Sample records for intersatellite link isl

  1. Intersatellite Link (ISL) application to commercial communications satellites. Volume 2: Technical final report

    NASA Technical Reports Server (NTRS)

    Young, S. Lee

    1987-01-01

    Intersatellite Link (ISL) applications can improve and expand communication satellite services in a number of ways. As the demand for orbital slots within prime regions of the geostationary arc increases, attention is being focused on ISLs as a method to utilize this resource more efficiently and circumvent saturation. Various GEO-to-GEO applications were determined that provide potential benefits over existing communication systems. A set of criteria was developed to assess the potential applications. Intersatellite link models, network system architectures, and payload configurations were developed. For each of the chosen ISL applications, ISL versus non-ISL satellite systems architectures were derived. Both microwave and optical ISL implementation approaches were evaluated for payload sizing and cost analysis. The technological availability for ISL implementations was assessed. Critical subsystems technology areas were identified, and an estamate of the schedule and cost to advance the technology to the requiered state of readiness was made.

  2. Intersatellite Link (ISL) application to commercial communications satellites. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Young, S. Lee

    1987-01-01

    Based on a comprehensive evaluation of the fundamental Intersatellite Link (ISL) systems characteristics, potential applications of ISLs to domestic, regional, and global commercial satellite communications were identified, and their cost-effectiveness and other systems benefits quantified wherever possible. Implementation scenarios for the cost-effective communications satellite systems employing ISLs were developed for the first launch in 1993 to 1994 and widespread use of ISLs in the early 2000's. Critical technology requirements for both the microwave (60 GHz) and optical (0.85 micron) ISL implementations were identified, and their technology development programs, including schedule and cost estimates, were derived.

  3. Microwave intersatellite links for communications satellites

    NASA Technical Reports Server (NTRS)

    Welti, G. R.

    1982-01-01

    Applications and interface requirements for intersatellite links (ISLs) between commercial communications satellites are reviewed, ranging from ISLs between widely separated satellites to ISLs between clustered satellites. On-board processing architectures for ISLs employing a variety of modulation schemes are described. These schemes include FM remodulation and QPSK regeneration in combination with switching and buffering. The various architectures are compared in terms of complexity, required performance, antenna size, mass, and power.

  4. Intersatellite link application to commercial communications satellites

    NASA Technical Reports Server (NTRS)

    Lee, Young S.; Atia, Ali E.; Ponchak, Denise S.

    1988-01-01

    The fundamental characteristics of intersatellite link (ISL) systems, and their application to domestic, regional, and global satellite communications, are described. The quantitative advantages of using ISLs to improve orbit utilization, spectrum occupancy, transmission delay (compared to multi-hop links), coverage, and connectivity, and to reduce the number of earth station antennas, are also presented. Cost-effectiveness and other systems benefits of using ISLs are identified, and the technical and systems planning aspects of ISL systems implementation are addressed.

  5. Optical intersatellite links - Application to commercial satellite communications

    NASA Technical Reports Server (NTRS)

    Paul, D.; Faris, F.; Garlow, R.; Inukai, T.; Pontano, B.; Razdan, R.; Ganz, Aura; Caudill, L.

    1992-01-01

    Application of optical intersatellite links for commercial satellite communications services is addressed in this paper. The feasibility of commercialization centers around basic issues such as the need and derived benefits, implementation complexity and overall cost. In this paper, commercialization of optical ISLs is assessed in terms of the services provided, systems requirements and feasibility of appropriate technology. Both long- and short-range ISLs for GEO-GEO, GEO-LEO and LEO applications are considered. Impact of systems requirements on the payload design and use of advanced technology in reducing its mass, power, and volume requirements are discussed.

  6. APM for a Constellation Intersatellite Link - EM Qualification and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Hartel, Frank; Kozilek, Horst

    2016-01-01

    For an Intersatellite Link (ISL) of a future constellation program, a study phase was initiated by ESA to design a mechanism for Radio Frequency communication. Airbus DS Friedrichshafen (ADSF) proposed a design based on the Antenna Pointing Mechanism (APM) family with modifications that met the stated needs of the constellation. A qualification program was started beginning in September 2015 to verify the launch and thermal loads and the equipment performance (Radio Frequency, Pointing, Microvibration and Magnetic Moment). Technical challenges identified with the Engineering Model will be discussed within this paper.

  7. Ranging Consistency Based on Ranging-Compensated Temperature-Sensing Sensor for Inter-Satellite Link of Navigation Constellation

    PubMed Central

    Meng, Zhijun; Yang, Jun; Guo, Xiye; Zhou, Yongbin

    2017-01-01

    Global Navigation Satellite System performance can be significantly enhanced by introducing inter-satellite links (ISLs) in navigation constellation. The improvement in position, velocity, and time accuracy as well as the realization of autonomous functions requires ISL distance measurement data as the original input. To build a high-performance ISL, the ranging consistency among navigation satellites is an urgent problem to be solved. In this study, we focus on the variation in the ranging delay caused by the sensitivity of the ISL payload equipment to the ambient temperature in space and propose a simple and low-power temperature-sensing ranging compensation sensor suitable for onboard equipment. The experimental results show that, after the temperature-sensing ranging compensation of the ISL payload equipment, the ranging consistency becomes less than 0.2 ns when the temperature change is 90 °C. PMID:28608809

  8. Time synchronization of new-generation BDS satellites using inter-satellite link measurements

    NASA Astrophysics Data System (ADS)

    Pan, Junyang; Hu, Xiaogong; Zhou, Shanshi; Tang, Chengpan; Guo, Rui; Zhu, Lingfeng; Tang, Guifeng; Hu, Guangming

    2018-01-01

    Autonomous satellite navigation is based on the ability of a Global Navigation Satellite System (GNSS), such as Beidou, to estimate orbits and clock parameters onboard satellites using Inter-Satellite Link (ISL) measurements instead of tracking data from a ground monitoring network. This paper focuses on the time synchronization of new-generation Beidou Navigation Satellite System (BDS) satellites equipped with an ISL payload. Two modes of Ka-band ISL measurements, Time Division Multiple Access (TDMA) mode and the continuous link mode, were used onboard these BDS satellites. Using a mathematical formulation for each measurement mode along with a derivation of the satellite clock offsets, geometric ranges from the dual one-way measurements were introduced. Then, pseudoranges and clock offsets were evaluated for the new-generation BDS satellites. The evaluation shows that the ranging accuracies of TDMA ISL and the continuous link are approximately 4 cm and 1 cm (root mean square, RMS), respectively. Both lead to ISL clock offset residuals of less than 0.3 ns (RMS). For further validation, time synchronization between these satellites to a ground control station keeping the systematic time in BDT was conducted using L-band Two-way Satellite Time Frequency Transfer (TWSTFT). System errors in the ISL measurements were calibrated by comparing the derived clock offsets with the TWSTFT. The standard deviations of the estimated ISL system errors are less than 0.3 ns, and the calibrated ISL clock parameters are consistent with that of the L-band TWSTFT. For the regional BDS network, the addition of ISL measurements for medium orbit (MEO) BDS satellites increased the clock tracking coverage by more than 40% for each orbital revolution. As a result, the clock predicting error for the satellite M1S was improved from 3.59 to 0.86 ns (RMS), and the predicting error of the satellite M2S was improved from 1.94 to 0.57 ns (RMS), which is a significant improvement by a factor of 3-4.

  9. The Availability of Space Service for Inter-Satellite Links in Navigation Constellations

    PubMed Central

    Tang, Yinyin; Wang, Yueke; Chen, Jianyun

    2016-01-01

    Global navigation satellite systems (GNSS) are widely used in low Earth orbit (LEO) satellite navigation; however, their availability is poor for users in medium Earth orbits (MEO), and high Earth orbits (HEO). With the increasing demand for navigation from MEO and HEO users, the inadequate coverage of GNSS has emerged. Inter-satellite links (ISLs) are used for ranging and communication between navigation satellites and can also serve space users that are outside the navigation constellation. This paper aims to summarize their application method and analyze their service performance. The mathematical model of visibility is proposed and then the availability of time division ISLs is analyzed based on global grid points. The BeiDou navigation constellation is used as an example for numerical simulation. Simulation results show that the availability can be enhanced by scheduling more satellites and larger beams, while the presence of more users lowers the availability. The availability of navigation signals will be strengthened when combined with the signals from the ISLs. ISLs can improve the space service volume (SSV) of navigation constellations, and are therefore a promising method for navigation in MEO/HEO spacecraft. PMID:27548181

  10. The scheme of LLSST based on inter-satellite link for planet gravity field measurement in deep-space mission

    NASA Astrophysics Data System (ADS)

    Yang, Yikang; Li, Xue; Liu, Lei

    2009-12-01

    Gravity field measurement for the interested planets and their moos in solar system, such as Luna and Mars, is one important task in the next step of deep-space mission. In this paper, Similar to GRACE mission, LLSST and DOWR technology of common-orbit master-slave satellites around task planet is inherited in this scheme. Furthermore, by intersatellite 2-way UQPSK-DSSS link, time synchronization and data processing are implemented autonomously by masterslave satellites instead of GPS and ground facilities supporting system. Conclusion is derived that the ISL DOWR based on 2-way incoherent time synchronization has the same precise level to GRACE DOWR based on GPS time synchronization. Moreover, because of inter-satellite link, the proposed scheme is rather autonomous for gravity field measurement of the task planet in deep-space mission.

  11. 5.6 Gbps optical intersatellite communication link

    NASA Astrophysics Data System (ADS)

    Smutny, Berry; Kaempfner, Hartmut; Muehlnikel, Gerd; Sterr, Uwe; Wandernoth, Bernhard; Heine, Frank; Hildebrand, Ulrich; Dallmann, Daniel; Reinhardt, Martin; Freier, Axel; Lange, Robert; Boehmer, Knut; Feldhaus, Thomas; Mueller, Juergen; Weichert, Andreas; Greulich, Peter; Seel, Stefan; Meyer, Rolf; Czichy, Reinhard

    2009-02-01

    A 5.6 Gbps optical communication link has been verified in-orbit. The intersatellite link uses homodyne BPSK (binary phase shift keying) and allows to transmit data with a duplex data rate of 5.6 Gbps and a bit error rate better than 10-9 between two LEO satellites, NFIRE (U.S.) and TerraSAR-X, Germany). We report on the terminal design and the link performance during the measurement campaign. As an outlook we report on the flight units adapted to LEO-to-GEO intersatellite links that TESAT currently builds and on plans to study GEO-to-ground links.

  12. Do future commercial broadband communication satellites really need laser-communication intersatellite links (ISLs)?

    NASA Astrophysics Data System (ADS)

    Freidell, James E.

    1997-04-01

    Large commercial satellite programs requiring ISLs are growing in number and maturing. An important segment of the commercial satellite market, and its ISL needs, is discussed in the paper. ISL value will increase as long-haul terrestrial backbones become increasingly congested. Providing interregional and intercontinental connectivity via ISL presents far lower cost and fewer problems than relying on terrestrial fiber-optic networks. To demonstrate this, a new metric is proposed which allows 'apples-to- apples' cost/performance comparisons between laser communications in GEO, LEO, and terrestrial fiber-optics. ISL requirements in to the next decade are predicted >= 50-100 Gb/s full duplex. Many attitudinal changes must be embraced among those who choose to focus on this new commercial business. Foremost among these is a preponderance to delivering fully acceptable hardware fast and at low cost, as opposed to merely designing such. Considerable attention must be given business considerations foreign to professionals who have spent time in the government or government contracting sectors. Successful ISL customers will come to recognize that ISLs are not commodity products. Failure to embrace these attitudes will nonetheless constitute decision to which the commercial market, and particularly the financial market, will appropriately respond.

  13. Orbit determination of the Next-Generation Beidou satellites with Intersatellite link measurements and a priori orbit constraints

    NASA Astrophysics Data System (ADS)

    Ren, Xia; Yang, Yuanxi; Zhu, Jun; Xu, Tianhe

    2017-11-01

    Intersatellite Link (ISL) technology helps to realize the auto update of broadcast ephemeris and clock error parameters for Global Navigation Satellite System (GNSS). ISL constitutes an important approach with which to both improve the observation geometry and extend the tracking coverage of China's Beidou Navigation Satellite System (BDS). However, ISL-only orbit determination might lead to the constellation drift, rotation, and even lead to the divergence in orbit determination. Fortunately, predicted orbits with good precision can be used as a priori information with which to constrain the estimated satellite orbit parameters. Therefore, the precision of satellite autonomous orbit determination can be improved by consideration of a priori orbit information, and vice versa. However, the errors of rotation and translation in a priori orbit will remain in the ultimate result. This paper proposes a constrained precise orbit determination (POD) method for a sub-constellation of the new Beidou satellite constellation with only a few ISLs. The observation model of dual one-way measurements eliminating satellite clock errors is presented, and the orbit determination precision is analyzed with different data processing backgrounds. The conclusions are as follows. (1) With ISLs, the estimated parameters are strongly correlated, especially the positions and velocities of satellites. (2) The performance of determined BDS orbits will be improved by the constraints with more precise priori orbits. The POD precision is better than 45 m with a priori orbit constrain of 100 m precision (e.g., predicted orbits by telemetry tracking and control system), and is better than 6 m with precise priori orbit constraints of 10 m precision (e.g., predicted orbits by international GNSS monitoring & Assessment System (iGMAS)). (3) The POD precision is improved by additional ISLs. Constrained by a priori iGMAS orbits, the POD precision with two, three, and four ISLs is better than 6, 3, and 2

  14. Initial results of centralized autonomous orbit determination of the new-generation BDS satellites with inter-satellite link measurements

    NASA Astrophysics Data System (ADS)

    Tang, Chengpan; Hu, Xiaogong; Zhou, Shanshi; Liu, Li; Pan, Junyang; Chen, Liucheng; Guo, Rui; Zhu, Lingfeng; Hu, Guangming; Li, Xiaojie; He, Feng; Chang, Zhiqiao

    2018-01-01

    Autonomous orbit determination is the ability of navigation satellites to estimate the orbit parameters on-board using inter-satellite link (ISL) measurements. This study mainly focuses on data processing of the ISL measurements as a new measurement type and its application on the centralized autonomous orbit determination of the new-generation Beidou navigation satellite system satellites for the first time. The ISL measurements are dual one-way measurements that follow a time division multiple access (TDMA) structure. The ranging error of the ISL measurements is less than 0.25 ns. This paper proposes a derivation approach to the satellite clock offsets and the geometric distances from TDMA dual one-way measurements without a loss of accuracy. The derived clock offsets are used for time synchronization, and the derived geometry distances are used for autonomous orbit determination. The clock offsets from the ISL measurements are consistent with the L-band two-way satellite, and time-frequency transfer clock measurements and the detrended residuals vary within 0.5 ns. The centralized autonomous orbit determination is conducted in a batch mode on a ground-capable server for the feasibility study. Constant hardware delays are present in the geometric distances and become the largest source of error in the autonomous orbit determination. Therefore, the hardware delays are estimated simultaneously with the satellite orbits. To avoid uncertainties in the constellation orientation, a ground anchor station that "observes" the satellites with on-board ISL payloads is introduced into the orbit determination. The root-mean-square values of orbit determination residuals are within 10.0 cm, and the standard deviation of the estimated ISL hardware delays is within 0.2 ns. The accuracy of the autonomous orbits is evaluated by analysis of overlap comparison and the satellite laser ranging (SLR) residuals and is compared with the accuracy of the L-band orbits. The results indicate

  15. A study of 60 GHz intersatellite link applications

    NASA Technical Reports Server (NTRS)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    1983-01-01

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  16. A study of 60 Gigahertz intersatellite link applications

    NASA Astrophysics Data System (ADS)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  17. A study of 60 Gigahertz intersatellite link applications

    NASA Technical Reports Server (NTRS)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    1983-01-01

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  18. A study of 60 GHz intersatellite link applications

    NASA Astrophysics Data System (ADS)

    Anzic, G.; Connolly, D. J.; Haugland, E. J.; Kosmahl, H. G.; Chitwood, J. S.

    Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed.

  19. Inter-satellite links for satellite autonomous integrity monitoring

    NASA Astrophysics Data System (ADS)

    Rodríguez-Pérez, Irma; García-Serrano, Cristina; Catalán Catalán, Carlos; García, Alvaro Mozo; Tavella, Patrizia; Galleani, Lorenzo; Amarillo, Francisco

    2011-01-01

    A new integrity monitoring mechanisms to be implemented on-board on a GNSS taking advantage of inter-satellite links has been introduced. This is based on accurate range and Doppler measurements not affected neither by atmospheric delays nor ground local degradation (multipath and interference). By a linear combination of the Inter-Satellite Links Observables, appropriate observables for both satellite orbits and clock monitoring are obtained and by the proposed algorithms it is possible to reduce the time-to-alarm and the probability of undetected satellite anomalies.Several test cases have been run to assess the performances of the new orbit and clock monitoring algorithms in front of a complete scenario (satellite-to-satellite and satellite-to-ground links) and in a satellite-only scenario. The results of this experimentation campaign demonstrate that the Orbit Monitoring Algorithm is able to detect orbital feared events when the position error at the worst user location is still under acceptable limits. For instance, an unplanned manoeuvre in the along-track direction is detected (with a probability of false alarm equals to 5 × 10-9) when the position error at the worst user location is 18 cm. The experimentation also reveals that the clock monitoring algorithm is able to detect phase jumps, frequency jumps and instability degradation on the clocks but the latency of detection as well as the detection performances strongly depends on the noise added by the clock measurement system.

  20. Modeling and Performance Analysis of 10 Gbps Inter-satellite Optical Wireless Communication Link

    NASA Astrophysics Data System (ADS)

    Singh, Mehtab

    2017-12-01

    Free-space optical (FSO) communication has the advantages of two of the most predominant data transmission technologies - optical fiber communication and wireless communication. Most of the technical aspects of FSO are similar to that of optical fiber communication, with major difference in the information signal propagation medium which is free space in case of FSO rather than silica glass in optical fiber communication. One of the most important applications of FSO is inter-satellite optical wireless communication (IsOWC) links which will be deployed in the future in space. The IsOWC links have many advantages over the previously existing microwave satellite communication technologies such as higher bandwidth, lower power consumption, low cost of implementation, light size, and weight. In this paper, modeling and performance analysis of a 10-Gbps inter-satellite communication link with two satellites separated at a distance of 1,200 km has been done using OPTISYSTEM simulation software. Performance has been analyzed on the basis of quality factor, signal to noise ratio (SNR), and total power of the received signal.

  1. Inter-satellite links: A versatile tool for geodesy and planetary and interplanetary navigation

    NASA Astrophysics Data System (ADS)

    Schlicht, Anja; Hugentobler, Urs; Hauk, Markus; Murböck, Michael; Pail, Roland

    2016-07-01

    With the use of low-low satellite-to-satellite tracking gravity field recovery made a big step forward. Based on this technique the Gravity Recovery And Climate Experiment (GRACE) mission delivers monthly gravity field with high precision, allowing to measure effects in Earth water storage basins and variations in ice mass in Greenland and Antarctica from space. GRACE is using a Ka-band inter-satellite ranging technique, GRACE Follow-On will in addition test optical ranging. In fundamental physics high-precision optical inter-satellite tracking will be used to detect gravitational waves in space, as a first step LISA Pathfinder was launched recently. Inter-satellite links are not only used for ranging, also data transfer in space is based on such links. ESA's European Data Relay System will be established in up-coming years to collect data from the low orbiting Sentinel satellites and transfer the high data rate to ground. The same link may be used for ranging, data transfer and time transfer, a functionality that is discussed for next generation Galileo satellites. But to exploit this synergy a common concept for all three tasks has to be developed. In this paper we show that with inter-satellite ranging techniques with µm accuracy the limited accuracy of GNSS based orbit determination of low Earth orbiters (LEO), which is due to the limitations of one-way microwave tracking (unsynchronized clocks, phase center variations and offsets of the sending and receiving antennas) can be overcome. In the ESA study GETRIS the following question is answered: How can a highly accurate and precise GEO-based two-way ranging method support GNSS tracking? The reduction of systematic errors in LEO precise orbit determination (POD) by exploiting the synergy between ranging, data- and time-transfer is assessed in a concept consisting of precise two-way GEO-LEO tracking (as used for data transfer) and an ultra-stable oscillator on-board of the geostationary satellite (GEO

  2. Parametric study of intersatellite CO2 laser data links

    NASA Astrophysics Data System (ADS)

    Bonek, E.; Lutz, H.

    The performance capability of current CO2 laser communication tecnology for intersatellite data links is evaluated. The link parameters, such as the distance, bit rate, ac signal-to-noise ratio, are related to the masses and the prime power requirements of satellite laser terminals using variables like the telescope (antenna) aperture diameter and the transmitted laser power. It is found that high data rates could be readily transmitted with telescopes of the order of only 10 cm in diameter, with the complte laser data terminals weighing between 25 kg and 70 kg and consuming prime power in the 90-300 W range. In addition, these terminals would require only about 0.1 cu m or less of volume and a very low movable antenna mass, which would alleviate constraints on satellite attitude control units in remote sensing missions.

  3. Investigation of coherent receiver designs in high-speed optical inter-satellite links using digital signal processing

    NASA Astrophysics Data System (ADS)

    Schaefer, S.; Gregory, M.; Rosenkranz, W.

    2017-09-01

    Due to higher data rates, better data security and unlicensed spectral usage optical inter-satellite links (OISL) offer an attractive alternative to conventional RF-communication. However, the very high transmission distances necessitate an optical receiver design enabling high receiver sensitivity which requires careful carrier synchronization and a quasi-coherent detection scheme.

  4. High Speed Inter-Satellite Communication System by Incorporating Hybrid Polarization-Wavelength Division Multiplexing Scheme

    NASA Astrophysics Data System (ADS)

    Chaudhary, Sushank; Chaudhary, Neha; Sharma, Saurabh; Choudhary, BC

    2017-12-01

    Inter-Satellite communication is one of remarkable technologies that can be used to communicate between satellites. This work is focused to carry out the investigations of polarization scheme by incorporating dense wavelength division multiplexing (DWDM) scheme in inter-satellite communication system. A 20×6 Gbps data are transported over inter-satellite optical link having span of 5,000 km to realize the total data transmission of 120 Gbps. Moreover, results are also reported with the effect of RZ and NRZ modulation schemes. The performance of proposed inter-satellite communication link is measured in terms of signal-to-noise ratio, received power and eye diagrams.

  5. Comparison of direct and heterodyne detection optical intersatellite communication links

    NASA Technical Reports Server (NTRS)

    Chen, C. C.; Gardner, C. S.

    1987-01-01

    The performance of direct and heterodyne detection optical intersatellite communication links are evaluated and compared. It is shown that the performance of optical links is very sensitive to the pointing and tracking errors at the transmitter and receiver. In the presence of random pointing and tracking errors, optimal antenna gains exist that will minimize the required transmitter power. In addition to limiting the antenna gains, random pointing and tracking errors also impose a power penalty in the link budget. This power penalty is between 1.6 to 3 dB for a direct detection QPPM link, and 3 to 5 dB for a heterodyne QFSK system. For the heterodyne systems, the carrier phase noise presents another major factor of performance degradation that must be considered. In contrast, the loss due to synchronization error is small. The link budgets for direct and heterodyne detection systems are evaluated. It is shown that, for systems with large pointing and tracking errors, the link budget is dominated by the spatial tracking error, and the direct detection system shows a superior performance because it is less sensitive to the spatial tracking error. On the other hand, for systems with small pointing and tracking jitters, the antenna gains are in general limited by the launch cost, and suboptimal antenna gains are often used in practice. In which case, the heterodyne system has a slightly higher power margin because of higher receiver sensitivity.

  6. Relative tracking control of constellation satellites considering inter-satellite link

    NASA Astrophysics Data System (ADS)

    Fakoor, M.; Amozegary, F.; Bakhtiari, M.; Daneshjou, K.

    2017-11-01

    In this article, two main issues related to the large-scale relative motion of satellites in the constellation are investigated to establish the Inter Satellite Link (ISL) which means the dynamic and control problems. In the section related to dynamic problems, a detailed and effective analytical solution is initially provided for the problem of satellite relative motion considering perturbations. The direct geometric method utilizing spherical coordinates is employed to achieve this solution. The evaluation of simulation shows that the solution obtained from the geometric method calculates the relative motion of the satellite with high accuracy. Thus, the proposed analytical solution will be applicable and effective. In the section related to control problems, the relative tracking control system between two satellites will be designed in order to establish a communication link between the satellites utilizing analytical solution for relative motion of satellites with respect to the reference trajectory. Sliding mode control approach is employed to develop the relative tracking control system for body to body and payload to payload tracking control. Efficiency of sliding mode control approach is compared with PID and LQR controllers. Two types of payload to payload tracking control considering with and without payload degree of freedom are designed and suitable one for practical ISL applications is introduced. Also, Fuzzy controller is utilized to eliminate the control input in the sliding mode controller.

  7. NASA 60 GHz intersatellite communication link definition study. Addendum A: Mixed baseband and IF signals

    NASA Technical Reports Server (NTRS)

    1986-01-01

    As part of a definition study for a 60 GHz intersatellite communications link system (ICLS), baseline design concepts for a channelized crosslink were identified. The crosslink would allow communications between geostationary satellites of the planned Tracking and Data Acquisition System (TDAS) and would accommodate a mixture of frequency translation coherent links (bent pipe links) and baseband-in/baseband-out links (mod/demod links). A 60 GHz communication system was developed for sizing and analyzing the crosslink. For the coherent links this system translates incoming signals directly up to the 60 GHz band; trunks the signals across from one satellite to a second satellite at 60 GHz then down converts to the proper frequency for re-transmission from the second satellite without converting to any intermediate frequencies. For the baseband-in/baseband-out links the baseband data is modulated on to the 60 GHz carrier at the transmitting satellite and demodulated at the receiving satellite. The frequency plan, equipment diagrams, and link calculations are presented along with results from sizing and reliability analyses.

  8. Simulative Analysis of Inter-Satellite Optical Wireless Communication (IsOWC) Link with EDFA

    NASA Astrophysics Data System (ADS)

    Singh, Mehtab; Singh, Navpreet

    2018-04-01

    In this paper, simulative analysis and performance comparison of different EDFA (Erbium-doped fiber amplifier) configurations in a 10 Gbps inter-satellite optical wireless communication (IsOWC) link have been reported for a 5,000 km long link and 1,550 nm operating wavelength. The results show that system in which both pre-amplifier and booster amplifier stages are implemented simultaneously outperforms systems with only pre-amplifier and booster amplifier stage. From the results, it can be seen that by deploying a transmission power level of 15 dBm, a link distance of 9,600 km can be achieved with a quality factor of 6.01 dB and BER (Bit error rate) of 1.07×10-9. Also, in this paper, the performance of an 8×7 Gbps WDM-IsOWC link has been reported. The results show that by using both EDFA pre-amplifier and booster amplifier stages, a link distance of 8,000 km for each channel is achievable with desired performance levels (Q≥6 and BER≤10-9). Also, the effect of channel spacing on the performance of WDM-IsOWC link is investigated. The results show that the received signal has acceptable performance levels when the channel spacing is 100 GHz but when the channel spacing is reduced to 80 GHz, the quality of the received signal degrades and link distance decreases.

  9. A Dual-Channel Acquisition Method Based on Extended Replica Folding Algorithm for Long Pseudo-Noise Code in Inter-Satellite Links.

    PubMed

    Zhao, Hongbo; Chen, Yuying; Feng, Wenquan; Zhuang, Chen

    2018-05-25

    Inter-satellite links are an important component of the new generation of satellite navigation systems, characterized by low signal-to-noise ratio (SNR), complex electromagnetic interference and the short time slot of each satellite, which brings difficulties to the acquisition stage. The inter-satellite link in both Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) adopt the long code spread spectrum system. However, long code acquisition is a difficult and time-consuming task due to the long code period. Traditional folding methods such as extended replica folding acquisition search technique (XFAST) and direct average are largely restricted because of code Doppler and additional SNR loss caused by replica folding. The dual folding method (DF-XFAST) and dual-channel method have been proposed to achieve long code acquisition in low SNR and high dynamic situations, respectively, but the former is easily affected by code Doppler and the latter is not fast enough. Considering the environment of inter-satellite links and the problems of existing algorithms, this paper proposes a new long code acquisition algorithm named dual-channel acquisition method based on the extended replica folding algorithm (DC-XFAST). This method employs dual channels for verification. Each channel contains an incoming signal block. Local code samples are folded and zero-padded to the length of the incoming signal block. After a circular FFT operation, the correlation results contain two peaks of the same magnitude and specified relative position. The detection process is eased through finding the two largest values. The verification takes all the full and partial peaks into account. Numerical results reveal that the DC-XFAST method can improve acquisition performance while acquisition speed is guaranteed. The method has a significantly higher acquisition probability than folding methods XFAST and DF-XFAST. Moreover, with the advantage of higher detection

  10. Simplified solution for osculating Keplerian parameter corrections of GEO satellites for intersatellite optical link

    NASA Astrophysics Data System (ADS)

    Yılmaz, Umit C.; Cavdar, Ismail H.

    2015-04-01

    In intersatellite optical communication, the Pointing, Acquisition and Tracking (PAT) phase is one of the important phases that needs to be completed successfully before initiating communication. In this paper, we focused on correcting the possible errors on the Geostationary Earth Orbit (GEO) by using azimuth and elevation errors between Low Earth Orbit (LEO) to GEO optical link during the PAT phase. To minimise the PAT duration, a simplified correction of longitude and inclination errors of the GEO satellite's osculating Keplerian parameters has been suggested. A simulation has been done considering the beaconless tracking and spiral-scanning technique. As a result, starting from the second day, we are able to reduce the uncertainty cone of the GEO satellite by about 200 μrad, if the values are larger than that quantity. The first day of the LEO-GEO links have been used to determine the parameters. Thanks to the corrections, the locking time onto the GEO satellite has been reduced, and more data are able to transmit to the GEO satellite.

  11. 47 CFR 25.279 - Inter-satellite service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Technical Operations § 25.279 Inter-satellite service. (a) Any satellite communicating with other space stations may use frequencies in the inter-satellite service as indicated in § 2.106 of this chapter. This...

  12. 47 CFR 25.279 - Inter-satellite service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Technical Operations § 25.279 Inter-satellite service. (a) Any satellite communicating with other space stations may use frequencies in the inter-satellite service as indicated in § 2.106 of this chapter. This...

  13. 47 CFR 25.279 - Inter-satellite service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Technical Operations § 25.279 Inter-satellite service. (a) Any satellite communicating with other space stations may use frequencies in the inter-satellite service as indicated in § 2.106 of this chapter. This...

  14. 47 CFR 25.279 - Inter-satellite service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Technical Operations § 25.279 Inter-satellite service. (a) Any satellite communicating with other space stations may use frequencies in the inter-satellite service as indicated in § 2.106 of this chapter. This...

  15. 47 CFR 25.279 - Inter-satellite service.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Technical Operations § 25.279 Inter-satellite service. (a) Any satellite communicating with other space stations may use frequencies in the inter-satellite service as indicated in § 2.106 of this chapter. This...

  16. Link establishment criterion and topology optimization for hybrid GPS satellite communications with laser crosslinks

    NASA Astrophysics Data System (ADS)

    Li, Lun; Wei, Sixiao; Tian, Xin; Hsieh, Li-Tse; Chen, Zhijiang; Pham, Khanh; Lyke, James; Chen, Genshe

    2018-05-01

    In the current global positioning system (GPS), the reliability of information transmissions can be enhanced with the aid of inter-satellite links (ISLs) or crosslinks between satellites. Instead of only using conventional radio frequency (RF) crosslinks, the laser crosslinks provide an option to significantly increase the data throughput. The connectivity and robustness of ISL are needed for analysis, especially for GPS constellations with laser crosslinks. In this paper, we first propose a hybrid GPS communication architecture in which uplinks and downlinks are established via RF signals and crosslinks are established via laser links. Then, we design an optical crosslink assignment criteria considering the practical optical communication factors such as optical line- of-sight (LOS) range, link distance, and angular velocity, etc. After that, to further improve the rationality of establishing crosslinks, a topology control algorithm is formulated to optimize GPS crosslink networks at both physical and network layers. The RF transmission features for uplink and downlink and optical transmission features for crosslinks are taken into account as constraints for the optimization problem. Finally, the proposed link establishment criteria are implemented for GPS communication with optical crosslinks. The designs of this paper provide a potential crosslink establishment and topology control algorithm for the next generation GPS.

  17. Design and Evaluation of 10-Gbps Inter-satellite Optical Wireless Communication Link for Improved Performance

    NASA Astrophysics Data System (ADS)

    Gupta, Amit; Nagpal, Shaina

    2017-05-01

    Inter-satellite optical wireless communication (IsOWC) systems can be chosen over existing microwave satellite systems for deploying in space in the future due to their high bandwidth, small size, light weight, low power and low cost. However, the IsOWC system suffers from various attenuations due to weather conditions, turbulence or scintillations which limit its performance and decreases its availability. So, in order to improve the performance, IsOWC system using directly modulated laser source is proposed in this work. The system is designed and evaluated to be suitable for high data rate transmissions up to 10 Gbps. The performance of the system is investigated in order to reduce the cost and complexity of link and improving the quality of information signal. Further the proposed IsOWC system is analysed using BER analyser, power meter and oscilloscope Visualizer.

  18. NASA 60 GHz intersatellite communication link definition study. Baseline document

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The overall system and component concepts for a 60 GHz intersatellite communications link system (ICLS) are described. The ICLS was designed to augment the capabilities of the current Tracking and Data Relay Satellite System (TDRSS), providing a data rate capacity large enough to accommodate the expected rates for user satellites (USAT's) in the post-1995 timeframe. The use of 60 GHz for the anticipated successor to TDRSS, the Tracking and Data Acquisition System (TDAS), was selected because of current technology development that will enable multigigibit data rates. Additionally, the attenuation of the earth's atmosphere at 60 GHz means that there is virtually no possibility of terrestrially generated interference (intentional or accidental) or terrestrially based intercept. The ICLS includes the following functional areas: (1) the ICLS payload package on the GEO TDAS satellite that communicates simultaneously with up to five LEO USAT's; (2) the payload package on the USAT that communicates with the TDAS satellite; and (3) the crosslink payload package on the TDAS satellite that communicates with another TDAS satellite. Two methods of data relay on-board the TDAS spacecraft were addressed. One is a complete baseband system (demod and remod) with a bi-directional 2 Gbps data stream; the other is a channelized system wherein some of the channels are baseband and others are merely frequency translated before re-transmission. Descriptions of the TDAS antenna, transmitter, receiver, and mechanical designs are presented.

  19. Considerations and Architectures for Inter-Satellite Communications in Distributed Spacecraft Systems

    NASA Technical Reports Server (NTRS)

    Edwards, Bernard; Horne, William; Israel, David; Kwadrat, Carl; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    This paper will identify the important characteristics and requirements necessary for inter-satellite communications in distributed spacecraft systems and present analysis results focusing on architectural and protocol comparisons. Emerging spacecraft systems plan to deploy multiple satellites in various "distributed" configurations ranging from close proximity formation flying to widely separated constellations. Distributed spacecraft configurations provide advantages for science exploration and operations since many activities useful for missions may be better served by distributing them between spacecraft. For example, many scientific observations can be enhanced through spatially separated platforms, such as for deep space interferometry. operating multiple distributed spacecraft as a mission requires coordination that may be best provided through inter-satellite communications. For example, several future distributed spacecraft systems envision autonomous operations requiring relative navigational calculations and coordinated attitude and position corrections. To conduct these operations, data must be exchanged between spacecraft. Direct cross-links between satellites provides an efficient and practical method for transferring data and commands. Unlike existing "bent-pipe" relay networks supporting space missions, no standard or widely-used method exists for cross-link communications. Consequently, to support these future missions, the characteristics necessary for inter-satellite communications need to be examined. At first glance, all of the missions look extremely different. Some missions call for tens to hundreds of nano-satellites in constant communications in close proximity to each other. Other missions call for a handful of satellites communicating very slowly over thousands to hundreds of thousands of kilometers. The paper will first classify distributed spacecraft missions to help guide the evaluation and definition of cross-link architectures and

  20. Coherent receiver design based on digital signal processing in optical high-speed intersatellite links with M-phase-shift keying

    NASA Astrophysics Data System (ADS)

    Schaefer, Semjon; Gregory, Mark; Rosenkranz, Werner

    2016-11-01

    We present simulative and experimental investigations of different coherent receiver designs for high-speed optical intersatellite links. We focus on frequency offset (FO) compensation in homodyne and intradyne detection systems. The considered laser communication terminal uses an optical phase-locked loop (OPLL), which ensures stable homodyne detection. However, the hardware complexity increases with the modulation order. Therefore, we show that software-based intradyne detection is an attractive alternative for OPLL-based homodyne systems. Our approach is based on digital FO and phase noise compensation, in order to achieve a more flexible coherent detection scheme. Analytic results will further show the theoretical impact of the different detection schemes on the receiver sensitivity. Finally, we compare the schemes in terms of bit error ratio measurements and optimal receiver design.

  1. Free-space laser communication technologies II; Proceedings of the Meeting, Los Angeles, CA, Jan. 15-17, 1990

    NASA Technical Reports Server (NTRS)

    Begley, David L. (Editor); Seery, Bernard D. (Editor)

    1990-01-01

    Various papers on free-space laser communication technologies are presented. Individual topics addressed include: optical intersatellite link experiment between the earth station and ETS-VI, the Goddard optical communications program, technologies and techniques for lasercom terminal size, weight, and cost reduction, laser beam acquisition and tracking system for ETS-VI laser communication equipment, analog dividers for acquisition and tracking signal normalization, fine pointing mechanism using multilayered piezoelectric actuator for optical ISL system, analysis of SILEX tracking sensor performance, new telescope concept for space communication, telescope considered as a very high gain antenna, design of compact transceiver optical systems for optical intersatellite links, ultralightweight optics for laser communications, highly sensitive measurement method for stray light and retroreflected light, depolarization effects on free space laser transceiver communication systems, in-orbit measurements of microaccelerations of ESA's communication satellite Olympus, high-performance laser diode transmitter for optical free space communication, diode-pumped Nd:host laser transmitter for intersatellite optical communications, single-frequency diode-pumped laser for free-space communication.

  2. Inter-satellite laser link acquisition with dual-way scanning for Space Advanced Gravity Measurements mission

    NASA Astrophysics Data System (ADS)

    Zhang, Jing-Yi; Ming, Min; Jiang, Yuan-Ze; Duan, Hui-Zong; Yeh, Hsien-Chi

    2018-06-01

    Laser link acquisition is a key technology for inter-satellite laser ranging and laser communication. In this paper, we present an acquisition scheme based on the differential power sensing method with dual-way scanning, which will be used in the next-generation gravity measurement mission proposed in China, called Space Advanced Gravity Measurements (SAGM). In this scheme, the laser beams emitted from two satellites are power-modulated at different frequencies to enable the signals of the two beams to be measured distinguishably, and their corresponding pointing angles are determined by using the differential power sensing method. As the master laser beam and the slave laser beam are decoupled, the dual-way scanning method, in which the laser beams of both the master and the slave satellites scan uncertainty cones simultaneously and independently, can be used, instead of the commonly used single-way scanning method, in which the laser beam of one satellite scans and that of the other one stares. Therefore, the acquisition time is reduced significantly. Numerical simulation and experiments of the acquisition process are performed using the design parameters of the SAGM mission. The results show that the average acquisition time is less than 10 s for a scanning range of 1-mrad radius with a success rate of more than 99%.

  3. Inter-satellites x-ray communication system

    NASA Astrophysics Data System (ADS)

    Mou, Huan; Li, Bao-quan

    2017-02-01

    An inter-satellite X-ray communication system is presented in this paper. X-ray has a strong penetrating power without almost attenuation for transmission in outer space when the energy of X-ray photons is more than 10KeV and the atmospheric pressure is lower than 10-1 Pa, so it is convincing of x-ray communication in inter-satellite communication and deep space exploration. Additionally, using X-ray photons as information carriers can be used in some communication applications that laser communication and radio frequency (RF) communication are not available, such as ionization blackout area communication. The inter-satellites X-ray communication system, including the grid modulated X-ray source, the high-sensitivity X-ray detector and the transmitting and receiving antenna, is described explicitly. As the X-ray transmitter, a vacuum-sealed miniature modulated X-ray source has been fabricated via the single-step brazing process in a vacuum furnace. Pulse modulation of X-rays, by means of controlling the voltage value of the grid electrode, is realized. Three focusing electrodes, meanwhile, are used to make the electron beam converge and finally 150μm focusing spot diameter is obtained. The X-ray detector based on silicon avalanche photodiodes (APDs) is chosen as the communication receiver on account of its high temporal resolution and non-vacuum operating environment. Furthermore, considering x-ray emission characteristic and communication distance of X-rays, the multilayer nested rotary parabolic optics is picked out as transmitting and receiving antenna. And as a new concept of the space communication, there will be more important scientific significance and application prospects, called "Next-Generation Communications".

  4. Laser Communication Demonstration System (LSCS) and Future Mobile Satellite Services

    NASA Technical Reports Server (NTRS)

    Chen, C. -C.; Lesh, J. R.

    1995-01-01

    The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth Orbit. For future global satellite communication systems using intersatellite links (ISLs), laser communications technology can offer reduced mass , reduced power requirements, and increased channel bandwidths without regulatory restraint. This paper provides comparisons with radio systems and status of the program.

  5. Homodyne BPSK-based optical inter-satellite communication links

    NASA Astrophysics Data System (ADS)

    Lange, Robert; Smutny, Berry

    2007-02-01

    Summer 2007, Tesat will verify laser communication terminals based on homodyne BPSK (binary phase shift keying) in-orbit. A 5.625 Gbps LEO-LEO laser communication link, established between the German satellite TerraSAR-X and the US satellite NFIRE, shall demonstrate the performance and advantages of laser communication. End of 2006, a further program has been kicked-off to demonstrate the performance of ~2 Gbps LEO-GEO laser communication links. The link is part of a data relais from the German LEO satellite TanDEM-X via a Geo satellite to ground. The LEO-to-GEO laser commmunication link can be extended to further ~2 Gpbs GEO-GEO, and GEO-to-ground links.

  6. 27 CFR 9.51 - Isle St. George.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Isle St. George. 9.51... St. George. (a) Name. The name of the viticultural area described in this section is “Isle St. George.” (b) Approved maps. The approved map for determining the boundary of the Isle St. George viticultural...

  7. 75 FR 65514 - Columbia Forest Products, Inc., Presque Isle Division, Presque Isle, ME; Notice of Affirmative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,110] Columbia Forest Products, Inc., Presque Isle Division, Presque Isle, ME; Notice of Affirmative Determination Regarding Application for Reconsideration By application dated February 16, 2010, workers requested administrative...

  8. R&D of a Next Generation LEO System for Global Multimedia Mobile Satellite Communications

    NASA Astrophysics Data System (ADS)

    Morikawa, E.; Motoyoshi, S.; Koyama, Y.; Suzuki, R.; Yasuda, Y.

    2002-01-01

    satellite communication systems. Therefore, the experimental DBF network with 16 radiating elements was developed for confirming a basic signal processing performance. A/D sampled data are processed by using FPGA circuit for beam forming by real-time basis. Optical Inter-Satellite Link Technology: The inter-satellite link (ISL) technology is also important, because the inter-satellite network is essential to realize the low delay network connection for multimedia services. The optical ISL simulator was developed for the study of optical modem and optical tracking mechanism. And the sensitivity of 56 photons/bit at 10-9 of error rate has been achieved by employing the Erbium doped fiber amplifier, polarizing filter and narrow band optical filter. Coude path type, the active universal joint (AUJ) type and two flat mirror type of optical antenna mechanism were developed. Satellite Network Technology: For constructing this optical ISL ring, the utilization of wavelength division multiplexing (WDM) technology is envisaged. By applying WDM technology to the optical intra-orbital ISL, logical mesh connections can be achieved by assigning the appropriate wavelength for the links among satellites. By using inclined orbit, inter-orbital ISL connection can be keep continuously. Therefore, WDM technology is also applicable to the inter-orbital ISL network. The satellite ATM network simulator was developed in order to investigate the effect of delay fluctuation caused by the satellite constellations. This simulator works as real-time basis by using commercial ATM switches and personal computers. This simulator was installed Dijkstra's algorithm to determine satellite routing path in order to minimize the end-to-end delay time from the source terminal to the destination terminal. The satellite IP network simulator has been developed in order to evaluate the congestion of the multimedia traffic. Variable Rate Modulation Technology: Considering the propagation impairments in the mobile

  9. Small optical inter-satellite communication system for small and micro satellites

    NASA Astrophysics Data System (ADS)

    Iwamoto, Kyohei; Nakao, Takashi; Ito, Taiji; Sano, Takeshi; Ishii, Tamotsu; Shibata, Keiichi; Ueno, Mitsuhiro; Ohta, Shinji; Komatsu, Hiromitsu; Araki, Tomohiro; Kobayashi, Yuta; Sawada, Hirotaka

    2017-02-01

    Small optical inter-satellite communication system to be installed into small and micro satellites flying on LEO are designed and experimentally verified of its fundamental functions. Small, light weighted, power efficient as well as usable data transmission rate optical inter-satellite communication system is one of promising approach to provide realtime data handling and operation capabilities for micro and small satellite constellations which have limited conditions of payload. Proposed system is designed to connect satellites with 4500 (km) long maximum to be able to talk with ground station continuously by relaying LEO satellites even when they are in their own maneuvers. Connecting satellites with 4500 (km) long with keeping steady data rate, accurate pointing and tracking method will be one of a crucial issue. In this paper, we propose a precious pointing and tracking method and system with a miniature optics and experimentally verified almost 10 (μrad) of pointing accuracy with more than 500 (mrad) of angular coverage.

  10. Three years coherent space to ground links: performance results and outlook for the optical ground station equipped with adaptive optics

    NASA Astrophysics Data System (ADS)

    Gregory, M.; Troendle, D.; Muehlnikel, G.; Heine, F.; Meyer, R.; Lutzer, M.; Czichy, R.

    2013-03-01

    Tesat is performing inter-satellite links (ISLs) for over 5 years now. Besides the successful demonstration of the suitability of coherent laser communication for high speed data transmission in space, Tesat has also conducted two major satellite to ground link (SGL) campaigns during the last 3 years. A transportable ground station has been developed to measure the impact of atmospheric turbulence to the coherent system. The SGLs have been performed between the Tesat optical ground station and the two LEO satellites TerraSAR-X and NFIRE, both equipped with a Tesat LCT. The capability of the LCTs of measuring the signal intensity on a direct detection sensor and on a coherent sensor simultaneously makes the system unique for investigating the atmospheric distortion impacts. In this paper the main results of the SGL campaigns are presented, including BER performance for the uplink and downlink. Measured scintillation profiles versus elevation angles at different weather conditions are illustrated. Finally preliminary results of an adaptive optics system are presented that has been developed to be used in the transportable adaptive optical ground station (T-AOGS) acting as the counter terminal for the LCT mounted on Alphasat, a geostationary satellite of the European Space Agency (ESA), in autumn 2013.

  11. Microwave vs optical crosslink study

    NASA Technical Reports Server (NTRS)

    Kwong, Paulman W.; Bruno, Ronald C.; Marshalek, Robert G.

    1992-01-01

    The intersatellite links (ISL's) at geostationary orbit is currently a missing link in commercial satellite services. Prior studies have found that potential application of ISL's to domestic, regional, and global satellites will provide more cost-effective services than the non-ISL's systems (i.e., multiple-hop systems). In addition, ISL's can improve and expand the existing satellite services in several aspects. For example, ISL's can conserve the scarce spectrum allocated for fixed satellite services (FSS) by avoiding multiple hopping of the relay stations. ISL's can also conserve prime orbit slot by effectively expanding the geostationary arc. As a result of the coverage extension by using ISL's more users will have direct access to the satellite network, thus providing reduced signal propagation delay and improved signal quality. Given the potential benefits of ISL's system, it is of interest to determine the appropriate implementations for some potential ISL architectures. Summary of the selected ISL network architecture as supplied by NASA are listed. The projected high data rate requirements (greater than 400 Mbps) suggest that high frequency RF or optical implementations are natural approaches. Both RF and optical systems have their own merits and weaknesses which make the choice between them dependent on the specific application. Due to its relatively mature technology base, the implementation risk associated with RF (at least 32 GHz) is lower than that of the optical ISL's. However, the relatively large antenna size required by RF ISL's payload may cause real-estate problems on the host spacecraft. In addition, because of the frequency sharing (for duplex multiple channels communications) within the limited bandwidth allocated, RF ISL's are more susceptible to inter-system and inter-channel interferences. On the other hand, optical ISL's can offer interference-free transmission and compact sized payload. However, the extremely narrow beam widths (on the

  12. Isl-1 down-regulates DRG cell proliferation during chicken embryo development.

    PubMed

    Chen, Dawei; Wang, Guoxin; Luo, Haoshu; Liu, Jiali; Cui, Sheng

    2010-01-01

    Protein Isl-1 RNA interference and over expression in early chicken embryo dorsal root ganglia (DRG) were used to investigate the function of Isl-1 in DRG cell proliferation. Isl-1 targeted shRNA expression vector and Isl-1 over-expression vector were transfected into chicken embryo DRG by in ovo electroporation. Then, the DRG proliferation rate was detected by BrdU immunohistochemistry. The rate of DRG cell proliferation increased after Isl-1 knock-down and decreased after Isl-1 over-expression. In this study, we found that Isl-1 negatively modulates DRG cell proliferation.

  13. Forest Resources of Isle Royale National Park 2010

    Treesearch

    Wilfred J. Previant; Linda M. Nagel; Scott A. Pugh; Christopher W. Woodall

    2012-01-01

    This publication provides a baseline overview of forest resources for Isle Royale National Park (Isle Royale) using data from the Forest Inventory and Analysis (FIA) Program of the U.S. Department of Agriculture, Forest Service. The availability of permanent FIA plots allows for the first-ever comparison of Isle Royale's forest conditions (2006-2010) to reserved...

  14. Isl1 Is required for multiple aspects of motor neuron development

    PubMed Central

    Liang, Xingqun; Song, Mi-Ryoung; Xu, ZengGuang; Lanuza, Guillermo M.; Liu, Yali; Zhuang, Tao; Chen, Yihan; Pfaff, Samuel L.; Evans, Sylvia M.; Sun, Yunfu

    2011-01-01

    The LIM homeodomain transcription factor Islet1 (Isl1) is expressed in multiple organs and plays essential roles during embryogenesis. Isl1 is required for the survival and specification of spinal cord motor neurons. Due to early embryonic lethality and loss of motor neurons, the role of Isl1 in other aspects of motor neuron development remains unclear. In this study, we generated Isl1 mutant mouse lines expressing graded doses of Isl1. Our study has revealed essential roles of Isl1 in multiple aspects of motor neuron development, including motor neuron cell body localization, motor column formation and axon growth. In addition, Isl1 is required for survival of cranial ganglia neurons. PMID:21569850

  15. Isl1 is required for multiple aspects of motor neuron development.

    PubMed

    Liang, Xingqun; Song, Mi-Ryoung; Xu, ZengGuang; Lanuza, Guillermo M; Liu, Yali; Zhuang, Tao; Chen, Yihan; Pfaff, Samuel L; Evans, Sylvia M; Sun, Yunfu

    2011-07-01

    The LIM homeodomain transcription factor Islet1 (Isl1) is expressed in multiple organs and plays essential roles during embryogenesis. Isl1 is required for the survival and specification of spinal cord motor neurons. Due to early embryonic lethality and loss of motor neurons, the role of Isl1 in other aspects of motor neuron development remains unclear. In this study, we generated Isl1 mutant mouse lines expressing graded doses of Isl1. Our study has revealed essential roles of Isl1 in multiple aspects of motor neuron development, including motor neuron cell body localization, motor column formation and axon growth. In addition, Isl1 is required for survival of cranial ganglia neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Isle of Jersey

    NASA Image and Video Library

    2002-10-29

    The Isle of Jersey (officially called the Bailiwick of Jersey) is the largest Channel Island, positioned in the Bay of Mont St Michel off the north-west coast of France. The island has a population of about 90,000, and covers about 90 square kilometers. The economy is based largely on international financial services, agriculture, and tourism. Called Caesaria in Roman times, Jersey becaame part of the Duchy of Normandy in 912. When William the Conqueror invaded and took the throne of England in 1066, the fortunes of Jersey then became linked to those in England, although the island manages its internal affairs through its own parliament, the States of Jersey. This image was acquired on September 23, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. http://photojournal.jpl.nasa.gov/catalog/PIA03879

  17. 27 CFR 9.51 - Isle St. George.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Isle St. George. 9.51 Section 9.51 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.51 Isle...

  18. 27 CFR 9.51 - Isle St. George.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Isle St. George. 9.51 Section 9.51 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.51 Isle...

  19. 27 CFR 9.51 - Isle St. George.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Isle St. George. 9.51 Section 9.51 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.51 Isle...

  20. Short-Arc Analysis of Intersatellite Tracking Data in a Gravity Mapping Mission

    NASA Technical Reports Server (NTRS)

    Rowlands, David D.; Ray, Richard D.; Chinn, Douglas S.; Lemoine, Frank G.; Smith, David E. (Technical Monitor)

    2001-01-01

    A technique for the analysis of low-low intersatellite range-rate data in a gravity mapping mission is explored. The technique is based on standard tracking data analysis for orbit determination but uses a spherical coordinate representation of the 12 epoch state parameters describing the baseline between the two satellites. This representation of the state parameters is exploited to allow the intersatellite range-rate analysis to benefit from information provided by other tracking data types without large simultaneous multiple data type solutions. The technique appears especially valuable for estimating gravity from short arcs (e.g., less than 15 minutes) of data. Gravity recovery simulations which use short arcs are compared with those using arcs a day in length. For a high-inclination orbit, the short-arc analysis recovers low-order gravity coefficients remarkably well, although higher order terms, especially sectorial terms, are less accurate. Simulations suggest that either long or short arcs of GRACE data are likely to improve parts of the geopotential spectrum by orders of magnitude.

  1. Investigation of Breakwater Stability at Presque Isle Peninsula Erie, Pennsylvania

    DTIC Science & Technology

    1989-05-01

    PRESQUE ISLE PENINSULA AD-A208 528 ERIE , PENNSYLVANIA by Peter J. Grace...STABILITY AT PRESQUE ISLE PENINSULA, ERIE . PENNSYLVANIA PART I: INTRODUCTION The Prototype 1. Harbor facilities at Erie , Pennsylvania , are protected...at Presque Isle Beaches, Erie , Pennsylvania ," Technical Report HL-83-15, US Army Engineer Waterways Experiment Station, Vicksburg, MS. Stevens, J.

  2. Presque Isle Peninsula, Erie, Pennsylvania. Volume I. Main Report. Revised.

    DTIC Science & Technology

    1980-11-01

    PRESQUE ISLE PENINSULA, ERIE , PENNSYLVANIA . Memorandum includimg~nviron- 1.6... Pennsylvania THE SECRETARY OF THE ARMY 1. I submit for transmission to Congress my report on Presque Isle Peninsula, Erie , Pennsylvania . It is...advanced engineering and design of the project for beach erosion control for Presque Isle Peninsula at Erie , Pennsylvania . 2. The District and

  3. Postnatal isl1+ cardioblasts enter fully differentiated cardiomyocyte lineages

    PubMed Central

    Laugwitz, Karl-Ludwig; Moretti, Alessandra; Lam, Jason; Gruber, Peter; Chen, Yinhong; Woodard, Sarah; Lin, Li-Zhu; Cai, Chen-Leng; Lu, Min Min; Reth, Michael; Platoshyn, Oleksandr; Yuan, Jason X.-J.; Evans, Sylvia; Chien, Kenneth R.

    2017-01-01

    The purification, renewal and differentiation of native cardiac progenitors would form a mechanistic underpinning for unravelling steps for cardiac cell lineage formation, and their links to forms of congenital and adult cardiac diseases1–3. Until now there has been little evidence for native cardiac precursor cells in the postnatal heart4. Herein, we report the identification of isl1+ cardiac progenitors in postnatal rat, mouse and human myocardium. A cardiac mesenchymal feeder layer allows renewal of the isolated progenitor cells with maintenance of their capability to adopt a fully differentiated cardiomyocyte phenotype. Tamoxifen-inducible Cre/lox technology enables selective marking of this progenitor cell population including its progeny, at a defined time, and purification to relative homogeneity. Co-culture studies with neonatal myocytes indicate that isl1+ cells represent authentic, endogenous cardiac progenitors (cardioblasts) that display highly efficient conversion to a mature cardiac phenotype with stable expression of myocytic markers (25%) in the absence of cell fusion, intact Ca2+-cycling, and the generation of action potentials. The discovery of native cardioblasts represents a genetically based system to identify steps in cardiac cell lineage formation and maturation in development and disease. PMID:15703750

  4. Conservation genetics of the endangered Isle Royale gray wolf

    USGS Publications Warehouse

    Wayne, R.K.; Lehman, N.; Girman, D.; Gogan, P.J.P.; Gilbert, D.A.; Hansen, K.; Peterson, R.O.; Seal, U.S.; Eisenhawer, Andrew; Mech, L.D.; Krumenaker, R.J.

    1991-01-01

    The small group of wolves on Isle Royale has been studied for over three decades as a model of the relationship between large carnivores and their prey. During the last ten years the population declined from 50 individuals to as few as 12 individuals. The causes of this decline may be food shortages, disease, or reduced genetic variability. We address the issues of genetic variability and relationships of Isle Royale wolves using allozyme electrophoresis, mtDNA restriction-site analysis, and multilocus hypervariable minisatellite DNA analysis (genetic fingerprinting). Our results indicate that approximately 50% of the allozyme heterozygosity has been lost in the island population, a decline similar to that expected if no immigration had occurred from the mainland. The genetic fingerprinting data indicate that the seven sampled Isle Royale wolves are as similar as captive populations of siblings. Surprisingly, the Isle Royale wolves have an mtDNA genotype that is very rare on the mainland, being found in only one of 144 mainland wolves. This suggests that the remaining Isle Royale wolves are probably derived from a single female founder.

  5. 77 FR 35903 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... zone on the waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety... Intracoastal Waterway, mile 226, at Emerald Isle, North Carolina. [[Page 35904

  6. ISLE (Image and Signal Processing LISP Environment) reference manual

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sherwood, R.J.; Searfus, R.M.

    1990-01-01

    ISLE is a rapid prototyping system for performing image and signal processing. It is designed to meet the needs of a person doing development of image and signal processing algorithms in a research environment. The image and signal processing modules in ISLE form a very capable package in themselves. They also provide a rich environment for quickly and easily integrating user-written software modules into the package. ISLE is well suited to applications in which there is a need to develop a processing algorithm in an interactive manner. It is straightforward to develop the algorithms, load it into ISLE, apply themore » algorithm to an image or signal, display the results, then modify the algorithm and repeat the develop-load-apply-display cycle. ISLE consists of a collection of image and signal processing modules integrated into a cohesive package through a standard command interpreter. ISLE developer elected to concentrate their effort on developing image and signal processing software rather than developing a command interpreter. A COMMON LISP interpreter was selected for the command interpreter because it already has the features desired in a command interpreter, it supports dynamic loading of modules for customization purposes, it supports run-time parameter and argument type checking, it is very well documented, and it is a commercially supported product. This manual is intended to be a reference manual for the ISLE functions The functions are grouped into a number of categories and briefly discussed in the Function Summary chapter. The full descriptions of the functions and all their arguments are given in the Function Descriptions chapter. 6 refs.« less

  7. 77 FR 44463 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety zone is... Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald Isle, North Carolina. The safety...

  8. 77 FR 64906 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-24

    ... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... zone on the waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety... NC 58 Fixed Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald Isle, North...

  9. 77 FR 57063 - Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-17

    ... 1625-AA00 Safety Zone, Atlantic Intracoastal Waterway; Emerald Isle, NC AGENCY: Coast Guard, DHS... zone on the waters of the Atlantic Intracoastal Waterway at Emerald Isle, North Carolina. The safety... NC 58 Fixed Bridge crossing the Atlantic Intracoastal Waterway, mile 226, at Emerald Isle, North...

  10. High bandwidth electro-optic technology for intersatellite optical communications

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.

    1992-01-01

    The research and development of electronic and electro-optic components for geosynchronous and low earth orbiting satellite optical high bandwidth communications at the NASA-Goddard Space Flight Center is reviewed. Intersatellite optical communications retains a strong reliance on microwave circuit technology in several areas - the microwave to optical interface, the laser transmitter modulation driver and the optical receiver. A microwave to optical interface is described requiring high bandwidth electronic downconverters and demodulators. Electrical bandwidth and current drive requirements for the laser modulation driver for three laser alternatives are discussed. Bandwidth and noise requirements are presented for optical receiver architectures.

  11. 36 CFR 7.38 - Isle Royale National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Isle Royale National Park. 7.38 Section 7.38 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.38 Isle Royale National Park. (a) Aircraft...

  12. 36 CFR 7.38 - Isle Royale National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Isle Royale National Park. 7.38 Section 7.38 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.38 Isle Royale National Park. (a) Aircraft...

  13. 36 CFR 7.38 - Isle Royale National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Isle Royale National Park. 7.38 Section 7.38 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.38 Isle Royale National Park. (a) Aircraft...

  14. 36 CFR 7.38 - Isle Royale National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Isle Royale National Park. 7.38 Section 7.38 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.38 Isle Royale National Park. (a) Aircraft...

  15. 36 CFR 7.38 - Isle Royale National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Isle Royale National Park. 7.38 Section 7.38 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.38 Isle Royale National Park. (a) Aircraft...

  16. A positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Qiao, E-mail: zhangqiao200824@126.com; Yang, Zhe, E-mail: zheyang@bjmu.edu.cn; Wang, Weiping, E-mail: wwp@bjmu.edu.cn

    2014-07-04

    Highlights: • ISL-1 is highly expressed in human pancreatic β-cells and DLBCL. • ISL-1 accelerates the tumorigenesis of DLBCL in vivo. • c-Myc positively regulates ISL-1 expression in DLBCL but not in pancreatic β-cells. • ISL-1 and c-Myc forms an ISL-1/c-Myc transcriptional complex only in DLBCL. • Positive feedback regulation of ISL-1 does not exist in normal pancreatic β-cell. - Abstract: Insulin enhancer binding protein-1 (ISL-1), a LIM-homeodomain transcription factor, has been reported to play essential roles in promoting adult pancreatic β-cells proliferation. Recent studies indicate that ISL-1 may also involve in the occurrence of a variety of tumors. However,more » whether ISL-1 has any functional effect on tumorigenesis, and what are the differences on ISL-1 function in distinct conditions, are completely unknown. In this study, we found that ISL-1 was highly expressed in human pancreatic β-cells, as well as in diffuse large B cell lymphoma (DLBCL), but to a much less extent in other normal tissues or tumor specimens. Further study revealed that ISL-1 promoted the proliferation of pancreatic β-cells and DLBCL cells, and also accelerated the tumorigenesis of DLBCL in vivo. We also found that ISL-1 could activate c-Myc transcription not only in pancreatic β-cells but also in DLBCL cells. However, a cell-specific feedback regulation was detectable only in DLBCL cells. This auto-regulatory loop was established by the interaction of ISL-1 and c-Myc to form an ISL-1/c-Myc transcriptional complex, and synergistically to promote ISL-1 transcription through binding on the ISL-1 promoter. Taken together, our results demonstrate a positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells, which might result in the functional diversities of ISL-1 in different physiological and pathological processes.« less

  17. Note: Digital laser frequency auto-locking for inter-satellite laser ranging

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Luo, Yingxin; Yeh, Hsien-Chi, E-mail: yexianji@mail.hust.edu.cn; Li, Hongyin

    2016-05-15

    We present a prototype of a laser frequency auto-locking and re-locking control system designed for laser frequency stabilization in inter-satellite laser ranging system. The controller has been implemented on field programmable gate arrays and programmed with LabVIEW software. The controller allows initial frequency calibrating and lock-in of a free-running laser to a Fabry-Pérot cavity. Since it allows automatic recovery from unlocked conditions, benefit derives to automated in-orbit operations. Program design and experimental results are demonstrated.

