equal to 1 m) inverted pendulum (IP) with its optical axis parallel to the carbon fiber pendulum leg. The 85-cm, carbon fiber rods making up the leg are very lightweight and rigid, and are supported by a flex-joint at the bottom (see figure). The gimbal-mounted laser is a weight-adjustable load of about 1.5 kg with its center of rotation co-located with the center of percussion of the inverted pendulum. This reduces the coupling of transverse motion at the base of the pendulum to angular motion of the laser at the top. The inverted pendulum is mounted on a gimbal with its center of rotation coinciding with the pivot position of the inverted pendulum flexure joint. This reduces coupling of ground tilt at the inverted pendulum base to motion of the laser mounted at the top. The mass of the top gimbal is adjusted to give the pendulum a very low resonant frequency (approximately equal to 10 mHz) that filters transverse seismic disturbances from the ground where the base is attached. The motion of the IP is monitored by an optical-lever sensor. The laser light is reflected by the mirror on the IP, and then is detected by a quadrant photo-detector (QPD). The position of the beam spot on the QPD corresponds to the tilt of the IP. Damping of this motion is provided by two coil and magnet pairs. The bottom gimbal mount consists of two plates. The IP is mounted on the second plate. The first plate is supported by two posts through needles and can be rotated about the axis connecting the tips of the needles. The second plate hangs from the first plate and can be rotated about the axis perpendicular to the first plate. As a result, the second plate acts as a two-axis rotation stage. Its center of rotation is located at the

  4. Label-free molecular beacons-based cascade amplification DNA machine for sensitive detection of telomerase activity.

    Science.gov (United States)

    Li, Kan; Wang, Lei; Xu, Xiaowen; Jiang, Wei

    2017-05-15

    Sensitive detection of telomerase activity is critical to cancer diagnosis, screening of anticancer drugs and evaluation of cancer therapy. Herein, a label-free molecular beacons-based DNA machine was developed for sensitive detection of telomerase activity. The DNA machine consisted of T7 exonuclease (T7 Exo), label-free recognition molecular beacon (RMB) and signal molecular beacon (SMB) with projecting 5'-terminuses, which can protect RMB and SMB from being digested by T7 Exo. Firstly, telomerase elongated telomerase substrate (TS) primer, generating a telomerase elongation production (TEP) with tandem repeats (TTAGGG)n. Next, TEP activated the DNA machine by hybridizing with RMB, unfolding RMB with a recessed 5'-terminus, making RMB deprotection from T7 Exo. Then T7 Exo-assisted cycling cleavage was incurred, releasing intact TEP and numerous DNA fragments (trigger DNA), which got recycling I. Subsequently, trigger DNA specifically opened SMB and was recycled by T7 Exo, liberating multiple G-quadruplex (G4) structures, which got recycling II. Finally, TEP and the liberative G4 structures strongly interacted with N-methyl-mesoporphyrin IX (NMM), yielding a significantly enhanced fluorescence together. In this way, per telomerase-mediated elongation event was efficiently converted into the greatly amplified fluorescence signals. Telomerase activity in crude HeLa cells extracts equivalent to 50 cells/mL was successfully measured with a linear range from 50 cells/mL to 2000 cells/mL. Besides, the strategy was also successfully used to assay the inhibition effect of a telomerase-inhibiting drug, demonstrating the strategy holds the potential to screen telomerase inhibitors.

  5. Gold nanoparticle-based beacon to detect STAT5b mRNA expression in living cells: a case optimized by bioinformatics screen

    Directory of Open Access Journals (Sweden)

    Deng D

    2015-04-01

    Full Text Available Dawei Deng,* Yang Li,* Jianpeng Xue, Jie Wang, Guanhua Ai, Xin Li, Yueqing GuDepartment of Biomedical Engineering, China Pharmaceutical University, Nanjing, People’s Republic of China*These authors contributed equally to this workAbstract: Messenger RNA (mRNA, a single-strand ribonucleic acid with functional gene information is usually abnormally expressed in cancer cells and has become a promising biomarker for the study of tumor progress. Hairpin DNA-coated gold nanoparticle (hDAuNP beacon containing a bare gold nanoparticle (AuNP as fluorescence quencher and thiol-terminated fluorescently labeled stem–loop–stem oligonucleotide sequences attached by Au–S bond is currently a new nanoscale biodiagnostic platform capable of mRNA detection, in which the design of the loop region sequence is crucial for hybridizing with the target mRNA. Hence, in this study, to improve the sensitivity and selectivity of hDAuNP beacon simultaneously, the loop region of hairpin DNA was screened by bioinformatics strategy. Here, signal transducer and activator of transcription 5b (STAT5b mRNA was selected and used as a practical example. The results from the combined characterizations using optical techniques, flow cytometry assay, and cell microscopic imaging showed that after optimization, the as-prepared hDAuNP beacon had higher selectivity and sensitivity for the detection of STAT5b mRNA in living cells, as compared with our previous beacon. Thus, the bioinformatics method may be a promising new strategy for assisting in the designing of the hDAuNP beacon, extending its application in the detection of mRNA expression and the resultant mRNA-based biological processes and disease pathogenesis.Keywords: molecular beacon, bioinformatics, gold nanoparticle, STAT5b mRNA, visual detection

  6. Electro-optic testbed utilizing a dynamic range gated Rayleigh beacon for atmospheric turbulence profiling

    Science.gov (United States)

    Zuraski, Steven M.; Fiorino, Steven T.; Beecher, Elizabeth A.; Figlewski, Nathan M.; Schmidt, Jason D.; McCrae, Jack E.

    2016-10-01

    The Photometry Analysis and Optical Tracking and Evaluation System (PANOPTES) Quad Axis Telescope is a unique four axis mount Ritchey-Chretien 24 inch telescope capable of tracking objects through the zenith without axes rotation delay (no Dead Zone). This paper describes enhancement components added to the quad axis mount telescope that will enable measurements supporting novel research and field testing focused on `three-dimensional' characterization of turbulent atmospheres, mitigation techniques, and new sensing modalities. These all support research and operational techniques relating to astronomical imaging and electro-optical propagation though the atmosphere, relative to sub-meter class telescopes in humid, continental environments. This effort will use custom designed and commercial off the shelf hardware; sub-system components discussed will include a wavefront sensor system, a co-aligned beam launch system, and a fiber coupled research laser. The wavefront sensing system has the ability to take measurements from a dynamic altitude adjustable laser beacon scattering spot, a key concept that enables rapid turbulence structure parameter measurements over an altitude varied integrated atmospheric volume. The sub-components are integrated with the overall goal of measuring a height-resolved volumetric profile for the atmospheric turbulence structure parameter at the site, and developing mobile techniques for such measurements. The design concept, part selection optimization, baseline component lab testing, and initial field measurements, will be discussed in the main sections of this paper. This project is a collaborative effort between the Air Force Research Labs Sensors Directorate and the Air Force Institute of Technology Center for Directed Energy.

  7. Theragnosis-based combined cancer therapy using doxorubicin-conjugated microRNA-221 molecular beacon.

    Science.gov (United States)

    Lee, Jonghwan; Choi, Kyung-Ju; Moon, Sung Ung; Kim, Soonhag

    2016-01-01

    Recently, microRNA (miRNA or miR) has emerged as a new cancer biomarker because of its high expression level in various cancer types and its role in the control of tumor suppressor genes. In cancer studies, molecular imaging and treatment based on target cancer markers have been combined to facilitate simultaneous cancer diagnosis and therapy. In this study, for combined therapy with diagnosis of cancer, we developed a doxorubicin-conjugated miR-221 molecular beacon (miR-221 DOXO MB) in a single platform composed of three different nucleotides: miR-221 binding sequence, black hole quencher 1 (BHQ1), and doxorubicin binding site. Imaging of endogenous miR-221 was achieved by specific hybridization between miR-221 and the miR-221 binding site in miR-221 DOXO MB. The presence of miR-221 triggered detachment of the quencher oligo and subsequent activation of a fluorescent signal of miR-221 DOXO MB. Simultaneous cancer therapy in C6 astrocytoma cells and nude mice was achieved by inhibition of miRNA-221 function that downregulates tumor suppressor genes. The detection of miR-221 expression and inhibition of miR-221 function by miR-221 DOXO MB provide the feasibility as a cancer theragnostic probe. Furthermore, a cytotoxic effect was induced by unloading of doxorubicin intercalated into miR-221 DOXO MB inside cells. Loss of miR-221 function and cytotoxicity induced by the miR-221 DOXO MB provides combined therapeutic efficacy against cancers. This method could be used as a new theragnostic probe with enhanced therapy to detect and inhibit many cancer-related miRNAs.

  8. G-Quadruplex DNAzyme Molecular Beacon for Amplified Colorimetric Biosensing of Pseudostellaria heterophylla

    Directory of Open Access Journals (Sweden)

    Juan Hu

    2013-01-01

    Full Text Available With an internal transcribed spacer of 18 S, 5.8 S and 26 S nuclear ribosomal DNA (nrDNA ITS as DNA marker, we report a colorimetric approach for authentication of Pseudostellaria heterophylla (PH and its counterfeit species based on the differentiation of the nrDNA ITS sequence. The assay possesses an unlabelled G-quadruplex DNAzyme molecular beacon (MB probe, employing complementary sequence as biorecognition element and 1:1:1:1 split G-quadruplex halves as reporter. In the absence of target DNA (T-DNA, the probe can shape intermolecular G-quadruplex structures capable of binding hemin to form G-quadruplex-hemin DNAzyme and catalyze the oxidation of ABTS2− to blue-green ABTS•− by H2O2. In the presence of T-DNA, T-DNA can hybridize with the complementary sequence to form a duplex structure, hindering the formation of the G-quadruplex structure and resulting in the loss of the catalytic activity. Consequently, a UV-Vis absorption signal decrease is observed in the ABTS2−-H2O2 system. The “turn-off” assay allows the detection of T-DNA from 1.0 × 10−9 to 3.0 × 10−7 mol·L−1 (R2 = 0.9906, with a low detection limit of 3.1 × 10−10 mol·L−1. The present study provides a sensitive and selective method and may serve as a foundation of utilizing the DNAzyme MB sensor for identifying traditional Chinese medicines.

  9. Beacon system based on light-emitting diode sources for runways lighting

    Science.gov (United States)

    Montes, Mario González; Vázquez, Daniel; Fernandez-Balbuena, Antonio A.; Bernabeu, Eusebio

    2014-06-01

    New aeronautical ground lighting techniques are becoming increasingly important to ensure the safety and reduce the maintenance costs of the plane's tracks. Until recently, tracks had embedded lighting systems whose sources were based on incandescent lamps. But incandescent lamps have several disadvantages: high energy consumption and frequent breakdowns that result in high maintenance costs (lamp average life-time is ˜1500 operating hours) and the lamp's technology has a lack of new lighting functions, such as signal handling and modification. To solve these problems, the industry has developed systems based on light-emitting diode (LED) technology with improved features: (1) LED lighting consumes one tenth the power, (2) it improves preventive maintenance (an LED's lifetime range is between 25,000 and 100,000 hours), and (3) LED lighting technology can be controlled remotely according to the needs of the track configuration. LEDs have been in use for more than three decades, but only recently, around 2002, have they begun to be used as visual aids, representing the greatest potential change for airport lighting since their inception in the 1920s. Currently, embedded LED systems are not being broadly used due to the specific constraints of the rules and regulations of airports (beacon dimensions, power system technology, etc.). The fundamental requirements applied to embedded lighting systems are to be hosted on a volume where the dimensions are usually critical and also to integrate all the essential components for operation. An embedded architecture that meets the lighting regulations for airport runways is presented. The present work is divided into three main tasks: development of an optical system to optimize lighting according to International Civil Aviation Organization, manufacturing prototype, and model validation.

  10. Ulli Beier; a Beacon in the Post- Colonial Renascence of Adire.

    Directory of Open Access Journals (Sweden)

    Margaret Olugbemisola Areo

    2013-11-01

    Full Text Available Oshogbo in Southwestern Nigeria was renowned for the Yoruba, patterned, indigo – dyed cloth; Adire. Traditionally called “ilu Aro”, home of indigo and indigo dyeing, the dyers in the town were patronized from far and near for their dyeing prowess. This art tradition however suffered a lull in the twilight of Nigerian Colonialism in the 1950s, due to lack of willing young apprentices to learn this generational art which traditionally, was passed from mothers to daughters, as the young girls now preferred Western education in an Eurocentric setting. Another challenge was the flooding of Nigerian markets with cheaper, imported textiles, which were not taxed, while the locally produced ones were. Hand in hand with these twin problems is the mindset of many educated Nigerians, who  then saw the Adire merely as rural cloth for poor, illiterate, rural dwellers. This trend however changed in the Post – Independence years of the 1960s, with the concerted efforts of certain individuals, among whom Ulli Beier shone as a beacon. Through a paradigm shift in apprentice education and tranning in this indigenous knowledge, his efforts not only brought a rebirth of the Adire  art, but also resulted in a dynamic new form of the art, which has become an inseparable part of the socio – cultural, visual  landscape of Osogbo, and  many other Adire art centres in Southwestern Nigeria The paper, an art historical research based on field work, consultation of literature materials and interviews of artists,  highlights the methods of training employed and bring to the fore  how  a paradigm shift in pedagogy, technic and technology can enhance the sustainability of many indigenous knowledge  in a fast changing world.

  11. A Biofunctional Molecular Beacon for Detecting Single Base Mutations in Cancer Cells.

    Science.gov (United States)

    Dong, Haiyan; Ma, Ji; Wang, Jie; Wu, Zai-Sheng; Sinko, Patrick J; Jia, Lee

    2016-04-05

    The development of a convenient and sensitive biosensing system to detect specific DNA sequences is an important issue in the field of genetic disease therapy. As a classic DNA detection technique, molecular beacon (MB) is often used in the biosensing system. However, it has intrinsic drawbacks, including high assay cost, complicated chemical modification, and operational complexity. In this study, we developed a simple and cost-effective label-free multifunctional MB (LMMB) by integrating elements of polymerization primer, template, target recognition, and G-quadruplex into one entity to detect target DNA. The core technique was accomplished by introducing a G-hairpin that features fragments of both G-quadruplex and target DNA recognition in the G-hairpin stem. Hybridization between LMMB and target DNA triggered conformational change between the G-hairpin and the common C-hairpin, resulting in significant SYBR-green signal amplification. The hybridization continues to the isothermal circular strand-displacement polymerization and accumulation of the double-stranded fragments, causing the uninterrupted extension of the LMMB without a need of chemical modification and other assistant DNA sequences. The novel and programmable LMMB could detect target DNA with sensitivity at 250 pmol/l with a linear range from 2 to 100 nmol/l and the relative standard deviation of 7.98%. The LMMB could sense a single base mutation from the normal DNA, and polymerase chain reaction (PCR) amplicons of the mutant-type cell line from the wild-type one. The total time required for preparation and assaying was only 25 minutes. Apparently, the LMMB shows great potential for detecting DNA and its mutations in biosamples, and therefore it opens up a new prospect for genetic disease therapy.

  12. Noise correlation-based adaptive polarimetric image representation for contrast enhancement of a polarized beacon in fog

    Science.gov (United States)

    Panigrahi, Swapnesh; Fade, Julien; Alouini, Mehdi

    2015-10-01

    We show the use of a simplified snapshot polarimetric camera along with an adaptive image processing for optimal detection of a polarized light beacon through fog. The adaptive representation is derived using theoretical noise analysis of the data at hand and is shown to be optimal in the Maximum likelihood sense. We report that the contrast enhancing optimal representation that depends on the background noise correlation differs in general from standard representations like polarimetric difference image or polarization filtered image. Lastly, we discuss a detection strategy to reduce the false positive counts.

  13. Study of fade and inter-fade durations in Ku- and Ka- band frequencies using OLYMPUS satellite beacons

    OpenAIRE

    Ajaz, Haroon

    1993-01-01

    Fade and inter-fade duration data obtained from the three beacons at 12, 20, and 30 GHz aboard the OLYMPUS satellite were analyzed. The different types of signal impairments and their causes were highlighted and a literature survey conducted. Twelve months of fade and inter-fade data were analyzed and the results of these statistics are presented in the form of tables and figures. The analysis was done on both the monthly and annual data. These tables and figures show that at t...

  14. The OSU self-phased array for propagation measurements using the 11.7 GHz CTS beacon

    Science.gov (United States)

    Theobold, D. M.; Hodge, D. B.

    1976-01-01

    A self phased array was developed for propagation measurements on an earth-space path. The 11.7 GHz CTS beacon was used as the signal source. The self phased array was used to measure angle of arrival as well as attenuation and scintillation statistics. The performance of the array is described, and sample data are presented. The tracking capability of the self phased array was also studied. This technique permits fully electronic, nonmechanical satellite tracking, thus simplifying unmanned operation and eliminating severe weather tracking constraints.

  15. Detection of Campylobacter jejuni and Campylobacter coli in chicken meat samples by real-time nucleic acid sequence-based amplification with molecular beacons.

    Science.gov (United States)

    Churruca, E; Girbau, C; Martínez, I; Mateo, E; Alonso, R; Fernández-Astorga, A

    2007-06-10

    A nucleic acid sequence-based amplification (NASBA) assay based on molecular beacons was used for real-time detection of Campylobacter jejuni and Campylobacter coli in samples of chicken meat. A set of specific primers and beacon probe were designed to target the 16S rRNA of both species. The real-time NASBA protocol including the RNA isolation was valid for both of the cell suspensions in buffered saline and the artificially contaminated chicken meat samples. The presence of rRNA could be correlated with cellular viability, following inactivation of the bacteria by heating, in inoculated chicken meat samples but not in RNase-free cell suspensions.

  16. Direct detection of circulating free DNA extracted from serum samples of breast cancer using locked nucleic acid molecular beacon.

    Science.gov (United States)

    Gui, Zhen; Wang, Quanbo; Li, Jinchang; Zhu, Mingchen; Yu, Lili; Xun, Tang; Yan, Feng; Ju, Huangxian

    2016-07-01

    As an emerging noninvasive blood biomarker, circulating free DNA (cfDNA) can be utilized to assess diagnosis, progression and evaluate prognosis of cancer. However, cfDNAs are not "naked", they can be part of complexes, or are bound to the surface of the cells via proteins, which make the detection more challenging. Here, a simple method for the detection of Ubiquitin-like with PHD and ring finger domains 1 (UHRF1) DNA exacted from serum of breast cancer (BC) has been developed using a novel locked nucleic acid molecular beacon (LNA-MB). In order to enhance the stability and detection efficiency of the probe in biofluids, we design a shared-stem molecular beacon containing a 27-mer loop and a 4-mer stem with DNA/LNA alternating bases. The fluorescence is released in the presence of target. The detection procedure is simple and can be completed within 1h. This method shows a sensitive response to UHRF1 DNA with a dynamic range of 3 orders of magnitude. The limit of detection is 11nM (S/N=3) with excellent selectivity. It can discriminate UHRF1 DNA from three-base mismatched DNA with a high specificity. More importantly, this method can distinguish the expression of serum UHRF1 DNA among 5 breast cancer patients and 5 healthy controls. The mentioned superiority may suggest that this assay can be served as a promising noninvasive detection tool for early BC diagnosis and monitoring.

  17. SOX2 and OCT4 mRNA-Expressing Cells, Detected by Molecular Beacons, Localize to the Center of Neurospheres during Differentiation

    DEFF Research Database (Denmark)

    Ilieva, Mirolyuba; Dufva, Martin

    2013-01-01

    Neurospheres are used as in vitro assay to measure the properties of neural stem cells. To investigate the molecular and phenotypic heterogeneity of neurospheres, molecular beacons (MBs) targeted against the stem cell markers OCT4 and SOX2 were designed, and synthesized with a 2'-O-methyl RNA...

  18. BEACON/MOD2A: a computer program for subcompartment analysis of nuclear reactor containment. A user's manual. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Wells, R. A.

    1979-03-01

    The BEACON code is a Best Estimate Advanced Containment code which being developed by EG and G, Idaho, Inc., at the Idaho National Engineering Laboratory. The program is designed to perform a best estimate analysis of the flow of a mixture of air, water, and steam in a nuclear reactor containment system under loss-of-coolant accident conditions. The code can simulate two-component, two-phase fluid flow in complex geometries using a combination of two-dimensional, one-dimensional, and lumped-parameter representations for the various parts of the system. The current version of BEACON, which is designated BEACON/MOD2A, contains mass and heat transfer models for wall film and for wall conduction. It is suitable for the evaluation of short term transients in PWR dry containment systems. This manual describes the models employed in BEACON/MOD2A and specifies code implementation requirements. It provides application information for input data preparation and for output data interpretation.

  19. 基于随机信标的水下 SLAM 导航方法%Underwater SLAM navigation algorithm based on random beacons

    Institute of Scientific and Technical Information of China (English)

    刘明雍; 董婷婷; 张立川

    2015-01-01

    研究了基于随机信标的水下同时制图定位(simultaneous localization and mapping,SLAM)导航定位方法。信标导航是目前导航领域的研究热点,但往往需要提前对信标位置进行标定。对此文中提出一种无需位置标定的随机信标导航方法,即在信标随机散布的情况下,通过量测信标和航行器间的距离和方位,用 SLAM 方法对随机信标位置进行估计,从而实现对航行器的导航,并在不同的信标密度和观测误差下分析了其导航精度。仿真结果表明,该导航方法具有良好的收敛性和定位精度。%An underwater simultaneous localization and mapping (SLAM)navigation algorithm based on random beacons is studied.At present,beacon navigation is extensively studied in the field of navigation,but it often needs to locate the beacon’s positon in advance.In this paper,we propose a navigation method based on random beacons that does not need position calibration,that is,when beacons are randomly dispersed,we use the SLAM method to estimate the position of the random beacons,thus to navigate the autonomous underwater vehicle (AUV)by observing the distance and orientation between the beacons and the AUV.We also analyze the navigation accuracy under different beacons density and different observation errors.Simulation results show that the algorithm performs well in both convergence and precision.

  20. WSN定位算法中信标节点的摆放与选择%Placement and Selection Algorithm of Beacon Nodes in WSN Localization

    Institute of Scientific and Technical Information of China (English)

    樊爱京; 朱小艳; 郭拯危; 李辉

    2012-01-01

    目前已有的无线传感器网络节点自定位算法研究中,针对信标节点的研究较少,而如何选择信标节点,以及信标节点如何摆放,都对定位精度有比较大的影响.为了定量地研究这个问题,首先证明了信标节点摆放方法与节点是否能被定位之间的关系的一个定理,然后给出三维空间中信标节点的摆放方法,最后提出一种基于线性方程组的条件数的信标节点选择算法,以便尽可能地提高基于测距的未知节点自定位精度.%Currently, few studies of wireless sensor network node localization algorithm were focused on the beacon nodes, but how to choose and place the beacon nodes has a large impact on the positioning accuracy. In order to quantitatively study this issue, a theorem was proved that offers a desiription of the relationship between the placement of beacon nodes and whether the unknown node could be located, then the beacon nodes placement method was designed. Finally, a beacon nodes selection algorithm was proposed based on the condition number of linear equations, so as to improve the accuracy of range-based localization algorithm.

  1. "Molecular beacon"-hosted thioflavin T: Applications for label-free fluorescent detection of iodide and logic operations.

    Science.gov (United States)

    Li, Yan-Yun; Jiang, Xiao-Qin; Lu, Ling-Fei; Zhang, Min; Shi, Guoyue

    2016-04-01

    In this work, we presented a simple, label-free and rapid-responsive fluorescence assay for iodide (I(-)) detection based on "molecular beacon (MB)"-hosted thioflavin T (ThT), achieving a limit of detection as low as 158 nM. The proposed method exhibited very good selectivity to I(-) ions over other anions interference due to the strong binding force between I(-) ions with Hg(2+). Upon the addition of I(-) ions, it would capture Hg(2+) from a T-Hg(2+)-T complex belonging to the MB-like DNA hairpin structure, which eventually quenched the initial fluorescence as output. In addition, it was successfully applied for operation of an integrated DNA logic gate system and to the determination of I(-) in real samples such as human urine.

  2. Proposal of a new generation of Laser Beacon for time calibration in the KM3NeT neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Real, Diego [IFIC, Instituto de Física Corpuscular, CSIC-Universidad de Valencia, C/Catedrático José Beltrán, 2. 46980 Paterna (Spain); Collaboration: KM3NeT Collaboration

    2014-11-18

    The KM3NeT collaboration aims at the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea consisting of a matrix of pressure resistant glass spheres holding each a set (31) of small area photomultipliers. The main motivation of the telescope is to observe cosmic neutrinos through the Cherenkov light induced in sea water by charged particles produced in neutrino interactions with the surrounding medium. A relative time calibration between photomultipliers of the order of 1 ns is required to achieve an optimal performance. To this end, several time calibration subsystems have been developed. In this article, the proposal of a last generation Laser Beacon, to be used in KM3NeT and developed to measure and monitor the relative time offsets between photomultipliers, is presented.

  3. A solid-state electrochemiluminescence biosensing switch for detection of DNA hybridization based on ferrocene-labeled molecular beacon

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaoying [School of Public Health, Southeast University, Nanjing 210009 (China); He Pingang, E-mail: pghe@chem.ecnu.edu.c [Department of Chemistry, East China Normal University, Shanghai 200062 (China); Fang Yuzhi, E-mail: yzfang@chem.ecnu.edu.c [Department of Chemistry, East China Normal University, Shanghai 200062 (China)

    2010-08-15

    A solid-state electrochemiluminescence (ECL) biosensing switch incorporating quenching of ECL of ruthenium(II) tris-(bipyridine) (Ru(bpy){sub 3}{sup 2+}) by ferrocene (Fc) has been successfully developed for DNA hybridization detection. The important issue for this biosensing system is based on the ferrocene-labeled molecular beacon (Fc-MB), i.e. using the special Fc-MB to react with the target DNA and then change its structure, resulting in an ECL intensity change. Under the optimal conditions, the difference of ECL intensity before and after the hybridization reaction ({Delta}I{sub ECL}) was linearly related to the concentration of the complementary sequence in the range of 10 fM-10 pM and the detection limit was down to 1.0 fM.

  4. The Berkeley Atmospheric CO2 Observation Network (BEACON): Measuring Greenhouse Gases and Criteria Pollutants within the Urban Dome

    Science.gov (United States)

    Teige, V. E.; Weichsel, K.; Hooker, A.; Wooldridge, P. J.; Cohen, R. C.

    2012-12-01

    Efforts to curb greenhouse gas emissions, while global in their impacts, often focus on local and regional scales for execution and are dependent on the actions of communities and individuals. Evaluating the effectiveness of local policies requires observations with much higher spatial resolution than are currently available---kilometer scale. The Berkeley Atmospheric CO2 Observation Network (BEACON):, launched at the end of 2011, aims to provide measurements of urban-scale concentrations of CO2, temperature, pressure, relative humidity, O3, CO, and NO2 with sufficient spatial and temporal resolution to characterize the sources of CO2 within cities. Our initial deployment in Oakland, California uses ~40 sensor packages at a roughly 2 km spacing throughout the city. We will present an initial analysis of the vertical gradients and other spatial patterns observed to date.

  5. Molecular beacon-enabled purification of living cells by targeting cell type-specific mRNAs.

    Science.gov (United States)

    Wile, Brian M; Ban, Kiwon; Yoon, Young-Sup; Bao, Gang

    2014-10-01

    Molecular beacons (MBs) are dual-labeled oligonucleotides that fluoresce only in the presence of complementary mRNA. The use of MBs to target specific mRNAs allows sorting of specific cells from a mixed cell population. In contrast to existing approaches that are limited by available surface markers or selectable metabolic characteristics, the MB-based method enables the isolation of a wide variety of cells. For example, the ability to purify specific cell types derived from pluripotent stem cells (PSCs) is important for basic research and therapeutics. In addition to providing a general protocol for MB design, validation and nucleofection into cells, we describe how to isolate a specific cell population from differentiating PSCs. By using this protocol, we have successfully isolated cardiomyocytes differentiated from mouse or human PSCs (hPSCs) with ∼ 97% purity, as confirmed by electrophysiology and immunocytochemistry. After designing MBs, their ordering and validation requires 2 weeks, and the isolation process requires 3 h.

  6. In vitro RNA release from a human rhinovirus monitored by means of a molecular beacon and chip electrophoresis.

    Science.gov (United States)

    Weiss, Victor U; Bliem, Christina; Gösler, Irene; Fedosyuk, Sofiya; Kratzmeier, Martin; Blaas, Dieter; Allmaier, Günter

    2016-06-01

    Liquid-phase electrophoresis either in the classical capillary format or miniaturized (chip CE) is a valuable tool for quality control of virus preparations and for targeting questions related to conformational changes of viruses during infection. We present an in vitro assay to follow the release of the RNA genome from a human rhinovirus (common cold virus) by using a molecular beacon (MB) and chip CE. The MB, a probe that becomes fluorescent upon hybridization to a complementary sequence, was designed to bind close to the 3' end of the viral genome. Addition of Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a well-known additive for reduction of bleaching and blinking of fluorophores in fluorescence microscopy, to the background electrolyte increased the sensitivity of our chip CE set-up. Hence, a fast, sensitive and straightforward method for the detection of viral RNA is introduced. Additionally, challenges of our assay will be discussed. In particular, we found that (i) desalting of virus preparations prior to analysis increased the recorded signal and (ii) the MB-RNA complex signal decreased with the time of virus storage at -70 °C. This suggests that 3'-proximal sequences of the viral RNA, if not the whole genome, underwent degradation during storage and/or freezing and thawing. In summary, we demonstrate, for two independent virus batches, that chip electrophoresis can be used to monitor MB hybridization to RNA released upon incubation of the native virus at 56 °C. Graphical Abstract Schematic of the study strategy: RNA released from HRV-A2 is detected by chip electrophoresis through the increase in fluorescence after genom complexation to a cognate molecular beacon.

  7. Gastroesophageal reflux in relation to adenocarcinomas of the esophagus: a pooled analysis from the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON.

