Science.gov

Sample records for acts propagation activities

  1. The ACTS propagation program

    NASA Technical Reports Server (NTRS)

    Chakraborty, Dayamoy; Davarian, Faramaz

    1991-01-01

    The purpose of the Advanced Communications Technology Satellite (ACTS) is to demonstrate the feasibility of the Ka-band (20 and 30 GHz) spectrum for satellite communications, as well as to help maintain U.S. leadership in satellite communications. ACTS incorporates such innovative schemes as time division multiple access (TDMA), microwave and baseband switching, onboard regeneration, and adaptive application of coding during rain-fade conditions. The success or failure of the ACTS experiment will depend on how accurately the rain-fade statistics and fade dynamics can be predicted in order to derive an appropriate algorithm that will combat weather vagaries, specifically for links with small terminals, such as very small aperture terminals (VSAT's) where the power margin is a premium. This article describes the planning process and hardware development program that will comply with the recommendations of the ACTS propagation study groups.

  2. ACTS propagation experiment discussion: Ka-band propagation measurements using the ACTS propagation terminal and the CSU-CHILL and Space Communications Technology Center Florida propagation program

    NASA Technical Reports Server (NTRS)

    Bringi, V. N.; Chandrasekar, V.; Mueller, Eugene A.; Turk, Joseph; Beaver, John; Helmken, Henry F.; Henning, Rudy

    1993-01-01

    Papers on Ka-band propagation measurements using the ACTS propagation terminal and the Colorado State University CHILL multiparameter radar and on Space Communications Technology Center Florida Propagation Program are discussed. Topics covered include: microwave radiative transfer and propagation models; NASA propagation terminal status; ACTS channel characteristics; FAU receive only terminal; FAU terminal status; and propagation testbed.

  3. Propagation measurements in Alaska using ACTS beacons

    NASA Technical Reports Server (NTRS)

    Mayer, Charles E.

    1991-01-01

    The placement of an ACTS propagation terminal in Alaska has several distinct advantages. First is the inclusion of a new and important climatic zone to the global propagation model. Second is the low elevation look angle from Alaska to ACTS. These two unique opportunities also present problems unique to the location, such as extreme temperatures and lower power levels. These problems are examined and compensatory solutions are presented.

  4. ACTS propagation terminal prototype planning and design

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz; Pergal, F.; Chakraborty, D.; Stutzman, Warren L.

    1990-01-01

    The planning and design of a prototype propagation receiving terminal for beacon signals at 27 and 20 GHz bands are examined. The developmental plan is discussed, followed by technical design considerations including, the Advanced Communications Technology Satellite (ACTS) system salient features and frequency plan, beacon signal parameters and specifications, system calculations, and terminal hardware design issues.

  5. Proceedings of the Seventeenth NASA Propagation Experimenters Meeting (NAPEX 17) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz (Editor)

    1993-01-01

    The NASA Propagation Experimenters Meeting (NAPEX) is convened annually to discuss studies made on radio wave propagation by investors from domestic and international organizations. NAPEX 17 was held on 15 June 1993. The meeting was organized into two technical sessions. The first session was dedicated to slant path propagation studies and experiments. The second session focused on propagation studies for mobile and personal communications. Preceding NAPEX 17, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop was held on 14 June 1993 to review ACTS propagation activities with emphasis on ACTS experiments status and data collection, processing, and exchange.

  6. Proceedings of the Fifteenth NASA Propagation Experimenters Meeting (NAPEX 15) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz (Editor)

    1991-01-01

    The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. The meeting was organized into three technical sessions. The first session was dedicated to Olympus and ACTS studies and experiments, the second session was focused on the propagation studies and measurements, and the third session covered computer-based propagation model development. In total, sixteen technical papers and some informal contributions were presented. Following NAPEX 15, the Advanced Communications Technology Satellite (ACTS) miniworkshop was held on 29 Jun. 1991, to review ACTS propagation activities, with emphasis on ACTS hardware development and experiment planning. Five papers were presented.

  7. Proceedings of the Fourteenth NASA Propagation Experimenters Meeting (NAPEX 14) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz (Editor)

    1990-01-01

    The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. NAPEX XIV was held on May 11, 1990, at the Balcones Research Centers, University of Texas, Austin, Texas. The meeting was organized into two technical sessions: Satellite (ACTS) and the Olympus Spacecraft, while the second focused on the fixed and mobile satellite propagation studies and experiments. Following NAPEX XIV, the ACTS Miniworkshop was held at the Hotel Driskill, Austin, Texas, on May 12, 1990, to review ACTS propagation activities since the First ACTS Propagation Studies Workshop was held in Santa Monica, California, on November 28 and 29, 1989.

  8. Proceedings of the Eighteenth NASA Propagation Experimenters Meeting (NAPEX 18) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz (Editor)

    1994-01-01

    The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. Participants included representatives from Canada, the Netherlands, England, and the United States, including researchers from universities, government agencies, and private industry. The meeting was organized into two technical sessions. The first session was dedicated to slant path propagation studies and experiments. The second session focused on propagation studies for mobile, personal, and sound broadcast systems. In total, 14 technical papers and some informal contributions were presented. Preceding NAPEX_17, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop was held to review ACTS propagation activities.

  9. Proceedings of the 16th NASA Propagation Experimenters Meeting (NAPEX 16) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz (Editor)

    1992-01-01

    The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. NAPEX 16 was held on May 29, 1992 in Houston, Texas. The meeting was organized into two technical sessions. The first session was dedicated to slant path propagation studies and measurements. The second session focused on Olympus propagation measurements and results. Following NAPEX 16, the Advanced Communications Technology Satellite (ACTS) Miniworkshop was held to review ACTS propagation activities with emphasis on ACTS hardware development and experiment planning. Eight technical papers were presented by contributors from government agencies, private industry, and university research establishments.

  10. ACTS Project and Propagation Program Update

    NASA Technical Reports Server (NTRS)

    Bauer, Robert

    1996-01-01

    Spacecraft operations continue to be nominal and the sixth eclipse season completed. Battery reconditioning to be re-evaluated before the fall eclipse. Other topics covered include: Inclined orbit; Experiments program; Reorganizations; Program timeline; and propagation program status.

  11. Proceedings of the Twentieth NASA Propagation Experimenters Meeting (NAPEX XX) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Golshan, Nassar (Editor)

    1996-01-01

    The NASA Propagation Experimenters (NAPEX) Meeting and associated Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop convene yearly to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications (satcom)industry, academia, and government with an interest in space-ground radio wave propagation have peer discussion of work in progress, disseminate propagation results, and interact with the satcom industry. NAPEX XX, in Fairbanks, Alaska, June 4-5, 1996, had three sessions: (1) "ACTS Propagation Study: Background, Objectives, and Outcomes," covered results from thirteen station-years of Ka-band experiments; (2) "Propagation Studies for Mobile and Personal Satellite Applications," provided the latest developments in measurement, modeling, and dissemination of propagation phenomena of interest to the mobile, personal, and aeronautical satcom industry; and (3)"Propagation Research Topics," covered a range of topics including space/ground optical propagation experiments, propagation databases, the NASA Propagation Web Site, and revision plans for the NASA propagation effects handbooks. The ACTS Miniworkshop, June 6, 1996, covered ACTS status, engineering support for ACTS propagation terminals, and the ACTS Propagation Data Center. A plenary session made specific recommendations for the future direction of the program.

  12. Proceedings of the Twenty-First NASA Propagation Experiments Meeting (NAPEX XXI) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser (Editor)

    1997-01-01

    The NASA Propagation Experimenters (NAPEX) meeting is convened each year to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications industry, academia and government who have an interest in space-ground radio wave propagation are invited to NAPEX meetings for discussions and exchange of information. The reports delivered at this meeting by program managers and investigators present recent activities and future plans. This forum provides an opportunity for peer discussion of work in progress, timely dissemination of propagation results, and close interaction with the satellite communications industry. NAPEX XXI took place in El Segundo, California on June 11-12, 1997 and consisted of three sessions. Session 1, entitled "ACTS Propagation Study Results & Outcome " covered the results of 20 station-years of Ka-band radio-wave propagation experiments. Session 11, 'Ka-band Propagation Studies and Models,' provided the latest developments in modeling, and analysis of experimental results about radio wave propagation phenomena for design of Ka-band satellite communications systems. Session 111, 'Propagation Research Topics,' covered a diverse range of propagation topics of interest to the space community, including overviews of handbooks and databases on radio wave propagation. The ACTS Propagation Studies miniworkshop was held on June 13, 1997 and consisted of a technical session in the morning and a plenary session in the afternoon. The morning session covered updates on the status of the ACTS Project & Propagation Program, engineering support for ACTS Propagation Terminals, and the Data Center. The plenary session made specific recommendations for the future direction of the program.

  13. Proceedings of the 19th NASA Propagation Experimenters Meeting (NAPEX 19) and the 7th Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop (APSW 7)

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz (Editor)

    1995-01-01

    The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. NAPEX 19 was held on 14 Jun. 1995, in Fort Collins, Colorado. Participants included representatives from Canada, Japan, and the United States, including researchers from universities, government agencies, and private industry. The meeting focused on mobile personal satellite systems and the use of 20/30-GHz band for fixed and mobile satellite applications. In total, 18 technical papers were presented. Following NAPEX 19, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop 7 (APSW 7) was held on 15-16 Jun. 1995, to review ACTS propagation activities with emphasis on the experimenters' status reports and dissemination of propagation data to industry.

  14. Ka-Band Propagation Studies using the ACTS Propagation Terminal and the CSU-CHILL Multiparameter Radar

    NASA Technical Reports Server (NTRS)

    Bringi, V. N.; Beaver, John

    1996-01-01

    One of the first experimental communications satellites using Ka-band technology is the NASA Advanced Communications Technology Satellite (ACTS). In September 1993, ACTS was deployed into a geostationary orbit near 100 degrees W longitude by the space shuttle Discovery. The ACTS system supports both communication and propagation experiments at the 20/30 GHz frequency bands. The propagation experiment involves multi-year attenuation measurements along the satellite-Earth slant path.

  15. Active Wave Propagation and Sensing in Plates

    NASA Technical Reports Server (NTRS)

    Ghoshal, Anindya; Martin, William N.; Sundaresan, Mannur J.; Schulz, Mark J.; Ferguson, Frederick

    2001-01-01

    Health monitoring of aerospace structures can be done using an active interrogation approach with diagnostic Lamb waves. Piezoelectric patches are often used to generate the waves, and it is helpful to understand how these waves propagate through a structure. To give a basic understanding of the actual physical process of wave propagation, a model is developed to simulate asymmetric wave propagation in a panel and to produce a movie of the wave motion. The waves can be generated using piezoceramic patches of any size or shape. The propagation, reflection, and interference of the waves are represented in the model. Measuring the wave propagation is the second important aspect of damage detection. Continuous sensors are useful for measuring waves because of the distributed nature of the sensor and the wave. Two sensor designs are modeled, and their effectiveness in measuring acoustic waves is studied. The simulation model developed is useful to understand wave propagation and to optimize the type of sensors that might be used for health monitoring of plate-like structures.

  16. Ka-band propagation studies using the ACTS propagation terminal and the CSU-CHILL multiparameter, Doppler radar

    NASA Technical Reports Server (NTRS)

    Beaver, J.; Turk, J.; Bringi, V. N.

    1995-01-01

    An increase in the demand for satellite communications has led to an overcrowding of the current spectrums being used - mainly at C and Ku bands. To alleviate this overcrowding, new technology is being developed to open up the Ka-band for communications use. One of the first experimental communications satellites using this technology is NASA's Advanced Communications Technology Satellite (ACTS). In Sept. 1993, ACTS was deployed into a geostationary orbit near 100 deg W longitude. The ACTS system employs two Ka-band beacons for propagation experiments, one at 20.185 GHz and another at 27.505 GHz. Attenuation due to rain and tropospheric scintillations will adversely affect new technologies proposed for this spectrum. Therefore, before being used commercially, propagation effects at Ka-band must be studied. Colorado State University is one of eight sites across the United States and Canada conducting propagations studies; each site is equipped with the ACTS propagation terminal (APT). With each site located in a different climatic zone, the main objective of the propagation experiment is to obtain monthly and yearly attenuation statistics. Each site also has secondary objectives that are site dependent. At CSU, the CSU-CHILL radar facility is being used to obtain polarimetric radar data along the ACTS propagation path. During the expected two to four year period of the project, it is hoped to study several significant weather events. The S-band radar will be used to obtain Ka-band attenuation estimates and to initialize propagation models that have been developed, to help classify propagation events measured by the APT. Preliminary attenuation estimates for two attenuation events will be shown here - a bright band case that occurred on 13 May 1994 and a convective case that occurred on 20 Jun. 1994. The computations used to obtain Ka-band attenuation estimates from S-band radar data are detailed. Results from the two events are shown.

  17. Proceedings of the Twentieth NASA Propagation Experimenters Meeting (NAPEX 20) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser (Editor)

    1996-01-01

    The NASA Propagation Experimenters (NAPEX) Meeting is convened each year to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications (satcom) industry, academia, and government who have an interest in space-ground radio wave propagation are invited to NAPEX meetings for discussions and exchange of information. The reports delivered at these meetings by program managers and investigators present recent activities and future plans. This forum provides an opportunity for peer discussion of work in progress, timely dissemination of propagation results, and close interaction with the satcom industry.

  18. Learning activism, acting with phronesis

    NASA Astrophysics Data System (ADS)

    Lee, Yew-Jin

    2015-12-01

    The article "Socio-political development of private school children mobilising for disadvantaged others" by Darren Hoeg, Natalie Lemelin, and Lawrence Bencze described a language-learning curriculum that drew on elements of Socioscientific issues and Science, Technology, Society and Environment. Results showed that with a number of enabling factors acting in concert, learning about and engagement in practical action for social justice and equity are possible. An alternative but highly compatible framework is now introduced—phronetic social research—as an action-oriented, wisdom-seeking research stance for the social sciences. By so doing, it is hoped that forms of phronetic social research can gain wider currency among those that promote activism as one of many valued outcomes of an education in science.

  19. ACTS (Advanced Communications Technology Satellite) Propagation Experiment: Preprocessing Software User's Manual

    NASA Technical Reports Server (NTRS)

    Crane, Robert K.; Wang, Xuhe; Westenhaver, David

    1996-01-01

    The preprocessing software manual describes the Actspp program originally developed to observe and diagnose Advanced Communications Technology Satellite (ACTS) propagation terminal/receiver problems. However, it has been quite useful for automating the preprocessing functions needed to convert the terminal output to useful attenuation estimates. Prior to having data acceptable for archival functions, the individual receiver system must be calibrated and the power level shifts caused by ranging tone modulation must be received. Actspp provides three output files: the daylog, the diurnal coefficient file, and the file that contains calibration information.

  20. Can Neural Activity Propagate by Endogenous Electrical Field?

    PubMed Central

    Qiu, Chen; Shivacharan, Rajat S.; Zhang, Mingming

    2015-01-01

    It is widely accepted that synaptic transmissions and gap junctions are the major governing mechanisms for signal traveling in the neural system. Yet, a group of neural waves, either physiological or pathological, share the same speed of ∼0.1 m/s without synaptic transmission or gap junctions, and this speed is not consistent with axonal conduction or ionic diffusion. The only explanation left is an electrical field effect. We tested the hypothesis that endogenous electric fields are sufficient to explain the propagation with in silico and in vitro experiments. Simulation results show that field effects alone can indeed mediate propagation across layers of neurons with speeds of 0.12 ± 0.09 m/s with pathological kinetics, and 0.11 ± 0.03 m/s with physiologic kinetics, both generating weak field amplitudes of ∼2–6 mV/mm. Further, the model predicted that propagation speed values are inversely proportional to the cell-to-cell distances, but do not significantly change with extracellular resistivity, membrane capacitance, or membrane resistance. In vitro recordings in mice hippocampi produced similar speeds (0.10 ± 0.03 m/s) and field amplitudes (2.5–5 mV/mm), and by applying a blocking field, the propagation speed was greatly reduced. Finally, osmolarity experiments confirmed the model's prediction that cell-to-cell distance inversely affects propagation speed. Together, these results show that despite their weak amplitude, electric fields can be solely responsible for spike propagation at ∼0.1 m/s. This phenomenon could be important to explain the slow propagation of epileptic activity and other normal propagations at similar speeds. SIGNIFICANCE STATEMENT Neural activity (waves or spikes) can propagate using well documented mechanisms such as synaptic transmission, gap junctions, or diffusion. However, the purpose of this paper is to provide an explanation for experimental data showing that neural signals can propagate by means other than synaptic

  1. Proceedings of the Twenty-First NASA Propagation Experimenters Meeting (NAPEX XXI) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser (Editor)

    1997-01-01

    The NASA Propagation Experimenters (NAPEX) meeting is convened each year to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications industry, academia and government who have an interest in space-ground radio wave propagation are invited to NAPEX meetings for discussions and exchange of information. The reports delivered at this meeting by program managers and investigators present recent activities and future plans. This forum provides an opportunity for peer discussion of work in progress, timely dissemination of propagation results, and close interaction with the satellite communications industry.

  2. Planned LMSS propagation experiment using ACTS: Preliminary antenna pointing results during mobile operations

    NASA Technical Reports Server (NTRS)

    Rowland, John R.; Goldhirsh, Julius; Vogel, Wolfhard J.; Torrence, Geoffrey W.

    1991-01-01

    An overview and a status description of the planned LMSS mobile K band experiment with ACTS is presented. As a precursor to the ACTS mobile measurements at 20.185 GHz, measurements at 19.77 GHz employing the Olympus satellite were originally planned. However, because of the demise of Olympus in June of 1991, the efforts described here are focused towards the ACTS measurements. In particular, we describe the design and testing results of a gyro controlled mobile-antenna pointing system. Preliminary pointing measurements during mobile operations indicate that the present system is suitable for measurements employing a 15 cm aperture (beamwidth at approximately 7 deg) receiving antenna operating with ACTS in the high gain transponder mode. This should enable measurements with pattern losses smaller than plus or minus 1 dB over more than 95 percent of the driving distance. Measurements with the present mount system employing a 60 cm aperture (beamwidth at approximately 1.7 deg) results in pattern losses smaller than plus or minus 3 dB for 70 percent of the driving distance. Acceptable propagation measurements may still be made with this system by employing developed software to flag out bad data points due to extreme pointing errors. The receiver system including associated computer control software has been designed and assembled. Plans are underway to integrate the antenna mount with the receiver on the University of Texas mobile receiving van and repeat the pointing tests on highways employing a recently designed radome system.

  3. Can Neural Activity Propagate by Endogenous Electrical Field?

    PubMed

    Qiu, Chen; Shivacharan, Rajat S; Zhang, Mingming; Durand, Dominique M

    2015-12-01

    It is widely accepted that synaptic transmissions and gap junctions are the major governing mechanisms for signal traveling in the neural system. Yet, a group of neural waves, either physiological or pathological, share the same speed of ∼0.1 m/s without synaptic transmission or gap junctions, and this speed is not consistent with axonal conduction or ionic diffusion. The only explanation left is an electrical field effect. We tested the hypothesis that endogenous electric fields are sufficient to explain the propagation with in silico and in vitro experiments. Simulation results show that field effects alone can indeed mediate propagation across layers of neurons with speeds of 0.12 ± 0.09 m/s with pathological kinetics, and 0.11 ± 0.03 m/s with physiologic kinetics, both generating weak field amplitudes of ∼2-6 mV/mm. Further, the model predicted that propagation speed values are inversely proportional to the cell-to-cell distances, but do not significantly change with extracellular resistivity, membrane capacitance, or membrane resistance. In vitro recordings in mice hippocampi produced similar speeds (0.10 ± 0.03 m/s) and field amplitudes (2.5-5 mV/mm), and by applying a blocking field, the propagation speed was greatly reduced. Finally, osmolarity experiments confirmed the model's prediction that cell-to-cell distance inversely affects propagation speed. Together, these results show that despite their weak amplitude, electric fields can be solely responsible for spike propagation at ∼0.1 m/s. This phenomenon could be important to explain the slow propagation of epileptic activity and other normal propagations at similar speeds.

  4. On the propagation of Voigt waves in energetically active materials

    NASA Astrophysics Data System (ADS)

    Mackay, Tom G.; Lakhtakia, Akhlesh

    2016-11-01

    If Voigt-wave propagation is possible in a dissipative anisotropic dielectric material characterised by the permittivity dyadic \\mathop{\\varepsilon }\\limits\\raise{2pt=}, then it is also possible in the analogous energetically active material characterised by the permittivity dyadic \\mathop{\\tilde{\\varepsilon }}\\limits\\raise{2pt=}, where \\mathop{\\tilde{\\varepsilon }}\\limits\\raise{2pt=} is the hermitian conjugate of \\mathop{\\varepsilon }\\limits\\raise{2pt=}. This symmetry follows directly from a theoretical analysis of the necessary and sufficient conditions for Voigt-wave propagation in anisotropic materials. As a consequence of this symmetry, a porous dissipative material that exhibits Voigt-wave propagation can be used to construct a material that allows the propagation of Voigt waves with attendant linear gain in amplitude with propagation distance, by means of infiltration with an electrically or optically activated dye, for example. This phenomenon is captured by the Bruggeman formalism for homogenised composite materials based on isotropic dielectric component materials that are randomly distributed as oriented spheroidal particles.

  5. Exploring primary care activities in ACT teams.

    PubMed

    Vanderlip, Erik R; Williams, Nancy A; Fiedorowicz, Jess G; Katon, Wayne

    2014-05-01

    People with serious mental illness often receive inadequate primary and preventive care services. Federal healthcare reform endorses team-based care that provides high quality primary and preventive care to at risk populations. Assertive community treatment (ACT) teams offer a proven, standardized treatment approach effective in improving mental health outcomes for the seriously mentally ill. Much is known about the effectiveness of ACT teams in improving mental health outcomes, but the degree to which medical care needs are addressed is not established. The purpose of this study was to explore the extent to which ACT teams address the physical health of the population they serve. ACT team leaders were invited to complete an anonymous, web-based survey to explore attitudes and activities involving the primary care needs of their clients. Information was collected regarding the use of health screening tools, physical health assessments, provision of medical care and collaboration with primary care systems. Data was analyzed from 127 team leaders across the country, of which 55 completed the entire survey. Nearly every ACT team leader believed ACT teams have a role in identifying and managing the medical co-morbidities of their clientele. ACT teams report participation in many primary care activities. ACT teams are providing a substantial amount of primary and preventive services to their population. The survey suggests standardization of physical health identification, management or referral processes within ACT teams may result in improved quality of medical care. ACT teams are in a unique position to improve physical health care by virtue of having medically trained staff and frequent, close contact with their clients.

  6. Propagation of Action Potentials: An Active Participation Exercise.

    ERIC Educational Resources Information Center

    Felsten, Gary

    1998-01-01

    Describes an active participation exercise that demonstrates the propagation of action potentials (the ability to transmit information through the neural network, dependent upon chemical interactions in the brain). Students assume the structure and function of the network by lining up around the room and communicating through hand signals and…

  7. How networks communicate: propagation patterns in spontaneous brain activity.

    PubMed

    Mitra, Anish; Raichle, Marcus E

    2016-10-01

    Initially regarded as 'noise', spontaneous (intrinsic) activity accounts for a large portion of the brain's metabolic cost. Moreover, it is now widely known that infra-slow (less than 0.1 Hz) spontaneous activity, measured using resting state functional magnetic resonance imaging of the blood oxygen level-dependent (BOLD) signal, is correlated within functionally defined resting state networks (RSNs). However, despite these advances, the temporal organization of spontaneous BOLD fluctuations has remained elusive. By studying temporal lags in the resting state BOLD signal, we have recently shown that spontaneous BOLD fluctuations consist of remarkably reproducible patterns of whole brain propagation. Embedded in these propagation patterns are unidirectional 'motifs' which, in turn, give rise to RSNs. Additionally, propagation patterns are markedly altered as a function of state, whether physiological or pathological. Understanding such propagation patterns will likely yield deeper insights into the role of spontaneous activity in brain function in health and disease.This article is part of the themed issue 'Interpreting blood oxygen level-dependent: a dialogue between cognitive and cellular neuroscience'. PMID:27574315

  8. Correlation of S-Band Weather Radar Reflectivity and ACTS Propagation Data in Florida

    NASA Technical Reports Server (NTRS)

    Wolfe, Eric E.; Flikkema, Paul G.; Henning, Rudolf E.

    1997-01-01

    Previous work has shown that Ka-band attenuation due to rainfall and corresponding S-band reflectivity are highly correlated. This paper reports on work whose goal is to determine the feasibility of estimation and, by extension, prediction of one parameter from the other using the Florida ACTS propagation terminal (APT) and the nearby WSR-88D S-band Doppler weather radar facility operated by the National Weather Service. This work is distinguished from previous efforts in this area by (1) the use of a single-polarized radar, preventing estimation of the drop size distribution (e.g., with dual polarization) and (2) the fact that the radar and APT sites are not co-located. Our approach consists of locating the radar volume elements along the satellite slant path and then, from measured reflectivity, estimating the specific attenuation for each associated path segment. The sum of these contributions yields an estimation of the millimeter-wave attenuation on the space-ground link. Seven days of data from both systems are analyzed using this procedure. The results indicate that definite correlation of S-band reflectivity and Ka-band attenuation exists even under the restriciton of this experiment. Based on these results, it appears possible to estimate Ka-band attenuation using widely available operational weather radar data. Conversely, it may be possible to augment current radar reflectivity data and coverage with low-cost attenuation or sky temperature data to improve the estimation of rain rates.

  9. Active elastic metamaterials for subwavelength wave propagation control

    NASA Astrophysics Data System (ADS)

    Chen, Y. Y.; Huang, G. L.

    2015-06-01

    Recent research activities in elastic metamaterials demonstrate a significant potential for subwavelength wave propagation control owing to their interior locally resonant mechanism. The growing technological developments in electro/magnetomechanical couplings of smart materials have introduced a controlling degree of freedom for passive elastic metamaterials. Active elastic metamaterials could allow for a fine control of material physical behavior and thereby induce new functional properties that cannot be produced by passive approaches. In this paper, two types of active elastic metamaterials with shunted piezoelectric materials and electrorheological elastomers are proposed. Theoretical analyses and numerical validations of the active elastic metamaterials with detailed microstructures are presented for designing adaptive applications in band gap structures and extraordinary waveguides. The active elastic metamaterial could provide a new design methodology for adaptive wave filters, high signal-to-noise sensors, and structural health monitoring applications.

  10. Dike propagation in active volcanoes: importance, evidence, models and perspectives

    NASA Astrophysics Data System (ADS)

    Acocella, V.

    2011-12-01

    Most eruptions are fed by dikes; therefore, better knowledge of dike propagation is crucial to improve our understanding of how magma is transferred and extruded at volcanoes. Dike pattern data from a few tens of active volcanic edifices show how dike propagation in a volcano is not a random process; rather, it depends from the following factors (listed in order of importance): the presence of relief, the shape of the edifice, the proximity to the surface, and regional tectonic control. Relief enhances the development of radial dikes, which may also cluster following volcano elongation or regional patterns. Dikes approaching the surface of volcanic edifices, regardless of their initial orientation, reorient to become radial (parallel to the maximum gravitational stress); in presence of scarps, dikes reorient subparallel to the scarp (perpendicular to the minimum gravitational stress). These relationships have been also observed or inferred during eruptions at Etna, Stromboli, Vesuvio (Italy), Erta Ale (Afar) and Faial (Azores). While numerical modelling of dike propagation remains challenging, analogue models of dike emplacement have been performed over a few decades, also supporting part of the above-described evidence. Analogue models have been mostly conducted injecting air or water within gelatine and, recently, injecting vegetable oil within sand. More sophisticated analogue modelling is foreseen for the future, using a more appropriate scaling, a larger sensitivity and providing a more quantitative approach in capturing relationships. More in general, future research on dikes should be devoted towards identifying dike propagation paths, dike arrest mechanisms, and likely locations of vent formation at specific volcanoes, to better aid hazards assessment.

  11. Regular Wave Propagation Out of Noise in Chemical Active Media

    SciTech Connect

    Alonso, S.; Sendina-Nadal, I.; Perez-Munuzuri, V.; Sancho, J. M.; Sagues, F.

    2001-08-13

    A pacemaker, regularly emitting chemical waves, is created out of noise when an excitable photosensitive Belousov-Zhabotinsky medium, strictly unable to autonomously initiate autowaves, is forced with a spatiotemporal patterned random illumination. These experimental observations are also reproduced numerically by using a set of reaction-diffusion equations for an activator-inhibitor model, and further analytically interpreted in terms of genuine coupling effects arising from parametric fluctuations. Within the same framework we also address situations of noise-sustained propagation in subexcitable media.

  12. Circadian rhythms in neuronal activity propagate through output circuits

    PubMed Central

    Cavey, Matthieu; Collins, Ben; Bertet, Claire; Blau, Justin

    2016-01-01

    24hr rhythms in behavior are organized by a network of circadian pacemaker neurons. Rhythmic activity in this network is generated by intrinsic rhythms in clock neuron physiology and communication between clock neurons. However, it is poorly understood how the activity of a small number of pacemaker neurons is translated into rhythmic behavior of the whole animal. To understand this, we screened for signals that could identify circadian output circuits in Drosophila. We found that Leucokinin neuropeptide (LK) and its receptor (LK-R) are required for normal behavioral rhythms. This LK/LK-R circuit connects pacemaker neurons to brain areas that regulate locomotor activity and sleep. Our experiments revealed that pacemaker neurons impose rhythmic activity and excitability on LK and LK-R expressing neurons. We also found pacemaker neuron-dependent activity rhythms in DH44-expressing neurons, a second circadian output pathway. We conclude that rhythmic clock neuron activity propagates to multiple downstream circuits to orchestrate behavioral rhythms. PMID:26928065

  13. Influence of sorption on sound propagation in granular activated carbon.

    PubMed

    Venegas, Rodolfo; Umnova, Olga

    2016-08-01

    Granular activated carbon (GAC) has numerous applications due to its ability to adsorb and desorb gas molecules. Recently, it has been shown to exhibit unusually high low frequency sound absorption. This behavior is determined by both the multi-scale nature of the material, i.e., the existence of three scales of heterogeneities, and physical processes specific to micro- and nanometer-size pores, i.e., rarefaction and sorption effects. To account for these processes a model for sound propagation in GAC is developed in this work. A methodology for characterizing GAC which includes optical granulometry, flow resistivity measurements, and the derivation of the inner-particle model parameters from acoustical and non-acoustical measurements is also presented. The model agrees with measurements of normal incidence surface impedance and sound absorption coefficient on three different GAC samples. PMID:27586708

  14. Correlations Decrease with Propagation of Spiking Activity in the Mouse Barrel Cortex

    PubMed Central

    Ranganathan, Gayathri Nattar; Koester, Helmut Joachim

    2011-01-01

    Propagation of suprathreshold spiking activity through neuronal populations is important for the function of the central nervous system. Neural correlations have an impact on cortical function particularly on the signaling of information and propagation of spiking activity. Therefore we measured the change in correlations as suprathreshold spiking activity propagated between recurrent neuronal networks of the mammalian cerebral cortex. Using optical methods we recorded spiking activity from large samples of neurons from two neural populations simultaneously. The results indicate that correlations decreased as spiking activity propagated from layer 4 to layer 2/3 in the rodent barrel cortex. PMID:21629764

  15. Homeostatic Activity-Dependent Tuning of Recurrent Networks for Robust Propagation of Activity

    PubMed Central

    Evers, Jan Felix; Eglen, Stephen J.

    2016-01-01

    Developing neuronal networks display spontaneous bursts of action potentials that are necessary for circuit organization and tuning. While spontaneous activity has been shown to instruct map formation in sensory circuits, it is unknown whether it plays a role in the organization of motor networks that produce rhythmic output. Using computational modeling, we investigate how recurrent networks of excitatory and inhibitory neuronal populations assemble to produce robust patterns of unidirectional and precisely timed propagating activity during organism locomotion. One example is provided by the motor network in Drosophila larvae, which generates propagating peristaltic waves of muscle contractions during crawling. We examine two activity-dependent models, which tune weak network connectivity based on spontaneous activity patterns: a Hebbian model, where coincident activity in neighboring populations strengthens connections between them; and a homeostatic model, where connections are homeostatically regulated to maintain a constant level of excitatory activity based on spontaneous input. The homeostatic model successfully tunes network connectivity to generate robust activity patterns with appropriate timing relationships between neighboring populations. These timing relationships can be modulated by the properties of spontaneous activity, suggesting its instructive role for generating functional variability in network output. In contrast, the Hebbian model fails to produce the tight timing relationships between neighboring populations required for unidirectional activity propagation, even when additional assumptions are imposed to constrain synaptic growth. These results argue that homeostatic mechanisms are more likely than Hebbian mechanisms to tune weak connectivity based on spontaneous input in a recurrent network for rhythm generation and robust activity propagation. SIGNIFICANCE STATEMENT How are neural circuits organized and tuned to maintain stable function

  16. Use of Artificial Propagation and Supplementation for Rebuilding Salmon Stocks Listed under the Endangered Species Act : Recovery Issues for Threatened and Endangered Snake River Salmon : Technical Report 5 of 11.

    SciTech Connect

    Lichatowich, Jim; Watson, Bruce

    1993-06-01

    Conventional hatcheries, supplementation, and habitat protection are management activities located on a production continuum. At one end of the continuum is the conventional hatchery which attempts to separate artificially propagated fish from naturally reproducing populations. On the other end of the continuum is natural production. Supplementation which attempts to increase natural production through the use of artificial propagation lies somewhere between natural production and conventional hatcheries on the continuum. The use of artificial propagation in the recovery of listed species is controversial. Guidance on the use of artificial propagation in the recovery of listed species comes from three sources: The Endangered Species Act (ESA), US Fish and Wildlife Service (USFWS) policies and National Marine Fisheries Service (NMFS) guidelines.

  17. Self-organization of synchronous activity propagation in neuronal networks driven by local excitation.

    PubMed

    Bayati, Mehdi; Valizadeh, Alireza; Abbassian, Abdolhossein; Cheng, Sen

    2015-01-01

    Many experimental and theoretical studies have suggested that the reliable propagation of synchronous neural activity is crucial for neural information processing. The propagation of synchronous firing activity in so-called synfire chains has been studied extensively in feed-forward networks of spiking neurons. However, it remains unclear how such neural activity could emerge in recurrent neuronal networks through synaptic plasticity. In this study, we investigate whether local excitation, i.e., neurons that fire at a higher frequency than the other, spontaneously active neurons in the network, can shape a network to allow for synchronous activity propagation. We use two-dimensional, locally connected and heterogeneous neuronal networks with spike-timing dependent plasticity (STDP). We find that, in our model, local excitation drives profound network changes within seconds. In the emergent network, neural activity propagates synchronously through the network. This activity originates from the site of the local excitation and propagates through the network. The synchronous activity propagation persists, even when the local excitation is removed, since it derives from the synaptic weight matrix. Importantly, once this connectivity is established it remains stable even in the presence of spontaneous activity. Our results suggest that synfire-chain-like activity can emerge in a relatively simple way in realistic neural networks by locally exciting the desired origin of the neuronal sequence.

  18. ACT/ICAPS: Thermoplastic composite activities

    NASA Technical Reports Server (NTRS)

    Renieri, M. P.; Burpo, S. J.; Roundy, L. M.; Todd, S. M.

    1992-01-01

    McDonnell Aircraft Company (MCAIR) is teamed with Douglas Aircraft Company (DAC) under NASA's Advanced Composite Technology (ACT) initiative in a program entitled Innovative Composite Aircraft Primary Structures (ICAPS). Efforts at MCAIR have focused on the use of thermoplastic composite materials in the development of structural details associated with an advanced fighter fuselage section with applicability to transport design. Based on innovative design/manufacturing concepts for the fuselage section primary structure, elements were designed, fabricated, and structurally tested. These elements focused on key issues such as thick composite lugs and low cost forming of fastenerless, stiffener/moldline concepts. Manufacturing techniques included autoclave consideration, single diaphragm co-consolidation (SDCC), and roll-forming.

  19. Topic-Aware Physical Activity Propagation in a Health Social Network

    PubMed Central

    Phan, Nhathai; Ebrahimi, Javid; Kil, Dave; Piniewski, Brigitte; Dou, Dejing

    2016-01-01

    Modeling physical activity propagation, such as physical exercise level and intensity, is the key to preventing the conduct that can lead to obesity; it can also help spread wellness behavior in a social network. PMID:27087794

  20. Texture Guided Active Appearance Model Propagation for Prostate Segmentation

    NASA Astrophysics Data System (ADS)

    Ghose, Soumya; Oliver, Arnau; Martí, Robert; Lladó, Xavier; Freixenet, Jordi; Vilanova, Joan C.; Meriaudeau, Fabrice

    Fusion of Magnetic Resonance Imaging (MRI) and Trans Rectal Ultra Sound (TRUS) images during TRUS guided prostate biopsy improves localization of the malignant tissues. Segmented prostate in TRUS and MRI improve registration accuracy and reduce computational cost of the procedure. However, accurate segmentation of the prostate in TRUS images can be a challenging task due to low signal to noise ratio, heterogeneous intensity distribution inside the prostate, and imaging artifacts like speckle noise and shadow. We propose to use texture features from approximation coefficients of Haar wavelet transform for propagation of a shape and appearance based statistical model to segment the prostate in a multi-resolution framework. A parametric model of the propagating contour is derived from Principal Component Analysis of prior shape and texture informations of the prostate from the training data. The parameters are then modified with prior knowledge of the optimization space to achieve optimal prostate segmentation. The proposed method achieves a mean Dice Similarity Coefficient value of 0.95±0.01, and mean segmentation time of 0.72±0.05 seconds when validated on 25 TRUS images, grabbed from video sequences, in a leave-one-out validation framework. Our proposed model performs computationally efficient accurate prostate segmentation in presence of intensity heterogeneity and imaging artifacts.

  1. Propagated infra-slow intrinsic brain activity reorganizes across wake and slow wave sleep.

    PubMed

    Mitra, Anish; Snyder, Abraham Z; Tagliazucchi, Enzo; Laufs, Helmut; Raichle, Marcus E

    2015-11-09

    Propagation of slow intrinsic brain activity has been widely observed in electrophysiogical studies of slow wave sleep (SWS). However, in human resting state fMRI (rs-fMRI), intrinsic activity has been understood predominantly in terms of zero-lag temporal synchrony (functional connectivity) within systems known as resting state networks (RSNs). Prior rs-fMRI studies have found that RSNs are generally preserved across wake and sleep. Here, we use a recently developed analysis technique to study propagation of infra-slow intrinsic blood oxygen level dependent (BOLD) signals in normal adults during wake and SWS. This analysis reveals marked changes in propagation patterns in SWS vs. wake. Broadly, ordered propagation is preserved within traditionally defined RSNs but lost between RSNs. Additionally, propagation between cerebral cortex and subcortical structures reverses directions, and intra-cortical propagation becomes reorganized, especially in visual and sensorimotor cortices. These findings show that propagated rs-fMRI activity informs theoretical accounts of the neural functions of sleep.

  2. Propagated infra-slow intrinsic brain activity reorganizes across wake and slow wave sleep

    PubMed Central

    Mitra, Anish; Snyder, Abraham Z; Tagliazucchi, Enzo; Laufs, Helmut; Raichle, Marcus E

    2015-01-01

    Propagation of slow intrinsic brain activity has been widely observed in electrophysiogical studies of slow wave sleep (SWS). However, in human resting state fMRI (rs-fMRI), intrinsic activity has been understood predominantly in terms of zero-lag temporal synchrony (functional connectivity) within systems known as resting state networks (RSNs). Prior rs-fMRI studies have found that RSNs are generally preserved across wake and sleep. Here, we use a recently developed analysis technique to study propagation of infra-slow intrinsic blood oxygen level dependent (BOLD) signals in normal adults during wake and SWS. This analysis reveals marked changes in propagation patterns in SWS vs. wake. Broadly, ordered propagation is preserved within traditionally defined RSNs but lost between RSNs. Additionally, propagation between cerebral cortex and subcortical structures reverses directions, and intra-cortical propagation becomes reorganized, especially in visual and sensorimotor cortices. These findings show that propagated rs-fMRI activity informs theoretical accounts of the neural functions of sleep. DOI: http://dx.doi.org/10.7554/eLife.10781.001 PMID:26551562

  3. Statistical approach to evaluating active reduction of crack propagation in aluminum panels with piezoelectric actuator patches

    NASA Astrophysics Data System (ADS)

    Platz, R.; Stapp, C.; Hanselka, H.

    2011-08-01

    Fatigue cracks in light-weight shell or panel structures may lead to major failures when used for sealing or load-carrying purposes. This paper describes investigations into the potential of piezoelectric actuator patches that are applied to the surface of an already cracked thin aluminum panel to actively reduce the propagation of fatigue cracks. With active reduction of fatigue crack propagation, uncertainties in the cracked structure's strength, which always remain present even when the structure is used under damage tolerance conditions, e.g. airplane fuselages, could be lowered. The main idea is to lower the cyclic stress intensity factor near the crack tip with actively induced mechanical compression forces using thin low voltage piezoelectric actuator patches applied to the panel's surface. With lowering of the cyclic stress intensity, the rate of crack propagation in an already cracked thin aluminum panel will be reduced significantly. First, this paper discusses the proper placement and alignment of thin piezoelectric actuator patches near the crack tip to induce the mechanical compression forces necessary for reduction of crack propagation by numerical simulations. Second, the potential for crack propagation reduction will be investigated statistically by an experimental sample test examining three cases: a cracked aluminum host structure (i) without, (ii) with but passive, and (iii) with activated piezoelectric actuator patches. It will be seen that activated piezoelectric actuator patches lead to a significant reduction in crack propagation.

  4. JPL Activated Carbon Treatment System (ACTS) for sewage

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An Activated Carbon Treatment System (ACTS) was developed for sewage treatment and is being applied to a one-million gallon per day sewage treatment pilot plant in Orange County California. Activities reported include pyrolysis and activation of carbon-sewage sludge, and activated carbon treatment of sewage to meet ocean discharge standards. The ACTS Sewage treatment operations include carbon-sewage treatment, primary and secondary clarifiers, gravity (multi-media) filter, filter press dewatering, flash drying of carbon-sewage filter cake, and sludge pyrolysis and activation. Tests were conducted on a laboratory scale, 10,000 gallon per day demonstration plant and pilot test equipment. Preliminary economic studies are favorable to the ACTS process relative to activated sludge treatment for a 175,000,000 gallon per day sewage treatment plant.

  5. ALVIN investigation of an active propagating rift system, Galapagos 95.5° W

    USGS Publications Warehouse

    Hey, R.N.; Sinton, J.M.; Kleinrock, M.C.; Yonover, R.N.; MacDonald, K.C.; Miller, S.P.; Searle, R.C.; Christie, D.M.; Atwater, T.M.; Sleep, N.H.; Johnson, H. Paul; Neal, C.A.

    1992-01-01

    ALVIN investigations have defined the fine-scale structural and volcanic patterns produced by active rift and spreading center propagation and failure near 95.5° W on the Galapagos spreading center. Behind the initial lithospheric rifting, which is propagating nearly due west at about 50 km m.y.−1, a triangular block of preexisting lithosphere is being stretched and fractured, with some recent volcanism along curving fissures. A well-organized seafloor spreading center, an extensively faulted and fissured volcanic ridge, develops ~ 10 km (~ 200,000 years) behind the tectonic rift tip. Regional variations in the chemical compositions of the youngest lavas collected during this program contrast with those encompassing the entire 3 m.y. of propagation history for this region. A maximum in degree of magmatic differentiation occurs about 9 km behind the propagating rift tip, in a region of diffuse rifting. The propagating spreading center shows a gentle gradient in magmatic differentiation culminating at the SW-curving spreading center tip. Except for the doomed rift, which is in a constructional phase, tectonic activity also dominates over volcanic activity along the failing spreading system. In contrast to the propagating rift, failing rift lavas show a highly restricted range of compositions consistent with derivation from a declining upwelling zone accompanying rift failure. The lithosphere transferred from the Cocos to the Nazca plate by this propagator is extensively faulted and characterized by ubiquitous talus in one of the most tectonically disrupted areas of seafloor known. The pseudofault scarps, where the preexisting lithosphere was rifted apart, appear to include both normal and propagator lavas and are thus more lithologically complex than previously thought. Biological communities, probably vestimentiferan tubeworms, occur near the top of the outer pseudofault scarp, although no hydrothermal venting was observed.

  6. Columnar interactions determine horizontal propagation of recurrent network activity in neocortex

    PubMed Central

    Wester, Jason C.; Contreras, Diego

    2012-01-01

    The cortex is organized in vertical and horizontal circuits that determine the spatiotemporal properties of distributed cortical activity. Despite detailed knowledge of synaptic interactions among individual cells in the neocortex, little is known about the rules governing interactions among local populations. Here we used self-sustained recurrent activity generated in cortex, also known as up-states, in rat thalamocortical slices in vitro to understand interactions among laminar and horizontal circuits. By means of intracellular recordings and fast optical imaging with voltage sensitive dyes, we show that single thalamic inputs activate the cortical column in a preferential L4→L2/3→L5 sequence, followed by horizontal propagation with a leading front in supra and infragranular layers. To understand the laminar and columnar interactions, we used focal injections of TTX to block activity in small local populations, while preserving functional connectivity in the rest of the network. We show that L2/3 alone, without underlying L5, does not generate self-sustained activity and is inefficient propagating activity horizontally. In contrast, L5 sustains activity in the absence of L2/3 and is necessary and sufficient to propagate activity horizontally. However, loss of L2/3 delays horizontal propagation via L5. Finally, L5 amplifies activity in L2/3. Our results show for the first time that columnar interactions between supra and infragranular layers are required for the normal propagation of activity in the neocortex. Our data suggest that supra and infragranular circuits with their specific and complex set of inputs and outputs, work in tandem to determine the patterns of cortical activation observed in vivo. PMID:22514308

  7. Autaptic pacemaker mediated propagation of weak rhythmic activity across small-world neuronal networks

    NASA Astrophysics Data System (ADS)

    Yilmaz, Ergin; Baysal, Veli; Ozer, Mahmut; Perc, Matjaž

    2016-02-01

    We study the effects of an autapse, which is mathematically described as a self-feedback loop, on the propagation of weak, localized pacemaker activity across a Newman-Watts small-world network consisting of stochastic Hodgkin-Huxley neurons. We consider that only the pacemaker neuron, which is stimulated by a subthreshold periodic signal, has an electrical autapse that is characterized by a coupling strength and a delay time. We focus on the impact of the coupling strength, the network structure, the properties of the weak periodic stimulus, and the properties of the autapse on the transmission of localized pacemaker activity. Obtained results indicate the existence of optimal channel noise intensity for the propagation of the localized rhythm. Under optimal conditions, the autapse can significantly improve the propagation of pacemaker activity, but only for a specific range of the autaptic coupling strength. Moreover, the autaptic delay time has to be equal to the intrinsic oscillation period of the Hodgkin-Huxley neuron or its integer multiples. We analyze the inter-spike interval histogram and show that the autapse enhances or suppresses the propagation of the localized rhythm by increasing or decreasing the phase locking between the spiking of the pacemaker neuron and the weak periodic signal. In particular, when the autaptic delay time is equal to the intrinsic period of oscillations an optimal phase locking takes place, resulting in a dominant time scale of the spiking activity. We also investigate the effects of the network structure and the coupling strength on the propagation of pacemaker activity. We find that there exist an optimal coupling strength and an optimal network structure that together warrant an optimal propagation of the localized rhythm.

  8. Age Discrimination in Employment Act of 1967; A Report Covering Activities in Connection with the Act During 1969.

    ERIC Educational Resources Information Center

    Wage and Labor Standards Administration (DOL), Washington, DC.

    This annual report on the Age Discrimination in Employment Act describes activities conducted under the Act in 1969. The Act prohibits discrimination in any of the terms of employment against individuals between 40 and 65 years of age. Coverage is extended to employers of 25 or more persons in occupations for which age is not a bona fide…

  9. Propagating waves of activity in the neocortex: what they are, what they do.

    PubMed

    Wu, Jian-Young; Xiaoying Huang; Chuan Zhang

    2008-10-01

    The development of voltage-sensitive dyes (VSD) and fast optical imaging techniques have brought us a new tool for examining spatiotemporal patterns of population neuronal activity in the neocortex. Propagating waves have been observed during almost every type of cortical processing examined by VSD imaging or electrode arrays. These waves provide subthreshold depolarization to individual neurons and increase their spiking probability. Therefore, the propagation of the waves sets up a spatiotemporal framework for increased excitability in neuronal populations, which can help to determine when and where the neurons are likely to fire. In this review, first discussed is propagating waves observed in various systems and possible mechanisms for generating and sustaining these waves. Then discussed are wave dynamics as an emergent behavior of the population activity that can, in turn, influence the activity of individual neurons. The functions of spontaneous and sensory-evoked waves remain to be explored. An important next step will be to examine the interaction between dynamics of propagating waves and functions in the cortex, and to verify if cortical processing can be modified when these waves are altered. PMID:18997124

  10. [Increase of rising activity of commercial yeasts by application of stress conditions during their propagation].

    PubMed

    Galvagno, M A; Cerrutti, P

    2004-01-01

    Rising activity determined as CO2 production of two commercial strains of Saccharomyces cerevisiae could be increased mainly in sweet bread doughs by introducing a "starvation/pulse feeding" schedule of sugar cane molasses during a fed-batch propagation. Such increase was strain dependent. Except for the trehalose intracellular level, other traits related to the yeast industrial performance were unaffected. Applicability of method for baker's yeast industrial production is discussed.

  11. Temporal Asymmetry in Dark–Bright Processing Initiates Propagating Activity across Primary Visual Cortex

    PubMed Central

    Rekauzke, Sascha; Nortmann, Nora; Staadt, Robert; Hock, Howard S.; Schöner, Gregor

    2016-01-01

    Differences between visual pathways representing darks and lights have been shown to affect spatial resolution and detection timing. Both psychophysical and physiological studies suggest an underlying retinal origin with amplification in primary visual cortex (V1). Here we show that temporal asymmetries in the processing of darks and lights create motion in terms of propagating activity across V1. Exploiting the high spatiotemporal resolution of voltage-sensitive dye imaging, we captured population responses to abrupt local changes of luminance in cat V1. For stimulation we used two neighboring small squares presented on either bright or dark backgrounds. When a single square changed from dark to bright or vice versa, we found coherent population activity emerging at the respective retinal input locations. However, faster rising and decay times were obtained for the bright to dark than the dark to bright changes. When the two squares changed luminance simultaneously in opposite polarities, we detected a propagating wave front of activity that originated at the cortical location representing the darkened square and rapidly expanded toward the region representing the brightened location. Thus, simultaneous input led to sequential activation across cortical retinotopy. Importantly, this effect was independent of the squares' contrast with the background. We suggest imbalance in dark–bright processing as a driving force in the generation of wave-like activity. Such propagation may convey motion signals and influence perception of shape whenever abrupt shifts in visual objects or gaze cause counterchange of luminance at high-contrast borders. SIGNIFICANCE STATEMENT An elementary process in vision is the detection of darks and lights through the retina via ON and OFF channels. Psychophysical and physiological studies suggest that differences between these channels affect spatial resolution and detection thresholds. Here we show that temporal asymmetries in the

  12. Antimicrobial activity of extracts from in vivo and in vitro propagated Lamium album L. plants.

    PubMed

    Chipeva, Valentina Aleksandrova; Petrova, Detelina Christova; Geneva, Milena Evgenieva; Dimitrova, Milena Angelova; Moncheva, Penka Angelova; Kapchina-Toteva, Veneta Michova

    2013-01-01

    The antimicrobial activity of 18 different extracts from in vivo and in vitro grown L. album L. plants was evaluated against clinical bacteria and yeasts using the well diffusion method. All the used extracts demonstrated antibacterial activity, whereas only the water extracts from leaves (in vivo) possessed antifungal activity against Candida albicans NBIMCC 72 and Candida glabrata NBIMCC 8673 (14 and 20 mm diameter of inhibition zones and MIC 10 mg/ml, respectively). The methanol and ethanol extracts obtained from the in vitro propagated plants had a broader spectrum of antibacterial activity than those from in vivo plants, while the opposite tendency was observed for the chloroform extracts. All tested flower extracts possessed antimicrobial activity. The chloroform extract from in vivo flowers demonstrated the highest activity against E. faecalis NBIMCC 3915, S. aureus NBIMCC 3703, P. hauseri NBIMCC 1339 and P. aeruginosa NBIMCC 3700 (22 mm, 13 mm, 11 mm, 23 mm zone diameter of inhibition and MIC 0.313 mg/ml, respectively). The water extracts from leaves (both in vivo and in vitro) possessed higher antibacterial activity than extract from flowers. The obtained results showed that both in vivo and in vitro propagated L. album L. could be used as a source of antibacterial substances.

  13. Effects of Calcium Spikes in the Layer 5 Pyramidal Neuron on Coincidence Detection and Activity Propagation.

    PubMed

    Chua, Yansong; Morrison, Abigail

    2016-01-01

    The role of dendritic spiking mechanisms in neural processing is so far poorly understood. To investigate the role of calcium spikes in the functional properties of the single neuron and recurrent networks, we investigated a three compartment neuron model of the layer 5 pyramidal neuron with calcium dynamics in the distal compartment. By performing single neuron simulations with noisy synaptic input and occasional large coincident input at either just the distal compartment or at both somatic and distal compartments, we show that the presence of calcium spikes confers a substantial advantage for coincidence detection in the former case and a lesser advantage in the latter. We further show that the experimentally observed critical frequency phenomenon, in which action potentials triggered by stimuli near the soma above a certain frequency trigger a calcium spike at distal dendrites, leading to further somatic depolarization, is not exhibited by a neuron receiving realistically noisy synaptic input, and so is unlikely to be a necessary component of coincidence detection. We next investigate the effect of calcium spikes in propagation of spiking activities in a feed-forward network (FFN) embedded in a balanced recurrent network. The excitatory neurons in the network are again connected to either just the distal, or both somatic and distal compartments. With purely distal connectivity, activity propagation is stable and distinguishable for a large range of recurrent synaptic strengths if the feed-forward connections are sufficiently strong, but propagation does not occur in the absence of calcium spikes. When connections are made to both the somatic and the distal compartments, activity propagation is achieved for neurons with active calcium dynamics at a much smaller number of neurons per pool, compared to a network of passive neurons, but quickly becomes unstable as the strength of recurrent synapses increases. Activity propagation at higher scaling factors can be

  14. Effects of Calcium Spikes in the Layer 5 Pyramidal Neuron on Coincidence Detection and Activity Propagation

    PubMed Central

    Chua, Yansong; Morrison, Abigail

    2016-01-01

    The role of dendritic spiking mechanisms in neural processing is so far poorly understood. To investigate the role of calcium spikes in the functional properties of the single neuron and recurrent networks, we investigated a three compartment neuron model of the layer 5 pyramidal neuron with calcium dynamics in the distal compartment. By performing single neuron simulations with noisy synaptic input and occasional large coincident input at either just the distal compartment or at both somatic and distal compartments, we show that the presence of calcium spikes confers a substantial advantage for coincidence detection in the former case and a lesser advantage in the latter. We further show that the experimentally observed critical frequency phenomenon, in which action potentials triggered by stimuli near the soma above a certain frequency trigger a calcium spike at distal dendrites, leading to further somatic depolarization, is not exhibited by a neuron receiving realistically noisy synaptic input, and so is unlikely to be a necessary component of coincidence detection. We next investigate the effect of calcium spikes in propagation of spiking activities in a feed-forward network (FFN) embedded in a balanced recurrent network. The excitatory neurons in the network are again connected to either just the distal, or both somatic and distal compartments. With purely distal connectivity, activity propagation is stable and distinguishable for a large range of recurrent synaptic strengths if the feed-forward connections are sufficiently strong, but propagation does not occur in the absence of calcium spikes. When connections are made to both the somatic and the distal compartments, activity propagation is achieved for neurons with active calcium dynamics at a much smaller number of neurons per pool, compared to a network of passive neurons, but quickly becomes unstable as the strength of recurrent synapses increases. Activity propagation at higher scaling factors can be

  15. Plumes of neuronal activity propagate in three dimensions through the nuclear avian brain

    PubMed Central

    2014-01-01

    Background In mammals, the slow-oscillations of neuronal membrane potentials (reflected in the electroencephalogram as high-amplitude, slow-waves), which occur during non-rapid eye movement sleep and anesthesia, propagate across the neocortex largely as two-dimensional traveling waves. However, it remains unknown if the traveling nature of slow-waves is unique to the laminar cytoarchitecture and associated computational properties of the neocortex. Results We demonstrate that local field potential slow-waves and correlated multiunit activity propagate as complex three-dimensional plumes of neuronal activity through the avian brain, owing to its non-laminar, nuclear neuronal cytoarchitecture. Conclusions The traveling nature of slow-waves is not dependent upon the laminar organization of the neocortex, and is unlikely to subserve functions unique to this pattern of neuronal organization. Finally, the three-dimensional geometry of propagating plumes may reflect computational properties not found in mammals that contributed to the evolution of nuclear neuronal organization and complex cognition in birds. PMID:24580797

  16. Protein Folding Activity of the Ribosome is involved in Yeast Prion Propagation

    PubMed Central

    Blondel, Marc; Soubigou, Flavie; Evrard, Justine; Nguyen, Phu hai; Hasin, Naushaba; Chédin, Stéphane; Gillet, Reynald; Contesse, Marie-Astrid; Friocourt, Gaëlle; Stahl, Guillaume; Jones, Gary W.; Voisset, Cécile

    2016-01-01

    6AP and GA are potent inhibitors of yeast and mammalian prions and also specific inhibitors of PFAR, the protein-folding activity borne by domain V of the large rRNA of the large subunit of the ribosome. We therefore explored the link between PFAR and yeast prion [PSI+] using both PFAR-enriched mutants and site-directed methylation. We demonstrate that PFAR is involved in propagation and de novo formation of [PSI+]. PFAR and the yeast heat-shock protein Hsp104 partially compensate each other for [PSI+] propagation. Our data also provide insight into new functions for the ribosome in basal thermotolerance and heat-shocked protein refolding. PFAR is thus an evolutionarily conserved cell component implicated in the prion life cycle, and we propose that it could be a potential therapeutic target for human protein misfolding diseases. PMID:27633137

  17. Protein Folding Activity of the Ribosome is involved in Yeast Prion Propagation.

    PubMed

    Blondel, Marc; Soubigou, Flavie; Evrard, Justine; Nguyen, Phu Hai; Hasin, Naushaba; Chédin, Stéphane; Gillet, Reynald; Contesse, Marie-Astrid; Friocourt, Gaëlle; Stahl, Guillaume; Jones, Gary W; Voisset, Cécile

    2016-01-01

    6AP and GA are potent inhibitors of yeast and mammalian prions and also specific inhibitors of PFAR, the protein-folding activity borne by domain V of the large rRNA of the large subunit of the ribosome. We therefore explored the link between PFAR and yeast prion [PSI(+)] using both PFAR-enriched mutants and site-directed methylation. We demonstrate that PFAR is involved in propagation and de novo formation of [PSI(+)]. PFAR and the yeast heat-shock protein Hsp104 partially compensate each other for [PSI(+)] propagation. Our data also provide insight into new functions for the ribosome in basal thermotolerance and heat-shocked protein refolding. PFAR is thus an evolutionarily conserved cell component implicated in the prion life cycle, and we propose that it could be a potential therapeutic target for human protein misfolding diseases. PMID:27633137

  18. Activity Catalog Tool (ACT) user manual, version 2.0

    NASA Technical Reports Server (NTRS)

    Segal, Leon D.; Andre, Anthony D.

    1994-01-01

    This report comprises the user manual for version 2.0 of the Activity Catalog Tool (ACT) software program, developed by Leon D. Segal and Anthony D. Andre in cooperation with NASA Ames Aerospace Human Factors Research Division, FLR branch. ACT is a software tool for recording and analyzing sequences of activity over time that runs on the Macintosh platform. It was designed as an aid for professionals who are interested in observing and understanding human behavior in field settings, or from video or audio recordings of the same. Specifically, the program is aimed at two primary areas of interest: human-machine interactions and interactions between humans. The program provides a means by which an observer can record an observed sequence of events, logging such parameters as frequency and duration of particular events. The program goes further by providing the user with a quantified description of the observed sequence, through application of a basic set of statistical routines, and enables merging and appending of several files and more extensive analysis of the resultant data.

  19. Human activity recognition based on feature selection in smart home using back-propagation algorithm.

    PubMed

    Fang, Hongqing; He, Lei; Si, Hao; Liu, Peng; Xie, Xiaolei

    2014-09-01

    In this paper, Back-propagation(BP) algorithm has been used to train the feed forward neural network for human activity recognition in smart home environments, and inter-class distance method for feature selection of observed motion sensor events is discussed and tested. And then, the human activity recognition performances of neural network using BP algorithm have been evaluated and compared with other probabilistic algorithms: Naïve Bayes(NB) classifier and Hidden Markov Model(HMM). The results show that different feature datasets yield different activity recognition accuracy. The selection of unsuitable feature datasets increases the computational complexity and degrades the activity recognition accuracy. Furthermore, neural network using BP algorithm has relatively better human activity recognition performances than NB classifier and HMM.

  20. Ex Vivo Propagation of Human Corneal Stromal "Activated Keratocytes" for Tissue Engineering.

    PubMed

    Yam, Gary Hin-Fai; Yusoff, Nur Zahirah Binte M; Kadaba, Aishwarya; Tian, Dechao; Myint, Htoon Hla; Beuerman, Roger W; Zhou, Lei; Mehta, Jodhbir S

    2015-01-01

    Keratoconus is a corneal disorder characterized by a thinning of stromal tissue, and the affected patients have induced astigmatism and visual impairment. It is associated with a loss of corneal stromal keratocytes (CSKs). Hence, reconstructing stromal tissue with autologous CSK replacement can be a viable alternative to corneal transplantation, which is restricted by the global donor material shortage and graft rejection. Human CSKs are normally quiescent and express unique markers, like aldehyde dehydrogenases and keratocan. In serum culture, they proliferate, but lose their characteristic phenotype and become stromal fibroblasts. Here we report a novel culture cocktail to ex vivo propagate and maintain CSKs. Primary human CSKs were obtained from adult donors and cultured with soluble human amnion stromal extract (ASE), rho-associated coiled-coil-forming protein serine/threonine kinase inhibitor Y-27632, and insulin-like growth factor-1 (collectively named as ERI). Protein profiling using mass spectrometry followed by MetaCore™ pathway analysis predicted that ASE proteins might participate in transforming growth factor-β (TGF-β) signaling and fibroblast development, cell adhesion, extracellular matrix remodeling, and immune response. In culture with 0.5% fetal bovine serum and ERI, the population of "activated keratocytes" was expanded. They had much lowered expression of both keratocyte and fibroblast markers, suppressed TGF-β-mediated Smad2/3 activation, and lacked fibroblast-mediated collagen contractibility. These "activated keratoctyes" could be propagated for six to eight passages ex vivo, and they regained CSK-specific dendritic morphology and gene marker expression, including aldehyde dehydrogenases, lumican, and keratocan biosynthesis, expression, and secretion when returned to serum-depleted ERI condition. This novel cocktail maintained human CSKs in both adherent and suspension cultures with proper keratocyte features and without the

  1. Ex Vivo Propagation of Human Corneal Stromal "Activated Keratocytes" for Tissue Engineering.

    PubMed

    Yam, Gary Hin-Fai; Yusoff, Nur Zahirah Binte M; Kadaba, Aishwarya; Tian, Dechao; Myint, Htoon Hla; Beuerman, Roger W; Zhou, Lei; Mehta, Jodhbir S

    2015-01-01

    Keratoconus is a corneal disorder characterized by a thinning of stromal tissue, and the affected patients have induced astigmatism and visual impairment. It is associated with a loss of corneal stromal keratocytes (CSKs). Hence, reconstructing stromal tissue with autologous CSK replacement can be a viable alternative to corneal transplantation, which is restricted by the global donor material shortage and graft rejection. Human CSKs are normally quiescent and express unique markers, like aldehyde dehydrogenases and keratocan. In serum culture, they proliferate, but lose their characteristic phenotype and become stromal fibroblasts. Here we report a novel culture cocktail to ex vivo propagate and maintain CSKs. Primary human CSKs were obtained from adult donors and cultured with soluble human amnion stromal extract (ASE), rho-associated coiled-coil-forming protein serine/threonine kinase inhibitor Y-27632, and insulin-like growth factor-1 (collectively named as ERI). Protein profiling using mass spectrometry followed by MetaCore™ pathway analysis predicted that ASE proteins might participate in transforming growth factor-β (TGF-β) signaling and fibroblast development, cell adhesion, extracellular matrix remodeling, and immune response. In culture with 0.5% fetal bovine serum and ERI, the population of "activated keratocytes" was expanded. They had much lowered expression of both keratocyte and fibroblast markers, suppressed TGF-β-mediated Smad2/3 activation, and lacked fibroblast-mediated collagen contractibility. These "activated keratoctyes" could be propagated for six to eight passages ex vivo, and they regained CSK-specific dendritic morphology and gene marker expression, including aldehyde dehydrogenases, lumican, and keratocan biosynthesis, expression, and secretion when returned to serum-depleted ERI condition. This novel cocktail maintained human CSKs in both adherent and suspension cultures with proper keratocyte features and without the

  2. Blast shockwaves propagate Ca(2+) activity via purinergic astrocyte networks in human central nervous system cells.

    PubMed

    Ravin, Rea; Blank, Paul S; Busse, Brad; Ravin, Nitay; Vira, Shaleen; Bezrukov, Ludmila; Waters, Hang; Guerrero-Cazares, Hugo; Quinones-Hinojosa, Alfredo; Lee, Philip R; Fields, R Douglas; Bezrukov, Sergey M; Zimmerberg, Joshua

    2016-01-01

    In a recent study of the pathophysiology of mild, blast-induced traumatic brain injury (bTBI) the exposure of dissociated, central nervous system (CNS) cells to simulated blast resulted in propagating waves of elevated intracellular Ca(2+). Here we show, in dissociated human CNS cultures, that these calcium waves primarily propagate through astrocyte-dependent, purinergic signaling pathways that are blocked by P2 antagonists. Human, compared to rat, astrocytes had an increased calcium response and prolonged calcium wave propagation kinetics, suggesting that in our model system rat CNS cells are less responsive to simulated blast. Furthermore, in response to simulated blast, human CNS cells have increased expressions of a reactive astrocyte marker, glial fibrillary acidic protein (GFAP) and a protease, matrix metallopeptidase 9 (MMP-9). The conjoint increased expression of GFAP and MMP-9 and a purinergic ATP (P2) receptor antagonist reduction in calcium response identifies both potential mechanisms for sustained changes in brain function following primary bTBI and therapeutic strategies targeting abnormal astrocyte activity. PMID:27162174

  3. Blast shockwaves propagate Ca2+ activity via purinergic astrocyte networks in human central nervous system cells

    PubMed Central

    Ravin, Rea; Blank, Paul S.; Busse, Brad; Ravin, Nitay; Vira, Shaleen; Bezrukov, Ludmila; Waters, Hang; Guerrero-Cazares, Hugo; Quinones-Hinojosa, Alfredo; Lee, Philip R.; Fields, R. Douglas; Bezrukov, Sergey M.; Zimmerberg, Joshua

    2016-01-01

    In a recent study of the pathophysiology of mild, blast-induced traumatic brain injury (bTBI) the exposure of dissociated, central nervous system (CNS) cells to simulated blast resulted in propagating waves of elevated intracellular Ca2+. Here we show, in dissociated human CNS cultures, that these calcium waves primarily propagate through astrocyte-dependent, purinergic signaling pathways that are blocked by P2 antagonists. Human, compared to rat, astrocytes had an increased calcium response and prolonged calcium wave propagation kinetics, suggesting that in our model system rat CNS cells are less responsive to simulated blast. Furthermore, in response to simulated blast, human CNS cells have increased expressions of a reactive astrocyte marker, glial fibrillary acidic protein (GFAP) and a protease, matrix metallopeptidase 9 (MMP-9). The conjoint increased expression of GFAP and MMP-9 and a purinergic ATP (P2) receptor antagonist reduction in calcium response identifies both potential mechanisms for sustained changes in brain function following primary bTBI and therapeutic strategies targeting abnormal astrocyte activity. PMID:27162174

  4. Active control and spatial mapping of mid-infrared propagating surface plasmons.

    PubMed

    Ribaudo, T; Shaner, E A; Howard, S S; Gmachl, C; Wang, X J; Choa, F-S; Wasserman, D

    2009-04-27

    Periodic arrays of subwavelength apertures in metal films have been shown to exhibit strongly enhanced transmission at wavelengths determined by the periodicity of the film as well as the optical properties of the metal and surrounding dielectric material. Here we investigate the coupling between such a grating and a Quantum Cascade Laser. By actively tuning the optical properties of our grating, we control the coupling of laser light to the plasmonic structure, switching our grating from a predominantly transmitting state to a state that allows coupling to propagating surface waves, which can then be imaged on the metallic surface.