  18. A high-efficiency 59- to 64-GHz TWT for intersatellite communications

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Ramins, Peter; Force, Dale A.; Limburg, Helen C.; Tammaru, Ivo

    1991-01-01

    The design of a 75-W, 59- to 64- GHz TWT with a predicted overall efficiency in excess of 40 percent is described. This intersatellite communications TWT, designated Model 961HA, employs a coupled-cavity slow-wave structure with a two-step velocity taper and an isotropic graphite multistage depressed collector (MDC). Because the RF efficiency of this TWT is less than 8 percent, an MDC design providing a very high collector efficiency was necessary to achieve the overall efficiency goal of 40 percent.

  19. Large brown seaweeds of the British Isles: Evidence of changes in abundance over four decades

    NASA Astrophysics Data System (ADS)

    Yesson, Chris; Bush, Laura E.; Davies, Andrew J.; Maggs, Christine A.; Brodie, Juliet

    2015-03-01

    The large brown seaweeds (macroalgae) are keystone species in intertidal and shallow subtidal marine ecosystems and are harvested for food and other products. Recently, there have been sporadic, often anecdotal, reports of local abundance declines around the British Isles, but regional surveys have rarely revisited sites to determine possible changes. An assessment was undertaken of changes in the abundance of large brown seaweeds around the British Isles using historical survey data, and determination of whether any changes were linked with climate change. Data were analysed from multiple surveys for 14 habitat-forming and commercially important species of Phaeophyceae, covering orders Laminariales, Fucales and Tilopteridales. Changes in abundance were assessed for sites over the period 1974-2010. Trends in distribution were compared to summer and winter sea surface temperatures (SST). Results revealed regional patterns of both increase and decrease in abundance for multiple species, with significant declines in the south for kelp species and increases in northern and central areas for some kelp and wracks. Abundance patterns of 10 of the 14 species showed a significant association with SSTs, but there was a mixture of positive and negative responses. This is the first British Isles-wide observation of declining abundance of large brown seaweeds. Historical surveys provide useful data to examine trends in abundance, but the ad hoc nature of these studies limit the conclusions that can be drawn. Although the British Isles remains a stronghold for large brown algae, it is imperative that systematic surveys are undertaken to monitor changes.

  20. Inter-satellite calibration of FengYun 3 medium energy electron fluxes with POES electron measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Ni, Binbin; Xiang, Zheng; Zhang, Xianguo; Zhang, Xiaoxin; Gu, Xudong; Fu, Song; Cao, Xing; Zou, Zhengyang

    2018-05-01

    We perform an L-shell dependent inter-satellite calibration of FengYun 3 medium energy electron measurements with POES measurements based on rough orbital conjunctions within 5 min × 0.1 L × 0.5 MLT. By comparing electron flux data between the U.S. Polar Orbiting Environmental Satellites (POES) and Chinese sun-synchronous satellites including FY-3B and FY-3C for a whole year of 2014, we attempt to remove less reliable data and evaluate systematic uncertainties associated with the FY-3B and FY-3C datasets, expecting to quantify the inter-satellite calibration factors for the 150-350 keV energy channel at L = 2-7. Compared to the POES data, the FY-3B and FY-3C data generally exhibit a similar trend of electron flux variations but more or less underestimate them within a factor of 5 for the medium electron energy 150-350 keV channel. Good consistency in the flux conjunctions after the inter-calibration procedures gives us certain confidence to generalize our method to calibrate electron flux measurements from various satellite instruments.

  1. Changes in Sea Levels around the British Isles Revisited (Invited)

    NASA Astrophysics Data System (ADS)

    Teferle, F. N.; Hansen, D. N.; Bingley, R. M.; Williams, S. D.; Woodworth, P. L.; Gehrels, W. R.; Bradley, S. L.; Stocchi, P.

    2009-12-01

    Recently a number of new and/or updated sources for estimates of vertical land movements for the British Isles have become available allowing the relative and average changes in sea levels for this region to be revisited. The geodetic data set stems from a combination of re-processed continuous Global Positioning System (GPS) measurements from stations in the British Isles and from a global reference frame network, and absolute gravity (AG) measurements from two stations in the British Isles. The geologic data set of late Holocene sea level indicators has recently been updated, now applying corrections for the 20th century sea level rise, syphoning effect and late Holocene global ice melt, and expanded to Northern Ireland and Ireland. Several new model predictions of the glacial isostatic adjustment (GIA) process active in this region form the modelling data set of vertical land movements for the British Isles. Correcting the updated revised local reference (RLR) trends from the Permanent Service for Mean Sea Level (PSMSL) with these vertical land movement data sets, regional and averaged changes in sea levels around the British Isles have been investigated. Special focus is thereby also given to the coastal areas that have recently been identified within the UK Climate Projections 2009.

  2. Functional Diversification of Motor Neuron-specific Isl1 Enhancers during Evolution

    PubMed Central

    Kim, Namhee; Park, Chungoo; Jeong, Yongsu; Song, Mi-Ryoung

    2015-01-01

    Functional diversification of motor neurons has occurred in order to selectively control the movements of different body parts including head, trunk and limbs. Here we report that transcription of Isl1, a major gene necessary for motor neuron identity, is controlled by two enhancers, CREST1 (E1) and CREST2 (E2) that allow selective gene expression of Isl1 in motor neurons. Introduction of GFP reporters into the chick neural tube revealed that E1 is active in hindbrain motor neurons and spinal cord motor neurons, whereas E2 is active in the lateral motor column (LMC) of the spinal cord, which controls the limb muscles. Genome-wide ChIP-Seq analysis combined with reporter assays showed that Phox2 and the Isl1-Lhx3 complex bind to E1 and drive hindbrain and spinal cord-specific expression of Isl1, respectively. Interestingly, Lhx3 alone was sufficient to activate E1, and this may contribute to the initiation of Isl1 expression when progenitors have just developed into motor neurons. E2 was induced by onecut 1 (OC-1) factor that permits Isl1 expression in LMCm neurons. Interestingly, the core region of E1 has been conserved in evolution, even in the lamprey, a jawless vertebrate with primitive motor neurons. All E1 sequences from lamprey to mouse responded equally well to Phox2a and the Isl1-Lhx3 complex. Conversely, E2, the enhancer for limb-innervating motor neurons, was only found in tetrapod animals. This suggests that evolutionarily-conserved enhancers permit the diversification of motor neurons. PMID:26447474

  3. Functional Diversification of Motor Neuron-specific Isl1 Enhancers during Evolution.

    PubMed

    Kim, Namhee; Park, Chungoo; Jeong, Yongsu; Song, Mi-Ryoung

    2015-10-01

    Functional diversification of motor neurons has occurred in order to selectively control the movements of different body parts including head, trunk and limbs. Here we report that transcription of Isl1, a major gene necessary for motor neuron identity, is controlled by two enhancers, CREST1 (E1) and CREST2 (E2) that allow selective gene expression of Isl1 in motor neurons. Introduction of GFP reporters into the chick neural tube revealed that E1 is active in hindbrain motor neurons and spinal cord motor neurons, whereas E2 is active in the lateral motor column (LMC) of the spinal cord, which controls the limb muscles. Genome-wide ChIP-Seq analysis combined with reporter assays showed that Phox2 and the Isl1-Lhx3 complex bind to E1 and drive hindbrain and spinal cord-specific expression of Isl1, respectively. Interestingly, Lhx3 alone was sufficient to activate E1, and this may contribute to the initiation of Isl1 expression when progenitors have just developed into motor neurons. E2 was induced by onecut 1 (OC-1) factor that permits Isl1 expression in LMCm neurons. Interestingly, the core region of E1 has been conserved in evolution, even in the lamprey, a jawless vertebrate with primitive motor neurons. All E1 sequences from lamprey to mouse responded equally well to Phox2a and the Isl1-Lhx3 complex. Conversely, E2, the enhancer for limb-innervating motor neurons, was only found in tetrapod animals. This suggests that evolutionarily-conserved enhancers permit the diversification of motor neurons.

  4. Impact of Various Parameters on the Performance of Inter-aircraft Optical Wireless Communication Link

    NASA Astrophysics Data System (ADS)

    Singh, Mehtab

    2017-12-01

    Optical wireless communication (OWC) systems also known as Free space optics (FSO) are capable of providing high channel bandwidth, high data transmission rates, low power consumption, and high security. OWC links are being considered in different applications such as inter-satellite links, terrestrial links, and inter-aircraft communication links. This paper investigates the impact of different system parameters such as transmission power level, operating wavelength, transmitter pointing error angle, bit transmission rate, atmospheric attenuation, antenna aperture diameter, geometric losses, the responsivity of the photodetector, and link range on the performance of inter-aircraft optical wireless communication link.

  5. A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation

    PubMed Central

    Chen, Qing; Zhang, Jinxiu; Hu, Ze

    2017-01-01

    This article investigates the dynamic topology control problem of satellite cluster networks (SCNs) in Earth observation (EO) missions by applying a novel metric of stability for inter-satellite links (ISLs). The properties of the periodicity and predictability of satellites’ relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT) strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime. PMID:28241474

  6. A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation.

    PubMed

    Chen, Qing; Zhang, Jinxiu; Hu, Ze

    2017-02-23

    This article investigates the dynamic topology control problemof satellite cluster networks (SCNs) in Earth observation (EO) missions by applying a novel metric of stability for inter-satellite links (ISLs). The properties of the periodicity and predictability of satellites' relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT) strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime.

  7. 33 CFR 110.179 - Skidaway River, Isle of Hope, Ga.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Skidaway River, Isle of Hope, Ga. 110.179 Section 110.179 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.179 Skidaway River, Isle of Hope, Ga. (a) The...

  8. 75 FR 36292 - Safety Zone; Bay Swim III, Presque Isle Bay, Erie, PA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-25

    ... of Presque Isle Bay, Lake Erie, near Erie, Pennsylvania between 9 a.m. to 11 a.m. on June 26, 2010.... The safety zone will encompass specified waters of Presque Isle Bay, Erie, Pennsylvania starting at...-AA00 Safety Zone; Bay Swim III, Presque Isle Bay, Erie, PA AGENCY: Coast Guard, DHS. ACTION: Temporary...

  9. The case for watchful waiting with Isle Royale's wolf population

    USGS Publications Warehouse

    Mech, L. David

    2013-01-01

    In "Should Isle Royale Wolves be Reintroduced? A Case Study on Wilderness Management in a Changing World," Vucetich et al. concluded with the hope that their analysis “motivates broader discussion that deepens understanding of the specifics on Isle Royale and the underlying principles” (2012: 137). This article represents an attempt to continue that discussion.

  10. 78 FR 11094 - Drawbridge Operation Regulation; James River, Between Isle of Wight and Newport News, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... Operation Regulation; James River, Between Isle of Wight and Newport News, VA AGENCY: Coast Guard, DHS... River, mile 5.0, between Isle of Wight and Newport News, VA. This deviation is necessary to facilitate... Isle of Isle and Newport News, VA opens on signal. The James River Bridge has vertical clearances in...

  11. LIM homeobox transcription factor Isl1 is required for melatonin synthesis in the pig pineal gland.

    PubMed

    Zhang, Jinglin; Qiu, Jingtao; Zhou, Yewen; Wang, Yue; Li, Hongjiao; Zhang, Taojie; Jiang, Ying; Gou, Kemian; Cui, Sheng

    2018-02-26

    Melatonin is a key hormone that regulates circadian rhythms, metabolism, and reproduction. However, the mechanisms of melatonin synthesis and secretion have not been fully defined. The purpose of this study was to investigate the functions of the LIM homeobox transcription factor Isl1 in regulating melatonin synthesis and secretion in porcine pineal gland. We found that Isl1 is highly expressed in the melatonin-producing cells in the porcine pineal gland. Further functional studies demonstrate that Isl1 knockdown in cultured primary porcine pinealocytes results in the decline of melatonin and arylalkylamine N-acetyltransferase (AANAT) mRNA levels by 29.2% and 72.2%, respectively, whereas Isl1 overexpression raised by 1.3-fold and 2.7-fold. In addition, the enhancing effect of norepinephrine (NE) on melatonin synthesis was abolished by Isl1 knockdown. The in vivo intracerebroventricular NE injections upregulate Isl1 mRNA and protein levels by about threefold and 4.5-fold in the porcine pineal gland. We then examined the changes in Isl1 expression in the pineal gland and global melatonin levels throughout the day. The results show that Isl1 protein level at 24:00 is 2.5-fold higher than that at 12:00, which is parallel to melatonin levels. We further found that Isl1 increases the activity of AANAT promoter, and the effect of NE on Isl1 expression was blocked by an ERK inhibitor. Collectively, the results presented here demonstrate that Isl1 positively modulates melatonin synthesis by targeting AANAT, via the ERK signaling pathway of NE. These suggest that Isl1 plays important roles in maintaining the daily circadian rhythm. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Isle Royale National Park transportation study

    DOT National Transportation Integrated Search

    2015-04-02

    Isle Royale National Park is a remote archipelago located in western Lake Superior, fourteen miles from the closest mainland and 60 : miles from the parks headquarters in Houghton, MI. While visitors treasure the parks pristine environment and sol...

  13. Movements of brown bullheads in Presque Isle Bay, Lake Erie, Pennsylvania

    USGS Publications Warehouse

    Millard, M.J.; Smith, D.R.; Obert, E.; Grazio, J.; Bartron, M.L.; Wellington, C.; Grise, S.; Rafferty, S.; Wellington, R.; Julian, S.

    2009-01-01

    Presque Isle Bay, Lake Erie, was listed as an Area of Concern (AOC) by the International Joint Commission in part because of the high incidence of external tumor in brown bullheads. Verifying the source of the possible contaminant exposure is critical to addressing the AOC designation. We used telemetry tracking (n = 49 fish) to test the hypothesis that adult bullheads captured within the bay during spawning season do not exit the bay during the post-spawning summer and fall months. We analyzed genetic variation at 15 microsatellite loci for 112 adult fish from 5 locations, 4 inside the bay and 1 outside, in order to test for possible differences. Data from fixed-station receivers suggested fish did not leave Presque Isle Bay during the study period. Predicted locations outside Presque Isle Bay were only 0.1% of all predicted locations and were below the 0.2% error rate based on known manual relocations. However, there was evidence for movement within Presque Isle Bay. Most movement was between Misery Bay or Lagoons and the open bay area. Whereas telemetry results showed tendency for adult site fidelity, genetic results showed no differences among locations, indicating that there is a single panmictic population. Our telemetry data suggest that brown bullheads are likely a useful indicator species for environmental conditions in Presque Isle Bay, since adults likely are retained in the system.

  14. 33 CFR 100.912 - Detroit Bell Isle Grand Prix, Detroit, MI.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Detroit Bell Isle Grand Prix, Detroit, MI. 100.912 Section 100.912 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.912 Detroit Bell Isle Grand...

  15. Erosion and deterioration of Isles Dernieres Barrier Island arc, Louisiana: 1842-1988

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McBride, R.A.; Westphal, K.; Penland, S.

    1989-09-01

    The Isles Dernieres barrier island arc is the most rapidly eroding coastline in the US. Located on the Mississippi River delta plain in Terrebonne Parish, Louisiana, the Isles Dernieres consists of four smaller islands in a 32-km long chain. From west to east, these islands are known as Raccoon Island, Whiskey Island, Trinity Island, and East Island. The barrier island arc is separated from the mainland by Caillou Bay, Boca Caillou, and Lake Pelto lagoonal systems. The abandonment and transgression of the Bayou Petit Caillou delta (part of the larger Lafourche delta complex) over the last 600 years, along withmore » sea level rise, repeated storm impacts, and rapid shoreface erosion, have led to the formation of the Isles Dernieres. Continued transgressive submergence combined with a diminishing sediment supply are driving the extreme coastal erosion found in the Isles Dernieres.« less

  16. Genetic variability among lake whitefish from Isle Royale and the Upper Great Lakes

    USGS Publications Warehouse

    Stott, Wendylee; Todd, Thomas N.; Kallemeyn, Larry

    2004-01-01

    The coregonine fishes from Isle Royale National Park represent a unique group that has escaped the successional changes observed elsewhere in North America. Analysis of microsatellite DNA loci revealed significant genetic differences among samples of lake whitefish (Coregonus clupeaformis) from Isle Royale, Lake Superior, and Lake Huron. The amount of genetic variation observed is consistent with that seen in other studies of whitefishes from North America. The lake whitefish from Isle Royale had previously been assigned sub-species status, but no evidence was found to support this. The effects of common ancestry and demographics both play a role in determining the relatedness of the populations. As with other fish species from Isle Royale and the upper Great Lakes, the lake whitefish have their origins in the Mississippi refugium.

  17. Optical data communication for Earth observation satellite systems

    NASA Astrophysics Data System (ADS)

    Fischer, J.; Loecherbach, E.

    1991-10-01

    The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to future optical communication satellite systems is given. During the last decade Earth observation became more and more important for the extension of the knowledge about our planet and the human influence on nature. Today pictures taken by satellites are used, for example, to discover mineral resources or to predict harvest, crops, climate, and environment variations and their influence on the population. A new and up to date application for Earth observation satellites can be the verification of disarmament arrangements and the control of crises areas. To solve these tasks a system of Earth observing satellites with sensors tailored to the envisaged mission is necessary. Besides these low Earth orbiting satellites, a global Earth observation system consists of at least two data relay satellites. The communication between the satellites will be established via Inter-Satellite Links (ISL) and Inter-Orbit Links (IOL). On these links, bitrates up to 1 Gbit/s must be taken into account. Due to the increasing scarcity of suitable frequencies, higher carrier frequencies must probably be considered, and possible interference with terrestrial radio relay systems are two main problems for a realization in microwave technique. One important step to tackle these problems is the use of optical frequencies for IOL's and ISL's.

  18. Optical phase locked loop for transparent inter-satellite communications.

    PubMed

    Herzog, F; Kudielka, K; Erni, D; Bächtold, W

    2005-05-16

    A novel type of optical phase locked loop (OPLL), optimized for homodyne inter-satellite communication, is presented. The loop employs a conventional 180? 3 dB optical hybrid and an AC-coupled balanced front end. No residual carrier transmission is required for phase locking. The loop accepts analog as well as digital data and various modulation formats. The only requirement to the transmitted user signal is a constant envelope. Phase error extraction occurs through applying a small sinusoidal local oscillator (LO) phase disturbance, while measuring its impact on the power of the baseband output signal. First experimental results indicate a receiver sensitivity of 36 photons/bit (-55.7 dBm) for a BER of 10 ;-9, when transmitting a PRBS-31 signal at a data rate of 400 Mbit/s. The system setup employs diode-pumped Nd:YAG lasers at a wavelength of 1.06 mum.

  19. Optical phase locked loop for transparent inter-satellite communications

    NASA Astrophysics Data System (ADS)

    Herzog, F.; Kudielka, K.; Erni, D.; Bächtold, W.

    2005-05-01

    A novel type of optical phase locked loop (OPLL), optimized for homodyne inter-satellite communication, is presented. The loop employs a conventional 180◦ 3 dB optical hybrid and an AC-coupled balanced front end. No residual carrier transmission is required for phase locking. The loop accepts analog as well as digital data and various modulation formats. The only requirement to the transmitted user signal is a constant envelope. Phase error extraction occurs through applying a small sinusoidal local oscillator (LO) phase disturbance, while measuring its impact on the power of the baseband output signal. First experimental results indicate a receiver sensitivity of 36 photons/bit (-55.7 dBm) for a BER of 10 ^-9, when transmitting a PRBS-31 signal at a data rate of 400 Mbit/s. The system setup employs diode-pumped Nd:YAG lasers at a wavelength of 1.06 μm.

  20. 75 FR 51379 - Safety Zone; Celebrate Erie, Presque Isle Bay, Erie, PA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... display. DATES: This rule is effective from 9:30 p.m. until 10:30 p.m. on August 22, 2010. ADDRESSES...: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on Presque Isle Bay... Presque Isle Bay in Erie, PA during the Celebrate Erie fireworks display, August 22, 2010. This temporary...

  1. Note: Inter-satellite laser range-rate measurement by using digital phase locked loop.

    PubMed

    Liang, Yu-Rong; Duan, Hui-Zong; Xiao, Xin-Long; Wei, Bing-Bing; Yeh, Hsien-Chi

    2015-01-01

    This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future's gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10(-8) Hz/Hz(1/2)@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

  2. Note: Inter-satellite laser range-rate measurement by using digital phase locked loop

    NASA Astrophysics Data System (ADS)

    Liang, Yu-Rong; Duan, Hui-Zong; Xiao, Xin-Long; Wei, Bing-Bing; Yeh, Hsien-Chi

    2015-01-01

    This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future's gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10-8 Hz/Hz1/2@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

  3. Modulation and coding for throughput-efficient optical free-space links

    NASA Technical Reports Server (NTRS)

    Georghiades, Costas N.

    1993-01-01

    Optical direct-detection systems are currently being considered for some high-speed inter-satellite links, where data-rates of a few hundred megabits per second are evisioned under power and pulsewidth constraints. In this paper we investigate the capacity, cutoff-rate and error-probability performance of uncoded and trellis-coded systems for various modulation schemes and under various throughput and power constraints. Modulation schemes considered are on-off keying (OOK), pulse-position modulation (PPM), overlapping PPM (OPPM) and multi-pulse (combinatorial) PPM (MPPM).

  4. ISL1 and BRN3B co-regulate the differentiation of murine retinal ganglion cells

    PubMed Central

    Pan, Ling; Deng, Min; Xie, Xiaoling; Gan, Lin

    2009-01-01

    SUMMARY LIM-homeodomain (HD) and POU-HD transcription factors play critical roles in neurogenesis. However, it remains largely unknown how they cooperate in this process and what downstream target genes they regulate. Here we show that ISL1, a LIM-HD protein, is co-expressed with BRN3B, a POU-HD factor, in nascent, post-mitotic retinal ganglion cells (RGCs). Similar to the Brn3b-null retinas, retina-specific deletion of Isl1 results in the apoptosis of a majority of RGCs and in RGC axon guidance defects. The Isl1 and Brn3b double null mice display more severe retinal abnormalities with a near complete loss of RGCs, indicating the synergistic functions of these two factors. Furthermore, we show that both Isl1 and Brn3b function downstream of Math5 to regulate the expression of a common set of RGC-specific genes. Whole retina chromatin immunoprecipitation and in vitro transactivation assays reveal that ISL1 and BRN3B concurrently bind to and synergistically regulate the expression of a common set of RGC-specific genes. Thus, our results uncover a novel regulatory mechanism of BRN3B and ISL1 in RGC differentiation. PMID:18434421

  5. CIP, a cardiac Isl1-interacting protein, represses cardiomyocyte hypertrophy

    PubMed Central

    Huang, Zhan-Peng; Seok, Hee Young; Zhou, Bin; Chen, Jinghai; Chen, Jian-Fu; Tao, Yazhong; Pu, William T.; Wang, Da-Zhi

    2012-01-01

    Rationale Mammalian heart has minimal regenerative capacity. In response to mechanical or pathological stress, the heart undergoes cardiac remodeling. Pressure and volume overload in the heart cause increased size (hypertrophic growth) of cardiomyocytes. Whereas the regulatory pathways that activate cardiac hypertrophy have been well established, the molecular events that inhibit or repress cardiac hypertrophy are less known. Objective To identify and investigate novel regulators that modulate cardiac hypertrophy. Methods and Results Here, we report the identification, characterization and functional examination of CIP, a novel cardiac Isl1-interacting protein. CIP was identified from a bioinformatic search for novel cardiac-expressed genes in mouse embryonic hearts. CIP encodes a nuclear protein without recognizable motifs. Northern blotting, in situ hybridization and reporter gene tracing demonstrated that CIP is highly expressed in cardiomyocytes of developing and adult hearts. Yeast-two-hybrid screening identified Isl1, a LIM/homeodomain transcription factor essential for the specification of cardiac progenitor cells in the second heart field, as a co-factor of CIP. CIP directly interacted with Isl1 and we mapped the domains of these two proteins which mediate their interaction. We show that CIP represses the transcriptional activity of Isl1 in the activation of the MEF2C enhancer. The expression of CIP was dramatically reduced in hypertrophic cardiomyocytes. Most importantly, overexpression of CIP repressed agonist-induced cardiomyocyte hypertrophy. Conclusions Our studies therefore identify CIP a novel regulator of cardiac hypertrophy. PMID:22343712

  6. CIP, a cardiac Isl1-interacting protein, represses cardiomyocyte hypertrophy.

    PubMed

    Huang, Zhan-Peng; Young Seok, Hee; Zhou, Bin; Chen, Jinghai; Chen, Jian-Fu; Tao, Yazhong; Pu, William T; Wang, Da-Zhi

    2012-03-16

    Mammalian heart has minimal regenerative capacity. In response to mechanical or pathological stress, the heart undergoes cardiac remodeling. Pressure and volume overload in the heart cause increased size (hypertrophic growth) of cardiomyocytes. Whereas the regulatory pathways that activate cardiac hypertrophy have been well-established, the molecular events that inhibit or repress cardiac hypertrophy are less known. To identify and investigate novel regulators that modulate cardiac hypertrophy. Here, we report the identification, characterization, and functional examination of a novel cardiac Isl1-interacting protein (CIP). CIP was identified from a bioinformatic search for novel cardiac-expressed genes in mouse embryonic hearts. CIP encodes a nuclear protein without recognizable motifs. Northern blotting, in situ hybridization, and reporter gene tracing demonstrated that CIP is highly expressed in cardiomyocytes of developing and adult hearts. Yeast two-hybrid screening identified Isl1, a LIM/homeodomain transcription factor essential for the specification of cardiac progenitor cells in the second heart field, as a cofactor of CIP. CIP directly interacted with Isl1, and we mapped the domains of these two proteins, which mediate their interaction. We show that CIP represses the transcriptional activity of Isl1 in the activation of the myocyte enhancer factor 2C. The expression of CIP was dramatically reduced in hypertrophic cardiomyocytes. Most importantly, overexpression of CIP repressed agonist-induced cardiomyocyte hypertrophy. Our studies therefore identify CIP as a novel regulator of cardiac hypertrophy.

  7. Expression of the LIM-Homeodomain Protein Isl1 in the Developing and Mature Mouse Retina

    PubMed Central

    Elshatory, Yasser; Deng, Min; Xie, Xiaoling; Gan, Lin

    2010-01-01

    The mammalian retina is comprised of six major neuronal cell types and is subdivided into more morphological and physiological subtypes. The transcriptional machinery underlying these subtype fate choices is largely unknown. The LIM-homeodomain protein, Isl1, plays an essential role in central nervous system (CNS) differentiation but its relationship to retinal neurogenesis remains unknown. We report here its dynamic spatiotemporal expression in the mouse retina. Among bipolar interneurons, Isl1 expression commences at postnatal day (P)5 and is later restricted to ON-bipolar cells. The intensity of Isl1 expression is found to segregate the pool of ON-bipolar cells into rod and ON-cone bipolar cells with higher expression in rod bipolar cells. As bipolar cell development proceeds from P5–10 the colocalization of Isl1 and the pan-bipolar cell marker Chx10 reveals the organization of ON-center bipolar cell nuclei to the upper portion of the inner nuclear layer. Further, whereas Isl1 is predominantly a ganglion cell marker prior to embryonic day (E)15.5, at E15.5 and later its expression in nonganglion cells expands. We demonstrate that these Isl1-positive, nonganglion cells acquire the expression of amacrine cell markers embryonically, likely representing nascent cholinergic amacrine cells. Taken together, Isl1 is expressed during the maturation of and is later maintained in retinal ganglion cells and subtypes of amacrine and bipolar cells where it may function in the maintenance of these cells into adulthood. J. Comp. Neurol. 503: 182–197, 2007. PMID:17480014

  8. Measuring plume-related exhumation of the British Isles in Early Cenozoic times

    NASA Astrophysics Data System (ADS)

    Cogné, Nathan; Doepke, Daniel; Chew, David; Stuart, Finlay M.; Mark, Chris

    2016-12-01

    Mantle plumes have been proposed to exert a first-order control on the morphology of Earth's surface. However, there is little consensus on the lifespan of the convectively supported topography. Here, we focus on the Cenozoic uplift and exhumation history of the British Isles. While uplift in the absence of major regional tectonic activity has long been documented, the causative mechanism is highly controversial, and direct exhumation estimates are hindered by the near-complete absence of onshore post-Cretaceous sediments (outside Northern Ireland) and the truncated stratigraphic record of many offshore basins. Two main hypotheses have been developed by previous studies: epeirogenic exhumation driven by the proto-Iceland plume, or multiple phases of Cenozoic compression driven by far-field stresses. Here, we present a new thermochronological dataset comprising 43 apatite fission track (AFT) and 102 (U-Th-Sm)/He (AHe) dates from the onshore British Isles. Inverse modelling of vertical sample profiles allows us to define well-constrained regional cooling histories. Crucially, during the Paleocene, the thermal history models show that a rapid exhumation pulse (1-2.5 km) occurred, focused on the Irish Sea. Exhumation is greatest in the north of the Irish Sea region, and decreases in intensity to the south and west. The spatial pattern of Paleocene exhumation is in agreement with the extent of magmatic underplating inferred from geophysical studies, and the timing of uplift and exhumation is synchronous with emplacement of the plume-related British and Irish Paleogene Igneous Province (BIPIP). Prior to the Paleocene exhumation pulse, the Mesozoic onshore exhumation pulse is mainly linked to the uplift and erosion of the hinterland during the complex and long-lived rifting history of the neighbouring offshore basins. The extent of Neogene exhumation is difficult to constrain due to the poor sensitivity of the AHe and AFT systems at low temperatures. We conclude that the

  9. Intersatellite Link Design Issues

    DTIC Science & Technology

    1985-01-01

    of Science degree by Richard S. Fuhrmann has been approved for the Tel ecommunications Program by Frank S. Barnes Sadel W.’MaleyK Date --- 45 N... means , the holier of a monopoly when it comes to satellites. In the early . 70"s, the low cost per circuit qenerated interest in Nil Fj domestic

  10. A Millimeter-Wave Cavity-Backed Suspended Substrate Stripline Antenna

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.

    1999-01-01

    Future generation satellite communication systems in near-Earth orbit will operate at frequencies in the higher mm-wave frequency bands. These satellite systems require low-profile, high gain, light weight and low cost antennas for communications to and from Earth as well as for inter-satellite links (ISL). At higher mm-wave frequencies, the conductor loss of conventional microstrip line is high and consequently the feed network loss of patch antenna arrays is also high. The high loss lowers the array efficiency, and in addition lowers the G/T ratio in a receiving array. Recently a radial line slot antenna array has been demonstrated to have high gain and efficiency at 60 GHz. In this paper, the design, fabrication and characterization of a V-Band (50-75 GHz), cavity backed, circular aperture antenna with suspended substrate stripline (SSS) feed is presented.

  11. Unusual July 10, 1996, rock fall at Happy Isles, Yosemite National Park, California

    USGS Publications Warehouse

    Wieczorek, G.F.; Snyder, J.B.; Waitt, R.B.; Morrissey, M.M.; Uhrhammer, R.A.; Harp, E.L.; Norris, R.D.; Bursik, M.I.; Finewood, L.G.

    2000-01-01

    Effects of the July 10, 1996, rock fall at Happy Isles in Yosemite National Park, California, were unusual compared to most rock falls. Two main rock masses fell about 14 s apart from a 665-m-high cliff southeast of Glacier Point onto a talus slope above Happy Isles in the eastern part of Yosemite Valley. The two impacts were recorded by seismographs as much as 200 km away. Although the impact area of the rock falls was not particularly large, the falls generated an airblast and an abrasive dense sandy cloud that devastated a larger area downslope of the impact sites toward the Happy Isles Nature Center. Immediately downslope of the impacts, the airblast had velocities exceeding 110 m/s and toppled or snapped about 1000 trees. Even at distances of 0.5 km from impact, wind velocities snapped or toppled large trees, causing one fatality and several serious injuries beyond the Happy Isles Nature Center. A dense sandy cloud trailed the airblast and abraded fallen trunks and trees left standing. The Happy Isles rock fall is one of the few known worldwide to have generated an airblast and abrasive dense sandy cloud. The relatively high velocity of the rock fall at impact, estimated to be 110-120 m/s, influenced the severity and areal extent of the airblast at Happy Isles. Specific geologic and topographic conditions, typical of steep glaciated valleys and mountainous terrain, contributed to the rock-fall release and determined its travel path, resulting in a high velocity at impact that generated the devastating airblast and sandy cloud. The unusual effects of this rock fall emphasize the importance of considering collateral geologic hazards, such as airblasts from rock falls, in hazard assessment and planning development of mountainous areas.

  12. Note: Inter-satellite laser range-rate measurement by using digital phase locked loop

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liang, Yu-Rong; Department of Electronics and Information Engineering, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074; Duan, Hui-Zong

    2015-01-15

    This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future’s gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10{sup −8} Hz/Hz{sup 1/2}@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

  13. Phasemeter core for intersatellite laser heterodyne interferometry: modelling, simulations and experiments

    NASA Astrophysics Data System (ADS)

    Gerberding, Oliver; Sheard, Benjamin; Bykov, Iouri; Kullmann, Joachim; Esteban Delgado, Juan Jose; Danzmann, Karsten; Heinzel, Gerhard

    2013-12-01

    Intersatellite laser interferometry is a central component of future space-borne gravity instruments like Laser Interferometer Space Antenna (LISA), evolved LISA, NGO and future geodesy missions. The inherently small laser wavelength allows us to measure distance variations with extremely high precision by interfering a reference beam with a measurement beam. The readout of such interferometers is often based on tracking phasemeters, which are able to measure the phase of an incoming beatnote with high precision over a wide range of frequencies. The implementation of such phasemeters is based on all digital phase-locked loops (ADPLL), hosted in FPGAs. Here, we present a precise model of an ADPLL that allows us to design such a readout algorithm and we support our analysis by numerical performance measurements and experiments with analogue signals.

  14. Coherent detection of position errors in inter-satellite laser communications

    NASA Astrophysics Data System (ADS)

    Xu, Nan; Liu, Liren; Liu, De'an; Sun, Jianfeng; Luan, Zhu

    2007-09-01

    Due to the improved receiver sensitivity and wavelength selectivity, coherent detection became an attractive alternative to direct detection in inter-satellite laser communications. A novel method to coherent detection of position errors information is proposed. Coherent communication system generally consists of receive telescope, local oscillator, optical hybrid, photoelectric detector and optical phase lock loop (OPLL). Based on the system composing, this method adds CCD and computer as position error detector. CCD captures interference pattern while detection of transmission data from the transmitter laser. After processed and analyzed by computer, target position information is obtained from characteristic parameter of the interference pattern. The position errors as the control signal of PAT subsystem drive the receiver telescope to keep tracking to the target. Theoretical deviation and analysis is presented. The application extends to coherent laser rang finder, in which object distance and position information can be obtained simultaneously.

  15. ISLES: Probing Extra Dimensions Using a Superconducting Accelerometer

    NASA Technical Reports Server (NTRS)

    Paik, Ho Jung; Moody, M. Vol; Prieto-Gortcheva, Violeta A.

    2003-01-01

    In string theories, extra dimensions must be compactified. The possibility that gravity can have large radii of compactification leads to a violation of the inverse square law at submillimeter distances. The objective of ISLES is to perform a null test of Newton s law in space with a resolution of one part in 10(exp 5) or better at 100 microns. The experiment will be cooled to less than or equal to 2 K, which permits superconducting magnetic levitation of the test masses. To minimize Newtonian errors, ISLES employs a near null source, a circular disk of large diameter-to-thickness ratio. Two test masses, also disk-shaped, are suspended on the two sides of the source mass at a nominal distance of 100 microns. The signal is detected by a superconducting differential accelerometer. A ground test apparatus is under construction.

  16. Population limitation and the wolves of Isle Royale

    USGS Publications Warehouse

    Peterson, Rolf O.; Thomas, Nancy J.; Thurber, Joanne M.; Vucetich, John A.; Waite, Thomas A.

    1998-01-01

    Population regulation for gray wolves in Isle Royale National Park, Michigan, was examined in 1987-1995 when wolves were in chronic decline following a crash of the population in 1981-1982. Canine parvovirus (CPV-2) was probably influential during the crash, but it disappeared by the late 1980s. High mortality abruptly ceased after 1988, but low recruitment in the absence of disease and obvious shortage of food prevented recovery of the wolf population. In 1983-1995, with a comparable number of moose '10 years old as potential prey, wolves were only half as numerous as in 1959-1980. A simulation of annual fluctuations in effective population size (Ne) for wolves on Isle Royale suggests that their genetic heterozygosity has declined ca. 13% with each generation and ca. 80% in the 50- year history of this population. Inbreeding depression and stochastic demographic variation both remain possible explanations for recent low recruitment.

  17. A Millimeter-wave Cavity-backed Suspended Substrate Stripline Antenna

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.

    1999-01-01

    Future generation satellite communication systems in near-Earth orbit will operate at frequencies in the higher mm-wave frequency hands. These satellite systems require low-profile, high gain, light weight and low cost antennas for communications to and from Earth as well as for inter-satellite links (ISL). At higher mm-wave frequencies, the conductor loss of conventional microstrip line is high and consequently the feed network loss of patch antenna arrays is also high. The high loss lowers the array efficiency and in addition lowers the G/T ratio in a receiving array. Recently a radial line slot antenna array has been demonstrated to have high gain and efficiency at 60 GHz. In this paper, the design, fabrication and characterization of a V-Band (50-75 GHz) 4 x 4 planar array of cavity backed circular aperture antennas with suspended substrate stripline (SSS) corporate feed is presented.

  18. Distributed Timing and Localization (DiGiTaL)

    NASA Technical Reports Server (NTRS)

    D'Amico, Simone; Hunter, Roger C.; Baker, Christopher

    2017-01-01

    The Distributed Timing and Localization (DiGiTaL) system provides nano satellite formations with unprecedented,centimeter-level navigation accuracy in real time and nanosecond-level time synchronization. This is achieved through the integration of a multi-constellation Global Navigation Satellite System (GNSS) receiver, a Chip-Scale Atomic Clock (CSAC), and a dedicated Inter-Satellite Link (ISL). In comparison, traditional single spacecraft GNSS navigation solutions are accurate only to the meter-level due to the sole usage of coarse pseudo-range measurements. To meet the strict requirements of future miniaturized distributed space systems, DiGiTaL uses powerful error-cancelling combinations of raw carrier-phase measurements which are exchanged between the swarming nano satellites through a decentralized network. A reduced-dynamics estimation architecture on board each individual nano satellite processes the resulting millimeter-level noise measurements to reconstruct the fullformation state with high accuracy.

  19. ISLE: Intelligent Selection of Loop Electronics. A CLIPS/C++/INGRES integrated application

    NASA Technical Reports Server (NTRS)

    Fischer, Lynn; Cary, Judson; Currie, Andrew

    1990-01-01

    The Intelligent Selection of Loop Electronics (ISLE) system is an integrated knowledge-based system that is used to configure, evaluate, and rank possible network carrier equipment known as Digital Loop Carrier (DLC), which will be used to meet the demands of forecasted telephone services. Determining the best carrier systems and carrier architectures, while minimizing the cost, meeting corporate policies and addressing area service demands, has become a formidable task. Network planners and engineers use the ISLE system to assist them in this task of selecting and configuring the appropriate loop electronics equipment for future telephone services. The ISLE application is an integrated system consisting of a knowledge base, implemented in CLIPS (a planner application), C++, and an object database created from existing INGRES database information. The embedibility, performance, and portability of CLIPS provided us with a tool with which to capture, clarify, and refine corporate knowledge and distribute this knowledge within a larger functional system to network planners and engineers throughout U S WEST.

  20. Erosion and deterioration of the Isles Dernieres Barrier Island Arc, Louisiana, U.S.A.: 1853 to 1988

    USGS Publications Warehouse

    McBride, Randolph A.; Penland, Shea; Jaffe, Bruce E.; Williams, S. Jeffress; Sallenger, Asbury H.; Westphal, Karen A.

    1989-01-01

    Using cartographic and aerial photography data from the years 1853, 1890, 1934, 1956, 1978, 1984, and 1988, shoreline change maps of the Isles Dernieres barrier island arc were constructed. These data were accurately superimposed, using a computer mapping system, which removed projection, datum, scale, and other cartographic inconsistencies. Linear, areal, and perimeter measurements indicate that the Isles Dernieres are suffering rapid rates of coastal erosion, land loss, and breakup. Bayside and gulfside erosion, in combination with sediment shortage and subsidence, have caused the Isles Dernieres to narrow through time. In addition, the core of the barrier island arc does not migrate landward and instead, breaks up in place as a result of inlet breaching and development. This is in contrast to other models of landward barrier island migration during transgression. If these trends continue, the Isles Dernieres will likely evolve into a subaqueous inner-shelf shoal by the early 21st century. Loss of the Isles Dernieres barrier island arc will severely impact the Terrebonne parish estuary, resulting in decreased environmental quality and increased public risk from storms and hurricanes.

  1. Development of a 75-watt 60-GHz traveling-wave tube for intersatellite communications

    NASA Technical Reports Server (NTRS)

    Rousseau, A. L.; Tammaru, I.; Vaszari, J. P.

    1988-01-01

    This program covers the initial design and development of a 75 watt, 60 GHz traveling-wave tube for intersatellite communications. The objective frequency band was 59 to 64 GHz, with a minimum tube gain of 35 dB. The objective overall efficiency at saturation was 40 percent. The tube, designated the 961H, used a coupled-cavity interaction circuit with periodic permanent magnet beam focusing to minimize the weight. For efficiency enhancement, it incorporated a four-stage depressed collector capable of radiation cooling in space. The electron gun had a low-temperature (type-M) cathode and an isolated anode. Two tubes were built and tested; one feasibility model with a single-stage collector and one experimental model that incorporated the multistage collector.

  2. Body concentration of caesium-137 in patients from Western Isles of Scotland.

    PubMed Central

    Isles, C G; Robertson, I; Macleod, J A; Preston, T; East, B W; Hole, D J; Lever, A F

    1991-01-01

    OBJECTIVES--To compare caesium-137 concentrations in patients from the Western Isles Health Board, Glasgow area, and other parts of the Scottish mainland, and to investigate the source of 137Cs in patients from the Western Isles. DESIGN--Study of hypertensive patients having electrolyte concentrations measured, including 137Cs. Interview by questionnaire of island subjects about intake of foods likely to contain radiocaesium and the source of these foods. Measurement of 137Cs and 134Cs in food, urine, and vegetation. SETTING--Scottish mainland and Western Isles, 1979-86. All measurements before Chernobyl nuclear accident. PATIENTS--413 consecutive patients referred to the blood pressure unit for investigation of hypertension. 60 from the Western Isles, including 44 from North Uist; 32 from North Uist participated in the dietary analysis. MAIN OUTCOME MEASURES--Concentration of radiocaesium in the body, urine, food, and vegetation. Islanders' consumption of local produce. RESULTS--Patients from the Western Isles had five times higher body concentrations of 137Cs (median 2.54 (interquartile range 1.25-3.73)) Bq/gK) than did patients from around Glasgow (0.47 (0.26-0.66) Bq/gK) and other parts of the Scottish mainland (0.42 (0.24-0.71) Bq/gK). Islanders often consumed local milk and mutton, but ate local fish rarely. 137Cs and 134Cs were present in coastal (21.6 Bq/kg 137Cs, 0.25 Bq/kg 134Cs) and moorland (135.9, 0.65 Bq/kg) grasses and in islanders' urine (2.01, 0.013 Bq/l). Lower concentrations (0.336, 0.004 Bq/l), were found in the urine of Glasgow controls (p less than 0.001 for both isotopes). CONCLUSIONS--Islanders have excess body 137Cs concentrations, most of which probably comes from local milk and lamb. The radioactivity is not above the recommended safety limit. The presence of 134Cs suggests that nuclear reprocessing is the source of some of the radiocaesium. PMID:1906765

  3. Rocks at Belle-Isle, Port-Domois, Claude Monet

    ERIC Educational Resources Information Center

    Rauch, Marion Cosgrove

    2004-01-01

    This article is a description of the artist Claude Monet. The article describes the life and art of Claude Monet, focusing in on his work, Rocks at Bell-Isle, Port-Domois. A brief discussion of the significant elements of the painting is provided. The article also includes a list of discussion questions and suggested classroom activities.

  4. Implementing a sustainable clinical supervision model for Isles nurses in Orkney.

    PubMed

    Hall, Ian

    2018-03-02

    The Isles Network of Care (INOC) community nurses work at the extreme of the remote and rural continuum, working mostly as lone practitioners. Following the development of sustainable clinical supervision model for Isles nurses in Orkney, clinical supervision was found to improve both peer support and governance for this group of isolated staff. A literature overview identified the transition of clinical supervision in general nursing over 24 years from 'carrot' to 'stick'. The study included a questionnaire survey that was sent to the 2017 Queen's Nursing Institute Scotland cohort to elicit information about the nurses' experience of clinical supervision. The survey found that 55% provide supervision and 40% receive it. Health board encouragement of its use was found to be disappointingly low at 40%. The INOC nurses were surveyed about the new peer-support (restorative) model, which relies on video-conference contact to allow face to face interaction between isolated isles nurses. Feedback prompted a review of clinical supervision pairings, and the frequency and methods of meeting. The need for supervisor training led to agreement with the Remote and Rural Health Education Alliance to provide relevant support. The perceived benefits of supervision included increased support and reflection, and improved relationships with isolated colleagues.

  5. The individual supported living (ISL) manual: a planning and review instrument for individual supported living arrangements for adults with intellectual and developmental disabilities.

    PubMed

    Cocks, E; Thoresen, S; Williamson, M; Boaden, R

    2014-07-01

    Following the closure of large residential facilities over the past several decades, emphasis on community living for adults with developmental disabilities has strengthened. However, the concept of community living is ambiguous. The term is often associated with congregation of people with disabilities in ordinary houses 'in' the community. Group homes, the most common contemporary formal expression of 'community living', may use ordinary houses and accommodate a small number of residents comparable to a large family. Individual supported living (ISL) arrangements around a single person with a disability using person-centred principles are occurring with increasing frequency. The ISL manual was developed over 4 years in two sequential research projects to produce a quality framework articulating ISL and operationalising the framework into a review and planning instrument for ISL arrangements. The ISL manual was developed in three stages and overseen by a reference group of key stakeholders purposively recruited as well-versed in ISL. The first stage operationalised the quality framework over two half-day workshops with a group of key informants. Participants identified indicators and sources of evidence for each attribute of the quality framework. The quality framework, indicators, and sources of evidence were compiled into an initial evaluation instrument of nine themes consisting of 27 attributes. This was piloted in two rounds to enhance the utility of the instrument and develop the final manual which contained eight themes and 21 attributes. A comprehensive literature search was carried out to identify relevant empirical ISL studies. The literature search identified four empirical studies that incorporated ISL over the preceding 3 years. A previous literature search from the first research project that produced the quality framework spanned 27 years and identified five empirical studies. We concluded that the empirical base for developing evidence for the

  6. British Isles Field Experience: An Initiative in International Education.

    ERIC Educational Resources Information Center

    Martin, William J.

    The British Isles Field Experience (BIFE) program was initiated at Williamsport Area Community College (WACC) to provide a group of WACC faculty and staff members with individual and group activities of a personal, professional, and cultural nature in order to promote an international perspective that can be infused into student, collegiate, and…

  7. Survey Development for Assessing Learning Identity in an ISLE Classroom

    NASA Astrophysics Data System (ADS)

    Li, Sissi L.; Roth, Jennifer A.; Demaree, Dedra

    2010-10-01

    Innovative STEM curricula such as the ISLE (Investigative Science Learning Environment) curriculum [1] are centered on active engagement in social learning processes as a means to achieve curricular goals. Classroom practices are highly interactive to facilitate students' development of authentic scientist abilities. To the students, these classroom practices often seem very different from their previous learning experiences in terms of behavioral expectations, attitude, and what it means to learn. Consequently, students must modify their identity as learners in addition to physics conceptual understanding in order to participate productively in this learning environment. Using a survey we developed, we want to assess their 1) expectations of student and teacher roles, 2) self efficacy towards skills supported in ISLE and 3) attitudes towards social learning as well as how these change as a result of their experience in this curriculum. We will discuss the development, validation and preliminary findings of the survey.

  8. Rayleigh wave tomography of the British Isles from ambient seismic noise

    NASA Astrophysics Data System (ADS)

    Nicolson, Heather; Curtis, Andrew; Baptie, Brian

    2014-08-01

    We present the first Rayleigh wave group speed maps of the British Isles constructed from ambient seismic noise. The maps also constitute the first surface wave tomography study of the crust under the British Isles at a relatively high resolution. We computed interferometric, interstation Rayleigh waves from vertical component records of ambient seismic noise recorded on 63 broad-band and short-period stations across the UK and Ireland. Group velocity measurements were made from the resulting surface wave dispersion curves between 5 and 25 s using a multiple phase-matched filter method. Uncertainties in the group velocities were computed by calculating the standard deviation of four dispersion curves constructed by stacking a random selection of daily cross-correlations. Where an uncertainty could not be obtained for a ray path using this method, we estimated it as a function of the interreceiver distance. Group velocity maps were computed for 5-25-s period using the Fast Marching forward solution of the eikonal equation and iterative, linearized inversion. At short and intermediate periods, the maps show remarkable agreement with the major geological features of the British Isles including: terrane boundaries in Scotland; regions of late Palaeozoic basement uplift; areas of exposed late Proterozoic/early Palaeozoic rocks in southwest Scotland, northern England and northwest Wales and, sedimentary basins formed during the Mesozoic such as the Irish Sea Basin, the Chester Basin, the Worcester Graben and the Wessex Basin. The maps also show a consistent low-velocity anomaly in the region of the Midlands Platform, a Proterozoic crustal block in the English Midlands. At longer periods, which are sensitive velocities in the lower crustal/upper mantle, the maps suggest that the depth of Moho beneath the British Isles decreases towards the north and west. Areas of fast velocity in the lower crust also coincide with areas thought to be associated with underplating of the

  9. The geologic story of Isle Royale National Park

    USGS Publications Warehouse

    Huber, N. King

    1975-01-01

    Isle Royale is an outstanding example of relatively undisturbed northwoods lake wilderness. But more than simple preservation of such an environment is involved in its inclusion in our National Park System. Its isolation from the mainland provides an almost untouched laboratory for research in the natural sciences, especially those studies whose very nature depends upon such isolation. One excellent example of such research is the intensive study of the predator-prey relationship of the timber wolf and moose, long sponsored by the National Park Service and Purdue University. In probably no other place in North America are the necessary ecological conditions for such a study so admirably fulfilled as on Isle Royale. The development of a natural laboratory with such conditions is ultimately dependent upon geologic processes and events that although not unique in themselves, produced in their interplay a unique result, the island archipelago as we know it today, with its hills and valleys, swamps and bogs the ecological framework of the plant and animal world. Even the most casual visitor can hardly fail to be struck by the fiordlike nature of many of the bays, the chains of fringing islands, the ridge-and-valley topography, and the linear nature of all these features. The distinctive topography of the archipelago is, of course, only the latest manifestation of geologic processes in operation since time immemorial. Fragments of geologic history going back over a billion years can be read from the rocks of the island, and with additional data from other parts of the Lake Superior region, we can fill in some of the story of Isle Royale. After more than a hundred years of study by man, the story is still incomplete. But then, geologic stories are seldom complete, and what we do know allows a deeper appreciation of one of our most naturally preserved parks and whets our curiosity about the missing fragments.

  10. Optical satellite communications in Europe

    NASA Astrophysics Data System (ADS)

    Sodnik, Zoran; Lutz, Hanspeter; Furch, Bernhard; Meyer, Rolf

    2010-02-01

    This paper describes optical satellite communication activities based on technology developments, which started in Europe more than 30 years ago and led in 2001 to the world-first optical inter-satellite communication link experiment (SILEX). SILEX proved that optical communication technologies can be reliably mastered in space and in 2006 the Japanese Space Agency (JAXA) joined the optical inter-satellite experiment from their own satellite. Since 2008 the German Space Agency (DLR) is operating an inter-satellite link between the NFIRE and TerraSAR-X satellites based on a second generation of laser communication technology, which will be used for the new European Data Relay Satellite (EDRS) system to be deployed in 2013.

  11. Research on formation of microsatellite communication with genetic algorithm.

    PubMed

    Wu, Guoqiang; Bai, Yuguang; Sun, Zhaowei

    2013-01-01

    For the formation of three microsatellites which fly in the same orbit and perform three-dimensional solid mapping for terra, this paper proposes an optimizing design method of space circular formation order based on improved generic algorithm and provides an intersatellite direct spread spectrum communication system. The calculating equation of LEO formation flying satellite intersatellite links is guided by the special requirements of formation-flying microsatellite intersatellite links, and the transmitter power is also confirmed throughout the simulation. The method of space circular formation order optimizing design based on improved generic algorithm is given, and it can keep formation order steady for a long time under various absorb impetus. The intersatellite direct spread spectrum communication system is also provided. It can be found that, when the distance is 1 km and the data rate is 1 Mbps, the input wave matches preferably with the output wave. And LDPC code can improve the communication performance. The correct capability of (512, 256) LDPC code is better than (2, 1, 7) convolution code, distinctively. The design system can satisfy the communication requirements of microsatellites. So, the presented method provides a significant theory foundation for formation-flying and intersatellite communication.

  12. Erosional patterns of the Isles Dernieres, Louisiana, in relation to meteorological influences

    USGS Publications Warehouse

    Dingler, J.R.; Reiss, T.E.; Plant, N.G.

    1993-01-01

    Over the past 100 years, the Isles Dernieres, a low-lying barrier-island chain along the central Louisiana coast, has eroded extensively. This erosion has resulted in more than 1 km of northward beach-face retreat and the loss of 71% of the total island area. The primary causes for the erosion are wind and wave attack, diminished sand supply, and relative sea-level rise. Five years of detailed topographic surveys show that a beach on the central Isles Dernieres changed significantly in both shape and sediment volume; however, the pattern of change was not the same each year. In contrast to the relatively slow erosion caused by cold fronts, hurricane Gilbert, a category 5 hurricane that passed about 800 km south of the Isles Dernieres in September 1988, produced differential beach-face retreat of about 9 m at mean sea level and 40 m at an elevation of 0.5 m. Most of the sediment eroded from the beach face was deposited on the backshore, which resulted in only a small loss of sediment from the beach and a noteworthy decrease in beach-face slope. During the two years following hurricane Gilbert, the mean-sea-level contour remained stationary while the beach face slowly returned to its pre-Gilbert shape. "Cold-front' magnitude of retreat is expected to continue until another large hurricane alters the erosional pattern. -from Authors

  13. Phylogenetic analysis and antifouling potentials of culturable fungi in mangrove sediments from Techeng Isle, China.

    PubMed

    Zhang, Xiao-Yong; Fu, Wen; Chen, Xiao; Yan, Mu-Ting; Huang, Xian-De; Bao, Jie

    2018-06-09

    To search for more microbial resources for screening environment-friendly antifoulants, we investigated the phylogenetic diversity and antifouling potentials of culturable fungi in mangrove sediments from Techeng Isle, China. A total of 176 isolates belonging to 57 fungal taxa were recovered and identified. The high levels of diversity and abundance of mangrove fungi from Techeng Isle were in accordance with previous studies on fungi from other mangrove ecosystems. Fifteen of the 176 isolates demonstrated high divergence (87-93%) from the known fungal taxa in GenBank. Moreover, 26 isolates recorded in mangrove ecosystems for the first time. These results suggested that mangrove sediments from Techeng Isle harbored some new fungal communities compared with other mangrove ecosystems. The antifouling activity of 57 representative isolates (belonging to 57 different fungal taxa) was tested against three marine bacteria (Loktanella hongkongensis, Micrococcus luteus and Pseudoalteromonas piscida) and two marine macrofoulers (bryozoan Bugula neritina and barnacle Balanus amphitrite). Approximately 40% of the tested isolates displayed distinct antifouling activity. Furthermore, 17 fungal isolates were found to display strong or a wide spectrum of antifouling activity in this study, suggesting that these isolates deserve further study as potential sources of novel antifouling metabolites. To our knowledge, this is the first report on the investigation of the phylogenetic diversity and antifouling potential of culturable fungi in mangrove sediments from Techeng Isle, China. These results contribute to our knowledge of mangrove fungi and further increases the pool of fungi available for natural bioactive product screening.

  14. The optical communication link outage probability in satellite formation flying

    NASA Astrophysics Data System (ADS)

    Arnon, Shlomi; Gill, Eberhard

    2014-02-01

    In recent years, several space systems consisting of multiple satellites flying in close formation have been proposed for various purposes such as interferometric synthetic aperture radar measurement (TerraSAR-X and the TanDEM-X), detecting extra-solar earth-like planets (Terrestrial Planet Finder-TPF and Darwin), and demonstrating distributed space systems (DARPA F6 project). Another important purpose, which is the concern of this paper, is for improving radio frequency communication to mobile terrestrial and maritime subscribers. In this case, radio frequency signals from several satellites coherently combine such that the received/transmit signal strength is increased proportionally with the number of satellites in the formation. This increase in signal strength allows to enhance the communication data rate and/or to reduce energy consumption and the antenna size of terrestrial mobile users' equipment. However, a coherent combination of signals without aligning the phases of the individual communication signals interrupts the communication and outage link between the satellites and the user. The accuracy of the phase estimation is a function of the inter-satellite laser ranging system performance. This paper derives an outage probability model of a coherent combination communication system as a function of the pointing vibration and jitter statistics of an inter-satellite laser ranging system tool. The coherent combination probability model, which could be used to improve the communication to mobile subscribers in air, sea and ground is the main importance of this work.

  15. In-Suit Light Exercise (ISLE) Prebreathe Protocol Peer Review Assessment. Volume 1

    NASA Technical Reports Server (NTRS)

    Brady, Timothy K.; Polk, James D.

    2011-01-01

    The performance of extravehicular activity (EVA) by National Aeronautics and Space Administration astronauts involves the risk of decompression sickness. This risk has been mitigated by the use of oxygen "prebreathe" to effectively wash out tissue nitrogen prior to each EVA. Now that the Space Shuttle Program (SSP) is being retired, high-pressure oxygen will become a limited resource. The In-Suit Light Exercise (ISLE) Prebreathe Protocol offers several potential benefits including its potential to save 6 pounds of oxygen per EVA. At the request of the NASA Engineering and Safety Center, the peer review convened on October 14, 2010. The major recommendation of the Review Committee was that the ISLE protocol was acceptable for operational use as a prebreathe option prior to EVA. The results from the peer review are contained in this document.

  16. Design of 2*6 optical hybrid in inter-satellite coherent laser communications

    NASA Astrophysics Data System (ADS)

    Xu, Nan; Liu, Liren; Liu, De'an; Wan, Lingyu; Zhou, Yu

    2008-08-01

    Compared with direct detection, homodyne binary phase shift keying receivers can achieve the best sensitivity theoretically, and became the trend of the research and application in inter-satellite coherent laser communications. In coherent optical communication systems an optical hybrid is an essential component of the receiver. It demodulates the incoming signal by mixing it with the local oscillator. We present a design of a 2*6 optical hybrid. 4 output ports of the hybrid give the narrow mixed beams of the incoming signal and the local oscillator shifted by 90°for communication, and the others give the wide mixed beams with a shifted degree of 180°for position errors detection. CCD captures the interference pattern from the wide beams, and then the pattern is processed and analyzed by the computer. Target position information is obtained from characteristic parameter of the interference pattern. The position errors as the control signals of PAT (pointing, acquisition and tracking) subsystem drive the receiver telescope to keep tracking to the target. The application extends to coherent laser rang finder.

  17. Research on Formation of Microsatellite Communication with Genetic Algorithm

    PubMed Central

    Wu, Guoqiang; Bai, Yuguang; Sun, Zhaowei

    2013-01-01

    For the formation of three microsatellites which fly in the same orbit and perform three-dimensional solid mapping for terra, this paper proposes an optimizing design method of space circular formation order based on improved generic algorithm and provides an intersatellite direct spread spectrum communication system. The calculating equation of LEO formation flying satellite intersatellite links is guided by the special requirements of formation-flying microsatellite intersatellite links, and the transmitter power is also confirmed throughout the simulation. The method of space circular formation order optimizing design based on improved generic algorithm is given, and it can keep formation order steady for a long time under various absorb impetus. The intersatellite direct spread spectrum communication system is also provided. It can be found that, when the distance is 1 km and the data rate is 1 Mbps, the input wave matches preferably with the output wave. And LDPC code can improve the communication performance. The correct capability of (512, 256) LDPC code is better than (2, 1, 7) convolution code, distinctively. The design system can satisfy the communication requirements of microsatellites. So, the presented method provides a significant theory foundation for formation-flying and intersatellite communication. PMID:24078796

  18. 76 FR 52266 - Safety Zone; Coast Guard Exercise, Detroit River, Ambassador Bridge to the Western Tip of Belle Isle

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ...-AA00 Safety Zone; Coast Guard Exercise, Detroit River, Ambassador Bridge to the Western Tip of Belle... Bridge to the western tip of Belle Isle. This safety zone is intended to restrict vessels from portions.... on August 23, 2011. The safety zone will begin at Ambassador Bridge to the western tip of Belle Isle...

  19. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles of... yards having its center on Shag Rock in the vicinity of Duck Island at latitude 43°00′12″, longitude 70...

  20. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles of... yards having its center on Shag Rock in the vicinity of Duck Island at latitude 43°00′12″, longitude 70...

  1. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles of... yards having its center on Shag Rock in the vicinity of Duck Island at latitude 43°00′12″, longitude 70...

  2. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles of... yards having its center on Shag Rock in the vicinity of Duck Island at latitude 43°00′12″, longitude 70...

  3. 33 CFR 334.40 - Atlantic Ocean in vicinity of Duck Island, Maine, Isles of Shoals; naval aircraft bombing target...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Duck Island, Maine, Isles of Shoals; naval aircraft bombing target area. 334.40 Section 334.40... AND RESTRICTED AREA REGULATIONS § 334.40 Atlantic Ocean in vicinity of Duck Island, Maine, Isles of... yards having its center on Shag Rock in the vicinity of Duck Island at latitude 43°00′12″, longitude 70...

  4. Preliminary clinical results with the ISL laser

    NASA Astrophysics Data System (ADS)

    Hoppeler, Thomas; Gloor, Balder

    1992-08-01

    The ISL laser (Intelligent Surgical Lasers, Inc.), a Nd:YLF picosecond pulse laser, is currently being used under investigational device exemption to perform microsurgery of the anterior segment of the eye. At different study sites procedures for cataract fragmentation and iridotomy, as well as for posterior capsulotomy after cataract surgery, are under evaluation. Other potential applications include: sclerostomy ab interno, the cutting of membranes in the anterior and posterior segment of the eye; corneal incisions; and corneal intrastromal effects. We discuss various clinically relevant aspects of the use of this picosecond laser. An overview of different computer controlled laser patterns is given.