    Directory of Open Access Journals (Sweden)

    Michael B Cook

    Full Text Available Previous studies have evidenced an association between gastroesophageal reflux and esophageal adenocarcinoma (EA. It is unknown to what extent these associations vary by population, age, sex, body mass index, and cigarette smoking, or whether duration and frequency of symptoms interact in predicting risk. The Barrett's and Esophageal Adenocarcinoma Consortium (BEACON allowed an in-depth assessment of these issues.Detailed information on heartburn and regurgitation symptoms and covariates were available from five BEACON case-control studies of EA and esophagogastric junction adenocarcinoma (EGJA. We conducted single-study multivariable logistic regressions followed by random-effects meta-analysis. Stratified analyses, meta-regressions, and sensitivity analyses were also conducted.Five studies provided 1,128 EA cases, 1,229 EGJA cases, and 4,057 controls for analysis. All summary estimates indicated positive, significant associations between heartburn/regurgitation symptoms and EA. Increasing heartburn duration was associated with increasing EA risk; odds ratios were 2.80, 3.85, and 6.24 for symptom durations of <10 years, 10 to <20 years, and ≥20 years. Associations with EGJA were slighter weaker, but still statistically significant for those with the highest exposure. Both frequency and duration of heartburn/regurgitation symptoms were independently associated with higher risk. We observed similar strengths of associations when stratified by age, sex, cigarette smoking, and body mass index.This analysis indicates that the association between heartburn/regurgitation symptoms and EA is strong, increases with increased duration and/or frequency, and is consistent across major risk factors. Weaker associations for EGJA suggest that this cancer site has a dissimilar pathogenesis or represents a mixed population of patients.

  8. High-throughput real-time assay based on molecular beacons for HIV-1 integrase 3'-processing reaction

    Institute of Scientific and Technical Information of China (English)

    Hong-qiu HE; Xiao-hui MA; Bin LIU; Xiao-yi ZHANG; Wei-zu CHEN; Cun-xin WANG; Shao-hui CHENG

    2007-01-01

    Aim: To develop a high-throughput real-time assay based on molecular beacons to monitor the integrase 3'-processing reaction in vitro and apply it to inhibitor screening.Methods: The recombinant human immunodeficiency virus (HIV)-1 integrase (IN) is incubated with a 38 mer oligonucleotide substrate, a sequence identical to the U5 end of HIV-1 long terminal repeats (LTR). Based on the fluores-cence properties of molecular beacons, the substrate is designed to form a stem-loop structure labeled with a fluorophore at the 5' end and a quencher at the 3'end.IN cleaves the terminal 3'-dinucleotide containing the quencher, resulting in an increase in fluorescence which can be monitored on a spectrofluorometer. To optimize this assay, tests were performed to investigate the effects of substrates, enzyme and the metal ion concentrations on the IN activity and optimal param-eters were obtained. Moreover, 2 IN inhibitors were employed to test the perfor-mance of this assay in antiviral compound screening.Results: The fluorescent intensity of the reaction mixture varies linearly with time and is proportional to the velocity of the 3'-processing reaction. Tests were performed and the results showed that the optimal rate was obtained for a reaction mixture containing 50 mg/L recom-binant HIV-1 IN, 400 nmol/L substrate, and 10 mmol/L Mn2+. The IN 3'-processing reaction under the optimal conditions showed a more than 18-fold increase in the fluorescence intensity compared to the enzyme-free control. The IC50 values of the IN inhibitors obtained in our assay were similar to the values obtained from a radiolabeled substrate assay.Conclusion: Our results demonstrated that this is a fast, reliable, and sensitive method to monitor HIV IN 3'-processing reaction and that it can be used for inhibitor screening.

  9. Molecular Beacon Based DNA Computing Model for General Satisfiability Problem%可满足问题的分子信标计算模型

    Institute of Scientific and Technical Information of China (English)

    殷志祥; 崔建中; 支凌迎; 孙侠; 黄晓慧

    2008-01-01

    分子信标(Molecular Beacon)是一种发夹状的荧光探针,它可以特异地和那些与分子信标的环(Loop)互补的核酸靶序列杂交,具有单个碱基错配的检测能力.肽核酸(Peptide Nucleic Acid)是人工合成的核酸(DNA)的类似物.PNA骨架为酰胺键,与DNA补链杂交更稳定,可以阻止聚合酶延伸反应.文中将可满足问题的约束变量编码于分子信标的环部识别区,通过分子信标与使得给定范式为真的变量的PNA补链杂交,再利用PNA链可以阻止聚合酶延伸反应的性质,用限制性内切酶EcoRI降解对应于非解的分子信标,最后通过加热表面使分子信标构形发生变化,产生荧光读解.提出的可满足问题的分子信标计算模型具有可靠性高、无需观察和记录计算的中间结果、读解简单等优点.%Molecular Beacon is a hairpin-shaped fluorescent probe,which can hybridize with great specificity target sequence that is complement to its loop sequence.The specificity of Molec-ular Beacon is as high as single base mismatch detection.Peptide Nucleic Acid (PNA) is an artifi-cial synthesized analogue of nature occurring DNA,in which the DNA sugar-phosphate backbone has been replaced by a pseudo-peptide.Thus the hybridization of PNA to complement DNA strand is more specific and stable than that of DNA to DNA.PNA can stop polymerase extension reaction as well.In this paper,Molecular Beacons were employed to encode variables in satisfi-ability problem and complement PNA strands were added and allowed to hybridize with Molecular Beacon.The hybridized PNA strands on Molecular Beacon stopped polymerase extension reac-tion,causing Molecular Beacon corresponding to non-solution were digested by means of restric-tion endonuclease EcoRI.The remaining Molecular Beacons encoding solutions were read out via heating.The appealing characteristics of proposed method in this paper are: Reliable,no obser-vation and record of midst solution,easy solution detection.

  10. In-cell protease assay systems based on trans-localizing molecular beacon proteins using HCV protease as a model system.

    Directory of Open Access Journals (Sweden)

    Jeong Hee Kim

    Full Text Available This study describes a sensitive in-cell protease detection system that enables direct fluorescence detection of a target protease and its inhibition inside living cells. This live-cell imaging system provides a fluorescent molecular beacon protein comprised of an intracellular translocation signal sequence, a protease-specific cleavage sequence, and a fluorescent tag sequence(s. The molecular beacon protein is designed to change its intracellular localization upon cleavage by a target protease, i.e., from the cytosol to a subcellular organelle or from a subcellular organelle to the cytosol. Protease activity can be monitored at the single cell level, and accordingly the entire cell population expressing the protease can be accurately enumerated. The clear cellular change in fluorescence pattern makes this system an ideal tool for various life science and drug discovery research, including high throughput and high content screening applications.

  11. 基于iBeacon的精细室内定位方法研究%Research on Elaborate Indoor Positioning Method Based on iBeacon Firmware

    Institute of Scientific and Technical Information of China (English)

    张倬胜; 马方方; 薛静远; 艾浩军

    2015-01-01

    苹果公司发布的iBeacon作为一种粗精度位置感知服务体系,得到了广泛关注。针对更精细的广域位置服务,提出了基于iBeacon的无线指纹定位方法,并给出了图书馆的位置服务示例。%Apple released iBeacon as a rough-precision position sensing distance service system, it has attracted extensive attention. For more sophisticated wide-area location services, wireless fingerprinting positioning method is proposed based on iBeacon, and an example of location based service system of library is given.

  12. Development of a high-precision selenodetic coordinate system for the physical surface of the Moon based on LED beacons on its surface

    Science.gov (United States)

    Shirenin, A. M.; Mazurova, E. M.; Bagrov, A. V.

    2016-11-01

    The paper presents a mathematical algorithm for processing an array of angular measurements of light beacons on images of the lunar surface onboard a polar artificial lunar satellite (PALS) during the Luna-Glob mission and coordinate-time referencing of the PALS for the development of reference selenocentric coordinate systems. The algorithm makes it possible to obtain angular positions of point light beacons located on the surface of the Moon in selenocentric celestial coordinates. The operation of measurement systems that determine the position and orientation of the PALS during its active existence have been numerically simulated. Recommendations have been made for the optimal use of different types of measurements, including ground radio trajectory measurements, navigational star sensors based on the onboard star catalog, gyroscopic orientation systems, and space videos of the lunar surface.

  13. 基于Beacon的图书馆LBS应用研究%Research on application of LBS in library based on Beacon

    Institute of Scientific and Technical Information of China (English)

    孙婷婷; 颜凯; 董茜

    2016-01-01

    通过对Beacon的技术原理与应用现状进行分析研究,提出了5种基于Beacon的图书馆基于位置的服务(LBS )应用方案,包括消息推送、馆内导览、读者行为分析、情景式信息素养培训和馆内导航。结合应用方案,设计了基于Beacon的图书馆LBS应用的系统功能、系统架构和硬件部署方案。并指出在实际建设中Bea‐con存在的局限性。通过建设基于Beacon的图书馆LBS应用可以为读者提供情景驱动式的智能化服务,提高图书馆服务质量。%With the research of the Beacon′s technical principles and application status ,five solutions of location based service (LBS) in library based on Beacon were proposed in this paper ,including push notifications ,tour guide ,reader behavior analysis ,situational information literacy training and the navigation of library .On the foundation of solution design ,system functions ,system architecture and hardware deployment scheme of library LBS based on Beacon were designed in detail .Furthermore , some limitations of Beacon in the actual construction were pointed out .Based on Beacon ,library could provide the intellectualized service driven by scene to improve the quality of Library services .

  14. Dual-channel detection of metallothioneins and mercury based on a mercury-mediated aptamer beacon using thymidine-mercury-thymidine complex as a quencher.

    Science.gov (United States)

    Chen, Si-Han; Wang, Yong-Sheng; Chen, Yun-Sheng; Tang, Xian; Cao, Jin-Xiu; Li, Ming-Hui; Wang, Xiao-Feng; Zhu, Yu-Feng; Huang, Yan-Qin

    2015-01-01

    A novel dual-channel strategy for the detection of metallothioneins (MTs) and Hg(2+) has been developed based on a mercury-mediated aptamer beacon (MAB) using thymidine-mercury-thymidine complex as a quencher for the first time. In the presence of Hg(2+), the T-rich oligonucleotide with a 6-carboxyfluorescein (TRO-FAM) can form an aptamer beacon via the formation of T-Hg(2+)-T base pairs, which results in a fluorescence quenching of the sensing system owing to the fluorescence resonance energy transfer (FRET) from the fluorophore of FAM to the terminated T-Hg(2+)-T base pair. The addition of MTs into this solution leads to the disruption of the T-Hg(2+)-T complex, resulting in an increase of the fluorescent signal of the system. In the optimizing condition, ΔF was directly proportional to the concentrations ranging from 5.63 nM to 0.275 μM for MTs, and 14.2 nM to 0.30 μM for Hg(2+) with the detection limits of 1.69 nM and 4.28 nM, respectively. The proposed dual-channel method avoids the label steps of a quencher in common molecular beacon strategies, without tedious procedure or the requirement of sophisticated equipment, and is rapid, inexpensive and sensitive.

  15. Three-dimensional structure of DNA self-assembly based on molecular beacon%基于分子信标的DNA自组装立体结构

    Institute of Scientific and Technical Information of China (English)

    刘静; 殷志祥

    2014-01-01

    文章讨论了分子信标技术和DNA自组装作为DNA计算的重要模型,并对近年来分子信标技术和DNA自组装技术的发展状况进行了总结;将分子信标技术的优势融入DNA自组装模型,提出一种DNA四面体结构,并利用该结构解决布尔逻辑运算问题。%Molecular beacon and DNA self-assembly as the important DNA computing model are dis-cussed ,and recent developments of molecular beacon technology and DNA self-assembly technology are summarized .The advantages of molecular beacon technology are integrated into DNA self-assem-bly model ,and a tetrahedron structure of DNA is proposed to solve the problem of the Boolean logical operation .

  16. Rapid and direct quantitative detection of viable bifidobacteria in probiotic yogurt by combination of ethidium monoazide and real-time PCR using a molecular beacon approach.

    Science.gov (United States)

    Meng, X C; Pang, R; Wang, C; Wang, L Q

    2010-11-01

    The potential of ethidium monoazide (EMA) real-time PCR method based on molecular beacon probe for rapid detection of viable bifidobacteria present in probiotic yogurt was evaluated in this work. A real-time PCR with molecular beacon assay was developed to determine genus Bifidobacterium quantitatively in order to increase the sensitivity and specificity of assay. EMA was used to treat probiotic yogurt prior to DNA extraction and real-time PCR detection to allow detection of only viable bacteria. The primer set of Bif-F/Bif-R which is genus-specific for Bifid. was designed. The specificity of the probes ensures that no signal is generated by non-target amplicons. Linear regression analysis demonstrated a good correlation (R² = 0·9948) between the EMA real-time PCR results and the plate counting, and real-time quantitative PCR results correlated adequately with enumeration of bifidobacteria by culture for commercial probiotic yogurt. This culture-independent approach is promising for the direct and rapid detection of viable bifidobacteria in commercial probiotic yogurt, and the detection can be carried out within 4 h. The detection limit for this method is about 10⁴ cell/ml. In conclusion, the direct quantitative EMA real-time PCR assay based on molecular beacon described in this research is a rapid and quantitative method.

  17. Solar Beacon System of Open- air Park%露天停车场太阳能导标系统

    Institute of Scientific and Technical Information of China (English)

    邹亮; 朱玲湘

    2011-01-01

    With the more increasing vehicles, parking and security issues are brought to our attention, park planning has been taken as a key consideration in urban construction planning. Especially for openair car park, there are some widespread problems such as parking lines unclear at night etc. To solve the problem, this paper is com- mitted to standard open - air car park guidance system design and research based on solar, ultrasonic and wireless transmission technology. The solar beacon system of open - air park proposed in this can use lighting beacons to guide the vehicle to quickly find a parking space in poor visibility (night, rain, fog, etc. ) environments, but also clearly shows guide spaces marked boundaries to effectively use the limited parking space. The study and achieve- ments in this paper will have good practical value in the field of intelligent Transportation System.%城市的建设规划已经把停车场列为重点考虑问题,日益增加的车辆及其停放问题和安全问题都受到人们的普遍关注。特别是对于露天停车场目前广泛存在着晚间车位线不清等问题,本文针对上述实际情况,以太阳能、超声波与无线传输技术为基础,致力于露天停车场导标系统的设计与研究,利用发光导标引导车辆,使驾驶员在能见度低(晚上、大雨、大雾等)的环境下也能够迅速的找到车位,同时导标还能够明确显示车位界限,从而有效利用停车场的有限空间。本文所研究内容及其成果在智能交通领域具有很好的现实价值。

  18. Efficacy and safety of QVA149 compared to the concurrent administration of its monocomponents indacaterol and glycopyrronium: the BEACON study

    Directory of Open Access Journals (Sweden)

    Dahl R

    2013-10-01

    Full Text Available Ronald Dahl,1 Dalal Jadayel,2 Vijay KT Alagappan,3 Hungta Chen,3 Donald Banerji31Department of Dermatology, Allergy Centre, Odense University Hospital, Odense, Denmark; 2Novartis Horsham Research Centre, Horsham, UK; 3Novartis Pharmaceuticals Corporation, East Hanover, NJ, USAIntroduction: The BEACON study evaluated the efficacy and safety of QVA149, a once-daily dual bronchodilator containing a fixed-dose combination of the long-acting β2-agonist (LABA indacaterol and long-acting muscarinic antagonist (LAMA glycopyrronium (NVA237, in development for the treatment of patients with chronic obstructive pulmonary disease (COPD, compared with the free-dose concurrent administration of indacaterol plus glycopyrronium (IND+GLY.Methods: In this multicenter, double-blind, parallel group study, patients with stage II or stage III COPD (Global initiative for chronic Obstructive Lung Disease [GOLD] 2010 were randomized (1:1 to once-daily QVA149 (110 µg indacaterol/50 µg glycopyrronium or concurrent administration of indacaterol (150 µg and glycopyrronium (50 µg via the Breezhaler® device (Novartis AG, Basel, Switzerland for 4 weeks. The primary endpoint was to evaluate the noninferiority of QVA149 as compared with concurrent administration of IND+GLY, for trough forced expiratory volume in 1 second (FEV1 after 4 weeks of treatment. The other assessments included FEV1 area under the curve from 0 to 4 hours (AUC0–4 hours at day 1 and week 4, symptom scores, rescue medication use, safety, and tolerability over the 4-week study period.Results: Of 193 patients randomized, 187 (96.9% completed the study. Trough FEV1 at week 4 for QVA149 and IND+GLY was 1.46 L ± 0.02 and 1.46 L ± 0.18, respectively. The FEV1 AUC0–4 hours at day 1 and week 4 were similar between the two treatment groups. Both treatment groups had a similar reduction in symptom scores and rescue medication use for the 4-week treatment period. Overall, 25.6% of patients in QVA149 group

  19. Systematic interpretation of molecular beacon PCR for identifying rpoB mutations in Mycobacterium tuberculosis isolates with mixed resistant and susceptible bacteria

    Science.gov (United States)

    Gomez, Diana I.; Fisher-Hoch, Susan P.; Bordt, Andrea S.; Quitugua, Teresa N.; Robledo, Jaime; Alvarez, Nataly; Correa, Nidia; McCormick, Joseph B.; Restrepo, Blanca I.

    2010-01-01

    Detection of multi-drug resistant tuberculosis (MDR-TB), a frequent cause of treatment failure, takes two or more weeks to identify by culture. Rifampicin (RIF) resistance is a hallmark of MDR-TB, and detection of mutations in the rpoB gene of Mycobacterium tuberculosis using molecular beacon probes with real-time quantitative PCR (qPCR) is a novel approach that takes ≤ 2 days. However, qPCR identification of resistant isolates, particularly for isolates with mixed RIF-susceptible and RIF-resistant bacteria, is reader-dependent and limits its clinical use. The aim of this study was to develop an objective, reader independent method to define rpoB mutants using beacon qPCR. This would facilitate the transition from a research protocol to the clinical setting, where high-throughput methods with objective interpretation are required. For this, DNAs from 107 M. tuberculosis clinical isolates with known susceptibility to RIF by culture-based methods were obtained from two regions where isolates have not previously been subjected to evaluation using molecular beacon qPCR: The Texas-Mexico border and Colombia. Using coded DNA specimens, mutations within an 81 bp hot-spot region of rpoB were established by qPCR with five beacons spanning this region. Visual and mathematical approaches were used to establish whether the qPCR cycle threshold (Ct) of the experimental isolate was significantly higher (mutant) compared to a reference wild-type isolate. Visual classification of the beacon qPCR required reader training for strains with a mixture of RIF-susceptible and resistant bacteria. Only then, the visual interpretation by an experienced reader had 100% sensitivity and 94.6% specificity versus RIF-resistance by culture phenotype, and 98.1% sensitivity and 100% specificity versus mutations based on DNA sequence. The mathematical approach was 98% sensitive and 94.5% specific versus culture, and 96.2% sensitive and 100% specific versus DNA sequence. Our findings indicate the

  20. Dual hairpin-like molecular beacon based on coralyne-adenosine interaction for sensing melamine in dairy products.

    Science.gov (United States)

    Wang, Guangfeng; Zhu, Yanhong; Chen, Ling; Zhang, Xiaojun

    2014-11-01

    This study presents a novel dual hairpin-like molecular beacon (MB) for the selective and sensitive detection of melamine (MA) based on the conjugation of MA and thymine. In this protocol, the coordination between coralyne and adenosine (A) leaded a dual hairpin-like MB and the fluorophore-quencher pair is close proximity resulting in the fluorescence quenching. With the addition of MA, it conjugated with thymine in the loop part of dual hairpin-like MB by triple H-bonds, triggering the dissociation of the dual hairpin-like MB. The resulting spatial separation of the fluorophore from quencher induced the enhancement in fluorescence emission. Under the optimized conditions, the sensor exhibited a wide linear range of 8×10(-9)-1.6×10(-5) M (R(2)=0.9969) towards MA, with a low detection limit of 5 nM, approximately 4000 times lower than the Drug Administration and the US Food estimated MA safety limit. The real milk samples were also investigated with a satisfying result.

  1. Selective amyloid β oligomer assay based on abasic site-containing molecular beacon and enzyme-free amplification.

    Science.gov (United States)

    Zhu, Linling; Zhang, Junying; Wang, Fengyang; Wang, Ya; Lu, Linlin; Feng, Chongchong; Xu, Zhiai; Zhang, Wen

    2016-04-15

    Amyloid-beta (Aβ) oligomers are highly toxic species in the process of Aβ aggregation and are regarded as potent therapeutic targets and diagnostic markers for Alzheimer's disease (AD). Herein, a label-free molecular beacon (MB) system integrated with enzyme-free amplification strategy was developed for simple and highly selective assay of Aβ oligomers. The MB system was constructed with abasic site (AP site)-containing stem-loop DNA and a fluorescent ligand 2-amino-5,6,7-trimethyl-1,8-naphyridine (ATMND), of which the fluorescence was quenched upon binding to the AP site in DNA stem. Enzyme-free amplification was realized by target-triggered continuous opening of two delicately designed MBs (MB1 and MB2). Target DNA hybridization with MB1 and then MB2 resulted in the release of two ATMND molecules in one binding event. Subsequent target recycling could greatly amplify the detection sensitivity due to the greatly enhanced turn-on emission of ATMND fluorescence. Combining with Aβ oligomers aptamers, the strategy was applied to analyze Aβ oligomers and the results showed that it could quantify Aβ oligomers with high selectivity and monitor the Aβ aggregation process. This novel method may be conducive to improve the diagnosis and pathogenic study of Alzheimer's disease.

  2. Monitoring p21 mRNA expression in living cell based on molecular beacon fluorescence increasing rate

    Institute of Scientific and Technical Information of China (English)

    TANG HongXing; YANG XiaoHai; WANG KeMin; TAN WeiHong; LIU Bin; HE LiFang; WANG Wei

    2008-01-01

    Studying the expression level of mRNA in living cells will offer tremendous opportunities for ad-vancement in cell biology research, disease diagnostics, and drug discovery. In this paper, a molecular beacon (MB) specific for the important tumor suppressor gene p21 has been designed and synthesized. The fluorescence signal was detected in real-time after the MB entered the cytoplasm of nasopharyn-geal carcinoma cells. After injecting the p21MB into nasopharyngeal carcinoma cell and p33-trans-fected nasopharyngeal carcinoma cell, the consistent increase of fluorescent signal intensity was de-tected in both cell lines, and maximum fluorescence intensity achieved in about 15 min. In about 4 min following microinjection, the fluorescence increasing rate was significantly different between these two cell lines, which indicate the different p21 mRNA expression levels. The results obtained in the real-time detection were also validated by RT-PCR. Analysis of the initial fluorescence increasing rate can effi-ciently reduce the side effect of enzyme and improve the accuracy in living cell mRNA detection.

  3. Non-genetic Purification of Ventricular Cardiomyocytes from Differentiating Embryonic Stem Cells through Molecular Beacons Targeting IRX-4

    Directory of Open Access Journals (Sweden)

    Kiwon Ban

    2015-12-01

    Full Text Available Isolation of ventricular cardiomyocytes (vCMs has been challenging due to the lack of specific surface markers. Here we show that vCMs can be purified from differentiating mouse embryonic stem cells (mESCs using molecular beacons (MBs targeting specific intracellular mRNAs. We designed MBs (IRX4 MBs to target mRNA encoding Iroquois homeobox protein 4 (Irx4, a transcription factor specific for vCMs. To purify mESC vCMs, IRX4 MBs were delivered into cardiomyogenically differentiating mESCs, and IRX4 MBs-positive cells were FACS-sorted. We found that, of the cells isolated, ∼98% displayed vCM-like action potentials by electrophysiological analyses. These MB-purified vCMs continuously maintained their CM characteristics as verified by spontaneous beating, Ca2+ transient, and expression of vCM-specific proteins. Our study shows the feasibility of isolating pure vCMs via cell sorting without modifying host genes. The homogeneous and functional ventricular CMs generated via the MB-based method can be useful for disease investigation, drug discovery, and cell-based therapies.

  4. Expression patterns of prion protein gene in differential genotypes sheep: quantification using molecular beacon real-time RT-PCR.

    Science.gov (United States)

    Wang, Chuan; Wu, Run; Li, Fa-Di; Liu, Lei; Zhang, Xiao-Li; Zhao, Chun-Lin; Diao, Xiao-Long; Guan, Hong-Wei

    2011-06-01

    Determination of the transcription level of cellular prion protein (PrP(C)) is essential for understanding its role in organisms and revealing mechanism of susceptibility and resistance to scrapie. However, the expression of prion protein (PrP) mRNA in sheep has not been quantified in great detail in digestive tract which is important during scrapie spread through oral route. Herein, we report on measurement of sheep PrP mRNA using absolute quantitative real-time RT-PCR. Total RNA was isolated from five different regions of the central nervous system (CNS), four regions of lymphoid system, eleven regions of digestive tract, and two reproductive organ tissues of eight sheep of two different genotypes (ARR/ARQ and ARH/ARQ) and PrP mRNA was quantified by real-time RT-PCR using molecular beacon. The results showed that highest levels of PrP mRNA were expressed in thalamus and cerebrum (P mRNA expression in sheep for further studies of pathogenesis of prion diseases.

  5. 基于 iBeacon 技术的智慧会展前景眺望

    Institute of Scientific and Technical Information of China (English)

    张彦玲; 乔哲

    2016-01-01

    随着智能手机的普及和无线信号的覆盖,室内定位技术在各个领域得到快速应用,尤其是在智慧会展领域。室内定位技术在会展人流量实时监控、足迹追踪、安全预警、线上线下融合、信息精准推广等方面起着极为重要的作用。首先介绍了室内定位技术在会展中的应用,其次介绍了以 iBeacon 为代表的基础服务平台架构,包括部署、配置和巡检三部分,助力精准营销,最后指出室内定位技术的发展方向和亟待解决的问题。

  6. A label-free fluorescent molecular beacon based on DNA-Ag nanoclusters for the construction of versatile Biosensors.

    Science.gov (United States)

    Cao, Qiao; Teng, Ye; Yang, Xuan; Wang, Jin; Wang, Erkang

    2015-12-15

    In this paper, we developed a simple, low-cost and sensitive DNA sequences detection biosensor based on a label-free molecular beacon (MB) whose DNA hairpin structure terminal has a guanine-rich sequence that can enhance fluorescence of silver nanoclusters (Ag NCs). Without hybridization between hairpin probe and target DNA, the Ag NCs presented bright fluorescence for the proximity of guanine-rich sequences (GRSs). After binding with target DNA, the hairpin shape was destroyed which results in a decrease of the Ag NCs fluorescence intensity. With this biosensor, we detected three disease-related genes that were the human immunodeficiency virus (HIV) gene, hepatitis B virus (HBV) gene and human T-lymphotropic virus type I (HTLV-I) gene. The detection limits based on S/N of 3 were 4.4 nM, 6.8 nM and 8.5 nM for HIV gene, HBV gene and HTLV-I gene, respectively. Our sensor was also of high selectivity and could distinguish even one nucleotide mismatched target.

  7. Calculation on the Layout of A LED Optical Beacon with Three Sources%三光源 LED 光信标空间布局优化计算

    Institute of Scientific and Technical Information of China (English)

    王彩玲

    2015-01-01

    The optical beacon is an important position indicator in aviation , sea transportation and the sea life saving .With the need of the remote indication , the optical beacon with LED sources , owing to high brightness and luminous efficiency , is presented .Based on the established mathematical model of the light beam , the layout of the beacon with three lamp-houses is calculated theoretically , and the optimal layout , the ranges and the sizes of the blind zenos of the beacon are discussed .The results provide a theoretical guide for the structure design of the beacon essentially , and the method can be referred to layout of other multi-sources beacon .%在航空、海运及海上救生等各方面,光学信标是一种重要的光学指示手段。为了适应较远作用距离的要求,提出了采用高亮度、高发光效率的LED光源的光学信标。针对采用三光源光信标的空间布局进行了相关理论计算,建立光束空间数学模型,给出三光源的最佳空间布置,并计算出光信标盲区范围及盲区大小。本文的计算结果为光信标的结构设计提供必要的理论基础,其计算方法为多光源信标空间布局计算提供一定的参考。

  8. An ultrasensitive alloyed near-infrared quinternary quantum dot-molecular beacon nanodiagnostic bioprobe for influenza virus RNA.

    Science.gov (United States)

    Adegoke, Oluwasesan; Kato, Tatsuya; Park, Enoch Y

    2016-06-15

    Conventional techniques used to diagnose influenza virus face several challenges, such as low sensitivity, slow detection, false positive results and misinterpreted data. Hence, diagnostic probes that can offer robust detection qualities, such as high sensitivity, rapid detection, elimination of false positive data, and specificity for influenza virus, are urgently needed. The near-infrared (NIR) range is an attractive spectral window due to low photon absorption by biological tissues, hence well-constructed fluorescent biosensors that emit within the NIR window can offer an improved limit of detection (LOD). Here, we demonstrate the use of a newly synthesized NIR quinternary alloyed CdZnSeTeS quantum dots (QDs) as an ultrasensitive fluorescence reporter in a conjugated molecular beacon (MB) assay to detect extremely low concentrations of influenza virus H1N1 RNA. Under optimum conditions, two different strains of influenza virus H1N1 RNA were detected based on fluorescence enhancement signal transduction. We successfully discriminated between two different strains of influenza virus H1N1 RNA based on the number of complementary nucleotide base pairs of the MB to the target RNA sequence. The merits of our bioprobe system are rapid detection, high sensitivity (detects H1N1 viral RNA down to 2 copies/mL), specificity and versatility (detects H1N1 viral RNA in human serum). For comparison, a conventional CdSe/ZnS-MB probe could not detect the extremely low concentrations of H1N1 viral RNA detected by our NIR alloyed CdZnSeTeS-MB probe. Our bioprobe detection system produced a LOD as low as ~1 copy/mL and is more sensitive than conventional molecular tests and rapid influenza detection tests (RIDTS) probes.

  9. Age-specific risk factor profiles of adenocarcinomas of the esophagus: A pooled analysis from the international BEACON consortium.