  5. Valuing the Endangered Species Antirrhinum lopesianum: Neuroprotective Activities and Strategies for in vitro Plant Propagation

    PubMed Central

    Gomes, Andreia; Fortalezas, Sofia; Pimpão, Rui; Figueira, Inês; Maroco, João; Aguiar, Carlos; Ferreira, Ricardo B.; Miguel, Célia; Santos, Cláudia N.

    2013-01-01

    Plant phytochemicals are described as possessing considerable neuroprotective properties, due to radical scavenging capacity and acetylcholinesterase inhibitory activity, important bioactivities in neurodegeneration. Antirrhinum lopesianum is a rare endemism from the Iberian Peninsula, occurring at the northeastern border between Portugal and Spain. It is classified as Endangered, due to its highly fragmented geographical occupation, facing a high risk of extinction in the Portuguese territory, within 20 years. Here, we describe for the first time the chemical characterization of extracts of the species concerning total phenol content, flavonoid content and antioxidant properties. The profile of high performance liquid chromatography with diode array detector (HPLC-DAD) of the polyphenol-enriched fraction of plant extracts was also performed, showing the great potential of the species as a source of bioactive phytochemical compounds. A. lopesianum’s potential for neuroprotection was revealed by a significant acetylcholinesterase inhibitory activity and also by a neuroprotective effect on a human cell model of neurodegeneration. Moreover, this is the first report describing a successful procedure for the in vitro propagation of this endangered species. The comparison of phenolic content and the HPLC-DAD profile of wild and in vitro propagated plants revealed that in vitro plants maintain the ability to produce secondary metabolites, but the profiles are differentially affected by the growth regulators. The results presented here greatly contribute to the value for this species regarding its potential as a source of phytochemicals with prospective neuroprotective health benefits. PMID:26784465

  6. Active Control of Coupled Wave Propagation in Fluid-Filled Elastic Cylindrical Shells.

    NASA Astrophysics Data System (ADS)

    Brevart, Bertrand Jean

    The vibrational energy propagating in straight fluid-filled elastic pipes is carried by the structure as well as by the internal fluid. This study demonstrates that, whether the propagating energy is predominantly conveyed in the shell or in the fluid, large attenuations of the total power flow may be achieved by using an active control approach. As the shell and fluid motions are fully coupled, the implementation of intrusive sources/sensors in the acoustic field can be also avoided. The approach is based on using radial control forces applied to the outer shell wall and error sensors observing the structural motion. The cylindrical shell is assumed to be infinite, in vacuo or filled with water. The first disturbance source investigated is a propagating free wave of circumferential order n = 0 or n = 1. The control forces are appropriate harmonic line forces radially applied to the structure. The radial displacement of the shell wall at discrete locations downstream of the control forces is minimized using linear quadratic optimal control theory. The attenuation of the total power flow in the system after control is used to study the impact of the fluid on the performance of the control approach. Results for the shell in vacuo are presented for comparison. Considering the breathing mode (n = 0), the fluid decreases the control performance when the disturbance is a structural-type incident wave. Significant reductions of the transmitted power flow can be achieved when the disturbance is a fluid-type of wave. Regarding the beam mode (n = 1), the fluid increases the control performance below the first acoustic cut-off frequency and decreases it above this frequency. The analytical study is then extended to the active control of the pipe vibrations induced by more realistic disturbances such as a point force or an internal monopole source. The point force disturbance addresses the problem of mechanical excitation whereas the internal monopole source directs the

  7. Intra- and Interhemispheric Propagation of Electrophysiological Synchronous Activity and Its Modulation by Serotonin in the Cingulate Cortex of Juvenile Mice.

    PubMed

    Rovira, Víctor; Geijo-Barrientos, Emilio

    2016-01-01

    Disinhibition of the cortex (e.g., by GABA -receptor blockade) generates synchronous and oscillatory electrophysiological activity that propagates along the cortex. We have studied, in brain slices of the cingulate cortex of mice (postnatal age 14-20 days), the propagation along layer 2/3 as well as the interhemispheric propagation through the corpus callosum of synchronous discharges recorded extracellularly and evoked in the presence of 10 μM bicuculline by electrical stimulation of layer 1. The latency of the responses obtained at the same distance from the stimulus electrode was longer in anterior cingulate cortex (ACC: 39.53 ± 2.83 ms, n = 7) than in retrosplenial cortex slices (RSC: 21.99 ± 2.75 ms, n = 5; p<0.05), which is equivalent to a lower propagation velocity in the dorso-ventral direction in ACC than in RSC slices (43.0 mm/s vs 72.9 mm/s). We studied the modulation of this propagation by serotonin. Serotonin significantly increased the latency of the intracortical synchronous discharges (18.9% in the ipsilateral hemisphere and 40.2% in the contralateral hemisphere), and also increased the interhemispheric propagation time by 86.4%. These actions of serotonin were mimicked by the activation of either 5-HT1B or 5-HT2A receptors, but not by the activation of the 5-HT1A subtype. These findings provide further knowledge about the propagation of synchronic electrical activity in the cerebral cortex, including its modulation by serotonin, and suggest the presence of deep differences between the ACC and RSC in the structure of the local cortical microcircuits underlying the propagation of synchronous discharges.

  8. Intra- and Interhemispheric Propagation of Electrophysiological Synchronous Activity and Its Modulation by Serotonin in the Cingulate Cortex of Juvenile Mice

    PubMed Central

    Rovira, Víctor; Geijo-Barrientos, Emilio

    2016-01-01

    Disinhibition of the cortex (e.g., by GABA -receptor blockade) generates synchronous and oscillatory electrophysiological activity that propagates along the cortex. We have studied, in brain slices of the cingulate cortex of mice (postnatal age 14–20 days), the propagation along layer 2/3 as well as the interhemispheric propagation through the corpus callosum of synchronous discharges recorded extracellularly and evoked in the presence of 10 μM bicuculline by electrical stimulation of layer 1. The latency of the responses obtained at the same distance from the stimulus electrode was longer in anterior cingulate cortex (ACC: 39.53 ± 2.83 ms, n = 7) than in retrosplenial cortex slices (RSC: 21.99 ± 2.75 ms, n = 5; p<0.05), which is equivalent to a lower propagation velocity in the dorso-ventral direction in ACC than in RSC slices (43.0 mm/s vs 72.9 mm/s). We studied the modulation of this propagation by serotonin. Serotonin significantly increased the latency of the intracortical synchronous discharges (18.9% in the ipsilateral hemisphere and 40.2% in the contralateral hemisphere), and also increased the interhemispheric propagation time by 86.4%. These actions of serotonin were mimicked by the activation of either 5-HT1B or 5-HT2A receptors, but not by the activation of the 5-HT1A subtype. These findings provide further knowledge about the propagation of synchronic electrical activity in the cerebral cortex, including its modulation by serotonin, and suggest the presence of deep differences between the ACC and RSC in the structure of the local cortical microcircuits underlying the propagation of synchronous discharges. PMID:26930051

  9. Intra- and Interhemispheric Propagation of Electrophysiological Synchronous Activity and Its Modulation by Serotonin in the Cingulate Cortex of Juvenile Mice.

    PubMed

    Rovira, Víctor; Geijo-Barrientos, Emilio

    2016-01-01

    Disinhibition of the cortex (e.g., by GABA -receptor blockade) generates synchronous and oscillatory electrophysiological activity that propagates along the cortex. We have studied, in brain slices of the cingulate cortex of mice (postnatal age 14-20 days), the propagation along layer 2/3 as well as the interhemispheric propagation through the corpus callosum of synchronous discharges recorded extracellularly and evoked in the presence of 10 μM bicuculline by electrical stimulation of layer 1. The latency of the responses obtained at the same distance from the stimulus electrode was longer in anterior cingulate cortex (ACC: 39.53 ± 2.83 ms, n = 7) than in retrosplenial cortex slices (RSC: 21.99 ± 2.75 ms, n = 5; p<0.05), which is equivalent to a lower propagation velocity in the dorso-ventral direction in ACC than in RSC slices (43.0 mm/s vs 72.9 mm/s). We studied the modulation of this propagation by serotonin. Serotonin significantly increased the latency of the intracortical synchronous discharges (18.9% in the ipsilateral hemisphere and 40.2% in the contralateral hemisphere), and also increased the interhemispheric propagation time by 86.4%. These actions of serotonin were mimicked by the activation of either 5-HT1B or 5-HT2A receptors, but not by the activation of the 5-HT1A subtype. These findings provide further knowledge about the propagation of synchronic electrical activity in the cerebral cortex, including its modulation by serotonin, and suggest the presence of deep differences between the ACC and RSC in the structure of the local cortical microcircuits underlying the propagation of synchronous discharges. PMID:26930051

  10. Sensory and decision-related activity propagate in a cortical feedback loop during touch perception.

    PubMed

    Kwon, Sung Eun; Yang, Hongdian; Minamisawa, Genki; O'Connor, Daniel H

    2016-09-01

    The brain transforms physical sensory stimuli into meaningful perceptions. In animals making choices about sensory stimuli, neuronal activity in successive cortical stages reflects a progression from sensation to decision. Feedforward and feedback pathways connecting cortical areas are critical for this transformation. However, the computational functions of these pathways are poorly understood because pathway-specific activity has rarely been monitored during a perceptual task. Using cellular-resolution, pathway-specific imaging, we measured neuronal activity across primary (S1) and secondary (S2) somatosensory cortices of mice performing a tactile detection task. S1 encoded the stimulus better than S2, while S2 activity more strongly reflected perceptual choice. S1 neurons projecting to S2 fed forward activity that predicted choice. Activity encoding touch and choice propagated in an S1-S2 loop along feedforward and feedback axons. Our results suggest that sensory inputs converge into a perceptual outcome as feedforward computations are reinforced in a feedback loop. PMID:27437910

  11. Longitudinal and transverse propagation of surface mechanomyographic waves generated by single motor unit activity.

    PubMed

    Cescon, Corrado; Madeleine, Pascal; Farina, Dario

    2008-09-01

    Multi-channel surface mechanomyographic (MMG) signals generated by individual motor units were analyzed to investigate whether the surface mechanical waves induced by fiber contraction propagate over the skin surface. The MMG signals were recorded from the tibialis anterior muscle of ten healthy subjects with 13 uniaxial accelerometers, located both along and transverse to the fiber direction. Intramuscular electromyographic signals served to identify individual motor units whose action potentials were used to trigger the averaging of the MMG signals. The spike-triggered averaged MMG had similar characteristics in locations along the longitudinal direction; however, its amplitude decreased along the transverse direction. Moreover, the time-to-positive peak increased along the transverse direction, indicating a transverse wave propagation with a velocity of 2.4 +/- 1.1 m/s in the linear direction. The results support the hypothesis that the MMG signal mainly originates from muscle fiber displacement underlining a bending mode due to contraction and provide the basis for interpreting the interference MMG in relation to motor unit activity.

  12. Spatio-temporal PLC activation in parallel with intracellular Ca2+ wave propagation in mechanically stimulated single MDCK cells.

    PubMed

    Tsukamoto, Akira; Hayashida, Yasunori; Furukawa, Katsuko S; Ushida, Takashi

    2010-03-01

    Intracellular Ca2+ transients are evoked either by the opening of Ca2+ channels on the plasma membrane or by phospholipase C (PLC) activation resulting in IP3 production. Ca2+ wave propagation is known to occur in mechanically stimulated cells; however, it remains uncertain whether and how PLC activation is involved in intracellular Ca2+ wave propagation in mechanically stimulated cells. To answer these questions, it is indispensable to clarify the spatio-temporal relations between intracellular Ca2+ wave propagation and PLC activation. Thus, we visualized both cytosolic Ca2+ and PLC activation using a real-time dual-imaging system in individual Mardin-Darby Canine Kidney (MDCK) cells. This system allowed us to simultaneously observe intracellular Ca2+ wave propagation and PLC activation in a spatio-temporal manner in a single mechanically stimulated MDCK cell. The results showed that PLC was activated not only in the mechanically stimulated region but also in other subcellular regions in parallel with intracellular Ca2+ wave propagation. These results support a model in which PLC is involved in Ca2+ signaling amplification in mechanically stimulated cells.

  13. 77 FR 1947 - Agency Information Collection Activities: Jade Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-12

    ... Act of 2008 (JADE Act) prohibits the importation of ``Burmese covered articles'' (jadeite, rubies, and articles of jewelry containing jadeite or rubies mined or extracted from Burma), and sets forth conditions for the importation of ``non-Burmese covered articles'' (jadeite, rubies, and articles of...

  14. Van Allen Probes observation and modeling of chorus excitation and propagation during weak geomagnetic activities

    SciTech Connect

    He, Yihua; Xiao, Fuliang; Zhou, Qinghua; Yang, Chang; Liu, Si; Baker, D. N.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; Reeves, G. D.; Funsten, H. O.; Blake, J. B.

    2015-08-20

    We report correlated data on nightside chorus waves and energetic electrons during two small storm periods: 1 November 2012 (Dst ≈ –45) and 14 January 2013 (Dst ≈ –18). The Van Allen Probes simultaneously observed strong chorus waves at locations L = 5.8 – 6.3, with a lower frequency band 0.1–0.5fce and a peak spectral density ~10–4 nT2/Hz. In the same period, the fluxes and anisotropy of energetic (~10–300 keV) electrons were greatly enhanced in the interval of large negative interplanetary magnetic field Bz. Using a bi-Maxwellian distribution to model the observed electron distribution, we perform ray tracing simulations to show that nightside chorus waves are indeed produced by the observed electron distribution with a peak growth for a field-aligned propagation approximately between 0.3fce and 0.4fce, at latitude <7°. Moreover, chorus waves launched with initial normal angles either θ < 90° or > 90° propagate along the field either northward or southward and then bounce back either away from Earth for a lower frequency or toward Earth for higher frequencies. The current results indicate that nightside chorus waves can be excited even during weak geomagnetic activities in cases of continuous injection associated with negative Bz. Furthermore, we examine a dayside event during a small storm C on 8 May 2014 (Dst ≈ –45) and find that the observed anisotropic energetic electron distributions potentially contribute to the generation of dayside chorus waves, but this requires more thorough studies in the future.

  15. Van Allen Probes observation and modeling of chorus excitation and propagation during weak geomagnetic activities

    DOE PAGES

    He, Yihua; Xiao, Fuliang; Zhou, Qinghua; Yang, Chang; Liu, Si; Baker, D. N.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; et al

    2015-08-20

    We report correlated data on nightside chorus waves and energetic electrons during two small storm periods: 1 November 2012 (Dst ≈ –45) and 14 January 2013 (Dst ≈ –18). The Van Allen Probes simultaneously observed strong chorus waves at locations L = 5.8 – 6.3, with a lower frequency band 0.1–0.5fce and a peak spectral density ~10–4 nT2/Hz. In the same period, the fluxes and anisotropy of energetic (~10–300 keV) electrons were greatly enhanced in the interval of large negative interplanetary magnetic field Bz. Using a bi-Maxwellian distribution to model the observed electron distribution, we perform ray tracing simulations tomore » show that nightside chorus waves are indeed produced by the observed electron distribution with a peak growth for a field-aligned propagation approximately between 0.3fce and 0.4fce, at latitude <7°. Moreover, chorus waves launched with initial normal angles either θ < 90° or > 90° propagate along the field either northward or southward and then bounce back either away from Earth for a lower frequency or toward Earth for higher frequencies. The current results indicate that nightside chorus waves can be excited even during weak geomagnetic activities in cases of continuous injection associated with negative Bz. Furthermore, we examine a dayside event during a small storm C on 8 May 2014 (Dst ≈ –45) and find that the observed anisotropic energetic electron distributions potentially contribute to the generation of dayside chorus waves, but this requires more thorough studies in the future.« less

  16. Influence of optical activity on rogue waves propagating in chiral optical fibers

    NASA Astrophysics Data System (ADS)

    Temgoua, D. D. Estelle; Kofane, T. C.

    2016-06-01

    We derive the nonlinear Schrödinger (NLS) equation in chiral optical fiber with right- and left-hand nonlinear polarization. We use the similarity transformation to reduce the generalized chiral NLS equation to the higher-order integrable Hirota equation. We present the first- and second-order rational solutions of the chiral NLS equation with variable and constant coefficients, based on the modified Darboux transformation method. For some specific set of parameters, the features of chiral optical rogue waves are analyzed from analytical results, showing the influence of optical activity on waves. We also generate the exact solutions of the two-component coupled nonlinear Schrödinger equations, which describe optical activity effects on the propagation of rogue waves, and their properties in linear and nonlinear coupling cases are investigated. The condition of modulation instability of the background reveals the existence of vector rogue waves and the number of stable and unstable branches. Controllability of chiral optical rogue waves is examined by numerical simulations and may bring potential applications in optical fibers and in many other physical systems.

  17. Influence of optical activity on rogue waves propagating in chiral optical fibers.

    PubMed

    Temgoua, D D Estelle; Kofane, T C

    2016-06-01

    We derive the nonlinear Schrödinger (NLS) equation in chiral optical fiber with right- and left-hand nonlinear polarization. We use the similarity transformation to reduce the generalized chiral NLS equation to the higher-order integrable Hirota equation. We present the first- and second-order rational solutions of the chiral NLS equation with variable and constant coefficients, based on the modified Darboux transformation method. For some specific set of parameters, the features of chiral optical rogue waves are analyzed from analytical results, showing the influence of optical activity on waves. We also generate the exact solutions of the two-component coupled nonlinear Schrödinger equations, which describe optical activity effects on the propagation of rogue waves, and their properties in linear and nonlinear coupling cases are investigated. The condition of modulation instability of the background reveals the existence of vector rogue waves and the number of stable and unstable branches. Controllability of chiral optical rogue waves is examined by numerical simulations and may bring potential applications in optical fibers and in many other physical systems. PMID:27415269

  18. Efficient influenza B virus propagation due to deficient interferon-induced antiviral activity in MDCK cells.

    PubMed

    Frensing, Timo; Seitz, Claudius; Heynisch, Bjoern; Patzina, Corinna; Kochs, Georg; Reichl, Udo

    2011-09-22

    Influenza B virus infections are mainly restricted to humans, which is partially caused by the inability of influenza B virus NS1 protein to counteract the innate immune response of other species. However, for cell culture-based influenza vaccine production non-human cells, such as Madin-Darby canine kidney (MDCK) cells, are commonly used. Therefore, the impact of cellular pathogen defence mechanisms on influenza B virus propagation in MDCK cells was analysed in this study. Activation of the cellular antiviral defence by interferon stimulation slowed down influenza B virus replication at early time points but after 48h the same virus titres were reached in stimulated and control cells. Furthermore, suppression of the antiviral host defence by transient expression of a viral antagonist, the rabies virus phosphoprotein, could not increase influenza B virus replication. Finally, canine Myxovirus resistance (Mx) proteins showed no antiviral activity in an influenza B virus-specific minireplicon assay in contrast to the murine Mx1 protein. Taken together, these results indicate that an insufficient antiviral defence in MDCK cells promotes efficient influenza B virus replication favouring the use of MDCK cells in influenza vaccine production.

  19. Active learning for semi-supervised clustering based on locally linear propagation reconstruction.

    PubMed

    Chang, Chin-Chun; Lin, Po-Yi

    2015-03-01

    The success of semi-supervised clustering relies on the effectiveness of side information. To get effective side information, a new active learner learning pairwise constraints known as must-link and cannot-link constraints is proposed in this paper. Three novel techniques are developed for learning effective pairwise constraints. The first technique is used to identify samples less important to cluster structures. This technique makes use of a kernel version of locally linear embedding for manifold learning. Samples neither important to locally linear propagation reconstructions of other samples nor on flat patches in the learned manifold are regarded as unimportant samples. The second is a novel criterion for query selection. This criterion considers not only the importance of a sample to expanding the space coverage of the learned samples but also the expected number of queries needed to learn the sample. To facilitate semi-supervised clustering, the third technique yields inferred must-links for passing information about flat patches in the learned manifold to semi-supervised clustering algorithms. Experimental results have shown that the learned pairwise constraints can capture the underlying cluster structures and proven the feasibility of the proposed approach.

  20. Preliminary Study on Active Modulation of Polar Mesosphere Summer Echoes with the Radio Propagation in Layered Space Dusty Plasma

    NASA Astrophysics Data System (ADS)

    Zhou, Shengguo; Li, Hailong; Fu, Luyao; Wang, Maoyan

    2016-06-01

    Radar echoes intensity of polar mesosphere summer echoes (PMSE) is greatly affected by the temperature of dusty plasma and the frequency of electromagnetic wave about the radar. In this paper, a new method is developed to explain the active experiment results of PMSE. The theory of wave propagation in a layered media is used to study the propagation characteristics of an electromagnetic wave at different electron temperatures. The simulation results show that the variation tendency of the reflected power fraction almost agrees with the results observed by radar in the European Incoherent Scatter Scientific Association (EISCAT). The radar echoes intensity of PMSE greatly decreases with the increase of the radio frequency and the enhancement of the electron temperature. supported by National Natural Science Foundation of China (Nos. 41104097 and 41304119) and by the National Key Laboratory of Electromagnetic Environment, China Research Institute of Radiowave Propagation (CRIRP)

  1. Risk analysis for rumor propagation in metropolises based on improved 8-state ICSAR model and dynamic personal activity trajectories

    NASA Astrophysics Data System (ADS)

    Zhang, N.; Huang, H.; Duarte, M.; Zhang, J.

    2016-06-01

    Social media has developed extremely fast in metropolises in recent years resulting in more and more rumors disturbing our daily lives. Knowing the characteristics of rumor propagation in metropolises can help the government make efficient rumor refutation plans. In this paper, we established a dynamic spatio-temporal comprehensive risk assessment model for rumor propagation based on an improved 8-state ICSAR model (Ignorant, Information Carrier, Information Spreader, Advocate, Removal), large personal activity trajectory data, and governmental rumor refutation (anti-rumor) scenarios. Combining these relevant data with the 'big' traffic data on the use of subways, buses, and taxis, we simulated daily oral communications among inhabitants in Beijing. In order to analyze rumor and anti-rumor competition in the actual social network, personal resistance, personal preference, conformity, rumor intensity, government rumor refutation and other influencing factors were considered. Based on the developed risk assessment model, a long-term dynamic rumor propagation simulation for a seven day period was conducted and a comprehensive rumor propagation risk distribution map was obtained. A set of the sensitivity analyses were conducted for different social media and propagation routes. We assessed different anti-rumor coverage ratios and the rumor-spreading thresholds at which the government started to launch anti-rumor actions. The results we obtained provide worthwhile references useful for governmental decision making towards control of social-disrupting rumors.

  2. High-Speed imaging reveals opposing effects of chronic stress and antidepressants on neuronal activity propagation through the hippocampal trisynaptic circuit

    PubMed Central

    Stepan, Jens; Hladky, Florian; Uribe, Andrés; Holsboer, Florian; Schmidt, Mathias V.; Eder, Matthias

    2015-01-01

    Antidepressants (ADs) are used as first-line treatment for most stress-related psychiatric disorders. The alterations in brain circuit dynamics that can arise from stress exposure and underlie therapeutic actions of ADs remain, however, poorly understood. Here, enabled by a recently developed voltage-sensitive dye imaging (VSDI) assay in mouse brain slices, we examined the impact of chronic stress and concentration-dependent effects of eight clinically used ADs (belonging to different chemical/functional classes) on evoked neuronal activity propagations through the hippocampal trisynaptic circuitry (HTC: perforant path → dentate gyrus (DG) → area CA3 → area CA1). Exposure of mice to chronic social defeat stress led to markedly weakened activity propagations (“HTC-Waves”). In contrast, at concentrations in the low micromolar range, all ADs, which were bath applied to slices, caused an amplification of HTC-Waves in CA regions (invariably in area CA1). The fast-acting “antidepressant” ketamine, the mood stabilizer lithium, and brain-derived neurotrophic factor (BDNF) exerted comparable enhancing effects, whereas the antipsychotic haloperidol and the anxiolytic diazepam attenuated HTC-Waves. Collectively, we provide direct experimental evidence that chronic stress can depress neuronal signal flow through the HTC and demonstrate shared opposing effects of ADs. Thus, our study points to a circuit-level mechanism of ADs to counteract stress-induced impairment of hippocampal network function. However, the observed effects of ADs are impossible to depend on enhanced neurogenesis. PMID:26594153

  3. Statistical and Prediction modeling of the Ka Band Using Experimental Results from ACTS Propagation Terminals at 20.185 and 27.505 GHZ

    NASA Technical Reports Server (NTRS)

    Ogunwuyi, Oluwatosin O.

    2004-01-01

    With the increase in demand for wireless communication services, most of the operating frequency bands have become very congested. The increase of wireless costumers is only fractional contribution to this phenomenon. The demand for more services such as video streams and internet explorer which require a lot of band width has been a more significant contributor to the congestion in a communication system. One way to increase the amount of information or data per unit of time transmitted with in a wireless communication system is to use a higher radio frequency. However in spite the advantage available in the using higher frequency bands such as, the Ka-band, higher frequencies also implies short wavelengths. And shorter wavelengths are more susceptible to rain attenuation. Until the Advanced Communication Technology Satellite (ACTS) was launched, the Ka- band frequency was virtually unused - the majority of communication satellites operated in lower frequency bands called the C- and Ku- bands. Ka-band is desirable because its higher frequency allows wide bandwidth applications, smaller spacecraft and ground terminal components, and stronger signal strength. Since the Ka-band is a high frequency band, the millimeter wavelengths of the signals are easily degraded by rain. This problem known as rain fade or rain attenuation The Advanced Communication Technology Satellite (ACTS) propagation experiment has collected 5 years of Radio Frequency (RF) attenuation data from December 1993 to November 1997. The objective of my summer work is to help develop the statistics and prediction techniques that will help to better characterize the Ka Frequency band. The statistical analysis consists of seasonal and cumulative five-year attenuation statistics for the 20.2 and 27.5 GHz. The cumulative five-year results give the link outage that occurs for a given link margin. The experiment has seven ground station terminals that can be attributed to a unique rain zone climate. The

  4. Thinking Globally and Acting Locally: Environmental Education Teaching Activities.

    ERIC Educational Resources Information Center

    Mann, Lori D.; Stapp, William B.

    Provided are teaching activities related to: (1) food production and distribution; (2) energy; (3) transportation; (4) solid waste; (5) chemicals in the environment; (6) resource management; (7) pollution; (8) population; (9) world linkages; (10) endangered species; and (11) lifestyle and environment. The activities, designed to help learners…

  5. 77 FR 13617 - Agency Information Collection Activities: Customs Modernization Act Recordkeeping Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Customs Modernization Act Recordkeeping Requirements AGENCY: U.S. Customs and Border Protection (CBP), Department of... concerning the Customs Modernization Act Recordkeeping Requirements. This request for comment is being...

  6. Rehabilitation Services Administration Annual Report, Fiscal Year 2004: Report on Federal Activities under the "Rehabilitation Act"

    ERIC Educational Resources Information Center

    US Department of Education, 2007

    2007-01-01

    The "Rehabilitation Act of 1973," as amended (the act), provides the legislative basis for programs and activities that assist individuals with disabilities in the pursuit of gainful employment, independence, self-sufficiency and full integration into community life. This report is intended to provide a description of accomplishments and progress…

  7. Polarized light propagation in multiply scattering media exhibiting both linear birefringence and optical activity: Monte Carlo model and experimental methodology.

    PubMed

    Wood, Michael F G; Guo, Xinxin; Vitkin, I Alex

    2007-01-01

    A Monte Carlo model for polarized light propagation in birefringent, optically active, multiply scattering media is developed in an effort to accurately represent the propagation of polarized light in biological tissue. The model employs the Jones N-matrix formalism to combine both linear birefringence and optical activity into a single effect that can be applied to photons as they propagate between scattering events. Polyacrylamide phantoms with strain-induced birefringence, sucrose-induced optical activity, and polystyrene microspheres as scattering particles are used for experimental validation. Measurements are made using a Stokes polarimeter that detects scattered light in different geometries, and compared to the results of Monte Carlo simulations run with similar parameters. The results show close agreement between the experimental measurements and Monte Carlo calculations for phantoms exhibiting turbidity and birefringence, as well as for phantoms exhibiting turbidity, birefringence, and optical activity. Other scattering-independent polarization properties can be incorporated into the developed Jones N-matrix formalism, enabling quantification of the polarization effects via an accurate polarization-sensitive Monte Carlo model. PMID:17343504

  8. Activation and propagation of tumor infiltrating lymphocytes on clinical-grade designer artificial antigen presenting cells for adoptive immunotherapy of melanoma

    PubMed Central

    Forget, Marie-Andrée; Malu, Shruti; Liu, Hui; Toth, Christopher; Maiti, Sourindra; Kale, Charuta; Haymaker, Cara; Bernatchez, Chantale; Huls, Helen; Wang, Ena; Marincola, Francesco M.; Hwu, Patrick; Cooper, Laurence J. N.; Radvanyi, Laszlo G.

    2014-01-01

    PURPOSE Adoptive cell therapy (ACT) with autologous tumor infiltrating lymphocytes (TIL) is a therapy for metastatic melanoma with response rates up to 50%. However, the generation of the TIL transfer product is challenging, requiring pooled allogeneic normal donor peripheral blood mononuclear cells (PBMC) used in vitro as “feeders” to support a rapid expansion protocol (REP). Here, we optimized a platform to propagate TIL to a clinical scale using K562-cells genetically modified to express costimulatory molecules such as CD86, CD137-ligand and membrane-bound IL-15 to function as artificial antigen-presenting cell (aAPC) as an alternative to using PBMC feeders. EXPERIMENTAL DESIGN We used aAPC or γ-irradiated PBMC feeders to propagate TIL and measured rates of expansion. The activation and differentiation state was evaluated by flow cytometry and differential gene expression analyses. Clonal diversity was assessed based on pattern of T-cell receptor (TCR) usage. T-cell effector function was measured by evaluation of cytotoxic granule content and killing of target cells. RESULTS The aAPC propagated TIL at numbers equivalent to that found with PBMC feeders, while increasing the frequency of CD8+ T-cell expansion with a comparable effector-memory phenotype. mRNA profiling revealed an up-regulation of genes in the Wnt and stem-cell pathways with the aAPC. The aAPC platform did not skew clonal diversity and CD8+ T cells showed comparable anti-tumor function as those expanded with PBMC feeders. CONCLUSIONS TIL can be rapidly expanded with aAPC to clinical scale generating T cells with similar phenotypic and effector profiles as with PBMC feeders. These data support the clinical-application of aAPC to manufacture TIL for the treatment of melanoma. PMID:25304728

  9. Activators and repressors: A balancing act for X-inactivation.

    PubMed

    Goodrich, Leeanne; Panning, Barbara; Leung, Karen Nicole

    2016-08-01

    In early female embryos X-chromosome inactivation occurs concomitant with up regulation of the non-coding RNA, Xist, on the future inactive X-chromosome. Up regulation of Xist and coating of the future inactive X is sufficient to induce silencing. Therefore unlocking the mechanisms of X-chromosome inactivation requires thorough understanding of the transcriptional regulators, both activators and repressors, which control Xist. Mouse pluripotent embryonic stem cells, which have two active X chromosomes, provide a tractable ex vivo model system for studying X-chromosome inactivation, since this process is triggered by differentiation signals in these cultured cells. Yet there are significant discrepancies found between ex vivo analyses in mouse embryonic stem cells and in vivo studies of early embryos. In this review we elaborate on potential models of how Xist is up regulated on a single X chromosome in female cells and how ex vivo and in vivo analyses enlighten our understanding of the activators and repressors that control this non-coding RNA gene.

  10. Activators and repressors: A balancing act for X-inactivation.

    PubMed

    Goodrich, Leeanne; Panning, Barbara; Leung, Karen Nicole

    2016-08-01

    In early female embryos X-chromosome inactivation occurs concomitant with up regulation of the non-coding RNA, Xist, on the future inactive X-chromosome. Up regulation of Xist and coating of the future inactive X is sufficient to induce silencing. Therefore unlocking the mechanisms of X-chromosome inactivation requires thorough understanding of the transcriptional regulators, both activators and repressors, which control Xist. Mouse pluripotent embryonic stem cells, which have two active X chromosomes, provide a tractable ex vivo model system for studying X-chromosome inactivation, since this process is triggered by differentiation signals in these cultured cells. Yet there are significant discrepancies found between ex vivo analyses in mouse embryonic stem cells and in vivo studies of early embryos. In this review we elaborate on potential models of how Xist is up regulated on a single X chromosome in female cells and how ex vivo and in vivo analyses enlighten our understanding of the activators and repressors that control this non-coding RNA gene. PMID:27223409

  11. Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

    SciTech Connect

    Wang, Jilin; Gu, Yunle; Li, Zili; Wang, Weimin; Fu, Zhengyi

    2013-06-01

    Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH{sub 4} played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B{sub 2}O{sub 3} and KBH{sub 4} as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH{sub 4} played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed.

  12. Typing of HLA class II and class I antigens using PHA-activated, IL-2-propagated T lymphocytes.

    PubMed

    Leshem, B; Cohen, I; Sherman, L; Brautbar, C; Kedar, E

    1988-06-28

    We describe here a simple procedure, by which HLA class II antigens can be accurately and reliably identified in those patients where there is minimal or absent expression of HLA-DR,DQw antigens on B cells, or when the total number of leukocytes recovered from the patients do not permit reliable typing. Ficoll-Hypaque-separated peripheral blood mononuclear leukocytes, fresh or cryopreserved, were activated by PHA and then propagated in IL-2-containing medium until enough cells for typing were obtained (usually 7-14 days). At this stage, the cultured cells were shown to be primarily T cells (greater than 90% CD3+). Since the activated T cells propagate in the presence of IL-2, even a small number (10(4] of fresh or cryopreserved patients' cells suffice for this protocol. To date we have been able to successfully HLA-DR,DQw type 34/34 bone marrow transplantation candidates and 12/12 long-term dialysis patients, who were untypable using fresh cells. HLA-DR,DQw antigens on activated T cells from normal individuals were identical to those found on their uncultured B cells. In addition, class I antigens that were undetectable on the uncultured cells of one patient could be identified on activated T cells. The HLA antigens identified on the patients' activated T cells were confirmed by phenotypic analysis of cells from family members. PMID:3260612

  13. NASA Propagation Studies Website

    NASA Technical Reports Server (NTRS)

    Angkasa, Krisjani S.

    1996-01-01

    This paper describes an Internet website which provides information to enable the development of new commerical satellite systems and services by providing timely data and models about the propagation of satellite radio signals. In partnership with industry and academia, the program leverages NASA assets, currently the Advanced Communications Technology Satellite (ACTS), to obtain propagation data. The findings of the study are disseminated through refereed journals, NASA reference publications, workshops, electronic media, and direct interface with industry.

  14. Overview of NATO/AC 243/Panel 3 activities concerning radiowave propagation in coastal environments

    NASA Astrophysics Data System (ADS)

    Christophe, F.; Douchin, N.; Hurtaud, Y.; Dion, D.; Makaruschka, R.; Heemskerk, H.; Anderson, K.

    1995-02-01

    The performances of most systems operating at RF and millimeter waves can be seriously affected by propagation effects. That is the reason why NATO established the Research Study group No. 8 (RSG8) within Panel 3 (physics and electronics) of Defense Research Group (AC 243), with its Propagation Subgroup (PSG) responsible for the propagation aspects. Comparison of mm and other wavelengths was to be considered. In maritime and coastal environments, the use of such wavelengths for various military applications like anti-ship seekers, fire control radars, ship to ship communications or Electronic Support Measurements (ESM) led to the setting up of specific measurement campaigns; the last three are reported hereafter. The first two experiments used facilities close to Lorient, on the Atlantic coast, and Toulon, on the Mediterranean coast of France, with the purpose of documenting the refractive effects for medium range over the horizon paths. These experiments where are referred to as Lorient 89 and Toulon 90 campaigns, are described in this paper, and some typical results are presented. The latest cooperative work of RSG8/PSG took place recently (fall 1993) near Lorient, on a line-of-sight 10 km path over seawater. This experiment, referred to as Lorient 93 campaign, was devoted to the analysis of phase-front distortions due to multipath along with refractive effects, and to the assessment of performances for naval systems like short range tracking radars. Analysis of the data, either on a statistical base or as specific case studies, is being performed presently, but some early typical results will be given in this paper after a detailed description of the experiment.

  15. Tunnel Propagation Following Defibrillation with ICD Shocks: Hidden Postshock Activations in the Left Ventricular Wall Underlie Isoelectric Window

    PubMed Central

    Constantino, Jason; Long, Yun; Ashihara, Takashi; Trayanova, Natalia A.

    2010-01-01

    Background Following near-defibrillation threshold (DFT) shocks from an ICD, the first postshock activation that leads to defibrillation failure arises focally after an isolelectric window (IW). The mechanisms underlying the IW remain incompletely understood. Objective The goal of this study was to provide mechanistic insight into the origins of postshock activations and IW following ICD shocks, and to link shock outcome to the preshock state of the ventricles. We hypothesized that the non-uniform ICD field results in the formation of an intramural excitable area (tunnel) only in the LV free wall, through which both pre-existing and new shock-induced wavefronts propagate during the IW. Methods Simulations were conducted using a realistic 3-D model of defibrillation in the rabbit ventricles. Biphasic ICD shocks of varying strengths were delivered to 27 different fibrillatory states. Results Following near-DFT shocks, regardless of preshock state, the main postshock excitable area was always located within LV free wall, creating an intramural tunnel. Either preexisting fibrillatory or shock-induced wavefronts propagated during the IW (duration of up to 74ms) in this tunnel and emerged as breakthroughs on LV epicardium. Preshock activity within the LV played a significant role in shock outcome: large number of preshock filaments resulted in an IW associated with tunnel propagation of preexisting rather than shock-induced wavefronts. Furthermore, shocks were more likely to succeed if LV excitable area was smaller. Conclusions The LV intramural excitable area is the primary reason for near-DFT failure. Any intervention that decreases the extent of this area will improve the likelihood of defibrillation success. PMID:20348028

  16. Eikonal-based initiation of fibrillatory activity in thin-walled cardiac propagation models

    NASA Astrophysics Data System (ADS)

    Herlin, Antoine; Jacquemet, Vincent

    2011-12-01

    Reentrant arrhythmias can be simulated in electrophysiological models of electrical impulse propagation governed by a reaction-diffusion system. To facilitate the initiation of a large number of independent episodes of simulated arrhythmias with controllable level of complexity, a new approach is proposed for thin-walled geometries in which depolarization wave dynamics is essentially two-dimensional. Points representing phase singularities are first randomly distributed over the epicardial surface and are assigned a topological charge (direction of rotation). A qualitatively-correct phase map is then reconstructed on the whole surface by interpolation. The eikonal-diffusion equation is used to iteratively regularize the phase map based on a priori information on wavefront propagation. An initial condition for the reaction-diffusion model is created from the resulting phase map with multiple functional/anatomical reentries. Results in an atrial model demonstrate the ability to generate statistical realizations of the same dynamics and to vary the level of complexity measured by the number of phase singularities. A library of 100 simulations with an average number of phase singularities ranging from 1 to 10 is created. An extension to volumetric patient-specific atrial models including fiber orientation and a fast conducting system is presented to illustrate possible applications.

  17. 45 CFR 90.3 - What programs or activities does the Age Discrimination Act of 1975 cover?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Discrimination Act of 1975 cover? 90.3 Section 90.3 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES... FINANCIAL ASSISTANCE General § 90.3 What programs or activities does the Age Discrimination Act of 1975 cover? (a) The Age Discrimination Act of 1975 applies to any program or activity receiving...

  18. Community Environmental Response Facilitation Act (CERFA) report, Pueblo Depot Activity, Colorado. Final report

    SciTech Connect

    Not Available

    1994-04-11

    This report presents the results of the Community Environmental Response Facilitation Act (CERFA) investigation conducted by Environmental Resources Management (ERM) at Pueblo Depot Activity (PUDA), a U.S. Government property selected for closure by the Base Realignment and Closure (BRAC) Commission. Under CERFA, Federal agencies are required to identify expeditiously real property that can be immediately reused and redeveloped. Satisfying this objective requires the identification of real property where no hazardous substances or petroleum products, regulated by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), were stored for one year or more, known to have been released, or disposed. Pueblo depot activity, CERFA, Base closure, BRAC.

  19. Atmospheric-pressure plasma jets: Effect of gas flow, active species, and snake-like bullet propagation

    SciTech Connect

    Wu, S.; Wang, Z.; Huang, Q.; Tan, X.; Lu, X.; Ostrikov, K.

    2013-02-15

    Cold atmospheric-pressure plasma jets have recently attracted enormous interest owing to numerous applications in plasma biology, health care, medicine, and nanotechnology. A dedicated study of the interaction between the upstream and downstream plasma plumes revealed that the active species (electrons, ions, excited OH, metastable Ar, and nitrogen-related species) generated by the upstream plasma plume enhance the propagation of the downstream plasma plume. At gas flows exceeding 2 l/min, the downstream plasma plume is longer than the upstream plasma plume. Detailed plasma diagnostics and discharge species analysis suggest that this effect is due to the electrons and ions that are generated by the upstream plasma and flow into the downstream plume. This in turn leads to the relatively higher electron density in the downstream plasma. Moreover, high-speed photography reveals a highly unusual behavior of the plasma bullets, which propagate in snake-like motions, very differently from the previous reports. This behavior is related to the hydrodynamic instability of the gas flow, which results in non-uniform distributions of long-lifetime active species in the discharge tube and of surface charges on the inner surface of the tube.

  20. 77 FR 27787 - Agency Information Collection Activities: Customs Modernization Act Recordkeeping Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... collection was previously published in the Federal Register (77 FR 13617) on March 7, 2012, allowing for a 60... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Customs Modernization Act Recordkeeping Requirements AGENCY: U.S. Customs and Border Protection, Department of...

  1. Report on Federal Activities under the Rehabilitation Act. Annual Report, Fiscal Year 2001

    ERIC Educational Resources Information Center

    US Department of Education, 2005

    2005-01-01

    The Rehabilitation Act of 1973, as amended, provides the legislative basis for programs and activities that assist individuals with disabilities in the pursuit of gainful employment, independence, self-sufficiency and full integration into community life. This report is intended to provide a description of accomplishments and progress made under…

  2. 76 FR 40723 - Agency Information Collection Activities; Proposed Collection; Comment Request; Clean Water Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    ... AGENCY Agency Information Collection Activities; Proposed Collection; Comment Request; Clean Water Act... is planning to submit a request to renew an existing approved Information Collection Request (ICR) to... of the proposed information collection as described below. DATES: Comments must be submitted on...

  3. A Review of CBO's Activities in 2008 under the Unfunded Mandates Reform Act. A CBO Report

    ERIC Educational Resources Information Center

    Lex, Leo

    2009-01-01

    In this report, part of an annual series that began in 1997, the Congressional Budget Office (CBO) reviews its activities under the Unfunded Mandates Reform Act of 1995. The report covers public laws enacted and legislation considered by the Congress in 2008 that would impose federal mandates on state, local, or tribal governments or on the…

  4. Prediction of Reaction Kinetic in Mechanically Activated Self-Propagating High-Temperature Synthesis Process

    NASA Astrophysics Data System (ADS)

    Razavi, Mansour

    2012-12-01

    In this paper we have tried to develop a semi-empirical formula for estimation of starting time of reactions during mechanical alloying process according to self-propagating high temperature synthesis (SHS) mechanism. For this purpose, three SHS systems containing Ti-C, Mo-Si and Si-C were selected and their behaviors were observed. Aforementioned systems were milled in a planetary ball mill equipped with temperature sensor detector of cups. Samplings were done at different times of discontinuously milling. To change mills' energy, stainless steel and tungsten carbide balls were used. In order to detect the phases and characterizations of milled powder, XRD instrument was utilized. Results showed that all productions were synthesized after sudden increase in temperature. Maximum measured temperature and critical time had up and downtrends for production of TiC, MoSi2 and SiC, respectively. Crystalline size of milled powder had nano-meter scale. By using experimental data along with theoretical equations, a semi-empirical formula between critical time for transformation of raw materials to productions, type of milled system and ball mill parameter can be presented with high accuracy. According to calculated formula, critical time was related to ball mill energy and Gibbs free energy of milled system with direct and inverse proportionality, respectively.

  5. Assessment of MSFCs Process for the Development and Activation of Space Act Agreement

    NASA Technical Reports Server (NTRS)

    Daugherty, Rachel

    2014-01-01

    Space Act Agreements (SAAs) are contractual agreements that NASA utilizes to form partnerships with researchers, industry, and academia to stimulate cutting-edge innovation within the science and technology communities. center dot This study assessed the current SAA development and activation process at Marshall Space Flight Center (MSFC) to determine if improvements could be implemented to increase productivity, decrease time to activation, and improve the quality of deliverables.

  6. Nonstructural 5A Protein of Hepatitis C Virus Regulates Soluble Resistance-Related Calcium-Binding Protein Activity for Viral Propagation

    PubMed Central

    Tran, Giao V. Q.; Luong, Trang T. D.; Park, Eun-Mee; Kim, Jong-Wook; Choi, Jae-Woong; Park, Chorong; Lim, Yun-Sook

    2015-01-01

    ABSTRACT Hepatitis C virus (HCV) is a major cause of chronic liver disease and is highly dependent on cellular proteins for virus propagation. To identify the cellular factors involved in HCV propagation, we recently performed protein microarray assays using the HCV nonstructural 5A (NS5A) protein as a probe. Of 90 cellular protein candidates, we selected the soluble resistance-related calcium-binding protein (sorcin) for further characterization. Sorcin is a calcium-binding protein and is highly expressed in certain cancer cells. We verified that NS5A interacted with sorcin through domain I of NS5A, and phosphorylation of the threonine residue 155 of sorcin played a crucial role in protein interaction. Small interfering RNA (siRNA)-mediated knockdown of sorcin impaired HCV propagation. Silencing of sorcin expression resulted in a decrease of HCV assembly without affecting HCV RNA and protein levels. We further demonstrated that polo-like kinase 1 (PLK1)-mediated phosphorylation of sorcin was increased by NS5A. We showed that both phosphorylation and calcium-binding activity of sorcin were required for HCV propagation. These data indicate that HCV modulates sorcin activity via NS5A protein for its own propagation. IMPORTANCE Sorcin is a calcium-binding protein and regulates intracellular calcium homeostasis. HCV NS5A interacts with sorcin, and phosphorylation of sorcin is required for protein interaction. Gene silencing of sorcin impaired HCV propagation at the assembly step of the HCV life cycle. Sorcin is phosphorylated by PLK1 via protein interaction. We showed that sorcin interacted with both NS5A and PLK1, and PLK1-mediated phosphorylation of sorcin was increased by NS5A. Moreover, calcium-binding activity of sorcin played a crucial role in HCV propagation. These data provide evidence that HCV regulates host calcium metabolism for virus propagation, and thus manipulation of sorcin activity may represent a novel therapeutic target for HCV. PMID:26719254

  7. ChIP-seq Mapping of Distant-Acting Enhancers and Their In Vivo Activities

    SciTech Connect

    Visel, Axel; Pennacchio, Len A.

    2011-06-01

    The genomic location and function of most distant-acting transcriptional enhancers in the human genome remains unknown We performed ChIP-seq for various transcriptional coactivator proteins (such as p300) directly from different embryonic mouse tissues, identifying thousands of binding sitesTransgenic mouse experiments show that p300 and other co-activator peaks are highly predictive of genomic location AND tissue-specific activity patterns of distant-acting enhancersMost enhancers are active only in one or very few tissues Genomic location of tissue-specific p300 peaks correlates with tissue-specific expression of nearby genes Most binding sites are conserved, but the global degree of conservation varies between tissues

  8. Implementation of the 2011 Therapeutic Activity Act: will commercialization improve the financial performance of Polish hospitals?

    PubMed

    Sagan, Anna; Sobczak, Alicja

    2014-11-01

    The Therapeutic Activity Act that came into force on 1 July 2011 was aimed at achieving a large-scale transformation of public hospitals into Commercial Code companies. The change of the legal form, from a public entity to a for-profit company, was expected to improve the poor economic efficiency of the public hospital sector. However, the mere change of the legal form does not guarantee a better financial performance of hospitals and thus the success of the Act. In many cases, deep internal changes are needed to achieve improvements in the financial performance of particular hospitals. In addition, a set of other measures at the national and regional levels, such as the mapping of health needs of the population, have to accompany the legal transformations in order to improve the efficiency of the hospital sector. The recent slowdown in the rate of the transformations is another factor that renders the success of the Act uncertain.

  9. The spatial response of nonlinear strain propagation in response to actively driven microspheres through entangled actin networks

    NASA Astrophysics Data System (ADS)

    Falzone, Tobias; Blair, Savanna; Robertson-Anderson, Rae

    2015-03-01

    The semiflexible biopolymer actin, a ubiquitous component of nearly all biological organisms, plays an important role in many mechanically-driven processes such as muscle contraction, cancer invasion and cell motility. As such, entangled actin networks, which possess unique and complex viscoelastic properties, have been the subject of much theoretical and experimental work. However, due to this viscoelastic complexity, much is still unknown regarding the correlation of the applied stress on actin networks to the induced filament strain at the molecular and micro scale. Here, we use simultaneous optical trapping and fluorescence microscopy to characterize the link between applied microscopic forces and strain propagation as a function of strain rate and concentration. Specifically, we track fiduciary markers on entangled actin filaments before, during and after actively driving embedded microspheres through the network. These measurements provide much needed insight into the molecular-level dynamics connecting stress and strain in semiflexible polymer networks.

  10. Myofascial trigger points: spontaneous electrical activity and its consequences for pain induction and propagation.

    PubMed

    Ge, Hong-You; Fernández-de-Las-Peñas, César; Yue, Shou-Wei

    2011-03-25

    Active myofascial trigger points are one of the major peripheral pain generators for regional and generalized musculoskeletal pain conditions. Myofascial trigger points are also the targets for acupuncture and/or dry needling therapies. Recent evidence in the understanding of the pathophysiology of myofascial trigger points supports The Integrated Hypothesis for the trigger point formation; however unanswered questions remain. Current evidence shows that spontaneous electrical activity at myofascial trigger point originates from the extrafusal motor endplate. The spontaneous electrical activity represents focal muscle fiber contraction and/or muscle cramp potentials depending on trigger point sensitivity. Local pain and tenderness at myofascial trigger points are largely due to nociceptor sensitization with a lesser contribution from non-nociceptor sensitization. Nociceptor and non-nociceptor sensitization at myofascial trigger points may be part of the process of muscle ischemia associated with sustained focal muscle contraction and/or muscle cramps. Referred pain is dependent on the sensitivity of myofascial trigger points. Active myofascial trigger points may play an important role in the transition from localized pain to generalized pain conditions via the enhanced central sensitization, decreased descending inhibition and dysfunctional motor control strategy.

  11. Babcock-Leighton solar dynamo: the role of downward pumping and the equatorward propagation of activity

    NASA Astrophysics Data System (ADS)

    Karak, Bidya Binay; Cameron, Robert

    2016-05-01

    We investigate the role of downward magnetic pumping near the surface using a kinematic Babcock-Leighton model. We find that the pumping causes the poloidal field to become predominately radial in the near-surface shear layer. This allows the negative radial shear in the near-surface layer to effectively act on the radial field to produce a toroidal field. Consequently, we observe a clear equatorward migration of the toroidal field at low latitudes even when there is no meridional flow in the deep CZ. We show a case where the period of a dynamo wave solution is approximately 11 years. Flux transport models are also shown with periods close to 11 years. Both the dynamo wave and flux transport dynamo are thus able to reproduce some of the observed features of solar cycle. The main difference between the two types of dynamo is the value of $\\alpha$ required to produce dynamo action. In both types of dynamo, the surface meridional flow helps to advect and build the polar field in high latitudes, while in flux transport dynamo the equatorward flow near the bottom of CZ advects toroidal field to cause the equatorward migration in butterfly wings and this advection makes the dynamo easier by transporting strong toroidal field to low latitudes where $\\alpha$ effect works. Another conclusion of our study is that the magnetic pumping suppresses the diffusion of fields through the photospheric surface which helps to achieve the 11-year dynamo cycle at a moderately larger value of magnetic diffusivity than has previously been used.

  12. Characterization of Novel Antimalarial Compound ACT-451840: Preclinical Assessment of Activity and Dose–Efficacy Modeling

    PubMed Central

    Le Bihan, Amélie; Angulo-Barturen, Iñigo; Binkert, Christoph; Boss, Christoph; Brun, Reto; Brunner, Ralf; Buchmann, Stephan; Dechering, Koen J.; Delves, Michael; Ewerling, Sonja; Ferrer, Santiago; Fischli, Christoph; Gamo–Benito, Francisco Javier; Heidmann, Bibia; Jiménez-Díaz, María Belén; Leroy, Didier; Martínez, Maria Santos; Meyer, Solange; Moehrle, Joerg J.; Noviyanti, Rintis; Sanz, Laura María; Sauerwein, Robert W.; Scheurer, Christian; Schleiferboeck, Sarah; Sinden, Robert; Snyder, Christopher; Straimer, Judith; Wirjanata, Grennady; Marfurt, Jutta; Weller, Thomas; Clozel, Martine; Wittlin, Sergio

    2016-01-01

    Background Artemisinin resistance observed in Southeast Asia threatens the continued use of artemisinin-based combination therapy in endemic countries. Additionally, the diversity of chemical mode of action in the global portfolio of marketed antimalarials is extremely limited. Addressing the urgent need for the development of new antimalarials, a chemical class of potent antimalarial compounds with a novel mode of action was recently identified. Herein, the preclinical characterization of one of these compounds, ACT-451840, conducted in partnership with academic and industrial groups is presented. Method and Findings The properties of ACT-451840 are described, including its spectrum of activities against multiple life cycle stages of the human malaria parasite Plasmodium falciparum (asexual and sexual) and Plasmodium vivax (asexual) as well as oral in vivo efficacies in two murine malaria models that permit infection with the human and the rodent parasites P. falciparum and Plasmodium berghei, respectively. In vitro, ACT-451840 showed a 50% inhibition concentration of 0.4 nM (standard deviation [SD]: ± 0.0 nM) against the drug-sensitive P. falciparum NF54 strain. The 90% effective doses in the in vivo efficacy models were 3.7 mg/kg against P. falciparum (95% confidence interval: 3.3–4.9 mg/kg) and 13 mg/kg against P. berghei (95% confidence interval: 11–16 mg/kg). ACT-451840 potently prevented male gamete formation from the gametocyte stage with a 50% inhibition concentration of 5.89 nM (SD: ± 1.80 nM) and dose-dependently blocked oocyst development in the mosquito with a 50% inhibitory concentration of 30 nM (range: 23–39). The compound’s preclinical safety profile is presented and is in line with the published results of the first-in-man study in healthy male participants, in whom ACT-451840 was well tolerated. Pharmacokinetic/pharmacodynamic (PK/PD) modeling was applied using efficacy in the murine models (defined either as antimalarial activity or as

  13. Feed-Forward Propagation of Temporal and Rate Information between Cortical Populations during Coherent Activation in Engineered In Vitro Networks.

    PubMed

    DeMarse, Thomas B; Pan, Liangbin; Alagapan, Sankaraleengam; Brewer, Gregory J; Wheeler, Bruce C

    2016-01-01

    Transient propagation of information across neuronal assembles is thought to underlie many cognitive processes. However, the nature of the neural code that is embedded within these transmissions remains uncertain. Much of our understanding of how information is transmitted among these assemblies has been derived from computational models. While these models have been instrumental in understanding these processes they often make simplifying assumptions about the biophysical properties of neurons that may influence the nature and properties expressed. To address this issue we created an in vitro analog of a feed-forward network composed of two small populations (also referred to as assemblies or layers) of living dissociated rat cortical neurons. The populations were separated by, and communicated through, a microelectromechanical systems (MEMS) device containing a strip of microscale tunnels. Delayed culturing of one population in the first layer followed by the second a few days later induced the unidirectional growth of axons through the microtunnels resulting in a primarily feed-forward communication between these two small neural populations. In this study we systematically manipulated the number of tunnels that connected each layer and hence, the number of axons providing communication between those populations. We then assess the effect of reducing the number of tunnels has upon the properties of between-layer communication capacity and fidelity of neural transmission among spike trains transmitted across and within layers. We show evidence based on Victor-Purpura's and van Rossum's spike train similarity metrics supporting the presence of both rate and temporal information embedded within these transmissions whose fidelity increased during communication both between and within layers when the number of tunnels are increased. We also provide evidence reinforcing the role of synchronized activity upon transmission fidelity during the spontaneous synchronized

  14. Feed-Forward Propagation of Temporal and Rate Information between Cortical Populations during Coherent Activation in Engineered In Vitro Networks

    PubMed Central

    DeMarse, Thomas B.; Pan, Liangbin; Alagapan, Sankaraleengam; Brewer, Gregory J.; Wheeler, Bruce C.

    2016-01-01

    Transient propagation of information across neuronal assembles is thought to underlie many cognitive processes. However, the nature of the neural code that is embedded within these transmissions remains uncertain. Much of our understanding of how information is transmitted among these assemblies has been derived from computational models. While these models have been instrumental in understanding these processes they often make simplifying assumptions about the biophysical properties of neurons that may influence the nature and properties expressed. To address this issue we created an in vitro analog of a feed-forward network composed of two small populations (also referred to as assemblies or layers) of living dissociated rat cortical neurons. The populations were separated by, and communicated through, a microelectromechanical systems (MEMS) device containing a strip of microscale tunnels. Delayed culturing of one population in the first layer followed by the second a few days later induced the unidirectional growth of axons through the microtunnels resulting in a primarily feed-forward communication between these two small neural populations. In this study we systematically manipulated the number of tunnels that connected each layer and hence, the number of axons providing communication between those populations. We then assess the effect of reducing the number of tunnels has upon the properties of between-layer communication capacity and fidelity of neural transmission among spike trains transmitted across and within layers. We show evidence based on Victor-Purpura’s and van Rossum’s spike train similarity metrics supporting the presence of both rate and temporal information embedded within these transmissions whose fidelity increased during communication both between and within layers when the number of tunnels are increased. We also provide evidence reinforcing the role of synchronized activity upon transmission fidelity during the spontaneous

  15. 50 CFR 80.51 - What activities are eligible for funding under the Dingell-Johnson Sport Fish Restoration Act?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... under the Dingell-Johnson Sport Fish Restoration Act? 80.51 Section 80.51 Wildlife and Fisheries UNITED... SPORT FISH RESTORATION PROGRAM ADMINISTRATIVE REQUIREMENTS, PITTMAN-ROBERTSON WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS Eligible Activities § 80.51 What activities are eligible...

  16. 50 CFR 80.50 - What activities are eligible for funding under the Pittman-Robertson Wildlife Restoration Act?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... under the Pittman-Robertson Wildlife Restoration Act? 80.50 Section 80.50 Wildlife and Fisheries UNITED... SPORT FISH RESTORATION PROGRAM ADMINISTRATIVE REQUIREMENTS, PITTMAN-ROBERTSON WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS Eligible Activities § 80.50 What activities are eligible...

  17. 50 CFR 80.50 - What activities are eligible for funding under the Pittman-Robertson Wildlife Restoration Act?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SPORT FISH RESTORATION PROGRAM ADMINISTRATIVE REQUIREMENTS, PITTMAN-ROBERTSON WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS Eligible Activities § 80.50 What activities are eligible...

  18. Atmospheric Propagation

    NASA Technical Reports Server (NTRS)

    Embleton, Tony F. W.; Daigle, Gilles A.

    1991-01-01

    Reviewed here is the current state of knowledge with respect to each basic mechanism of sound propagation in the atmosphere and how each mechanism changes the spectral or temporal characteristics of the sound received at a distance from the source. Some of the basic processes affecting sound wave propagation which are present in any situation are discussed. They are geometrical spreading, molecular absorption, and turbulent scattering. In geometrical spreading, sound levels decrease with increasing distance from the source; there is no frequency dependence. In molecular absorption, sound energy is converted into heat as the sound wave propagates through the air; there is a strong dependence on frequency. In turbulent scattering, local variations in wind velocity and temperature induce fluctuations in phase and amplitude of the sound waves as they propagate through an inhomogeneous medium; there is a moderate dependence on frequency.

  19. Magnetohydrodynamic (MHD) analyses of various forms of activity and their propagation through helio spheric space

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    1987-01-01

    Theoretical and numerical modeling of solar activity and its effects on the solar atmosphere within the context of magnetohydrodynamics were examined. Specifically, the scientific objectives were concerned with the physical mechanisms for the flare energy build-up and subsequent release. In addition, transport of this energy to the corona and solar wind was also investigated. Well-posed, physically self-consistent, numerical simulation models that are based upon magnetohydrodynamics were sought. A systematic investigation of the basic processes that determine the macroscopic dynamic behavior of solar and heliospheric phenomena was conducted. A total of twenty-three articles were accepted and published in major journals. The major achievements are summarized.

  20. Motor patterns of the small intestine explained by phase-amplitude coupling of two pacemaker activities: the critical importance of propagation velocity.

    PubMed

    Huizinga, Jan D; Parsons, Sean P; Chen, Ji-Hong; Pawelka, Andrew; Pistilli, Marc; Li, Chunpei; Yu, Yuanjie; Ye, Pengfei; Liu, Qing; Tong, Mengting; Zhu, Yong Fang; Wei, Defei

    2015-09-15

    Phase-amplitude coupling of two pacemaker activities of the small intestine, the omnipresent slow wave activity generated by interstitial cells of Cajal of the myenteric plexus (ICC-MP) and the stimulus-dependent rhythmic transient depolarizations generated by ICC of the deep muscular plexus (ICC-DMP), was recently hypothesized to underlie the orchestration of the segmentation motor pattern. The aim of the present study was to increase our understanding of phase-amplitude coupling through modeling. In particular the importance of propagation velocity of the ICC-DMP component was investigated. The outcome of the modeling was compared with motor patterns recorded from the rat or mouse intestine from which propagation velocities within the different patterns were measured. The results show that the classical segmentation motor pattern occurs when the ICC-DMP component has a low propagation velocity (<0.05 cm/s). When the ICC-DMP component has a propagation velocity in the same order of magnitude as that of the slow wave activity (∼1 cm/s), cluster type propulsive activity occurs which is in fact the dominant propulsive activity of the intestine. Hence, the only difference between the generation of propagating cluster contractions and the Cannon-type segmentation motor pattern is the propagation velocity of the low-frequency component, the rhythmic transient depolarizations originating from the ICC-DMP. Importantly, the proposed mechanism explains why both motor patterns have distinct rhythmic waxing and waning of the amplitude of contractions. The hypothesis is brought forward that the velocity is modulated by neural regulation of gap junction conductance within the ICC-DMP network.

  1. Activation and propagation of Ca2+ release from inside the sarcoplasmic reticulum network of mammalian skeletal muscle.

    PubMed

    Cully, Tanya R; Edwards, Joshua N; Launikonis, Bradley S

    2014-09-01

    Skeletal muscle fibres are large and highly elongated cells specialized for producing the force required for posture and movement. The process of controlling the production of force within the muscle, known as excitation-contraction coupling, requires virtually simultaneous release of large amounts of Ca(2+) from the sarcoplasmic reticulum (SR) at the level of every sarcomere within the muscle fibre. Here we imaged Ca(2+) movements within the SR, tubular (t-) system and in the cytoplasm to observe that the SR of skeletal muscle is a connected network capable of allowing diffusion of Ca(2+) within its lumen to promote the propagation of Ca(2+) release throughout the fibre under conditions where inhibition of SR ryanodine receptors (RyRs) was reduced. Reduction of cytoplasmic [Mg(2+)] ([Mg(2+)]cyto) induced a leak of Ca(2+) through RyRs, causing a reduction in SR Ca(2+) buffering power argued to be due to a breakdown of SR calsequestrin polymers, leading to a local elevation of [Ca(2+)]SR. The local rise in [Ca(2+)]SR, an intra-SR Ca(2+) transient, induced a local diffusely rising [Ca(2+)]cyto. A prolonged Ca(2+) wave lasting tens of seconds or more was generated from these events. Ca(2+) waves were dependent on the diffusion of Ca(2+) within the lumen of the SR and ended as [Ca(2+)]SR dropped to low levels to inactivate RyRs. Inactivation of RyRs allowed re-accumulation of [Ca(2+)]SR and the activation of secondary Ca(2+) waves in the persistent presence of low [Mg(2+)]cyto if the threshold [Ca(2+)]SR for RyR opening could be reached. Secondary Ca(2+) waves occurred without an abrupt reduction in SR Ca(2+) buffering power. Ca(2+) release and wave propagation occurred in the absence of Ca(2+)-induced Ca(2+) release. These observations are consistent with the activation of Ca(2+) release through RyRs of lowered cytoplasmic inhibition by [Ca(2+)]SR or store overload-induced Ca(2+) release. Restitution of SR Ca(2+) buffering power to its initially high value required

  2. ACT Test

    MedlinePlus

    ... this page helpful? Also known as: ACT; Activated Coagulation Time Formal name: Activated Clotting Time Related tests: ... in the blood called platelets and proteins called coagulation factors are activated in a sequence of steps ...

  3. Activation of Akt is essential for the propagation of mitochondrial respiratory stress signaling and activation of the transcriptional coactivator heterogeneous ribonucleoprotein A2.

    PubMed

    Guha, Manti; Fang, Ji-Kang; Monks, Robert; Birnbaum, Morris J; Avadhani, Narayan G

    2010-10-15

    Mitochondrial respiratory stress (also called mitochondrial retrograde signaling) activates a Ca(2+)/calcineurin-mediated signal that culminates in transcription activation/repression of a large number of nuclear genes. This signal is propagated through activation of the regulatory proteins NFκB c-Rel/p50, C/EBPδ, CREB, and NFAT. Additionally, the heterogeneous ribonucleoprotein A2 (hnRNPA2) functions as a coactivator in up-regulating the transcription of Cathepsin L, RyR1, and Glut-4, the target genes of stress signaling. Activation of IGF1R, which causes a metabolic switch to glycolysis, cell invasiveness, and resistance to apoptosis, is a phenotypic hallmark of C2C12 myoblasts subjected to mitochondrial stress. In this study, we report that mitochondrial stress leads to increased expression, activation, and nuclear localization of Akt1. Mitochondrial respiratory stress also activates Akt1-gene expression, which involves hnRNPA2 as a coactivator, indicating a complex interdependency of these two factors. Using Akt1(-/-) mouse embryonic fibroblasts and Akt1 mRNA-silenced C2C12 cells, we show that Akt1-mediated phosphorylation is crucial for the activation and recruitment of hnRNPA2 to the enhanceosome complex. Akt1 mRNA silencing in mtDNA-depleted cells resulted in reversal of the invasive phenotype, accompanied by sensitivity to apoptotic stimuli. These results show that Akt1 is an important regulator of the nuclear transcriptional response to mitochondrial stress.