  5. Life history variation among four lake trout morphs at Isle Royale, Lake Superior

    USGS Publications Warehouse

    Hansen, Michael J.; Nate, Nancy A.; Muir, Andrew M.; Bronte, Charles R.; Zimmerman, Mara S.; Krueger, Charles C.

    2016-01-01

    Life history traits were compared among four morphs of lake trout at Isle Royale, Lake Superior. Of 738 lake trout caught at Isle Royale, 701 were assigned to a morph (119 humpers, 160 leans, 85 redfins, and 337 siscowets) using a combination of statistical analysis of head and body shape and visual assignment. On average, redfins were longer (544 mm), heavier (1,481 g), heavier at length (Wr = 94), more buoyant, and older (22 years) than siscowets (519 mm; 1,221 g; 90; 19 years), leans (479 mm; 854 g; 82; 13 years), and humpers (443 mm; 697 g; 87; 17 years). On average, leans grew from a younger age at length = 0 and shorter length at age = 0, at a faster early growth rate to a longer asymptotic length than the other three morphs, while redfins grew at a slower instantaneous rate and humpers grew to a shorter asymptotic length than other morphs. On average, leans were longer (562 mm) and older (15 years) at 50% maturity than redfins (427 mm, 12 years), siscowets (401 mm, 11 years), or humpers (394 mm, 13 years). Life history parameters did not differ between males and females within each morph. We conclude that differences in life history attributes of lean, humper, redfin, and siscowet morphs of lake trout are consistent with differential habitat use in waters around Isle Royale, Lake Superior.

  6. ISLE (Image and Signal LISP Environment): A functional language interface for signal and image processing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Azevedo, S.G.; Fitch, J.P.

    1987-10-21

    Conventional software interfaces that use imperative computer commands or menu interactions are often restrictive environments when used for researching new algorithms or analyzing processed experimental data. We found this to be true with current signal-processing software (SIG). As an alternative, ''functional language'' interfaces provide features such as command nesting for a more natural interaction with the data. The Image and Signal LISP Environment (ISLE) is an example of an interpreted functional language interface based on common LISP. Advantages of ISLE include multidimensional and multiple data-type independence through dispatching functions, dynamic loading of new functions, and connections to artificial intelligence (AI)more » software. 10 refs.« less

  7. Comparative expression analysis of POU4F1, POU4F2 and ISL1 in developing mouse cochleovestibular ganglion neurons

    PubMed Central

    Deng, Min; Yang, Hua; Xie, Xiaoling; Liang, Guoqing; Gan, Lin

    2014-01-01

    POU-homeodomain and LIM-homeodomain transcription factors are expressed in developing projection neurons within retina, inner ear, dorsal root ganglion, and trigeminal ganglion, and play synergistic roles in their differentiation and survival. Here, using immunohistochemistry, we present a comparative analysis of the spatiotemporal expression pattern of POU4F1, POU4F2, and ISL1 during the development of cochleovestibular ganglion (CVG) neurons in mouse inner ear. At early stages, when otic neurons are first detected in the otic epithelium (OE) and migrate into periotic mesenchyme to form the CVG, POU4F1 and ISL1 are co-expressed in a majority of the delaminated CVG neurons, which are marked by NEUROD1 expression, but POU4F1 is absent in the otic epithelium. The onset of POU4F2 expression starts after that of POU4F1 and ISL1, and is observed in the NEUROD1-negative, post-mitotic CVG neurons. When the CVG neurons innervate the vestibular and cochlear sensory organs, the expression of POU4F1, POU4F2, and ISL1 continues in both vestibular and spiral ganglion cells. Later in development, POU4F1 expression becomes down-regulated in a majority of spiral ganglion (SG) neurons and more neurons express POU4F2 expression while ISL1 expression is maintained. The differential as well as overlapping expression of POU4F1, POU4F2, and ISL1 combined with previous studies suggests possible functional interaction and regulatory relationship of these transcription factors in the development of inner ear neurons. PMID:24709358

  8. Unionid bivalves (Mollusca: Bivalvia: Unionidae) of Presque Isle Bay, Erie, Pennsylvania

    USGS Publications Warehouse

    Masteller, E.C.; Maleski, K.R.; Schloesser, D.W.

    1993-01-01

    The purpose of this study was to determine species composition and relative abundance of unionid bivalves (Mollusca: Bivalvia: Unionidae) in Presque Isle Bay, Erie, Pennsylvania 1990-1992. This information was compared with data from the only other extensive survey of unionids in the bay conducted in 1909-1911 (Ortmann 1919) to assess changes over the 80 years preceding the present study. A total of 1,540 individuals representing 18 species were collected in 1990-1992. Five relatively common species (between 7 and 42% of total individuals), six uncommon species (2 and 6%), and seven rare species (<1%) were found. The rare species were Anodontoides ferussacianus, Lasmigona costata, Ligumia recta, Ptychobranchus fasciolaris, Quadrula pustulosa pustulosa, Strophitus undaulatus, and Truncilla donaciformis. Five of the species found in Presque Isle Bay (Leptodea fragilis, Ligumia nasuta, Potamilus alatus, Quadrula quadrula, and Truncilla donaciformis) are listed as critically imperiled and one species (Truncilla truncata) as extirpated in the State of Pennsylvania by the Western Pennsylvania Conservancy. Comparisons between unionid populations in 1909-1911 and 1990-1992 indicate few substantial changes occurred during the past 80 years. A total of 22 species were found; 21 in 1909-1911 and 18 in 1990-1992. Seventeen species were found in both studies, an additional four in 1909-1911 and one in 1990-1992. The relative abundance of 11 of the 17 species found in both studies remained stable (i.e., common or uncommon) over the past 80 years. Only four species listed as uncommon in 1909-1911 were listed as rare in 1990-1992. However, the invasion of the zebra mussel (Dreissena polymorpha) is considered a threat to the continued existence of the entire Unionidae fauna in Presque Isle Bay, a unique habitat of the Great Lakes.

  9. Variogram analysis of stable oxygen isotope composition of daily precipitation over the British Isles

    NASA Astrophysics Data System (ADS)

    Kohán, Balázs; Tyler, Jonathan; Jones, Matthew; Kern, Zoltán

    2017-04-01

    practically perpendicular to it. In this case, however, directions of the axes appear misaligned with the flow direction. -We could not observe similar characteristic patterns in the last variogram calculated from the Jan 25 data set. These preliminary results suggest that variogram analysis is a promising approach to link δ18OP patterns to atmospheric processes. NKFIH: SNN118205/ARRS: N1-0054 References 1.Tyler, J. J., Jones, M., Arrowsmith, C., Allott, T., & Leng, M. J. (2016). Spatial patterns in the oxygen isotope composition of daily rainfall in the British Isles. Climate Dynamics 47:1971-1987 2.Webster, R. Oliver M.A. (2007) Geostatistics for Environmental Scientists. John Wiley & Sons, Chichester

  10. Isle of Jersey

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Isle of Jersey (officially called the Bailiwick of Jersey) is the largest Channel Island, positioned in the Bay of Mont St Michel off the north-west coast of France. The island has a population of about 90,000, and covers about 90 square kilometers. The economy is based largely on international financial services, agriculture, and tourism. Called Caesaria in Roman times, Jersey became part of the Duchy of Normandy in 912. When William the Conqueror invaded and took the throne of England in 1066, the fortunes of Jersey then became linked to those in England, although the island manages its internal affairs through its own parliament, the States of Jersey. This image was acquired on September 23, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena

  11. Tidal inlet development and migration in Isles Dernieres Barrier Island Arc, Louisiana

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jaffe, B.E.; Sallenger, A.H.; List, J.H.

    The Isles Dernieres barrier arc formed about 420 years ago in response to the abandonment of the Bayou Petit Caillou delta of the Mississippi River. Over the past 100 years, the arc has undergone rapid erosion, with much of the Gulf shorelines retreating more than 1 km (10 m/year). Today, the island area is less than 25% of what it was 100 years ago. Most of this areal loss is from a narrowing of the islands as both the bay and Gulf shorelines retreated. A significant portion, however, is due to development of two large tidal inlets that segmented themore » 32 km long arc into three groups of islands from what was a nearly continuous island in 1890. The presence of these inlets and two recently formed smaller ones alters longshore transport and island erosion patterns. To predict the future of the Isles Dernieres, the authors must understand the history and processes of tidal inlet development.« less

  12. In-Suit Light Exercise (ISLE) Prebreathe Protocol Peer Review Assessment. Part 2; Appendices

    NASA Technical Reports Server (NTRS)

    Brady, Timothy K.; Polk, James D.

    2011-01-01

    The performance of extravehicular activity (EVA) by National Aeronautics and Space Administration astronauts involves the risk of decompression sickness. This risk has been mitigated by the use of oxygen "prebreathe" to effectively wash out tissue nitrogen prior to each EVA. Now that the Space Shuttle Program (SSP) is being retired, high-pressure oxygen will become a limited resource. The In-Suit Light Exercise (ISLE) Prebreathe Protocol offers several potential benefits including its potential to save 6 pounds of oxygen per EVA. At the request of the NASA Engineering and Safety Center, the peer review convened on October 14, 2010. The major recommendation of the Review Committee was that the ISLE protocol was acceptable for operational use as a prebreathe option prior to EVA. The appendices to Volume I of the report are contained in this document.

  13. What Do Learning Scientists Do? A Survey of the ISLS Membership

    ERIC Educational Resources Information Center

    Yoon, Susan A.; Hmelo-Silver, Cindy E.

    2017-01-01

    This study responds to a question that people working in the field of learning sciences get asked regularly: What do learning scientists do? Earlier attempts to answer this question came from a need to define a new field of educational research. Now that the International Society of the Learning Sciences (ISLS) has grown into a robust and…

  14. An oasis of fertility on a barren island: earthworms at Papadil, Isle of Rum

    Treesearch

    K.R. Butt; C.N.  Lowe; Mac Callaham; V.  Nuutinen

    2016-01-01

    The Isle of Rum, Inner Hebrides, has an impoverished earthworm fauna as the soils are generally acidic and nutrient-poor. Species associated with human habitation are found around deserted crofting settlements subjected to

  15. Trauma on the Isle of Man.

    PubMed Central

    Hackney, R G; Varley, G; Stevens, D; Green, A

    1993-01-01

    The Isle of Man Tourist Trophy motorcycle races remain one of the most popular venues for motorcycle races. This is despite the reduced status of the event. The reason for the loss of world championship and formula one status is the nature of the road racing circuit itself. The twisting narrow roads are only closed to the public at certain times during the practice and race weeks. Motorcycling visitors to the event attempt to emulate their heroes on machines capable of high speeds. Casualties from both visitors and racers are dealt with efficiently by an expanded medical service. This includes the use of an aeromedical evacuation helicopter. Casualties from the visitors exceeded those from the racers themselves during the period reported. Images Figure 1 Figure 2 Figure 4 Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 PMID:8457818

  16. Multiband phase-modulated radio over IsOWC link with balanced coherent homodyne detection

    NASA Astrophysics Data System (ADS)

    Zong, Kang; Zhu, Jiang

    2017-11-01

    In this paper, we present a multiband phase-modulated radio over intersatellite optical wireless communication (IsOWC) link with balanced coherent homodyne detection. The proposed system can provide high linearity for transparent transport of multiband radio frequency (RF) signals and better receiver sensitivity than intensity modulated with direct detection (IM/DD) system. The exact analytical expression of signal to noise and distortion ratio (SNDR) is derived considering the third-order intermodulation product and amplifier spontaneous emission (ASE) noise. Numerical results of SNDR with various number of subchannels and modulation index are given. Results indicate that the optimal modulation index exists to maximize the SNDR. With the same system parameters, the value of the optimal modulation index will decrease with the increase of number of subchannels.

  17. Field Philosophy: Environmental Learning and Moral Development in Isle Royale National Park

    ERIC Educational Resources Information Center

    Goralnik, Lissy; Nelson, Michael Paul

    2017-01-01

    We conducted a qualitative analysis of 5 years of student writing data to understand learning and moral development on a field philosophy course in Isle Royale National Park. We were interested in the connection between physical experiences in the natural world and the way students care about or value nonhuman beings, natural systems, and place.…

  18. Food of young-of-the-year lake trout (Salvelinus namaycush) in Presque Isle Harbor, Lake Superior

    USGS Publications Warehouse

    Swedberg, Donald V.; Peck, James W.

    1984-01-01

    The food habits of young lake trout (Salvelinus namaycush) were studied by examining the digestive tracts of 293 young-of-the-year collected in Presque Isle Harbor, Lake Superior. Lake trout in the 25 to 27-mm length range started to eat food organisms before all of their yolk material was absorbed. Organisms consumed by the 25 to 27-mm young-of-the-year included Chironomidae, Copepoda (Harpacticoida, Calanoida, Cyclopoida), and Cladocerea (Daphnia spp., Bosmina sp., Chydorus sp.). Chironomid pupae and chironomid larvae accounted for 74% and 5%, respectively, of the total volume of food eaten by the young lake trout in Presque Isle Harbor. Although copepods, cladocerans, and mysids were present in many stomachs, their contribution to the total volume of food was only 15%. Some lake trout in the 32 to 54-mm length range had consumed fry of sculpin (Cottus spp.) or rainbow smelt (Osmerus mordax), but the overall contribution of fish fry to the total volume of food was only 4% (frequency of occurrence, 10%). The lake trout in Presque Isle Harbor fed heavily on planktonic organisms, sparingly on benthic organisms, and were opportunistic feeders that appeared to prey on whatever forage organisms were available in the shallow nearshore waters.

  19. Nearshore habitat and fish community associations of coaster brook trout in Isle Royale, Lake Superior

    USGS Publications Warehouse

    Gorman, O.T.; Moore, S.A.; Carlson, A.J.; Quinlan, H.R.

    2008-01-01

    We characterized the nearshore habitat and fish community composition of approximately 300 km of shoreline within and adjacent to the major embayments of Isle Royale, Lake Superior. Sampling yielded 17 species, of which 12 were widespread and represented a common element of the Lake Superior fish community, including cisco Coregonus artedi, lake whitefish C. clupeaformis, round whitefish Prosopium cylindraceum, lake trout Salvelinus namaycush, rainbow smelt Osmerus mordax, lake chub Couesius plumbeus, longnose sucker Catostomus catostomus, white sucker C. commersonii, trout-perch Percopsis omiscomaycus, ninespine stickleback Pungitius pungitius, burbot Lota lota, and slimy sculpin Cottus cognatus. The presence of brook trout S. fontinalis in an embayment was associated with the common species of the Isle Royale nearshore fish community, particularly cisco, longnose sucker, and round whitefish. However, brook trout were present in only five embayments and were common only in Tobin Harbor. Most Isle Royale embayments had broadly overlapping ranges of nearshore habitats. Within embayments, fish were distributed along a habitat gradient from less-protected rocky habitat near the mouth to highly protected habitat with mixed and finer substrates at the head. Embayments with brook trout had greater mean protection from the open lake, greater variation in depth, greater mean cover, and higher mean frequencies of large substrates (cobble, boulder, and bedrock). Within those embayments, brook trout were associated with habitat patches with higher mean frequencies of small substrates (particularly sand and coarse gravel). Within Tobin Harbor, brook trout were associated with midembayment habitat and species assemblages, especially those locations with a mixture of sand, gravel, and cobble substrates, an absence of bedrock, and the presence of round whitefish, white sucker, and trout-perch. Comparison of embayments with the model, Tobin Harbor, showed that six embayments

  20. Archaeology. Sedimentary DNA from a submerged site reveals wheat in the British Isles 8000 years ago.

    PubMed

    Smith, Oliver; Momber, Garry; Bates, Richard; Garwood, Paul; Fitch, Simon; Pallen, Mark; Gaffney, Vincent; Allaby, Robin G

    2015-02-27

    The Mesolithic-to-Neolithic transition marked the time when a hunter-gatherer economy gave way to agriculture, coinciding with rising sea levels. Bouldnor Cliff, is a submarine archaeological site off the Isle of Wight in the United Kingdom that has a well-preserved Mesolithic paleosol dated to 8000 years before the present. We analyzed a core obtained from sealed sediments, combining evidence from microgeomorphology and microfossils with sedimentary ancient DNA (sedaDNA) analyses to reconstruct floral and faunal changes during the occupation of this site, before it was submerged. In agreement with palynological analyses, the sedaDNA sequences suggest a mixed habitat of oak forest and herbaceous plants. However, they also provide evidence of wheat 2000 years earlier than mainland Britain and 400 years earlier than proximate European sites. These results suggest that sophisticated social networks linked the Neolithic front in southern Europe to the Mesolithic peoples of northern Europe. Copyright © 2015, American Association for the Advancement of Science.

  1. Processes controlling the retreat of the Isles Dernieres, a Louisiana barrier-island chain

    USGS Publications Warehouse

    Dingler, John R.; Reiss, Thomas E.

    1991-01-01

    The Isles Dernieres is a low-lying, transgressive barrier-island chain situated about 150 km west of the modern Mississippi delta. Much of the Isles Dernieres consists of highly dissected salt-marsh muds that lie at or slightly above sea level and are covered by a veneer of sand along the shoreline facing the Gulf of Mexico. Maximum berm elevations are generally less than 1.5 m above mean sea level. Since the mid-1800s, the initial island has been fragmented into four islands, and the beach face has retreated landward at a rate of more than 10 m/yr. The dominant processes controlling degradation of the chain are cold fronts that pass through the area several times each year and occasional hurricanes. Beach surveys over a 2-year period on the Isles Dernieres document irreversible beach-face retreat in conjunction with multiple cold fronts and one major hurricane (Gilbert). Although both the hurricane and the cold fronts caused the island to erode, the erosional patterns of the two storm types differed from each other. During the two years, over 60 cold fronts collectively caused about 37 m of beach-face retreat, whereas Gilbert itself produced more than 40 m of retreat. A major difference between the two storm types was in the percentage of washover sand produced by each. Commonly, the cold fronts did not create enough of a storm surge to overtop the berm, so most of the material removed from the beach face must have moved offshore or alongshore. Gilbert, in contrast, inundated the study site, and essentially all the sand removed from the beach face moved to the backshore.

  2. MicroRNA-31 suppresses the self-renewal capability of α2δ1+ liver tumor-initiating cells by targeting ISL1.

    PubMed

    Zhang, Yuan; Zhao, Wei; Han, Haibo; Li, Sheng; Chen, Dongji; Zhang, Zhiqian

    2017-10-20

    Accumulating evidence demonstrates that miRNAs, a class of small non-coding RNAs, are involved in the regulation of tumor-initiating cells (TICs) which are considered to be the origin of cancer development according to the cancer stem cell hypothesis. We have previously identified that miR-31 may play suppressive roles in α2δ1 + hepatocellular carcinoma (HCC) TICs. Here, we confirm that the expression of miR-31 is significantly downregulated in α2δ1 + HCC TICs. Overexpression of miR-31 in α2δ1 + HCC TICs results in significant suppression of the self-renewal and tumorigenicity abilities of these cells. Conversely, knockdown the expression of miR-31 in PLC/PRF/5 cells is able to reprogram them into TICs with stem cell-like properties. Furthermore, the expression of ISL LIM Homeobox 1(ISL1), a transcription factor involved in recognition of undifferentiated cardiac progenitors, is negatively regulated by miR-31, and the luciferase reporters' activities with the 3'-UTRs of ISL1 are inhibited significantly by miR-31. Collectively, our results suggest that miR-31 can negatively regulate the self-renewal ability of α2δ1 + liver TICs via silencing ISL1 .

  3. Age, growth, and maturity of round whitefish of the Apostle Islands and Isle Royale Regions, Lake Superior

    USGS Publications Warehouse

    Bailey, Merryll M.

    1963-01-01

    The round whitefish has been of some commercial importance in the upper Great Lakes but production in Lake Superior has generally been small; the United States average was 26,600 pounds for 1929-59. This study is based on 1,173 fish collected in the Apostle Islands in 1958-60 and 103 collected at Isle Royale in 1958 and 1960. The average age of 6.0 years at Isle Royale was concluded to be significantly higher than the mean of 4.2 years in the Apostle Islands. The body-scale relation is a straight line with an intercept of 1.1 inches on the length axis. Weight of Apostle Islands round whitefish captured in several months increased as the 3.22 power of the length. Growth in length was relatively slow; nearly or fully 7 years were required to reach an acceptable commercial length of 14 inches in both the Apostle Islands and at Isle Royale. The calculated weights at the end of the seventh year were 12.6 ounces in the Apostle Islands and 13.8 ounces at Isle Royale. Minimum length at maturity of male round whitefish (7.0-7.4 inches) was less than that of females (8.5-8.9 inches). At age-group II, 11.1 percent of male round whitefish, but only 1.5 percent of the females were mature. All males were mature as age-group V and all females as age-group VI. Males dominated the younger age groups but females were more numerous in the older ones. Estimates of the number of eggs in 37 round whitefish ovaries yielded an average of 5,330 eggs for fish 10.5-17.4 inches long.

  4. Centroid measurement error of CMOS detector in the presence of detector noise for inter-satellite optical communications

    NASA Astrophysics Data System (ADS)

    Li, Xin; Zhou, Shihong; Ma, Jing; Tan, Liying; Shen, Tao

    2013-08-01

    CMOS is a good candidate tracking detector for satellite optical communications systems with outstanding feature of sub-window for the development of APS (Active Pixel Sensor) technology. For inter-satellite optical communications it is critical to estimate the direction of incident laser beam precisely by measuring the centroid position of incident beam spot. The presence of detector noise results in measurement error, which degrades the tracking performance of systems. In this research, the measurement error of CMOS is derived taking consideration of detector noise. It is shown that the measurement error depends on pixel noise, size of the tracking sub-window (pixels number), intensity of incident laser beam, relative size of beam spot. The influences of these factors are analyzed by numerical simulation. We hope the results obtained in this research will be helpful in the design of CMOS detector satellite optical communications systems.

  5. Impact of 1985 hurricanes on Isles Dernieres, Louisiana: Temporal and spatial analysis of coastal geomorphic changes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Debusshere, K.; Westphal, K.; Penland, S.

    1989-09-01

    Catastrophic geomorphic changes occurred in the Isles Dernieres barrier island arc as a result of the direct impact of three hurricanes in 1985. The severity of the impact of hurricanes Danny, Elena, and Juan had not been equaled since the landfall of hurricanes Betsy and Camille in the late 1960s. The Isles Dernieres had not been subjected to a direct hurricane landfall since hurricane Bob in 1979. The recent hurricane impacts provided the USGS/LGS Louisiana Cooperative Barrier Island and Land Loss Study the opportunity to examine the process-response characteristics of this low-profile transgressive barrier island arc to multiple hurricane impactsmore » in a single hurricane season. The geomorphic changes along the Isles Dernieres were determined using four sequential airborne videotape surveys acquired in July 1984, July 1985 (pre-storm), August 1985 (post-Danny) and November 1985 (post-Juan) and mapped on 1:24,000 base maps produced from concurrent vertical aerial photography. A coastal geomorphic classification was developed to describe, quantify, and map the alongshore geomorphic, sedimentologic , and vegetative character of this barrier shoreline. The classification consists of three levels of descriptors: (1) primary morphology to define the predominant longshore morphology, (2) modifiers to depict the small-scale longshore features, and (3) variants to locate and quantify important coastal features, not mappable at the scale used.« less

  6. Geostationary platform systems concepts definition study. Volume 2A: Appendixes, book 1

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Appendixes addressing various aspects of a geostationary platform concepts definition study are given. Communication platform traffic requirements, video conferencing forecast, intersatellite link capacity requirements, link budgets, payload data, payload assignments, and platform synthesis are addressed.

  7. 76 FR 60525 - Final Wilderness and Backcountry Management Plan and Environmental Impact Statement for Isle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... and Environmental Impact Statement for Isle Royale National Park, MI AGENCY: National Park Service... the availability of a Final Wilderness and Backcountry Management Plan and Environmental Impact... the Internet through the NPS Planning, Environment, and Public Comment Web site ( http://parkplanning...

  8. Wolf research in the Isle Royale wilderness: do the ends justify the means?

    Treesearch

    Jack G. Oelfke; Rolf O. Peterson; John A. Vucetich; Leah M. Vucetich

    2000-01-01

    Isle Royale National Park is a remote island ecosystem in Lake Superior. A long-term research program investigating the wolf and moose populations in the Park has provided the public and scientific community with valuable information on the ecology of these species in this wilderness setting. A persistent decline within the wolf population led to a change in the...

  9. Imaging a fossil oolitic system with GPR, insights into the exposures of the Isle of Portland (UK)

    NASA Astrophysics Data System (ADS)

    Moreau, Julien; Hansen, Trine L.; Nielsen, Lars

    2015-04-01

    The Isle of Portland shows exposure of uppermost Jurassic oolitic carbonate all along its coast. The stone of Portland properties are famous as standards for concrete composition, as building material but also for sculpture. As a consequence, the Isle has been quarried intensively for hundreds of years. The regional exposure quality is very high with a potential 3D control. The site has seen generations of geologist trainees coming for field work. The Wessex Basin where the Isle is sitting contains an active petroleum system and the geologists visiting/training there use the carbonates of Portland as an analogue to equivalent Middle-East oil and gas reservoir. Surprisingly, although the site has a tremendous potential to understand the 3D architecture and the sedimentary dynamic of an oolitic system, only punctual observations of logs (1D), sometimes correlated have been published. Several studies place a shore line between the Isle and the continent striking NEE-SWW and facing towards the Channel. Facies changes are attributed to rapid sea-level variations and Walter's Law. We have collected an extensive GPR survey of the same stratigraphic interval (The Portland Freestone). With a total of 99 GPR profiles, we have produced grids on top of most of the coastal cliffs and quarry faces. We have encountered 3 main architectures: 2-m-high bars with steep clinoforms, 10s of metres-wide channels plugged with a variety of organisms and stacked aggrading bundles of multidirectional dunesets. Our dataset does not illustrate any major unconformity which could be attributed to a sharp sea-level drop. We have interpreted our sedimentary architecture to be the result of various hydrodynamic conditions associated with a mix of wave and tide influences. The Isle shows an island barrier complex which progrades into the basin but also expands laterally filling up the available space and cannibalising itself. More proximal facies are effectively observed in the north of the island

  10. Abnormal chemical element concentrations in lichens of Isle Royale National Park

    USGS Publications Warehouse

    Bennett, J.P.

    1995-01-01

    Lichens have been used for many years to monitor changes in deposited airborne chemical elements in many areas, but few studies have focused on areas suspected of experiencing slightly elevated pollution. Detection of subtle patterns of slightly elevated pollutants calls for developing several lines of evidence as opposed to single line studies used in heavily polluted areas. This study of two lichen species, Hypogymnia physodes and Evernia mesomorpha, in Isle Royale National Park, Michigan compares the concentrations and ranks of elements with the concentrations and ranks of the elements in the earth's crust, changes in element concentrations over a nine year period, and the geography of element concentrations in the park. S, Zn, Pb, Cd and Se were elevated in both species and higher in rank compared to the concentrations and ranks in the earth's crust. Toxic elements increased 123% in Hypogymnia and 62% in Evernia over 9 years, compared to increases of 45% and 59% for non-toxic elements in each species, respectively. Geographically, the lichens at certain localities with higher exposures experienced higher than average element concentrations. Finally, tissue concentrations of Mn, S and Se at some localities were above levels known to be either toxic or similar to those found in polluted areas. These four lines of evidence suggest that Isle Royale National Park is experiencing the onset of chronic air pollution stress from a number of sources.

  11. Perceived nuisance of mosquitoes on the Isle of Sheppey, Kent, UK.

    PubMed

    Hutchinson, Robert A; Lindsay, Steve W

    2006-09-01

    Little is known about the biting nuisance of mosquitoes in the UK, despite the high numbers found in some locations. A telephone questionnaire survey was used to determine the perceived nuisance of biting insects on the Isle of Sheppey, Kent, a place notorious for mosquitoes. Two hundred randomly selected individuals were interviewed and asked if they suffered from mosquito bites. If they answered yes, they were asked to describe where and when they were bitten, and what measures they took against mosquitoes. Forty-six percent of respondents completed the questionnaire. Of those, 50% reported being bitten by mosquitoes, mostly outside during the summer. Seventy percent said that most biting occurred during the evening and night. Of those respondents who protected themselves against biting (27), most used repellents (70%), with the remainder changing their behaviour to avoid mosquitoes, including closing or screening windows (33%), wearing thicker clothes (7%) and spraying insecticide (4%). One person slept under a bednet in summer (4%). This study provides evidence that on the Isle of Sheppey mosquitoes are considered a major nuisance by a sizeable proportion of the population. Since there is growing interest in the threat posed by new and emerging diseases in the UK, health authorities will need to make substantial efforts to inform and reassure the public about the threats posed by mosquitoes in areas where they are common.

  12. Assessment and Calibration of Terrestrial Water Storage in North America with GRACE Level-1B Inter-satellite Residuals

    NASA Astrophysics Data System (ADS)

    Loomis, B.; Luthcke, S. B.

    2016-12-01

    The global time-variable gravity products from GRACE continue to provide unique and important measurements of vertically integrated terrestrial water storage (TWS). Despite substantial improvements in recent years to the quality of the GRACE solutions and analysis techniques, significant disagreements can still exist between various approaches to compute basin scale TWS. Applying the GRACE spherical harmonic solutions to TWS analysis requires the selection, design, and implementation of one of a wide variety of available filters. It is common to then estimate and apply a set of scale factors to these filtered solutions in an attempt to restore lost signal. The advent of global mascon solutions, such as those produced by our group at NASA GSFC, are an important advancement in time-variable gravity estimation. This method applies data-driven regularization at the normal equation level, resulting in improved estimates of regional TWS. Though mascons are a valuable product, the design of the constraint matrix, the global minimization of observation residuals, and the arc-specific parameters, all introduce the possibility that localized basin scale signals are not perfectly recovered. The precise inter-satellite ranging instrument provides the primary observation set for the GRACE gravity solutions. Recently, we have developed an approach to analyze and calibrate basin scale TWS estimates directly from the inter-satellite observation residuals. To summarize, we compute the range-acceleration residuals for two different forward models by executing separate runs of our Level-1B processing system. We then quantify the linear relationship that exists between the modeled mass and the residual differences, defining a simple differential correction procedure that is applied to the modeled signals. This new calibration procedure does not require the computationally expensive formation and inversion of normal equations, and it eliminates any influence the solution technique may

  13. Development of a 1-m Class Telescope at TMF to Support Optical Communications Demonstrations

    NASA Technical Reports Server (NTRS)

    Wilson, K. E.; Sandusky, J.

    1998-01-01

    With the impetus towards high data rate communications in inter-satellite and space-to-ground links, the small size, low-mass, and low-power consumption of optical communications is seen as a viable alternative to radio frequency links.

  14. Trends in winter circulation over the British Isles and central Europe in twenty-first century projections by 25 CMIP5 GCMs

    NASA Astrophysics Data System (ADS)

    Stryhal, Jan; Huth, Radan

    2018-03-01

    Winter midlatitude atmospheric circulation has been extensively studied for its tight link to surface weather, and automated circulation classifications have often been used to this end. Here, eight such classifications are applied to daily sea level pressure patterns simulated by an ensemble of CMIP5 GCMs twenty-first century projections for the British Isles and central Europe in order to robustly estimate future changes in frequency, persistence, and strength of synoptic-scale circulation there. All methods are able to identify present-day biases of models reported before, such as an overestimated occurrence of zonal flow and underestimation of anticyclonic conditions and easterly advection, although the strength of these biases varies among the methods. In future, models show that the zonal flow will become more frequent while the strength of the mean flow is not projected to change. Over the British Isles, the models that better simulate the latitude of zonal flow over the historical period indicate a slight equatorward shift of westerlies in their projections, while the poleward expansion of circulation—expected in future at global scale—is apparent in those models that have large errors. Over central Europe, some classifications indicate an increase in persistence and especially in frequency of anticyclonic types, which is, however, shown to be rather an artifact of some methods than a real feature. On the other hand, the easterly flow is robustly projected to become markedly weaker in central Europe, which we hypothesize might be an important factor contributing to the projected decrease of cold extremes there.

  15. A Smart City Application: A Fully Controlled Street Lighting Isle Based on Raspberry-Pi Card, a ZigBee Sensor Network and WiMAX

    PubMed Central

    Leccese, Fabio; Cagnetti, Marco; Trinca, Daniele

    2014-01-01

    A smart city application has been realized and tested. It is a fully remote controlled isle of lamp posts based on new technologies. It has been designed and organized in different hierarchical layers, which perform local activities to physically control the lamp posts and transmit information with another for remote control. Locally, each lamp post uses an electronic card for management and a ZigBee tlc network transmits data to a central control unit, which manages the whole isle. The central unit is realized with a Raspberry-Pi control card due to its good computing performance at very low price. Finally, a WiMAX connection was tested and used to remotely control the smart grid, thus overcoming the distance limitations of commercial Wi-Fi networks. The isle has been realized and tested for some months in the field. PMID:25529206

  16. A smart city application: a fully controlled street lighting isle based on Raspberry-Pi card, a ZigBee sensor network and WiMAX.

    PubMed

    Leccese, Fabio; Cagnetti, Marco; Trinca, Daniele

    2014-12-18

    A smart city application has been realized and tested. It is a fully remote controlled isle of lamp posts based on new technologies. It has been designed and organized in different hierarchical layers, which perform local activities to physically control the lamp posts and transmit information with another for remote control. Locally, each lamp post uses an electronic card for management and a ZigBee tlc network transmits data to a central control unit, which manages the whole isle. The central unit is realized with a Raspberry-Pi control card due to its good computing performance at very low price. Finally, a WiMAX connection was tested and used to remotely control the smart grid, thus overcoming the distance limitations of commercial Wi-Fi networks. The isle has been realized and tested for some months in the field.

  17. Food intake rates of inactive fish are positively linked to boldness in three-spined sticklebacks Gasterosteus aculeatus.

    PubMed

    Jolles, J W; Manica, A; Boogert, N J

    2016-04-01

    To investigate the link between personality and maximum food intake of inactive individuals, food-deprived three-spined sticklebacks Gasterosteus aculeatus at rest in their home compartments were provided with ad libitum prey items. Bolder individuals ate considerably more than shyer individuals, even after accounting for body size, while sociability did not have an effect. These findings support pace-of-life theory predicting that life-history strategies are linked to boldness. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

  18. Assessing the British Isles CH4 flux using aircraft and ground-based sampling: a case study on 12 May 2015

    NASA Astrophysics Data System (ADS)

    Pitt, Joseph

    2017-04-01

    Aircraft and ground-based sampling of atmospheric greenhouse gas composition over the British Isles was conducted between 2014 and 2016 as part of the Greenhouse gAs UK and Global Emissions (GAUGE) project. We report a case study focussing on two research aircraft flights conducted on 12 May 2015 to sample inflow and outflow across the British Isles. We have employed the NAME Lagrangian dispersion model to simulate CH4 mole fraction enhancements corresponding to aircraft and ground-based sample times and locations, using CH4 surface fluxes derived from a composite flux inventory, which included both anthropogenic and natural sources. For each sampling location, variations in the baseline CH4 mole fraction were derived using the MOZART global chemical transport model, and added to the NAME enhancements to produce a dataset of modelled CH4 mole fractions which can be compared to the measurements. Using a multiple variable regression technique, we derive CH4 fluxes for the British Isles region from both aircraft and ground-based datasets. We discuss the applicability of our approach for both datasets, and conclude that in this case the assumptions inherent in our method are much better satisfied for the aircraft data than for the ground-based data. Using the aircraft data we derive a possible range of scale factors for the prior inventory flux of 0.53 - 0.97, with a central estimate of 0.82 based on our assessment of the most likely apportionment of model uncertainty. This leads to a posterior estimate of the British Isles CH4 flux of 67 kg s-1 - 121 kg s-1, with a central value of 103 kg s-1.

  19. Production and Electrical Characterization Tests of the ISL Detector and a Trigger Design for Higgs Boson Searches at CDF

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Munar Ara, Antoni

    2002-01-01

    This thesis is structured as follows: Chapter 1. gives a brief review of the Higgs mechanism in the Standard Model and the electroweak symmetry breaking. The Standard Model Higgs boson phenomenology at Tevatron energies is reviewed. Chapter 2. describes the upgraded Fermilab laboratory accelerator complex, and the upgraded CDF detector. Chapter 3. gives a brief overview of the more relevant aspects of the silicon detectors, and the ISL is described in detail. Chapter 4. describes the construction of the ISL ladders, the full custom testing setup (functionality tests, laser test, burn-in test andmore » $$\\beta$$-source measurements), and the problems encountered during the ISL ladders construction. The procedures for ladder grading are also discussed. Chapter 5. describes the multilevel trigger system of the CDF detector, and the trigger primitives available at each level. The most relevant offine event observables are briefly discussed. In Chapter 6 the procedures to estimate the trigger rate and trigger effciency calculation are described. The particularities of triggering in $$p\\bar{p}$$ collisions at high luminosities are discussed. Chapter 7. and Chapter 8. are dedicated to study an effcient trigger strategy for the $$H + W/Z \\to b\\bar{b}jj$$ channel and the $$H + Z \\to b\\bar{b} \

  20. Rural Governance, Community Empowerment and the New Institutionalism: A Case Study of the Isle of Wight

    ERIC Educational Resources Information Center

    Clark, David; Southern, Rebekah; Beer, Julian

    2007-01-01

    This article compares two different institutional models--state-sponsored rural partnerships and community-based development trusts--for engaging and empowering local communities in area-based regeneration, using the Isle of Wight as a case study. Following a critical review of the literature on community governance, we evaluate the effectiveness…

  1. Detection of pointing errors with CMOS-based camera in intersatellite optical communications

    NASA Astrophysics Data System (ADS)

    Yu, Si-yuan; Ma, Jing; Tan, Li-ying

    2005-01-01

    For very high data rates, intersatellite optical communications hold a potential performance edge over microwave communications. Acquisition and Tracking problem is critical because of the narrow transmit beam. A single array detector in some systems performs both spatial acquisition and tracking functions to detect pointing errors, so both wide field of view and high update rate is required. The past systems tend to employ CCD-based camera with complex readout arrangements, but the additional complexity reduces the applicability of the array based tracking concept. With the development of CMOS array, CMOS-based cameras can employ the single array detector concept. The area of interest feature of the CMOS-based camera allows a PAT system to specify portion of the array. The maximum allowed frame rate increases as the size of the area of interest decreases under certain conditions. A commercially available CMOS camera with 105 fps @ 640×480 is employed in our PAT simulation system, in which only part pixels are used in fact. Beams angle varying in the field of view can be detected after getting across a Cassegrain telescope and an optical focus system. Spot pixel values (8 bits per pixel) reading out from CMOS are transmitted to a DSP subsystem via IEEE 1394 bus, and pointing errors can be computed by the centroid equation. It was shown in test that: (1) 500 fps @ 100×100 is available in acquisition when the field of view is 1mrad; (2)3k fps @ 10×10 is available in tracking when the field of view is 0.1mrad.

  2. Multiband DSB-SC modulated radio over IsOWC link with coherent homodyne detection

    NASA Astrophysics Data System (ADS)

    Kang, Zong; Zhu, Jiang

    2018-02-01

    In this paper, we present a multiband double sideband-suppressed carrier (DSB-SC) modulated radio over intersatellite optical wireless communication (IsOWC) link with coherent homodyne detection. The proposed system can provide the transparent transport of multiband radio frequency (RF) signals with higher linearity and better receiver sensitivity than the intensity modulated with direct detection (IM/DD) scheme. The full system model and the exactly analytical expression of signal to noise and distortion ratio (SNDR) are derived considering the third-order intermodulation product and amplifier spontaneous emission (ASE) noise. The finite extinction ratio (ER) of Mach-Zehnder Modulator (MZM) and the saturation property of erbium doped fiber amplifier (EDFA) are also considered. Numerical results of SNDR with various numbers of subchannels and ERs are given. Results indicate that the optimal modulation index exists to maximize the SNDR and the power of local oscillator (LO) carrier should be within an appropriate range.

  3. Manx Gaelic: The Manx Gaelic Language in Education in the Isle of Man. Regional Dossiers Series

    ERIC Educational Resources Information Center

    McArdle, Fiona, Comp.; Teare, Robert, Comp.

    2016-01-01

    This regional dossier aims at providing a concise description of and basic statistics on minority language education in a specific region of Europe--the Isle of Man. Aspects that are addressed include features of the education system, recent educational policies, main actors, legal arrangements, and support structures, as well as quantitative…

  4. Simulative Investigation on the Effect of Different Parameters on the Performance of IsOWC System

    NASA Astrophysics Data System (ADS)

    Singh, Mehtab

    2017-08-01

    Inter-satellite communication links are very crucial between satellites orbiting around the earth in order to transmit information between them and also for the purpose of data relaying from one satellite station to other stations and ground stations. Inter-satellite optical wireless communication (IsOWC) links involve the application of optical wireless signals as compared to radio frequency signals used in traditional satellite communication systems. One of the major problems leading to the performance degradation of IsOWC link is the signal degradation due to satellite vibrations also known as pointing errors. In this paper, the performance of an IsOWC communication link has been investigated for different system parameters such as data transmission rates, antenna aperture diameter, transmission power levels, operating wavelength and responsivity of photodiode by analyzing Q-factor, signal-to-noise ratio (SNR), and total power of received signal to mitigate the effects of signal degradation of received signal due to satellite vibrations.

  5. The O and H stable isotope composition of freshwaters in the British Isles. 2. Surface waters and groundwater

    NASA Astrophysics Data System (ADS)

    Darling, W. G.; Bath, A. H.; Talbot, J. C.

    The utility of stable isotopes as tracers of the water molecule has a long pedigree. The study reported here is part of an attempt to establish a comprehensive isotopic "baseline" for the British Isles as background data for a range of applications. Part 1 of this study (Darling and Talbot, 2003) considered the isotopic composition of rainfall in Britain and Ireland. The present paper is concerned with the composition of surface waters and groundwater. In isotopic terms, surface waters (other than some upland streams) are poorly characterised in the British Isles; their potential variability has yet to be widely used as an aid in hydrological research. In what may be the first study of a major British river, a monthly isotopic record of the upper River Thames during 1998 was obtained. This shows high damping of the isotopic variation compared to that in rainfall over most of the year, though significant fluctuations were seen for the autumn months. Smaller rivers such as the Stour and Darent show a more subdued response to the balance between runoff and baseflow. The relationship between the isotopic composition of rainfall and groundwater is also considered. From a limited database, it appears that whereas Chalk groundwater is a representative mixture of weighted average annual rainfall, for Triassic sandstone groundwater there is a seasonal selection of rainfall biased towards isotopically-depleted winter recharge. This may be primarily the result of physical differences between the infiltration characteristics of rock types, though other factors (vegetation, glacial history) could be involved. In the main, however, groundwaters appear to be representative of bulk rainfall within an error band of 0.5‰ δ18O. Contour maps of the δ18O and δ2H content of recent groundwaters in the British Isles show a fundamental SW-NE depletion effect modified by topography. The range of measured values, while much smaller than those for rainfall, still covers some ‰ for δ18

  6. Performance evaluation and optimization of multiband phase-modulated radio over IsOWC link with balanced coherent homodyne detection

    NASA Astrophysics Data System (ADS)

    Zong, Kang; Zhu, Jiang

    2018-04-01

    In this paper, we present a multiband phase-modulated (PM) radio over intersatellite optical wireless communication (IsOWC) link with balanced coherent homodyne detection. The proposed system can provide the transparent transport of multiband radio frequency (RF) signals with higher linearity and better receiver sensitivity than intensity modulated with direct detection (IM/DD) system. The expressions of RF gain, noise figure (NF) and third-order spurious-free dynamic range (SFDR) are derived considering the third-order intermodulation product and amplifier spontaneous emission (ASE) noise. The optimal power of local oscillator (LO) optical signal is also derived theoretically. Numerical results for RF gain, NF and third-order SFDR are given for demonstration. Results indicate that the gain of the optical preamplifier and the power of LO optical signal should be optimized to obtain the satisfactory performance.

  7. Ground water for public water supply at Windigo, Isle Royale National Park, Michigan

    USGS Publications Warehouse

    Grannemann, N.G.; Twenter, F.R.

    1982-01-01

    Three test holes drilled at Windigo in Isle Royale National Park in 1981 indicate that the ophitic basaltic lava flows underlying the area contain little water and cannot be considered a source for public water supply. The holes were 135, 175, and 71 feet deep. One hole yielded about 1 gallon of water perminute; the other two yielded less. Glacial deposits seem to offer the best opportunity for developing a ground-water supply of 5 to 10 gallons per minute.

  8. Methylation of HOXA9 and ISL1 Predicts Patient Outcome in High-Grade Non-Invasive Bladder Cancer

    PubMed Central

    Kitchen, Mark O.; Bryan, Richard T.; Haworth, Kim E.; Emes, Richard D.; Luscombe, Christopher; Gommersall, Lyndon; Cheng, K. K.; Zeegers, Maurice P.; James, Nicholas D.; Devall, Adam J.; Fryer, Anthony A.; Farrell, William E.

    2015-01-01

    Introduction Inappropriate DNA methylation is frequently associated with human tumour development, and in specific cases, is associated with clinical outcomes. Previous reports of DNA methylation in low/intermediate grade non-muscle invasive bladder cancer (NMIBC) have suggested that specific patterns of DNA methylation may have a role as diagnostic or prognostic biomarkers. In view of the aggressive and clinically unpredictable nature of high-grade (HG) NMIBC, and the current shortage of the preferred treatment option (Bacillus:Calmette-Guerin), novel methylation analyses may similarly reveal biomarkers of disease outcome that could risk-stratify patients and guide clinical management at initial diagnosis. Methods Promoter-associated CpG island methylation was determined in primary tumour tissue of 36 initial presentation high-grade NMIBCs, 12 low/intermediate-grade NMIBCs and 3 normal bladder controls. The genes HOXA9, ISL1, NKX6-2, SPAG6, ZIC1 and ZNF154 were selected for investigation on the basis of previous reports and/or prognostic utility in low/intermediate-grade NMIBC. Methylation was determined by Pyrosequencing of sodium-bisulphite converted DNA, and then correlated with gene expression using RT-qPCR. Methylation was additionally correlated with tumour behaviour, including tumour recurrence and progression to muscle invasive bladder cancer or metastases. Results The ISL1 genes’ promoter-associated island was more frequently methylated in recurrent and progressive high-grade tumours than their non-recurrent counterparts (60.0% vs. 18.2%, p = 0.008). ISL1 and HOXA9 showed significantly higher mean methylation in recurrent and progressive tumours compared to non-recurrent tumours (43.3% vs. 20.9%, p = 0.016 and 34.5% vs 17.6%, p = 0.017, respectively). Concurrent ISL1/HOXA9 methylation in HG-NMIBC reliably predicted tumour recurrence and progression within one year (Positive Predictive Value 91.7%), and was associated with disease-specific mortality (DSM

  9. Detonation Product EOS Studies: Using ISLS to Refine Cheetah

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zaug, J M; Howard, W M; Fried, L E

    2001-08-08

    Knowledge of an effective interatomic potential function underlies any effort to predict or rationalize the properties of solids and liquids. The experiments we undertake are directed towards determination of equilibrium and dynamic properties of simple fluids at densities sufficiently high that traditional computational methods and semi-empirical forms successful at ambient conditions may require reconsideration. In this paper we present high-pressure and temperature experimental sound speed data on a simple fluid, methanol. Impulsive Stimulated Light Scattering (ISLS) conducted on diamond-anvil cell (DAC) encapsulated samples offers an experimental approach to determine cross-pair potential interactions through equation of state determinations. In addition themore » kinetics of structural relaxation in fluids can be studied. We compare our experimental results with our thermochemical computational model Cheetah. Computational models are systematically improved with each addition of experimental data.« less

  10. Detonation Product EOS Studies: Using ISLS to Refine Cheetah

    NASA Astrophysics Data System (ADS)

    Zaug, J. M.; Howard, W. M.; Fried, L. E.; Hansen, D. W.

    2002-07-01

    Knowledge of an effective interatomic potential function underlies any effort to predict or rationalize the properties of solids and liquids. The experiments we undertake are directed towards determination of equilibrium and dynamic properties of simple fluids at densities sufficiently high that traditional computational methods and semi-empirical forms successful at ambient conditions may require reconsideration. In this paper we present high-pressure and temperature experimental sound speed data on a simple fluid, methanol. Impulsive Stimulated Light Scattering (ISLS) conducted on diamond-anvil cell (DAC) encapsulated samples offers an experimental approach to determine cross-pair potential interactions through equation of state determinations. In addition the kinetics of structural relaxation in fluids can be studied. We compare our experimental results with our thermochemical computational model Cheetah. Experimentally grounded computational models provide a good basis to confidently understand the chemical nature of reactions at extreme conditions.

  11. A Lower Carboniferous two-stage extensional basin along the Avalon-Meguma terrane boundary: Evidence from southeastern Isle Madame, Nova Scotia

    USGS Publications Warehouse

    Force, E.R.; Barr, S.M.

    2006-01-01

    Anomalously thick and coarse clastic sedimentary successions, including over 5000 m of conglomerate, are exposed on Isle Madame off the southern coast of Cape Breton Island. Two steeply to moderately dipping stratigraphic packages are recognized: one involving Horton and lower Windsor groups (Tournasian-Visean); the other involving upper Windsor and Mabou (Visean-Namurian) groups. Also anomalous on Isle Madame are three long narrow belts of "basement" rocks, together with voluminous chloritic microbreccia and minor semi-ductile mylonite, which are separated from the conglomerate-dominated successions by faults. The angular relations between the cataclastic rocks and the conglomerate units, combined with the presence of cataclasite clasts in the conglomerate units and evidence of dip-slip faults within the basin, suggest an extensional setting, where listric normal faults outline detachment allochthons. Allochthon geometry requires two stages of extension, the older stage completed in early Windsor Group time and including most of the island, and the more local younger stage completed in Mabou Group time. Domino-style upper-plate faulting in the younger stage locally repeated the older detachment relation of basement and conglomerate to form the observed narrow belts. Re-rotation of older successions in the younger stage also locally overturned the Horton Group. These features developed within a broad zone of Carboniferous dextral transcurrent faulting between already-docked Avalon and Meguma terranes. Sites of transpression and transtension alternated along the Cobequid-Chedabucto fault zone that separated these terranes. The earlier extensional features in Isle Madame likely represent the northern headwall and associated clastic debris of a pull-apart or other type of transtensional basin developed along part of this fault zone that had become listric; they were repeated and exposed by being up-ended in the second stage of extension, also on listric faults. The

  12. Emerging European winter precipitation pattern linked to atmospheric circulation changes over the North Atlantic region in recent decades

    NASA Astrophysics Data System (ADS)

    Ummenhofer, Caroline C.; Seo, Hyodae; Kwon, Young-Oh; Parfitt, Rhys; Brands, Swen; Joyce, Terrence M.

    2017-08-01

    Dominant European winter precipitation patterns over the past century, along with their associated extratropical North Atlantic circulation changes, are evaluated using cluster analysis. Contrary to the four regimes traditionally identified based on daily wintertime atmospheric circulation patterns, five distinct seasonal precipitation regimes are detected here. Recurrent precipitation patterns in each regime are linked to changes in atmospheric blocking, storm track, and sea surface temperatures across the North Atlantic region. Multidecadal variability in the frequency of the precipitation patterns reveals more (fewer) winters with wet conditions in northern (southern) Europe in recent decades and an emerging distinct pattern of enhanced wintertime precipitation over the northern British Isles. This pattern has become unusually common since the 1980s and is associated with changes in moisture transport and more frequent atmospheric river events. The observed precipitation changes post-1950 coincide with changes in storm track activity over the central/eastern North Atlantic toward the northern British Isles.

  13. Temporal genetic variation of the red fox, Vulpes vulpes, across western Europe and the British Isles

    NASA Astrophysics Data System (ADS)

    Edwards, Ceiridwen J.; Soulsbury, Carl D.; Statham, Mark J.; Ho, Simon Y. W.; Wall, Dave; Dolf, Gaudenz; Iossa, Graziella; Baker, Phillip J.; Harris, Stephen; Sacks, Benjamin N.; Bradley, Daniel G.

    2012-12-01

    Quaternary climatic fluctuations have had profound effects on the phylogeographic structure of many species. Classically, species were thought to have become isolated in peninsular refugia, but there is limited evidence that large, non-polar species survived outside traditional refugial areas. We examined the phylogeographic structure of the red fox (Vulpes vulpes), a species that shows high ecological adaptability in the western Palaearctic region. We compared mitochondrial DNA sequences (cytochrome b and control region) from 399 modern and 31 ancient individuals from across Europe. Our objective was to test whether red foxes colonised the British Isles from mainland Europe in the late Pleistocene, or whether there is evidence that they persisted in the region through the Last Glacial Maximum. We found red foxes to show a high degree of phylogeographic structuring across Europe and, consistent with palaeontological and ancient DNA evidence, confirmed via phylogenetic indicators that red foxes were persistent in areas outside peninsular refugia during the last ice age. Bayesian analyses and tests of neutrality indicated population expansion. We conclude that there is evidence that red foxes from the British Isles derived from central European populations that became isolated after the closure of the landbridge with Europe.

  14. Temporal genetic variation of the red fox, Vulpes vulpes, across western Europe and the British Isles.

    PubMed

    Edwards, Ceiridwen J; Soulsbury, Carl D; Statham, Mark J; Ho, Simon Y W; Wall, Dave; Dolf, Gaudenz; Iossa, Graziella; Baker, Phillip J; Harris, Stephen; Sacks, Benjamin N; Bradley, Daniel G

    2012-12-04

    Quaternary climatic fluctuations have had profound effects on the phylogeographic structure of many species. Classically, species were thought to have become isolated in peninsular refugia, but there is limited evidence that large, non-polar species survived outside traditional refugial areas. We examined the phylogeographic structure of the red fox ( Vulpes vulpes ), a species that shows high ecological adaptability in the western Palaearctic region. We compared mitochondrial DNA sequences (cytochrome b and control region) from 399 modern and 31 ancient individuals from across Europe. Our objective was to test whether red foxes colonised the British Isles from mainland Europe in the late Pleistocene, or whether there is evidence that they persisted in the region through the Last Glacial Maximum. We found red foxes to show a high degree of phylogeographic structuring across Europe and, consistent with palaeontological and ancient DNA evidence, confirmed via phylogenetic indicators that red foxes were persistent in areas outside peninsular refugia during the last ice age. Bayesian analyses and tests of neutrality indicated population expansion. We conclude that there is evidence that red foxes from the British Isles derived from central European populations that became isolated after the closure of the landbridge with Europe.

  15. Improving niche projections of plant species under climate change: Silene acaulis on the British Isles as a case study

    NASA Astrophysics Data System (ADS)

    Ferrarini, Alessandro; Alsafran, Mohammed H. S. A.; Dai, Junhu; Alatalo, Juha M.

    2018-04-01

    Empirical works to assist in choosing climatically relevant variables in the attempt to predict climate change impacts on plant species are limited. Further uncertainties arise in choice of an appropriate niche model. In this study we devised and tested a sharp methodological framework, based on stringent variable ranking and filtering and flexible model selection, to minimize uncertainty in both niche modelling and successive projection of plant species distributions. We used our approach to develop an accurate, parsimonious model of Silene acaulis (L.) presence/absence on the British Isles and to project its presence/absence under climate change. The approach suggests the importance of (a) defining a reduced set of climate variables, actually relevant to species presence/absence, from an extensive list of climate predictors, and (b) considering climate extremes instead of, or together with, climate averages in projections of plant species presence/absence under future climate scenarios. Our methodological approach reduced the number of relevant climate predictors by 95.23% (from 84 to only 4), while simultaneously achieving high cross-validated accuracy (97.84%) confirming enhanced model performance. Projections produced under different climate scenarios suggest that S. acaulis will likely face climate-driven fast decline in suitable areas on the British Isles, and that upward and northward shifts to occupy new climatically suitable areas are improbable in the future. Our results also imply that conservation measures for S. acaulis based upon assisted colonization are unlikely to succeed on the British Isles due to the absence of climatically suitable habitat, so different conservation actions (seed banks and/or botanical gardens) are needed.

  16. Intersatellite Calibration of Microwave Radiometers for GPM

    NASA Astrophysics Data System (ADS)

    Wilheit, T. T.

    2010-12-01

    The aim of the GPM mission is to measure precipitation globally with high temporal resolution by using a constellation of satellites logically united by the GPM Core Satellite which will be in a non-sunsynchronous, medium inclination orbit. The usefulness of the combined product depends on the consistency of precipitation retrievals from the various microwave radiometers. The calibration requirements for this consistency are quite daunting requiring a multi-layered approach. The radiometers can vary considerably in their frequencies, view angles, polarizations and spatial resolutions depending on their primary application and other constraints. The planned parametric algorithms will correct for the varying viewing parameters, but they are still vulnerable to calibration errors, both relative and absolute. The GPM Intersatellite Calibration Working Group (aka X-CAL) will adjust the calibration of all the radiometers to a common consensus standard for the GPM Level 1C product to be used in precipitation retrievals. Finally, each Precipitation Algorithm Working Group must have its own strategy for removing the residual errors. If the final adjustments are small, the credibility of the precipitation retrievals will be enhanced. Before intercomparing, the radiometers must be self consistent on a scan-wise and orbit-wise basis. Pre-screening for this consistency constitutes the first step in the intercomparison. The radiometers are then compared pair-wise with the microwave radiometer (GMI) on the GPM Core Satellite. Two distinct approaches are used for sake of cross-checking the results. On the one hand, nearly simultaneous observations are collected at the cross-over points of the orbits and the observations of one are converted to virtual observations of the other using a radiative transfer model to permit comparisons. The complementary approach collects histograms of brightness temperature from each instrument. In each case a model is needed to translate the

  17. ETS-5, ETS-6, and COMETS projects in Japan

    NASA Technical Reports Server (NTRS)

    Iida, Takashi; Wakana, Hiromitsu; Obara, Noriaki

    1992-01-01

    Three satellite communication projects now in progress in Japan are described. The first is a project to establish a telecommunication network for tele-education, TV conference, and tele-medicine in the Asia-Pacific region by using the Japan's Engineering Test Satellite-5 (ETS-5). The second is a project of the ETS-6 satellite, to be launched in 1993, for inter-satellite communication, mobile and fixed communication, and millimeter wave personal communication experiments. The third is a project of the Communications and Broadcasting Engineering Test Satellite (COMETS), to be launched in 1997, for advanced mobile satellite communication, inter-satellite link, and advanced broadcasting experiments at higher frequencies.

  18. Genomic Variation of Inbreeding and Ancestry in the Remaining Two Isle Royale Wolves.

    PubMed

    Hedrick, Philip W; Kardos, Marty; Peterson, Rolf O; Vucetich, John A

    2017-03-01

    Inbreeding, relatedness, and ancestry have traditionally been estimated with pedigree information, however, molecular genomic data can provide more detailed examination of these properties. For example, pedigree information provides estimation of the expected value of these measures but molecular genomic data can estimate the realized values of these measures in individuals. Here, we generate the theoretical distribution of inbreeding, relatedness, and ancestry for the individuals in the pedigree of the Isle Royale wolves, the first examination of such variation in a wild population with a known pedigree. We use the 38 autosomes of the dog genome and their estimated map lengths in our genomic analysis. Although it is known that the remaining wolves are highly inbred, closely related, and descend from only 3 ancestors, our analyses suggest that there is significant variation in the realized inbreeding and relatedness around pedigree expectations. For example, the expected inbreeding in a hypothetical offspring from the 2 remaining wolves is 0.438 but the realized 95% genomic confidence interval is from 0.311 to 0.565. For individual chromosomes, a substantial proportion of the whole chromosomes are completely identical by descent. This examination provides a background to use when analyzing molecular genomic data for individual levels of inbreeding, relatedness, and ancestry. The level of variation in these measures is a function of the time to the common ancestor(s), the number of chromosomes, and the rate of recombination. In the Isle Royale wolf population, the few generations to a common ancestor results in the high variance in genomic inbreeding. © The American Genetic Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. A Conceptual Framework for Tactical Private Satellite Networks

    DTIC Science & Technology

    2008-09-01

    will be deployed on a controlled basis so as not to consume valuable bandwidth during critical time windows. Faults inside the network can be tracked ... attitude control , timing, and navigation - More precise station keeping - Optical LANs and inter-satellite links - Inter satellite links - New...Cluster operations, such as electromagnetic formation flying systems and remote attitude determination systems. • Distributed spacecraft computing

  20. Genomic evaluation, breed identification, and population structure of Guernsey cattle in North America, Great Britain, and the Isle of Guernsey

    USDA-ARS?s Scientific Manuscript database

    Genomic evaluations of dairy cattle in the United States have been available for Brown Swiss, Holsteins, and Jerseys since 2009 and for Ayrshire since 2013. As of January 2015, 2,263 Guernsey bulls and cows had genotypes from collaboration between the United States, Canada, England and the Isle of G...

  1. Isles within islets: The lattice origin of small-world networks in pancreatic tissues

    NASA Astrophysics Data System (ADS)

    Barua, Amlan K.; Goel, Pranay

    2016-02-01

    The traditional computational model of the pancreatic islets of Langerhans is a lattice of β-cells connected with gap junctions. Numerous studies have investigated the behavior of networks of coupled β-cells and have shown that gap junctions synchronize bursting strongly. This simplistic architecture of islets, however, seems increasingly untenable at the face of recent experimental advances. In a microfluidics experiment on isolated islets, Rocheleau et al. (2004) showed a failure of penetration of excitation when one end received high glucose and other end was not excited sufficiently; this suggested that gap junctions may not be efficient at inducing synchrony throughout the islet. Recently, Stozer et al. (2013) have argued that the functional networks of β-cells in an islet are small world. Their results implicate the existence of a few long-range connections among cells in the network. The physiological reason underlying this claim is not well understood. These studies cast doubt on the original lattice model that largely predict an all-or-none synchrony among the cells. Here we have attempted to reconcile these observations in a unified framework. We assume that cells in the islet are coupled randomly to their nearest neighbors with some probability, p. We simulated detailed β-cell bursting in such islets. By varying p systematically we were led to network parameters similar to those obtained by Stozer et al. (2013). We find that the networks within islets break up into components giving rise to smaller isles within the super structure-isles-within-islets, as it were. This structure can also account for the partial excitation seen by Rocheleau et al. (2004). Our updated view of islet architecture thus explains the paradox how islets can have strongly synchronizing gap junctions, and be weakly coordinated at the same time.

  2. 77 FR 4897 - Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, VA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ...-AA00 Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, VA AGENCY: Coast... provide for the safety of life on navigable waters during the live-fire gun exercises on the M/V Del Monte... associated with the live-fire gun exercise. DATES: This rule is effective in the CFR on February 1, 2012...

  3. 76 FR 31848 - Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, Virginia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-02

    ...-AA00 Safety Zone; M/V Del Monte Live-Fire Gun Exercise, James River, Isle of Wight, Virginia AGENCY... provide for the safety of life on navigable waters during the live-fire gun exercises on the M/V Del Monte... associated with the live-fire gun exercise. DATES: This rule will be effective from 11 a.m. June 6, 2011...