    Science.gov (United States)

    Drahos, Jennifer; Xiao, Qian; Risch, Harvey A; Freedman, Neal D; Abnet, Christian C; Anderson, Lesley A; Bernstein, Leslie; Brown, Linda; Chow, Wong-Ho; Gammon, Marilie D; Kamangar, Farin; Liao, Linda M; Murray, Liam J; Ward, Mary H; Ye, Weimin; Wu, Anna H; Vaughan, Thomas L; Whiteman, David C; Cook, Michael B

    2016-01-01

    Esophageal (EA) and esophagogastric junction (EGJA) adenocarcinoma have been steadily increasing in frequency in younger people; however, the etiology of these cancers is poorly understood. We therefore investigated associations of body mass index (BMI), cigarette smoking, alcohol consumption, gastroesophageal reflux and use of nonsteroidal anti-inflammatory drugs (NSAIDs) in relation to age-specific risks of EA and EGJA. We pooled individual participant data from eight population-based, case-control studies within the international Barrett's and Esophageal Adenocarcinoma Consortium (BEACON). The analysis included 1,363 EA patients, 1,472 EGJA patients and 5,728 control participants. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for age-specific (<50, 50-59, 60-69, ≥70 years) cancer outcomes, as well as interactions by age. BMI, smoking status and pack-years, recurrent gastroesophageal reflux and frequency of gastroesophageal reflux were positively associated with EA and EGJA in each age group. Early-onset EA (<50 years) had stronger associations with recurrent gastroesophageal reflux (OR = 8.06, 95% CI: 4.52, 14.37; peffect modification  = 0.01) and BMI (ORBMI ≥ 30 vs . <25  = 4.19, 95% CI: 2.23, 7.87; peffect modification  = 0.04), relative to older age groups. In contrast, inverse associations of NSAID use were strongest in the oldest age group (≥70 years), although this apparent difference was not statistically significant. Age-specific associations with EGJA showed similar, but slightly weaker patterns and no statistically significant differences by age were observed. Our study provides evidence that associations between obesity and gastroesophageal reflux are stronger among earlier onset EA cancers.

  10. Novel Molecular Beacon Probe-Based Real-Time RT-PCR Assay for Diagnosis of Crimean-Congo Hemorrhagic Fever Encountered in India

    Directory of Open Access Journals (Sweden)

    Aman Kamboj

    2014-01-01

    Full Text Available Crimean-Congo hemorrhagic fever (CCHF is an emerging zoonotic disease in India and requires immediate detection of infection both for preventing further transmission and for controlling the infection. The present study describes development, optimization, and evaluation of a novel molecular beacon-based real-time RT-PCR assay for rapid, sensitive, and specific diagnosis of Crimean-Congo hemorrhagic fever virus (CCHFV. The developed assay was found to be a better alternative to the reported TaqMan assay for routine diagnosis of CCHF.

  11. 一种基于模糊逻辑的自适应信标交换算法%An adaptive beacon exchange algorithm based on fuzzy logic

    Institute of Scientific and Technical Information of China (English)

    李玉龙; 戚云军; 张衡阳

    2015-01-01

    针对移动无线传感器网络中贪婪地理路由协议采用固定信标周期导致通信暂盲的问题,提出了一种基于模糊逻辑的自适应信标交换算法。该算法以节点移动速度、节点剩余能量和邻居节点的数量作为评价因素,利用模糊逻辑控制机制确定自适应的信标周期,提高了邻居表构建与维护的准确性与实时性,为贪婪地理转发提供了可靠依据。仿真结果表明:该算法有效减少了通信暂盲现象,降低了控制开销和平均端到端时延,提高了分组交付率,适用于对传输可靠性要求高的大规模移动无线传感器网络。%Aiming at problem that temporary communication blindness caused by greedy geographical routing protocol adopts stationary beacon exchange in mobile wireless sensor networks( WSNs),a novel adaptive beacon exchange algorithm is proposed. The algorithm adopts node moving speed,node residual energy,number of neighboring nodes as evaluation factors and confirm adaptive beacon period using fuzzy logic control mechanism. The adaptive beacon exchange algorithm can increase accuracy and realtime of neighbors table construction and maintenance and provide reliable basis for greedy geographical relay. Simulation shows that the proposed algorithm reduce phenomenon of temporary communication blindness,increases packet delivery ratio and reduce average end-to-end delay as well as control overhead,so it is suitable for application of large-scale mobile WSNs,which has high requirement for transmission reliability.

  12. Method of Soldier Localization in Battlefield Based on Mobile Beacon in Unmanned Aerial Vehicle%一种基于无人机移动信标的战场士兵定位方法的研究

    Institute of Scientific and Technical Information of China (English)

    高丹丹; 吴宝明; 王圣超; 苏清章

    2012-01-01

    目的:以战场士兵搜索为背景,研究一种新的基于无人机移动信标的战场士兵定位方法.方法:无人机沿“∞”模型飞行,机载信标获取相对地理位置信息,并且周期性地发送唤醒信号;士兵节点被唤醒后,发送RSSI数据包,再次进入休眠状态;移动信标接收士兵节点RSSI数据包,在接收位置形成该节点对应的虚拟信标;计算士兵节点到所对应的虚拟信标的距离矩阵,从而进一步计算士兵节点的相对地理坐标.结果:仿真测试随机布设20个结构相同的士兵节点,当平均每个士兵节点对应的虚拟信标数为8.3个时,平均定位误差为7.78%.结论:基于无人机移动信标的定位方法具有较高的定位精度,有望用于战场士兵定位.%Objective To develop a new method of localization based on mobile beacon for searching and rescuing of the wounded in battlefield. Methods When the unmanned aerial vehicle (UAV) was flying along the model "∞", the beacon in the vehicle got the relative location information, and sent the periodic wake-up signals. When receiving the wake-up signals, the unknown position soldiers sent RSSI, and fell asleep again. Beacon collected the RSSI and formed a corresponding virtual beacon. Beacon calculated the distance between the unknown node and the corresponding virtual beacons, and calculated node relative location, which would be sent to the rear headquarters. Results In simulation, 20 soldier nodes with same style were laid randomly. When the average virtual beacon per 1 soldier was 8.3, the average localization error was 7.78%. Conclusion The proposed localization method based on mobile beacon in UAV possesses a better location accuracy, which is expected for battlefield soldier location.[Chinese Medical Equipment Journal,2012,33 (4)r4-6

  13. WSN中信标节点移动情况下的定位方法研究%Research on Localization Algorithm with Beacon Movement in Wireless Sensor Network

    Institute of Scientific and Technical Information of China (English)

    何文秀; 夏明; 赵小敏; 程荣; 陈庆章

    2011-01-01

    Localization is one of the basic theories and key technologies in wireless sensor network (WSN). However, in practical applications , the locations of some beacons would change due to various reasons after deployment, which leads to other unknown nodes rely on these beacons can not been accurately located. In order to solve the localization problems with beacons movement, this paper proposed an area division based beacon movement detection algorithm (AD-BMD), through two judgment processes to determine which beacon have moved, and set a coordinates confidence value for each beacon. In order to use moving beacons and unmoving beacons more reasonably, this paper also proposed a beacon movement detection based beacon optimal selection localization algorithm (BMD-BOS), through selecting beacons reasonably to calculate the position of unknown nodes. Experiment results show that AD-BMD has high correct rate and low error rate. Compared with LB and SSV, AD-BMD has better performance. The localization accuracy of BMD-BOS is much higher than N-BMD's and D-BMD's.%定位技术是无线传感器网络的基础理论和关键技术之一.在实际应用中,一些信标节点在部署以后其位置由于各种原因而会发生漂移,由此就使得依赖于这些信标节点来定位的其他节点将无法准确定位,或者产生很大定位误差.本文针对信标节点产生漂移情况下的节点定位问题,提出了一种基于区域划分的信标节点移动检测算法(AD-BMD),在区域划分的基础上,通过两次判定过程将移动的信标节点检测出来,并为每个信标设置了坐标可信度值.为合理利用移动的和未移动的信标节点,提出一种基于信标移动检测的信标择优定位算法(BMD-BOS),通过合理选择信标节点来对其它未知节点进行定位.实验结果证明,AD-BMD算法具有很高的检测正确率和较低错误率,检测效果好于LB和SSV方法.BMD-BOS算法的定位精度远远高于没有进行移

  14. Mapping plasma structures in the high-latitude ionosphere using beacon satellite, incoherent scatter radar and ground-based magnetometer observations

    Directory of Open Access Journals (Sweden)

    T. Neubert

    2002-06-01

    Full Text Available In the autumn of the year 2000, four radio receivers capable of tracking various beacon satellites were set up along the southwestern coast of Greenland. They are used to reconstruct images of the ionospheric plasma density distribution via the tomographic method. In order to test and validate tomographic imaging under the highly variable conditions often prevailing in the high-latitude ionosphere, a time interval was selected when the Sondrestrom incoherent scatter radar conducted measurements of the ionospheric plasma density while the radio receivers tracked a number of beacon satellites. A comparison between two-dimensional images of the plasma density distribution obtained from the radar and the satellite receivers revealed generally good agreement between radar measurements and tomographic images. Observed discrepancies can be attributed to F region plasma patches moving through the field of view with a speed of several hundred meters per second, thereby smearing out the tomographic image. A notable mismatch occurred around local magnetic midnight when a magnetospheric substorm breakup occurred in the vicinity of southwest Greenland (identified from ground-based magnetometer observations. The breakup was associated with a sudden intensification of the westward auroral electrojet which was centered at about 69 and extended up to some 73 corrected geomagnetic latitude. Ground-based magnetometer data may thus have the potential of indicating when the tomographic method is at risk and may fail. We finally outline the application of tomographic imaging, when combined with magnetic field data, to estimate ionospheric Joule heating rates.

  15. Research of Indoor Route Guidance System Based on iBeacon%基于iBeacon的室内路径引导系统研究

    Institute of Scientific and Technical Information of China (English)

    张斌; 宋英杰

    2016-01-01

    基于iBeacon的室内路径引导系统可以精确的检测室内用户的移动方向,并能够收集用户移动模式的上下文感知收集用户信息,提供精确的引导路线,并将引导信息通过消息推送的形式通知用户。真机实验表明,基于iBeacon的室内路线引导系统较其他系统能够提供更精确的引导信息。%The Indoor Route Guidance System based on iBeacon can accurately detect the moving direction of the indoor user,collect user information through the context awareness of the user mobile mode,provide accurate route guidance,and push the guidance information to the user.Experiments show that the indoor route guidance system based on iBeacon provides more accurate guidance information than other systems.

  16. First results from the ionospheric tomography experiment using beacon TEC data obtained by means of a network along a longitude of 136°E over Japan

    Science.gov (United States)

    Thampi, Smitha V.; Yamamoto, Mamoru

    2010-03-01

    A chain of newly designed GNU (GNU is not UNIX) Radio Beacon Receivers (GRBR) has recently been established over Japan, primarily for tomographic imaging of the ionosphere over this region. Receivers installed at Shionomisaki (33.45°N, 135.8°E), Shigaraki (34.8°N, 136.1°E), and Fukui (36°N, 136°E) continuously track low earth orbiting satellites (LEOS), mainly OSCAR, Cosmos, and FORMOSAT-3/COSMIC, to obtain simultaneous total electron content (TEC) data from these three locations, which are then used for the tomographic reconstruction of ionospheric electron densities. This is the first GRBR network established for TEC observations, and the first beacon-based tomographic imaging in Japanese longitudes. The first tomographic images revealed the temporal evolution with all of the major features in the ionospheric electron density distribution over Japan. A comparison of the tomographically reconstructed electron densities with the ƒ o F 2 data from Kokubunji (35°N, 139°E) revealed that there was good agreement between the datasets. These first results show the potential of GRBR and its network for making continuous, unattended ionospheric TEC measurements and for tomographic imaging of the ionosphere.

  17. An ensemble average method to estimate absolute TEC using radio beacon-based differential phase measurements: Applicability to regions of large latitudinal gradients in plasma density

    Science.gov (United States)

    Thampi, Smitha V.; Bagiya, Mala S.; Chakrabarty, D.; Acharya, Y. B.; Yamamoto, M.

    2014-12-01

    A GNU Radio Beacon Receiver (GRBR) system for total electron content (TEC) measurements using 150 and 400 MHz transmissions from Low-Earth Orbiting Satellites (LEOS) is fabricated in house and made operational at Ahmedabad (23.04°N, 72.54°E geographic, dip latitude 17°N) since May 2013. This system receives the 150 and 400 MHz transmissions from high-inclination LEOS. The first few days of observations are presented in this work to bring out the efficacy of an ensemble average method to convert the relative TECs to absolute TECs. This method is a modified version of the differential Doppler-based method proposed by de Mendonca (1962) and suitable even for ionospheric regions with large spatial gradients. Comparison of TECs derived from a collocated GPS receiver shows that the absolute TECs estimated by this method are reliable estimates over regions with large spatial gradient. This method is useful even when only one receiving station is available. The differences between these observations are discussed to bring out the importance of the spatial differences between the ionospheric pierce points of these satellites. A few examples of the latitudinal variation of TEC during different local times using GRBR measurements are also presented, which demonstrates the potential of radio beacon measurements in capturing the large-scale plasma transport processes in the low-latitude ionosphere.

  18. Sensitive HIV-1 detection in a homogeneous solution based on an electrochemical molecular beacon coupled with a nafion-graphene composite film modified screen-printed carbon electrode.

    Science.gov (United States)

    Li, Bo; Li, Zhengliang; Situ, Bo; Dai, Zong; Liu, Qinlan; Wang, Qian; Gu, Dayong; Zheng, Lei

    2014-02-15

    A novel electrochemical sensing assay for sensitive determination of HIV-1 in a homogeneous solution has been developed using an electrochemical molecular beacon combined with a nafion-graphene composite film modified screen-printed carbon electrode (nafion-graphene/SPCE). The electrochemical molecular beacon (CAs-MB), comprising a special recognition sequence for the conserved region of the HIV-1 gag gene and a pair of carminic acid molecules as a marker, can indicate the presence of the HIV-1 target by its on/off electrochemical signal behavior. It is suitable for direct, electrochemical determination of HIV-1, thereby simplifying the detection procedure and improving the signal-to-noise (S/N) ratio. To further improve the sensitivity, the nafion-graphene/SPCE was used to monitor changes in the CAs-MB, which has notable advantages, such as being ultrasensitive, inexpensive, and disposable. Under optimized conditions, the peak currents showed a linear relationship with the logarithm of target oligonucleotide concentrations ranging from 40 nM to 2.56 μM, with a detection limit of 5 nM (S/N=3). This sensing assay also displays a good stability, with a recovery of 88-106.8% and RSD<7% (n=5) in real serum samples. This work may lead to the development of an effective method for early point-of-care diagnosis of HIV-1 infection.

  19. Systematic interpretation of molecular beacon polymerase chain reaction for identifying rpoB mutations in Mycobacterium tuberculosis isolates with mixed resistant and susceptible bacteria.

    Science.gov (United States)

    Gomez, Diana I; Fisher-Hoch, Susan P; Bordt, Andrea S; Quitugua, Teresa N; Robledo, Jaime; Alvarez, Nataly; Correa, Nidia; McCormick, Joseph B; Restrepo, Blanca I

    2010-05-01

    Detection of multidrug-resistant tuberculosis (MDR-TB), a frequent cause of treatment failure, takes 2 or more weeks to identify by culture. Rifampicin (RIF) resistance is a hallmark of MDR-TB, and detection of mutations in the rpoB gene of Mycobacterium tuberculosis using molecular beacon probes with real-time quantitative polymerase chain reaction (qPCR) is a novel approach that takes Visual and mathematical approaches were used to establish whether the qPCR cycle threshold of the experimental isolate was significantly higher (mutant) compared to a reference wild-type isolate. Visual classification of the beacon qPCR required reader training for strains with a mixture of RIF-susceptible and RIF-resistant bacteria. Only then had the visual interpretation by an experienced reader had 100% sensitivity and 94.6% specificity versus RIF resistance by culture phenotype and 98.1% sensitivity and 100% specificity versus mutations based on DNA sequence. The mathematical approach was 98% sensitive and 94.5% specific versus culture and 96.2% sensitive and 100% specific versus DNA sequence. Our findings indicate the mathematical approach has advantages over the visual reading, in that it uses a Microsoft Excel template to eliminate reader bias or inexperience, and allows objective interpretation from high-throughput analyses even in the presence of a mixture of RIF-resistant and RIF-susceptible isolates without the need for reader training.

  20. Gold Nanoparticle-Quantum Dot Fluorescent Nanohybrid: Application for Localized Surface Plasmon Resonance-induced Molecular Beacon Ultrasensitive DNA Detection

    Science.gov (United States)

    Adegoke, Oluwasesan; Park, Enoch Y.

    2016-11-01

    In biosensor design, localized surface plasmon resonance (LSPR)-induced signal from gold nanoparticle (AuNP)-conjugated reporter can produce highly sensitive nanohybrid systems. In order to retain the physicochemical properties of AuNPs upon conjugation, high colloidal stability in aqueous solution is needed. In this work, the colloidal stability with respect to the zeta potential (ZP) of four negatively charged thiol-functionalized AuNPs, thioglycolic (TGA)-AuNPs, 3-mercaptopropionic acid (MPA)-AuNPs, l-cysteine-AuNPs and l-glutathione (GSH)-AuNPs, and a cationic cyteamine-capped AuNPs was studied at various pHs, ionic strength, and NP concentration. A strong dependence of the ZP charge on the nanoparticle (NP) concentration was observed. High colloidal stability was exhibited between pH 3 and 9 for the negatively charged AuNPs and between pH 3 and 7 for the cationic AuNPs. With respect to the ionic strength, high colloidal stability was exhibited at ≤104 μM for TGA-AuNPs, l-cysteine-AuNPs, and GSH-AuNPs, whereas ≤103 μM is recommended for MPA-AuNPs. For the cationic AuNPs, very low ionic strength of ≤10 μM is recommended due to deprotonation at higher concentration. GSH-AuNPs were thereafter bonded to SiO2-functionalized alloyed CdZnSeS/ZnSe1.0S1.3 quantum dots (SiO2-Qdots) to form a plasmon-enhanced AuNP-SiO2-Qdots fluorescent nanohybrid. The AuNP-SiO2-Qdots conjugate was afterward conjugated to a molecular beacon (MB), thus forming an ultrasensitive LSPR-induced SiO2-Qdots-MB biosensor probe that detected a perfect nucleotide DNA sequence at a concentration as low as 10 fg/mL. The limit of detection was 11 fg/mL (1.4 fM) while the biosensor probe efficiently distinguished between single-base mismatch and noncomplementary sequence target.

  1. Metody určování polohy v uzavřených prostorách prostřednictvím technologie iBeacon

    OpenAIRE

    2015-01-01

    This thesis compares indoor location methods with emphasis on iBeacon technology and its potential. In the review part of the thesis, basic technological properties are outlined. Further, a concept of application for indoor location is proposed. Finally, a set of experiments is described and the results are evaluated.

  2. 基于未知-信标迭代及圆环交汇的WSN定位算法%Localization Algorithm Based on Unknown-Beacon Iterative and Annulus Intersection in WSN

    Institute of Scientific and Technical Information of China (English)

    杨前程

    2016-01-01

    针对圆环交汇与网格扫描算法在定位时要求信标节点数量满足一定规模的缺陷,提出一种未知-信标迭代的基于圆环交汇与网格扫描改进算法。该算法通过将已定位的未知节点视为已知条件使用,引入信标节点迭代方法,解决了少量信标节点定位精度低的问题,增加了未知节点中已定位节点的循环利用。实验结果表明,改进算法提高了定位精度,并降低了对信标节点规模的依赖。%Aiming at the defect that the annulus intersection and grid scan algorithm required the number of beacon nodes to meet the size of a certain scale,the author proposed an improved algorithm based on annulus intersection and grid scan for unknown-beacon iterative.The algorithm took the localized unknown nodes as the known condition. The algorithm solved the problem of low localization precision of a small number of beacon nodes and increased the recycling utilization of the localized nodes in the unknown nodes by introducing the beacon node iterative method.Experimental results show that the improved algorithm can improve the localization precision and reduce the dependence on the scale of beacon nodes.

  3. Lateral Beacons - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  4. Opportunistic beacon networks

    NARCIS (Netherlands)

    Türkes, Okan

    2016-01-01

    Modern society is surrounded by an ample spectrum of personal mobile devices with short-range wireless communication support. This ubiquity creates an immense potential of new concepts for people-centric ad hoc networks that can be applied to every personal and social dimension of life. The last dec

  5. Beacon of Development

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Premier Wen Jiabao sends crucial signals to the international community at UN headquarters For the first time since he took office five years ago, Chinese Premier Wen Jiabao addressed the United Nations in New York on September

  6. Ligation-rolling circle amplification combined with γ-cyclodextrin mediated stemless molecular beacon for sensitive and specific genotyping of single-nucleotide polymorphism.

    Science.gov (United States)

    Zou, Zhen; Qing, Zhihe; He, Xiaoxiao; Wang, Kemin; He, Dinggeng; Shi, Hui; Yang, Xue; Qing, Taiping; Yang, Xiaoxiao

    2014-07-01

    A novel approach for highly sensitive and selective genotyping of single-nucleotide polymorphism (SNP) has been developed based on ligation-rolling circle amplification (L-RCA) and stemless molecular beacon. In this approach, two tailored DNA probes were involved. The stemless molecular beacon, formed through the inclusion interactions of γ-cyclodextrin (γ-CD) and bis-pyrene labeled DNA fragment, was served as signal probe. In the absence of mutant target, the two pyrene molecules were bound in the γ-CD cavity to form an excimer and showed a strong fluorescence at 475 nm. It was here named γ-CD-P-MB. The padlock DNA probe was designed as recognition probe. Upon the recognition of a point mutation DNA targets, the padlock probe was ligated to generate a circular template. An RCA amplification was then initiated using the circular template in the presence of Phi29 polymerase and dNTPs. The L-RCA products, containing repetitive sequence units, subsequently hybridized with the γ-CD-P-MB. This made pyrene molecules away from γ-CD cavity and caused a decrease of excimer fluorescence. As a proof-of-concept, SNP typing of β-thalassemia gene at position -28 was investigated using this approach. The detection limit of mutated target was determined to be 40 fM. In addition, DNA ligase offered high fidelity in distinguishing the mismatched bases at the ligation site, resulting in positive detection of mutant target even when the ratio of the wildtype to the mutant is 999:1. Given these attractive characteristics, the developed approach might provide a great genotyping platform for pathogenic diagnosis and genetic analysis.

  7. Highly sensitive detection of cancer-related genes based on complete fluorescence restoration of a molecular beacon with a functional overhang.

    Science.gov (United States)

    Li, Feng; Zhou, Ying-Ying; Peng, Ting; Xu, Huo; Zhang, Rong-Bo; Zhao, Hui; Wang, Zheng-Yong; Lv, Jian-Xin; Wu, Zai-Sheng; Shen, Zhi-Fa

    2016-07-21

    The accurate detection of cancer-related genes is of great significance for early diagnosis and targeted therapy of cancer. In this contribution, an automatically cycling operation of a functional overhang-containing molecular beacon (OMB)-based sensing system was proposed to perform amplification detection of the p53 gene. Contrary to the common molecular beacon (MB), a target DNA is designated to hybridize with a label-free recognition probe (RP) with a hairpin structure rather than OMB. In the presence of a target DNA of interest, the locked primer in RP opens and triggers the subsequent amplification procedures. The newly-developed OMB is not only capable of accomplishing cyclical nucleic acid strand-displacement polymerization (CNDP) with the help of polymerase and nicking endonuclease, but is also cleaved by restriction endonucleases, removing the quencher away from the fluorophore. Thus, the target DNA at an extremely low concentration is expected to generate a considerable amount of double-stranded and cleaved OMBs, and the quenched fluorescence is completely restored, leading to a dramatic increase in fluorescence intensity. Utilizing this sensing platform, the target gene can be detected down to 8.2 pM in a homogeneous way, and a linear response range of 0.01 to 150 nM could be obtained. More strikingly, the mutant genes can be easily distinguished from the wild-type ones. The proof-of-concept demonstrations reported herein are expected to promote the development of DNA biosensing systems, showing great potential in basic research and clinical diagnosis.

  8. Evaluation of a molecular beacon real-time PCR assay for detection of Baylisascaris procyonis in different soil types and water samples.

    Science.gov (United States)

    Gatcombe, Rachel R; Jothikumar, Narayanan; Dangoudoubiyam, Sriveny; Kazacos, Kevin R; Hill, Vincent R

    2010-01-01

    Baylisascaris procyonis is a helminth parasite commonly found in North American raccoons (Procyon lotor) that is a cause of clinical neural, ocular, and visceral larva migrans in humans when infective eggs are ingested. Rapid detection of B. procyonis eggs in contaminated soil and water would assist public health analysts in evaluating risks associated with public exposure to areas of known raccoon activity. In this study, a molecular beacon probe-based real-time polymerase chain reaction (PCR) assay was developed to enable rapid and specific detection of eggs of Baylisascaris spp. The molecular beacon assay targeted the cytochrome oxidase subunit 2 (cox-2) gene of B. procyonis. To determine method sensitivity, experiments testing various egg levels (250, 25, and five eggs) were performed by seeding into 0.5-g soil samples or 0.5-mL water samples. Different soil sample types were extracted using a commercial nucleic acid extraction kit. Specificity testing using previously characterized helminth tissue specimens indicated that the assay was specific to Baylisascaris spp. Little real-time PCR inhibition was observed for most of the soil and water samples. A seed level of 250 eggs was detected for all soil types, and two seed levels (25 and five eggs) were detected for surface water samples. These results demonstrate that the reported real-time PCR assay was effective for the sensitive detection of B. procyonis in a wide range of soil types, and should be a useful tool for investigations of soil or water potentially contaminated with eggs of this parasite.

  9. Improving DV-Hop Localisation Algorithm Based on Mobile Beacon for WSNs%传感器网络基于移动信标改进的DV-Hop定位算法

    Institute of Scientific and Technical Information of China (English)

    谢晓松; 程良伦

    2011-01-01

    无线传感器网络节点定位算法的精度多依赖于信标节点的密度,但信标节点成本高,约为普通节点的100倍以上,为了降低定位的成本,提出了一种基于移动信标和DV-Hop的无线传感器网络节点定位算法(MBWDV-Hop).该算法在DV-Hop定位算法的基础上,利用一个移动的信标节点在网络中按预定的路径移动并不断地广播自己的位置信息,形成多个虚拟信标,未知节点记录到每个虚拟信标的跳数,并采用加权处理的方法计算平均跳距及其与各虚拟信标的距离,最后利用三边测量法计算未知节点的位置信息,实现节点精确定位.由于只采用一个移动信标,降低了定位的成本和布网的复杂度.最后通过仿真证明算法可以提高定位精度,降低定位成本,提高了定位的效率.%The precision of localisation algorithm for wireless sensor networks mostly relies on the density of beacon node, but the beacon node is very expensive, approximately more than 100 times of the ordinary node. In order to curtail the cost of localisation, we propose a kind of WSN localisation algorithm based on mobile beacon and DV-Hop (MBWDV-Hop). In this algorithm, on the basis of DV-Hop localisation algorithm, a mobile beacon node is used to move around the network according to destined path and to broadcast continually the messages with regard to its own localisation, and this forms a lot of virtual beacons in network. The unknown node records the number of hops from each virtual beacon and uses weighedprocessing method to calculate the average of one-hop distance and the distances between it itself and each virtual beacon. At the end, trilateration method is used to calculate the position information of the unknown node to achieve accurate localisation of the node. Since only one mobile beacon is used in this algorithm, the cost of localisation and the complexity of network deployment can be reduced. Simulation result demonstrates that

  10. 基于Beacon技术的儿童游乐项目设计研究%A Research of Children Amusement Project Design Based on Beacon Technology

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Experience economy gradually becomes the characteristic of the time, such as the representative theme park, and amusement park which contain a huge development market. In view of the issues within domestic children amusement parks, the lack of effective design and planning, or undesirable service quality, the paper aims to provide some new ideas and approach to design it better. It starts from the Beacon technology and the big data processing technology. Speciifcally, with the big data accumulated by Beacon location aware technology, the theories based on experience will be built, thus with the analysis of the need of children and their feeling, an activity data can be collected. With the analyzed result, it is able to provide approaches to construct higher level children amusement parks. Finally, with a certain theory and practical evidence, the new ideas and ways for designing and building the amusement project can be carried out.%体验经济正逐步成为时代的特征,作为体验经济代表的主题公园、游乐场等有着巨大的市场发展空间。针对国内儿童游乐项目缺乏有效的设计及规划,及其服务质量并不能满足儿童消费者的需求等问题,主要运用Beacon技术及大数据处理技术,为儿童游乐项目设计提供一些新的思路和方法。即以Beacon位置感知技术为基础形成大数据,通过大数据技术结合体验设计理论,分析儿童对游乐项目的需求、体验感受、活动数据等,为建立高水平的儿童游乐项目设计提供相应的路径,最终为儿童游乐项目设计实施新的思路和方法,提供一定的理论与实践依据。

  11. 基于自适应信标交换的方向广播协议%Directional broadcasting protocol based on adaptive beacon exchange

    Institute of Scientific and Technical Information of China (English)

    吴学文; 顾欣

    2015-01-01

    A novel directional broadcast considering intersection via adaptive beaconing (DB-IA)based on the analysis of consi-dering crossroads broadcast protocol was proposed.Adaptive beacon exchange mechanism was used to obtain the information of network topology,and node with the longest distance was selected to broadcast packet for each road,greatly reducing broadcast hop.DB-IA adopted acknowledgement (ACK)packets to ensure the reliability of broadcast.The combination of bi-directional propagation and carry-and-forward resolved the problem of network fragment.DB-IA controled the rebroadcast sequence by set-ting incremental backoff counter implicitly,in which way the relay nodes rebroadcasted in a timely and orderly fashion.Simula-tion results indicate that DB-IA performs better on effectiveness and reliability in different scenarios,which means it is suitable for traffic safety messages.%在分析考虑十字路口的广播协议的基础上,提出一种基于自适应信标交换的方向广播协议DB-IA。通过自适应信标交换机制获取网络拓扑信息,在各路段上选择最远节点转播分组,较大程度上减少广播跳数。采用ACK确认机制,结合双向传输和存储-转发策略缓解网络空洞造成的广播中断问题,提高广播的可靠性。通过设置递增的退避时间控制转播队列,使转播快速、有序完成。仿真结果表明,DB-IA具有相对较好且稳定的性能,适合交通安全类信息传输。

  12. Correcting Localization Error with a Single Beacon for AUV%一种利用单信标修正AUV定位误差的方法

    Institute of Scientific and Technical Information of China (English)

    张福斌; 张永清

    2012-01-01

    The localization error of an AUV's integrated navigation positioning system, which is composed of strapdown inertial navigation system (SINS), Doppler velocity logger (DVL) and depth sensor, increases with time, and the hidden performance of the AUV will decrease in correcting the error via GPS. In this paper, a new method is proposed to correct the localization error of the AUV's navigation system by adopting a fixed beacon under water. In this method, the principle of acoustic ranging is used to measure the distance between AUV and beacon, then the real-time position of the AUV is calculated according to spacial geometric relationships, and the localization error of the AUV's navigation system is corrected by Kalman filter. Simulation results show that the present approach can correct AUV's localization error effectively, which infers an application value in engineering.%针对配置有捷联惯导(SINS)/多普勒速度仪(DVL)/深度传感器组合导航定位系统的自主水下航行器(AUV)的定位误差随时间增大,以及采用GPS修正定位误差引起的AUV隐蔽性降低等问题,提出了一种利用水下固定单信标修正SINS/DVL/深度传感器组合定位误差的方法.该方法首先利用水声测距原理测量出AUV与水下固定单信标的距离,然后基于空间几何关系计算出AUV的实时位置,最后通过卡尔曼滤波连续修正AUV的定位误差.仿真结果表明,该方法可以有效减小AUV的定位误差,有较好的工程应用价值.