  4. The Ka-Band Propagation Measurements campaign at JPL

    NASA Technical Reports Server (NTRS)

    Chakraborty, D.; Davarian, Faramaz; Stutzman, Warren L.

    1993-01-01

    The objectives of the JPL-managed Propagation Program are discussed, and the types of activities performed to meet these objectives are described. Particular consideration is given to activities of the NASA-sponsored Ka-Band Propagation Measurement campaign, which was established to investigate the applicability of using the Ka-band (20/30 GHz) for satellite telecommunications via ESA's OLYMPUS satellite, which is a precursor to NASA's ACTS. The basic physics involved in this problem are discussed, and the OLYMPUS-program data collected to date are reviewed.

  5. A brief review on anti diabetic plants: Global distribution, active ingredients, extraction techniques and acting mechanisms

    PubMed Central

    Chan, Chung-Hung; Ngoh, Gek-Cheng; Yusoff, Rozita

    2012-01-01

    A study has been conducted with the aim to provide researchers with general information on anti diabetic extracts based on relevant research articles collected from 34 reliable medical journals. The study showed that Asian and African continents have 56% and 17% share of the worldwide distribution of therapeutic herbal plants, respectively. In Asia, India and China are the leading countries in herbal plants research, and there has been an increase in medicinal research on plants extract for diabetes treatment since 1995 in these regions. The information collected shows that plant leaves are about 20% more favorable for storing active ingredients, as compared to other parts of herbal plants. A brief review on the extraction techniques for the mentioned parts is also included. Furthermore, the acting mechanisms for the anti diabetic activity were described, and the related active ingredients were identified. The findings reveal that most of the anti diabetic research is focused on the alteration of glucose metabolism to prevent diabetes. PMID:22654401

  6. Organogermanium compounds as inhibitors of the activity of direct acting mutagens in Salmonella typhimurium.

    PubMed

    Schimmer, O; Eschelbach, H; Breitinger, D K; Grützner, T; Wick, H

    1997-12-01

    The organogermanium compounds bis(D,L-lactato)germanium(IV), bis(L-lactato)germanium(IV), bis (thiolactato)germanium(IV) and bis(thioglycolato)germanium(IV) were tested for their antimutagenic activity in Salmonella typhimurium strains TA98 and TA100. Each compound showed moderate activity against the mutagenic effect of nitroaromatic compounds and weak effects against the mutagenic activity of ethylmethane sulfonate. No inhibition of mutagenicity was observed against the indirect acting promutagens benzo(a)pyrene and 2-aminoanthracene. The compounds differed only quantitatively in their antimutagenicity spectrum. It is concluded from these results that an intracellular mechanism is involved in the inhibition of ethylmethane sulfonate-induced mutagenicity. The effect is probably produced, at least partially, at the level of DNA repair. Frameshift mutations seem to be prevented with higher efficiency than base pair substitutions.

  7. A Search for Coriolis Forces Acting on Tilt in Bipolar Active Regions

    NASA Astrophysics Data System (ADS)

    McClintock, B. H.

    2013-12-01

    Bipolar active regions tend to be tilted with respect to the East - West equator of the Sun in accordance with Joy's law that describes the average tilt angle as a function of latitude. As individual bipolar active regions emerge, tilt angles vary with time. Data collected by the Helioseismic and Magnetic Imager aboard the Solar Dynamic Observatory at a higher cadence than previous data allow for a more continuous analysis of emerging regions over their lifetimes. It is theorized that rising magnetic flux-tubes, which emerge as active regions on the surface, are tilted by Coriolis forces acting on the retrograde flow inside the tubes. We will search for and measure any decrease in tilt near the end of emergence, as an indicator of Coriolis forces ending.

  8. Chamber propagation

    SciTech Connect

    Langdon, B.

    1991-01-16

    Propagation of a heavy ion beam to the target appears possible under conditions thought to be realizable by several reactor designs. Beam quality at the lens is believed to provide adequate intensity at the target -- but the beam must pass through chamber debris and its self fields along the way. This paper reviews present consensus on propagation modes and presents recent results on the effects of photoionization of the beam ions by thermal x-rays from the heated target. Ballistic propagation through very low densities is a conservative mode. The more-speculative self-pinched mode, at 1 to 10 Torr, offers reactor advantages and is being re-examined by others. 13 refs.

  9. Two Seemingly Homologous Noncoding RNAs Act Hierarchically to Activate glmS mRNA Translation

    PubMed Central

    Urban, Johannes H; Vogel, Jörg

    2008-01-01

    Small noncoding RNAs (sRNA) can function as posttranscriptional activators of gene expression to regulate stress responses and metabolism. We here describe the mechanisms by which two sRNAs, GlmY and GlmZ, activate the Escherichia coli glmS mRNA, coding for an essential enzyme in amino-sugar metabolism. The two sRNAs, although being highly similar in sequence and structure, act in a hierarchical manner. GlmZ, together with the RNA chaperone, Hfq, directly activates glmS mRNA translation by an anti-antisense mechanism. In contrast, GlmY acts upstream of GlmZ and positively regulates glmS by antagonizing GlmZ RNA inactivation. We also report the first example, to our knowledge, of mRNA expression being controlled by the poly(A) status of a chromosomally encoded sRNA. We show that in wild-type cells, GlmY RNA is unstable due to 3′ end polyadenylation; whereas in an E. coli pcnB mutant defective in RNA polyadenylation, GlmY is stabilized and accumulates, which in turn stabilizes GlmZ and causes GlmS overproduction. Our study reveals hierarchical action of two well-conserved sRNAs in a complex regulatory cascade that controls the glmS mRNA. Similar cascades of noncoding RNA regulators may operate in other organisms. PMID:18351803

  10. NEU3 activity enhances EGFR activation without affecting EGFR expression and acts on its sialylation levels.

    PubMed

    Mozzi, Alessandra; Forcella, Matilde; Riva, Alice; Difrancesco, Carlotta; Molinari, Francesca; Martin, Vittoria; Papini, Nadia; Bernasconi, Barbara; Nonnis, Simona; Tedeschi, Gabriella; Mazzucchelli, Luca; Monti, Eugenio; Fusi, Paola; Frattini, Milo

    2015-08-01

    Several studies performed over the last decade have focused on the role of sialylation in the progression of cancer and, in particular, on the association between deregulation of sialidases and tumorigenic transformation. The plasma membrane-associated sialidase NEU3 is often deregulated in colorectal cancer (CRC), and it was shown that this enzyme co-immunoprecipitates in HeLa cells with epidermal growth factor receptor (EGFR), the molecular target of most recent monoclonal antibody-based therapies against CRC. To investigate the role of NEU3 sialidase on EGFR deregulation in CRC, we first collected data on NEU3 gene expression levels from a library of commercial colon cell lines, demonstrating that NEU3 transcription is upregulated in these cell lines. We also found EGFR to be hyperphosphorylated in all cell lines, with the exception of SW620 cells and the CCD841 normal intestinal cell line. By comparing the effects induced by overexpression of either the wild-type or the inactive mutant form of NEU3 on EGFR, we demonstrated that the active form of NEU3 enhanced receptor activation without affecting EGFR mRNA or protein expression. Moreover, through western blots and mass spectrometry analysis, we found that EGFR immunoprecipitated from cells overexpressing active NEU3, unlike the receptor from mock cells and cells overexpressing inactive NEU3, is desialylated. On the whole, our data demonstrate that, besides the already reported indirect EGFR activation through GM3, sialidase NEU3 could also play a role on EGFR activation through its desialylation. PMID:25922362

  11. The Properties of Large Amplitude Whistler Mode Waves in the Magnetosphere: Propagation and Relationship with Geomagnetic Activity

    NASA Technical Reports Server (NTRS)

    Wilson, L. B., III; Cattell, C. A.; Kellogg, P. J.; Wygant, J. R.; Goetz, K.; Breneman, A.; Kersten, K.

    2011-01-01

    Wepresent resultsof a studyof the characteristicsof very large amplitude whistler mode waves inside the terrestrial magnetosphere at radial distances of less than 15 RE using waveform capture data from the Wind spacecraft. We observed 247 whistler mode waves with at least one electric field component (105/247 had !80 mV/m peak!to!peak amplitudes) and 66 whistler mode waves with at least one search coil magnetic field component (38/66 had !0.8 nT peak!to!peak amplitudes). Wave vectors determined from events with three magnetic field components indicate that 30/46 propagate within 20 of the ambient magnetic field, though some are more oblique (up to "50 ). No relationship was observed between wave normal angle and GSM latitude. 162/247 of the large amplitude whistler mode waves were observed during magnetically active periods (AE > 200 nT). 217 out of 247 total whistler mode waves examined were observed inside the radiation belts. We present a waveform capture with the largest whistler wave magnetic field amplitude (^8 nT peak!to!peak) ever reported in the radiation belts. The estimated Poynting flux magnitude associated with this wave is ^300 mW/m2, roughly four orders of magnitude above estimates from previous satellite measurements. Such large Poynting flux values are consistent with rapid energization of electrons.

  12. Estimating the active space of male koala bellows: propagation of cues to size and identity in a Eucalyptus forest.

    PubMed

    Charlton, Benjamin D; Reby, David; Ellis, William A H; Brumm, Jacqui; Fitch, W Tecumseh

    2012-01-01

    Examining how increasing distance affects the information content of vocal signals is fundamental for determining the active space of a given species' vocal communication system. In the current study we played back male koala bellows in a Eucalyptus forest to determine the extent that individual classification of male koala bellows becomes less accurate over distance, and also to quantify how individually distinctive acoustic features of bellows and size-related information degrade over distance. Our results show that the formant frequencies of bellows derived from Linear Predictive Coding can be used to classify calls to male koalas over distances of 1-50 m. Further analysis revealed that the upper formant frequencies and formant frequency spacing were the most stable acoustic features of male bellows as they propagated through the Eucalyptus canopy. Taken together these findings suggest that koalas could recognise known individuals at distances of up to 50 m and indicate that they should attend to variation in the upper formant frequencies and formant frequency spacing when assessing the identity of callers. Furthermore, since the formant frequency spacing is also a cue to male body size in this species and its variation over distance remained very low compared to documented inter-individual variation, we suggest that male koalas would still be reliably classified as small, medium or large by receivers at distances of up to 150 m.

  13. Single-domain intrabodies against hepatitis C virus core inhibit viral propagation and core-induced NFκB activation.

    PubMed

    Suzuki, Ryosuke; Saito, Kenji; Matsuda, Mami; Sato, Mitsuru; Kanegae, Yumi; Shi, Guoli; Watashi, Koichi; Aizaki, Hideki; Chiba, Joe; Saito, Izumu; Wakita, Takaji; Suzuki, Tetsuro

    2016-04-01

    Hepatitis C virus (HCV) core plays a key role in viral particle formation and is involved in viral pathogenesis. Here, constructs for single-domain intrabodies consisting of variable regions derived from mouse mAbs against HCV core were established. Expressed single-domain intrabodies were shown to bind to HCV core, and inhibit the growth of cell culture-produced HCV derived from JFH-1 (genotype 2a) and a TH (genotype 1b)/JFH-1 chimera. Adenovirus vectors expressing intrabodies were also capable of reducing HCV propagation. Intrabody expression did not affect viral entry or genome replication of single-round infectious trans-complemented HCV particles. However, intrabody expression reduced intracellular and extracellular infectious titres in CD81-defective Huh7-25 cells transfected with the HCV genome, suggesting that these intrabodies impair HCV assembly. Furthermore, intrabody expression suppressed HCV core-induced NFκB promoter activity. These intrabodies may therefore serve as tools for elucidating the role of core in HCV pathogenesis. PMID:26861864

  14. [Guidelines for certification of Activated clotting time (ACT) according to the EN ISO 22870 standards].

    PubMed

    Lasne, Dominique; Bauters, Anne; Le Querrec, Agnès; Bourdin, Carole; Voisin, Sophie

    2015-01-01

    Point of care testing (POCT) must comply with regulatory requirements according to standard EN ISO 22870, which identify biologists as responsible for POCT. Activated clotting time (ACT) is mandatory to monitor on whole blood, anticoagulation achieved by unfractionated heparin during cardiopulmonary bypass (CPB) or cardiac catheterization. This test has no equivalent in the laboratory. With the aim to help the multidisciplinary groups for POCT supervision when they have to analyse the wish of medical departments to use ACT and to help the biologists to be in accordance with the standard, we present the guidelines of the GEHT (Groupe d'étude d'hémostase et thrombose) subcommittee "CEC et Biologie délocalisée" for the certification of ACT. These guidelines are based on the SFBC guidelines for the certification of POCT and on the analysis of the literature to ascertain the justification of clinical need and assess the analytical performance of main analyzers used in France, as well as on a survey conducted with French and Belgian biologists.

  15. Contextual interactions determine whether the Drosophila homeodomain protein, Vnd, acts as a repressor or activator

    PubMed Central

    Yu, Zhongxin; Syu, Li-Jyun; Mellerick, Dervla M.

    2005-01-01

    At the molecular level, members of the NKx2.2 family of transcription factors establish neural compartment boundaries by repressing the expression of homeobox genes specific for adjacent domains [Muhr et al. (2001) Cell, 104, 861–873; Weiss et al. (1998) Genes Dev., 12, 3591–3602]. The Drosophila homologue, vnd, interacts genetically with the high-mobility group protein, Dichaete, in a manner suggesting co-operative activation [Zhao and Skeath (2002) Development, 129, 1165–1174]. However, evidence for direct interactions and transcriptional activation is lacking. Here, we present molecular evidence for the interaction of Vnd and Dichaete that leads to the activation of target gene expression. Two-hybrid interaction assays indicate that Dichaete binds the Vnd homeodomain, and additional Vnd sequences stabilize this interaction. In addition, Vnd has two activation domains that are typically masked in the intact protein. Whether vnd can activate or repress transcription is context-dependent. Full-length Vnd, when expressed as a Gal4 fusion protein, acts as a repressor containing multiple repression domains. A divergent domain in the N-terminus, not found in vertebrate Vnd-like proteins, causes the strongest repression. The co-repressor, Groucho, enhances Vnd repression, and these two proteins physically interact. The data presented indicate that the activation and repression domains of Vnd are complex, and whether Vnd functions as a transcriptional repressor or activator depends on both intra- and inter-molecular interactions. PMID:15640442

  16. 10 CFR 50.13 - Attacks and destructive acts by enemies of the United States; and defense activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Attacks and destructive acts by enemies of the United States; and defense activities. 50.13 Section 50.13 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Requirement of License, Exceptions § 50.13 Attacks and destructive acts by enemies of the United...

  17. 10 CFR 50.13 - Attacks and destructive acts by enemies of the United States; and defense activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Attacks and destructive acts by enemies of the United... destructive acts by enemies of the United States; and defense activities. An applicant for a license to... an enemy of the United States, whether a foreign government or other person, or (b) use or...

  18. The NASA radiowave propagation program

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz

    1990-01-01

    The objectives of the NASA radiowave Propagation Program are to enable new satellite communication applications and to enhance existing satellite communication networks. These objectives are achieved by supporting radio wave propagation studies and disseminating the study results in a timely fashion. Studies initiated by this program in the 1980s enabled the infant concept of conducting mobile communications via satellite to reach a state of relative maturity in 1990. The program also supported the satellite communications community by publishing and revising two handbooks dealing with radio wave propagation effects for frequencies below and above 10 GHz, respectively. The program has served the international community through its support of the International Telecommunications Union. It supports state of the art work at universities. Currently, the program is focusing on the Advanced Communications Technology Satellite (ACTS) and its propagation needs. An overview of the program's involvement in the ACTS project is given.

  19. The NASA radiowave propagation program

    NASA Astrophysics Data System (ADS)

    Davarian, Faramaz

    The objectives of the NASA radiowave Propagation Program are to enable new satellite communication applications and to enhance existing satellite communication networks. These objectives are achieved by supporting radio wave propagation studies and disseminating the study results in a timely fashion. Studies initiated by this program in the 1980s enabled the infant concept of conducting mobile communications via satellite to reach a state of relative maturity in 1990. The program also supported the satellite communications community by publishing and revising two handbooks dealing with radio wave propagation effects for frequencies below and above 10 GHz, respectively. The program has served the international community through its support of the International Telecommunications Union. It supports state of the art work at universities. Currently, the program is focusing on the Advanced Communications Technology Satellite (ACTS) and its propagation needs. An overview of the program's involvement in the ACTS project is given.

  20. Neuropeptide F peptides act through unique signaling pathways to affect cardiac activity.

    PubMed

    Setzu, M; Biolchini, M; Lilliu, A; Manca, M; Muroni, P; Poddighe, S; Bass, C; Angioy, A M; Nichols, R

    2012-02-01

    Elucidating how neuropeptides affect physiology may result in delineating peptidergic mechanisms and identifying antagonists for application in basic and translational science. Human neuropeptide Y (NPY) regulates cardiac activity; frequently invertebrates contain orthologs of vertebrate peptides. We report invertebrate NPY-like neuropeptide F (NPF) arrested the signal frequency of the slow phase of the cardiac cycle (EC50 = 1 pM); however, signal frequency of the fast phase was affected only minimally. Neuropeptide F decreased the duration of the slow phase by ~70% (EC50 = 0.6 pM), but increased the duration of the fast phase by ~57% (EC50 = 10nM). Short NPF-1 (sNPF-1) decreased the signal frequency of the slow phase by ~70% (EC50 = 9 nM); yet, signal frequency of the fast phase was unaffected. Short NPF-1 decreased the duration of the slow phase ~55% (EC50 ~50 nM), but increased the duration of the fast phase ~20% without dose dependency. Neuropeptide F and sNPF-1 increased isoelectric period duration. This novel report demonstrated NPY-like peptides are cardioactive but functionally unique. These data contribute to understanding how invertebrate orthologs affect cardiovascular activity. Dipteran fast and slow phases may be generated from separate pacemakers in the abdominal heart and in the anterior thoracocephalic aorta, respectively. Thus, our research suggests NPF and sNPF-1 act through different mechanisms to regulate cardiac activity. Invertebrate NPY-like peptides act in olfaction and feeding yet mechanisms which are associated with their cardioactive effects remain unknown; our work may provide evidence linking their roles in sensory response and cardiac activity.

  1. Neuropeptide F peptides act through unique signaling pathways to affect cardiac activity

    PubMed Central

    Setzu, M.; Biolchini, M.; Lilliu, A.; Manca, M.; Muroni, P.; Poddighe, S.; Bass, C.; Angioy, A.M.; Nichols, R.

    2012-01-01

    Elucidating how neuropeptides affect physiology may result in delineating peptidergic mechanisms and identifying antagonists for application in basic and translational science. Human neuropeptide Y (NPY) regulates cardiac activity; frequently invertebrates contain orthologs of vertebrate peptides. We report invertebrate NPY-like neuropeptide F (NPF) arrested the signal frequency of the slow phase of the cardiac cycle (EC50 = 1 pM); however, signal frequency of the fast phase was affected only minimally. Neuropeptide F decreased the duration of the slow phase by ~70% (EC50 = 0.6 pM), but increased the duration of the fast phase by ~57% (EC50 = 10 nM). Short NPF-1 (sNPF-1) decreased the signal frequency of the slow phase by ~70% (EC50 = 9 nM); yet, signal frequency of the fast phase was unaffected. Short NPF-1 decreased the duration of the slow phase ~55% (EC50 ~ 50 nM), but increased the duration of the fast phase ~20% without dose dependency. Neuropeptide F and sNPF-1 increased isoelectric period duration. This novel report demonstrated NPY-like peptides are cardioactive but functionally unique. These data contribute to understanding how invertebrate orthologs affect cardiovascular activity. Dipteran fast and slow phases may be generated from separate pacemakers in the abdominal heart and in the anterior thoracocephalic aorta, respectively. Thus, our research suggests NPF and sNPF-1 act through different mechanisms to regulate cardiac activity. Invertebrate NPY-like peptides act in olfaction and feeding yet mechanisms which are associated with their cardioactive effects remain unknown; our work may provide evidence linking their roles in sensory response and cardiac activity. PMID:22289500

  2. Integrative application of active controls (IAAC) technology to an advanced subsonic transport project. Initial act configuration design study

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The performance and economic benefits of a constrained application of Active Controls Technology (ACT) are identified, and the approach to airplane design is established for subsequent steps leading to the development of a less constrained final ACT configuration. The active controls configurations are measured against a conventional baseline configuration, a state-of-the-art transport, to determine whether the performance and economic changes resulting from ACT merit proceeding with the project. The technology established by the conventional baseline configuration was held constant except for the addition of ACT. The wing, with the same planform, was moved forward on the initial ACT configuration to move the loading range aft relative to the wing mean aerodynamic chord. Wing trailing-edge surfaces and surface controls also were reconfigured for load alleviation and structural stabilization.

  3. Lateral propagation of active normal faults throughout pre-existing fault zones: an example from the Southern Apennines, Italy

    NASA Astrophysics Data System (ADS)

    Agosta, Fabrizio; Prosser, Giacomo; Ivo Giano, Salvatore

    2013-04-01

    The main active structures in the Southern Apennines are represented by a set of NW-trending normal faults, which are mainly located in the axial sector of the chain. Evidences arising from neotectonics and seismology show activity of a composite seismic source, the Irpinia - Agri Valley, located across the Campania-Basilicata border. This seismic source is made up of two right-stepping, individual seismic sources forming a relay ramp. Each individual seismic source consists of a series of nearly parallel normal fault segments. The relay ramp area, located around the Vietri di Potenza town, is bounded by two seismic segments, the San Gregorio Magno Fault, to the NW, and the Pergola-Melandro Fault, to the SE. The possible interaction between the two right-stepping fault segments has not been proven yet, since the fault system of the area has never been analyzed in detail. This work is aimed at assessing the geometry of such fault system, inferring the relative age of the different fault sets by studying the crosscutting relationships, characterizing the micromechanics of fault rocks associated to the various fault sets, and understanding the modalities of lateral propagation of the two bounding fault segments. Crosscutting relationships are recognized by combining classical geological mapping with morphotectonic methods. This latter approach, which include the analysis of aerial photographs and field inspection of quaternary slope deposits, is used to identify the most recent structures among those cropping out in the field area. In the relay ramp area, normal faults crosscut different tectonic units of the Apennine chain piled up, essentially, during the Middle to Late Miocene. The topmost unit (only few tens of meter-thick) consists of a mélange containing blocks of different lithologies in a clayish matrix. The intermediate thrust sheet consists of 1-1.5 km-thick platform carbonates of late Triassic-Jurassic age, with dolomites at the base and limestones at the

  4. Active normal faulting during the 1997 seismic sequence in Colfiorito, Umbria: Did slip propagate to the surface?

    NASA Astrophysics Data System (ADS)

    Mildon, Zoë K.; Roberts, Gerald P.; Faure Walker, Joanna P.; Wedmore, Luke N. J.; McCaffrey, Ken J. W.

    2016-10-01

    In order to determine whether slip during an earthquake on the 26th September 1997 propagated to the surface, structural data have been collected along a bedrock fault scarp in Umbria, Italy. These collected data are used to investigate the relationship between the throw associated with a debated surface rupture (observed as a pale unweathered stripe at the base of the bedrock fault scarp) and the strike, dip and slip-vector. Previous studies have suggested that the surface rupture was produced either by primary surface slip or secondary compaction of hangingwall sediments. Some authors favour the latter because sparse surface fault dip measurements do not match nodal plane dips at depth. It is demonstrated herein that the strike, dip and height of the surface rupture, represented by a pale unweathered stripe at the base of the bedrock scarp, shows a systematic relationship with respect to the geometry and kinematics of faulting in the bedrock. The strike and dip co-vary and the throw is greatest where the strike is oblique to the slip-vector azimuth where the highest dip values are recorded. This implies that the throw values vary to accommodate spatial variation in the strike and dip of the fault across fault plane corrugations, a feature that is predicted by theory describing conservation of strain along faults, but not by compaction. Furthermore, published earthquake locations and reported fault dips are consistent with the analysed surface scarps when natural variation for surface dips and uncertainty for nodal plane dips at depth are taken into account. This implies that the fresh stripe is indeed a primary coseismic surface rupture whose slip is connected to the seismogenic fault at depth. We discuss how this knowledge of the locations and geometry of the active faults can be used as an input for seismic hazard assessment.

  5. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transpot project-demonstration act system definition

    NASA Technical Reports Server (NTRS)

    Hanks, G. W.; Shomber, H. A.; Crumb, C. B.; Flora, C. C.; Macdonald, K. A. B.; Smith, R. D.; Sassi, A. P.; Dorwart, R. J.

    1982-01-01

    The 1985 ACT airplane is the Final Active Controls Technology (ACT) Airplane with the addition of three-axis fly by wire. Thus it retains all the efficiency features of the full ACT system plus the weight and cost savings accruing from deletion of the mechanical control system. The control system implements the full IAAC spectrum of active controls except flutter-mode control, judged essentially nonbeneficial, and incorporates new control surfaces called flaperons to make the most of wing-load alleviation. This redundant electronic system is conservatively designed to preserve the extreme reliability required of crucial short-period pitch augmentation, which provides more than half of the fuel savings.

  6. Phytochemicals increase the antibacterial activity of antibiotics by acting on a drug efflux pump

    PubMed Central

    Ohene-Agyei, Thelma; Mowla, Rumana; Rahman, Taufiq; Venter, Henrietta

    2014-01-01

    Drug efflux pumps confer resistance upon bacteria to a wide range of antibiotics from various classes. The expression of efflux pumps are also implicated in virulence and biofilm formation. Moreover, organisms can only acquire resistance in the presence of active drug efflux pumps. Therefore, efflux pump inhibitors (EPIs) are attractive compounds to reverse multidrug resistance and to prevent the development of resistance in clinically relevant bacterial pathogens. We investigated the potential of pure compounds isolated from plants to act as EPIs. In silico screening was used to predict the bioactivity of plant compounds and to compare that with the known EPI, phe-arg-β-naphthylamide (PAβN). Subsequently, promising products have been tested for their ability to inhibit efflux. Plumbagin nordihydroguaretic acid (NDGA) and to a lesser degree shikonin, acted as sensitizers of drug-resistant bacteria to currently used antibiotics and were able to inhibit the efflux pump-mediated removal of substrate from cells. We demonstrated the feasibility of in silico screening to identify compounds that potentiate the action of antibiotics against drug-resistant strains and which might be potentially useful lead compounds for an EPI discovery program. PMID:25224951

  7. Nurses' attitudes to active voluntary euthanasia: a survey in the ACT.

    PubMed

    Kitchener, B A

    1998-04-01

    National public opinion polls show a large majority of Australians are in favour of active voluntary euthanasia (AVE). However, most members of the public have had only limited direct experience with dying people. For this reason, surveys of the opinions of medical practitioners and nurses on this issue are of great interest. The present study involved a postal survey in late 1996 of 2,000 randomly selected registered nurses from the Australian Capital Territory (ACT). The ACT has had extensive public debate about this issue. The questionnaire included some questions asked in earlier Australian surveys of the general public and health practitioners. Responses were received from 1218 nurses (61%). A majority of nurses who responded supported AVE as 'sometimes right', be it homicide by request (72%) or physician-assisted suicide (71%). A slightly smaller majority believed the law should be changed to allow homicide by request (69%) and physician-assisted suicide (67%). If AVE were legal, 66% of the nurses indicated they were willing to be involved in the procedure. Only 30% were willing to assist patients to give themselves the lethal dose, while 14% were willing to administer the lethal dose to the patient. Comparing these results with previous surveys, it appears that nurses are less in favour of AVE than the public, but more in favour than medical practitioners. PMID:9744194

  8. Factor C acts as a lipopolysaccharide-responsive C3 convertase in horseshoe crab complement activation.

    PubMed

    Ariki, Shigeru; Takahara, Shusaku; Shibata, Toshio; Fukuoka, Takaaki; Ozaki, Aya; Endo, Yuichi; Fujita, Teizo; Koshiba, Takumi; Kawabata, Shun-ichiro

    2008-12-01

    The complement system in vertebrates plays an important role in host defense against and clearance of invading microbes, in which complement component C3 plays an essential role in the opsonization of pathogens, whereas the molecular mechanism underlying C3 activation in invertebrates remains unknown. In an effort to understand the molecular activation mechanism of invertebrate C3, we isolated and characterized an ortholog of C3 (designated TtC3) from the horseshoe crab Tachypleus tridentatus. Flow cytometric analysis using an Ab against TtC3 revealed that the horseshoe crab complement system opsonizes both Gram-negative and Gram-positive bacteria. Evaluation of the ability of various pathogen-associated molecular patterns to promote the proteolytic conversion of TtC3 to TtC3b in hemocyanin-depleted plasma indicated that LPS, but not zymosan, peptidoglycan, or laminarin, strongly induces this conversion, highlighting the selective response of the complement system to LPS stimulation. Although originally characterized as an LPS-sensitive initiator of hemolymph coagulation stored within hemocytes, we identified factor C in hemolymph plasma. An anti-factor C Ab inhibited various LPS-induced phenomena, including plasma amidase activity, the proteolytic activation of TtC3, and the deposition of TtC3b on the surface of Gram-negative bacteria. Moreover, activated factor C present on the surface of Gram-negative bacteria directly catalyzed the proteolytic conversion of the purified TtC3, thereby promoting TtC3b deposition. We conclude that factor C acts as an LPS-responsive C3 convertase on the surface of invading Gram-negative bacteria in the initial phase of horseshoe crab complement activation.

  9. Clonal evolution enhances leukemia propagating cell frequency in T-cell acute lymphoblastic leukemia through Akt/mTORC1 pathway activation

    PubMed Central

    Blackburn, Jessica S.; Liu, Sali; Wilder, Jayme L.; Dobrinski, Kimberly P.; Lobbardi, Riadh; Moore, Finola E.; Martinez, Sarah A.; Chen, Eleanor Y.; Lee, Charles; Langenau, David M.

    2014-01-01

    SUMMARY Clonal evolution and intratumoral heterogeneity drive cancer progression through unknown molecular mechanisms. To address this issue, functional differences between single T-cell acute lymphoblastic leukemia (T-ALL) clones were assessed using a zebrafish transgenic model. Functional variation was observed within individual clones, with a minority of clones enhancing growth rate and leukemia propagating potential with time. Akt pathway activation was acquired in a subset of these evolved clones, which increased the number of leukemia propagating cells through activating mTORC1, elevated growth rate likely by stabilizing the Myc protein, and rendered cells resistant to dexamethasone, which was reversed by combined treatment with an Akt inhibitor. Thus, T-ALL clones spontaneously and continuously evolve to drive leukemia progression even in the absence of therapy-induced selection. PMID:24613413

  10. Fly DPP10 acts as a channel ancillary subunit and possesses peptidase activity

    PubMed Central

    Shiina, Yohei; Muto, Tomohiro; Zhang, Zhili; Baihaqie, Ahmad; Yoshizawa, Takamasa; Lee, Hye-in J.; Park, Eulsoon; Tsukiji, Shinya; Takimoto, Koichi

    2016-01-01

    Mammalian DPP6 (DPPX) and DPP10 (DPPY) belong to a family of dipeptidyl peptidases, but lack enzyme activity. Instead, these proteins form complexes with voltage-gated K+ channels in Kv4 family to control their gating and other properties. Here, we find that the fly DPP10 ortholog acts as an ancillary subunit of Kv4 channels and digests peptides. Similarly to mammalian DPP10, the fly ortholog tightly binds to rat Kv4.3 protein. The association causes negative shifts in voltage dependence of channel activation and steady state inactivation. It also results in faster inactivation and recovery from inactivation. In addition to its channel regulatory role, fly DPP10 exhibits significant dipeptidyl peptidase activity with Gly-Pro-MCA (glycyl-L-proline 4-methylcoumaryl-7-amide) as a substrate. Heterologously expressed Flag-tagged fly DPP10 and human DPP4 show similar Km values towards this substrate. However, fly DPP10 exhibits approximately a 6-times-lower relative kcat value normalized with anti-Flag immunoreactivity than human DPP4. These results demonstrate that fly DPP10 is a dual functional protein, controlling Kv4 channel gating and removing bioactive peptides. PMID:27198182

  11. Motor activity affects adult skeletal muscle re-innervation acting via tyrosine kinase receptors.

    PubMed

    Sartini, Stefano; Bartolini, Fanny; Ambrogini, Patrizia; Betti, Michele; Ciuffoli, Stefano; Lattanzi, Davide; Di Palma, Michael; Cuppini, Riccardo

    2013-05-01

    Recently, muscle expression of brain-derived neurotrophic factor (BDNF) mRNA and protein under activity control has been reported. BDNF is a neurotrophin known to be involved in axon sprouting in the CNS. Hence, we set out to study the effect of chronic treadmill mid-intensity running on adult rat muscle re-innervation, and to explore the involvement of BDNF and tropomyosin-related kinase (Trk) receptors. After nerve crush, muscle re-innervation was evaluated using intracellular recordings, tension recordings, immunostaining and Western blot analyses. An enhanced muscle multiple innervation was found in running rats that was fully reversed to control values blocking Trk receptors or interrupting the running activity. An increase in muscle multiple innervation was also found in sedentary rats treated with a selective TrkB receptor agonist. The expression of TrkB receptors by intramuscular axons was demonstrated, and increased muscle expression of BDNF was found in running animals. The increase in muscle multiple innervation was consistent with the faster muscle re-innervation that we found in running animals. We conclude that, when regenerating axons contact muscle cells, muscle activity progressively increases modulating BDNF and possibly other growth factors, which in turn, acting via Trk receptors, induce axon sprouting to re-innervate skeletal muscle.

  12. An Active Ac/Ds Transposon System for Activation Tagging in Tomato Cultivar M82 Using Clonal Propagation1[W][OA

    PubMed Central

    Carter, Jared D.; Pereira, Andy; Dickerman, Allan W.; Veilleux, Richard E.

    2013-01-01

    Tomato (Solanum lycopersicum) is a model organism for Solanaceae in both molecular and agronomic research. This project utilized Agrobacterium tumefaciens transformation and the transposon-tagging construct Activator (Ac)/Dissociator (Ds)-ATag-Bar_gosGFP to produce activation-tagged and knockout mutants in the processing tomato cultivar M82. The construct carried hygromycin resistance (hyg), green fluorescent protein (GFP), and the transposase (TPase) of maize (Zea mays) Activator major transcript X054214.1 on the stable Ac element, along with a 35S enhancer tetramer and glufosinate herbicide resistance (BAR) on the mobile Ds-ATag element. An in vitro propagation strategy was used to produce a population of 25 T0 plants from a single transformed plant regenerated in tissue culture. A T1 population of 11,000 selfed and cv M82 backcrossed progeny was produced from the functional T0 line. This population was screened using glufosinate herbicide, hygromycin leaf painting, and multiplex polymerase chain reaction (PCR). Insertion sites of transposed Ds-ATag elements were identified through thermal asymmetric interlaced PCR, and resulting product sequences were aligned to the recently published tomato genome. A population of 509 independent, Ds-only transposant lines spanning all 12 tomato chromosomes has been developed. Insertion site analysis demonstrated that more than 80% of these lines harbored Ds insertions conducive to activation tagging. The capacity of the Ds-ATag element to alter transcription was verified by quantitative real-time reverse transcription-PCR in two mutant lines. The transposon-tagged lines have been immortalized in seed stocks and can be accessed through an online database, providing a unique resource for tomato breeding and analysis of gene function in the background of a commercial tomato cultivar. PMID:23569107

  13. Active microrheology of entangled blends of DNA and Actin link polymer flexibility to induced molecular deformations and stress propagation

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Robert; Robertson-Anderson, Rae; Anderson Research Team

    Actin is a ubiquitous structural protein in the cytoskeleton that gives cells shape and rigidity, and plays important roles in mechanical processes such as cell motility and division. Actin's diverse roles stem from its ability to polymerize into semiflexible filaments that are less than one persistence length (17 µm) in length, and form entangled networks that display unique viscoelastic properties. We previously found that entangled actin networks propagate microscale forces over several persistence lengths (>60 m) and takes minutes to relax. DNA, oppositely, has thousands of persistence lengths (50 nm) per chain, exhibits minimal force propagation, and takes only seconds to re-equilibrate. To directly determine the role of flexibility in mechanical response and force propagation of entangled networks, we use optical tweezers and fluorescence microscopy to investigate blends of actin and DNA. We use optically driven microspheres to perturb the network far from equilibrium and measure the force the network creates in response to the induced force. We simultaneously track partially labeled actin filaments during the perturbation and subsequent relaxation period. We characterize filament deformation and show explicitly how induced microscale forces propagate through the network.

  14. 29 CFR 779.110 - Employees in retailing whose activities may bring them under the Act.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to Which the Act May Apply: Basic Principles and Individual Coverage Employees Engaged in Commerce Or in the... under the Act. 779.110 Section 779.110 Labor Regulations Relating to Labor (Continued) WAGE AND...

  15. 29 CFR 779.110 - Employees in retailing whose activities may bring them under the Act.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to Which the Act May Apply: Basic Principles and Individual Coverage Employees Engaged in Commerce Or in the... under the Act. 779.110 Section 779.110 Labor Regulations Relating to Labor (Continued) WAGE AND...

  16. 29 CFR 779.110 - Employees in retailing whose activities may bring them under the Act.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to Which the Act May Apply: Basic Principles and Individual Coverage Employees Engaged in Commerce Or in the... under the Act. 779.110 Section 779.110 Labor Regulations Relating to Labor (Continued) WAGE AND...

  17. 29 CFR 779.110 - Employees in retailing whose activities may bring them under the Act.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... REGULATIONS THE FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to Which the Act May Apply: Basic Principles and Individual Coverage Employees Engaged in Commerce Or in the... under the Act. 779.110 Section 779.110 Labor Regulations Relating to Labor (Continued) WAGE AND...

  18. 75 FR 9423 - Agency Information Collection Activities: African Growth and Opportunity Act Certificate of Origin

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... Opportunity Act Certificate of Origin AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland... requirement concerning the African Growth and Opportunity Act Certificate of Origin (AGOA). This request for...: Title: African Growth and Opportunity Act Certificate of Origin. OMB Number: 1651-0082. Form...

  19. 78 FR 28239 - Agency Information Collection Activities; Andean Trade Preferences Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ... Register (78 FR 15031) on March 8, 2013, allowing for a 60-day comment period. This notice allows for an... Preferences Act AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION: 30-Day... approval in accordance with the Paperwork Reduction Act: Andean Trade Preferences Act. This is a...

  20. 76 FR 8766 - Agency Information Collection Activities: Andean Trade Preference Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... Register (75 FR 73118) on November 29, 2010, allowing for a 60-day comment period. This notice allows for... Preference Act AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION: 30-Day... accordance with the Paperwork Reduction Act: Andean Trade Preference Act. This is a proposed extension of...

  1. 78 FR 42103 - Agency Information Collection Activities: African Growth and Opportunity Act Certificate of Origin

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-15

    ... Opportunity Act Certificate of Origin AGENCY: U.S. Customs and Border Protection, Department of Homeland... accordance with the Paperwork Reduction Act: African Growth and Opportunity Act Certificate of Origin (AGOA... previously published in the Federal Register (78 FR 26650) on May 7, 2013, allowing for a 60-day...

  2. 78 FR 26650 - Agency Information Collection Activities: African Growth and Opportunity Act Certificate of Origin

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-07

    ... Opportunity Act Certificate of Origin AGENCY: U.S. Customs and Border Protection, Department of Homeland... Certificate of Origin (AGOA). This request for comments is being made pursuant to the Paperwork Reduction Act...: Title: African Growth and Opportunity Act Certificate of Origin. OMB Number: 1651-0082. Form...

  3. Characteristics of electron cyclotron harmonic waves observed in an active two-point propagation experiment in the ionosphere

    NASA Astrophysics Data System (ADS)

    James, H. G.; Wallis, D. D.

    2008-07-01

    Electrostatic electron cyclotron waves (ECWs), also-called electron Bernstein waves, observed at harmonics nfc of the electron cyclotron frequency fc were transmitted over field-aligned emitter-receiver separations of hundreds of meters in the active rocket experiment OEDIPUS-C. Although the 300-μs rectangular current pulses into the emitting antenna were smoothly maintained during the experiment, the resulting ECW pulses at the receiver exhibited considerable variety in both the time and frequency domains. A full hot-plasma dispersion relation has been applied to ray-tracing investigations to identify the rays that could connect the emitter and receiver in a smoothly varying model of the auroral ionospheric magnetoplasma. Theoretical connecting rays were limited to frequencies extending from 1 to a few kilohertz above 2fc, which was about 2.6 MHz. But the observed pulse spectra extended over a much broader bandwidth, from several kilohertz below nfc to several kilohertz above, for n = 2, 3, and 4. The broadening is interpreted as a consequence of Doppler effect caused by payload motion and backscatter of the ECWs. Field-aligned density irregularities typical of the auroral topside ionosphere or waves nonlinearly induced by the intense near fields of the HEX antenna may act as the scatterers.

  4. Arsenic trioxide and reduced glutathione act synergistically to augment inhibition of thyroid peroxidase activity in vitro.

    PubMed

    Palazzolo, Dominic L; Ely, Emily A

    2015-05-01

    Thyroid peroxidase (TPO) is the enzyme involved in thyroid hormone synthesis. Arsenic trioxide (As2O3) is known to inhibit TPO activity in vitro. This inhibition is believed to occur when As2O3 binds to TPO's free sulfhydryl groups. Reduced glutathione (GSH) is also known to inhibit TPO activity in vitro. This inhibition may occur because GSH acts as a competitive substrate for hydrogen peroxide, or possibly reduce the oxidized form of iodide, requirements for TPO action. On the other hand, one could speculate that GSH reduces arsenic-induced TPO inhibition by interacting directly with arsenic or TPO, consequently limiting arsenic's ability to inhibit TPO activity. Since GSH is known to inhibit thyroid hormone synthesis while at the same time it is also known to be an important antioxidant preventing cellular damage induced by oxidative stress and protecting the thyroid gland from oxidative damage induced by arsenic, we wanted to determine if a combination of As2O3 and reduced GSH would either attenuate or augment the As2O3-induced inhibition on TPO activity. Using an in vitro system, TPO was assayed spectrophotometrically in the presence of As2O3 (0.01, 0.1, 1, and 10 ppm), GSH (0.1, 1, 5, and 10 ppm), and As2O3 (0.1 ppm) and GSH (0.01, 0.1, 1, or 10 ppm) combinations. Our results show that 0.1, 1.0, and 10 ppm As2O3 inhibit TPO activity. Similarly, 5 and 10 ppm GSH also inhibit TPO activity. When 0.1 ppm As2O3 (i.e., the lowest dose of arsenic able to partially inhibit TPO activity) is combined with 0.01, 0.1, 1.0, or 10 ppm GSH inhibition of in vitro TPO activity is augmented as indicated by complete inhibition of TPO. The mechanism of this augmentation and whether it translates to living systems remains unclear.

  5. 50 CFR 80.50 - What activities are eligible for funding under the Pittman-Robertson Wildlife Restoration Act?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) FINANCIAL ASSISTANCE-WILDLIFE AND SPORT FISH RESTORATION PROGRAM ADMINISTRATIVE REQUIREMENTS, PITTMAN-ROBERTSON WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS Eligible Activities § 80.50 What activities...

  6. PKR is activated by cellular dsRNAs during mitosis and acts as a mitotic regulator

    PubMed Central

    Kim, Yoosik; Lee, Jung Hyun; Park, Jong-Eun; Cho, Jun; Yi, Hyerim; Kim, V. Narry

    2014-01-01

    dsRNA-dependent protein kinase R (PKR) is a ubiquitously expressed enzyme well known for its roles in immune response. Upon binding to viral dsRNA, PKR undergoes autophosphorylation, and the phosphorylated PKR (pPKR) regulates translation and multiple signaling pathways in infected cells. Here, we found that PKR is activated in uninfected cells, specifically during mitosis, by binding to dsRNAs formed by inverted Alu repeats (IRAlus). While PKR and IRAlu-containing RNAs are segregated in the cytosol and nucleus of interphase cells, respectively, they interact during mitosis when nuclear structure is disrupted. Once phosphorylated, PKR suppresses global translation by phosphorylating the α subunit of eukaryotic initiation factor 2 (eIF2α). In addition, pPKR acts as an upstream kinase for c-Jun N-terminal kinase and regulates the levels of multiple mitotic factors such as CYCLINS A and B and POLO-LIKE KINASE 1 and phosphorylation of HISTONE H3. Disruption of PKR activation via RNAi or expression of a transdominant-negative mutant leads to misregulation of the mitotic factors, delay in mitotic progression, and defects in cytokinesis. Our study unveils a novel function of PKR and endogenous dsRNAs as signaling molecules during the mitosis of uninfected cells. PMID:24939934

  7. Assessment of MSFCs Process for the Development and Activation of Space Act Agreements

    NASA Technical Reports Server (NTRS)

    Daugherty, Rachel A.

    2014-01-01

    A Space Act Agreement (SAA) is a contractual vehicle that NASA utilizes to form partnerships with non-NASA entities to stimulate cutting-edge innovation within the science and technology communities while concurrently supporting the NASA missions. SAAs are similar to traditional contracts in that they involve the commitment of Agency resources but allow more flexibility and are more cost effective to implement than traditional contracts. Consequently, the use of SAAs to develop partnerships has greatly increased over the past several years. To facilitate this influx of SAAs, Marshall Space Flight Center (MSFC) developed a process during a kaizen event to streamline and improve the quality of SAAs developed at the Center level. This study assessed the current SAA process to determine if improvements could be implemented to increase productivity, decrease time to activation, and improve the quality of deliverables. Using a combination of direct procedural observation, personnel interviews, and statistical analysis, elements of the process in need of remediation were identified and potential solutions developed. The findings focus primarily on the difficulties surrounding tracking and enforcing process adherence and communication issues among stakeholders. Potential solutions include utilizing customer relationship management (CRM) software to facilitate process coordination and co-locating or potentially merging the two separate organizations involved in SAA development and activation at MSFC.

  8. PKR is activated by cellular dsRNAs during mitosis and acts as a mitotic regulator.

    PubMed

    Kim, Yoosik; Lee, Jung Hyun; Park, Jong-Eun; Cho, Jun; Yi, Hyerim; Kim, V Narry

    2014-06-15

    dsRNA-dependent protein kinase R (PKR) is a ubiquitously expressed enzyme well known for its roles in immune response. Upon binding to viral dsRNA, PKR undergoes autophosphorylation, and the phosphorylated PKR (pPKR) regulates translation and multiple signaling pathways in infected cells. Here, we found that PKR is activated in uninfected cells, specifically during mitosis, by binding to dsRNAs formed by inverted Alu repeats (IRAlus). While PKR and IRAlu-containing RNAs are segregated in the cytosol and nucleus of interphase cells, respectively, they interact during mitosis when nuclear structure is disrupted. Once phosphorylated, PKR suppresses global translation by phosphorylating the α subunit of eukaryotic initiation factor 2 (eIF2α). In addition, pPKR acts as an upstream kinase for c-Jun N-terminal kinase and regulates the levels of multiple mitotic factors such as cyclins A and B and Polo-like kinase 1 and phosphorylation of histone H3. Disruption of PKR activation via RNAi or expression of a transdominant-negative mutant leads to misregulation of the mitotic factors, delay in mitotic progression, and defects in cytokinesis. Our study unveils a novel function of PKR and endogenous dsRNAs as signaling molecules during the mitosis of uninfected cells.

  9. Acting Atoms.

    ERIC Educational Resources Information Center

    Farin, Susan Archie

    1997-01-01

    Describes a fun game in which students act as electrons, protons, and neutrons. This activity is designed to help students develop a concrete understanding of the abstract concept of atomic structure. (DKM)

  10. Annual Report to the President and to the Congress on Federal Activities Related to the Rehabilitation Act of 1973 as Amended. Fiscal Year 1991.

    ERIC Educational Resources Information Center

    Rehabilitation Services Administration (ED), Washington, DC.

    This annual report (fiscal year 1991) summarizes information on mandated federal activities of the Rehabilitation Services Administration and related agencies under the Rehabilitation Act of 1973. The report is organized following the titles and sections of the Act. Under the Act's General Provisions are activities of the Office of the…

  11. Proceedings of the Thirteenth NASA Propagation Experimenters Meeting (NAPEX 13)

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz (Editor)

    1989-01-01

    The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. The meeting was organized into three technical sessions: the first focused on mobile satellite propagation; the second examined the propagation effects for frequencies above 10 GHz; and the third addressed studies devoted exclusively to the Olympus/Advanced Communications Technology Satellite (ACTS) Program.

  12. Neuropeptide Y acts in the paraventricular nucleus to suppress sympathetic nerve activity and its baroreflex regulation.

    PubMed

    Cassaglia, Priscila A; Shi, Zhigang; Li, Baoxin; Reis, Wagner L; Clute-Reinig, Nicholas M; Stern, Javier E; Brooks, Virginia L

    2014-04-01

    Neuropeptide Y (NPY), a brain neuromodulator that has been strongly implicated in the regulation of energy balance, also acts centrally to inhibit sympathetic nerve activity (SNA); however, the site and mechanism of action are unknown. In chloralose-anaesthetized female rats, nanoinjection of NPY into the paraventricular nucleus of the hypothalamus (PVN) dose-dependently suppressed lumbar SNA (LSNA) and its baroreflex regulation, and these effects were blocked by prior inhibition of NPY Y1 or Y5 receptors. Moreover, PVN injection of Y1 and Y5 receptor antagonists in otherwise untreated rats increased basal and baroreflex control of LSNA, indicating that endogenous NPY tonically inhibits PVN presympathetic neurons. The sympathoexcitation following blockade of PVN NPY inhibition was eliminated by prior PVN nanoinjection of the melanocortin 3/4 receptor inhibitor SHU9119. Moreover, presympathetic neurons, identified immunohistochemically using cholera toxin b neuronal tract tracing from the rostral ventrolateral medulla (RVLM), express NPY Y1 receptor immunoreactivity, and patch-clamp recordings revealed that both NPY and α-melanocyte-stimulating hormone (α-MSH) inhibit and stimulate, respectively, PVN-RVLM neurons. Collectively, these data suggest that PVN NPY inputs converge with α-MSH to influence presympathetic neurons. Together these results identify endogenous NPY as a novel and potent inhibitory neuromodulator within the PVN that may contribute to changes in SNA that occur in states associated with altered energy balance, such as obesity and pregnancy. PMID:24535439

  13. Role of gastrocnemius activation in knee joint biomechanics: gastrocnemius acts as an ACL antagonist.

    PubMed

    Adouni, M; Shirazi-Adl, A; Marouane, H

    2016-01-01

    Gastrocnemius is a premier muscle crossing the knee, but its role in knee biomechanics and on the anterior cruciate ligament (ACL) remains less clear when compared to hamstrings and quadriceps. The effect of changes in gastrocnemius force at late stance when it peaks on the knee joint response and ACL force was initially investigated using a lower extremity musculoskeletal model driven by gait kinematics-kinetics. The tibiofemoral joint under isolated isometric contraction of gastrocnemius was subsequently analyzed at different force levels and flexion angles (0°-90°). Changes in gastrocnemius force at late stance markedly influenced hamstrings forces. Gastrocnemius acted as ACL antagonist by substantially increasing its force. Simulations under isolated contraction of gastrocnemius confirmed this role at all flexion angles, in particular, at extreme knee flexion angles (0° and 90°). Constraint on varus/valgus rotations substantially decreased this effect. Although hamstrings and gastrocnemius are both knee joint flexors, they play opposite roles in respectively protecting or loading ACL. Although the quadriceps is also recognized as antagonist of ACL, at larger joint flexion and in contrast to quadriceps, activity in gastrocnemius substantially increased ACL forces (anteromedial bundle). The fact that gastrocnemius is an antagonist of ACL should help in effective prevention and management of ACL injuries.

  14. 78 FR 15031 - Agency Information Collection Activities: Andean Trade Preferences Act

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... Preferences Act AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland Security. ACTION: 60... the Andean Trade Preferences. This request for comment is being made pursuant to the Paperwork... Preferences Act. OMB Number: 1651-0091. Form Number: CBP Forms 449 and 17. Abstract: This collection...

  15. Investigating possible influence of solar activity on some reported seismic-induced ionospheric precursors via VLF wave propagation in Earth-ionosphere waveguide

    NASA Astrophysics Data System (ADS)

    Nwankwo, Victor U. J.; Chakrabarti, Sandip Kumar; Sasmal, Sudipta; Ray, Suman

    2016-07-01

    The diurnal propagation characteristic of VLF radio signal have been widely used to study pre-seismic ionospheric anomalies, some of which are often reported to be associated with the event. On the other hand, Solar particle events and geomagnetic activity also drive changes in the magnetosphere, which modify ionospheric parameters through the Earth's magnetic field. There are also effects originating from planetary and tidal waves, thermospheric tides and stratospheric warming. Distinguishing or separating seismically induced ionospheric fluctuations from those of other origin remain vital and challenging. In this work, we investigated the influence of solar and geomagnetic origin on some reported 'seismic ionospheric precursors' before a few major earthquakes. We also investigated anomalies in VLF day-length signal during period of low solar and geomagnetic activity (in relation to seismic activity), to understand the occurrence of VLF anomaly that are unrelated to seismicity and solar activity.

  16. 18 CFR 1309.4 - What programs or activities are covered by the Act and this part?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true What programs or activities are covered by the Act and this part? 1309.4 Section 1309.4 Conservation of Power and Water... purpose legislative body which: (i) Provides any benefits or assistance to persons based on age; or...

  17. 18 CFR 1309.4 - What programs or activities are covered by the Act and this part?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false What programs or activities are covered by the Act and this part? 1309.4 Section 1309.4 Conservation of Power and Water... purpose legislative body which: (i) Provides any benefits or assistance to persons based on age; or...

  18. 18 CFR 1309.4 - What programs or activities are covered by the Act and this part?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false What programs or activities are covered by the Act and this part? 1309.4 Section 1309.4 Conservation of Power and Water... purpose legislative body which: (i) Provides any benefits or assistance to persons based on age; or...

  19. 18 CFR 1309.4 - What programs or activities are covered by the Act and this part?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false What programs or activities are covered by the Act and this part? 1309.4 Section 1309.4 Conservation of Power and Water... purpose legislative body which: (i) Provides any benefits or assistance to persons based on age; or...

  20. 18 CFR 1309.4 - What programs or activities are covered by the Act and this part?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false What programs or activities are covered by the Act and this part? 1309.4 Section 1309.4 Conservation of Power and Water... purpose legislative body which: (i) Provides any benefits or assistance to persons based on age; or...

  1. Serial follow-up of presurgical treatment using pasireotide long-acting release with or without octreotide long-acting release for naïve active acromegaly.

    PubMed

    Chang, Jan-Shun; Tseng, Ham-Min; Chang, Tien-Chun

    2016-06-01

    The aim of the present study was to evaluate the serial changes of GH and IGF-1 in seven patients with naïve, active acromegaly following presurgical treatment of the somatostatin analog pasireotide long-acting release (LAR) and octreotide LAR. The patients were treated with pasireotide LAR with or without octreotide LAR for two years and underwent transsphenoidal adenomectomy. After treatment with the somatostatin analogs, the surgical cure rate was similar to that in patients who underwent transsphenoidal surgery alone. Diabetes insipidus was not identified in any patients after the operation. Pasireotide LAR was effective on GH as well as IGF-1 suppression and tumor size decreasing when used as the primary therapy. Future large-population studies to investigate the surgical curative rate after presurgical treatment with somatostatin analogs in patients with acromegaly and macroadenomas close to the cavernous sinus are warranted. However, that hyperglycemia developed following pre-surgical treatment with pasireotide should take into consideration. PMID:27117887

  2. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Final ACT configuration evaluation

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Final ACT Configuration Evaluation Task of the Integrated Application of Active Controls (IAAC) technology project within the energy efficient transport program is summarized. The Final ACT Configuration, through application of Active Controls Technology (ACT) in combination with increased wing span, exhibits significant performance improvements over the conventional baseline configuration. At the design range for these configurations, 3590 km, the block fuel used is 10% less for the Final ACT Configuration, with significant reductions in fuel usage at all operational ranges. Results of this improved fuel usage and additional system and airframe costs and the complexity required to achieve it were analyzed to determine its economic effects. For a 926 km mission, the incremental return on investment is nearly 25% at 1980 fuel prices. For longer range missions or increased fuel prices, the return is greater. The technical risks encountered in the Final ACT Configuration design and the research and development effort required to reduce these risks to levels acceptable for commercial airplane design are identified.

  3. Comparative effects of long-acting and short-acting loop diuretics on cardiac sympathetic nerve activity in patients with chronic heart failure

    PubMed Central

    Matsuo, Yae; Kasama, Shu; Toyama, Takuji; Funada, Ryuichi; Takama, Noriaki; Koitabashi, Norimichi; Ichikawa, Shuichi; Suzuki, Yasuyuki; Matsumoto, Naoya; Sato, Yuichi; Kurabayashi, Masahiko

    2016-01-01

    Objective Short-acting loop diuretics are known to enhance cardiac sympathetic nerve activity (CSNA) in patients with chronic heart failure (CHF). The effects of two loop diuretics—long-acting azosemide and short-acting furosemide—on CSNA were evaluated using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in patients with CHF. Methods The present study was a subanalysis of our previously published study, which had reported that serial 123I-MIBG studies were the most useful prognostic indicator in patients with CHF. Patients with CHF (n=208, left ventricular ejection fraction <45%) but no history of cardiac events for at least 5 months prior to the study were identified according to their histories of acute decompensated heart failure requiring hospitalisation. Patients underwent 123I-MIBG scintigraphy immediately before hospital discharge and at a 6-month follow-up. The delayed % denervation, delayed heart/mediastinum count (H/M) ratio and washout rate (WR) were determined using 123I-MIBG scintigraphy. A total of 108 patients were selected, and propensity score matching was used to compare patients treated with either oral azosemide (n=54) or furosemide (n=54). Results After treatment, 123I-MIBG scintigraphic parameters improved in both groups. However, the degree of change in % denervation was −13.8±10.5 in the azosemide group and −5.7±12.7 in the furosemide group (p<0.01), the change in H/M ratio was 0.20±0.16 in the azosemide group and 0.06±0.19 in the furosemide group (p<0.01), and the change in WR was −11.3±9.2% in the azosemide group and −3.0±12.7% in the furosemide group (p<0.01). Moreover, multivariate analysis showed an independent and significant positive relationship between furosemide and δ-WR from hospital discharge to 6 months after treatment in patients with CHF (p=0.001). Conclusions These findings indicate that azosemide suppresses CSNA compared with furosemide in patients with CHF. Trial registration number UMIN000000626

  4. S2F, a leaf-specific trans-acting factor, binds to a novel cis-acting element and differentially activates the RPL21 gene.

    PubMed Central

    Lagrange, T; Gauvin, S; Yeo, H J; Mache, R

    1997-01-01

    Tissue-specific factors control the differential expression of nuclear genes encoding plastid proteins. To identify some of these factors, the light-independent spinach RPL21 gene encoding the plastid ribosomal protein L21 was chosen as a model. The RPL21 promoter organization was defined by transient and stable transfections of RPL21 promoter deletion mutants fused to a reporter gene. The following results were obtained. (1) We identified a strong core promoter, spanning the transcription start site region, sufficient to drive high levels of gene expression. (2) We identified two non-overlapping positive and negative domains, located upstream from the core promoter region, that modulate core promoter activity independently of light. (3) We found that the positive domain contains a new cis-acting element, the S2 site, related to but different from the light-responsive GT-1 binding site. We show that the S2 site binds a leaf-specific nuclear factor (named S2F). The S2 site is conserved in the promoter region of many nuclear genes encoding plastid proteins. Experiments with transgenic tobacco plants confirmed that the S2 site is critical for positive domain activity in leaf tissues. The S2 site is thus identified as a new tissue-specific, light-independent regulatory element. PMID:9286115

  5. Does glaciation act to limit the topography of active mountain belts? Evidence from the Patagonian Andes

    NASA Astrophysics Data System (ADS)

    Thomson, S. N.

    2003-04-01

    Fission-track thermochronological analysis of the Patagonian Andes of southern Chile, particularly in the region of the major intra-arc Liquiñe-Ofqui transpressional fault zone (42° to 46°S), has revealed a complex pattern of late Cenozoic accelerated cooling. The fault zone has been the focus of localised enhanced cooling, attributed to denudation, since ca. 16 to 10 Ma. Several fault blocks can be identified, differentiated by their different cooling histories and total amounts of late Cenozoic cooling. The transpressional nature of this fault zone implies that enhanced cooling was caused by the preferential erosion of variably uplifting fault blocks that formed part of a large, possibly crustal scale "transpressional flower structure". Despite the spatially variable cooling rates and apparent differential denudation across the different fault blocks, the topography (particularly mean and maximum elevation) across these fault blocks is relatively uniform. This implies that this landscape is close to topographic steady-state, such that denudation has managed to approximately balance transpression related rock uplift, despite the spatial variability of the latter during the late Cenozoic. The most dominant denudation process in the Patagonian Andes is glacial erosion. Late Cenozoic glaciation in Patagonia is well known from studies made on the Patagonian ice fields (the third largest in the World). For example, values for the mean equilibrium line altitude (the altitude where annual glacial accumulation and ablation are the same - roughly equivalent to the snowline) can be cited for both the present day and the last glacial maximum. Incorporating these values in to a quantitative analysis of the topography across the different fault blocks using DEM data supports ideas outlined by Brozovic et al. (1997) who quote that where active mountain belts intersect the snowline, the high rates of glacial erosion processes can act at rates sufficient to place a limit on

  6. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Test act system validation

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The primary objective of the Test Active Control Technology (ACT) System laboratory tests was to verify and validate the system concept, hardware, and software. The initial lab tests were open loop hardware tests of the Test ACT System as designed and built. During the course of the testing, minor problems were uncovered and corrected. Major software tests were run. The initial software testing was also open loop. These tests examined pitch control laws, wing load alleviation, signal selection/fault detection (SSFD), and output management. The Test ACT System was modified to interface with the direct drive valve (DDV) modules. The initial testing identified problem areas with DDV nonlinearities, valve friction induced limit cycling, DDV control loop instability, and channel command mismatch. The other DDV issue investigated was the ability to detect and isolate failures. Some simple schemes for failure detection were tested but were not completely satisfactory. The Test ACT System architecture continues to appear promising for ACT/FBW applications in systems that must be immune to worst case generic digital faults, and be able to tolerate two sequential nongeneric faults with no reduction in performance. The challenge in such an implementation would be to keep the analog element sufficiently simple to achieve the necessary reliability.

  7. Organizational integrity of entities that are implementing programs and activities under the Leadership Act. Final rule.

    PubMed

    2010-04-13

    The Department is issuing a final rule establishing the organizational integrity requirements for Federal funding recipients under the United States Leadership Against HIV/AIDS, Tuberculosis, and Malaria Act of 2003 (Leadership Act). This rule requires that funding announcements and agreements with funding recipients include a clause that states that the recipient is opposed to prostitution and sex trafficking because of the psychological and physical risks they pose for women, men and children. This rule also modifies the requirements for recipient-affiliate separation and eliminates the requirement for an additional certification by funding recipients.

  8. Organizational integrity of entities that are implementing programs and activities under the Leadership Act. Final rule.

    PubMed

    2010-04-13

    The Department is issuing a final rule establishing the organizational integrity requirements for Federal funding recipients under the United States Leadership Against HIV/AIDS, Tuberculosis, and Malaria Act of 2003 (Leadership Act). This rule requires that funding announcements and agreements with funding recipients include a clause that states that the recipient is opposed to prostitution and sex trafficking because of the psychological and physical risks they pose for women, men and children. This rule also modifies the requirements for recipient-affiliate separation and eliminates the requirement for an additional certification by funding recipients. PMID:20387319

  9. The C-terminal domain of the bacterial SSB protein acts as a DNA maintenance hub at active chromosome replication forks.

    PubMed

    Costes, Audrey; Lecointe, François; McGovern, Stephen; Quevillon-Cheruel, Sophie; Polard, Patrice

    2010-01-01

    We have investigated in vivo the role of the carboxy-terminal domain of the Bacillus subtilis Single-Stranded DNA Binding protein (SSB(Cter)) as a recruitment platform at active chromosomal forks for many proteins of the genome maintenance machineries. We probed this SSB(Cter) interactome using GFP fusions and by Tap-tag and biochemical analysis. It includes at least 12 proteins. The interactome was previously shown to include PriA, RecG, and RecQ and extended in this study by addition of DnaE, SbcC, RarA, RecJ, RecO, XseA, Ung, YpbB, and YrrC. Targeting of YpbB to active forks appears to depend on RecS, a RecQ paralogue, with which it forms a stable complex. Most of these SSB partners are conserved in bacteria, while others, such as the essential DNA polymerase DnaE, YrrC, and the YpbB/RecS complex, appear to be specific to B. subtilis. SSB(Cter) deletion has a moderate impact on B. subtilis cell growth. However, it markedly affects the efficiency of repair of damaged genomic DNA and arrested replication forks. ssbΔCter mutant cells appear deficient in RecA loading on ssDNA, explaining their inefficiency in triggering the SOS response upon exposure to genotoxic agents. Together, our findings show that the bacterial SSB(Cter) acts as a DNA maintenance hub at active chromosomal forks that secures their propagation along the genome. PMID:21170359

  10. A propagation of error analysis of the enzyme activity expression. A model for determining the total system random error of a kinetic enzyme analyzer.

    PubMed

    Tiffany, T O; Thayer, P C; Coelho, C M; Manning, G B

    1976-09-01

    We present a total system error evaluation of random error, based on a propagation of error analysis of the expression for the calculation of enzyme activity. A simple expression is derived that contains terms for photometric error, timing uncertainty, temperature-control error, sample and reagent volume errors, and pathlength error. This error expression was developed in general to provide a simple means of evaluating the magnitude of random error in an analytical system and in particular to provide an error evaluation protocol for the assessment of the error components in a prototype Miniature Centrifugal Analyzer system. Individual system components of error are measured. These measured error components are combined in the error expressiion to predict performance. Enzyme activity measurements are made to correlate with the projected error data. In conclusion, it is demonstrated that this is one method for permitting the clinical chemist and the instrument manufacturer to establish reasonable error limits. PMID:954193

  11. Flexibility and Coordination among Acts of Visualization and Analysis in a Pattern Generalization Activity

    ERIC Educational Resources Information Center

    Nilsson, Per; Juter, Kristina

    2011-01-01

    This study aims at exploring processes of flexibility and coordination among acts of visualization and analysis in students' attempt to reach a general formula for a three-dimensional pattern generalizing task. The investigation draws on a case-study analysis of two 15-year-old girls working together on a task in which they are asked to calculate…

  12. Membrane binding events in the initiation and propagation phases of tissue factor-initiated zymogen activation under flow.