  4. Deposition and cycling of sulfur controls mercury accumulation in Isle Royale fish

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Paul E. Drevnick; Donald E. Canfield; Patrick R. Gorski

    2007-11-01

    Mercury contamination of fish is a global problem. Consumption of contaminated fish is the primary route of methylmercury exposure in humans and is detrimental to health. Newly mandated reductions in anthropogenic mercury emissions aim to reduce atmospheric mercury deposition and thus mercury concentrations in fish. However, factors other than mercury deposition are important for mercury bioaccumulation in fish. In the lakes of Isle Royale, U.S.A., reduced rates of sulfate deposition since the Clean Air Act of 1970 have caused mercury concentrations in fish to decline to levels that are safe for human consumption, even without a discernible decrease in mercurymore » deposition. Therefore, reductions in anthropogenic sulfur emissions may provide a synergistic solution to the mercury problem in sulfate-limited freshwaters. 71 refs., 3 figs., 1 tab.« less

  5. Water-resources reconnaissance of Isle de la Gonave, Haiti

    USGS Publications Warehouse

    Troester, J.W.; Turvey, M.D.

    2004-01-01

    Isle de la Gonave is a 750-km2 island off the coast of Haiti. The depth to the water table ranges from less than 30 m in the Eocene and Upper Miocene limestones to over 60 m in the 300-m-thick Quaternary limestone. Annual precipitation ranges from 800-1,400 mm. Most precipitation is lost through evapotranspiration and there is virtually no surface water. Roughly estimated from chloride mass balance, about 4% of the precipitation recharges the karst aquifer. Cave pools and springs are a common source for water. Hand-dug wells provide water in coastal areas. Few productive wells have been drilled deeper than 60 m. Reconnaissance field analyses indicate that groundwater in the interior is a calcium-bicarbonate type, whereas water at the coast is a sodium-chloride type that exceeds World Health Organization recommended values for sodium and chloride. Tests for the presence of hydrogen sulfide-producing bacteria were negative in most drilled wells, but positive in cave pools, hand-dug wells, and most springs, indicating bacterial contamination of most water sources. Because of the difficulties in obtaining freshwater, the 110,000 inhabitants use an average of only 7 L per person per day.

  6. Camping impact management at Isle Royale National Park: An evaluation of visitor activity containment policies from the perspective of social conditions

    Treesearch

    Tracy A. Farrell; Jeffrey L. Marion

    2000-01-01

    A survey of backcountry and wilderness campsites at Isle Royale National Park reveals that the park’s policies for managing visitor impacts have been remarkably effective in limiting the areal extent of camping-related disturbance. However, the dense spatial arrangement of designated campsites within backcountry campgrounds has also contributed to problems with visitor...

  7. Distinctive Feature Extraction for Indian Sign Language (ISL) Gesture using Scale Invariant Feature Transform (SIFT)

    NASA Astrophysics Data System (ADS)

    Patil, Sandeep Baburao; Sinha, G. R.

    2017-02-01

    India, having less awareness towards the deaf and dumb peoples leads to increase the communication gap between deaf and hard hearing community. Sign language is commonly developed for deaf and hard hearing peoples to convey their message by generating the different sign pattern. The scale invariant feature transform was introduced by David Lowe to perform reliable matching between different images of the same object. This paper implements the various phases of scale invariant feature transform to extract the distinctive features from Indian sign language gestures. The experimental result shows the time constraint for each phase and the number of features extracted for 26 ISL gestures.

  8. ISLE (Image and Signal Lisp Environment): A functional language interface for signal and image processing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Azevedo, S.G.; Fitch, J.P.

    1987-05-01

    Conventional software interfaces which utilize imperative computer commands or menu interactions are often restrictive environments when used for researching new algorithms or analyzing processed experimental data. We found this to be true with current signal processing software (SIG). Existing ''functional language'' interfaces provide features such as command nesting for a more natural interaction with the data. The Image and Signal Lisp Environment (ISLE) will be discussed as an example of an interpreted functional language interface based on Common LISP. Additional benefits include multidimensional and multiple data-type independence through dispatching functions, dynamic loading of new functions, and connections to artificial intelligencemore » software.« less

  9. Optimization of the Medium for the Production of Extracellular Amylase by the Pseudomonas stutzeri ISL B5 Isolated from Municipal Solid Waste

    PubMed Central

    Dutta, Prajesh; Deb, Akash

    2016-01-01

    The management of municipal solid waste is one of the major problems of the present world. The use of microbial enzymes for sustainable management of the solid waste is the need of the time. In the present study, we have isolated a potent amylase producing strain (ISL B5) from municipal solid waste. The strain was identified as Pseudomonas stutzeri (P. stutzeri) both biochemically and by 16S rDNA sequencing. The optimization studies revealed that the strain ISL B5 exhibited maximum activity in the liquid media containing 2% starch (2.77 U/ml), 0.8% peptone (2.77 U/ml), and 0.001% Ca2+ ion (2.49 U/ml) under the pH 7.5 (2.59 U/ml), temperature 40°C (2.63 U/ml), and 25 h of incubation period (2.49 U/ml). The highest activity of crude enzyme has also been optimized at the pH 8 (2.49 U/ml). PMID:28096816

  10. Modeling to Predict Escherichia coli at Presque Isle Beach 2, City of Erie, Erie County, Pennsylvania

    USGS Publications Warehouse

    Zimmerman, Tammy M.

    2008-01-01

    The Lake Erie beaches in Pennsylvania are a valuable recreational resource for Erie County. Concentrations of Escherichia coli (E. coli) at monitored beaches in Presque Isle State Park in Erie, Pa., occasionally exceed the single-sample bathing-water standard of 235 colonies per 100 milliliters resulting in potentially unsafe swimming conditions and prompting beach managers to post public advisories or to close beaches to recreation. To supplement the current method for assessing recreational water quality (E. coli concentrations from the previous day), a predictive regression model for E. coli concentrations at Presque Isle Beach 2 was developed from data collected during the 2004 and 2005 recreational seasons. Model output included predicted E. coli concentrations and exceedance probabilities--the probability that E. coli concentrations would exceed the standard. For this study, E. coli concentrations and other water-quality and environmental data were collected during the 2006 recreational season at Presque Isle Beach 2. The data from 2006, an independent year, were used to test (validate) the 2004-2005 predictive regression model and compare the model performance to the current method. Using 2006 data, the 2004-2005 model yielded more correct responses and better predicted exceedances of the standard than the use of E. coli concentrations from the previous day. The differences were not pronounced, however, and more data are needed. For example, the model correctly predicted exceedances of the standard 11 percent of the time (1 out of 9 exceedances that occurred in 2006) whereas using the E. coli concentrations from the previous day did not result in any correctly predicted exceedances. After validation, new models were developed by adding the 2006 data to the 2004-2005 dataset and by analyzing the data in 2- and 3-year combinations. Results showed that excluding the 2004 data (using 2005 and 2006 data only) yielded the best model. Explanatory variables in the

  11. Operational Art in Pontiac’s War

    DTIC Science & Technology

    2015-05-23

    and Fort Presque Isle lay along the supply route connecting Fort Pitt over land to Lake Erie further linking across the water to major forts through...expedition in early August. Traveling south along the coast of Lake Erie , Bradstreet first stopped at Presque Isle . Bradstreet was hesitant to initiate...destroyed Fort Presque Isle . The next stop was Sandusky Bay, where Dalyell took some men several miles inland to rout Huron warriors from the village of

  12. Monitoring and modeling to predict Escherichia coli at Presque Isle Beach 2, City of Erie, Erie County, Pennsylvania

    USGS Publications Warehouse

    Zimmerman, Tammy M.

    2006-01-01

    The Lake Erie shoreline in Pennsylvania spans nearly 40 miles and is a valuable recreational resource for Erie County. Nearly 7 miles of the Lake Erie shoreline lies within Presque Isle State Park in Erie, Pa. Concentrations of Escherichia coli (E. coli) bacteria at permitted Presque Isle beaches occasionally exceed the single-sample bathing-water standard, resulting in unsafe swimming conditions and closure of the beaches. E. coli concentrations and other water-quality and environmental data collected at Presque Isle Beach 2 during the 2004 and 2005 recreational seasons were used to develop models using tobit regression analyses to predict E. coli concentrations. All variables statistically related to E. coli concentrations were included in the initial regression analyses, and after several iterations, only those explanatory variables that made the models significantly better at predicting E. coli concentrations were included in the final models. Regression models were developed using data from 2004, 2005, and the combined 2-year dataset. Variables in the 2004 model and the combined 2004-2005 model were log10 turbidity, rain weight, wave height (calculated), and wind direction. Variables in the 2005 model were log10 turbidity and wind direction. Explanatory variables not included in the final models were water temperature, streamflow, wind speed, and current speed; model results indicated these variables did not meet significance criteria at the 95-percent confidence level (probabilities were greater than 0.05). The predicted E. coli concentrations produced by the models were used to develop probabilities that concentrations would exceed the single-sample bathing-water standard for E. coli of 235 colonies per 100 milliliters. Analysis of the exceedence probabilities helped determine a threshold probability for each model, chosen such that the correct number of exceedences and nonexceedences was maximized and the number of false positives and false negatives was

  13. LA SAFE and Isle de Jean Charles: Regional Adaptation and Community Resettlement Planning

    NASA Astrophysics Data System (ADS)

    Sanders, M.

    2017-12-01

    LA SAFE, or Louisiana's Strategic Adaptations for Future Environments, is a strategic framework for community development utilizing future projections of coastal land loss and flood risk as a determining factor in regional growth management and local planning initiatives along a 10, 25, and 50 year timeline. LA SAFE utilizes the input of passionate local citizen leaders and organizations committed to enabling community members to take proactive steps towards mitigating risk and increasing resilience against coastal issues. The project aims to acknowledge that adaptation and restoration must go hand-in-hand with addressing community growth and contraction, as well as realizing Louisiana's most vulnerable coastal communities will need to contemplate resettlement over the next 50 years. The project's outlook is to become a global leader for adaptation and cultural design and restoration. Connecting a global interest with the project and offering extensive ways for people to learn about the issues and get involved will provide an immense amount of support necessary for future coastal environments around the world. This presentation will focus on the output of a year-long planning effort across a six-parish target area encompassing several vulnerable coastal Louisiana locales. The Resettlement of Isle de Jean Charles is a federally-funded and first-of-its kind initiative marking Louisiana's first attempt to relocate a vulnerable coastal community at-scale and as a group. Due to a myriad of environmental factors, the Island has experienced 98 percent land loss since 1955, leading to many of the Island's historical inhabitants to retreat to higher, drier landscapes. In moving the community at-scale, the project seeks to inject new life into the community and its residents in relocating the community to higher, safer ground, while also developing the new community in such a way that it maximizes economic development, job training, and educational opportunities and can be a

  14. The 60 GHz antenna system analyses for intersatellite links, phase A

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A tradeoff study for 60 GHz antenna systems applicable to an advanced Tracking and Data Acquisition System is also discussed. A conceptual design of a preferred antenna system is also discussed. The tradeoff results for four types of antenna systems are presented: (1) Reflector/fixed feed, (2) Mechanical scan, (3) Electronic scan; and (4) Hybrid mechanical/electronic scan. The 12 candidate antennas were assessed on the basis of a preliminary design and a performance analysis then were scored against 15 weighted parameters. This process resulted in the ranking of the 12 candidates for the two applications, namely, for the geostationary TDAS only with a narrow field of view and for low orbit user satellites with a wide field of view.

  15. Environmental impact of the MV CITA on the foreshore of Porth Hellick, Isles of Scilly.

    PubMed

    Smith, Nicola A

    2004-12-01

    The grounding of the container feeder vessel MV CITA on Newfoundland Rocks, Isles of Scilly, had an effect on the surrounding biota and benthic environment. Included in the CITA's cargo were five 40 ft containers holding pallets of polyester film used in the production of audio and visual recording tapes. The wreckage presented a minor but potentially chronic source of pollution through the delayed release of polythene film, which was left on the seabed as it was considered insufficiently valuable to warrant salvage. The polythene disintegrated and was washed upon the foreshore of Porth Hellick in minute shreds. The adjacent foreshore and two control sites within the islands were analysed using a 5-strand line and vegetation survey with 10 random quadrats within each line to determine the environmental impact of the polythene.

  16. Modelling moose–forest interactions under different predation scenarios at Isle Royale National Park, USA

    USGS Publications Warehouse

    DeJager, Nathan R.; Rohweder, Jason; Miranda, Brian R.; Sturtevant, Brian R.; Fox, Timothy J.; Romanski, Mark C.

    2017-01-01

    Loss of top predators may contribute to high ungulate population densities and chronic over-browsing of forest ecosystems. However, spatial and temporal variability in the strength of interactions between predators and ungulates occurs over scales that are much shorter than the scales over which forest communities change, making it difficult to characterize trophic cascades in forest ecosystems. We applied the LANDIS-II forest succession model and a recently developed ungulate browsing extension to model how the moose population could interact with the forest ecosystem of Isle Royale National Park, USA, under three different wolf predation scenarios. We contrasted a 100-yr future without wolves (no predation) with two predation scenarios (weak, long-term average predation rates and strong, higher than average rates). Increasing predation rates led to lower peak moose population densities, lower biomass removal rates, and higher estimates of forage availability and landscape carrying capacity, especially during the first 40 yr of simulations. Thereafter, moose population density was similar for all predation scenarios, but available forage biomass and the carrying capacity of the landscape continued to diverge among predation scenarios. Changes in total aboveground live biomass and species composition were most pronounced in the no predation and weak predation scenarios. Consistent with smaller-scale studies, high browsing rates led to reductions in the biomass of heavily browsed Populus tremuloides, Betula papyrifera, and Abies balsamea, and increases in the biomass of unbrowsed Picea glauca and Picea mariana, especially after the simulation year 2050, when existing boreal hardwood stands at Isle Royale are projected to senesce. As a consequence, lower predation rates corresponded with a landscape that progressively shifted toward dominance by Picea glauca and Picea mariana, and lacking available forage biomass. Consistencies with previously documented

  17. Inter-Satellite Calibration Linkages for the Visible and Near-Infrared Channels of the Advanced Very High Resolution Radiometer on the NOAA-7, -9, and -11 Spacecraft. Revised

    NASA Technical Reports Server (NTRS)

    NagarajaRao, C. R.; Chen, J.

    1996-01-01

    The post-launch degradation of the visible (channel 1: 0.58- 068 microns) and near-infrared (channel 2: approx. 0.72 - l.l microns) channels of the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-7, -9, and -11 Polar-orbiting Operational Environmental Satellites (POES) was estimated using the south-eastern part of the Libyan Desert as a radiometrically stable calibration target. The relative annual degradation rates, in per cent, for the two channels are, respectively: 3.6 and 4.3 (NOAA-7); 5.9 and 3.5 (NOAA-9); and 1.2 and 2.0 (NOAA-11). Using the relative degradation rates thus determined, in conjunction with absolute calibrations based on congruent path aircraft/satellite radiance measurements over White Sands, New Mexico (USA), the variation in time of the absolute gain or slope of the AVHRR on NOAA-9 was evaluated. Inter-satellite calibration linkages were established, using the AVHRR on NOAA-9 as a normalization standard. Formulae for the calculation of calibrated radiances and albedos (AVHRR usage), based on these interlinkages, are given for the three AVHRRs.

  18. Tidal flow dynamics and background fluorescence of the Atlantic Intracoastal Waterway in the vicinity of Sullivan’s Island and the Isle of Palms, South Carolina, 2011-12

    USGS Publications Warehouse

    Conrads, Paul; Journey, Celeste A.; Clark, Jimmy M.; Levesque, Victor A.

    2013-01-01

    To effectively plan site-specific studies to understand the connection between wastewater effluent and shellfish beds, data are needed concerning flow dynamics and background fluorescence in the Atlantic Intracoastal Waterway near the effluent outfalls on Sullivan’s Island and the Isle of Palms. Tidal flows were computed by the U.S. Geological Survey for three stations and longitudinal water-quality profiles were collected at high and low tide. Flows for the three U.S. Geological Survey stations, the Atlantic Intracoastal Waterway by the Isle of Palms Marina, the Atlantic Intracoastal Waterway by the Ben M. Sawyer Memorial Bridge at Sullivan’s Island, and Breach Inlet, were computed for the 53-day period from December 4, 2011, to January 26, 2012. The largest flows occurred at Breach Inlet and ranged from -58,600 cubic feet per second (ft3/s) toward the Atlantic Intracoastal Waterway to 63,300 ft3/s toward the Atlantic Ocean. Of the two stations on the Atlantic Intracoastal Waterway, the Sullivan’s Island station had the larger flows and ranged from -6,360 ft3/s to the southwest (toward Charleston Harbor) to 8,930 ft3/s to the northeast. Computed tidal flow at the Isle of Palms station ranged from -3,460 ft3/s toward the southwest to 6,410 ft3/s toward the northeast. The synoptic water-quality study showed that the stations were well mixed vertically and horizontally. All fluorescence measurements (recorded as rhodamine concentration) were below the accuracy of the sensor and the background fluorescence would not likely interfere with a dye-tracer study.

  19. Cold-front driven storm erosion and overwash in the central part of the Isles Dernieres, a Louisiana barrier-island arc

    USGS Publications Warehouse

    Dingler, J.R.; Reiss, T.E.

    1990-01-01

    Tropical and extratropical storms produce significant erosion on the barrier islands of Louisiana. Over the past 100 years, such storms have produced at least 2 km of northward beach-face retreat and the loss of 63% of the surface area of the Isles Dernieres, a low-lying barrier-island arc along the central Louisiana coast. Elevations on the islands within the arc are typically less than 2 m above mean sea level. The islands typically have a washover-flat topography with occasional, poorly developed, dune-terrace topography consisting of low-lying and broken dunes. The central part of the arc consists of salt-marsh deposits overlain by washover sands along the Gulf of Mexico shoreline. Sand thicknesses range from zero behind the beach, to less than 2 m under the berm crest, and back to zero in the first nearshore trough. The sand veneer is sufficiently thin that storms can strip all the sand from the beach face, exposing the underlying marsh deposits. The geomorphic changes produced by cold fronts, a type of extratropical storm that commonly affect the Isles Dernieres between late fall and early spring are described. Between August 1986 and September 1987, repeated surveys along eleven shore-normal transects that covered 400 m of shoreline revealed the timing and extent of cold-front-produced beach change along a typical section of the central Isles Dernieres. During the study period, the beach face retreated approximately 20 m during the cold-front season but did not rebuild during the subsequent summer. Because the volume of sand deposited on the backshore (5600 m3) was less than the volume of material lost from the beach face (19,200 m3), approximately 13,600 m3 of material disappeared. Assuming that underlying marsh deposits decrease in volume in direct proportion to the amount of beach-face retreat, an estimate of the mud loss during the study period is 14,000 m3. Thus, the decrease in volume along the profiles can be accounted for without removing any sand

  20. Role of amplified spontaneous emission in optical free-space communication links with optical amplification: impact on isolation and data transmission and utilization for pointing, acquisition, and

    NASA Astrophysics Data System (ADS)

    Winzer, Peter J.; Kalmar, Andras; Leeb, Walter R.

    1999-04-01

    We investigate the role of amplified spontaneous emission (ASE) produced by an optical booster amplifier at the transmitter of free-space optical communication links. In a communication terminal with a single telescope for both transmission and reception, this ASE power has to be taken into account in connection with transmit-to-receive channel isolation, especially since it partly occupies the same state of polarization and the same frequency band as the receive signal. We show that the booster ASE intercepted by the receiver can represent a non-negligible source of background radiation: In a typical optical intersatellite link scenario, the ASE power spectral density generated by the booster amplifier at the transmitter and coupled to the receiver will be on the order of 10-20 W/Hz, which equals the background radiation of the sun. Exploiting these findings for pointing, acquisition, and tracking (PAT) purposes, we describe a patent-pending PAT system doing without beacon lasers and without the need for diverting a part of the data signal for PAT. Utilizing the transmit booster ASE over a bandwidth of e.g. 20 nm at the receiver, a total power of about -46 dBm is available for PAT purposes without extra power consumption at the transmitter and without the need for beacon lAser alignment.

  1. Management practices that concentrate visitor activities: Camping impact management at Isle Royale National Park, USA

    USGS Publications Warehouse

    Marion, J.L.; Farrell, T.A.

    2002-01-01

    This study assessed campsite conditions and the effectiveness of campsite impact management strategies at Isle Royale National Park, USA. Protocols for assessing indicators of vegetation and soil conditions were developed and applied to 156 campsites and 88 shelters within 36 backcountry campgrounds. The average site was 68 m2 and 83% of sites lost vegetation over areas less than 47 m2. Results reveal that management actions to spatially concentrate camping activities and reduce camping disturbance have been highly successful. Comparisons of disturbed area/overnight stay among other protected areas reinforces this assertion. These reductions in area of camping disturbance are attributed to a designated site camping policy, limitation on site numbers, construction of sites in sloping terrain, use of facilities, and an ongoing program of campsite maintenance. Such actions are most appropriate in higher use backcountry and wilderness settings.

  2. The celestial mechanics approach: application to data of the GRACE mission

    NASA Astrophysics Data System (ADS)

    Beutler, Gerhard; Jäggi, Adrian; Mervart, Leoš; Meyer, Ulrich

    2010-11-01

    The celestial mechanics approach (CMA) has its roots in the Bernese GPS software and was extensively used for determining the orbits of high-orbiting satellites. The CMA was extended to determine the orbits of Low Earth Orbiting satellites (LEOs) equipped with GPS receivers and of constellations of LEOs equipped in addition with inter-satellite links. In recent years the CMA was further developed and used for gravity field determination. The CMA was developed by the Astronomical Institute of the University of Bern (AIUB). The CMA is presented from the theoretical perspective in (Beutler et al. 2010). The key elements of the CMA are illustrated here using data from 50 days of GPS, K-Band, and accelerometer observations gathered by the Gravity Recovery And Climate Experiment (GRACE) mission in 2007. We study in particular the impact of (1) analyzing different observables [Global Positioning System (GPS) observations only, inter-satellite measurements only], (2) analyzing a combination of observations of different types on the level of the normal equation systems (NEQs), (3) using accelerometer data, (4) different orbit parametrizations (short-arc, reduced-dynamic) by imposing different constraints on the stochastic orbit parameters, and (5) using either the inter-satellite ranges or their time derivatives. The so-called GRACE baseline, i.e., the achievable accuracy of the GRACE gravity field for a particular solution strategy, is established for the CMA.

  3. Characterisation of a serotype O1 Yersinia ruckeri isolate from the Isle of Man: further evidence that O antigen serotype is not a reliable indicator of virulence

    USDA-ARS?s Scientific Manuscript database

    As part of a routine disease surveillance exercise, a culture of the Gram negative bacterial pathogen Yersinia ruckeri was obtained from one of 150 largely asymptomatic rainbow trout from a farm on the Isle of Man, an island off the North West coast of Great Britain. This is the first reported isol...

  4. Four decades of microwave satellite soil moisture observations: Part 2. Product validation and inter-satellite comparisons

    NASA Astrophysics Data System (ADS)

    Karthikeyan, L.; Pan, Ming; Wanders, Niko; Kumar, D. Nagesh; Wood, Eric F.

    2017-11-01

    Soil moisture is widely recognized as an important land surface variable that provides a deeper knowledge of land-atmosphere interactions and climate change. Space-borne passive and active microwave sensors have become valuable and essential sources of soil moisture observations at global scales. Over the past four decades, several active and passive microwave sensors have been deployed, along with the recent launch of two fully dedicated missions (SMOS and SMAP). Signifying the four decades of microwave remote sensing of soil moisture, this Part 2 of the two-part review series aims to present an overview of how our knowledge in this field has improved in terms of the design of sensors and their accuracy for retrieving soil moisture. The first part discusses the developments made in active and passive microwave soil moisture retrieval algorithms. We assess the evolution of the products of various sensors over the last four decades, in terms of daily coverage, temporal performance, and spatial performance, by comparing the products of eight passive sensors (SMMR, SSM/I, TMI, AMSR-E, WindSAT, AMSR2, SMOS and SMAP), two active sensors (ERS-Scatterometer, MetOp-ASCAT), and one active/passive merged soil moisture product (ESA-CCI combined product) with the International Soil Moisture Network (ISMN) in-situ stations and the Variable Infiltration Capacity (VIC) land surface model simulations over the Contiguous United States (CONUS). In the process, the regional impacts of vegetation conditions on the spatial and temporal performance of soil moisture products are investigated. We also carried out inter-satellite comparisons to study the roles of sensor design and algorithms on the retrieval accuracy. We find that substantial improvements have been made over recent years in this field in terms of daily coverage, retrieval accuracy, and temporal dynamics. We conclude that the microwave soil moisture products have significantly evolved in the last four decades and will

  5. Emerging technologies for communication satellite payloads

    NASA Astrophysics Data System (ADS)

    Yüceer, Mehmet

    2012-04-01

    Recent developments in payload designs will allow more flexible and efficient use of telecommunication satellites. Important modifications in repeater designs, antenna structures and spectrum policies open up exciting opportunities for GEO satellites to support a variety of emerging applications, ranging from telemedicine to real-time data transfer between LEO satellite and ground station. This study gives information about the emerging technologies in the design of communication satellites' transceiver subsystem and demonstrates the feasibility of using fiber optic links for the local oscillator distribution in future satellite payloads together with the optical inter-satellite link.

  6. Advanced communications payload for mobile applications

    NASA Technical Reports Server (NTRS)

    Ames, S. A.; Kwan, R. K.

    1990-01-01

    An advanced satellite payload is proposed for single hop linking of mobile terminals of all classes as well as Very Small Aperture Terminal's (VSAT's). It relies on an intensive use of communications on-board processing and beam hopping for efficient link design to maximize capacity and a large satellite antenna aperture and high satellite transmitter power to minimize the cost of the ground terminals. Intersatellite links are used to improve the link quality and for high capacity relay. Power budgets are presented for links between the satellite and mobile, VSAT, and hub terminals. Defeating the effects of shadowing and fading requires the use of differentially coherent demodulation, concatenated forward error correction coding, and interleaving, all on a single link basis.

  7. Predictors of suicidality across the life span: the Isle of Wight study.

    PubMed

    Pickles, A; Aglan, A; Collishaw, S; Messer, J; Rutter, M; Maughan, B

    2010-09-01

    Data from a representative community sample were used to explore predictors of lifetime suicidality and to examine associations between distal adolescent and more proximal adult risks. Data are from a midlife follow-up of the Isle of Wight study, an epidemiological sample of adolescents assessed in 1968. Ratings of psychiatric symptoms and disorder, relationships and family functioning and adversity were made in adolescence; adult assessments included lifetime psychiatric history and suicidality, neuroticism and retrospective reports of childhood sexual abuse and harsh parenting. A wide range of measures of childhood psychopathology, adverse experiences and interpersonal difficulties were associated with adult suicidality; associations were particularly strong for adolescent irritability, worry and depression. In multivariate analyses, substantial proportions of these effects could be explained by their association with adult psychopathology and neuroticism, but additional effects remained for adolescent irritability and worry. Factors of importance for long-term suicidality risk are evident in adolescence. These include family and experiential adversities as well as psychopathology. In particular, markers of adolescent worry and irritability appeared both potent risks and ones with additional effects beyond associations with adult disorder and adult neuroticism.

  8. Objective Assessment of Groundwater Resources for the Isle of Wight, UK

    NASA Astrophysics Data System (ADS)

    Simpson, M.; Butler, A. P.; McIntyre, N.

    2012-12-01

    -of-the-art climate projections and population change forecasts to generate projections of change for future scenarios. A case study illustrating the use of this methodology is presented. The Isle of Wight, a small island off the south coast of England with a population of 140,000, is exceptionally water stressed by UK standards and currently dependent on mainland transfers. These transfers are under review due to environmental pressure on the neighbouring county of Hampshire. Alongside this, a high population growth rate and the southerly location make the Isle of Wight the most likely part of the UK to be affected by reduced water availability. Lower Greensands and Chalk aquifer systems provide most of the island's non-imported water, yet these remain poorly understood. The principle reason for this is the exceptionally complex geology, a result of the island's location at the convergence of two asymmetric anticlinal structures and, in the case of the Lower Greensand group, multiple layers of alternating aquiferous and non-aquiferous material. A statistical assessment of borehole data may provide evidence for groundwater processes where direct lithological analysis is not appropriate. Through development of a credible groundwater systems model and sensible projections of future water availability, critical information can be provided to influence future water management policy.

  9. Implications of postseismic gravity change following the great 2004 Sumatra-Andaman earthquake from the regional harmonic analysis of GRACE intersatellite tracking data

    USGS Publications Warehouse

    Han, S.-C.; Sauber, J.; Luthcke, S.B.; Ji, C.; Pollitz., F. F.

    2008-01-01

    We report Gravity Recovery and Climate Experiment (GRACE) satellite observations of coseismic displacements and postseismic transients from the great Sumatra-Andaman Islands (thrust event; Mw ???9.2) earthquake in December 2004. Instead of using global spherical harmonic solutions of monthly gravity fields, we estimated the gravity changes directly using intersatellite range-rate data with regionally concentrated spherical Slepian basis functions every 15-day interval. We found significant step-like (coseismic) and exponential-like (postseismic) behavior in the time series of estimated coefficients (from May 2003 to April 2007) for the spherical Slepian function's. After deriving coseismic slip estimates from seismic and geodetic data that spanned different time intervals, we estimated and evaluated postseismic relaxation mechanisms with alternate asthenosphere viscosity models. The large spatial coverage and uniform accuracy of our GRACE solution enabled us to clearly delineate a postseismic transient signal in the first 2 years of postearthquake GRACE data. Our preferred interpretation of the long-wavelength components of the postseismic avity change is biviscous viscoelastic flow. We estimated a transient viscosity of 5 ??17 Pa s and a steady state viscosity of 5 ?? 1018 - 1019 Pa s. Additional years of the GRACE observations should provide improved steady state viscosity estimates. In contrast to our interpretation of coseismic gravity change, the prominent postearthquake positive gravity change around the Nicobar Islands is accounted for by seafloor uplift with less postseismic perturbation in intrinsic density in the region surrounding the earthquake. Copyright 2008 by the American Geophysical Union.

  10. Inter-Satellite Communications Considerations and Requirements for Distributed Spacecraft and Formation Flying Systems

    NASA Technical Reports Server (NTRS)

    Kwadrat, Carl F.; Horne, William D.; Edwards, Bernard L.

    2002-01-01

    In order to avoid selecting inadequate inter-spacecraft cross-link communications standards for Distributed Spacecraft System (DSS) missions, it is first necessary to identify cross-link communications strategies and requirements common to a cross-section of proposed missions. This paper addresses the cross-link communication strategies and requirements derived from a survey of 39 DSS mission descriptions that are projected for potential launch within the next 20 years. The inter-spacecraft communications strategies presented are derived from the topological and communications constraints from the DSS missions surveyed. Basic functional requirements are derived from an analysis of the fundamental activities that must be undertaken to establish and maintain a cross-link between two DSS spacecraft. Cross-link bandwidth requirements are derived from high-level assessments of mission science objectives and operations concepts. Finally, a preliminary assessment of possible cross-link standards is presented within the context of the basic operational and interoperability requirements.

  11. Air blasts generated by rockfall impacts: Analysis of the 1996 Happy Isles event in Yosemite National Park

    USGS Publications Warehouse

    Morrissey, M.M.; Savage, W.Z.; Wieczorek, G.F.

    1999-01-01

    The July 10, 1996, Happy Isles rockfall in Yosemite National Park, California, released 23,000 to 38,000 m3 of granite in four separate events. The impacts of the first two events which involved a 550-m free fall, generated seismic waves and atmospheric pressure waves (air blasts). We focus on the dynamic behavior of the second air blast that downed over 1000 trees, destroyed a bridge, demolished a snack bar, and caused one fatality and several injuries. Calculated velocities for the air blast from a two-phase, finite difference model are compared to velocities estimated from tree damage. From tornadic studies of tree damage, the air blast is estimated to have traveled <108-120 m/s within 50 m from the impact and decreased to <10-20 m/s within 500 m from the impact. The numerical model simulates the two-dimensional propagation of an air blast through a dusty atmosphere with initial conditions defined by the impact velocity and pressure. The impact velocity (105-107 m/s) is estimated from the Colorado Rockfall Simulation Program that simulates rockfall trajectories. The impact pressure (0.5 MPa) is constrained by the kinetic energy of the impact (1010-1012 J) estimated from the seismic energy generated by the impact. Results from the air blast simulations indicate that the second Happy Isles air blast (weak shock wave) traveled with an initial velocity above the local sound speed. The size and location of the first impact are thought to have injected <50 wt % dust into the atmosphere. This amount of dust lowered the local atmospheric sound speed to ???220 m/s. The discrepancy between calculated velocity data and field estimated velocity data (???220 m/s versus ???110 m/s) is attributed to energy dissipated by the downing of trees and additional entrainment of debris into the atmosphere not included in the calculations. Copyright 1999 by the American Geophysical Union.

  12. Air blasts generated by rockfall impacts: Analysis of the 1996 Happy Isles event in Yosemite National Park

    NASA Astrophysics Data System (ADS)

    Morrissey, M. M.; Savage, W. Z.; Wieczorek, G. F.

    1999-10-01

    The July 10, 1996, Happy Isles rockfall in Yosemite National Park, California, released 23,000 to 38,000 m3 of granite in four separate events. The impacts of the first two events which involved a 550-m free fall, generated seismic waves and atmospheric pressure waves (air blasts). We focus on the dynamic behavior of the second air blast that downed over 1000 trees, destroyed a bridge, demolished a snack bar, and caused one fatality and several injuries. Calculated velocities for the air blast from a two-phase, finite difference model are compared to velocities estimated from tree damage. From tornadic studies of tree damage, the air blast is estimated to have traveled <108-120 m/s within 50 m from the impact and decreased to <10-20 m/s within 500 m from the impact. The numerical model simulates the two-dimensional propagation of an air blast through a dusty atmosphere with initial conditions defined by the impact velocity and pressure. The impact velocity (105-107 m/s) is estimated from the Colorado Rockfall Simulation Program that simulates rockfall trajectories. The impact pressure (0.5 MPa) is constrained by the kinetic energy of the impact (1010-1012 J) estimated from the seismic energy generated by the impact. Results from the air blast simulations indicate that the second Happy Isles air blast (weak shock wave) traveled with an initial velocity above the local sound speed. The size and location of the first impact are thought to have injected <50 wt% dust into the atmosphere. This amount of dust lowered the local atmospheric sound speed to ˜220 m/s. The discrepancy between calculated velocity data and field estimated velocity data (˜220 m/s versus ˜110 m/s) is attributed to energy dissipated by the downing of trees and additional entrainment of debris into the atmosphere not included in the calculations.

  13. A statistical model for Windstorm Variability over the British Isles based on Large-scale Atmospheric and Oceanic Mechanisms

    NASA Astrophysics Data System (ADS)

    Kirchner-Bossi, Nicolas; Befort, Daniel J.; Wild, Simon B.; Ulbrich, Uwe; Leckebusch, Gregor C.

    2016-04-01

    Time-clustered winter storms are responsible for a majority of the wind-induced losses in Europe. Over last years, different atmospheric and oceanic large-scale mechanisms as the North Atlantic Oscillation (NAO) or the Meridional Overturning Circulation (MOC) have been proven to drive some significant portion of the windstorm variability over Europe. In this work we systematically investigate the influence of different large-scale natural variability modes: more than 20 indices related to those mechanisms with proven or potential influence on the windstorm frequency variability over Europe - mostly SST- or pressure-based - are derived by means of ECMWF ERA-20C reanalysis during the last century (1902-2009), and compared to the windstorm variability for the European winter (DJF). Windstorms are defined and tracked as in Leckebusch et al. (2008). The derived indices are then employed to develop a statistical procedure including a stepwise Multiple Linear Regression (MLR) and an Artificial Neural Network (ANN), aiming to hindcast the inter-annual (DJF) regional windstorm frequency variability in a case study for the British Isles. This case study reveals 13 indices with a statistically significant coupling with seasonal windstorm counts. The Scandinavian Pattern (SCA) showed the strongest correlation (0.61), followed by the NAO (0.48) and the Polar/Eurasia Pattern (0.46). The obtained indices (standard-normalised) are selected as predictors for a windstorm variability hindcast model applied for the British Isles. First, a stepwise linear regression is performed, to identify which mechanisms can explain windstorm variability best. Finally, the indices retained by the stepwise regression are used to develop a multlayer perceptron-based ANN that hindcasted seasonal windstorm frequency and clustering. Eight indices (SCA, NAO, EA, PDO, W.NAtl.SST, AMO (unsmoothed), EA/WR and Trop.N.Atl SST) are retained by the stepwise regression. Among them, SCA showed the highest linear

  14. Single Event Effects and Total Dose Testing of the Intersil ISL 70003SEH Integrated Point of Load Converter

    NASA Astrophysics Data System (ADS)

    van Vonno, N. W.; White, J. D.; Pearce, L. G.; Thomson, E. J.; Gill, J. S.; Mansilla, O. E.

    2014-08-01

    Single-event transient (SET) phenomena in power management applications has evolved into a key issue, particularly in point of load (POL) buck regulators, as the loads driven by these devices are sensitive to even short-term overvoltage conditions. We preface this paper by a discussion of earlier destructive and nondestructive SEE testing of Intersil integrated point of load regulators, with emphasis on SET phenomena and some of the lessons learned in this work. We then report recent results of SET and destructive SEE testing of the ISL70003SEH POL converter, together with a brief discussion of the part's electrical and radiation hardness specifications. We conclude with a brief overview of low and high dose rate total dose testing of the part.

  15. High speed QPPM direct detection optical communication receivers for FSDD intersatellite links

    NASA Technical Reports Server (NTRS)

    Davidson, Frederic M.; Sun, Xiaoli

    1993-01-01

    This final report consists of four separate reports, one for each project involved in this contract. The first report is entitled '325 Mbps QPPM (quaternary pulse position modulation) Direct Detection Free Space Optical Communication Encoder and Receiver,' which was our primary work. The second report is entitled 'Test Results of the 325 Mbps QPPM High Speed Data Transmission GaAs ASICs,' which describes our work in connection with Galaxy Microsystems, Inc. who produced these ASICs for NASA. The third report, 'Receiver Performance Analysis of BPPM Optical Communication Systems Using 1.3 micron Wavelength Transmitter and InGaAs PIN Photodiodes,' was prepared at the request of the NASA/Photonics Branch for their efforts in upgrading the 1773 optical fiber data bus. The fourth report, 'Photomultiplier Tubes for Use at 1.064 micron Wavelength,' was also prepared at the request of the NASA/Photonics Branch as a research project.

  16. Potentials of RF/FSO Communication in UAS Operations

    NASA Astrophysics Data System (ADS)

    Griethe, Wolfgang; Heine, Frank

    2013-08-01

    Free Space Optical Communications (FSOC) has gained particular attention during the past few years and is progressing continuously. With the successful in-orbit verification of a Laser Communication Terminal (LCT), the coherent homodyne BPSK scheme advanced to a standard for Free-Space Optical Communication (FSOC) which now prevails more and more. The LCT is presently operated on satellites in Low Earth Orbit (LEO). In the near future, the LCT will be operated in Geosynchronous Orbit (GEO) onboard the ALPHASAT-TDP and the European Data Relay System (EDRS). In other words, the LCT has reached a point of maturity to realize its practical application. With existence of such space assets the time has come for other utilization beyond that of optical Inter-Satellite Links (ISL). Aeronautical applications, as for instance High Altitude Long Endurance (HALE) or Medium Altitude Long Endurance (MALE) Unmanned Aerial Systems (UAS) have to be addressed. This is caused due to an extremely high demand for bandwidth. Driving factors and advantages of FSOC in HALE/MALE UAS missions are highlighted. Numerous practice-related issues are described concerning the space segment, the aeronautical segment as well as the ground segment. The advantages for UAS missions are described resulting from the utilization of FSOC exclusively for wideband transmission of sensor data while vehicle Command & Control (C2) can be maintained, as before, via RF communication. Moreover, the paper discusses FSOC as an enabler for the integration of air and space-based wideband Intelligence, Surveillance & Reconnaissance (ISR) systems into existent military command and control networks. From the given information it can be concluded that FSOC contributes to the future increase of air-and space power.

  17. Free-space laser communication technologies; Proceedings of the Meeting, Los Angeles, CA, Jan. 11, 12, 1988

    NASA Astrophysics Data System (ADS)

    Koepf, Gerhard A.; Begley, David L.

    1988-01-01

    The present conference discusses topics in free-space laser communications, laser link characteristics, satellite laser communication systems, optoelectronic components for laser communications, and space laser subsystem technologies. Attention is given to Space Station-based deep-space communication experiments, the application of intersatellite links to operational satellite systems, high-power 0.87 micron channel substrate planar lasers for spaceborne communications, a ground experiment using a CO2 laser transceiver for free-space communications, studies of laser ranging to the TOPEX satellite, diffraction-limited tracking for space communications, and the compact implementation of a real-time, acoustooptic SAR processor.

  18. Camping impact management at Isle Royale National Park: an evaluation of visitor activity containment policies from the perspective of social conditions

    USGS Publications Warehouse

    Farrell, T.A.; Marion, J.L.

    2000-01-01

    A survey of backcountry and wilderness campsites at Isle Royale National Park reveals that the park?s policies for managing visitor impacts have been remarkably effective in limiting the areal extent of camping-related disturbance. However, the dense spatial arrangement of designated campsites within backcountry campgrounds has also contributed to problems with visitor crowding and conflict. Only 9% of the sites had no other sites visible, while 22% had three or more other sites visible. Mean intersite distance was only 76 feet, and 34% of the sites are within 50 feet of another site. Visitor education programs and selected relocation of sites could reduce these social problems.

  19. Coarse pointing mechanism assembly for satellite interlink experiment

    NASA Technical Reports Server (NTRS)

    Maeusli, P. A.; Ivorra, M. T.; Gass, V.; Berthoud, J. F.

    1996-01-01

    Since 1975, MECANEX S.A. has been manufacturing components for solar array drives and mechanisms used in space applications. In 1991, work was started in an early phase C (Engineering Model) on a Coarse Pointing Mechanism Assembly (CPMA) for the Semiconductor-laser Inter-satellite Link EXperiment (SILEX). This paper deals with the history, the evolution, and the lessons learned from taking over a pre-design in 1991 to the delivery of last flight models (FM 5 & 6) in 1995.

  20. Controls of late Palaeozoic and Mesozoic extension in the British Isles: evidence from seismic reflection data in the Central North Sea

    NASA Astrophysics Data System (ADS)

    Smith, K.; Cameron, T. D. J.

    2009-04-01

    Controls of late Palaeozoic and Mesozoic extension in the British Isles: evidence from seismic reflection data in the Central North Sea. Kevin Smith (1) and Don Cameron (2) (1) British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA. (ksm@bgs.ac.uk). (2) British Geological Survey, 376 Gilmerton Road, Edinburgh, EH17 7QS. In the area of the British Isles during the late Devonian and early Carboniferous, the oblique convergence of Laurentia and Gondwana imposed a torque on the adjoining terranes of Baltica and Avalonia. Their resulting clockwise rotation was accommodated by widely distributed N-S extension in the intervening zones previously formed by Caledonian and Acadian convergence. South of Laurentia and Baltica, late Palaeozoic extension was focused (1) at terrane margins, (2) in areas of limited Caledonian-Acadian plutonism, and (3) in places where the western (Iapetus) and eastern (Tornquist) convergence zones intersect at a high angle. One of these latter areas lies in Central England immediately north of the Midland Microcraton (part of Eastern Avalonia), where thermal subsidence associated with early Carboniferous extension gave rise to the late Carboniferous Pennine Basin. Interpretation of an extensive set of 3D and 2D long-offset seismic reflection data suggests that a similar area of enhanced extension at a fold belt intersection lies to north of the Mid North Sea High in the middle of the Central North Sea. Variscan uplift and inversion of the late Palaeozoic basins began to predominate in mid-Carboniferous times as final amalgamation of all the different terranes to form Pangaea curtailed the initial episode of extension and thermal subsidence. This change in the tectonic regime was associated with the onset of tholeiitic volcanism within the convergence zones, and was followed by localised extension during the earliest Permian. Evidence obtained from seismic interpretation of the deep structure of the UK sector of the Central

  1. Zircon geochronology and Hf-O isotope geochemistry from granites in the Iapetus Suture Zone in Ireland and the Isle of Man

    NASA Astrophysics Data System (ADS)

    Fritschle, Tobias; Daly, J. Stephen; Whitehouse, Martin J.; McConnell, Brian; Buhre, Stephan

    2014-05-01

    Late Caledonian syn- to post-orogenic granites located in the Iapetus Suture Zone (ISZ) in Ireland and Britain have been related to A-type subduction and possible slab breakoff [1] following the Laurentia-Avalonian collision. Lack of reliable age data (especially in Ireland) has inhibited petrogenetic investigations of these rocks. Hence, ion microprobe U-Pb and oxygen isotope analyses as well as LA-MC-ICPMS Lu-Hf isotopic measurements on zircons from Irish and Isle of Man granites have been undertaken to provide better constraints on this enigmatic episode of the Caledonian Orogeny. Four stages of Late Caledonian granitic magmatism (c. 435, 417, 410 and 394 Ma) are indicated by U-Pb dating of oscillatory-zoned magmatic zircons. The Crossdoney, Kentstown, Drogheda and Ballynamuddagh granites together with a rhyolite from Glenamaddy have yielded U-Pb concordia ages, interpreted as intrusion-ages, between 419.9 ± 4.3 Ma (Glenamaddy) and 415.8 ± 2.0 Ma (Crossdoney) with a weighted average of 417.5 ± 0.9 Ma (MSWD = 1.3). The Glenamaddy Granite - which intruded the Glenamaddy Rhyolite - yielded an age of 410 ± 2.1 Ma. In addition, the Rockabill Granite yielded a younger age of 393.9 ± 1.9 Ma, whereas the Carnsore Granite yielded an older age of 434.6 ± 1.9 Ma. Inherited zircons (487 to 453 Ma) occur in several of the granites, and are interpreted to have been derived from Ordovician arc magmatic rocks accreted within the ISZ. A younger group of c. 440 Ma inherited zircons occurs in the c. 417 Ma Crossdoney and Ballynamuddagh granites. These grains could be related to continued or renewed Silurian arc magmatism. Hf-O isotopic measurements on the dated zircon grains range between -2 and +7 ɛHfi units and 5.5 to 8.5 o δ18O. These are interpreted to indicate the contribution of juvenile mantle melts - possibly derived from the Ordovician arc - to some of the granites. Significant heterogeneities in zircon oxygen isotopes in at least four of the granites further

  2. Geothermal potential of Caledonian granites in Ireland and the Isle of Man: Implications from hydrothermal alteration

    NASA Astrophysics Data System (ADS)

    Fritschle, Tobias; Daly, J. Stephen; Whitehouse, Martin J.; Buhre, Stephan; McConnell, Brian; The Iretherm Team

    2015-04-01

    . Fritschle, T., Daly, J.S., Whitehouse, M.J., Buhre, S., McConnell, B., 2015. Geothermal potential of Caledonian granites astride the Iapetus Suture Zone in Ireland and the Isle of Man - Implications for EGS prospectivity. Proceedings World Geothermal Congress 2015, in press. Fritschle, T., Daly, J.S., Whitehouse, M.J., McConnell, B., Buhre, S., 2014. Zircon geochronology and Hf-O isotope geochemistry from granites in the Iapetus Suture Zone in Ireland and the Isle of Man. Geophysical Research Abstracts 16, EGU-2014-801.

  3. Population structure and abundance of arsenite-oxidizing bacteria along an arsenic pollution gradient in waters of the upper isle River Basin, France.

    PubMed

    Quéméneur, Marianne; Cébron, Aurélie; Billard, Patrick; Battaglia-Brunet, Fabienne; Garrido, Francis; Leyval, Corinne; Joulian, Catherine

    2010-07-01

    Denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR (qPCR) were successfully developed to monitor functional aoxB genes as markers of aerobic arsenite oxidizers. DGGE profiles showed a shift in the structure of the aoxB-carrying bacterial population, composed of members of the Alpha-, Beta- and Gammaproteobacteria, depending on arsenic (As) and E(h) levels in Upper Isle River Basin waters. The highest aoxB gene densities were found in the most As-polluted oxic surface waters but without any significant correlation with environmental factors. Arsenite oxidizers seem to play a key role in As mobility in As-impacted waters.

  4. Archive of digital CHIRP seismic reflection data collected during USGS cruise 06SCC01 offshore of Isles Dernieres, Louisiana, June 2006

    USGS Publications Warehouse

    Harrison, Arnell S.; Dadisman, Shawn V.; Ferina, Nick F.; Wiese, Dana S.; Flocks, James G.

    2007-01-01

    In June of 2006, the U.S. Geological Survey conducted a geophysical survey offshore of Isles Dernieres, Louisiana. This report serves as an archive of unprocessed digital CHIRP seismic reflection data, trackline maps, navigation files, GIS information, Field Activity Collection System (FACS) logs, observer's logbook, and formal FGDC metadata. Gained digital images of the seismic profiles are also provided. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic UNIX (SU). Example SU processing scripts and USGS software for viewing the SEG-Y files (Zihlman, 1992) are also provided.

  5. Optoelectronics research for communication programs at the Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.

    1991-01-01

    Current optoelectronics research and development of high-power, high-bandwidth laser transmitters, high-bandwidth, high-sensitivity optical receivers, pointing, acquisition and tracking components, and experimental and theoretical system modeling at the NASA Goddard Space Flight Center is reviewed. Program hardware and space flight milestones are presented. It is believed that these experiments will pave the way for intersatellite optical communications links for both the NASA Advanced Tracking and Data Relay Satellite System and commercial users in the 21st century.

  6. Carfentanil and xylazine for immobilization of moose (Alces alces) on Isle Royale.

    PubMed

    Seal, U S; Schmitt, S M; Peterson, R O

    1985-01-01

    Twenty-one moose were captured on Isle Royale between 28 May and 2 June 1984 at licks on the western end of the island. The animals were darted, at ranges of 10 to 35 m, with 3-cc dart syringes containing 3 or 4 mg of carfentanil and 100 or 175 mg of xylazine. Three animals were drugged with carfentanil alone. Immobilization time ranged from 2.5 to 6 min. There was no excitement phase evident in 18 of the animals and they rarely moved more than 30 m after darting. Reversal was begun at 30 to 90 min after darting using naloxone and diprenorphine given intramuscularly (i.m.) and intravenously (i.v.). Recovery time varied from 10 min to 3 hr with the longer times occurring at the higher doses of immobilizing drugs. Two animals died within 30 hr, one as the result of aspiration of rumen contents and the other was unable to get on its feet and was euthanized. Analysis of blood samples from the 18 moose immobilized with the drug combination yielded hemoglobin values of 13.1 +/- 0.3 g/dl, hematocrit: 37.6 +/- 0.7%, red blood cells: 5.46 +/- 0.1 million/microliter, leucocytes: 6.1 +/- 0.4 thousand/microliter, and serum urea nitrogen: 29.3 +/- 1.6 mg/dl. Our experience indicated that quiet, undisturbed moose can be immobilized with 3 mg carfentanil and 100 mg or less of xylazine.

  7. Eclipse-induced wind changes over the British Isles on the 20 March 2015

    PubMed Central

    2016-01-01

    The British Isles benefits from dense meteorological observation networks, enabling insights into the still-unresolved effects of solar eclipse events on the near-surface wind field. The near-surface effects of the solar eclipse of 20 March 2015 are derived through comparison of output from the Met Office’s operational weather forecast model (which is ignorant of the eclipse) with data from two meteorological networks: the Met Office’s land surface station (MIDAS) network and a roadside measurement network operated by Vaisala. Synoptic-evolution relative calculations reveal the cooling and increase in relative humidity almost universally attributed to eclipse events. In addition, a slackening of wind speeds by up to about 2 knots in already weak winds and backing in wind direction of about 20° under clear skies across middle England are attributed to the eclipse event. The slackening of wind speed is consistent with the previously reported boundary layer stabilization during eclipse events. Wind direction changes have previously been attributed to a large-scale ‘eclipse-induced cold-cored cyclone’, mountain slope flows, and changes in the strength of sea breezes. A new explanation is proposed here by analogy with nocturnal wind changes at sunset and shown to predict direction changes consistent with those observed. This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’. PMID:27550759

  8. Age, growth, maturity, and fecundity of 'humper' lake trout, Isle Royale, Lake Superior

    USGS Publications Warehouse

    Rahrer, Jerold F.

    1965-01-01

    Humper lake trout are one of the several races or subpopulations of lake trout in Lake Superior. This study is based on 3,705 fish collected on a reef south of Isle Royale near the eastern end. The mean lengths of humper trout from commercial gill nets were smaller than those of lean lake trout. Members of age-groups VII, VIII, and IX represented 81.5 per cent of the commercial humper catch. The body-scale relation was described by two intersecting straight lines. The weight of humper trout increased as the 3.282 power of the length. Growth in length was slow and ranged from 1.6 to 3.5 inches per year. Annual increments were greatest in the first, sixth, and seventh years. Growth in weight was also slow but increased each year. Humper trout became legal (1 1/2 pounds) in the eighth year of life and reached 5 pounds in 11 years. All fish longer than 19.1 inches and older than age-group VIII were mature; the shortest mature fish were: males, 12.7 inches; females, 14.7 inches. At minimum legal size, 98 per cent of the males and 56 per cent of the females were mature. Humper trout produced an average of 1,351 eggs per fish or 516 per pound.

  9. Impact of CO2 emissions on the geoecological state of landscapes of the British Isles: carbon footprint versus the assimilation potential

    NASA Astrophysics Data System (ADS)

    Romanova, Emma; Bulokhov, Anton; Arshinova, Marina

    2017-04-01

    The geoecological state of landscapes is determined by the type and intensity of anthropogenic impacts, the ability of geosystems to sustain them and the number of population living within a particular landscape unit. The main sources of CO2 emissions are thermal power plants, industrial facilities, transport and waste utilization. In Great Britain 163 enterprises produce 254.7 MMT CO2Eq. and 20 enterprises in Ireland - 17.8 MMT CO2Eq. Total transport emissions are 122 MMT CO2Eq. Utilization of solid wastes collected on the British Isles produces about 4.2 MMT CO2Eq. The spatial pattern of CO2 sources within the landscapes is particularly mosaic. Among the indicators which characterize the capacity of landscapes to neutralize wastes the assimilation potential (AP) is particularly important. The neutralization is based on the process of sequestration of gaseous substances, i.e. their accumulation in leaves, branches and stocks during respiration and growth of trees and in water bodies by aquatic organisms. Thus the AP is calculated basing on the area of forests and wetlands which perform the regulating services in landscapes. Total absorbing capacity of forests of the British Isles is 6.805 MMT CO2Eq. Inland waters cover 0.01% of the territory and their assimilating role is minor. The evaluation procedure includes several analytical steps: 1) inventory of the volumes of CO2 emissions by all anthropogenic sources within the borders of natural geosystems; 2) calculation of the area of CO2 assimilation in landscapes and the maximum possible volumes of CO2 sequestration; 3) comparison of the volumes of emissions and the assimilation potential of each landscape, classification of landscapes into debtors (with the deficit of AP) and creditors (with surplus AP); 4) calculation of population in each landscape; 5) risk assessment for the inhabitants living within landscapes-debtors; 6) classification and mapping of landscapes according to their geoecological state. The

  10. Population Structure and Abundance of Arsenite-Oxidizing Bacteria along an Arsenic Pollution Gradient in Waters of the Upper Isle River Basin, France▿ †

    PubMed Central

    Quéméneur, Marianne; Cébron, Aurélie; Billard, Patrick; Battaglia-Brunet, Fabienne; Garrido, Francis; Leyval, Corinne; Joulian, Catherine

    2010-01-01

    Denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR (qPCR) were successfully developed to monitor functional aoxB genes as markers of aerobic arsenite oxidizers. DGGE profiles showed a shift in the structure of the aoxB-carrying bacterial population, composed of members of the Alpha-, Beta- and Gammaproteobacteria, depending on arsenic (As) and Eh levels in Upper Isle River Basin waters. The highest aoxB gene densities were found in the most As-polluted oxic surface waters but without any significant correlation with environmental factors. Arsenite oxidizers seem to play a key role in As mobility in As-impacted waters. PMID:20453153

  11. An advanced OBP-based payload operating in an asynchronous network for future data relay satellites utilising CCSDS-standard data structures

    NASA Technical Reports Server (NTRS)

    Grant, M.; Vernucci, A.

    1991-01-01

    A possible Data Relay Satellite System (DRSS) topology and network architecture is introduced. An asynchronous network concept, whereby each link (Inter-orbit, Inter-satellite, Feeder) is allowed to operate on its own clock, without causing loss of information, in conjunction with packet data structures, such as those specified by the CCSDS for advanced orbiting systems is discussed. A matching OBP payload architecture is described, highlighting the advantages provided by the OBP-based concept and then giving some indications on the OBP mass/power requirements.

  12. Conceptual communications system design in the 25.25-27.5 and 37.0-40.5 GHz frequency bands

    NASA Technical Reports Server (NTRS)

    Thompson, Michael W.

    1993-01-01

    Future space applications are likely to rely heavily on Ka-band frequencies (20-40 GHz) for communications traffic. Many space research activities are now conducted using S-band and X-band frequencies, which are becoming congested and require a degree of pre-coordination. In addition to providing relief from frequency congestion, Ka-band technologies offer potential size, weight, and power savings when compared to lower frequency bands. The use of the 37.0-37.5 and 40.0-40.5 GHz bands for future planetary missions was recently approved at the 1992 World Administrative Radio Conference (WARC-92). WARC-92 also allocated the band 25.25-27.5 GHz to the Intersatellite Service on a primary basis to accommodate Data Relay Satellite return link requirements. Intersatellite links are defined to be between artificial satellites and thus a communication link with the surface of a planetary body, such as the moon, and a relay satellite orbiting that body are not permitted in this frequency band. This report provides information about preliminary communications system concepts for forward and return links for earth-Mars and earth-lunar links using the 37.0-37.5 (return link) and 40.0-40.5 (forward link) GHz frequency bands. In this study we concentrate primarily on a conceptual system for communications between earth and a single lunar surface terminal (LST), and between earth and a single Mars surface terminal (MST). Due to large space losses, these links have the most stringent link requirements for an overall interplanetary system. The earth ground station is assumed to be the Deep Space Network (DSN) using either 34 meter or 70 meter antennas. We also develop preliminary communications concepts for a space-to-space system operating at near 26 GHz. Space-to-space applications can encompass a variety of operating conditions, and we consider several 'typical' scenarios described in more detail later in this report. Among these scenarios are vehicle-to-vehicle communications

  13. Free-space laser communication technologies III; Proceedings of the Meeting, Los Angeles, CA, Jan. 21, 22, 1991

    NASA Technical Reports Server (NTRS)

    Begley, David L. (Editor); Seery, Bernard D. (Editor)

    1991-01-01

    The present volume on free-space laser communication technologies discusses system analysis, performance, and applications, pointing, acquisition, and tracking in beam control, laboratory demonstration systems, and transmitter and critical component technologies. Attention is given to a space station laser communication transceiver, meeting intersatellite links mission requirements by an adequate optical terminal design, an optical approach to proximity-operations communications for Space Station Freedom, and optical space-to-ground link availability assessment and diversity requirements. Topics addressed include nonmechanical steering of laser beams by multiple aperture antennas, a free-space simulator for laser transmission, heterodyne acquisition and tracking in a free-space diode laser link, and laser terminal attitude determination via autonomous star tracking. Also discussed are stability considerations in relay lens design for optical communications, liquid crystals for lasercom applications, and narrowband optical interference filters.

  14. Role of endogenous insulin gene enhancer protein ISL-1 in angiogenesis

    PubMed Central

    Xiong, Si-qi; Jiang, Hai-bo; Li, Yan-xiu; Li, Hai-bo; Xu, Hui-zhuo; Wu, Zhen-kai; Zheng, Wei

    2016-01-01

    Objective To elucidate the role of insulin gene enhancer protein ISL-1 (Islet-1) in angiogenesis and regulation of vascular endothelial growth factor (VEGF) expression in vitro and in vivo. Methods siRNA targeting Islet-1 was transfected to human umbilical vein endothelial cell lines (HUVECs). The expression of Islet-1 and VEGF in the cultured cells was measured using real-time PCR and immunoblotting. 3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide; thiazolyl blue (MTT) assay was used to analyze the proliferation of HUVECs affected by Islet-1. Wound healing and Transwell assays were conducted to assess the motility of HUVECs. The formation of capillary-like structures was examined using growth factor–reduced Matrigel. siRNA targeting Islet-1 was intravitreally injected into the murine model of oxygen-induced retinopathy (OIR). Retinal neovascularization was evaluated with angiography using fluorescein-labeled dextran and then quantified histologically. Real-time PCR and immunoblotting were used to determine whether local Islet-1 silencing affected the expression of Islet-1 and VEGF in murine retinas. Results The expression of Islet-1 and VEGF in HUVECs was knocked down by siRNA. Reduced endogenous Islet-1 levels in cultured cells greatly inhibited the proliferation, migration, and tube formation in HUVECs in vitro. Retinal neovascularization following injection of Islet-1 siRNA was significantly reduced compared with that of the contralateral control eye. Histological analysis indicated that the neovascular nuclei protruding into the vitreous cavity were decreased. Furthermore, the Islet-1 and VEGF expression levels were downregulated in murine retinas treated with siRNA against Islet-1. Conclusions Reducing the expression of endogenous Islet-1 inhibits proliferation, migration, and tube formation in vascular endothelial cells in vitro and suppresses retinal angiogenesis in vivo. Endogenous Islet-1 regulates angiogenesis via VEGF. PMID:27994436

  15. Tsunami Evacuation Exercises: the Case of Heraklion, Crete Isl., Greece

    NASA Astrophysics Data System (ADS)

    Triantafyllou, I.; Charalampakis, M.; Bocchini, G. M.; Novikova, T.; Papadopoulos, G. A.

    2016-12-01

    Effective tsunami evacuation requires appropriate awareness as regards good shelters selection. Field exercises may improve public awareness. A field exercise was organized in Heraklion, Crete Isl., in 2016. The area is part of the Hellenic Arc which is the most active structure in the Mediterranean. Large earthquakes triggered tsunamis that hit Heraklion in the past, such in AD 1303. After selecting various fault models, simulation of the 1303 tsunami showed important inundation zone in Heraklion. For the exercise needs a team of 30 volunteers was divided in 3 groups of 10 people each. Everyone was equipped with a mobile phone and a GPS device. The 3 groups were gathered in 3 coastal spots Heraklion situated 400 m apart each other. The scenario was that immediately after receiving in their mobile a tsunami warning message they will set on their personal GPS device and start evacuating inland on the best way they believed to do so. In each group, only 5 out of 10 volunteers were notified beforehand that the Eleftherias Square, located inland at distance satisfying evacuation needs in case of repeat of the 1303 tsunami, would be a good shelter to go. Using the Road Graph Plugin of QGIS, we calculated the shortest path distances which found equal to 800, 700 and 680 m. Adopting average velocity of 3 km/h we found that these distances can be covered within 18, 16 and 15 min, respectively. The routes towards the settlement spots as well as the times needed to arrive there by each one of the 30 volunteers were recorded by their personal GPS devices. The processing of the GPS tracks and their comparison with the theoretical routes and times showed good evacuation performance which is encouraging for the next phases of the Heraklion tsunami hazard mitigation program. This is contribution to the EU-FP7 projects ZIP (Zooming In between Plates, grant no: 604713, 2013) and ASTARTE (Assessment, Strategy And Risk Reduction for Tsunamis in Europe), grant no: 603839, 2013.