  13. A novel enzyme-linked immunosorbent assay for detection of Escherichia coli O157:H7 using immunomagnetic and beacon gold nanoparticles.

    Science.gov (United States)

    Shen, Zhiqiang; Hou, Nannan; Jin, Min; Qiu, Zhigang; Wang, Jingfeng; Zhang, Bin; Wang, Xinwei; Wang, Jie; Zhou, Dongsheng; Li, Junwen

    2014-01-01

    This paper presents a functional nanoparticle-enhanced enzyme-linked immunosorbent assay (FNP-ELISA) for detection of enterohemorrhagic Escherichia coli (EHEC) O157:H7. Immunomagnetic nanoparticles (IMMPs) conjugated with monoclonal anti-O157:H7 antibody were used to capture E. coli O157:H7. Beacon gold nanoparticles (B-GNPs) coated with polyclonal anti-O157:H7 and biotin single-stranded DNA (B-DNA) were then subjective to immunoreaction with E. coli O157:H7, which was followed by streptavidin-horseradish peroxidase (Strep-HRP) conjugated with B-GNPs based on a biotin-avidin system. The solutions containing E. coli O157:H7, IMMPs, B-GNPs, and Strep-HRP were collected for detecting color change. The signal was significantly amplified with detection limits of 68 CFU mL(-1) in PBS and 6.8 × 10(2) to 6.8 × 10(3) CFU mL(-1) in the food samples. The FNP-ELISA method developed in this study was two orders of magnitude more sensitive than immunomagnetic separation ELISA (IMS-ELISA) and four orders of magnitude more sensitive than C-ELISA. The entire detection process of E. coli O157:H7 lasted only 3 h, and thus FNP-ELISA is considered as a time-saving method.

  14. Molecular imaging of a cancer-targeting theragnostics probe using a nucleolin aptamer- and microRNA-221 molecular beacon-conjugated nanoparticle.

    Science.gov (United States)

    Kim, Jin Kyeoung; Choi, Kyung-Ju; Lee, Minhyung; Jo, Mi-hee; Kim, Soonhag

    2012-01-01

    MicroRNAs (miRNA, miR) have been reported as cancer biomarkers that regulate tumor suppressor genes. Hence, simultaneous detecting and inhibiting of miRNA function will be useful as a cancer theragnostics probe to minimize side effects and invasiveness. In this study, we developed a cancer-targeting therangostics probe in a single system using an AS1411 aptamer - and miRNA-221 molecular beacon (miR-221 MB)-conjugated magnetic fluorescence (MF) nanoparticle (MFAS miR-221 MB) to simultaneously target to cancer tissue, image intracellularly expressed miRNA-221 and treat miRNA-221-involved carcinogenesis. AS1411 aptamer-conjugated MF (MFAS) nanoparticles displayed a great selectivity and delivery into various cancer cell lines. The miR-221 MB detached from the MFAS miR-221 MB in the cytoplasm of C6 cells clearly imaged miRNA-221 biogenesis and simultaneously resulted in antitumor therapeutic effects by inhibiting miRNA function, indicating a successful astrocytoma-targeting theragnostics. MFAS miRNA MB can be easily applied to other cancers by simply changing a targeted miRNA highly expressed in cancers.

  15. Ultrasensitive electrochemical biosensor for specific detection of DNA based on molecular beacon mediated circular strand displacement polymerization and hyperbranched rolling circle amplification.

    Science.gov (United States)

    Li, Xiaolu; Guo, Jing; Zhai, Qian; Xia, Jing; Yi, Gang

    2016-08-31

    Using a cascade signal amplification strategy, an ultrasensitive electrochemical biosensor for specific detection of DNA based on molecular beacon (MB) mediated circular strand displacement polymerization (CSDP) and hyperbranched rolling circle amplification (HRCA) was proposed. The hybridization of MB probe to target DNA resulted in a conformational change of the MB and triggered the CSDP in the presence of bio-primer and Klenow fragment (KF exo(-)), leading to multiple biotin-tagged DNA duplex. Furthermore, the HRCA was implemented to product amounts of double-stranded DNA (ds-DNA) fragments using phi29 DNA polymerase via biotin-streptavidin interaction. After the product of HRCA binded numerous biotinylated detection probes, an ultrasensitive electrochemical readout by further employing the streptavidin-alkaline phosphatase. The proposed biosensor exhibited excellent detection sensitivity and specificity with a log-linear response to target DNA from 0.01 fM to 10 pM as low as 8.9 aM. The proposed method allowed DNA detection with simplicity, rapidness, low cost and high specificity, which might have the potential for application in clinical molecular diagnostics and environmental monitoring.

  16. Multiplex bioimaging of piRNA molecular pathway-regulated theragnostic effects in a single breast cancer cell using a piRNA molecular beacon.

    Science.gov (United States)

    Lee, Youn Jung; Moon, Sung Ung; Park, Min Geun; Jung, Woon Yong; Park, Yong Keun; Song, Sung Kyu; Ryu, Je Gyu; Lee, Yong Seung; Heo, Hye Jung; Gu, Ha Na; Cho, Su Jeong; Ali, Bahy A; Al-Khedhairy, Abdulaziz A; Lee, Ilkyun; Kim, Soonhag

    2016-09-01

    Recently, PIWI-interacting small non-coding RNAs (piRNAs) have emerged as novel cancer biomarkers candidate because of their high expression level in various cancer types and role in the control of tumor suppressor genes. In this study, a novel breast cancer theragnostics probe based on a single system targeting the piRNA-36026 (piR-36026) molecular pathway was developed using a piR-36026 molecular beacon (MB). The piR-36026 MB successfully visualized endogenous piR-36026 biogenesis, which is highly expressed in MCF7 cells (a human breast cancer cell line), and simultaneously inhibited piR-36026-mediated cancer progression in vitro and in vivo. We discovered two tumor suppressor proteins, SERPINA1 and LRAT, that were directly regulated as endogenous piR-36026 target genes in MCF7 cells. Furthermore, multiplex bioimaging of a single MCF7 cell following treatment with piR-36026 MB clearly visualized the direct molecular interaction of piRNA-36026 with SERPINA1 or LRAT and subsequent molecular therapeutic responses including caspase-3 and PI in the nucleus.

  17. Enzyme-free and label-free ultra-sensitive colorimetric detection of Pb(2+) using molecular beacon and DNAzyme based amplification strategy.

    Science.gov (United States)

    Yun, Wen; Cai, Dingzhou; Jiang, JiaoLai; Zhao, Pengxiang; Huang, Yu; Sang, Ge

    2016-06-15

    An enzyme-free and label-free colorimetric Pb(2+) sensor based on DNAzyme and molecular beacon (MB) has been developed and demonstrated by recycle using enzyme strand for signal amplification. The substrate strand DNA (S-DNA) of DNAzyme could be converted into MB structure with base pairs of stem part at the both ends. The MB could hybridize with enzyme strand DNA (E-DNA) to form DNAzyme, and be activated and cleaved in the presence of Pb(2+). The cleaved MB is much less stable, releasing from the DNAzyme as two product pieces. The product pieces of MB are flexible and could bind to unmodified AuNPs to effectively stabilize them against salt-induced aggregation. Then, the E-DNA is liberated to catalyze the next reaction and amplify the response signal. By taking advantage of repeated using of E-DNA, our proposed method exhibited high sensitive for Pb(2+) detection in a linear range from 0.05 to 5 nM with detection limit of 20 pM by UV-vis spectrometer. Moreover, this method was also used for determination of Pb(2+) in river water samples with satisfying results. Importantly, this strategy could reach high sensitivity without any modification and complex enzymatic or hairpins based amplification procedures.

  18. Trifunctional molecular beacon-mediated quadratic amplification for highly sensitive and rapid detection of mercury(II) ion with tunable dynamic range.

    Science.gov (United States)

    Zhao, Yue; Liu, Huaqing; Chen, Feng; Bai, Min; Zhao, Junwu; Zhao, Yongxi

    2016-12-15

    Analyses of target with low abundance or concentration varying over many orders of magnitude are severe challenges faced by numerous assay methods due to their modest sensitivity and limited dynamic range. Here, we introduce a homogeneous and rapid quadratic polynomial amplification strategy through rational design of a trifunctional molecular beacon, which serves as not only a reporter molecule but also a bridge to couple two stage amplification modules without adding any reaction components or process other than basic linear amplification. As a test bed for our studies, we took mercury(II) ion as an example and obtained a high sensitivity with detection limit down to 200 pM within 30min. In order to create a tunable dynamic range, homotropic allostery is employed to modulate the target specific binding. When the number of metal binding site varies from 1 to 3, signal response is programmed accordingly with useful dynamic range spanning 50, 25 and 10 folds, respectively. Furthermore, the applicability of the proposed method in river water and biological samples are successfully verified with good recovery and reproducibility, indicating considerable potential for its practicality in complex real samples.

  19. Real-time imaging of the epithelial-mesenchymal transition using microRNA-200a sequence-based molecular beacon-conjugated magnetic nanoparticles.

    Directory of Open Access Journals (Sweden)

    YoonSeok Choi

    Full Text Available The epithelial-mesenchymal transition (EMT plays important roles in tumor progression to metastasis. Thus, the development of an imaging probe that can monitor transient periods of the EMT process in live cells is required for a better understanding of metastatic process. Inspired by the fact that the mRNA expression levels of zinc finger E-box-binding homeobox 1 (ZEB1 increase when cells adopt mesenchyme characteristics and that microRNA-200a (miR-200a can bind to ZEB1 mRNA, we conjugated molecular beacon (MB mimicking mature miR-200a to magnetic nanoparticles (miR-200a-MB-MNPs and devised an imaging method to observe transitional changes in the cells during EMT. Transforming growth factor-β1 treated epithelial cells and breast cancer cell lines representing both epithelial and mesenchymal phenotypes were used for the validation of miR-200a-MB-MNPs as an EMT imaging probe. The real-time imaging of live cells acquired with the induction of EMT revealed an increase in fluorescence signals by miR-200a-MB-MNPs, cell morphology alterations, and the loss of cell-cell adhesion. Our results suggest that miR-200a-MB-MNPs can be used as an imaging probe for the real-time monitoring of the EMT process in live cells.

  20. Nicking endonuclease-assisted signal amplification of a split molecular aptamer beacon for biomolecule detection using graphene oxide as a sensing platform.

    Science.gov (United States)

    Li, Xiang; Ding, Xuelian; Fan, Jing

    2015-12-07

    Sensitive and selective detection of ultralow concentrations of specific biomolecules is important in early clinical diagnoses and biomedical applications. Many types of aptasensors have been developed for the detection of various biomolecules, but usually suffer from false positive signals and high background signals. In this work, we have developed an amplified fluorescence aptasensor platform for ultrasensitive biomolecule detection based on enzyme-assisted target-recycling signal amplification and graphene oxide. By using a split molecular aptamer beacon and a nicking enzyme, the typical problem of false positive signals can be effectively resolved. Only in the presence of a target biomolecule, the sensor system is able to generate a positive signal, which significantly improves the selectivity of the aptasensor. Moreover, using graphene oxide as a super-quencher can effectively reduce the high background signal of a sensing platform. We select vascular endothelial growth factor (VEGF) and adenosine triphosphate (ATP) as model analytes in the current proof-of-concept experiments. It is shown that under optimized conditions, our strategy exhibits high sensitivity and selectivity for the quantification of VEGF and ATP with a low detection limit (1 pM and 4 nM, respectively). In addition, this biosensor has been successfully utilized in the analysis of real biological samples.

  1. Effect of a Dual Charge on the DNA-Conjugated Redox Probe on DNA Sensing by Short Hairpin Beacons Tethered to Gold Electrodes.

    Science.gov (United States)

    Kékedy-Nagy, László; Shipovskov, Stepan; Ferapontova, Elena E

    2016-08-16

    Charges of redox species can critically affect both the interfacial state of DNA and electrochemistry of DNA-conjugated redox labels and, as a result, the electroanalytical performance of those systems. Here, we show that the kinetics of electron transfer (ET) between the gold electrode and methylene blue (MB) label conjugated to a double-stranded (ds) DNA tethered to gold strongly depend on the charge of the MB molecule, and that affects the performance of genosensors exploiting MB-labeled hairpin DNA beacons. Positively charged MB binds to dsDNA via electrostatic and intercalative/groove binding, and this binding allows the DNA-mediated electrochemistry of MB intercalated into the duplex and, as a result, a complex mode of the electrochemical signal change upon hairpin hybridization to the target DNA, dominated by the "on-off" signal change mode at nanomolar levels of the analyzed DNA. When MB bears an additional carboxylic group, the negative charge provided by this group prevents intimate interactions between MB and DNA, and then the ET in duplexes is limited by the diffusion of the MB-conjugated dsDNA (the phenomenon first shown in Farjami , E. ; Clima , L. ; Gothelf , K. ; Ferapontova , E. E. Anal. Chem. 2011 , 83 , 1594 ) providing the robust "off-on" nanomolar DNA sensing. Those results can be extended to other intercalating redox probes and are of strategic importance for design and development of electrochemical hybridization sensors exploiting DNA nanoswitchable architectures.

  2. Novel multifunction-integrated molecular beacon for the amplification detection of DNA hybridization based on primer/template-free isothermal polymerization.

    Science.gov (United States)

    Dong, Haiyan; Wu, Zai-Sheng; Xu, Jianguo; Ma, Ji; Zhang, Huijuan; Wang, Jie; Shen, Weiyu; Xie, Jingjing; Jia, Lee

    2015-10-15

    Molecular beacon (MB) is widely explored as a signaling probe in powerful biosensing systems, for example, enzyme-assisted strand displacement amplification (SDA)-based system. The existing polymerization-based amplification system is often composed of recognition element, primer, template and fluorescence reporter. To develop a new MB sensing system and simply the signal amplification design, we herein attempted to propose a multifunctional integrated MB (MI-MB) for the polymerization amplification detection of target DNA via introducing a G-rich fragment into the loop of MB without using any exogenous auxiliary oligonucleotide probe. Utilizing only one MI-MB probe, the p53 target gene could trigger the cycles of hybridization/polymerization/displacement, resulting in amplification of the target hybridization event. Thus, the p53 gene can be detected down to 5 × 10(-10)M with the linear response range from 5 × 10(-10)M to 4 × 10(-7)M. Using the MI-MB, we could readily discriminate the point mutation-contained p53 from the wild-type one. As a proof-of-concept study, owing to its simplicity and multifunction, including recognition, replication, amplification and signaling, the MI-MB exhibits the great potential for the development of different biosensors for various biomedical applications, especially, for early cancer diagnosis.

  3. Molecular beacon-based real-time PCR detection of primary isolates of Salmonella Typhimurium and Salmonella Enteritidis in environmental and clinical samples

    Directory of Open Access Journals (Sweden)

    Emmanuel Maria A

    2009-05-01

    Full Text Available Abstract Background A fast and simple two-step multiplex real-time PCR assay has been developed to replace the traditional, laborious Salmonella serotyping procedure. Molecular beacons were incorporated into the assay as probes for target DNA. Target sequences were regions of the invA, prot6E and fliC genes specific for Salmonella spp. Salmonella Enteritidis and Salmonella Typhimurium, respectively, the two most clinically relevant serotypes. An internal amplification positive control was included in the experiment to ensure the optimal functioning of the PCR and detect possible PCR inhibition. Three sets of primers were used for the amplification of the target sequences. The results were compared to those of the Kauffmann-White antigenic classification scheme. Results The assay was 100% sensitive and specific, correctly identifying all 44 Salmonella strains, all 21 samples of S. Enteritidis and all 17 samples of S. Typhimurium tested in this work. Therefore, the entire experiment had specificity and sensitivity of 100%. The detection limit was down to 10 copies of DNA target per 25 μl reaction. Conclusion The assay can amplify and analyse a large number of samples in approximately 8 hours, compared to the 4 to 5 days conventional identification takes, and is thus considered a very promising method for detecting the two major serotypes of Salmonella quickly and accurately from clinical and environmental samples.

  4. High-power QCW microsecond-pulse solid-state sodium beacon laser with spiking suppression and D2b re-pumping.

    Science.gov (United States)

    Bian, Qi; Bo, Yong; Zuo, Jun-wei; Guo, Chuan; Xu, Chang; Tu, Wei; Shen, Yu; Zong, Nan; Yuan, Lei; Gao, Hong-wei; Peng, Qin-jun; Chen, Hong-bin; Feng, Lu; Jin, Kai; Wei, Kai; Cui, Da-fu; Xue, Sui-jian; Zhang, Yu-dong; Xu, Zu-yan

    2016-04-15

    A 65 W quasi-continuous-wave microsecond-pulse solid-state sodium beacon laser tuned to the sodium D2a line has been developed with a linewidth of 0.3 GHz, beam quality of M2=1.38, and pulse width of 120 μs at a repetition rate of 500 Hz by sum-frequency mixing 1319 and 1064 nm diode-pumped Nd:YAG master-oscillator power-amplifier systems. The laser wavelength stability is less than ±0.15 GHz through feedback controlling. The laser spiking due to relaxation oscillations is suppressed by inserting frequency doublers in both 1319 and 1064 nm oscillators. Sodium D2b re-pumping is accomplished by tuning the frequency of the electro-optic modulator with the right D2a-D2b offset. A bright sodium laser guide star with a photon return of 1820 photons/cm2/s was achieved with the laser system when a 32 W circular polarized beam was projected to the sky during our field test at the Xinglong Observatory.

  5. BlueDetect: An iBeacon-Enabled Scheme for Accurate and Energy-Efficient Indoor-Outdoor Detection and Seamless Location-Based Service

    Directory of Open Access Journals (Sweden)

    Han Zou

    2016-02-01

    Full Text Available The location and contextual status (indoor or outdoor is fundamental and critical information for upper-layer applications, such as activity recognition and location-based services (LBS for individuals. In addition, optimizations of building management systems (BMS, such as the pre-cooling or heating process of the air-conditioning system according to the human traffic entering or exiting a building, can utilize the information, as well. The emerging mobile devices, which are equipped with various sensors, become a feasible and flexible platform to perform indoor-outdoor (IO detection. However, power-hungry sensors, such as GPS and WiFi, should be used with caution due to the constrained battery storage on mobile device. We propose BlueDetect: an accurate, fast response and energy-efficient scheme for IO detection and seamless LBS running on the mobile device based on the emerging low-power iBeacon technology. By leveraging the on-broad Bluetooth module and our proposed algorithms, BlueDetect provides a precise IO detection service that can turn on/off on-board power-hungry sensors smartly and automatically, optimize their performances and reduce the power consumption of mobile devices simultaneously. Moreover, seamless positioning and navigation services can be realized by it, especially in a semi-outdoor environment, which cannot be achieved by GPS or an indoor positioning system (IPS easily. We prototype BlueDetect on Android mobile devices and evaluate its performance comprehensively. The experimental results have validated the superiority of BlueDetect in terms of IO detection accuracy, localization accuracy and energy consumption.

  6. Synthesis and sensing integration: A novel enzymatic reaction modulated Nanoclusters Beacon (NCB) "Illumination" strategy for label-free biosensing and logic gate operation.

    Science.gov (United States)

    Hong, Lu; Zhou, Fu; Wang, Guangfeng; Zhang, Xiaojun

    2016-12-15

    A novel fluorescent label-free "turn-on" NAD(+) and adenosine triphosphate (ATP) biosensing strategy is proposed by fully exploiting ligation triggered Nanocluster Beacon (NCB). In the presence of the target, the split NCB was brought to intact, which brought the C-rich sequence and enhancer sequence in close proximity resulting in the lightening of dark DNA/AgNCs ("On" mode). Further application was presented for logic gate operation and aptasensor construction. The feasibility was investigated by Ultraviolet-visible spectroscopy (UV-vis), Fluorescence, lifetime and High Resolution Transmission Electron Microscopy (HRTEM) etc. The strategy displayed good performance in the detection of NAD(+) and ATP, with the detection limit of 0.002nM and 0.001mM, the linear range of 10-1000nM and 0.003-0.01mM, respectively. Due to the DNA/AgNCs as fluorescence reporter, the completely label-free fluorescent strategy boasts the features of simplicity and low cost, and showing little reliance on the sensing environment. Meanwhile, the regulation by overhang G-rich sequence not relying on Förster energy transfer quenching manifests the high signal-to-background ratios (S/B ratios). This method not only provided a simple, economical and reliable fluorescent NAD(+) assay but also explored a flexible G-rich sequence regulated NCB probe for the fluorescent biosensors. Furthermore, this sensing mode was expanded to the application of a logic gate design, which exhibited a high performance for not only versatile biosensors construction but also for molecular computing application.

  7. An ultrasensitive SiO2-encapsulated alloyed CdZnSeS quantum dot-molecular beacon nanobiosensor for norovirus.

    Science.gov (United States)

    Adegoke, Oluwasesan; Seo, Min-Woong; Kato, Tatsuya; Kawahito, Shoji; Park, Enoch Y

    2016-12-15

    Ultrasensitive, rapid and selective diagnostic probes are urgently needed to overcome the limitations of traditional probes for norovirus (NV). Here, we report the detection of NV genogroup II via nucleic acid hybridization technology using a quantum dot (QD)-conjugated molecular beacon (MB) probe. To boost the sensitivity of the MB assay system, an ultrasensitive QD fluorophore with unique optical properties was synthesized, characterized and exploited as a fluorescence signal generator. Alloyed thioglycolic (TGA)-capped CdZnSeS QDs with a high photoluminescence (PL) quantum yield (QY) value of 92% were synthesized, and a modified silanization method was employed to encapsulate the thiol-capped QDs in a silica layer. The resulting highly luminescent alloyed SiO2-coated CdZnSeS QDs had a remarkable PL QY value of 98%. Transmission electron microscopy and dynamic light scattering confirmed the monodispersity of the alloyed nanocrystals, and zeta potential analysis confirmed their colloidal stability. Powder X-ray diffraction and PL lifetime measurements confirmed the surface modification of the QDs. The alloyed TGA-capped and SiO2-coated CdZnSeS QD-conjugated MB bioprobes detected extremely low concentrations of NV RNA. Ultrasensitive detection of low concentrations of NV RNA with a limit of detection (LOD) of 8.2copies/mL in human serum and a LOD of 9.3 copies/mL in buffer was achieved using the SiO2-coated CdZnSeS QD-MB probes, an increase in sensitivity of 3-fold compared with the detection limit for NV RNA using TGA-capped CdZnSeS QD-MBs. The additional merits of our detection system are rapidity, specificity and improved sensitivity over conventional molecular test probes.

  8. A modified molecular beacons-based multiplex real-time PCR assay for simultaneous detection of eight foodborne pathogens in a single reaction and its application.

    Science.gov (United States)

    Hu, Qinghua; Lyu, Dongyue; Shi, Xiaolu; Jiang, Yixiang; Lin, Yiman; Li, Yinghui; Qiu, Yaqun; He, Lianhua; Zhang, Ran; Li, Qingge

    2014-03-01

    Foodborne disease outbreaks are often caused by one of the major pathogens. Early identification of the causal pathogen is crucial for disease control and prevention. We describe a real-time polymerase chain reaction (rtPCR) assay that can identify, in a single reaction, up to eight common foodborne bacterial pathogens, including Salmonella enterica subsp. enterica, Listeria monocytogenes, Escherichia coli O157, Vibrio parahaemolyticus, V. vulnificus, Campylobacter jejuni, Enterobacter sakazakii, and Shigella spp. This multiplex rtPCR assay takes advantage of modified molecular beacons and the multicolor combinational probe coding strategy to discriminate each pathogen and the homo-tag assisted non-dimer (HAND) system to prevent dimer formation. The detection limits of the assay ranged from 1.3×10(3) colony-forming units (CFU)/g stool (L. monocytogenes) to 1.6×10(4) CFU/g stool (Shigella spp.). The target genes were 100% specific as assessed on 986 reference strains covering 41 species since no cross-reactions were observed. The assay was applied to the detection of foodborne pathogens in 11,167 clinical samples and the results were compared with culture methods for further validation. The sensitivity and specificity of the rtPCR were 100% and 99%, respectively. When performed in a 96-well rtPCR system, more than 90 samples could be analyzed within 3 h. Given the high accuracy, sensitivity, specificity, and short turn-around time, the established assay could be used for the rapid and reliable identification of the causative pathogens responsible for a certain foodborne disease outbreak and rapid screening of these major foodborne pathogens in laboratory-based surveillance of outpatient clinical samples or even food samples.

  9. An AUV Navigation Method Based on Range Measurement Using a Single Beacon%单信标距离测量的AUV导航方法

    Institute of Scientific and Technical Information of China (English)

    张淼; 李闻白; 王冬

    2012-01-01

    针对单信标测距导航方法中的系统可观测性和洋流干扰问题,通过建立自主水下航行器(Autonomous Underwater Vehicle,AUV)的三维运动学模型,利用线性时变系统的局部可观测性理论得到了系统关于AUV运动路径的可观测性条件,并采用扩展Kalman滤波导航算法实现了对AUV的位置和未知洋流的在线估计.仿真结果表明,对于满足系统可观测性的运动路径,该导航方法可有效抑制洋流干扰下系统的定位误差增长,使定位误差保持有界,并对未知洋流做出较为准确的估计.%The research amis at the observability of the navigation system and the disturbance of the ocean currents in the range measurement by using a single beacon. The paper proposes a three dimensional (3D) underwater navigation approach for autonomous underwater vehicle (AUV). By building the kinematic model of AUV and using the local observability theories of a linear varying system,the observability conditions in relation to 3D trajectories of AUV are obtained . And the online estimation of the AUV's position and unknown currents are achieved by means of the extended Kalman filtering navigation algorithm. Simulation results show that the navigation approach can restrain the growth of the localization errors with current disturbances to keep the errors bounded, and achieve accurate estimation of the unknown currents.

  10. Comparative Evaluation of Sloppy Molecular Beacon and Dual-Labeled Probe Melting Temperature Assays to Identify Mutations in Mycobacterium tuberculosis Resulting in Rifampin, Fluoroquinolone and Aminoglycoside Resistance.

    Directory of Open Access Journals (Sweden)

    Sandy S Roh

    Full Text Available Several molecular assays to detect resistance to Rifampin, the Fluoroquinolones, and Aminoglycosides in Mycobacterium tuberculosis (M. tuberculosis have been recently described. A systematic approach for comparing these assays in the laboratory is needed in order to determine the relative advantage of each assay and to decide which ones should be advanced to evaluation. We performed an analytic comparison of a Sloppy Molecular Beacon (SMB melting temperature (Tm assay and a Dual labeled probe (DLP Tm assay. Both assays targeted the M. tuberculosis rpoB, gyrA, rrs genes and the eis promoter region. The sensitivity and specificity to detect mutations, analytic limit of detection (LOD and the detection of heteroresistance were tested using a panel of 56 clinical DNA samples from drug resistant M. tuberculosis strains. Both SMB and DLP assays detected 29/29 (100% samples with rpoB RRDR mutations and 3/3 (100% samples with eis promoter mutations correctly. The SMB assay detected all 17/17 gyrA mutants and 22/22 rrs mutants, while the DLP assay detected 16/17 (94% gyrA mutants and 12/22 (55% rrs mutants. Both assays showed comparable LODs for detecting rpoB and eis mutations; however, the SMB assay LODs were at least two logs better for detecting wild type and mutants in gyrA and rrs targets. The SMB assay was also moderately better at detecting heteroresistance. In summary, both assays appeared to be promising methods to detect drug resistance associated mutations in M. tuberculosis; however, the relative advantage of each assay varied under each test condition.

  11. Beacon-control-based Routing Protocols for Urban VANETs%面向城市环境VANETS的基于beacon控制的路由协议

    Institute of Scientific and Technical Information of China (English)

    黄欣; 余思东; 万荣泽

    2014-01-01

    车载网络(Vehicular ad hoc networks,VANETs)是一种特殊形式的网络,具有节点高速移动、拓扑频繁的变化的特性,这些特性为消息的传播带来挑战,路由机制是实现消息传递的关键因素;地理位置路由被广泛地应用于VANETS,要求节点周期广播beacon消息;然而,节点周期地广播beacon消息,降低了路由性能,特别是在城市区域,由于节点密集,每个节点均广播beacon消息,恶化了路由性能;为此,针对城市环境,提出基于beacon控制的路由协议RPBC (Routing protocol with beacon control);在RPBC中,并非每个节点广播beacon消息,而设置有效的机制选择部分节点广播,从而降低了beacon冗余,同时,采用最短路径算法,减少数据传输跳数;仿真结果表明,提出的RBPC在分组投递率、端到端传输时延以及路由开销方面均有较好的性能.

  12. MiRNA-Related SNPs and Risk of Esophageal Adenocarcinoma and Barrett's Esophagus: Post Genome-Wide Association Analysis in the BEACON Consortium.