    PubMed

    Haynes, Laura M; Dubief, Yves C; Mann, Kenneth G

    2012-02-17

    This study investigates the dynamics of zymogen activation when both extrinsic tenase and prothrombinase are assembled on an appropriate membrane. Although the activation of prothrombin by surface-localized prothrombinase is clearly mediated by flow-induced dilutional effects, we find that when factor X is activated in isolation by surface-localized extrinsic tenase, it exhibits characteristics of diffusion-mediated activation in which diffusion of substrate to the catalytically active region is rate-limiting. When prothrombin and factor X are activated coincident with each other, competition for available membrane binding sites masks the diffusion-limiting effects of factor X activation. To verify the role of membrane binding in the activation of factor X by extrinsic tenase under flow conditions, we demonstrate that bovine lactadherin competes for both factor X and Xa binding sites, limiting factor X activation and forcing the release of bound factor Xa from the membrane at a venous shear rate (100 s(-1)). Finally, we present steady-state models of prothrombin and factor X activation under flow showing that zymogen and enzyme membrane binding events further regulate the coagulation process in an open system representative of the vasculature geometry.

  13. 29 CFR 779.110 - Employees in retailing whose activities may bring them under the Act.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... retail or service field whose individual activities constitute engagement in interstate or foreign... individual activities ordinarily constitute engagement in commerce or in the production of goods for...

  14. Annual Report to the President and the Congress on Federal Activities Related to the Administration of the Rehabilitation Act of 1973, as Amended. Fiscal Year 1981. Executive Summary.

    ERIC Educational Resources Information Center

    Rehabilitation Services Administration (ED), Washington, DC.

    The fiscal year 1981 annual report of the Rehabilitation Services Administration's activities under the Rehabilitation Act of 1973, as amended, is presented; program operations, program development activities, functions of the National Institute of Handicapped Research, and other provisions of the Act, are described. Program operations include:…

  15. [Clinical study of prejudicing autochthonous speech act (thought)--acceleration of the activity in the remission process of schizophrenia].

    PubMed

    Kato, S

    1997-01-01

    Schizophrenics occasionally experience guilty feeling at having insulted someone such as having said "You fool" or "Die" to a new acquaintance. They also experience guilty feeling from autochthonous thought, a feeling of having prejudiced his neighbour. This latter autochthonous thought is considered to be closely related with the former prejudicing speech act. The author would provisionally call these phenomenons of prejudice, prejudicing autochthonous speech act (or prejudicing autochthonous thought), particularly in the case in which the object of prejudice is an intimate real other, or a co-presenting other. Based on his own nine cases, the author has first described the clinical characteristics of this symptom, and then developed psychopathological considerations to draw a attention to the therapeutic importance of this symptom. On the symptomatological ground, the prejudicing autochthonous speech act (thought) belongs to psychomotor verbal hallucinations (J. Séglas), more precisely to the soliloquy type of this hallucination. On the clinical ground, this symptom is likely to follow auditory hallucination caused by an acute state or that of recovery period from this state. Furthermore, it is not infrequent that general improvement as well as remission follow the appearance of this symptom. This symptomatological change of the center of gravity, that is, the gradual transition from auditory hallucination to prejudicing autochthonous speech act (thought) is considered to correspond to a change of the patient's position in relation to others. This position, once experienced passively, is now experienced actively. In other words, the patient, coming out of an acute psychotic state and opening to an intersubjective world, is confronted with a high tension relationship with others. The prejudicing autochthonous speech act (thought) appears in this situation, to restore the patient's own subjectivity in coping with the pressure of real others. In this case, this

  16. Advanced Communications Technology Satellite (ACTS)

    NASA Technical Reports Server (NTRS)

    Schertler, Ronald J.; Gedney, Richard T.

    1992-01-01

    An overview of the NASA ACTS program is presented. The key technologies of ACTS include spot beams, on-board baseband processing and routing, wide bandwidth (900 MHz), and Ka-band transponders. The discussion covers system description, current status of the spacecraft development, ACTS earth stations, NGS traffic terminal, USAT, land and aeronautical mobiles, high data rate and propagation receive only terminals, and ACTS experiments program.

  17. Photoelectron circular dichroism in the multiphoton ionization by short laser pulses. I. Propagation of single-active-electron wave packets in chiral pseudo-potentials

    SciTech Connect

    Artemyev, Anton N.; Müller, Anne D.; Demekhin, Philipp V.; Hochstuhl, David

    2015-06-28

    A theoretical method to study the angle-resolved multiphoton ionization of polyatomic molecules is developed. It is based on the time-dependent formulation of the Single Center (TDSC) method and consists in the propagation of single-active-electron wave packets in the effective molecular potentials in the presence of intense laser pulses. For this purpose, the time-dependent Schrödinger equation for one electron, moving in a molecular field and interacting with an arbitrary laser pulse, is solved in spherical coordinates by an efficient numerical approach. As a test, the method is applied to the one- and two-photon ionizations of a model methane-like chiral system by circularly polarized short intense high-frequency laser pulses. Thereby, we analyze the photoelectron circular dichroism (PECD) in the momentum distribution. The considered model application illustrates the capability of the TDSC method to study multiphoton PECD in fixed-in-space and randomly oriented chiral molecules.

  18. Forgetting ACT UP

    ERIC Educational Resources Information Center

    Juhasz, Alexandra

    2012-01-01

    When ACT UP is remembered as the pinnacle of postmodern activism, other forms and forums of activism that were taking place during that time--practices that were linked, related, just modern, in dialogue or even opposition to ACT UP's "confrontational activism"--are forgotten. In its time, ACT UP was embedded in New York City, and a larger world,…

  19. Clinical evaluation of the i-STAT kaolin activated clotting time (ACT) test in different clinical settings in a large academic urban medical center: comparison with the Medtronic ACT Plus.

    PubMed

    Lewandrowski, Elizabeth Lee; Van Cott, Elizabeth M; Gregory, Kimberly; Jang, Ik-Kyung; Lewandrowski, Kent B

    2011-05-01

    Historically, it has been difficult for hospitals to change methods for activated clotting time (ACT) testing because of differences in ACT values obtained with different instruments, wide differences in target ranges used in different procedures, and the difficulty of performing crossover studies at the bedside in critical care situations. There are limited published data comparing the i-STAT (Abbott Point of Care, Princeton, NJ) kaolin ACT with the Medtronic ACT Plus (Medtronic, Minneapolis, MN). The i-STAT system can perform ACT testing in addition to testing of a number of critical care analytes and may offer potential advantages over other ACT analyzers. Comparison of ACT values on 121 simultaneous split-sample tests yielded an R(2) of 0.88 with i-STAT = 0.79 Medtronic + 72.0. The Pearson correlation was R = 0.94, indicating statistically significant correlation between the 2 methods. Based on this comparison, we were able to implement the i-STAT ACT throughout our institution without changing target ranges for any individual procedure. PMID:21502428

  20. Effect of realistic grounds and atmospheric conditions on single-channel active control of outdoor sound propagation

    NASA Astrophysics Data System (ADS)

    Nakashima, Ann; Hodgson, Murray

    2005-03-01

    Engine run-up tests are a part of routine aircraft maintenance at the Vancouver International Airport. A source of noise complaints is the Dash-8 aircraft, which emits low-frequency, tonal noise. Active noise control is a potentially cost-effective alternative to passive noise-control methods, which are ineffective at controlling low-frequency noise. Since the run-up tests are performed outdoors, the effects of outdoor conditions on the performance of an active control system must be considered. In this paper, the results of a preliminary investigation of the effects of realistic meteorological conditions and ground impedance on the performance of a single-channel active-control system are presented. Computer simulations of single-channel active control of a monopole source were performed using the Green's-function parabolic-equation method. Different realistic atmospheric conditions, and reflective or soft ground, were used in the simulations. The results show that atmospheric refraction causes fluctuations in the noise attenuation achieved by a single-channel control system, and has the overall effect of decreasing its performance, making the system ineffective in some cases. .

  1. 76 FR 57799 - Agency Information Collection Activities; Proposal That Electronic Filing of Bank Secrecy Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ..., tax, and regulatory matters, or in the conduct of intelligence or counter-intelligence activities to... scope of the BSA to intelligence or counter-intelligence activities to protect against international... FR 42405, 42407-9 (July 21, 2008). Current Action: In support of Treasury's paperless initiative...

  2. A balancing act of the brain: activations and deactivations driven by cognitive load

    PubMed Central

    Arsalidou, Marie; Pascual-Leone, Juan; Johnson, Janice; Morris, Drew; Taylor, Margot J

    2013-01-01

    The majority of neuroimaging studies focus on brain activity during performance of cognitive tasks; however, some studies focus on brain areas that activate in the absence of a task. Despite the surge of research comparing these contrasted areas of brain function, their interrelation is not well understood. We systematically manipulated cognitive load in a working memory task to examine concurrently the relation between activity elicited by the task versus activity during control conditions. We presented adults with six levels of task demand, and compared those with three conditions without a task. Using whole-brain analysis, we found positive linear relations between cortical activity and task difficulty in areas including middle frontal gyrus and dorsal cingulate; negative linear relations were found in medial frontal gyrus and posterior cingulate. These findings demonstrated balancing of activation patterns between two mental processes, which were both modulated by task difficulty. Frontal areas followed a graded pattern more closely than other regions. These data also showed that working memory has limited capacity in adults: an upper bound of seven items and a lower bound of four items. Overall, working memory and default-mode processes, when studied concurrently, reveal mutually competing activation patterns. PMID:23785659

  3. Benevolent sexist ideology attributed to an abusive partner decreases women's active coping responses to acts of sexual violence.

    PubMed

    Durán, Mercedes; Moya, Miguel; Megías, Jesús L

    2014-05-01

    This article describes three studies in which we explored the influence of the sexist ideology attributed to the perpetrator on women's responses to hypothetical acts of sexual assault perpetrated by male intimate partners. In Study 1 (n = 83), college women read three sexual assault scenarios in the context of an intimate relationship. The male partner's sexist ideology (benevolent, hostile, or control) was manipulated within participants. Women showed less active responses when the partner had been described as a benevolent sexist man. This effect was replicated in Study 2 (n = 103), which showed a relationship between women's less active responses and the belief that benevolent sexist men are very attracted to and interested in their partners. Study 3 (n = 130) demonstrated experimentally that women's responses are less active when they are exposed to information that indicates that the perpetrator is both high in benevolent sexism and highly attracted to his victim than when the latter information is not provided. Results suggest that sexist ideology and particularly benevolent sexism-attributed to the perpetrator in this case-is highly important in women's reactions to acts of sexual violence perpetrated by male intimate partners.

  4. Application of the French Space Operation Act and the Development of Space Activities in the Field of Launchers

    NASA Astrophysics Data System (ADS)

    Cahuzac, F.; Biard, A.

    2012-01-01

    The development of space activities has led France to define a new legal framework: French Space Operation Act (FSOA). The aim of this act, is to define the conditions according to which the French government authorizes and checks the spatial operations under its jurisdiction or its international responsibility as State of launch, according to the international treaties of the UN on space, in particular the Treaty (1967) on Principles Governing the Activities of States in the Exploration and Use of Outer Space, the Convention ( 1972 ) on International Liability for Damage Caused by Space Objects, and the Convention (1975) on Registration of Objects Launched into Outer Space. The main European space centre is the Guiana Space Centre (CSG), settled in France. A clarification of the French legal framework was compulsory to allow the arrival of new launchers (Soyuz and Vega). This act defines the competent authority, the procedure of authorization and licenses, the regime for operations led from foreign countries, the control of spatial objects, the enabling of inspectors, the delegation of monitoring to CNES, the procedure for urgent measures necessary for the safety, the registration of spatial objects. In this framework, the operator is fully responsible of the operation that he leads. He is subjected to a regime of authorization and to governmental technical monitoring delegated to CNES. In case of litigation, the operator gets the State guarantee above a certain level of damage to third party. The introduction of FSOA has led to issue a Technical Regulation set forth, in particular for the safety of persons and property, the protection of public health and the environment. This general regulation is completed by a specific regulation applicable to CSG that covers the preparation phase of the launch, and all specificities of the launch range, as regards the beginning of the launch. The Technical Regulation is based on 30 years of Ariane's activities and on the

  5. Reduced intercellular coupling leads to paradoxical propagation across the Purkinje-ventricular junction and aberrant myocardial activation

    PubMed Central

    Morley, Gregory E.; Danik, Stephan B.; Bernstein, Scott; Sun, Yanjie; Rosner, Gregg; Gutstein, David E.; Fishman, Glenn I.

    2005-01-01

    Ventricular tachycardia is a common heart rhythm disorder and a frequent cause of sudden cardiac death. Aberrant cell–cell coupling through gap junction channels, a process termed gap junction remodeling, is observed in many of the major forms of human heart disease and is associated with increased arrhythmic risk in both humans and in animal models. Genetically engineered mice with cardiac-restricted knockout of Connexin43, the major cardiac gap junctional protein, uniformly develop sudden cardiac death, although a detailed electrophysiological understanding of their profound arrhythmic propensity is unclear. Using voltage-sensitive dyes and high resolution optical mapping techniques, we found that uncoupling of the ventricular myocardium results in ectopic sites of ventricular activation. Our data indicate that this behavior reflects alterations in source-sink relationships and paradoxical conduction across normally quiescent Purkinje-ventricular muscle junctions. The aberrant activation profiles are associated with wavefront collisions, which in the setting of slow conduction may account for the highly arrhythmogenic behavior of Connexin43-deficient hearts. Thus, the extent of gap junction remodeling in diseased myocardium is a critical determinant of cardiac excitation patterns and arrhythmia susceptibility. PMID:15753312

  6. Reduced intercellular coupling leads to paradoxical propagation across the Purkinje-ventricular junction and aberrant myocardial activation.

    PubMed

    Morley, Gregory E; Danik, Stephan B; Bernstein, Scott; Sun, Yanjie; Rosner, Gregg; Gutstein, David E; Fishman, Glenn I

    2005-03-15

    Ventricular tachycardia is a common heart rhythm disorder and a frequent cause of sudden cardiac death. Aberrant cell-cell coupling through gap junction channels, a process termed gap junction remodeling, is observed in many of the major forms of human heart disease and is associated with increased arrhythmic risk in both humans and in animal models. Genetically engineered mice with cardiac-restricted knockout of Connexin43, the major cardiac gap junctional protein, uniformly develop sudden cardiac death, although a detailed electrophysiological understanding of their profound arrhythmic propensity is unclear. Using voltage-sensitive dyes and high resolution optical mapping techniques, we found that uncoupling of the ventricular myocardium results in ectopic sites of ventricular activation. Our data indicate that this behavior reflects alterations in source-sink relationships and paradoxical conduction across normally quiescent Purkinje-ventricular muscle junctions. The aberrant activation profiles are associated with wavefront collisions, which in the setting of slow conduction may account for the highly arrhythmogenic behavior of Connexin43-deficient hearts. Thus, the extent of gap junction remodeling in diseased myocardium is a critical determinant of cardiac excitation patterns and arrhythmia susceptibility. PMID:15753312

  7. Cdk1 activity acts as a quantitative platform for coordinating cell cycle progression with periodic transcription

    PubMed Central

    Banyai, Gabor; Baïdi, Feriel; Coudreuse, Damien; Szilagyi, Zsolt

    2016-01-01

    Cell proliferation is regulated by cyclin-dependent kinases (Cdks) and requires the periodic expression of particular gene clusters in different cell cycle phases. However, the interplay between the networks that generate these transcriptional oscillations and the core cell cycle machinery remains largely unexplored. In this work, we use a synthetic regulable Cdk1 module to demonstrate that periodic expression is governed by quantitative changes in Cdk1 activity, with different clusters directly responding to specific activity levels. We further establish that cell cycle events neither participate in nor interfere with the Cdk1-driven transcriptional program, provided that cells are exposed to the appropriate Cdk1 activities. These findings contrast with current models that propose self-sustained and Cdk1-independent transcriptional oscillations. Our work therefore supports a model in which Cdk1 activity serves as a quantitative platform for coordinating cell cycle transitions with the expression of critical genes to bring about proper cell cycle progression. PMID:27045731

  8. PP2A and GSK-3beta act antagonistically to regulate active zone development.

    PubMed

    Viquez, Natasha M; Füger, Petra; Valakh, Vera; Daniels, Richard W; Rasse, Tobias M; DiAntonio, Aaron

    2009-09-16

    The synapse is composed of an active zone apposed to a postsynaptic cluster of neurotransmitter receptors. Each Drosophila neuromuscular junction comprises hundreds of such individual release sites apposed to clusters of glutamate receptors. Here, we show that protein phosphatase 2A (PP2A) is required for the development of structurally normal active zones opposite glutamate receptors. When PP2A is inhibited presynaptically, many glutamate receptor clusters are unapposed to Bruchpilot (Brp), an active zone protein required for normal transmitter release. These unapposed receptors are not due to presynaptic retraction of synaptic boutons, since other presynaptic components are still apposed to the entire postsynaptic specialization. Instead, these data suggest that Brp localization is regulated at the level of individual release sites. Live imaging of glutamate receptors demonstrates that this disruption to active zone development is accompanied by abnormal postsynaptic development, with decreased formation of glutamate receptor clusters. Remarkably, inhibition of the serine-threonine kinase GSK-3beta completely suppresses the active zone defect, as well as other synaptic morphology phenotypes associated with inhibition of PP2A. These data suggest that PP2A and GSK-3beta function antagonistically to control active zone development, providing a potential mechanism for regulating synaptic efficacy at a single release site.

  9. Nonlinear biochemical signal processing via noise propagation

    NASA Astrophysics Data System (ADS)

    Kim, Kyung Hyuk; Qian, Hong; Sauro, Herbert M.

    2013-10-01

    Single-cell studies often show significant phenotypic variability due to the stochastic nature of intra-cellular biochemical reactions. When the numbers of molecules, e.g., transcription factors and regulatory enzymes, are in low abundance, fluctuations in biochemical activities become significant and such "noise" can propagate through regulatory cascades in terms of biochemical reaction networks. Here we develop an intuitive, yet fully quantitative method for analyzing how noise affects cellular phenotypes based on identifying a system's nonlinearities and noise propagations. We observe that such noise can simultaneously enhance sensitivities in one behavioral region while reducing sensitivities in another. Employing this novel phenomenon we designed three biochemical signal processing modules: (a) A gene regulatory network that acts as a concentration detector with both enhanced amplitude and sensitivity. (b) A non-cooperative positive feedback system, with a graded dose-response in the deterministic case, that serves as a bistable switch due to noise-induced ultra-sensitivity. (c) A noise-induced linear amplifier for gene regulation that requires no feedback. The methods developed in the present work allow one to understand and engineer nonlinear biochemical signal processors based on fluctuation-induced phenotypes.

  10. Nonlinear biochemical signal processing via noise propagation.

    PubMed

    Kim, Kyung Hyuk; Qian, Hong; Sauro, Herbert M

    2013-10-14

    Single-cell studies often show significant phenotypic variability due to the stochastic nature of intra-cellular biochemical reactions. When the numbers of molecules, e.g., transcription factors and regulatory enzymes, are in low abundance, fluctuations in biochemical activities become significant and such "noise" can propagate through regulatory cascades in terms of biochemical reaction networks. Here we develop an intuitive, yet fully quantitative method for analyzing how noise affects cellular phenotypes based on identifying a system's nonlinearities and noise propagations. We observe that such noise can simultaneously enhance sensitivities in one behavioral region while reducing sensitivities in another. Employing this novel phenomenon we designed three biochemical signal processing modules: (a) A gene regulatory network that acts as a concentration detector with both enhanced amplitude and sensitivity. (b) A non-cooperative positive feedback system, with a graded dose-response in the deterministic case, that serves as a bistable switch due to noise-induced ultra-sensitivity. (c) A noise-induced linear amplifier for gene regulation that requires no feedback. The methods developed in the present work allow one to understand and engineer nonlinear biochemical signal processors based on fluctuation-induced phenotypes.

  11. The universal propagator

    NASA Technical Reports Server (NTRS)

    Klauder, John R.

    1993-01-01

    For a general Hamiltonian appropriate to a single canonical degree of freedom, a universal propagator with the property that it correctly evolves the coherent-state Hilbert space representatives for an arbitrary fiducial vector is characterized and defined. The universal propagator is explicitly constructed for the harmonic oscillator, with a result that differs from the conventional propagators for this system.

  12. Balancing act: approaches to healthy eating and physical activity among Boston public housing residents.

    PubMed

    Scammell, Madeleine Kangsen; Torres, Shioban; Wayman, Julie; Greenwood, Nechama; Thomas, Gerry; Kozlowski, Lauren; Bowen, Deborah

    2015-01-01

    Boston public housing residents are more likely to report fair or poor health status, been diagnosed with obesity, and to be physically inactive compared with other Boston residents (Digenis-Bury, Brooks, Chen, Ostrem, & Horsburgh, 2008 ). Little is known about perceptions of and opportunities for healthy eating and physical activity in this population. We conducted eight focus groups at public housing developments to explore residents' views regarding opportunities and barriers to healthy eating and physical activity. Sixty-seven English- and Spanish-speaking residents participated. Transcripts were analyzed using qualitative content analysis. All residents described the challenge of balancing considerations of food quality, access, and affordability. Other findings included underutilized nutritional resources; abundant availability of unhealthy food; and economic and structural barriers to exercise. Transportation-related challenges were a dominant theme. Building opportunities for physical activity and providing access to affordable and quality food choices may be important interventions for promoting health among public housing residents.

  13. Leinamycin E1 acting as an anticancer prodrug activated by reactive oxygen species

    PubMed Central

    Huang, Sheng-Xiong; Yun, Bong-Sik; Ma, Ming; Basu, Hirak S.; Church, Dawn R.; Ingenhorst, Gudrun; Huang, Yong; Yang, Dong; Lohman, Jeremy R.; Tang, Gong-Li; Ju, Jianhua; Liu, Tao; Wilding, George; Shen, Ben

    2015-01-01

    Leinamycin (LNM) is a potent antitumor antibiotic produced by Streptomyces atroolivaceus S-140, featuring an unusual 1,3-dioxo-1,2-dithiolane moiety that is spiro-fused to a thiazole-containing 18-membered lactam ring. Upon reductive activation in the presence of cellular thiols, LNM exerts its antitumor activity by an episulfonium ion-mediated DNA alkylation. Previously, we have cloned the lnm gene cluster from S. atroolivaceus S-140 and characterized the biosynthetic machinery responsible for the 18-membered lactam backbone and the alkyl branch at C3 of LNM. We now report the isolation and characterization of leinamycin E1 (LNM E1) from S. atroolivacues SB3033, a ΔlnmE mutant strain of S. atroolivaceus S-140. Complementary to the reductive activation of LNM by cellular thiols, LNM E1 can be oxidatively activated by cellular reactive oxygen species (ROS) to generate a similar episulfonium ion intermediate, thereby alkylating DNA and leading to eventual cell death. The feasibility of exploiting LNM E1 as an anticancer prodrug activated by ROS was demonstrated in two prostate cancer cell lines, LNCaP and DU-145. Because many cancer cells are under higher cellular oxidative stress with increased levels of ROS than normal cells, these findings support the idea of exploiting ROS as a means to target cancer cells and highlight LNM E1 as a novel lead for the development of anticancer prodrugs activated by ROS. The structure of LNM E1 also reveals critical new insights into LNM biosynthesis, setting the stage to investigate sulfur incorporation, as well as the tailoring steps that convert the nascent hybrid peptide–polyketide biosynthetic intermediate into LNM. PMID:26056295

  14. Introducing endo-xylanase activity into an exo-acting arabinofuranosidase that targets side chains.

    PubMed

    McKee, Lauren S; Peña, Maria J; Rogowski, Artur; Jackson, Adam; Lewis, Richard J; York, William S; Krogh, Kristian B R M; Viksø-Nielsen, Anders; Skjøt, Michael; Gilbert, Harry J; Marles-Wright, Jon

    2012-04-24

    The degradation of the plant cell wall by glycoside hydrolases is central to environmentally sustainable industries. The major polysaccharides of the plant cell wall are cellulose and xylan, a highly decorated β-1,4-xylopyranose polymer. Glycoside hydrolases displaying multiple catalytic functions may simplify the enzymes required to degrade plant cell walls, increasing the industrial potential of these composite structures. Here we test the hypothesis that glycoside hydrolase family 43 (GH43) provides a suitable scaffold for introducing additional catalytic functions into enzymes that target complex structures in the plant cell wall. We report the crystal structure of Humicola insolens AXHd3 (HiAXHd3), a GH43 arabinofuranosidase that hydrolyses O3-linked arabinose of doubly substituted xylans, a feature of the polysaccharide that is recalcitrant to degradation. HiAXHd3 displays an N-terminal five-bladed β-propeller domain and a C-terminal β-sandwich domain. The interface between the domains comprises a xylan binding cleft that houses the active site pocket. Substrate specificity is conferred by a shallow arabinose binding pocket adjacent to the deep active site pocket, and through the orientation of the xylan backbone. Modification of the rim of the active site introduces endo-xylanase activity, whereas the resultant enzyme variant, Y166A, retains arabinofuranosidase activity. These data show that the active site of HiAXHd3 is tuned to hydrolyse arabinofuranosyl or xylosyl linkages, and it is the topology of the distal regions of the substrate binding surface that confers specificity. This report demonstrates that GH43 provides a platform for generating bespoke multifunctional enzymes that target industrially significant complex substrates, exemplified by the plant cell wall.

  15. Caught in the act: covalent cross-linking captures activator-coactivator interactions in vivo.

    PubMed

    Krishnamurthy, Malathy; Dugan, Amanda; Nwokoye, Adaora; Fung, Yik-Hong; Lancia, Jody K; Majmudar, Chinmay Y; Mapp, Anna K

    2011-12-16

    Currently there are few methods suitable for the discovery and characterization of transient, moderate affinity protein-protein interactions in their native environment, despite their prominent role in a host of cellular functions including protein folding, signal transduction, and transcriptional activation. Here we demonstrate that a genetically encoded photoactivatable amino acid, p-benzoyl-l-phenylalanine, can be used to capture transient and/or low affinity binding partners in an in vivo setting. In this study, we focused on ensnaring the coactivator binding partners of the transcriptional activator VP16 in S. cerevisiae. The interactions between transcriptional activators and coactivators in eukaryotes are moderate in affinity and short-lived, and due in part to these characteristics, identification of the direct binding partners of activators in vivo has met with only limited success. We find through in vivo photo-cross-linking that VP16 contacts the Swi/Snf chromatin-remodeling complex through the ATPase Snf2(BRG1/BRM) and the subunit Snf5 with two distinct regions of the activation domain. An analogous experiment with Gal4 reveals that Snf2 is also a target of this activator. These results suggest that Snf2 may be a valuable target for small molecule probe discovery given the prominent role the Swi/Snf complex family plays in development and in disease. More significantly, the successful implementation of the in vivo cross-linking methodology in this setting demonstrates that it can be applied to the discovery and characterization of a broad range of transient and/or modest affinity protein-protein interactions. PMID:21977905

  16. The Clean Water Act

    SciTech Connect

    Piatt, J.

    1995-12-31

    The Federal Water Pollution Control Act, commonly called the Clean Water Act (CWA), was adopted on 18 October 1972. Since then it has been amended 18 times, the last amendments were adopted on 4 February 1987. As established, its objective is: to restore and maintain the chemical, physical, and biological integrity of the Nation`s waters. And has, as an interim goal: water quality which provides for the protection and propagation of fish, shellfish, and wildlife and provides for recreation in and on the water. It should be noted that Congress established as the Act`s ultimate goal: the discharge of pollutants into the navigable waters be eliminated. The Act set out to meet this lofty objective and goal through the development and implementation of controls on the point source discharges and the nonpoint source release of pollutants. The regulation of point and nonpoint sources as well as future requirements are discussed.

  17. 77 FR 35323 - National Environmental Policy Act: Categorical Exclusions for Soil and Water Restoration Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... for Soil and Water Restoration Activities AGENCY: Forest Service, USDA. ACTION: Notice of proposed... effects of soil and water restoration projects that are intended to restore the flow of waters into... lands occupied by roads and trails to natural conditions. The proposed road and trail...

  18. 78 FR 56153 - National Environmental Policy Act: Categorical Exclusions for Soil and Water Restoration Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ... was published in the Federal Register on June 13, 2012 (77 FR 35323), for a 60-day comment period. The... effect on the environment (48 FR 34263), also see 40 CFR 1500... for Soil and Water Restoration Activities AGENCY: Forest Service, USDA. ACTION: Final rule....

  19. Two different factors act separately or together to specify functionally distinct activities at a single transcriptional enhancer.

    PubMed Central

    DeFranco, D; Yamamoto, K R

    1986-01-01

    The expression of genes fused downstream of the Moloney murine sarcoma virus (MoMSV) long terminal repeat is stimulated by glucocorticoids. We mapped the glucocorticoid response element that conferred this hormonal regulation and found that it is a hormone-dependent transcriptional enhancer, designated Sg; it resides within DNA fragments that also carry a previously described enhancer element (B. Levinson, G. Khoury, G. Vande Woude, and P. Gruss, Nature [London] 295:568-572, 1982), here termed Sa, whose activity is independent of the hormone. Nuclease footprinting revealed that purified glucocorticoid receptor bound at multiple discrete sites within and at the borders of the tandemly repeated sequence motif that defines Sa. The Sa and Sg activities stimulated the apparent efficiency of cognate or heterologous promoter utilization, individually providing modest enhancement and in concert yielding higher levels of activity. A deletion mutant lacking most of the tandem repeat but retaining a single receptor footprint sequence lost Sa activity but still conferred Sg activity. The two enhancer components could also be distinguished physiologically: both were operative within cultured rat fibroblasts, but only Sg activity was detectable in rat exocrine pancreas cells. Therefore, the sequence determinants of Sa and Sg activity may be interdigitated, and when both components are active, the receptor and a putative Sa factor can apparently bind and act simultaneously. We concluded that MoMSV enhancer activity is effected by at least two distinct binding factors, suggesting that combinatorial regulation of promoter function can be mediated even from a single genetic element. Images PMID:3023887

  20. The calcium-activated chloride channel anoctamin 1 acts as a heat sensor in nociceptive neurons.

    PubMed

    Cho, Hawon; Yang, Young Duk; Lee, Jesun; Lee, Byeongjoon; Kim, Tahnbee; Jang, Yongwoo; Back, Seung Keun; Na, Heung Sik; Harfe, Brian D; Wang, Fan; Raouf, Ramin; Wood, John N; Oh, Uhtaek

    2012-05-27

    Nociceptors are a subset of small primary afferent neurons that respond to noxious chemical, thermal and mechanical stimuli. Ion channels in nociceptors respond differently to noxious stimuli and generate electrical signals in different ways. Anoctamin 1 (ANO1 also known as TMEM16A) is a Ca(2+)-activated chloride channel that is essential for numerous physiological functions. We found that ANO1 was activated by temperatures over 44 °C with steep heat sensitivity. ANO1 was expressed in small sensory neurons and was highly colocalized with nociceptor markers, which suggests that it may be involved in nociception. Application of heat ramps to dorsal root ganglion (DRG) neurons elicited robust ANO1-dependent depolarization. Furthermore, knockdown or deletion of ANO1 in DRG neurons substantially reduced nociceptive behavior in thermal pain models. These results indicate that ANO1 is a heat sensor that detects nociceptive thermal stimuli in sensory neurons and possibly mediates nociception.

  1. Hepatitis C Virus RNA Replication Depends on Specific Cis- and Trans-Acting Activities of Viral Nonstructural Proteins

    PubMed Central

    Kazakov, Teymur; Yang, Feng; Ramanathan, Harish N.; Kohlway, Andrew; Diamond, Michael S.; Lindenbach, Brett D.

    2015-01-01

    Many positive-strand RNA viruses encode genes that can function in trans, whereas other genes are required in cis for genome replication. The mechanisms underlying trans- and cis-preferences are not fully understood. Here, we evaluate this concept for hepatitis C virus (HCV), an important cause of chronic liver disease and member of the Flaviviridae family. HCV encodes five nonstructural (NS) genes that are required for RNA replication. To date, only two of these genes, NS4B and NS5A, have been trans-complemented, leading to suggestions that other replicase genes work only in cis. We describe a new quantitative system to measure the cis- and trans-requirements for HCV NS gene function in RNA replication and identify several lethal mutations in the NS3, NS4A, NS4B, NS5A, and NS5B genes that can be complemented in trans, alone or in combination, by expressing the NS3–5B polyprotein from a synthetic mRNA. Although NS5B RNA binding and polymerase activities can be supplied in trans, NS5B protein expression was required in cis, indicating that NS5B has a cis-acting role in replicase assembly distinct from its known enzymatic activity. Furthermore, the RNA binding and NTPase activities of the NS3 helicase domain were required in cis, suggesting that these activities play an essential role in RNA template selection. A comprehensive complementation group analysis revealed functional linkages between NS3-4A and NS4B and between NS5B and the upstream NS3–5A genes. Finally, NS5B polymerase activity segregated with a daclatasvir-sensitive NS5A activity, which could explain the synergy of this antiviral compound with nucleoside analogs in patients. Together, these studies define several new aspects of HCV replicase structure-function, help to explain the potency of HCV-specific combination therapies, and provide an experimental framework for the study of cis- and trans-acting activities in positive-strand RNA virus replication more generally. PMID:25875808

  2. Phosphorylation acts positively and negatively to regulate MRTF-A subcellular localisation and activity

    PubMed Central

    Panayiotou, Richard; Miralles, Francesc; Pawlowski, Rafal; Diring, Jessica; Flynn, Helen R; Skehel, Mark; Treisman, Richard

    2016-01-01

    The myocardin-related transcription factors (MRTF-A and MRTF-B) regulate cytoskeletal genes through their partner transcription factor SRF. The MRTFs bind G-actin, and signal-regulated changes in cellular G-actin concentration control their nuclear accumulation. The MRTFs also undergo Rho- and ERK-dependent phosphorylation, but the function of MRTF phosphorylation, and the elements and signals involved in MRTF-A nuclear export are largely unexplored. We show that Rho-dependent MRTF-A phosphorylation reflects relief from an inhibitory function of nuclear actin. We map multiple sites of serum-induced phosphorylation, most of which are S/T-P motifs and show that S/T-P phosphorylation is required for transcriptional activation. ERK-mediated S98 phosphorylation inhibits assembly of G-actin complexes on the MRTF-A regulatory RPEL domain, promoting nuclear import. In contrast, S33 phosphorylation potentiates the activity of an autonomous Crm1-dependent N-terminal NES, which cooperates with five other NES elements to exclude MRTF-A from the nucleus. Phosphorylation thus plays positive and negative roles in the regulation of MRTF-A. DOI: http://dx.doi.org/10.7554/eLife.15460.001 PMID:27304076

  3. On the mathematical integration of the nervous tissue based on the S-propagator formalism: II. Numerical simulations for molecular-dependent activity.

    PubMed

    Chauvet, Pierre; Chauvet, Gilbert A

    2002-12-01

    In a previous article (G. A. Chauvet, 2002), presenting a theoretical approach for integrating physiological functions in nervous tissue, we showed that a specific hierarchical representation, incorporating the novel concepts of non-symmetry and non-locality, and an appropriate formalism (the S-propagator formalism) could provide a good description of a living system in general, and the nervous system in particular. We now show that, in the framework of this theory, in spite of the complexity inherent to nervous tissue and the great number of elementary mechanisms involved, the numerical resolution of the global non-local system allows us to envisage simulations that would otherwise be impossible to realize. Here, the study is limited to one physiological function, i.e., the spatiotemporal variation of membrane potential in neuronal tissue. We demonstrate that the role of the kinetic constants at the molecular level is in agreement with the observed activity of the neuronal network. The method also reveals the critical role of the maximum density of synapses along the dendritic tree in the behavior of the network. This illustrates the great advantage of the theoretical approach in studying separately any other complementary coupled function without having to modify the computational methods used here. The application of this method to the spatiotemporal variation of synaptic efficacy, which is the basis of the learning and memory function, will be treated in a forthcoming paper. PMID:15011284

  4. Active compensation of aperture discontinuities for WFIRST-AFTA: analytical and numerical comparison of propagation methods and preliminary results with a WFIRST-AFTA-like pupil

    NASA Astrophysics Data System (ADS)

    Mazoyer, Johan; Pueyo, Laurent; Norman, Colin; N'Diaye, Mamadou; van der Marel, Roeland P.; Soummer, Rémi

    2016-03-01

    The new frontier in the quest for the highest contrast levels in the focal plane of a coronagraph is now the correction of the large diffraction artifacts introduced at the science camera by apertures of increasing complexity. Indeed, the future generation of space- and ground-based coronagraphic instruments will be mounted on on-axis and/or segmented telescopes; the design of coronagraphic instruments for such observatories is currently a domain undergoing rapid progress. One approach consists of using two sequential deformable mirrors (DMs) to correct for aberrations introduced by secondary mirror structures and segmentation of the primary mirror. The coronagraph for the WFIRST-AFTA mission will be the first of such instruments in space with a two-DM wavefront control system. Regardless of the control algorithm for these multiple DMs, they will have to rely on quick and accurate simulation of the propagation effects introduced by the out-of-pupil surface. In the first part of this paper, we present the analytical description of the different approximations to simulate these propagation effects. In Appendix A, we prove analytically that in the special case of surfaces inducing a converging beam, the Fresnel method yields high fidelity for simulations of these effects. We provide numerical simulations showing this effect. In the second part, we use these tools in the framework of the active compensation of aperture discontinuities (ACAD) technique applied to pupil geometries similar to WFIRST-AFTA. We present these simulations in the context of the optical layout of the high-contrast imager for complex aperture telescopes, which will test ACAD on a optical bench. The results of this analysis show that using the ACAD method, an apodized pupil Lyot coronagraph, and the performance of our current DMs, we are able to obtain, in numerical simulations, a dark hole with a WFIRST-AFTA-like. Our numerical simulation shows that we can obtain contrast better than 2×10-9 in

  5. An internal disulfide bond acts as a switch for intein activity

    PubMed Central

    Nicastri, Michael C.; Xega, Kristina; Li, Lingyun; Xie, Jian; Wang, Chunyu; Linhardt, Robert J.; Reitter, Julie N.; Mills, Kenneth V.

    2013-01-01

    Inteins are intervening polypeptides that catalyze their own removal from flanking exteins, concomitant to the ligation of the exteins. The intein that interrupts the DP2 (large) subunit of DNA Polymerase II from Methanoculleus marisnigri (Mma) can promote protein splicing. However, protein splicing can be prevented or reduced by over-expression under non-reducing conditions, due to the formation of a disulfide bond between two internal intein Cys residues. This redox sensitivity leads to differential activity in different strains of E. coli as well as in different cell compartments. The redox-dependent control of in vivo protein splicing in an intein derived from an anaerobe that can occupy multiple environments hints at a possible physiological role for protein splicing. PMID:23906287

  6. PPARδ Activation Acts Cooperatively with 3-Phosphoinositide-Dependent Protein Kinase-1 to Enhance Mammary Tumorigenesis

    PubMed Central

    Pollock, Claire B.; Yin, Yuzhi; Yuan, Hongyan; Zeng, Xiao; King, Sruthi; Li, Xin; Kopelovich, Levy; Albanese, Chris; Glazer, Robert I.

    2011-01-01

    Peroxisome proliferator-activated receptorδ (PPARδ) is a transcription factor that is associated with metabolic gene regulation and inflammation. It has been implicated in tumor promotion and in the regulation of 3-phosphoinositide-dependent kinase-1 (PDK1). PDK1 is a key regulator of the AGC protein kinase family, which includes the proto-oncogene AKT/PKB implicated in several malignancies, including breast cancer. To assess the role of PDK1 in mammary tumorigenesis and its interaction with PPARδ, transgenic mice were generated in which PDK1 was expressed in mammary epithelium under the control of the MMTV enhancer/promoter region. Transgene expression increased pT308AKT and pS9GSK3β, but did not alter phosphorylation of mTOR, 4EBP1, ribosomal protein S6 and PKCα. The transgenic mammary gland also expressed higher levels of PPARδ and a gene expression profile resembling wild-type mice maintained on a diet containing the PPARδ agonist, GW501516. Both wild-type and transgenic mice treated with GW501516 exhibited accelerated rates of tumor formation that were more pronounced in transgenic animals. GW501516 treatment was accompanied by a distinct metabolic gene expression and metabolomic signature that was not present in untreated animals. GW501516-treated transgenic mice expressed higher levels of fatty acid and phospholipid metabolites than treated wild-type mice, suggesting the involvement of PDK1 in enhancing PPARδ-driven energy metabolism. These results reveal that PPARδ activation elicits a distinct metabolic and metabolomic profile in tumors that is in part related to PDK1 and AKT signaling. PMID:21297860

  7. GIT2 Acts as a Systems-Level Coordinator of Neurometabolic Activity and Pathophysiological Aging

    PubMed Central

    Martin, Bronwen; Chadwick, Wayne; Janssens, Jonathan; Premont, Richard T.; Schmalzigaug, Robert; Becker, Kevin G.; Lehrmann, Elin; Wood, William H.; Zhang, Yongqing; Siddiqui, Sana; Park, Sung-Soo; Cong, Wei-na; Daimon, Caitlin M.; Maudsley, Stuart

    2016-01-01

    Aging represents one of the most complicated and highly integrated somatic processes. Healthy aging is suggested to rely upon the coherent regulation of hormonal and neuronal communication between the central nervous system and peripheral tissues. The hypothalamus is one of the main structures in the body responsible for sustaining an efficient interaction between energy balance and neurological activity and therefore likely coordinates multiple systems in the aging process. We previously identified, in hypothalamic and peripheral tissues, the G protein-coupled receptor kinase interacting protein 2 (GIT2) as a stress response and aging regulator. As metabolic status profoundly affects aging trajectories, we investigated the role of GIT2 in regulating metabolic activity. We found that genomic deletion of GIT2 alters hypothalamic transcriptomic signatures related to diabetes and metabolic pathways. Deletion of GIT2 reduced whole animal respiratory exchange ratios away from those related to primary glucose usage for energy homeostasis. GIT2 knockout (GIT2KO) mice demonstrated lower insulin secretion levels, disruption of pancreatic islet beta cell mass, elevated plasma glucose, and insulin resistance. High-dimensionality transcriptomic signatures from islets isolated from GIT2KO mice indicated a disruption of beta cell development. Additionally, GIT2 expression was prematurely elevated in pancreatic and hypothalamic tissues from diabetic-state mice (db/db), compared to age-matched wild type (WT) controls, further supporting the role of GIT2 in metabolic regulation and aging. We also found that the physical interaction of pancreatic GIT2 with the insulin receptor and insulin receptor substrate 2 was diminished in db/db mice compared to WT mice. Therefore, GIT2 appears to exert a multidimensional “keystone” role in regulating the aging process by coordinating somatic responses to energy deficits. PMID:26834700

  8. Experiments for Ka-band mobile applications: The ACTS mobile terminal

    NASA Technical Reports Server (NTRS)

    Estabrook, Polly; Dessouky, Khaled; Jedrey, Thomas

    1990-01-01

    To explore the potential of Ka-band to support mobile satellite services, the Jet Propulsion Laboratory (JPL) has initiated the design and development of a Ka-band land-mobile terminal to be used with the Advanced Communications Technology Satellite (ACTS). The planned experimental setup with ACTS is described. Brief functional descriptions of the mobile and fixed terminals are provided. The inputs required from the propagation community to support the design activities and the planned experiments are also discussed.

  9. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project. ACT/Control/Guidance System study, volume 1

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The active control technology (ACT) control/guidance system task of the integrated application of active controls (IAAC) technology project within the NASA energy efficient transport program was documented. The air traffic environment of navigation and air traffic control systems and procedures were extrapolated. An approach to listing flight functions which will be performed by systems and crew of an ACT configured airplane of the 1990s, and a determination of function criticalities to safety of flight, are the basis of candidate integrated ACT/Control/Guidance System architecture. The system mechanizes five active control functions: pitch augmented stability, angle of attack limiting, lateral/directional augmented stability, gust load alleviation, and maneuver load control. The scope and requirements of a program for simulating the integrated ACT avionics and flight deck system, with pilot in the loop, are defined, system and crew interface elements are simulated, and mechanization is recommended. Relationships between system design and crew roles and procedures are evaluated.

  10. Faults paragenesis and paleostress state in the zone of actively propagating continental strike-slip on the example of North Khangai fault (Northern Mongolia)

    NASA Astrophysics Data System (ADS)

    Sankov, Vladimir; Parfeevets, Anna

    2014-05-01

    Sublatitudinal North Khangai fault extends from Ubsunuur basin to the eastern part of the Selenga corridor trough 800 km. It is the northern boundary of the massive Mongolian block and limits of the Baikal rift system structures propagation in the south (Logatchev, 2003). Late Cenozoic and present-day fault activity are expressed in the left-lateral displacements of a different order of river valleys and high seismicity. We have carried out studies of the kinematics of active faults and palaeostresses reconstruction in the zone of the dynamic influence of North Khangai fault, the width of which varies along the strike and can exceeds 100 km. The result shows that the fault zone has a longitudinal and a transverse zoning. Longitudinal zonation presented gradual change from west to east regions of compression and transpression regimes (Khan-Khukhey ridge) to strike-slip regime (Bolnay ridge) and strike-slip and transtensive regimes (west of Selenga corridor). Strike-slip zones are represented by linearly concentrated rupture deformations. In contrast, near the termination of the fault the cluster fault deformation formed. Here, from north to south, there are radical changes in the palaeostress state. In the north-western sector (east of Selenga corridor) strike-slip faults, strike-slip faults with normal components and normal faults are dominated. For this sector the stress tensors of extensive, transtension and strike-slip regimes are typical. South-western sector is separated from the north-eastern one by massive Buren Nuruu ridge within which the active faults are not identified. In the south-western sector between the Orkhon and Tola rivers the cluster of NW thrusts and N-S strike-slip faults with reverse component are discovered. The faults are perfectly expressed by NW and N-S scarps in the relief. The most structures dip to the east and north-east. Holocene fault activity is demonstrated by the hanging river valleys and horizontal displacements with amplitudes

  11. Fathoms Below: Propagation of Deep Water-driven Fractures and Implications for Surface Expression and Temporally-varying Activity at Europa

    NASA Astrophysics Data System (ADS)

    Walker, C. C.; Craft, K.; Schmidt, B. E.

    2015-12-01

    The fracture and failure of Europa's icy shell are not only observable scars of variable stress and activity throughout its evolution, they also serve key as mechanisms in the interaction of surface and subsurface material, and thus crucial aspects of the study of crustal overturn and ice shell habitability. Galileo images, our best and only reasonable-resolution views of Europa until the Europa Multiple Flyby Mission arrives in the coming decades, illustrates a single snapshot in time in Europa's history from which we deduce many temporally-based hypotheses. One of those hypotheses, which we investigate here, is that sub-surface water-both in the form of Great Lake-sized perched water pockets in the near-surface and the larger global ocean below-drives the deformation, fracture, and failure of the surface. Using Galileo's snapshot in time, we use a 2D/3D hydraulic fracturing model to investigate the propagation of vertical fractures upward into the ice shell, motion of water within and between fractures, and the subsequent break-up of ice over shallow water, forming the chaos regions and other smaller surface features. We will present results from a cohesive fragmentation model to determine the time over which chaos formation occurs, and use a fracking model to determine the time interval required to allow water to escape from basal fractures in the ice shell. In determining the style, energy, and timescale of these processes, we constrain temporal variability in observable activity and topography at the surface. Finally, we compare these results to similar settings on Earth-Antarctica-where we have much higher resolution imagery and observations to better understand how sub-surface water can affect ice surface morphology, which most certainly have implications for future flyby and surface lander exploration.

  12. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    PubMed

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity. PMID:16169172

  13. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    PubMed

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity.

  14. The S4-S5 linker acts as a signal integrator for HERG K+ channel activation and deactivation gating.

    PubMed

    Ng, Chai Ann; Perry, Matthew D; Tan, Peter S; Hill, Adam P; Kuchel, Philip W; Vandenberg, Jamie I

    2012-01-01

    Human ether-à-go-go-related gene (hERG) K(+) channels have unusual gating kinetics. Characterised by slow activation/deactivation but rapid inactivation/recovery from inactivation, the unique gating kinetics underlie the central role hERG channels play in cardiac repolarisation. The slow activation and deactivation kinetics are regulated in part by the S4-S5 linker, which couples movement of the voltage sensor domain to opening of the activation gate at the distal end of the inner helix of the pore domain. It has also been suggested that cytosolic domains may interact with the S4-S5 linker to regulate activation and deactivation kinetics. Here, we show that the solution structure of a peptide corresponding to the S4-S5 linker of hERG contains an amphipathic helix. The effects of mutations at the majority of residues in the S4-S5 linker of hERG were consistent with the previously identified role in coupling voltage sensor movement to the activation gate. However, mutations to Ser543, Tyr545, Gly546 and Ala548 had more complex phenotypes indicating that these residues are involved in additional interactions. We propose a model in which the S4-S5 linker, in addition to coupling VSD movement to the activation gate, also contributes to interactions that stabilise the closed state and a separate set of interactions that stabilise the open state. The S4-S5 linker therefore acts as a signal integrator and plays a crucial role in the slow deactivation kinetics of the channel.

  15. CAUGHT IN THE ACT: STRONG, ACTIVE RAM PRESSURE STRIPPING IN VIRGO CLUSTER SPIRAL NGC 4330

    SciTech Connect

    Abramson, Anne; Kenney, Jeffrey D. P.; Crowl, Hugh H.; Van Gorkom, J. H.; Schiminovich, David; Chung, Aeree; Vollmer, Bernd E-mail: jeff.kenney@yale.edu E-mail: jvangork@astro.columbia.edu E-mail: achung@yonsei.ac.kr

    2011-05-15

    We present a multi-wavelength study of NGC 4330, a highly inclined spiral galaxy in the Virgo Cluster which is a clear example of strong, ongoing intracluster medium-interstellar medium (ICM-ISM) ram pressure stripping. The H I has been removed from well within the undisturbed old stellar disk, to 50%-65% of R{sub 25}. Multi-wavelength data (WIYN BVR-H{alpha}, Very Large Array 21 cm H I and radio continuum, and Galaxy Evolution Explorer NUV and FUV) reveal several one-sided extraplanar features likely caused by ram pressure at an intermediate disk-wind angle. At the leading edge of the interaction, the H{alpha} and dust extinction curve sharply out of the disk in a remarkable and distinctive 'upturn' feature that may be generally useful as a diagnostic indicator of active ram pressure. On the trailing side, the ISM is stretched out in a long tail which contains 10% of the galaxy's total H I emission, 6%-9% of its NUV-FUV emission, but only 2% of the H{alpha}. The centroid of the H I tail is downwind of the UV/H{alpha} tail, suggesting that the ICM wind has shifted most of the ISM downwind over the course of the past 10-300 Myr. Along the major axis, the disk is highly asymmetric in the UV, but more symmetric in H{alpha} and H I, also implying recent changes in the distributions of gas and star formation. The UV-optical colors indicate very different star formation histories for the leading and trailing sides of the galaxy. On the leading side, a strong gradient in the UV-optical colors of the gas-stripped disk suggests that it has taken 200-400 Myr to strip the gas from a radius of >8 to 5 kpc, but on the trailing side there is no age gradient. All our data suggest a scenario in which NGC 4330 is falling into the cluster center for the first time and has experienced a significant increase in ram pressure over the last 200-400 Myr. Many of the UV-bright stars that form outside the thin disk due to ram pressure will ultimately produce stellar thick disk and halo

  16. Transcription factors GAF and HSF act at distinct regulatory steps to modulate stress-induced gene activation

    PubMed Central

    Fuda, Nicholas J.; Mahat, Dig B.; Core, Leighton J.; Guertin, Michael J.

    2016-01-01

    The coordinated regulation of gene expression at the transcriptional level is fundamental to development and homeostasis. Inducible systems are invaluable when studying transcription because the regulatory process can be triggered instantaneously, allowing the tracking of ordered mechanistic events. Here, we use precision run-on sequencing (PRO-seq) to examine the genome-wide heat shock (HS) response in Drosophila and the function of two key transcription factors on the immediate transcription activation or repression of all genes regulated by HS. We identify the primary HS response genes and the rate-limiting steps in the transcription cycle that GAGA-associated factor (GAF) and HS factor (HSF) regulate. We demonstrate that GAF acts upstream of promoter-proximally paused RNA polymerase II (Pol II) formation (likely at the step of chromatin opening) and that GAF-facilitated Pol II pausing is critical for HS activation. In contrast, HSF is dispensable for establishing or maintaining Pol II pausing but is critical for the release of paused Pol II into the gene body at a subset of highly activated genes. Additionally, HSF has no detectable role in the rapid HS repression of thousands of genes. PMID:27492368

  17. Histone Methyltransferase Inhibitors Are Orally Bioavailable, Fast-Acting Molecules with Activity against Different Species Causing Malaria in Humans

    PubMed Central

    Sundriyal, Sandeep; Caron, Joachim; Chen, Patty; Witkowski, Benoit; Menard, Didier; Suwanarusk, Rossarin; Renia, Laurent; Nosten, Francois; Jiménez-Díaz, María Belén; Angulo-Barturen, Iñigo; Martínez, María Santos; Ferrer, Santiago; Sanz, Laura M.; Gamo, Francisco-Javier; Wittlin, Sergio; Duffy, Sandra; Avery, Vicky M.; Ruecker, Andrea; Delves, Michael J.; Sinden, Robert E.; Fuchter, Matthew J.

    2014-01-01

    Current antimalarials are under continuous threat due to the relentless development of drug resistance by malaria parasites. We previously reported promising in vitro parasite-killing activity with the histone methyltransferase inhibitor BIX-01294 and its analogue TM2-115. Here, we further characterize these diaminoquinazolines for in vitro and in vivo efficacy and pharmacokinetic properties to prioritize and direct compound development. BIX-01294 and TM2-115 displayed potent in vitro activity, with 50% inhibitory concentrations (IC50s) of <50 nM against drug-sensitive laboratory strains and multidrug-resistant field isolates, including artemisinin-refractory Plasmodium falciparum isolates. Activities against ex vivo clinical isolates of both P. falciparum and Plasmodium vivax were similar, with potencies of 300 to 400 nM. Sexual-stage gametocyte inhibition occurs at micromolar levels; however, mature gametocyte progression to gamete formation is inhibited at submicromolar concentrations. Parasite reduction ratio analysis confirms a high asexual-stage rate of killing. Both compounds examined displayed oral efficacy in in vivo mouse models of Plasmodium berghei and P. falciparum infection. The discovery of a rapid and broadly acting antimalarial compound class targeting blood stage infection, including transmission stage parasites, and effective against multiple malaria-causing species reveals the diaminoquinazoline scaffold to be a very promising lead for development into greatly needed novel therapies to control malaria. PMID:25421480

  18. Histone methyltransferase inhibitors are orally bioavailable, fast-acting molecules with activity against different species causing malaria in humans.

    PubMed

    Malmquist, Nicholas A; Sundriyal, Sandeep; Caron, Joachim; Chen, Patty; Witkowski, Benoit; Menard, Didier; Suwanarusk, Rossarin; Renia, Laurent; Nosten, Francois; Jiménez-Díaz, María Belén; Angulo-Barturen, Iñigo; Santos Martínez, María; Ferrer, Santiago; Sanz, Laura M; Gamo, Francisco-Javier; Wittlin, Sergio; Duffy, Sandra; Avery, Vicky M; Ruecker, Andrea; Delves, Michael J; Sinden, Robert E; Fuchter, Matthew J; Scherf, Artur

    2015-02-01

    Current antimalarials are under continuous threat due to the relentless development of drug resistance by malaria parasites. We previously reported promising in vitro parasite-killing activity with the histone methyltransferase inhibitor BIX-01294 and its analogue TM2-115. Here, we further characterize these diaminoquinazolines for in vitro and in vivo efficacy and pharmacokinetic properties to prioritize and direct compound development. BIX-01294 and TM2-115 displayed potent in vitro activity, with 50% inhibitory concentrations (IC50s) of <50 nM against drug-sensitive laboratory strains and multidrug-resistant field isolates, including artemisinin-refractory Plasmodium falciparum isolates. Activities against ex vivo clinical isolates of both P. falciparum and Plasmodium vivax were similar, with potencies of 300 to 400 nM. Sexual-stage gametocyte inhibition occurs at micromolar levels; however, mature gametocyte progression to gamete formation is inhibited at submicromolar concentrations. Parasite reduction ratio analysis confirms a high asexual-stage rate of killing. Both compounds examined displayed oral efficacy in in vivo mouse models of Plasmodium berghei and P. falciparum infection. The discovery of a rapid and broadly acting antimalarial compound class targeting blood stage infection, including transmission stage parasites, and effective against multiple malaria-causing species reveals the diaminoquinazoline scaffold to be a very promising lead for development into greatly needed novel therapies to control malaria. PMID:25421480

  19. Histone methyltransferase inhibitors are orally bioavailable, fast-acting molecules with activity against different species causing malaria in humans.

    PubMed

    Malmquist, Nicholas A; Sundriyal, Sandeep; Caron, Joachim; Chen, Patty; Witkowski, Benoit; Menard, Didier; Suwanarusk, Rossarin; Renia, Laurent; Nosten, Francois; Jiménez-Díaz, María Belén; Angulo-Barturen, Iñigo; Santos Martínez, María; Ferrer, Santiago; Sanz, Laura M; Gamo, Francisco-Javier; Wittlin, Sergio; Duffy, Sandra; Avery, Vicky M; Ruecker, Andrea; Delves, Michael J; Sinden, Robert E; Fuchter, Matthew J; Scherf, Artur

    2015-02-01

    Current antimalarials are under continuous threat due to the relentless development of drug resistance by malaria parasites. We previously reported promising in vitro parasite-killing activity with the histone methyltransferase inhibitor BIX-01294 and its analogue TM2-115. Here, we further characterize these diaminoquinazolines for in vitro and in vivo efficacy and pharmacokinetic properties to prioritize and direct compound development. BIX-01294 and TM2-115 displayed potent in vitro activity, with 50% inhibitory concentrations (IC50s) of <50 nM against drug-sensitive laboratory strains and multidrug-resistant field isolates, including artemisinin-refractory Plasmodium falciparum isolates. Activities against ex vivo clinical isolates of both P. falciparum and Plasmodium vivax were similar, with potencies of 300 to 400 nM. Sexual-stage gametocyte inhibition occurs at micromolar levels; however, mature gametocyte progression to gamete formation is inhibited at submicromolar concentrations. Parasite reduction ratio analysis confirms a high asexual-stage rate of killing. Both compounds examined displayed oral efficacy in in vivo mouse models of Plasmodium berghei and P. falciparum infection. The discovery of a rapid and broadly acting antimalarial compound class targeting blood stage infection, including transmission stage parasites, and effective against multiple malaria-causing species reveals the diaminoquinazoline scaffold to be a very promising lead for development into greatly needed novel therapies to control malaria.

  20. NASA Propagation Studies Website

    NASA Technical Reports Server (NTRS)

    Angkasa, Krisjani S.

    1996-01-01

    The NASA propagation studies objective is to enable the development of new commercial satellite communication systems and services by providing timely data and models about propagation of satellite radio signals through the intervening environment and to support NASA missions. In partnership with industry and academia, the program leverages unique NASA assets (currently Advanced Communications Technology Satellite) to obtain propagation data. The findings of the study are disseminated through referred journals, NASA reference publications, workshops, electronic media, and direct interface with industry.

  1. 45 CFR 90.3 - What programs or activities does the Age Discrimination Act of 1975 cover?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Assistance Act of 1972 (31 U.S.C. 1221 et seq.). (b) The Age Discrimination Act of 1975 does not apply to: (1... employment under the Comprehensive Employment and Training Act of 1974 (CETA), (29 U.S.C. 801 et seq.)....

  2. A 'Propagating' Active Across-Arc Normal Fault Shows Rupture Process of the Basement: the Case of the Southwestern Ryukyu Arc

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.; Shinjo, R.; Nakamura, M.; Kubo, A.; Doi, A.; Tamanaha, S.

    2011-12-01

    Ryukyu Arc is located on the southwestern extension of Japanese Island-arc towards the east of Taiwan Island along the margin of the Asian continent off China. The island-arc forms an arcuate trench-arc-backarc system. A NW-ward subduction of the Philippine Sea Plate (PSP)at a rate of 6-8 cm/y relative to the Eurasian Plate (EP) causes frequent earthquakes. The PSP is subducting almost normally in the north-central area and more obliquely around the southwestern area. Behind the arc-trench system, the Okinawa Trough (OT) was formed by back-arc rifting, where active hydrothermal vent systems have been discovered. Several across-arc submarine faults are located in the central and southern Ryukyu Arc. The East Ishigaki Fault (EIF) is one of the across-arc normal faults located in the southwestern Ryukyu Arc, ranging by 44km and extending from SE to NW. This fault was surveyed by SEABAT8160 multibeam echo sounder and by ROV Hyper-Dolphin in 2005 and 2008. The result shows that the main fault consists of five fault segments. A branched segment from the main fault was also observed. The southernmost segment is most mature (oldest but still active) and the northernmost one is most nascent. This suggests the north-westward propagation of the fault rupture corresponding to the rifting of the southwestern OT and the southward retreat of the arc-trench system. Considering that the fault is segmented and in some part branched, propagation might take place episodically rather than continuously from SE to NW. The ROV survey also revealed the rupture process of the limestone basement along this fault from the nascent stage to the mature stage. Most of the rock samples collected from the basement outcrop were limestone blocks (or calcareous sedimentary rocks). Limestone basement was observed to the west on the hanging wall far away from the main fault scarp. Then fine-grained sand with ripple marks was observed towards the main scarp. Limestone basement was observed on the main

  3. Antimicrobial activity and biologic potential of silver-substituted calcium phosphate constructs produced with self-propagating high-temperature synthesis.

    PubMed

    Vollmer, N L; Spear, J R; Ayers, R A

    2016-06-01

    There is significant demand for synthetic bone substitute materials that can decrease the incidence of implant-based bacterial infections. The intent of this research was to evaluate the antimicrobial activity and biologic potential of calcium phosphate (CaP) constructs substituted with silver (Ag) that were produced via self-propagating high-temperature synthesis (SHS). SHS is a combustion synthesis technique that has successfully generated porous CaP bioceramics intended for use in bone repair. SHS reactions are highly versatile; dopants can be added to the reactant powders to alter product chemistry and morphology. In this research, Ag powder was added to the reactants generating porous CaP constructs containing 0.5, 1, or 2 wt% Ag. Antibacterial performance of the constructs was assessed against Escherichia coli, a representative model for Gram-negative bacteria. Liquid solutions (1 μg/mL) of CaP-Ag particles to phosphate buffered saline were incubated with 10(5) cells/mL. After 24 h, 10 μL of solution were spread on an LB agar plate and cultured for 24 h at 37 °C. Samples cultured with CaP-Ag showed complete bacterial inhibition while the controls (E. coli only and CaP without Ag) exhibited significant colony formation. The effects of Ag concentration on cytotoxicity and biocompatibility were tested in vitro. At 7 days, osteoblasts uniformly enveloped the CaP-Ag particles and displayed a healthy flattened morphology suggesting the concentrations of Ag incorporated into constructs were not cytotoxic. CaP-Ag constructs produced via SHS represent a source of synthetic bone substitute materials that could potentially inhibit, or reduce the incidence of post-operative bacterial infections. PMID:27094319

  4. The study of electromagnetic wave propagation in photonic crystals via planewave based transfer (scattering) matrix method with active gain material applications

    NASA Astrophysics Data System (ADS)

    Li, Ming

    In this dissertation, a set of numerical simulation tools are developed under previous work to efficiently and accurately study one-dimensional (1D), two-dimensional (2D), 2D slab and three-dimensional (3D) photonic crystal structures and their defects effects by means of spectrum (transmission, reflection, absorption), band structure (dispersion relation), and electric and/or magnetic fields distribution (mode profiles). Further more, the lasing property and spontaneous emission behaviors are studied when active gain materials are presented in the photonic crystal structures. First, the planewave based transfer (scattering) matrix method (TMM) is described in every detail along with a brief review of photonic crystal history (Chapter 1 and 2). As a frequency domain method, TMM has the following major advantages over other numerical methods: (1) the planewave basis makes Maxwell's Equations a linear algebra problem and there are mature numerical package to solve linear algebra problem such as Lapack and Scalapack (for parallel computation). (2) Transfer (scattering) matrix method make 3D problem into 2D slices and link all slices together via the scattering matrix (S matrix) which reduces computation time and memory usage dramatically and makes 3D real photonic crystal devices design possible; and this also makes the simulated domain no length limitation along the propagation direction (ideal for waveguide simulation). (3) It is a frequency domain method and calculation results are all for steady state, without the influences of finite time span convolution effects and/or transient effects. (4) TMM can treat dispersive material (such as metal at visible light) naturally without introducing any additional computation; and meanwhile TMM can also deal with anisotropic material and magnetic material (such as perfectly matched layer) naturally from its algorithms. (5) Extension of TMM to deal with active gain material can be done through an iteration procedure with gain

  5. Eukaryotic translation initiation factor 5 (eIF5) acts as a classical GTPase-activator protein.

    PubMed

    Paulin, F E; Campbell, L E; O'Brien, K; Loughlin, J; Proud, C G

    2001-01-01

    GTP hydrolysis occurs at several specific stages during the initiation, elongation, and termination stages of mRNA translation. However, it is unclear how GTP hydrolysis occurs; it has previously been suggested to involve a GTPase active center in the ribosome, although proof for this is lacking. Alternatively, it could involve the translation factors themselves, e.g., be similar to the situation for small G in which the GTPase active site involves arginine residues contributed by a further protein termed a GTPase-activator protein (GAP). During translation initiation in eukaryotes, initiation factor eIF5 is required for hydrolysis of GTP bound to eIF2 (the protein which brings the initiator Met-tRNA(i) to the 40S subunit). Here we show that eIF5 displays the hallmarks of a classical GAP (e.g., RasGAP). Firstly, its interaction with eIF2 is enhanced by AlF(4)(-). Secondly, eIF5 possesses a conserved arginine (Arg15) which, like the "arginine fingers" of classical GAPs, is flanked by hydrophobic residues. Mutation of Arg15 to methionine abolishes the ability of eIF5 either to stimulate GTP hydrolysis or to support mRNA translation in vitro. Mutation studies suggest that a second conserved arginine (Arg48) also contributes to the GTPase active site of the eIF2.eIF5 complex. Our data thus show that eIF5 behaves as a classical GAP and that GTP hydrolysis during translation involves proteins extrinsic to the ribosome. Indeed, inspection of their sequences suggests that other translation factors may also act as GAPs. PMID:11166181

  6. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Hanks, G. W.; Shomber, H. A.; Dethman, H. A.; Gratzer, L. B.; Maeshiro, A.; Gangsaas, D.; Blight, J. D.; Buchan, S. M.; Crumb, C. B.; Dorwart, R. J.

    1981-01-01

    The current status of the Active Controls Technology (ACT) for the advanced subsonic transport project is investigated through analysis of the systems technical data. Control systems technologies under examination include computerized reliability analysis, pitch axis fly by wire actuator, flaperon actuation system design trade study, control law synthesis and analysis, flutter mode control and gust load alleviation analysis, and implementation of alternative ACT systems. Extensive analysis of the computer techniques involved in each system is included.