  16. Lap time simulation and design optimisation of a brushed DC electric motorcycle for the Isle of Man TT Zero Challenge

    NASA Astrophysics Data System (ADS)

    Dal Bianco, N.; Lot, R.; Matthys, K.

    2018-01-01

    This works regards the design of an electric motorcycle for the annual Isle of Man TT Zero Challenge. Optimal control theory was used to perform lap time simulation and design optimisation. A bespoked model was developed, featuring 3D road topology, vehicle dynamics and electric power train, composed of a lithium battery pack, brushed DC motors and motor controller. The model runs simulations over the entire ? or ? of the Snaefell Mountain Course. The work is validated using experimental data from the BX chassis of the Brunel Racing team, which ran during the 2009 to 2015 TT Zero races. Optimal control is used to improve drive train and power train configurations. Findings demonstrate computational efficiency, good lap time prediction and design optimisation potential, achieving a 2 minutes reduction of the reference lap time through changes in final drive gear ratio, battery pack size and motor configuration.

  17. Latent volcanic heat and further unique aspects of early diagenetic stratiform copper mineralization in the White Pine-Presque Isle District, northern Michigan

    NASA Astrophysics Data System (ADS)

    Brown, Alex C.

    2018-06-01

    The curious occurrence of copper-rich early diagenetic sediment-hosted stratiform copper mineralization in the finest-grained facies of Nonesuch greybeds in northern Michigan has been previously attributed to the warming of cupriferous brines in the footwall Copper Harbor Conglomerate by latent volcanic heat from the subjacent Porcupine Volcanics shield volcano. That anomalous footwall warming is employed here to explain other unique aspects of the White Pine-Presque Isle mineralization: the abrupt downward sulfide zoning from disseminated pyrite to chalcocite across the top of the cupriferous zone; the absence of bornite and chalcopyrite in the cupriferous zone proper; and the essential absence of pseudomorphs after pyrite euhedra and framboidal aggregates within the cupriferous zone proper, as well as the relatively coarse-grained character of disseminated chalcocite in the cupriferous zone.

  18. Microplastic in beach sediments of the Isle of Rügen (Baltic Sea) - Implementing a novel glass elutriation column.

    PubMed

    Hengstmann, Elena; Tamminga, Matthias; Vom Bruch, Constantin; Fischer, Elke Kerstin

    2018-01-01

    To extent the understanding on microplastics in the marine environment we performed a case study at four beaches on the Isle of Rügen considering abundance and spatial distribution of microplastics in beach sediments. For the analysis, density separation via a glass elutriation column was implemented. In advance, efficiencies were tested for two polymers, being not buoyant in water. Recovery rates of 80% for PET and 72% for PVC particles in sandy samples were achieved. A median abundance of 88.10 (Q 1 =55.01/Q 3 =114.72) microplastic particles per kg dry sediment or 2862.56 (Q 1 =1787.34/Q 3 =3727.28) particles per m 2 was found at the beaches on Rügen. Fibers were more abundant than fragments at all beaches. In this study, no statistically significant differences but only tendencies were determined between the beaches with different exposition and anthropogenic activity as well as for distribution patterns which showed that microplastic fragments accumulate in topographic depressions, similar to macrolitter items. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Reduced electrical bandwidth receivers for direct detection 4-ary PPM optical communication intersatellite links

    NASA Technical Reports Server (NTRS)

    Davidson, Frederic M.; Sun, Xiaoli

    1993-01-01

    One of the major sources of noise in a direct detection optical communication receiver is the shot noise due to the quantum nature of the photodetector. The shot noise is signal dependent and is neither Gaussian nor wide sense stationary. When a photomultiplier tube (PMT) or an avalanche photodiode (APD) is used, there is also a multiplicative excess noise due to the randomness of the internal photodetector gain. Generally speaking, the radio frequency (RF) communication theory cannot be applied to direct detection optical communication systems because noise in RF communication systems is usually additive and Gaussian. A receiver structure which is mathematically optimal for signal dependent shot noise is derived. Several suboptimal receiver structures are discussed and compared with the optimal receiver. The objective is to find a receiver structure which is easy to implement and gives close to optimal performance.

  20. The paleohydrology of Lower Cretaceous seasonal wetlands, Isle of Wight, southern England

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wright, V.P.; Taylor, K.G.; Beck, V.H.

    2000-05-01

    The floodplain deposits of the Wealden Group (Lower Cretaceous) of the Isle of Wight, southern England, were formed in a seasonal wetland setting, a type of environment widespread today along higher-order tropical and subtropical river systems but rarely identified in the geological record. The unit consists of four main lithofacies: sheet sandstones with dinosaur footprint casts; green-gray mudstones with vertebrate remains, abundant lignite, pyrite, and siderite; spectacularly color-mottled mudstones with goethite and locally pseudo-anticlines; and red mudstones with pseudo-anticlines, hematite, and carbonate nodules. The sheet sandstones are interpreted as crevasse deposits; the green-gray mudstones were deposited in shallow ponds onmore » the floodplain, which acted as sinks for debris released by local floods following wildfires; the mottled mudstones represent surface-water gley soils formed in seasonally waterlogged areas; and the red mudstones resemble present-day Vertisols that formed on topographically elevated areas only intermittently flooded. These mudstones show vertical transitions from one to another, and although they could be interpreted as components of simple catenas, the absence of associated facies changes implies that topographic differences were not the only control. It is proposed that these three mudstone types formed as seasonal wetland catenas, in which differences in soil drainage conditions resulted from variations in the flooding hydroperiod affecting areas with minor relief differences, rather than drainage variability simply reflecting static topographic differences. Such seasonal wetland systems are rarely documented in the stratigraphic record despite being a widespread environment in present-day tropical regions, and the Wealden deposits are used to identify criteria for the recognition of this important environment in the rock record. These southern English wetlands are compared with other Lower Cretaceous wetlands from

  1. Low {delta}{sup 18}O magma, Isle of Skye, Scotland: Evidence from zircons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gilliam, C.E.; Valley, J.W.

    1997-12-01

    Zircons in Tertiary granitic rocks from the Isle of Skye, Scotland were resistant to measurable oxygen isotope exchange during intense hydrothermal activity in the subvolcanic environment. Five granite bodies from the Western Red Hills complex were investigated; four have {sup 18}O (Zrc) = 4.1 {+-} 0.2{per_thousand} (VSMOW) while the fifth, which intruded before major cauldron subsidence, is 2{per_thousand} lower. Zircons from Lewisian gneiss are visually and isotopically distinct indicating that zircons in the granite are not xenocrysts from the Lewisian basement. Analysis of different magnetic and size fractions of zircon shows no significant correlation to {delta}{sup 18}O supporting the conclusionmore » that these values represent the true magmatic compositions and that the Western Red Hills granites intruded as low {delta}{sup 18}O magmas with a whole rock {delta}{sup 18}O {le} 6.0%. Quartz separates from four granites are close to the calculated magmatic values in {delta}{sup 18}O, but in the fifth, values are 5% lower indicating variable exchange of quartz with low {delta}{sup 18}O heated meteoric waters. These results might be explained by magmatic interaction with hydrothermally altered crust early in the evolution of the granites, before crystallization of zircon, followed by interaction with later hydrothermal fluids. Alternatively, independent evidence for low {delta}{sup 18}O mafic magmatism in NW Scotland suggests the presence of large quantities of low {delta}{sup 18}O subducted ocean crust in the subcontinental lithosphere that could contaminate or be the source of low {delta}{sup 18}O mantle-derived melts. 31 refs., 4 figs., 1 tab.« less

  2. Study of LEO-SAT microwave link for broad-band mobile satellite communication system

    NASA Technical Reports Server (NTRS)

    Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

    1993-01-01

    In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

  3. Optoelectronic devices product assurance guideline for space application

    NASA Astrophysics Data System (ADS)

    Bensoussan, A.; Vanzi, M.

    2017-11-01

    New opportunities are emerging for the implementation of hardware sub-systems based on OptoElectronic Devices (OED) for space application. Since the end of this decade the main players for space systems namely designers and users including Industries, Agencies, Manufacturers and Laboratories are strongly demanding of adequate strategies to qualify and validate new optoelectronics products and sub-systems [1]. The long term space application mission will require to address either inter-satellite link (free space communication, positioning systems, tracking) or intra-satellite connectivity/flexibility/reconfigurability or high volume of data transfer between equipment installed into payload.

  4. Ephemeroptera, Plecoptera, and Trichoptera on Isle Royale National Park, USA, compared to mainland species pool and size distribution

    PubMed Central

    DeWalt, R. Edward; South, Eric J.

    2015-01-01

    Abstract Extensive sampling for aquatic insects was conducted in the orders Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) (EPT) of Isle Royale National Park (ISRO), Michigan, United States of America, during summer 2013. The island was ice covered until 8,000 to 10,000 years ago and is isolated by 22–70 km distance from the mainland. Two hypotheses were examined: that ISRO EPT richness would be much reduced from the mainland, and that the species colonizing ISRO would be of smaller size than mainland, adults presumably using updrafts to bridge the distance from mainland sources. Data sets were developed for known mainland EPT species and size for those species. The first hypothesis was confirmed with the mainland species pool consisting of 417 EPT, while ISRO is known to support 73 species. Richness of EPT is directly related to the number of specimens examined. Small streams supported five EPT species, while 15–25 species were found in larger streams. Lakeshores had intermediate diversity. The second hypothesis was substantiated for stoneflies, but not for mayflies or caddisflies. Stoneflies apparently are poorer fliers than either of the other two orders. PMID:26692811

  5. Ephemeroptera, Plecoptera, and Trichoptera on Isle Royale National Park, USA, compared to mainland species pool and size distribution.

    PubMed

    DeWalt, R Edward; South, Eric J

    2015-01-01

    Extensive sampling for aquatic insects was conducted in the orders Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) (EPT) of Isle Royale National Park (ISRO), Michigan, United States of America, during summer 2013. The island was ice covered until 8,000 to 10,000 years ago and is isolated by 22-70 km distance from the mainland. Two hypotheses were examined: that ISRO EPT richness would be much reduced from the mainland, and that the species colonizing ISRO would be of smaller size than mainland, adults presumably using updrafts to bridge the distance from mainland sources. Data sets were developed for known mainland EPT species and size for those species. The first hypothesis was confirmed with the mainland species pool consisting of 417 EPT, while ISRO is known to support 73 species. Richness of EPT is directly related to the number of specimens examined. Small streams supported five EPT species, while 15-25 species were found in larger streams. Lakeshores had intermediate diversity. The second hypothesis was substantiated for stoneflies, but not for mayflies or caddisflies. Stoneflies apparently are poorer fliers than either of the other two orders.

  6. Death on a strange isle: the mortality of the stone workers of Purbeck in the nineteenth century.

    PubMed

    Hinde, Andrew; Edgar, Michael

    2010-01-01

    This paper analyses the mortality of a group of rural workers in an extractive industry, the stone quarriers of the Isle of Purbeck in the southern English county of Dorset. The analysis uses a database created by nominal record linkage of the census enumerators' books and the Church of England baptism and burial registers to estimate age-specific death rates at all ages for males and females, and hence statistics such as the expectation of life at birth. The results are compared with mortality statistics published by the Registrar General of England and Wales (on the basis of the civil registers of deaths) for the registration district of Wareham, in which Purbeck is situated. The stone quarriers had heavier mortality levels than the rest of the population of Purbeck. Closer inspection, however, reveals that their high mortality was confined to males, and was almost entirely due to especially high mortality among boys aged less than five years. In contrast to the experience of coal and metal ore miners, adult male mortality among stone workers was no higher than that among the general population. The final section of the paper considers possible explanations for these results, and suggests that excess mortality among boys in Purbeck from lung diseases might have been responsible.

  7. Inter-satellite optical communications: from SILEX to next generation systems

    NASA Astrophysics Data System (ADS)

    Laurent, Bernard; Planche, Gilles; Michel, Cyril

    2004-06-01

    The continuous growth in data rate demand, the importance of real time commanding and real time access to the information for diverse civilian and military applications as well as the in-orbit demonstration of optical communication have led to boost the interest of such systems for future applications. After a presentation of the different fields of application and their associated performances requirements, this paper presents the possible optical link candidates. Then, the architecture, the design and the performances of new optical terminal generations, which profits from SILEX experience and the use of new technologies such as SiC and APS, are detailed. This new optimised generation, highly simplified with respect to SILEX terminals and dimensioned to offer higher data rate, presents attractive mass, volume and power characteristics compatible with a simple accommodation on the host vehicle.

  8. A confidential enquiry into emergency hospital admissions on the Isle of Wight, UK.

    PubMed Central

    Denman-Johnson, M; Bingham, P; George, S

    1997-01-01

    OBJECTIVES: To quantify the proportion of potentially avoidable emergency short term admissions to hospital and to identify ways in which they could have been avoided. DESIGN: Confidential enquiry by peer review group. SETTING: St Mary's Hospital, Newport, Isle of Wight. SUBJECTS: All emergency, short term admissions (discharged home within five days) to medicine, general surgery, orthopaedics, gynaecology, ENT, and ophthalmology specialties for 28 (24 hour) days over a six month period in 1994. MAIN OUTCOME MEASURES: Appropriateness of admissions decided by the peer group, the peer group's opinion of ideal management, and the patients' views on the appropriateness of their admission. RESULTS: Altogether 139 cases satisfied the inclusion criteria. Complete data were collected on 123 cases and the peer group considered 81 in the time available. Twenty one of the 81 cases were judged "potentially avoidable". These represent 9.5% (95% CI 6.3%, 13.5%) of short term admissions to the specialties studied. The peer group considered that seven of 10 patients referred by a general practitioner (GP) could have been managed by the GP alone and that the remaining three had been referred appropriately but need not have been admitted had a consultant opinion been available in the accident and emergency (A&E) department. Two of the 10 would have required home support to avoid hospital admission. Five of 11 patients who referred themselves to A&E could have been discharged home without admission and without recourse to a specialist opinion. The remaining six could have been discharged had a consultant opinion been available in A&E. CONCLUSIONS: Urgent consultant opinion, either in A&E or in an outpatient clinic, would have prevented most of these inappropriate admissions, and home support would have expedited the ability to discharge some patients. Further research into the costs and benefits of methods for providing these services is needed urgently. PMID:9328544

  9. Infectious pancreatic necrosis virus in Atlantic salmon, Salmo salar L., post-smolts in the Shetland Isles, Scotland: virus identification, histopathology, immunohistochemistry and genetic comparison with Scottish mainland isolates.

    PubMed

    Smail, D A; Bain, N; Bruno, D W; King, J A; Thompson, F; Pendrey, D J; Morrice, S; Cunningham, C O

    2006-01-01

    During mid-June 1999 peak mortalities of 11% of the total stock per week were seen at a sea cage site of Atlantic salmon, Salmo salar L., post-smolts in the Shetland Isles, Scotland. Virus was isolated on chinook salmon embryo (CHSE) cells in a standard diagnostic test and infectious pancreatic necrosis virus (IPNV) identified by enzyme-linked immunosorbent assay. IPNV was confirmed as serogroup A by a cell immunofluorescent antibody test using the cross-reactive monoclonal antibody AS-1. Four weeks after the main outbreak, virus titres in surviving moribund fish were assayed at >10(10) TCID50 g(-1) kidney. Histopathology of moribund fish was characterized by pancreatic acinar cell necrosis and a marked catarrhal enteritis of the intestinal mucosa. In the liver, necrosis, leucocytic infiltration and a generalized cell vacuolation were noted. IPNV-specific immunostaining was demonstrated in pancreas, liver, heart, gill and kidney tissue. The nucleotide sequence of the coding region of segment A was determined from the Shetland isolate. A 1180 bp fragment of the VP2 gene of this isolate was compared with a 1979 reference isolate from mainland Scottish Atlantic salmon, La/79 and another more recent mainland isolate, 432/00. Both A2 isolates were derived from carrier fish without signs of IPN and serotyped by a plaque neutralization test. The Shetland isolate shows a different nucleotide and amino acid sequence compared with the two isolates from carrier fish. These latter isolates showed identical amino acid sequences in the fragment examined, despite the 21 years separating the isolations. Sequence comparisons with other A2 (Sp) isolates on the database confirm all three Scottish isolates are A2 (Sp).

  10. Variations in the concentration of plutonium, strontium-90 and total alpha-emitters in human teeth collected within the British Isles.

    PubMed

    O'Donnell, R G; Mitchell, P I; Priest, N D; Strange, L; Fox, A; Henshaw, D L; Long, S C

    1997-08-18

    Concentrations of plutonium-239, plutonium-240, strontium-90 and total alpha-emitters have been measured in children's teeth collected throughout Great Britain and Ireland. The concentrations of plutonium and strontium-90 were measured in batched samples, each containing approximately 50 teeth, using low-background radiochemical methods. The concentrations of total alpha-emitters were determined in single teeth using alpha-sensitive plastic track detectors. The results showed that the average concentrations of total alpha-emitters and strontium-90 were approximately one to three orders of magnitude greater than the equivalent concentrations of plutonium-239,240. Regression analyses indicated that the concentrations of plutonium, but not strontium-90 or total alpha-emitters, decreased with increasing distance from the Sellafield nuclear fuel reprocessing plant-suggesting that this plant is a source of plutonium contamination in the wider population of the British Isles. Nevertheless, the measured absolute concentrations of plutonium (mean = 5 +/- 4 mBq kg-1 ash wt.) were so low that they are considered to present an insignificant radiological hazard.

  11. Marine litter abundance and distribution on beaches on the Isle of Rügen considering the influence of exposition, morphology and recreational activities.

    PubMed

    Hengstmann, Elena; Gräwe, Dennis; Tamminga, Matthias; Fischer, Elke Kerstin

    2017-02-15

    The abundance, weight and composition of marine debris were determined at the northwest coast of the Isle of Rügen in 2015. A total number of 1115 macrolitter items were registered, resulting in an abundance of 304±88.96 items per 100m of beach length and therefore being greater than the abundances found for other beaches at the Baltic Sea. Macrolitter items were predominantly composed of plastic, on average 83%. The four beaches under investigation have different exposition as well as touristic levels. The differing influence of wind and water currents as well as recreational activities on the macrolitter at these beaches was detectable. The distribution of items within a beach segment was analyzed by implementing D-GPS and drone aerial photography. The results of this analysis suggested that the identity of the substrate as well as the presence of vegetation are both major influencing factors in the macrolitter distribution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. NASAs EDSN Aims to Overcome the Operational Challenges of CubeSat Constellations and Demonstrate an Economical Swarm of 8 CubeSats Useful for Space Science Investigations

    NASA Technical Reports Server (NTRS)

    Smith, Harrison Brodsky; Hu, Steven Hung Kee; Cockrell, James J.

    2013-01-01

    Operators of a constellation of CubeSats have to confront a number of daunting challenges that can be cost prohibitive, or operationally prohibitive, to missions that could otherwise be enabled by a satellite constellation. Challenges including operations complexity, intersatellite communication, intersatellite navigation, and time sharing tasks between satellites are all complicated by operating with the usual CubeSat size, power, and budget constraints. EDSN pioneers innovative solutions to these problems as they are presented on the nano-scale satellite platform.

  13. An Enhancer Near ISL1 and an Ultraconserved Exon of PCBP2 areDerived from a Retroposon

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bejerano, Gill; Lowe, Craig; Ahituv, Nadav

    2005-11-27

    Hundreds of highly conserved distal cis-regulatory elementshave been characterized to date in vertebrate genomes1. Many thousandsmore are predicted based on comparative genomics2,3. Yet, in starkcontrast to the genes they regulate, virtually none of these regions canbe traced using sequence similarity in invertebrates, leaving theirevolutionary origin obscure. Here we show that a class of conserved,primarily non-coding regions in tetrapods originated from a novel shortinterspersed repetitive element (SINE) retroposon family that was activein Sarcopterygii (lobe-finned fishes and terrestrial vertebrates) in theSilurian at least 410 Mya4, and, remarkably, appears to be recentlyactive in the "living fossil" Indonesian coelacanth, Latimeriamenadoensis. We show that onemore » copy is a distal enhancer, located 500kbfrom the neuro-developmental gene ISL1. Several others represent new,possibly regulatory, alternatively spliced exons in the middle ofpre-existing Sarcopterygian genes. One of these is the>200bpultraconserved region5, 100 percent identical in mammals, and 80 percentidentical to the coelacanth SINE, that contains a 31aa alternativelyspliced exon of the mRNA processing gene PCBP26. These add to a growinglist of examples7 in which relics of transposable elements have acquireda function that serves their host, a process termed "exaptation"8, andprovide an origin for at least some of the highly-conservedvertebrate-specific genomic sequences recently discovered usingcomparative genomics.« less

  14. Japan's telecommunications - New initiatives in space communications

    NASA Astrophysics Data System (ADS)

    Iida, T.

    1992-04-01

    Despite recent advances in optical transmission technology, intensive R&D work in the field of satellite communications is now being undertaken in Japan. It is believed that satellites offer advantages in several important areas, including wide coverage broadcasting, immediacy of service, suitability for the implementation of HDTV, and advantages in disaster communications and other social services. Here, some experimental projects in the field of satellite communications planned in Japan for the 1990s are summarized. In particular, attention is given to broadcast satellite development, intersatellite links, advanced mobile communication concepts, large antenna assembly experiment, small satellite R&D, and Pan-Pacific information network experiment.

  15. Design and Validation of High Date Rate Ka-Band Software Defined Radio for Small Satellite

    NASA Technical Reports Server (NTRS)

    Xia, Tian

    2016-01-01

    The Design and Validation of High Date Rate Ka- Band Software Defined Radio for Small Satellite project will develop a novel Ka-band software defined radio (SDR) that is capable of establishing high data rate inter-satellite links with a throughput of 500 megabits per second (Mb/s) and providing millimeter ranging precision. The system will be designed to operate with high performance and reliability that is robust against various interference effects and network anomalies. The Ka-band radio resulting from this work will improve upon state of the art Ka-band radios in terms of dimensional size, mass and power dissipation, which limit their use in small satellites.

  16. The network and transmission of based on the principle of laser multipoint communication

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Liu, Xianzhu; Jiang, Huilin; Hu, Yuan; Jiang, Lun

    2014-11-01

    Space laser communication is the perfectly choose to the earth integrated information backbone network in the future. This paper introduces the structure of the earth integrated information network that is a large capacity integrated high-speed broadband information network, a variety of communications platforms were densely interconnected together, such as the land, sea, air and deep air users or aircraft, the technologies of the intelligent high-speed processing, switching and routing were adopt. According to the principle of maximum effective comprehensive utilization of information resources, get accurately information, fast processing and efficient transmission through inter-satellite, satellite earth, sky and ground station and other links. Namely it will be a space-based, air-based and ground-based integrated information network. It will be started from the trends of laser communication. The current situation of laser multi-point communications were expounded, the transmission scheme of the dynamic multi-point between wireless laser communication n network has been carefully studied, a variety of laser communication network transmission schemes the corresponding characteristics and scope described in detail , described the optical multiplexer machine that based on the multiport form of communication is applied to relay backbone link; the optical multiplexer-based on the form of the segmentation receiver field of view is applied to small angle link, the optical multiplexer-based form of three concentric spheres structure is applied to short distances, motorized occasions, and the multi-point stitching structure based on the rotation paraboloid is applied to inter-satellite communications in detail. The multi-point laser communication terminal apparatus consist of the transmitting and receiving antenna, a relay optical system, the spectroscopic system, communication system and communication receiver transmitter system. The communication forms of optical

  17. People of the British Isles: preliminary analysis of genotypes and surnames in a UK-control population

    PubMed Central

    Winney, Bruce; Boumertit, Abdelhamid; Day, Tammy; Davison, Dan; Echeta, Chikodi; Evseeva, Irina; Hutnik, Katarzyna; Leslie, Stephen; Nicodemus, Kristin; Royrvik, Ellen C; Tonks, Susan; Yang, Xiaofeng; Cheshire, James; Longley, Paul; Mateos, Pablo; Groom, Alexandra; Relton, Caroline; Bishop, D Tim; Black, Kathryn; Northwood, Emma; Parkinson, Louise; Frayling, Timothy M; Steele, Anna; Sampson, Julian R; King, Turi; Dixon, Ron; Middleton, Derek; Jennings, Barbara; Bowden, Rory; Donnelly, Peter; Bodmer, Walter

    2012-01-01

    There is a great deal of interest in a fine-scale population structure in the UK, both as a signature of historical immigration events and because of the effect population structure may have on disease association studies. Although population structure appears to have a minor impact on the current generation of genome-wide association studies, it is likely to have a significant part in the next generation of studies designed to search for rare variants. A powerful way of detecting such structure is to control and document carefully the provenance of the samples involved. In this study, we describe the collection of a cohort of rural UK samples (The People of the British Isles), aimed at providing a well-characterised UK-control population that can be used as a resource by the research community, as well as providing a fine-scale genetic information on the British population. So far, some 4000 samples have been collected, the majority of which fit the criteria of coming from a rural area and having all four grandparents from approximately the same area. Analysis of the first 3865 samples that have been geocoded indicates that 75% have a mean distance between grandparental places of birth of 37.3 km, and that about 70% of grandparental places of birth can be classed as rural. Preliminary genotyping of 1057 samples demonstrates the value of these samples for investigating a fine-scale population structure within the UK, and shows how this can be enhanced by the use of surnames. PMID:21829225

  18. People of the British Isles: preliminary analysis of genotypes and surnames in a UK-control population.

    PubMed

    Winney, Bruce; Boumertit, Abdelhamid; Day, Tammy; Davison, Dan; Echeta, Chikodi; Evseeva, Irina; Hutnik, Katarzyna; Leslie, Stephen; Nicodemus, Kristin; Royrvik, Ellen C; Tonks, Susan; Yang, Xiaofeng; Cheshire, James; Longley, Paul; Mateos, Pablo; Groom, Alexandra; Relton, Caroline; Bishop, D Tim; Black, Kathryn; Northwood, Emma; Parkinson, Louise; Frayling, Timothy M; Steele, Anna; Sampson, Julian R; King, Turi; Dixon, Ron; Middleton, Derek; Jennings, Barbara; Bowden, Rory; Donnelly, Peter; Bodmer, Walter

    2012-02-01

    There is a great deal of interest in a fine-scale population structure in the UK, both as a signature of historical immigration events and because of the effect population structure may have on disease association studies. Although population structure appears to have a minor impact on the current generation of genome-wide association studies, it is likely to have a significant part in the next generation of studies designed to search for rare variants. A powerful way of detecting such structure is to control and document carefully the provenance of the samples involved. In this study, we describe the collection of a cohort of rural UK samples (The People of the British Isles), aimed at providing a well-characterised UK-control population that can be used as a resource by the research community, as well as providing a fine-scale genetic information on the British population. So far, some 4000 samples have been collected, the majority of which fit the criteria of coming from a rural area and having all four grandparents from approximately the same area. Analysis of the first 3865 samples that have been geocoded indicates that 75% have a mean distance between grandparental places of birth of 37.3 km, and that about 70% of grandparental places of birth can be classed as rural. Preliminary genotyping of 1057 samples demonstrates the value of these samples for investigating a fine-scale population structure within the UK, and shows how this can be enhanced by the use of surnames.

  19. A comparison of lead pollution record in Sphagnum peat with known historical Pb emission rates in the British Isles and the Czech Republic

    NASA Astrophysics Data System (ADS)

    Novak, Martin; Erel, Yigal; Zemanova, Leona; Bottrell, Simon H.; Adamova, Marie

    Vertical Pb concentration gradients and isotope ratios ( 206Pb/ 207Pb, 208Pb/ 207Pb) are reported for five 210Pb-dated Sphagnum peat profiles. The studied peat bogs are in the British Isles (Thorne Moors, England; Mull, Scotland; and Connemara, Eire) and central Europe (Ocean, northern Czech Republic; Rybarenska slat, southern Czech Republic). Both the U.K. and the Czech Republic experienced maximum Pb emissions from Ag-Pb smelting around 1880. Pb emissions from coal burning peaked in 1955 in the U.K. and in the 1980s in the Czech Republic. In both countries, use of alkyl-lead additives to gasoline resulted in large Pb emissions between 1950 and 2000. We hypothesized that peaks in Pb emissions from smelting, coal burning and gasoline burning, respectively, should be mirrored in the peat profiles. However, a more complicated pattern emerged. Maximum annual Pb accumulation rates occurred in 1870 at Ocean, 1940 at Thorne Moors, 1988 at Rybarenska slat, and 1990 at Mull and Connemara. Atmospheric Pb inputs decreased in the order Thorne Moors ≥ Ocean > Rybarenska slat > Mull > Connemara. The Ocean bog was unique in the central European region in that its maximum Pb pollution dated back to the 19th century and coincided with maximum Pb smelting at Freiberg and Pribram. In contrast, numerous previously studied sites showed no Pb accumulation maximum in the 19th century, but increasing pollution until the 1980s. It remains unclear why Ocean did not record the regional peak in Pb emissions caused by high coal and gasoline burning around 1980, while an array of nearby bogs studied previously did record the 1980 coal/gasoline peak, but no 1880 smelting peak. Mean 206Pb/ 207Pb ratios of potential pollution sources were 1.07 and 1.11 for gasoline, 1.17 and 1.17 for local ores, and 1.18 and 1.19 for coal in the U.K. and the Czech Republic, respectively. The calculated percentages of gasoline-derived Pb in peat (≤55% for the British Isles and ≤63% for the Czech Republic

  20. General Review On The Investigations Conducted At Institute Saint-Louis (ISL) In The Field Of Holographic Nondestructive Testing

    NASA Astrophysics Data System (ADS)

    Smigielski, P.

    1982-10-01

    Among the various methods presently used in the field of nondestructive testing, optical holography is expected to become a very useful and promising tool in the near future. In fact, holography offers a number of advantages which should be briefly outlined here : direct and overall visualization of defects (disbonding, formation of cracks, inhomogeneities...) on large sufaces (of several square meters). Furthermore there is no interaction with the object under test and the surface to be studied has not to be treated. Finally holography is characterized by a high spatial resolution and a great sensitivity (it is possible to detect deformations as small as a few microns). In contrast to other modern techniques,holography is relatively unexpensive and can be used on-site with pulsed lasers. The general principles of holography and of methods using holographic interferometry will be recalled (double-exposure holographic interferometry, real-time holographic interferometry, "time-average" holographic interferometry). Thereafter the activities in which ISL is presently engaged will be reported briefly, that is laboratory feasibility tests and experiments conducted on-site in an industrial environment with the aid, in general, of pulsed ruby lasers : testing of adhesive bonding in solid propellant rockers and in aircraft structures, detection and observation of cracking in fatigue tests, visua-lization of the modes of vibration of mechanical structures, experiments conducted on air-craft subjected to maintenance checking, etc.

  1. An Update on the CCSDS Optical Communications Working Group

    NASA Technical Reports Server (NTRS)

    Edwards, Bernard L.; Schulz, Klaus-Juergen; Hamkins, Jonathan; Robinson, Bryan; Alliss, Randall; Daddato, Robert; Schmidt, Christopher; Giggebach, Dirk; Braatz, Lena

    2017-01-01

    International space agencies around the world are currently developing optical communication systems for Near Earth and Deep Space applications for both robotic and human rated spacecraft. These applications include both links between spacecraft and links between spacecraft and ground. The Interagency Operation Advisory Group (IOAG) has stated that there is a strong business case for international cross support of spacecraft optical links. It further concluded that in order to enable cross support the links must be standardized. This paper will overview the history and structure of the space communications international standards body, the Consultative Committee for Space Data Systems (CCSDS), that will develop the standards and provide an update on the proceedings of the Optical Communications Working Group within CCSDS. This paper will also describe the set of optical communications standards being developed and outline some of the issues that must be addressed in the next few years. The paper will address in particular the ongoing work on application scenarios for deep space to ground called High Photon Efficiency, for LEO to ground called Low Complexity, for inter-satellite and near Earth to ground called High Data Rate, as well as associated atmospheric measurement techniques and link operations concepts.

  2. "Is It Really for Talking?": The Implications of Associating a Minority Language with the School

    ERIC Educational Resources Information Center

    Smith-Christmas, Cassie

    2017-01-01

    This paper examines how caregivers in a bilingual family discursively link Gaelic to a school context when interacting with Maggie, an eight year-old who is currently enrolled in Gaelic Medium Education on the Isle of Skye, Scotland. The paper argues that the caregivers achieve this discursive framing primarily through treating Gaelic as a…

  3. The Use of Simulators for Training In-Flight and Emergency Procedures,

    DTIC Science & Technology

    1980-06-01

    statistical differences in performance between the two groups were found. Creelman (39) reported that students trained in the SNJ Link with a contact landing...isl . Project No. NM 00-5.7.01. Pensacola, FL: U.S. Naval School of Aviation MTdTici7US.Nval Air station, March 1952. 39. Creelman , J. A. Evaluation of

  4. Relative Navigation Strategies for the Magnetopheric Multiscale Mission

    NASA Technical Reports Server (NTRS)

    Gramling, Cheryl; Carpenter, Russell; Lee, Taesul; Long, Anne

    2004-01-01

    This paper evaluates several navigation approaches for the Magnetospheric Multiscale (MMS) mission, which consists of a tetrahedral formation of satellites flying in highly eccentric Earth orbits. For this investigation, inter-satellite separations of approximately 10 kilometers near apogee are used for the first two phases of the MMS mission. Navigation approaches were studied using ground station two-way Doppler measurements, Global Positioning System (GPS) pseudorange measurements, and cross-link range measurements between the members of the formation. An absolute position accuracy of 15 kilometers or better can be achieved with most of the approaches studied, and a relative position accuracy of 100 meters or better can be achieved at apogee in several cases.

  5. Network flexibility of the IRIDIUM (R) Global Mobile Satellite System

    NASA Technical Reports Server (NTRS)

    Hutcheson, Jonathan; Laurin, Mala

    1995-01-01

    The IRIDIUM system is a global personal communications system supported by a constellation of 66 low earth orbit (LEO) satellites and a collection of earth-based 'gateway' switching installations. Like traditional wireless cellular systems, coverage is achieved by a grid of cells in which bandwidth is reused for spectral efficiency. Unlike any cellular system ever built, the moving cells can be shared by multiple switching facilities. Noteworthy features of the IRIDIUM system include inter-satellite links, a GSM-based telephony architecture, and a geographically controlled system access process. These features, working in concert, permit flexible and reliable administration of the worldwide service area by gateway operators. This paper will explore this unique concept.

  6. Engineering calculations for communications systems planning

    NASA Technical Reports Server (NTRS)

    Levis, C. A.; Martin, C. H.; Wang, C. W.; Gonsalvez, D.

    1982-01-01

    The single entry interference problem is treated for frequency sharing between the broadcasting satellite and intersatellite services near 23 GHz. It is recommended that very long (more than 120 longitude difference) intersatellite hops be relegated to the unshared portion of the band. When this is done, it is found that suitable orbit assignments can be determined easily with the aid of a set of universal curves. An attempt to develop synthesis procedures for optimally assigning frequencies and orbital slots for the broadcasting satellite service in region 2 was initiated. Several discrete programming and continuous optimization techniques are discussed.

  7. Igneous sills record far-field and near-field stress interactions during volcano construction: Isle of Mull, Scotland

    NASA Astrophysics Data System (ADS)

    Stephens, T. L.; Walker, R. J.; Healy, D.; Bubeck, A.; England, R. W.; McCaffrey, K. J. W.

    2017-11-01

    Sill emplacement is typically associated with horizontally mechanically layered host rocks in a near-hydrostatic far-field stress state, where contrasting mechanical properties across the layers promote transitions from dykes, or inclined sheets, to sills. We used detailed field observations from the Loch Scridain Sill Complex (Isle of Mull, UK), and mechanical models to show that layering is not always the dominant control on sill emplacement. The studied sills have consistently shallow dips (1°-25°) and cut vertically bedded and foliated metamorphic basement rocks, and horizontally bedded cover sedimentary rocks and lavas. Horizontal and shallowly-dipping fractures in the host rock were intruded with vertical opening in all cases, whilst steeply-dipping discontinuities within the sequence (i.e. vertical fractures and foliation in the basement, and vertical polygonal joints in the lavas) were not intruded during sill emplacement. Mechanical models of slip tendency, dilation tendency, and fracture susceptibility for local and overall sill geometry data, support a radial horizontal compression during sill emplacement. Our models show that dykes and sills across Mull were emplaced during NW-SE horizontal shortening, related to a far-field tectonic stress state. The dykes generally accommodated phases of NE-SW horizontal tectonic extension, whereas the sills record the superposition of the far-field stress with a near-field stress state, imposed by emplacement of the Mull Central Volcano. We show that through detailed geometric characterisation coupled with mechanical modelling, sills may be used as an indication of fluctuations in the paleostress state.

  8. New trends in laser satellite communications: design and limitations

    NASA Astrophysics Data System (ADS)

    Císar, J.; Wilfert, O.; Fanjul-Vélez, F.; Ortega-Quijano, N.; Arce-Diego, J. L.

    2008-11-01

    Optical communications offer a capable alternative to radio frequency (RF) communications for applications where high data-rate is required. This technology is particularly promising and challenging in the field of future inter-satellite communications. The term laser satellite communications (LSC) stands for optical links between satellites and/or high altitude platforms (HAPs). However, optical links between an earth station and a satellite or HAPs can be also involved. This work gives an overview of nowadays laser satellite communications. Particularly, it is focused on the factors causing degradation of the optical beam in the atmosphere. If an optical link passes through the atmosphere, it suffers from various influences such as attenuation due to absorption and scattering, intensity fluctuations due to atmospheric turbulence and background radiation. Furthermore, platform vibrations cause mispointing and following tracking losses. Suitable devices and used pointing and tracking system for laser satellite communications are discussed. At the end, various scenarios of the optical links and calculations of their power link budgets and limitations are designed. Implemented software is used for calculation of optical links. This work proves that the Free Space Optics (FSO) systems on mobile platforms, like satellites and HAPs are a promising solution for future communication networks.

  9. Declines in moose population density at Isle Royle National Park, MI, USA and accompanied changes in landscape patterns

    USGS Publications Warehouse

    De Jager, N. R.; Pastor, J.

    2009-01-01

    Ungulate herbivores create patterns of forage availability, plant species composition, and soil fertility as they range across large landscapes and consume large quantities of plant material. Over time, herbivore populations fluctuate, producing great potential for spatio-temporal landscape dynamics. In this study, we extend the spatial and temporal extent of a long-term investigation of the relationship of landscape patterns to moose foraging behavior at Isle Royale National Park, MI. We examined how patterns of browse availability and consumption, plant basal area, and soil fertility changed during a recent decline in the moose population. We used geostatistics to examine changes in the nature of spatial patterns in two valleys over 18 years and across short-range and long-range distance scales. Landscape patterns of available and consumed browse changed from either repeated patches or randomly distributed patches in 1988-1992 to random point distributions by 2007 after a recent record high peak followed by a rapid decline in the moose population. Patterns of available and consumed browse became decoupled during the moose population low, which is in contrast to coupled patterns during the earlier high moose population. Distributions of plant basal area and soil nitrogen availability also switched from repeated patches to randomly distributed patches in one valley and to random point distributions in the other valley. Rapid declines in moose population density may release vegetation and soil fertility from browsing pressure and in turn create random landscape patterns. ?? Springer Science+Business Media B.V. 2009.

  10. Status of High Data Rate Intersatellite Laser Communication as an Enabler for Earth and Space Science

    NASA Astrophysics Data System (ADS)

    Heine, F.; Zech, H.; Motzigemba, M.

    2017-12-01

    Space based laser communication is supporting earth observation and science missions with Gbps data download capabilities. Currently the Sentinel 1 and Sentinel 2 spacecrafts from the Copernicus earth observation program of the European Commission are using the Gbps laser communication links developed by Tesat Spacecom to download low latency data products via a commercial geostationary laser relay station- the European Data Relay Service- (EDRS) as a standard data path, in parallel to the conventional radio frequency links. The paper reports on the status of high bandwidth space laser communication as an enabler for small and large space science missions ranging from cube sat applications in low earth orbit to deep space missions. Space based laser communication has left the experimental phase and will support space science missions with unprecedented data rates.

  11. Linking atmospheric blocking to European temperature extremes in spring

    NASA Astrophysics Data System (ADS)

    Brunner, Lukas; Hegerl, Gabriele; Steiner, Andrea

    2017-04-01

    The weather in Europe is influenced by a range of dynamical features such as the Atlantic storm tracks, the jet stream, and atmospheric blocking. Blocking describes an atmospheric situation in which a stationary and persistent high pressure system interrupts the climatological flow for several days to weeks. It can trigger cold and warm spells which is of special relevance during the spring season because vegetation is particularly vulnerable to extreme temperatures in the early greening phase. We investigate European cold and warm spells in the 36 springs from 1979 to 2014 in temperature data from the European daily high-resolution gridded dataset (E-OBS) and connect them to blocking derived from geopotential height fields from ERA-Interim. A highly significant link between blocking and both, cold and warm spells is found that changes during spring. Resolving monthly frequencies, we find a shift in the preferred locations of blocking throughout spring. The maximum blocking frequency during cold spells shifts from Scandinavia to the British Isles in March and April. During warm spells it continuously shifts further northward during the spring season. The location of the block is found to be essential for the sign of the relationship. Blocking over the north-eastern Atlantic and over northern Europe is strongly linked to cold conditions, while blocking over central Europe is associated with warm conditions. Consistently the spatial distribution of temperature extremes across Europe is highly sensitive to the occurrence of blocking. More than 80 % of cold spells in south-eastern Europe occur during blocking, compared to less than 30 % in northern Europe. Warm spells show the opposite pattern and more than 70 % co-occur with blocking in northern Europe, compared to less than 30 % in parts of southern Europe. We find considerable interannual variability over the analysis period from 1979 to 2014 but also a decrease in cold spells and an increase in warm spells

  12. Parasitic nematodes of the genus Syphacia Seurat, 1916 infecting Muridae in the British Isles, and the peculiar case of Syphacia frederici.

    PubMed

    Stewart, Alex; Lowe, Ann; Smales, Lesley; Bajer, Anna; Bradley, Jan; Dwużnik, Dorota; Franssen, Frits; Griffith, Jack; Stuart, Peter; Turner, Cyan; Zaleśny, Grzegorz; Behnke, Jerzy M

    2018-03-01

    Syphacia stroma (von Linstow, 1884) Morgan, 1932 and Syphacia frederici Roman, 1945 are oxyurid nematodes that parasitize two murid rodents, Apodemus sylvaticus and Apodemus flavicollis, on the European mainland. Only S. stroma has been recorded previously in Apodemus spp. from the British Isles. Despite the paucity of earlier reports, we identified S. frederici in four disparate British sites, two in Nottinghamshire, one each in Berkshire and Anglesey, Wales. Identification was based on their site in the host (caecum and not small intestine), on key morphological criteria that differentiate this species from S. stroma (in particular the tail of female worms) and by sequencing two genetic loci (cytochrome C oxidase 1 gene and a section of ribosomal DNA). Sequences derived from both genetic loci of putative British S. frederici isolates formed a tight clade with sequences from continental worms known to be S. frederici, clearly distinguishing these isolates from S. stroma which formed a tight clade of its own, distinct from clades representative of Syphacia obvelata from Mus and S. muris from Rattus. The data in this paper therefore constitute the first record of S. frederici from British wood mice, and confirm the status of this species as distinct from both S. obvelata and S. stroma.

  13. Recent advancements in GRACE mascon regularization and uncertainty assessment

    NASA Astrophysics Data System (ADS)

    Loomis, B. D.; Luthcke, S. B.

    2017-12-01

    The latest release of the NASA Goddard Space Flight Center (GSFC) global time-variable gravity mascon product applies a new regularization strategy along with new methods for estimating noise and leakage uncertainties. The critical design component of mascon estimation is the construction of the applied regularization matrices, and different strategies exist between the different centers that produce mascon solutions. The new approach from GSFC directly applies the pre-fit Level 1B inter-satellite range-acceleration residuals in the design of time-dependent regularization matrices, which are recomputed at each step of our iterative solution method. We summarize this new approach, demonstrating the simultaneous increase in recovered time-variable gravity signal and reduction in the post-fit inter-satellite residual magnitudes, until solution convergence occurs. We also present our new approach for estimating mascon noise uncertainties, which are calibrated to the post-fit inter-satellite residuals. Lastly, we present a new technique for end users to quickly estimate the signal leakage errors for any selected grouping of mascons, and we test the viability of this leakage assessment procedure on the mascon solutions produced by other processing centers.

  14. Satellite analog FDMA/FM to digital TDMA conversion

    NASA Technical Reports Server (NTRS)

    Driggers, T.; Nguyen, T.; Kolavennu, V.

    1987-01-01

    The results of a study which investigated design issues regarding the use of analog to digital (A/D) conversion on board a satellite are presented. The need for A/D, and of course D/A as well, conversion arose from a satellite design which required analog FDMA/FM up and down links to/from a digitally modulated intersatellite link. There are also some advantages when one must interconnect a large number of various spot beams which are using analog, and therefore cannot take advantage of SS/TDMA switching among the beams, thus resulting in low fill factors. Various tradeoffs were performed regarding the implementation of on-board A/D processing, including mass, power, and costs. The various technologies which were considered included flash ADCs, surface acoustic wave (SAW) devices, and digital signal processing (DSP) chips. Impact analyses were also performed to determine the effect on ground stations to convert to digital if the A/D approach were not implemented.

  15. Fiber-based free-space optical coherent receiver with vibration compensation mechanism.

    PubMed

    Zhang, Ruochi; Wang, Jianmin; Zhao, Guang; Lv, Junyi

    2013-07-29

    We propose a novel fiber-based free-space optical (FSO) coherent receiver for inter-satellite communication. The receiver takes advantage of established fiber-optic components and utilizes the fine-pointing subsystem installed in FSO terminals to minimize the influence of satellite platform vibrations. The received beam is coupled to a single-mode fiber, and the coupling efficiency of the system is investigated both analytically and experimentally. A receiving sensitivity of -38 dBm is obtained at the forward error correction limit with a transmission rate of 22.4 Gbit/s. The proposed receiver is shown to be a promising component for inter-satellite optical communication.

  16. Colonisation and extinction in relation to competition and resource partitioning in acanthocephalans of freshwater fishes of the British Isles.

    PubMed

    Lyndon, A R; Kennedy, C R

    2001-01-01

    This paper challenges two paradigms long held in relation to the ecology of parasites in freshwater systems: (1) autogenic species are poorer colonisers than allogenic ones; and (2) parasites with direct life cycles are more successful colonisers than those with complex life cycles. Using new and existing data for Acanthocephala in freshwater fish from the British Isles, it is suggested that all six species present have been able to colonise and persist successfully, in spite of the supposed limitations of their autogenic life-style. It is proposed that these parasites have overcome these limitations by a variety of means, which apply equally to all species considered. Foremost among these is the utilisation of a migratory fish host as either a preferred or a suitable host in their life cycle, allowing colonisation of new areas and rescue effects in established areas, whilst equally important is the use of a common and widespread crustacean as the intermediate host. In addition, all six species appear to exhibit resource partitioning by host at either or both the larval and adult stages, thus reducing the potential for competition and further facilitating colonisation and survival. This hypothesis is supported by data from previous studies both on acanthocephalans from Europe and North America and on other autogenic parasites. It also provides an explanation for the apparently atypical host utilisation patterns of some acanthocephalan species in areas on the edge of their distributions, notably in Ireland.

  17. A cross-cultural exploration of abortion fund patients in the USA and the Republic of Ireland, Northern Ireland and the Isle of Man.

    PubMed

    Ely, Gretchen E; Hales, Travis W; Jackson, D Lynn

    2018-05-01

    This paper details results of a study examining administrative case data from 2010-2015 from abortion funds serving the USA and the Republic of Ireland, Northern Ireland and the Isle of Man. Driven by the available data, the researchers compared organisational characteristics, patient characteristics, procedural costs, patient resources and the ratio between patient resources and procedural costs. Independent t-tests were conducted to assess whether differences in characteristics, costs or resources were significant. The number of patients serviced by abortion funds across the two datasets increased yearly from 2010-2015. While patients in the USA had more resources, on average, to contribute to their abortion procedure, Irish, Northern Irish and Manx patients had the resources to pay for a greater percentage of their costs, on average, which was mainly attributable to the differences in gestational age of those helped by the different abortion funds. Patients across all nations were similar in terms of their marital status, average age and number of existing children. Patients across these countries face expensive procedures and a lack of resources that are bridged in part by abortion fund assistance.

  18. Possible signals of poleward surface ocean heat transport, of Arctic basal ice melt, and of the twentieth century solar maximum in the 1904-2012 Isle of Man daily timeseries

    NASA Astrophysics Data System (ADS)

    Matthews, J. B.; Matthews, J. B. R.

    2014-01-01

    This is the second of two papers on observational timeseries of top of ocean heat capture. The first reports hourly and daily meridional central tropical Pacific top 3 m timeseries showing high Southern Hemisphere evaporation (2.67 m yr-1) and Northern Hemisphere trapped heat (12 MJ m-2 day-1). We suggested that wind drift/geostrophic stratified gyre circulation transported warm water to the Arctic and led to three phases of Arctic basal ice melt and fluxes of brackish nutrient-rich waters to north Atlantic on centennial timescales. Here we examine daily top metre 1904-2012 timeseries at Isle of Man west coast ~54° N for evidence of tropical and polar surface waters. We compare these to Central England (CET) daily land-air temperatures and to Arctic floating ice heat content and extent. We find three phases of ocean surface heating consistent with basal icemelt buffering greenhouse gas warming until a regime shift post-1986 led to the modern surface temperature rise of ~1 °C in 20 yr. Three phases were: warming +0.018 °C yr-1 from 1904-1939, slight cooling -0.002 °C yr-11940-86 and strong warming +0.037 °C yr-1 1986-2012. For the same periods CET land-air showed: warming +0.015 °C yr-1, slight cooling -0.004 °C yr-1, about half SST warming at +0.018 °C yr-1. The mid-century cooling and a 1959/1963 hot/cold event is consistent with sunspot/solar radiation maximum 1923-2008 leading to record volumes of Arctic ice meltwater and runoff that peaked in 1962/3 British Isles extreme cold winter. The warming Arctic resulted in wind regime and surface water regime shifts post 1986. This coincides with the onset of rapid Arctic annual ice melt. Continued heat imbalance is likely to lead to tidewater glacier basal icemelt and future sealevel rise after remaining relatively stable over 4000 yr. Our work needs confirmation by further fieldwork concentrating on the dynamics and thermodynamics of ocean top 3 m that controls the 93 % anthropogenic global warming in the

  19. Isoliquiritigenin, a flavonoid from licorice, blocks M2 macrophage polarization in colitis-associated tumorigenesis through downregulating PGE{sub 2} and IL-6

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhao, Haixia; Zhang, Xinhua; Chen, Xuewei

    M2 macrophage polarization is implicated in colorectal cancer development. Isoliquiritigenin (ISL), a flavonoid from licorice, has been reported to prevent azoxymethane (AOM) induced colon carcinogenesis in animal models. Here, in a mouse model of colitis-associated tumorigenesis induced by AOM/dextran sodium sulfate (DSS), we investigated the chemopreventive effects of ISL and its mechanisms of action. Mice were treated with AOM/DSS and randomized to receive either vehicle or ISL (3, 15 and 75 mg/kg). Tumor load, histology, immunohistochemistry, and gene and protein expressions were determined. Intragastric administration of ISL for 12 weeks significantly decreased colon cancer incidence, multiplicity and tumor size bymore » 60%, 55.4% and 42.6%, respectively. Moreover, ISL inhibited M2 macrophage polarization. Such changes were accompanied by downregulation of PGE{sub 2} and IL-6 signaling. Importantly, depletion of macrophages by clodronate (Clod) or zoledronic acid (ZA) reversed the effects of ISL. In parallel, in vitro studies also demonstrated that ISL limited the M2 polarization of RAW264.7 cells and mouse peritoneal macrophages with concomitant inactivation of PGE{sub 2}/PPARδ and IL-6/STAT3 signaling. Conversely, exogenous addition of PGE{sub 2} or IL-6, or overexpression of constitutively active STAT3 reversed ISL-mediated inhibition of M2 macrophage polarization. In summary, dietary flavonoid ISL effectively inhibits colitis-associated tumorigenesis through hampering M2 macrophage polarization mediated by the interplay between PGE{sub 2} and IL-6. Thus, inhibition of M2 macrophage polarization is likely to represent a promising strategy for chemoprevention of colorectal cancer. - Highlights: • Isoliquiritigenin (ISL) prevents colitis-associated tumorigenesis. • ISL inhibits M2 macrophage polarization in vivo and in vitro. • ISL inhibits PGE{sub 2} and IL-6 signaling in colitis-associated tumorigenesis. • ISL may be an attractive candidate

  20. 76 FR 15366 - Additional Designation of Entities Pursuant to Executive Order 13382

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

    ..., Manning House, 21 Bucks Road, Douglas IM1 3DA, Man, Isle of; Business Registration Document 003648V (Man..., Man, Isle of; Business Registration Document 003645V (Man, Isle of) issued 2 Mar 2009 [NPWMD] Neuman...] Springthorpe Limited, Manning House, 21 Bucks Road, Douglas IM1 3DA, Man, Isle of; Business Registration...

  1. Bone structure of the temporo-mandibular joint in the individuals aged 18-25.

    PubMed

    Parafiniuk, M; Gutsch-Trepka, A; Trepka, S; Sycz, K; Wolski, S; Parafiniuk, W

    1998-01-01

    Osteohistometric studies were performed in 15 female and 15 male cadavers aged 18-25. Condyloid process and right and left acetabulum of the temporo-mandibular joint have been studied. Density has been investigated using monitor screen linked with microscope (magnification 80x). Density in the spongy part of the condyloid process was 26.67-26.77%; in the subchondrial layer--72.13-72.72%, and in the acetabular wall 75.03-75.91%. Microscopic structure of the bones of the temporo-mandibular joint revealed no differences when compared with images of compact and cancellous bone shown in the histology textbooks. Sex and the side of the body had no influence on microscopic image and proportional bone density. Isles of chondrocytes in the trabeculae of the spongy structure of the condyloid process were found in 4 cases and isles of the condensed bone resembling the compact pattern in 7 cases.

  2. Twentieth-century atmospheric river activity along the west coasts of Europe and North America: algorithm formulation, reanalysis uncertainty and links to atmospheric circulation patterns

    NASA Astrophysics Data System (ADS)

    Brands, S.; Gutiérrez, J. M.; San-Martín, D.

    2017-05-01

    subregions, the PNA-link is significant in British Columbia and the Gulf of Alaska and the WP-link is so along the U.S. West Coast. During OND, these links are significant in the Gulf of Alaska only. If AR-counts are calculated upon persistent (instead of instantaneous) ARs, the link to the NAO weakens over the British Isles and western Iberia. For the experimental set-ups most closely mirroring those applied in Lavers et al. (J Geophys Res Atmos 117, 2012. doi: 10.1029/2012JD018027) and Ramos et al. (J Hydrometeorol 16(2):579-597, 2015. doi: 10.1175/JHM-D-14-0103.1), the NAO-links are completely or partly insignificant indicating that the inclusion of the persistence criterion notably alters the results. Visual support for the present study is provided by an exhaustive historical atmospheric river archive built at http://www.meteo.unican.es/atmospheric-rivers.

  3. An advanced domestic satellite communications system

    NASA Technical Reports Server (NTRS)

    1980-01-01

    An updated traffic projection for U.S. domestic satellite communications service covering a period of 15 years; mid-1980 to mid-1995 was prepared. This model takes into account expected technology advances and reductions in transmission costs, legislative and regulatory changes permitting increased competition, and rising energy costs which will encourage more extensive substitution of telecommunications for travel. The historical development and current status of satellite systems are discussed as well as the characteristics of follow-on systems. Orbital arc utilization, spacecraft configuration for single shuttle launch, Earth station configuration, and system costs are examined. Areas which require technology development include multiple beam frequency reuse antennas, on-board switching, intersatellite links, and ka-band operation. Packing and deployment schemes for enclosing the satellite within the shuttle orbiter bay must also be devised.

  4. Isoliquiritigenin exhibits anti-proliferative properties in the pituitary independent of estrogen receptor function

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Weis, Karen E.; Raetzman, Lori T., E-mail: raetzma

    The plant flavonoid isoliquiritigenin (ISL) is a botanical estrogen widely taken as an herbal supplement to ease the symptoms of menopause. ISL has been also shown to have anti-tumor properties in a number of cancer cell backgrounds. However, the effects of ISL on normal cells are less well known and virtually unstudied in the context of the pituitary gland. We have established a pituitary explant culture model to screen chemical agents for gene expression changes within the pituitary gland during a period of active proliferation and differentiation. Using this whole-organ culture system we found ISL to be weakly estrogenic basedmore » on its ability to induce Cckar mRNA expression, an estrogen receptor (ER) mediated gene. Using a range of ISL from 200 nM to 200 μM, we discovered that ISL promoted cell proliferation at a low concentration, yet potently inhibited proliferation at the highest concentration. ICI 182,780 failed to antagonize ISL's repression of pituitary cell proliferation, indicating the effect is independent of ER signaling. Coincident with a decrease in proliferating cells, we observed down-regulation of transcript for cyclin D2 and E2 and a strong induction of mRNA and protein for the cyclin dependent kinase inhibitor Cdkn1a (p21). Importantly, high dose ISL did not alter the balance of progenitor vs. differentiated cell types within the pituitary explants and they seemed otherwise healthy; however, TUNEL staining revealed an increase in apoptotic cell death in ISL treated cultures. Our results merit further examination of ISL as an anti-tumor agent in the pituitary gland. - Highlights: • Isoliquiritigenin possesses weak estrogenic activity based on induction of Cckar. • ISL can be anti-proliferative in pituitary explants without altering cell lineages. • Anti-proliferative behavior of ISL is not estrogen receptor mediated. • ISL induces p21 expression leading to cell cycle arrest and apoptosis.« less

  5. Dietary compound isoliquiritigenin prevents mammary carcinogenesis by inhibiting breast cancer stem cells through WIF1 demethylation.

    PubMed

    Wang, Neng; Wang, Zhiyu; Wang, Yu; Xie, Xiaoming; Shen, Jiangang; Peng, Cheng; You, Jieshu; Peng, Fu; Tang, Hailin; Guan, Xinyuan; Chen, Jianping

    2015-01-01

    Breast cancer stem cells (CSCs) are considered as the root of mammary tumorigenesis. Previous studies have demonstrated that ISL efficiently limited the activities of breast CSCs. However, the cancer prevention activities of ISL and its precise molecular mechanisms remain largely unknown. Here, we report a novel function of ISL as a natural demethylation agent targeting WIF1 to prevent breast cancer. ISL administration suppressed in vivo breast cancer initiation and progression, accompanied by reduced CSC-like populations. A global gene expression profile assay further identified WIF1 as the main response gene of ISL treatment, accompanied by the simultaneous downregulation of β-catenin signaling and G0/G1 phase arrest in breast CSCs. In addition, WIF1 inhibition significantly relieved the CSC-limiting effects of ISL and methylation analysis further revealed that ISL enhanced WIF1 gene expression via promoting the demethylation of its promoter, which was closely correlated with the inhibition of DNMT1 methyltransferase. Molecular docking analysis finally revealed that ISL could stably dock into the catalytic domain of DNMT1. Taken together, our findings not only provide preclinical evidence to demonstrate the use of ISL as a dietary supplement to inhibit mammary carcinogenesis but also shed novel light on WIF1 as an epigenetic target for breast cancer prevention.

  6. Links between North Atlantic atmospheric blocking and recent trends in European winter precipitation

    NASA Astrophysics Data System (ADS)

    Ummenhofer, Caroline; Seo, Hyodae; Kwon, Young-Oh; Joyce, Terrence

    2015-04-01

    European precipitation has sustained robust trends during wintertime (January - March) over recent decades. Central, western, and northern Europe have become wetter by an average 0.1-0.3% per annum for the period 1901-2010, while southern Europe, including the Iberian Peninsula, much of Italy and the Balkan States, has sustained drying of -0.2% per annum or more over the same period. The overall pattern is consistent across different observational precipitation products, while the magnitude of the precipitation trends varies amongst data sets. Using cluster analysis, which identifies recurrent states (or regimes) of European winter precipitation by grouping them according to an objective similarity criterion, changes in the frequency of dominant winter precipitation patterns over the past century are evaluated. Considerable multi-decadal variability exists in the frequency of dominant winter precipitation patterns: more recent decades are characterised by significantly fewer winters with anomalous wet conditions over southern, western, and central Europe. In contrast, winters with dry conditions in western and southern Europe, but above-average rainfall in western Scandinavia and the northern British Isles, have been more common recently. We evaluate the associated multi-decadal large-scale circulation changes across the broader extratropical North Atlantic region, which accompany the observed wintertime precipitation variability using the 20th Century reanalysis product. Some influence of the North Atlantic Oscillation (NAO) is apparent in modulating the frequency of dominant precipitation patterns. However, recent trends in the characteristics of atmospheric blocking across the North Atlantic sector indicate a change in the dominant blocking centres (near Greenland, the British Isles, and west of the Iberian Peninsula). Associated changes in sea level pressure, storm track position and strength, and oceanic heat fluxes across the North Atlantic region are also

  7. Arctic Ocean Tides from GRACE Satellite Accelerations

    NASA Astrophysics Data System (ADS)

    Killett, B.; Wahr, J. M.; Desai, S. D.; Yuan, D.; Watkins, M. M.

    2010-12-01

    Because missions such as TOPEX/POSEIDON don't extend to high latitudes, Arctic ocean tidal solutions aren't constrained by altimetry data. The resulting errors in tidal models alias into monthly GRACE gravity field solutions at all latitudes. Fortunately, GRACE inter-satellite ranging data can be used to solve for these tides directly. Seven years of GRACE inter-satellite acceleration data are inverted using a mascon approach to solve for residual amplitudes and phases of major solar and lunar tides in the Arctic ocean relative to FES 2004. Simulations are performed to test the inversion algorithm's performance, and uncertainty estimates are derived from the tidal signal over land. Truncation error magnitudes and patterns are compared to the residual tidal signals.

  8. Optical Phased Array Antennas using Coupled Vertical Cavity Surface Emitting Lasers

    NASA Technical Reports Server (NTRS)

    Mueller, Carl H.; Rojas, Roberto A.; Nessel, James A.; Miranda, Felix A.

    2007-01-01

    High data rate communication links are needed to meet the needs of NASA as well as other organizations to develop space-based optical communication systems. These systems must be robust to high radiation environments, reliable, and operate over a wide temperature range. Highly desirable features include beam steering capability, reconfigurability, low power consumption, and small aperture size. Optical communication links, using coupled vertical cavity surface emitting laser radiating elements are promising candidates for the transmit portion of these communication links. In this talk we describe a mission scenario, and how the antenna requirements are derived from the mission needs. We describe a potential architecture for this type of antenna, and outline the advantages and drawbacks of this approach relative to competing technologies. The technology we are proposing used coupled arrays of 1550 nm vertical cavity surface emitting lasers for transmission. The feasibility of coupling these arrays together, to form coherent high-power beams that can be modulated at data rates exceeding 1 Gbps, will be explored. We will propose an architecture that enables electronic beam steering, thus mitigating the need for ancillary acquisition, tracking and beam pointing equipment such as needed for current optical communicatin systems. The beam-steering capability we are proposing also opens the possibility of using this technology for inter-satellite communicatin links, and satellite-to-surface links.