    Directory of Open Access Journals (Sweden)

    Matthew F Buas

    Full Text Available Incidence of esophageal adenocarcinoma (EA has increased substantially in recent decades. Multiple risk factors have been identified for EA and its precursor, Barrett's esophagus (BE, such as reflux, European ancestry, male sex, obesity, and tobacco smoking, and several germline genetic variants were recently associated with disease risk. Using data from the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON genome-wide association study (GWAS of 2,515 EA cases, 3,295 BE cases, and 3,207 controls, we examined single nucleotide polymorphisms (SNPs that potentially affect the biogenesis or biological activity of microRNAs (miRNAs, small non-coding RNAs implicated in post-transcriptional gene regulation, and deregulated in many cancers, including EA. Polymorphisms in three classes of genes were examined for association with risk of EA or BE: miRNA biogenesis genes (157 SNPs, 21 genes; miRNA gene loci (234 SNPs, 210 genes; and miRNA-targeted mRNAs (177 SNPs, 158 genes. Nominal associations (P0.50, and we did not find evidence for interactions between variants analyzed and two risk factors for EA/BE (smoking and obesity. This analysis provides the most extensive assessment to date of miRNA-related SNPs in relation to risk of EA and BE. While common genetic variants within components of the miRNA biogenesis core pathway appear unlikely to modulate susceptibility to EA or BE, further studies may be warranted to examine potential associations between unassessed variants in miRNA genes and targets with disease risk.

  13. Beacon-control-based routing protocols for Urban VANETS%城市环境VANETS下的基于beacon控制的路由方案

    Institute of Scientific and Technical Information of China (English)

    黄煜栋; 王万良; 郑厚天

    2014-01-01

    车载网络(Vehicular ad hoc networks, VANETs)是一种特殊形式的网络,具有节点高速移动、拓扑频繁的变化的特性。这些特性为消息的传播带来挑战。路由机制是实现消息传递的关键因素。地理位置路由被广泛地应用于VANETS,要求节点周期广播beacon消息。然而,节点周期地广播beacon消息,降低了路由性能,特别是在城市区域,由于节点密集,每个节点均广播beacon消息,恶化了路由性能。为此,针对城市环境,提出基于beacon控制的路由协议RPBC(Routing protocol with beacon control)。在RPBC中,并非每个节点广播beacon消息,而设置有效的机制选择部分节点广播,从而降低了beacon冗余,同时,采用最短路径算法,减少数据传输跳数。仿真结果表明,提出的RBPC在分组投递率、端到端传输时延以及路由开销方面均有较好的性能。

  14. BlueDetect: An iBeacon-Enabled Scheme for Accurate and Energy-Efficient Indoor-Outdoor Detection and Seamless Location-Based Service.

    Science.gov (United States)

    Zou, Han; Jiang, Hao; Luo, Yiwen; Zhu, Jianjie; Lu, Xiaoxuan; Xie, Lihua

    2016-02-22

    The location and contextual status (indoor or outdoor) is fundamental and critical information for upper-layer applications, such as activity recognition and location-based services (LBS) for individuals. In addition, optimizations of building management systems (BMS), such as the pre-cooling or heating process of the air-conditioning system according to the human traffic entering or exiting a building, can utilize the information, as well. The emerging mobile devices, which are equipped with various sensors, become a feasible and flexible platform to perform indoor-outdoor (IO) detection. However, power-hungry sensors, such as GPS and WiFi, should be used with caution due to the constrained battery storage on mobile device. We propose BlueDetect: an accurate, fast response and energy-efficient scheme for IO detection and seamless LBS running on the mobile device based on the emerging low-power iBeacon technology. By leveraging the on-broad Bluetooth module and our proposed algorithms, BlueDetect provides a precise IO detection service that can turn on/off on-board power-hungry sensors smartly and automatically, optimize their performances and reduce the power consumption of mobile devices simultaneously. Moreover, seamless positioning and navigation services can be realized by it, especially in a semi-outdoor environment, which cannot be achieved by GPS or an indoor positioning system (IPS) easily. We prototype BlueDetect on Android mobile devices and evaluate its performance comprehensively. The experimental results have validated the superiority of BlueDetect in terms of IO detection accuracy, localization accuracy and energy consumption.

  15. Racial Differences in Processes of Care at End of Life in VA Medical Centers: Planned Secondary Analysis of Data from the BEACON Trial

    Science.gov (United States)

    Williams, Beverly R.; Dionne-Odom, J. Nicholas; Redden, David T.; Noh, Hyunjin; Goode, Patricia S.; Kvale, Elizabeth; Bakitas, Marie; Bailey, F. Amos

    2016-01-01

    Abstract Background: Racial differences exist for a number of health conditions, services, and outcomes, including end-of-life (EOL) care. Objective: The aim of the study was to examine differences in processes of care in the last 7 days of life between African American and white inpatients. Methods: Secondary analysis was conducted of data collected in the Best Practices for End-of-Life Care for Our Nation's Veterans (BEACON) trial (conducted 2005–2011). Subjects were 4891 inpatient decedents in six Veterans Administration Medical Centers. Data were abstracted from decedents' medical records. Multi-variable analyses were conducted to examine the relationship between race and each of 18 EOL processes of care controlling for patient characteristics, study site, year of death, and whether the observation was pre- or post-intervention. Results: The sample consisted of 1690 African American patients (34.6%) and 3201 white patients (65.4%). African Americans were less likely to have: do not resuscitate (DNR) orders (odds ratio [OR]: 0.67; p = 0.004), advance directives (OR: 0.71; p = 0.023), active opioid orders (OR: 0.64, p = 0.0008), opioid medications administered (OR: 0.61, p = 0.004), benzodiazepine orders (OR: 0.68, p < 0.0001), benzodiazepines administered (OR: 0.61, p < 0.0001), antipsychotics administered (OR: 0.73, p = 0.004), and steroids administered (OR: 0.76, p = 0.020). Racial differences were not found for other processes of care, including palliative care consultation, pastoral care, antipsychotic and steroid orders, and location of death. Conclusions: Racial differences exist in some but not all aspects of EOL care. Further study is needed to understand the extent to which racial differences reflect different patient needs and preferences and whether interventions are needed to reduce disparities in patient/family education or access to quality EOL care. PMID:26840851

  16. Species detection using HyBeacon(®) probe technology: Working towards rapid onsite testing in non-human forensic and food authentication applications.

    Science.gov (United States)

    Dawnay, Nick; Hughes, Rebecca; Court, Denise Syndercombe; Duxbury, Nicola

    2016-01-01

    Identifying individual species or determining species' composition in an unknown sample is important for a variety of forensic applications. Food authentication, monitoring illegal trade in endangered species, forensic entomology, sexual assault case work and counter terrorism are just some of the fields that can require the detection of the biological species present. Traditional laboratory based approaches employ a wide variety of tools and technologies and exploit a number of different species specific traits including morphology, molecular differences and immuno-chemical analyses. A large number of these approaches require laboratory based apparatus and results can take a number of days to be returned to investigating authorities. Having a presumptive test for rapid identification could lead to savings in terms of cost and time and allow sample prioritisation if confirmatory testing in a laboratory is required later. This model study describes the development of an assay using a single HyBeacon(®) probe and melt curve analyses allowing rapid screening and authentication of food products labelled as Atlantic cod (Gadus morhua). Exploiting melt curve detection of species specific SNP sites on the COI gene the test allows detection of a target species (Atlantic cod) and closely related species which may be used as substitutes. The assay has been designed for use with the Field Portable ParaDNA system, a molecular detection platform for non-expert users. The entire process from sampling to result takes approximately 75min. Validation studies were performed on both single source genomic DNA, mixed genomic DNA and commercial samples. Data suggests the assay has a lower limit of detection of 31 pg DNA. The specificity of the assay to Atlantic cod was measured by testing highly processed food samples including frozen, defrosted and cooked fish fillets as well as fish fingers, battered fish fillet and fish pie. Ninety-six (92.7%) of all Atlantic cod food products

  17. The quick detection of mutation site of eodon 463 in katG gene of INH resistant MTB by molecular beacon%耐异烟肼结核杆菌Kat G463condon点突变的分子信标快速检测

    Institute of Scientific and Technical Information of China (English)

    陈庆海; 府伟灵; 张雪; 王易伟; 边志衡; 匡红

    2009-01-01

    目的 应用分子信标探针检测结核杆菌耐异烟肼kat G463condon点突变,并与测序结果比较以验证该检测方法.方法 运用软件对Beacon designer设计,katG基因包含463condon的分子信标,建立其扩增体系及分子信标芯片检测方法,对扩增产物测序并作比较.结果 通过CDC相机观测到结核标准株及耐异烟肼PCR产物与分子信标杂交后荧光信号区别明显;16株耐异烟肼组与10株H37RV标准株对照组荧光信号强度比较,耐异烟肼组463condon突变检出率为37%,分子信标检测方法与测序法符合率达93%.结论 分子信标技术是一种具有高灵敏核酸点突变检测技术;分子信标芯片检测方法与测序法符合率较好.%Objective To detect the mutation site of codon 463 in katG gene of INH resistant MTB by molecular beacon probe, and verify the detecting method by comparing with gene sequencing. Methods The software Beacon designer,was used to design codon 463 molecular beacon probe and the amplification system,and then the method was compared with gene sequencing. Results The difference between PCR products from standard strain and INH resistant one is obvious in detecting the fluores-cent light by use of CDC camera. We detected and compare the fluorescent light signal of INH resistant strains group (n= 16) and H37RV standard strains group (n= 10). The detection rate of codon 463 mutation accounted for 37% by comparing the above two groups. The coincidence rate of molecular beacon detection method and sequencing assay was 93 %. Conclusion The molecular beacon method is a technology with characteristics of high sensitiveness and specificity in detecting nucleic acid. The co-incidence rate is good between molecular beacon chip way and sequencing.

  18. Recognition of the Frontier Defensive Organization in Early China---Centered by the jiaqu houguan’ s Beacon Tower with a Definite Name or with an Ordinal Number Name%早期中国边塞防御组织再认识--以甲渠候官的实名燧、序数燧为中心

    Institute of Scientific and Technical Information of China (English)

    蒋丹丹; 孙兆华

    2015-01-01

    There are rich materials about jiaqu houguan’ s beacon tower names in Han bamboo slips.Study centered by the beacon tower with a definite name or an ordinal number name will get a new understanding about the frontier defensive organization in early China.The function of jiaqu houguan’ s beacon tower name with a definite name or an ordinal number name is to defense or detect.Respectively speaking, some of the beacon towers with definite names in jiaqu’ s Henan frontier are accessible by postal communication, while the beacon towers with ordinal number names or some with definite names in jiaqu’ s Hebei frontier are hard to be got the difference from the former ones.There are similarities between jiaqu houguan ’ s beacon towers with definite names or ordinal number names and people’ s names or streets’ names in Qin and Han dynasties, for instance, to show the opposed relationships between Han and Xionglu, the pursuit to Kongfu, the pursuit to long life and propitiousness and so on.The nomination of the beacon tower’ s name and the street’ s name may also have a contact with the relative location.%汉简中关于甲渠候官烽燧名称的材料极为丰富,以实名隧与序数燧为中心进行研究,可以对早期中国边塞防御组织有新的认识。甲渠候官的实名燧、序数燧的职能,主要是防御和候望。分而言之,甲渠河南道上塞的部分实名燧承担着通邮的职能,而甲渠河北塞的序数燧和部分实名燧目前难以探求到其区别于前者的独特职能。甲渠候官的实名燧、序数燧的命名特点与秦汉时代的人名、里名有相似之处,如体现汉匈关系对立、追求武功、追求长寿和吉祥等。燧名和里名的命名或许还有地理位置上的联系。

  19. 低占空比无线传感器网络同步 MAC 协议最优信标间隔分析%The Optimal Beacon Interval for Synchronous MAC in Low Duty-Cycle Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    邢宇龙; 陈永锐; 易卫东; 段成华

    2016-01-01

    Energy efficiency is a fundamental theme in the design of wireless sensor networks protocols ,especially for medium access control (MAC) protocols .An energy‐efficient MAC protocol can significantly elongate the lifetime of wireless sensor networks by reducing the duty‐cycle of sensor nodes to an ultra‐low level .Synchronous MAC can be even more efficient in data transfer at the cost of requiring tight time synchronization through periodical beacon dissemination . The length of the beacon interval may greatly affect the energy efficiency of a synchronous MAC .A shorter beacon interval leads to higher synchronization cost due to frequent beacon sending and receiving ,while a longer beacon interval will lead to a larger guard time and longer idle listening due to clock drift . Therefore ,there is a tradeoff between these two parts of energy consumption .In this paper ,we investigate the optimal beacon interval for synchronous MAC in low duty‐cycle sensor networks ,and then present a strategy that adaptively utilizes the optimal beacon interval in a TDMA‐based MAC protocol (called Opt‐TDMA) .By configuring the beacon interval to its optimal value according to the data packets rate and network size ,Opt‐TDMA can reduce the overall power consumption of both sending/receiving beacons and data packets . Experimental results demonstrate that Opt‐TDMA is more energy‐efficient than pure TDMA protocol and SCP‐MAC by using optimal beacon interval and contention‐free transmission .%能量效率是无线传感器网络协议设计的首要考虑因素。无线传感器网络中,介质访问控制层(medium access control ,MAC)协议通过降低节点的占空比来降低网络能耗,延长网络的生命周期。相比其他 MAC 协议,尽管同步 MAC 需要周期性分发信标来保持严格的时间同步,但却在数据传输方面具有更高的能量效率。信标间隔的长短直接影响同步 M AC 能量效率的高低。一方面

  20. UHV交流输电线路有源干扰下无方向信标台功率限值的分析%Analysis of Non-directional Radio Beacon Power Limit Under the Condition of Active Interference Caused by UHV AC Transmission Line

    Institute of Scientific and Technical Information of China (English)

    周铖路; 翁木云; 陈凤

    2015-01-01

    有关UHV交流输电线路与无方向信标台电磁兼容方面的研究主要集中在防护距离的分析,对间距无法满足要求时的兼容问题研究较少。为此,从台站频谱参数入手,分析特高压交流输电线路有源干扰下无方向信标台的发射功率限值。首先介绍无方向信标台的工作原理及配置区域,然后分析UHV交流输电线路对台站的干扰机理,最后根据飞行航迹,以防护率为干扰判别依据,结合防护距离的研究,分别针对航路无方向信标台、近距无方向信标台和远距无方向信标台进行有效辐射功率的分析。结果表明,在给定条件下,对于航路和远距无方向信标台,有效辐射功率分别大于5.298 W、5.273 W时,机载无线电罗盘不受干扰;对于近距无方向信标台,与输电线路始终满足兼容的要求,无需分析限值。%The EMC research between UHV AC transmission line and non-directional radio beacon mainly focused on the protection distance while the study of EMC is little when the protection distance cannot meet the requirements. Therefore, the non-directional radio beacon power limit under the condition of active interference caused by UHV AC transmission line is analyzed from the aspect of spectrum parameters. Firstly, the working principle and configuration area of non-directional radio beacon are introduced. Then the interference mechanism of non-directional radio beacon from UHV AC transmission line is analyzed. Finally, the effective radiated power (ERP) of route non-directional radio beacon, close non-directional radio beacon and distance non-directional radio beacon are analyzed according to the flight path and protection ratio in combination with protection distance research. The results show that under the given conditions, route non-directional radio beacon and distance non-directional radio beacon’s ERP should be greater than 5.298 W and 5.273 W respectively to keep

  1. Beacons of the Experience Economy

    DEFF Research Database (Denmark)

    Delica, Kristian Nagel

    2014-01-01

    This essay outlines the boundaries among various interests in the library sector; among positions that prioritize libraries as aesthetically appealing junctions of the experience economy versus positions that prioritize the library as a community forum. The main emphasis is placed on developments...

  2. A Beam Tracking Algorithm Based on Satellite Beacon Signals for Phased Array in Mobile Satellite Communications%一种基于信标的移动卫通相控阵波束跟踪算法

    Institute of Scientific and Technical Information of China (English)

    陈鹏; 张慧

    2012-01-01

    In this paper a beam tracking algorithm based on satellite beacon signals is proposed and realized. The method is suitable for all kinds of phased array type mobile satellite communication antennas. It overcomes the difficulty of detecting the extremely weak satellite beacon signals and then the tracking performance is greatly improved. The highlight of the algorithm is the beam tracking process can be run without the help of gyroscopes and thus improves the survivability in the extreme environments. The algorithm was implemented and verified in a Ku band phased array mobile satellite antenna.%提出并实现了一种利用卫星信标信号来实施基于相控阵天线的波束跟踪算法。该方法适用于采用相控阵天线技术的各种卫星“动中通”天线,克服了卫星信标信号强度弱,检测困难的弱点,提高了跟踪信噪比,同时采用了软件无线电方式解调可以提供最大的灵活性。跟踪算法的最大优点是没有任何陀螺仪的辅助,极大地提高了天线在各种极端运动环境下的适应能力。算法最终在自行研制的Ku波段相控阵移动卫星天线系统上获得验证。

  3. Rapid detection of fluoroquinolone-resistant and heteroresistant Mycobacterium tuberculosis by use of sloppy molecular beacons and dual melting-temperature codes in a real-time PCR assay.

    Science.gov (United States)

    Chakravorty, Soumitesh; Aladegbami, Bola; Thoms, Kimberley; Lee, Jong Seok; Lee, Eun Gae; Rajan, Vignesh; Cho, Eun-Jin; Kim, Hyunchul; Kwak, Hyunkyung; Kurepina, Natalia; Cho, Sang-Nae; Kreiswirth, Barry; Via, Laura E; Barry, Clifton E; Alland, David

    2011-03-01

    Fluoroquinolones (FQ) are important second-line drugs to treat tuberculosis; however, FQ resistance is an emerging problem. Resistance has been mainly attributed to mutations in a 21-bp region of the Mycobacterium tuberculosis gyrA gene, often called the quinolone resistance-determining region (QRDR). We have developed a simple, rapid, and specific assay to detect FQ resistance-determining QRDR mutations. The assay amplifies the M. tuberculosis gyrA QRDR in an asymmetrical PCR followed by probing with two sloppy molecular beacons (SMBs) spanning the entire QRDR. Mutations are detected by melting temperature (T(m)) shifts that occur when the SMBs bind to mismatched sequences. By testing DNA targets corresponding to all known QRDR mutations, we found that one or both of the SMBs produced a T(m) shift of at least 3.6°C for each mutation, making mutation detection very robust. The assay was also able to identify mixtures of wild-type and mutant DNA, with QRDR mutants identified in samples containing as little as 5 to 10% mutant DNA. The assay was blindly validated for its ability to identify the QRDR mutations on DNA extracted from clinical M. tuberculosis strains. Fifty QRDR wild-type samples, 34 QRDR mutant samples, and 8 heteroresistant samples containing mixtures of wild-type and mutant DNA were analyzed. The results showed 100% concordance to conventional DNA sequencing, including a complete identification of all of the mixtures. This SMB T(m) shift assay will be a valuable molecular tool to rapidly detect FQ resistance and to detect the emergence of FQ heteroresistance in clinical samples from tuberculosis patients.

  4. System Design of Real-Time Localization Radio Beacon in Dynamic Environment%动态环境可实时定位无线信标机系统设计

    Institute of Scientific and Technical Information of China (English)

    曹翱翔; 张会新; 刘文怡

    2015-01-01

    提出一种动态环境下能实时定位箭载记录器的回收系统方案。由随记录器一起下落的信标发射机、天上无人机及地面接收设备组成的搜索网络,实时获取记录器的位置信息。经实验得出,记录器在空中某一时刻的位置信息:纬度39°04.18264,经度111°44.72132,海拔高度1411.1 m;落地后位置信息:纬度39°04.16500,经度111°44.73090,海拔高度1333.0 m。结果表明,根据实时得到的位置点绘制出了下落轨迹,实现了对记录器的快速找寻。%Proposed a real-time locating system solution about recycling the recorder carried on rocket under dynamic environment. The search network is consisted by the beacon transmitter along with the falling recorder,the unmanned aerial vehicle in the sky and ground receiving equipment,which can achieve real-time location informa-tion of the recorder. Through the experiment,the positioning information of the recorder at a time in the air are lati-tude 39° 04. 182 64, longitude 111° 44. 721 32, altitude 1411. 1 m;After landing position information:latitude 39°04.165 00,longitude 111°44.730 90,altitude 1 333.0 m. The result show the whereabouts trace of the recorder is drew according to the real-time position information,seeking to quick back.

  5. 基于锚同心圆的改进加权质心WSN定位算法%An Improved Weighted Centroid Localization Algorithm Based on Concentric Anchor- Beacons for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    李尧尧; 廖红云; 曾孝平; 吴小林

    2011-01-01

    Concentric anchor beacons (CAB) localization algorithm is a range -free wireless sensor networks localization algorithm. Comparing with the traditional range localization algorithm, although it can reduce the nodes energy consumption, the localization accuracy is no better than traditional range localization approaches. In order to further improve the accuracy of localizing nodes, an improved weighted centroid algorithm based on CAB is proposed after analyzing the radio propagation path loss. First, the process of this improved algorithm is introduced. Then, the influence of communication radius on the accuracy of this new localization algorithm was simulated. After that, the accuracy of this localization algorithm were compared with the existing several kinds of range - free localization methods. Simulation results show that this new algorithm has a higher positioning accuracy and not sensitive to communication radius, and it has some value in productive practice.%研究无线传感器定位准确性问题,针对测量位置节点信息,为了提高无线传感器网络的定位精度,采用同心圆定位算法(CAB)是一种免测距的无线传感器定位算法,相比于传统的测距方法能降低节点的能量消耗,但是定位精度却不及传统的测距定位方法.提出在同心圆定位算法(CAB)的基础上,通过分析无线电传播路径损耗采用了一种加权同心圆定位算法.给出了算法的流程,仿真分析了通信半径对新算法定位精度的影响,比较了算法定位精度与现有的几种免测距定位方法的定位精度.仿真结果表明,改进算法有较高的定位精度而且对距离不敏感,对实际工程提供应用价值.

  6. Passive Localization of Underwater Acoustic Beacons

    Science.gov (United States)

    1993-09-01

    maxtime) TickCounto; aborto ; FSRead(gASerRefln,&numCharln,&addressBuf); TalkSail(’O); iistart the PTR’s data collecticn DrawString(w\\p: H) I display a...34); aborto ; EventLoopO; II main execution loop RAMSDClose(sPortA); HI must close the RAM Drivers before shutdown 193 free(gw); //must release the...kNumExp+l),sizeof(double)); if(wtrue ==NULL) DrawString("\\pCan’t allocate memory for data collection!!! ); aborto ; Nvmeas = calloc(3L*(kStep~kNumExp+l

  7. Scalable beaconing for cooperative adaptive cruise control

    NARCIS (Netherlands)

    Eenennaam, van Emiel Martijn

    2013-01-01

    Over the past two hundred years, automotive technology has evolved from mechanised horse carriage to high-tech systems which pack more computing power than the entire space program that put Neil Armstrong on the moon. Hand-in-hand with this evolution came a proliferation of ownership and use of cars

  8. Beacons for supporting lunar landing navigation

    Science.gov (United States)

    Theil, Stephan; Bora, Leonardo

    2017-03-01

    Current and future planetary exploration missions involve a landing on the target celestial body. Almost all of these landing missions are currently relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. As soon as an infrastructure at the landing site exists, the requirements as well as conditions change for vehicles landing close to this existing infrastructure. This paper investigates the options for ground-based infrastructure supporting the onboard navigation system and analyzes the impact on the achievable navigation accuracy. For that purpose, the paper starts with an existing navigation architecture based on optical navigation and extends it with measurements to support navigation with ground infrastructure. A scenario of lunar landing is simulated and the provided functions of the ground infrastructure as well as the location with respect to the landing site are evaluated. The results are analyzed and discussed.

  9. Dynamic Bluetooth beacons for people with disabilities

    DEFF Research Database (Denmark)

    Alapetite, Alexandre; Hansen, John Paulin

    This paper focuses on digital aids for sight impairment and motor disabilities. We propose an Internet of Things (IoT) platform for discovering nearby items, getting their status, and interacting with them by e.g. voice commands or gaze gestures. The technology is based on Bluetooth Low Energy, w...

  10. Dynamic Bluetooth beacons for people with disabilities

    DEFF Research Database (Denmark)

    Alapetite, Alexandre; Hansen, John Paulin

    2017-01-01

    This paper focuses on digital aids for sight impairment and motor disabilities. We propose an Internet of Things (IoT) platform for discovering nearby items, getting their status, and interacting with them by e.g. voice commands or gaze gestures. The technology is based on Bluetooth Low Energy, w...

  11. Faster than the Brighter-Light Beacon

    Science.gov (United States)

    Baune, S.

    2009-01-01

    We analyse the motion of a spot of light projected onto a flat screen by a rotating source. We find that the motion of the spot has many interesting features such as spot splitting and superluminal effects. Our discussion is well suited for undergraduates and can be an interesting add-on in their curriculum, giving them new insights into the…

  12. Faraday polarization fluctuations of satellite beacon signals

    Science.gov (United States)

    Lee, M. C.; Klobuchar, J. A.

    1988-01-01

    The anisotropic effects of random density irregularities in causing Faraday polarization fluctuations of VHF radio signals are examined, taking both rod-like and sheet-like irregularities into consideration. It is found that the variance of Faraday polarization fluctuations depends on the ratio of perpendicular to parallel correlation lengths. The anisotropic effect of rod-like ionospheric irregularities are shown to be most appreciable for longitudinal propagation. The anisotropic effect of sheet-like ionospheric irregularities, however, is not strongly dependent on the radio propagation angle. During transionospheric propagation at large angles with respect to the geomagnetic field, sheet-like irregularities may cause greater Faraday polarization fluctuations than rod-like irregularities.

  13. GAMMA-RAY BURSTS, NEW COSMOLOGICAL BEACONS

    Directory of Open Access Journals (Sweden)

    V. Avila-Reese

    2009-01-01

    Full Text Available Long Gamma-Ray Bursts (GRBs are the brightest electromagnetic explosions in the Universe, associated to the death of massive stars. As such, GRBs are potential tracers of the evolution of the cosmic massive star formation, metallicity, and Initial Mass Function. GRBs also proved to be appealing cosmological distance indicators. This opens a unique opportunity to constrain the cosmic expansion history up to redshifts 5-6. A brief review on both subjects is presented here.

  14. Clinical study on diagnostic utility of Survivin-molecular beacons in bladder cancer%Survivin分子信标诊断膀胱肿瘤的临床应用研究

    Institute of Scientific and Technical Information of China (English)

    王新阳; 贺大林; 杨小杰; 赵军

    2013-01-01

    Objective:To develop a sensitive method for detection of bladder cancer cells the cast-off cells of bladder cancer patients,we examine the feasibility by using molecular beacon (MB) probes specific for a tumor specific Survivin mRNA.Methods:MB analyzed the survivn mRNA in bladder cancer cell 5637,J82 and identified by Western blot.Urine cytology,MB test,and Western blot were carried to test,cancer tissue of 35 bladder cancer patients and 35 health adults.Results:Survivin MB could detect the expression of Survivin gene and generated fluorescent signals in the cancer cells,and not detect in normal prostate fibroblast cells.MB detected cancerous cells in 80% of confirmed bladder cancer patients (28/35).The specificity was 77.1% (27/35).Survivin protein was detected by western blot in 71.4% (25/35) of these patients.The two methods had high consistency.The sensitivity and specificity of urine cytology was 28.6% (10/35),100% (35/35).Conclusion:Survivin MB is specific and sensitive molecular probe for detecting bladder cancer cells and urine cast-off cells of bladder cancer patients.It has great potential for the development of a clinical diagnostic procedure for early detection of bladder cancer and follow-up after operation.%目的:探讨分子信标检测尿脱落细胞Survivn mRNA的可行性,寻找一种能够早期诊断膀胱肿瘤的方法.方法:分子信标检测膀胱肿瘤5637、J82细胞Survivin mRNA的表达,并通过Western bolt方法验证,并对35例膀胱移行细胞癌患者和35名正常健康成人行分子信标检测尿脱落细胞,Western bolt检测组织中的Survivin含量,同时行尿脱落细胞学检查.结果:Survivin分子信标检测肿瘤细胞内的Survivin表达且具有高特异性.以随机100个细胞中60个以上的细胞为阳性做为阳性标准,确定MB-cy3的阳性率为80% (28/35),特异性为77.1%(27/35);Western bolt检测的阳性率为71.4%(25/35).两种实验方法对细胞和蛋白质中Survivin的检

  15. Real-time fluorescence PCR-molecular beacon assay for detecting mutations in rpoB genes of rifampin-resistant Mycobacterium tuberculosis%实时荧光PCR分子信标检测耐利福平结核分枝杆菌印rpoB基因

    Institute of Scientific and Technical Information of China (English)

    孙桂芝; 高铁杰; 钟镐镐; 康丽军; 张治国; 衡万杰; 吴秉铨; 刘威

    2008-01-01

    Objective To establish a rapid method to detect mutations in rpoB genes of rifampin-resistant Mycobacterium tubereulosis in dinical specimens using Real-time fluorescence PCR molecular beacon assay.Methods 174 strains of Mvcobacterium tuberculosis clinical isolates were analyzed using real-time fluorescence PCR molecular beacon assay foilowed with DNA sequencing while 12 strains of NTM and 4 strains of bacteria other than Mycobacterium tuberculosis were used as the contrast.Results Eighty-two 89.1 of 92 rifampin (RIF)-resistant strains and 3 of 82 RIF-sensitive strains were found to harbor mutation in the rpoB gene using real-time fluorescence PCR-molecular beacon assay.The specificity, sensitivity,and accuracy of this assay were 96.3%,89.1%,and 92.5%,respectively-Eithty-three of 92 RIF-resistant strains and 1 of 82 RIF-sensitive strains were found to harbor mutation in the rpoB gene using the direct DNA sequencing.The specificity,sensitivity,and accuracy of the direct DNA sequencing were 98.8,90.2%,and 94.2%,respectively.As compared with real-time PCR molecular beacon assay,171 of 174(98.3%)strains of myeobactefium tuberculosis clinical isolates had the salne results.Conclusion Real-time fluorescence PCR-molecular beacon assay can be used as a rapid screen method to detect RIF-resistant isolates.%目的 应用实时荧光PCR分子信标技术,建立快速检测临床标本中结核分枝杆菌利福平rpoB相关耐药突变点方法,探讨其缩短耐药实验报告时间的临床应用价值.方法 以分枝杆菌药物敏感性实验绝对浓度法为标准,12株非结核分枝杆菌、4株非分枝杆菌作对照,对174例结核患者临床分离株应用实时荧光PCR分子信标方法,检测利福平rpoB核心区域的耐药突变点并将结果与直接测序进行比较.结果 (1)实时荧光PCR分子信标方法:82例结核分枝杆菌利福平敏感菌株中,3例发生rpoB基因突变,特异度为96.3%;92例结核分枝杆菌利福平耐药菌株中,82

  16. Quantitative detection of the expression of six miRNAs in patients with ischemic cardiovascular diseaseby using fluorescence real-time PCR utilizing molecular beacon and gold nanoparticles%用金纳米-分子信标的荧光定量PCR新技术研究6个miRNAs在心肌缺血患者中的表达

    Institute of Scientific and Technical Information of China (English)

    何凤屏; 徐新; 马绍椿; 唐良秋; 刘凤莲; 马占忠; 刘彦明

    2013-01-01

    Objective To investigate the usage of a novel fluorescence real-time polymerase chain ration(RT-PCR) technology u-tilizing gold nanoparticle(AuNP) and molecular beacon(MB) probe for the quantitative detection of 6 microRNAs(miRNAs) in patients at different stage of ischemic cardiovascular disease.Methods The expression of the 6 miRNAs in 200 patients with ischemic cardiovascular disease were detected by using the sensitive detection method constructed in this study, and the results were validated by flexible multi-analyte profiling(xMAP).Results In patients group with acute myocardial ischemia,the serum levels of miRNA-21,miRNA-133,miRNA-199,miRNA-208 and miRNA-499 were significantly up-regulated in 1 - 3 hours after the onset of acute myocardial infarction.In patients group with chronic myocardial ischemia, the expression of miRNA-21, miRNA-133, miRNA-199 and miRNA-1 were significantly up-regulated in patients combined with primary hypertension and myocardial ischemia.And the expression levels of the miRNAs mentioned above were significantly higher in the two patients groups than those in control group(P 0.05).结论 新建立的金纳米-分子信标探针的实时荧光定量PCR技术可作为早期检测miRNAs新的实验方法,为心肌梗死患者的早期诊断提供新的检测手段.