  7. DCA1 Acts as a Transcriptional Co-activator of DST and Contributes to Drought and Salt Tolerance in Rice

    PubMed Central

    Cui, Long-Gang; Shan, Jun-Xiang; Shi, Min; Gao, Ji-Ping; Lin, Hong-Xuan

    2015-01-01

    Natural disasters, including drought and salt stress, seriously threaten food security. In previous work we cloned a key zinc finger transcription factor gene, Drought and Salt Tolerance (DST), a negative regulator of drought and salt tolerance that controls stomatal aperture in rice. However, the exact mechanism by which DST regulates the expression of target genes remains unknown. In the present study, we demonstrated that DST Co-activator 1 (DCA1), a previously unknown CHY zinc finger protein, acts as an interacting co-activator of DST. DST was found to physically interact with itself and to form a heterologous tetramer with DCA1. This transcriptional complex appears to regulate the expression of peroxidase 24 precursor (Prx 24), a gene encoding an H2O2 scavenger that is more highly expressed in guard cells. Downregulation of DCA1 significantly enhanced drought and salt tolerance in rice, and overexpression of DCA1 increased sensitivity to stress treatment. These phenotypes were mainly influenced by DCA1 and negatively regulated stomatal closure through the direct modulation of genes associated with H2O2 homeostasis. Our findings establish a framework for plant drought and salt stress tolerance through the DCA1-DST-Prx24 pathway. Moreover, due to the evolutionary and functional conservation of DCA1 and DST in plants, engineering of this pathway has the potential to improve tolerance to abiotic stress in other important crop species. PMID:26496194

  8. Clobetasol and Halcinonide Act as Smoothened Agonists to Promote Myelin Gene Expression and RxRγ Receptor Activation.

    PubMed

    Porcu, Giampiero; Serone, Eliseo; De Nardis, Velia; Di Giandomenico, Daniele; Lucisano, Giuseppe; Scardapane, Marco; Poma, Anna; Ragnini-Wilson, Antonella

    2015-01-01

    One of the causes of permanent disability in chronic multiple sclerosis patients is the inability of oligodendrocyte progenitor cells (OPCs) to terminate their maturation program at lesions. To identify key regulators of myelin gene expression acting at the last stages of OPC maturation we developed a drug repositioning strategy based on the mouse immortalized oligodendrocyte (OL) cell line Oli-neu brought to the premyelination stage by stably expressing a key factor regulating the last stages of OL maturation. The Prestwick Chemical Library of 1,200 FDA-approved compound(s) was repositioned at three dosages based on the induction of Myelin Basic Protein (MBP) expression. Drug hits were further validated using dosage-dependent reproducibility tests and biochemical assays. The glucocorticoid class of compounds was the most highly represented and we found that they can be divided in three groups according to their efficacy on MBP up-regulation. Since target identification is crucial before bringing compounds to the clinic, we searched for common targets of the primary screen hits based on their known chemical-target interactomes, and the pathways predicted by top ranking compounds were validated using specific inhibitors. Two of the top ranking compounds, Halcinonide and Clobetasol, act as Smoothened (Smo) agonists to up-regulate myelin gene expression in the Oli-neuM cell line. Further, RxRγ activation is required for MBP expression upon Halcinonide and Clobetasol treatment. These data indicate Clobetasol and Halcinonide as potential promyelinating drugs and also provide a mechanistic understanding of their mode of action in the pathway leading to myelination in OPCs. Furthermore, our classification of glucocorticoids with respect to MBP expression provides important novel insights into their effects in the CNS and a rational criteria for their choice in combinatorial therapies in de-myelinating diseases. PMID:26658258

  9. Clobetasol and Halcinonide Act as Smoothened Agonists to Promote Myelin Gene Expression and RxRγ Receptor Activation

    PubMed Central

    De Nardis, Velia; Di Giandomenico, Daniele; Lucisano, Giuseppe; Scardapane, Marco; Poma, Anna; Ragnini-Wilson, Antonella

    2015-01-01

    One of the causes of permanent disability in chronic multiple sclerosis patients is the inability of oligodendrocyte progenitor cells (OPCs) to terminate their maturation program at lesions. To identify key regulators of myelin gene expression acting at the last stages of OPC maturation we developed a drug repositioning strategy based on the mouse immortalized oligodendrocyte (OL) cell line Oli-neu brought to the premyelination stage by stably expressing a key factor regulating the last stages of OL maturation. The Prestwick Chemical Library® of 1,200 FDA-approved compound(s) was repositioned at three dosages based on the induction of Myelin Basic Protein (MBP) expression. Drug hits were further validated using dosage-dependent reproducibility tests and biochemical assays. The glucocorticoid class of compounds was the most highly represented and we found that they can be divided in three groups according to their efficacy on MBP up-regulation. Since target identification is crucial before bringing compounds to the clinic, we searched for common targets of the primary screen hits based on their known chemical-target interactomes, and the pathways predicted by top ranking compounds were validated using specific inhibitors. Two of the top ranking compounds, Halcinonide and Clobetasol, act as Smoothened (Smo) agonists to up-regulate myelin gene expression in the Oli-neuM cell line. Further, RxRγ activation is required for MBP expression upon Halcinonide and Clobetasol treatment. These data indicate Clobetasol and Halcinonide as potential promyelinating drugs and also provide a mechanistic understanding of their mode of action in the pathway leading to myelination in OPCs. Furthermore, our classification of glucocorticoids with respect to MBP expression provides important novel insights into their effects in the CNS and a rational criteria for their choice in combinatorial therapies in de-myelinating diseases. PMID:26658258

  10. Clobetasol and Halcinonide Act as Smoothened Agonists to Promote Myelin Gene Expression and RxRγ Receptor Activation.

    PubMed

    Porcu, Giampiero; Serone, Eliseo; De Nardis, Velia; Di Giandomenico, Daniele; Lucisano, Giuseppe; Scardapane, Marco; Poma, Anna; Ragnini-Wilson, Antonella

    2015-01-01

    One of the causes of permanent disability in chronic multiple sclerosis patients is the inability of oligodendrocyte progenitor cells (OPCs) to terminate their maturation program at lesions. To identify key regulators of myelin gene expression acting at the last stages of OPC maturation we developed a drug repositioning strategy based on the mouse immortalized oligodendrocyte (OL) cell line Oli-neu brought to the premyelination stage by stably expressing a key factor regulating the last stages of OL maturation. The Prestwick Chemical Library of 1,200 FDA-approved compound(s) was repositioned at three dosages based on the induction of Myelin Basic Protein (MBP) expression. Drug hits were further validated using dosage-dependent reproducibility tests and biochemical assays. The glucocorticoid class of compounds was the most highly represented and we found that they can be divided in three groups according to their efficacy on MBP up-regulation. Since target identification is crucial before bringing compounds to the clinic, we searched for common targets of the primary screen hits based on their known chemical-target interactomes, and the pathways predicted by top ranking compounds were validated using specific inhibitors. Two of the top ranking compounds, Halcinonide and Clobetasol, act as Smoothened (Smo) agonists to up-regulate myelin gene expression in the Oli-neuM cell line. Further, RxRγ activation is required for MBP expression upon Halcinonide and Clobetasol treatment. These data indicate Clobetasol and Halcinonide as potential promyelinating drugs and also provide a mechanistic understanding of their mode of action in the pathway leading to myelination in OPCs. Furthermore, our classification of glucocorticoids with respect to MBP expression provides important novel insights into their effects in the CNS and a rational criteria for their choice in combinatorial therapies in de-myelinating diseases.

  11. Limitations in scatter propagation

    NASA Astrophysics Data System (ADS)

    Lampert, E. W.

    1982-04-01

    A short description of the main scatter propagation mechanisms is presented; troposcatter, meteor burst communication and chaff scatter. For these propagation modes, in particular for troposcatter, the important specific limitations discussed are: link budget and resulting hardware consequences, diversity, mobility, information transfer and intermodulation and intersymbol interference, frequency range and future extension in frequency range for troposcatter, and compatibility with other services (EMC).

  12. NASA Propagation Information Center

    NASA Technical Reports Server (NTRS)

    Smith, Ernest K.; Flock, Warren L.

    1989-01-01

    The NASA Propagation Information Center became formally operational in July 1988. It is located in the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. The Center is several things: a communications medium for the propagation with the outside world, a mechanism for internal communication within the program, and an aid to management.

  13. NASA propagation information center

    NASA Astrophysics Data System (ADS)

    Smith, Ernest K.; Flock, Warren L.

    1990-07-01

    The NASA Propagation Information Center became formally operational in July 1988. It is located in the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. The center is several things: a communications medium for the propagation with the outside world, a mechanism for internal communication within the program, and an aid to management.

  14. Propagation data bases

    NASA Astrophysics Data System (ADS)

    1981-12-01

    Existing data bases accumulated as the result of experiments to gather propagation data on millimeter wave Earth-space links are described. The satellites used are described and results of the significant experiments conducted in the United States are summarized. The data bases consist primarily of cumulative attenuation statistics, though some depolarization measurements are included. Additional summaries of propagation data are cited.

  15. Propagation research in Japan

    NASA Technical Reports Server (NTRS)

    Wakana, Hiromitsu

    1991-01-01

    L-band propagation measurements for land-mobile, maritime, and aeronautical satellite communications have been carried out by using the Japanese Engineering Test Satellite-Five (ETS-5) which was launched in Aug. 1987. This paper presents propagation characteristics for each of the mobile satellite communication channels.

  16. 7alpha-Hydroxypregnenolone acts as a neuronal activator to stimulate locomotor activity of breeding newts by means of the dopaminergic system.

    PubMed

    Matsunaga, Masahiro; Ukena, Kazuyoshi; Baulieu, Etienne-Emile; Tsutsui, Kazuyoshi

    2004-12-01

    It is becoming clear that steroids can be synthesized de novo by the brain and other nervous systems. Such steroids are called neurosteroids, and de novo neurosteroidogenesis from cholesterol is a conserved property of vertebrate brains. In this study, we show that the newt brain actively produces 7alpha-hydroxypregnenolone, a previously undescribed amphibian neurosteroid that stimulates locomotor activity. 7alpha-hydroxypregnenolone was identified as a most abundant amphibian neurosteroid in the newt brain by using biochemical techniques combined with HPLC, TLC, and GC-MS analyses. The production of 7alpha-hydroxypregnenolone in the diencephalon and rhombencephalon was higher than that in the telencephalon and peripheral steroidogenic glands. In addition, 7alpha-hydroxypregnenolone synthesis in the brain showed marked changes during the annual breeding cycle, with a maximal level in the spring breeding period when locomotor activity of the newt increases. Behavioral analysis of newts in the nonbreeding period demonstrated that administration of this previously undescribed amphibian neurosteroid acutely increased locomotor activity. In vitro analysis further revealed that 7alpha-hydroxypregnenolone treatment resulted in a dose-dependent increase in the release of dopamine from cultured brain tissue of nonbreeding newts. The effect of this neurosteroid on locomotion also was abolished by dopamine D(2)-like receptor antagonists. These results indicate that 7alpha-hydroxypregnenolone acts as a neuronal activator to stimulate locomotor activity of breeding newts through the dopaminergic system. This study demonstrates a physiological function of 7alpha-hydroxypregnenolone that has not been described previously in any vertebrate class. This study also provides findings on the regulatory mechanism of locomotor activity from a unique standpoint.

  17. Millimeter wavelength propagation studies

    NASA Technical Reports Server (NTRS)

    Hodge, D. B.

    1974-01-01

    The investigations conducted for the Millimeter Wavelength Propagation Studies during the period December, 1966, to June 1974 are reported. These efforts included the preparation for the ATS-5 Millimeter Wavelength Propagation Experiment and the subsequent data acquisition and data analysis. The emphasis of the OSU participation in this experiment was placed on the determination of reliability improvement resulting from the use of space diversity on a millimeter wavelength earth-space communication link. Related measurements included the determination of the correlation between radiometric temperature and attenuation along the earth-space propagation path. Along with this experimental effort a theoretical model was developed for the prediction of attenuation statistics on single and spatially separated earth space propagation paths. A High Resolution Radar/Radiometer System and Low Resolution Radar System were developed and implemented for the study of intense rain cells in preparation for the ATS-6 Millimeter Wavelength Propagation Experiment.

  18. Wave propagation phenomena

    NASA Astrophysics Data System (ADS)

    Groenenboom, P. H. L.

    The phenomenon of wave propagation is encountered frequently in a variety of engineering disciplines. It has been realized that for a growing number of problems the solution can only be obtained by discretization of the boundary. Advantages of the Boundary Element Method (BEM) over domain-type methods are related to the reduction of the number of space dimensions and of the modelling effort. It is demonstrated how the BEM can be applied to wave propagation phenomena by establishing the fundamental relationships. A numerical solution procedure is also suggested. In connection with a discussion of the retarded potential formulation, it is shown how the wave propagation problem can be cast into a Boundary Integral Formulation (BIF). The wave propagation problem in the BIF can be solved by time-successive evaluation of the boundary integrals. The example of pressure wave propagation following a sodium-water reaction in a Liquid Metal cooled Fast Breeder Reactor steam generator is discussed.

  19. Gear crack propagation investigations

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Ballarini, Roberto

    1996-01-01

    Analytical and experimental studies were performed to investigate the effect of gear rim thickness on crack propagation life. The FRANC (FRacture ANalysis Code) computer program was used to simulate crack propagation. The FRANC program used principles of linear elastic fracture mechanics, finite element modeling, and a unique re-meshing scheme to determine crack tip stress distributions, estimate stress intensity factors, and model crack propagation. Various fatigue crack growth models were used to estimate crack propagation life based on the calculated stress intensity factors. Experimental tests were performed in a gear fatigue rig to validate predicted crack propagation results. Test gears were installed with special crack propagation gages in the tooth fillet region to measure bending fatigue crack growth. Good correlation between predicted and measured crack growth was achieved when the fatigue crack closure concept was introduced into the analysis. As the gear rim thickness decreased, the compressive cyclic stress in the gear tooth fillet region increased. This retarded crack growth and increased the number of crack propagation cycles to failure.

  20. SET1 and p300 act synergistically, through coupled histone modifications, in transcriptional activation by p53.

    PubMed

    Tang, Zhanyun; Chen, Wei-Yi; Shimada, Miho; Nguyen, Uyen T T; Kim, Jaehoon; Sun, Xiao-Jian; Sengoku, Toru; McGinty, Robert K; Fernandez, Joseph P; Muir, Tom W; Roeder, Robert G

    2013-07-18

    The H3K4me3 mark in chromatin is closely correlated with actively transcribed genes, although the mechanisms involved in its generation and function are not fully understood. In vitro studies with recombinant chromatin and purified human factors demonstrate a robust SET1 complex (SET1C)-mediated H3K4 trimethylation that is dependent upon p53- and p300-mediated H3 acetylation, a corresponding SET1C-mediated enhancement of p53- and p300-dependent transcription that reflects a primary effect of SET1C through H3K4 trimethylation, and direct SET1C-p53 and SET1C-p300 interactions indicative of a targeted recruitment mechanism. Complementary cell-based assays demonstrate a DNA-damage-induced p53-SET1C interaction, a corresponding enrichment of SET1C and H3K4me3 on a p53 target gene (p21/WAF1), and a corresponding codependency of H3K4 trimethylation and transcription upon p300 and SET1C. These results establish a mechanism in which SET1C and p300 act cooperatively, through direct interactions and coupled histone modifications, to facilitate the function of p53. PMID:23870121

  1. 33 CFR 120.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and to the local office of the Federal Bureau of Investigation (FBI). Also, if your vessel is a U.S..., DEPARTMENT OF HOMELAND SECURITY SECURITY OF VESSELS SECURITY OF PASSENGER VESSELS Security Program § 120.220... officer must report each breach of security, unlawful act, or threat of an unlawful act against any......

  2. 33 CFR 120.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and to the local office of the Federal Bureau of Investigation (FBI). Also, if your vessel is a U.S..., DEPARTMENT OF HOMELAND SECURITY SECURITY OF VESSELS SECURITY OF PASSENGER VESSELS Security Program § 120.220... officer must report each breach of security, unlawful act, or threat of an unlawful act against any......

  3. 33 CFR 120.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and to the local office of the Federal Bureau of Investigation (FBI). Also, if your vessel is a U.S..., DEPARTMENT OF HOMELAND SECURITY SECURITY OF VESSELS SECURITY OF PASSENGER VESSELS Security Program § 120.220... officer must report each breach of security, unlawful act, or threat of an unlawful act against any......

  4. 33 CFR 120.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and to the local office of the Federal Bureau of Investigation (FBI). Also, if your vessel is a U.S..., DEPARTMENT OF HOMELAND SECURITY SECURITY OF VESSELS SECURITY OF PASSENGER VESSELS Security Program § 120.220... officer must report each breach of security, unlawful act, or threat of an unlawful act against any......

  5. 33 CFR 120.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and to the local office of the Federal Bureau of Investigation (FBI). Also, if your vessel is a U.S..., DEPARTMENT OF HOMELAND SECURITY SECURITY OF VESSELS SECURITY OF PASSENGER VESSELS Security Program § 120.220... officer must report each breach of security, unlawful act, or threat of an unlawful act against any......

  6. Propagation of Environmental Noise

    ERIC Educational Resources Information Center

    Lyon, R. H.

    1973-01-01

    Solutions for environmental noise pollution lie in systematic study of many basic processes such as reflection, scattering, and spreading. Noise propagation processes should be identified in different situations and assessed for their relative importance. (PS)

  7. Wave Propagation Program

    SciTech Connect

    McCandless, Kathleen; Petersson, Anders; Nilsson, Stefan; Sjogreen, Bjorn

    2007-01-08

    WPP is a massively parallel, 3D, C++, finite-difference elastodynamic wave propagation code. Typical applications for wave propagation with WPP include: evaluation of seismic event scenarios and damage from earthquakes, non-destructive evaluation of materials, underground facility detection, oil and gas exploration, predicting the electro-magnetic fields in accelerators, and acoustic noise generation. For more information, see User’s Manual [1].

  8. Database for propagation models

    NASA Technical Reports Server (NTRS)

    Kantak, Anil V.

    1991-01-01

    A propagation researcher or a systems engineer who intends to use the results of a propagation experiment is generally faced with various database tasks such as the selection of the computer software, the hardware, and the writing of the programs to pass the data through the models of interest. This task is repeated every time a new experiment is conducted or the same experiment is carried out at a different location generating different data. Thus the users of this data have to spend a considerable portion of their time learning how to implement the computer hardware and the software towards the desired end. This situation may be facilitated considerably if an easily accessible propagation database is created that has all the accepted (standardized) propagation phenomena models approved by the propagation research community. Also, the handling of data will become easier for the user. Such a database construction can only stimulate the growth of the propagation research it if is available to all the researchers, so that the results of the experiment conducted by one researcher can be examined independently by another, without different hardware and software being used. The database may be made flexible so that the researchers need not be confined only to the contents of the database. Another way in which the database may help the researchers is by the fact that they will not have to document the software and hardware tools used in their research since the propagation research community will know the database already. The following sections show a possible database construction, as well as properties of the database for the propagation research.

  9. Resource allocation using constraint propagation

    NASA Technical Reports Server (NTRS)

    Rogers, John S.

    1990-01-01

    The concept of constraint propagation was discussed. Performance increases are possible with careful application of these constraint mechanisms. The degree of performance increase is related to the interdependence of the different activities resource usage. Although this method of applying constraints to activities and resources is often beneficial, it is obvious that this is no panacea cure for the computational woes that are experienced by dynamic resource allocation and scheduling problems. A combined effort for execution optimization in all areas of the system during development and the selection of the appropriate development environment is still the best method of producing an efficient system.

  10. Career Education Activities Supported Under the Career Education Incentive Act (Public Law 95-207). Third Year's Program (Fiscal Year 1981 Funding).

    ERIC Educational Resources Information Center

    Office of Career Education (ED), Washington, DC.

    This report describes the fiscal year 1981 appropriations for implementing the third year of activities under the Career Education Incentive Act. Summarized first are three projects involving the demonstration and validation of a comprehensive elementary/secondary career project in a local setting (in the Ceres Unified School District in…

  11. Factors Associated with Implementation of the South Carolina Students Health and Fitness Act of 2005: Elementary School Principals' and Physical Activity Directors' Ratings

    ERIC Educational Resources Information Center

    Evans, Miriam Jones

    2012-01-01

    This study explores factors associated with implementation of the physical education and physical activity standards of the South Carolina Students Health and Fitness Act of 2005 in Title I elementary schools. The study was framed using selected components of the diffusion of innovations theory, which looked at characteristics of the law and their…

  12. Performance test results of noninvasive characterization of Resource Conservation and Recovery Act surrogate waste by prompt gamma neutron activation analysis

    SciTech Connect

    Gehrke, R.J.; Streier, G.G.

    1997-03-01

    During FY-96, a performance test was carried out with funding from the Mixed Waste Focus Area (MWFA) of the Department of Energy (DOE) to determine the noninvasive elemental assay capabilities of commercial companies for Resource Conservation and Recovery Act (RCRA) metals present in 8-gal drums containing surrogate waste. Commercial companies were required to be experienced in the use of prompt gamma neutron activation analysis (PGNAA) techniques and to have a prototype assay system with which to conduct the test assays. Potential participants were identified through responses to a call for proposals advertised in the Commerce Business Daily and through personal contacts. Six companies were originally identified. Two of these six were willing and able to participate in the performance test, as described in the test plan, with some subsidizing from the DOE MWFA. The tests were conducted with surrogate sludge waste because (1) a large volume of this type of waste awaits final disposition and (2) sludge tends to be somewhat homogeneous. The surrogate concentrations of the above RCRA metals ranged from {approximately} 300 ppm to {approximately} 20,000 ppm. The lower limit was chosen as an estimate of the expected sensitivity of detection required by noninvasive, pretreatment elemental assay systems to be of value for operational and compliance purposes and to still be achievable with state-of-the-art methods of analysis. The upper limit of {approximately} 20,000 ppm was chosen because it is the opinion of the author that assay above this concentration level is within current state-of-the-art methods for most RCRA constituents. This report is organized into three parts: Part 1, Test Plan to Evaluate the Technical Status of Noninvasive Elemental Assay Techniques for Hazardous Waste; Part 2, Participants` Results; and Part 3, Evaluation of and Comments on Participants` Results.

  13. The redox-active drug metronidazole and thiol-depleting garlic compounds act synergistically in the protist parasite Spironucleus vortens.

    PubMed

    Williams, C F; Vacca, A R; Dunham, L; Lloyd, D; Coogan, M P; Evans, G; Graz, M; Cable, J

    2016-01-01

    Spironucleus vortens is a protozoan parasite associated with significant mortalities in the freshwater angelfish, Pterophyllum scalare. Control of this parasite is especially problematic due to restrictions on the use of the drug of choice, metronidazole (MTZ), on fish farms. Use of garlic (Allium sativum) is undergoing a renaissance following experimental validations of its antimicrobial efficiency. Ajoene ((E,Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide), is a stable transformation product of allicin, the primary biologically active component of garlic. In the current study, an ajoene oil crude extract had a minimum inhibitory concentration (MIC) of 40μg/ml against S. vortens. GC-MS and NMR spectroscopy revealed this ajoene extract contained a mixture of the (E) and (Z)-ajoene isomers along with diallyl disulphide (DADS) and diallyl trisulphide (DATS). The only component of the ajoene crude oil found to substantially inhibit S. vortens growth by optical density monitoring (Bioscreen C Reader) was (Z)-ajoene (MIC 16μg/ml). Ajoene oil acted in synergy with MTZ in vitro, reducing the individual MIC of this drug (4μg/ml) by 16-fold, and that of ajoene oil by 200-fold with a fractional inhibitory concentration (FIC) index of 0.263. This synergistic interaction was confirmed in vivo. S. vortens-infected Pterophyllum scalare angelfish dosed orally with 0.5% (v/w) MTZ combined with 0.05% (v/w) ajoene displayed a significant reduction in faecal trophozoite count, whilst those fed on 0.5% MTZ flakes (half the recommended oral dose) alone did not. This study demonstrates for the first time the synergistic interaction between the synthetic drug MTZ and natural ajoene oil both in vitro and in vivo. Future work should evaluate the potential synergy of ajoene and MTZ against MTZ-resistant bacteria and protists. PMID:26968264

  14. The redox-active drug metronidazole and thiol-depleting garlic compounds act synergistically in the protist parasite Spironucleus vortens.

    PubMed

    Williams, C F; Vacca, A R; Dunham, L; Lloyd, D; Coogan, M P; Evans, G; Graz, M; Cable, J

    2016-01-01

    Spironucleus vortens is a protozoan parasite associated with significant mortalities in the freshwater angelfish, Pterophyllum scalare. Control of this parasite is especially problematic due to restrictions on the use of the drug of choice, metronidazole (MTZ), on fish farms. Use of garlic (Allium sativum) is undergoing a renaissance following experimental validations of its antimicrobial efficiency. Ajoene ((E,Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide), is a stable transformation product of allicin, the primary biologically active component of garlic. In the current study, an ajoene oil crude extract had a minimum inhibitory concentration (MIC) of 40μg/ml against S. vortens. GC-MS and NMR spectroscopy revealed this ajoene extract contained a mixture of the (E) and (Z)-ajoene isomers along with diallyl disulphide (DADS) and diallyl trisulphide (DATS). The only component of the ajoene crude oil found to substantially inhibit S. vortens growth by optical density monitoring (Bioscreen C Reader) was (Z)-ajoene (MIC 16μg/ml). Ajoene oil acted in synergy with MTZ in vitro, reducing the individual MIC of this drug (4μg/ml) by 16-fold, and that of ajoene oil by 200-fold with a fractional inhibitory concentration (FIC) index of 0.263. This synergistic interaction was confirmed in vivo. S. vortens-infected Pterophyllum scalare angelfish dosed orally with 0.5% (v/w) MTZ combined with 0.05% (v/w) ajoene displayed a significant reduction in faecal trophozoite count, whilst those fed on 0.5% MTZ flakes (half the recommended oral dose) alone did not. This study demonstrates for the first time the synergistic interaction between the synthetic drug MTZ and natural ajoene oil both in vitro and in vivo. Future work should evaluate the potential synergy of ajoene and MTZ against MTZ-resistant bacteria and protists.

  15. Chlamydia screening for sexually active young women under the Affordable Care Act: new opportunities and lingering barriers.

    PubMed

    Loosier, Penny S; Malcarney, Mary-Beth; Slive, Lauren; Cramer, Ryan C; Burgess, Brittany; Hoover, Karen W; Romaguera, Raul

    2014-09-01

    The Affordable Care Act of 2010 (ACA) contains a provision requiring private insurers issuing or renewing plans on or after September 23, 2010, to provide, without cost sharing, preventive services recommended by US Preventive Services Task Force (grades A and B), among other recommending bodies. As a grade A recommendation, chlamydia screening for sexually active young women 24 years and younger and older women at risk for chlamydia falls under this requirement. This article examines the potential effect on chlamydia screening among this population across private and public health plans and identifies lingering barriers not addressed by this legislation. Examination of the impact on women with private insurance touches upon the distinction between coverage under grandfathered plans, where the requirement does not apply, and nongrandfathered plans, where the requirement does apply. Acquisition of private health insurance through health insurance Marketplaces is also discussed. For public health plans, coverage of preventive services without cost sharing differs for individuals enrolled in standard Medicaid, covered under the Medicaid expansion included in the ACA, or those enrolled under the Children's Health Insurance Program or who fall under Early, Periodic, Screening, Diagnosis and Treatment criteria. The discussion of lingering barriers not addressed by the ACA includes the uninsured, physician reimbursement, cost sharing, confidentiality, low rates of appropriate sexual history taking by providers, and disclosures of sensitive information. In addition, the role of safety net programs that provide health care to individuals regardless of ability to pay is examined in light of the expectation that they also remain a payer of last resort. PMID:25118966

  16. Dike Propagation Near Drifts

    SciTech Connect

    NA

    2002-03-04

    The purpose of this Analysis and Model Report (AMR) supporting the Site Recommendation/License Application (SR/LA) for the Yucca Mountain Project is the development of elementary analyses of the interactions of a hypothetical dike with a repository drift (i.e., tunnel) and with the drift contents at the potential Yucca Mountain repository. This effort is intended to support the analysis of disruptive events for Total System Performance Assessment (TSPA). This AMR supports the Process Model Report (PMR) on disruptive events (CRWMS M&O 2000a). This purpose is documented in the development plan (DP) ''Coordinate Modeling of Dike Propagation Near Drifts Consequences for TSPA-SR/LA'' (CRWMS M&O 2000b). Evaluation of that Development Plan and the work to be conducted to prepare Interim Change Notice (ICN) 1 of this report, which now includes the design option of ''Open'' drifts, indicated that no revision to that DP was needed. These analyses are intended to provide reasonable bounds for a number of expected effects: (1) Temperature changes to the waste package from exposure to magma; (2) The gas flow available to degrade waste containers during the intrusion; (3) Movement of the waste package as it is displaced by the gas, pyroclasts and magma from the intruding dike (the number of packages damaged); (4) Movement of the backfill (Backfill is treated here as a design option); (5) The nature of the mechanics of the dike/drift interaction. These analyses serve two objectives: to provide preliminary analyses needed to support evaluation of the consequences of an intrusive event and to provide a basis for addressing some of the concerns of the Nuclear Regulatory Commission (NRC) expressed in the Igneous Activity Issue Resolution Status Report.

  17. ACT: Acting Out Central Theme.

    ERIC Educational Resources Information Center

    Kise, Joan Duff

    1982-01-01

    The author describes ACT (Acting Out Central Theme), a method for dealing with psychomotor, cognitive, and affective domains in slow readers. The ACT approach involves three sessions which focus on discussion of a theme such as friendship, presentaton of the theme as a skit, and assignment of topics to individual students. (SW)

  18. DROMO Propagator Revisited

    NASA Astrophysics Data System (ADS)

    Urrutxua, H.; Sanjurjo-Rivo, M.; Peláez, J.

    2013-12-01

    In year 2000 a house-made orbital propagator was developed by the SDGUPM (former Grupo de Dinámica de Tethers) based in a set of redundant variables including Euler parameters. This propagator was called DROMO. and it was mainly used in numerical simulations of electrodynamic tethers. It was presented for the first time in the international meeting V Jornadas de Trabajo en Mecánica Celeste, held in Albarracín, Spain, in 2002 (see reference 1). The special perturbation method associated with DROMO can be consulted in the paper.2 In year 1975, Andre Deprit in reference 3 proposes a propagation scheme very similar to the one in which DROMO is based, by using the ideal frame concept of Hansen. The different approaches used in references 3 and 2 gave rise to a small controversy. In this paper we carried out a different deduction of the DROMO propagator, underlining its close relation with the Hansen ideal frame concept, and also the similarities and the differences with the theory carried out by Deprit in 3. Simultaneously we introduce some improvements in the formulation that leads to a more synthetic propagator.

  19. First-in-Humans Study of the Safety, Tolerability, and Pharmacokinetics of ACT-451840, a New Chemical Entity with Antimalarial Activity

    PubMed Central

    Bruderer, Shirin; Hurst, Noémie; de Kanter, Ruben; Miraval, Tommaso; Pfeifer, Thomas; Donazzolo, Yves

    2014-01-01

    Emerging resistance to antimalarial agents raises the need for new drugs. ACT-451840 is a new compound with potent activity against sensitive and resistant Plasmodium falciparum strains. This was a first-in-humans single-ascending-dose study to investigate the safety, tolerability, and pharmacokinetics of ACT-451840 across doses of 10, 50, 200, and 500 mg in healthy male subjects. In the 200- and 500-mg dose groups, the effect of food was investigated, and antimalarial activity was assessed using an ex vivo bioassay with P. falciparum. No (serious) adverse events leading to discontinuation were reported. At the highest dose level, the peak drug concentration (Cmax) and the area under the plasma concentration-time curve from zero to infinity of ACT-451840 under fasted conditions reached 11.9 ng/ml and 100.6 ng · h/ml, respectively, and these were approximately 13-fold higher under fed conditions. Food did not affect the half-life (approximately 34 h) of the drug, while the Cmax was attained 2.0 and 3.5 h postdose under fasted and fed conditions, respectively. The plasma concentrations estimated by the bioassay were approximately 4-fold higher than those measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Several potentially active metabolites were also identified. ACT-451840 was well tolerated across all doses. Exposure to ACT-451840 significantly increased with food. The bioassay indicated the presence of circulating active metabolites. (This study has been registered at ClinicalTrials.gov under registration no. NCT02186002.) PMID:25421475

  20. First-in-humans study of the safety, tolerability, and pharmacokinetics of ACT-451840, a new chemical entity with antimalarial activity.

    PubMed

    Bruderer, Shirin; Hurst, Noémie; de Kanter, Ruben; Miraval, Tommaso; Pfeifer, Thomas; Donazzolo, Yves; Dingemanse, Jasper

    2015-02-01

    Emerging resistance to antimalarial agents raises the need for new drugs. ACT-451840 is a new compound with potent activity against sensitive and resistant Plasmodium falciparum strains. This was a first-in-humans single-ascending-dose study to investigate the safety, tolerability, and pharmacokinetics of ACT-451840 across doses of 10, 50, 200, and 500 mg in healthy male subjects. In the 200- and 500-mg dose groups, the effect of food was investigated, and antimalarial activity was assessed using an ex vivo bioassay with P. falciparum. No (serious) adverse events leading to discontinuation were reported. At the highest dose level, the peak drug concentration (Cmax) and the area under the plasma concentration-time curve from zero to infinity of ACT-451840 under fasted conditions reached 11.9 ng/ml and 100.6 ng·h/ml, respectively, and these were approximately 13-fold higher under fed conditions. Food did not affect the half-life (approximately 34 h) of the drug, while the Cmax was attained 2.0 and 3.5 h postdose under fasted and fed conditions, respectively. The plasma concentrations estimated by the bioassay were approximately 4-fold higher than those measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Several potentially active metabolites were also identified. ACT-451840 was well tolerated across all doses. Exposure to ACT-451840 significantly increased with food. The bioassay indicated the presence of circulating active metabolites. (This study has been registered at ClinicalTrials.gov under registration no. NCT02186002.). PMID:25421475

  1. Screening for trans-acting factors and other factors involved in the activating or silencing of the gamma-globin gene during human ontogeny.

    PubMed

    Ma, Yan-Ni; Zhang, Xin; Zhang, Jun-Wu; Zhang, Xin-Hua; Wang, Rong-Xin

    2007-06-01

    Researchers hope to increase gamma-globin expression by controlling potential trans-acting factors that specifically activate the gamma-globin gene in fetuses or silence this gene in adults to potentially treat sickle cell disease and beta-thalassemias. To characterize genes encoding such factors, we analyzed the differential expression of mRNAs in erythroid induction cultures of CD34+ cells derived from normal adult bone marrow, umbilical cord blood, and bone marrow from a patient with heterocellular hereditary persistence of fetal hemoglobin. Using differential-display - reverse-transcription PCR analysis, we identified a number of genes with differential expression in the above-mentioned cells. The differential expression of some genes was also confirmed by quantitative real-time PCR. Our data provide important clues for identifying and validating trans-activators that activate the gamma-globin gene in fetuses, and trans-acting factors involved in silencing the gamma-globin gene in adults.

  2. [Criminal responsibility in schizophrenia with special attention to the mental state during the criminal act--a study based upon the activation-recurrence phenomenon].

    PubMed

    Higashi, Takahiro

    2009-01-01

    In this article, psychiatric arguments regarding criminal responsibility in schizophrenia are reviewed, and it is pointed out that the arguments have been influenced by the theory of process psychosis. Moreover, two cases judged on the basis of the activation-recurrence phenomenon are exemplified, and fundamental issues are discussed. Investigating the mental state just before the crime helps when deliberating over criminal responsibility. A study of the activation-recurrence phenomenon, conducted by Shinkai and Miyasaka, contributes toward clarifying the recurrence of the micropsychotic state during the criminal act. Generally, schizophrenia is characterized by an alternation between the micropsychotic and basic normal states, and classified clinically into severe, moderate, and mild according to the level of susceptibility to the occurrence of the activation-recurrence phenomenon. Differentiating between the form and contents of the micropsychotic state is of marked importance in schizophrenia. In addition, identifying the form facilitates the distinction between behaviors while sane and those during schizophrenic episodes. Practically, the activating stimuli, which are likely to trigger the micropsychotic state, are applied in the interview to establish the psychiatric testimony based upon the activation-recurrence phenomenon. After the diagnosis of schizophrenia has been confirmed, the examinee is exposed to the stimuli possibly activating the micropsychotic state during the criminal act. Observing the recurrence of the micropsychotic state and its frequency enables estimation of the susceptibility to the occurrence of the activation-recurrence phenomenon and the mental state during the criminal act. Therefore, if a micropsychotic state during the criminal act can be confirmed, the inability to be held legally responsible is postulated. In contrast, if a micropsychotic state during the criminal act cannot be confirmed, the specialist giving the psychiatric

  3. Automatic crack propagation tracking

    NASA Technical Reports Server (NTRS)

    Shephard, M. S.; Weidner, T. J.; Yehia, N. A. B.; Burd, G. S.

    1985-01-01

    A finite element based approach to fully automatic crack propagation tracking is presented. The procedure presented combines fully automatic mesh generation with linear fracture mechanics techniques in a geometrically based finite element code capable of automatically tracking cracks in two-dimensional domains. The automatic mesh generator employs the modified-quadtree technique. Crack propagation increment and direction are predicted using a modified maximum dilatational strain energy density criterion employing the numerical results obtained by meshes of quadratic displacement and singular crack tip finite elements. Example problems are included to demonstrate the procedure.

  4. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study, volume 1

    NASA Technical Reports Server (NTRS)

    Hanks, G. W.; Shomber, H. A.; Dethman, H. A.; Gratzer, L. B.; Maeshiro, A.; Gangsaas, D.; Blight, J. D.; Buchan, S. M.; Crumb, C. B.; Dorwart, R. J.

    1981-01-01

    An active controls technology (ACT) system architecture was selected based on current technology system elements and optimal control theory was evaluated for use in analyzing and synthesizing ACT multiple control laws. The system selected employs three redundant computers to implement all of the ACT functions, four redundant smaller computers to implement the crucial pitch-augmented stability function, and a separate maintenance and display computer. The reliability objective of probability of crucial function failure of less than 1 x 10 to the -9th power per flight of 1 hr can be met with current technology system components, if the software is assumed fault free and coverage approaching 1.0 can be provided. The optimal control theory approach to ACT control law synthesis yielded comparable control law performance much more systematically and directly than the classical s-domain approach. The ACT control law performance, although somewhat degraded by the inclusion of representative nonlinearities, remained quite effective. Certain high-frequency gust-load alleviation functions may require increased surface rate capability.

  5. 50 CFR 80.51 - What activities are eligible for funding under the Dingell-Johnson Sport Fish Restoration Act?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... under the Dingell-Johnson Sport Fish Restoration Act? 80.51 Section 80.51 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) FINANCIAL ASSISTANCE-WILDLIFE SPORT FISH RESTORATION PROGRAM ADMINISTRATIVE REQUIREMENTS, PITTMAN-ROBERTSON WILDLIFE RESTORATION...

  6. A Synthesis of Activities Leading to the Enactment of the Vocational Education Act of 1963. Final Report.

    ERIC Educational Resources Information Center

    Ellis, Mary Louise

    The Vocational Education Act of 1963 was an apparent outgrowth of economic conditions and societal needs which existed in the United States in the late 1950's and early 1960's. The nation's most urgent domestic problem was unemployment while paradoxically millions of jobs which required skilled workers continued unfilled. This study was concerned…

  7. 45 CFR 90.3 - What programs or activities does the Age Discrimination Act of 1975 cover?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Discrimination Act of 1975 cover? 90.3 Section 90.3 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES...) An age distinction contained in that part of a Federal, State or local statute or ordinance adopted by an elected, general purpose legislative body which: (i) Provides any benefits or assistance...

  8. 20 CFR 667.220 - What Workforce Investment Act title I functions and activities constitute the costs of...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... program costs to the benefitting cost objectives/categories based on documented distributions of actual... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false What Workforce Investment Act title I...? 667.220 Section 667.220 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT...

  9. 20 CFR 667.220 - What Workforce Investment Act title I functions and activities constitute the costs of...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... program costs to the benefitting cost objectives/categories based on documented distributions of actual... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false What Workforce Investment Act title I...? 667.220 Section 667.220 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT...

  10. 33 CFR 128.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Federal Bureau of Investigation (FBI), and to the local police agency having jurisdiction over the..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT FACILITIES SECURITY OF PASSENGER TERMINALS Security... terminal security officer must report each breach of security, unlawful act, or threat of an unlawful...

  11. 33 CFR 128.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Federal Bureau of Investigation (FBI), and to the local police agency having jurisdiction over the..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT FACILITIES SECURITY OF PASSENGER TERMINALS Security... terminal security officer must report each breach of security, unlawful act, or threat of an unlawful...

  12. 33 CFR 128.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Federal Bureau of Investigation (FBI), and to the local police agency having jurisdiction over the..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT FACILITIES SECURITY OF PASSENGER TERMINALS Security... terminal security officer must report each breach of security, unlawful act, or threat of an unlawful...

  13. 33 CFR 128.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Federal Bureau of Investigation (FBI), and to the local police agency having jurisdiction over the..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT FACILITIES SECURITY OF PASSENGER TERMINALS Security... terminal security officer must report each breach of security, unlawful act, or threat of an unlawful...

  14. 33 CFR 128.220 - What must I do to report an unlawful act and related activity?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Federal Bureau of Investigation (FBI), and to the local police agency having jurisdiction over the..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) WATERFRONT FACILITIES SECURITY OF PASSENGER TERMINALS Security... terminal security officer must report each breach of security, unlawful act, or threat of an unlawful...

  15. DROMO propagator revisited

    NASA Astrophysics Data System (ADS)

    Urrutxua, Hodei; Sanjurjo-Rivo, Manuel; Peláez, Jesús

    2016-01-01

    In the year 2000 an in-house orbital propagator called DROMO (Peláez et al. in Celest Mech Dyn Astron 97:131-150, 2007. doi: 10.1007/s10569-006-9056-3) was developed by the Space Dynamics Group of the Technical University of Madrid, based in a set of redundant variables including Euler-Rodrigues parameters. An original deduction of the DROMO propagator is carried out, underlining its close relation with the ideal frame concept introduced by Hansen (Abh der Math-Phys Cl der Kon Sachs Ges der Wissensch 5:41-218, 1857). Based on the very same concept, Deprit (J Res Natl Bur Stand Sect B Math Sci 79B(1-2):1-15, 1975) proposed a formulation for orbit propagation. In this paper, similarities and differences with the theory carried out by Deprit are analyzed. Simultaneously, some improvements are introduced in the formulation, that lead to a more synthetic and better performing propagator. Also, the long-term effect of the oblateness of the primary is studied in terms of DROMO variables, and new numerical results are presented to evaluate the performance of the method.

  16. COBE nonspinning attitude propagation

    NASA Technical Reports Server (NTRS)

    Chu, D.

    1989-01-01

    The Cosmic Background Explorer (COBE) spacecraft will exhibit complex attitude motion consisting of a spin rate of approximately -0.8 revolution per minute (rpm) about the x-axis and simultaneous precession of the spin axis at a rate of one revolution per orbit (rpo) about the nearly perpendicular spacecraft-to-Sun vector. The effect of the combined spinning and precession is to make accurate attitude propagation difficult and the 1-degree (3 sigma) solution accuracy goal problematic. To improve this situation, an intermediate reference frame is introduced, and the angular velocity divided into two parts. The nonspinning part is that which would be observed if there were no rotation about the X-axis. The spinning part is simply the X-axis component of the angular velocity. The two are propagated independently and combined whenever the complete attitude is needed. This approach is better than the usual one-step method because each of the two angular velocities look nearly constant in their respective reference frames. Since the angular velocities are almost constant, the approximations made in discrete time propagation are more nearly true. To demonstrate the advantages of this nonspinning method, attitude is propagated as outlined above and is then compared with the results of the one-step method. Over the 100-minute COBE orbit, the one-step error grows to several degrees while the nonspinning error remains negligible.

  17. A nonlinear model of ionic wave propagation along microtubules.

    PubMed

    Satarić, M V; Ilić, D I; Ralević, N; Tuszynski, Jack Adam

    2009-06-01

    Microtubules (MTs) are important cytoskeletal polymers engaged in a number of specific cellular activities including the traffic of organelles using motor proteins, cellular architecture and motility, cell division and a possible participation in information processing within neuronal functioning. How MTs operate and process electrical information is still largely unknown. In this paper we investigate the conditions enabling MTs to act as electrical transmission lines for ion flows along their lengths. We introduce a model in which each tubulin dimer is viewed as an electric element with a capacitive, inductive and resistive characteristics arising due to polyelectrolyte nature of MTs. Based on Kirchhoff's laws taken in the continuum limit, a nonlinear partial differential equation is derived and analyzed. We demonstrate that it can be used to describe the electrostatic potential coupled to the propagating localized ionic waves. PMID:19259657

  18. Transcriptional activation of the herpes simplex virus type 1 UL38 promoter conferred by the cis-acting downstream activation sequence is mediated by a cellular transcription factor.

    PubMed Central

    Guzowski, J F; Singh, J; Wagner, E K

    1994-01-01

    The herpes simplex virus (HSV) type 1 strict late (gamma) UL38 promoter contains three cis-acting transcriptional elements: a TATA box, a specific initiator element, and the downstream activation sequence (DAS). DAS is located between positions +20 and +33 within the 5' untranslated leader region and strongly influences transcript levels during productive infection. In this communication, we further characterize DAS and investigate its mechanism of action. DAS function has a strict spacing requirement, and DAS contains an essential 6-bp core element. A similarly positioned element from the gamma gC gene (UL44) has partial DAS function within the UL38 promoter context, and the promoter controlling expression of the gamma US11 transcript contains an identically located element with functional and sequence similarity to UL38 DAS. These data suggest that downstream elements are a common feature of many HSV gamma promoters. Results with recombinant viruses containing modifications of the TATA box or initiator element of the UL38 promoter suggest that DAS functions to increase transcription initiation and not the efficiency of transcription elongation. In vitro transcription assays using uninfected HeLa nuclear extracts show that, as in productive infection with recombinant viruses, the deletion of DAS from the UL38 promoter dramatically decreases RNA expression. Finally, electrophoretic mobility shift assays and UV cross-linking experiments show that DAS DNA forms a specific, stable complex with a cellular protein (the DAS-binding factor) of approximately 35 kDa. These data strongly suggest that the interaction of cellular DAS-binding factor with DAS is required for efficient expression of UL38 and other HSV late genes. Images PMID:7966567

  19. Juggling Act

    ERIC Educational Resources Information Center

    Rudalevige, Andrew

    2009-01-01

    Two education bills from George W. Bush's first term are long overdue for reauthorization. One, of course, is the No Child Left Behind Act (NCLB), passed in late 2001. The other is the Education Sciences Reform Act (ESRA), which in November 2002 replaced the Office of Educational Research and Improvement (OERI) with a new Institute of Education…

  20. Synaptic Contacts Enhance Cell-to-Cell Tau Pathology Propagation.

    PubMed

    Calafate, Sara; Buist, Arjan; Miskiewicz, Katarzyna; Vijayan, Vinoy; Daneels, Guy; de Strooper, Bart; de Wit, Joris; Verstreken, Patrik; Moechars, Diederik

    2015-05-26

    Accumulation of insoluble Tau protein aggregates and stereotypical propagation of Tau pathology through the brain are common hallmarks of tauopathies, including Alzheimer's disease (AD). Propagation of Tau pathology appears to occur along connected neurons, but whether synaptic contacts between neurons are facilitating propagation has not been demonstrated. Using quantitative in vitro models, we demonstrate that, in parallel to non-synaptic mechanisms, synapses, but not merely the close distance between the cells, enhance the propagation of Tau pathology between acceptor hippocampal neurons and Tau donor cells. Similarly, in an artificial neuronal network using microfluidic devices, synapses and synaptic activity are promoting neuronal Tau pathology propagation in parallel to the non-synaptic mechanisms. Our work indicates that the physical presence of synaptic contacts between neurons facilitate Tau pathology propagation. These findings can have implications for synaptic repair therapies, which may turn out to have adverse effects by promoting propagation of Tau pathology.

  1. In vitro propagation by asymbiotic seed germination and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity studies of tissue culture raised plants of three medicinally important species of dendrobium.

    PubMed

    Lo, Shu-Fung; Nalawade, Satish Manohar; Mulabagal, Vanisree; Matthew, Susan; Chen, Chung-Li; Kuo, Chao-Lin; Tsay, Hsin-Sheng

    2004-05-01

    A simple and efficient plant propagation system has been developed by asymbiotic germination of seeds in three medicinally important Dendrobium species, namely, Dendrobium tosaense, Dendrobium moniliforme, and Dendrobium linawianum. Plants obtained from natural habitats were grown in the greenhouse. The flowers were hand pollinated. Seeds of the capsules derived after 12 weeks of hand-pollination germinated asymbiotically (50-74%) on half strength Murashige and Skoog's (MS) basal medium with 3% sucrose and solidified with 0.9% Difco agar. Active growth in the germinated seedlings was achieved by re-culturing on full strength MS basal medium supplemented with 8% banana homogenate, 8% potato homogenate, 8% coconut water, 1.5% sucrose and 0.9% Difco agar. Healthy plantlets, transferred to plastic trays containing moss or moss and tree fern, successfully acclimatized (84-100%) in the greenhouse. A marked varied response was observed in the free radical scavenging activity of methanolic extracts of in vitro propagated plants, on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical using a UV spectrophotometer assay. Methanolic extracts were prepared by dissolving the powdered plant material, obtained from six months old in vitro propagated plants, each about 5 g, in boiling methanol. The percentage of scavenging effect of D. tosaense extract was 95.9% at 0.4 mg/ml concentration, whereas D. monoliforme, and D. linawianum extracts scavenged 83.4% and 92.3%, respectively, at a concentration of 0.4 mg/ml. All the extracts scavenged DPPH radical significantly in a concentration dependent manner. PMID:15133256

  2. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Test act system description

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The engineering and fabrication of the test ACT system, produced in the third program element of the IAAC Project is documented. The system incorporates pitch-augmented stability and wing-load alleviation, plus full authority fly-by-wire control of the elevators. The pitch-augmented stability is designed to have reliability sufficient to allow flight with neutral or negative inherent longitudinal stability.

  3. Results of screening activities in salt states prior to the enactment of the Nationall Waste Policy Act

    SciTech Connect

    Carbiener, W.A.

    1983-01-01

    The identification of potential sites for a nuclear waste repository through screening procedures in the salt states is a well-established, deliberate process. This screening process has made it possible to carry out detailed studies of many of the most promising potential sites, and general studies of all the sites, in anticipation of the siting guidelines specified in the Nuclear Waste Policy Act. The screening work completed prior to the passage of the Act allowed the Secretary of Energy to identify seven salt sites as potentially acceptable under the provisions of Section 116(a) of the Act. These sites were formally identified by letters from Secretary Hodel to the states of Texas, Utah, Mississippi, and Louisiana on February 2, 1983. The potentially acceptable salt sites were in Deaf Smith and Swisher Counties in Texas; Davis and Lavender Canyons in the Gibson Dome location in Utah; Richton and Cypress Creek Domes in Mississippi; and Vacherie Dome in Louisiana. Further screening will include comparison of each potentially acceptable site against disqualification factors and selection of a preferred site in each of the three geohydrologic settings from those remaining, in accordance with the siting guidelines. These steps will be documented in statutory Environmental Assessments prepared for each site to be nominated for detailed characterization. 9 references.

  4. Strong and Coherent Coupling between Localized and Propagating Phonon Polaritons.

    PubMed

    Gubbin, Christopher R; Martini, Francesco; Politi, Alberto; Maier, Stefan A; De Liberato, Simone

    2016-06-17

    Following the recent observation of localized phonon polaritons in user-defined silicon carbide nanoresonators, here we demonstrate strong and coherent coupling between those localized modes and propagating phonon polaritons bound to the surface of the nanoresonator's substrate. In order to obtain phase matching, the nanoresonators have been fabricated to serve the double function of hosting the localized modes, while also acting as a grating for the propagating ones. The coherent coupling between long lived, optically accessible localized modes, and low-loss propagative ones, opens the way to the design and realization of phonon-polariton based coherent circuits. PMID:27367398

  5. Strong and Coherent Coupling between Localized and Propagating Phonon Polaritons

    NASA Astrophysics Data System (ADS)

    Gubbin, Christopher R.; Martini, Francesco; Politi, Alberto; Maier, Stefan A.; De Liberato, Simone

    2016-06-01

    Following the recent observation of localized phonon polaritons in user-defined silicon carbide nanoresonators, here we demonstrate strong and coherent coupling between those localized modes and propagating phonon polaritons bound to the surface of the nanoresonator's substrate. In order to obtain phase matching, the nanoresonators have been fabricated to serve the double function of hosting the localized modes, while also acting as a grating for the propagating ones. The coherent coupling between long lived, optically accessible localized modes, and low-loss propagative ones, opens the way to the design and realization of phonon-polariton based coherent circuits.

  6. Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Current and Advanced Technology ACT control system definition tasks of the Integrated Application of Active Controls (IAAC) Technology project within the Energy Efficient Transport Program are summarized. The systems mechanize six active control functions: (1) pitch augmented stability; (2) angle of attack limiting; (3) lateral/directional augmented stability; (4) gust load alleviation; (5) maneuver load control; and (6) flutter mode control. The redundant digital control systems meet all function requirements with required reliability and declining weight and cost as advanced technology is introduced.

  7. Transionospheric Propagation Code (TIPC)

    SciTech Connect

    Roussel-Dupre, R.; Kelley, T.A.

    1990-10-01

    The Transionospheric Propagation Code is a computer program developed at Los Alamos National Lab to perform certain tasks related to the detection of vhf signals following propagation through the ionosphere. The code is written in Fortran 77, runs interactively and was designed to be as machine independent as possible. A menu format in which the user is prompted to supply appropriate parameters for a given task has been adopted for the input while the output is primarily in the form of graphics. The user has the option of selecting from five basic tasks, namely transionospheric propagation, signal filtering, signal processing, DTOA study, and DTOA uncertainty study. For the first task a specified signal is convolved against the impulse response function of the ionosphere to obtain the transionospheric signal. The user is given a choice of four analytic forms for the input pulse or of supplying a tabular form. The option of adding Gaussian-distributed white noise of spectral noise to the input signal is also provided. The deterministic ionosphere is characterized to first order in terms of a total electron content (TEC) along the propagation path. In addition, a scattering model parameterized in terms of a frequency coherence bandwidth is also available. In the second task, detection is simulated by convolving a given filter response against the transionospheric signal. The user is given a choice of a wideband filter or a narrowband Gaussian filter. It is also possible to input a filter response. The third task provides for quadrature detection, envelope detection, and three different techniques for time-tagging the arrival of the transionospheric signal at specified receivers. The latter algorithms can be used to determine a TEC and thus take out the effects of the ionosphere to first order. Task four allows the user to construct a table of delta-times-of-arrival (DTOAs) vs TECs for a specified pair of receivers.

  8. Florida's propagation report

    NASA Technical Reports Server (NTRS)

    Helmken, Henry; Henning, Rudolf

    1994-01-01

    One of the key goals of the Florida Center is to obtain a maximum of useful information on propagation behavior unique to its subtropical weather and subtropical climate. Such weather data is of particular interest when it is (or has the potential to become) useful for developing and implementing techniques to compensate for adverse weather effects. Also discussed are data observations, current challenges, CDF's, sun movement, and diversity experiments.

  9. Longitudinal elastic wave propagation characteristics of inertant acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Kulkarni, Prateek P.; Manimala, James M.

    2016-06-01

    Longitudinal elastic wave propagation characteristics of acoustic metamaterials with various inerter configurations are investigated using their representative one-dimensional discrete element lattice models. Inerters are dynamic mass-amplifying mechanical elements that are activated by a difference in acceleration across them. They have a small device mass but can provide a relatively large dynamic mass presence depending on accelerations in systems that employ them. The effect of introducing inerters both in local attachments and in the lattice was examined vis-à-vis the propagation characteristics of locally resonant acoustic metamaterials. A simple effective model based on mass, stiffness, or their combined equivalent was used to establish dispersion behavior and quantify attenuation within bandgaps. Depending on inerter configurations in local attachments or in the lattice, both up-shift and down-shift in the bandgap frequency range and their extent are shown to be possible while retaining static mass addition to the host structure to a minimum. Further, frequency-dependent negative and even extreme effective-stiffness regimes are encountered. The feasibility of employing tuned combinations of such mass-delimited inertant configurations to engineer acoustic metamaterials that act as high-pass filters without the use of grounded elements or even as complete longitudinal wave inhibitors is shown. Potential device implications and strategies for practical applications are also discussed.

  10. Waves on Reissner's membrane: a mechanism for the propagation of otoacoustic emissions from the cochlea.

    PubMed

    Reichenbach, Tobias; Stefanovic, Aleksandra; Nin, Fumiaki; Hudspeth, A J

    2012-04-19

    Sound is detected and converted into electrical signals within the ear. The cochlea not only acts as a passive detector of sound, however, but can also produce tones itself. These otoacoustic emissions are a striking manifestation of the cochlea's mechanical active process. A controversy remains of how these mechanical signals propagate back to the middle ear, from which they are emitted as sound. Here, we combine theoretical and experimental studies to show that mechanical signals can be transmitted by waves on Reissner's membrane, an elastic structure within the cochlea. We develop a theory for wave propagation on Reissner's membrane and its role in otoacoustic emissions. Employing a scanning laser interferometer, we measure traveling waves on Reissner's membrane in the gerbil, guinea pig, and chinchilla. The results are in accord with the theory and thus support a role for Reissner's membrane in otoacoustic emissions. PMID:22580949

  11. Waves on Reissner's membrane: a mechanism for the propagation of otoacoustic emissions from the cochlea.

    PubMed

    Reichenbach, Tobias; Stefanovic, Aleksandra; Nin, Fumiaki; Hudspeth, A J

    2012-04-19

    Sound is detected and converted into electrical signals within the ear. The cochlea not only acts as a passive detector of sound, however, but can also produce tones itself. These otoacoustic emissions are a striking manifestation of the cochlea's mechanical active process. A controversy remains of how these mechanical signals propagate back to the middle ear, from which they are emitted as sound. Here, we combine theoretical and experimental studies to show that mechanical signals can be transmitted by waves on Reissner's membrane, an elastic structure within the cochlea. We develop a theory for wave propagation on Reissner's membrane and its role in otoacoustic emissions. Employing a scanning laser interferometer, we measure traveling waves on Reissner's membrane in the gerbil, guinea pig, and chinchilla. The results are in accord with the theory and thus support a role for Reissner's membrane in otoacoustic emissions.

  12. Presentations of the Ninth Advanced Communications Technology Satellite Propagation Studies Workshop (APSW IX)

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser (Editor)

    1997-01-01

    The Advanced Communications Technology Satellite Propagation Studies Workshop (APSW) is convened each year to present the results of the ACTS Propagation Campaign. Representatives from the satellite communications (satcom) industry, academia, and government are invited to APSW for discussions and exchange of information. The ACTS Propagation campaign is completing three years of Ka-Band data collection at seven sites in North America. Through this effort, NASA is making a major contribution to growth of satcom services by providing timely propagation data and models for predicting the performance of Ka-Band satellite communications systems.

  13. A liver X receptor (LXR)-{beta} alternative splicing variant (LXRBSV) acts as an RNA co-activator of LXR-{beta}

    SciTech Connect

    Hashimoto, Koshi; Ishida, Emi; Matsumoto, Shunichi; Shibusawa, Nobuyuki; Okada, Shuichi; Monden, Tsuyoshi; Satoh, Tetsurou; Yamada, Masanobu; Mori, Masatomo

    2009-12-25

    We report the isolation and functional characterization of a novel transcriptional co-activator, termed LXRBSV. LXRBSV is an alternative splicing variant of liver X receptor (LXR)-{beta} LXRBSV has an intronic sequence between exons 2 and 3 in the mouse LXR-{beta} gene. The LXRBSV gene is expressed in various tissues including the liver and brain. We sub-cloned LXRBSV into pSG5, a mammalian expression vector, and LXRBSV in pSG5 augmented human Sterol Response Element Binding Protein (SREBP)-1c promoter activity in HepG2 cells in a ligand (TO901317) dependent manner. The transactivation mediated by LXRBSV is selective for LXR-{beta}. The LXRBSV protein was deduced to be 64 amino acids in length; however, a GAL4-LXRBSV fusion protein was not able to induce transactivation. Serial deletion constructs of LXRBSV demonstrated that the intronic sequence inserted in LXRBSV is required for its transactivation activity. An ATG mutant of LXRBSV was able to induce transactivation as wild type. Furthermore, LXRBSV functions in the presence of cycloheximide. Taken together, we have concluded that LXRBSV acts as an RNA transcript not as a protein. In the current study, we have demonstrated for the first time that an alternative splicing variant of a nuclear receptor acts as an RNA co-activator.

  14. Atmospheric propagation issues relevant to optical communications

    NASA Technical Reports Server (NTRS)

    Churnside, James H.; Shaik, Kamran

    1989-01-01

    Atmospheric propagation issues relevant to space-to-ground optical communications for near-earth applications are studied. Propagation effects, current optical communication activities, potential applications, and communication techniques are surveyed. It is concluded that a direct-detection space-to-ground link using redundant receiver sites and temporal encoding is likely to be employed to transmit earth-sensing satellite data to the ground some time in the future. Low-level, long-term studies of link availability, fading statistics, and turbulence climatology are recommended to support this type of application.

  15. PIV uncertainty propagation

    NASA Astrophysics Data System (ADS)

    Sciacchitano, Andrea; Wieneke, Bernhard

    2016-08-01

    This paper discusses the propagation of the instantaneous uncertainty of PIV measurements to statistical and instantaneous quantities of interest derived from the velocity field. The expression of the uncertainty of vorticity, velocity divergence, mean value and Reynolds stresses is derived. It is shown that the uncertainty of vorticity and velocity divergence requires the knowledge of the spatial correlation between the error of the x and y particle image displacement, which depends upon the measurement spatial resolution. The uncertainty of statistical quantities is often dominated by the random uncertainty due to the finite sample size and decreases with the square root of the effective number of independent samples. Monte Carlo simulations are conducted to assess the accuracy of the uncertainty propagation formulae. Furthermore, three experimental assessments are carried out. In the first experiment, a turntable is used to simulate a rigid rotation flow field. The estimated uncertainty of the vorticity is compared with the actual vorticity error root-mean-square, with differences between the two quantities within 5-10% for different interrogation window sizes and overlap factors. A turbulent jet flow is investigated in the second experimental assessment. The reference velocity, which is used to compute the reference value of the instantaneous flow properties of interest, is obtained with an auxiliary PIV system, which features a higher dynamic range than the measurement system. Finally, the uncertainty quantification of statistical quantities is assessed via PIV measurements in a cavity flow. The comparison between estimated uncertainty and actual error demonstrates the accuracy of the proposed uncertainty propagation methodology.

  16. Temporal scaling in information propagation.

    PubMed

    Huang, Junming; Li, Chao; Wang, Wen-Qiang; Shen, Hua-Wei; Li, Guojie; Cheng, Xue-Qi

    2014-01-01

    For the study of information propagation, one fundamental problem is uncovering universal laws governing the dynamics of information propagation. This problem, from the microscopic perspective, is formulated as estimating the propagation probability that a piece of information propagates from one individual to another. Such a propagation probability generally depends on two major classes of factors: the intrinsic attractiveness of information and the interactions between individuals. Despite the fact that the temporal effect of attractiveness is widely studied, temporal laws underlying individual interactions remain unclear, causing inaccurate prediction of information propagation on evolving social networks. In this report, we empirically study the dynamics of information propagation, using the dataset from a population-scale social media website. We discover a temporal scaling in information propagation: the probability a message propagates between two individuals decays with the length of time latency since their latest interaction, obeying a power-law rule. Leveraging the scaling law, we further propose a temporal model to estimate future propagation probabilities between individuals, reducing the error rate of information propagation prediction from 6.7% to 2.6% and improving viral marketing with 9.7% incremental customers. PMID:24939414

  17. Temporal scaling in information propagation

    NASA Astrophysics Data System (ADS)

    Huang, Junming; Li, Chao; Wang, Wen-Qiang; Shen, Hua-Wei; Li, Guojie; Cheng, Xue-Qi

    2014-06-01

    For the study of information propagation, one fundamental problem is uncovering universal laws governing the dynamics of information propagation. This problem, from the microscopic perspective, is formulated as estimating the propagation probability that a piece of information propagates from one individual to another. Such a propagation probability generally depends on two major classes of factors: the intrinsic attractiveness of information and the interactions between individuals. Despite the fact that the temporal effect of attractiveness is widely studied, temporal laws underlying individual interactions remain unclear, causing inaccurate prediction of information propagation on evolving social networks. In this report, we empirically study the dynamics of information propagation, using the dataset from a population-scale social media website. We discover a temporal scaling in information propagation: the probability a message propagates between two individuals decays with the length of time latency since their latest interaction, obeying a power-law rule. Leveraging the scaling law, we further propose a temporal model to estimate future propagation probabilities between individuals, reducing the error rate of information propagation prediction from 6.7% to 2.6% and improving viral marketing with 9.7% incremental customers.

  18. Transport with Feynman propagators

    SciTech Connect

    White, R.H.

    1990-11-06

    Richard Feynman's formulation of quantum electrodynamics suggests a Monte Carlo algorithm for calculating wave propagation. We call this the Sum Over All Paths (SOAP) method. The method is applied to calculate diffraction by double slits of finite width and by a reflection grating. Calculations of reflection by plane and parabolic mirrors of finite aperture and from several figured surfaces are shown. An application to a one-dimensional scattering problem is discussed. A variation of SOAP can be applied to the diffusion equation. 2 refs., 8 figs.

  19. Studies on polyamine and ornithine metabolism in rat colon: effects of two synergistically. Acting inducers of ornithine decarboxylase activity

    SciTech Connect

    Stanley, B.A.

    1987-01-01

    Ornithine decarboxylase (ODC) activity in rat colon mucosa was determined by the release of /sup 14/CO/sub 2/ from radiolabeled ornithine in the presence (total enzyme) or absence (holoenzyme) of added pyridoxal-5'-phosphate (PLP). Total leucine incorporation into acid-precipitable protein over 30 minute was calculated by dividing the /sup 3/H-leucine in protein by the specific activity of the intracellular leucine. Amino acids, polyamines, and PLP-semicarbazide were quantified by high pressure liquid chromatography. Ornithine aminotransaminase activity (OAT) was measured as the quantity of pyrolline (5-carboxy) produced from alpha-ketoglutarate and ornithine. After 10 weeks on a high or no vitamin B/sub 6/ diet, no change in basal ODC activity was seen; however, sodium deoxycholate instillation in vitamin B/sub 6/ deficient rats led to a large increase in total but not holo-ODC activity. In rats fed normal chow diet, no increases in mucosal PLP levels were seen after either treatment. Increases in general protein synthesis rate could not account for the peaks in ODC activity after either stimulus. Putrescine increases were proportional to peaks of ODC activity after either stimulus, while spermine levels remained depressed for 18 hours after starvation/refeeding. Ornithine levels were increased after either stimulus, and this increase was linked to decreases in OAT activity, indicating short-term coordination of overall ornithine metabolism to favor polyamine biosynthesis.