  9. Predicting missing links and identifying spurious links via likelihood analysis

    NASA Astrophysics Data System (ADS)

    Pan, Liming; Zhou, Tao; Lü, Linyuan; Hu, Chin-Kun

    2016-03-01

    Real network data is often incomplete and noisy, where link prediction algorithms and spurious link identification algorithms can be applied. Thus far, it lacks a general method to transform network organizing mechanisms to link prediction algorithms. Here we use an algorithmic framework where a network’s probability is calculated according to a predefined structural Hamiltonian that takes into account the network organizing principles, and a non-observed link is scored by the conditional probability of adding the link to the observed network. Extensive numerical simulations show that the proposed algorithm has remarkably higher accuracy than the state-of-the-art methods in uncovering missing links and identifying spurious links in many complex biological and social networks. Such method also finds applications in exploring the underlying network evolutionary mechanisms.

  10. Predicting missing links and identifying spurious links via likelihood analysis

    PubMed Central

    Pan, Liming; Zhou, Tao; Lü, Linyuan; Hu, Chin-Kun

    2016-01-01

    Real network data is often incomplete and noisy, where link prediction algorithms and spurious link identification algorithms can be applied. Thus far, it lacks a general method to transform network organizing mechanisms to link prediction algorithms. Here we use an algorithmic framework where a network’s probability is calculated according to a predefined structural Hamiltonian that takes into account the network organizing principles, and a non-observed link is scored by the conditional probability of adding the link to the observed network. Extensive numerical simulations show that the proposed algorithm has remarkably higher accuracy than the state-of-the-art methods in uncovering missing links and identifying spurious links in many complex biological and social networks. Such method also finds applications in exploring the underlying network evolutionary mechanisms. PMID:26961965

  11. Crustal Anatexis by Upwelling Mantle Melts in the N.Atlantic Igneous Province: the Isle of Rum, NW Scotland.

    NASA Astrophysics Data System (ADS)

    Hertogen, J.; Meyer, R.; Nicoll, G.; Troll, V. R.; Ellam, R. M.; Emeleus, C. H.

    2008-12-01

    Crustal anatexis is a common process in the rift-to-drift evolution during continental breakup and the formation of Volcanic Rifted Margins (VRM) systems. 'Early felsic-later mafic' volcanic rock associations on the Continent Ocean Boundary (COB) of the N.Atlantic Ocean have been sampled by ODP drilling on the SE Greenland margin and the the Vøring Plateau (Norwegian Sea). Such associations also occur further inland in the British Paleocene Igneous Province, such as on the Isle of Rum (e.g., Troll et al., Contrib. Min. Petrol., 2004, 147, p.722). Sr and Nd isotope and trace element geochemistry show that the Rum rhyodacites are the products of melting of Lewisian amphibolite gneiss. There are no indications of a melt contribution from Lewisian granulite gneiss. The amphibolite gneiss parent rock had experienced an ancient Cs and Rb loss, possibly during a Caledonian event, which caused 87Sr/86Sr heterogeneity in the crustal source of silicic melts. The dacites and early gabbros of Rum are mixtures of crustal melts and primary mantle melts. Rare Earth Element modelling shows that late stage picritic melts on Rum are close analogues for the parent melts of the Rum Layered Suite, and for the mantle melts that caused crustal anatexis of the Lewisian gneiss. These primary mantle melts have close affinities to MORB whose trace element content varies from slightly depleted to slightly enriched. The 'early felsic-later mafic' volcanic associations from Rum, and from the now drowned seaward dipping wedges on the shelf of SE Greenland and on the Vøring Plateau show geochemical differences that result from variations in the regional crustal composition and the depth at which crustal anatexis took place.

  12. Access to medicines in remote and rural areas: a survey of residents in the Scottish Highlands & Western Isles.

    PubMed

    Rushworth, G F; Diack, L; MacRobbie, A; Munoz, S-A; Pfleger, S; Stewart, D

    2015-03-01

    Sparsely populated areas are potentially predisposed to health inequalities due to limited access to services. This study aimed to explore and describe issues of access to medicines and related advice experienced by residents of the Scottish Highlands and Western Isles. Cross-sectional cohort study. Anonymized questionnaires were mailed to a random sample of 6000 residents aged ≥18 years identified from the electoral register. The questionnaire contained items on: access to medicines; interactions with health care services; and perceptions of the services. Results were analysed using descriptive, inferential and spatial statistics. Adjusted response rate was 49.5% (2913/5889). Almost two thirds (63.4%, 1847) were prescribed medicines regularly, 88.5% (1634) of whom considered the source convenient. Pharmacy (73.8%, 1364) or dispensing GP (24.0%, 443) were the most accessed sources. Prescription medicine advice was mainly obtained from the GP (55.7%, 1029). Respondents ≥80 years old were significantly (P < 0.0001) more likely to live alone (45.3%, 92) compared with those <80 (15.8%, 424). Almost a fifth (16.5%, 31) of those >80 years living alone disagreed that they obtained prescribed medicines from a convenient source. The majority of respondents who felt they did not have a convenient medicines source, regardless of urban/rural classification, lived within five miles of a pharmacy or GP practice. Respondents accessed medicines and advice from a variety of sources. While most considered their access to medicines convenient, there were issues for those over 80 years and living alone. Perceived convenience would not appear to be solely based on geographical proximity to supply source. This requires further exploration given that these individuals are likely to have long-term conditions and be prescribed medicines on a chronic basis. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  13. Precipitation links (PrecipLinks) - a prototype directory for precipitation information

    NASA Technical Reports Server (NTRS)

    Velanthapillia, Balendran; Stocker, Erich Franz

    2006-01-01

    This poster describes a web directory of research oriented precipitation links. In this era of sophisticated search engines and web agents, it might seem counterproductive to establish such a directory of links. However, entering precipitation into a search engine like google will yield over one million hits. To further exacerbate this situation many of the returned links are dead, duplicates of other links, incomplete, or only marginally related to research precipitation or even the broader precipitation area. Sometimes connecting the linked URL causes the browser to lose context and not be able to get back to the original page. Even using more sophisticated search engines query parameters or agents while reducing the overall return doesn't eliminate all of the other issues listed. As part of the development of the measurement-based Precipitation Processing System (PPS) that will support Tropical Rainfall Measuring Mission (TRMM) version 7 reprocessing and the Global Precipitation Measurement (GPM) mission a precipitation links (PrecipLinks) facility is being developed. PrecipLinks is intended to share locations of other sites that contain information or data pertaining to precipitation research. Potential contributors can log-on to the PrecipLinks website and register their site for inclusion in the directory. The price for inclusion is the requirement to place a link back to PrecipLinks on the webpage that is registered. This ensures that users will be able to easily get back to PrecipLinks regardless of any context issues that browsers might have. Perhaps more importantly users while visiting one site that they know can be referred to a location that has many others sites with which they might not be familiar. PrecipLinks is designed to have a very flat structure. This poster summarizes these categories (information, data, services) and the reasons for their selection. Providers may register multiple pages to which they wish to direct users. However, each page

  14. Sex-linked dominant

    MedlinePlus

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  15. The EDSN Intersatellite Communications Architecture

    NASA Technical Reports Server (NTRS)

    Hanson, John; Chartres, James; Sanchez, Hugo; Oyadomari, Ken

    2014-01-01

    The Edison Demonstration of Smallsat Networks (EDSN) is a swarm of eight 1.5U Cubesats developed by the NASA Ames Research Center under the Small Spacecraft Technology Program (SSTP) within NASA Space Technology Mission Directorate (STMD). EDSN, scheduled for launch in late 2014, is designed to explore the use of small spacecraft networks to make synchronized, multipoint scientific measurements, and to organize and pass those data to the ground through their network. Networked swarms of these small spacecraft will open new horizons in astronomy, Earth observations and solar physics. Their range of applications include the formation of synthetic aperture radars for Earth sensing systems, large aperture observatories for next generation telescopes and the collection of spatially distributed measurements of time varying systems, probing the Earth's magnetosphere, Earth-Sun interactions and the Earth's geopotential. The EDSN communications network is maintained and operated by a simple set of predefined rules operating independently on all eight spacecraft without direction from ground based systems. One spacecraft serves as a central node, requesting and collecting data from the other seven spacecraft, organizing the data and passing it to a ground station at regular intervals. The central node is rotated among the spacecraft on a regular basis, providing robustness against the failure of a single spacecraft. This paper describes the communication architecture of the EDSN network and its operation with small spacecraft of limited electrical power, computing power and communication range. Furthermore, the problems of collecting and prioritizing data through a system that has data throughput bottlenecks are addressed. Finally, future network enhancements that can be built on top of the current EDSN hardware are discussed.

  16. Impact of random pointing and tracking errors on the design of coherent and incoherent optical intersatellite communication links

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung; Gardner, Chester S.

    1989-01-01

    Given the rms transmitter pointing error and the desired probability of bit error (PBE), it can be shown that an optimal transmitter antenna gain exists which minimizes the required transmitter power. Given the rms local oscillator tracking error, an optimum receiver antenna gain can be found which optimizes the receiver performance. The impact of pointing and tracking errors on the design of direct-detection pulse-position modulation (PPM) and heterodyne noncoherent frequency-shift keying (NCFSK) systems are then analyzed in terms of constraints on the antenna size and the power penalty incurred. It is shown that in the limit of large spatial tracking errors, the advantage in receiver sensitivity for the heterodyne system is quickly offset by the smaller antenna gain and the higher power penalty due to tracking errors. In contrast, for systems with small spatial tracking errors, the heterodyne system is superior because of the higher receiver sensitivity.

  17. Report of Accomplishments under the Airport Improvement Program.

    DTIC Science & Technology

    1982-09-30

    Acquire snow removal equipment; conduct City of Portland feasibility study. Portland International (PRIMARY) Presque Isle 01 $ 15,840 Airport Master Plan...update to terminal City of Presque Isle area plan). Northern Maine Regional (PRIMARY) Presque Isle 02 $ 118,869 Rehabilitate terminal access road...City of Presque Isle Northern Maine Regional (PRIMARY) Rockland 01 $ 40,252 Airport Master Plan (update). Knox County Knox County Regional (COMMERCIAL

  18. Detached Breakwaters for Shore Protection.

    DTIC Science & Technology

    1986-01-01

    Presque Isle , Pennsylvania 23. At Presque Isle on Lake Erie , a segmented system of over 50 de- tached breakwaters is planned...Erosion at Presque Isle , Erie , Pennsylvania ," CERC Technical Report HL-83-15, US Army Engineer Waterways Experiment Station, Vicksburg, Miss. Seelig...by Seabergh (1983) on Presque Isle Pen- insula, Erie , Pennsylvania , which is a recurved sandspit protecting Erie Har- bor. The peninsula has

  19. Environmental Assessment for Toxecon Retrofit for Mercury and Multi-Pollutant Control, Presque Isle Power Plant, Marquette, Michigan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    N /A

    This Environmental Assessment (EA) evaluates environmental issues associated with constructing and operating an integrated emissions control system proposed by We Energies and its project partners with cost-shared funding support by DOE. The proposed project would be demonstrated at the existing 90-MW Units 7, 8, and 9 of We Energies' coal-fired Presque Isle Power Plant in Marquette, Michigan. The commercial-scale demonstrate would allow utilities to make decisions regarding the integrated emissions control system as a viable commercial option. DOE's share of the funding for the 5-year demonstration project would be about $25 million, while $25 million would also be provided bymore » We Energies and its project partners. This project was selected by DOE under the Clean Coal Power Initiative (CCPI) for negotiation of a cooperative agreement to demonstrate the integration of technologies to reduce emissions of mercury (Hg) and particulate matter, as well as potentially control sulfur dioxide (SO{sub 2}), oxides of nitrogen (NO{sub x}) and hydrochloric acid (HCl) emissions. DOE's decision is whether or not to fund the project. The EA evaluates the principal environmental issues, including air quality, waste management, and traffic, that could result from construction and operation of the proposed project. The EA also considers two reasonably foreseeable scenarios that could result from the no-action alternative in which DOE would not provide cost-shared funding for the proposed project. Key findings include that potential air quality impacts resulting from the proposed project would generally be beneficial because plantwide air emissions would decrease or continue at the same level. The decrease in stack exit temperature would decrease the plume rise, which could result in increased downwind ground-level concentrations of those air pollutants experience little or no decrease in stack emissions. However, results of air dispersion modeling indicated that no major

  20. Identifying the heterogeneity of young adult rhinitis through cluster analysis in the Isle of Wight birth cohort.

    PubMed

    Kurukulaaratchy, Ramesh J; Zhang, Hongmei; Patil, Veeresh; Raza, Abid; Karmaus, Wilfried; Ewart, Susan; Arshad, S Hasan

    2015-01-01

    Rhinitis affects many young adults and often shows comorbidity with asthma. We hypothesized that young adult rhinitis, like asthma, exhibits clinical heterogeneity identifiable by means of cluster analysis. Participants in the Isle of Wight birth cohort (n = 1456) were assessed at 1, 2, 4, 10, and 18 years of age. Cluster analysis was performed on those with rhinitis at age 18 years (n = 468) by using 13 variables defining clinical characteristics. Four clusters were identified. Patients in cluster 1 (n = 128 [27.4%]; ie, moderate childhood-onset rhinitis) had high atopy and eczema prevalence and high total IgE levels but low asthma prevalence. They showed the best lung function at 18 years of age, with normal fraction of exhaled nitric oxide (Feno), low bronchial hyperresponsiveness (BHR), and low bronchodilator reversibility (BDR) but high rhinitis symptoms and treatment. Patients in cluster 2 (n = 199 [42.5%]; ie, mild-adolescence-onset female rhinitis) had the lowest prevalence of comorbid atopy, asthma, and eczema. They had normal lung function and low BHR, BDR, Feno values, and total IgE levels plus low rhinitis symptoms, severity, and treatment. Patients in cluster 3 (n = 59 [12.6%]; ie, severe earliest-onset rhinitis with asthma) had the youngest rhinitis onset plus the highest comorbid asthma (of simultaneous onset) and atopy. They showed the most obstructed lung function with high BHR, BDR, and Feno values plus high rhinitis symptoms, severity, and treatment. Patient 4 in cluster 4 (n = 82 [17.5%]; ie, moderate childhood-onset male rhinitis with asthma) had high atopy, intermediate asthma, and low eczema. They had impaired lung function with high Feno values and total IgE levels but intermediate BHR and BDR. They had moderate rhinitis symptoms. Clinically distinctive adolescent rhinitis clusters are apparent with varying sex and asthma associations plus differing rhinitis severity and treatment needs. Copyright © 2014 American Academy of Allergy, Asthma

  1. SciLinks

    Science.gov Websites

    SciLinks Forgot your login? Sign up for FREE access Log In I'm a ... Teacher Student User Name questions and satisfy their curiosity Learn More Sign up for Free Access Sites in the SciLinks program . SciLinks-Targeted, Grade-Specific Web Content for your Books Free web content to extend and expand student

  2. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Montemayor, Eric J.; Didychuk, Allison L.; Liao, Honghong

    U6 small nuclear RNA (snRNA) is a key component of the active site of the spliceosome, a large ribonucleoprotein complex that catalyzes the splicing of precursor messenger RNA. Prior to its incorporation into the spliceosome, U6 is bound by the protein Prp24, which facilitates unwinding of the U6 internal stem-loop (ISL) so that it can pair with U4 snRNA. A previously reported crystal structure of the `core' of the U6 small nuclear ribonucleoprotein (snRNP) contained an ISL-stabilized A62G mutant of U6 bound to all four RNA-recognition motif (RRM) domains of Prp24 [Montemayoret al.(2014),Nature Struct. Mol. Biol.21, 544–551]. The structure revealedmore » a novel topology containing interlocked rings of protein and RNA that was not predicted by prior biochemical and genetic data. Here, the crystal structure of the U6 snRNP core with a wild-type ISL is reported. This complex crystallized in a new space group, apparently owing in part to the presence of an intramolecular cross-link in RRM1 that was not observed in the previously reported U6-A62G structure. The structure exhibits the same protein–RNA interface and maintains the unique interlocked topology. However, the orientation of the wild-type ISL is altered relative to the A62G mutant structure, suggesting inherent structural dynamics that may facilitate its pairing with U4. Consistent with their similar architectures in the crystalline state, the wild-type and A62G variants of U6 exhibit similar Prp24-binding affinities and electrophoretic mobilities when analyzed by gel-shift assay.« less

  3. Distinguishing Phenocrysts From Xenocrysts; Dating the Onset of Volcanic Activity on the Isle of Rum, Scotland.

    NASA Astrophysics Data System (ADS)

    Troll, V. R.; Nicoll, G. R.; Emeleus, H. C.; Donaldson, C. H.

    2005-12-01

    Major volcanic activity on the Isle of Rum started with eruption of rhyodacite, now preserved as intrusive and extrusive parts of the intra-caldera succession. A thick sequence of intra-caldera ignimbrites and sedimentary breccias are preserved in the north and south of the island. Twenty feldspar crystals of the rhyodacite were dated using Ar/Ar and yielded a mean apparent age of 60.83 ± 0.27Ma (MSWD = 3.4), consistent with previously published dates for the crosscutting (i.e. younger) ultrabasic-layered intrusion of 60.53 ± 0.08Ma, Hamilton et al., (1998, Nature). On an age versus probability plot the feldspars do not, however, show a simple Gaussian distribution, but a major peak at 60.33Ma and two smaller shoulders at approx 61.4Ma and 63Ma. Our preliminary interpretation of the older ages is that they include a) xenocrysts derived from earlier Tertiary plutonics (61.4Ma peak) and b) older feldspars that have largely re-equilibrated within the rhyodacite magma chamber, possibly derived from Lewisian gneiss (63Ma peak). This may imply a residence time of these xenocrysts in the magma chamber of up to several years; cf. Gansecki et al., (1996, Earth Planet Sci. Lett.). The youngest and strongest age peak at 60.33Ma is suggested to represent the rhyodacite event. The oxygen isotope composition of the rhyodacite feldspars (6.88 ‰) is in the range of magmatic phenocrysts (6-7.5 ‰) and Lewisian gneisses (5-8 ‰) and well above the very low oxygen isotope values usually associated with high-T alteration. Hydrothermal overprint due to the layered ultrabasic intrusion was therefore probably minimal. We suggest the 60.33 ± 0.21Ma crystal age represents the rhyodacite eruption/intrusion event, implying that the ultrabasic-layered suite was already forming at depth and emplaced at shallow structural levels quickly thereafter. These new age dates tie in very well with recent work by Chambers et al., (2005, Lithos), highlighting a very quick succession of events

  4. Holocene Evolution of Incised Coastal Channels on the Isle of Wight, UK: Interpretation via Numerical Simulation.

    NASA Astrophysics Data System (ADS)

    Leyland, J.; Darby, S. E.

    2006-12-01

    Incised coastal channels are found in numerous locations around the world where the shoreline morphology consists of cliffs. The incised coastal channels found on the Isle of Wight, UK, are known locally as `Chines' and debouche (up to 45m) through the soft cliffs of the south west coast, maintaining steep side walls subject to deep-seated mass wasting. These canyons offer sheltered locations and bare substrate, providing habitat for plant (Philonotis marchica, Anthoceros punctatos) and invertebrate (Psen atratinus, Baris analis, Melitaea cinxi) species of international importance. The base level of the Chines is highly dynamic, with episodes of sea cliff erosion causing the rejuvenation of the channel network. Consequently a key factor in Chine evolution is the relative balance between rates of cliff retreat and headwards incision caused by knickpoint migration. Specifically, there is concern that if contemporary coastal retreat rates are higher than the corresponding rates of knickpoint recession, there will be long-term a reduction in the overall extent of the Chines and their associated habitats. In an attempt to provide a long-term context for these issues, in this poster we explore the Holocene erosional history of the Chines using a numerical landscape evolution model. The model includes a stochastic cliff recession function that controls the position of the outlet boundary. Knickpoint recession rates are simulated using a detachment-limited channel erosion law wherein erosion rate is a power function of drainage area and stream gradient with model parameters defined using empirically- derived data. Simulations are undertaken for a range of imposed boundary conditions representing different scenarios of long-term cliff retreat forced by Holocene sea-level rise, plausible scenarios corresponding to cases where simulated and observed Chine and landscape forms match. The study provides an example of how a landscape evolution model could be used to reconstruct

  5. To Cross-Link or Not to Cross-Link? Cross-Linking Associated Foreign Body Response of Collagen-Based Devices

    PubMed Central

    Delgado, Luis M.; Bayon, Yves; Pandit, Abhay

    2015-01-01

    Collagen-based devices, in various physical conformations, are extensively used for tissue engineering and regenerative medicine applications. Given that the natural cross-linking pathway of collagen does not occur in vitro, chemical, physical, and biological cross-linking methods have been assessed over the years to control mechanical stability, degradation rate, and immunogenicity of the device upon implantation. Although in vitro data demonstrate that mechanical properties and degradation rate can be accurately controlled as a function of the cross-linking method utilized, preclinical and clinical data indicate that cross-linking methods employed may have adverse effects on host response, especially when potent cross-linking methods are employed. Experimental data suggest that more suitable cross-linking methods should be developed to achieve a balance between stability and functional remodeling. PMID:25517923

  6. Annotated Bibliography for Lake Erie. Volume II. Chemical,

    DTIC Science & Technology

    1974-10-01

    on the ecology of Presque Isle Bay, Erie , Pennsylvania . Environmental Sciences, Inc. Pittsburg, Pa. 232 p. Water quality in Presque Isle Bay is...Gottschall, Russell Y. 1930. Preliminary report on the phytoplankton and pollution in Presque Isle Bay, Lake Erie . Proc. Pa. Acad. Sci. 4:69-74. The...waters of Presque Isle Bay and vicinity are contaminated with sewage from the city of Erie . No evidence to date has been found of anaerobic respiration or

  7. Are flood occurrences in Europe linked to specific atmospheric circulation types?

    NASA Astrophysics Data System (ADS)

    Prudhomme, C.; Genevier, M.

    2009-04-01

    N* of CTi using historical frequencies of occurrence. N* represents the number of days preceding a flood when the atmospheric conditions could significantly influence flood production processes, and could be interpreted as an upper limit of the concentration time of the basin. This evaluates the persistence of an atmospheric circulation type CTi prior to a flood event, and the associated level of significance. The indicators are calculated at-site and discussed regionally. Results show significant links with two circulation types related to Cyclonic Westerly (Wz) and the Low over the British Isles (TB), while the anticyclonic north-westerly type (Nea) systematically doesn't occur before any flood event. References Barredo, J.I., 2007. Major flood disasters in Europe: 1950-2005. Natural Hazards and Earth System Sciences, 42 doi: 10.1007/s11069-006-9065-2: 125-148. Hess, P. and Brezowsky, H., 1977. Katalog der Grobwetterlagen Europas 1881-1976. 3 verbesserte und ergäntze Auflage. Ber Dt. Wetterd. 15 (113). James, P.M., 2007. An objective classification method for Hess and Brezowsky Grosswetterlagen over Europe. Theoretical and Applied Climatology, 88(1): 17-42.

  8. Reconfigurable phased antenna array for extending cubesat operations to Ka-band: Design and feasibility

    NASA Astrophysics Data System (ADS)

    Buttazzoni, G.; Comisso, M.; Cuttin, A.; Fragiacomo, M.; Vescovo, R.; Vincenti Gatti, R.

    2017-08-01

    Started as educational tools, CubeSats have immediately encountered the favor of the scientific community, subsequently becoming viable platforms for research and commercial applications. To ensure competitive data rates, some pioneers have started to explore the usage of the Ka-band beside the conventional amateur radio frequencies. In this context, this study proposes a phased antenna array design for Ka-band downlink operations consisting of 8×8 circularly polarized subarrays of microstrip patches filling one face of a single CubeSat unit. The conceived structure is developed to support 1.5 GHz bandwidth and dual-task missions, whose feasibility is verified by proper link budgets. The dual-task operations are enabled by a low-complexity phase-only control algorithm that provides pattern reconfigurability in order to satisfy both orbiting and intersatellite missions, while remaining adherent to the cost-effective CubeSat paradigm.

  9. Space-based communications infrastructure for developing countries

    NASA Astrophysics Data System (ADS)

    Barker, Keith; Barnes, Carl; Price, K. M.

    1995-08-01

    This study examines the potential use of satellites to augment the telecommunications infrastructure of developing countries with advanced satellites. The study investigated the potential market for using satellites in developing countries, the role of satellites in national information infrastructures (NII), the technical feasibility of augmenting NIIs with satellites, and a nation's financial conditions necessary for procuring satellite systems. In addition, the study examined several technical areas including onboard processing, intersatellite links, frequency of operation, multibeam and active antennas, and advanced satellite technologies. The marketing portion of this study focused on three case studies: China, Brazil, and Mexico. These cases represent countries in various stages of telecommunication infrastructure development. The study concludes by defining the needs of developing countries for satellites, and recommends steps that both industry and NASA can take to improve the competitiveness of U.S. satellite manufacturing.

  10. Space-based Communications Infrastructure for Developing Countries

    NASA Technical Reports Server (NTRS)

    Barker, Keith; Barnes, Carl; Price, K. M.

    1995-01-01

    This study examines the potential use of satellites to augment the telecommunications infrastructure of developing countries with advanced satellites. The study investigated the potential market for using satellites in developing countries, the role of satellites in national information infractructures (NII), the technical feasibility of augmenting NIIs with satellites, and a nation's financial conditions necessary for procuring satellite systems. In addition, the study examined several technical areas including onboard processing, intersatellite links, frequency of operation, multibeam and active antennas, and advanced satellite technologies. The marketing portion of this study focused on three case studies: China, Brazil, and Mexico. These cases represent countries in various stages of telecommunication infrastructure development. The study concludes by defining the needs of developing countries for satellites, and recommends steps that both industry and NASA can take to improve the competitiveness of U.S. satellite manufacturing.

  11. Link-N: The missing link towards intervertebral disc repair is species-specific

    PubMed Central

    Bach, Frances C.; Laagland, Lisanne T.; Grant, Michael P.; Creemers, Laura B.; Ito, Keita; Meij, Björn P.; Mwale, Fackson

    2017-01-01

    Introduction Degeneration of the intervertebral disc (IVD) is a frequent cause for back pain in humans and dogs. Link-N stabilizes proteoglycan aggregates in cartilaginous tissues and exerts growth factor-like effects. The human variant of Link-N facilitates IVD regeneration in several species in vitro by inducing Smad1 signaling, but it is not clear whether this is species specific. Dogs with IVD disease could possibly benefit from Link-N treatment, but Link-N has not been tested on canine IVD cells. If Link-N appears to be effective in canines, this would facilitate translation of Link-N into the clinic using the dog as an in vivo large animal model for human IVD degeneration. Materials and methods This study’s objective was to determine the effect of the human and canine variant of Link-N and short (s) Link-N on canine chondrocyte-like cells (CLCs) and compare this to those on already studied species, i.e. human and bovine CLCs. Extracellular matrix (ECM) production was determined by measuring glycosaminoglycan (GAG) content and histological evaluation. Additionally, the micro-aggregates’ DNA content was measured. Phosphorylated (p) Smad1 and -2 levels were determined using ELISA. Results Human (s)Link-N induced GAG deposition in human and bovine CLCs, as expected. In contrast, canine (s)Link-N did not affect ECM production in human CLCs, while it mainly induced collagen type I and II deposition in bovine CLCs. In canine CLCs, both canine and human (s)Link-N induced negligible GAG deposition. Surprisingly, human and canine (s)Link-N did not induce Smad signaling in human and bovine CLCs. Human and canine (s)Link-N only mildly increased pSmad1 and Smad2 levels in canine CLCs. Conclusions Human and canine (s)Link-N exerted species-specific effects on CLCs from early degenerated IVDs. Both variants, however, lacked the potency as canine IVD regeneration agent. While these studies demonstrate the challenges of translational studies in large animal models, (s)Link

  12. Link-N: The missing link towards intervertebral disc repair is species-specific.

    PubMed

    Bach, Frances C; Laagland, Lisanne T; Grant, Michael P; Creemers, Laura B; Ito, Keita; Meij, Björn P; Mwale, Fackson; Tryfonidou, Marianna A

    2017-01-01

    Degeneration of the intervertebral disc (IVD) is a frequent cause for back pain in humans and dogs. Link-N stabilizes proteoglycan aggregates in cartilaginous tissues and exerts growth factor-like effects. The human variant of Link-N facilitates IVD regeneration in several species in vitro by inducing Smad1 signaling, but it is not clear whether this is species specific. Dogs with IVD disease could possibly benefit from Link-N treatment, but Link-N has not been tested on canine IVD cells. If Link-N appears to be effective in canines, this would facilitate translation of Link-N into the clinic using the dog as an in vivo large animal model for human IVD degeneration. This study's objective was to determine the effect of the human and canine variant of Link-N and short (s) Link-N on canine chondrocyte-like cells (CLCs) and compare this to those on already studied species, i.e. human and bovine CLCs. Extracellular matrix (ECM) production was determined by measuring glycosaminoglycan (GAG) content and histological evaluation. Additionally, the micro-aggregates' DNA content was measured. Phosphorylated (p) Smad1 and -2 levels were determined using ELISA. Human (s)Link-N induced GAG deposition in human and bovine CLCs, as expected. In contrast, canine (s)Link-N did not affect ECM production in human CLCs, while it mainly induced collagen type I and II deposition in bovine CLCs. In canine CLCs, both canine and human (s)Link-N induced negligible GAG deposition. Surprisingly, human and canine (s)Link-N did not induce Smad signaling in human and bovine CLCs. Human and canine (s)Link-N only mildly increased pSmad1 and Smad2 levels in canine CLCs. Human and canine (s)Link-N exerted species-specific effects on CLCs from early degenerated IVDs. Both variants, however, lacked the potency as canine IVD regeneration agent. While these studies demonstrate the challenges of translational studies in large animal models, (s)Link-N still holds a regenerative potential for humans.

  13. Endocrine Secretory Reserve and Proinsulin Processing in Recipients of Islet of Langerhans Versus Whole Pancreas Transplants

    PubMed Central

    Elkhafif, Nabeel M.; Borot, Sophie; Morel, Philippe; Demuylder-Mischler, Sandrine; Giovannoni, Laurianne; Toso, Christian; Bosco, Domenico; Berney, Thierry

    2013-01-01

    OBJECTIVE β-Cells have demonstrated altered proinsulin processing after islet transplantation. We compare β-cell metabolic responses and proinsulin processing in pancreas and islet transplant recipients with respect to healthy control subjects. RESEARCH DESIGN AND METHODS We studied 15 islet and 32 pancreas transplant recipients. Islet subjects were subdivided into insulin-requiring (IR-ISL, n = 6) and insulin-independent (II-ISL, n = 9) groups. Ten healthy subjects served as control subjects. Subjects were administered an intravenous arginine stimulation test, and insulin, C-peptide, total proinsulin, intact proinsulin, and proinsulin fragment levels were determined from serum samples. Acute insulin response (AIR) and proinsulin processing rates were calculated. RESULTS We found that basal insulin and C-peptide levels were higher in the pancreas group than in all other groups. II-ISL patients had basal insulin and C-peptide levels similar to healthy control subjects. The IR-ISL group had significantly lower AIRs than all other groups. Basal processing rates were higher in the pancreas and II-ISL groups than in healthy control subjects and the IR-ISL group. After arginine stimulation, all groups had elevated processing rates, with the exception of the IR-ISL group. CONCLUSIONS Our data suggest that II-ISL transplant recipients can maintain basal metabolic parameters similar to healthy control subjects at the cost of a higher rate of proinsulin processing. IR-ISL transplant recipients, on the other hand, demonstrate both lower insulin response and lower basal rates of proinsulin processing even after arginine stimulation. PMID:24041681

  14. Ubiquitousness of link-density and link-pattern communities in real-world networks

    NASA Astrophysics Data System (ADS)

    Šubelj, L.; Bajec, M.

    2012-01-01

    Community structure appears to be an intrinsic property of many complex real-world networks. However, recent work shows that real-world networks reveal even more sophisticated modules than classical cohesive (link-density) communities. In particular, networks can also be naturally partitioned according to similar patterns of connectedness among the nodes, revealing link-pattern communities. We here propose a propagation based algorithm that can extract both link-density and link-pattern communities, without any prior knowledge of the true structure. The algorithm was first validated on different classes of synthetic benchmark networks with community structure, and also on random networks. We have further applied the algorithm to different social, information, technological and biological networks, where it indeed reveals meaningful (composites of) link-density and link-pattern communities. The results thus seem to imply that, similarly as link-density counterparts, link-pattern communities appear ubiquitous in nature and design.

  15. Isoliquiritigenin protects against sepsis-induced lung and liver injury by reducing inflammatory responses.

    PubMed

    Chen, Xiong; Cai, Xueding; Le, Rongrong; Zhang, Man; Gu, Xuemei; Shen, Feixia; Hong, Guangliang; Chen, Zimiao

    2018-02-05

    Sepsis, one of the most fatal diseases worldwide, often leads to multiple organ failure, mainly due to uncontrolled inflammatory responses. Despite accumulating knowledge obtained in recent years, effective drugs to treat sepsis in the clinic are still urgently needed. Isoliquiritigenin (ISL), a chalcone compound, has been reported to exert anti-inflammatory properties. However, little is known about the effects of ISL on sepsis and its related complications. In this study, we investigated the potential protective effects of ISL on lipopolysaccharide (LPS)-induced injuries and identified the mechanisms underlying these effects. ISL inhibited inflammatory cytokine expression in mouse primary peritoneal macrophages (MPMs) exposed to LPS. In an acute lung injury (ALI) mouse model, ISL prevented LPS-induced structural damage and inflammatory cell infiltration. Additionally, pretreatment with ISL attenuated sepsis-induced lung and liver injury, accompanied by a reduction in inflammatory responses. Moreover, these protective effects were mediated by the nuclear factor kappa B (NF-κB) pathway-mediated inhibition of inflammatory responses in vitro and in vivo. Our study suggests that ISL may be a potential therapeutic agent for sepsis-induced injuries. Copyright © 2017. Published by Elsevier Inc.

  16. Cattaraugus Creek Harbor, New York General Design Memorandum. Phase II. (Detailed Design). Volume II. Appendix E. Littoral Processes and Sedimentation in the Cattaraugus Embayment, New York. Appendix F. Sediment Transport in Cattaraugus Creek.

    DTIC Science & Technology

    1976-03-01

    beaches than any other part of the southeastern shoreline of Lake Erie . It is the only major sand accumulation zone with the exception of Presque Isle , in...52 20. Photographs of zonal site #10. 54 21. Photograph and map of zonal site #11, Presque Isle , Pa. 57 F22. Photographs and beach profiles at zonal...site #11. 59 23. Photograph of zonal site #12, the recurved spit area on Presque Isle , Pa. 62 24. Block diagram of recurved spit area of Presque Isle

  17. Light-induced cross-linking and post-cross-linking modification of polyglycidol.

    PubMed

    Marquardt, F; Bruns, M; Keul, H; Yagci, Y; Möller, M

    2018-02-08

    The photoinduced radical generation process has received renewed interest due to its economic and ecological appeal. Herein the light-induced cross-linking of functional polyglycidol and its post-cross-linking modification are presented. Linear polyglycidol was first functionalized with a tertiary amine in a two-step reaction. Dimethylaminopropyl functional polyglycidol was cross-linked in a UV-light mediated reaction with camphorquinone as a type II photoinitiator. The cross-linked polyglycidol was further functionalized by quaternization with various organoiodine compounds. Aqueous dispersions of the cross-linked polymers were investigated by means of DLS and zeta potential measurements. Polymer films were evaluated by DSC and XPS.

  18. Wallops Low Elevation Link Analysis for the Constellation Launch/Ascent Links

    NASA Technical Reports Server (NTRS)

    Cheung, Keith; Ho, C.; Kantak, A.; Lee, C.; Tye, R.; Richards, E.; Sham, C.; Schlesinger, A.; Barritt, B.

    2011-01-01

    To execute the President's Vision for Space Exploration, the Constellation Program (CxP) was formed to build the next generation spacecraft Orion and launch vehicles Ares, to transport human and cargo to International Space Station (ISS), moon, and Mars. This paper focuses on the detailed link analysis for Orion/Ares s launch and ascent links with Wallops 11.3m antenna (1) Orion's Dissimilar Voice link: 10.24 Kbps, 2-way (2) Ares Developmental Flight Instrument link, 20 Mbps, downlink. Three launch trajectories are considered: TD7-E, F (Feb), and G (Aug). In certain launch scenarios, the critical events of main engine cutoff (MECO) and Separation occur during the low elevation regime of WFF s downrange -- less than 5 degree elevation angle. The goal of the study is to access if there is enough link margins for WFF to track the DV and DFI links.

  19. Preliminary assessment of bioengineered fringing shoreline reefs in Grand Isle and Breton Sound, Louisiana

    USGS Publications Warehouse

    La Peyre, Megan K.; Schwarting, Lindsay; Miller, Shea

    2013-01-01

    Restoration of three-dimensional shell habitats in coastal Louisiana presents a valuable and potentially self-sustaining approach to providing shoreline protection and critical nekton habitat and may contribute to water quality maintenance. The use of what has been called “living shorelines” is particularly promising because in addition to the hypothesized shoreline protection services, it is predicted that, if built and located in viable sites, these living shorelines may ultimately contribute to water quality maintenance through filtration of bivalves and may enhance nekton habitat. This approach, however, has not been tested extensively in different shallow water estuarine settings; understanding under what conditions a living shoreline must have to support a sustainable oyster population, and where these reefs may provide valuable shoreline protection, is key to ensuring that this approach provides an effective tool for coastal restoration. This project gathered preliminary data on the sustainability and shoreline stabilization of three large bioengineered fringing reefs located in Grand Isle, Lake Eloi, and Lake Fortuna, Louisiana. We collected preconstruction and postconstruction physiochemical and biological data by using a before-after-control-impact approach to evaluate the effectiveness of these living shoreline structures on reducing marsh erosion, enabling reef sustainability, and providing other ecosystem benefits. Although this project was originally designed to compare reef performance and impacts across three different locations over 2 years, delays in construction because of the Deepwater Horizon oil spill resulted in reefs being built from 12 to 18 months later than anticipated. As a result, monitoring postconstruction was severely limited. One reef, Grand Isle, was completed in March 2011 and monitored up to 18 months postcreation, whereas Lake Eloi and Lake Fortuna reefs were not completed until January 2012, and only 8 months of

  20. Instrument Noise Simulation for GRACE Follow-On

    NASA Astrophysics Data System (ADS)

    Darbeheshti, N.; Mueller, V.; Wegener, H.; Hewitson, M.; Heinzel, G.; Naeimi, M.; Flury, J.

    2016-12-01

    The quality of the temporal gravity field from GRACE Follow-On mission depends on its multi-sensor system consisting of inter-satellite ranging with microwave and laser ranging instrument, GNSS orbit tracking, accelerometry, and attitude sensing. In this presentation, the noise models for GRACE Follow-On major instruments are described and their effect on the estimation of Earth's gravity field accuracy are discussed. To do this the spectrum of the instruments noise models has been related to the spectrum of the disturbing potential of the Earth's gravity field. The instrument noise models are available to the geodesy community through GRACE Follow-On mock data challenges. The performance of gravity field recovery approaches can be tested by comparing observation residuals to the simulated instrument noises. The instrument noise models will also provide valuable insight for inter-satellite ranging configurations beyond GRACE Follow-On.

  1. International Service Learning: Conceptual Frameworks and Research. IUPUI Series on Service Learning Research 1

    ERIC Educational Resources Information Center

    Bringle, Robert G., Ed.; Hatcher, Julie A., Ed.; Jones, Steven G., Ed.

    2010-01-01

    This book focuses on conducting research on International Service Learning (ISL), which includes developing and evaluating hypotheses about ISL outcomes and measuring its impact on students, faculty, and communities. The book argues that rigorous research is essential to improving the quality of ISL's implementation and delivery, and providing the…

  2. The chain of cross-contamination: link-by-link.

    PubMed

    Schwartz, Jeanne

    2002-01-01

    Conscious efforts must be made to break the chain of cross-contamination--link-by-link. Pay attention to detail Avoid being careless Avoid touching objects while wearing soiled gloves Frequently wash hands (15-second hand washing) to remove pathogens--before and after gloving, and before handling food or drink Wear all PPE, and change accordingly.

  3. Node, Node-Link, and Node-Link-Group Diagrams: An Evaluation.

    PubMed

    Saket, Bahador; Simonetto, Paolo; Kobourov, Stephen; Börner, Katy

    2014-12-01

    Effectively showing the relationships between objects in a dataset is one of the main tasks in information visualization. Typically there is a well-defined notion of distance between pairs of objects, and traditional approaches such as principal component analysis or multi-dimensional scaling are used to place the objects as points in 2D space, so that similar objects are close to each other. In another typical setting, the dataset is visualized as a network graph, where related nodes are connected by links. More recently, datasets are also visualized as maps, where in addition to nodes and links, there is an explicit representation of groups and clusters. We consider these three Techniques, characterized by a progressive increase of the amount of encoded information: node diagrams, node-link diagrams and node-link-group diagrams. We assess these three types of diagrams with a controlled experiment that covers nine different tasks falling broadly in three categories: node-based tasks, network-based tasks and group-based tasks. Our findings indicate that adding links, or links and group representations, does not negatively impact performance (time and accuracy) of node-based tasks. Similarly, adding group representations does not negatively impact the performance of network-based tasks. Node-link-group diagrams outperform the others on group-based tasks. These conclusions contradict results in other studies, in similar but subtly different settings. Taken together, however, such results can have significant implications for the design of standard and domain snecific visualizations tools.

  4. Effect of Link Flexibility on tip position of a single link robotic arm

    NASA Astrophysics Data System (ADS)

    Madhusudan Raju, E.; Siva Rama Krishna, L.; Mouli, Y. Sharath Chandra; Nageswara Rao, V.

    2015-12-01

    The flexible robots are widely used in space applications due to their quick response, lower energy consumption, lower overall mass and operation at high speed compared to conventional industrial rigid link robots. These robots are inherently flexible, so that the kinematics of flexible robots can't be solved with rigid body assumptions. The flexibility in links and joints affects end-point positioning accuracy of the robot. It is important to model the link kinematics with precision which in turn simplifies modelling of dynamics of flexible robots. The main objective of this paper is to evaluate the effect of link flexibility on a tip position of a single link robotic arm for a given motion. The joint is assumed to be rigid and only link flexibility is considered. The kinematics of flexible link problem is evaluated by Assumed Modes Method (AMM) using MAT LAB Programming. To evaluate the effect of link flexibility (with and without payload) of robotic arm, the normalized tip deviation is found for flexible link with respect to a rigid link. Finally, the limiting inertia for payload mass is found if the allowable tip deviation is 5%.

  5. Linking Research, Education and Public Engagement in Geoscience: Leadership and Strategic Partnerships.

    NASA Astrophysics Data System (ADS)

    Moosavi, S. C.

    2017-12-01

    By their very nature, the geosciences address societal challenges requiring a complex interplay between the research community, geoscience educators and public engagement with the general population to build their knowledge base and convince them to act appropriately to implement policies guided by scientific understanding. The most effective responses to geoscience challenges arise when strong collaborative structures connecting research, education and the public are in place to afford rapid communication and trust at all stages of the investigative and policy implementation processes. Educational programs that involve students and scientists via service learning exploring high profile issues of community interest and outreach to teachers through professional development build the network of relationships with geoscientists to respond rapidly to solve societal problems. These pre-existing personal connections simultaneously hold wider credibility with the public than unfamiliar scientific experts less accustomed to speaking to general audiences. The Geological Society of America is leveraging the research and educational experience of its members to build a self-sustaining state/regional network of K-12 professional development workshops designed to link the academic, research, governmental and industrial communities. The goal is not only to improve the content knowledge and pedagogical skills which teachers bring to their students, but also to build a diverse community of trust capable of responding to geoscience challenges in a fashion relevant to local communities. Dr. Moosavi is building this program by drawing on his background as a biogeochemistry researcher with 20 years experience focused on use of place-based approaches in general education and pre- and in-service teacher preparation in Research 1 and comprehensive universities, liberal arts and community colleges and high school. Experience with K-12 professional development working with the Minnesota

  6. Linked Ocean Data

    NASA Astrophysics Data System (ADS)

    Leadbetter, Adam; Arko, Robert; Chandler, Cynthia; Shepherd, Adam

    2014-05-01

    "Linked Data" is a term used in Computer Science to encapsulate a methodology for publishing data and metadata in a structured format so that links may be created and exploited between objects. Berners-Lee (2006) outlines the following four design principles of a Linked Data system: Use Uniform Resource Identifiers (URIs) as names for things. Use HyperText Transfer Protocol (HTTP) URIs so that people can look up those names. When someone looks up a URI, provide useful information, using the standards (Resource Description Framework [RDF] and the RDF query language [SPARQL]). Include links to other URIs so that they can discover more things. In 2010, Berners-Lee revisited his original design plan for Linked Data to encourage data owners along a path to "good Linked Data". This revision involved the creation of a five star rating system for Linked Data outlined below. One star: Available on the web (in any format). Two stars: Available as machine-readable structured data (e.g. An Excel spreadsheet instead of an image scan of a table). Three stars: As two stars plus the use of a non-proprietary format (e.g. Comma Separated Values instead of Excel). Four stars: As three stars plus the use of open standards from the World Wide Web Commission (W3C) (i.e. RDF and SPARQL) to identify things, so that people can point to your data and metadata. Five stars: All the above plus link your data to other people's data to provide context Here we present work building on the SeaDataNet common vocabularies served by the NERC Vocabulary Server, connecting projects such as the Rolling Deck to Repository (R2R) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO) and other vocabularies such as the Marine Metadata Interoperability Ontology Register and Repository and the NASA Global Change Master Directory to create a Linked Ocean Data cloud. Publishing the vocabularies and metadata in standard RDF XML and exposing SPARQL endpoints renders them five-star Linked

  7. Nano and micro mechanical properties of uncross-linked and cross-linked chitosan films

    PubMed Central

    Aryaei, Ashkan; Jayatissa, Ahalapitiya H.; Jayasuriya, A. Champa

    2016-01-01

    The aim of this study is to determine the nano and micro mechanical properties for uncross-linked and cross-linked chitosan films. Specifically, we looked at nanoindentation hardness, microhardness, and elastic modulus. It is important to study the nano and microscale mechanical properties of chitosan since chitosan has been widely used for biomedical applications. Using the solvent-cast method, the chitosan films were prepared at room temperature on the cleaned glass plates. The chitosan solution was prepared by dissolving chitosan in acetic acid 1% (v/v). Tripolyphosphate (TPP) was used to create the cross-links between amine groups in chitosan and phosphate groups in TPP. In this study, atomic force microscopy was used to measure the nanoindentation hardness and surface topography of the uncross-linked and cross-linked chitosan films. Elastic modulus was then calculated from the nanoindentation results. The effective elastic modulus was determined by microhardness with some modifications to previous theories. The microhardness of the chitosan films were measured using Vicker’s hardness meter under three different loads. Our results show that the microhardness and elastic modulus for cross-linked chitosan films are higher than the uncross-linked films. However, the cross-linked chitosan films show increased brittleness when compared to uncross-linked films. By increasing the load magnitude, the microhardness increases for both uncross-linked and cross-linked chitosan films. PMID:22100082

  8. Stage 2 Report for Reformulation Phase I General Design Memorandum, Cleveland Harbor, Ohio. Volume II. Appendices. Revision.

    DTIC Science & Technology

    1983-02-01

    Harbor Lighthouse Pointe Betsie Light Station Pennsylvania Port Sanilac Light Station Presque Isle Light Station Presque Isle Light Rock of Ages Light...Marquette, MI : 0.6 : 0.4 0.1 0 : 0 : 0 : 0 : : 0 : 0 : - Presque Isle , MI: 2.4 1.4 1.4 1.3 : 1.4 1.5 1.0 : 0.9 : 0.4 1.3 8.6 Silver Bay, MN 5.0 : 4.1...conditions. The long distance sourcing patterns of Outer Harbor iron ore (Silver Bay, Duluth-Superior, Escanaba, Presque Isle ) also favors the use of

  9. An evidential link prediction method and link predictability based on Shannon entropy

    NASA Astrophysics Data System (ADS)

    Yin, Likang; Zheng, Haoyang; Bian, Tian; Deng, Yong

    2017-09-01

    Predicting missing links is of both theoretical value and practical interest in network science. In this paper, we empirically investigate a new link prediction method base on similarity and compare nine well-known local similarity measures on nine real networks. Most of the previous studies focus on the accuracy, however, it is crucial to consider the link predictability as an initial property of networks itself. Hence, this paper has proposed a new link prediction approach called evidential measure (EM) based on Dempster-Shafer theory. Moreover, this paper proposed a new method to measure link predictability via local information and Shannon entropy.

  10. Enacting Informal Science Learning: Exploring the Battle for Informal Learning

    ERIC Educational Resources Information Center

    Clapham, Andrew

    2016-01-01

    Informal Science Learning (ISL) is a policy narrative of interest in the United Kingdom and abroad. This paper explores how a group of English secondary school science teachers, enacted ISL science clubs through employing the Periodic Table of Videos. It examines how these teachers "battled" to enact ISL policy in performative conditions…

  11. A Small Spacecraft Swarm Deployment and Stationkeeping Strategy for Sun-Earth L1 Halo Orbits

    NASA Technical Reports Server (NTRS)

    Conn, Tracie R.; Bookbinder, Jay

    2018-01-01

    Spacecraft orbits about the Sun-Earth librarian point L1 have been of interest since the 1950s. An L1 halo orbit was first achieved with the International Sun-Earth Explorer-3 (ISEE-3) mission, and similar orbits around Sun-Earth L1 were achieved in the Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE), Genesis, and Deep Space Climate Observatory (DSCOVR) missions. With recent advancements in CubeSat technology, we envision that it will soon be feasible to deploy CubeSats at L1. As opposed to these prior missions where one large satellite orbited alone, a swarm of CubeSats at L1 would enable novel science data return, providing a topology for intersatellite measurements of heliophysics phenomena both spatially and temporally, at varying spatial scales.The purpose of this iPoster is to present a flight dynamics strategy for a swarm of numerous CubeSats orbiting Sun-Earth L1. The presented method is a coupled, two-part solution. First, we present a deployment strategy for the CubeSats that is optimized to produce prescribed, time-varying intersatellite baselines for the purposes of collecting magnetometer data as well as radiometric measurements from cross-links. Second, we employ a loose control strategy that was successfully applied to SOHO and ACE for minimized stationkeeping fuel expenditure. We emphasize that the presented solution is practical within the current state-of-the-art and heritage CubeSat technology, citing capabilities of CubeSat designs that will launch on the upcoming Exploration Mission 1 (EM-1) to lunar orbits and beyond. Within this iPoster, we present animations of the simulated deployment strategy and resulting spacecraft trajectories. Mission design parameters such as total delta-v required for long-term station keeping and minimummaximummean spacecraft separation distances are also presented.

  12. A Small Spacecraft Swarm Deployment and Stationkeeping Strategy for Sun-Earth L1 Halo Orbits

    NASA Astrophysics Data System (ADS)

    Renea Conn, Tracie; Bookbinder, Jay

    2018-01-01

    Spacecraft orbits about the Sun-Earth librarian point L1 have been of interest since the 1950s. An L1 halo orbit was first achieved with the International Sun-Earth Explorer-3 (ISEE-3) mission, and similar orbits around Sun-Earth L1 were achieved in the Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE), Genesis, and Deep Space Climate Observatory (DSCOVR) missions. With recent advancements in CubeSat technology, we envision that it will soon be feasible to deploy CubeSats at L1. As opposed to these prior missions where one large satellite orbited alone, a swarm of CubeSats at L1 would enable novel science data return, providing a topology for intersatellite measurements of heliophysics phenomena both spatially and temporally, at varying spatial scales.The purpose of this iPoster is to present a flight dynamics strategy for a swarm of numerous CubeSats orbiting Sun-Earth L1. The presented method is a coupled, two-part solution. First, we present a deployment strategy for the CubeSats that is optimized to produce prescribed, time-varying intersatellite baselines for the purposes of collecting magnetometer data as well as radiometric measurements from cross-links. Second, we employ a loose control strategy that was successfully applied to SOHO and ACE for minimized stationkeeping propellant expenditure. We emphasize that the presented solution is practical within the current state-of-the-art and heritage CubeSat technology, citing capabilities of CubeSat designs that will launch on the upcoming Exploration Mission 1 (EM-1) to lunar orbits and beyond. Within this iPoster, we present animations of the simulated deployment strategy and resulting spacecraft trajectories. Mission design parameters such as total Δv required for long-term station keeping and minimum/maximum/mean spacecraft separation distances are also presented.

  13. AAH Cage Out-Link and In-Link Antenna Characterization

    NASA Technical Reports Server (NTRS)

    Jeutter, Dean C.

    1998-01-01

    This final report encapsulates the accomplishments of the third year of work on an Advanced Biotelemetry System (ABTS). Overall MU/ABTS project objectives are to provide a biotelemetry system that can collect data from and send commands to an implanted biotransceiver. This system will provide for studies of rodent development in space. The system must be capable of operating in a metal animal cage environment. An important goal is the development of a small, "smart", micropower, implantable biotransceiver with eight-channel data output and single channel command input capabilities with the flexibility for easy customization for a variety of physiologic investigations. The NASA Ames/Marquette University Joint Research work has been devoted to the system design of such a new state of the art biotelemetry system, having multiple physiologic inputs, and bi-directional data transfer capabilities. This work has provided a successful prototype system that connects, by two-way radio links, an addressable biotelemetry system that provides communication between an animal biotelemeter prototype and a personal computer. The operational features of the prototype system are: (1) two-way PCM communication with implanted biotelemeter; (2) microcontroller based biotelemeter; (3) out-link: wideband FSK (60 kBaud); (4) in-link: OOK (2.4 kbaud); (5) septum antenna arrays (In/Out-Links); and (6) personal computer data interface. The important requirement of this third year's work, to demonstrate two-way communication with transmit and receive antennas inside the metal animal cage, has been successfully accomplished. The advances discussed in this report demonstrate that the AAH cage antenna system can provide Out-link and In-link capability for the ABTS bi-directional telemetry system, and can serve as a benchmark for project status. Additions and enhancements to the most recent (April 1997) prototype cage and antenna have been implemented. The implementation, testing, and

  14. AAH Cage Out-Link and In-Link Antenna Characterization

    NASA Technical Reports Server (NTRS)

    Jeutter, Dean C.

    1998-01-01

    This final report encapsulates the accomplishments of the third year of work on an Advanced Biotelemetry System (ABTS). Overall MU/ABTS project objectives are to provide a biotelemetry system that can collect data from and send commands to an implanted biotransceiver. This system will provide for studies of rodent development in space. The system must be capable of operating in a metal animal cage environment. An important goal is the development of a small, "smart", micropower, -channel data output and single channel command implantable biotransceiver with eight input capabilities with the flexibility for easy customization for a variety of physiologic investigations. The NASA Ames/Marquette University Joint Research work has been devoted to the system design of such a new state of the art biotelemetry system, having multiple physiologic inputs, and bi-directional data transfer capabilities. This work has provided a successful prototype system that connects, by two-way radio links, an addressable biotelemetry system that provides communication between an animal biotelemeter prototype and a personal computer. The operational features of the prototype system are listed below: Two-Way PCM Communication with Implanted Biotelemeter Microcontroller Based Biotelemeter Out-Link: Wideband FSK (60 kbaud) In-Link: OOK (2.4 kbaud) Septum Antenna Arrays (In/Out-Links) Personal Computer Data Interface The important requirement of this third year's work, to demonstrate two-way communication with transmit and receive antennas inside the metal animal cage, has been successfully accomplished. The advances discussed in this report demonstrate that the AAH cage antenna system can provide Out-link and In-link capability for the ABTS bi-directional telemetry system, and can serve as a benchmark for project status.

  15. Beach Nourishment Techniques. Report 3. Typical U.S. Beach Nourishment Projects Using Offshore Sand Deposits.

    DTIC Science & Technology

    1981-05-01

    Cooperative Beach Erosion Control Project at Presque Isle Peninsula, Erie , Pennsylvania ," Buffalo, N. Y. U. S. Army Engineer District, Charleston. 1963 (Mar...104 Presque Isle , Pa .. .. ..................... 109 REFERENCES .. ............................ 115 2A BEACH NOURISHMENT...RIVER COUNTY, FL T PRESQUE ISLE . PA Figure 1. Beach fill projects location map ...../ ...... studies have been authorized, or which are publicly owned

  16. Geological Character and Mineral Resources of South Central Lake Erie.

    DTIC Science & Technology

    1982-10-01

    Presque Isle Peninsula, Erie , Pennsylvania , being conducted by the U.S. Army Engineer District...the Pennsylvania shoreline. Because of its position and morphology, Presque Isle acts as a natural offshore breakwater for Erie Harbor, blocking the...Research Center, Fort Belvoir, Va. (in preparation, 1982). U.S. ARMY ENGINEER DISTRICT, BUFFALO, " Presque Isle Peninsula, Erie , Pennsylvania ,"

  17. A wind tunnel study of flows over idealised urban surfaces with roughness sublayer corrections

    NASA Astrophysics Data System (ADS)

    Ho, Yat-Kiu; Liu, Chun-Ho

    2017-10-01

    Dynamics in the roughness (RSLs) and inertial (ISLs) sublayers in the turbulent boundary layers (TBLs) over idealised urban surfaces are investigated analytically and experimentally. In this paper, we derive an analytical solution to the mean velocity profile, which is a continuous function applicable to both RSL and ISL, over rough surfaces in isothermal conditions. Afterwards, a modified mixing-length model for RSL/ISL transport is developed that elucidates how surface roughness affects the turbulence motions. A series of wind tunnel experiments are conducted to measure the vertical profiles of mean and fluctuating velocities, together with momentum flux over various configurations of surface-mounted ribs in cross flows using hot-wire anemometry (HWA). The analytical solution agrees well with the wind tunnel result that improves the estimate to mean velocity profile over urban surfaces and TBL dynamics as well. The thicknesses of RSL and ISL are calculated by monitoring the convergence/divergence between the temporally averaged and spatio-temporally averaged profiles of momentum flux. It is found that the height of RSL/ISL interface is a function of surface roughness. Examining the direct, physical influence of roughness elements on near-surface RSL flows reveals that the TBL flows over rough surfaces exhibit turbulence motions of two different length scales which are functions of the RSL and ISL structure. Conclusively, given a TBL, the rougher the surface, the higher is the RSL intruding upward that would thinner the ISL up to 50 %. Therefore, the conventional ISL log-law approximation to TBL flows over urban surfaces should be applied with caution.

  18. The Missing Link: The Use of Link Words and Phrases as a Link to Manuscript Quality

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.

    2016-01-01

    In this article, I provide a typology of transition words/phrases. This typology comprises 12 dimensions of link words/phrases that capture 277 link words/phrases. Using QDA Miner, WordStat, and SPSS--a computer-assisted mixed methods data analysis software, content analysis software, and statistical software, respectively--I analyzed 74…

  19. EB Ford revisited: assessing the long-term stability of wing-spot patterns and population genetic structure of the meadow brown butterfly on the Isles of Scilly

    PubMed Central

    Baxter, S W; Hoffman, J I; Tregenza, T; Wedell, N; Hosken, D J

    2017-01-01

    Understanding selection in the wild remains a major aim of evolutionary ecology and work by Ford and colleagues on the meadow brown butterfly Maniola jurtina did much to ignite this agenda. A great deal of their work was conducted during the 1950s on the Isles of Scilly. They documented island-specific wing-spot patterns that remained consistent over about a decade, but patterns on some islands changed after environmental perturbation. It was suggested that these wing-spot patterns reflected island-specific selection and that there was little migration between islands. However, genetic studies to test the underlying assumption of restricted migration are lacking and it is also unknown whether the originally described wing-spot patterns have persisted over time. We therefore collected female butterflies from five of Ford's original study locations, including three large islands (St Mary's, St Martin's and Tresco) and two small islands (Tean and St Helen's). Wing-spot patterns had not changed appreciably over time on three of the islands (two large and one small), but were significantly different on the other two. Furthermore, analysis of 176 amplified fragment length polymorphisms revealed significant genome-wide differentiation among the five islands. Our findings are consistent with Ford's conclusions that despite the close proximity of these islands, there is restricted gene flow among them. PMID:27804964

  20. Annotated Bibliography for Lake Erie. Volume IV. Physical,

    DTIC Science & Technology

    1974-10-01

    Presque Isle Bay, Erie , Pennsylvania - interim report. Environ- mental Sciences Inc. Pittsburg, Pa. 235 P. The factors... Presque Isle Peninsula, Erie , Pennsylvania , indicates apparent correlation of initial high erosion rates of placed beach fill with sand size character...changes since 1854. (CE) 777. U. S. Army Corps of Engineers. 1960. Presque Isle Peninsula, Erie , Pennsylvania , beach erosion con- trol study.

  1. British isles lupus assessment group 2004 index is valid for assessment of disease activity in systemic lupus erythematosus

    PubMed Central

    Yee, Chee-Seng; Farewell, Vernon; Isenberg, David A; Rahman, Anisur; Teh, Lee-Suan; Griffiths, Bridget; Bruce, Ian N; Ahmad, Yasmeen; Prabu, Athiveeraramapandian; Akil, Mohammed; McHugh, Neil; D'Cruz, David; Khamashta, Munther A; Maddison, Peter; Gordon, Caroline

    2007-01-01

    Objective To determine the construct and criterion validity of the British Isles Lupus Assessment Group 2004 (BILAG-2004) index for assessing disease activity in systemic lupus erythematosus (SLE). Methods Patients with SLE were recruited into a multicenter cross-sectional study. Data on SLE disease activity (scores on the BILAG-2004 index, Classic BILAG index, and Systemic Lupus Erythematosus Disease Activity Index 2000 [SLEDAI-2K]), investigations, and therapy were collected. Overall BILAG-2004 and overall Classic BILAG scores were determined by the highest score achieved in any of the individual systems in the respective index. Erythrocyte sedimentation rates (ESRs), C3 levels, C4 levels, anti–double-stranded DNA (anti-dsDNA) levels, and SLEDAI-2K scores were used in the analysis of construct validity, and increase in therapy was used as the criterion for active disease in the analysis of criterion validity. Statistical analyses were performed using ordinal logistic regression for construct validity and logistic regression for criterion validity. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results Of the 369 patients with SLE, 92.7% were women, 59.9% were white, 18.4% were Afro-Caribbean and 18.4% were South Asian. Their mean ± SD age was 41.6 ± 13.2 years and mean disease duration was 8.8 ± 7.7 years. More than 1 assessment was obtained on 88.6% of the patients, and a total of 1,510 assessments were obtained. Increasing overall scores on the BILAG-2004 index were associated with increasing ESRs, decreasing C3 levels, decreasing C4 levels, elevated anti-dsDNA levels, and increasing SLEDAI-2K scores (all P < 0.01). Increase in therapy was observed more frequently in patients with overall BILAG-2004 scores reflecting higher disease activity. Scores indicating active disease (overall BILAG-2004 scores of A and B) were significantly associated with increase in therapy (odds ratio [OR] 19.3, P

  2. Link!: Potential Field Guidance Algorithm for In-Flight Linking of Multi-Rotor Aircraft

    NASA Technical Reports Server (NTRS)

    Cooper, John R.; Rothhaar, Paul M.