  17. Beacons along the road (Historians and their teachers)

    NARCIS (Netherlands)

    Ankersmit, Frank

    2006-01-01

    One may be born as a great musicist (Mozart or Mendelssohn), one may be born as a great scientist or mathematician (such as Newton or Gauss) - and the same is true, again, of poets (such as Rimbaud), as was recognized already in Antiquity. Think of the old dictum 'poeta nascitur, not fit'. But this

  18. Detection of Periodic Beacon Loads in Electrical Distribution Substation Data

    Energy Technology Data Exchange (ETDEWEB)

    Hammerstrom, Donald J.; Guttromson, Ross T.; Lu, Ning; Boyd, Paul A.; Trudnowski, Daniel; Chassin, David P.; Bonebrake, Christopher A.; Shaw, James M.

    2006-05-31

    This research explores methods for identifying a whether a load is sending a signal to the utility SCADA system. Such a system can identify whether various loads are signialing using existing SCADA infrastructure, that is, without added, high cost communications infrastructure.

  19. BEACON: A Summary Framework to Overcome Potential Reimbursement Hurdles

    NARCIS (Netherlands)

    Dunlop, William C. N.; Mullins, C. Daniel; Pirk, Olaf; Goeree, Ron; Postma, Maarten J.; Enstone, Ashley; Heron, Louise

    2016-01-01

    Objective: To provide a framework for addressing payers’ criteria during the development of pharmaceuticals. Methods: A conceptual framework was presented to an international health economic expert panel for discussion. A structured literature search (from 2010 to May 2015), using the following data

  20. BEACON : A Summary Framework to Overcome Potential Reimbursement Hurdles

    NARCIS (Netherlands)

    Dunlop, William C. N.; Mullins, C. Daniel; Pirk, Olaf; Goeree, Ron; Postma, Maarten J.; Enstone, Ashley; Heron, Louise

    2016-01-01

    Objective To provide a framework for addressing payers' criteria during the development of pharmaceuticals. Methods A conceptual framework was presented to an international health economic expert panel for discussion. A structured literature search (from 2010 to May 2015), using the following databa

  1. Modeling Formation of Globular Clusters: Beacons of Galactic Star Formation

    CERN Document Server

    Gnedin, Oleg Y

    2010-01-01

    Modern hydrodynamic simulations of galaxy formation are able to predict accurately the rates and locations of the assembly of giant molecular clouds in early galaxies. These clouds could host star clusters with the masses and sizes of real globular clusters. I describe current state-of-the-art simulations aimed at understanding the origin of the cluster mass function and metallicity distribution. Metallicity bimodality of globular cluster systems appears to be a natural outcome of hierarchical formation and gradually declining fraction of cold gas in galaxies. Globular cluster formation was most prominent at redshifts z>3, when massive star clusters may have contributed as much as 20% of all galactic star formation.

  2. Old Flames and New Beacons: The Luminosity of Online Learning

    Science.gov (United States)

    McNulty, Ray

    2013-01-01

    A few years ago, the author saw a video of a pop concert. It looked just like concerts of his youth: a well-lit stage amid a darkened crowd flecked with small wavering lights. He laughed when he realized, however, that the swaying glow was coming not from cigarette lighters but from LCD screens. This juxtaposition of old flames and new beacons…

  3. RR Lyrae the Stellar Beacons of the Galactic Structure

    CERN Document Server

    Bono, Giuseppe; Caputo, Filippina; Coppola, Giuseppina; Giovenali, Katia; Marconi, Marcella; Piersimoni, Anna Marina; Stellingwerf, Robert F

    2011-01-01

    We present some recent findings concerning the use of RR Lyrae as distance indicators and stellar tracers. We outline pros and cons of field and cluster RR Lyrae stars and discuss recent theoretical findings concerning the use of the Bailey (amplitude vs pulsation period) diagram to constrain the possible occurrence of Helium enhanced RR Lyrae stars. Nonlinear, convective RR Lyrae models indicate that the pulsation properties of RR Lyrae stars are minimally affected by the helium content. The main difference between canonical and He enhanced models is due to the increase in luminosity predicted by evolutionary models. Moreover, we focus our attention on the near-infrared Period-Luminosity (PL) relation of RR Lyrae and summarize observational evidence concerning the slope of the K-band PL relation in a few globulars (M92, Reticulum, M5, Omega Cen) covering a range in metallicity of ~1 dex. Current findings suggest that the slope has a mild dependence on the metal content when moving from the metal-poor to the ...

  4. Improving Indoor Localization Using Bluetooth Low Energy Beacons

    Directory of Open Access Journals (Sweden)

    Pavel Kriz

    2016-01-01

    Full Text Available The paper describes basic principles of a radio-based indoor localization and focuses on the improvement of its results with the aid of a new Bluetooth Low Energy technology. The advantage of this technology lies in its support by contemporary mobile devices, especially by smartphones and tablets. We have implemented a distributed system for collecting radio fingerprints by mobile devices with the Android operating system. This system enables volunteers to create radio-maps and update them continuously. New Bluetooth Low Energy transmitters (Apple uses its “iBeacon” brand name for these devices have been installed on the floor of the building in addition to existing WiFi access points. The localization of stationary objects based on WiFi, Bluetooth Low Energy, and their combination has been evaluated using the data measured during the experiment in the building. Several configurations of the transmitters’ arrangement, several ways of combination of the data from both technologies, and other parameters influencing the accuracy of the stationary localization have been tested.

  5. A Spinach molecular beacon triggered by strand displacement.

    Science.gov (United States)

    Bhadra, Sanchita; Ellington, Andrew D

    2014-08-01

    We have re-engineered the fluorescent RNA aptamer Spinach to be activated in a sequence-dependent manner. The original Spinach aptamer was extended at its 5'- and 3'-ends to create Spinach.ST, which is predicted to fold into an inactive conformation and thus prevent association with the small molecule fluorophore DFHBI. Hybridization of a specific trigger oligonucleotide to a designed toehold leads to toehold-initiated strand displacement and refolds Spinach into the active, fluorophore-binding conformation. Spinach.ST not only specifically detects its target oligonucleotide but can discriminate readily against single-nucleotide mismatches. RNA amplicons produced during nucleic acid sequence-based amplification (NASBA) of DNA or RNA targets could be specifically detected and reported in real-time by conformational activation of Spinach.ST generated by in vitro transcription. In order to adapt any target sequence to detection by a Spinach reporter we used a primer design technique that brings together otherwise distal toehold sequences via hairpin formation. The same techniques could potentially be used to adapt common Spinach reporters to non-nucleic acid analytes, rather than by making fusions between aptamers and Spinach.

  6. The Fifth Guiding Principle: Beacon, Banality, or Pandora's Box?

    Science.gov (United States)

    Morris, Michael

    2009-01-01

    Successfully providing guidance to others is no easy task. Such is the challenge faced by committees charged with developing guidelines for ethical professional practice. The process of establishing and revising the Program Evaluation Standards (Joint Committee, 1994), for example, is a multiyear task that must seems endless to participants: a…

  7. Location based content delivery solution using iBeacon

    OpenAIRE

    2015-01-01

    There is a growing trend of using mobile devices in retail stores. Access to instant product related information is desirable by consumers in making a purchase decision. This information may include offers or sales discount associated with a product, comparing prices, ingredients or materials composition and many more. Retail business owners have seen this as a big opportunity to increase their in-store sales and they are adapting various technologies to deliver helpful contents and informati...

  8. 33 CFR 62.23 - Beacons and buoys.

    Science.gov (United States)

    2010-07-01

    ... electronic navigation. Buoys vary in reliability because: (i) Buoy positions represented on nautical charts... not coincide with the dots or circles representing them on charts. (iii) Buoy positions are...

  9. Early Detection of Breast Cancer Using Molecular Beacons

    Science.gov (United States)

    2008-01-01

    279-84, 1999 Feb. 6. Ramachandra S. Machin L. Ashley S. Monaghan P. Gusterson BA. Immunohistochemical distribution of c-erbB-2 in in situ breast...kidney cell line 293 (ATCC). The AdEasy system was pro- vided by Dr. Bert Vogelstein at The Johns Hopkins University. Additional vector amplification

  10. Beacon Position and Attitude Navigation Aided by a Magnetometer

    Science.gov (United States)

    2010-06-01

    i · B . (12) When the scale and shift influences of the analog circuitry are considered, the actual measurement of the magnetometer is M = s...1350–1351. 22. Carta , D. G.; Lackowski, D. H. Estimation of Orthogonal Transformations in Strapdown Inertial Systems. IEEE Transactions on

  11. Storm-Time Ionospheric Disturbances Monitored by GPS Beacon Measurements

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Total Electron Content (TEC) during three great storms, from April to August 2000, was collected by means of a GPS receiver located in Jingzhou (30. 4° N, 112. 2° E). The time-latitude-dependent features of ionospheric storms are identified using TEC difference images based on the deviations of TEC during storm relative to quiet time. The responses of ionospheric TEC to magnetic storms were analyzed. The results show that: 1) In middle and low latitude, ionospheric storms effects are more apparent in local day time than at night; 2) Ionospheric storm effects are more dominant near the hump of the equatorial anomaly region than in other regions of TEC measurements; 3) The positive effects during the main phase of iono spheric storm may be caused by electric fields in low latitude; 4) During the recovery period of ionospheric storm, the negative phase of storm may be due to the perturbation of the neutral gas composition.

  12. Exploiting beacons for scalable broadcast data dissemination in VANETs

    NARCIS (Netherlands)

    Schwartz, Ramon S.; Das, Kallol; Scholten, Hans; Havinga, Paul

    2012-01-01

    Vehicular Ad-hoc Networks (VANETs) enable the timely broadcast dissemination of event-driven messages to interested vehicles. However, when dealing with broadcast communication, suppression techniques must be designed to prevent the so-called broadcast storm problem. Numerous suppression schemes aim

  13. RFID:A Beacon of Light in the Banking System

    Institute of Scientific and Technical Information of China (English)

    Elizabeth; Wasserman

    2009-01-01

    Although RFID won’t fix the mortgage problem,banks are investing in the technology to improve other business practices-a move they believe will pay off in dollars and sense. By RFID Journal,used with pemission

  14. Opportunistic Beacon Networks: Information Dissemination via Wireless Network Identifiers

    NARCIS (Netherlands)

    Türkes, Okan; Scholten, Hans; Havinga, Paul J.M.

    2016-01-01

    This paper presents OBN, a universal opportunistic ad hoc networking model particularly intended for smart mobile devices. It enables fast and lightweight data dissemination in wireless community networks through the utilization of universally-available wireless network identifiers. As a ubiquitous

  15. BEACON : A Summary Framework to Overcome Potential Reimbursement Hurdles

    NARCIS (Netherlands)

    Dunlop, William C N; Mullins, C Daniel; Pirk, Olaf; Goeree, Ron; Postma, Maarten J; Enstone, Ashley; Heron, Louise

    2016-01-01

    OBJECTIVE: To provide a framework for addressing payers' criteria during the development of pharmaceuticals. METHODS: A conceptual framework was presented to an international health economic expert panel for discussion. A structured literature search (from 2010 to May 2015), using the following data

  16. Molecular Beacons: Powerful Tools for Imaging RNA in Living Cells

    OpenAIRE

    Ricardo Monroy-Contreras; Luis Vaca

    2011-01-01

    Recent advances in RNA functional studies highlights the pivotal role of these molecules in cell physiology. Diverse methods have been implemented to measure the expression levels of various RNA species, using either purified RNA or fixed cells. Despite the fact that fixed cells offer the possibility to observe the spatial distribution of RNA, assays with capability to real-time monitoring RNA transport into living cells are needed to further understand the role of RNA dynamics in cellular fu...

  17. Close-Range Tracking of Underwater Vehicles Using Light Beacons.

    Science.gov (United States)

    Bosch, Josep; Gracias, Nuno; Ridao, Pere; Istenič, Klemen; Ribas, David

    2016-03-25

    This paper presents a new tracking system for autonomous underwater vehicles (AUVs) navigating in a close formation, based on computer vision and the use of active light markers. While acoustic localization can be very effective from medium to long distances, it is not so advantageous in short distances when the safety of the vehicles requires higher accuracy and update rates. The proposed system allows the estimation of the pose of a target vehicle at short ranges, with high accuracy and execution speed. To extend the field of view, an omnidirectional camera is used. This camera provides a full coverage of the lower hemisphere and enables the concurrent tracking of multiple vehicles in different positions. The system was evaluated in real sea conditions by tracking vehicles in mapping missions, where it demonstrated robust operation during extended periods of time.

  18. Exploring the Transformative Potential of Bluetooth Beacons in Higher Education

    Science.gov (United States)

    McDonald, Kieran; Glover, Ian

    2016-01-01

    The growing ubiquity of smartphones and tablet devices integrated into personal, social and professional life, facilitated by expansive communication networks globally, has the potential to disrupt higher education. Academics and students are considering the future possibilities of exploiting these tools and utilising networks to consolidate and…

  19. Close-Range Tracking of Underwater Vehicles Using Light Beacons

    Science.gov (United States)

    Bosch, Josep; Gracias, Nuno; Ridao, Pere; Istenič, Klemen; Ribas, David

    2016-01-01

    This paper presents a new tracking system for autonomous underwater vehicles (AUVs) navigating in a close formation, based on computer vision and the use of active light markers. While acoustic localization can be very effective from medium to long distances, it is not so advantageous in short distances when the safety of the vehicles requires higher accuracy and update rates. The proposed system allows the estimation of the pose of a target vehicle at short ranges, with high accuracy and execution speed. To extend the field of view, an omnidirectional camera is used. This camera provides a full coverage of the lower hemisphere and enables the concurrent tracking of multiple vehicles in different positions. The system was evaluated in real sea conditions by tracking vehicles in mapping missions, where it demonstrated robust operation during extended periods of time. PMID:27023547

  20. The detection of HBV DNA G1896A point mutation with locked nucleic acid technology combined with molecular beacon%锁核酸结合分子信标技术检测乙型肝炎病毒DNA G1896A点突变研究

    Institute of Scientific and Technical Information of China (English)

    张红; 郑欣; 宋庆涛; 蔡剑英; 王大明; 曾劲峰; 叶贤林; 熊文

    2012-01-01

    Objective The aim of this study is to investigate and evaluate the real-time fluorescent PCR detection method of hepatitis B virus (HBV) DNA G1896A point mutations. Methods A total of 158 HBV samples which had been analyzed for G1896A mutation were selected, including 150 non-mutation samples and 58 mutant samples. The molecular beacon probe was designed in the mutant region, and the sample was processed with locked nucleic acid in the point mutation region. The pre C region G1896A point mutations of HBV was detected with Fluorescent PCR, then use DNA sequencing to confirm 8 mutant samples, 6 heterozygous samples, and 19 non-mutation samples which had been detected by real-time fluorescent PCR detection method. Results (l)Both the sensitivity of mutant plasmids and of wild-type plasmids achieved 100 copies/ml. (2)There was no detection signal when we used mutant probe to detect the high concentration of wild-type plasmids. It was the same when we used wild-type probe to detect the high concentration of mutant plasmids. (3)The mutant could be detected when the mutational template accounted for 5% of the total heterozygous. (4)All the result of detection with sequencing coincided with that of detection with real-time fluorescent PCR detection method. Conclusion Because real-time fluorescent PCR detection method can rapidly, easily, and exactly detect the HBV DNA G1896A point mutation, thus it is an important method to detect point mutations and has important clinical value.%目的 研究和评估乙型肝炎病毒(HBV)DNA G1896A点突变的实时荧光PCR检测方法.方法 收集经测序验证HBV DNA G1896A未突变的野生型样本150例和已发生突变的突变型样本58例,在突变区域设计分子信标探针,点突变处进行锁核酸处理,利用荧光PCR方法检测HBV前C区G1896A点突变;再从临床标本中随机抽取18例、8例和19例荧光PCR结果分别显示为G1896A突变的标本、杂合的标本以及野生型的标本的PCR

  1. Enhancing School Asthma Action Plans: Qualitative Results from Southeast Minnesota Beacon Stakeholder Groups

    Science.gov (United States)

    Egginton, Jason S.; Textor, Lauren; Knoebel, Erin; McWilliams, Deborah; Aleman, Marty; Yawn, Barbara

    2013-01-01

    Background: This study explores ways southeast Minnesota schools currently address asthma problems, identifies areas for improvement, and assesses the potential value of asthma action plans (AAPs) in schools. Methods: Focus groups were used to query stakeholder groups on asthma care in schools. Groups were held separately for elementary school…

  2. Label-free molecular beacon for real-time monitoring of DNA polymerase activity.

    Science.gov (United States)

    Ma, Changbei; Liu, Haisheng; Wang, Jun; Jin, Shunxin; Wang, Kemin

    2016-05-01

    Traditional methods for assaying DNA polymerase activity are discontinuous, time consuming, and laborious. Here, we report a new approach for label-free and real-time monitoring of DNA polymerase activity using a Thioflavin T (ThT) probe. In the presence of DNA polymerase, the DNA primer could be elongated through polymerase reaction to open MB1, leading to the release of the G-quartets. These then bind to ThT to form ThT/G-quadruplexes with an obvious fluorescence generation. It exhibits a satisfying detection result for the activity of DNA polymerase with a low detection limit of 0.05 unit/ml. In addition, no labeling with a fluorophore or a fluorophore-quencher pair is required; this method is fairly simple, fast, and low cost. Furthermore, the proposed method was also applied to assay the inhibition of DNA polymerase activity. This approach may offer potential applications in drug screening, clinical diagnostics, and some other related biomedical research.

  3. Fluorescence monitoring of riboswitch transcription regulation using a dual molecular beacon assay

    OpenAIRE

    Chinnappan, Raja; Dubé, Audrey; Lemay, Jean-François; Daniel A Lafontaine

    2013-01-01

    Riboswitches are mRNA elements that specifically bind cellular metabolites and control gene expression by modifying their structure. As riboswitches often control essential genes in pathogenic bacteria, riboswitches have been proposed as new targets for antibiotics. High-throughput screening provides a powerful approach to identify riboswitch ligand analogs that could act as powerful antibacterial drugs. Biochemical assays have already been used to find riboswitch-binding analogs, but those m...

  4. The Effects of Beacons, Comments, and Tasks on Program Comprehension Process in Software Maintenance

    Science.gov (United States)

    Fan, Quyin

    2010-01-01

    Program comprehension is the most important and frequent process in software maintenance. Extensive research has found that individual characteristics of programmers, differences of computer programs, and differences of task-driven motivations are the major factors that affect the program comprehension results. There is no study specifically…

  5. Adaptive polarimetric image representation for contrast optimization of a polarized beacon through fog

    CERN Document Server

    Panigrahi, Swapnesh; Alouini, Mehdi

    2015-01-01

    We present a contrast-maximizing optimal linear representation of polarimetric images obtained from a snapshot polarimetric camera for enhanced vision of a polarized light source in obscured weather conditions (fog, haze, cloud) over long distances (above 1 km). We quantitatively compare the gain in contrast obtained by different linear representations of the experimental polarimetric images taken during rapidly varying foggy conditions. It is shown that the adaptive image representation that depends on the correlation in background noise fluctuations in the two polarimetric images provides an optimal contrast enhancement over all weather conditions as opposed to a simple difference image which underperforms during low visibility conditions. Finally, we derive the analytic expression of the gain in contrast obtained with this optimal representation and show that the experimental results are in agreement with the assumed correlated Gaussian noise model.

  6. Pulsars as celestial beacons to detect the motion of the Earth

    CERN Document Server

    Ruggiero, Matteo Luca; Tartaglia, Angelo

    2010-01-01

    We apply a previously proposed relativistic positioning method based on the use of pulsed signals from sources at infinity, to the reconstruction of the world-line of the Earth in the reference frame of distant pulsars. The method considers the null four-vectors built from the period of the pulses and the direction cosines of the propagation from each source. Starting from a simplified problem (a receiver at rest) we have been able to calibrate our procedure, evidencing the influence of the uncertainty on the arrival times of the pulses as measured by the receiver, and of the numerical treatment of the data. The most relevant parameter turns out to be the accuracy of the clock used by the receiver. Actually the uncertainty used in the simulations combines both the accuracy of the clock and the fluctuations in the sources. The method has then been applied to the case of the Earth, simulating the arrival times of the signals from four pulsars at the location of the Parkes radiotelescope in Australia. A rough ap...

  7. Women Participation in Leadership Positions: A Beacon of Social Change in Nigeria

    Directory of Open Access Journals (Sweden)

    Igbokwe, J. O.

    2013-08-01

    Full Text Available Discrimination of women against elective and appointive policy making positions at Federal, State and Local levels is still prevalent. The work is taking a critical look at the role of women in leadership positions in Nigeria with specific aim of shading light on the fact that women are agents of social change. It is observed that notwithstanding the cultural barriers and discrimination against womenfolk, they are naturally endowed to become indispensable tool for nation’s building. Therefore, if given the opportunity to participate in the general governance structure, our economy can eventually surmount the apparent developmental hurdles and can create positive impact in society.

  8. Noise adaptive fading Kalman filter for free-space laser communication beacon tracking.

    Science.gov (United States)

    Li, Lixing; Huang, Yongmei; Wang, Qiang; Yang, Fasheng

    2016-10-20

    We proposed a prediction algorithm for laser communication pointing, acquisition, and tracking (PAT) subsystems in order to further improve PAT accuracy and reduce the effect of processing delay. In terms of this prediction algorithm, a fading Kalman filter is employed, with the observation noise obtained by the gray value distribution of the laser images. Moreover, to better fit the dynamics of a laser target, the two-stage dynamic model has been chosen as the state transition model for Kalman filtering. In addition, the two-stage dynamic model has been modified by accommodating its form to a change of time lag, thereby compensating the effect of time delay. A series of horizontal path (17 km) experiments under different atmospheric conditions were conducted in the fields. According to the experimental results, the algorithm we proposed could effectively reduce the tracking error and improve pointing accuracy.

  9. A Ka-band (32 GHz) beacon link experiment (KABLE) with Mars Observer

    Science.gov (United States)

    Riley, A. L.; Hansen, D. M.; Mileant, A.; Hartop, R. W.

    1987-02-01

    A proposal for a Ka-Band (32 GHz) Link Experiment (KABLE) with the Mars Observer mission was submitted to NASA. The experiment will rely on the fourth harmonic of the spacecraft X-band transmitter to generate a 33.6 GHz signal. The experiment will rely also on the Deep Space Network (DSN) receiving station equipped to simultaneously receive X- and Ka-band signals. The experiment will accurately measure the spacecraft-to-Earth telecommunication link performance at Ka-band and X-band (8.4 GHz).

  10. BLESSED with opportunistic beacons: a lightweight data dissemination model for smart mobile ad-hoc networks

    NARCIS (Netherlands)

    Türkes, Okan; Scholten, Hans; Havinga, Paul J.M.

    2015-01-01

    This paper introduces BLESSED, a universal opportunistic ad hoc networking model intended for smart mobile devices. It enables fast and lightweight data dissemination in wireless community networks through the complementary utilization of the IEEE 802.11 and Bluetooth Low Energy standards. As a ubiq

  11. Model-based advice for mechanical ventilation: From research (INVENT) to product (Beacon Caresystem).

    Science.gov (United States)

    Rees, Stephen E; Karbing, Dan S

    2015-01-01

    This paper describes the structure and functionality of a physiological model-based system for providing advice on the settings of mechanical ventilation. Use of the system is presented with examples of patients on support and control modes of mechanical ventilation.

  12. Decentralized Single-beacon Acoustic Navigation: Combined Communication and Navigation for Underwater Vehicles

    Science.gov (United States)

    2010-06-01

    OMB control number. 1. REPORT DATE JUN 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Decentralized...Fly Subsea Mission Corrections . . . . . . . . . . . . . . . 49 3.5 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 4...System Models 52 4.1 State Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4.2 Vehicle Process Model

  13. Photodynamic Molecular Beacons: An Image-Guided Therapeutic Approach to Breast Cancer Vertebral Metastases

    Science.gov (United States)

    2012-03-01

    flurescent protein , GFP) kindly provided by Dr. Joseph Wu (Stanford University) and a lentivirus kindly provided by Dr Ren-Ke Li, (University of...the tumors were 5!10 mm in diameter, the mice were fed a low- fluorescence diet (Harlan Tekland) for 4 days to reduce the autofluoresence background. A...not be a disadvantage in this application, since both MMP 10 and 12 also play roles in bone development and bone matrix solubilization.32!35 Since tumor

  14. Discrete Address Beacon System (DABS) Software System Reliability Modeling and Prediction.

    Science.gov (United States)

    1981-06-01

    8217-4 CN 0c CN14 -4 C14 00 coo ’-4 ’-4 004 Lf rCI ’.-4 0’ C4 : ’--4 1 - 00 T C0 o aa ’-. -4 -4C o _ ___ _ ___ _, CD4 CD L LPI 0n C oco co0 -~~ -U)- O Co0...fAlQ? > NIF T I ThiN CIIL PROP N4 INIT I)L-CkH I P 11NN i P’ub PAR-IT NO (J;. "I 1000l 1rAA 5ET CAP 13115 Ir4A"E 13004 EKE -70 1 /1C-002 FAA MISC I x...F1:0 Pi, BIT INCLTRECT C42006 SURY 10 / C. 79 0 C -0 1 C-2 DE;- C 00Y2-0063 COU’LTIPLE C4 :NCEL DATA ;FFDLM C040006 NM *rri/c: 79 11 7103 U C C,: G’-0

  15. Successful SDIs: does the Marine Geo-sector provide a much-needed beacon?

    NARCIS (Netherlands)

    Welle Donker, F.M.

    2010-01-01

    With Directive 2007/2/EC of the European Parliament and of the Council of 14 March 2007 establishing an Infrastructure for Spatial Information in the European Community (INSPIRE) in the process of being implemented in most EU Member States, the aim is to develop a European spatial data infrastructur

  16. Metal-organic framework-based molecular beacons for multiplexed DNA detection by synchronous fluorescence analysis.

    Science.gov (United States)

    Ye, Tai; Liu, Yufei; Luo, Ming; Xiang, Xia; Ji, Xinghu; Zhou, Guohua; He, Zhike

    2014-04-07

    We report a new sensor combined two dimensional metal-organic framework (MOF), N,N-bis(2-hydroxy-ethyl)dithiooxamidato copper(II) (H2dtoaCu), with the hairpin-structured oligonucleotides and demonstrate its feasibility in detecting multiplexed sequence-specific DNA. The key component of this sensor (MOF-MBs) is the hairpin-structured fluorescent oligonucleotide that allows the MOFs to function as both a "nanoscaffold" for the oligonucleotide and a "nanoquencher" of the fluorophore. An oligonucleotide sequence fragment of wild-type HBV (T1) and a reverse-transcription oligonucleotide sequence of RNA fragment of HIV (T2) were used as model systems. While in the presence of the targets, the fluorescence of dyes was recovered by forming a double strand structure. Multiplex DNA detection can be realized by synchronous scanning fluorescence spectrometry, and there was no cross reaction between the two probes. Under the optimum conditions, the fluorescence intensities of two dyes all exhibit good linear dependence on their target DNA concentration in the range of 1-10 nM with the detection limit of 0.87 nM and 0.22 nM for T1 and T2, respectively. As a proof of concept, the MOF-MBs have been successfully used as a potential sensing platform for simultaneous detection of multiplexed DNA.