  20. The Effects of Pragmatic Consciousness-­-Raising Activities on the Learning of Speech Acts in the Beginning CFL Classroom

    ERIC Educational Resources Information Center

    Yang, Li; Zhu, Jia

    2016-01-01

    This study investigates the effects of instruction on learners' pragmatic competence by integrating pragmatic consciousness-raising (PCR) activities into a beginning-level Chinese language course during one academic semester. The study also examines the effect of integrating the PCR activities, i.e., before or after the instruction of a…

  1. Effects of fluctuations on propagating fronts

    NASA Astrophysics Data System (ADS)

    Panja, Debabrata

    Propagating fronts are seen in varieties of nonequilibrium pattern forming systems in Physics, Chemistry and Biology. In the last two decades, many researchers have contributed to the understanding of the underlying dynamics of the propagating fronts. Of these, the deterministic and mean-field dynamics of the fronts were mostly understood in late 1980s and 1990s. On the other hand, although the earliest work on the effect of fluctuations on propagating fronts dates back to early 1980s, the subject of fluctuating fronts did not reach its adolescence until the mid 1990s. From there onwards the last few years witnessed a surge in activities in the effect of fluctuations on propagating fronts. Scores of papers have been written on this subject since then, contributing to a significant maturity of our understanding, and only recently a full picture of fluctuating fronts has started to emerge. This review is an attempt to collect all the works on fluctuating (propagating) fronts in a coherent and cogent manner in proper perspective. It is based on the idea of making our knowledge in this field available to a broader audience, and it is also expected to help to collect bits and pieces of loose thread-ends together for possible further investigation.

  2. Fourth International Symposium on Long-Range Sound Propagation

    NASA Technical Reports Server (NTRS)

    Willshire, William L., Jr. (Compiler)

    1990-01-01

    Long range sound propagation is an aspect of many acoustical problems ranging from en route aircraft noise to the acoustic detection of aircraft. Over the past decade, the University of Mississippi and the Open University of England, together with a third institution, have held a symposium approx. every 2 years so that experts in the field of long range propagation could exchange information on current research, identify areas needing additional work, and coordinate activities as much as possible. The Fourth International Symposium on Long Range Sound Propagation was jointly sponsored by the University of Mississippi, the Open University of England, and NASA. Papers were given in the following areas: ground effects on propagation; infrasound propagation; and meteorological effects on sound propagation. A compilation of the presentations made at the symposium is presented along with a list of attendees, and the agenda.

  3. Insulin-like growth factor 1 receptor and p38 mitogen-activated protein kinase signals inversely regulate signal transducer and activator of transcription 3 activity to control human dental pulp stem cell quiescence, propagation, and differentiation.

    PubMed

    Vandomme, Jerome; Touil, Yasmine; Ostyn, Pauline; Olejnik, Cecile; Flamenco, Pilar; El Machhour, Raja; Segard, Pascaline; Masselot, Bernadette; Bailliez, Yves; Formstecher, Pierre; Polakowska, Renata

    2014-04-15

    Dental pulp stem cells (DPSCs) remain quiescent until activated in response to severe dental pulp damage. Once activated, they exit quiescence and enter regenerative odontogenesis, producing reparative dentin. The factors and signaling molecules that control the quiescence/activation and commitment to differentiation of human DPSCs are not known. In this study, we determined that the inhibition of insulin-like growth factor 1 receptor (IGF-1R) and p38 mitogen-activated protein kinase (p38 MAPK) signaling commonly activates DPSCs and promotes their exit from the G0 phase of the cell cycle as well as from the pyronin Y(low) stem cell compartment. The inhibition of these two pathways, however, inversely determines DPSC fate. In contrast to p38 MAPK inhibitors, IGF-1R inhibitors enhance dental pulp cell sphere-forming capacity and reduce the cells' colony-forming capacity without inducing cell death. The inverse cellular changes initiated by IGF-1R and p38 MAPK inhibitors were accompanied by inverse changes in the levels of active signal transducer and activator of transcription 3 (STAT3) factor, inactive glycogen synthase kinase 3, and matrix extracellular phosphoglycoprotein, a marker of early odontoblast differentiation. Our data suggest that there is cross talk between the IGF-1R and p38 MAPK signaling pathways in DPSCs and that the signals provided by these pathways converge at STAT3 and inversely regulate its activity to maintain quiescence or to promote self-renewal and differentiation of the cells. We propose a working model that explains the possible interactions between IGF-1R and p38 MAPK at the molecular level and describes the cellular consequences of these interactions. This model may inspire further fundamental study and stimulate research on the clinical applications of DPSC in cellular therapy and tissue regeneration. PMID:24266654

  4. Cis and trans-acting elements involved in the activation of Arabidopsis thaliana A1 gene encoding the translation elongation factor EF-1 alpha.

    PubMed Central

    Curie, C; Liboz, T; Bardet, C; Gander, E; Médale, C; Axelos, M; Lescure, B

    1991-01-01

    In A. thaliana the translation elongation factor EF-1 alpha is encoded by a small multigenic family of four members (A1-A4). The A1 gene promoter has been dissected and examined in a transient expression system using the GUS reporter gene. Deletion analysis has shown that several elements are involved in the activation process. One cis-acting domain, the TEF 1 box, has been accurately mapped 100 bp upstream of the transcription initiation site. This domain is the target for trans-acting factors identified in nuclear extracts prepared from A. thaliana. Homologies are found between the TEF 1 box and sequences present at the same location within the A2, A3 and A4 promoters. This observation, together with those obtained from gel retardation assays performed using DNA fragments from the A4 promoter, suggest that the activation process mediated by the TEF 1 element is conserved among the A. thaliana EF-1 alpha genes. Analysis of nearly full length cDNA clones has shown that in addition to a single intron located within the coding region, the A1 gene contains a second intron located within the 5' non coding region. Such an intron is also present within the A2, A3 and A4 genes. This 5' intervening sequence appears to be essential to obtain a maximum GUS activity driven by the A1 gene promoter. Images PMID:1840652

  5. Hoxb-2 transcriptional activation in rhombomeres 3 and 5 requires an evolutionarily conserved cis-acting element in addition to the Krox-20 binding site.

    PubMed Central

    Vesque, C; Maconochie, M; Nonchev, S; Ariza-McNaughton, L; Kuroiwa, A; Charnay, P; Krumlauf, R

    1996-01-01

    Segmentation is a key feature of the development of the vertebrate hindbrain where it involves the generation of repetitive morphological units termed rhombomeres (r). Hox genes are likely to play an essential role in the specification of segmental identity and we have been investigating their regulation. We show here that the mouse and chicken Hoxb-2 genes are dependent for their expression in r3 and r5 on homologous enhancer elements and on binding to this enhancer of the r3/r5-specific transcriptional activator Krox-20. Among the three Krox-20 binding sites of the mouse Hoxb-2 enhancer, only the high-affinity site is absolutely necessary for activity. In contrast, we have identified an additional cis-acting element, Box1, essential for r3/r5 enhancer activity. It is conserved both in sequence and in position respective to the high-affinity Krox-20 binding site within the mouse and chicken enhancers. Furthermore, a short 44 bp sequence spanning the Box1 and Krox-20 sites can act as an r3/r5 enhancer when oligomerized. Box1 may therefore constitute a recognition sequence for another factor cooperating with Krox-20. Taken together, these data demonstrate the conservation of Hox gene regulation and of Krox-20 function during vertebrate evolution. Images PMID:8895582

  6. 20 CFR 667.220 - What Workforce Investment Act title I functions and activities constitute the costs of...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... cash management functions; (ii) Procurement and purchasing functions; (iii) Property management functions; (iv) Personnel management functions; (v) Payroll functions; (vi) Coordinating the resolution of... functions and activities constitute the costs of administration subject to the administrative cost...

  7. Novel oxime-bearing coumarin derivatives act as potent Nrf2/ARE activators in vitro and in mouse model.

    PubMed

    Chang, Ken-Ming; Chen, Huang-Hui; Wang, Tai-Chi; Chen, I-Li; Chen, Yu-Tsen; Yang, Shyh-Chyun; Chen, Yeh-Long; Chang, Hsin-Huei; Huang, Chih-Hsiang; Chang, Jang-Yang; Shih, Chuan; Kuo, Ching-Chuan; Tzeng, Cherng-Chyi

    2015-12-01

    We have designed and synthesized certain novel oxime- and amide-bearing coumarin derivatives as nuclear factor erythroid 2 p45-related factor 2 (Nrf2) activators. The potency of these compounds was measured by antioxidant responsive element (ARE)-driven luciferase activity, level of Nrf2-related cytoprotective genes and proteins, and antioxidant activity. Among them, (Z)-3-(2-(hydroxyimino)-2-phenylethoxy)-2H-chromen-2-one (17a) was the most active, and more potent than the positive t-BHQ in the induction of ARE-driven luciferase activity. Exposure of HSC-3 cells to various concentrations of 17a strongly increased Nrf2 nuclear translocation and the expression level of Nrf2-mediated cytoprotective proteins in a concentration-dependent manner. HSC-3 cells pretreated with 17a significantly reduced t-BOOH-induced oxidative stress. In the animal experiment, Nrf2-mediated cytoprotective proteins, such as aldo-keto reductase 1 subunit C-1 (AKR1C1), glutathione reductase (GR), and heme oxygenase (HO-1), were obviously elevated in the liver of 17a-treated mice than that of control. These results suggested that novel oxime-bearing coumarin 17a is able to activate Nrf2/ARE pathway in vivo and are therefore seen as a promising candidate for further investigation.

  8. Sea Changes - ACT : Artists and Scientists collaborating to promote ocean activism and conservation. (www.seachanges.org)

    NASA Astrophysics Data System (ADS)

    Lueker, T.

    2012-12-01

    We are a group of ocean scientists, artists, and educators working to publicize the urgent environmental problems facing our ocean environs, including overfishing, climate change and ocean acidification, and environmental degradation due to plastic and other forms of pollution. Our team leader, Kira Carrillo Corser, is an artist and educator known nationally for affecting policy and social change. Our collaboration results from the DNA of Creativity Project - the brainchild of Patricia Frischer, co-ordinator for the San Diego Visual Arts Network (http://dnaofc.weebly.com). The DNA of Creativity funded teams composed of artists and scientists with the goal of fusing the creative energies of both into projects that will enhance the public's perception of creativity, and make the complexities of art and science collaborations accessible to a new and larger audience. Sea Changes - ACT was funded initially by the DNA of Creativity Project. Our project goals are : 1) To entice people to participate in the joys of discovery of art AND science and 2) To motivate the public to work for real, committed and innovative change to protect our oceans. Part of our strategy for achieving our goals is to create a traveling art installation to illustrate the beauty of the oceans and to instill in our viewers the joys of discovery and creativity that we as scientists and artists pursue. And following this, to make the destructive changes occurring in the ocean and the future consequences more visible and understandable. We will develop lesson plans to integrate our ideas into the educational system and we are documenting our collaborative and creative process to inform future art-science collaborations. Finally, after emotionally connecting with our viewers to provide a means to ACT to make real and positive CHANGES for the future. Our project aims to build commitment and action for environmental conservation and stewardship as we combine scientific research with ways to take action

  9. Ethyl Pyruvate Emerges as a Safe and Fast Acting Agent against Trypanosoma brucei by Targeting Pyruvate Kinase Activity

    PubMed Central

    Worku, Netsanet; Stich, August; Daugschies, Arwid; Wenzel, Iris; Kurz, Randy; Thieme, Rene; Kurz, Susanne; Birkenmeier, Gerd

    2015-01-01

    Background Human African Trypanosomiasis (HAT) also called sleeping sickness is an infectious disease in humans caused by an extracellular protozoan parasite. The disease, if left untreated, results in 100% mortality. Currently available drugs are full of severe drawbacks and fail to escape the fast development of trypanosoma resistance. Due to similarities in cell metabolism between cancerous tumors and trypanosoma cells, some of the current registered drugs against HAT have also been tested in cancer chemotherapy. Here we demonstrate for the first time that the simple ester, ethyl pyruvate, comprises such properties. Results The current study covers the efficacy and corresponding target evaluation of ethyl pyruvate on T. brucei cell lines using a combination of biochemical techniques including cell proliferation assays, enzyme kinetics, phasecontrast microscopic video imaging and ex vivo toxicity tests. We have shown that ethyl pyruvate effectively kills trypanosomes most probably by net ATP depletion through inhibition of pyruvate kinase (Ki = 3.0±0.29 mM). The potential of ethyl pyruvate as a trypanocidal compound is also strengthened by its fast acting property, killing cells within three hours post exposure. This has been demonstrated using video imaging of live cells as well as concentration and time dependency experiments. Most importantly, ethyl pyruvate produces minimal side effects in human red cells and is known to easily cross the blood-brain-barrier. This makes it a promising candidate for effective treatment of the two clinical stages of sleeping sickness. Trypanosome drug-resistance tests indicate irreversible cell death and a low incidence of resistance development under experimental conditions. Conclusion Our results present ethyl pyruvate as a safe and fast acting trypanocidal compound and show that it inhibits the enzyme pyruvate kinase. Competitive inhibition of this enzyme was found to cause ATP depletion and cell death. Due to its ability to

  10. Shaping propagation invariant laser beams

    NASA Astrophysics Data System (ADS)

    Soskind, Michael; Soskind, Rose; Soskind, Yakov

    2015-11-01

    Propagation-invariant structured laser beams possess several unique properties and play an important role in various photonics applications. The majority of propagation invariant beams are produced in the form of laser modes emanating from stable laser cavities. Therefore, their spatial structure is limited by the intracavity mode formation. We show that several types of anamorphic optical systems (AOSs) can be effectively employed to shape laser beams into a variety of propagation invariant structured fields with different shapes and phase distributions. We present a propagation matrix approach for designing AOSs and defining mode-matching conditions required for preserving propagation invariance of the output shaped fields. The propagation matrix approach was selected, as it provides a more straightforward approach in designing AOSs for shaping propagation-invariant laser beams than the alternative technique based on the Gouy phase evolution, especially in the case of multielement AOSs. Several practical configurations of optical systems that are suitable for shaping input laser beams into a diverse variety of structured propagation invariant laser beams are also presented. The laser beam shaping approach was applied by modeling propagation characteristics of several input laser beam types, including Hermite-Gaussian, Laguerre-Gaussian, and Ince-Gaussian structured field distributions. The influence of the Ince-Gaussian beam semifocal separation parameter and the azimuthal orientation between the input laser beams and the AOSs onto the resulting shape of the propagation invariant laser beams is presented as well.

  11. An analysis of rumor propagation based on propagation force

    NASA Astrophysics Data System (ADS)

    Zhao, Zhen-jun; Liu, Yong-mei; Wang, Ke-xi

    2016-02-01

    A propagation force is introduced into the analysis of rumor propagation to address uncertainty in the process. The propagation force is portrayed as a fuzzy variable, and a category of new parameters with fuzzy variables is defined. The classic susceptible, infected, recovered (SIR) model is modified using these parameters, a fuzzy reproductive number is introduced into the modified model, and the rationality of the fuzzy reproductive number is illuminated through calculation and comparison. Rumor control strategies are also discussed.

  12. Bck2 Acts through the MADS Box Protein Mcm1 to Activate Cell-Cycle-Regulated Genes in Budding Yeast

    PubMed Central

    Bastajian, Nazareth; Friesen, Helena; Andrews, Brenda J.

    2013-01-01

    The Bck2 protein is a potent genetic regulator of cell-cycle-dependent gene expression in budding yeast. To date, most experiments have focused on assessing a potential role for Bck2 in activation of the G1/S-specific transcription factors SBF (Swi4, Swi6) and MBF (Mbp1, Swi6), yet the mechanism of gene activation by Bck2 has remained obscure. We performed a yeast two-hybrid screen using a truncated version of Bck2 and discovered six novel Bck2-binding partners including Mcm1, an essential protein that binds to and activates M/G1 promoters through Early Cell cycle Box (ECB) elements as well as to G2/M promoters. At M/G1 promoters Mcm1 is inhibited by association with two repressors, Yox1 or Yhp1, and gene activation ensues once repression is relieved by an unknown activating signal. Here, we show that Bck2 interacts physically with Mcm1 to activate genes during G1 phase. We used chromatin immunoprecipitation (ChIP) experiments to show that Bck2 localizes to the promoters of M/G1-specific genes, in a manner dependent on functional ECB elements, as well as to the promoters of G1/S and G2/M genes. The Bck2-Mcm1 interaction requires valine 69 on Mcm1, a residue known to be required for interaction with Yox1. Overexpression of BCK2 decreases Yox1 localization to the early G1-specific CLN3 promoter and rescues the lethality caused by overexpression of YOX1. Our data suggest that Yox1 and Bck2 may compete for access to the Mcm1-ECB scaffold to ensure appropriate activation of the initial suite of genes required for cell cycle commitment. PMID:23675312

  13. Berberine acts as a natural inhibitor of Wnt/β-catenin signaling--identification of more active 13-arylalkyl derivatives.

    PubMed

    Albring, Kai Frederik; Weidemüller, Julia; Mittag, Sonnhild; Weiske, Jörg; Friedrich, Karlheinz; Geroni, M Cristina; Lombardi, Paolo; Huber, Otmar

    2013-01-01

    Aberrant activation of the canonical Wnt/β-catenin signaling pathway has been reported for numerous tumors of different origins. In most cases, mutations in components of the Wnt signaling pathway or in β-catenin itself were detected which ultimately induce a genetic program that promotes cell proliferation and attenuates apoptosis. Thus, targeting of Wnt/β-catenin signaling is of specific therapeutic interest. Herein, we investigated the plant-derived isoquinoline alkaloid berberine, which has been reported to have anticancer activity, and synthetic 13-arylalkyl derivatives thereof for their effects on Wnt/β-catenin signaling. Berberine did not show major effects on viability of HEK-293 embryonic kidney and HCT116 colon carcinoma cells and was not toxic in concentrations up to 20 µM. Berberine inhibited β-catenin transcriptional activity and attenuated anchorage-independent growth. As a result of berberine treatment, cellular levels of active β-catenin were reduced concomitant with an increase in the expression of E-cadherin. However, in unstimulated cells, the effects on β-catenin levels were low. A screen of synthetic 13-arylalkyl berberine derivatives identified compounds exhibiting activities superior to those of the naturally occurring parent substance with more than 100-fold lower EC50 values for Wnt-repression. Thus, berberine and its synthetic derivatives represent potential therapeutic agents to inhibit Wnt/β-catenin signaling in tumorigenesis.

  14. Lipolanthionine peptides act as inhibitors of TLR2-mediated IL-8 secretion. Synthesis and structure-activity relationships.

    PubMed

    Seyberth, Tobias; Voss, Söhnke; Brock, Roland; Wiesmüller, Karl-Heinz; Jung, Günther

    2006-03-01

    Lipoproteins from gram-positive and -negative bacteria, mycoplasma, and shorter synthetic lipopeptide analogues activate cells of the innate immune system via the Toll-like receptor TLR2/TLR1 or TLR2/TLR6 heterodimers. For this reason, these compounds constitute highly active adjuvants for vaccines either admixed or covalently linked. The lanthionine scaffold has structural similarity with the S-(2,3-dihydroxypropyl)cysteine core structure of the lipopeptides. Therefore, lanthionine-based lipopeptide amides were synthesized and probed for activity as potential TLR2 agonists or antagonists. A collection of analytically defined lipolanthionine peptide amides exhibited an inhibitory effect of the TLR2-mediated IL-8 secretion when applied in high molar excess to the agonistic synthetic lipopeptide Pam3Cys-Ser-(Lys)4-OH. Structure-activity relationships revealed the influence of the chirality of the two alpha-carbon atoms, the chain lengths of the attached fatty acids and fatty amines, and the oxidation level of the sulfur atom on the inhibitory activity of the lipolanthionine peptide amides. PMID:16509590

  15. What powers the starburst activity of NGC 1068? Star-driven gravitational instabilities caught in the act

    NASA Astrophysics Data System (ADS)

    Romeo, Alessandro B.; Fathi, Kambiz

    2016-08-01

    We explore the role that gravitational instability plays in NGC 1068, a nearby Seyfert galaxy that exhibits unusually vigorous starburst activity. For this purpose, we use the Romeo-Falstad disc instability diagnostics and data from the BIMA Survey of Nearby Galaxies, the Sloan Digital Sky Survey and the Spectrographic Areal Unit for Research on Optical Nebulae. Our analysis illustrates that NGC 1068 is a gravitationally unstable `monster'. Its starburst disc is subject to unusually powerful instabilities. Several processes, including feedback from the active galactic nucleus and starburst activity, try to quench such instabilities from inside out by depressing the surface density of molecular gas across the central kpc, but they do not succeed. Gravitational instability `wins' because it is driven by the stars via their much higher surface density. In this process, stars and molecular gas are strongly coupled, and it is such a coupling that ultimately triggers local gravitational collapse/fragmentation in the molecular gas.

  16. Tribolium castaneum Apolipophorin-III acts as an immune response protein against Bacillus thuringiensis Cry3Ba toxic activity.

    PubMed

    Contreras, Estefanía; Rausell, Carolina; Real, M Dolores

    2013-07-01

    In this study, a 2.1-fold Apolipophorin-III mRNA up-regulation was found in Tribolium castaneum larvae challenged with Bacillus thuringiensis Cry3Ba spore-crystal mixture. Knockdown of Apolipophorin-III by RNAi resulted in increased T. castaneum larvae susceptibility following Cry3Ba spore-crystal treatment, demonstrating Apolipophorin-III involvement in insect defense against B. thuringiensis. We showed that Apolipophorin-III participates in T. castaneum immune response to B. thuringiensis activating the prophenoloxidase cascade since: (i) phenoloxidase activity significantly increased after Cry3Ba spore-crystal treatment compared to untreated or Cry1Ac spore-crystal treated larvae and (ii) phenoloxidase activity in Cry3Ba spore-crystal treated Apolipophorin-III silenced larvae was 71±14% lower than that of non-silenced intoxicated larvae.

  17. Interaction of pentobarbital with gabaergic drugs acting on the Cl(-)-ATPase activity of the plasma membranes from bream brain (Abramis brama L.).

    PubMed

    Menzikov, Sergey; Menzikova, Olga

    2002-12-16

    The present study was designed to investigate the role of the interaction of pentobarbital with gamma-aminobutyric acid (GABA)ergic drugs acting on the Cl(-)-adenosine triphosphate (ATP)ase activity of the plasma membranes fraction of bream brain. The preincubation and then incubation of the membranes with pentobarbital as well as with other GABAergic ligands was conducted at physiologic pH (7.4), i.e. at the condition where the Cl(-)-ATPase activity is not detected. Pentobarbital (1-100 microM) induces Cl(-)-ATPase activity, however at high concentration (1,000 microM) no effect of the ligand was found. In addition pentobarbital (50 microM) enhances the effect of low concentration of GABA (1 microM) on the Cl(-)-ATPase activity, but inhibits the action of high concentration of GABA (100 microM) on the enzyme. Whereas no activating effect of pentobarbital in the presence of baclofen (1 microM) was found. The blocker of GABA(A)-receptors, picrotoxin (50 microM) and bicuculline (5 microM) eliminated the action of pentobarbital on the enzyme. The present results provide evidence for the first time that at physiologic pH in incubation medium the interaction of pentobarbital with GABAergic drugs on the Cl(-)-ATPase activity is similar to the effects of these ligands on the GABA(A)-receptor.

  18. Caught in the act: the crystal structure of cleaved cathepsin L bound to the active site of Cathepsin L.

    PubMed

    Sosnowski, Piotr; Turk, Dušan

    2016-04-01

    Cathepsin L is a ubiquitously expressed papain-like cysteine protease involved in the endosomal degradation of proteins and has numerous roles in physiological and pathological processes, such as arthritis, osteoporosis, and cancer. Insight into the specificity of cathepsin L is important for elucidating its physiological roles and drug discovery. To study interactions with synthetic ligands, we prepared a presumably inactive mutant and crystallized it. Unexpectedly, the crystal structure determined at 1.4 Å revealed that the cathepsin L molecule is cleaved, with the cleaved region trapped in the active site cleft of the neighboring molecule. Hence, the catalytic mutant demonstrated low levels of catalytic activity. PMID:26992470

  19. Caught in the act: the crystal structure of cleaved cathepsin L bound to the active site of Cathepsin L.

    PubMed

    Sosnowski, Piotr; Turk, Dušan

    2016-04-01

    Cathepsin L is a ubiquitously expressed papain-like cysteine protease involved in the endosomal degradation of proteins and has numerous roles in physiological and pathological processes, such as arthritis, osteoporosis, and cancer. Insight into the specificity of cathepsin L is important for elucidating its physiological roles and drug discovery. To study interactions with synthetic ligands, we prepared a presumably inactive mutant and crystallized it. Unexpectedly, the crystal structure determined at 1.4 Å revealed that the cathepsin L molecule is cleaved, with the cleaved region trapped in the active site cleft of the neighboring molecule. Hence, the catalytic mutant demonstrated low levels of catalytic activity.

  20. 77 FR 59204 - Agency Information Collection Activities: Affidavit of Support Under Section 213A of the Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-26

    ... Register on June 1, 2012, at 77 FR 32658, allowing for a 60-day public comment period. USCIS did receive... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Affidavit of.... Citizenship and Immigration Services (USCIS) will be submitting the following information collection...

  1. 12 CFR Appendix A to Part 242 - Financial Activities for Purposes of Title I of the Dodd-Frank Act

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... See also the Board's interpretation of bank management consulting advice (12 CFR 225.131). (1) On any... securities of the client institution; or (2) Allows a management official, as defined in 12 CFR 212.2(h), of... Board's interpretation on courier activities (12 CFR 225.129), which sets forth conditions for...

  2. NSC23766, a widely used inhibitor of Rac1 activation, additionally acts as a competitive antagonist at muscarinic acetylcholine receptors.

    PubMed

    Levay, Magdolna; Krobert, Kurt Allen; Wittig, Karola; Voigt, Niels; Bermudez, Marcel; Wolber, Gerhard; Dobrev, Dobromir; Levy, Finn Olav; Wieland, Thomas

    2013-10-01

    Small molecules interfering with Rac1 activation are considered as potential drugs and are already studied in animal models. A widely used inhibitor without reported attenuation of RhoA activity is NSC23766 [(N(6)-[2-[[4-(diethylamino)-1-methylbutyl]amino]-6-methyl-4-pyrimidinyl]-2-methyl-4,6-quinolinediamine trihydrochloride]. We found that NSC23766 inhibits the M2 muscarinic acetylcholine receptor (M2 mAChR)-induced Rac1 activation in neonatal rat cardiac myocytes. Surprisingly, NSC27366 concomitantly suppressed the carbachol-induced RhoA activation and a M2 mAChR-induced inotropic response in isolated neonatal rat hearts requiring the activation of Rho-dependent kinases. We therefore aimed to identify the mechanisms by which NSC23766 interferes with the differentially mediated, M2 mAChR-induced responses. Interestingly, NSC23766 caused a rightward shift of the carbachol concentration response curve for the positive inotropic response without modifying carbachol efficacy. To analyze the specificity of NSC23766, we compared the carbachol and the similarly Giβγ-mediated, adenosine-induced activation of Gi protein-regulated potassium channel (GIRK) channels in human atrial myocytes. Application of NSC23766 blocked the carbachol-induced K(+) current but had no effect on the adenosine-induced GIRK current. Similarly, an adenosine A1 receptor-induced positive inotropic response in neonatal rat hearts was not attenuated by NSC23766. To investigate its specificity toward the different mAChR types, we studied the carbachol-induced elevation of intracellular Ca(2+) concentrations in human embryonic kidney 293 (HEK-293) cells expressing M1, M2, or M3 mAChRs. NSC23766 caused a concentration-dependent rightward shift of the carbachol concentration response curves at all mAChRs. Thus, NSC23766 is not only an inhibitor of Rac1 activation, but it is within the same concentration range a competitive antagonist at mAChRs. Molecular docking analysis at M2 and M3 mAChR crystal

  3. A Longitudinal Study of the Effects of Instrumental and Emotional Social Support on Physical Activity in Underserved Adolescents in the ACT Trial

    PubMed Central

    Siceloff, E. Rebekah; Wilson, Dawn K.; Van Horn, Lee

    2014-01-01

    Background Few previous studies have examined the influence of instrumental and emotional social support on physical activity (PA) longitudinally in underserved adolescents. Purpose This longitudinal study was a secondary analysis of the Active by Choice Today (ACT) trial examining whether instrumental social support predicts increases in PA in underserved adolescents, above and beyond emotional social support provided by family or peers. Methods Students in 6th grade (N=1422, 73% African American, 54% female, Mage=11 years) in the ACT trial participated. At baseline and 19 weeks, previously validated measures of social support (family instrumental, family emotional, and peer emotional) were completed and moderate-to-vigorous PA (MVPA) was assessed using 7-day accelerometry estimates. Results A mixed ANCOVA demonstrated that baseline (p=.02) and change in family instrumental support (p=.01), but not emotional support from family or peers, predicted increases in MVPA across a 19-week period. Conclusions Future interventions in underserved adolescents should enhance opportunities for instrumental support for PA. PMID:24327135

  4. Testing for clonal propagation.

    PubMed

    Gregorius, H-R

    2005-02-01

    The conceptual basis for testing clonal propagation is reconsidered with the result that two steps need to be distinguished clearly: (1) specification of the characteristics of multilocus genotype frequencies that result from sexual reproduction together with the kinds of deviations from these characteristics that are produced by clonal propagation, and (2) a statistical method for detecting these deviations in random samples. It is pointed out that a meaningful characterization of sexual reproduction reflects the association of genes in (multilocus) genotypes within the bounds set by the underlying gene frequencies. An appropriate measure of relative gene association is developed which is equivalent to a multilocus generalization of the standardized gametic disequilibrium (linkage disequilibrium). Its application to the characterization of sexually produced multilocus genotypes is demonstrated. The resulting hypothesis on the frequency of a sexually produced genotype is tested with the help of the (significance) probability of obtaining at least two copies of the genotype in question in a random sample of a given size. If at least two copies of the genotype are observed in a sample, and if the probability is significant, then the hypothesis of sexual reproduction is rejected in favor of the assumption that all copies of the genotype belong to the same clone. Common testing approaches rest on the hypothesis of completely independent association of genes in genotypes and on the (significance) probability of obtaining at least as many copies of a genotype as observed in a sample. The validity of these approaches is discussed in relation to the above considerations and recommendations are set out for conducting appropriate tests.

  5. Helix 3 acts as a conformational hinge in Class A GPCR activation: An analysis of interhelical interaction energies in crystal structures.

    PubMed

    Lans, Isaias; Dalton, James A R; Giraldo, Jesús

    2015-12-01

    A collection of crystal structures of rhodopsin, β2-adrenergic and adenosine A2A receptors in active, intermediate and inactive states were selected for structural and energetic analyses to identify the changes involved in the activation/deactivation of Class A GPCRs. A set of helix interactions exclusive to either inactive or active/intermediate states were identified. The analysis of these interactions distinguished some local conformational changes involved in receptor activation, in particular, a packing between the intracellular domains of transmembrane helices H3 and H7 and a separation between those of H2 and H6. Also, differential movements of the extracellular and intracellular domains of these helices are apparent. Moreover, a segment of residues in helix H3, including residues L/I3.40 to L3.43, is identified as a key component of the activation mechanism, acting as a conformational hinge between extracellular and intracellular regions. Remarkably, the influence on the activation process of some glutamic and aspartic acidic residues and, as a consequence, the influence of variations on local pH is highlighted. Structural hypotheses that arose from the analysis of rhodopsin, β2-adrenergic and adenosine A2A receptors were tested on the active and inactive M2 muscarinic acetylcholine receptor structures and further discussed in the context of the new mechanistic insights provided by the recently determined active and inactive crystal structures of the μ-opioid receptor. Overall, the structural and energetic analyses of the interhelical interactions present in this collection of Class A GPCRs suggests the existence of a common general activation mechanism featuring a chemical space useful for drug discovery exploration.

  6. Propagation effects at millimeter wavelengths

    NASA Astrophysics Data System (ADS)

    Crane, R. K.

    The lower atmosphere can affect millimeter wave communication system performance by producing large variations in signal level. Several different propagation phenomena are responsible absorption by oxygen and water vapor, scattering by turbulent fluctuations in the index of refraction, and attenuation by clouds, fog, or rain. Models are available for the calculation of propagation effects on a path when the meteorological conditions are known. This paper reviews the available propagation models for the prediction of link reliability.

  7. Propagation Terminal Design and Measurements

    NASA Technical Reports Server (NTRS)

    Nessel, James

    2015-01-01

    The NASA propagation terminal has been designed and developed by the Glenn Research Center and is presently deployed at over 5 NASA and partner ground stations worldwide collecting information on the effects of the atmosphere on Ka-band and millimeter wave communications links. This lecture provides an overview of the fundamentals and requirements of the measurement of atmospheric propagation effects and, specifically, the types of hardware and digital signal processing techniques employed by current state-of-the-art propagation terminal systems.

  8. Mdm2 ligase dead mutants did not act in a dominant negative manner to re-activate p53, but promoted tumor cell growth.

    PubMed

    Swaroop, Manju; Sun, Yi

    2003-01-01

    Mdm2 (murine double minute 2) is an oncogene, first identified in BALB/c 3T3 cells. Over-expression and gene amplification of Mdm2 were found in a variety of human cancers. Recently, Mdm2 was found to be an E3 ubiquitin ligase that promotes degradation of p53, which contributes significantly to its oncogenic activity. In this study, we test a hypothesis that Mdm2 ligase dead mutants, which retained p53 binding activity but lost degradation activity, would act in a dominant negative manner to re-activate p53, especially upon stressed conditions. Five Mdm2 constructs expressing wild-type and E3 ligase-dead Mdm2 proteins were generated in a Tet-Off system and transfected into MCF-7 breast cancer cells (p53+/+ with Mdm2 overexpression) as well as MCF10A immortalized breast cells (p53+/+ without Mdm2 overexpression) as a normal control. We found that expression of Mdm2 mutants were tightly regulated by doxycycline. Withdrawal of doxycycline in culture medium triggered overexpression of Mdm2 mutants. However, expression of ligase dead mutants in MCF7 and MCF10A cells did not reactivate p53 as shown by a luciferase-reporter transcription assay and Western blot of p53 and its downstream target p21 under either unstressed condition or after exposure to DNA damaging agents. Biologically, over-expression of Mdm2 mutants had no effect on p53-induced apoptosis following DNA damage. Interestingly, over-expression of Mdm2 mutants promoted growth of MCF7 tumor cells probably via a p53-independent mechanism. Over-expression of Mdm2 mutants, however, had no effect on the growth of normal MCF10A cells and did not cause their transformation. Thus, ligase dead mutants of Mdm2 did not act in a dominant negative manner to reactivate p53 and they are not oncogenes in MCF10A cells.

  9. Indole Glucocorticoid Receptor Antagonists Active in a Model of Dyslipidemia Act via a Unique Association with an Agonist Binding Site.

    PubMed

    Luz, John G; Carson, Matthew W; Condon, Bradley; Clawson, David; Pustilnik, Anna; Kohlman, Daniel T; Barr, Robert J; Bean, James S; Dill, M Joelle; Sindelar, Dana K; Maletic, Milan; Coghlan, Michael J

    2015-08-27

    To further elucidate the structural activity correlation of glucocorticoid receptor (GR) antagonism, the crystal structure of the GR ligand-binding domain (GR LBD) complex with a nonsteroidal antagonist, compound 8, was determined. This novel indole sulfonamide shows in vitro activity comparable to known GR antagonists such as mifepristone, and notably, this molecule lowers LDL (-74%) and raises HDL (+73%) in a hamster model of dyslipidemia. This is the first reported crystal structure of the GR LBD bound to a nonsteroidal antagonist, and this article provides additional elements for the design and pharmacology of clinically relevant nonsteroidal GR antagonists that may have greater selectivity and fewer side effects than their steroidal counterparts. PMID:26218343

  10. GGNBP2 acts as a tumor suppressor by inhibiting estrogen receptor α activity in breast cancer cells.

    PubMed

    Lan, Zi-Jian; Hu, YunHui; Zhang, Sheng; Li, Xian; Zhou, Huaxin; Ding, Jixiang; Klinge, Carolyn M; Radde, Brandie N; Cooney, Austin J; Zhang, Jin; Lei, Zhenmin

    2016-07-01

    Gametogenetin-binding protein 2 (GGNBP2) is encoded in human chromosome 17q12-q23, a region known as a breast and ovarian cancer susceptibility locus. GGNBP2, also referred to ZFP403, has a single C2H2 zinc finger and a consensus LxxLL nuclear receptor-binding motif. Here, we demonstrate that GGNBP2 expression is reduced in primary human breast tumors and in breast cancer cell lines, including T47D, MCF-7, LCC9, LY2, and MDA-MB-231 compared with normal, immortalized estrogen receptor α (ERα) negative MCF-10A and MCF10F breast epithelial cells. Overexpression of GGNBP2 inhibits the proliferation of T47D and MCF-7 ERα positive breast cancer cells without affecting MCF-10A and MCF10F. Stable GGNBP2 overexpression in T47D cells inhibits 17β-estradiol (E2)-stimulated proliferation as well as migration, invasion, anchorage-independent growth in vitro, and xenograft tumor growth in mice. We further demonstrate that GGNBP2 protein physically interacts with ERα, inhibits E2-induced activation of estrogen response element-driven reporter activity, and attenuates ER target gene expression in T47D cells. In summary, our in vitro and in vivo findings suggest that GGNBP2 is a novel breast cancer tumor suppressor functioning as a nuclear receptor corepressor to inhibit ERα activity and tumorigenesis. PMID:27357812

  11. The Cytoskeleton-associated PDZ-LIM Protein, ALP, Acts on Serum Response Factor Activity to Regulate Muscle Differentiation

    PubMed Central

    Pashmforoush, Mohammad; Vegezzi, Cristina; Chien, Kenneth R.; Auffray, Charles; Beckerle, Mary C.

    2007-01-01

    In this report, an antisense RNA strategy has allowed us to show that disruption of ALP expression affects the expression of the muscle transcription factors myogenin and MyoD, resulting in the inhibition of muscle differentiation. Introduction of a MyoD expression construct into ALP-antisense cells is sufficient to restore the capacity of the cells to differentiate, illustrating that ALP function occurs upstream of MyoD. It is known that MyoD is under the control of serum response factor (SRF), a transcriptional regulator whose activity is modulated by actin dynamics. A dramatic reduction of actin filament bundles is observed in ALP-antisense cells and treatment of these cells with the actin-stabilizing drug jasplakinolide stimulates SRF activity and restores the capacity of the cells to differentiate. Furthermore, we show that modulation of ALP expression influences SRF activity, the level of its coactivator, MAL, and muscle differentiation. Collectively, these results suggest a critical role of ALP on muscle differentiation, likely via cytoskeletal regulation of SRF. PMID:17332502

  12. Abcb4 acts as multixenobiotic transporter and active barrier against chemical uptake in zebrafish (Danio rerio) embryos

    PubMed Central

    2013-01-01

    Background In mammals, ABCB1 constitutes a cellular “first line of defense” against a wide array of chemicals and drugs conferring cellular multidrug or multixenobiotic resistance (MDR/MXR). We tested the hypothesis that an ABCB1 ortholog serves as protection for the sensitive developmental processes in zebrafish embryos against adverse compounds dissolved in the water. Results Indication for ABCB1-type efflux counteracting the accumulation of chemicals in zebrafish embryos comes from experiments with fluorescent and toxic transporter substrates and inhibitors. With inhibitors present, levels of fluorescent dyes in embryo tissue and sensitivity of embryos to toxic substrates were generally elevated. We verified two predicted sequences from zebrafish, previously annotated as abcb1, by cloning; our synteny analyses, however, identified them as abcb4 and abcb5, respectively. The abcb1 gene is absent in the zebrafish genome and we explored whether instead Abcb4 and/or Abcb5 show toxicant defense properties. Quantitative real-time polymerase chain reaction (qPCR) analyses showed the presence of transcripts of both genes throughout the first 48 hours of zebrafish development. Similar to transporter inhibitors, morpholino knock-down of Abcb4 increased accumulation of fluorescent substrates in embryo tissue and sensitivity of embryos toward toxic compounds. In contrast, morpholino knock-down of Abcb5 did not exert this effect. ATPase assays with recombinant protein obtained with the baculovirus expression system confirmed that dye and toxic compounds act as substrates of zebrafish Abcb4 and inhibitors block its function. The compounds tested comprised model substrates of human ABCB1, namely the fluorescent dyes rhodamine B and calcein-am and the toxic compounds vinblastine, vincristine and doxorubicin; cyclosporin A, PSC833, MK571 and verapamil were applied as inhibitors. Additionally, tests were performed with ecotoxicologically relevant compounds: phenanthrene (a

  13. Implications of Spatiotemporal Regulation of Shigella flexneri Type Three Secretion Activity on Effector Functions: Think Globally, Act Locally.

    PubMed

    Campbell-Valois, F-X; Pontier, Stéphanie M

    2016-01-01

    Shigella spp. are Gram-negative bacterial pathogens that infect human colonic epithelia and cause bacterial dysentery. These bacteria express multiple copies of a syringe-like protein complex, the Type Three Secretion apparatus (T3SA), which is instrumental in the etiology of the disease. The T3SA triggers the plasma membrane (PM) engulfment of the bacteria by host cells during the initial entry process. It then enables bacteria to escape the resulting phagocytic-like vacuole. Freed bacteria form actin comets to move in the cytoplasm, which provokes bacterial collision with the inner leaflet of the PM. This phenomenon culminates in T3SA-dependent secondary uptake and vacuolar rupture in neighboring cells in a process akin to what is observed during entry and named cell-to-cell spread. The activity of the T3SA of Shigella flexneri was recently demonstrated to display an on/off regulation during the infection. While the T3SA is active when bacteria are in contact with PM-derived compartments, it switches to an inactive state when bacteria are released within the cytosol. These observations indicate that effector proteins transiting through the T3SA are therefore translocated in a highly time and space constrained fashion, likely impacting on their cellular distribution. Herein, we present what is currently known about the composition, the assembly and the regulation of the T3SA activity and discuss the consequences of the on/off regulation of T3SA on Shigella effector properties and functions during the infection. Specific examples that will be developed include the role of effectors IcsB and VirA in the escape from LC3/ATG8-positive vacuoles formed during cell-to-cell spread and of IpaJ protease activity against N-miristoylated proteins. The conservation of a similar regulation of T3SA activity in other pathogens such as Salmonella or Enteropathogenic Escherichia coli will also be briefly discussed. PMID:27014638

  14. Implications of Spatiotemporal Regulation of Shigella flexneri Type Three Secretion Activity on Effector Functions: Think Globally, Act Locally

    PubMed Central

    Campbell-Valois, F.-X.; Pontier, Stéphanie M.

    2016-01-01

    Shigella spp. are Gram-negative bacterial pathogens that infect human colonic epithelia and cause bacterial dysentery. These bacteria express multiple copies of a syringe-like protein complex, the Type Three Secretion apparatus (T3SA), which is instrumental in the etiology of the disease. The T3SA triggers the plasma membrane (PM) engulfment of the bacteria by host cells during the initial entry process. It then enables bacteria to escape the resulting phagocytic-like vacuole. Freed bacteria form actin comets to move in the cytoplasm, which provokes bacterial collision with the inner leaflet of the PM. This phenomenon culminates in T3SA-dependent secondary uptake and vacuolar rupture in neighboring cells in a process akin to what is observed during entry and named cell-to-cell spread. The activity of the T3SA of Shigella flexneri was recently demonstrated to display an on/off regulation during the infection. While the T3SA is active when bacteria are in contact with PM-derived compartments, it switches to an inactive state when bacteria are released within the cytosol. These observations indicate that effector proteins transiting through the T3SA are therefore translocated in a highly time and space constrained fashion, likely impacting on their cellular distribution. Herein, we present what is currently known about the composition, the assembly and the regulation of the T3SA activity and discuss the consequences of the on/off regulation of T3SA on Shigella effector properties and functions during the infection. Specific examples that will be developed include the role of effectors IcsB and VirA in the escape from LC3/ATG8-positive vacuoles formed during cell-to-cell spread and of IpaJ protease activity against N-miristoylated proteins. The conservation of a similar regulation of T3SA activity in other pathogens such as Salmonella or Enteropathogenic Escherichia coli will also be briefly discussed. PMID:27014638

  15. Colchicine therapy in acute coronary syndrome patients acts on caspase-1 to suppress NLRP3 inflammasome monocyte activation.

    PubMed

    Robertson, Stacy; Martínez, Gonzalo J; Payet, Cloe A; Barraclough, Jennifer Y; Celermajer, David S; Bursill, Christina; Patel, Sanjay

    2016-07-01

    Inflammasome activation, with subsequent release of pro-inflammatory cytokines interleukin-1β (IL-1β) and IL-18, has recently been implicated in atherosclerosis-associated inflammation. This study aims to assess in acute coronary syndrome (ACS) patients (1) inflammasome activation in circulating monocytes and (2) whether short-term oral colchicine, a recognized anti-inflammatory agent that has been shown to be cardio-protective in clinical studies, might acutely suppress inflammasome-dependent inflammation. ACS patients (n=21) were randomized to oral colchicine (1 mg followed by 0.5 mg 1 h later) or no treatment, and compared with untreated healthy controls (n=9). Peripheral venous blood was sampled pre- (day 1) and 24 h post- (day 2) treatment. Monocytes were cultured and stimulated with ATP. Analysis of key inflammasome markers was performed by ELISA. IL-1β secretion increased by 580.4% (P<0.01) in ACS patients compared with controls but only with ATP stimulation. Untreated ACS patients secreted significantly higher levels of IL-18 compared with healthy controls independent of ATP stimulation (P<0.05). Colchicine treatment in ACS patients markedly reduced intracellular and secreted levels of IL-1β compared with pre-treatment levels (P<0.05 for both), as well as significantly reducing pro-caspase-1 mRNA levels by 57.7% and secreted caspase-1 protein levels by 30.2% compared with untreated patients (P<0.05 for both). Monocytes from ACS patients are 'primed' to secrete inflammasome-related cytokines and short-term colchicine acutely and markedly suppresses monocyte caspase-1 activity, thereby reducing monocyte secretion of IL-1β.

  16. Inhibitory responses in Aplysia pleural sensory neurons act to block excitability, transmitter release, and PKC Apl II activation.

    PubMed

    Dunn, Tyler W; Farah, Carole A; Sossin, Wayne S

    2012-01-01

    Expression of the 5-HT(1Apl(a)) receptor in Aplysia pleural sensory neurons inhibited 5-HT-mediated translocation of the novel PKC Apl II in sensory neurons and prevented PKC-dependent synaptic facilitation at sensory to motoneuron synapses (Nagakura et al. 2010). We now demonstrate that the ability of inhibitory receptors to block PKC activation is a general feature of inhibitory receptors and is found after expression of the 5-HT(1Apl(b)) receptor and with activation of endogenous dopamine and FMRFamide receptors in sensory neurons. Pleural sensory neurons are heterogeneous for their inhibitory response to endogenous transmitters, with dopamine being the most prevalent, followed by FMRFamide, and only a small number of neurons with inhibitory responses to 5-HT. The inhibitory response is dominant, reduces membrane excitability and synaptic efficacy, and can reverse 5-HT facilitation at both naive and depressed synapses. Indeed, dopamine can reverse PKC translocation during the continued application of 5-HT. Reversal of translocation can also be seen after translocation mediated by an analog of diacylglycerol, suggesting inhibition is not through blockade of diacylglycerol production. The effects of inhibition on PKC translocation can be rescued by phosphatidic acid, consistent with the inhibitory response involving a reduction or block of production of this lipid. However, phosphatidic acid could not recover PKC-dependent synaptic facilitation due to an additional inhibitory effect on the non-L-type calcium flux linked to synaptic transmission. In summary, we find a novel mechanism downstream of inhibitory receptors linked to inhibition of PKC activation in Aplysia sensory neurons. PMID:21994260

  17. Isoproterenol Acts as a Biased Agonist of the Alpha-1A-Adrenoceptor that Selectively Activates the MAPK/ERK Pathway

    PubMed Central

    Copik, Alicja. J.; Baldys, Aleksander; Nguyen, Khanh; Sahdeo, Sunil; Ho, Hoangdung; Kosaka, Alan; Dietrich, Paul J.; Fitch, Bill; Raymond, John R.; Ford, Anthony P. D. W.; Button, Donald; Milla, Marcos E.

    2015-01-01

    The α1A-AR is thought to couple predominantly to the Gαq/PLC pathway and lead to phosphoinositide hydrolysis and calcium mobilization, although certain agonists acting at this receptor have been reported to trigger activation of arachidonic acid formation and MAPK pathways. For several G protein-coupled receptors (GPCRs) agonists can manifest a bias for activation of particular effector signaling output, i.e. not all agonists of a given GPCR generate responses through utilization of the same signaling cascade(s). Previous work with Gαq coupling-defective variants of α1A-AR, as well as a combination of Ca2+ channel blockers, uncovered cross-talk between α1A-AR and β2-AR that leads to potentiation of a Gαq-independent signaling cascade in response to α1A-AR activation. We hypothesized that molecules exist that act as biased agonists to selectively activate this pathway. In this report, isoproterenol (Iso), typically viewed as β-AR-selective agonist, was examined with respect to activation of α1A-AR. α1A-AR selective antagonists were used to specifically block Iso evoked signaling in different cellular backgrounds and confirm its action at α1A-AR. Iso induced signaling at α1A-AR was further interrogated by probing steps along the Gαq /PLC, Gαs and MAPK/ERK pathways. In HEK-293/EBNA cells transiently transduced with α1A-AR, and CHO_α1A-AR stable cells, Iso evoked low potency ERK activity as well as Ca2+ mobilization that could be blocked by α1A-AR selective antagonists. The kinetics of Iso induced Ca2+ transients differed from typical Gαq- mediated Ca2+ mobilization, lacking both the fast IP3R mediated response and the sustained phase of Ca2+ re-entry. Moreover, no inositol phosphate (IP) accumulation could be detected in either cell line after stimulation with Iso, but activation was accompanied by receptor internalization. Data are presented that indicate that Iso represents a novel type of α1A-AR partial agonist with signaling bias toward MAPK

  18. The HMG-box transcription factor SoxNeuro acts with Tcf to control Wg/Wnt signaling activity.

    PubMed

    Chao, Anna T; Jones, Whitney M; Bejsovec, Amy

    2007-03-01

    Wnt signaling specifies cell fates in many tissues during vertebrate and invertebrate embryogenesis. To understand better how Wnt signaling is regulated during development, we have performed genetic screens to isolate mutations that suppress or enhance mutations in the fly Wnt homolog, wingless (wg). We find that loss-of-function mutations in the neural determinant SoxNeuro (also known as Sox-neuro, SoxN) partially suppress wg mutant pattern defects. SoxN encodes a HMG-box-containing protein related to the vertebrate Sox1, Sox2 and Sox3 proteins, which have been implicated in patterning events in the early mouse embryo. In Drosophila, SoxN has previously been shown to specify neural progenitors in the embryonic central nervous system. Here, we show that SoxN negatively regulates Wg pathway activity in the embryonic epidermis. Loss of SoxN function hyperactivates the Wg pathway, whereas its overexpression represses pathway activity. Epistasis analysis with other components of the Wg pathway places SoxN at the level of the transcription factor Pan (also known as Lef, Tcf) in regulating target gene expression. In human cell culture assays, SoxN represses Tcf-responsive reporter expression, indicating that the fly gene product can interact with mammalian Wnt pathway components. In both flies and in human cells, SoxN repression is potentiated by adding ectopic Tcf, suggesting that SoxN interacts with the repressor form of Tcf to influence Wg/Wnt target gene transcription. PMID:17267442

  19. Sall1 maintains nephron progenitors and nascent nephrons by acting as both an activator and a repressor.

    PubMed

    Kanda, Shoichiro; Tanigawa, Shunsuke; Ohmori, Tomoko; Taguchi, Atsuhiro; Kudo, Kuniko; Suzuki, Yutaka; Sato, Yuki; Hino, Shinjiro; Sander, Maike; Perantoni, Alan O; Sugano, Sumio; Nakao, Mitsuyoshi; Nishinakamura, Ryuichi

    2014-11-01

    The balanced self-renewal and differentiation of nephron progenitors are critical for kidney development and controlled, in part, by the transcription factor Six2, which antagonizes canonical Wnt signaling-mediated differentiation. A nuclear factor, Sall1, is expressed in Six2-positive progenitors as well as differentiating nascent nephrons, and it is essential for kidney formation. However, the molecular functions and targets of Sall1, especially the functions and targets in the nephron progenitors, remain unknown. Here, we report that Sall1 deletion in Six2-positive nephron progenitors results in severe progenitor depletion and apoptosis of the differentiating nephrons in mice. Analysis of mice with an inducible Sall1 deletion revealed that Sall1 activates genes expressed in progenitors while repressing genes expressed in differentiating nephrons. Sall1 and Six2 co-occupied many progenitor-related gene loci, and Sall1 bound to Six2 biochemically. In contrast, Sall1 did not bind to the Wnt4 locus suppressed by Six2. Sall1-mediated repression was also independent of its binding to DNA. Thus, Sall1 maintains nephron progenitors and their derivatives by a unique mechanism, which partly overlaps but is distinct from that of Six2: Sall1 activates progenitor-related genes in Six2-positive nephron progenitors and represses gene expression in Six2-negative differentiating nascent nephrons.

  20. IPP51, a chalcone acting as a microtubule inhibitor with in vivo antitumor activity against bladder carcinoma

    PubMed Central

    Martel-Frachet, Véronique; Keramidas, Michelle; Nurisso, Alessandra; DeBonis, Salvatore; Rome, Claire; Coll, Jean-Luc; Boumendjel, Ahcène; Skoufias, Dimitrios A.; Ronot, Xavier

    2015-01-01

    We previously identified 1-(2,4-dimethoxyphenyl)-3-(1-methylindolyl) propenone (IPP51), a new chalcone derivative that is capable of inducing prometaphase arrest and subsequent apoptosis of bladder cancer cells. Here, we demonstrate that IPP51 selectively inhibits proliferation of tumor-derived cells versus normal non-tumor cells. IPP51 interfered with spindle formation and mitotic chromosome alignment. Accumulation of cyclin B1 and mitotic checkpoint proteins Bub1 and BubR1 on chromosomes in IPP51 treated cells indicated the activation of spindle-assembly checkpoint, which is consistent with the mitotic arrest. The antimitotic actions of other chalcones are often associated with microtubule disruption. Indeed, IPP51 inhibited tubulin polymerization in an in vitro assay with purified tubulin. In cells, IPP51 induced an increase in soluble tubulin. Furthermore, IPP51 inhibited in vitro capillary-like tube formation by endothelial cells, indicating that it has anti-angiogenic activity. Molecular docking showed that the indol group of IPP51 can be accommodated in the colchicine binding site of tubulin. This characteristic was confirmed by an in vitro competition assay demonstrating that IPP51 can compete for colchicine binding to soluble tubulin. Finally, in a human bladder xenograft mouse model, IPP51 inhibited tumor growth without signs of toxicity. Altogether, these findings suggest that IPP51 is an attractive new microtubule-targeting agent with potential chemotherapeutic value. PMID:26036640

  1. IPP51, a chalcone acting as a microtubule inhibitor with in vivo antitumor activity against bladder carcinoma.

    PubMed

    Martel-Frachet, Véronique; Keramidas, Michelle; Nurisso, Alessandra; DeBonis, Salvatore; Rome, Claire; Coll, Jean-Luc; Boumendjel, Ahcène; Skoufias, Dimitrios A; Ronot, Xavier

    2015-06-10

    We previously identified 1-(2,4-dimethoxyphenyl)-3-(1-methylindolyl) propenone (IPP51), a new chalcone derivative that is capable of inducing prometaphase arrest and subsequent apoptosis of bladder cancer cells. Here, we demonstrate that IPP51 selectively inhibits proliferation of tumor-derived cells versus normal non-tumor cells. IPP51 interfered with spindle formation and mitotic chromosome alignment. Accumulation of cyclin B1 and mitotic checkpoint proteins Bub1 and BubR1 on chromosomes in IPP51 treated cells indicated the activation of spindle-assembly checkpoint, which is consistent with the mitotic arrest. The antimitotic actions of other chalcones are often associated with microtubule disruption. Indeed, IPP51 inhibited tubulin polymerization in an in vitro assay with purified tubulin. In cells, IPP51 induced an increase in soluble tubulin. Furthermore, IPP51 inhibited in vitro capillary-like tube formation by endothelial cells, indicating that it has anti-angiogenic activity. Molecular docking showed that the indol group of IPP51 can be accommodated in the colchicine binding site of tubulin. This characteristic was confirmed by an in vitro competition assay demonstrating that IPP51 can compete for colchicine binding to soluble tubulin. Finally, in a human bladder xenograft mouse model, IPP51 inhibited tumor growth without signs of toxicity. Altogether, these findings suggest that IPP51 is an attractive new microtubule-targeting agent with potential chemotherapeutic value. PMID:26036640

  2. Leptin acts in the forebrain to differentially influence baroreflex control of lumbar, renal, and splanchnic sympathetic nerve activity and heart rate.

    PubMed

    Li, Baoxin; Shi, Zhigang; Cassaglia, Priscila A; Brooks, Virginia L

    2013-04-01

    Although leptin is known to increase sympathetic nerve activity (SNA), we tested the hypothesis that leptin also enhances baroreflex control of SNA and heart rate (HR). Using α-chloralose anesthetized male rats, mean arterial pressure (MAP), HR, lumbar SNA (LSNA), splanchnic SNA (SSNA), and renal SNA (RSNA) were recorded before and for 2 hours after lateral cerebroventricular leptin or artificial cerebrospinal fluid administration. Baroreflex function was assessed using a 4-parameter sigmoidal fit of HR and SNA responses to slow ramp (3-5 minutes) changes in MAP, induced by intravenous infusion of nitroprusside and phenylephrine. Leptin (3 μg) increased (P<0.05) basal LSNA, SSNA, RSNA, HR, and MAP, and the LSNA, SSNA, RSNA, and HR baroreflex maxima. Leptin also increased gain of baroreflex control of LSNA and RSNA, but not of SSNA or HR. The elevations in HR were eliminated by pretreatment with methscopalamine, to block parasympathetic nerve activity; however, after cardiac sympathetic blockade with atenolol, leptin still increased basal HR and MAP and the HR baroreflex maximum and minimum. Leptin (1.5 μg) also increased LSNA and enhanced LSNA baroreflex gain and maximum, but did not alter MAP, HR, or the HR baroreflex. Lateral cerebroventricular artificial cerebrospinal fluid had no effects. Finally, to test whether leptin acts in the brain stem, leptin (3 μg) was infused into the 4th ventricle; however, no significant changes were observed. In conclusion, leptin acts in the forebrain to differentially influence baroreflex control of LSNA, RSNA, SSNA, and HR, with the latter action mediated via suppression of parasympathetic nerve activity. PMID:23424232

  3. Early cerebral activities of the environmental estrogen bisphenol A appear to act via the somatostatin receptor subtype sst(2).

    PubMed Central

    Facciolo, Rosa Maria; Alò, Raffaella; Madeo, Maria; Canonaco, Marcello; Dessì-Fulgheri, Francesco

    2002-01-01

    Recently, considerable interest has been aroused by the specific actions of bisphenol A (BPA). The present investigation represents a first study dealing with the interaction of BPA with the biologically more active somatostatin receptor subtype (sst(2)) in the rat limbic circuit. After treating pregnant female Sprague-Dawley rats with two doses (400 microg/kg/day; 40 microg/kg/day) of BPA, the binding activity of the above receptor subtype was evaluated in some limbic regions of the offspring. The higher dose proved to be the more effective one, as demonstrated by the elevated affinity of sst(2) with its specific radioligand, [(125)I]-Tyr(0)somatostatin-14. The most dramatic effects of BPA on sst(2) levels occurred at the low-affinity states of such a subtype in some telencephalic limbic areas of postnatal rats (10 days of age; postnatal day [PND] 10). These included lower (p < 0.05) sst(2) levels in the gyrus dentate of the hippocampus and basomedial nucleus of the amygdala; significantly higher (p < 0.01) levels were observed only for the high-affinity states of the periventricular nucleus of the hypothalamus. A similar trend was maintained in PND 23 rats with the exception of much lower levels of the high-affinity sst(2) receptor subtype in the amygdala nucleus and ventromedial hypothalamic nucleus. However, greater changes produced by this environmental estrogen were reported when the binding activity of sst(2) was checked in the presence of the two more important selective agonists (zolpidem and Ro 15-4513) specific for the alpha-containing Gamma-aminobutyric acid (GABA) type A receptor complex. In this case, an even greater potentiating effect (p < 0.001) was mainly obtained for the low-affinity sst(2) receptor subtype in PND 10 animals, with the exception of the high-affinity type in the ventromedial hypothalamic nucleus and gyrus dentate. These results support the contention that an sst(2) subtype alpha-containing GABA type A receptor system might

  4. A Dimeric Chlorite Dismutase Exhibits O2-Generating Activity and Acts as a Chlorite Antioxidant in Klebsiella pneumoniae MGH 78578

    PubMed Central

    2015-01-01

    Chlorite dismutases (Clds) convert chlorite to O2 and Cl–, stabilizing heme in the presence of strong oxidants and forming the O=O bond with high efficiency. The enzyme from the pathogen Klebsiella pneumoniae (KpCld) represents a subfamily of Clds that share most of their active site structure with efficient O2-producing Clds, even though they have a truncated monomeric structure, exist as a dimer rather than a pentamer, and come from Gram-negative bacteria without a known need to degrade chlorite. We hypothesized that KpCld, like others in its subfamily, should be able to make O2 and may serve an in vivo antioxidant function. Here, it is demonstrated that it degrades chlorite with limited turnovers relative to the respiratory Clds, in part because of the loss of hypochlorous acid from the active site and destruction of the heme. The observation of hypochlorous acid, the expected leaving group accompanying transfer of an oxygen atom to the ferric heme, is consistent with the more open, solvent-exposed heme environment predicted by spectroscopic measurements and inferred from the crystal structures of related proteins. KpCld is more susceptible to oxidative degradation under turnover conditions than the well-characterized Clds associated with perchlorate respiration. However, wild-type K. pneumoniae has a significant growth advantage in the presence of chlorate relative to a Δcld knockout strain, specifically under nitrate-respiring conditions. This suggests that a physiological function of KpCld may be detoxification of endogenously produced chlorite. PMID:25437493

  5. The Arabidopsis CORI3 promoter contains two cis-acting regulatory regions required for transcriptional activity in companion cells.

    PubMed

    Tsuwamoto, Ryo; Harada, Takeo

    2011-09-01

    Companion cells are metabolically active and functionally specialized cells that behave as terminals for the transport of materials between phloem and the surrounding tissue. Although previous research has clarified the distinct function of companion cells, it is still largely unknown how plants establish and maintain the special identity of these cells. To shed further light on this issue, we carried out expressed sequence tag (EST) analysis. To minimize the difficulty of dissociating and gathering intact companion cells, vascular strings with an abundant content of companion cells were excised from the petioles of Brassica napus. By random sequencing with a string-specific cDNA library derived by suppression subtractive hybridization between the string itself and the petiole from which it had been removed, we identified 377 ESTs and assembled them into 247 EST groups. The most frequent EST was ExBdl-102 (15 of 377 ESTs), which showed the highest sequence similarity to the Arabidopsis CORI3 (CORONATINE INDUCED 3) gene. The CORI3 promoter:GUS showed predominant expression in the vascular tissue of Arabidopsis. Through transient expression assay using Brassica vasculature and gene-gun-mediated transient assay, we found two integrated cis-regulatory regions of the CORI3 promoter. This work has provided not only string-specific EST information and shown that two novel cis-regulatory regions sustain transcriptional activity in companion cells, but also a series of procedures for efficiently examining the transcriptional framework of companion cells by exploiting the histochemical advantage of B. napus as an experimental material. PMID:21559970

  6. Modeling turbulent flame propagation

    SciTech Connect

    Ashurst, W.T.

    1994-08-01

    Laser diagnostics and flow simulation techniques axe now providing information that if available fifty years ago, would have allowed Damkoehler to show how turbulence generates flame area. In the absence of this information, many turbulent flame speed models have been created, most based on Kolmogorov concepts which ignore the turbulence vortical structure, Over the last twenty years, the vorticity structure in mixing layers and jets has been shown to determine the entrainment and mixing behavior and these effects need to be duplicated by combustion models. Turbulence simulations reveal the intense vorticity structure as filaments and simulations of passive flamelet propagation show how this vorticity Creates flame area and defines the shape of the expected chemical reaction surface. Understanding how volume expansion interacts with flow structure should improve experimental methods for determining turbulent flame speed. Since the last decade has given us such powerful new tools to create and see turbulent combustion microscopic behavior, it seems that a solution of turbulent combustion within the next decade would not be surprising in the hindsight of 2004.

  7. Seismic wave propagation modeling

    SciTech Connect

    Jones, E.M.; Olsen, K.B.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). A hybrid, finite-difference technique was developed for modeling nonlinear soil amplification from three-dimensional, finite-fault radiation patters for earthquakes in arbitrary earth models. The method was applied to the 17 January 1994 Northridge earthquake. Particle velocities were computed on a plane at 5-km depth, immediately above the causative fault. Time-series of the strike-perpendicular, lateral velocities then were propagated vertically in a soil column typical of the San Fernando Valley. Suitable material models were adapted from a suite used to model ground motions at the US Nevada Test Site. The effects of nonlinearity reduced relative spectral amplitudes by about 40% at frequencies above 1.5 Hz but only by 10% at lower frequencies. Runs made with source-depth amplitudes increased by a factor of two showed relative amplitudes above 1.5 Hz reduced by a total of 70% above 1.5 Hz and 20% at lower frequencies. Runs made with elastic-plastic material models showed similar behavior to runs made with Masing-Rule models.

  8. The functional BPV-1 E2 trans-activating protein can act as a repressor by preventing formation of the initiation complex.

    PubMed

    Dostatni, N; Lambert, P F; Sousa, R; Ham, J; Howley, P M; Yaniv, M

    1991-09-01

    The products encoded by the E2 open reading frame of the papillomaviruses are DNA-binding transcription factors involved in the positive or negative regulation of multiple viral promoters. To further understand the mechanisms by which the same transcription factor may act differentially, the full-length BPV-1 E2 protein was expressed and purified from yeast and assayed in vitro for its capacity to modulate transcription. E2 stimulated transcription of the HSV thymidine kinase (TK) promoter when E2-binding sites were positioned in an enhancer configuration approximately 100 bp upstream of the promoter start site. In contrast, the same full-length E2 protein repressed transcription of the HPV-18 E6/E7 P105 promoter. This repression was mediated through binding to the E2 DNA-binding site immediately upstream of the P105 promoter TATA box and could be abrogated by preincubation of the HPV-18 P105 promoter template with the nuclear extract allowing the formation of the preinitiation complex. In vitro DNA-binding experiments with purified E2 and TFIID showed that binding of E2 to its DNA target placed at different positions with respect to the TATA box differentially affects binding of TFIID to its cognate site. In these respects, E2 is similar to the bacteriophage lambda repressor, which can act either as a repressor or an activator of transcription depending on the position of its binding sites relative to the promoter sequences. PMID:1653173

  9. Propagating Resource Constraints Using Mutual Exclusion Reasoning

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Sanchez, Romeo; Do, Minh B.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    One of the most recent techniques for propagating resource constraints in Constraint Based scheduling is Energy Constraint. This technique focuses in precedence based scheduling, where precedence relations are taken into account rather than the absolute position of activities. Although, this particular technique proved to be efficient on discrete unary resources, it provides only loose bounds for jobs using discrete multi-capacity resources. In this paper we show how mutual exclusion reasoning can be used to propagate time bounds for activities using discrete resources. We show that our technique based on critical path analysis and mutex reasoning is just as effective on unary resources, and also shows that it is more effective on multi-capacity resources, through both examples and empirical study.