    2017-01-01

    Link! is a multi-center NASA e ort to study the feasibility of multi-aircraft aerial docking systems. In these systems, a group of vehicles physically link to each other during flight to form a larger ensemble vehicle with increased aerodynamic performance and mission utility. This paper presents a potential field guidance algorithm for a group of multi-rotor vehicles to link to each other during flight. The linking is done in pairs. Each vehicle first selects a mate. Then the potential field is constructed with three rules: move towards the mate, avoid collisions with non-mates, and stay close to the rest of the group. Once a pair links, they are then considered to be a single vehicle. After each pair is linked, the process repeats until there is only one vehicle left. The paper contains simulation results for a system of 16 vehicles.

  3. History of the Coastal Engineering Research Center 1963-1983, Volume 1

    DTIC Science & Technology

    1991-01-01

    jn the groin and sand replenishment projects at Newport Beach, California; Presque Isle Peninsu la on Lake Erie at Erie , Pennsyl - varua; and...of Environmental Resources in dune building field tests at Ludington State Park, Michigan, and Presque Isle State Park. Pennsylvania . After the...Shelf." 3 . Dennis W. Berg ... J- actor’> Affecting Beach Nourishmem Requirements. Presque Isle Peninsula, Erie , Pennsy lvania,’’ Great Lakes

  4. A comprehensive comparison of network similarities for link prediction and spurious link elimination

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Qiu, Dan; Zeng, An; Xiao, Jinghua

    2018-06-01

    Identifying missing interactions in complex networks, known as link prediction, is realized by estimating the likelihood of the existence of a link between two nodes according to the observed links and nodes' attributes. Similar approaches have also been employed to identify and remove spurious links in networks which is crucial for improving the reliability of network data. In network science, the likelihood for two nodes having a connection strongly depends on their structural similarity. The key to address these two problems thus becomes how to objectively measure the similarity between nodes in networks. In the literature, numerous network similarity metrics have been proposed and their accuracy has been discussed independently in previous works. In this paper, we systematically compare the accuracy of 18 similarity metrics in both link prediction and spurious link elimination when the observed networks are very sparse or consist of inaccurate linking information. Interestingly, some methods have high prediction accuracy, they tend to perform low accuracy in identification spurious interaction. We further find that methods can be classified into several cluster according to their behaviors. This work is useful for guiding future use of these similarity metrics for different purposes.

  5. Broken Links Tools

    EPA Pesticide Factsheets

    Some of these tools can be used on Drupal pages that are not published yet, or on non-Drupal content. Some, such as the Bookmarklet tools, can help make checking and correcting your links easier when used alongside Drupal's link reports.

  6. Autophagy participates in isoliquiritigenin-induced melanin degradation in human epidermal keratinocytes through PI3K/AKT/mTOR signaling.

    PubMed

    Yang, Zhibo; Zeng, Biyun; Pan, Yi; Huang, Pan; Wang, Chang

    2018-01-01

    Melanin is the pigment responsible for the color of human skin and hair. Melanin serves as a double-edge sword which can exert both protective and spot-causing effects on skin. Although melanin has an important role in protecting the skin against UV damage, an excessive or uneven melanin production can lead to the formation of freckles and age spots. Isoliquiritigenin (ISL) has been reported to inhibit melanin synthesis; however, its role in melanin degradation remains unclear. In the present study, we evaluated the detailed function of ISL in melanin degradation in human epidermal keratinocytes. Since autophagy has been reported to be related to melanin degradation, we also examined the activation of autophagy by ISL treatment in keratinocytes by measurement of autophagy-related proteins, ATG7, LC3 and p62. Moreover, si-ATG7-induced ATG7 knockdown and autophagy inhibitor 3-MA decreased LC3 II protein levels and increased PMEL17, p62 and melanin levels in HaCaT cells, which could be partially reversed by ISL treatment, indicating that autophagy participated in melanin degradation. The decreased p-AKT and p-mTOR proteins upon ISL treatment indicated the involvement of PI3K/AKT/mTOR signaling in ISL-induced melanin degradation. Taken together, we demonstrated that autophagy participates in ISL-induced melanin degradation in human epidermal keratinocytes through PI3K/AKT/mTOR signaling. Copyright © 2017. Published by Elsevier Masson SAS.

  7. Property Values Associated with the Failure of Individual Links in a System with Multiple Weak and Strong Links.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Helton, Jon C.; Brooks, Dusty Marie; Sallaberry, Cedric Jean-Marie.

    Representations are developed and illustrated for the distribution of link property values at the time of link failure in the presence of aleatory uncertainty in link properties. The following topics are considered: (i) defining properties for weak links and strong links, (ii) cumulative distribution functions (CDFs) for link failure time, (iii) integral-based derivation of CDFs for link property at time of link failure, (iv) sampling-based approximation of CDFs for link property at time of link failure, (v) verification of integral-based and sampling-based determinations of CDFs for link property at time of link failure, (vi) distributions of link properties conditional onmore » time of link failure, and (vii) equivalence of two different integral-based derivations of CDFs for link property at time of link failure.« less

  8. Improving local clustering based top-L link prediction methods via asymmetric link clustering information

    NASA Astrophysics Data System (ADS)

    Wu, Zhihao; Lin, Youfang; Zhao, Yiji; Yan, Hongyan

    2018-02-01

    Networks can represent a wide range of complex systems, such as social, biological and technological systems. Link prediction is one of the most important problems in network analysis, and has attracted much research interest recently. Many link prediction methods have been proposed to solve this problem with various techniques. We can note that clustering information plays an important role in solving the link prediction problem. In previous literatures, we find node clustering coefficient appears frequently in many link prediction methods. However, node clustering coefficient is limited to describe the role of a common-neighbor in different local networks, because it cannot distinguish different clustering abilities of a node to different node pairs. In this paper, we shift our focus from nodes to links, and propose the concept of asymmetric link clustering (ALC) coefficient. Further, we improve three node clustering based link prediction methods via the concept of ALC. The experimental results demonstrate that ALC-based methods outperform node clustering based methods, especially achieving remarkable improvements on food web, hamster friendship and Internet networks. Besides, comparing with other methods, the performance of ALC-based methods are very stable in both globalized and personalized top-L link prediction tasks.

  9. Evaluation of Relative Navigation Algorithms for Formation-Flying Satellites

    NASA Technical Reports Server (NTRS)

    Kelbel, David; Lee, Taesul; Long, Anne; Carpenter, J. Russell; Gramling, Cheryl

    2001-01-01

    Goddard Space Flight Center is currently developing advanced spacecraft systems to provide autonomous navigation and control of formation flyers. This paper discusses autonomous relative navigation performance for formations in eccentric, medium, and high-altitude Earth orbits using Global Positioning System (GPS) Standard Positioning Service (SPS) and intersatellite range measurements. The performance of several candidate relative navigation approaches is evaluated. These analyses indicate that the relative navigation accuracy is primarily a function of the frequency of acquisition and tracking of the GPS signals. A relative navigation position accuracy of 0.5 meters root-mean-square (RMS) can be achieved for formations in medium-attitude eccentric orbits that can continuously track at least one GPS signal. A relative navigation position accuracy of better than 75 meters RMS can be achieved for formations in high-altitude eccentric orbits that have sparse tracking of the GPS signals. The addition of round-trip intersatellite range measurements can significantly improve relative navigation accuracy for formations with sparse tracking of the GPS signals.

  10. Global Warming Estimation from MSU

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, Robert, Jr.

    1999-01-01

    In this study, we have developed time series of global temperature from 1980-97 based on the Microwave Sounding Unit (MSU) Ch 2 (53.74 GHz) observations taken from polar-orbiting NOAA operational satellites. In order to create these time series, systematic errors (approx. 0.1 K) in the Ch 2 data arising from inter-satellite differences are removed objectively. On the other hand, smaller systematic errors (approx. 0.03 K) in the data due to orbital drift of each satellite cannot be removed objectively. Such errors are expected to remain in the time series and leave an uncertainty in the inferred global temperature trend. With the help of a statistical method, the error in the MSU inferred global temperature trend resulting from orbital drifts and residual inter-satellite differences of all satellites is estimated to be 0.06 K decade. Incorporating this error, our analysis shows that the global temperature increased at a rate of 0.13 +/- 0.06 K decade during 1980-97.

  11. Publishing Data on Physical Samples Using the GeoLink Ontology and Linked Data Platforms

    NASA Astrophysics Data System (ADS)

    Ji, P.; Arko, R. A.; Lehnert, K. A.; Song, L.; Carter, M. R.; Hsu, L.

    2015-12-01

    Interdisciplinary Earth Data Alliance (IEDA), one of partners in EarthCube GeoLink project, seeks to explore the extent to which the use of GeoLink reusable Ontology Design Patterns (ODPs) and linked data platforms in IEDA data infrastructure can make research data more easily accessible and valuable. Linked data for the System for Earth Sample Registration (SESAR) is the first effort of IEDA to show how linked data enhance the presentation of IEDA data system architecture. SESAR Linked Data maps each table and column in SESAR database to RDF class and property based on GeoLink view, which build on the top of GeoLink ODPs. Then, uses D2RQ dumping the contents of SESAR database into RDF triples on the basis of mapping results. And, the dumped RDF triples is loaded into GRAPHDB, an RDF graph database, as permanent data in the form of atomic facts expressed as subjects, predicates and objects which provide support for semantic interoperability between IEDA and other GeoLink partners. Finally, an integrated browsing and searching interface build on Callimachus, a highly scalable platform for publishing linked data, is introduced to make sense of data stored in triplestore. Drill down and through features are built in the interface to help users locating content efficiently. The drill down feature enables users to explore beyond the summary information in the instance list of a specific class and into the detail from the specific instance page. The drill through feature enables users to jump from one instance to another one by simply clicking the link of the latter nested in the former region. Additionally, OpenLayers map is embedded into the interface to enhance the attractiveness of the presentation of instance which has geospatial information. Furthermore, by linking instances in the SESAR datasets to matching or corresponding instances in external sets, the presentation has been enriched with additional information about related classes like person, cruise, etc.

  12. Levels of mature cross-links and advanced glycation end product cross-links in human vitreous.

    PubMed

    Matsumoto, Yukihiro; Takahashi, Masaaki; Chikuda, Makoto; Arai, Kiyomi

    2002-01-01

    To determine the levels of pyridinoline and deoxypyridinoline, two mature enzymatic cross-links, and pentosidine, an advanced glycation end product (AGE) cross-link, in the human vitreous, and to investigate the correlations among the cross-links and the effects of aging and diabetes mellitus (DM) on the levels of cross-links. Forty-five vitreous samples were collected from 32 patients (32 eyes) undergoing vitrectomy for diabetic retinopathy (DM group) and from 13 patients (13 eyes) (control group) who were age- and sex-matched patients with idiopathic macular hole or epiretinal membrane with no systemic conditions. The levels of the cross-links were determined using high-performance liquid chromatography after acid hydrolysis and pretreatment with SP-Sephadex. The levels of pentosidine, pyridinoline, and deoxypyridinoline were 27.3 +/- 23.1 (mean +/- SD) pmol/mL (detectable in 45 of 45 specimens), 79.0 +/- 40.2 ng/mL (43 of 45 specimens), and 54.0 +/- 9.5 (32 of 45 specimens) ng/mL, respectively. When the vitreous samples from the DM and the control groups were compared, a significant difference (P <.05) was found in the pentosidine level but not in the levels of pyridinoline or deoxypyridinoline. No significant correlations were found between age and the cross-links. Significant correlations (P <.01) were found among the cross-links. The results indicate that mature cross-link substances exist in the human vitreous. The results also suggest that glycation may occur in the vitreous after mature cross-links form and result in the formation of AGE cross-links. In human vitreous from patients with DM, increased levels of AGE cross-links may stabilize the formation of mature cross-links, but they did not increase the mature cross-links.

  13. Erie Harbor, Pennsylvania, Channel Shoaling Analysis

    DTIC Science & Technology

    2011-07-01

    Presque Isle is located on the southern shore of Lake Erie and shelters the federal harbor at Erie , Pennsylvania . The US Army...the evaluation of the shoaling and dredging of sediment materials from Erie Harbor as part of the Presque Isle , Pennsylvania 204 feasibility study...ERDC TR-11-4 1 1 Introduction Problem statement Presque Isle is located on the southern shore of Lake Erie , Pennsylvania at the city of Erie

  14. Disposal of Vessel Wastes: Shipboard and Shoreside Facilities. Phase 2. Graywater

    DTIC Science & Technology

    1979-07-01

    Increase in Concentration Resulting from Daily Loadings and Vessel-Induced Mixing 45 3-7 Annual Loadings to Presque Isle - Marquette Harbor from...in port for 24 hours (Upper Lakes Reference Group, 1977a). Two harbors were considered for case studies. The first harbor, Presque Isle -Marquette...harbor. Presque Isle -Marquette The existing conditions of the harbor are considered to be of high quality with respect to coastal waters, the open waters

  15. Islet-1 Controls the Differentiation of Retinal Bipolar and Cholinergic Amacrine Cells

    PubMed Central

    Elshatory, Yasser; Everhart, Drew; Deng, Min; Xie, Xiaoling; Barlow, Robert B.; Gan, Lin

    2010-01-01

    Whereas the mammalian retina possesses a repertoire of factors known to establish general retinal cell types, these factors alone cannot explain the vast diversity of neuronal subtypes. In other CNS regions, the differentiation of diverse neuronal pools is governed by coordinately acting LIM-homeodomain proteins including the Islet-class factor Islet-1 (Isl1). We report that deletion of Isl1 profoundly disrupts retinal function as assessed by electroretinograms and vision as assessed by optomotor behavior. These deficits are coupled with marked reductions in mature ON- and OFF-bipolar (>76%), cholinergic amacrine (93%), and ganglion (71%) cells. Mosaic deletion of Isl1 permitted a chimeric analysis of “wild-type” cells in a predominantly Isl1-null environment, demonstrating a cell-autonomous role for Isl1 in rod bipolar and cholinergic amacrine development. Furthermore, the effects on bipolar cell development appear to be dissociable from the preceding retinal ganglion cell loss, because Pou4f2-null mice are devoid of similar defects in bipolar cell marker expression. Expression of the ON- and OFF-bipolar cell differentiation factors Bhlhb4 and Vsx1, respectively, requires the presence of Isl1, whereas the early bipolar cell marker Prox1 initially did not. Thus, Isl1 is required for engaging bipolar differentiation pathways but not for general bipolar cell specification. Spatiotemporal expression analysis of additional LIM-homeobox genes identifies a LIM-homeobox gene network during bipolar cell development that includes Lhx3 and Lhx4. We conclude that Isl1 has an indispensable role in retinal neuron differentiation within restricted cell populations and this function may reflect a broader role for other LIM-homeobox genes in retinal development, and perhaps in establishing neuronal subtypes. PMID:18003851

  16. An instrumented spatial linkage for measuring knee joint kinematics.

    PubMed

    Rosvold, Joshua M; Atarod, Mohammad; Frank, Cyril B; Shrive, Nigel G

    2016-01-01

    In this study, the design and development of a highly accurate instrumented spatial linkage (ISL) for kinematic analysis of the ovine stifle joint is described. The ovine knee is a promising biomechanical model of the human knee joint. The ISL consists of six digital rotational encoders providing six degrees of freedom (6-DOF) to its motion. The ISL makes use of the complete and parametrically continuous (CPC) kinematic modeling method to describe the kinematic relationship between encoder readings and the relative positions and orientation of its two ends. The CPC method is useful when calibrating the ISL, because a small change in parameters corresponds to a small change in calculated positions and orientations and thus a smaller optimization error, compared to other kinematic models. The ISL is attached rigidly to the femur and the tibia for motion capture, and the CPC kinematic model is then employed to transform the angle sensor readings to relative motion of the two ends of the linkage, and thereby, the stifle joint motion. The positional accuracy for ISL after calibration and optimization was 0.3±0.2mm (mean +/- standard deviation). The ISL was also evaluated dynamically to ensure that accurate results were maintained, and achieved an accuracy of 0.1mm. Compared to the traditional motion capture methods, this system provides increased accuracy, reduced processing time, and ease of use. Future work will be on the application of the ISL to the ovine gait and determination of in vivo joint motions and tissue loads. Accurate measurement of knee joint kinematics is essential in understanding injury mechanisms and development of potential preventive or treatment strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. 50 Mbps free space direct detection laser diode optical communication system with Q = 4 PPM signaling

    NASA Technical Reports Server (NTRS)

    Sun, Xiaoli; Davidson, Frederic; Field, Christopher

    1990-01-01

    A 50 Mbps direct detection optical communication system for use in an intersatellite link was constructed with an AlGaAs laser diode transmitter and a silicon avalanche photodiode photodetector. The system used a Q = 4 PPM format. The receiver consisted of a maximum likelihood PPM detector and a timing recovery subsystem. The PPM slot clock was recovered at the receiver by using a transition detector followed by a PLL. The PPM word clock was recovered by using a second PLL whose input was derived from the presence of back-to-back PPM pulses contained in the received random PPM pulse sequences. The system achieved a bit error rate of 0.000001 at less than 50 detected signal photons/information bit. The receiver was capable of acquiring and maintaining slot and word synchronization for received signal levels greater than 20 photons/information bit, at which the receiver bit error rate was about 0.01.

  18. EarthCube GeoLink: Semantics and Linked Data for the Geosciences

    NASA Astrophysics Data System (ADS)

    Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Fils, D.; Hitzler, P.; Janowicz, K.; Ji, P.; Jones, M. B.; Krisnadhi, A.; Lehnert, K. A.; Mickle, A.; Narock, T.; O'Brien, M.; Raymond, L. M.; Schildhauer, M.; Shepherd, A.; Wiebe, P. H.

    2015-12-01

    The NSF EarthCube initiative is building next-generation cyberinfrastructure to aid geoscientists in collecting, accessing, analyzing, sharing, and visualizing their data and knowledge. The EarthCube GeoLink Building Block project focuses on a specific set of software protocols and vocabularies, often characterized as the Semantic Web and "Linked Data", to publish data online in a way that is easily discoverable, accessible, and interoperable. GeoLink brings together specialists from the computer science, geoscience, and library science domains, and includes data from a network of NSF-funded repositories that support scientific studies in marine geology, marine ecosystems, biogeochemistry, and paleoclimatology. We are working collaboratively with closely-related Building Block projects including EarthCollab and CINERGI, and solicit feedback from RCN projects including Cyberinfrastructure for Paleogeosciences (C4P) and iSamples. GeoLink has developed a modular ontology that describes essential geoscience research concepts; published data from seven collections (to date) on the Web as geospatially-enabled Linked Data using this ontology; matched and mapped data between collections using shared identifiers for investigators, repositories, datasets, funding awards, platforms, research cruises, physical specimens, and gazetteer features; and aggregated the results in a shared knowledgebase that can be queried via a standard SPARQL endpoint. Client applications have been built around the knowledgebase, including a Web/map-based data browser using the Leaflet JavaScript library and a simple query service using the OpenSearch format. Future development will include extending and refining the GeoLink ontology, adding content from additional repositories, developing semi-automated algorithms to enhance metadata, and further work on client applications.

  19. LinkMind: link optimization in swarming mobile sensor networks.

    PubMed

    Ngo, Trung Dung

    2011-01-01

    A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm is demonstrated and evaluated in simulation.

  20. LinkMind: Link Optimization in Swarming Mobile Sensor Networks

    PubMed Central

    Ngo, Trung Dung

    2011-01-01

    A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm is demonstrated and evaluated in simulation. PMID:22164070

  1. Isoliquiritigenin-Induced Differentiation in Mouse Melanoma B16F0 Cell Line

    PubMed Central

    Chen, Xiaoyu; Zhang, Bo; Yuan, Xuan; Yang, Fan; Liu, Jinglei; Zhao, Hong; Liu, Liangliang; Wang, Yanming; Wang, Zhenhua; Zheng, Qiusheng

    2012-01-01

    The chemotherapeutical treatment is very limited for malignant melanoma, a highly lethal disease occurs globally. Natural products derived from traditional Chinese medicine licorice are attractive in quest new treatments due to their anti-tumor activities. A new dietary flavonoid isoliquiritigenin (ISL) were thus investigated to indentify its anti-melanoma activities on mouse melanoma B16F0 cells in present study. Using biochemical and free radical biological experiments in vitro, we identified the pro-differentiated profiles of ISL and evaluated the role of reactive oxygen species (ROS) during B16F0 cell differentiation. The data showed a strong dose-response relationship between ISL exposure and the characteristics of B16F0 differentiation in terms of morphology changes and melanogenesis. The accumulated intercellular ROS during exposure are necessary to support ISL-induced differentiation, which was proven by additional redox modulators. It was confirmed further by the relative activities of enzymes and genes modulated melanogenesis in ISL-treatments with or without ROS modulators. The tumorigenicity of ISL-treated cells was limited significantly by using the colony formation assay in vitro and an animal model assay in vivo respectively. Our research demonstrated that isoliquiritigenin is a differentiation-inducing agent, and its mechanisms involve ROS accumulation facilitating melanogenesis. PMID:23304254

  2. Isoliquiritigenin-induced differentiation in mouse melanoma B16F0 cell line.

    PubMed

    Chen, Xiaoyu; Zhang, Bo; Yuan, Xuan; Yang, Fan; Liu, Jinglei; Zhao, Hong; Liu, Liangliang; Wang, Yanming; Wang, Zhenhua; Zheng, Qiusheng

    2012-01-01

    The chemotherapeutical treatment is very limited for malignant melanoma, a highly lethal disease occurs globally. Natural products derived from traditional Chinese medicine licorice are attractive in quest new treatments due to their anti-tumor activities. A new dietary flavonoid isoliquiritigenin (ISL) were thus investigated to indentify its anti-melanoma activities on mouse melanoma B16F0 cells in present study. Using biochemical and free radical biological experiments in vitro, we identified the pro-differentiated profiles of ISL and evaluated the role of reactive oxygen species (ROS) during B16F0 cell differentiation. The data showed a strong dose-response relationship between ISL exposure and the characteristics of B16F0 differentiation in terms of morphology changes and melanogenesis. The accumulated intercellular ROS during exposure are necessary to support ISL-induced differentiation, which was proven by additional redox modulators. It was confirmed further by the relative activities of enzymes and genes modulated melanogenesis in ISL-treatments with or without ROS modulators. The tumorigenicity of ISL-treated cells was limited significantly by using the colony formation assay in vitro and an animal model assay in vivo respectively. Our research demonstrated that isoliquiritigenin is a differentiation-inducing agent, and its mechanisms involve ROS accumulation facilitating melanogenesis.

  3. Optical studies of CaS:Eu,Sm infrared stimulable phosphors

    NASA Astrophysics Data System (ADS)

    Tamura, Yasuaki; Shibukawa, Atsushi

    1993-07-01

    The photoluminescence (PL) and infrared stimulated luminescence (ISL) spectra of CaS:Eu,Sm infrared stimulable phosphors (ISPs) are studied. In addition, the concentration dependence of ISL intensity is examined. Sm(3+) and Eu(2+) related structures are found in both the PL excitation and emission spectra. Two types of Sm(3+) are found, one of which exhibits strong emission at around 650 nm and the other weak emission compared to the other emissions at around 565 nm and 605 nm. These are assigned to an asymmetric and a symmetric site, respectively. ISL excitation spectra coincide with the Eu(2+) 4f(sup 7) to 4f(sup 6)5d(sup 1) and 4f(sup 6)6s(sup 1) transitions and range from 220 to 650 nm. ISL emission spectra coincide with the Eu(2+) 4f(sup 6)5d(sup 1) to 4f(sup 7) transition and range from 550 to 750 nm. ISL stimulation spectra range from 0.8 micron to 1.7 micron and are thought to indicate the Sm(2+) ion transition from 4f(sup 6) to 4f(sup 5)5d(sup 1). The maximum ISL intensity is obtained from a sample with Eu and Sm concentrations of 500 and 130 ppm, respectively.

  4. Optical Studies of CaS:Eu, Sm Infrared Stimulable Phosphors

    NASA Astrophysics Data System (ADS)

    Tamura, Yasuaki; Shibukawa, Atsushi

    1993-07-01

    The photoluminescence (PL) and infrared stimulated luminescence (ISL) spectra of CaS:Eu,Sm infrared stimulable phosphors (ISPs) are studied. In addition, the concentration dependence of ISL intensity is examined. Sm3+- and Eu2+-related structures are found in both the PL excitation and emission spectra. Two types of Sm3+ are found, one of which exhibits strong emission at around 650 nm and the other, weak emission compared to the other emissions at around 565 nm and 605 nm. These are assigned to an asymmetric and a symmetric site, respectively. ISL excitation spectra coincide with the Eu2+ 4f7 to 4f65d1 and 4f66s1 transitions and range from 220 to 650 nm. ISL emission spectra coincide with the Eu2+ 4f65d1 to 4f7 transition and range from 550 to 750 nm. ISL stimulation spectra range from 0.8 μm to 1.7 μm and are thought to indicate the Sm2+ ion transition from 4f6 to 4f55d1. The maximum ISL intensity is obtained from a sample with Eu and Sm concentrations of 500 and 130 ppm, respectively.

  5. Age differences in search of web pages: the effects of link size, link number, and clutter.

    PubMed

    Grahame, Michael; Laberge, Jason; Scialfa, Charles T

    2004-01-01

    Reaction time, eye movements, and errors were measured during visual search of Web pages to determine age-related differences in performance as a function of link size, link number, link location, and clutter. Participants (15 young adults, M = 23 years; 14 older adults, M = 57 years) searched Web pages for target links that varied from trial to trial. During one half of the trials, links were enlarged from 10-point to 12-point font. Target location was distributed among the left, center, and bottom portions of the screen. Clutter was manipulated according to the percentage of used space, including graphics and text, and the number of potentially distracting nontarget links was varied. Increased link size improved performance, whereas increased clutter and links hampered search, especially for older adults. Results also showed that links located in the left region of the page were found most easily. Actual or potential applications of this research include Web site design to increase usability, particularly for older adults.

  6. Design, calibration and validation of a novel 3D printed instrumented spatial linkage that measures changes in the rotational axes of the tibiofemoral joint.

    PubMed

    Bonny, Daniel P; Hull, M L; Howell, S M

    2014-01-01

    An accurate axis-finding technique is required to measure any changes from normal caused by total knee arthroplasty in the flexion-extension (F-E) and longitudinal rotation (LR) axes of the tibiofemoral joint. In a previous paper, we computationally determined how best to design and use an instrumented spatial linkage (ISL) to locate the F-E and LR axes such that rotational and translational errors were minimized. However, the ISL was not built and consequently was not calibrated; thus the errors in locating these axes were not quantified on an actual ISL. Moreover, previous methods to calibrate an ISL used calibration devices with accuracies that were either undocumented or insufficient for the device to serve as a gold-standard. Accordingly, the objectives were to (1) construct an ISL using the previously established guidelines,(2) calibrate the ISL using an improved method, and (3) quantify the error in measuring changes in the F-E and LR axes. A 3D printed ISL was constructed and calibrated using a coordinate measuring machine, which served as a gold standard. Validation was performed using a fixture that represented the tibiofemoral joint with an adjustable F-E axis and the errors in measuring changes to the positions and orientations of the F-E and LR axes were quantified. The resulting root mean squared errors (RMSEs) of the calibration residuals using the new calibration method were 0.24, 0.33, and 0.15 mm for the anterior-posterior, medial-lateral, and proximal-distal positions, respectively, and 0.11, 0.10, and 0.09 deg for varus-valgus, flexion-extension, and internal-external orientations, respectively. All RMSEs were below 0.29% of the respective full-scale range. When measuring changes to the F-E or LR axes, each orientation error was below 0.5 deg; when measuring changes in the F-E axis, each position error was below 1.0 mm. The largest position RMSE was when measuring a medial-lateral change in the LR axis (1.2 mm). Despite the large size

  7. Link prediction with node clustering coefficient

    NASA Astrophysics Data System (ADS)

    Wu, Zhihao; Lin, Youfang; Wang, Jing; Gregory, Steve

    2016-06-01

    Predicting missing links in incomplete complex networks efficiently and accurately is still a challenging problem. The recently proposed Cannistrai-Alanis-Ravai (CAR) index shows the power of local link/triangle information in improving link-prediction accuracy. Inspired by the idea of employing local link/triangle information, we propose a new similarity index with more local structure information. In our method, local link/triangle structure information can be conveyed by clustering coefficient of common-neighbors directly. The reason why clustering coefficient has good effectiveness in estimating the contribution of a common-neighbor is that it employs links existing between neighbors of a common-neighbor and these links have the same structural position with the candidate link to this common-neighbor. In our experiments, three estimators: precision, AUP and AUC are used to evaluate the accuracy of link prediction algorithms. Experimental results on ten tested networks drawn from various fields show that our new index is more effective in predicting missing links than CAR index, especially for networks with low correlation between number of common-neighbors and number of links between common-neighbors.

  8. Porous Cross-Linked Polyimide Networks

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B. (Inventor); Guo, Haiquan (Inventor)

    2015-01-01

    Porous cross-linked polyimide networks are provided. The networks comprise an anhydride end-capped polyamic acid oligomer. The oligomer (i) comprises a repeating unit of a dianhydride and a diamine and terminal anhydride groups, (ii) has an average degree of polymerization of 10 to 50, (iii) has been cross-linked via a cross-linking agent, comprising three or more amine groups, at a balanced stoichiometry of the amine groups to the terminal anhydride groups, and (iv) has been chemically imidized to yield the porous cross-linked polyimide network. Also provided are porous cross-linked polyimide aerogels comprising a cross-linked and imidized anhydride end-capped polyamic acid oligomer, wherein the oligomer comprises a repeating unit of a dianhydride and a diamine, and the aerogel has a density of 0.10 to 0.333 g/cm.sup.3 and a Young's modulus of 1.7 to 102 MPa. Also provided are thin films comprising aerogels, and methods of making porous cross-linked polyimide networks.

  9. Annotated Bibliography for Lake Erie. Volume I. Biological,

    DTIC Science & Technology

    1974-10-01

    varieties of naiades from I Lake Erie . Nautilus. 32(l):9-12. Three new varieties of naiades collected at Presque Isle , Pennsylvania are carefully...E. 1909. A botanical survey of Presque Isle , Erie County, Pennsylvania . Annals Carnegie Mus. Pittsburgh, Penn. Pub. 53. 5(l):2 9-421. This study...of vegetation on Presque Isle . (SM) 401. Jennings, Otto E. 1930. A survey of the phytoplankton at Erie , Pennsylvania . Science. 71(1848):560-61. A

  10. Beach Erosional Hot Spots: Types, Causes, and Solutions

    DTIC Science & Technology

    2001-09-01

    Pope, and McClung (1999) showed that variable erosion rates along a beach nourishment project on Presque Isle , Pennsylvania (Lake Erie ) were related to...and McClung, J. K. (1999). “Coastal response to a detached breakwater system: Presque Isle , Erie , PA, U.S.A,” Proc. Coastal Sediments ’99, ASCE...borrow pits located too close to shore at Grand Isle , LA. The resultant cuspate shoreline was subsequently predicted by refraction analysis

  11. Islet 1 specifies the identity of hypothalamic melanocortin neurons and is critical for normal food intake and adiposity in adulthood

    PubMed Central

    Nasif, Sofia; de Souza, Flavio S. J.; González, Laura E.; Yamashita, Miho; Orquera, Daniela P.; Rubinstein, Marcelo

    2015-01-01

    Food intake and body weight regulation depend on proper expression of the proopiomelanocortin gene (Pomc) in a group of neurons located in the mediobasal hypothalamus of all vertebrates. These neurons release POMC-encoded melanocortins, which are potent anorexigenic neuropeptides, and their absence from mice or humans leads to hyperphagia and severe obesity. Although the pathophysiology of hypothalamic POMC neurons is well understood, the genetic program that establishes the neuronal melanocortinergic phenotype and maintains a fully functional neuronal POMC phenotype throughout adulthood remains unknown. Here, we report that the early expression of the LIM-homeodomain transcription factor Islet 1 (ISL1) in the developing hypothalamus promotes the terminal differentiation of melanocortinergic neurons and is essential for hypothalamic Pomc expression since its initial onset and throughout the entire lifetime. We detected ISL1 in the prospective hypothalamus just before the onset of Pomc expression and, from then on, Pomc and Isl1 coexpress. ISL1 binds in vitro and in vivo to critical homeodomain binding DNA motifs present in the neuronal Pomc enhancers nPE1 and nPE2, and mutations of these sites completely disrupt the ability of these enhancers to drive reporter gene expression to hypothalamic POMC neurons in transgenic mice and zebrafish. ISL1 is necessary for hypothalamic Pomc expression during mouse and zebrafish embryogenesis. Furthermore, conditional Isl1 inactivation from POMC neurons impairs Pomc expression, leading to hyperphagia and obesity. Our results demonstrate that ISL1 specifies the identity of hypothalamic melanocortin neurons and is required for melanocortin-induced satiety and normal adiposity throughout the entire lifespan. PMID:25825735

  12. Sustaining and improving an international service-learning partnership: Evaluation of an evidence-based service delivery model.

    PubMed

    Hayward, Lorna M; Li, Li

    2017-06-01

    International service learning (ISL) is an instructional method used by physical therapist educators in the United States (US) to prepare students for rendering culturally competent care. ISL is a faculty led student learning opportunity that includes academic instruction and community service in an international context. Research exists that explores student experiences with ISL, but studies that evaluate ISL partnerships and include global stakeholder feedback are lacking. The purposes of this study were to: 1) integrate a partnership evaluation component into an existing curriculum-based ISL model and 2) through evaluation identify benefits, drawbacks, and suggestions for improving and sustaining the academic-community partnership. Community-based participatory research design using a mixed methods approach was used to evaluate a ISL partnership between a US-based physical therapy program and a service site in Ecuador. Participants were 31 staff working at the global service site. Over three years, 11 interviews were conducted and 26 surveys were administered to global partner staff. Data were analyzed using qualitative thematic content analysis and descriptive statistics. Partnership benefits included the following: continuity of ISL team leadership, targeted rehabilitative efforts, sensitivity to cultural norms, respectful communication, and interaction with local community. Drawbacks were as follows: deficits in cultural awareness, language barriers, and poor treatment carryover. Suggestions for sustaining the relationship incorporated: additional pre-trip communication, education of staff, and improved language skills. As more US teams deliver clinical services abroad, intentional evaluation approaches must include the global stakeholder in the planning, implementation, and evaluation phases to maximize partnerships benefits.

  13. Active Semi-Supervised Community Detection Based on Must-Link and Cannot-Link Constraints

    PubMed Central

    Cheng, Jianjun; Leng, Mingwei; Li, Longjie; Zhou, Hanhai; Chen, Xiaoyun

    2014-01-01

    Community structure detection is of great importance because it can help in discovering the relationship between the function and the topology structure of a network. Many community detection algorithms have been proposed, but how to incorporate the prior knowledge in the detection process remains a challenging problem. In this paper, we propose a semi-supervised community detection algorithm, which makes full utilization of the must-link and cannot-link constraints to guide the process of community detection and thereby extracts high-quality community structures from networks. To acquire the high-quality must-link and cannot-link constraints, we also propose a semi-supervised component generation algorithm based on active learning, which actively selects nodes with maximum utility for the proposed semi-supervised community detection algorithm step by step, and then generates the must-link and cannot-link constraints by accessing a noiseless oracle. Extensive experiments were carried out, and the experimental results show that the introduction of active learning into the problem of community detection makes a success. Our proposed method can extract high-quality community structures from networks, and significantly outperforms other comparison methods. PMID:25329660

  14. Cross-linking of type I collagen with microbial transglutaminase: identification of cross-linking sites.

    PubMed

    Stachel, Ines; Schwarzenbolz, Uwe; Henle, Thomas; Meyer, Michael

    2010-03-08

    Collagen is a popular biomaterial. To deal with its lack of thermal stability and its weak resistance to proteolytic degradation, collagen-based materials are stabilized via different cross-linking procedures. Regarding the potential toxicity of residual cross-linking agents, enzyme-mediated cross-linking would provide an alternative and nontoxic method for collagen stabilization. The results of this study show that type I collagen is a substrate for mTG. However, epsilon-(gamma-glutamyl)lysine cross-links are only incorporated at elevated temperatures when the protein is partially or completely denatured. A maximum number of 5.4 cross-links per collagen monomer were found for heat-denatured collagen. Labeling with the primary amine monodansylcadaverine revealed that at least half of the cross-links are located within the triple helical region of the collagen molecule. Because the triple helix is highly ordered in its native state, this finding might explain why the glutamine residues are inaccessible for mTG under nondenaturing conditions.

  15. Synthesising topological links

    DOE PAGES

    Baas, Nils A.; Seeman, Nadrian C.; Stacey, Andrew

    2014-10-14

    In this paper, we discuss the chemical synthesis of topological links, in particular higher order links which have the Brunnian property (namely that removal of any one component unlinks the entire system). Finally, we suggest how to obtain both two dimensional and three dimensional objects (surfaces and solids, respectively) which also have this Brunnian property.

  16. The tsunami-like sea level disturbance in Crotone harbor, Italy, after the Mw6.5 strike-slip earthquake of 17 November 2015 in Lefkada Isl., Ionian Sea, Greece

    NASA Astrophysics Data System (ADS)

    Novikova, Tatyana; Annunziato, Alessandro; Charalampakis, Marinos; Romano, Fabrizio; Volpe, Manuela; Tonini, Roberto; Gerardinger, Andrea; Papadopoulos, Gerassimos A.

    2016-04-01

    On 17 November 2015 an Mw6.5 earthquake ruptured offshore Lefkada Isl. in Ionian Sea, Greece, causing two human victims, minor damage and several ground failures including coastal landslides. Fault plane solutions released by CMT/Harvard, NOA and other institutes have indicated that the faulting style was strike-slip right-lateral, which is quite typical for the area, as for example, the Mw6.3 event that occurred on August 14, 2003, in exactly the same fault zone. In spite of the very low tsunami potential commonly associated to this faulting mechanism, a tsunami-like sea level change was recorded after the earthquake by one tide-gauge in the Crotone harbor, Italy. Preliminary tsunami numerical simulations were performed to reproduce the observed signal. The spectral analysis of the synthetic mareograms close to the entrance of the harbor shows the presence of some peaks that could justify the relation between the natural port resonance and the observed wave amplification. Of particular interest is the coupling between the tsunami energy and the natural modes of basin oscillation enhancing tsunami wave amplitude in harbors through resonance, as shown in some historical events in the Mediterranean Sea and elsewhere. This research is a contribution to the EU-FP7 tsunami research project ASTARTE (Assessment, Strategy And Risk Reduction for Tsunamis in Europe), grant agreement no: 603839, 2013-10-30.

  17. Downregulation of COX-2 and CYP 4A signaling by isoliquiritigenin inhibits human breast cancer metastasis through preventing anoikis resistance, migration and invasion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zheng, Hao; Li, Ying; Wang, Yuzhong

    Flavonoids exert extensive in vitro anti-invasive and in vivo anti-metastatic activities. Anoikis resistance occurs at multiple key stages of the metastatic cascade. Here, we demonstrate that isoliquiritigenin (ISL), a flavonoid from Glycyrrhiza glabra, inhibits human breast cancer metastasis by preventing anoikis resistance, migration and invasion through downregulating cyclooxygenase (COX)-2 and cytochrome P450 (CYP) 4A signaling. ISL induced anoikis in MDA-MB-231 and BT-549 human breast cancer cells as evidenced by flow cytometry and the detection of caspase cleavage. Moreover, ISL inhibited the mRNA expression of phospholipase A2, COX-2 and CYP 4A and decreased the secretion of prostaglandin E{sub 2} (PGE{sub 2})more » and 20-hydroxyeicosatetraenoic acid (20-HETE) in detached MDA-MB-231 cells. In addition, it decreased the levels of phospho-PI3K (Tyr{sup 458}), phospho-PDK (Ser{sup 241}) and phospho-Akt (Thr{sup 308}). Conversely, the exogenous addition of PGE{sub 2}, WIT003 (a 20-HETE analog) and an EP4 agonist (CAY10580) or overexpression of constitutively active Akt reversed ISL-induced anoikis. ISL exerted the in vitro anti-migratory and anti-invasive activities, whereas the addition of PGE{sub 2}, WIT003 and CAY10580 or overexpression of constitutively active Akt reversed the in vitro anti-migratory and anti-invasive activities of ISL in MDA-MB-231 cells. Notably, ISL inhibited the in vivo lung metastasis of MDA-MB-231 cells, together with decreased intratumoral levels of PGE{sub 2}, 20-HETE and phospho-Akt (Thr{sup 308}). In conclusion, ISL inhibits breast cancer metastasis by preventing anoikis resistance, migration and invasion via downregulating COX-2 and CYP 4A signaling. It suggests that ISL could be a promising multi-target agent for preventing breast cancer metastasis, and anoikis could represent a novel mechanism through which flavonoids may exert the anti-metastatic activities. - Highlights: • Isoliquiritigenin induces anoikis and suppresses

  18. Airborne Data Link Study Report

    DOT National Transportation Integrated Search

    1996-01-01

    This report represents evaluations of Data Link products and services in a simulated aviation opearation. The study addresses key issues related to alerting schemes for Data Link messages, positioning of Data Link displays, and mode of presentation o...

  19. Lake Erie Water Level Study. Appendix F. Environmental Effects.

    DTIC Science & Technology

    1981-07-01

    were reevaluated with weight being placed on the most recent data. The wetland area in Pennsylvania was limited to that area on and around Presque Isle ...and East Harbor, Sandusky Bay, Northeast Yacht Club, Mentor Harbor, Presque Isle Bay, Port Dover, and Sturgeon Creek. In Lake Ontario the regulation...valued at close to 4 million dollars (Melski 1973), and the winter ice fishery was valued at 1.1 million dollars. Presque Isle Bay (which is on the

  20. Ice Engineering: Ice Jams, Winter 2002-2003

    DTIC Science & Technology

    2004-07-01

    located between Caribou and Fort Fairfield, and from Presque Isle and Washburn (NWS 2003i). Of the seven, four were reported in December and three...the towns of Washburn and Presque Isle ) was estimated to be one-quarter of a mile long in December. This jam remained in place until 21 April 2003...then appeared to break in half, sending the downstream floe of ice southeast through the town of Presque Isle while the most upstream section of

  1. Changes in Rates of Shore Retreat, Lake Michigan, 1967-1976.

    DTIC Science & Technology

    1979-12-01

    D.C., Apr. 1946. BERG, D.W., "Factors Affecting Beach Nourishment at Presque Isle Peninsula, Erie , Pennsylvania ," Proceedings of the Ninth Conference on...concern the behavior of beach fill at Presque Isle Peninsula on Lake Erie . Guidelines for moni- toring the effect of shore protection works in the Great...NTIS AD 631 520). BERG, D.W., and DUANE, D.B., "Effects of Particle Size and Distribution on Stability of Artificially Filled Beach, Presque Isle

  2. The Emerging Shield. The Air Force and the Evolution of Continental Air Defense 1945-1960

    DTIC Science & Technology

    1991-01-01

    flight plans other than those reported to the Presque Isle site. No one blamed the pilots; they had reported their changes in flighit to Canadian flight...monitor stations. Communications between the stations and ADC’s Presque Isle radar site had failed, and the course changes were not identified in the...Identification Zone: 134 "Pregnant Goose": 20 GOC on coast of: 156 Presque Isle , Maine: 170-71 Northw st emergency air defense for: Project CHARLEs: 145

  3. Measuring Link-Resolver Success: Comparing 360 Link with a Local Implementation of WebBridge

    ERIC Educational Resources Information Center

    Herrera, Gail

    2011-01-01

    This study reviewed link resolver success comparing 360 Link and a local implementation of WebBridge. Two methods were used: (1) comparing article-level access and (2) examining technical issues for 384 randomly sampled OpenURLs. Google Analytics was used to collect user-generated OpenURLs. For both methods, 360 Link out-performed the local…

  4. Expression of Terminal Effector Genes in Mammalian Neurons Is Maintained by a Dynamic Relay of Transient Enhancers.

    PubMed

    Rhee, Ho Sung; Closser, Michael; Guo, Yuchun; Bashkirova, Elizaveta V; Tan, G Christopher; Gifford, David K; Wichterle, Hynek

    2016-12-21

    Generic spinal motor neuron identity is established by cooperative binding of programming transcription factors (TFs), Isl1 and Lhx3, to motor-neuron-specific enhancers. How expression of effector genes is maintained following downregulation of programming TFs in maturing neurons remains unknown. High-resolution exonuclease (ChIP-exo) mapping revealed that the majority of enhancers established by programming TFs are rapidly deactivated following Lhx3 downregulation in stem-cell-derived hypaxial motor neurons. Isl1 is released from nascent motor neuron enhancers and recruited to new enhancers bound by clusters of Onecut1 in maturing neurons. Synthetic enhancer reporter assays revealed that Isl1 operates as an integrator factor, translating the density of Lhx3 or Onecut1 binding sites into transient enhancer activity. Importantly, independent Isl1/Lhx3- and Isl1/Onecut1-bound enhancers contribute to sustained expression of motor neuron effector genes, demonstrating that outwardly stable expression of terminal effector genes in postmitotic neurons is controlled by a dynamic relay of stage-specific enhancers. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Radiation cross-linked collagen/dextran dermal scaffolds: effects of dextran on cross-linking and degradation.

    PubMed

    Zhang, Yaqing; Zhang, Xiangmei; Xu, Ling; Wei, Shicheng; Zhai, Maolin

    2015-01-01

    Ionizing radiation effectively cross-links collagen into network with enhanced anti-degradability and biocompatibility, while radiation-cross-linked collagen scaffold lacks flexibility, satisfactory surface appearance, and performs poor in cell penetration and ingrowth. To make the radiation-cross-linked collagen scaffold to serve as an ideal artificial dermis, dextran was incorporated into collagen. Scaffolds with the collagen/dextran (Col/Dex) ratios of 10/0, 7/3, and 5/5 were fabricated via (60)Co γ-irradiation cross-linking, followed by lyophilization. The morphology, microstructure, physicochemical, and biological properties were investigated. Compared with pure collagen, scaffolds with dextran demonstrated more porous appearance, enhanced hydrophilicity while the cross-linking density was lower with the consequence of larger pore size, higher water uptake, as well as reduced stiffness. Accelerated degradation was observed when dextran was incorporated in both the in vitro and in vivo assays, which led to earlier integration with cell and host tissue. The effect of dextran on degradation was ascribed to the decreased cross-linking density, looser microstructure, more porous and hydrophilic surface. Considering the better appearance, softness, moderate degradation rate due to controllable cross-linking degree and good biocompatibility as well, radiation-cross-linked collagen/dextran scaffolds are expected to serve as promising artificial dermal substitutes.

  6. 76 FR 18938 - Changes in Flood Elevation Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... Isles Beach, 18070 Review. Collins Avenue, Sunny Isles Beach, FL 33160. Monroe (FEMA Docket No.: B.... Jim Schmidt, December 24, 2010 460277 No.: B-1156) of Lincoln County August 26, 2010; Chairman...

  7. Linking Policy | Smokefree 60+

    Cancer.gov

    Links to individual pages within the Smokefree 60+ website are permissible, provided attribution is made to 60plus.smokefree.gov and any descriptive notes accurately reflect the content of the linked page(s).

  8. Implementing the LIM code: the structural basis for cell type-specific assembly of LIM-homeodomain complexes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhati, Mugdha; Lee, Christopher; Nancarrow, Amy L.

    2008-09-03

    LIM-homeodomain (LIM-HD) transcription factors form a combinatorial 'LIM code' that contributes to the specification of cell types. In the ventral spinal cord, the binary LIM homeobox protein 3 (Lhx3)/LIM domain-binding protein 1 (Ldb1) complex specifies the formation of V2 interneurons. The additional expression of islet-1 (Isl1) in adjacent cells instead specifies the formation of motor neurons through assembly of a ternary complex in which Isl1 contacts both Lhx3 and Ldb1, displacing Lhx3 as the binding partner of Ldb1. However, little is known about how this molecular switch occurs. Here, we have identified the 30-residue Lhx3-binding domain on Isl1 (Isl1{sub LBD}).more » Although the LIM interaction domain of Ldb1 (Ldb1{sub LID}) and Isl1{sub LBD} share low levels of sequence homology, X-ray and NMR structures reveal that they bind Lhx3 in an identical manner, that is, Isl1{sub LBD} mimics Ldb1{sub LID}. These data provide a structural basis for the formation of cell type-specific protein-protein interactions in which unstructured linear motifs with diverse sequences compete to bind protein partners. The resulting alternate protein complexes can target different genes to regulate key biological events.« less

  9. Sensing and communication trade-offs in picosatellite formation flying missions.

    PubMed

    Arnon, Shlomi; Kedar, Debbie

    2009-10-01

    One of the primary challenges in all small satellite design is the attainment of adequate sensing and communication capabilities within the stringent spatial limitations. These can be defined in terms of surface area expenditure for the different payloads. There is an inevitable trade-off between enhancing the sensing capacity at the expense of reducing communication capabilities on the one hand and, on the other hand, increasing the communication capacity to the detriment of the sensing ability. Careful balancing of the conflicting demands is necessary to achieve acceptable performance levels. In this paper we study two intersatellite optical wireless communication scenarios: (i) a direct link between two satellites and (ii) a folded path link between a master satellite and a picosatellite equipped with a modulatable retroreflector. In the latter case the picosatellite does not have a laser transmitter and the data carrier is the retroreflected beam from the master satellite. The data rate, which is bounded by the sensing payload resolution, is derived using diffraction theory and Shannon capacity considerations. We develop a mathematical model to describe the interrelations between sensing and communication facilities in a picosatellite flight formation using optical technologies and demonstrate system performance trade-offs with a numerical example.

  10. O-linked oligosaccharides on insulin receptor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Collier, E.; Gorden, P.

    1991-02-01

    The insulin receptor, an integral membrane glycoprotein, is synthesized as a single-chain precursor that is cleaved to produce two mature subunits, both of which contain N-linked oligosaccharide chains and covalently linked fatty acids. We report that the beta-subunit also contains O-linked oligosaccharides. The proreceptor, alpha-subunit, and beta-subunit were labeled with (3H)mannose and (3H)galactose in the presence or absence of an inhibitor of O-linked glycosylation. Tryptic peptides from each component were separated by reverse-phase high-performance liquid chromatography. N- and O-linked oligosaccharide chains were identified on these peptides by specific enzymatic digestions. The proreceptor and alpha-subunit contained only N-linked oligosaccharides, whereas themore » beta-subunit contained both N- and O-linked oligosaccharides. The O-linked oligosaccharide chains were attached to a single tryptic fraction of the beta-subunit, which also contained N-linked chains. This fraction was further localized to the NH2-terminal tryptic peptide of the beta-subunit by specific immunoprecipitation with an anti-peptide antibody with specificity for this region. Binding of insulin and autophosphorylation of the beta-subunit were not dependent on O-linked glycosylation, because cells grown in the presence of the inhibitor exhibited a normal dose response to insulin. Therefore, the insulin receptor contains O-linked oligosaccharides on the NH2-terminal tryptic peptide of the beta-subunit, and these O-linked oligosaccharides are not necessary to the binding or autophosphorylation function of the receptor.« less

  11. Open loop model for WDM links

    NASA Astrophysics Data System (ADS)

    D, Meena; Francis, Fredy; T, Sarath K.; E, Dipin; Srinivas, T.; K, Jayasree V.

    2014-10-01

    Wavelength Division Multiplexing (WDM) techniques overfibrelinks helps to exploit the high bandwidth capacity of single mode fibres. A typical WDM link consisting of laser source, multiplexer/demultiplexer, amplifier and detectoris considered for obtaining the open loop gain model of the link. The methodology used here is to obtain individual component models using mathematical and different curve fitting techniques. These individual models are then combined to obtain the WDM link model. The objective is to deduce a single variable model for the WDM link in terms of input current to system. Thus it provides a black box solution for a link. The Root Mean Square Error (RMSE) associated with each of the approximated models is given for comparison. This will help the designer to select the suitable WDM link model during a complex link design.

  12. TWSTFT Link Calibration Report

    DTIC Science & Technology

    2015-09-01

    1 Annex II. TWSTFT link calibration with a GPS calibrator Calibration reference: CI-888-2015 Version history: ZJ/V0/25Feb2015, V0a,b/HE/ZJ...7Mar; V0s/VZ9Mar; V0d,e,f+/DM10,17Mar; V1.0/1Apr; Final version 1Sept2015 TWSTFT link calibration report -- Calibration of the Lab(k)-PTB UTC...bipm.org * Coordinator Abstract This report includes the calibration results of the Lab(k)-PTB TWSTFT link and closure measurements of the BIPM

  13. Using expert knowledge for test linking.

    PubMed

    Bolsinova, Maria; Hoijtink, Herbert; Vermeulen, Jorine Adinda; Béguin, Anton

    2017-12-01

    Linking and equating procedures are used to make the results of different test forms comparable. In the cases where no assumption of random equivalent groups can be made some form of linking design is used. In practice the amount of data available to link the two tests is often very limited due to logistic and security reasons, which affects the precision of linking procedures. This study proposes to enhance the quality of linking procedures based on sparse data by using Bayesian methods which combine the information in the linking data with background information captured in informative prior distributions. We propose two methods for the elicitation of prior knowledge about the difference in difficulty of two tests from subject-matter experts and explain how these results can be used in the specification of priors. To illustrate the proposed methods and evaluate the quality of linking with and without informative priors, an empirical example of linking primary school mathematics tests is presented. The results suggest that informative priors can increase the precision of linking without decreasing the accuracy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Di-isodityrosine is the intermolecular cross-link of isodityrosine-rich extensin analogs cross-linked in vitro.

    PubMed

    Held, Michael A; Tan, Li; Kamyab, Abdolreza; Hare, Michael; Shpak, Elena; Kieliszewski, Marcia J

    2004-12-31

    Extensins are cell wall hydroxyproline-rich glycoproteins that form covalent networks putatively involving tyrosyl and lysyl residues in cross-links catalyzed by one or more extensin peroxidases. The precise cross-links remain to be chemically identified both as network components in muro and as enzymic products generated in vitro with native extensin monomers as substrates. However, some extensin monomers contain variations within their putative cross-linking motifs that complicate cross-link identification. Other simpler extensins are recalcitrant to isolation including the ubiquitous P3-type extensin whose major repetitive motif, Hyp)(4)-Ser-Hyp-Ser-(Hyp)(4)-Tyr-Tyr-Tyr-Lys, is of particular interest, not least because its Tyr-Tyr-Tyr intramolecular isodityrosine cross-link motifs are also putative candidates for further intermolecular cross-linking to form di-isodityrosine. Therefore, we designed a set of extensin analogs encoding tandem repeats of the P3 motif, including Tyr --> Phe and Lys --> Leu variations. Expression of these P3 analogs in Nicotiana tabacum cells yielded glycoproteins with virtually all Pro residues hydroxylated and subsequently arabinosylated and with likely galactosylated Ser residues. This was consistent with earlier analyses of P3 glycopeptides isolated from cell wall digests and the predictions of the Hyp contiguity hypothesis. The tyrosine-rich P3 analogs also contained isodityrosine, formed in vivo. Significantly, these isodityrosine-containing analogs were further cross-linked in vitro by an extensin peroxidase to form the tetra-tyrosine intermolecular cross-link amino acid di-isodityrosine. This is the first identification of an inter-molecular cross-link amino acid in an extensin module and corroborates earlier suggestions that di-isodityrosine represents one mechanism for cross-linking extensins in muro.

  15. Preliminary Results from NASA/GSFC Ka-Band High Rate Demonstration for Near-Earth Communications

    NASA Technical Reports Server (NTRS)

    Wong, Yen; Gioannini, Bryan; Bundick, Steven N.; Miller, David T.

    2004-01-01

    In early 2000, the National Aeronautics and Space Administration (NASA) commenced the Ka-Band Transition Project (KaTP) as another step towards satisfying wideband communication requirements of the space research and earth exploration-satellite services. The KaTP team upgraded the ground segment portion of NASA's Space Network (SN) in order to enable high data rate space science and earth science services communications. The SN ground segment is located at the White Sands Complex (WSC) in New Mexico. NASA conducted the SN ground segment upgrades in conjunction with space segment upgrades implemented via the Tracking and Data Relay Satellite (TDRS)-HIJ project. The three new geostationary data relay satellites developed under the TDRS-HIJ project support the use of the inter-satellite service (ISS) allocation in the 25.25-27.5 GHz band (the 26 GHz band) to receive high speed data from low earth-orbiting customer spacecraft. The TDRS H spacecraft (designated TDRS-8) is currently operational at a 171 degrees west longitude. TDRS I and J spacecraft on-orbit testing has been completed. These spacecraft support 650 MHz-wide Ka-band telemetry links that are referred to as return links. The 650 MHz-wide Ka-band telemetry links have the capability to support data rates up to at least 1.2 Gbps. Therefore, the TDRS-HIJ spacecraft will significantly enhance the existing data rate elements of the NASA Space Network that operate at S-band and Ku-band.

  16. Adjustable link for kinematic mounting systems

    DOEpatents

    Hale, Layton C.

    1997-01-01

    An adjustable link for kinematic mounting systems. The adjustable link is a low-cost, passive device that provides backlash-free adjustment along its single constraint direction and flexural freedom in all other directions. The adjustable link comprises two spheres, two sockets in which the spheres are adjustable retain, and a connection link threadly connected at each end to the spheres, to provide a single direction of restraint and to adjust the length or distance between the sockets. Six such adjustable links provide for six degrees of freedom for mounting an instrument on a support. The adjustable link has applications in any machine or instrument requiring precision adjustment in six degrees of freedom, isolation from deformations of the supporting platform, and/or additional structural damping. The damping is accomplished by using a hollow connection link that contains an inner rod and a viscoelastic separation layer between the two.

  17. Adjustable link for kinematic mounting systems

    DOEpatents

    Hale, L.C.

    1997-07-01

    An adjustable link for kinematic mounting systems is disclosed. The adjustable link is a low-cost, passive device that provides backlash-free adjustment along its single constraint direction and flexural freedom in all other directions. The adjustable link comprises two spheres, two sockets in which the spheres are adjustable retain, and a connection link threadly connected at each end to the spheres, to provide a single direction of restraint and to adjust the length or distance between the sockets. Six such adjustable links provide for six degrees of freedom for mounting an instrument on a support. The adjustable link has applications in any machine or instrument requiring precision adjustment in six degrees of freedom, isolation from deformations of the supporting platform, and/or additional structural damping. The damping is accomplished by using a hollow connection link that contains an inner rod and a viscoelastic separation layer between the two. 3 figs.

  18. Inter-satellite time transfer: Techniques and applications

    NASA Technical Reports Server (NTRS)

    Detoma, Edoardo; Wardrip, S. Clark

    1990-01-01

    A brief review is presented of the well known time transfer techniques that have been studied and tested throughout the years. The applicability of time transfer techniques to a timing service as provided through a TDRS/DRS System, the problems related to the choice of the timing signal within the constraints imposed by the existing systems, and the possible practical implementations, including a description of the time synchronization support via TDRSS to the Gamma Ray Observatory (GRO) are discussed.

  19. Status of Electrostatic Accelerometer Development for Gravity Recovery and Climate Experiment Follow-On Mission (GRACE FO)

    NASA Astrophysics Data System (ADS)

    Perrot, Eddy; Boulanger, Damien; Christophe, Bruno; Foulon, Bernard; Liorzou, Françoise; Lebat, Vincent; Huynh, Phuong-Anh

    2015-04-01

    The GRACE FO mission, led by the JPL (Jet Propulsion Laboratory), is an Earth-orbiting gravity mission, continuation of the GRACE mission, which will produce an accurate model of the Earth's gravity field variation providing global climatic data during five years at least. The mission involves two satellites in a loosely controlled tandem formation, with a micro-wave link measuring the inter-satellites distance variation. Earth's mass distribution non-uniformities cause variations of the inter-satellite distance. This variation is measured to recover gravity, after subtracting the non-gravitational contributors, as the residual drag. ONERA (the French Aerospace Lab) is developing, manufacturing and testing electrostatic accelerometers measuring this residual drag applied on the satellites. The accelerometer is composed of two main parts: the Sensor Unit (including the Sensor Unit Mechanics - SUM - and the Front-End Electronic Unit - FEEU) and the Interface Control Unit - ICU. In the Accelerometer Core, located in the Sensor Unit Mechanics, the proof mass is levitated and maintained at the center of an electrode cage by electrostatic forces. Thus, any drag acceleration applied on the satellite involves a variation on the servo-controlled electrostatic suspension of the mass. The voltage on the electrodes providing this electrostatic force is the measurement output of the accelerometer. The impact of the accelerometer defaults (geometry, electronic and parasitic forces) leads to bias, misalignment and scale factor error, non-linearity and noise. Some of these accelerometer defaults are characterized by tests with micro-gravity pendulum bench on ground and with drops in ZARM catapult. The Critical Design Review was achieved successfully on September 2014. The Engineering Model (EM) was integrated and tested successfully, with ground levitation, drops, Electromagnetic Compatibility and thermal vacuum. The integration of the first Flight Model has begun on December 2014

  20. Tests Results of the Electrostatic Accelerometer Flight Models for Gravity Recovery and Climate Experiment Follow-On Mission (GRACE FO)

    NASA Astrophysics Data System (ADS)

    Perrot, E.; Boulanger, D.; Christophe, B.; Foulon, B.; Lebat, V.; Huynh, P. A.; Liorzou, F.

    2015-12-01

    The GRACE FO mission, led by the JPL (Jet Propulsion Laboratory), is an Earth-orbiting gravity mission, continuation of the GRACE mission, which will produce an accurate model of the Earth's gravity field variation providing global climatic data during five years at least. The mission involves two satellites in a loosely controlled tandem formation, with a micro-wave link measuring the inter-satellites distance variation. Earth's mass distribution non-uniformities cause variations of the inter-satellite distance. This variation is measured to recover gravity, after subtracting the non-gravitational contributors, as the residual drag. ONERA (the French Aerospace Lab) is developing, manufacturing and testing electrostatic accelerometers measuring this residual drag applied on the satellites. The accelerometer is composed of two main parts: the Sensor Unit (including the Sensor Unit Mechanics - SUM - and the Front-End Electronic Unit - FEEU) and the Interface Control Unit - ICU. In the Accelerometer Core, located in the Sensor Unit Mechanics, the proof mass is levitated and maintained at the center of an electrode cage by electrostatic forces. Thus, any drag acceleration applied on the satellite involves a variation on the servo-controlled electrostatic suspension of the mass. The voltage on the electrodes providing this electrostatic force is the output measurement of the accelerometer. The impact of the accelerometer defaults (geometry, electronic and parasitic forces) leads to bias, misalignment and scale factor error, non-linearity and noise. Some of these accelerometer defaults are characterized by tests with micro-gravity pendulum bench on ground and with drops in ZARM catapult. The Critical Design Review was achieved successfully on September 2014. The Engineering Model (EM) was integrated and tested successfully, with ground levitation, drops, Electromagnetic Compatibility and thermal vacuum. The integration of the two Flight Models was done on July 2015. The

  1. Status of Electrostatic Accelerometer Development for Gravity Recovery and Climate Experiment Follow-on Mission (GRACE FO)

    NASA Astrophysics Data System (ADS)

    Lebat, V.; Boulanger, D.; Christophe, B.; Foulon, B.; Liorzou, F.; Perrot, E.; Huynh, P. A.