  17. Fusing Bluetooth Beacon Data with Wi-Fi Radiomaps for Improved Indoor Localization

    Directory of Open Access Journals (Sweden)

    Loizos Kanaris

    2017-04-01

    Full Text Available Indoor user localization and tracking are instrumental to a broad range of services and applications in the Internet of Things (IoT and particularly in Body Sensor Networks (BSN and Ambient Assisted Living (AAL scenarios. Due to the widespread availability of IEEE 802.11, many localization platforms have been proposed, based on the Wi-Fi Received Signal Strength (RSS indicator, using algorithms such as K-Nearest Neighbour (KNN, Maximum A Posteriori (MAP and Minimum Mean Square Error (MMSE. In this paper, we introduce a hybrid method that combines the simplicity (and low cost of Bluetooth Low Energy (BLE and the popular 802.11 infrastructure, to improve the accuracy of indoor localization platforms. Building on KNN, we propose a new positioning algorithm (dubbed i-KNN which is able to filter the initial fingerprint dataset (i.e., the radiomap, after considering the proximity of RSS fingerprints with respect to the BLE devices. In this way, i-KNN provides an optimised small subset of possible user locations, based on which it finally estimates the user position. The proposed methodology achieves fast positioning estimation due to the utilization of a fragment of the initial fingerprint dataset, while at the same time improves positioning accuracy by minimizing any calculation errors.

  18. Fusing Bluetooth Beacon Data with Wi-Fi Radiomaps for Improved Indoor Localization.

    Science.gov (United States)

    Kanaris, Loizos; Kokkinis, Akis; Liotta, Antonio; Stavrou, Stavros

    2017-04-10

    Indoor user localization and tracking are instrumental to a broad range of services and applications in the Internet of Things (IoT) and particularly in Body Sensor Networks (BSN) and Ambient Assisted Living (AAL) scenarios. Due to the widespread availability of IEEE 802.11, many localization platforms have been proposed, based on the Wi-Fi Received Signal Strength (RSS) indicator, using algorithms such as K-Nearest Neighbour (KNN), Maximum A Posteriori (MAP) and Minimum Mean Square Error (MMSE). In this paper, we introduce a hybrid method that combines the simplicity (and low cost) of Bluetooth Low Energy (BLE) and the popular 802.11 infrastructure, to improve the accuracy of indoor localization platforms. Building on KNN, we propose a new positioning algorithm (dubbed i-KNN) which is able to filter the initial fingerprint dataset (i.e., the radiomap), after considering the proximity of RSS fingerprints with respect to the BLE devices. In this way, i-KNN provides an optimised small subset of possible user locations, based on which it finally estimates the user position. The proposed methodology achieves fast positioning estimation due to the utilization of a fragment of the initial fingerprint dataset, while at the same time improves positioning accuracy by minimizing any calculation errors.

  19. Christianity in Africa: A Beacon of Hope for Christianity in Europe

    OpenAIRE

    Michael Fuseini Wandusim

    2015-01-01

    World Christianity has experienced several changes including its spread and decline across the world. Following what Andrew F. Walls terms as “Serial character of Christian advance,” Christianity has moved from Europe, its previous heartland to other continents like Africa, Asia and Latin America. Today in Europe, in general terms, Christianity can be described in words such as ‘declining’, ‘empty pews’, ‘dying’, ‘few pews filled with only old folks’, etc. Given the seemingly hopeless nature ...

  20. HEIGHT CODE TABLES FOR USE WITH AIR TRAFFIC CONTROL RADAR BEACON SYSTEM

    Science.gov (United States)

    The Seventh Communications Division of the International Civil Aviation Organization ( ICAO ) has recommended the adoption of a digital code for...characteristic; (5) Height transmission with respect to a fixed datum of 1013.2 millibars (29.92 inches of mercury). The code, as recommended by ICAO , is

  1. PayPal推出移动支付配件Beacon

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    日前,PayPal发布了支持蓝牙支付的附件设备Beac-nn,不仅方便商家通过移动设备与客广,进行连接,同时客户进行支付时无需手机,直接通过蓝牙即叮完成支付。

  2. Learning from Health Information Exchange Technical Architecture and Implementation in Seven Beacon Communities

    OpenAIRE

    McCarthy, Douglas B.; Propp, Karen; Cohen, Alexander; Sabharwal, Raj; Schachter, Abigail A; Rein, Alison L

    2014-01-01

    As health care providers adopt and make “meaningful use” of health information technology (health IT), communities and delivery systems must set up the infrastructure to facilitate health information exchange (HIE) between providers and numerous other stakeholders who have a role in supporting health and care. By facilitating better communication and coordination between providers, HIE has the potential to improve clinical decision-making and continuity of care, while reducing unnecessary use...

  3. A Novel 3D Multilateration Sensor Using Distributed Ultrasonic Beacons for Indoor Navigation

    Directory of Open Access Journals (Sweden)

    Rohan Kapoor

    2016-10-01

    Full Text Available Navigation and guidance systems are a critical part of any autonomous vehicle. In this paper, a novel sensor grid using 40 KHz ultrasonic transmitters is presented for adoption in indoor 3D positioning applications. In the proposed technique, a vehicle measures the arrival time of incoming ultrasonic signals and calculates the position without broadcasting to the grid. This system allows for conducting silent or covert operations and can also be used for the simultaneous navigation of a large number of vehicles. The transmitters and receivers employed are first described. Transmission lobe patterns and receiver directionality determine the geometry of transmitter clusters. Range and accuracy of measurements dictate the number of sensors required to navigate in a given volume. Laboratory experiments were performed in which a small array of transmitters was set up and the sensor system was tested for position accuracy. The prototype system is shown to have a 1-sigma position error of about 16 cm, with errors between 7 and 11 cm in the local horizontal coordinates. This research work provides foundations for the future development of ultrasonic navigation sensors for a variety of autonomous vehicle applications.

  4. Head-Tail Galaxies: Beacons of High-Density Regions in Clusters

    CERN Document Server

    Mao, Minnie Y; Stevens, Jamie B; Wotherspoon, Simon J

    2008-01-01

    Using radio data at 1.4 GHz from the ATCA we identify five head-tail (HT) galaxies in the central region of the Horologium-Reticulum Supercluster (HRS). Physical parameters of the HT galaxies were determined along with substructure in the HRS to probe the relationship between environment and radio properties. Using a density enhancement technique applied to 582 spectroscopic measurements in the 2 degree x 2 degree region about A3125/A3128, we find all five HT galaxies reside in regions of extremely high density (>100 galaxies/Mpc^3). In fact, the environments surrounding HT galaxies are statistically denser than those environments surrounding non-HT galaxies and among the densest environments in a cluster. Additionally, the HT galaxies are found in regions of enhanced X-ray emission and we show that the enhanced density continues out to substructure groups of 10 members. We propose that it is the high densities that allow ram pressure to bend the HT galaxies as opposed to previously proposed mechanisms relyin...

  5. Perancangan Prototipe Transmitter Beacon Black Box Locator Acoustic 37.5 kHz Pingers

    Directory of Open Access Journals (Sweden)

    RUSTAMAJI RUSTAMAJI

    2016-08-01

    Full Text Available ABSTRAK Pingers transmitter berfungsi untuk memancarkan sinyal atau getaran pulsa akustik pada black box. Frekuensi sinyal yang dipancarkan sebesar 37,5 kHz yang dimodulasikan oleh pulsa dengan durasi 10 ms setiap interval 1 second. Modulasi yang digunakan adalah modulasi on off keying. Dalam penelitian ini dibuat perancangan pingers transmitter yang tersusun atas rangkaian osilator, timer, inverter, switch dan rangkaian amplifier. Frekuensi 37,5 kHz tersebut dibangkitkan oleh rangkaian osilator colpitts, sedangkan lebar pulsa dengan durasi 10 ms dan pengulangan pulsa setiap interval 1 second dibangkitkan oleh rangkaian timer. Berdasarkan perancangan yang telah dibuat, output sinyal yang dihasilkan oleh prototipe pingers transmitter tersebut sebesar 37,69 kHz dengan lebar pulsa 9,8 ms setiap interval 1 second. Kata kunci: Black box, pingers transmitter, on off keying.   ABSTRACT Pingers transmitter is used to emits a signal or pulse of acoustic vibrations  in black box. The frequency of the transmitted signal is 37.5 kHz which is modulated by pulses with a duration of 10 ms every interval 1 second. The modulation that used this research is on off keying modulation. In this research, made the design of pingers transmitter which arrange of the oscillator circuit,timer, inverter, switch, and amplifier circuit. The 37.5 kHz frequency is generated by the colpitts oscillator circuit, while the pulse width with a duration of 10 ms,and each pulse repetition interval of 1 second generated by timer circuit. Based on the design that have made, signal output from the pingers transmitter prototype is 37.69 kHz, with the pulse width 9.8 ms every 1 second interval. Keywords : Black box, pingers transmitter, on off keying.

  6. Effect of Coude Pupil Rotation on Sodium Laser Beacon Perspective Elongation

    Science.gov (United States)

    2011-03-01

    This material is declared a work of the U.S. Govern- ment and is not subject to copyright protection in the United States. AFIT/GE/ENG/11-28 EFFECT...19 FOV Field of View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 ELT Extremely...its effect on the propagation of light. Adaptive optics (AO) systems are discussed as a method to measure and compensate for turbulence, and sodium

  7. A Fuzzy Logic Approach to Beaconing for Vehicular Ad hoc Networks

    NARCIS (Netherlands)

    Ghafoor, Kayhan Zrar; Bakar, Kamalrulnizam Abu; Eenennaam, van Martijn; Khokhar, Rashid Hafeez; Gonzalez, Alberto J.

    2011-01-01

    Vehicular Ad Hoc Network (VANET) is an emerging field of technology that allows vehicles to communicate together in the absence of fixed infrastructure. The basic premise of VANET is that in order for a vehicle to detect other vehicles in the vicinity. This cognizance, awareness of other vehicles, c

  8. A Beacon of Light: Tougaloo during the Presidency of Dr. Adam Daniel Beittel (1960-1964)

    Science.gov (United States)

    Speed, John Gregory

    2014-01-01

    This study examines leadership efforts that supported the civil rights movements that came from administrators and professors, students and staff at Tougaloo College between 1960 and 1964. A review of literature reveals that little has been written about the college's role in the Civil Rights Movement during this time. Thus, one goal of this study…

  9. Beacons In the Dark: Using Novae and Supernovae to Detect Dwarf Galaxies in the Local Universe

    CERN Document Server

    Conroy, Charlie

    2015-01-01

    We propose that luminous transients, including novae and supernovae, can be used to detect the faintest galaxies in the universe. Beyond a few Mpc, dwarf galaxies with stellar masses $<10^6 M_{\\odot}$ will likely be too faint and/or too low in surface brightness to be directly detected in upcoming large area ground-based photometric surveys. However, single epoch LSST photometry will be able to detect novae to distances of $\\sim30$ Mpc and SNe to Gpc-scale distances. Depending on the form of the stellar mass-halo mass relation and the underlying star formation histories of low mass dwarfs, the expected nova rates will be a few to $\\sim100$ yr$^{-1}$ and the expected SN rates (including both type Ia and core-collapse) will be $\\sim10^2-10^4$ within the observable ($4\\pi$ sr) volume. The transient rate associated with intrahalo stars will be comparably large, but these transients will be located close to bright galaxies, in contrast to the dwarfs, which should trace the underlying large scale structure of th...

  10. A beacon in the cytoplasm: Tracking translation of single mRNAs.

    Science.gov (United States)

    Pingali, Hema V; Hilliker, Angela K

    2016-09-12

    Translation is carefully regulated to control protein levels and allow quick responses to changes in the environment. Certain questions about translation in vivo have been unattainable until now. In this issue, Pichon et al. (2016. J. Cell Biol http://dx.doi.org/10.1083/jcb.201605024) describe a new technique to allow real-time monitoring of translation on single mRNAs.

  11. Galectin-3 in bone tumor microenvironment: a beacon for individual skeletal metastasis management.

    Science.gov (United States)

    Nakajima, Kosei; Kho, Dong Hyo; Yanagawa, Takashi; Zimel, Melissa; Heath, Elisabeth; Hogan, Victor; Raz, Avraham

    2016-06-01

    The skeleton is frequently a secondary growth site of disseminated cancers, often leading to painful and devastating clinical outcomes. Metastatic cancer distorts bone marrow homeostasis through tumor-derived factors, which shapes different bone tumor microenvironments depending on the tumor cells' origin. Here, we propose a novel insight on tumor-secreted Galectin-3 (Gal-3) that controls the induction of an inflammatory cascade, differentiation of osteoblasts, osteoclasts, and bone marrow cells, resulting in bone destruction and therapeutic failure. In the approaching era of personalized medicine, the current treatment modalities targeting bone metastatic environments are provided to the patient with limited consideration of the cancer cells' origin. Our new outlook suggests delivering individual tumor microenvironment treatments based on the expression level/activity/functionality of tumor-derived factors, rather than utilizing a commonly shared therapeutic umbrella. The notion of "Gal-3-associated bone remodeling" could be the first step toward a specific personalized therapy for each cancer type generating a different bone niche in patients afflicted with non-curable bone metastasis.

  12. The Subject Headings of the Morris Swett Library, USAFAS. Revised.

    Science.gov (United States)

    1980-05-15

    Rifle. Ammunition, Beacon. See Iluminants - Beacon shells. AMMUNITION, BIOLOGICAL. AMMUNITION, BLANK. x Hlank armunition. AMMUNITION, CANISTER. (UL 400...illumination x Star shells - Beacon shells x Ammunition, Beacon - Candles - Flares - Flares, Aeroplanes x Aeroplanes - Flares - Iluminating shells (UL 440.1

  13. Students' Reflections on the Relevance and Quality of Highly Ranked Doctoral Programs in Educational Administration: Beacons of Leadership Preparation?

    Science.gov (United States)

    Hoyle, John R.; Torres, Mario S., Jr.

    2008-01-01

    The manner by which colleges and universities prepare school leaders in doctoral programs is being called into question. One report is stirring much controversy for its unflattering portrayal of administrator preparation programs. In a 2005 report entitled "Educating School Leaders," former Columbia University president Art Levine characterizes…

  14. Molecular and atomic line surveys of galaxies I: the dense, star-forming phase as a beacon

    CERN Document Server

    Geach, James E

    2012-01-01

    We predict the space density of molecular gas reservoirs in the Universe, and place a lower limit on the number counts of carbon monoxide (CO), hydrogen cyanide (HCN) molecular and [CII] atomic emission lines in blind redshift surveys in the submillimeter-centimeter spectral regime. Our model uses: (a) recently available HCN Spectral Line Energy Distributions (SLEDs) of local Luminous Infrared Galaxies (LIRGs, L_IR>10^11 L_sun), (b) a value for epsilon=SFR/M_dense(H_2) provided by new developments in the study of star formation feedback on the interstellar medium and (c) a model for the evolution of the infrared luminosity density. Minimal 'emergent' CO SLEDs from the dense gas reservoirs expected in all star-forming systems in the Universe are then computed from the HCN SLEDs since warm, HCN-bright gas will necessarily be CO-bright, with the dense star-forming gas phase setting an obvious minimum to the total molecular gas mass of any star-forming galaxy. We include [CII] as the most important of the far-inf...

  15. Resource and Technology: A Beacon for Change in the Reform of Jamaica's Secondary Education System--or a "Pipedream"?

    Science.gov (United States)

    Jennings, Zellynne

    2012-01-01

    Different strategies are being employed worldwide to prepare school-leavers for the world of work. Central to the Reform of Secondary Education (ROSE) in Jamaica in the 1990s was the achievement of goals of access, equity and quality through the implementation of a common curriculum in all schools. Within this reform, Resource and Technology (R&T)…

  16. Cumulative fade statistics and prediction methods associated with the COMSTAR beacon signal at 28.56 GHz

    Science.gov (United States)

    Goldhirsh, J.

    1978-01-01

    The paper presents cumulative fade statistics for the period April 1977 to March 1978 and reviews the rain attenuation predictive efforts using radar and disdrometer data for the summer of 1977. Attention is given to the receiving and radar systems as well as the disdrometer-raingage system. Discussion of the fade statistics covers the yearly, monthly and time of day statistics. Consideration is given to measured and predicted attenuation events, measured and predicted probability distributions as well as an empirical calibration adjustment. It is noted that in spite of many reasons for noncorrelation, the radar results do correlate well. Finally, it is concluded that the results demonstrate the utility of using radar coupled with disdrometer measurements for predicting individual fade events as well as long term fade distributions associated with satellite communications through rain.

  17. Measuring Tilt and Focus for Sodium Beacon Adaptive Optics on the Starfile 3.5 Meter Telescope -- Conference Proceedings (Preprint)

    Science.gov (United States)

    2008-09-01

    in detail by Link and Foucault . [2] They show these approaches to focus control have comparable performance in the presence of atmospheric turbulence... Foucault B., Investigation of focus control for NGAS, Starfire Optical Range internal memo, 8 May 2007. 3. Goodman J., Introduction to Fourier Optics

  18. A novel strategy for human papillomavirus detection and genotyping with SybrGreen and molecular beacon polymerase chain reaction

    NARCIS (Netherlands)

    Szuhai, K; Sandhaus, E; Kolkman-Uljee, SM; Lemaitre, M; Truffert, JC; Dirks, RW; Tanke, HJ; Fleuren, GJ; Schuuring, E; Raap, AK

    2001-01-01

    Human papillomaviruses (HPVs) play an important role in the pathogenesis of cervical cancer. For identification of the large number of different HPV types found in (pre)malignant lesions, a robust methodology is needed that combines general HPV detection with HPV genotyping. We have developed for fo

  19. Overview of On-line Core Monitoring System BEACON%BEACON堆芯在线监测系统概述

    Institute of Scientific and Technical Information of China (English)

    戴青; 陈笑松

    2013-01-01

    历经20多年的发展,堆芯在线监测系统的核心技术在国际上的发展已趋于成熟,但国内仍无可与之相比的综合系统.通过对全球应用最广泛的堆芯监测系统——BEACON进行调研分析,为自主研发此类系统提供技术指引.BEACON利用堆外中子探测器、堆芯出口热电偶、堆内可移动探测器的测量数据,进行堆芯监视、测量数据分析以及预测.在节点均匀的假设下,以有效快中子群(EFG)模型简化扩散方程求解,再用格林函数对全堆芯插值,最后利用样条函数拟合探测器数据,给出较为准确的堆芯功率分布.BEACON的显著技术特点包括能进行非稳态下的堆芯监测,引用节点展开法(NEM)增加堆芯功率重构的准确性,以及使用单点校准技术增加两次全堆校准间的间隔.

  20. Conceptual, Experimental and Compass-beacon Ontologies--The Principles, concepts and methodology of BMKI(Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    BAO Han-fei

    2005-01-01

    This article discussed the basic three components of an information unit(IU), ie the Carrier(C), Feature (F) and Value(Ⅴ), and presented and several different types of feature, including the static, relation and process features(SF ,RF and PF respectively). It also discussed about the knowledge for statistical group(KP) and for individual(KI) and the transformation mechanisms between them. Then both the philosophy and application attributes of ontology have been explored and two new concepts, ie ontology of existence(EO) and ontology of application (OA) were created. The paper gave an integrated sketch of the whole medical knowledge engineering cause,which is thought to be composed of three areas: conceptual, experimental and compass-beakon ontoloies (CO,EO, CBO, respectively). And based on those considerations BMKI achieved its fundamental formula.

  1. Single-point mutation detection in RNA extracts using gold nanoparticles modified with hydrophobic molecular beacon-like structures.

    Science.gov (United States)

    Latorre, Alfonso; Posch, Christian; Garcimartín, Yolanda; Ortiz-Urda, Susana; Somoza, Álvaro

    2014-03-21

    Gold nanoparticles functionalized with oligonucleotides that bear a cholesterol group are used as gene sensors. The hydrophobic molecule is buried inside the nanostructure but when the complementary RNA sequence is present the structure unfolds exposing the cholesterol group to the water molecules. This rearrangement leads to the aggregation of the nanostructures.

  2. Aspect Determination Using a Beacon with a Spiral Wave Front: Modeling and Performance Analysis in Operational Environments

    Science.gov (United States)

    2014-12-19

    phase dif- ference will be approximately equal to the aspect angle. V. LIMITATIONS The examples and applications of the mathematical transformation of the...Applied Physics Laboratory, University of Washington, Seattle, WA, USA, where he is currently a Senior Physicist in the Acoustics Department. His

  3. Quantum dots based molecular beacons for in vitro and in vivo detection of MMP-2 on tumor.

    Science.gov (United States)

    Li, Xin; Deng, Dawei; Xue, Jianpeng; Qu, Lingzhi; Achilefu, Samuel; Gu, Yueqing

    2014-11-15

    Matrix metalloproteinase-2 (MMP-2) is a protease related to tumor invasion and metastasis. It is heavily secreted by malignant tumor cells, allowing the protease to serve as an imaging biomarker of cancer. In this study, a novel sensing system based on fluorescence resonance energy transfer (FRET) from quantum dot (QD, the donor) to organic dye (the acceptor) was constructed for the in vitro and in vivo detection of matrix metalloproteinases-2 via a MMP-2-specific peptide substrate (GPLGVRGKGG). Specifically, 535 nm-emitting CdTe QD were bound to Rhodamine B (RB) through the peptide for in vitro detection of MMP-2, while 720 nm-emitting CdTeS QDs was linked to near infrared dye ICG-Der-02 (MPA) by the peptide for measurement in vivo. When these probes were exposed to MMP-2, the selective cleavage of the peptide resulted in the recovery of fluorescence from QDs. By using the produced 540QD-peptide-RB and 720QD-peptide-MPA probes, we successfully examined MMP-2 in live cells and tumor on nude mouse, respectively. Due to the tunable fluorescence of Qds, this nanosensor can be fine-tuned for a wide range of applications such as the detection of different biomarkers and early diagnosis of disease.

  4. REAL-TIME DETECTION OF SURVIVIN mRNA EXPRESSION IN CERVICAL CANCER CELL LINES USING MOLECULAR BEACON IMAGING

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The initiated growth of human cancer cells of-ten mostly come fromthe abnor mal expression ofgenes.Survivinis anapotosis inhibitor of IAPfami-ly,cloned by Ambrosini in1997usingthe cDNAofeffector cell protease receptor-1(EPR-1),and is thekey gene for the development and advancement oftumor.Inthe present study,the feasibility of detec-ting the expression of survivin mRNA was exam-inedincervical cancer cell lines using molecular bea-coni maging technology.MATERIALS AND METHODS1Cervical cancer cell lines and ce...

  5. 14 CFR 171.273 - Maintenance and operations requirements.

    Science.gov (United States)

    2010-01-01

    ... beacon power, and modulation. (18) The following information concerning the ISMLS facility: (i) Facility... emission and frequencies of the ISMLS localizer, glide path, beacon markers, and associated compass... marker beacon radiation characteristics must be conducted in accordance with the maintenance...

  6. Reflections on a giant of brain science: How lucky we are having Walter J. Freeman as our beacon in cognitive neurodynamics research.

    Science.gov (United States)

    Kozma, Robert

    2016-12-01

    Walter J. Freeman was a giant of the field of neuroscience whose visionary work contributed various experimental and theoretical breakthroughs to brain research in the past 60 years. He has pioneered a number of Electroencephalogram and Electrocorticogram tools and approaches that shaped the field, while "Freeman Neurodynamics" is a theoretical concept that is widely known, used, and respected among neuroscientists all over the world. His recent death is a profound loss to neuroscience and biomedical engineering. Many of his revolutionary ideas on brain dynamics have been ahead of their time by decades. We summarize his following groundbreaking achievements: (1) Mass Action in the Nervous System, from microscopic (single cell) recordings, through mesoscopic populations, to large-scale collective brain patterns underlying cognition; (2) Freeman-Kachalsky model of multi-scale, modular brain dynamics; (3) cinematic theory of cognitive dynamics; (4) phase transitions in cortical dynamics modeled with random graphs and quantum field theory; (5) philosophical aspects of intentionality, consciousness, and the unity of brain-mind-body. His work has been admired by many of his neuroscientist colleagues and followers. At the same time, his multidisciplinary approach combining advanced concepts of control theory and the mathematics of nonlinear systems and chaos, poses significant challenges to those who wish to thoroughly understand his message. The goal of this commemorative paper is to review key aspects of Freeman's neurodynamics and to provide some handles to gain better understanding about Freeman's extraordinary intellectual achievement.

  7. The Impact of a Traffic Alert and Collision Avoidance System on the Air Traffic Control Radar Beacon System and Mode S System in the Los Angeles Basin.

    Science.gov (United States)

    1985-05-01

    Suppressions Per Second (Standard Deviation) (491) (514) (468) (481) Average Mode S Suppressions -- 271 -- 155 . Per Second Due to - TCAS i M...0) C1 - N1 NC -: 0< H fl. ,f) SN.- - N NO w a) C C/ C-) E-12.4 * lO/~ AAPM -~/I()Appendix E i~o~r/AA/tlmH4/.1 co 00, clim a,, H mL- 0 E-n -4 ’--4 4- Ln...LO r% LO j. C E-13’ -Vr ~ Y~"v *~- W)T/ -’ AAPM - 14/3 h.N NN U)) 0 C-4 C C-4 ) H -- 1-4t- (NW cc U) ( N U) Lr.f E-1 4 󈨄 DOT/FAA/P-84/30 LIST OF

  8. Rationale and Trial Design of Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes : The Occurrence of Renal Events (BEACON)

    NARCIS (Netherlands)

    de Zeeuw, Dick; Akizawa, Tadao; Agarwal, Rajiv; Audhya, Paul; Bakrise, George L.; Chin, Melanie; Krauth, Melissa; Heerspink, Hiddo J. Lambers; Meyer, Colin J.; McMurray, John J.; Parving, Hans-Henrik; Pergola, Pablo E.; Remuzzi, Giuseppe; Toto, Robert D.; Vaziri, Nosratola D.; Wanner, Christoph; Warnock, David G.; Wittes, Janet; Chertow, Glenn M.

    2013-01-01

    Background: Chronic kidney disease (CKD) associated with type 2 diabetes mellitus constitutes a global epidemic complicated by considerable renal and cardiovascular morbidity and mortality, despite the provision of inhibitors of the renin-angiotensin-aldosterone system (RAAS). Bardoxolone methyl, a

  9. A beacon of new physics: The Pioneer anomaly modelled as a path based speed loss driven by the externalisation of aggregate non-inertial QM energy

    CERN Document Server

    Boom, Paul G ten

    2012-01-01

    This treatise outlines how a real non-systematic based Pioneer anomaly, with its implied violation (re: 'low' mass bodies only) of both general relativity's weak equivalence principle and the Newtonian inverse-square law, can be successfully modelled. These theoretical hurdles and various awkward observational constraints, such as the low value of Pioneer 11's anomaly pre-Saturn encounter, have not been convincingly modelled to date. Notwithstanding the recent trend to embrace a non-constant Sun/Earth-directed heat based explanation of this anomalous deceleration, the actual: nature, direction, and temporal and spatial variation of the Pioneer anomaly remain an open arena of research. Working backwards from the observational evidence, and rethinking: time, mass, quantum entanglement and non-locality, we hypothesise a mechanism involving a quantum mechanical energy source and a new type of 'gravitational' field; neither of which lie within general relativity's domain of formulation/application. By way of a sys...

  10. The LED Beacon prototype system for the on-shore time calibration of the KM3NeT-IT Towers

    Science.gov (United States)

    De Bonis, Giulia; Ameli, Fabrizio; Nicolau, Carlo A.; Simeone, Francesco

    2016-04-01

    The first implementation of the KM3NeT-IT neutrino telescope consists in the installation of 24 Strings and 8 Towers. Focusing on the Towers, the idea behind this work is to exploit the LED sources mounted in the OMs to develop a complementary system, on shore and before the deployment, for the determination of time delays, aiming at the characterizations of the time response of the different elements of the detector. During the assembling of the first tower, a set of measurements has been carried out; the test set-up and the measurement procedure are described, together with preliminary results of the calibration system. Lesson learnt is quite encouraging: uncertainties of the order of 400 ps are reached with very few cautions taken during the short calibration session, and with large room for improvement, making this system feasible and effective for the KM3NeT-IT experiment.

  11. 金融监管:货币市场基金发展的护航灯%Financial Supervision: A Guiding Beacon for Development of Currency Market Fund

    Institute of Scientific and Technical Information of China (English)

    高树棠; 程贵; 刘艳

    2007-01-01

    货币市场基金(Money Market Funds.MMF,以下简称MMF),是指按法律规定、投资干低风险的一种共同基金。它一般投资于低风险的政府证券、银行定期存单、商业票据和其他高流动性、低风险、收益稳定的短期证券。可见,作为基金,它具有一般基金的集中管理、共担风险、共享收益的特征;作为货币市场基金,它又具有流动性高、风险低的特点。

  12. Near-Infrared Fluorescence Imaging Guided Therapy: Molecular Beacon-Based Photosensitizers Triggered by Breast Cancer-Specific mRNA

    Science.gov (United States)

    2007-05-01

    27 and induces apoptosis upon irradiation.26,28 This semisynthetic PS, obtained by three steps from Spirulina algae , has a long- wavelength absorption...nm) and PDT (over 50% singlet oxygen yield) (13, 14). This semisynthetic photosensitizer, obtained by three steps from Spirulina algae , has minimal...succinimide ester-containing pyropheophorbide acid (Pyro), which was prepared from chlorophyll (Chl, the plant counterpart of BChl) extracted from Spirulina

  13. 分子信标PCR检测志贺菌ipaH基因%Detection of Shigella Gene ipaH Using Molecular Beacons

    Institute of Scientific and Technical Information of China (English)

    赵丽华; 周勇; 万成松

    2006-01-01

    目的用分子信标探针PCR快速检测志贺菌属(Shigella).方法根据GenBank上公布的福氏志贺菌M32063株ipaH基因序列,设计引物和分子信标探针,以4种细菌进行对照,进行特异性和灵敏度分析,建立Shigella的实时PCR技术快速检测,应用于食物中毒和食品检测.结果检测20个样本,Shigella呈阳性,其它呈阴性,时间约2 h.结论Shigella分子信标探针技术具有快速、灵敏度高、特异性强等特点,可用于Shigella食物中毒快速诊断和食品微生物检测,为食源性疾病的早期、准确诊断提供新的检测手段.