  10. The Arabidopsis thaliana STYLISH1 Protein Acts as a Transcriptional Activator Regulating Auxin Biosynthesis[C][W

    PubMed Central

    Eklund, D. Magnus; Ståldal, Veronika; Valsecchi, Isabel; Cierlik, Izabela; Eriksson, Caitriona; Hiratsu, Keiichiro; Ohme-Takagi, Masaru; Sundström, Jens F.; Thelander, Mattias; Ezcurra, Inés; Sundberg, Eva

    2010-01-01

    The establishment and maintenance of auxin maxima in vascular plants is regulated by auxin biosynthesis and polar intercellular auxin flow. The disruption of normal auxin biosynthesis in mouse-ear cress (Arabidopsis thaliana) leads to severe abnormalities, suggesting that spatiotemporal regulation of auxin biosynthesis is fundamental for normal growth and development. We have shown previously that the induction of the SHORT-INTERNODES/STYLISH (SHI/STY) family member STY1 results in increased transcript levels of the YUCCA (YUC) family member YUC4 and also higher auxin levels and auxin biosynthesis rates in Arabidopsis seedlings. We have also shown previously that SHI/STY family members redundantly affect development of flowers and leaves. Here, we further examine the function of STY1 by analyzing its DNA and protein binding properties. Our results suggest that STY1, and most likely other SHI/STY members, are DNA binding transcriptional activators that target genes encoding proteins mediating auxin biosynthesis. This suggests that the SHI/STY family members are essential regulators of auxin-mediated leaf and flower development. Furthermore, the lack of a shoot apical meristem in seedlings carrying a fusion construct between STY1 and a repressor domain, SRDX, suggests that STY1, and other SHI/STY members, has a role in the formation and/or maintenance of the shoot apical meristem, possibly by regulating auxin levels in the embryo. PMID:20154152

  11. A novel small-molecule inhibitor of influenza A virus acts by suppressing PA endonuclease activity of the viral polymerase

    PubMed Central

    Yuan, Shuofeng; Chu, Hin; Singh, Kailash; Zhao, Hanjun; Zhang, Ke; Kao, Richard Y. T.; Chow, Billy K. C.; Zhou, Jie; Zheng, Bo-Jian

    2016-01-01

    The RNA-dependent RNA polymerase of influenza A virus comprises conserved and independently-folded subdomains with defined functionalities. The N-terminal domain of the PA subunit (PAN) harbors the endonuclease function so that it can serve as a desired target for drug discovery. To identify a class of anti-influenza inhibitors that impedes PAN endonuclease activity, a screening approach that integrated the fluorescence resonance energy transfer based endonuclease inhibitory assay with the DNA gel-based endonuclease inhibitory assay was conducted, followed by the evaluation of antiviral efficacies and potential cytotoxicity of the primary hits in vitro and in vivo. A small-molecule compound ANA-0 was identified as a potent inhibitor against the replication of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9 and H9N2, in cell cultures. Combinational treatment of zanamivir and ANA-0 exerted synergistic anti-influenza effect in vitro. Intranasal administration of ANA-0 protected mice from lethal challenge and reduced lung viral loads in H1N1 virus infected BALB/c mice. In summary, ANA-0 shows potential to be developed to novel anti-influenza agents. PMID:26956222

  12. Length heterogeneity at conserved sequence block 2 in human mitochondrial DNA acts as a rheostat for RNA polymerase POLRMT activity

    PubMed Central

    Tan, Benedict G.; Wellesley, Frederick C.; Savery, Nigel J.; Szczelkun, Mark D.

    2016-01-01

    The guanine (G)-tract of conserved sequence block 2 (CSB 2) in human mitochondrial DNA can result in transcription termination due to formation of a hybrid G-quadruplex between the nascent RNA and the nontemplate DNA strand. This structure can then influence genome replication, stability and localization. Here we surveyed the frequency of variation in sequence identity and length at CSB 2 amongst human mitochondrial genomes and used in vitro transcription to assess the effects of this length heterogeneity on the activity of the mitochondrial RNA polymerase, POLRMT. In general, increased G-tract length correlated with increased termination levels. However, variation in the population favoured CSB 2 sequences which produced efficient termination while particularly weak or strong signals were avoided. For all variants examined, the 3′ end of the transcripts mapped to the same downstream sequences and were prevented from terminating by addition of the transcription factor TEFM. We propose that CSB 2 length heterogeneity allows variation in the efficiency of transcription termination without affecting the position of the products or the capacity for regulation by TEFM. PMID:27436287

  13. Signal transducer and activator of transcription 1 (STAT1) acts like an oncogene in malignant pleural mesothelioma.

    PubMed

    Arzt, Lisa; Kothmaier, Hannelore; Halbwedl, Iris; Quehenberger, Franz; Popper, Helmut H

    2014-07-01

    Malignant pleural mesothelioma (MPM) is the most common primary tumor of the pleura. Its incidence is increasing in Europe and the prognosis remains poor. We compared epithelioid MPM in short and long survivors, and identified signal transducer and activator of transcription 1 (STAT1) as probably being responsible for antiapoptotic signaling and chemoresistance. Six mesothelioma cell lines were evaluated by Western Blot. We also analyzed 16 epithelioid MPM tissue samples for the phosphorylation status of STAT1 and the expression of its negative regulator, the suppressor of cytokine signaling 1 (SOCS1). Formalin-fixed and paraffin-embedded tissue specimens were evaluated by protein-lysate microarray and immunohistochemistry. We found STAT1 to be highly expressed and STAT3 downregulated in MPM cell lines. The expression of STAT1 phosphorylated on tyrosine 701 (Y701) was increased by interferon-gamma (IFN-γ) treatment, whereas SOCS1 was not expressed. The expression of STAT1 phosphorylated on serine 727 (S727) was not detected in mesothelioma cell lines and was not stimulated by IFN-γ. STAT1 was phosphorylated on tyrosine 701 and serine 727 in MPM tissue samples. The expression of pSTAT1-Y701 was increased compared to pSTAT1-S727. SOCS1 was again not detectable. STAT1 is upregulated in MPM, and its action may be prolonged by a loss of the negative regulator SOCS1. STAT1 might, therefore, be a target for therapeutic intervention, with the intention to restore apoptotic mechanisms and sensitivity to chemotherapy. However, other regulatory mechanisms need to be investigated to clarify if lack of expression of SOCS1 is the only reason for sustained STAT1 expression in MPM.

  14. UNC-16 (JIP3) Acts Through Synapse-Assembly Proteins to Inhibit the Active Transport of Cell Soma Organelles to Caenorhabditis elegans Motor Neuron Axons

    PubMed Central

    Edwards, Stacey L.; Morrison, Logan M.; Yorks, Rosalina M.; Hoover, Christopher M.; Boominathan, Soorajnath; Miller, Kenneth G.

    2015-01-01

    The conserved protein UNC-16 (JIP3) inhibits the active transport of some cell soma organelles, such as lysosomes, early endosomes, and Golgi, to the synaptic region of axons. However, little is known about UNC-16’s organelle transport regulatory function, which is distinct from its Kinesin-1 adaptor function. We used an unc-16 suppressor screen in Caenorhabditis elegans to discover that UNC-16 acts through CDK-5 (Cdk5) and two conserved synapse assembly proteins: SAD-1 (SAD-A Kinase), and SYD-2 (Liprin-α). Genetic analysis of all combinations of double and triple mutants in unc-16(+) and unc-16(−) backgrounds showed that the three proteins (CDK-5, SAD-1, and SYD-2) are all part of the same organelle transport regulatory system, which we named the CSS system based on its founder proteins. Further genetic analysis revealed roles for SYD-1 (another synapse assembly protein) and STRADα (a SAD-1-interacting protein) in the CSS system. In an unc-16(−) background, loss of the CSS system improved the sluggish locomotion of unc-16 mutants, inhibited axonal lysosome accumulation, and led to the dynein-dependent accumulation of lysosomes in dendrites. Time-lapse imaging of lysosomes in CSS system mutants in unc-16(+) and unc-16(−) backgrounds revealed active transport defects consistent with the steady-state distributions of lysosomes. UNC-16 also uses the CSS system to regulate the distribution of early endosomes in neurons and, to a lesser extent, Golgi. The data reveal a new and unprecedented role for synapse assembly proteins, acting as part of the newly defined CSS system, in mediating UNC-16’s organelle transport regulatory function. PMID:26354976

  15. UNC-16 (JIP3) Acts Through Synapse-Assembly Proteins to Inhibit the Active Transport of Cell Soma Organelles to Caenorhabditis elegans Motor Neuron Axons.

    PubMed

    Edwards, Stacey L; Morrison, Logan M; Yorks, Rosalina M; Hoover, Christopher M; Boominathan, Soorajnath; Miller, Kenneth G

    2015-09-01

    The conserved protein UNC-16 (JIP3) inhibits the active transport of some cell soma organelles, such as lysosomes, early endosomes, and Golgi, to the synaptic region of axons. However, little is known about UNC-16's organelle transport regulatory function, which is distinct from its Kinesin-1 adaptor function. We used an unc-16 suppressor screen in Caenorhabditis elegans to discover that UNC-16 acts through CDK-5 (Cdk5) and two conserved synapse assembly proteins: SAD-1 (SAD-A Kinase), and SYD-2 (Liprin-α). Genetic analysis of all combinations of double and triple mutants in unc-16(+) and unc-16(-) backgrounds showed that the three proteins (CDK-5, SAD-1, and SYD-2) are all part of the same organelle transport regulatory system, which we named the CSS system based on its founder proteins. Further genetic analysis revealed roles for SYD-1 (another synapse assembly protein) and STRADα (a SAD-1-interacting protein) in the CSS system. In an unc-16(-) background, loss of the CSS system improved the sluggish locomotion of unc-16 mutants, inhibited axonal lysosome accumulation, and led to the dynein-dependent accumulation of lysosomes in dendrites. Time-lapse imaging of lysosomes in CSS system mutants in unc-16(+) and unc-16(-) backgrounds revealed active transport defects consistent with the steady-state distributions of lysosomes. UNC-16 also uses the CSS system to regulate the distribution of early endosomes in neurons and, to a lesser extent, Golgi. The data reveal a new and unprecedented role for synapse assembly proteins, acting as part of the newly defined CSS system, in mediating UNC-16's organelle transport regulatory function.

  16. TALE1 from Xanthomonas axonopodis pv. manihotis acts as a transcriptional activator in plant cells and is important for pathogenicity in cassava plants.

    PubMed

    Castiblanco, Luisa F; Gil, Juliana; Rojas, Alejandro; Osorio, Daniela; Gutiérrez, Sonia; Muñoz-Bodnar, Alejandra; Perez-Quintero, Alvaro L; Koebnik, Ralf; Szurek, Boris; López, Camilo; Restrepo, Silvia; Verdier, Valérie; Bernal, Adriana J

    2013-01-01

    Many plant-pathogenic bacteria suppress pathogen-associated molecular pattern (PAMP)-triggered immunity by injecting effector proteins into the host cytoplasm during infection through the type III secretion system (TTSS). This type III secretome plays an important role in bacterial pathogenicity in susceptible hosts. Xanthomonas axonopodis pv. manihotis (Xam), the causal agent of cassava bacterial blight, injects several effector proteins into the host cell, including TALE1(Xam) . This protein is a member of the Transcriptional Activator-Like effector (TALE) protein family, formerly known as the AvrBs3/PthA family. TALE1(Xam) has 13.5 tandem repeats of 34 amino acids each, as well as two nuclear localization signals and an acidic activation domain at the C-terminus. In this work, we demonstrate the importance of TALE1(Xam) in the pathogenicity of Xam. We use versions of the gene that lack different domains in the protein in structure-function studies to show that the eukaryotic domains at the 3' end are critical for pathogenicity. In addition, we demonstrate that, similar to the characterized TALE proteins from other Xanthomonas species, TALE1(Xam) acts as a transcriptional activator in plant cells. This is the first report of the identification of a TALE in Xam, and contributes to our understanding of the pathogenicity mechanisms employed by this bacterium to colonize and cause disease in cassava. PMID:22947214

  17. AguR, a Transmembrane Transcription Activator of the Putrescine Biosynthesis Operon in Lactococcus lactis, Acts in Response to the Agmatine Concentration

    PubMed Central

    Linares, Daniel M.; del Rio, Beatriz; Redruello, Begoña; Ladero, Victor; Martin, M. Cruz; de Jong, Anne; Kuipers, Oscar P.; Fernandez, Maria

    2015-01-01

    Dairy industry fermentative processes mostly use Lactococcus lactis as a starter. However, some dairy L. lactis strains produce putrescine, a biogenic amine that raises food safety and spoilage concerns, via the agmatine deiminase (AGDI) pathway. The enzymatic activities responsible for putrescine biosynthesis in this bacterium are encoded by the AGDI gene cluster. The role of the catabolic genes aguB, aguD, aguA, and aguC has been studied, but knowledge regarding the role of aguR (the first gene in the cluster) remains limited. In the present work, aguR was found to be a very low level constitutively expressed gene that is essential for putrescine biosynthesis and is transcribed independently of the polycistronic mRNA encoding the catabolic genes (aguBDAC). In response to agmatine, AguR acts as a transcriptional activator of the aguB promoter (PaguB), which drives the transcription of the aguBDAC operon. Inverted sequences required for PaguB activity were identified by deletion analysis. Further work indicated that AguR is a transmembrane protein which might function as a one-component signal transduction system that senses the agmatine concentration of the medium and, accordingly, regulates the transcription of the aguBDAC operon through a C-terminal cytoplasmic DNA-binding domain typically found in LuxR-like proteins. PMID:26116671

  18. AguR, a Transmembrane Transcription Activator of the Putrescine Biosynthesis Operon in Lactococcus lactis, Acts in Response to the Agmatine Concentration.

    PubMed

    Linares, Daniel M; Del Rio, Beatriz; Redruello, Begoña; Ladero, Victor; Martin, M Cruz; de Jong, Anne; Kuipers, Oscar P; Fernandez, Maria; Alvarez, Miguel A

    2015-09-01

    Dairy industry fermentative processes mostly use Lactococcus lactis as a starter. However, some dairy L. lactis strains produce putrescine, a biogenic amine that raises food safety and spoilage concerns, via the agmatine deiminase (AGDI) pathway. The enzymatic activities responsible for putrescine biosynthesis in this bacterium are encoded by the AGDI gene cluster. The role of the catabolic genes aguB, aguD, aguA, and aguC has been studied, but knowledge regarding the role of aguR (the first gene in the cluster) remains limited. In the present work, aguR was found to be a very low level constitutively expressed gene that is essential for putrescine biosynthesis and is transcribed independently of the polycistronic mRNA encoding the catabolic genes (aguBDAC). In response to agmatine, AguR acts as a transcriptional activator of the aguB promoter (PaguB), which drives the transcription of the aguBDAC operon. Inverted sequences required for PaguB activity were identified by deletion analysis. Further work indicated that AguR is a transmembrane protein which might function as a one-component signal transduction system that senses the agmatine concentration of the medium and, accordingly, regulates the transcription of the aguBDAC operon through a C-terminal cytoplasmic DNA-binding domain typically found in LuxR-like proteins.

  19. The Slicer Activity of ARGONAUTE1 Is Required Specifically for the Phasing, Not Production, of Trans-Acting Short Interfering RNAs in Arabidopsis[OPEN

    PubMed Central

    Marchais, Antonin; Poulsen, Christian; Hauptmann, Judith; Meister, Gunter

    2016-01-01

    ARGONAUTE1 (AGO1) mediates posttranscriptional silencing by microRNAs (miRNAs) and short interfering RNAS (siRNAs). AGO1-catalyzed RNA cleavage (slicing) represses miRNA targets, but current models also highlight the roles of slicing in formation of siRNAs and siRNA-AGO1 complexes. miRNA-guided slicing is required for biogenesis of phased, trans-acting siRNAs (tasiRNAs), whose cleaved precursor fragments are converted to double-stranded RNA by RNA-dependent RNA polymerase 6 (RDR6). In addition, unwinding of duplex siRNA bound to AGO1 requires passenger strand cleavage in vitro. In this study, we analyze how mutation of four metal ion-coordinating residues of Arabidopsis thaliana AGO1 affects slicer activity in vitro and siRNA function in vivo. We show that while all four residues are required for slicer activity, they do not contribute equally to catalysis. Moreover, passenger strand cleavage is required for assembly of active AGO1-siRNA complexes in vivo, and many AGO1-bound siRNAs are trimmed in the absence of slicer activity. Remarkably, seedlings defective in AGO1 slicer activity produce abundant siRNAs from tasiRNA loci in vivo. These siRNAs depend on RDR6 and SUPPRESSOR OF GENE SILENCING3, but unlike wild-type tasiRNAs, they are unphased. These results demonstrate that slicing is solely required for phase definition of tasiRNAs, and they strongly support recruitment of RDR6 by AGO1 rather than by cleavage fragments. PMID:27354557

  20. Anisotropic propagation of Ca2+ waves in isolated cardiomyocytes.

    PubMed Central

    Engel, J; Fechner, M; Sowerby, A J; Finch, S A; Stier, A

    1994-01-01

    Digital imaging microscopy of fluor-3 fluorescence was used to study the propagation of intracellular Ca2+ waves in isolated adult rat cardiomyocytes from 17 to 37 degrees C. Ca2+ waves spread in both transverse and longitudinal direction of a myocyte. Transverse propagation was pronounced in waves starting from a focus at the edge of a myocyte and in waves following an irregular, curved path (spiral waves). For the former type of waves, propagation velocities were determined. Both transverse and longitudinal wave components propagated at constant velocity ranging from 30 to 125 micron/s. Myocytes were anisotropic with respect to wave propagation: waves propagated faster in the longitudinal than in the transverse direction. The ratio between longitudinal and transverse velocity increased from 1.30 at 17 degrees C to 1.55 at 37 degrees C. Apparent activation energies for transverse and longitudinal wave propagation were estimated to be -20 kJ/mol, suggesting that these processes are limited by diffusion of Ca2+. Direction-dependent propagation velocities are interpreted to result from the highly ordered structure of the myocytes, especially from the anisotropic arrangement of diffusion obstacles such as myofilaments and mitochondria. Images FIGURE 1 FIGURE 2 FIGURE 4 PMID:8075316

  1. Waves on Reissner’s membrane: a mechanism for the propagation of otoacoustic emissions from the cochlea

    PubMed Central

    Reichenbach, Tobias; Stefanovic, Aleksandra; Nin, Fumiaki; Hudspeth, A. J.

    2012-01-01

    Summary Sound is detected and converted into electrical signals within the ear. The cochlea not only acts as a passive detector of sound, however, but can also produce tones itself. These otoacoustic emissions are a striking manifestation of the cochlea’s mechanical active process. A controversy remains of how these mechanical signals propagate back to the middle ear, from which they are emitted as sound. Here we combine theoretical and experimental studies to show that mechanical signals can be transmitted by waves on Reissner’s membrane, an elastic structure within the cochea. We develop a theory for wave propagation on Reissner’s membrane and its role in otoacoustic emissions. Employing a scanning laser interferometer, we measure traveling waves on Reissner’s membrane in the gerbil, guinea pig, and chinchilla. The results accord with the theory and thus support a role for Reissner’s membrane in otoacoustic emissions. PMID:22580949

  2. VLF Waveguide Propagation: The Basics

    NASA Astrophysics Data System (ADS)

    Lynn, Kenneth J. W.

    2010-10-01

    In recent times, research has moved towards using VLF radio transmissions propagating in the earth-ionosphere waveguide as a detector of a variety of transient geophysical phenomena. A correct interpretation of such results depends critically on understanding the propagation characteristics of the path being monitored. The observed effects will vary depending on time of day, path length, path orientation, magnetic latitude and VLF frequency. This paper provides a brief tutorial of the relevant propagation dependencies for medium to long VLF paths best understood in terms of waveguide mode theory together with results either not previously published, not published in the open scientific literature or whose significance has been little recognised.

  3. The RADLAC beam propagation experiment

    SciTech Connect

    Frost, C.A.; Shope, S.L.; Mazarakis, M.G.; Poukey, J.W.; Wagner, J.S.; Turman, B.N.; Crist, C.E. ); Welch, D.R.; Struve, K.W. )

    1992-01-01

    The most recent RADLAC experiments studied propagation and hose stability of a high current beam propagating in the atmosphere, and confirmed the convective nature of the hose instability. The unique combination of high beam current and extremely small initial perturbation, allowed saturation of the hose instability to be observed for the first time. Data on high current propagation was needed because the current scaling is more complex than energy scaling. It was important to collect data at atmospheric pressure to insure that subtle air chemistry effects such as avalanche did not distort the experiment. With this philosophy, the results should be directly scaleable to applications at higher energy.

  4. The RADLAC beam propagation experiment

    SciTech Connect

    Frost, C.A.; Shope, S.L.; Mazarakis, M.G.; Poukey, J.W.; Wagner, J.S.; Turman, B.N.; Crist, C.E.; Welch, D.R.; Struve, K.W.

    1992-06-01

    The most recent RADLAC experiments studied propagation and hose stability of a high current beam propagating in the atmosphere, and confirmed the convective nature of the hose instability. The unique combination of high beam current and extremely small initial perturbation, allowed saturation of the hose instability to be observed for the first time. Data on high current propagation was needed because the current scaling is more complex than energy scaling. It was important to collect data at atmospheric pressure to insure that subtle air chemistry effects such as avalanche did not distort the experiment. With this philosophy, the results should be directly scaleable to applications at higher energy.

  5. Uncertainty propagation in nuclear forensics.

    PubMed

    Pommé, S; Jerome, S M; Venchiarutti, C

    2014-07-01

    Uncertainty propagation formulae are presented for age dating in support of nuclear forensics. The age of radioactive material in this context refers to the time elapsed since a particular radionuclide was chemically separated from its decay product(s). The decay of the parent radionuclide and ingrowth of the daughter nuclide are governed by statistical decay laws. Mathematical equations allow calculation of the age of specific nuclear material through the atom ratio between parent and daughter nuclides, or through the activity ratio provided that the daughter nuclide is also unstable. The derivation of the uncertainty formulae of the age may present some difficulty to the user community and so the exact solutions, some approximations, a graphical representation and their interpretation are presented in this work. Typical nuclides of interest are actinides in the context of non-proliferation commitments. The uncertainty analysis is applied to a set of important parent-daughter pairs and the need for more precise half-life data is examined.

  6. Mineral replacement front propagation in deformed rocks

    NASA Astrophysics Data System (ADS)

    Beaudoin, Nicolas; Koehn, Daniel; Kelka, Ulrich

    2015-04-01

    Fluid migrations are a major agent of contaminant transport leading to mineral replacement in rocks, impacting their properties as porosity, permeability, and rheology. Understanding the physical and chemical mechanisms that govern mineralogical replacement during and after deformation is required to better understand complex interplays between fluid and rocks that are involved in faulting, seismic cycle, and resource distribution in the upper crust. Dolomitization process related to hydrothermal fluid flow is one of the most studied and debated replacement processes in earth sciences. Dolomitization of limestone is of economic importance as well, as it stands as unconventional oil reservoirs and is systematically observed in Mississippian-Valley Type ore deposit. Despite recent breakthrough about dolomitization processes at large-scale, the small-scale propagation of the reaction front remains unclear. It is poorly documented in the occurrence of stylolites and fractures in the medium while pressure-solution and fracture network development are the most efficient deformation accomodation mechanism in limestone from early compaction to layer-parallel shortening. Thus, the impact of such network on geometry of replaced bodies and on replacement front propagation deserves specific attention. This contribution illustrates the role of fracture and stylolites on the propagation of a reaction front. In a 2 dimensional numerical model we simulate the dolomitization front propagation in a heterogeneous porous medium. The propagation of the reaction front is governed by the competition between advection and diffusion processes, and takes into account reaction rates, disorder in the location of the potential replacement seeds, and permeability heterogeneities. We add stylolites and fractures that can act as barriers or drains to fluid flow according to their orientation and mineralogical content, which can or cannot react with the contaminant. The patterns produced from

  7. Proceedings of the Eleventh Advanced Communications Technology Satellite Propagation Studies Workshop (APSW 11)

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser (Editor); Ho, Christian (Editor)

    1998-01-01

    The Advanced Communications Technology Satellite Propagation Studies Workshop (APSW) is convened each year to present the results of the Advanced Communications Technology Satellite (ACTS) Ka-band propagation campaign. Representatives from the space community including industry, academia, and government who are interested in radiowave propagation at Ka-band are invited to APSW for discussions and exchange of information. The ACTS Propagation campaign will complete five years of Ka-Band data collection at seven sites in North America by December 31, 1998. Through this effort, NASA is making a major contribution to the effective utilization of this band by providing timely propagation data and models for predicting the performance of Ka-band links between space and ground.

  8. Act resilient.

    PubMed

    Joseph, Genie; Bice-Stephens, Wynona

    2014-01-01

    Attendees have reported changing from being fearful to serene, from listless to energized, from disengaged to connected, and becoming markedly less anxious in a few weeks. Anecdotally, self-reported stress levels have been reduced by over 50% after just one class. Attendees learn not to be afraid of their feelings by working with emotions in a playful manner. When a person can act angry, but separate himself from his personal story, the emotional energy exists in a separate form that is not attached to specific events, and can be more easily dealt with and neutralized. Attendees are taught to "take out the emotional trash" through expressive comedy. They become less intimated by their own emotional intensity and triggers as they learn how even metaphorical buckets of anger, shame, guilt and hurt can be emotionally emptied. The added benefit is that this is accomplished without the disclosure of personal information of the requirement to reexperience past pain which can trigger its own cascade of stress. PMID:24706248

  9. 48 CFR 50.205-1 - SAFETY Act Considerations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Fostering Effective Technologies Act of 2002 50.205-1 SAFETY Act Considerations. (a) SAFETY Act applicability. Requiring activities should review requirements to identify potential technologies that prevent... acquisitions involving such technologies, the requiring activity should ascertain through discussions with...

  10. High mobility group box 1 can enhance NF-κB activation and act as a pro-inflammatory molecule in the Pacific oyster, Crassostrea gigas.

    PubMed

    Li, Jun; Zhang, Yang; Xiang, Zhiming; Xiao, Shu; Yu, Feng; Yu, Ziniu

    2013-07-01

    High-mobility group box 1 (HMGB1), a highly conserved DNA-binding protein, is involved in nucleosome formation and transcriptional regulation, and can also act as an extracellular cytokine to trigger inflammation and immune responses. In this study, we identified a HMGB1 gene (hereafter designated as CgHMGB1) in the Pacific oyster Crassostrea gigas. The full-length CgHMGB1 cDNA is 833 bp including 5' and 3'-untranslated regions (UTRs) of 145 and 79 bp, respectively, and an open reading frame (ORF) of 609 bp. The gene encodes a 202 amino acid polypeptide with an estimated molecular mass of 23.3 kDa. Sequence alignment shows that CgHMGB1 contains two basic HMG boxes and a highly acidic C-terminal domain. Recombinant CgHMGB1 proteins can enhance the mRNA level of various inflammatory cytokines in vivo. Typically, CgHMGB1 is localized in the nucleus, though lipopolysaccharide can induce its release to cytoplasm. Moreover, luciferase reporter assays reveal that CgHMGB1 cannot stimulate Nuclear Factor-κB reporter activity alone, but it can enhance Rel-dependent NF-κB activation in a dose-dependent manner. CgHMGB1 is highly expressed in hemocytes and its transcripts are significantly more abundant following bacterial challenge. Our results suggest that CgHMGB1 plays an essential role in innate defense by enhancing Rel-activated NF-κB activity and inducing the expression of inflammatory cytokines.

  11. Reconstruction of nonlinear wave propagation

    DOEpatents

    Fleischer, Jason W; Barsi, Christopher; Wan, Wenjie

    2013-04-23

    Disclosed are systems and methods for characterizing a nonlinear propagation environment by numerically propagating a measured output waveform resulting from a known input waveform. The numerical propagation reconstructs the input waveform, and in the process, the nonlinear environment is characterized. In certain embodiments, knowledge of the characterized nonlinear environment facilitates determination of an unknown input based on a measured output. Similarly, knowledge of the characterized nonlinear environment also facilitates formation of a desired output based on a configurable input. In both situations, the input thus characterized and the output thus obtained include features that would normally be lost in linear propagations. Such features can include evanescent waves and peripheral waves, such that an image thus obtained are inherently wide-angle, farfield form of microscopy.

  12. Activity of the human immunodeficiency virus type 1 cell cycle-dependent internal ribosomal entry site is modulated by IRES trans-acting factors

    PubMed Central

    Vallejos, Maricarmen; Deforges, Jules; Plank, Terra-Dawn M.; Letelier, Alejandro; Ramdohr, Pablo; Abraham, Christopher G.; Valiente-Echeverría, Fernando; Kieft, Jeffrey S.; Sargueil, Bruno; López-Lastra, Marcelo

    2011-01-01

    The 5′ leader of the human immunodeficiency virus type 1 (HIV-1) genomic RNA harbors an internal ribosome entry site (IRES) that is functional during the G2/M phase of the cell cycle. Here we show that translation initiation mediated by the HIV-1 IRES requires the participation of trans-acting cellular factors other than the canonical translational machinery. We used ‘standard’ chemical and enzymatic probes and an ‘RNA SHAPE’ analysis to model the structure of the HIV-1 5′ leader and we show, by means of a footprinting assay, that G2/M extracts provide protections to regions previously identified as crucial for HIV-1 IRES activity. We also assessed the impact of mutations on IRES function. Strikingly, mutations did not significantly affect IRES activity suggesting that the requirement for pre-formed stable secondary or tertiary structure within the HIV-1 IRES may not be as strict as has been described for other viral IRESes. Finally, we used a proteomic approach to identify cellular proteins within the G2/M extracts that interact with the HIV-1 5′ leader. Together, data show that HIV-1 IRES-mediated translation initiation is modulated by cellular proteins. PMID:21482538

  13. MAP4K family kinases act in parallel to MST1/2 to activate LATS1/2 in the Hippo pathway

    PubMed Central

    Meng, Zhipeng; Moroishi, Toshiro; Mottier-Pavie, Violaine; Plouffe, Steven W.; Hansen, Carsten G.; Hong, Audrey W.; Park, Hyun Woo; Mo, Jung-Soon; Lu, Wenqi; Lu, Shicong; Flores, Fabian; Yu, Fa-Xing; Halder, Georg; Guan, Kun-Liang

    2015-01-01

    The Hippo pathway plays a central role in tissue homoeostasis, and its dysregulation contributes to tumorigenesis. Core components of the Hippo pathway include a kinase cascade of MST1/2 and LATS1/2 and the transcription co-activators YAP/TAZ. In response to stimulation, LATS1/2 phosphorylate and inhibit YAP/TAZ, the main effectors of the Hippo pathway. Accumulating evidence suggests that MST1/2 are not required for the regulation of YAP/TAZ. Here we show that deletion of LATS1/2 but not MST1/2 abolishes YAP/TAZ phosphorylation. We have identified MAP4K family members—Drosophila Happyhour homologues MAP4K1/2/3 and Misshapen homologues MAP4K4/6/7—as direct LATS1/2-activating kinases. Combined deletion of MAP4Ks and MST1/2, but neither alone, suppresses phosphorylation of LATS1/2 and YAP/TAZ in response to a wide range of signals. Our results demonstrate that MAP4Ks act in parallel to and are partially redundant with MST1/2 in the regulation of LATS1/2 and YAP/TAZ, and establish MAP4Ks as components of the expanded Hippo pathway. PMID:26437443

  14. Small heat shock protein IbpB acts as a robust chaperone in living cells by hierarchically activating its multi-type substrate-binding residues.

    PubMed

    Fu, Xinmiao; Shi, Xiaodong; Yin, Linxiang; Liu, Jiafeng; Joo, Keehyoung; Lee, Jooyoung; Chang, Zengyi

    2013-04-26

    As ubiquitous molecular chaperones, small heat shock proteins (sHSPs) are crucial for protein homeostasis. It is not clear why sHSPs are able to bind a wide spectrum of non-native substrate proteins and how such binding is enhanced by heat shock. Here, by utilizing a genetically incorporated photo-cross-linker (p-benzoyl-l-phenylalanine), we systematically characterized the substrate-binding residues in IbpB (a sHSP from Escherichia coli) in living cells over a wide spectrum of temperatures (from 20 to 50 °C). A total of 20 and 48 residues were identified at normal and heat shock temperatures, respectively. They are not necessarily hydrophobic and can be classified into three types: types I and II were activated at low and normal temperatures, respectively, and type III mediated oligomerization at low temperature but switched to substrate binding at heat shock temperature. In addition, substrate binding of IbpB in living cells began at temperatures as low as 25 °C and was further enhanced upon temperature elevation. Together, these in vivo data provide novel structural insights into the wide substrate spectrum of sHSPs and suggest that sHSP is able to hierarchically activate its multi-type substrate-binding residues and thus act as a robust chaperone in cells under fluctuating growth conditions.

  15. Fundamentals of Seismic Wave Propagation

    NASA Astrophysics Data System (ADS)

    Chapman, Chris

    2004-08-01

    Presenting a comprehensive introduction to the propagation of high-frequency body-waves in elastodynamics, this volume develops the theory of seismic wave propagation in acoustic, elastic and anisotropic media to allow seismic waves to be modelled in complex, realistic three-dimensional Earth models. The book is a text for graduate courses in theoretical seismology, and a reference for all academic and industrial seismologists using numerical modelling methods. Exercises and suggestions for further reading are included in each chapter.

  16. Learning Activism, Acting with Phronesis

    ERIC Educational Resources Information Center

    Lee, Yew-Jin

    2015-01-01

    The article "Socio-political development of private school children mobilising for disadvantaged others" by Darren Hoeg, Natalie Lemelin, and Lawrence Bencze described a language-learning curriculum that drew on elements of Socioscientific issues and Science, Technology, Society and Environment. Results showed that with a number of…

  17. Propagation of the deformation front beyond a decollement disrupted by a step : from the Jura case to general conclusions.

    NASA Astrophysics Data System (ADS)

    Caer, Typhaine; Souloumiac, Pauline; Maillot, Bertrand; Leturmy, Pascale

    2016-04-01

    The North of the Jura fold-and-thrust-belt is an example of a thin-skin belt developed over a disrupted décollement. During Oligocene, the area of the current northern Jura undergoes the West European E-W extension that opens the Rhine and Bresse grabens, offsetting the Triassic evaporitic décollement layer. During Miocene, the alpine, roughly N-S, compressive regime folds this prefractured cover. The presence of deformation to the North of a step down in the décollement is sometimes interpreted as the proof of the activation of a deeper décollement, on the basis that outward propagation of deformation must activate shallower decollements and cannot activate deeper ones. Using the limit analysis theory, we demonstrate that for a given set of physical parameters (friction/cohesion), a lowered portion of a décollement can be reactivated depending on the height of the offset and on the topography above it. By sandbox experiment, we illustrate the general behavior of this localization along a disrupted décollement, we show that the offsets represent slowdowns in the deformation. They act as catching points that localize a ramp until the created topography is sufficient to block the ongoing deformation on this ramp allowing it propagation farther along the lowered portion of the décollement level. We use the mechanical analysis to quantify the general conditions in which an offset can block or not the propagation of deformation.

  18. Monascin and ankaflavin act as natural AMPK activators with PPARα agonist activity to down-regulate nonalcoholic steatohepatitis in high-fat diet-fed C57BL/6 mice.

    PubMed

    Hsu, Wei-Hsuan; Chen, Ting-Hung; Lee, Bao-Hong; Hsu, Ya-Wen; Pan, Tzu-Ming

    2014-02-01

    Yellow pigments monascin (MS) and ankaflavin (AK) are secondary metabolites derived from Monascus-fermented products. The hypolipidemic and anti-inflammatory effects of MS and AK indicate that they have potential on preventing or curing nonalcoholic fatty liver disease (NAFLD). Oleic acid (OA) and high-fat diet were used to induce steatosis in FL83B hepatocytes and NAFLD in mice, respectively. We found that both MS and AK prevented fatty acid accumulation in hepatocytes by inhibiting fatty acid uptake, lipogenesis, and promoting fatty acid beta-oxidation mediated by activating peroxisome proliferator-activated receptor (PPAR)-α and AMP-activated kinase (AMPK). Furthermore, MS and AK significantly attenuated high-fat diet-induced elevation of total cholesterol (TC), triaceylglycerol (TG), free fatty acid (FFA), and low density lipoprotein-cholesterol (LDL-C) in plasma. MS and AK promoted AMPK phosphorylation, suppressed the steatosis-related mRNA expression and inflammatory cytokines secretion, as well as upregulated farnesoid X receptor (FXR), peroxisome proliferator-activated receptor gamma co-activator (PGC)-1α, and PPARα expression to induce fatty acid oxidation in the liver of mice. We provided evidence that MS and AK act as PPARα agonists to upregulate AMPK activity and attenuate NAFLD. MS and AK may be supplied in food supplements or developed as functional foods to reduce the risk of diabetes and obesity. PMID:24275089

  19. Orbital Propagation of Momentum Exchange Tether Systems

    NASA Technical Reports Server (NTRS)

    Westerhoff, John

    2002-01-01

    An advanced concept in in-space transportation currently being studied is the Momentum-Exchange/Electrodynamic Reboost Tether System (MXER). The system acts as a large momentum wheel, imparting a Av to a payload in low earth orbit (LEO) at the expense of its own orbital energy. After throwing a payload, the system reboosts itself using an electrodynamic tether to push against Earth's magnetic field and brings itself back up to an operational orbit to prepare for the next payload. The ability to reboost itself allows for continued reuse of the system without the expenditure of propellants. Considering the cost of lifting propellant from the ,ground to LEO to do the same Av boost at $10000 per pound, the system cuts the launch cost of the payload dramatically, and subsequently, the MXER system pays for itself after a small number of missions.1 One of the technical hurdles to be overcome with the MXER concept is the rendezvous maneuver. The rendezvous window for the capture of the payload is on the order of a few seconds, as opposed to traditional docking maneuvers, which can take as long ets necessary to complete a precise docking. The payload, therefore, must be able to match its orbit to meet up with the capture device on the end of the tether at a specific time and location in the future. In order to be able to determine that location, the MXER system must be numerically propagated forward in time to predict where the capture device will be at that instant. It should be kept in mind that the propagation computation must be done faster than real-time. This study focuses on the efforts to find and/or build the tools necessary to numerically propagate the motion of the MXER system as accurately as possible.

  20. 76 FR 39367 - Migratory Bird Permits; Changes in the Regulations Governing Raptor Propagation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... of proposed rulemaking. SUMMARY: We solicit recommendations on whether the bald eagle (Haliaeetus...: Public Comments Propagation of bald eagles and golden eagles has not been allowed under the raptor... Act (MBTA, 16 U.S.C. 703 et seq.) and the Bald and Golden Eagle Protection Act (BGEPA, 16 U.S.C....

  1. Propagation considerations in the American Mobile Satellite system design

    NASA Technical Reports Server (NTRS)

    Kittiver, Charles; Sigler, Charles E., Jr.

    1993-01-01

    An overview of the American Mobile Satellite Corporation (AMSC) mobile satellite services (MSS) system with special emphasis given to the propagation issues that were considered in the design is presented. The aspects of the voice codec design that effect system performance in a shadowed environment are discussed. The strategies for overcoming Ku-Band rain fades in the uplink and downlink paths of the gateway station are presented. A land mobile propagation study that has both measurement and simulation activities is described.

  2. Propagation of electromagnetic radiation in mitochondria?

    PubMed

    Thar, Roland; Kühl, Michael

    2004-09-21

    Mitochondria are the main source of ultra-weak chemiluminescence generated by reactive oxygen species, which are continuously formed during the mitochondrial oxidative metabolism. Vertebrate cells show typically filamentous mitochondria associated with the microtubules of the cytoskeleton, forming together a continuous network (mitochondrial reticulum). The refractive index of both mitochondria and microtubules is higher than the surrounding cytoplasm, which results that the mitochondrial reticulum can act as an optical waveguide, i.e. electromagnetic radiation can propagate within the network. A detailed analysis of the inner structure of mitochondria shows, that they can be optically modelled as a multi-layer system with alternating indices of refraction. The parameters of this multi-layer system are dependent on the physiologic state of the mitochondria. The effect of the multi-layer system on electromagnetic radiation propagating along the mitochondrial reticulum is analysed by the transfer-matrix method. If induced light emission could take place in mitochondria, the multi-layer system could lead to lasing action like it has been realized in technical distributed feedback laser. Based on former reports about the influence of external illumination on the physiology of mitochondria it is speculated whether there exists some kind of long-range interaction between individual mitochondria mediated by electromagnetic radiation.

  3. Designing microcapsule arrays that propagate chemical signals

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Amitabh; Balazs, Anna C.

    2010-08-01

    Using analysis and simulation, we show how ordered arrays of microcapsules in solution can be harnessed to propagate chemical signals in directed and controllable ways, allowing the signals to be transmitted over macroscopic distances. The system encompasses two types of capsules that are localized on an adhesive surface. The “signaling” capsules release inducer molecules, which trigger “targets” to release nanoparticles. The released nanoparticles can bind to the underlying surface and thus, create adhesion gradients, which then propel the signaling capsules to shuttle between neighboring targets. This arrangement acts like a relay, so that triggering target capsules at a particular location in the array also triggers target capsules in adjacent locations. For an array containing two target columns, our simulations and analysis show that steady input signal leads to a sustained periodic output. For an array containing multiple target columns, we show that by introducing a prescribed ratio of nanoparticle release rates between successive target columns, a chemical signal can be propagated along the array without dissipation. We also demonstrate that similar signal transmission cannot be performed via diffusion alone.

  4. The physical theory and propagation model of THz atmospheric propagation

    NASA Astrophysics Data System (ADS)

    Wang, R.; Yao, J. Q.; Xu, D. G.; Wang, J. L.; Wang, P.

    2011-02-01

    Terahertz (THz) radiation is extensively applied in diverse fields, such as space communication, Earth environment observation, atmosphere science, remote sensing and so on. And the research on propagation features of THz wave in the atmosphere becomes more and more important. This paper firstly illuminates the advantages and outlook of THz in space technology. Then it introduces the theoretical framework of THz atmospheric propagation, including some fundamental physical concepts and processes. The attenuation effect (especially the absorption of water vapor), the scattering of aerosol particles and the effect of turbulent flow mainly influence THz atmosphere propagation. Fundamental physical laws are illuminated as well, such as Lamber-beer law, Mie scattering theory and radiative transfer equation. The last part comprises the demonstration and comparison of THz atmosphere propagation models like Moliere(V5), SARTre and AMATERASU. The essential problems are the deep analysis of physical mechanism of this process, the construction of atmospheric propagation model and databases of every kind of material in the atmosphere, and the standardization of measurement procedures.

  5. Activation of signalling by the activin receptor complex.

    PubMed Central

    Attisano, L; Wrana, J L; Montalvo, E; Massagué, J

    1996-01-01

    Activin exerts its effects by simultaneously binding to two types of p rotein serine/threonine kinase receptors, each type existing in various isoforms. Using the ActR-IB and ActR-IIB receptor isoforms, we have investigated the mechanism of activin receptor activation. ActR-IIB are phosphoproteins with demonstrable affinity for each other. However, activin addition strongly promotes an interaction between these two proteins. Activin binds directly to ActR-IIB, and this complex associates with ActR-IB, which does not bind ligand on its own. In the resulting complex, ActR-IB becomes hyperphosphorylated, and this requires the kinase activity of ActR-IIB. Mutation of conserved serines and threonines in the GS domain, a region just upstream of the kinase domain in ActR-IB, abrogates both phosphorylation and signal propagation, suggesting that this domain contains phosphorylation sites required for signalling. ActR-IB activation can be mimicked by mutation of Thr-206 to aspartic acid, which yields a construct, ActR-IB(T206D), that signals in the absence of ligand. Furthermore, the signalling activity of this mutant construct is undisturbed by overexpression of a dominant negative kinase-defective ActR-IIB construct, indicating that ActR-IB(T206D) can signal independently of ActR-IIB. The evidence suggests that ActR-IIB acts as a primary activin receptor and ActR-IB acts as a downstream transducer of activin signals. PMID:8622651

  6. Toxic Substances Control Act

    SciTech Connect

    Not Available

    1992-05-15

    This Reference Book contains a current copy of the Toxic Substances Control Act and those regulations that implement the statute and appear to be most relevant to DOE activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. Questions concerning this Reference Book may be directed to Mark Petts, EH-231 (202/586-2609).

  7. Budesonide epimer R or dexamethasone selectively inhibit platelet-activating factor-induced or interleukin 1β-induced DNA binding activity of cis-acting transcription factors and cyclooxygenase-2 gene expression in human epidermal keratinocytes

    PubMed Central

    Lukiw, Walter J.; Pelaez, Ricardo Palacios; Martinez, Jorge; Bazan, Nicolas G.

    1998-01-01

    To further understand the molecular mechanism of glucocorticoid action on gene expression, DNA-binding activities of the cis-acting transcription factors activator protein 1 (AP1), AP2, Egr1 (zif268), NF-κB, the signal transducers and activators of transcription proteins gamma interferon activation site (GAS), Sis-inducible element, and the TATA binding protein transcription factor II D (TFIID) were examined in human epidermal keratinocytes. The cytokine interleukin 1β (IL-1β) and platelet-activating factor (PAF), both potent mediators of inflammation, were used as triggers for gene expression. Budesonide epimer R (BUDeR) and dexamethasone (DEX) were studied as potential antagonists. BUDeR or DEX before IL-1β- or PAF-mediated gene induction elicited strong inhibition of AP1-, GAS-, and in particular NF-κB-DNA binding (P < 0.001, ANOVA). Only small effects were noted on AP2, Egr1 (zif268), and Sis-inducible element-DNA binding (P > 0.05). No significant effect was noted on the basal transcription factor TFIID recognition of TATA-containing core promoter sequences (P > 0.68). To test the hypothesis that changing cis-acting transcription factor binding activity may be involved in inflammatory-response related gene transcription, RNA message abundance for human cyclooxygenase (COX)-1 and -2 (E.C.1.14.99.1) was assessed in parallel by using reverse transcription–PCR. Although the COX-1 gene was found to be expressed at constitutively low levels, the TATA-containing COX-2 gene, which contains AP1-like, GAS, and NF-κB DNA-binding sites in its immediate promoter, was found to be strongly induced by IL-1β or PAF (P < 0.001). BUDeR and DEX both suppressed COX-2 RNA message generation; however, no correlation was associated with TFIID–DNA binding. These results suggest that on stimulation by mediators of inflammation, although the basal transcription machinery remains intact, modulation of cis-activating transcription factor AP1, GAS, and NF-κB-DNA binding by the

  8. Reversible competitive α-ketoheterocycle inhibitors of fatty acid amide hydrolase containing additional conformational constraints in the acyl side chain: orally active, long-acting analgesics.

    PubMed

    Ezzili, Cyrine; Mileni, Mauro; McGlinchey, Nicholas; Long, Jonathan Z; Kinsey, Steven G; Hochstatter, Dustin G; Stevens, Raymond C; Lichtman, Aron H; Cravatt, Benjamin F; Bilsky, Edward J; Boger, Dale L

    2011-04-28

    A series of α-ketooxazoles containing conformational constraints in the C2 acyl side chain of 2 (OL-135) were examined as inhibitors of fatty acid amide hydrolase (FAAH). Only one of the two possible enantiomers displayed potent FAAH inhibition (S vs R enantiomer), and their potency is comparable or improved relative to 2, indicating that the conformational restriction in the C2 acyl side chain is achievable. A cocrystal X-ray structure of the α-ketoheterocycle 12 bound to a humanized variant of rat FAAH revealed its binding details, confirmed that the (S)-enantiomer is the bound active inhibitor, shed light on the origin of the enantiomeric selectivity, and confirmed that the catalytic Ser241 is covalently bound to the electrophilic carbonyl as a deprotonated hemiketal. Preliminary in vivo characterization of the inhibitors 12 and 14 is reported demonstrating that they raise brain anandamide levels following either intraperitoneal (ip) or oral (po) administration indicative of effective in vivo FAAH inhibition. Significantly, the oral administration of 12 caused dramatic accumulation of anandamide in the brain, with peak levels achieved between 1.5 and 3 h, and these elevations were maintained over 9 h. Additional studies of these two representative members of the series (12 and 14) in models of thermal hyperalgesia and neuropathic pain are reported, including the demonstration that 12 administered orally significantly attenuated mechanical (>6 h) and cold (>9 h) allodynia for sustained periods consistent with its long-acting effects in raising the endogenous concentration of anandamide.

  9. The circadian clock gene Bmal1 acts as a potential anti-oncogene in pancreatic cancer by activating the p53 tumor suppressor pathway.

    PubMed

    Jiang, Weiliang; Zhao, Senlin; Jiang, Xiaohua; Zhang, Erquan; Hu, Guoyong; Hu, Bin; Zheng, Ping; Xiao, Junhua; Lu, Zhanjun; Lu, Yingying; Ni, Jianbo; Chen, Congying; Wang, Xingpeng; Yang, Lijuan; Wan, Rong

    2016-02-28

    Disruption of the circadian clock has been shown to be associated with tumor development. This study aimed to investigate the role of the core circadian gene Bmal1 in pancreatic cancer (PC). We first found that the levels of Bmal1 were downregulated in PC samples and were closely correlated with the clinicopathological features of patients. To dissect the underlying mechanism, we performed a RNA-seq assay followed by systematic gene function and pathway enrichment analyses. We detected an anti-apoptotic and pro-proliferative transcriptome profile after Bmal1 knockdown in PC cells. Further in vitro and in vivo studies confirmed that Bmal1 overexpression significantly inhibited cell proliferation and invasion and induced G2/M cell cycle arrest, whereas Bmal1 knockdown promoted PC growth, as demonstrated in Bmal1-manipulated AsPC-1 and BxPC-3 cell lines. Our mechanistic studies indicated that Bmal1 could directly bind to the p53 gene promoter and thereby transcriptionally activate the downstream tumor suppressor pathway in a p53-dependent manner. In sum, our findings suggest that Bmal1 acts as an anti-oncogene in PC and represents a potential biomarker for its diagnosis.

  10. Endogenous GLP-1 acts on paraventricular nucleus to suppress feeding: projection from nucleus tractus solitarius and activation of corticotropin-releasing hormone, nesfatin-1 and oxytocin neurons.

    PubMed

    Katsurada, Kenichi; Maejima, Yuko; Nakata, Masanori; Kodaira, Misato; Suyama, Shigetomo; Iwasaki, Yusaku; Kario, Kazuomi; Yada, Toshihiko

    2014-08-22

    Glucagon-like peptide-1 (GLP-1) receptor agonists have been used to treat type 2 diabetic patients and shown to reduce food intake and body weight. The anorexigenic effects of GLP-1 and GLP-1 receptor agonists are thought to be mediated primarily via the hypothalamic paraventricular nucleus (PVN). GLP-1, an intestinal hormone, is also localized in the nucleus tractus solitarius (NTS) of the brain stem. However, the role of endogenous GLP-1, particularly that in the NTS neurons, in feeding regulation remains to be established. The present study examined whether the NTS GLP-1 neurons project to PVN and whether the endogenous GLP-1 acts on PVN to restrict feeding. Intra-PVN injection of GLP-1 receptor antagonist exendin (9-39) increased food intake. Injection of retrograde tracer into PVN combined with immunohistochemistry for GLP-1 in NTS revealed direct projection of NTS GLP-1 neurons to PVN. Moreover, GLP-1 evoked Ca(2+) signaling in single neurons isolated from PVN. The majority of GLP-1-responsive neurons were immunoreactive predominantly to corticotropin-releasing hormone (CRH) and nesfatin-1, and less frequently to oxytocin. These results indicate that endogenous GLP-1 targets PVN to restrict feeding behavior, in which the projection from NTS GLP-1 neurons and activation of CRH and nesfatin-1 neurons might be implicated. This study reveals a neuronal basis for the anorexigenic effect of endogenous GLP-1 in the brain.

  11. VIS/ACT: The next episode

    NASA Technical Reports Server (NTRS)

    Maney, Tucker; Hamburger, Henry

    1993-01-01

    VIS/ACT is a multi-media educational system for aircrew coordination training (ACT). Students view video segments, answer questions that are adjusted to individual performance, and engage in related activities. Although the system puts the student in a reactive critiquing role, it has proved effective in improving performance on active targeted ACT skills, in group simulation tasks. VIS/ACT itself is the product of coordination among three Navy agencies.

  12. Alkalic (ocean-island basalt type) and calc-alkalic volcanism in the Mexican volcanic belt: A case for plume-related magmatism and propagating rifting at an active margin?

    NASA Astrophysics Data System (ADS)

    Márquez, Alvaro; Oyarzun, Roberto; Doblas, Miguel; Verma, Surendra P.

    1999-01-01

    The Mexican volcanic belt has been traditionally regarded as a classic case of subduction-related calc-alkalic volcanism. However, a series of geologic, geophysical, and petrological arguments makes this simple relationship doubtful. A seismic gap beneath the belt, a large-scale mantle anomaly, a graben triple-junction domain, and the presence of volumetrically important oceanic-island basalt (OIB) volcanism throughout the belt suggest a more complex tectonic scenario involving plume- and subduction-related processes. We here propose a model involving the development of a propagating rift opening from west to east in response to plume activity. The process started in Miocene time within the western sector of the belt (Guadalajara) and gave rise to a graben triple junction and OIB-type and calc-alkalic volcanism. Extension and volcanism proceeded to the east, giving rise to progressively younger ages for the initiation of OIB-type volcanism: (1) Miocene in the west (e.g., Guadalajara), (2) Pliocene in the central zone (e.g., Michoacán-Guanajuato), and (3) Quaternary farther east (e.g., Chichinautzin). Geochemical evidence suggests that part of the modern calc-alkalic volcanism (e.g., Chichinautzin) may be derived from magma mixing between the OIB mafic magmas and silicic, crust-derived magmas. However, we do not preclude some influence of the subducting slab in the generation of other (e.g., Jorullo) calc-alkalic volcanic rocks. Our model suggests a currently unrooted upper plume attached to the subcontinental lithosphere, which defines a hot zone beneath the Mexican volcanic belt.

  13. Propagating substorm injection fronts

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Arnoldy, R. L.; Feynman, J.; Hardy, D. A.

    1981-01-01

    It is argued that a series of two-satellite observations leads to a clarification of substorm plasma injection, in which boundary motion plays a major role. Emphasis is put on a type of event characterized by abrupt, dispersionless changes in electron intensity and a coincident perturbation that consists of both a field magnitude increase and a small rotation toward more dipolar orientation. Comparing plasma observations at two points, it is found that in active, preinjection conditions the two most important features of the plasma sheet are: (1) the low-energy convection boundary for near-zero energy particles, determined by the magnitude of the large-scale convection electric field; and (2) the precipitation-flow boundary layer between the hot plasma sheet and the atmospherically contaminated inner plasma sheet.

  14. Atmospheric millimeter wave propagation model

    NASA Astrophysics Data System (ADS)

    Liebe, H. J.

    1983-12-01

    The neutral atmosphere is characterized for the frequency range from 1 to 300 GHz as nonturbulent propagation medium. Attenuation and propagation delay effects are predicated from meteorological data sets: pressure, temperature, humidity, suspended particle concentration, and rain rate. The physical data base of the propagation model consists of four terms: (1) resonance information for 30 water vapor and 48 oxygen absorption lines in the form of intensity coefficients and center frequency for each line; (2) a composite (oxygen, water vapor, and nitrogen) continum spectrum; (3) a hydrosol attenuation term for haze, fog, and cloud conditions; and (4) a rain attenuation model. Oxygen lines extend into the mesosphere, where they behave in a complicated manner due to the Zeeman effect.

  15. Propagation of New Innovations: An Approach to Classify Human Behavior and Movement from Available Social Network Data

    NASA Technical Reports Server (NTRS)

    Mahmud, Faisal; Samiul, Hasan

    2010-01-01

    It is interesting to observe new innovations, products, or ideas propagating into the society. One important factor of this propagation is the role of individual's social network; while another factor is individual's activities. In this paper, an approach will be made to analyze the propagation of different ideas in a popular social network. Individuals' responses to different activities in the network will be analyzed. The properties of network will also be investigated for successful propagation of innovations.

  16. Dynamical Realism and Uncertainty Propagation

    NASA Astrophysics Data System (ADS)

    Park, Inkwan

    In recent years, Space Situational Awareness (SSA) has become increasingly important as the number of tracked Resident Space Objects (RSOs) continues their growth. One of the most significant technical discussions in SSA is how to propagate state uncertainty in a consistent way with the highly nonlinear dynamical environment. In order to keep pace with this situation, various methods have been proposed to propagate uncertainty accurately by capturing the nonlinearity of the dynamical system. We notice that all of the methods commonly focus on a way to describe the dynamical system as precisely as possible based on a mathematical perspective. This study proposes a new perspective based on understanding dynamics of the evolution of uncertainty itself. We expect that profound insights of the dynamical system could present the possibility to develop a new method for accurate uncertainty propagation. These approaches are naturally concluded in goals of the study. At first, we investigate the most dominant factors in the evolution of uncertainty to realize the dynamical system more rigorously. Second, we aim at developing the new method based on the first investigation enabling orbit uncertainty propagation efficiently while maintaining accuracy. We eliminate the short-period variations from the dynamical system, called a simplified dynamical system (SDS), to investigate the most dominant factors. In order to achieve this goal, the Lie transformation method is introduced since this transformation can define the solutions for each variation separately. From the first investigation, we conclude that the secular variations, including the long-period variations, are dominant for the propagation of uncertainty, i.e., short-period variations are negligible. Then, we develop the new method by combining the SDS and the higher-order nonlinear expansion method, called state transition tensors (STTs). The new method retains advantages of the SDS and the STTs and propagates

  17. Propagators in polymer quantum mechanics

    SciTech Connect

    Flores-González, Ernesto Morales-Técotl, Hugo A. Reyes, Juan D.

    2013-09-15

    Polymer Quantum Mechanics is based on some of the techniques used in the loop quantization of gravity that are adapted to describe systems possessing a finite number of degrees of freedom. It has been used in two ways: on one hand it has been used to represent some aspects of the loop quantization in a simpler context, and, on the other, it has been applied to each of the infinite mechanical modes of other systems. Indeed, this polymer approach was recently implemented for the free scalar field propagator. In this work we compute the polymer propagators of the free particle and a particle in a box; amusingly, just as in the non polymeric case, the one of the particle in a box may be computed also from that of the free particle using the method of images. We verify the propagators hereby obtained satisfy standard properties such as: consistency with initial conditions, composition and Green’s function character. Furthermore they are also shown to reduce to the usual Schrödinger propagators in the limit of small parameter μ{sub 0}, the length scale introduced in the polymer dynamics and which plays a role analog of that of Planck length in Quantum Gravity. -- Highlights: •Formulas for propagators of free and particle in a box in polymer quantum mechanics. •Initial conditions, composition and Green’s function character is checked. •Propagators reduce to corresponding Schrödinger ones in an appropriately defined limit. •Results show overall consistency of the polymer framework. •For the particle in a box results are also verified using formula from method of images.

  18. Telomerase deficiency in a colonial ascidian after prolonged asexual propagation.

    PubMed

    Sköld, Helen Nilsson; Asplund, Maria E; Wood, Christine A; Bishop, John D D

    2011-06-15

    In organisms that propagate by agametic cloning, the parental body is the reproductive unit and fitness increases with clonal size, so that colonial metazoans, despite lack of experimental data, have been considered potentially immortal. Using asexual propagation rate as a measure of somatic performance, and telomerase activity and relative telomere length as molecular markers of senescence, old (7-12 years) asexual strains of a colonial ascidian, Diplosoma listerianum, were compared with their recent sexually produced progeny. We report for the first time evidence for long-term molecular senescence in asexual lineages of a metazoan, and that only passage between sexual generations provides total rejuvenation permitting indefinite propagation and growth. Thus, this colonial ascidian has not fully escaped ageing. The possibility of somatic replicative senescence also potentially helps to explain why metazoans, with the capacity for asexual propagation through agametic cloning, commonly undergo cycles of sexual reproduction in the wild.

  19. Sodium ions, acting at high-affinity extracellular sites, inhibit sodium-ATPase activity of the sodium pump by slowing dephosphorylation.

    PubMed Central

    Beaugé, L A; Glynn, I M

    1979-01-01

    1. It is known that extracellular Na+ ions, in low concentrations, inhibit Na+-ATPase activity in resealed red cell ghosts and that this inhibition is reversed by high concentrations of extracellular Na+. We have attempted to elucidate these actions of extracellular Na+ by investigating the dependence on Na+ concentration of (a) ATP-ADP exchange and Na+-ATPase activity both in native and in N-ethylmaleimide (NEM)-treated (Na+ + K+)-ATPase from pig kidney, and (b) the rate of hydrolysis of the phosphorylated kidney enzyme in the absence of K+ ions. 2. With the native enzyme, ATP-ADP exchange and Na+-ATPase activity showed similar responses to changes in Na+ concentration: a steep but S-shaped rise between 0 and 2.5 mM, a slight fall (exchange) or a plateau (ATPase) between 2.5 and 10 mM, and a roughly linear rise between 10 and 150 mM. With NEM-treated enzyme, the ATP-ADP exchange, which was greatly accelerated, showed no sign either of inhibition at intermediate Na+ concentrations or of the reversal of that inhibition at higher concentrations. The exchange rate increased with Na+ concentration in a smooth curve and was half-maximal at about 7 mM. 3. The effects, on ATP-ADP exchange, of changing the concentrations of ATP, ADP and Mg have also been investigated. With both native and NEM-treated enzyme, the interactions of ATP, ADP and Mg are complicated; they show that, for the reaction leading to ATP formation, either free ADP rather than MgADP is the substrate, or Mg2+ ions are inhibitory (or both). 4. Since NEM, in the conditions in which we have used it, is believed to act by inhibiting the conversion of an ADP-sensitive form of the phosphoenzyme (E1P) to an ADP-insensitive form (E2P), the absence of Na+ inhibition of ATP-ADP exchange in NEM-treated enzyme, together with the parallel effects of Na+ ions on the ATP-ADP exchange activity and on the Na+-ATPase activity of native enzyme, suggests that the inhibitory effect of external Na+ occurs after the conversion

  20. NASA Propagation Program Status and Propagation Needs of Satcom Industry

    NASA Technical Reports Server (NTRS)

    Golshan, Nassar

    1996-01-01

    The program objective is to enable the development of new commercial satellite systems and services and to support NASA's programs by providing timely data and models about propagation of satellite radio signals though the intervening environment. Provisions include new services, higher frequencies, higher data rates, different environments (mobile, indoors, fixed), and different orbits (geostationary, low earth orbit).

  1. Nonstationary noise propagation with sources

    NASA Astrophysics Data System (ADS)

    Ben-Benjamin, J. S.; Cohen, L.

    2014-06-01

    We discuss a number of topics relevant to noise propagation in dispersive media. We formulate the problem of pulse propagation with a source term in phase space and show that a four dimensional Wigner distribution is required. The four dimensional Wigner distribution is that of space and time and also wavenumber and frequency. The four dimensional Wigner spectrum is equivalent to the space-time autocorrelation function. We also apply the quantum path method to improve the phase space approximation previously obtained. In addition we discuss motion in a Snell's law medium.

  2. Buckle propagation in tubular structures

    SciTech Connect

    Nogueira, A.C.; Tassoulas, J.L.

    1995-12-01

    A novel method for the analysis of buckle propagation in tubes such as tendons of tension leg platforms and pipelines for deep-water applications is presented. Results are reported for the propagation pressure and state deformation in tubes of various materials (SS-304, CS-1010 and X-52 steel tubes) with a wide range of values of the diameter-to-thickness ratio (D/t). Not only the method overcomes the prohibitive computational demands of earlier procedures, but also it is in excellent agreement with experimental data for all values of D/t investigated (from D/t = 78 to as low as D/t = 12.8).

  3. [The activity of the State Sanitary Inspectorate after implementation of the act of January, 23 2009 "Amending certain acts regarding reorganization and redistribution of competences of the public administration at the provincial level"].

    PubMed

    Rudaś, Dariusz; Skórczewski, Krzysztof

    2011-01-01

    The restructuring of the State Sanitary Inspectorate was determined by the need to adjust the existing system to the new structure- and task-oriented standards introduced by the administrative reforms at the provincial level. This brought about a lot of changes in the way State County Sanitary Inspectors operate. For first few months after the enforcement of the Act of January 23.2009 amending certain acts regarding reorganization and redistribution of competences of the public administration at the provincial level (Journal of Laws, No. 92, item. 753, 2009) brought about a lot of ambiguities and expectations. Such unresolved issues are typical for the initial or transition period after implementation of a new law. The approach to the operation of the State Sanitary Inspectorate at the county level depicted in the article lays the emphasis on the challenges in the legal and task-oriented domain that arose after coming into force of the aforementioned amendment. By way of conclusion, the authors of the article briefly summaries the practical outcomes of the transformations undergone by the State Sanitary Inspectorate at the county level.

  4. Promoter propagation in prokaryotes

    PubMed Central

    Matus-Garcia, Mariana; Nijveen, Harm; van Passel, Mark W. J.

    2012-01-01

    Transcriptional activation or ‘rewiring’ of silent genes is an important, yet poorly understood, phenomenon in prokaryotic genomes. Anecdotal evidence coming from experimental evolution studies in bacterial systems has shown the promptness of adaptation upon appropriate selective pressure. In many cases, a partial or complete promoter is mobilized to silent genes from elsewhere in the genome. We term hereafter such recruited regulatory sequences as Putative Mobile Promoters (PMPs) and we hypothesize they have a large impact on rapid adaptation of novel or cryptic functions. Querying all publicly available prokaryotic genomes (1362) uncovered >4000 families of highly conserved PMPs (50 to 100 long with ≥80% nt identity) in 1043 genomes from 424 different genera. The genomes with the largest number of PMP families are Anabaena variabilis (28 families), Geobacter uraniireducens (27 families) and Cyanothece PCC7424 (25 families). Family size varied from 2 to 93 homologous promoters (in Desulfurivibrio alkaliphilus). Some PMPs are present in particular species, but some are conserved across distant genera. The identified PMPs represent a conservative dataset of very recent or conserved events of mobilization of non-coding DNA and thus they constitute evidence of an extensive reservoir of recyclable regulatory sequences for rapid transcriptional rewiring. PMID:22933716

  5. Clonal propagation of softwoods.

    PubMed

    Thorpe, Trevor A; Harry, Indra S; Yeung, Edward C

    2006-01-01

    Softwoods or gymnosperms, which make up 60% of the forested areas of the world, are economically important as a source of lumber, pulp, and paper. Reforestation is a major activity worldwide and the potential benefits of using clonal planting stock have long been recognized. Tissue culture clonal methods or micropropagation is a newer approach that can be achieved by enhancing axillary bud breaking, production of adventitious buds (organogenesis), and somatic embryogenesis. Plantlet production via organogenesis requires at least four stages: (1) bud induction on the explant, (2) shoot development and multiplication, (3) rooting of developed shoots, and (4) hardening of plantlets. Similarly, the production of plantlets via somatic embryogenesis, which has the potential to produce a larger number of plantlets, and in a shorter period of time, also requires several stages. These include (1) induction, maintenance, and proliferation of embryogenic tissue; (2) maturation (both morphological and physiological) of somatic embryos; and (3) germination and conversion of the somatic embryos. In this chapter, plantlet production via organogenesis from seedling and adolescent/mature explants and somatic embryogenesis from immature and mature seeds of white spruce (Picea glauca) are outlined. PMID:16673916

  6. Potent Antiviral Activities of the Direct-Acting Antivirals ABT-493 and ABT-530 with Three-Day Monotherapy for Hepatitis C Virus Genotype 1 Infection

    PubMed Central

    O'Riordan, William D.; Asatryan, Armen; Freilich, Bradley L.; Box, Terry D.; Overcash, J. Scott; Lovell, Sandra; Ng, Teresa I.; Liu, Wei; Campbell, Andrew; Lin, Chih-Wei; Yao, Betty; Kort, Jens

    2015-01-01

    ABT-493 is a hepatitis C virus (HCV) nonstructural (NS) protein 3/4A protease inhibitor, and ABT-530 is an HCV NS5A inhibitor. These direct-acting antivirals (DAAs) demonstrated potent antiviral activity against major HCV genotypes and high barriers to resistance in vitro. In this open-label dose-ranging trial, antiviral activity and safety were assessed during 3 days of monotherapy with ABT-493 or ABT-530 in treatment-naive adults with HCV genotype 1 infection, with or without compensated cirrhosis. The presence of baseline resistance-associated variants (RAVs) was also evaluated. The mean maximal decreases in HCV RNA levels from baseline were approximately 4 log10 IU/ml for all ABT-493 doses ranging from 100 mg to 700 mg and for ABT-530 doses of ≥40 mg. There were no meaningful differences in viral load declines for patients with versus without compensated cirrhosis. Twenty-four (50%) of the baseline samples from patients treated with ABT-493 had RAVs to NS3/4A protease inhibitors. Among 40 patients treated with ABT-530, 6 (15%) carried baseline RAVs to NS5A inhibitors. Viral load declines in patients with single baseline NS5A RAVs were similar to those in patients without RAVs. One patient harbored baseline RAVs at 3 NS5A positions and appeared to have a slightly less robust viral load decline on day 3 of monotherapy. No serious or grade 3 (severe) or higher adverse events and no clinically relevant laboratory abnormalities were observed with either compound. ABT-493 and ABT-530 demonstrated potent antiviral activity and acceptable safety during 3-day monotherapy in patients with HCV genotype 1 infection, with or without compensated cirrhosis. Based on these results, phase II studies assessing the combination of these DAAs for the treatment of chronic HCV infection in patients with or without compensated cirrhosis have been initiated. (This study has been registered at ClinicalTrials.gov under registration no. NCT01995071.) PMID:26711747

  7. Pindolol does not act only on 5-HT1A receptors in augmenting antidepressant activity in the mouse forced swimming test.