    2014-12-01

    The GRACE FO mission, led by the JPL (Jet Propulsion Laboratory), is an Earth-orbiting gravity mission, continuation of the GRACE mission, which will produce an accurate model of the Earth's gravity field variation providing global climatic data during five years at least. The mission involves two satellites in a loosely controlled tandem formation, with a micro-wave link measuring the inter-satellites distance variation. Earth's mass distribution non-uniformities cause variations of the inter-satellite distance. This variation is measured to recover gravity, after subtracting the non-gravitational contributors, as the residual drag. ONERA (the French Aerospace Lab) is developing, manufacturing and testing electrostatic accelerometers measuring this residual drag applied on the satellites. The accelerometer is composed of two main parts: the Sensor Unit (including the Sensor Unit Mechanics - SUM - and the Front-End Electronic Unit - FEEU) and the Interface Control Unit - ICU. In the Accelerometer Core, located in the Sensor Unit Mechanics, the proof mass is levitated and maintained at the center of an electrode cage by electrostatic forces. Thus, any drag acceleration applied on the satellite involves a variation on the servo-controlled electrostatic suspension of the mass. The voltage on the electrodes providing this electrostatic force is the measurement output of the accelerometer. The impact of the accelerometer defaults (geometry, electronic and parasitic forces) leads to bias, misalignment and scale factor error, non-linearity and noise. Some of these accelerometer defaults are characterized by tests with micro-gravity pendulum bench on ground and with drops in ZARM catapult. The Preliminary Design Review was achieved successfully on November 2013. The Engineering Model (EM) was integrated successfully and is under test, with ground levitation, drops, Electromagnetic Compatibility and thermal vacuum. The complete EM tests will be achieved on October 2014. The

  2. iss012e15918

    NASA Image and Video Library

    2006-01-24

    ISS012-E-15918 (24 Jan. 2006) --- Belle Isle and a portion of Newfoundland, Canada are featured in this image photographed by an Expedition 12 crew member on the International Space Station. Belle Isle (center) is surrounded by sea ice in this recent winter view. Belle Isle lies in the strait between the Island of Newfoundland and Labrador (the mainland portion of Canada’s province of Newfoundland). Small islands along the coast of Labrador appear in the top left corner. In this key location Belle Isle lies on the shortest shipping lanes between the Great Lakes and Europe, and also on the main north-south shipping route to Hudson Bay and the Northwest Territories. Snow and ice in this recent winter view obliterate the dozens of glacier-scoured lakes that dot the surface of the island. The single community of Belle Isle Landing on the southeast tip is equally hard to see. Ice patterns also show that the island lies at the meeting point of two sea currents. The Labrador Current flows from the northwest (top left), and a smaller current, driven by dominant westerly winds, flows from the southwest (lower left) out of the narrow Belle Isle Strait (out of frame lower left). Flow lines in sea ice indicate the sense of movement of the ice. Ice floes embedded in the Labrador Current appear in the upper part of the image as a relatively open pattern. Sea ice with a denser pattern enters from the lower left corner, banking against the west side of Belle Isle. Tendrils flow around capes at either end of the island, with an ice-free “shadow” on the opposite, downstream side. Eddies (center) in the ice patterns show where the currents interact, north and west of the island.

  3. Can common measures of core stability distinguish performance in a shoulder pressing task under stable and unstable conditions?

    PubMed

    Keogh, Justin W L; Aickin, Sam E; Oldham, Anthony R H

    2010-02-01

    The primary purpose of this study was to determine whether a range of static core stability (CS) measures could distinguish shoulder press performance in unstable vs. stable conditions. Thirty resistance-trained men gave informed consent to participate in this study. One-repetition maximum strength (from < 6 repetitions) was predicted in the seated shoulder dumbbell press performed in unstable (Swiss ball[SB]) and stable (back-support bench) environments. Three CS muscle endurance tests were performed, with 4 CS ratios also calculated. The degree of strength decrement, referred to as the instability strength level (ISL), was calculated by dividing the predicted 1RM Unstable score by the 1RM Stable score. All subjects were categorized as high (ISL > 0.90), moderate (0.85 < or = ISL < or = 0.90), or low (ISL < 0.85). Between-group differences for the high- and low-ISL groups were assessed using analysis of variance and effect sizes. Pearson product moment correlations were then performed to examine the relationships between the CS measures and the ISL for the entire group. No significant between-group differences (p = 0.132-0.999) or large effect sizes were observed for any of the CS measures. Trunk flexion endurance was the only CS measure significantly correlated to the ISL (r = 0.477). In line with muscular strength research, these results suggest that CS exhibits relatively high levels of task specificity and that CS performance in static single-joint exercises may not be highly related to that in more dynamic multijoint activities. Core stability training (with or without a SB) may therefore only lead to significant improvements in functional dynamic performance if the postures, mode and velocity of contraction performed in training, are similar to the competitive tasks.

  4. Robo2 determines subtype-specific axonal projections of trigeminal sensory neurons

    PubMed Central

    Pan, Y. Albert; Choy, Margaret; Prober, David A.; Schier, Alexander F.

    2012-01-01

    How neurons connect to form functional circuits is central to the understanding of the development and function of the nervous system. In the somatosensory system, perception of sensory stimuli to the head requires specific connections between trigeminal sensory neurons and their many target areas in the central nervous system. Different trigeminal subtypes have specialized functions and downstream circuits, but it has remained unclear how subtype-specific axonal projection patterns are formed. Using zebrafish as a model system, we followed the development of two trigeminal sensory neuron subtypes: one that expresses trpa1b, a nociceptive channel important for sensing environmental chemicals; and a distinct subtype labeled by an islet1 reporter (Isl1SS). We found that Trpa1b and Isl1SS neurons have overall similar axon trajectories but different branching morphologies and distributions of presynaptic sites. Compared with Trpa1b neurons, Isl1SS neurons display reduced branch growth and synaptogenesis at the hindbrain-spinal cord junction. The subtype-specific morphogenesis of Isl1SS neurons depends on the guidance receptor Robo2. robo2 is preferentially expressed in the Isl1SS subset and inhibits branch growth and synaptogenesis. In the absence of Robo2, Isl1SS afferents acquire many of the characteristics of Trpa1b afferents. These results reveal that subtype-specific activity of Robo2 regulates subcircuit morphogenesis in the trigeminal sensory system. PMID:22190641

  5. Japan Link Center (JaLC): link management and DOI assignment for Japanese electronic scholarly contents

    NASA Astrophysics Data System (ADS)

    Kato, Takafumi; Tsuchiya, Eri; Kubota, Soichi; Miyagawa, Yoshiyuki

    JST, cooperated with several national institutes, is currently developing “Japan Link Center”, which manages Japanese electronic scholarly contents (journal articles, books, dissertations etc.) in an integrated fashion using Digital Object Identifier (DOI). Japan Link Center will manage metadata and whereabouts information of the contents in the digital environment and provide domestic and international linking information, cite/cited information to activate dissemination of S&T information, furthermore, to strengthen transmission of S&T information from Japan. Japan Link Center is expected to be appointed as the 9th DOI registration agency (RA) in the world by the International DOI Foundation (IDF) this spring.

  6. A conceptual framework for international service-learning course planning: promoting a foundation for ethical practice in the physical therapy and occupational therapy professions.

    PubMed

    Lattanzi, Jill Black; Pechak, Celia

    2011-01-01

    As physical therapy (PT) and occupational therapy (OT) educational programs endeavor to foster core values of social responsibility, justice, and altruism in an increasingly global community, the incorporation of local and international service-learning (ISL) into the curriculum is growing. Much of the research has focused on the measurement of student learning, with little written about the impact on the host community. Proponents of global health initiatives are calling for consideration of all stakeholders to ensure ethical practice. This paper explores the current literature related to PT and OT ISL and builds a conceptual framework for ISL course planning. The essential phases in the framework include: 1) pre-experience planning/preparation stage, 2) field immersion experience stage, and 3) postexperience stage. The essential elements are: 1) cultural competency training, 2) communication and coordination with community, 3) comprehensive assessment, and 4) strategic planning. The authors suggest this framework as a practical tool to structure ISL courses with an explicit emphasis on ethical concerns. Additionally, they seek to foster more dialogue and action related to the promotion of ethical practices in ISL in PT and OT education programs.

  7. Experimental and Numerical Investigation of Vortical Structures in Lean Premixed Swirl-Stabilized Combustion

    NASA Astrophysics Data System (ADS)

    Taamallah, Soufien; Chakroun, Nadim; Shanbhogue, Santosh; Kewlani, Gaurav; Ghoniem, Ahmed

    2015-11-01

    A combined experimental and LES investigation is performed to identify the origin of major flow dynamics and vortical structures in a model gas turbine's swirl-stabilized turbulent combustor. Swirling flows in combustion lead to the formation of complex flow dynamics and vortical structures that can interact with flames and influence its stabilization. Our experimental results for non-reacting flow show the existence of large scale precession motion. The precessing vortex core (PVC) dynamics disappears with combustion but only above a threshold of equivalence ratio. In addition, large scale vortices along the inner shear layer (ISL) are observed. These structures interact with the ISL stabilized flame and contribute to its wrinkling. Next, the LES setup is validated against the flow field's low-order statistics and point temperature measurement in relevant areas of the chamber. Finally, we show that LES is capable of predicting the precession motion as well as the ISL vortices in the reacting case: we find that ISL vortices originate from a vortex core that is formed right downstream of the swirler's centerbody. The vortex core has a conical spiral shape resembling a corkscrew that interacts - as it winds out - with the flame when it reaches the ISL.

  8. Allergic sensitization and filaggrin variants predispose to the comorbidity of eczema, asthma, and rhinitis: results from the Isle of Wight birth cohort

    PubMed Central

    Ziyab, Ali H.; Karmaus, Wilfried; Zhang, Hongmei; Holloway, John W.; Steck, Susan E.; Ewart, Susan; Arshad, Syed Hasan

    2014-01-01

    Background Allergic sensitization and filaggrin gene (FLG) variants are important risk factors for allergic disorders; however, knowledge on their individual and interactive effects on the coexistence of eczema, asthma, and rhinitis is lacking. Objective This study aimed at investigating the single and combined effects of allergic sensitization and FLG variants on the development of single and multiple allergic disorders. Methods The Isle of Wight Birth Cohort (n = 1,456) has been examined at 1, 2, 4, 10, and 18 years of age. Repeated measurements of eczema, asthma, rhinitis, and skin prick tests were available for all follow-ups. FLG variants were genotyped in 1,150 participants. Associations of allergic sensitization and FLG variants with single and multiple allergic disorders were tested in log-binomial regression analysis. Results The prevalence of eczema-, asthma-, and rhinitis-only ranged from 5.6% to 8.5%, 4.9% to 10.2%, and 2.5% to 20.4%, respectively, during the first 18 years of life. The coexistence of allergic disorders is common, with approximately 2% of the population reporting the comorbidity of “eczema, asthma, and rhinitis” during the study period. In repeated measurement analyses, allergic sensitization and FLG variants, when analyzed separately, were associated with having single and multiple allergic disorders. Of particular significance, their combined effect increased the risk of “eczema and asthma” (RR = 13.67, 95% CI: 7.35 – 25.42), “asthma and rhinitis” (RR = 7.46, 95% CI: 5.07 – 10.98), and “eczema, asthma, and rhinitis” (RR = 23.44, 95% CI: 12.27 – 44.78). Conclusions and Clinical Relevance The coexistence of allergic disorders is frequent and allergic sensitization and FLG variants jointly increased risk of allergic comorbidities, which may represent more severe and complex clinical phenotypes. The interactive effect and the elevated proportion of allergic comorbidities associated with allergic sensitization and FLG

  9. Design and modelling of a link monitoring mechanism for the Common Data Link (CDL)

    NASA Astrophysics Data System (ADS)

    Eichelberger, John W., III

    1994-09-01

    The Common Data Link (CDL) is a full duplex, point-to-point microwave communications system used in imagery and signals intelligence collection systems. It provides a link between two remote Local Area Networks (LAN's) aboard collection and surface platforms. In a hostile environment, there is an overwhelming need to dynamically monitor the link and thus, limit the impact of jamming. This work describes steps taken to design, model, and evaluate a link monitoring system suitable for the CDL. The monitoring system is based on features and monitoring constructs of the Link Control Protocol (LCP) in the Point-to-Point Protocol (PPP) suite. The CDL model is based on a system of two remote Fiber Distributed Data Interface (FDDI) LAN's. In particular, the policies and mechanisms associated with monitoring are described in detail. An implementation of the required mechanisms using the OPNET network engineering tool is described. Performance data related to monitoring parameters is reported. Finally, integration of the FDDI-CDL model with the OPNET Internet model is described.

  10. [Sex-linked juvenile retinoschisis].

    PubMed

    François, P; Turut, P; Soltysik, C; Hache, J C

    1976-02-01

    About 13 observations of sexe linked juvenile retinoschisis, the authors describe the ophthalmoscopic, fluorographic and functional aspects of the disease whose caracteristics are:--its sexe linked recessive heredity; --its clinical characterestics associating: a microcystic macular degeneration, peripheral retinal lesions, vitreous body alterations, --an electroretinogram of the negative type.

  11. FAA Air Traffic Activity. Fiscal Year 1984.

    DTIC Science & Technology

    1984-09-30

    ZRC 2 0 0 2 0 PRESCOTT A? N ZAB 111 2 36 66 7 PRESQUE ISLE ME N I TBW 249 9 80 P5 67 PRESQUE ISLE ME N low 1831 6 1186 51C 129 _ PRESTON NJ N I WRI...FTS 226-7816, Commerical Commercial 202-472-7478. 313-226-7816. Int’l Communication Agency, 1776 Pennsylvania Houston Bookstore, 45 College Center...OPERATIONS 211137 105151 13288 67476 25222 SALEM "CNARY FIELD ISLE ) N40 ITINERANT OPERATIONS 44167 0 2029 37960 6178 LOCAL OPERATIONS 19359 15697 3662

  12. Great Lakes and St. Lawrence Seaway Navigation Season Extension. Volume 1. Main Report and Final Environmental Impact Statement

    DTIC Science & Technology

    1979-08-01

    MN - Taconite, MN - Silver Bay, MN - Presque Isle , MI - Marquette, MI 30 iC V.)Lake Michigan - Burns Harbor, IN - Gary, IN - Indiana, IN - Milwaukee...14,263 3.7 Presque Isle , MI 1,703 516 3.3 Marquette, MI 159 192 0.8 Taconite, MN 5,640 1,723 3.3 Silver Bay, MN 5,623 1,744 3.2 Ash-and, WI 250 668 0.4...required -for Taconite, Two Harbors, and Presque Isle and that only a single line of bubblers would be required in Ashland, MaLquette, and Silver Bay

  13. Genetics Home Reference: X-linked thrombocytopenia

    MedlinePlus

    ... Facebook Twitter Home Health Conditions X-linked thrombocytopenia X-linked thrombocytopenia Printable PDF Open All Close All ... Javascript to view the expand/collapse boxes. Description X-linked thrombocytopenia is a bleeding disorder that primarily ...

  14. Protective link for superconducting coil

    DOEpatents

    Umans, Stephen D [Belmont, MA

    2009-12-08

    A superconducting coil system includes a superconducting coil and a protective link of superconducting material coupled to the superconducting coil. A rotating machine includes first and second coils and a protective link of superconducting material. The second coil is operable to rotate with respect to the first coil. One of the first and second coils is a superconducting coil. The protective link is coupled to the superconducting coil.

  15. Using ATM over SATCOM links

    NASA Technical Reports Server (NTRS)

    Comparetto, Gary M.

    1995-01-01

    The Asynchronous Transfer Mode (ATM) protocol is studied from the standpoint of determining what limitations, if any, exist in using it over satellite links. It is concluded that, while there is nothing intrinsic about ATM that would generally preclude its use over satellite links, there are, however, several intrinsic characteristics of satellite links, as well as some satellite system configuration-specific issues, that must be taken into account.

  16. Optical communication in free space

    NASA Technical Reports Server (NTRS)

    Plotkin, H. H.; Mcavoy, N.; Fitzmaurice, M. W.

    1974-01-01

    Two classes of laser communication systems for handling very high data rates across inter-satellite distances are considered that provide for high antenna gains, wide modulation bandwidths, and optical receiver sensitivities. System design considerations are based upon the carbon dioxide laser modulation to accommodate digital or analog information, and the neodymium doped YAG laser pulse for digital modulation.

  17. micromap: A Package for Linked Micromaps

    EPA Science Inventory

    The R package micromap is used to create linked micromaps, which display statistical summaries associated with areal units, or polygons. Linked micromaps provide a means to simultaneously summarize and display both statistical and geographic distributions by linking statistical ...

  18. Spatial-Operator Algebra For Flexible-Link Manipulators

    NASA Technical Reports Server (NTRS)

    Jain, Abhinandan; Rodriguez, Guillermo

    1994-01-01

    Method of computing dynamics of multiple-flexible-link robotic manipulators based on spatial-operator algebra, which originally applied to rigid-link manipulators. Aspects of spatial-operator-algebra approach described in several previous articles in NASA Tech Briefs-most recently "Robot Control Based on Spatial-Operator Algebra" (NPO-17918). In extension of spatial-operator algebra to manipulators with flexible links, each link represented by finite-element model: mass of flexible link apportioned among smaller, lumped-mass rigid bodies, coupling of motions expressed in terms of vibrational modes. This leads to operator expression for modal-mass matrix of link.

  19. A Link-Level Simulator of the cdma2000 Reverse-Link Physical Layer

    PubMed Central

    Gharavi, H.; Chin, F.; Ban, K.; Wyatt-Millington, R.

    2003-01-01

    The cdma2000 system is an evolutionary enhancement of the IS-95 standards which support 3G services defined by the International Telecommunications Union (ITU). cdma2000 comes in two phases: 1XRTT and 3XRTT (1X and 3X indicates the number of 1.25 MHz wide radio carrier channels used and RTT stands for Radio Transmission Technology). The cdma2000 1XRTT, which operates within a 1.25 MHz bandwidth, can be utilized in existing IS-95 CDMA channels as it uses the same bandwidth, while 3XRTT requires the commitment of 5 MHz bandwidth to support higher data rates. This paper describes a software model implementation of the cdma2000 reverse link and its application for evaluating the effect of rake receiver design parameters on the system performance under various multipath fading conditions. The cdma2000 models were developed at the National Institute of Standards and Technology (NIST), using SPW (Signal Processing Worksystem) commercial software tools. The model has been developed in a generic manner that includes all the reverse link six radio configurations and their corresponding data rates, according to cdma2000 specifications. After briefly reviewing the traffic channel characteristics of the cdma2000 reverse link (subscriber to base station), the paper discusses the rake receiver implementation including an ideal rake receiver. It then evaluates the performance of each receiver for a Spreading Rate 3 (3XRTT) operation, which is considered as a true “3G” cdma2000 technology. These evaluations are based on the vehicular IMT-2000 (International Mobile Telecommunication 2000) channel model using the link budget defined in cdma2000 specifications for the reverse link. PMID:27413613

  20. Radio Links for the NASA ABTS

    NASA Technical Reports Server (NTRS)

    Jeutter, Dean C.

    1996-01-01

    Goals Determine Out-Link FSK Bandwidth Develop FSK Outlink Transmitter Develop Wideband Outlink FSK Receiver Develop OOK In-Link Transmitter Develop OOK In-Link Receiver Marry Out-Link & In-Link Components Outlink FSK Bandwidth preliminary inlink transmitter were accomplished in Summer 1995 visit. The calculation of FSK bandwidth is repeated in these notes. Spectrum analyzer measurements of the actual FSK spectrum agree well with the calculations. The goal to develop a wideband FSK receiver for outlink data was given first priority for end of Summer 1996 completion. The goal of developing OOK inlink transmitter and receiver system components and interfacing all outlink and inlink components into an operating closed loop prototypical system was given a December 1, 1996 completion date.

  1. 33 CFR 80.707 - Cape Romain, SC to Sullivans Island, SC.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... from Dewees Island to Isle of Palms. (f) A line formed by the centerline of the highway bridge between Isle of Palms and Sullivans Island over Breach Inlet. ... Island, SC. 80.707 Section 80.707 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND...

  2. 33 CFR 80.707 - Cape Romain, SC to Sullivans Island, SC.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... from Dewees Island to Isle of Palms. (f) A line formed by the centerline of the highway bridge between Isle of Palms and Sullivans Island over Breach Inlet. ... Island, SC. 80.707 Section 80.707 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND...

  3. Transportation Lines on the Great Lakes System; Transportation Series 3; 1980.

    DTIC Science & Technology

    1982-05-01

    I 94 24 29 O 22. SPAR NONE CALCITE, 1952 ELECTRIC, STEEL MICH. (221 LITTON GREAT LA ES CORP, MJV PRESQUE ISLE TOWBOAT; STEEL 107 141 IS S4 5 2 21...1464 - -6 LIGHT NONE ERIE , PA, 1973PRESQUE ISLE BARGE, STEEL 22251 94 974 104 104 . 12 - 5720 7 6, LIGHT SE4F-UNLOADIN- DO 1973 ELEC., 250’ BOOM- 10,000...MOTOR, DIESEL. 1 37 41 I t 230 -, PAST NONE LGONAC. 1948 STEEL NIC. (23) PARKER BOAT 4INI ERIE ISLE MOTOR, DIESEL, 4 6 6 24 2 9 330 2 16014o LIGHT

  4. Knickpoint retreat and transient bedrock channel morphology triggered by base-level fall in small bedrock river catchments: The case of the Isle of Jura, Scotland

    NASA Astrophysics Data System (ADS)

    Castillo, Miguel; Bishop, Paul; Jansen, John D.

    2013-01-01

    A sudden drop in river base-level can trigger a knickpoint that propagates throughout the fluvial network causing a transient state in the landscape. Knickpoint retreat has been confirmed in large fluvial settings (drainage areas > 100 km2) and field data suggest that the same applies to the case of small bedrock river catchments (drainage areas < 100 km2). Nevertheless, knickpoint recession on resistant lithologies with structure that potentially affects the retreat rate needs to be confirmed with field-based data. Moreover, it remains unclear whether small bedrock rivers can absorb base-level fall via knickpoint retreat. Here we evaluate the response of small bedrock rivers to base-level fall on the isle of Jura in western Scotland (UK), where rivers incise into dipping quartzite. The mapping of raised beach deposits and strath terraces, and the analysis of stream long profiles, were used to identify knickpoints that had been triggered by base-level fall. Our results indicate that the distance of knickpoint retreat scales to the drainage area in a power law function irrespective of structural setting. On the other hand, local channel slope and basin size influence the vertical distribution of knickpoints. As well, at low drainage areas (~ 4 km2) rivers are unable to absorb the full amount of base-level fall and channel reach morphology downstream of the knickpoint tends towards convexity. The results obtained here confirm that knickpoint retreat is mostly controlled by stream discharge, as has been observed for other transient landscapes. Local controls, reflecting basin size and channel slope, have an effect on the vertical distribution of knickpoints; such controls are also related to the ability of rivers to absorb the base-level fall.

  5. Shuttle/TDRSS modelling and link simulation study

    NASA Technical Reports Server (NTRS)

    Braun, W. R.; Mckenzie, T. M.; Biederman, L.; Lindsey, W. C.

    1979-01-01

    A Shuttle/TDRSS S-band and Ku-band link simulation package called LinCsim was developed for the evaluation of link performance for specific Shuttle signal designs. The link models were described in detail and the transmitter distortion parameters or user constraints were carefully defined. The overall link degradation (excluding hardware degradations) relative to an ideal BPSK channel were given for various sets of user constraint values. The performance sensitivity to each individual user constraint was then illustrated. The effect of excessive Spacelab clock jitter on the return link BER performance was also investigated as was the problem of subcarrier recovery for the K-band Shuttle return link signal.

  6. Performance of a laser microsatellite network with an optical preamplifier.

    PubMed

    Arnon, Shlomi

    2005-04-01

    Laser satellite communication (LSC) uses free space as a propagation medium for various applications, such as intersatellite communication or satellite networking. An LSC system includes a laser transmitter and an optical receiver. For communication to occur, the line of sight of the transmitter and the receiver must be aligned. However, mechanical vibration and electronic noise in the control system reduce alignment between the transmitter laser beam and the receiver field of view (FOV), which results in pointing errors. The outcome of pointing errors is fading of the received signal, which leads to impaired link performance. An LSC system is considered in which the optical preamplifier is incorporated into the receiver, and a bit error probability (BEP) model is derived that takes into account the statistics of the pointing error as well as the optical amplifier and communication system parameters. The model and the numerical calculation results indicate that random pointing errors of sigma(chi)2G > 0.05 penalize communication performance dramatically for all combinations of optical amplifier gains and noise figures that were calculated.

  7. Data distribution satellite

    NASA Technical Reports Server (NTRS)

    Price, Kent M.; Jorasch, Ronald E.; Wiskerchen, Michael J.

    1991-01-01

    A description is given of a data distribution satellite (DDS) system. The DDS would operate in conjunction with the tracking and data relay satellite system to give ground-based users real time, two-way access to instruments in space and space-gathered data. The scope of work includes the following: (1) user requirements are derived; (2) communication scenarios are synthesized; (3) system design constraints and projected technology availability are identified; (4) DDS communications payload configuration is derived, and the satellite is designed; (5) requirements for earth terminals and network control are given; (6) system costs are estimated, both life cycle costs and user fees; and (7) technology developments are recommended, and a technology development plan is given. The most important results obtained are as follows: (1) a satellite designed for launch in 2007 is feasible and has 10 Gb/s capacity, 5.5 kW power, and 2000 kg mass; (2) DDS features include on-board baseband switching, use of Ku- and Ka-bands, multiple optical intersatellite links; and (3) system user costs are competitive with projected terrestrial communication costs.

  8. Cross-Link Guided Molecular Modeling with ROSETTA

    PubMed Central

    Leitner, Alexander; Rosenberger, George; Aebersold, Ruedi; Malmström, Lars

    2013-01-01

    Chemical cross-links identified by mass spectrometry generate distance restraints that reveal low-resolution structural information on proteins and protein complexes. The technology to reliably generate such data has become mature and robust enough to shift the focus to the question of how these distance restraints can be best integrated into molecular modeling calculations. Here, we introduce three workflows for incorporating distance restraints generated by chemical cross-linking and mass spectrometry into ROSETTA protocols for comparative and de novo modeling and protein-protein docking. We demonstrate that the cross-link validation and visualization software Xwalk facilitates successful cross-link data integration. Besides the protocols we introduce XLdb, a database of chemical cross-links from 14 different publications with 506 intra-protein and 62 inter-protein cross-links, where each cross-link can be mapped on an experimental structure from the Protein Data Bank. Finally, we demonstrate on a protein-protein docking reference data set the impact of virtual cross-links on protein docking calculations and show that an inter-protein cross-link can reduce on average the RMSD of a docking prediction by 5.0 Å. The methods and results presented here provide guidelines for the effective integration of chemical cross-link data in molecular modeling calculations and should advance the structural analysis of particularly large and transient protein complexes via hybrid structural biology methods. PMID:24069194

  9. Testing mate choice and overdominance at MH in natural families of Atlantic salmon Salmo salar.

    PubMed

    Tentelier, C; Barroso-Gomila, O; Lepais, O; Manicki, A; Romero-Garmendia, I; Jugo, B M

    2017-04-01

    This study aimed to test mate choice and selection during early life stages on major histocompatibility (MH) genotype in natural families of Atlantic salmon Salmo salar spawners and juveniles, using nine microsatellites to reconstruct families, one microsatellite linked to an MH class I gene and one minisatellite linked to an MH class II gene. MH-based mate choice was only detected for the class I locus on the first year, with lower expected heterozygosity in the offspring of actually mated pairs than predicted under random mating. The genotype frequencies of MH-linked loci observed in the juveniles were compared with frequencies expected from Mendelian inheritance of parental alleles to detect selection during early life stages. No selection was detected on the locus linked to class I gene. For the locus linked to class II gene, observed heterozygosity was higher than expected in the first year and lower in the second year, suggesting overdominance and underdominance, respectively. Within family, juveniles' body size was linked to heterozygosity at the same locus, with longer heterozygotes in the first year and longer homozygotes in the second year. Selection therefore seems to differ from one locus to the other and from year to year. © 2017 The Fisheries Society of the British Isles.

  10. Seismic link at plate boundary

    NASA Astrophysics Data System (ADS)

    Ramdani, Faical; Kettani, Omar; Tadili, Benaissa

    2015-06-01

    Seismic triggering at plate boundaries has a very complex nature that includes seismic events at varying distances. The spatial orientation of triggering cannot be reduced to sequences from the main shocks. Seismic waves propagate at all times in all directions, particularly in highly active zones. No direct evidence can be obtained regarding which earthquakes trigger the shocks. The first approach is to determine the potential linked zones where triggering may occur. The second step is to determine the causality between the events and their triggered shocks. The spatial orientation of the links between events is established from pre-ordered networks and the adapted dependence of the spatio-temporal occurrence of earthquakes. Based on a coefficient of synchronous seismic activity to grid couples, we derive a network link by each threshold. The links of high thresholds are tested using the coherence of time series to determine the causality and related orientation. The resulting link orientations at the plate boundary conditions indicate that causal triggering seems to be localized along a major fault, as a stress transfer between two major faults, and parallel to the geothermal area extension.

  11. Links | CTIO

    Science.gov Websites

    MNRAS New Astronomy New Scientist PASP SAO/NASA ADS Science StarHeads (people) Newsletters, Newspapers & Other Links 4th Region Info Astronomy Pic of the Day AstroWeb CDS AstroResources STScI BBC news

  12. 76 FR 61472 - Culturally Significant Objects Imported for Exhibition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... DEPARTMENT OF STATE [Public Notice: 7634] Culturally Significant Objects Imported for Exhibition Determinations: ``The Game of Kings: Medieval Ivory Chessmen From the Isle of Lewis'' SUMMARY: Notice is hereby... objects to be included in the exhibition ``The Game of Kings: Medieval Ivory Chessmen from the Isle of...

  13. 75 FR 31505 - Bureau of Political-Military Affairs: Directorate of Defense Trade Controls; Notifications to the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-03

    ... Satellite from the Baikonur Cosmodrome in Kazakhstan. The United States Government is prepared to license... support the transfer of the ProtoStarII satellite Commercial Communication Satellite from ProtoStar Satellite Systems, Inc., Bermuda to SES Satellite Leasing Limited, Isle of Man, British Isles. The United...

  14. Interdisciplinary Teams, Mentorship and Intergenerational Service-Learning

    ERIC Educational Resources Information Center

    Weinreich, Donna M.

    2004-01-01

    This paper discusses the implementation of an intergenerational service-learning (IS-L) project with a mentorship component for graduate students at Western Michigan University's Gerontology Program. Two classes of students, one graduate and one undergraduate, taking introductory gerontology courses were brought together to complete IS-L projects…

  15. The OceanLink Project

    NASA Astrophysics Data System (ADS)

    Narock, T.; Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Finin, T.; Hitzler, P.; Krisnadhi, A.; Raymond, L. M.; Shepherd, A.; Wiebe, P. H.

    2014-12-01

    A wide spectrum of maturing methods and tools, collectively characterized as the Semantic Web, is helping to vastly improve the dissemination of scientific research. Creating semantic integration requires input from both domain and cyberinfrastructure scientists. OceanLink, an NSF EarthCube Building Block, is demonstrating semantic technologies through the integration of geoscience data repositories, library holdings, conference abstracts, and funded research awards. Meeting project objectives involves applying semantic technologies to support data representation, discovery, sharing and integration. Our semantic cyberinfrastructure components include ontology design patterns, Linked Data collections, semantic provenance, and associated services to enhance data and knowledge discovery, interoperation, and integration. We discuss how these components are integrated, the continued automated and semi-automated creation of semantic metadata, and techniques we have developed to integrate ontologies, link resources, and preserve provenance and attribution.

  16. Plan of advanced satellite communication experiments using ETS-6

    NASA Technical Reports Server (NTRS)

    Ikegami, Tetsushi

    1989-01-01

    In 1992, an Engineering Test Satellite 6 is scheduled to be launched by an H-2 rocket. The missions of ETS-6 are to establish basic technologies of inter-satellite communications using S-band, millimeter waves and optical beams and of fixed and mobile satellite communications using multibeam antenna on board the satellite. A plan of the experiments is introduced.

  17. Track with overlapping links for dry coal extrusion pumps

    DOEpatents

    Saunders, Timothy; Brady, John D

    2014-01-21

    A chain for a particulate material extrusion pump includes a plurality of links, each of the plurality of links having a link body and a link ledge, wherein each link ledge of the plurality of links at least partially overlaps the link body of an adjacent one of the plurality of links.

  18. Going global in physical therapist education: International Service-Learning in US-based programmes.

    PubMed

    Pechak, Celia; Thompson, Mary

    2011-12-01

     Internationalization is expanding its presence in higher education in the United States. Reflecting this trend that includes incorporating global perspectives in the curricula, physical therapist education programmes increasingly offer international opportunities such as International Service-Learning (ISL) to their students. Service-learning, a teaching strategy that integrates community service with structured learning activities, has gained broad acceptance in health professions education including physical therapy, and is therefore the focus of this paper. The specific purposes of this paper were to identify and analyse the commonalities that existed among established ISL programmes within physical therapist education programmes in terms of structures and processes, and to consider its broader implications for physical therapist education.   A descriptive, exploratory study was performed using grounded theory. Snowball and purposive, theoretical sampling yielded 14 faculty members with experience in international service, international learning or ISL in physical therapist education programmes. Faculty were interviewed by phone. Interview transcriptions and course documents were analysed applying grounded theory methodology. Data from eight programmes which met the operational definition of established ISL were used to address the purposes of this paper.   Five phases of establishing an ISL programme were identified: development, design, implementation, evaluation, and enhancement. Although no single model exists for ISL in physical therapist education; commonalities in structures and processes were identified in each phase. However, attention to service objectives and outcomes is lacking.   While analysis revealed that each programme shared commonalities and demonstrated differences in structures and processes compared with the other programmes, the study demonstrated a general lack of focus on formal community outcomes which raises ethical

  19. Mapping the x-linked lymphoproliferative syndrome

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Skare, J.C.; Milunsky, A.; Byron, K.S.

    1987-04-01

    The X-linked lymphoproliferative syndrome is triggered by Epstein-Barr virus infection and results in fatal mononucleosis, immunodeficiency, and lymphoproliferative disorders. This study shows that the mutation responsible for X-linked lymphoproliferative syndrome is genetically linked to a restriction fragment length polymorphism detected with the DXS42 probe (from Xq24-q27). The most likely recombination frequency between the loci is 4%, and the associated logarithm of the odds is 5.26. Haplotype analysis using flanking restriction fragment length polymorphism markers indicates that the locus for X-linked lymphoproliferative syndrome is distal to probe DXS42 but proximal to probe DXS99 (from Xq26-q27). It is now possible to predictmore » which members of a family with X-linked lymphoproliferative syndrome are carrier females and to diagnose the syndrome prenatally.« less

  20. Survival at Isle Royale.

    ERIC Educational Resources Information Center

    Ballone, Lena M.

    2001-01-01

    Describes a simulation based on the popular television show "Survivor" in which students work in groups and study physiological needs for human survival. Focuses on communication skills, problem solving, and cooperative learning. (YDS)

  1. Link Correlated Military Data for Better Decision Support

    DTIC Science & Technology

    2011-06-01

    automatically translated into URI based links, thus can greatly reduce man power cost on software development. 3 Linked Data Technique Tim Berners - Lee ...Linked Data - while Linked Data is usually considered as part of Semantic Web, or “the Semantic Web done right” as described by Tim himself - has been...Required data of automatic link construction mechanism on more kinds of correlations. References [1] B. L. Tim , “The next Web of open, linked data

  2. Of Mice and ‘Convicts’: Origin of the Australian House Mouse, Mus musculus

    PubMed Central

    Gabriel, Sofia I.; Stevens, Mark I.; Mathias, Maria da Luz; Searle, Jeremy B.

    2011-01-01

    The house mouse, Mus musculus, is one of the most ubiquitous invasive species worldwide and in Australia is particularly common and widespread, but where it originally came from is still unknown. Here we investigated this origin through a phylogeographic analysis of mitochondrial DNA sequences (D-loop) comparing mouse populations from Australia with those from the likely regional source area in Western Europe. Our results agree with human historical associations, showing a strong link between Australia and the British Isles. This outcome is of intrinsic and applied interest and helps to validate the colonization history of mice as a proxy for human settlement history. PMID:22174847

  3. International Service Learning: Analytical Review of Published Research Literature

    ERIC Educational Resources Information Center

    Dixon, Brett

    2015-01-01

    International service learning (ISL) is an emerging area of international education. This paper summarizes academic journal articles on ISL programs and organizes the relevant publications by academic disciplines, service learning project areas, and other topics. The basis for this review is relevant literature from full-text scholarly peer…

  4. Theoretical Frames and Teaching Styles of Physical Therapy Faculty Who Lead International Service-Learning Experiences

    ERIC Educational Resources Information Center

    Audette, Jennifer Gail

    2011-01-01

    Purpose: International service-learning (ISL) is popular in higher education, and many physical therapy educational programs are adding ISL opportunities to their curricula because doing so aligns with student interest and the increasingly global nature of the profession. The faculty leading these experiences have not been studied. Nearly all…

  5. Research Supporting Satellite Communications Technology

    NASA Technical Reports Server (NTRS)

    Horan Stephen; Lyman, Raphael

    2005-01-01

    This report describes the second year of research effort under the grant Research Supporting Satellite Communications Technology. The research program consists of two major projects: Fault Tolerant Link Establishment and the design of an Auto-Configurable Receiver. The Fault Tolerant Link Establishment protocol is being developed to assist the designers of satellite clusters to manage the inter-satellite communications. During this second year, the basic protocol design was validated with an extensive testing program. After this testing was completed, a channel error model was added to the protocol to permit the effects of channel errors to be measured. This error generation was used to test the effects of channel errors on Heartbeat and Token message passing. The C-language source code for the protocol modules was delivered to Goddard Space Flight Center for integration with the GSFC testbed. The need for a receiver autoconfiguration capability arises when a satellite-to-ground transmission is interrupted due to an unexpected event, the satellite transponder may reset to an unknown state and begin transmitting in a new mode. During Year 2, we completed testing of these algorithms when noise-induced bit errors were introduced. We also developed and tested an algorithm for estimating the data rate, assuming an NRZ-formatted signal corrupted with additive white Gaussian noise, and we took initial steps in integrating both algorithms into the SDR test bed at GSFC.

  6. Toward link predictability of complex networks

    PubMed Central

    Lü, Linyuan; Pan, Liming; Zhou, Tao; Zhang, Yi-Cheng; Stanley, H. Eugene

    2015-01-01

    The organization of real networks usually embodies both regularities and irregularities, and, in principle, the former can be modeled. The extent to which the formation of a network can be explained coincides with our ability to predict missing links. To understand network organization, we should be able to estimate link predictability. We assume that the regularity of a network is reflected in the consistency of structural features before and after a random removal of a small set of links. Based on the perturbation of the adjacency matrix, we propose a universal structural consistency index that is free of prior knowledge of network organization. Extensive experiments on disparate real-world networks demonstrate that (i) structural consistency is a good estimation of link predictability and (ii) a derivative algorithm outperforms state-of-the-art link prediction methods in both accuracy and robustness. This analysis has further applications in evaluating link prediction algorithms and monitoring sudden changes in evolving network mechanisms. It will provide unique fundamental insights into the above-mentioned academic research fields, and will foster the development of advanced information filtering technologies of interest to information technology practitioners. PMID:25659742

  7. Library links on medical school home pages.

    PubMed

    Thomas, Sheila L

    2011-01-01

    The purpose of this study was to assess the websites of American Association of Medical Colleges (AAMC)-member medical schools for the presence of library links. Sixty-one percent (n = 92) of home pages of the 150 member schools of the AAMC contain library links. For the 58 home pages not offering such links, 50 provided a pathway of two or three clicks to a library link. The absence of library links on 39% of AAMC medical school home pages indicates that the designers of those pages did not consider the library to be a primary destination for their visitors.

  8. Genetics Home Reference: X-linked dilated cardiomyopathy

    MedlinePlus

    ... Twitter Home Health Conditions X-linked dilated cardiomyopathy X-linked dilated cardiomyopathy Printable PDF Open All Close ... Javascript to view the expand/collapse boxes. Description X-linked dilated cardiomyopathy is a form of heart ...

  9. Genetics Home Reference: X-linked myotubular myopathy

    MedlinePlus

    ... Twitter Home Health Conditions X-linked myotubular myopathy X-linked myotubular myopathy Printable PDF Open All Close ... Javascript to view the expand/collapse boxes. Description X-linked myotubular myopathy is a condition that primarily ...

  10. Genetics Home Reference: X-linked sideroblastic anemia

    MedlinePlus

    ... Twitter Home Health Conditions X-linked sideroblastic anemia X-linked sideroblastic anemia Printable PDF Open All Close ... Javascript to view the expand/collapse boxes. Description X-linked sideroblastic anemia is an inherited disorder that ...

  11. Direct detection optical intersatellite link at 220 Mbps using AlGaAs laser diode and silicon APD with 4-ary PPM signaling

    NASA Technical Reports Server (NTRS)

    Sun, Xiaoli; Davidson, Frederic M.

    1990-01-01

    A newly developed 220 Mbps free-space 4-ary pulse position modulation (PPM) direct detection optical communication system is described. High speed GaAs integrated circuits were used to construct the PPM encoder and receiver electronic circuits. Both PPM slot and word timing recovery were provided in the PPM receiver. The optical transmitter consisted of an AlGaAs laser diode (Mitsubishi ML5702A, lambda=821nm) and a high speed driver unit. The photodetector consisted of a silicon avalanche photodiode (APD) (RCA30902S) preceded by an optical interference filter (delta lambda=10nm). Preliminary tests showed that the self-synchronized PPM receiver could achieve a receiver bit error rate of less than 10(exp -6) at 25 nW average received optical signal power or 360 photons per transmitted information bit. The relatively poor receiver sensitivity was believed to be caused by the insufficient electronic bandwidth of the APD preamplifier and the poor linearity of the preamplifier high frequency response.

  12. Managing Transformation: How Do Undergraduate Students Experience the Process of Reentry after International Service Learning?

    ERIC Educational Resources Information Center

    Hetzell, Leah B.

    2017-01-01

    As calls for institutions of higher education to educate globally competent citizens have intensified over the last two decades, the field of international service learning (ISL) has responded resoundingly. ISL programs have been implemented at many institutions and there have been countless studies that demonstrate the great power for student…

  13. "Disorienting, Fun or Meaningful?": Looking beyond the Boundaries of the Museum

    ERIC Educational Resources Information Center

    Birmingham, Daniel

    2016-01-01

    A growing body of research highlights how informal science learning environments (ISLE's) can alter modes of participation in science for youth who are traditionally marginalized in science (Calabrese Barton and Tan in "J Learn Sci" 19(2):187-229, 2010). While these findings reveal successful examples of ISLE's potential to bridge…

  14. The Transformative Potential of International Service-Learning at a University with a Christian Foundation in the UK

    ERIC Educational Resources Information Center

    Bamber, Phil

    2011-01-01

    This article draws upon the findings of a study at Liverpool Hope University (LHU) into the transformative nature of International Service-Learning (ISL) experiences for student participants. This research is concerned with the implications of these findings for professional practice, in particular how ISL is constructed in Higher Education policy…

  15. Natural resources interpretation: the role of researchers a new-old approach

    Treesearch

    Mark Gleason

    2002-01-01

    For the past several years interpretive programs for visitors at Isle Royale National Park have included presentations by natural resources researchers. These researchers are presenting the findings of their Lake Superior and Isle Royale National Park research directly to the public. This cooperative and developing project involves many individuals representing many...

  16. 76 FR 72920 - Notification of a Public Teleconference of the Chartered Science Advisory Board

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... Document ``Considerations Related to Post-Closure Monitoring of Uranium In-Situ ISL/ISR Sites.'' DATES: The... Monitoring of Uranium In-Situ ISL/ISR Sites.'' The SAB will comply with the provisions of FACA and all... Environmental Protection Standards for Uranium and Thorium Mill Tailings in regard to underground In-Situ Leach...

  17. 33 CFR 110.206 - Detroit River, Michigan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Detroit River, Michigan. 110.206... ANCHORAGE REGULATIONS Anchorage Grounds § 110.206 Detroit River, Michigan. (a) The Anchorage grounds. Belle Isle Anchorage. The area is in the Detroit River immediately downstream from Belle Isle on the U.S...

  18. SUNREL Related Links | Buildings | NREL

    Science.gov Websites

    SUNREL Related Links SUNREL Related Links DOE Simulation Software Tools Directory a directory of 301 building software tools for evaluation of energy efficiency, renewable energy, and sustainability in buildings. TREAT Software Program a computer program that uses SUNREL and is designed to provide

  19. Classifying quantum entanglement through topological links

    NASA Astrophysics Data System (ADS)

    Quinta, Gonçalo M.; André, Rui

    2018-04-01

    We propose an alternative classification scheme for quantum entanglement based on topological links. This is done by identifying a nonrigid ring to a particle, attributing the act of cutting and removing a ring to the operation of tracing out the particle, and associating linked rings to entangled particles. This analogy naturally leads us to a classification of multipartite quantum entanglement based on all possible distinct links for a given number of rings. To determine all different possibilities, we develop a formalism that associates any link to a polynomial, with each polynomial thereby defining a distinct equivalence class. To demonstrate the use of this classification scheme, we choose qubit quantum states as our example of physical system. A possible procedure to obtain qubit states from the polynomials is also introduced, providing an example state for each link class. We apply the formalism for the quantum systems of three and four qubits and demonstrate the potential of these tools in a context of qubit networks.

  20. When He Said Linking, He Really Meant Linking

    ERIC Educational Resources Information Center

    Chudnov, Daniel

    2009-01-01

    There are many reasons to improve web links, starting with their design. The author tends to think about "design" on the web in terms of two things: (1) graphic/industrial design; and (2) human usability. A nice, clean URI (uniform resource identifier) that does not change, is readable to humans, is amenable to common web behaviors such as…

  1. Measurement of impulse peak insertion loss from two acoustic test fixtures and four hearing protector conditions with an acoustic shock tube

    PubMed Central

    Murphy, William J.; Fackler, Cameron J.; Berger, Elliott H.; Shaw, Peter B.; Stergar, Mike

    2015-01-01

    Impulse peak insertion loss (IPIL) was studied with two acoustic test fixtures and four hearing protector conditions at the E-A-RCAL Laboratory. IPIL is the difference between the maximum estimated pressure for the open-ear condition and the maximum pressure measured when a hearing protector is placed on an acoustic test fixture (ATF). Two models of an ATF manufactured by the French-German Research Institute of Saint-Louis (ISL) were evaluated with high-level acoustic impulses created by an acoustic shock tube at levels of 134 decibels (dB), 150 dB, and 168 dB. The fixtures were identical except that the E-A-RCAL ISL fixture had ear canals that were 3 mm longer than the National Institute for Occupational Safety and Health (NIOSH) ISL fixture. Four hearing protection conditions were tested: Combat Arms earplug with the valve open, ETYPlugs® earplug, TacticalPro headset, and a dual-protector ETYPlugs earplug with TacticalPro earmuff. The IPILs measured for the E-A-RCAL fixture were 1.4 dB greater than the National Institute for Occupational Safety and Health (NIOSH) ISL ATF. For the E-A-RCAL ISL ATF, the left ear IPIL was 2.0 dB greater than the right ear IPIL. For the NIOSH ATF, the right ear IPIL was 0.3 dB greater than the left ear IPIL. PMID:26356380

  2. Interpreting Linked Psychomotor Performance Scores

    ERIC Educational Resources Information Center

    Looney, Marilyn A.

    2013-01-01

    Given that equating/linking applications are now appearing in kinesiology literature, this article provides an overview of the different types of linked test scores: equated, concordant, and predicted. It also addresses the different types of evidence required to determine whether the scores from two different field tests (measuring the same…

  3. Towards Linked Open Services and Processes

    NASA Astrophysics Data System (ADS)

    Krummenacher, Reto; Norton, Barry; Marte, Adrian

    The combination of semantic technology and Web services in form of 'Semantic Web Services' has until now been oriented towards extension of the WS-* stack with ontology-based descriptions. The same time, there is a strong movement away from this stack - for which the 'Web' part is little more than branding - towards RESTful services. The Linked Open Data initiative is a keen adopter of this approach and exposes many datasets via SPARQL endpoints and RESTful services. Our developing approach of 'Linked Open Services', whose current state is described in this paper, accommodates such Linked Data endpoints and general RESTful services alongside WS-* stack-based services with descriptions based on RDF and SPARQL. This capitalises on the Linked Data Cloud and makes service description and comprehension more easy and direct to the growing Linked Data community. Along the way, we show how the existing link between service messaging and the semantic viewpoint, commonly called 'lifting and lowering', is usually unduly restricted to ontology-based classification and misses how the effect of a service contributes to the knowledge of its consumer. Our SPARQL-based approach helps also in the composition of services as knowledge-centric processes, and encourages the development and exposure of services that communicate RDF.

  4. Mining gene link information for survival pathway hunting.

    PubMed

    Jing, Gao-Jian; Zhang, Zirui; Wang, Hong-Qiang; Zheng, Hong-Mei

    2015-08-01

    This study proposes a gene link-based method for survival time-related pathway hunting. In this method, the authors incorporate gene link information to estimate how a pathway is associated with cancer patient's survival time. Specifically, a gene link-based Cox proportional hazard model (Link-Cox) is established, in which two linked genes are considered together to represent a link variable and the association of the link with survival time is assessed using Cox proportional hazard model. On the basis of the Link-Cox model, the authors formulate a new statistic for measuring the association of a pathway with survival time of cancer patients, referred to as pathway survival score (PSS), by summarising survival significance over all the gene links in the pathway, and devise a permutation test to test the significance of an observed PSS. To evaluate the proposed method, the authors applied it to simulation data and two publicly available real-world gene expression data sets. Extensive comparisons with previous methods show the effectiveness and efficiency of the proposed method for survival pathway hunting.

  5. Game Changer: Linked Learning Detroit

    ERIC Educational Resources Information Center

    ConnectEd: The California Center for College and Career, 2016

    2016-01-01

    JP Morgan Chase joins the Skillman Foundation, the Ford Foundation, and the Ford Motor Company Fund, whose grants total $7 million and will connect 10,000 Detroit high school students to career education and work experiences over the next three years through Linked Learning Detroit. Learn about Linked Learning Detroit through interviews with…

  6. N(4)C-ethyl-N(4)C cross-linked DNA: synthesis and characterization of duplexes with interstrand cross-links of different orientations.

    PubMed

    Noronha, Anne M; Noll, David M; Wilds, Christopher J; Miller, Paul S

    2002-01-22

    The preparation and physical properties of short DNA duplexes that contain a N(4)C-ethyl-N(4)C interstrand cross-link are described. Duplexes that contain an interstrand cross-link between mismatched C-C residues and duplexes in which the C residues of a -CG- or -GC- step are linked to give "staggered" interstrand cross-links were prepared using a novel N(4)C-ethyl-N(4)C phosphoramidite reagent. Duplexes with the C-C mismatch cross-link have UV thermal transition temperatures that are 25 degrees C higher than the melting temperatures of control duplexes in which the cross-link is replaced with a G-C base pair. It appears that this cross-link stabilizes adjacent base pairs and does not perturb the structure of the helix, a conclusion that is supported by the CD spectrum of this duplex and by molecular models. An even higher level of stabilization, 49 degrees C, is seen with the duplex that contains a -CG- staggered cross-link. Molecular models suggest that this cross-link may induce propeller twisting in the cross-linked base pairs, and the CD spectrum of this duplex exhibits an unusual negative band at 298 nm, although the remainder of the spectrum is similar to that of B-form DNA. Mismatched C-C or -CG- staggered cross-linked duplexes that have complementary overhanging ends can undergo self-ligation catalyzed by T4 DNA ligase. Analysis of the ligated oligomers by nondenaturing polyacrylamide gel electrophoresis shows that the resulting oligomers migrate in a manner similar to that of a mixture of non-cross-linked control oligomers and suggests that these cross-links do not result in significant bending of the helix. However, the orientation of the staggered cross-link can have a significant effect on the structure and stability of the cross-linked duplex. Thus, the thermal stability of the duplex that contains a -GC- staggered cross-link is 10 degrees C lower than the melting temperature of the control, non-cross-linked duplex. Unlike the -CG- staggered cross-link

  7. Why should we publish Linked Data?

    NASA Astrophysics Data System (ADS)

    Blower, Jon; Riechert, Maik; Koubarakis, Manolis; Pace, Nino

    2016-04-01

    We use the Web every day to access information from all kinds of different sources. But the complexity and diversity of scientific data mean that discovering accessing and interpreting data remains a large challenge to researchers, decision-makers and other users. Different sources of useful information on data, algorithms, instruments and publications are scattered around the Web. How can we link all these things together to help users to better understand and exploit earth science data? How can we combine scientific data with other relevant data sources, when standards for describing and sharing data vary so widely between communities? "Linked Data" is a term that describes a set of standards and "best practices" for sharing data on the Web (http://www.w3.org/standards/semanticweb/data). These principles can be summarised as follows: 1. Create unique and persistent identifiers for the important "things" in a community (e.g. datasets, publications, algorithms, instruments). 2. Allow users to "look up" these identifiers on the web to find out more information about them. 3. Make this information machine-readable in a community-neutral format (such as RDF, Resource Description Framework). 4. Within this information, embed links to other things and concepts and say how these are related. 5. Optionally, provide web service interfaces to allow the user to perform sophisticated queries over this information (using a language such as SPARQL). The promise of Linked Data is that, through these techniques, data will be more discoverable, more comprehensible and more usable by different communities, not just the community that produced the data. As a result, many data providers (particularly public-sector institutions) are now publishing data in this way. However, this area is still in its infancy in terms of real-world applications. Data users need guidance and tools to help them use Linked Data. Data providers need reassurance that the investments they are making in

  8. The Role of Margin in Link Design and Optimization

    NASA Technical Reports Server (NTRS)

    Cheung, K.

    2015-01-01

    Link analysis is a system engineering process in the design, development, and operation of communication systems and networks. Link models that are mathematical abstractions representing the useful signal power and the undesirable noise and attenuation effects (including weather effects if the signal path transverses through the atmosphere) that are integrated into the link budget calculation that provides the estimates of signal power and noise power at the receiver. Then the link margin is applied which attempts to counteract the fluctuations of the signal and noise power to ensure reliable data delivery from transmitter to receiver. (Link margin is dictated by the link margin policy or requirements.) A simple link budgeting approach assumes link parameters to be deterministic values typically adopted a rule-of-thumb policy of 3 dB link margin. This policy works for most S- and X-band links due to their insensitivity to weather effects. But for higher frequency links like Ka-band, Ku-band, and optical communication links, it is unclear if a 3 dB link margin would guarantee link closure. Statistical link analysis that adopted the 2-sigma or 3-sigma link margin incorporates link uncertainties in the sigma calculation. (The Deep Space Network (DSN) link margin policies are 2-sigma for downlink and 3-sigma for uplink.) The link reliability can therefore be quantified statistically even for higher frequency links. However in the current statistical link analysis approach, link reliability is only expressed as the likelihood of exceeding the signal-to-noise ratio (SNR) threshold that corresponds to a given bit-error-rate (BER) or frame-error-rate (FER) requirement. The method does not provide the true BER or FER estimate of the link with margin, or the required signalto-noise ratio (SNR) that would meet the BER or FER requirement in the statistical sense. In this paper, we perform in-depth analysis on the relationship between BER/FER requirement, operating SNR, and

  9. Development of a high stability pointing mechanism for wide application

    NASA Technical Reports Server (NTRS)

    Brunnen, A. J. D.; Bentall, R. H.

    1982-01-01

    A recurrent requirement of spaceborne instruments and communications equipment is that of accurate pointing. This need is recognizable in such diverse applications as Star Sensor trimming, Momentum Wheel gimballing, in-orbit adjustment or alignment of equipment, inter-satellite communication and Antenna Pointing. A pointing mechanism of novel design having several advantages over the more conventional gimbal, centre-pivoted, or cross axis pointing concepts is described.

  10. Linking Schools of Thought to Schools of Practice

    ERIC Educational Resources Information Center

    Hunt, Lucy; Yoshida-Ehrmann, Erin

    2016-01-01

    Project Linking Learning ("Link") was created to target the needs of gifted students in urban school districts with historically underserved populations. Project Linking Learning implemented a linking curriculum between in-class instruction and an afterschool enrichment program for selected students in second through fifth grade.…

  11. CERES Web Links

    Atmospheric Science Data Center

    2013-03-21

    ...   Web Links to Relevant CERES Information Relevant information about CERES, CERES references, ... Instrument Working Group Home Page Aerosol Retrieval Web Page  (Center for Satellite Applications and Research) ...

  12. The read-write Linked Data Web.

    PubMed

    Berners-Lee, Tim; O'Hara, Kieron

    2013-03-28

    This paper discusses issues that will affect the future development of the Web, either increasing its power and utility, or alternatively suppressing its development. It argues for the importance of the continued development of the Linked Data Web, and describes the use of linked open data as an important component of that. Second, the paper defends the Web as a read-write medium, and goes on to consider how the read-write Linked Data Web could be achieved.

  13. 21 CFR 11.70 - Signature/record linking.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Signature/record linking. 11.70 Section 11.70 Food... RECORDS; ELECTRONIC SIGNATURES Electronic Records § 11.70 Signature/record linking. Electronic signatures and handwritten signatures executed to electronic records shall be linked to their respective...

  14. Knowledge-Linking Perceptions of Late-Elementary Students

    ERIC Educational Resources Information Center

    Schuh, Kathy L.; Kuo, Yi-Lung; Knupp, Tawnya L.

    2014-01-01

    This study describes student perceptions of potential elaborative or generative learning strategies called student knowledge links. This construct was assessed using the Student Knowledge Linking Instrument-Perceptions (SKLIP), a new learning inventory to measure late-elementary student perceptions of the creation of student knowledge links. After…

  15. Utility-Based Link Recommendation in Social Networks

    ERIC Educational Resources Information Center

    Li, Zhepeng

    2013-01-01

    Link recommendation, which suggests links to connect currently unlinked users, is a key functionality offered by major online social networking platforms. Salient examples of link recommendation include "people you may know"' on Facebook and "who to follow" on Twitter. A social networking platform has two types of stakeholder:…

  16. A Multi-step Transcriptional and Chromatin State Cascade Underlies Motor Neuron Programming from Embryonic Stem Cells.

    PubMed

    Velasco, Silvia; Ibrahim, Mahmoud M; Kakumanu, Akshay; Garipler, Görkem; Aydin, Begüm; Al-Sayegh, Mohamed Ahmed; Hirsekorn, Antje; Abdul-Rahman, Farah; Satija, Rahul; Ohler, Uwe; Mahony, Shaun; Mazzoni, Esteban O

    2017-02-02

    Direct cell programming via overexpression of transcription factors (TFs) aims to control cell fate with the degree of precision needed for clinical applications. However, the regulatory steps involved in successful terminal cell fate programming remain obscure. We have investigated the underlying mechanisms by looking at gene expression, chromatin states, and TF binding during the uniquely efficient Ngn2, Isl1, and Lhx3 motor neuron programming pathway. Our analysis reveals a highly dynamic process in which Ngn2 and the Isl1/Lhx3 pair initially engage distinct regulatory regions. Subsequently, Isl1/Lhx3 binding shifts from one set of targets to another, controlling regulatory region activity and gene expression as cell differentiation progresses. Binding of Isl1/Lhx3 to later motor neuron enhancers depends on the Ebf and Onecut TFs, which are induced by Ngn2 during the programming process. Thus, motor neuron programming is the product of two initially independent transcriptional modules that converge with a feedforward transcriptional logic. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Synergistic binding of transcription factors to cell-specific enhancers programs motor neuron identity

    PubMed Central

    Mazzoni, Esteban O; Mahony, Shaun; Closser, Michael; Morrison, Carolyn A; Nedelec, Stephane; Williams, Damian J; An, Disi; Gifford, David K; Wichterle, Hynek

    2013-01-01

    Efficient transcriptional programming promises to open new frontiers in regenerative medicine. However, mechanisms by which programming factors transform cell fate are unknown, preventing more rational selection of factors to generate desirable cell types. Three transcription factors, Ngn2, Isl1 and Lhx3, were sufficient to program rapidly and efficiently spinal motor neuron identity when expressed in differentiating mouse embryonic stem cells. Replacement of Lhx3 by Phox2a led to specification of cranial, rather than spinal, motor neurons. Chromatin immunoprecipitation–sequencing analysis of Isl1, Lhx3 and Phox2a binding sites revealed that the two cell fates were programmed by the recruitment of Isl1-Lhx3 and Isl1-Phox2a complexes to distinct genomic locations characterized by a unique grammar of homeodomain binding motifs. Our findings suggest that synergistic interactions among transcription factors determine the specificity of their recruitment to cell type–specific binding sites and illustrate how a single transcription factor can be repurposed to program different cell types. PMID:23872598

  18. Linking matrices in systems with periodic boundary conditions

    NASA Astrophysics Data System (ADS)

    Panagiotou, Eleni; Millett, Kenneth C.

    2018-06-01

    We study the linking matrix, a measure of entanglement for a collection of closed or open chains in 3-space based on the Gauss linking number. Periodic boundary conditions (PBC) are often used in the simulation of physical systems of filaments. To measure entanglement of closed or open chains in systems employing PBC we use the periodic linking matrix, based on the periodic linking number, defined in Panagiotou (2015 J. Comput. Phys. 300 533–73). We study the properties of the periodic linking matrix as a function of cell size. We provide analytical results concerning the eigenvalues of the periodic linking matrix and show that some of them are invariant of cell-size.

  19. Pricing unit-linked insurance with guaranteed benefit

    NASA Astrophysics Data System (ADS)

    Iqbal, M.; Novkaniza, F.; Novita, M.

    2017-07-01

    Unit-linked insurance is an investment-linked insurance, that is, the given benefit is the premium investment out-come. Recently, the most widely marketed insurance in the industry is unit-linked insurance with guaranteed benefit. With guaranteed benefit applied, the insurance benefits form is similar to the payoff form of European call option. Thereby, pricing European call option is involved in pricing unit-linked insurance with guaranteed benefit. The dynamics of investment outcome is assumed to follow stochastic interest rate. Hence, change of measure methods is used in pricing unit-linked insurance. The discount factor with stochastic interest rate needs to be modified as well to be zero coupon bond price. Eventually, the insurance premium is calculated by equivalence principle with guaranteed benefit and insurance period explicitly given.

  20. Power smart in-door optical wireless link design

    NASA Astrophysics Data System (ADS)

    Marraccini, P. J.; Riza, N. A.

    2011-12-01

    Presented for the first time, to the best of the authors´ knowledge, is the design of a power smart in-door optical wireless link that provides lossless beam propagation between Transmitter (T) and Receiver (R) for changing link distances. Each T/R unit uses a combination of fixed and variable focal length optics to smartly adjust the laser beam propagation parameters of minimum beam waist size and its location to produce the optimal zero propagation loss coupling condition at the R for that link distance. An Electronically Controlled Variable Focus Lens (ECVFL) is used to form the wide field-of-view search beam and change the beam size at R to form a low loss beam. The T/R unit can also deploy camera optics and thermal energy harvesting electronics to improve link operational smartness and efficiency. To demonstrate the principles of the beam conditioned low loss indoor link, a visible 633 nm laser link using an electro-wetting technology liquid ECVFL is demonstrated for a variable 1 to 4 m link range. Measurements indicate a 53% improvement over an unconditioned laser link at 4 m. Applications for this power efficient wireless link includes mobile computer platform communications and agile server rack interconnections in data centres.