  14. HIA 2016 DOE Zero Energy Ready Home Case Study: United Way of Long Island, United Veterans, Beacon House, Deer Park, NY

    Energy Technology Data Exchange (ETDEWEB)

    Pacific Northwest National Laboratory

    2016-09-01

    Case study of a DOE 2016 Housing Innovation Award winning affordable home in the mixed-humid climate that met the DOE Zero Energy Ready Home criteria and achieved a HERS 32 without PV or HERS 9 with PV.

  15. Beacon Applications in Mobile Library Location Based Service%Beacon在基于位置的移动图书馆服务中的应用

    Institute of Scientific and Technical Information of China (English)

    黄悦深; 刘敏

    2015-01-01

    [目的/意义]面对图书馆基于位置的服务需求日益增长的情况,研究利用Beacon技术构建基于位置的移动图书馆服务的应用方案.[方法/过程]分析Beacon技术的发展、原理及研究现状,对比分析Beacon与RFID、NFC两种已用于图书馆的智能感知技术的优缺点和适用范围.[结果/结论]基于Beacon的移动图书馆应用方案比现有的图书馆LBS构建方案具有更好的情景感知性、易用性和经济性.应用方案包括无缝式服务签到、情景化服务互动、黏着式服务推广.这些应用能深化图书馆与读者的互动关系,使移动图书馆服务具有更佳的适用性.

  16. DNA Detection of Toxoplasma gondii with a Magnetic Molecular Beacon Probe via CdTe@Ni Quantum Dots as Energy Donor

    Directory of Open Access Journals (Sweden)

    Shichao Xu

    2013-01-01

    Full Text Available A new method for detection of Toxoplasma gondii via DNA sensing technology was developed in this study. It was based on the mechanism of fluorescence resonance energy transfer (FRET in which multifunctional and magnetic-fluorescent CdTe@Ni quantum dots (mQDs were utilized as energy donor and a commercial BHQ2 as acceptor. The sensing probe was fabricated by labeling a stem-loop Toxoplasma gondii DNA oligonucleotide with CdTe@Ni mQDs at the 5′ end and BHQ2 at 3′ end, respectively. The surface assembly of CdTe on Ni core and the formation of CdTe@Ni were confirmed by XRD analysis. The sizes of CdTe, Ni nanoparticles, and CdTe@Ni were measured via TEM and XRD methods and estimated to be ~3 nm, ~15 nm, and ~20 nm, respectively. The sensing ability was investigated by the fluorescence spectrum (FS. An obvious fluorescence recovery was observed when the complete complimentary target Toxoplasma gondii DNA was introduced, which did not happen in the case of the target DNA with one-base pair mismatch. Our research indicates that the current sensing probe is sensitive and specific in detection of Toxoplasma gondii DNA and has great potential in Toxoplasmosis diagnosis.

  17. 一种Beacon协助的传感器网络定位方法%MOBILE BEACON-ASSISTED LOCALIZATION IN WIRELESS SENSOR NETWORKS

    Institute of Scientific and Technical Information of China (English)

    陈和康; 周水庚

    2009-01-01

    对无线传感器网络中的定位问题进行了研究,提出一种基于移动beacon协助的定位方法,该方法仅使用一个移动beacon即可完成对整个无线传感器网络的定位.给出两种beacon移动方式来进行定位,经过大量详实的仿真实验,验证了方法的有效性及定位的高精确度,可以将平均误差缩小到30厘米.

  18. Polymorphisms in Genes of Relevance for Oestrogen and Oxytocin Pathways and Risk of Barrett's Oesophagus and Oesophageal Adenocarcinoma: A Pooled Analysis from the BEACON Consortium.

    Directory of Open Access Journals (Sweden)

    Katarina Lagergren

    Full Text Available The strong male predominance in oesophageal adenocarcinoma (OAC and Barrett's oesophagus (BO continues to puzzle. Hormonal influence, e.g. oestrogen or oxytocin, might contribute.This genetic-epidemiological study pooled 14 studies from three continents, Australia, Europe, and North America. Polymorphisms in 3 key genes coding for the oestrogen pathway (receptor alpha (ESR1, receptor beta (ESR2, and aromatase (CYP19A1, and 3 key genes of the oxytocin pathway (the oxytocin receptor (OXTR, oxytocin protein (OXT, and cyclic ADP ribose hydrolase glycoprotein (CD38, were analysed using a gene-based approach, versatile gene-based test association study (VEGAS.Among 1508 OAC patients, 2383 BO patients, and 2170 controls, genetic variants within ESR1 were associated with BO in males (p = 0.0058 and an increased risk of OAC and BO combined in males (p = 0.0023. Genetic variants within OXTR were associated with an increased risk of BO in both sexes combined (p = 0.0035 and in males (p = 0.0012. We followed up these suggestive findings in a further smaller data set, but found no replication. There were no significant associations between the other 4 genes studied and risk of OAC, BO, separately on in combination, in males and females combined or in males only.Genetic variants in the oestrogen receptor alpha and the oxytocin receptor may be associated with an increased risk of BO or OAC, but replication in other large samples are needed.

  19. 基于iBeacon技术的安全性服装设计%Security clothing design based on iBeacon technology

    Institute of Scientific and Technical Information of China (English)

    沈雷; 方东根

    2015-01-01

    绿色生态时代下,服装安全受到人们越来越多的重视.电子信息技术和材料科学等多学科的发展与交叉运用,为服装安全设计提供了更多的可能.文章将iBeacon这项技术作为安全因子引入安全性服装的设计当中,针对iBeacon的低功耗、微定位以及无缝体验感等特性,结合服装的款式、色彩和材料,融入服装流行因素和设计工艺技巧,在安全性服装前期研究的基础上,提出一种具有新的安全功能,同时又解决电子元件不能水洗等弊病的新兴安全性服装的设计方法.通过对电子元件以及服装安全系统的综合评价,及对iBeacon安全性服装进行产业化可行性分析,使安全性服装的研究向前迈进.

  20. 基于iBeacon技术的井下人员设备定位系统%Underground personnel and equipment location system based on iBeacon technology

    Institute of Scientific and Technical Information of China (English)

    张航; 孙效玉; 田凤亮

    2016-01-01

    为了更好地解决矿山井下人员设备定位问题,深入分析了iBeacon室内定位技术的定位原理和算法,提出了基于iBeacon技术的井下人员设备定位系统设计方案,详细介绍了系统的架构、信标布设、移动App开发.应用iBeacon技术进行井下人员设备定位,具有定位精度高、部署方便、导航快捷等优势.

  1. Research on Indoor Positioning Technique Based on iBeacon Base Station%基于iBeacon基站的室内定位技术研究

    Institute of Scientific and Technical Information of China (English)

    石志京; 徐铁峰; 刘太君; 刘明伟

    2015-01-01

    提出了一种基于iBeacon基站的室内定位方案.在该技术方案中,iBeacon基站由蓝牙4.0模块组建,在需要定位的室内空间均匀部署一定数量的iBeacon基站,该基站周期性地向外界广播自己独有的与位置信息对应的UUID号.当持有蓝牙终端设备的用户进入该基站感应区,接收到基站广播的UUID号及RSSI值,通过加权的三环定位算法即可对用户进行精确定位.实验结果表明,该方案定位精度能达到2.5m以内,满足了绝大多数的室内定位技术要求.

  2. 应用iBeacon的O2O解决方案%Solution of O2O Using iBeacon Technology

    Institute of Scientific and Technical Information of China (English)

    马弢

    2015-01-01

    分析基于服务类电商的O2O模式兴起的原因及应用场景,对iBeacon等周边互联技术进行研究,介绍iBeacon技术的应用商业场景和局限性,最后对未来基于服务类电子商务的新商业模式进行了展望.

  3. YTL-A型遥控太阳能测验标志灯%YTL-A Type Solar Energy Beacon Light of Wireless Remote Control for Flow Measurement

    Institute of Scientific and Technical Information of China (English)

    张广海

    2003-01-01

    目前黄河上多使用吊船进行水文测验,测船的定位以六分仪为主,夜间测验靠标志灯指引方向,由于标志灯使用普通白炽灯,存在着许多问题,影响了测验的顺利进行.介绍了采用先进的发光材料研制的YTL-A型遥控太阳能测验标志灯.该测验标志灯应用于水文测验中,取得了较好的效果.

  4. 46 CFR 113.25-10 - Emergency red-flashing lights.

    Science.gov (United States)

    2010-10-01

    ... heard over the background noise, there must be a red-flashing light or rotating beacon, in addition to... system. (b) A red-flashing light or rotating beacon must be installed so that it is visible in the...

  5. 14 CFR 171.23 - Requests for IFR procedure.

    Science.gov (United States)

    2010-01-01

    ...) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Nondirectional Radio Beacon Facilities § 171.23... beacon facility that he owns must submit the following information with that request: (1) A...

  6. 14 CFR 171.21 - Scope.

    Science.gov (United States)

    2010-01-01

    ... FACILITIES NON-FEDERAL NAVIGATION FACILITIES Nondirectional Radio Beacon Facilities § 171.21 Scope. (a) This... radio beacon facilities that are to be involved in the approval of instrument flight rules and air traffic control procedures related to those facilities. (b) A nondirectional radio beacon (“H”...

  7. 14 CFR 171.309 - General requirements.

    Science.gov (United States)

    2010-01-01

    ... and may be integrated in the same equipment. (6) At locations where a VHF marker beacon (75 MHz) is..., remote control and indicator equipment. (4) VHF marker beacon (75 MHz), associated monitor, remote... beacon components listed in paragraph (b)(4) of this section must comply with the minimum...

  8. 33 CFR 110.138 - Boston Harbor, Mass.

    Science.gov (United States)

    2010-07-01

    ... Island Anchorage. Beginning at a point bearing 93°, 1,400 yards, from the aerial beacon on top of the Boston Custom House tower; thence to a point bearing 81°, 1,600 yards, from the aerial beacon on top of the Boston Custom House tower; thence to a point bearing 102°, 3,100 yards, from the aerial beacon...

  9. 副溶血性弧菌tdh基因的分子信标PCR技术检测%Detection of thermostable direct hemolysin gene in Vibrio parahaemolyticus by molecular beacon PCR

    Institute of Scientific and Technical Information of China (English)

    万成松; 谭翰清; 温文川

    2006-01-01

    目的 采用分子信标PCR技术进行副溶血性弧菌tdh基因检测.方法 在反应体系中加入分子信标探针,对13株副溶血性弧菌和其他细菌分别进行tdh基因实时和终点法荧光检测.结果 2株副溶血性弧菌和阳性质粒的终点法检测荧光值分别为114.9,95.2,90.0.实时PCR检测的CT值分别为26.2,26.8,32.0.其他肠道细菌终点法检测荧光值为47.0~69.1;CT值>32.0或无值,与琼脂糖电泳分析结果一致.结论 分子信标PCR技术可以准确、快速、实时、简便地进行副溶血性弧菌tdh基因检测.

  10. An X-ray and Multiwavelength Survey of Highly Radio-Loud Quasars at z > 4: Jet-Linked Emission in the Brightest Radio Beacons of the Early Universe

    CERN Document Server

    Wu, Jianfeng; Miller, Brendan P; Garmire, Gordon P; Schneider, Donald P; Vignali, Cristian

    2013-01-01

    (Abridged) We present a systematic study of the X-ray and multiwavelength properties of a sample of 17 highly radio-loud quasars (HRLQs) at z > 4 with sensitive X-ray coverage from new Chandra and archival Chandra, XMM-Newton, and Swift observations. Eight of the new and archival observations are reported in this work for the first time. New Chandra observations of two moderately radio-loud and highly optically luminous quasars at z > 4 are also reported. Our HRLQ sample represents the top ~5% of radio-loud quasars in terms of radio loudness. We found that our HRLQs have an X-ray emission enhancement over HRLQs at lower redshifts (by a typical factor of ~3), and this effect, after controlling for several factors which may introduce biases, has been solidly estimated to be significant at the 3-4 sigma level. HRLQs at z=3-4 are also found to have a similar X-ray emission enhancement over z < 3 HRLQs, which supports further the robustness of our results. We discuss models for the X-ray enhancement's origin in...

  11. Baseline characteristics in the Bardoxolone methyl EvAluation in patients with Chronic kidney disease and type 2 diabetes mellitus : the Occurrence of renal eveNts (BEACON) trial

    NARCIS (Netherlands)

    Heerspink, Hiddo J. Lambers; Chertow, Glenn M.; Akizawa, Tadao; Audhya, Paul; Bakris, George L.; Goldsberry, Angie; Krauth, Melissa; Linde, Peter; McMurray, John J.; Meyer, Colin J.; Parving, Hans-Henrik; Remuzzi, Giuseppe; Christ-Schmidt, Heidi; Toto, Robert D.; Vaziri, Nosratola D.; Wanner, Christoph; Wittes, Janet; Wrolstad, Danielle; de Zeeuw, Dick

    2013-01-01

    Background. Type 2 diabetes mellitus (T2DM) is the most important contributing cause of end-stage renal disease (ESRD) worldwide. Bardoxolone methyl, a nuclear factor-erythroid-2-related factor 2 activator, augments estimated glomerular filtration. The Bardoxolone methyl EvAluation in patients with

  12. 一种基于iBeacon和Wi-Fi的位置空间模型定位方法%A Space Model Positioning Method Based on iBeacon and Wi-Fi

    Institute of Scientific and Technical Information of China (English)

    孔勇平; 钟致民; 杨广龙; 张玉良

    2015-01-01

    从信号传播的物理建模转变为对信号环境与用户行为的建模,提出了一种基于iBeacon和Wi-Fi的位置空间模型定位技术和算法.通过iBeacon、空间位置及POI构建位置空间模型索引,并根据用户的常态行为特征,对空间位置和POI分别设置不同权重,最后通过位置空间模型索引计算终端的具体位置,显著提高了定位的合理性和精度.

  13. 基于iBeacon技术的微信"摇一摇"考勤系统的实现%The Application of WeChat "Shake-Around" to Attendance System Based on iBeacon Technology

    Institute of Scientific and Technical Information of China (English)

    郭玲

    2016-01-01

    介绍了一种结合移动互联网技术和智能手机应用实现的创新型考勤系统.系统采用iBeacon设备进行员工定位,使用微信"摇一摇"记录考勤行为,并推送考勤信息到后台处理程序,完成数据存储及数据分析统计.系统具有精确、高效、低成本和部署方便的特点.

  14. Application of Navigation System Based on iBeacon Technology in Tourist Attractions%基于iBeacon技术的导览系统在旅游景区的运用

    Institute of Scientific and Technical Information of China (English)

    连毅斌

    2016-01-01

    论述了基于iBeacon技术的导览系统在旅游景区的运用方案.导览系统为游客提供地图定位、线路规划、自助导游、消息推送等个性化服务的同时,还具有智能商业/商铺信息互动、智能停车引导、孩童走失预警等特殊服务功能.

  15. Study and Implementation of Library Indoor Positioning Based on WeChat and iBeacon%基于微信与iBeacon的图书馆室内定位的研究与实现

    Institute of Scientific and Technical Information of China (English)

    陈晨

    2016-01-01

    [目的/意义]旨在实现图书馆室内精确定位,指引读者更快找到所需资源,提升图书馆服务效率.[方法/过程]以微信公众平台为依托,结合蓝牙硬件设备iBeacon及HTML5页面,实现北京市委党校图书馆室内定位系统的设计与开发.[结果/结论]读者通过使用室内定位服务可更好地寻找到周边的优质图书资源,并且对图书馆的楼层布局有一个更全面的了解;基于蓝牙设备的图书馆室内定位成本低、准确度高,读者更有意愿主动通过它去了解图书馆的相关资源.

  16. 基于iBeacon的智能导览系统的设计与实现%The Design And Implementation Of Intelligence Guidance System Based On iBeacon

    Institute of Scientific and Technical Information of China (English)

    吴栋淦

    2014-01-01

    运行在移动互联网设备上的传统智能导览系统体验性不佳.文中介绍了一种使用iBeacon技术的智能导览系统.该技术能让移动互联网设备靠近iBeacon设备时进行响应.iBeacon设备使用低功耗蓝牙技术与移动互联设备进行数据传输.

  17. Research on Indoor Positioning Algorithm Based on BL4 .0 iBeacon Technology%基于BL4.0 iBeacon技术的室内定位算法研究

    Institute of Scientific and Technical Information of China (English)

    蔡文郁; 周展业; 张栋

    2016-01-01

    通过BL4.0 iBeacon技术进行室内定位,分析了最邻近值算法和贝叶斯算法的不足,提出一种将上述两者优点进行融合的算法.首先,使用最邻近值算法的优选区域限定,缩小贝叶斯算法对指纹库的搜索范围,然后,采用贝叶斯概率法计算各个iBeacon节点的信号强度值集合在指纹库中每一位置参考点对应的条件概率值,概率最大的点就是待测点的预测位置.实验结果表明,使用该算法计算的坐标准确度比较高,坐标误差较小,能明显提高室内定位的精度.

  18. Detection of the Salmonella invasion gene invA using molecular beacon probe%分子信标探针技术检测沙门菌invA基因

    Institute of Scientific and Technical Information of China (English)

    万成松; 李俊艾; 罗军

    2004-01-01

    目的研究沙门菌的分子信标基因检测方法.方法在PCR反应体系中加入分子信标探针,探针的5′端标记6-fluorescine(6-FAM),3′端标记4-(dimethylaminophenylazo)benzoicacid(DABCYL),对沙门菌invA基因PCR产物进行荧光检测.结果肠炎沙门菌、甲型副伤寒沙门菌、乙型副伤寒沙门菌、伤寒沙门菌"H"、伤寒沙门菌和肠侵袭型大肠杆菌的荧光值分别为161.6、104.5、85.9、83.1、94.8、46.1,Ax值(样本荧光值-空白对照荧光值)分别为121.3、64.2、45.6、42.8、54.5、5.8,沙门菌的Ax值均大于21,结果阳性,与琼脂糖电泳分析结果一致.结论分子信标探针技术可以准确、快速、简便进行沙门菌invA基因检测.

  19. Molecular beacon real-time PCR in the detection of Mycobacterium tuberculosis%分子信标荧光探针检测结核分枝杆菌的临床应用

    Institute of Scientific and Technical Information of China (English)

    张治国; 钟镐镐; 孙桂芝; 衡万杰; 吴秉铨; 韩跃飞

    2006-01-01

    目的:探讨分子信标荧光探针检测结核分枝杆菌的临床应用价值.方法:应用设置内参照的分子信标荧光探针检测178例肺结核标本,并与痰涂片和培养结果进行比较.结果:肺结核组分子信标荧光探针阳性率显著高于痰涂片和培养,检出率分别为56.2%(100/178),34.8%(62/178)、34.8%(62/178).结论:分子信标荧光探针具有较高的灵敏度和特异度,对结核病的辅助诊断有一定的临床意义.

  20. Fluorescence Quantitative PCR Detection of Transgenic Food Based on Molecular Beacon Probe%基于分子信标探针的荧光定量PCR方法检测转基因食品

    Institute of Scientific and Technical Information of China (English)

    刘光明; 苏文金; 蔡慧农; 蔡海松; 林新坚; 张伟光

    2006-01-01

    选择了内源基因大豆植物凝集素(lectin)、玉米转化酶(invertase)和外源基因花椰菜花叶病毒35S(CaMV35S)启动子的分子信标探针,确定了探针浓度和镁离子浓度等反应条件,分别对转基因大豆和转基因玉米系列标准品进行内源基因和外源基因的荧光PCR扩增,在PCR反应过程中分别以两种荧光通道信号分别追踪同一样品DNA内源基因和外源基因的扩增动力学变化,并依此绘制了循环阈值与转基因食品百分比含量之间的标准曲线,建立了转基因大豆和转基因玉米的分子信标探针-荧光定量PCR检测方法,该方法具有特异性强、敏感性高的特点,实现了对转基因食品的定量分析.图7表1参11

  1. Advanced Conveyance Security Device System Scalability Assessment: Combined 802.15.4 and IP Network Simulation

    Science.gov (United States)

    2009-02-01

    channel non-beaconed scan. The Test Report on CSD-DCP Latency [ 1 ] shows that using beacons for network discovery takes more time than not using beacons... 1 . SSC Pacific , “CSD Communications Test Report on CSD-DCP Latency and Multi- Lane Portal Wireless Range, Version 1.7,” Space and Naval Warfare...BIBLIOGRAPHY 1 . Bagrodia, R, et al, “An Accurate, Scalable Communication Effects Server for the FCS System of Systems Simulation Environment

  2. A review of fade detection techniques

    Science.gov (United States)

    Pergal, F. J.

    1990-01-01

    Several proposed propagation fade detection techniques are reviewed in light of general requirements presented for beacon fade characterization. The discussion includes an analysis of phase lock versus frequency lock beacon tracking loops and of excess noise injection type radiometers. The Advanced Communications Technology Satellite (ACTS) beacon fade detection schemes proposed by the Communications Satellite Corporation and the Jet Propulsion Laboratory are examined along with the fade detection technique used by Harris in the Advanced Communications Technology Satellite (ACTS) low burst rate (LBR) terminal.

  3. Mode S Baseline Radar Tracking.

    Science.gov (United States)

    1982-11-01

    range units and 20 azimuth units) overlaying the position of the beacon reports. In the cases analyzed where beacon reports were not radar reinforced ...82/53 j~ C ~ 7 C _ _ _ _ _ _ 4. Title end Su.btitle 5. Neget at. November 1982 MDDE S BASELINE RADAR TRACKIN4G 6. Poelin Orgeuianti.. Cede ACT-100...Ground Clutter 33 Mode S/ARTS III 100-Scan False Radar Track Summary 74 34 Percent Beacon Radar Reinforcement 77 vii INTRODUCTION PURPOSE. The purpose of

  4. 14 CFR 171.25 - Minimum requirements for approval.

    Science.gov (United States)

    2010-01-01

    ... (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Nondirectional Radio Beacon Facilities... met before the FAA will approve an IFR procedure for a non-Federal, nondirectional radio...

  5. 78 FR 61203 - Aviation Services

    Science.gov (United States)

    2013-10-03

    ... as the terms ``small business,'' ``small organization,'' and ``small governmental jurisdiction.'' In... Universal Access Transceiver; 1030 MHz for air traffic control radar beacon transponders; 1090 MHz...

  6. A contention-based efficient-information perception algorithm (CEiPA) for vehicular ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    Chen Lijia; Jiang Hao; Yan Puliu

    2009-01-01

    The problem of information dissemination is researched for vehicular ad-hoc networks (VANET) in this paper, and a contention-based efficient-information perception algorithm (CEiPA) is proposed. The idea of CEiPA is that beacons are delivered over VANET with limited lifetime and efficient information. CEiPA consists of two phases. The first one is initialization phase, during which the count timers Tcycle and Tlocal are set to start beacon delivery while Tcycle is also used to monitor and restart beaconing. The second one is beacon delivery phase. An elaborate distance function is employed to set contention delay for beacons of each vehicle. In this way beacons will be sent in order, which decreases the collision of beacons. Simulation results show that CEiPA enables each beacon to carry more efficient information and spread them over more vehicles with lower network overhead than the periodic beacon scheme. CEiPA is also flexible and scalable because the efficient information threshold it employs is a balance among the freshness of information, network overhead and perception area of a vehicle.

  7. Altruistic Backoff: Collision Avoidance for Receiver-Initiated MAC Protocols for Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Fafoutis, Xenofon; Orfanidis, Charalampos; Dragoni, Nicola

    2014-01-01

    In receiver-initiated medium access control (MAC) protocols for wireless sensor networks, communication is initiated by the receiver node which transmits beacons indicating its availability to receive data. In the case of multiple senders having traffic for a given receiver, such beacons form...... points where collisions are likely to happen. In this paper, we present altruistic backoff (AB), a novel collision avoidance mechanism that aims to avoid collisions before the transmission of a beacon. As a result of an early backoff, senders spend less time in idle listening waiting for a beacon, thus...

  8. Gold Nanoparticle-Based Sensors Activated by External Radio Frequency Fields

    DEFF Research Database (Denmark)

    Della Vedova, Paolo; Ilieva, Mirolyuba; Zhurbenko, Vitaliy

    2015-01-01

    A novel molecular beacon (a nanomachine) is constructed that can be actuated by a radio frequency (RF) field. The nanomachine consists of the following elements arranged in molecular beacon configuration: a gold nanoparticle that acts both as quencher for fluorescence and a localized heat source......; one reporter fluorochrome, and; a piece of DNA as a hinge and recognition sequence. When the nanomachines are irradiated with a 3 GHz RF field the fluorescence signal increases due to melting of the stem of the molecular beacon. A control experiment, performed using molecular beacons synthesized...

  9. 76 FR 52734 - Underwater Locating Devices (Acoustic) (Self-Powered)

    Science.gov (United States)

    2011-08-23

    ... Brazilian authorities but the flight data recorder and cockpit voice recorder were not recovered until April... for underwater locator beacons installed on flight recorders on airplanes performing public...

  10. 77 FR 73412 - Newspapers Used for Publication of Legal Notices in the Southwestern Region, Which Includes...

    Science.gov (United States)

    2012-12-10

    ...: --``Farmington Daily Times'', Farmington, New Mexico. Cibola National Forest and National Grasslands Notices for.... Taylor Ranger District Notices are published in:--``Cibola County Beacon'', Grants, New Mexico....

  11. 78 FR 77096 - Newspapers Used for Publication of Legal Notices in the Southwestern Region, Which Includes...

    Science.gov (United States)

    2013-12-20

    ...'', Farmington, New Mexico. Cibola National Forest and National Grasslands Notices for Availability for Comments... Notices are published in:--``Cibola County Beacon'', Grants, New Mexico. Magdalena Ranger District...

  12. 76 FR 75866 - Newspapers Used for Publication of Legal Notices in the Southwestern Region, Which Includes...

    Science.gov (United States)

    2011-12-05

    .... Cibola National Forest and National Grasslands Notices for Availability for Comments, Decisions and...:--``Cibola County Beacon'', Grants, New Mexico. Magdalena Ranger District Notices are published...

  13. Design and optimization of indoor optical wireless positioning systems

    Science.gov (United States)

    Bergen, Mark H.; Guerrero, Daniel; Jin, Xian; Hristovski, Blago A.; Chaves, Hugo A. L. F.; Klukas, Richard; Holzman, Jonathan F.

    2016-03-01

    Optical wireless (OW) technologies are an emerging field utilizing optical sources to replace existing radio wavelength technologies. The vast majority of work in OW focuses on communication; however, one smaller emerging field is indoor OW positioning. This emerging field essentially aims to replace GPS indoors. One of the primary competing methods in indoor OW positioning is angle-of-arrival (AOA). AOA positioning uses the received vectors from several optical beacons to triangulate its position. The reliability of this triangulation is fundamentally based on two aspects: the geometry of the optical receiver's location compared to the optical beacon locations, and the ability for the optical receiver to resolve the incident vectors correctly. The optical receiver is quantified based on the standard deviation of the azimuthal and polar angles that define the measured vector. The quality of the optical beacon geometry is quantified using dilution of precision (DOP). This proceeding discusses the AOA standard deviation of an ultra-wide field-of-view (FOV) lens along with the DOP characteristics for several optical beacon geometries. The optical beacon geometries used were simple triangle, square, and hexagon optical beacon geometries. To assist the implementation of large optical beacon geometries it is proposed to use both frequency and wavelength division multiplexing. It is found that with an ultra-wide FOV lens, coupled with the appropriately sized optical beacon geometry, allow for high accuracy positioning over a large area. The results of this work will enable reliable OW positioning deployments.

  14. 47 CFR 95.1401 - Frequency.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Frequency. 95.1401 Section 95.1401... SERVICES Personal Locator Beacons (PLB). § 95.1401 Frequency. The frequency band 406.0-406.1 MHz is an emergency and distress frequency band available for use by Personal Locator Beacons (PLBs). Personal...

  15. Range-based underwater vehicle localization in the presence of unknown ocean currents: Theory and experiments

    Digital Repository Service at National Institute of Oceanography (India)

    Bayat, M.; Crasta, N.; Aguiar, A.P.; Pascoal, A.M.

    , and an acoustic device that provides measurements of its distance to a set of stationary beacons. We consider the situation where the number of active beacons is not known in advance and may vary with time. The objective is to simultaneously localize the AUV...

  16. Internal Wave Generation Processes at Deep-Sills in the Luzon Passage Region of the South China Sea

    Science.gov (United States)

    2012-09-30

    a Benthos pinger, and Vader with an Xeos GPS iridium beacon. Both instruments were ballasted to fall at 0.75 m/s using two expendable weights. Vito...Initially, it was used with the Benthos pinger with 2 drop-weights, but was later switched to the Xeos GPS beacon with 1 drop-weight. The latter

  17. 南疆的烽燧

    Institute of Scientific and Technical Information of China (English)

    尚昌平; 方浩

    2015-01-01

    As hundreds of years went by, the important beacon towers built by past dynasties fell to ruin. Dependent for their upkeep on military needs, they all were eventually abandoned due to political turbulence or the difficulty of manning and upkeep in harsh natural conditions. Beacon towers lost their function and became outworn relics, useful only for pondering the past.

  18. Evolution in a Test Tube: Exploring the Structure and Function of RNA Probes

    Science.gov (United States)

    2008-05-02

    Beacon Aptamers. Biochemical and Biophysical Research Communications 359: 94-101. 7 Nutiu, R. and Li, Y. (2003). Structure-Switching Signaling...Selection of RNA Beacon Aptamers. Biochemical and Biophysical Research Communications 359: 94-101. “Polymerase Chain Reaction”, Access Excellence

  19. NPS-SCAT: A CubeSat Communications System Design, Test, and Integration

    Science.gov (United States)

    2009-06-01

    2450-120SA......................................85 Figure 21. CP2 With Beacon Antenna Structure Visible.......86 Figure 22. Half-wave dipole...Figure 21. CP2 With Beacon Antenna Structure Visible The radiation pattern of a dipole of arbitrary length can be generated through a MATLAB script

  20. Hypermedia Applications for Army Installation Master Planning

    Science.gov (United States)

    1993-01-01

    node E, "pizza 8 1. Habermas . Communication and the Evolution of Society (Beacon Press, 1979). 9 J. Forester. 10 1. Friend and A. Hickling, Planning...Planning Under Pressure (Pergamon, 1987). Gillenson. M.L., Database (Wiley, 1985). Habermas , J., Communication and the Evolution of Society (Beacon Press