    PubMed

    Bourin, M; Redrobe, J P; Baker, G B

    1998-04-01

    The present study was undertaken to identify the receptor subtypes involved in (+/-) pindolol's ability to enhance the effects of antidepressant drugs in the mouse forced swimming test. Interaction studies were performed with S 15535 (presynaptic 5-HT1A receptor agonist) and methiothepin (5-HT1B autoreceptor antagonist) in an attempt to attenuate or potentiate antidepressant-like activity. (+/-) Pindolol was tested in combination with selective agonists and antagonists at 5-HT1, 5-HT2 and 5-HT3 receptor subtypes. Pretreatment with S 15535 and methiothepin attenuated the activity of paroxetine, fluvoxamine and citalopram (32 mg/kg, i.p.; P < 0.01). (+/-) Pindolol (32 mg/kg, i.p.) induced significant anti-immobility effects when tested in combination with 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridyl)-1H-indole (RU 24969) (1 mg/kg, i.p.; P < 0.05), 1-(2-methoxyphenyl)-4-[-(2-phthalimido) butyl]piperazine) (NAN 190) (0.5 mg/kg; P < 0.05) and ondansetron (0.00001 mg/kg, i.p.; P < 0.01). Pretreatment with NAN 190 (0.5 mg/kg, i.p.) potentiated the effects of RU 24969 (1 mg/kg, i.p.; P < 0.05) and (+/-) pindolol (32 mg/kg, i.p.; P < 0.05) in the forced swimming test, as did ondansetron (0.00001 mg/kg, i.p.). Significant additive effects were induced when RU 24969 (1 mg/kg, i.p.) was tested in combination with NAN 190 (0.5 mg/kg, i.p.; P < 0.05), (+/-) pindolol (32 mg/kg, i.p.; P < 0.05) and ondansetron (0.0000 mg/kg, i.p.; P < 0.05). 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (1 mg/kg, i.p.) or ketanserin (8 mg/kg, i.p.) did not induce significant antidepressant-like effects with any of the agonists/antagonists tested. The results of the present study suggest that pindolol is acting at presynaptic 5-HT1B serotonergic receptors, in addition to the 5-HT1A subtype, in augmenting the activity of antidepressants in the mouse forced swimming test.

  8. Optical pulse propagation through clouds.

    PubMed

    Matter, J C; Bradley, R G

    1981-02-15

    The cloud impulse response (spatial and temporal) to optical pulse propagation has been measured. Experimental data are reported for the radiance function, pulse stretching, and (the first published) delay time. The results have been confirmed by Monte Carlo modeling. A geometric scattering model is presented explaining the temporal results for the test conditions.

  9. Optical pulse propagation through clouds.

    PubMed

    Matter, J C; Bradley, R G

    1981-07-01

    The cloud impulse response (spatial and temporal) to optical pulse propagation has been measured. Experimental data are reported for the radiance function, pulse stretching, and (the first published) delay time. The results have been confirmed by Monte Carlo modeling. A geometric scattering model is presented explaining the temporal results for the test conditions.

  10. Microwave Propagation in Dielectric Fluids.

    ERIC Educational Resources Information Center

    Lonc, W. P.

    1980-01-01

    Describes an undergraduate experiment designed to verify quantitatively the effect of a dielectric fluid's dielectric constant on the observed wavelength of microwave radiation propagating through the fluid. The fluid used is castor oil, and results agree with the expected behavior within 5 percent. (Author/CS)

  11. Wave equations for pulse propagation

    NASA Astrophysics Data System (ADS)

    Shore, B. W.

    1987-06-01

    Theoretical discussions of the propagation of pulses of laser radiation through atomic or molecular vapor rely on a number of traditional approximations for idealizing the radiation and the molecules, and for quantifying their mutual interaction by various equations of propagation (for the radiation) and excitation (for the molecules). In treating short-pulse phenomena it is essential to consider coherent excitation phenomena of the sort that is manifest in Rabi oscillations of atomic or molecular populations. Such processes are not adequately treated by rate equations for excitation nor by rate equations for radiation. As part of a more comprehensive treatment of the coupled equations that describe propagation of short pulses, this memo presents background discussion of the equations that describe the field. This memo discusses the origin, in Maxwell's equations, of the wave equation used in the description of pulse propagation. It notes the separation into lamellar and solenoidal (or longitudinal and transverse) and positive and negative frequency parts. It mentions the possibility of separating the polarization field into linear and nonlinear parts, in order to define a susceptibility or index of refraction and, from these, a phase and group velocity.

  12. Balloon atmospheric propagation experiment measurements

    NASA Technical Reports Server (NTRS)

    Minott, P. O.

    1973-01-01

    High altitude balloon measurements on laser beam fading during propagation through turbulent atmosphere show that a correlation between fading strength and stellar scintillation magnitudes exists. Graphs for stellar scintillation as a function of receiver aperture are used to predict fading bit error rates for neodymium-yag laser communication system.

  13. Large-scale rainfall diversity for ACTS

    NASA Technical Reports Server (NTRS)

    Lin, H. P.; Vogel, Wolfhard J.

    1993-01-01

    From the NOAA 15 minute precipitation file for the US, data were selected for a set of 23 stations spanning a 5 year period. The selection covers the spot beam locations for ACTS and the propagation experiment sites. There is a 2 percent probability of having any simultaneous rain at 3 or more stations, but this reduces to less than 0.001 percent at a rainfall rate of 40 mm/hr.

  14. [Propagation of shear waves in the muscle tissue].

    PubMed

    Afanas'eva, D A; Tsaturian, A K

    2010-01-01

    A mathematical model of the propagation of acoustic shear waves in muscle tissue is considered. The muscle is modelled by an incompressible transversely isotropic viscoelastic continuum with quasi-one-dimensional active tension. Two types of shear waves in an infinite medium have been established. The waves of the second type (transverse) propagate without attenuation even when myofibril viscosity is taken into account. A problem of standing transverse waves in a rectangular layer has been investigated numerically. The values of the problem parameters have been found for which the active tension or muscle tonus is easily estimated from the characteristics of standing waves. This value is informative for the diagnosis of muscle state.

  15. Influence of atmospheric structure and topography on infrasonic wave propagation

    NASA Astrophysics Data System (ADS)

    Lacanna, G.; Ichihara, M.; Iwakuni, M.; Takeo, M.; Iguchi, M.; Ripepe, M.

    2014-04-01

    The effects of topography and atmospheric structures on infrasonic wave propagation from a volcanic source were investigated using observations and numerical modeling. This paper presents the first long-term observational data set showing spatiotemporal variations in patterns of infrasound propagation at distances of up to 60 km from a persistently active infrasound source (Sakurajima Volcano, Japan). The data show that the amplitudes of infrasonic waves received at distant stations relative to those received at a reference station close to the source can vary up to an order of magnitude over short time intervals and short distances and that they do not follow the theoretical geometric decay expected for homogeneous media. Moreover, waveforms also change significantly in both time and space. Numerical simulations were performed using a two-dimensional finite difference time domain (2-D FDTD) method. Effects of atmospheric structure and topography are included in a vertical section parallel to the wave propagation direction. The simulation successfully reproduced the variations of amplitudes and waveforms. Results are interpreted in terms of wave refraction due to sound and wind speed gradients and wave diffraction at topographic barriers. Our numerical results indicate that both atmospheric and topographic propagation effects are nonnegligible. To evaluate the propagation effects and determine source processes in spatially and temporally varying infrasound data, atmospheric data with a time resolution higher than is currently available are required. If the data are available, the present results suggest that the propagation effects could be evaluated using 2-D FDTD modeling at realistic calculation times.

  16. Propagation of Spiking and Burst-Spiking Synchronous States in a Feed-Forward Neuronal Network

    NASA Astrophysics Data System (ADS)

    Zhang, Xi; Huang, Hong-Bin; Li, Pei-Jun; Wu, Fang-Ping; Wu, Wang-Jie; Jiang, Min

    2012-12-01

    Neuronal firing that carries information can propagate stably in neuronal networks. One important feature of the stable states is their spatiotemporal correlation (STC) developed in the propagation. The propagation of synchronous states of spiking and burst-spiking neuronal activities in a feed-forward neuronal network with high STC is studied. Different dynamic regions and synchronous regions of the second layer are clarified for spiking and burst-spiking neuronal activities. By calculating correlation, it is found that five layers are needed for stable propagation. Synchronous regions of the 4th layer and the 10th layer are compared.

  17. The effects of solidification on sill propagation dynamics and geometry

    NASA Astrophysics Data System (ADS)

    Lola, Chanceaux; Thierry, Menand

    2015-04-01

    structures similar to those of lava flows. Our experiments show how these lobate structures could reflect the effect of magma solidification during their emplacement. Moreover, these experiments show also that a non-continuous geometry as observed in the field does not necessarily involve multiple injections. Also, like dykes, a discontinuous propagation should be associated with bursts of seismic activity (e.g. Taisne and Tait, 2011; Taisne et al., 2011). Finally, sills are considered as the building blocks for constructing larger magmatic bodies as plutons. Our study shows how solidification effects restrict the surface of sills, which impacts directly the size of plutons constructed incrementally by amalgamated sills.

  18. Propagation of intense short laser pulses in a gas of atomic clusters.

    PubMed

    Gupta, Ayush; Antonsen, T M; Milchberg, H M

    2004-10-01

    We present a model and numerical simulations for the propagation of intense short laser pulses in gases of atomic clusters. As the pulse propagates through the clusters, they absorb energy, expand and explode. The clustered gas thus acts as a medium with time dependent effective dielectric constant. A self-consistent model for the cluster expansion and the laser pulse propagation is developed. Self-focusing of the laser pulse, coupling of laser energy to clusters and the evolution of the pulse spectrum are studied for a laser-cluster system with typical laboratory parameters.

  19. The Canadian Olympus propagation experiment

    NASA Astrophysics Data System (ADS)

    Olsen, R. L.; Makrakis, D.; Rogers, D. V.; Berube, R. C.; Lam, W. I.; Strickland, J. I.; Antar, Y. M. M.; Albert, J.; Tam, S. Y. K.; Foo, S. L.

    The planning of commercial and military satellite communications systems using the upper SHF and lower EHF bands has resulted in a need for more propagation data and models for these bands. This is especially true for VSAT systems using small attenuation margins for which accurate data are particularly scarce and existing models inaccurate. The Canadian Olympus propagation experiment, designed to obtain such data, is described. The experiment includes simultaneous attenuation and depolarization measurements using the 12-, 20-, and 30-GHz Olympus satellite beacons, radiometric measurements of attenuation at 14, 20, and 30 GHz, and polarimetric radar measurements at 9.6 GHz. One novel feature of the experiment is the attempt to use the radar data to help separate the statistics of melting layer attenuation from beacon-measured total attenuation.

  20. Long-range vertical propagation

    NASA Technical Reports Server (NTRS)

    Willshire, William L., Jr.; Garber, Donald P.

    1990-01-01

    Development of the advanced turboprop has led to concerns about en route noise. Advanced turboprops generate low-frequency, periodic noise signatures at relatively high levels. As demonstrated in a flight test of NASA Lewis Research Center's Propfan Test Assessment (PTA) airplane in Alabama in October 1987, the noise of an advanced turboprop operating at cruise altitudes can be audible on the ground. The assessment of the en route noise issue is difficult due to the variability in received noise levels caused by atmospheric propagation and the uncertainty in predicting community response to the relatively low-level en route noise, as compared to noise associated with airport operations. The En Route Noise Test was designed to address the atmospheric propagation of advanced turboprop noise from cruise altitudes and consisted of measuring the noise of an advance turboprop at cruise in close proximity to the turboprop and on the ground. Measured and predicted ground noise levels are presented.

  1. Atmospheric propagation of THz radiation.

    SciTech Connect

    Wanke, Michael Clement; Mangan, Michael A.; Foltynowicz, Robert J.

    2005-11-01

    In this investigation, we conduct a literature study of the best experimental and theoretical data available for thin and thick atmospheres on THz radiation propagation from 0.1 to 10 THz. We determined that for thick atmospheres no data exists beyond 450 GHz. For thin atmospheres data exists from 0.35 to 1.2 THz. We were successful in using FASE code with the HITRAN database to simulate the THz transmission spectrum for Mauna Kea from 0.1 to 2 THz. Lastly, we successfully measured the THz transmission spectra of laboratory atmospheres at relative humidities of 18 and 27%. In general, we found that an increase in the water content of the atmosphere led to a decrease in the THz transmission. We identified two potential windows in an Albuquerque atmosphere for THz propagation which were the regions from 1.2 to 1.4 THz and 1.4 to 1.6 THz.

  2. Propagator for finite range potentials

    SciTech Connect

    Cacciari, Ilaria; Moretti, Paolo

    2006-12-15

    The Schroedinger equation in integral form is applied to the one-dimensional scattering problem in the case of a general finite range, nonsingular potential. A simple expression for the Laplace transform of the transmission propagator is obtained in terms of the associated Fredholm determinant, by means of matrix methods; the particular form of the kernel and the peculiar aspects of the transmission problem play an important role. The application to an array of delta potentials is shown.

  3. Calculating Sonic-Boom Propagation

    NASA Technical Reports Server (NTRS)

    Darden, C. M.; Ting, L.

    1987-01-01

    Nonlinear effects included, enabling more-realistic modeling. Modified Method of Characteristics Sonic Boom Extrapolation Program (MMOC) is computer program for sonic-boom propagation that includes shock coalescence and incorporates effects of asymmetries due to volume and lift. Numerically integrates nonlinear governing equations using data on initial data line approximately one body length from aircraft and yields sonic-boom pressure at ground as function of time or of position at given time. MMOC written in FORTRAN IV.

  4. A database for propagation models

    NASA Technical Reports Server (NTRS)

    Kantak, Anil V.; Suwitra, Krisjani; Le, Chuong

    1995-01-01

    A database of various propagation phenomena models that can be used by telecommunications systems engineers to obtain parameter values for systems design is presented. This is an easy-to-use tool and is currently available for either a PC using Excel software under Windows environment or a Macintosh using Excel software for Macintosh. All the steps necessary to use the software are easy and many times self explanatory.

  5. Light propagation through atomic vapours

    NASA Astrophysics Data System (ADS)

    Siddons, Paul

    2014-05-01

    This tutorial presents the theory necessary to model the propagation of light through an atomic vapour. The history of atom-light interaction theories is reviewed, and examples of resulting applications are provided. A numerical model is developed and results presented. Analytic solutions to the theory are found, based on approximations to the numerical work. These solutions are found to be in excellent agreement with experimental measurements.

  6. Calibration of seismic wave propagation in Jordan

    SciTech Connect

    Al-Husien, A; Amrat, A; Harris, D; Mayeda, K; Nakanishi, K; Rodgers, A; Ruppert, S; Ryall, F; Skinnell, K; Yazjeen, T

    1999-07-23

    The Natural Resources Authority of Jordan (NRA), the USGS and LLNL have a collaborative project to improve the calibration of seismic propagation in Jordan and surrounding regions. This project serves common goals of CTBT calibration and earthquake hazard assessment in the region. These objectives include accurate location of local and regional earthquakes, calibration of magnitude scales, and the development of local and regional propagation models. In the CTBT context, better propagation models and more accurately located events in the Dead Sea rift region can serve as (potentially GT5) calibration events for generating IMS location corrections. The detection and collection of mining explosions underpins discrimination research. The principal activity of this project is the deployment of two broadband stations at Hittiyah (south Jordan) and Ruweishid (east Jordan). These stations provide additional paths in the region to constrain structure with surface wave and body wave tomography. The Ruweishid station is favorably placed to provide constraints on Arabian platform structure. Waveform modeling with long-period observations of larger earthquakes will provide constraints on 1-D velocity models of the crust and upper mantle. Data from these stations combined with phase observations from the 26 short-period stations of the Jordan National Seismic Network (JNSN) may allow the construction of a more detailed velocity model of Jordan. The Hittiyah station is an excellent source of ground truth information for the six phosphate mines of southern Jordan and Israel. Observations of mining explosions collected by this station have numerous uses: for definition of templates for screening mining explosions, as ground truth events for calibrating travel-time models, and as explosion populations in development and testing discriminants. Following previously established procedures for identifying explosions, we have identified more than 200 explosions from the first 85 days of

  7. Wave Propagation in Expanding Cell Layers

    NASA Astrophysics Data System (ADS)

    Utuje, Kazage J. Christophe; Banerjee, Shiladitya; Marchetti, M. Cristina

    2014-03-01

    The coordinated migration of groups of cells drives important biological processes, such as wound healing and morphogenesis. In this talk we present a minimal continuum model of an expanding cell monolayer coupling elastic deformations to myosin-based activity in the cells. The myosin-driven contractile activity is quantified by the chemical potential difference for the process of ATP hydrolysis by myosin motors. A new ingredient of the model is a feedback of the local strain rate of the monolayer on contractility that naturally yields a mechanism for viscoelasticity of the cellular medium. By combining analytics and numerics we show that this simple model reproduces qualitatively many experimental findings, including the build-up of contractile stresses at the center of the cell monolayer, and the existence of traveling mechanical waves that control spreading dynamics and stress propagation in the cell monolayer. KJCU and MCM were supported by the NSF through grants DMR-1004789 and DGE-1068780.

  8. Jet propagation through energetic materials

    SciTech Connect

    Pincosy, P; Poulsen, P

    2004-01-08

    In applications where jets propagate through energetic materials, they have been observed to become sufficiently perturbed to reduce their ability to effectively penetrate subsequent material. Analytical calculations of the jet Bernoulli flow provides an estimate of the onset and extent of such perturbations. Although two-dimensional calculations show the back-flow interaction pressure pulses, the symmetry dictates that the flow remains axial. In three dimensions the same pressure impulses can be asymmetrical if the jet is asymmetrical. The 3D calculations thus show parts of the jet having a significant component of radial velocity. On the average the downstream effects of this radial flow can be estimated and calculated by a 2D code by applying a symmetrical radial component to the jet at the appropriate position as the jet propagates through the energetic material. We have calculated the 3D propagation of a radio graphed TOW2 jet with measured variations in straightness and diameter. The resultant three-dimensional perturbations on the jet result in radial flow, which eventually tears apart the coherent jet flow. This calculated jet is compared with jet radiographs after passage through the energetic material for various material thickness and plate thicknesses. We noted that confinement due to a bounding metal plate on the energetic material extends the pressure duration and extent of the perturbation.

  9. Turbofan Acoustic Propagation and Radiation

    NASA Technical Reports Server (NTRS)

    Eversman, Walter

    2000-01-01

    This document describes progress in the development of finite element codes for the prediction of near and far field acoustic radiation from the inlet and aft fan ducts of turbofan engines. The report consists of nine papers which have appeared in archival journals and conference proceedings, or are presently in review for publication. Topics included are: 1. Aft Fan Duct Acoustic Radiation; 2. Mapped Infinite Wave Envelope Elements for Acoustic Radiation in a Uniformly Moving Medium; 3. A Reflection Free Boundary Condition for Propagation in Uniform Flow Using Mapped Infinite Wave Envelope Elements; 4. A Numerical Comparison Between Multiple-Scales and FEM Solution for Sound Propagation in Lined Flow Ducts; 5. Acoustic Propagation at High Frequencies in Ducts; 6. The Boundary Condition at an Impedance Wall in a Nonuniform Duct with Potential Flow; 7. A Reverse Flow Theorem and Acoustic Reciprocity in Compressible Potential Flows; 8. Reciprocity and Acoustics Power in One Dimensional Compressible Potential Flows; and 9. Numerical Experiments on Acoustic Reciprocity in Compressible Potential Flows.

  10. Calculations of precursor propagation in dispersive dielectrics.

    SciTech Connect

    Bacon, Larry Donald

    2003-08-01

    The present study is a numerical investigation of the propagation of electromagnetic transients in dispersive media. It considers propagation in water using Debye and composite Rocard-Powles-Lorentz models for the complex permittivity. The study addresses this question: For practical transmitted spectra, does precursor propagation provide any features that can be used to advantage over conventional signal propagation in models of dispersive media of interest? A companion experimental study is currently in progress that will attempt to measure the effects studied here.

  11. Swa2, the yeast homolog of mammalian auxilin, is specifically required for the propagation of the prion variant [URE 3‐1

    PubMed Central

    Troisi, Elizabeth M.; Rockman, Michael E.; Nguyen, Phil P.; Oliver, Emily E.

    2015-01-01

    Summary Yeast prions require a core set of chaperone proteins including Sis1, Hsp70 and Hsp104 to generate new amyloid templates for stable propagation, yet emerging studies indicate that propagation of some prions requires additional chaperone activities, demonstrating chaperone specificity beyond the common amyloid requirements. To comprehensively assess such prion‐specific requirements for the propagation of the [URE 3] prion variant [URE 3‐1], we screened 12 yeast cytosolic J‐proteins, and here we report a novel role for the J‐protein Swa2/Aux1. Swa2 is the sole yeast homolog of the mammalian protein auxilin, which, like Swa2, functions in vesicle‐mediated endocytosis by disassembling the structural lattice formed by the protein clathrin. We found that, in addition to Sis1, [URE 3‐1] is specifically dependent upon Swa2, but not on any of the 11 other J‐proteins. Further, we show that [URE 3‐1] propagation requires both a functional J‐domain and the tetratricopeptide repeat (TPR) domain, but surprisingly does not require Swa2‐clathrin binding. Because the J‐domain of Swa2 can be replaced with the J‐domains of other proteins, our data strongly suggest that prion‐chaperone specificity arises from the Swa2 TPR domain and supports a model where Swa2 acts through Hsp70, most likely to provide additional access points for Hsp104 to promote prion template generation. PMID:26031938

  12. 49 CFR 195.111 - Fracture propagation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Fracture propagation. 195.111 Section 195.111... PIPELINE Design Requirements § 195.111 Fracture propagation. A carbon dioxide pipeline system must be designed to mitigate the effects of fracture propagation....

  13. 49 CFR 195.111 - Fracture propagation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Fracture propagation. 195.111 Section 195.111... PIPELINE Design Requirements § 195.111 Fracture propagation. A carbon dioxide pipeline system must be designed to mitigate the effects of fracture propagation....

  14. 49 CFR 195.111 - Fracture propagation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Fracture propagation. 195.111 Section 195.111... PIPELINE Design Requirements § 195.111 Fracture propagation. A carbon dioxide pipeline system must be designed to mitigate the effects of fracture propagation....

  15. 49 CFR 195.111 - Fracture propagation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Fracture propagation. 195.111 Section 195.111... PIPELINE Design Requirements § 195.111 Fracture propagation. A carbon dioxide pipeline system must be designed to mitigate the effects of fracture propagation....

  16. 49 CFR 195.111 - Fracture propagation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Fracture propagation. 195.111 Section 195.111... PIPELINE Design Requirements § 195.111 Fracture propagation. A carbon dioxide pipeline system must be designed to mitigate the effects of fracture propagation....

  17. Japanese propagation experiments with ETS-5

    NASA Technical Reports Server (NTRS)

    Ikegami, Tetsushi

    1989-01-01

    Propagation experiments for maritime, aeronautical, and land mobile satellite communications were performed using Engineering Test Satellite-Five (ETS-5). The propagation experiments are one of major mission of Experimental Mobile Satellite System (EMSS) which is aimed for establishing basic technology for future general mobile satellite communication systems. A brief introduction is presented for the experimental results on propagation problems of ETS-5/EMSS.

  18. Library Services for Indian Tribes and Hawaiian Natives Program: Review of Program Activities, 1990. Title IV, Library Services and Construction Act.

    ERIC Educational Resources Information Center

    Fine, Beth, Comp.; Woolen, Viola, Comp.

    THe Library Services for Indian Tribes and Hawaiian natives Program, Title IV of the Library Services and Construction Act (LSCA), supports public library services to Indians and Hawaiian Natives. Two types of grants--Basic Grants and Special Projects--encourage the development and improvement of public library services through selected project…

  19. A Summary of Activities in Tennessee under Title I of the Higher Education Act of 1965. Third Progress and Evaluation Report.

    ERIC Educational Resources Information Center

    Tennessee Univ., Knoxville. State Agency for Title I.

    An evaluation was made of 38 programs being carried on in Tennessee colleges and universities in 1969 under Title I, Higher Education Act of 1965. During the first four years, 22 Tennessee institutions were involved in 69 proposals, and received a total of $676,385.15 in funds through June 30, 1969. Eight other subcontracts were also awarded to…

  20. Slow-Slip Propagation Speeds

    NASA Astrophysics Data System (ADS)

    Rubin, A. M.; Ampuero, J.

    2007-12-01

    Combined seismic and geodetic data from subduction zones and the Salton Trough have revealed slow slip events with reasonably well-defined propagation speeds. This in turn is suggestive of a more-or-less well- defined front separating nearly locked regions outside the slipping zone from interior regions that slide much more rapidly. Such crack-like nucleation fronts arise naturally in models of rate-and-state friction for lab-like values of a/b, where a and b are the coefficients of the velocity- and state-dependence of the frictional strength (with the surface being velocity-neutral for a/b=1). If the propagating front has a quasi-steady shape, the propagation and slip speeds are kinematically tied via the local slip gradient. Given a sufficiently sharp front, the slip gradient is given dimensionally by Δτp- r/μ', where Δτp-r is the peak-to-residual stress drop at the front and μ' the effective elastic shear modulus. Rate-and-state simulations indicate that Δτp-r is given reasonably accurately by bσ\\ln(Vmaxθi/Dc), where σ is the effective normal stress, Vmax is the maximum slip speed behind the propagating front, θi is the the value of "state" ahead of the propagating front, and Dc is the characteristic slip distance for state evolution. Except for a coefficient of order unity, Δτp-r is independent of the evolution law. This leads to Vprop/Vmax ~μ'/[bσ\\ln(Vmaxθi/Dc)]. For slip speeds a few orders of magnitude above background, \\ln(Vmaxθi/Dc) can with reasonable accuracy be assigned some representative value (~4-5, for example). Subduction zone transients propagate on the order of 10 km/day or 10-1 m/s. Geodetic data constrain the average slip speed to be a few times smaller than 1 cm/day or 10-7 m/s. However, numerical models indicate that the maximum slip speed at the front may be several times larger than the average, over a length scale that is probably too small to resolve geodetically, so a representative value of Vprop/Vmax may be ~106

  1. Belief propagation in genotype-phenotype networks.

    PubMed

    Moharil, Janhavi; May, Paul; Gaile, Daniel P; Blair, Rachael Hageman

    2016-03-01

    Graphical models have proven to be a valuable tool for connecting genotypes and phenotypes. Structural learning of phenotype-genotype networks has received considerable attention in the post-genome era. In recent years, a dozen different methods have emerged for network inference, which leverage natural variation that arises in certain genetic populations. The structure of the network itself can be used to form hypotheses based on the inferred direct and indirect network relationships, but represents a premature endpoint to the graphical analyses. In this work, we extend this endpoint. We examine the unexplored problem of perturbing a given network structure, and quantifying the system-wide effects on the network in a node-wise manner. The perturbation is achieved through the setting of values of phenotype node(s), which may reflect an inhibition or activation, and propagating this information through the entire network. We leverage belief propagation methods in Conditional Gaussian Bayesian Networks (CG-BNs), in order to absorb and propagate phenotypic evidence through the network. We show that the modeling assumptions adopted for genotype-phenotype networks represent an important sub-class of CG-BNs, which possess properties that ensure exact inference in the propagation scheme. The system-wide effects of the perturbation are quantified in a node-wise manner through the comparison of perturbed and unperturbed marginal distributions using a symmetric Kullback-Leibler divergence. Applications to kidney and skin cancer expression quantitative trait loci (eQTL) data from different mus musculus populations are presented. System-wide effects in the network were predicted and visualized across a spectrum of evidence. Sub-pathways and regions of the network responded in concert, suggesting co-regulation and coordination throughout the network in response to phenotypic changes. We demonstrate how these predicted system-wide effects can be examined in connection with

  2. Acoustic propagation in a thermally stratified atmosphere

    NASA Technical Reports Server (NTRS)

    Vanmoorhem, W. K.

    1985-01-01

    This report describes the activities during the fifth six month period of the investigation of acoustic propagation in the atmosphere with a realistic temperature profile. Progress has been achieved in two major directions: comparisons between the lapse model and experimental data taken by NASA during the second tower experiment, and development of a model propagation in an inversion. Data from the second tower experiment became available near the end of 1984 and some comparisons have been carried out, but this work is not complete. Problems with the temperature profiler during the experiment have produced temperature profiles that are difficult to fit the assumed variation of temperature with height, but in cases where reasonable fits have been obtained agreement between the model and the experiments are close. The major weaknesses in the model appear to be the presence of discontinuities in some regions, the low sound levels predicted near the source height, and difficulties with the argument of the Hankel function being outside the allowable range. Work on the inversion model has progressed slowly, and the rays for that case are discussed along with a simple energy conservation model of sound level enhancement in the inversion case.

  3. Determining dyke-propagation paths at Santorini volcano, Greece

    NASA Astrophysics Data System (ADS)

    Drymoni, Kyriaki; Browning, John; Lecoeur, Nora; Gudmundsson, Agust

    2016-04-01

    The volcanic Island of Santorini constitutes a complex of collapse calderas which has experienced a range of explosive and effusive volcanic eruptions and is still active. Numerous stratigraphic horizons which constitute the upper part of the volcano have widely different mechanical properties, resulting in local stresses that may act as dyke-traps, preventing the dykes from reaching the surface to erupt. Several caldera collapses (<3.6 ka) have exposed part of the stratigraphy and a dyke swarm (composed of at least 63 dykes, many arrested and some feeders) within a section of the northern caldera wall, allowing detailed examination. This ongoing study will (1) document the petrological and structural characteristics of feeder and non-feeder (arrested) dykes and estimate their frequency; (2) determine the physiochemical and mechanical conditions that control dyke arrest/dyke penetration at contacts between layers; (3) explore the fluid and mechanical conditions of the associated magma chamber(s) that must be satisfied for chamber rupture and dyke injection to occur; (4) make numerical and probabilistic models as to the likely dyke paths in heterogeneous and anisotropic crustal segments/volcanoes (such as Santorini), including the likelihood of injected dykes reaching the surface during an unrest period in a volcano of a given type; (5) compare the data collected from Santorini with existing data on dykes worldwide, particularly those on dykes in Tenerife and Iceland. The principal aim of the study is to provide models that, during an unrest period in Santorini and other similar volcanoes, allow us to forecast (a) the condition for magma-chamber rupture and dyke injection, and (b) the likely path of the resulting dyke. The latter includes assessment of the likelihood as to dyke arrest versus dyke propagation to the surface, the latter resulting in an eruption. For dyke-fed eruptions, the study will also provide methods for forecasting the likely volumetric flow

  4. A candidate mechanism underlying the variance of interictal spike propagation

    PubMed Central

    Sabolek, Helen R; Swiercz, Waldemar B.; Lillis, Kyle; Cash, Sydney S.; Huberfeld, Gilles; Zhao, Grace; Marie, Linda Ste.; Clemenceau, Stéphane; Barsh, Greg; Miles, Richard; Staley, Kevin J.

    2012-01-01

    Synchronous activation of neural networks is an important physiological mechanism, and dysregulation of synchrony forms the basis of epilepsy. We analyzed the propagation of synchronous activity through chronically epileptic neural networks. Electrocortigraphic recordings from epileptic patients demonstrate remarkable variance in the pathways of propagation between sequential interictal spikes (IIS). Calcium imaging in chronically epileptic slice cultures demonstrates that pathway variance depends on the presence of GABAergic inhibition and that spike propagation becomes stereotyped following GABA-R blockade. Computer modeling suggests that GABAergic quenching of local network activations leaves behind regions of refractory neurons, whose late recruitment forms the anatomical basis of variability during subsequent network activation. Targeted path scanning of slice cultures confirmed local activations, while ex vivo recordings of human epileptic tissue confirmed the dependence of interspike variance on GABA-mediated inhibition. These data support the hypothesis that the paths by which synchronous activity spread through an epileptic network change with each activation, based on the recent history of localized activity that has been successfully inhibited. PMID:22378874

  5. Studies on propagation of microbes in the airborne state

    NASA Technical Reports Server (NTRS)

    Dimmick, R. L.; Wolochow, H.; Straat, P.; Chatigny, M. A.

    1974-01-01

    An investigation was conducted to demonstrate whether airborne microbes could propagate. The procedure consisted of: (1) looking for dilution of a labelled base in DNA; (2) looking for labelling of DNA by mixing aerosols of the label and the cells; (3) examining changes in cell size; (4) testing the possibility of spore germination; and (5) seeking evidence of an increase in cell number. Results indicate that growth and propagation can occur under special conditions, principally at temperatures of approximately 30 C (87 F) and water activity equivalents of 0.95 to 0.98.

  6. Wave Propagation in Bimodular Geomaterials

    NASA Astrophysics Data System (ADS)

    Kuznetsova, Maria; Pasternak, Elena; Dyskin, Arcady; Pelinovsky, Efim

    2016-04-01

    Observations and laboratory experiments show that fragmented or layered geomaterials have the mechanical response dependent on the sign of the load. The most adequate model accounting for this effect is the theory of bimodular (bilinear) elasticity - a hyperelastic model with different elastic moduli for tension and compression. For most of geo- and structural materials (cohesionless soils, rocks, concrete, etc.) the difference between elastic moduli is such that their modulus in compression is considerably higher than that in tension. This feature has a profound effect on oscillations [1]; however, its effect on wave propagation has not been comprehensively investigated. It is believed that incorporation of bilinear elastic constitutive equations within theory of wave dynamics will bring a deeper insight to the study of mechanical behaviour of many geomaterials. The aim of this paper is to construct a mathematical model and develop analytical methods and numerical algorithms for analysing wave propagation in bimodular materials. Geophysical and exploration applications and applications in structural engineering are envisaged. The FEM modelling of wave propagation in a 1D semi-infinite bimodular material has been performed with the use of Marlow potential [2]. In the case of the initial load expressed by a harmonic pulse loading strong dependence on the pulse sign is observed: when tension is applied before compression, the phenomenon of disappearance of negative (compressive) strains takes place. References 1. Dyskin, A., Pasternak, E., & Pelinovsky, E. (2012). Periodic motions and resonances of impact oscillators. Journal of Sound and Vibration, 331(12), 2856-2873. 2. Marlow, R. S. (2008). A Second-Invariant Extension of the Marlow Model: Representing Tension and Compression Data Exactly. In ABAQUS Users' Conference.

  7. Continuous propagation of microalgae. III.

    NASA Technical Reports Server (NTRS)

    Hanson, D. T.; Fredrickson, A. G.; Tsuchiya, H. M.

    1971-01-01

    Data are presented which give the specific photosynthetic rate and the specific utilization rates of urea and carbon dioxide as functions of specific growth rate for Chlorella. A mathematical model expresses a set of mass balance relations between biotic and environmental materials. Criteria of validity are used to test this model. Predictive procedures are complemented by a particular model of microbial growth. Methods are demonstrated for predicting substrate utilization rates, production rates of extracellular metabolites, growth limiting conditions, and photosynthetic quotients from propagator variables.

  8. Energy propagation throughout chemical networks.

    PubMed

    Le Saux, Thomas; Plasson, Raphaël; Jullien, Ludovic

    2014-06-14

    In order to maintain their metabolism from an energy source, living cells rely on chains of energy transfer involving functionally identified components and organizations. However, propagation of a sustained energy flux through a cascade of reaction cycles has only been recently reproduced at a steady state in simple chemical systems. As observed in living cells, the spontaneous onset of energy-transfer chains notably drives local generation of singular dissipative chemical structures: continuous matter fluxes are dynamically maintained at boundaries between spatially and chemically segregated zones but in the absence of any membrane or predetermined material structure. PMID:24681890

  9. Ultrasound propagation measurements and applications

    NASA Technical Reports Server (NTRS)

    Lynnworth, L. C.; Papadakis, E. P.; Fowler, K. A.

    1977-01-01

    This paper reviews three systems designed for accurately measuring the propagation of ultrasonic pulses. The three systems are presented in order of velocity-measuring precision: + or - 100 ns, + or - 1 ns, + or - 0.2 ns. Also included is a brief discussion of phase and group velocities, with reference to dispersive, highly attenuating materials. Measurement of attenuation by pulse-echo buffer rod techniques is described briefly. These techniques and instruments have been used to measure sound velocity and attenuation in a variety of materials and shapes, over a wide temperature range.

  10. Modification Propagation in Complex Networks

    NASA Astrophysics Data System (ADS)

    Mouronte, Mary Luz; Vargas, María Luisa; Moyano, Luis Gregorio; Algarra, Francisco Javier García; Del Pozo, Luis Salvador

    To keep up with rapidly changing conditions, business systems and their associated networks are growing increasingly intricate as never before. By doing this, network management and operation costs not only rise, but are difficult even to measure. This fact must be regarded as a major constraint to system optimization initiatives, as well as a setback to derived economic benefits. In this work we introduce a simple model in order to estimate the relative cost associated to modification propagation in complex architectures. Our model can be used to anticipate costs caused by network evolution, as well as for planning and evaluating future architecture development while providing benefit optimization.

  11. In vitro propagation of chrysanthemum.

    PubMed

    Nencheva, D

    2010-01-01

    Chrysanthemum flowers Chrysanthemum x grandiflorum (Ramat.) Kitam., are commercially significant worldwide as there are large number of cultivars for cut flowers, pot flowers, and garden flowers. Commercial in vitro multiplication of chrysanthemum is often based on stem nodal explants with lateral meristems. This chapter describes a protocol for in vitro propagation from stem nodal explants and by direct organogenesis from pedicel explants producing large number of true-to-type plantlets in 4-8 week on Murashige and Skoog (MS) based media. Also, true mutants with changed flower color are obtained without producing chimeras after gamma-irradiation in mutation breeding.

  12. Land mobile satellite propagation measurements in Japan using ETS-V satellite

    NASA Technical Reports Server (NTRS)

    Obara, Noriaki; Tanaka, Kenji; Yamamoto, Shin-Ichi; Wakana, Hiromitsu

    1993-01-01

    Propagation characteristics of land mobile satellite communications channels have been investigated actively in recent years. Information of propagation characteristics associated with multipath fading and shadowing is required to design commercial land mobile satellite communications systems, including protocol and error correction method. CRL (Communications Research Laboratory) has carried out propagation measurements using the Engineering Test Satellite-V (ETS-V) at L band (1.5 GHz) through main roads in Japan by a medium gain antenna with an autotracking capability. This paper presents the propagation statistics obtained in this campaign.

  13. Error propagation in a digital avionic processor: A simulation-based study

    NASA Technical Reports Server (NTRS)

    Lomelino, D.; Iyer, R. K.

    1986-01-01

    An experimental analysis to study error propagation from the gate to the chip level is described. The target system is the CPU in the Bendix BDX-930, an avionic miniprocessor. Error activity data for the study was collected via a gate-level simulation. A family of distributions to characterize the error propagation, both within the chip and at the pins, was then generated. Based on these distributions, measures of error propagation and severity were defined. The analysis quantifies the dependency of the measured error propagation on the location of the fault and the type of instruction/microinstruction executed.

  14. Propagation failures, breathing fronts, and nonannihilation collisions in the ferroin-bromate-pyrocatechol system.

    PubMed

    Harati, Mohammad; Wang, Jichang

    2009-06-01

    The emergence of propagating pulses was investigated with the photosensitive ferroin-bromate-pyrocatechol reaction in capillary tubes, in which various interesting spatiotemporal behaviors such as propagation failure, breathing fronts, and transitions between propagating pulses and fronts have been observed. Rather than a mutual annihilation, the collision of a propagating pulse and a growing front forces the front to recede gradually. A phase diagram in the pyrocatechol-bromate concentration space shows that the pulse instabilities take place throughout the conditions at which the system generates wave activities, suggesting that the presence of coupled autocatalytic feedbacks may facilitate the onset of pulse instabilities.

  15. Laser-induced propagation and destruction of amyloid beta fibrils.

    PubMed

    Yagi, Hisashi; Ozawa, Daisaku; Sakurai, Kazumasa; Kawakami, Toru; Kuyama, Hiroki; Nishimura, Osamu; Shimanouchi, Toshinori; Kuboi, Ryoichi; Naiki, Hironobu; Goto, Yuji

    2010-06-18

    The amyloid deposition of amyloid beta (Abeta) peptides is a critical pathological event in Alzheimer disease (AD). Preventing the formation of amyloid deposits and removing preformed fibrils in tissues are important therapeutic strategies against AD. Previously, we reported the destruction of amyloid fibrils of beta(2)-microglobulin K3 fragments by laser irradiation coupled with the binding of amyloid-specific thioflavin T. Here, we studied the effects of a laser beam on Abeta fibrils. As was the case for K3 fibrils, extensive irradiation destroyed the preformed Abeta fibrils. However, irradiation during spontaneous fibril formation resulted in only the partial destruction of growing fibrils and a subsequent explosive propagation of fibrils. The explosive propagation was caused by an increase in the number of active ends due to breakage. The results not only reveal a case of fragmentation-induced propagation of fibrils but also provide insights into therapeutic strategies for AD.

  16. Approximate analytical solutions for excitation and propagation in cardiac tissue

    NASA Astrophysics Data System (ADS)

    Greene, D'Artagnan; Shiferaw, Yohannes

    2015-04-01

    It is well known that a variety of cardiac arrhythmias are initiated by a focal excitation in heart tissue. At the single cell level these currents are typically induced by intracellular processes such as spontaneous calcium release (SCR). However, it is not understood how the size and morphology of these focal excitations are related to the electrophysiological properties of cardiac cells. In this paper a detailed physiologically based ionic model is analyzed by projecting the excitation dynamics to a reduced one-dimensional parameter space. Based on this analysis we show that the inward current required for an excitation to occur is largely dictated by the voltage dependence of the inward rectifier potassium current (IK 1) , and is insensitive to the detailed properties of the sodium current. We derive an analytical expression relating the size of a stimulus and the critical current required to induce a propagating action potential (AP), and argue that this relationship determines the necessary number of cells that must undergo SCR in order to induce ectopic activity in cardiac tissue. Finally, we show that, once a focal excitation begins to propagate, its propagation characteristics, such as the conduction velocity and the critical radius for propagation, are largely determined by the sodium and gap junction currents with a substantially lesser effect due to repolarizing potassium currents. These results reveal the relationship between ion channel properties and important tissue scale processes such as excitation and propagation.

  17. Probabilistic infrasound propagation using ensemble based atmospheric perturbations

    NASA Astrophysics Data System (ADS)

    Smets, Pieter; Evers, Läslo

    2015-04-01

    The state of the atmosphere is of utmost importance for infrasound propagation. In propagation modelling, still, the true state of the atmosphere is mainly represented by the analysis. The analysis is the best deterministic estimate of the atmosphere using a data assimilation system existing of a General Circulation Model (GCM). However, the analysis excludes error variances of both model and observations. In addition, the coarse resolution of GCM results in averaging of, e.g., clouds or gravity waves, over larger regions known as parameterisation. Consequentially, arrivals due to fine-scale structure in wind and temperature can be missing. Therefore, infrasound propagation including the atmospheric best-estimate error variances based on the ensemble model is proposed. The ensemble system exists of model perturbations with an amplitude comparable to analysis error estimates to obtain a probability density function rather than one specific state as obtained from a deterministic system. The best-estimate analysis error variances are described by a set of perturbations using the European Centre for Medium-range Weather Forecasts (ECMWF) Ensemble Data Assimilation (EDA) system. Probabilistic infrasound propagation using 3-D ray tracing is demonstrated by one year of mining activity, e.g., blasting, in Gällivare, northern Sweden, observed at infrasound array IS37 in Norway, part of the International Monitoring System (IMS) for verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Probabilistic infrasound propagation is compared with the standard deterministic result obtained using the analysis.

  18. Normal and abnormal electrical propagation in the small intestine.

    PubMed

    Lammers, W J E P

    2015-02-01

    As in other muscular organs, small intestinal motility is determined to a large degree by the electrical activities that occur in the smooth muscle layers of the small intestine. In recent decades, the interstitial cells of Cajal, located in the myenteric plexus, have been shown to be responsible for the generation and propagation of the electrical impulse: the slow wave. It was also known that the slow waves as such do not cause contraction, but that the action potentials ('spikes') that are generated by the slow waves are responsible for the contractions. Recording from large number of extracellular electrodes simultaneously is one method to determine origin and pattern of propagation of these electrical signals. This review reports the characteristics of slow wave propagation through the intestinal tube, the occurrence of propagation blocks along its length, which explains the well-known decrease in frequency, and the specific propagation pattern of the spikes that follow the slow waves. But the value of high-resolution mapping is highest in discovering and analysing mechanisms of arrhythmias in the gut. Most recently, circus movements (also called 're-entries') have been described in the small intestine in several species. Moreover, several types of re-entries have now been described, some similar to what may occur in the heart, such as functional re-entries, but others more unique to the small intestine, such as circumferential re-entry. These findings seem to suggest the possibilities of hitherto unknown pathologies that may be present in the small intestine.

  19. Radial propagation of geodesic acoustic modes

    SciTech Connect

    Hager, Robert; Hallatschek, Klaus

    2009-07-15

    The GAM group velocity is estimated from the ratio of the radial free energy flux to the total free energy applying gyrokinetic and two-fluid theory. This method is much more robust than approaches that calculate the group velocity directly and can be generalized to include additional physics, e.g., magnetic geometry. The results are verified with the gyrokinetic code GYRO[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)], the two-fluid code NLET[K. Hallatschek and A. Zeiler, Phys. Plasmas 7, 2554 (2000)], and analytical calculations. GAM propagation must be kept in mind when discussing the windows of GAM activity observed experimentally and the match between linear theory and experimental GAM frequencies.

  20. Propagation of detonations in hydrazine vapor

    NASA Technical Reports Server (NTRS)

    Heinrich, H. J.

    1985-01-01

    In the range of greater hydrazine vapor pressure, detonation speed depends exclusively on the extent of the ammonia decomposition in the second reaction stage. As vapor pressure decreases, the ammonia disintegration speed becomes increasingly slower and the reaction reached in the reaction zone increasingly decreases until finally, in the vapor pressure range between 53 and 16 Torr, the contribution of the second stage to detonation propagation disappears, and only the first stage remains active. Since the disintegration speed of the hydrazine in this pressure range has decreased markedly as well, no level, but rather only spinning, detonations occur. Temporary separations of the impact front and the reaction zone in the process lead to fluctuations of the detonation speed.

  1. Slow crack propagation in heterogeneous materials.

    PubMed

    Kierfeld, J; Vinokur, V M

    2006-05-01

    Statistics and thermally activated dynamics of crack nucleation and propagation in a two-dimensional heterogeneous material containing quenched randomly distributed defects are studied theoretically. Using the generalized Griffith criterion we derive the equation of motion for the crack tip position accounting for dissipation, thermal noise, and the random forces arising from the defects. We find that aggregations of defects generating long-range interaction forces (e.g., clouds of dislocations) lead to anomalously slow creep of the crack tip or even to its complete arrest. We demonstrate that heterogeneous materials with frozen defects contain a large number of arrested microcracks and that their fracture toughness is enhanced to the experimentally accessible time scales.

  2. Gas-phase detonation propagation in mixture composition gradients.

    PubMed

    Kessler, D A; Gamezo, V N; Oran, E S

    2012-02-13

    The propagation of detonations through several fuel-air mixtures with spatially varying fuel concentrations is examined numerically. The detonations propagate through two-dimensional channels, inside of which the gradient of mixture composition is oriented normal to the direction of propagation. The simulations are performed using a two-component, single-step reaction model calibrated so that one-dimensional detonation properties of model low- and high-activation-energy mixtures are similar to those observed in a typical hydrocarbon-air mixture. In the low-activation-energy mixture, the reaction zone structure is complex, consisting of curved fuel-lean and fuel-rich detonations near the line of stoichiometry that transition to decoupled shocks and turbulent deflagrations near the channel walls where the mixture is extremely fuel-lean or fuel-rich. Reactants that are not consumed by the leading detonation combine downstream and burn in a diffusion flame. Detonation cells produced by the unstable reaction front vary in size across the channel, growing larger away from the line of stoichiometry. As the size of the channel decreases relative to the size of a detonation cell, the effect of the mixture composition gradient is lessened and cells of similar sizes form. In the high-activation-energy mixture, detonations propagate more slowly as the magnitude of the mixture composition gradient is increased and can be quenched in a large enough gradient. PMID:22213660

  3. Burst propagation in Texas Helimak

    NASA Astrophysics Data System (ADS)

    Pereira, F. A. C.; Toufen, D. L.; Guimarães-Filho, Z. O.; Caldas, I. L.; Gentle, K. W.

    2016-05-01

    We present investigations of extreme events (bursts) propagating in the Texas Helimak, a toroidal plasma device in which the radial electric field can be changed by application of bias. In the experiments analyzed, a large grid of Langmuir probes measuring ion saturation current fluctuations is used to study the burst propagation and its dependence on the applied bias voltage. We confirm previous results reported on the turbulence intermittency in the Texas Helimak, extending them to a larger radial interval with a density ranging from a uniform decay to an almost uniform value. For our analysis, we introduce an improved procedure, based on a multiprobe bidimensional conditional averaging method, to assure precise determination of burst statistical properties and their spatial profiles. We verify that intermittent bursts have properties that vary in the radial direction. The number of bursts depends on the radial position and on the applied bias voltage. On the other hand, the burst characteristic time and size do not depend on the applied bias voltage. The bias voltage modifies the vertical and radial burst velocity profiles differently. The burst velocity is smaller than the turbulence phase velocity in almost all the analyzed region.

  4. Joint Acoustic Propagation Experiment (JAPE)

    NASA Technical Reports Server (NTRS)

    Carnes, Benny L.; Olsen, Robert O.; Kennedy, Bruce W.

    1993-01-01

    The Joint Acoustic Propagation Experiment (JAPE), performed under the auspices of NATO and the Acoustics Working Group, was conducted at White Sands Missile Range, New Mexico, USA, during the period 11-28 Jul. 1991. JAPE consisted of 220 trials using various acoustic sources including speakers, propane cannon, various types of military vehicles, helicopters, a 155mm howitzer, and static high explosives. Of primary importance to the performance of these tests was the intensive characterization of the atmosphere before and during the trials. Because of the wide range of interests on the part of the participants, JAPE was organized in such a manner to provide a broad cross section of test configurations. These included short and long range propagation from fixed and moving vehicles, terrain masking, and vehicle detection. A number of independent trials were also performed by individual participating agencies using the assets available during JAPE. These tests, while not documented in this report, provided substantial and important data to those groups. Perhaps the most significant feature of JAPE is the establishment of a permanent data base which can be used by not only the participants but by others interested in acoustics. A follow-on test was performed by NASA LaRC during the period 19-29 Aug. 1991 at the same location. These trials consisted of 59 overflights of supersonic aircraft in order to establish the relationship between atmospheric turbulence and the received sonic boom energy at the surface.

  5. Orbit propagation in Minkowskian geometry

    NASA Astrophysics Data System (ADS)

    Roa, Javier; Peláez, Jesús

    2015-09-01

    The geometry of hyperbolic orbits suggests that Minkowskian geometry, and not Euclidean, may provide the most adequate description of the motion. This idea is explored in order to derive a new regularized formulation for propagating arbitrarily perturbed hyperbolic orbits. The mathematical foundations underlying Minkowski space-time are exploited to describe hyperbolic orbits. Hypercomplex numbers are introduced to define the rotations, vectors, and metrics in the problem: the evolution of the eccentricity vector is described on the Minkowski plane in terms of hyperbolic numbers, and the orbital plane is described on the inertial reference using quaternions. A set of eight orbital elements is introduced, namely a time-element, the components of the eccentricity vector in , the semimajor axis, and the components of the quaternion defining the orbital plane. The resulting formulation provides a deep insight into the geometry of hyperbolic orbits. The performance of the formulation in long-term propagations is studied. The orbits of four hyperbolic comets are integrated and the accuracy of the solution is compared to other regularized formulations. The resulting formulation improves the stability of the integration process and it is not affected by the perihelion passage. It provides a level of accuracy that may not be reached by the compared formulations, at the cost of increasing the computational time.

  6. OPEX propagation measurements and studies

    NASA Technical Reports Server (NTRS)

    Arbesser-Rastburg, Bertram

    1990-01-01

    With the launch of the telecommunications Olympus satellite a new area began for the Olympus Propagation Experiments (OPEX) group. The years of preparations are now paying off - the experiments are underway and the co-operative effort is now turning its attention to the processing and analysis of data and to the interpretation of results. The aim here is to give a short review of the accomplishments made since NAPEX 13 and the work planned for the future. When ESA's Olympus was launched in summer of 1989 it carried a payload producing three unmodulated beacons at 12.5, 19.8, and 29.7 GHz. The main purpose of these beacons is to enable scientists to carry out long term slant path propagation experiments at these frequencies. The OPEX group, which was set up under ESA auspices in 1980, had been preparing for this event very carefully. The specifications for the equipment to be used and the elaboration of standard procedures for data processing and analysis have been worked out jointly. Today the OPEX community includes approximately 30 groups of experimenters. Immediately after achieving platform stability at the orbital location at 341 degrees east, ESA performed the In-Orbit Tests. Most measurements were carried out in Belgium using terminals specially developed for this purpose. A summary of the test results is given.

  7. Simplified propagation of standard uncertainties

    SciTech Connect

    Shull, A.H.

    1997-06-09

    An essential part of any measurement control program is adequate knowledge of the uncertainties of the measurement system standards. Only with an estimate of the standards` uncertainties can one determine if the standard is adequate for its intended use or can one calculate the total uncertainty of the measurement process. Purchased standards usually have estimates of uncertainty on their certificates. However, when standards are prepared and characterized by a laboratory, variance propagation is required to estimate the uncertainty of the standard. Traditional variance propagation typically involves tedious use of partial derivatives, unfriendly software and the availability of statistical expertise. As a result, the uncertainty of prepared standards is often not determined or determined incorrectly. For situations meeting stated assumptions, easier shortcut methods of estimation are now available which eliminate the need for partial derivatives and require only a spreadsheet or calculator. A system of simplifying the calculations by dividing into subgroups of absolute and relative uncertainties is utilized. These methods also incorporate the International Standards Organization (ISO) concepts for combining systematic and random uncertainties as published in their Guide to the Expression of Measurement Uncertainty. Details of the simplified methods and examples of their use are included in the paper.

  8. Estimation of the propagation characteristics of elastic waves propagating through a partially saturated sand soil

    NASA Astrophysics Data System (ADS)

    Nakayama, M.; Kawakata, H.; Doi, I.; Takahashi, N.

    2015-12-01

    Recently, landslides due to heavy rain and/or earthquakes have been increasing and severe damage occurred in Japan in some cases (e.g., Chigira et al., 2013, Geomorph.). One of the principle factors activating landslides is groundwater. Continuous measurements of moisture in soil and/or pore pressure are performed to investigate the groundwater behavior. However, such measurements give information on only local behavior of the groundwater. To monitor the state of target slope, it is better to measure signals affected by the behavior of groundwater in a widely surrounding region. The elastic waves propagating through the medium under the target slope are one of candidates of such signals. In this study, we measure propagating waves through a sand soil made in laboratory, injecting water into it from the bottom. We investigate the characteristics of the propagating waves. We drop sand particles in a container (750 mm long, 300 mm wide and 400 mm high) freely and made a sand soil. The sand soil consists of two layers. One is made of larger sand particles (0.2-0.4 mm in diameter) and the other is made of smaller sand particles (0.05-0.2 mm in diameter). The dry density of these sand layers is about 1.45 g/cm3. We install a shaker for generating elastic waves, accelerometers and pore pressure gauges in the sand soil. We apply small voltage steps repeatedly, and we continuously measure elastic waves propagating through the sand soil at a sampling rate of 51.2 ksps for a period including the water injection period. We estimate the spatio-temporal variation in the maximum cross-correlation coefficients and the corresponding time lags, using template waveforms recorded in the initial period as references. The coefficient for the waveforms recorded at the accelerometer attached to the tip of the shaker is almost stable in high values with a slight decrease down to 0.94 in the period when the sand particles around the shaker are considered to become wet. On the other hand

  9. Recovery Act Milestones

    ScienceCinema

    Rogers, Matt

    2016-07-12

    Every 100 days, the Department of Energy is held accountable for a progress report on the American Recovery and Reinvestment Act. Update at 200 days, hosted by Matt Rogers, Senior Advisor to Secretary Steven Chu for Recovery Act Implementation.

  10. Recovery Act Milestones

    SciTech Connect

    Rogers, Matt

    2009-01-01

    Every 100 days, the Department of Energy is held accountable for a progress report on the American Recovery and Reinvestment Act. Update at 200 days, hosted by Matt Rogers, Senior Advisor to Secretary Steven Chu for Recovery Act Implementation.

  11. ACTS data center

    NASA Technical Reports Server (NTRS)

    Syed, Ali; Vogel, Wolfhard J.

    1993-01-01

    Viewgraphs on ACTS Data Center status report are included. Topics covered include: ACTS Data Center Functions; data flow overview; PPD flow; RAW data flow; data compression; PPD distribution; RAW Data Archival; PPD Audit; and data analysis.

  12. Acting to gain information

    NASA Technical Reports Server (NTRS)

    Rosenchein, Stanley J.; Burns, J. Brian; Chapman, David; Kaelbling, Leslie P.; Kahn, Philip; Nishihara, H. Keith; Turk, Matthew

    1993-01-01

    This report is concerned with agents that act to gain information. In previous work, we developed agent models combining qualitative modeling with real-time control. That work, however, focused primarily on actions that affect physical states of the environment. The current study extends that work by explicitly considering problems of active information-gathering and by exploring specialized aspects of information-gathering in computational perception, learning, and language. In our theoretical investigations, we analyzed agents into their perceptual and action components and identified these with elements of a state-machine model of control. The mathematical properties of each was developed in isolation and interactions were then studied. We considered the complexity dimension and the uncertainty dimension and related these to intelligent-agent design issues. We also explored active information gathering in visual processing. Working within the active vision paradigm, we developed a concept of 'minimal meaningful measurements' suitable for demand-driven vision. We then developed and tested an architecture for ongoing recognition and interpretation of visual information. In the area of information gathering through learning, we explored techniques for coping with combinatorial complexity. We also explored information gathering through explicit linguistic action by considering the nature of conversational rules, coordination, and situated communication behavior.

  13. The dermatology acting internship.

    PubMed

    Stephens, John B; Raimer, Sharon S; Wagner, Richard F

    2011-07-15

    Acting internships are an important component of modern day medical school curriculum. Several specialties outside of internal medicine now offer acting internship experiences to fourth year medical students. We have found that a dermatology acting internship is a valuable experience for fourth year medical students who are interested in pursuing a residency in dermatology. Our experience with the dermatology acting internship over the 2010-2011 academic year is described.

  14. Long-Term Trends in Space-Ground Atmospheric Propagation Measurements

    NASA Technical Reports Server (NTRS)

    Zemba, Michael J.; Morse, Jacquelynne R.; Nessel, James A.

    2015-01-01

    Propagation measurement campaigns are critical to characterizing the atmospheric behavior of a location and efficiently designing space-ground links. However, as global climate change affects weather patterns, the long-term trends of propagation data may be impacted over periods of decades or longer. Particularly, at high microwave frequencies (10 GHz and above), rain plays a dominant role in the attenuation statistics, and it has been observed that rain events over the past 50 years have trended toward increased frequency, intensity, and rain height. In the interest of quantifying the impact of these phenomena on long-term trends in propagation data, this paper compares two 20 GHz measurement campaigns both conducted at NASA's White Sands facility in New Mexico. The first is from the Advanced Communication Technology Satellite (ACTS) propagation campaign from 1994 - 1998, while the second is amplitude data recorded during a site test interferometer (STI) phase characterization campaign from 2009 - 2014.

  15. Long-Term Trends in Space-Ground Atmospheric Propagation Measurements

    NASA Technical Reports Server (NTRS)

    Zemba, Michael J.; Nessel, James A.; Morse, Jacquelynne R.

    2015-01-01

    Propagation measurement campaigns are critical to characterizing the atmospheric behavior of a location and efficiently designing space-ground links. However, as global climate change affects weather patterns, the long-term trends of propagation data may be impacted over periods of decades or longer. Particularly, at high microwave frequencies (10 GHz and above), rain plays a dominant role in the attenuation statistics, and it has been observed that rain events over the past 50 years have trended toward increased frequency, intensity, and rain height. In the interest of quantifying the impact of these phenomena on long-term trends in propagation data, this paper compares two 20 GHz measurement campaigns both conducted at NASAs White Sands facility in New Mexico. The first is from the Advanced Communications Technology Satellite (ACTS) propagation campaign from 1994 to 1998, while the second is amplitude data recorded during a site test interferometer (STI) phase characterization campaign from 2009 to 2014.

  16. Progress in front propagation research

    NASA Astrophysics Data System (ADS)

    Fort, Joaquim; Pujol, Toni

    2008-08-01

    We review the progress in the field of front propagation in recent years. We survey many physical, biophysical and cross-disciplinary applications, including reduced-variable models of combustion flames, Reid's paradox of rapid forest range expansions, the European colonization of North America during the 19th century, the Neolithic transition in Europe from 13 000 to 5000 years ago, the description of subsistence boundaries, the formation of cultural boundaries, the spread of genetic mutations, theory and experiments on virus infections, models of cancer tumors, etc. Recent theoretical advances are unified in a single framework, encompassing very diverse systems such as those with biased random walks, distributed delays, sequential reaction and dispersion, cohabitation models, age structure and systems with several interacting species. Directions for future progress are outlined.

  17. Transhorizon propagation of decameter waves

    NASA Astrophysics Data System (ADS)

    Kalinin, Yu. K.; Shchelkalin, A. V.

    2013-04-01

    Solutions to the problem of the point source field in a spherically layered medium are analyzed. For a three-layer waveguide model, a solution in the form of the Watson integral was used. A consideration of the singularities in the plane of the integration variable made it possible to represent the integral as a superposition of three waves. Two of them are connected with the interaction of the primary spherical wave with the lower convex and upper concave interfaces. The third wave is connected with the alternate action with both interfaces. The fourth wave is caused by the interaction between the primary wave and random inhomogeneities of the external medium (the ionosphere). Here, simulation was carried out based on Green equations. The considered unique data of flight measurements of the point source field strength indicate the efficiency of simulating the transhorizon propagation of decameter waves based on the superposition of all four aforesaid wave packets.

  18. IBEX - annular beam propagation experiment

    SciTech Connect

    Mazarakis, M G; Miller, R B; Shope, S L; Poukey, J W; Ramirez, J J; Ekdahl, C A; Adler, R J

    1983-01-01

    IBEX is a 4-MV, 100-kA, 20-ns cylindrical isolated Blumlein accelerator. In the experiments reported here, the accelerator is fitted with a specially designed foilless diode which is completely immersed in a uniform magnetic field. Several diode geometries have been studied as a function of magnetic field strength. The beam propagates a distance of 50 cm (approx. 10 cyclotron wavelengths) in vacuum before either striking a beam stop or being extracted through a thin foil. The extracted beam was successfully transported 60 cm downstream into a drift pipe filled either with 80 or 640 torr air. The main objectives of this experiment were to establish the proper parameters for the most quiescent 4 MV, 20 to 40 kA annular beam, and to compare the results with available theory and numerical code simulations.

  19. Vibration Propagation in Spider Webs

    NASA Astrophysics Data System (ADS)

    Hatton, Ross; Otto, Andrew; Elias, Damian

    Due to their poor eyesight, spiders rely on web vibrations for situational awareness. Web-borne vibrations are used to determine the location of prey, predators, and potential mates. The influence of web geometry and composition on web vibrations is important for understanding spider's behavior and ecology. Past studies on web vibrations have experimentally measured the frequency response of web geometries by removing threads from existing webs. The full influence of web structure and tension distribution on vibration transmission; however, has not been addressed in prior work. We have constructed physical artificial webs and computer models to better understand the effect of web structure on vibration transmission. These models provide insight into the propagation of vibrations through the webs, the frequency response of the bare web, and the influence of the spider's mass and stiffness on the vibration transmission patterns. Funded by NSF-1504428.

  20. Vasopressin modulates the spontaneous electrical activity in aortic cells (line A7r5) by acting on three different types of ionic channels.

    PubMed Central

    Van Renterghem, C; Romey, G; Lazdunski, M

    1988-01-01

    A7r5 smooth muscle (aorta) cells have a spontaneous electrical activity. Application of vasopressin produces a hyperpolarization accompanied by an interruption of the spontaneous activity, which is followed by a depolarization associated with a recovery of the spiking activity. Vasopressin action is produced by an action of the peptide on three different types of ionic channels. Vasopressin activates a Ca2+-sensitive K+ conductance, presumably by producing inositol 1,4,5-trisphosphate intracellularly and liberating Ca2+ from internal stores. This activation is transient (0.5-4 min) and is related to the vasopressin-induced hyperpolarization. Intracellular perfusion of inositol trisphosphate triggers by itself a transient K+ current and prevents subsequent activation by vasopressin. Vasopressin inhibits an L-type Ca2+ channel through both protein kinase C activation and a [Ca2+]i-dependent inactivation mechanism triggered by inositol trisphosphate production. The addition of the activation of a Ca2+-sensitive K+ channel and of the inhibition of a voltage-sensitive Ca2+ channel is responsible for the transient blockade of the spontaneous activity. Vasopressin also provokes the activation of an inward current (2-20 min) due to a nonselective channel able to transfer Ca2+, Na+, K+, and Cs+ across the membrane. This effect of the peptide is associated with the depolarization following the hyperpolarization phase. Images PMID:2461570